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1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (C) 2007 Oracle.  All rights reserved.
4  */
5 
6 #include <crypto/hash.h>
7 #include <linux/kernel.h>
8 #include <linux/bio.h>
9 #include <linux/blk-cgroup.h>
10 #include <linux/file.h>
11 #include <linux/fs.h>
12 #include <linux/pagemap.h>
13 #include <linux/highmem.h>
14 #include <linux/time.h>
15 #include <linux/init.h>
16 #include <linux/string.h>
17 #include <linux/backing-dev.h>
18 #include <linux/writeback.h>
19 #include <linux/compat.h>
20 #include <linux/xattr.h>
21 #include <linux/posix_acl.h>
22 #include <linux/falloc.h>
23 #include <linux/slab.h>
24 #include <linux/ratelimit.h>
25 #include <linux/btrfs.h>
26 #include <linux/blkdev.h>
27 #include <linux/posix_acl_xattr.h>
28 #include <linux/uio.h>
29 #include <linux/magic.h>
30 #include <linux/iversion.h>
31 #include <linux/swap.h>
32 #include <linux/migrate.h>
33 #include <linux/sched/mm.h>
34 #include <linux/iomap.h>
35 #include <asm/unaligned.h>
36 #include <linux/fsverity.h>
37 #include "misc.h"
38 #include "ctree.h"
39 #include "disk-io.h"
40 #include "transaction.h"
41 #include "btrfs_inode.h"
42 #include "print-tree.h"
43 #include "ordered-data.h"
44 #include "xattr.h"
45 #include "tree-log.h"
46 #include "volumes.h"
47 #include "compression.h"
48 #include "locking.h"
49 #include "free-space-cache.h"
50 #include "props.h"
51 #include "qgroup.h"
52 #include "delalloc-space.h"
53 #include "block-group.h"
54 #include "space-info.h"
55 #include "zoned.h"
56 #include "subpage.h"
57 #include "inode-item.h"
58 
59 struct btrfs_iget_args {
60 	u64 ino;
61 	struct btrfs_root *root;
62 };
63 
64 struct btrfs_dio_data {
65 	ssize_t submitted;
66 	struct extent_changeset *data_reserved;
67 	bool data_space_reserved;
68 	bool nocow_done;
69 };
70 
71 struct btrfs_dio_private {
72 	struct inode *inode;
73 
74 	/*
75 	 * Since DIO can use anonymous page, we cannot use page_offset() to
76 	 * grab the file offset, thus need a dedicated member for file offset.
77 	 */
78 	u64 file_offset;
79 	/* Used for bio::bi_size */
80 	u32 bytes;
81 
82 	/*
83 	 * References to this structure. There is one reference per in-flight
84 	 * bio plus one while we're still setting up.
85 	 */
86 	refcount_t refs;
87 
88 	/* Array of checksums */
89 	u8 *csums;
90 
91 	/* This must be last */
92 	struct bio bio;
93 };
94 
95 static struct bio_set btrfs_dio_bioset;
96 
97 struct btrfs_rename_ctx {
98 	/* Output field. Stores the index number of the old directory entry. */
99 	u64 index;
100 };
101 
102 static const struct inode_operations btrfs_dir_inode_operations;
103 static const struct inode_operations btrfs_symlink_inode_operations;
104 static const struct inode_operations btrfs_special_inode_operations;
105 static const struct inode_operations btrfs_file_inode_operations;
106 static const struct address_space_operations btrfs_aops;
107 static const struct file_operations btrfs_dir_file_operations;
108 
109 static struct kmem_cache *btrfs_inode_cachep;
110 struct kmem_cache *btrfs_trans_handle_cachep;
111 struct kmem_cache *btrfs_path_cachep;
112 struct kmem_cache *btrfs_free_space_cachep;
113 struct kmem_cache *btrfs_free_space_bitmap_cachep;
114 
115 static int btrfs_setsize(struct inode *inode, struct iattr *attr);
116 static int btrfs_truncate(struct inode *inode, bool skip_writeback);
117 static noinline int cow_file_range(struct btrfs_inode *inode,
118 				   struct page *locked_page,
119 				   u64 start, u64 end, int *page_started,
120 				   unsigned long *nr_written, int unlock,
121 				   u64 *done_offset);
122 static struct extent_map *create_io_em(struct btrfs_inode *inode, u64 start,
123 				       u64 len, u64 orig_start, u64 block_start,
124 				       u64 block_len, u64 orig_block_len,
125 				       u64 ram_bytes, int compress_type,
126 				       int type);
127 
128 /*
129  * btrfs_inode_lock - lock inode i_rwsem based on arguments passed
130  *
131  * ilock_flags can have the following bit set:
132  *
133  * BTRFS_ILOCK_SHARED - acquire a shared lock on the inode
134  * BTRFS_ILOCK_TRY - try to acquire the lock, if fails on first attempt
135  *		     return -EAGAIN
136  * BTRFS_ILOCK_MMAP - acquire a write lock on the i_mmap_lock
137  */
btrfs_inode_lock(struct inode * inode,unsigned int ilock_flags)138 int btrfs_inode_lock(struct inode *inode, unsigned int ilock_flags)
139 {
140 	if (ilock_flags & BTRFS_ILOCK_SHARED) {
141 		if (ilock_flags & BTRFS_ILOCK_TRY) {
142 			if (!inode_trylock_shared(inode))
143 				return -EAGAIN;
144 			else
145 				return 0;
146 		}
147 		inode_lock_shared(inode);
148 	} else {
149 		if (ilock_flags & BTRFS_ILOCK_TRY) {
150 			if (!inode_trylock(inode))
151 				return -EAGAIN;
152 			else
153 				return 0;
154 		}
155 		inode_lock(inode);
156 	}
157 	if (ilock_flags & BTRFS_ILOCK_MMAP)
158 		down_write(&BTRFS_I(inode)->i_mmap_lock);
159 	return 0;
160 }
161 
162 /*
163  * btrfs_inode_unlock - unock inode i_rwsem
164  *
165  * ilock_flags should contain the same bits set as passed to btrfs_inode_lock()
166  * to decide whether the lock acquired is shared or exclusive.
167  */
btrfs_inode_unlock(struct inode * inode,unsigned int ilock_flags)168 void btrfs_inode_unlock(struct inode *inode, unsigned int ilock_flags)
169 {
170 	if (ilock_flags & BTRFS_ILOCK_MMAP)
171 		up_write(&BTRFS_I(inode)->i_mmap_lock);
172 	if (ilock_flags & BTRFS_ILOCK_SHARED)
173 		inode_unlock_shared(inode);
174 	else
175 		inode_unlock(inode);
176 }
177 
178 /*
179  * Cleanup all submitted ordered extents in specified range to handle errors
180  * from the btrfs_run_delalloc_range() callback.
181  *
182  * NOTE: caller must ensure that when an error happens, it can not call
183  * extent_clear_unlock_delalloc() to clear both the bits EXTENT_DO_ACCOUNTING
184  * and EXTENT_DELALLOC simultaneously, because that causes the reserved metadata
185  * to be released, which we want to happen only when finishing the ordered
186  * extent (btrfs_finish_ordered_io()).
187  */
btrfs_cleanup_ordered_extents(struct btrfs_inode * inode,struct page * locked_page,u64 offset,u64 bytes)188 static inline void btrfs_cleanup_ordered_extents(struct btrfs_inode *inode,
189 						 struct page *locked_page,
190 						 u64 offset, u64 bytes)
191 {
192 	unsigned long index = offset >> PAGE_SHIFT;
193 	unsigned long end_index = (offset + bytes - 1) >> PAGE_SHIFT;
194 	u64 page_start, page_end;
195 	struct page *page;
196 
197 	if (locked_page) {
198 		page_start = page_offset(locked_page);
199 		page_end = page_start + PAGE_SIZE - 1;
200 	}
201 
202 	while (index <= end_index) {
203 		/*
204 		 * For locked page, we will call end_extent_writepage() on it
205 		 * in run_delalloc_range() for the error handling.  That
206 		 * end_extent_writepage() function will call
207 		 * btrfs_mark_ordered_io_finished() to clear page Ordered and
208 		 * run the ordered extent accounting.
209 		 *
210 		 * Here we can't just clear the Ordered bit, or
211 		 * btrfs_mark_ordered_io_finished() would skip the accounting
212 		 * for the page range, and the ordered extent will never finish.
213 		 */
214 		if (locked_page && index == (page_start >> PAGE_SHIFT)) {
215 			index++;
216 			continue;
217 		}
218 		page = find_get_page(inode->vfs_inode.i_mapping, index);
219 		index++;
220 		if (!page)
221 			continue;
222 
223 		/*
224 		 * Here we just clear all Ordered bits for every page in the
225 		 * range, then btrfs_mark_ordered_io_finished() will handle
226 		 * the ordered extent accounting for the range.
227 		 */
228 		btrfs_page_clamp_clear_ordered(inode->root->fs_info, page,
229 					       offset, bytes);
230 		put_page(page);
231 	}
232 
233 	if (locked_page) {
234 		/* The locked page covers the full range, nothing needs to be done */
235 		if (bytes + offset <= page_start + PAGE_SIZE)
236 			return;
237 		/*
238 		 * In case this page belongs to the delalloc range being
239 		 * instantiated then skip it, since the first page of a range is
240 		 * going to be properly cleaned up by the caller of
241 		 * run_delalloc_range
242 		 */
243 		if (page_start >= offset && page_end <= (offset + bytes - 1)) {
244 			bytes = offset + bytes - page_offset(locked_page) - PAGE_SIZE;
245 			offset = page_offset(locked_page) + PAGE_SIZE;
246 		}
247 	}
248 
249 	return btrfs_mark_ordered_io_finished(inode, NULL, offset, bytes, false);
250 }
251 
252 static int btrfs_dirty_inode(struct inode *inode);
253 
btrfs_init_inode_security(struct btrfs_trans_handle * trans,struct btrfs_new_inode_args * args)254 static int btrfs_init_inode_security(struct btrfs_trans_handle *trans,
255 				     struct btrfs_new_inode_args *args)
256 {
257 	int err;
258 
259 	if (args->default_acl) {
260 		err = __btrfs_set_acl(trans, args->inode, args->default_acl,
261 				      ACL_TYPE_DEFAULT);
262 		if (err)
263 			return err;
264 	}
265 	if (args->acl) {
266 		err = __btrfs_set_acl(trans, args->inode, args->acl, ACL_TYPE_ACCESS);
267 		if (err)
268 			return err;
269 	}
270 	if (!args->default_acl && !args->acl)
271 		cache_no_acl(args->inode);
272 	return btrfs_xattr_security_init(trans, args->inode, args->dir,
273 					 &args->dentry->d_name);
274 }
275 
276 /*
277  * this does all the hard work for inserting an inline extent into
278  * the btree.  The caller should have done a btrfs_drop_extents so that
279  * no overlapping inline items exist in the btree
280  */
insert_inline_extent(struct btrfs_trans_handle * trans,struct btrfs_path * path,struct btrfs_inode * inode,bool extent_inserted,size_t size,size_t compressed_size,int compress_type,struct page ** compressed_pages,bool update_i_size)281 static int insert_inline_extent(struct btrfs_trans_handle *trans,
282 				struct btrfs_path *path,
283 				struct btrfs_inode *inode, bool extent_inserted,
284 				size_t size, size_t compressed_size,
285 				int compress_type,
286 				struct page **compressed_pages,
287 				bool update_i_size)
288 {
289 	struct btrfs_root *root = inode->root;
290 	struct extent_buffer *leaf;
291 	struct page *page = NULL;
292 	char *kaddr;
293 	unsigned long ptr;
294 	struct btrfs_file_extent_item *ei;
295 	int ret;
296 	size_t cur_size = size;
297 	u64 i_size;
298 
299 	ASSERT((compressed_size > 0 && compressed_pages) ||
300 	       (compressed_size == 0 && !compressed_pages));
301 
302 	if (compressed_size && compressed_pages)
303 		cur_size = compressed_size;
304 
305 	if (!extent_inserted) {
306 		struct btrfs_key key;
307 		size_t datasize;
308 
309 		key.objectid = btrfs_ino(inode);
310 		key.offset = 0;
311 		key.type = BTRFS_EXTENT_DATA_KEY;
312 
313 		datasize = btrfs_file_extent_calc_inline_size(cur_size);
314 		ret = btrfs_insert_empty_item(trans, root, path, &key,
315 					      datasize);
316 		if (ret)
317 			goto fail;
318 	}
319 	leaf = path->nodes[0];
320 	ei = btrfs_item_ptr(leaf, path->slots[0],
321 			    struct btrfs_file_extent_item);
322 	btrfs_set_file_extent_generation(leaf, ei, trans->transid);
323 	btrfs_set_file_extent_type(leaf, ei, BTRFS_FILE_EXTENT_INLINE);
324 	btrfs_set_file_extent_encryption(leaf, ei, 0);
325 	btrfs_set_file_extent_other_encoding(leaf, ei, 0);
326 	btrfs_set_file_extent_ram_bytes(leaf, ei, size);
327 	ptr = btrfs_file_extent_inline_start(ei);
328 
329 	if (compress_type != BTRFS_COMPRESS_NONE) {
330 		struct page *cpage;
331 		int i = 0;
332 		while (compressed_size > 0) {
333 			cpage = compressed_pages[i];
334 			cur_size = min_t(unsigned long, compressed_size,
335 				       PAGE_SIZE);
336 
337 			kaddr = kmap_local_page(cpage);
338 			write_extent_buffer(leaf, kaddr, ptr, cur_size);
339 			kunmap_local(kaddr);
340 
341 			i++;
342 			ptr += cur_size;
343 			compressed_size -= cur_size;
344 		}
345 		btrfs_set_file_extent_compression(leaf, ei,
346 						  compress_type);
347 	} else {
348 		page = find_get_page(inode->vfs_inode.i_mapping, 0);
349 		btrfs_set_file_extent_compression(leaf, ei, 0);
350 		kaddr = kmap_local_page(page);
351 		write_extent_buffer(leaf, kaddr, ptr, size);
352 		kunmap_local(kaddr);
353 		put_page(page);
354 	}
355 	btrfs_mark_buffer_dirty(leaf);
356 	btrfs_release_path(path);
357 
358 	/*
359 	 * We align size to sectorsize for inline extents just for simplicity
360 	 * sake.
361 	 */
362 	ret = btrfs_inode_set_file_extent_range(inode, 0,
363 					ALIGN(size, root->fs_info->sectorsize));
364 	if (ret)
365 		goto fail;
366 
367 	/*
368 	 * We're an inline extent, so nobody can extend the file past i_size
369 	 * without locking a page we already have locked.
370 	 *
371 	 * We must do any i_size and inode updates before we unlock the pages.
372 	 * Otherwise we could end up racing with unlink.
373 	 */
374 	i_size = i_size_read(&inode->vfs_inode);
375 	if (update_i_size && size > i_size) {
376 		i_size_write(&inode->vfs_inode, size);
377 		i_size = size;
378 	}
379 	inode->disk_i_size = i_size;
380 
381 fail:
382 	return ret;
383 }
384 
385 
386 /*
387  * conditionally insert an inline extent into the file.  This
388  * does the checks required to make sure the data is small enough
389  * to fit as an inline extent.
390  */
cow_file_range_inline(struct btrfs_inode * inode,u64 size,size_t compressed_size,int compress_type,struct page ** compressed_pages,bool update_i_size)391 static noinline int cow_file_range_inline(struct btrfs_inode *inode, u64 size,
392 					  size_t compressed_size,
393 					  int compress_type,
394 					  struct page **compressed_pages,
395 					  bool update_i_size)
396 {
397 	struct btrfs_drop_extents_args drop_args = { 0 };
398 	struct btrfs_root *root = inode->root;
399 	struct btrfs_fs_info *fs_info = root->fs_info;
400 	struct btrfs_trans_handle *trans;
401 	u64 data_len = (compressed_size ?: size);
402 	int ret;
403 	struct btrfs_path *path;
404 
405 	/*
406 	 * We can create an inline extent if it ends at or beyond the current
407 	 * i_size, is no larger than a sector (decompressed), and the (possibly
408 	 * compressed) data fits in a leaf and the configured maximum inline
409 	 * size.
410 	 */
411 	if (size < i_size_read(&inode->vfs_inode) ||
412 	    size > fs_info->sectorsize ||
413 	    data_len > BTRFS_MAX_INLINE_DATA_SIZE(fs_info) ||
414 	    data_len > fs_info->max_inline)
415 		return 1;
416 
417 	path = btrfs_alloc_path();
418 	if (!path)
419 		return -ENOMEM;
420 
421 	trans = btrfs_join_transaction(root);
422 	if (IS_ERR(trans)) {
423 		btrfs_free_path(path);
424 		return PTR_ERR(trans);
425 	}
426 	trans->block_rsv = &inode->block_rsv;
427 
428 	drop_args.path = path;
429 	drop_args.start = 0;
430 	drop_args.end = fs_info->sectorsize;
431 	drop_args.drop_cache = true;
432 	drop_args.replace_extent = true;
433 	drop_args.extent_item_size = btrfs_file_extent_calc_inline_size(data_len);
434 	ret = btrfs_drop_extents(trans, root, inode, &drop_args);
435 	if (ret) {
436 		btrfs_abort_transaction(trans, ret);
437 		goto out;
438 	}
439 
440 	ret = insert_inline_extent(trans, path, inode, drop_args.extent_inserted,
441 				   size, compressed_size, compress_type,
442 				   compressed_pages, update_i_size);
443 	if (ret && ret != -ENOSPC) {
444 		btrfs_abort_transaction(trans, ret);
445 		goto out;
446 	} else if (ret == -ENOSPC) {
447 		ret = 1;
448 		goto out;
449 	}
450 
451 	btrfs_update_inode_bytes(inode, size, drop_args.bytes_found);
452 	ret = btrfs_update_inode(trans, root, inode);
453 	if (ret && ret != -ENOSPC) {
454 		btrfs_abort_transaction(trans, ret);
455 		goto out;
456 	} else if (ret == -ENOSPC) {
457 		ret = 1;
458 		goto out;
459 	}
460 
461 	btrfs_set_inode_full_sync(inode);
462 out:
463 	/*
464 	 * Don't forget to free the reserved space, as for inlined extent
465 	 * it won't count as data extent, free them directly here.
466 	 * And at reserve time, it's always aligned to page size, so
467 	 * just free one page here.
468 	 */
469 	btrfs_qgroup_free_data(inode, NULL, 0, PAGE_SIZE, NULL);
470 	btrfs_free_path(path);
471 	btrfs_end_transaction(trans);
472 	return ret;
473 }
474 
475 struct async_extent {
476 	u64 start;
477 	u64 ram_size;
478 	u64 compressed_size;
479 	struct page **pages;
480 	unsigned long nr_pages;
481 	int compress_type;
482 	struct list_head list;
483 };
484 
485 struct async_chunk {
486 	struct inode *inode;
487 	struct page *locked_page;
488 	u64 start;
489 	u64 end;
490 	blk_opf_t write_flags;
491 	struct list_head extents;
492 	struct cgroup_subsys_state *blkcg_css;
493 	struct btrfs_work work;
494 	struct async_cow *async_cow;
495 };
496 
497 struct async_cow {
498 	atomic_t num_chunks;
499 	struct async_chunk chunks[];
500 };
501 
add_async_extent(struct async_chunk * cow,u64 start,u64 ram_size,u64 compressed_size,struct page ** pages,unsigned long nr_pages,int compress_type)502 static noinline int add_async_extent(struct async_chunk *cow,
503 				     u64 start, u64 ram_size,
504 				     u64 compressed_size,
505 				     struct page **pages,
506 				     unsigned long nr_pages,
507 				     int compress_type)
508 {
509 	struct async_extent *async_extent;
510 
511 	async_extent = kmalloc(sizeof(*async_extent), GFP_NOFS);
512 	BUG_ON(!async_extent); /* -ENOMEM */
513 	async_extent->start = start;
514 	async_extent->ram_size = ram_size;
515 	async_extent->compressed_size = compressed_size;
516 	async_extent->pages = pages;
517 	async_extent->nr_pages = nr_pages;
518 	async_extent->compress_type = compress_type;
519 	list_add_tail(&async_extent->list, &cow->extents);
520 	return 0;
521 }
522 
523 /*
524  * Check if the inode needs to be submitted to compression, based on mount
525  * options, defragmentation, properties or heuristics.
526  */
inode_need_compress(struct btrfs_inode * inode,u64 start,u64 end)527 static inline int inode_need_compress(struct btrfs_inode *inode, u64 start,
528 				      u64 end)
529 {
530 	struct btrfs_fs_info *fs_info = inode->root->fs_info;
531 
532 	if (!btrfs_inode_can_compress(inode)) {
533 		WARN(IS_ENABLED(CONFIG_BTRFS_DEBUG),
534 			KERN_ERR "BTRFS: unexpected compression for ino %llu\n",
535 			btrfs_ino(inode));
536 		return 0;
537 	}
538 	/*
539 	 * Special check for subpage.
540 	 *
541 	 * We lock the full page then run each delalloc range in the page, thus
542 	 * for the following case, we will hit some subpage specific corner case:
543 	 *
544 	 * 0		32K		64K
545 	 * |	|///////|	|///////|
546 	 *		\- A		\- B
547 	 *
548 	 * In above case, both range A and range B will try to unlock the full
549 	 * page [0, 64K), causing the one finished later will have page
550 	 * unlocked already, triggering various page lock requirement BUG_ON()s.
551 	 *
552 	 * So here we add an artificial limit that subpage compression can only
553 	 * if the range is fully page aligned.
554 	 *
555 	 * In theory we only need to ensure the first page is fully covered, but
556 	 * the tailing partial page will be locked until the full compression
557 	 * finishes, delaying the write of other range.
558 	 *
559 	 * TODO: Make btrfs_run_delalloc_range() to lock all delalloc range
560 	 * first to prevent any submitted async extent to unlock the full page.
561 	 * By this, we can ensure for subpage case that only the last async_cow
562 	 * will unlock the full page.
563 	 */
564 	if (fs_info->sectorsize < PAGE_SIZE) {
565 		if (!PAGE_ALIGNED(start) ||
566 		    !PAGE_ALIGNED(end + 1))
567 			return 0;
568 	}
569 
570 	/* force compress */
571 	if (btrfs_test_opt(fs_info, FORCE_COMPRESS))
572 		return 1;
573 	/* defrag ioctl */
574 	if (inode->defrag_compress)
575 		return 1;
576 	/* bad compression ratios */
577 	if (inode->flags & BTRFS_INODE_NOCOMPRESS)
578 		return 0;
579 	if (btrfs_test_opt(fs_info, COMPRESS) ||
580 	    inode->flags & BTRFS_INODE_COMPRESS ||
581 	    inode->prop_compress)
582 		return btrfs_compress_heuristic(&inode->vfs_inode, start, end);
583 	return 0;
584 }
585 
inode_should_defrag(struct btrfs_inode * inode,u64 start,u64 end,u64 num_bytes,u32 small_write)586 static inline void inode_should_defrag(struct btrfs_inode *inode,
587 		u64 start, u64 end, u64 num_bytes, u32 small_write)
588 {
589 	/* If this is a small write inside eof, kick off a defrag */
590 	if (num_bytes < small_write &&
591 	    (start > 0 || end + 1 < inode->disk_i_size))
592 		btrfs_add_inode_defrag(NULL, inode, small_write);
593 }
594 
595 /*
596  * we create compressed extents in two phases.  The first
597  * phase compresses a range of pages that have already been
598  * locked (both pages and state bits are locked).
599  *
600  * This is done inside an ordered work queue, and the compression
601  * is spread across many cpus.  The actual IO submission is step
602  * two, and the ordered work queue takes care of making sure that
603  * happens in the same order things were put onto the queue by
604  * writepages and friends.
605  *
606  * If this code finds it can't get good compression, it puts an
607  * entry onto the work queue to write the uncompressed bytes.  This
608  * makes sure that both compressed inodes and uncompressed inodes
609  * are written in the same order that the flusher thread sent them
610  * down.
611  */
compress_file_range(struct async_chunk * async_chunk)612 static noinline int compress_file_range(struct async_chunk *async_chunk)
613 {
614 	struct inode *inode = async_chunk->inode;
615 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
616 	u64 blocksize = fs_info->sectorsize;
617 	u64 start = async_chunk->start;
618 	u64 end = async_chunk->end;
619 	u64 actual_end;
620 	u64 i_size;
621 	int ret = 0;
622 	struct page **pages = NULL;
623 	unsigned long nr_pages;
624 	unsigned long total_compressed = 0;
625 	unsigned long total_in = 0;
626 	int i;
627 	int will_compress;
628 	int compress_type = fs_info->compress_type;
629 	int compressed_extents = 0;
630 	int redirty = 0;
631 
632 	inode_should_defrag(BTRFS_I(inode), start, end, end - start + 1,
633 			SZ_16K);
634 
635 	/*
636 	 * We need to save i_size before now because it could change in between
637 	 * us evaluating the size and assigning it.  This is because we lock and
638 	 * unlock the page in truncate and fallocate, and then modify the i_size
639 	 * later on.
640 	 *
641 	 * The barriers are to emulate READ_ONCE, remove that once i_size_read
642 	 * does that for us.
643 	 */
644 	barrier();
645 	i_size = i_size_read(inode);
646 	barrier();
647 	actual_end = min_t(u64, i_size, end + 1);
648 again:
649 	will_compress = 0;
650 	nr_pages = (end >> PAGE_SHIFT) - (start >> PAGE_SHIFT) + 1;
651 	nr_pages = min_t(unsigned long, nr_pages,
652 			BTRFS_MAX_COMPRESSED / PAGE_SIZE);
653 
654 	/*
655 	 * we don't want to send crud past the end of i_size through
656 	 * compression, that's just a waste of CPU time.  So, if the
657 	 * end of the file is before the start of our current
658 	 * requested range of bytes, we bail out to the uncompressed
659 	 * cleanup code that can deal with all of this.
660 	 *
661 	 * It isn't really the fastest way to fix things, but this is a
662 	 * very uncommon corner.
663 	 */
664 	if (actual_end <= start)
665 		goto cleanup_and_bail_uncompressed;
666 
667 	total_compressed = actual_end - start;
668 
669 	/*
670 	 * Skip compression for a small file range(<=blocksize) that
671 	 * isn't an inline extent, since it doesn't save disk space at all.
672 	 */
673 	if (total_compressed <= blocksize &&
674 	   (start > 0 || end + 1 < BTRFS_I(inode)->disk_i_size))
675 		goto cleanup_and_bail_uncompressed;
676 
677 	/*
678 	 * For subpage case, we require full page alignment for the sector
679 	 * aligned range.
680 	 * Thus we must also check against @actual_end, not just @end.
681 	 */
682 	if (blocksize < PAGE_SIZE) {
683 		if (!PAGE_ALIGNED(start) ||
684 		    !PAGE_ALIGNED(round_up(actual_end, blocksize)))
685 			goto cleanup_and_bail_uncompressed;
686 	}
687 
688 	total_compressed = min_t(unsigned long, total_compressed,
689 			BTRFS_MAX_UNCOMPRESSED);
690 	total_in = 0;
691 	ret = 0;
692 
693 	/*
694 	 * we do compression for mount -o compress and when the
695 	 * inode has not been flagged as nocompress.  This flag can
696 	 * change at any time if we discover bad compression ratios.
697 	 */
698 	if (inode_need_compress(BTRFS_I(inode), start, end)) {
699 		WARN_ON(pages);
700 		pages = kcalloc(nr_pages, sizeof(struct page *), GFP_NOFS);
701 		if (!pages) {
702 			/* just bail out to the uncompressed code */
703 			nr_pages = 0;
704 			goto cont;
705 		}
706 
707 		if (BTRFS_I(inode)->defrag_compress)
708 			compress_type = BTRFS_I(inode)->defrag_compress;
709 		else if (BTRFS_I(inode)->prop_compress)
710 			compress_type = BTRFS_I(inode)->prop_compress;
711 
712 		/*
713 		 * we need to call clear_page_dirty_for_io on each
714 		 * page in the range.  Otherwise applications with the file
715 		 * mmap'd can wander in and change the page contents while
716 		 * we are compressing them.
717 		 *
718 		 * If the compression fails for any reason, we set the pages
719 		 * dirty again later on.
720 		 *
721 		 * Note that the remaining part is redirtied, the start pointer
722 		 * has moved, the end is the original one.
723 		 */
724 		if (!redirty) {
725 			extent_range_clear_dirty_for_io(inode, start, end);
726 			redirty = 1;
727 		}
728 
729 		/* Compression level is applied here and only here */
730 		ret = btrfs_compress_pages(
731 			compress_type | (fs_info->compress_level << 4),
732 					   inode->i_mapping, start,
733 					   pages,
734 					   &nr_pages,
735 					   &total_in,
736 					   &total_compressed);
737 
738 		if (!ret) {
739 			unsigned long offset = offset_in_page(total_compressed);
740 			struct page *page = pages[nr_pages - 1];
741 
742 			/* zero the tail end of the last page, we might be
743 			 * sending it down to disk
744 			 */
745 			if (offset)
746 				memzero_page(page, offset, PAGE_SIZE - offset);
747 			will_compress = 1;
748 		}
749 	}
750 cont:
751 	/*
752 	 * Check cow_file_range() for why we don't even try to create inline
753 	 * extent for subpage case.
754 	 */
755 	if (start == 0 && fs_info->sectorsize == PAGE_SIZE) {
756 		/* lets try to make an inline extent */
757 		if (ret || total_in < actual_end) {
758 			/* we didn't compress the entire range, try
759 			 * to make an uncompressed inline extent.
760 			 */
761 			ret = cow_file_range_inline(BTRFS_I(inode), actual_end,
762 						    0, BTRFS_COMPRESS_NONE,
763 						    NULL, false);
764 		} else {
765 			/* try making a compressed inline extent */
766 			ret = cow_file_range_inline(BTRFS_I(inode), actual_end,
767 						    total_compressed,
768 						    compress_type, pages,
769 						    false);
770 		}
771 		if (ret <= 0) {
772 			unsigned long clear_flags = EXTENT_DELALLOC |
773 				EXTENT_DELALLOC_NEW | EXTENT_DEFRAG |
774 				EXTENT_DO_ACCOUNTING;
775 			unsigned long page_error_op;
776 
777 			page_error_op = ret < 0 ? PAGE_SET_ERROR : 0;
778 
779 			/*
780 			 * inline extent creation worked or returned error,
781 			 * we don't need to create any more async work items.
782 			 * Unlock and free up our temp pages.
783 			 *
784 			 * We use DO_ACCOUNTING here because we need the
785 			 * delalloc_release_metadata to be done _after_ we drop
786 			 * our outstanding extent for clearing delalloc for this
787 			 * range.
788 			 */
789 			extent_clear_unlock_delalloc(BTRFS_I(inode), start, end,
790 						     NULL,
791 						     clear_flags,
792 						     PAGE_UNLOCK |
793 						     PAGE_START_WRITEBACK |
794 						     page_error_op |
795 						     PAGE_END_WRITEBACK);
796 
797 			/*
798 			 * Ensure we only free the compressed pages if we have
799 			 * them allocated, as we can still reach here with
800 			 * inode_need_compress() == false.
801 			 */
802 			if (pages) {
803 				for (i = 0; i < nr_pages; i++) {
804 					WARN_ON(pages[i]->mapping);
805 					put_page(pages[i]);
806 				}
807 				kfree(pages);
808 			}
809 			return 0;
810 		}
811 	}
812 
813 	if (will_compress) {
814 		/*
815 		 * we aren't doing an inline extent round the compressed size
816 		 * up to a block size boundary so the allocator does sane
817 		 * things
818 		 */
819 		total_compressed = ALIGN(total_compressed, blocksize);
820 
821 		/*
822 		 * one last check to make sure the compression is really a
823 		 * win, compare the page count read with the blocks on disk,
824 		 * compression must free at least one sector size
825 		 */
826 		total_in = round_up(total_in, fs_info->sectorsize);
827 		if (total_compressed + blocksize <= total_in) {
828 			compressed_extents++;
829 
830 			/*
831 			 * The async work queues will take care of doing actual
832 			 * allocation on disk for these compressed pages, and
833 			 * will submit them to the elevator.
834 			 */
835 			add_async_extent(async_chunk, start, total_in,
836 					total_compressed, pages, nr_pages,
837 					compress_type);
838 
839 			if (start + total_in < end) {
840 				start += total_in;
841 				pages = NULL;
842 				cond_resched();
843 				goto again;
844 			}
845 			return compressed_extents;
846 		}
847 	}
848 	if (pages) {
849 		/*
850 		 * the compression code ran but failed to make things smaller,
851 		 * free any pages it allocated and our page pointer array
852 		 */
853 		for (i = 0; i < nr_pages; i++) {
854 			WARN_ON(pages[i]->mapping);
855 			put_page(pages[i]);
856 		}
857 		kfree(pages);
858 		pages = NULL;
859 		total_compressed = 0;
860 		nr_pages = 0;
861 
862 		/* flag the file so we don't compress in the future */
863 		if (!btrfs_test_opt(fs_info, FORCE_COMPRESS) &&
864 		    !(BTRFS_I(inode)->prop_compress)) {
865 			BTRFS_I(inode)->flags |= BTRFS_INODE_NOCOMPRESS;
866 		}
867 	}
868 cleanup_and_bail_uncompressed:
869 	/*
870 	 * No compression, but we still need to write the pages in the file
871 	 * we've been given so far.  redirty the locked page if it corresponds
872 	 * to our extent and set things up for the async work queue to run
873 	 * cow_file_range to do the normal delalloc dance.
874 	 */
875 	if (async_chunk->locked_page &&
876 	    (page_offset(async_chunk->locked_page) >= start &&
877 	     page_offset(async_chunk->locked_page)) <= end) {
878 		__set_page_dirty_nobuffers(async_chunk->locked_page);
879 		/* unlocked later on in the async handlers */
880 	}
881 
882 	if (redirty)
883 		extent_range_redirty_for_io(inode, start, end);
884 	add_async_extent(async_chunk, start, end - start + 1, 0, NULL, 0,
885 			 BTRFS_COMPRESS_NONE);
886 	compressed_extents++;
887 
888 	return compressed_extents;
889 }
890 
free_async_extent_pages(struct async_extent * async_extent)891 static void free_async_extent_pages(struct async_extent *async_extent)
892 {
893 	int i;
894 
895 	if (!async_extent->pages)
896 		return;
897 
898 	for (i = 0; i < async_extent->nr_pages; i++) {
899 		WARN_ON(async_extent->pages[i]->mapping);
900 		put_page(async_extent->pages[i]);
901 	}
902 	kfree(async_extent->pages);
903 	async_extent->nr_pages = 0;
904 	async_extent->pages = NULL;
905 }
906 
submit_uncompressed_range(struct btrfs_inode * inode,struct async_extent * async_extent,struct page * locked_page)907 static int submit_uncompressed_range(struct btrfs_inode *inode,
908 				     struct async_extent *async_extent,
909 				     struct page *locked_page)
910 {
911 	u64 start = async_extent->start;
912 	u64 end = async_extent->start + async_extent->ram_size - 1;
913 	unsigned long nr_written = 0;
914 	int page_started = 0;
915 	int ret;
916 
917 	/*
918 	 * Call cow_file_range() to run the delalloc range directly, since we
919 	 * won't go to NOCOW or async path again.
920 	 *
921 	 * Also we call cow_file_range() with @unlock_page == 0, so that we
922 	 * can directly submit them without interruption.
923 	 */
924 	ret = cow_file_range(inode, locked_page, start, end, &page_started,
925 			     &nr_written, 0, NULL);
926 	/* Inline extent inserted, page gets unlocked and everything is done */
927 	if (page_started) {
928 		ret = 0;
929 		goto out;
930 	}
931 	if (ret < 0) {
932 		btrfs_cleanup_ordered_extents(inode, locked_page, start, end - start + 1);
933 		if (locked_page) {
934 			const u64 page_start = page_offset(locked_page);
935 			const u64 page_end = page_start + PAGE_SIZE - 1;
936 
937 			btrfs_page_set_error(inode->root->fs_info, locked_page,
938 					     page_start, PAGE_SIZE);
939 			set_page_writeback(locked_page);
940 			end_page_writeback(locked_page);
941 			end_extent_writepage(locked_page, ret, page_start, page_end);
942 			unlock_page(locked_page);
943 		}
944 		goto out;
945 	}
946 
947 	ret = extent_write_locked_range(&inode->vfs_inode, start, end);
948 	/* All pages will be unlocked, including @locked_page */
949 out:
950 	kfree(async_extent);
951 	return ret;
952 }
953 
submit_one_async_extent(struct btrfs_inode * inode,struct async_chunk * async_chunk,struct async_extent * async_extent,u64 * alloc_hint)954 static int submit_one_async_extent(struct btrfs_inode *inode,
955 				   struct async_chunk *async_chunk,
956 				   struct async_extent *async_extent,
957 				   u64 *alloc_hint)
958 {
959 	struct extent_io_tree *io_tree = &inode->io_tree;
960 	struct btrfs_root *root = inode->root;
961 	struct btrfs_fs_info *fs_info = root->fs_info;
962 	struct btrfs_key ins;
963 	struct page *locked_page = NULL;
964 	struct extent_map *em;
965 	int ret = 0;
966 	u64 start = async_extent->start;
967 	u64 end = async_extent->start + async_extent->ram_size - 1;
968 
969 	/*
970 	 * If async_chunk->locked_page is in the async_extent range, we need to
971 	 * handle it.
972 	 */
973 	if (async_chunk->locked_page) {
974 		u64 locked_page_start = page_offset(async_chunk->locked_page);
975 		u64 locked_page_end = locked_page_start + PAGE_SIZE - 1;
976 
977 		if (!(start >= locked_page_end || end <= locked_page_start))
978 			locked_page = async_chunk->locked_page;
979 	}
980 	lock_extent(io_tree, start, end, NULL);
981 
982 	/* We have fall back to uncompressed write */
983 	if (!async_extent->pages)
984 		return submit_uncompressed_range(inode, async_extent, locked_page);
985 
986 	ret = btrfs_reserve_extent(root, async_extent->ram_size,
987 				   async_extent->compressed_size,
988 				   async_extent->compressed_size,
989 				   0, *alloc_hint, &ins, 1, 1);
990 	if (ret) {
991 		free_async_extent_pages(async_extent);
992 		/*
993 		 * Here we used to try again by going back to non-compressed
994 		 * path for ENOSPC.  But we can't reserve space even for
995 		 * compressed size, how could it work for uncompressed size
996 		 * which requires larger size?  So here we directly go error
997 		 * path.
998 		 */
999 		goto out_free;
1000 	}
1001 
1002 	/* Here we're doing allocation and writeback of the compressed pages */
1003 	em = create_io_em(inode, start,
1004 			  async_extent->ram_size,	/* len */
1005 			  start,			/* orig_start */
1006 			  ins.objectid,			/* block_start */
1007 			  ins.offset,			/* block_len */
1008 			  ins.offset,			/* orig_block_len */
1009 			  async_extent->ram_size,	/* ram_bytes */
1010 			  async_extent->compress_type,
1011 			  BTRFS_ORDERED_COMPRESSED);
1012 	if (IS_ERR(em)) {
1013 		ret = PTR_ERR(em);
1014 		goto out_free_reserve;
1015 	}
1016 	free_extent_map(em);
1017 
1018 	ret = btrfs_add_ordered_extent(inode, start,		/* file_offset */
1019 				       async_extent->ram_size,	/* num_bytes */
1020 				       async_extent->ram_size,	/* ram_bytes */
1021 				       ins.objectid,		/* disk_bytenr */
1022 				       ins.offset,		/* disk_num_bytes */
1023 				       0,			/* offset */
1024 				       1 << BTRFS_ORDERED_COMPRESSED,
1025 				       async_extent->compress_type);
1026 	if (ret) {
1027 		btrfs_drop_extent_map_range(inode, start, end, false);
1028 		goto out_free_reserve;
1029 	}
1030 	btrfs_dec_block_group_reservations(fs_info, ins.objectid);
1031 
1032 	/* Clear dirty, set writeback and unlock the pages. */
1033 	extent_clear_unlock_delalloc(inode, start, end,
1034 			NULL, EXTENT_LOCKED | EXTENT_DELALLOC,
1035 			PAGE_UNLOCK | PAGE_START_WRITEBACK);
1036 	if (btrfs_submit_compressed_write(inode, start,	/* file_offset */
1037 			    async_extent->ram_size,	/* num_bytes */
1038 			    ins.objectid,		/* disk_bytenr */
1039 			    ins.offset,			/* compressed_len */
1040 			    async_extent->pages,	/* compressed_pages */
1041 			    async_extent->nr_pages,
1042 			    async_chunk->write_flags,
1043 			    async_chunk->blkcg_css, true)) {
1044 		const u64 start = async_extent->start;
1045 		const u64 end = start + async_extent->ram_size - 1;
1046 
1047 		btrfs_writepage_endio_finish_ordered(inode, NULL, start, end, 0);
1048 
1049 		extent_clear_unlock_delalloc(inode, start, end, NULL, 0,
1050 					     PAGE_END_WRITEBACK | PAGE_SET_ERROR);
1051 		free_async_extent_pages(async_extent);
1052 	}
1053 	*alloc_hint = ins.objectid + ins.offset;
1054 	kfree(async_extent);
1055 	return ret;
1056 
1057 out_free_reserve:
1058 	btrfs_dec_block_group_reservations(fs_info, ins.objectid);
1059 	btrfs_free_reserved_extent(fs_info, ins.objectid, ins.offset, 1);
1060 out_free:
1061 	extent_clear_unlock_delalloc(inode, start, end,
1062 				     NULL, EXTENT_LOCKED | EXTENT_DELALLOC |
1063 				     EXTENT_DELALLOC_NEW |
1064 				     EXTENT_DEFRAG | EXTENT_DO_ACCOUNTING,
1065 				     PAGE_UNLOCK | PAGE_START_WRITEBACK |
1066 				     PAGE_END_WRITEBACK | PAGE_SET_ERROR);
1067 	free_async_extent_pages(async_extent);
1068 	kfree(async_extent);
1069 	return ret;
1070 }
1071 
1072 /*
1073  * Phase two of compressed writeback.  This is the ordered portion of the code,
1074  * which only gets called in the order the work was queued.  We walk all the
1075  * async extents created by compress_file_range and send them down to the disk.
1076  */
submit_compressed_extents(struct async_chunk * async_chunk)1077 static noinline void submit_compressed_extents(struct async_chunk *async_chunk)
1078 {
1079 	struct btrfs_inode *inode = BTRFS_I(async_chunk->inode);
1080 	struct btrfs_fs_info *fs_info = inode->root->fs_info;
1081 	struct async_extent *async_extent;
1082 	u64 alloc_hint = 0;
1083 	int ret = 0;
1084 
1085 	while (!list_empty(&async_chunk->extents)) {
1086 		u64 extent_start;
1087 		u64 ram_size;
1088 
1089 		async_extent = list_entry(async_chunk->extents.next,
1090 					  struct async_extent, list);
1091 		list_del(&async_extent->list);
1092 		extent_start = async_extent->start;
1093 		ram_size = async_extent->ram_size;
1094 
1095 		ret = submit_one_async_extent(inode, async_chunk, async_extent,
1096 					      &alloc_hint);
1097 		btrfs_debug(fs_info,
1098 "async extent submission failed root=%lld inode=%llu start=%llu len=%llu ret=%d",
1099 			    inode->root->root_key.objectid,
1100 			    btrfs_ino(inode), extent_start, ram_size, ret);
1101 	}
1102 }
1103 
get_extent_allocation_hint(struct btrfs_inode * inode,u64 start,u64 num_bytes)1104 static u64 get_extent_allocation_hint(struct btrfs_inode *inode, u64 start,
1105 				      u64 num_bytes)
1106 {
1107 	struct extent_map_tree *em_tree = &inode->extent_tree;
1108 	struct extent_map *em;
1109 	u64 alloc_hint = 0;
1110 
1111 	read_lock(&em_tree->lock);
1112 	em = search_extent_mapping(em_tree, start, num_bytes);
1113 	if (em) {
1114 		/*
1115 		 * if block start isn't an actual block number then find the
1116 		 * first block in this inode and use that as a hint.  If that
1117 		 * block is also bogus then just don't worry about it.
1118 		 */
1119 		if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
1120 			free_extent_map(em);
1121 			em = search_extent_mapping(em_tree, 0, 0);
1122 			if (em && em->block_start < EXTENT_MAP_LAST_BYTE)
1123 				alloc_hint = em->block_start;
1124 			if (em)
1125 				free_extent_map(em);
1126 		} else {
1127 			alloc_hint = em->block_start;
1128 			free_extent_map(em);
1129 		}
1130 	}
1131 	read_unlock(&em_tree->lock);
1132 
1133 	return alloc_hint;
1134 }
1135 
1136 /*
1137  * when extent_io.c finds a delayed allocation range in the file,
1138  * the call backs end up in this code.  The basic idea is to
1139  * allocate extents on disk for the range, and create ordered data structs
1140  * in ram to track those extents.
1141  *
1142  * locked_page is the page that writepage had locked already.  We use
1143  * it to make sure we don't do extra locks or unlocks.
1144  *
1145  * *page_started is set to one if we unlock locked_page and do everything
1146  * required to start IO on it.  It may be clean and already done with
1147  * IO when we return.
1148  *
1149  * When unlock == 1, we unlock the pages in successfully allocated regions.
1150  * When unlock == 0, we leave them locked for writing them out.
1151  *
1152  * However, we unlock all the pages except @locked_page in case of failure.
1153  *
1154  * In summary, page locking state will be as follow:
1155  *
1156  * - page_started == 1 (return value)
1157  *     - All the pages are unlocked. IO is started.
1158  *     - Note that this can happen only on success
1159  * - unlock == 1
1160  *     - All the pages except @locked_page are unlocked in any case
1161  * - unlock == 0
1162  *     - On success, all the pages are locked for writing out them
1163  *     - On failure, all the pages except @locked_page are unlocked
1164  *
1165  * When a failure happens in the second or later iteration of the
1166  * while-loop, the ordered extents created in previous iterations are kept
1167  * intact. So, the caller must clean them up by calling
1168  * btrfs_cleanup_ordered_extents(). See btrfs_run_delalloc_range() for
1169  * example.
1170  */
cow_file_range(struct btrfs_inode * inode,struct page * locked_page,u64 start,u64 end,int * page_started,unsigned long * nr_written,int unlock,u64 * done_offset)1171 static noinline int cow_file_range(struct btrfs_inode *inode,
1172 				   struct page *locked_page,
1173 				   u64 start, u64 end, int *page_started,
1174 				   unsigned long *nr_written, int unlock,
1175 				   u64 *done_offset)
1176 {
1177 	struct btrfs_root *root = inode->root;
1178 	struct btrfs_fs_info *fs_info = root->fs_info;
1179 	u64 alloc_hint = 0;
1180 	u64 orig_start = start;
1181 	u64 num_bytes;
1182 	unsigned long ram_size;
1183 	u64 cur_alloc_size = 0;
1184 	u64 min_alloc_size;
1185 	u64 blocksize = fs_info->sectorsize;
1186 	struct btrfs_key ins;
1187 	struct extent_map *em;
1188 	unsigned clear_bits;
1189 	unsigned long page_ops;
1190 	bool extent_reserved = false;
1191 	int ret = 0;
1192 
1193 	if (btrfs_is_free_space_inode(inode)) {
1194 		ret = -EINVAL;
1195 		goto out_unlock;
1196 	}
1197 
1198 	num_bytes = ALIGN(end - start + 1, blocksize);
1199 	num_bytes = max(blocksize,  num_bytes);
1200 	ASSERT(num_bytes <= btrfs_super_total_bytes(fs_info->super_copy));
1201 
1202 	inode_should_defrag(inode, start, end, num_bytes, SZ_64K);
1203 
1204 	/*
1205 	 * Due to the page size limit, for subpage we can only trigger the
1206 	 * writeback for the dirty sectors of page, that means data writeback
1207 	 * is doing more writeback than what we want.
1208 	 *
1209 	 * This is especially unexpected for some call sites like fallocate,
1210 	 * where we only increase i_size after everything is done.
1211 	 * This means we can trigger inline extent even if we didn't want to.
1212 	 * So here we skip inline extent creation completely.
1213 	 */
1214 	if (start == 0 && fs_info->sectorsize == PAGE_SIZE) {
1215 		u64 actual_end = min_t(u64, i_size_read(&inode->vfs_inode),
1216 				       end + 1);
1217 
1218 		/* lets try to make an inline extent */
1219 		ret = cow_file_range_inline(inode, actual_end, 0,
1220 					    BTRFS_COMPRESS_NONE, NULL, false);
1221 		if (ret == 0) {
1222 			/*
1223 			 * We use DO_ACCOUNTING here because we need the
1224 			 * delalloc_release_metadata to be run _after_ we drop
1225 			 * our outstanding extent for clearing delalloc for this
1226 			 * range.
1227 			 */
1228 			extent_clear_unlock_delalloc(inode, start, end,
1229 				     locked_page,
1230 				     EXTENT_LOCKED | EXTENT_DELALLOC |
1231 				     EXTENT_DELALLOC_NEW | EXTENT_DEFRAG |
1232 				     EXTENT_DO_ACCOUNTING, PAGE_UNLOCK |
1233 				     PAGE_START_WRITEBACK | PAGE_END_WRITEBACK);
1234 			*nr_written = *nr_written +
1235 			     (end - start + PAGE_SIZE) / PAGE_SIZE;
1236 			*page_started = 1;
1237 			/*
1238 			 * locked_page is locked by the caller of
1239 			 * writepage_delalloc(), not locked by
1240 			 * __process_pages_contig().
1241 			 *
1242 			 * We can't let __process_pages_contig() to unlock it,
1243 			 * as it doesn't have any subpage::writers recorded.
1244 			 *
1245 			 * Here we manually unlock the page, since the caller
1246 			 * can't use page_started to determine if it's an
1247 			 * inline extent or a compressed extent.
1248 			 */
1249 			unlock_page(locked_page);
1250 			goto out;
1251 		} else if (ret < 0) {
1252 			goto out_unlock;
1253 		}
1254 	}
1255 
1256 	alloc_hint = get_extent_allocation_hint(inode, start, num_bytes);
1257 
1258 	/*
1259 	 * Relocation relies on the relocated extents to have exactly the same
1260 	 * size as the original extents. Normally writeback for relocation data
1261 	 * extents follows a NOCOW path because relocation preallocates the
1262 	 * extents. However, due to an operation such as scrub turning a block
1263 	 * group to RO mode, it may fallback to COW mode, so we must make sure
1264 	 * an extent allocated during COW has exactly the requested size and can
1265 	 * not be split into smaller extents, otherwise relocation breaks and
1266 	 * fails during the stage where it updates the bytenr of file extent
1267 	 * items.
1268 	 */
1269 	if (btrfs_is_data_reloc_root(root))
1270 		min_alloc_size = num_bytes;
1271 	else
1272 		min_alloc_size = fs_info->sectorsize;
1273 
1274 	while (num_bytes > 0) {
1275 		cur_alloc_size = num_bytes;
1276 		ret = btrfs_reserve_extent(root, cur_alloc_size, cur_alloc_size,
1277 					   min_alloc_size, 0, alloc_hint,
1278 					   &ins, 1, 1);
1279 		if (ret < 0)
1280 			goto out_unlock;
1281 		cur_alloc_size = ins.offset;
1282 		extent_reserved = true;
1283 
1284 		ram_size = ins.offset;
1285 		em = create_io_em(inode, start, ins.offset, /* len */
1286 				  start, /* orig_start */
1287 				  ins.objectid, /* block_start */
1288 				  ins.offset, /* block_len */
1289 				  ins.offset, /* orig_block_len */
1290 				  ram_size, /* ram_bytes */
1291 				  BTRFS_COMPRESS_NONE, /* compress_type */
1292 				  BTRFS_ORDERED_REGULAR /* type */);
1293 		if (IS_ERR(em)) {
1294 			ret = PTR_ERR(em);
1295 			goto out_reserve;
1296 		}
1297 		free_extent_map(em);
1298 
1299 		ret = btrfs_add_ordered_extent(inode, start, ram_size, ram_size,
1300 					       ins.objectid, cur_alloc_size, 0,
1301 					       1 << BTRFS_ORDERED_REGULAR,
1302 					       BTRFS_COMPRESS_NONE);
1303 		if (ret)
1304 			goto out_drop_extent_cache;
1305 
1306 		if (btrfs_is_data_reloc_root(root)) {
1307 			ret = btrfs_reloc_clone_csums(inode, start,
1308 						      cur_alloc_size);
1309 			/*
1310 			 * Only drop cache here, and process as normal.
1311 			 *
1312 			 * We must not allow extent_clear_unlock_delalloc()
1313 			 * at out_unlock label to free meta of this ordered
1314 			 * extent, as its meta should be freed by
1315 			 * btrfs_finish_ordered_io().
1316 			 *
1317 			 * So we must continue until @start is increased to
1318 			 * skip current ordered extent.
1319 			 */
1320 			if (ret)
1321 				btrfs_drop_extent_map_range(inode, start,
1322 							    start + ram_size - 1,
1323 							    false);
1324 		}
1325 
1326 		btrfs_dec_block_group_reservations(fs_info, ins.objectid);
1327 
1328 		/*
1329 		 * We're not doing compressed IO, don't unlock the first page
1330 		 * (which the caller expects to stay locked), don't clear any
1331 		 * dirty bits and don't set any writeback bits
1332 		 *
1333 		 * Do set the Ordered (Private2) bit so we know this page was
1334 		 * properly setup for writepage.
1335 		 */
1336 		page_ops = unlock ? PAGE_UNLOCK : 0;
1337 		page_ops |= PAGE_SET_ORDERED;
1338 
1339 		extent_clear_unlock_delalloc(inode, start, start + ram_size - 1,
1340 					     locked_page,
1341 					     EXTENT_LOCKED | EXTENT_DELALLOC,
1342 					     page_ops);
1343 		if (num_bytes < cur_alloc_size)
1344 			num_bytes = 0;
1345 		else
1346 			num_bytes -= cur_alloc_size;
1347 		alloc_hint = ins.objectid + ins.offset;
1348 		start += cur_alloc_size;
1349 		extent_reserved = false;
1350 
1351 		/*
1352 		 * btrfs_reloc_clone_csums() error, since start is increased
1353 		 * extent_clear_unlock_delalloc() at out_unlock label won't
1354 		 * free metadata of current ordered extent, we're OK to exit.
1355 		 */
1356 		if (ret)
1357 			goto out_unlock;
1358 	}
1359 out:
1360 	return ret;
1361 
1362 out_drop_extent_cache:
1363 	btrfs_drop_extent_map_range(inode, start, start + ram_size - 1, false);
1364 out_reserve:
1365 	btrfs_dec_block_group_reservations(fs_info, ins.objectid);
1366 	btrfs_free_reserved_extent(fs_info, ins.objectid, ins.offset, 1);
1367 out_unlock:
1368 	/*
1369 	 * If done_offset is non-NULL and ret == -EAGAIN, we expect the
1370 	 * caller to write out the successfully allocated region and retry.
1371 	 */
1372 	if (done_offset && ret == -EAGAIN) {
1373 		if (orig_start < start)
1374 			*done_offset = start - 1;
1375 		else
1376 			*done_offset = start;
1377 		return ret;
1378 	} else if (ret == -EAGAIN) {
1379 		/* Convert to -ENOSPC since the caller cannot retry. */
1380 		ret = -ENOSPC;
1381 	}
1382 
1383 	/*
1384 	 * Now, we have three regions to clean up:
1385 	 *
1386 	 * |-------(1)----|---(2)---|-------------(3)----------|
1387 	 * `- orig_start  `- start  `- start + cur_alloc_size  `- end
1388 	 *
1389 	 * We process each region below.
1390 	 */
1391 
1392 	clear_bits = EXTENT_LOCKED | EXTENT_DELALLOC | EXTENT_DELALLOC_NEW |
1393 		EXTENT_DEFRAG | EXTENT_CLEAR_META_RESV;
1394 	page_ops = PAGE_UNLOCK | PAGE_START_WRITEBACK | PAGE_END_WRITEBACK;
1395 
1396 	/*
1397 	 * For the range (1). We have already instantiated the ordered extents
1398 	 * for this region. They are cleaned up by
1399 	 * btrfs_cleanup_ordered_extents() in e.g,
1400 	 * btrfs_run_delalloc_range(). EXTENT_LOCKED | EXTENT_DELALLOC are
1401 	 * already cleared in the above loop. And, EXTENT_DELALLOC_NEW |
1402 	 * EXTENT_DEFRAG | EXTENT_CLEAR_META_RESV are handled by the cleanup
1403 	 * function.
1404 	 *
1405 	 * However, in case of unlock == 0, we still need to unlock the pages
1406 	 * (except @locked_page) to ensure all the pages are unlocked.
1407 	 */
1408 	if (!unlock && orig_start < start) {
1409 		if (!locked_page)
1410 			mapping_set_error(inode->vfs_inode.i_mapping, ret);
1411 		extent_clear_unlock_delalloc(inode, orig_start, start - 1,
1412 					     locked_page, 0, page_ops);
1413 	}
1414 
1415 	/*
1416 	 * For the range (2). If we reserved an extent for our delalloc range
1417 	 * (or a subrange) and failed to create the respective ordered extent,
1418 	 * then it means that when we reserved the extent we decremented the
1419 	 * extent's size from the data space_info's bytes_may_use counter and
1420 	 * incremented the space_info's bytes_reserved counter by the same
1421 	 * amount. We must make sure extent_clear_unlock_delalloc() does not try
1422 	 * to decrement again the data space_info's bytes_may_use counter,
1423 	 * therefore we do not pass it the flag EXTENT_CLEAR_DATA_RESV.
1424 	 */
1425 	if (extent_reserved) {
1426 		extent_clear_unlock_delalloc(inode, start,
1427 					     start + cur_alloc_size - 1,
1428 					     locked_page,
1429 					     clear_bits,
1430 					     page_ops);
1431 		start += cur_alloc_size;
1432 	}
1433 
1434 	/*
1435 	 * For the range (3). We never touched the region. In addition to the
1436 	 * clear_bits above, we add EXTENT_CLEAR_DATA_RESV to release the data
1437 	 * space_info's bytes_may_use counter, reserved in
1438 	 * btrfs_check_data_free_space().
1439 	 */
1440 	if (start < end) {
1441 		clear_bits |= EXTENT_CLEAR_DATA_RESV;
1442 		extent_clear_unlock_delalloc(inode, start, end, locked_page,
1443 					     clear_bits, page_ops);
1444 	}
1445 	return ret;
1446 }
1447 
1448 /*
1449  * work queue call back to started compression on a file and pages
1450  */
async_cow_start(struct btrfs_work * work)1451 static noinline void async_cow_start(struct btrfs_work *work)
1452 {
1453 	struct async_chunk *async_chunk;
1454 	int compressed_extents;
1455 
1456 	async_chunk = container_of(work, struct async_chunk, work);
1457 
1458 	compressed_extents = compress_file_range(async_chunk);
1459 	if (compressed_extents == 0) {
1460 		btrfs_add_delayed_iput(async_chunk->inode);
1461 		async_chunk->inode = NULL;
1462 	}
1463 }
1464 
1465 /*
1466  * work queue call back to submit previously compressed pages
1467  */
async_cow_submit(struct btrfs_work * work)1468 static noinline void async_cow_submit(struct btrfs_work *work)
1469 {
1470 	struct async_chunk *async_chunk = container_of(work, struct async_chunk,
1471 						     work);
1472 	struct btrfs_fs_info *fs_info = btrfs_work_owner(work);
1473 	unsigned long nr_pages;
1474 
1475 	nr_pages = (async_chunk->end - async_chunk->start + PAGE_SIZE) >>
1476 		PAGE_SHIFT;
1477 
1478 	/*
1479 	 * ->inode could be NULL if async_chunk_start has failed to compress,
1480 	 * in which case we don't have anything to submit, yet we need to
1481 	 * always adjust ->async_delalloc_pages as its paired with the init
1482 	 * happening in cow_file_range_async
1483 	 */
1484 	if (async_chunk->inode)
1485 		submit_compressed_extents(async_chunk);
1486 
1487 	/* atomic_sub_return implies a barrier */
1488 	if (atomic_sub_return(nr_pages, &fs_info->async_delalloc_pages) <
1489 	    5 * SZ_1M)
1490 		cond_wake_up_nomb(&fs_info->async_submit_wait);
1491 }
1492 
async_cow_free(struct btrfs_work * work)1493 static noinline void async_cow_free(struct btrfs_work *work)
1494 {
1495 	struct async_chunk *async_chunk;
1496 	struct async_cow *async_cow;
1497 
1498 	async_chunk = container_of(work, struct async_chunk, work);
1499 	if (async_chunk->inode)
1500 		btrfs_add_delayed_iput(async_chunk->inode);
1501 	if (async_chunk->blkcg_css)
1502 		css_put(async_chunk->blkcg_css);
1503 
1504 	async_cow = async_chunk->async_cow;
1505 	if (atomic_dec_and_test(&async_cow->num_chunks))
1506 		kvfree(async_cow);
1507 }
1508 
cow_file_range_async(struct btrfs_inode * inode,struct writeback_control * wbc,struct page * locked_page,u64 start,u64 end,int * page_started,unsigned long * nr_written)1509 static int cow_file_range_async(struct btrfs_inode *inode,
1510 				struct writeback_control *wbc,
1511 				struct page *locked_page,
1512 				u64 start, u64 end, int *page_started,
1513 				unsigned long *nr_written)
1514 {
1515 	struct btrfs_fs_info *fs_info = inode->root->fs_info;
1516 	struct cgroup_subsys_state *blkcg_css = wbc_blkcg_css(wbc);
1517 	struct async_cow *ctx;
1518 	struct async_chunk *async_chunk;
1519 	unsigned long nr_pages;
1520 	u64 cur_end;
1521 	u64 num_chunks = DIV_ROUND_UP(end - start, SZ_512K);
1522 	int i;
1523 	bool should_compress;
1524 	unsigned nofs_flag;
1525 	const blk_opf_t write_flags = wbc_to_write_flags(wbc);
1526 
1527 	unlock_extent(&inode->io_tree, start, end, NULL);
1528 
1529 	if (inode->flags & BTRFS_INODE_NOCOMPRESS &&
1530 	    !btrfs_test_opt(fs_info, FORCE_COMPRESS)) {
1531 		num_chunks = 1;
1532 		should_compress = false;
1533 	} else {
1534 		should_compress = true;
1535 	}
1536 
1537 	nofs_flag = memalloc_nofs_save();
1538 	ctx = kvmalloc(struct_size(ctx, chunks, num_chunks), GFP_KERNEL);
1539 	memalloc_nofs_restore(nofs_flag);
1540 
1541 	if (!ctx) {
1542 		unsigned clear_bits = EXTENT_LOCKED | EXTENT_DELALLOC |
1543 			EXTENT_DELALLOC_NEW | EXTENT_DEFRAG |
1544 			EXTENT_DO_ACCOUNTING;
1545 		unsigned long page_ops = PAGE_UNLOCK | PAGE_START_WRITEBACK |
1546 					 PAGE_END_WRITEBACK | PAGE_SET_ERROR;
1547 
1548 		extent_clear_unlock_delalloc(inode, start, end, locked_page,
1549 					     clear_bits, page_ops);
1550 		return -ENOMEM;
1551 	}
1552 
1553 	async_chunk = ctx->chunks;
1554 	atomic_set(&ctx->num_chunks, num_chunks);
1555 
1556 	for (i = 0; i < num_chunks; i++) {
1557 		if (should_compress)
1558 			cur_end = min(end, start + SZ_512K - 1);
1559 		else
1560 			cur_end = end;
1561 
1562 		/*
1563 		 * igrab is called higher up in the call chain, take only the
1564 		 * lightweight reference for the callback lifetime
1565 		 */
1566 		ihold(&inode->vfs_inode);
1567 		async_chunk[i].async_cow = ctx;
1568 		async_chunk[i].inode = &inode->vfs_inode;
1569 		async_chunk[i].start = start;
1570 		async_chunk[i].end = cur_end;
1571 		async_chunk[i].write_flags = write_flags;
1572 		INIT_LIST_HEAD(&async_chunk[i].extents);
1573 
1574 		/*
1575 		 * The locked_page comes all the way from writepage and its
1576 		 * the original page we were actually given.  As we spread
1577 		 * this large delalloc region across multiple async_chunk
1578 		 * structs, only the first struct needs a pointer to locked_page
1579 		 *
1580 		 * This way we don't need racey decisions about who is supposed
1581 		 * to unlock it.
1582 		 */
1583 		if (locked_page) {
1584 			/*
1585 			 * Depending on the compressibility, the pages might or
1586 			 * might not go through async.  We want all of them to
1587 			 * be accounted against wbc once.  Let's do it here
1588 			 * before the paths diverge.  wbc accounting is used
1589 			 * only for foreign writeback detection and doesn't
1590 			 * need full accuracy.  Just account the whole thing
1591 			 * against the first page.
1592 			 */
1593 			wbc_account_cgroup_owner(wbc, locked_page,
1594 						 cur_end - start);
1595 			async_chunk[i].locked_page = locked_page;
1596 			locked_page = NULL;
1597 		} else {
1598 			async_chunk[i].locked_page = NULL;
1599 		}
1600 
1601 		if (blkcg_css != blkcg_root_css) {
1602 			css_get(blkcg_css);
1603 			async_chunk[i].blkcg_css = blkcg_css;
1604 		} else {
1605 			async_chunk[i].blkcg_css = NULL;
1606 		}
1607 
1608 		btrfs_init_work(&async_chunk[i].work, async_cow_start,
1609 				async_cow_submit, async_cow_free);
1610 
1611 		nr_pages = DIV_ROUND_UP(cur_end - start, PAGE_SIZE);
1612 		atomic_add(nr_pages, &fs_info->async_delalloc_pages);
1613 
1614 		btrfs_queue_work(fs_info->delalloc_workers, &async_chunk[i].work);
1615 
1616 		*nr_written += nr_pages;
1617 		start = cur_end + 1;
1618 	}
1619 	*page_started = 1;
1620 	return 0;
1621 }
1622 
run_delalloc_zoned(struct btrfs_inode * inode,struct page * locked_page,u64 start,u64 end,int * page_started,unsigned long * nr_written)1623 static noinline int run_delalloc_zoned(struct btrfs_inode *inode,
1624 				       struct page *locked_page, u64 start,
1625 				       u64 end, int *page_started,
1626 				       unsigned long *nr_written)
1627 {
1628 	u64 done_offset = end;
1629 	int ret;
1630 	bool locked_page_done = false;
1631 
1632 	while (start <= end) {
1633 		ret = cow_file_range(inode, locked_page, start, end, page_started,
1634 				     nr_written, 0, &done_offset);
1635 		if (ret && ret != -EAGAIN)
1636 			return ret;
1637 
1638 		if (*page_started) {
1639 			ASSERT(ret == 0);
1640 			return 0;
1641 		}
1642 
1643 		if (ret == 0)
1644 			done_offset = end;
1645 
1646 		if (done_offset == start) {
1647 			wait_on_bit_io(&inode->root->fs_info->flags,
1648 				       BTRFS_FS_NEED_ZONE_FINISH,
1649 				       TASK_UNINTERRUPTIBLE);
1650 			continue;
1651 		}
1652 
1653 		if (!locked_page_done) {
1654 			__set_page_dirty_nobuffers(locked_page);
1655 			account_page_redirty(locked_page);
1656 		}
1657 		locked_page_done = true;
1658 		extent_write_locked_range(&inode->vfs_inode, start, done_offset);
1659 
1660 		start = done_offset + 1;
1661 	}
1662 
1663 	*page_started = 1;
1664 
1665 	return 0;
1666 }
1667 
csum_exist_in_range(struct btrfs_fs_info * fs_info,u64 bytenr,u64 num_bytes,bool nowait)1668 static noinline int csum_exist_in_range(struct btrfs_fs_info *fs_info,
1669 					u64 bytenr, u64 num_bytes, bool nowait)
1670 {
1671 	struct btrfs_root *csum_root = btrfs_csum_root(fs_info, bytenr);
1672 	struct btrfs_ordered_sum *sums;
1673 	int ret;
1674 	LIST_HEAD(list);
1675 
1676 	ret = btrfs_lookup_csums_range(csum_root, bytenr,
1677 				       bytenr + num_bytes - 1, &list, 0,
1678 				       nowait);
1679 	if (ret == 0 && list_empty(&list))
1680 		return 0;
1681 
1682 	while (!list_empty(&list)) {
1683 		sums = list_entry(list.next, struct btrfs_ordered_sum, list);
1684 		list_del(&sums->list);
1685 		kfree(sums);
1686 	}
1687 	if (ret < 0)
1688 		return ret;
1689 	return 1;
1690 }
1691 
fallback_to_cow(struct btrfs_inode * inode,struct page * locked_page,const u64 start,const u64 end,int * page_started,unsigned long * nr_written)1692 static int fallback_to_cow(struct btrfs_inode *inode, struct page *locked_page,
1693 			   const u64 start, const u64 end,
1694 			   int *page_started, unsigned long *nr_written)
1695 {
1696 	const bool is_space_ino = btrfs_is_free_space_inode(inode);
1697 	const bool is_reloc_ino = btrfs_is_data_reloc_root(inode->root);
1698 	const u64 range_bytes = end + 1 - start;
1699 	struct extent_io_tree *io_tree = &inode->io_tree;
1700 	u64 range_start = start;
1701 	u64 count;
1702 
1703 	/*
1704 	 * If EXTENT_NORESERVE is set it means that when the buffered write was
1705 	 * made we had not enough available data space and therefore we did not
1706 	 * reserve data space for it, since we though we could do NOCOW for the
1707 	 * respective file range (either there is prealloc extent or the inode
1708 	 * has the NOCOW bit set).
1709 	 *
1710 	 * However when we need to fallback to COW mode (because for example the
1711 	 * block group for the corresponding extent was turned to RO mode by a
1712 	 * scrub or relocation) we need to do the following:
1713 	 *
1714 	 * 1) We increment the bytes_may_use counter of the data space info.
1715 	 *    If COW succeeds, it allocates a new data extent and after doing
1716 	 *    that it decrements the space info's bytes_may_use counter and
1717 	 *    increments its bytes_reserved counter by the same amount (we do
1718 	 *    this at btrfs_add_reserved_bytes()). So we need to increment the
1719 	 *    bytes_may_use counter to compensate (when space is reserved at
1720 	 *    buffered write time, the bytes_may_use counter is incremented);
1721 	 *
1722 	 * 2) We clear the EXTENT_NORESERVE bit from the range. We do this so
1723 	 *    that if the COW path fails for any reason, it decrements (through
1724 	 *    extent_clear_unlock_delalloc()) the bytes_may_use counter of the
1725 	 *    data space info, which we incremented in the step above.
1726 	 *
1727 	 * If we need to fallback to cow and the inode corresponds to a free
1728 	 * space cache inode or an inode of the data relocation tree, we must
1729 	 * also increment bytes_may_use of the data space_info for the same
1730 	 * reason. Space caches and relocated data extents always get a prealloc
1731 	 * extent for them, however scrub or balance may have set the block
1732 	 * group that contains that extent to RO mode and therefore force COW
1733 	 * when starting writeback.
1734 	 */
1735 	count = count_range_bits(io_tree, &range_start, end, range_bytes,
1736 				 EXTENT_NORESERVE, 0);
1737 	if (count > 0 || is_space_ino || is_reloc_ino) {
1738 		u64 bytes = count;
1739 		struct btrfs_fs_info *fs_info = inode->root->fs_info;
1740 		struct btrfs_space_info *sinfo = fs_info->data_sinfo;
1741 
1742 		if (is_space_ino || is_reloc_ino)
1743 			bytes = range_bytes;
1744 
1745 		spin_lock(&sinfo->lock);
1746 		btrfs_space_info_update_bytes_may_use(fs_info, sinfo, bytes);
1747 		spin_unlock(&sinfo->lock);
1748 
1749 		if (count > 0)
1750 			clear_extent_bit(io_tree, start, end, EXTENT_NORESERVE,
1751 					 NULL);
1752 	}
1753 
1754 	return cow_file_range(inode, locked_page, start, end, page_started,
1755 			      nr_written, 1, NULL);
1756 }
1757 
1758 struct can_nocow_file_extent_args {
1759 	/* Input fields. */
1760 
1761 	/* Start file offset of the range we want to NOCOW. */
1762 	u64 start;
1763 	/* End file offset (inclusive) of the range we want to NOCOW. */
1764 	u64 end;
1765 	bool writeback_path;
1766 	bool strict;
1767 	/*
1768 	 * Free the path passed to can_nocow_file_extent() once it's not needed
1769 	 * anymore.
1770 	 */
1771 	bool free_path;
1772 
1773 	/* Output fields. Only set when can_nocow_file_extent() returns 1. */
1774 
1775 	u64 disk_bytenr;
1776 	u64 disk_num_bytes;
1777 	u64 extent_offset;
1778 	/* Number of bytes that can be written to in NOCOW mode. */
1779 	u64 num_bytes;
1780 };
1781 
1782 /*
1783  * Check if we can NOCOW the file extent that the path points to.
1784  * This function may return with the path released, so the caller should check
1785  * if path->nodes[0] is NULL or not if it needs to use the path afterwards.
1786  *
1787  * Returns: < 0 on error
1788  *            0 if we can not NOCOW
1789  *            1 if we can NOCOW
1790  */
can_nocow_file_extent(struct btrfs_path * path,struct btrfs_key * key,struct btrfs_inode * inode,struct can_nocow_file_extent_args * args)1791 static int can_nocow_file_extent(struct btrfs_path *path,
1792 				 struct btrfs_key *key,
1793 				 struct btrfs_inode *inode,
1794 				 struct can_nocow_file_extent_args *args)
1795 {
1796 	const bool is_freespace_inode = btrfs_is_free_space_inode(inode);
1797 	struct extent_buffer *leaf = path->nodes[0];
1798 	struct btrfs_root *root = inode->root;
1799 	struct btrfs_file_extent_item *fi;
1800 	u64 extent_end;
1801 	u8 extent_type;
1802 	int can_nocow = 0;
1803 	int ret = 0;
1804 	bool nowait = path->nowait;
1805 
1806 	fi = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_file_extent_item);
1807 	extent_type = btrfs_file_extent_type(leaf, fi);
1808 
1809 	if (extent_type == BTRFS_FILE_EXTENT_INLINE)
1810 		goto out;
1811 
1812 	/* Can't access these fields unless we know it's not an inline extent. */
1813 	args->disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
1814 	args->disk_num_bytes = btrfs_file_extent_disk_num_bytes(leaf, fi);
1815 	args->extent_offset = btrfs_file_extent_offset(leaf, fi);
1816 
1817 	if (!(inode->flags & BTRFS_INODE_NODATACOW) &&
1818 	    extent_type == BTRFS_FILE_EXTENT_REG)
1819 		goto out;
1820 
1821 	/*
1822 	 * If the extent was created before the generation where the last snapshot
1823 	 * for its subvolume was created, then this implies the extent is shared,
1824 	 * hence we must COW.
1825 	 */
1826 	if (!args->strict &&
1827 	    btrfs_file_extent_generation(leaf, fi) <=
1828 	    btrfs_root_last_snapshot(&root->root_item))
1829 		goto out;
1830 
1831 	/* An explicit hole, must COW. */
1832 	if (args->disk_bytenr == 0)
1833 		goto out;
1834 
1835 	/* Compressed/encrypted/encoded extents must be COWed. */
1836 	if (btrfs_file_extent_compression(leaf, fi) ||
1837 	    btrfs_file_extent_encryption(leaf, fi) ||
1838 	    btrfs_file_extent_other_encoding(leaf, fi))
1839 		goto out;
1840 
1841 	extent_end = btrfs_file_extent_end(path);
1842 
1843 	/*
1844 	 * The following checks can be expensive, as they need to take other
1845 	 * locks and do btree or rbtree searches, so release the path to avoid
1846 	 * blocking other tasks for too long.
1847 	 */
1848 	btrfs_release_path(path);
1849 
1850 	ret = btrfs_cross_ref_exist(root, btrfs_ino(inode),
1851 				    key->offset - args->extent_offset,
1852 				    args->disk_bytenr, args->strict, path);
1853 	WARN_ON_ONCE(ret > 0 && is_freespace_inode);
1854 	if (ret != 0)
1855 		goto out;
1856 
1857 	if (args->free_path) {
1858 		/*
1859 		 * We don't need the path anymore, plus through the
1860 		 * csum_exist_in_range() call below we will end up allocating
1861 		 * another path. So free the path to avoid unnecessary extra
1862 		 * memory usage.
1863 		 */
1864 		btrfs_free_path(path);
1865 		path = NULL;
1866 	}
1867 
1868 	/* If there are pending snapshots for this root, we must COW. */
1869 	if (args->writeback_path && !is_freespace_inode &&
1870 	    atomic_read(&root->snapshot_force_cow))
1871 		goto out;
1872 
1873 	args->disk_bytenr += args->extent_offset;
1874 	args->disk_bytenr += args->start - key->offset;
1875 	args->num_bytes = min(args->end + 1, extent_end) - args->start;
1876 
1877 	/*
1878 	 * Force COW if csums exist in the range. This ensures that csums for a
1879 	 * given extent are either valid or do not exist.
1880 	 */
1881 	ret = csum_exist_in_range(root->fs_info, args->disk_bytenr, args->num_bytes,
1882 				  nowait);
1883 	WARN_ON_ONCE(ret > 0 && is_freespace_inode);
1884 	if (ret != 0)
1885 		goto out;
1886 
1887 	can_nocow = 1;
1888  out:
1889 	if (args->free_path && path)
1890 		btrfs_free_path(path);
1891 
1892 	return ret < 0 ? ret : can_nocow;
1893 }
1894 
1895 /*
1896  * when nowcow writeback call back.  This checks for snapshots or COW copies
1897  * of the extents that exist in the file, and COWs the file as required.
1898  *
1899  * If no cow copies or snapshots exist, we write directly to the existing
1900  * blocks on disk
1901  */
run_delalloc_nocow(struct btrfs_inode * inode,struct page * locked_page,const u64 start,const u64 end,int * page_started,unsigned long * nr_written)1902 static noinline int run_delalloc_nocow(struct btrfs_inode *inode,
1903 				       struct page *locked_page,
1904 				       const u64 start, const u64 end,
1905 				       int *page_started,
1906 				       unsigned long *nr_written)
1907 {
1908 	struct btrfs_fs_info *fs_info = inode->root->fs_info;
1909 	struct btrfs_root *root = inode->root;
1910 	struct btrfs_path *path;
1911 	u64 cow_start = (u64)-1;
1912 	u64 cur_offset = start;
1913 	int ret;
1914 	bool check_prev = true;
1915 	u64 ino = btrfs_ino(inode);
1916 	struct btrfs_block_group *bg;
1917 	bool nocow = false;
1918 	struct can_nocow_file_extent_args nocow_args = { 0 };
1919 
1920 	path = btrfs_alloc_path();
1921 	if (!path) {
1922 		extent_clear_unlock_delalloc(inode, start, end, locked_page,
1923 					     EXTENT_LOCKED | EXTENT_DELALLOC |
1924 					     EXTENT_DO_ACCOUNTING |
1925 					     EXTENT_DEFRAG, PAGE_UNLOCK |
1926 					     PAGE_START_WRITEBACK |
1927 					     PAGE_END_WRITEBACK);
1928 		return -ENOMEM;
1929 	}
1930 
1931 	nocow_args.end = end;
1932 	nocow_args.writeback_path = true;
1933 
1934 	while (1) {
1935 		struct btrfs_key found_key;
1936 		struct btrfs_file_extent_item *fi;
1937 		struct extent_buffer *leaf;
1938 		u64 extent_end;
1939 		u64 ram_bytes;
1940 		u64 nocow_end;
1941 		int extent_type;
1942 
1943 		nocow = false;
1944 
1945 		ret = btrfs_lookup_file_extent(NULL, root, path, ino,
1946 					       cur_offset, 0);
1947 		if (ret < 0)
1948 			goto error;
1949 
1950 		/*
1951 		 * If there is no extent for our range when doing the initial
1952 		 * search, then go back to the previous slot as it will be the
1953 		 * one containing the search offset
1954 		 */
1955 		if (ret > 0 && path->slots[0] > 0 && check_prev) {
1956 			leaf = path->nodes[0];
1957 			btrfs_item_key_to_cpu(leaf, &found_key,
1958 					      path->slots[0] - 1);
1959 			if (found_key.objectid == ino &&
1960 			    found_key.type == BTRFS_EXTENT_DATA_KEY)
1961 				path->slots[0]--;
1962 		}
1963 		check_prev = false;
1964 next_slot:
1965 		/* Go to next leaf if we have exhausted the current one */
1966 		leaf = path->nodes[0];
1967 		if (path->slots[0] >= btrfs_header_nritems(leaf)) {
1968 			ret = btrfs_next_leaf(root, path);
1969 			if (ret < 0) {
1970 				if (cow_start != (u64)-1)
1971 					cur_offset = cow_start;
1972 				goto error;
1973 			}
1974 			if (ret > 0)
1975 				break;
1976 			leaf = path->nodes[0];
1977 		}
1978 
1979 		btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
1980 
1981 		/* Didn't find anything for our INO */
1982 		if (found_key.objectid > ino)
1983 			break;
1984 		/*
1985 		 * Keep searching until we find an EXTENT_ITEM or there are no
1986 		 * more extents for this inode
1987 		 */
1988 		if (WARN_ON_ONCE(found_key.objectid < ino) ||
1989 		    found_key.type < BTRFS_EXTENT_DATA_KEY) {
1990 			path->slots[0]++;
1991 			goto next_slot;
1992 		}
1993 
1994 		/* Found key is not EXTENT_DATA_KEY or starts after req range */
1995 		if (found_key.type > BTRFS_EXTENT_DATA_KEY ||
1996 		    found_key.offset > end)
1997 			break;
1998 
1999 		/*
2000 		 * If the found extent starts after requested offset, then
2001 		 * adjust extent_end to be right before this extent begins
2002 		 */
2003 		if (found_key.offset > cur_offset) {
2004 			extent_end = found_key.offset;
2005 			extent_type = 0;
2006 			goto out_check;
2007 		}
2008 
2009 		/*
2010 		 * Found extent which begins before our range and potentially
2011 		 * intersect it
2012 		 */
2013 		fi = btrfs_item_ptr(leaf, path->slots[0],
2014 				    struct btrfs_file_extent_item);
2015 		extent_type = btrfs_file_extent_type(leaf, fi);
2016 		/* If this is triggered then we have a memory corruption. */
2017 		ASSERT(extent_type < BTRFS_NR_FILE_EXTENT_TYPES);
2018 		if (WARN_ON(extent_type >= BTRFS_NR_FILE_EXTENT_TYPES)) {
2019 			ret = -EUCLEAN;
2020 			goto error;
2021 		}
2022 		ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi);
2023 		extent_end = btrfs_file_extent_end(path);
2024 
2025 		/*
2026 		 * If the extent we got ends before our current offset, skip to
2027 		 * the next extent.
2028 		 */
2029 		if (extent_end <= cur_offset) {
2030 			path->slots[0]++;
2031 			goto next_slot;
2032 		}
2033 
2034 		nocow_args.start = cur_offset;
2035 		ret = can_nocow_file_extent(path, &found_key, inode, &nocow_args);
2036 		if (ret < 0) {
2037 			if (cow_start != (u64)-1)
2038 				cur_offset = cow_start;
2039 			goto error;
2040 		} else if (ret == 0) {
2041 			goto out_check;
2042 		}
2043 
2044 		ret = 0;
2045 		bg = btrfs_inc_nocow_writers(fs_info, nocow_args.disk_bytenr);
2046 		if (bg)
2047 			nocow = true;
2048 out_check:
2049 		/*
2050 		 * If nocow is false then record the beginning of the range
2051 		 * that needs to be COWed
2052 		 */
2053 		if (!nocow) {
2054 			if (cow_start == (u64)-1)
2055 				cow_start = cur_offset;
2056 			cur_offset = extent_end;
2057 			if (cur_offset > end)
2058 				break;
2059 			if (!path->nodes[0])
2060 				continue;
2061 			path->slots[0]++;
2062 			goto next_slot;
2063 		}
2064 
2065 		/*
2066 		 * COW range from cow_start to found_key.offset - 1. As the key
2067 		 * will contain the beginning of the first extent that can be
2068 		 * NOCOW, following one which needs to be COW'ed
2069 		 */
2070 		if (cow_start != (u64)-1) {
2071 			ret = fallback_to_cow(inode, locked_page,
2072 					      cow_start, found_key.offset - 1,
2073 					      page_started, nr_written);
2074 			if (ret)
2075 				goto error;
2076 			cow_start = (u64)-1;
2077 		}
2078 
2079 		nocow_end = cur_offset + nocow_args.num_bytes - 1;
2080 
2081 		if (extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
2082 			u64 orig_start = found_key.offset - nocow_args.extent_offset;
2083 			struct extent_map *em;
2084 
2085 			em = create_io_em(inode, cur_offset, nocow_args.num_bytes,
2086 					  orig_start,
2087 					  nocow_args.disk_bytenr, /* block_start */
2088 					  nocow_args.num_bytes, /* block_len */
2089 					  nocow_args.disk_num_bytes, /* orig_block_len */
2090 					  ram_bytes, BTRFS_COMPRESS_NONE,
2091 					  BTRFS_ORDERED_PREALLOC);
2092 			if (IS_ERR(em)) {
2093 				ret = PTR_ERR(em);
2094 				goto error;
2095 			}
2096 			free_extent_map(em);
2097 			ret = btrfs_add_ordered_extent(inode,
2098 					cur_offset, nocow_args.num_bytes,
2099 					nocow_args.num_bytes,
2100 					nocow_args.disk_bytenr,
2101 					nocow_args.num_bytes, 0,
2102 					1 << BTRFS_ORDERED_PREALLOC,
2103 					BTRFS_COMPRESS_NONE);
2104 			if (ret) {
2105 				btrfs_drop_extent_map_range(inode, cur_offset,
2106 							    nocow_end, false);
2107 				goto error;
2108 			}
2109 		} else {
2110 			ret = btrfs_add_ordered_extent(inode, cur_offset,
2111 						       nocow_args.num_bytes,
2112 						       nocow_args.num_bytes,
2113 						       nocow_args.disk_bytenr,
2114 						       nocow_args.num_bytes,
2115 						       0,
2116 						       1 << BTRFS_ORDERED_NOCOW,
2117 						       BTRFS_COMPRESS_NONE);
2118 			if (ret)
2119 				goto error;
2120 		}
2121 
2122 		if (nocow) {
2123 			btrfs_dec_nocow_writers(bg);
2124 			nocow = false;
2125 		}
2126 
2127 		if (btrfs_is_data_reloc_root(root))
2128 			/*
2129 			 * Error handled later, as we must prevent
2130 			 * extent_clear_unlock_delalloc() in error handler
2131 			 * from freeing metadata of created ordered extent.
2132 			 */
2133 			ret = btrfs_reloc_clone_csums(inode, cur_offset,
2134 						      nocow_args.num_bytes);
2135 
2136 		extent_clear_unlock_delalloc(inode, cur_offset, nocow_end,
2137 					     locked_page, EXTENT_LOCKED |
2138 					     EXTENT_DELALLOC |
2139 					     EXTENT_CLEAR_DATA_RESV,
2140 					     PAGE_UNLOCK | PAGE_SET_ORDERED);
2141 
2142 		cur_offset = extent_end;
2143 
2144 		/*
2145 		 * btrfs_reloc_clone_csums() error, now we're OK to call error
2146 		 * handler, as metadata for created ordered extent will only
2147 		 * be freed by btrfs_finish_ordered_io().
2148 		 */
2149 		if (ret)
2150 			goto error;
2151 		if (cur_offset > end)
2152 			break;
2153 	}
2154 	btrfs_release_path(path);
2155 
2156 	if (cur_offset <= end && cow_start == (u64)-1)
2157 		cow_start = cur_offset;
2158 
2159 	if (cow_start != (u64)-1) {
2160 		cur_offset = end;
2161 		ret = fallback_to_cow(inode, locked_page, cow_start, end,
2162 				      page_started, nr_written);
2163 		if (ret)
2164 			goto error;
2165 	}
2166 
2167 error:
2168 	if (nocow)
2169 		btrfs_dec_nocow_writers(bg);
2170 
2171 	if (ret && cur_offset < end)
2172 		extent_clear_unlock_delalloc(inode, cur_offset, end,
2173 					     locked_page, EXTENT_LOCKED |
2174 					     EXTENT_DELALLOC | EXTENT_DEFRAG |
2175 					     EXTENT_DO_ACCOUNTING, PAGE_UNLOCK |
2176 					     PAGE_START_WRITEBACK |
2177 					     PAGE_END_WRITEBACK);
2178 	btrfs_free_path(path);
2179 	return ret;
2180 }
2181 
should_nocow(struct btrfs_inode * inode,u64 start,u64 end)2182 static bool should_nocow(struct btrfs_inode *inode, u64 start, u64 end)
2183 {
2184 	if (inode->flags & (BTRFS_INODE_NODATACOW | BTRFS_INODE_PREALLOC)) {
2185 		if (inode->defrag_bytes &&
2186 		    test_range_bit(&inode->io_tree, start, end, EXTENT_DEFRAG,
2187 				   0, NULL))
2188 			return false;
2189 		return true;
2190 	}
2191 	return false;
2192 }
2193 
2194 /*
2195  * Function to process delayed allocation (create CoW) for ranges which are
2196  * being touched for the first time.
2197  */
btrfs_run_delalloc_range(struct btrfs_inode * inode,struct page * locked_page,u64 start,u64 end,int * page_started,unsigned long * nr_written,struct writeback_control * wbc)2198 int btrfs_run_delalloc_range(struct btrfs_inode *inode, struct page *locked_page,
2199 		u64 start, u64 end, int *page_started, unsigned long *nr_written,
2200 		struct writeback_control *wbc)
2201 {
2202 	int ret;
2203 	const bool zoned = btrfs_is_zoned(inode->root->fs_info);
2204 
2205 	/*
2206 	 * The range must cover part of the @locked_page, or the returned
2207 	 * @page_started can confuse the caller.
2208 	 */
2209 	ASSERT(!(end <= page_offset(locked_page) ||
2210 		 start >= page_offset(locked_page) + PAGE_SIZE));
2211 
2212 	if (should_nocow(inode, start, end)) {
2213 		/*
2214 		 * Normally on a zoned device we're only doing COW writes, but
2215 		 * in case of relocation on a zoned filesystem we have taken
2216 		 * precaution, that we're only writing sequentially. It's safe
2217 		 * to use run_delalloc_nocow() here, like for  regular
2218 		 * preallocated inodes.
2219 		 */
2220 		ASSERT(!zoned || btrfs_is_data_reloc_root(inode->root));
2221 		ret = run_delalloc_nocow(inode, locked_page, start, end,
2222 					 page_started, nr_written);
2223 	} else if (!btrfs_inode_can_compress(inode) ||
2224 		   !inode_need_compress(inode, start, end)) {
2225 		if (zoned)
2226 			ret = run_delalloc_zoned(inode, locked_page, start, end,
2227 						 page_started, nr_written);
2228 		else
2229 			ret = cow_file_range(inode, locked_page, start, end,
2230 					     page_started, nr_written, 1, NULL);
2231 	} else {
2232 		set_bit(BTRFS_INODE_HAS_ASYNC_EXTENT, &inode->runtime_flags);
2233 		ret = cow_file_range_async(inode, wbc, locked_page, start, end,
2234 					   page_started, nr_written);
2235 	}
2236 	ASSERT(ret <= 0);
2237 	if (ret)
2238 		btrfs_cleanup_ordered_extents(inode, locked_page, start,
2239 					      end - start + 1);
2240 	return ret;
2241 }
2242 
btrfs_split_delalloc_extent(struct inode * inode,struct extent_state * orig,u64 split)2243 void btrfs_split_delalloc_extent(struct inode *inode,
2244 				 struct extent_state *orig, u64 split)
2245 {
2246 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2247 	u64 size;
2248 
2249 	/* not delalloc, ignore it */
2250 	if (!(orig->state & EXTENT_DELALLOC))
2251 		return;
2252 
2253 	size = orig->end - orig->start + 1;
2254 	if (size > fs_info->max_extent_size) {
2255 		u32 num_extents;
2256 		u64 new_size;
2257 
2258 		/*
2259 		 * See the explanation in btrfs_merge_delalloc_extent, the same
2260 		 * applies here, just in reverse.
2261 		 */
2262 		new_size = orig->end - split + 1;
2263 		num_extents = count_max_extents(fs_info, new_size);
2264 		new_size = split - orig->start;
2265 		num_extents += count_max_extents(fs_info, new_size);
2266 		if (count_max_extents(fs_info, size) >= num_extents)
2267 			return;
2268 	}
2269 
2270 	spin_lock(&BTRFS_I(inode)->lock);
2271 	btrfs_mod_outstanding_extents(BTRFS_I(inode), 1);
2272 	spin_unlock(&BTRFS_I(inode)->lock);
2273 }
2274 
2275 /*
2276  * Handle merged delayed allocation extents so we can keep track of new extents
2277  * that are just merged onto old extents, such as when we are doing sequential
2278  * writes, so we can properly account for the metadata space we'll need.
2279  */
btrfs_merge_delalloc_extent(struct inode * inode,struct extent_state * new,struct extent_state * other)2280 void btrfs_merge_delalloc_extent(struct inode *inode, struct extent_state *new,
2281 				 struct extent_state *other)
2282 {
2283 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2284 	u64 new_size, old_size;
2285 	u32 num_extents;
2286 
2287 	/* not delalloc, ignore it */
2288 	if (!(other->state & EXTENT_DELALLOC))
2289 		return;
2290 
2291 	if (new->start > other->start)
2292 		new_size = new->end - other->start + 1;
2293 	else
2294 		new_size = other->end - new->start + 1;
2295 
2296 	/* we're not bigger than the max, unreserve the space and go */
2297 	if (new_size <= fs_info->max_extent_size) {
2298 		spin_lock(&BTRFS_I(inode)->lock);
2299 		btrfs_mod_outstanding_extents(BTRFS_I(inode), -1);
2300 		spin_unlock(&BTRFS_I(inode)->lock);
2301 		return;
2302 	}
2303 
2304 	/*
2305 	 * We have to add up either side to figure out how many extents were
2306 	 * accounted for before we merged into one big extent.  If the number of
2307 	 * extents we accounted for is <= the amount we need for the new range
2308 	 * then we can return, otherwise drop.  Think of it like this
2309 	 *
2310 	 * [ 4k][MAX_SIZE]
2311 	 *
2312 	 * So we've grown the extent by a MAX_SIZE extent, this would mean we
2313 	 * need 2 outstanding extents, on one side we have 1 and the other side
2314 	 * we have 1 so they are == and we can return.  But in this case
2315 	 *
2316 	 * [MAX_SIZE+4k][MAX_SIZE+4k]
2317 	 *
2318 	 * Each range on their own accounts for 2 extents, but merged together
2319 	 * they are only 3 extents worth of accounting, so we need to drop in
2320 	 * this case.
2321 	 */
2322 	old_size = other->end - other->start + 1;
2323 	num_extents = count_max_extents(fs_info, old_size);
2324 	old_size = new->end - new->start + 1;
2325 	num_extents += count_max_extents(fs_info, old_size);
2326 	if (count_max_extents(fs_info, new_size) >= num_extents)
2327 		return;
2328 
2329 	spin_lock(&BTRFS_I(inode)->lock);
2330 	btrfs_mod_outstanding_extents(BTRFS_I(inode), -1);
2331 	spin_unlock(&BTRFS_I(inode)->lock);
2332 }
2333 
btrfs_add_delalloc_inodes(struct btrfs_root * root,struct inode * inode)2334 static void btrfs_add_delalloc_inodes(struct btrfs_root *root,
2335 				      struct inode *inode)
2336 {
2337 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2338 
2339 	spin_lock(&root->delalloc_lock);
2340 	if (list_empty(&BTRFS_I(inode)->delalloc_inodes)) {
2341 		list_add_tail(&BTRFS_I(inode)->delalloc_inodes,
2342 			      &root->delalloc_inodes);
2343 		set_bit(BTRFS_INODE_IN_DELALLOC_LIST,
2344 			&BTRFS_I(inode)->runtime_flags);
2345 		root->nr_delalloc_inodes++;
2346 		if (root->nr_delalloc_inodes == 1) {
2347 			spin_lock(&fs_info->delalloc_root_lock);
2348 			BUG_ON(!list_empty(&root->delalloc_root));
2349 			list_add_tail(&root->delalloc_root,
2350 				      &fs_info->delalloc_roots);
2351 			spin_unlock(&fs_info->delalloc_root_lock);
2352 		}
2353 	}
2354 	spin_unlock(&root->delalloc_lock);
2355 }
2356 
2357 
__btrfs_del_delalloc_inode(struct btrfs_root * root,struct btrfs_inode * inode)2358 void __btrfs_del_delalloc_inode(struct btrfs_root *root,
2359 				struct btrfs_inode *inode)
2360 {
2361 	struct btrfs_fs_info *fs_info = root->fs_info;
2362 
2363 	if (!list_empty(&inode->delalloc_inodes)) {
2364 		list_del_init(&inode->delalloc_inodes);
2365 		clear_bit(BTRFS_INODE_IN_DELALLOC_LIST,
2366 			  &inode->runtime_flags);
2367 		root->nr_delalloc_inodes--;
2368 		if (!root->nr_delalloc_inodes) {
2369 			ASSERT(list_empty(&root->delalloc_inodes));
2370 			spin_lock(&fs_info->delalloc_root_lock);
2371 			BUG_ON(list_empty(&root->delalloc_root));
2372 			list_del_init(&root->delalloc_root);
2373 			spin_unlock(&fs_info->delalloc_root_lock);
2374 		}
2375 	}
2376 }
2377 
btrfs_del_delalloc_inode(struct btrfs_root * root,struct btrfs_inode * inode)2378 static void btrfs_del_delalloc_inode(struct btrfs_root *root,
2379 				     struct btrfs_inode *inode)
2380 {
2381 	spin_lock(&root->delalloc_lock);
2382 	__btrfs_del_delalloc_inode(root, inode);
2383 	spin_unlock(&root->delalloc_lock);
2384 }
2385 
2386 /*
2387  * Properly track delayed allocation bytes in the inode and to maintain the
2388  * list of inodes that have pending delalloc work to be done.
2389  */
btrfs_set_delalloc_extent(struct inode * inode,struct extent_state * state,u32 bits)2390 void btrfs_set_delalloc_extent(struct inode *inode, struct extent_state *state,
2391 			       u32 bits)
2392 {
2393 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2394 
2395 	if ((bits & EXTENT_DEFRAG) && !(bits & EXTENT_DELALLOC))
2396 		WARN_ON(1);
2397 	/*
2398 	 * set_bit and clear bit hooks normally require _irqsave/restore
2399 	 * but in this case, we are only testing for the DELALLOC
2400 	 * bit, which is only set or cleared with irqs on
2401 	 */
2402 	if (!(state->state & EXTENT_DELALLOC) && (bits & EXTENT_DELALLOC)) {
2403 		struct btrfs_root *root = BTRFS_I(inode)->root;
2404 		u64 len = state->end + 1 - state->start;
2405 		u32 num_extents = count_max_extents(fs_info, len);
2406 		bool do_list = !btrfs_is_free_space_inode(BTRFS_I(inode));
2407 
2408 		spin_lock(&BTRFS_I(inode)->lock);
2409 		btrfs_mod_outstanding_extents(BTRFS_I(inode), num_extents);
2410 		spin_unlock(&BTRFS_I(inode)->lock);
2411 
2412 		/* For sanity tests */
2413 		if (btrfs_is_testing(fs_info))
2414 			return;
2415 
2416 		percpu_counter_add_batch(&fs_info->delalloc_bytes, len,
2417 					 fs_info->delalloc_batch);
2418 		spin_lock(&BTRFS_I(inode)->lock);
2419 		BTRFS_I(inode)->delalloc_bytes += len;
2420 		if (bits & EXTENT_DEFRAG)
2421 			BTRFS_I(inode)->defrag_bytes += len;
2422 		if (do_list && !test_bit(BTRFS_INODE_IN_DELALLOC_LIST,
2423 					 &BTRFS_I(inode)->runtime_flags))
2424 			btrfs_add_delalloc_inodes(root, inode);
2425 		spin_unlock(&BTRFS_I(inode)->lock);
2426 	}
2427 
2428 	if (!(state->state & EXTENT_DELALLOC_NEW) &&
2429 	    (bits & EXTENT_DELALLOC_NEW)) {
2430 		spin_lock(&BTRFS_I(inode)->lock);
2431 		BTRFS_I(inode)->new_delalloc_bytes += state->end + 1 -
2432 			state->start;
2433 		spin_unlock(&BTRFS_I(inode)->lock);
2434 	}
2435 }
2436 
2437 /*
2438  * Once a range is no longer delalloc this function ensures that proper
2439  * accounting happens.
2440  */
btrfs_clear_delalloc_extent(struct inode * vfs_inode,struct extent_state * state,u32 bits)2441 void btrfs_clear_delalloc_extent(struct inode *vfs_inode,
2442 				 struct extent_state *state, u32 bits)
2443 {
2444 	struct btrfs_inode *inode = BTRFS_I(vfs_inode);
2445 	struct btrfs_fs_info *fs_info = btrfs_sb(vfs_inode->i_sb);
2446 	u64 len = state->end + 1 - state->start;
2447 	u32 num_extents = count_max_extents(fs_info, len);
2448 
2449 	if ((state->state & EXTENT_DEFRAG) && (bits & EXTENT_DEFRAG)) {
2450 		spin_lock(&inode->lock);
2451 		inode->defrag_bytes -= len;
2452 		spin_unlock(&inode->lock);
2453 	}
2454 
2455 	/*
2456 	 * set_bit and clear bit hooks normally require _irqsave/restore
2457 	 * but in this case, we are only testing for the DELALLOC
2458 	 * bit, which is only set or cleared with irqs on
2459 	 */
2460 	if ((state->state & EXTENT_DELALLOC) && (bits & EXTENT_DELALLOC)) {
2461 		struct btrfs_root *root = inode->root;
2462 		bool do_list = !btrfs_is_free_space_inode(inode);
2463 
2464 		spin_lock(&inode->lock);
2465 		btrfs_mod_outstanding_extents(inode, -num_extents);
2466 		spin_unlock(&inode->lock);
2467 
2468 		/*
2469 		 * We don't reserve metadata space for space cache inodes so we
2470 		 * don't need to call delalloc_release_metadata if there is an
2471 		 * error.
2472 		 */
2473 		if (bits & EXTENT_CLEAR_META_RESV &&
2474 		    root != fs_info->tree_root)
2475 			btrfs_delalloc_release_metadata(inode, len, false);
2476 
2477 		/* For sanity tests. */
2478 		if (btrfs_is_testing(fs_info))
2479 			return;
2480 
2481 		if (!btrfs_is_data_reloc_root(root) &&
2482 		    do_list && !(state->state & EXTENT_NORESERVE) &&
2483 		    (bits & EXTENT_CLEAR_DATA_RESV))
2484 			btrfs_free_reserved_data_space_noquota(fs_info, len);
2485 
2486 		percpu_counter_add_batch(&fs_info->delalloc_bytes, -len,
2487 					 fs_info->delalloc_batch);
2488 		spin_lock(&inode->lock);
2489 		inode->delalloc_bytes -= len;
2490 		if (do_list && inode->delalloc_bytes == 0 &&
2491 		    test_bit(BTRFS_INODE_IN_DELALLOC_LIST,
2492 					&inode->runtime_flags))
2493 			btrfs_del_delalloc_inode(root, inode);
2494 		spin_unlock(&inode->lock);
2495 	}
2496 
2497 	if ((state->state & EXTENT_DELALLOC_NEW) &&
2498 	    (bits & EXTENT_DELALLOC_NEW)) {
2499 		spin_lock(&inode->lock);
2500 		ASSERT(inode->new_delalloc_bytes >= len);
2501 		inode->new_delalloc_bytes -= len;
2502 		if (bits & EXTENT_ADD_INODE_BYTES)
2503 			inode_add_bytes(&inode->vfs_inode, len);
2504 		spin_unlock(&inode->lock);
2505 	}
2506 }
2507 
2508 /*
2509  * in order to insert checksums into the metadata in large chunks,
2510  * we wait until bio submission time.   All the pages in the bio are
2511  * checksummed and sums are attached onto the ordered extent record.
2512  *
2513  * At IO completion time the cums attached on the ordered extent record
2514  * are inserted into the btree
2515  */
btrfs_submit_bio_start(struct inode * inode,struct bio * bio,u64 dio_file_offset)2516 static blk_status_t btrfs_submit_bio_start(struct inode *inode, struct bio *bio,
2517 					   u64 dio_file_offset)
2518 {
2519 	return btrfs_csum_one_bio(BTRFS_I(inode), bio, (u64)-1, false);
2520 }
2521 
2522 /*
2523  * Split an extent_map at [start, start + len]
2524  *
2525  * This function is intended to be used only for extract_ordered_extent().
2526  */
split_zoned_em(struct btrfs_inode * inode,u64 start,u64 len,u64 pre,u64 post)2527 static int split_zoned_em(struct btrfs_inode *inode, u64 start, u64 len,
2528 			  u64 pre, u64 post)
2529 {
2530 	struct extent_map_tree *em_tree = &inode->extent_tree;
2531 	struct extent_map *em;
2532 	struct extent_map *split_pre = NULL;
2533 	struct extent_map *split_mid = NULL;
2534 	struct extent_map *split_post = NULL;
2535 	int ret = 0;
2536 	unsigned long flags;
2537 
2538 	/* Sanity check */
2539 	if (pre == 0 && post == 0)
2540 		return 0;
2541 
2542 	split_pre = alloc_extent_map();
2543 	if (pre)
2544 		split_mid = alloc_extent_map();
2545 	if (post)
2546 		split_post = alloc_extent_map();
2547 	if (!split_pre || (pre && !split_mid) || (post && !split_post)) {
2548 		ret = -ENOMEM;
2549 		goto out;
2550 	}
2551 
2552 	ASSERT(pre + post < len);
2553 
2554 	lock_extent(&inode->io_tree, start, start + len - 1, NULL);
2555 	write_lock(&em_tree->lock);
2556 	em = lookup_extent_mapping(em_tree, start, len);
2557 	if (!em) {
2558 		ret = -EIO;
2559 		goto out_unlock;
2560 	}
2561 
2562 	ASSERT(em->len == len);
2563 	ASSERT(!test_bit(EXTENT_FLAG_COMPRESSED, &em->flags));
2564 	ASSERT(em->block_start < EXTENT_MAP_LAST_BYTE);
2565 	ASSERT(test_bit(EXTENT_FLAG_PINNED, &em->flags));
2566 	ASSERT(!test_bit(EXTENT_FLAG_LOGGING, &em->flags));
2567 	ASSERT(!list_empty(&em->list));
2568 
2569 	flags = em->flags;
2570 	clear_bit(EXTENT_FLAG_PINNED, &em->flags);
2571 
2572 	/* First, replace the em with a new extent_map starting from * em->start */
2573 	split_pre->start = em->start;
2574 	split_pre->len = (pre ? pre : em->len - post);
2575 	split_pre->orig_start = split_pre->start;
2576 	split_pre->block_start = em->block_start;
2577 	split_pre->block_len = split_pre->len;
2578 	split_pre->orig_block_len = split_pre->block_len;
2579 	split_pre->ram_bytes = split_pre->len;
2580 	split_pre->flags = flags;
2581 	split_pre->compress_type = em->compress_type;
2582 	split_pre->generation = em->generation;
2583 
2584 	replace_extent_mapping(em_tree, em, split_pre, 1);
2585 
2586 	/*
2587 	 * Now we only have an extent_map at:
2588 	 *     [em->start, em->start + pre] if pre != 0
2589 	 *     [em->start, em->start + em->len - post] if pre == 0
2590 	 */
2591 
2592 	if (pre) {
2593 		/* Insert the middle extent_map */
2594 		split_mid->start = em->start + pre;
2595 		split_mid->len = em->len - pre - post;
2596 		split_mid->orig_start = split_mid->start;
2597 		split_mid->block_start = em->block_start + pre;
2598 		split_mid->block_len = split_mid->len;
2599 		split_mid->orig_block_len = split_mid->block_len;
2600 		split_mid->ram_bytes = split_mid->len;
2601 		split_mid->flags = flags;
2602 		split_mid->compress_type = em->compress_type;
2603 		split_mid->generation = em->generation;
2604 		add_extent_mapping(em_tree, split_mid, 1);
2605 	}
2606 
2607 	if (post) {
2608 		split_post->start = em->start + em->len - post;
2609 		split_post->len = post;
2610 		split_post->orig_start = split_post->start;
2611 		split_post->block_start = em->block_start + em->len - post;
2612 		split_post->block_len = split_post->len;
2613 		split_post->orig_block_len = split_post->block_len;
2614 		split_post->ram_bytes = split_post->len;
2615 		split_post->flags = flags;
2616 		split_post->compress_type = em->compress_type;
2617 		split_post->generation = em->generation;
2618 		add_extent_mapping(em_tree, split_post, 1);
2619 	}
2620 
2621 	/* Once for us */
2622 	free_extent_map(em);
2623 	/* Once for the tree */
2624 	free_extent_map(em);
2625 
2626 out_unlock:
2627 	write_unlock(&em_tree->lock);
2628 	unlock_extent(&inode->io_tree, start, start + len - 1, NULL);
2629 out:
2630 	free_extent_map(split_pre);
2631 	free_extent_map(split_mid);
2632 	free_extent_map(split_post);
2633 
2634 	return ret;
2635 }
2636 
extract_ordered_extent(struct btrfs_inode * inode,struct bio * bio,loff_t file_offset)2637 static blk_status_t extract_ordered_extent(struct btrfs_inode *inode,
2638 					   struct bio *bio, loff_t file_offset)
2639 {
2640 	struct btrfs_ordered_extent *ordered;
2641 	u64 start = (u64)bio->bi_iter.bi_sector << SECTOR_SHIFT;
2642 	u64 file_len;
2643 	u64 len = bio->bi_iter.bi_size;
2644 	u64 end = start + len;
2645 	u64 ordered_end;
2646 	u64 pre, post;
2647 	int ret = 0;
2648 
2649 	ordered = btrfs_lookup_ordered_extent(inode, file_offset);
2650 	if (WARN_ON_ONCE(!ordered))
2651 		return BLK_STS_IOERR;
2652 
2653 	/* No need to split */
2654 	if (ordered->disk_num_bytes == len)
2655 		goto out;
2656 
2657 	/* We cannot split once end_bio'd ordered extent */
2658 	if (WARN_ON_ONCE(ordered->bytes_left != ordered->disk_num_bytes)) {
2659 		ret = -EINVAL;
2660 		goto out;
2661 	}
2662 
2663 	/* We cannot split a compressed ordered extent */
2664 	if (WARN_ON_ONCE(ordered->disk_num_bytes != ordered->num_bytes)) {
2665 		ret = -EINVAL;
2666 		goto out;
2667 	}
2668 
2669 	ordered_end = ordered->disk_bytenr + ordered->disk_num_bytes;
2670 	/* bio must be in one ordered extent */
2671 	if (WARN_ON_ONCE(start < ordered->disk_bytenr || end > ordered_end)) {
2672 		ret = -EINVAL;
2673 		goto out;
2674 	}
2675 
2676 	/* Checksum list should be empty */
2677 	if (WARN_ON_ONCE(!list_empty(&ordered->list))) {
2678 		ret = -EINVAL;
2679 		goto out;
2680 	}
2681 
2682 	file_len = ordered->num_bytes;
2683 	pre = start - ordered->disk_bytenr;
2684 	post = ordered_end - end;
2685 
2686 	ret = btrfs_split_ordered_extent(ordered, pre, post);
2687 	if (ret)
2688 		goto out;
2689 	ret = split_zoned_em(inode, file_offset, file_len, pre, post);
2690 
2691 out:
2692 	btrfs_put_ordered_extent(ordered);
2693 
2694 	return errno_to_blk_status(ret);
2695 }
2696 
btrfs_submit_data_write_bio(struct inode * inode,struct bio * bio,int mirror_num)2697 void btrfs_submit_data_write_bio(struct inode *inode, struct bio *bio, int mirror_num)
2698 {
2699 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2700 	struct btrfs_inode *bi = BTRFS_I(inode);
2701 	blk_status_t ret;
2702 
2703 	if (bio_op(bio) == REQ_OP_ZONE_APPEND) {
2704 		ret = extract_ordered_extent(bi, bio,
2705 				page_offset(bio_first_bvec_all(bio)->bv_page));
2706 		if (ret) {
2707 			btrfs_bio_end_io(btrfs_bio(bio), ret);
2708 			return;
2709 		}
2710 	}
2711 
2712 	/*
2713 	 * If we need to checksum, and the I/O is not issued by fsync and
2714 	 * friends, that is ->sync_writers != 0, defer the submission to a
2715 	 * workqueue to parallelize it.
2716 	 *
2717 	 * Csum items for reloc roots have already been cloned at this point,
2718 	 * so they are handled as part of the no-checksum case.
2719 	 */
2720 	if (!(bi->flags & BTRFS_INODE_NODATASUM) &&
2721 	    !test_bit(BTRFS_FS_STATE_NO_CSUMS, &fs_info->fs_state) &&
2722 	    !btrfs_is_data_reloc_root(bi->root)) {
2723 		if (!atomic_read(&bi->sync_writers) &&
2724 		    btrfs_wq_submit_bio(inode, bio, mirror_num, 0,
2725 					btrfs_submit_bio_start))
2726 			return;
2727 
2728 		ret = btrfs_csum_one_bio(bi, bio, (u64)-1, false);
2729 		if (ret) {
2730 			btrfs_bio_end_io(btrfs_bio(bio), ret);
2731 			return;
2732 		}
2733 	}
2734 	btrfs_submit_bio(fs_info, bio, mirror_num);
2735 }
2736 
btrfs_submit_data_read_bio(struct inode * inode,struct bio * bio,int mirror_num,enum btrfs_compression_type compress_type)2737 void btrfs_submit_data_read_bio(struct inode *inode, struct bio *bio,
2738 			int mirror_num, enum btrfs_compression_type compress_type)
2739 {
2740 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2741 	blk_status_t ret;
2742 
2743 	if (compress_type != BTRFS_COMPRESS_NONE) {
2744 		/*
2745 		 * btrfs_submit_compressed_read will handle completing the bio
2746 		 * if there were any errors, so just return here.
2747 		 */
2748 		btrfs_submit_compressed_read(inode, bio, mirror_num);
2749 		return;
2750 	}
2751 
2752 	/* Save the original iter for read repair */
2753 	btrfs_bio(bio)->iter = bio->bi_iter;
2754 
2755 	/*
2756 	 * Lookup bio sums does extra checks around whether we need to csum or
2757 	 * not, which is why we ignore skip_sum here.
2758 	 */
2759 	ret = btrfs_lookup_bio_sums(inode, bio, NULL);
2760 	if (ret) {
2761 		btrfs_bio_end_io(btrfs_bio(bio), ret);
2762 		return;
2763 	}
2764 
2765 	btrfs_submit_bio(fs_info, bio, mirror_num);
2766 }
2767 
2768 /*
2769  * given a list of ordered sums record them in the inode.  This happens
2770  * at IO completion time based on sums calculated at bio submission time.
2771  */
add_pending_csums(struct btrfs_trans_handle * trans,struct list_head * list)2772 static int add_pending_csums(struct btrfs_trans_handle *trans,
2773 			     struct list_head *list)
2774 {
2775 	struct btrfs_ordered_sum *sum;
2776 	struct btrfs_root *csum_root = NULL;
2777 	int ret;
2778 
2779 	list_for_each_entry(sum, list, list) {
2780 		trans->adding_csums = true;
2781 		if (!csum_root)
2782 			csum_root = btrfs_csum_root(trans->fs_info,
2783 						    sum->bytenr);
2784 		ret = btrfs_csum_file_blocks(trans, csum_root, sum);
2785 		trans->adding_csums = false;
2786 		if (ret)
2787 			return ret;
2788 	}
2789 	return 0;
2790 }
2791 
btrfs_find_new_delalloc_bytes(struct btrfs_inode * inode,const u64 start,const u64 len,struct extent_state ** cached_state)2792 static int btrfs_find_new_delalloc_bytes(struct btrfs_inode *inode,
2793 					 const u64 start,
2794 					 const u64 len,
2795 					 struct extent_state **cached_state)
2796 {
2797 	u64 search_start = start;
2798 	const u64 end = start + len - 1;
2799 
2800 	while (search_start < end) {
2801 		const u64 search_len = end - search_start + 1;
2802 		struct extent_map *em;
2803 		u64 em_len;
2804 		int ret = 0;
2805 
2806 		em = btrfs_get_extent(inode, NULL, 0, search_start, search_len);
2807 		if (IS_ERR(em))
2808 			return PTR_ERR(em);
2809 
2810 		if (em->block_start != EXTENT_MAP_HOLE)
2811 			goto next;
2812 
2813 		em_len = em->len;
2814 		if (em->start < search_start)
2815 			em_len -= search_start - em->start;
2816 		if (em_len > search_len)
2817 			em_len = search_len;
2818 
2819 		ret = set_extent_bit(&inode->io_tree, search_start,
2820 				     search_start + em_len - 1,
2821 				     EXTENT_DELALLOC_NEW, cached_state,
2822 				     GFP_NOFS);
2823 next:
2824 		search_start = extent_map_end(em);
2825 		free_extent_map(em);
2826 		if (ret)
2827 			return ret;
2828 	}
2829 	return 0;
2830 }
2831 
btrfs_set_extent_delalloc(struct btrfs_inode * inode,u64 start,u64 end,unsigned int extra_bits,struct extent_state ** cached_state)2832 int btrfs_set_extent_delalloc(struct btrfs_inode *inode, u64 start, u64 end,
2833 			      unsigned int extra_bits,
2834 			      struct extent_state **cached_state)
2835 {
2836 	WARN_ON(PAGE_ALIGNED(end));
2837 
2838 	if (start >= i_size_read(&inode->vfs_inode) &&
2839 	    !(inode->flags & BTRFS_INODE_PREALLOC)) {
2840 		/*
2841 		 * There can't be any extents following eof in this case so just
2842 		 * set the delalloc new bit for the range directly.
2843 		 */
2844 		extra_bits |= EXTENT_DELALLOC_NEW;
2845 	} else {
2846 		int ret;
2847 
2848 		ret = btrfs_find_new_delalloc_bytes(inode, start,
2849 						    end + 1 - start,
2850 						    cached_state);
2851 		if (ret)
2852 			return ret;
2853 	}
2854 
2855 	return set_extent_delalloc(&inode->io_tree, start, end, extra_bits,
2856 				   cached_state);
2857 }
2858 
2859 /* see btrfs_writepage_start_hook for details on why this is required */
2860 struct btrfs_writepage_fixup {
2861 	struct page *page;
2862 	struct inode *inode;
2863 	struct btrfs_work work;
2864 };
2865 
btrfs_writepage_fixup_worker(struct btrfs_work * work)2866 static void btrfs_writepage_fixup_worker(struct btrfs_work *work)
2867 {
2868 	struct btrfs_writepage_fixup *fixup;
2869 	struct btrfs_ordered_extent *ordered;
2870 	struct extent_state *cached_state = NULL;
2871 	struct extent_changeset *data_reserved = NULL;
2872 	struct page *page;
2873 	struct btrfs_inode *inode;
2874 	u64 page_start;
2875 	u64 page_end;
2876 	int ret = 0;
2877 	bool free_delalloc_space = true;
2878 
2879 	fixup = container_of(work, struct btrfs_writepage_fixup, work);
2880 	page = fixup->page;
2881 	inode = BTRFS_I(fixup->inode);
2882 	page_start = page_offset(page);
2883 	page_end = page_offset(page) + PAGE_SIZE - 1;
2884 
2885 	/*
2886 	 * This is similar to page_mkwrite, we need to reserve the space before
2887 	 * we take the page lock.
2888 	 */
2889 	ret = btrfs_delalloc_reserve_space(inode, &data_reserved, page_start,
2890 					   PAGE_SIZE);
2891 again:
2892 	lock_page(page);
2893 
2894 	/*
2895 	 * Before we queued this fixup, we took a reference on the page.
2896 	 * page->mapping may go NULL, but it shouldn't be moved to a different
2897 	 * address space.
2898 	 */
2899 	if (!page->mapping || !PageDirty(page) || !PageChecked(page)) {
2900 		/*
2901 		 * Unfortunately this is a little tricky, either
2902 		 *
2903 		 * 1) We got here and our page had already been dealt with and
2904 		 *    we reserved our space, thus ret == 0, so we need to just
2905 		 *    drop our space reservation and bail.  This can happen the
2906 		 *    first time we come into the fixup worker, or could happen
2907 		 *    while waiting for the ordered extent.
2908 		 * 2) Our page was already dealt with, but we happened to get an
2909 		 *    ENOSPC above from the btrfs_delalloc_reserve_space.  In
2910 		 *    this case we obviously don't have anything to release, but
2911 		 *    because the page was already dealt with we don't want to
2912 		 *    mark the page with an error, so make sure we're resetting
2913 		 *    ret to 0.  This is why we have this check _before_ the ret
2914 		 *    check, because we do not want to have a surprise ENOSPC
2915 		 *    when the page was already properly dealt with.
2916 		 */
2917 		if (!ret) {
2918 			btrfs_delalloc_release_extents(inode, PAGE_SIZE);
2919 			btrfs_delalloc_release_space(inode, data_reserved,
2920 						     page_start, PAGE_SIZE,
2921 						     true);
2922 		}
2923 		ret = 0;
2924 		goto out_page;
2925 	}
2926 
2927 	/*
2928 	 * We can't mess with the page state unless it is locked, so now that
2929 	 * it is locked bail if we failed to make our space reservation.
2930 	 */
2931 	if (ret)
2932 		goto out_page;
2933 
2934 	lock_extent(&inode->io_tree, page_start, page_end, &cached_state);
2935 
2936 	/* already ordered? We're done */
2937 	if (PageOrdered(page))
2938 		goto out_reserved;
2939 
2940 	ordered = btrfs_lookup_ordered_range(inode, page_start, PAGE_SIZE);
2941 	if (ordered) {
2942 		unlock_extent(&inode->io_tree, page_start, page_end,
2943 			      &cached_state);
2944 		unlock_page(page);
2945 		btrfs_start_ordered_extent(ordered, 1);
2946 		btrfs_put_ordered_extent(ordered);
2947 		goto again;
2948 	}
2949 
2950 	ret = btrfs_set_extent_delalloc(inode, page_start, page_end, 0,
2951 					&cached_state);
2952 	if (ret)
2953 		goto out_reserved;
2954 
2955 	/*
2956 	 * Everything went as planned, we're now the owner of a dirty page with
2957 	 * delayed allocation bits set and space reserved for our COW
2958 	 * destination.
2959 	 *
2960 	 * The page was dirty when we started, nothing should have cleaned it.
2961 	 */
2962 	BUG_ON(!PageDirty(page));
2963 	free_delalloc_space = false;
2964 out_reserved:
2965 	btrfs_delalloc_release_extents(inode, PAGE_SIZE);
2966 	if (free_delalloc_space)
2967 		btrfs_delalloc_release_space(inode, data_reserved, page_start,
2968 					     PAGE_SIZE, true);
2969 	unlock_extent(&inode->io_tree, page_start, page_end, &cached_state);
2970 out_page:
2971 	if (ret) {
2972 		/*
2973 		 * We hit ENOSPC or other errors.  Update the mapping and page
2974 		 * to reflect the errors and clean the page.
2975 		 */
2976 		mapping_set_error(page->mapping, ret);
2977 		end_extent_writepage(page, ret, page_start, page_end);
2978 		clear_page_dirty_for_io(page);
2979 		SetPageError(page);
2980 	}
2981 	btrfs_page_clear_checked(inode->root->fs_info, page, page_start, PAGE_SIZE);
2982 	unlock_page(page);
2983 	put_page(page);
2984 	kfree(fixup);
2985 	extent_changeset_free(data_reserved);
2986 	/*
2987 	 * As a precaution, do a delayed iput in case it would be the last iput
2988 	 * that could need flushing space. Recursing back to fixup worker would
2989 	 * deadlock.
2990 	 */
2991 	btrfs_add_delayed_iput(&inode->vfs_inode);
2992 }
2993 
2994 /*
2995  * There are a few paths in the higher layers of the kernel that directly
2996  * set the page dirty bit without asking the filesystem if it is a
2997  * good idea.  This causes problems because we want to make sure COW
2998  * properly happens and the data=ordered rules are followed.
2999  *
3000  * In our case any range that doesn't have the ORDERED bit set
3001  * hasn't been properly setup for IO.  We kick off an async process
3002  * to fix it up.  The async helper will wait for ordered extents, set
3003  * the delalloc bit and make it safe to write the page.
3004  */
btrfs_writepage_cow_fixup(struct page * page)3005 int btrfs_writepage_cow_fixup(struct page *page)
3006 {
3007 	struct inode *inode = page->mapping->host;
3008 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
3009 	struct btrfs_writepage_fixup *fixup;
3010 
3011 	/* This page has ordered extent covering it already */
3012 	if (PageOrdered(page))
3013 		return 0;
3014 
3015 	/*
3016 	 * PageChecked is set below when we create a fixup worker for this page,
3017 	 * don't try to create another one if we're already PageChecked()
3018 	 *
3019 	 * The extent_io writepage code will redirty the page if we send back
3020 	 * EAGAIN.
3021 	 */
3022 	if (PageChecked(page))
3023 		return -EAGAIN;
3024 
3025 	fixup = kzalloc(sizeof(*fixup), GFP_NOFS);
3026 	if (!fixup)
3027 		return -EAGAIN;
3028 
3029 	/*
3030 	 * We are already holding a reference to this inode from
3031 	 * write_cache_pages.  We need to hold it because the space reservation
3032 	 * takes place outside of the page lock, and we can't trust
3033 	 * page->mapping outside of the page lock.
3034 	 */
3035 	ihold(inode);
3036 	btrfs_page_set_checked(fs_info, page, page_offset(page), PAGE_SIZE);
3037 	get_page(page);
3038 	btrfs_init_work(&fixup->work, btrfs_writepage_fixup_worker, NULL, NULL);
3039 	fixup->page = page;
3040 	fixup->inode = inode;
3041 	btrfs_queue_work(fs_info->fixup_workers, &fixup->work);
3042 
3043 	return -EAGAIN;
3044 }
3045 
insert_reserved_file_extent(struct btrfs_trans_handle * trans,struct btrfs_inode * inode,u64 file_pos,struct btrfs_file_extent_item * stack_fi,const bool update_inode_bytes,u64 qgroup_reserved)3046 static int insert_reserved_file_extent(struct btrfs_trans_handle *trans,
3047 				       struct btrfs_inode *inode, u64 file_pos,
3048 				       struct btrfs_file_extent_item *stack_fi,
3049 				       const bool update_inode_bytes,
3050 				       u64 qgroup_reserved)
3051 {
3052 	struct btrfs_root *root = inode->root;
3053 	const u64 sectorsize = root->fs_info->sectorsize;
3054 	struct btrfs_path *path;
3055 	struct extent_buffer *leaf;
3056 	struct btrfs_key ins;
3057 	u64 disk_num_bytes = btrfs_stack_file_extent_disk_num_bytes(stack_fi);
3058 	u64 disk_bytenr = btrfs_stack_file_extent_disk_bytenr(stack_fi);
3059 	u64 offset = btrfs_stack_file_extent_offset(stack_fi);
3060 	u64 num_bytes = btrfs_stack_file_extent_num_bytes(stack_fi);
3061 	u64 ram_bytes = btrfs_stack_file_extent_ram_bytes(stack_fi);
3062 	struct btrfs_drop_extents_args drop_args = { 0 };
3063 	int ret;
3064 
3065 	path = btrfs_alloc_path();
3066 	if (!path)
3067 		return -ENOMEM;
3068 
3069 	/*
3070 	 * we may be replacing one extent in the tree with another.
3071 	 * The new extent is pinned in the extent map, and we don't want
3072 	 * to drop it from the cache until it is completely in the btree.
3073 	 *
3074 	 * So, tell btrfs_drop_extents to leave this extent in the cache.
3075 	 * the caller is expected to unpin it and allow it to be merged
3076 	 * with the others.
3077 	 */
3078 	drop_args.path = path;
3079 	drop_args.start = file_pos;
3080 	drop_args.end = file_pos + num_bytes;
3081 	drop_args.replace_extent = true;
3082 	drop_args.extent_item_size = sizeof(*stack_fi);
3083 	ret = btrfs_drop_extents(trans, root, inode, &drop_args);
3084 	if (ret)
3085 		goto out;
3086 
3087 	if (!drop_args.extent_inserted) {
3088 		ins.objectid = btrfs_ino(inode);
3089 		ins.offset = file_pos;
3090 		ins.type = BTRFS_EXTENT_DATA_KEY;
3091 
3092 		ret = btrfs_insert_empty_item(trans, root, path, &ins,
3093 					      sizeof(*stack_fi));
3094 		if (ret)
3095 			goto out;
3096 	}
3097 	leaf = path->nodes[0];
3098 	btrfs_set_stack_file_extent_generation(stack_fi, trans->transid);
3099 	write_extent_buffer(leaf, stack_fi,
3100 			btrfs_item_ptr_offset(leaf, path->slots[0]),
3101 			sizeof(struct btrfs_file_extent_item));
3102 
3103 	btrfs_mark_buffer_dirty(leaf);
3104 	btrfs_release_path(path);
3105 
3106 	/*
3107 	 * If we dropped an inline extent here, we know the range where it is
3108 	 * was not marked with the EXTENT_DELALLOC_NEW bit, so we update the
3109 	 * number of bytes only for that range containing the inline extent.
3110 	 * The remaining of the range will be processed when clearning the
3111 	 * EXTENT_DELALLOC_BIT bit through the ordered extent completion.
3112 	 */
3113 	if (file_pos == 0 && !IS_ALIGNED(drop_args.bytes_found, sectorsize)) {
3114 		u64 inline_size = round_down(drop_args.bytes_found, sectorsize);
3115 
3116 		inline_size = drop_args.bytes_found - inline_size;
3117 		btrfs_update_inode_bytes(inode, sectorsize, inline_size);
3118 		drop_args.bytes_found -= inline_size;
3119 		num_bytes -= sectorsize;
3120 	}
3121 
3122 	if (update_inode_bytes)
3123 		btrfs_update_inode_bytes(inode, num_bytes, drop_args.bytes_found);
3124 
3125 	ins.objectid = disk_bytenr;
3126 	ins.offset = disk_num_bytes;
3127 	ins.type = BTRFS_EXTENT_ITEM_KEY;
3128 
3129 	ret = btrfs_inode_set_file_extent_range(inode, file_pos, ram_bytes);
3130 	if (ret)
3131 		goto out;
3132 
3133 	ret = btrfs_alloc_reserved_file_extent(trans, root, btrfs_ino(inode),
3134 					       file_pos - offset,
3135 					       qgroup_reserved, &ins);
3136 out:
3137 	btrfs_free_path(path);
3138 
3139 	return ret;
3140 }
3141 
btrfs_release_delalloc_bytes(struct btrfs_fs_info * fs_info,u64 start,u64 len)3142 static void btrfs_release_delalloc_bytes(struct btrfs_fs_info *fs_info,
3143 					 u64 start, u64 len)
3144 {
3145 	struct btrfs_block_group *cache;
3146 
3147 	cache = btrfs_lookup_block_group(fs_info, start);
3148 	ASSERT(cache);
3149 
3150 	spin_lock(&cache->lock);
3151 	cache->delalloc_bytes -= len;
3152 	spin_unlock(&cache->lock);
3153 
3154 	btrfs_put_block_group(cache);
3155 }
3156 
insert_ordered_extent_file_extent(struct btrfs_trans_handle * trans,struct btrfs_ordered_extent * oe)3157 static int insert_ordered_extent_file_extent(struct btrfs_trans_handle *trans,
3158 					     struct btrfs_ordered_extent *oe)
3159 {
3160 	struct btrfs_file_extent_item stack_fi;
3161 	bool update_inode_bytes;
3162 	u64 num_bytes = oe->num_bytes;
3163 	u64 ram_bytes = oe->ram_bytes;
3164 
3165 	memset(&stack_fi, 0, sizeof(stack_fi));
3166 	btrfs_set_stack_file_extent_type(&stack_fi, BTRFS_FILE_EXTENT_REG);
3167 	btrfs_set_stack_file_extent_disk_bytenr(&stack_fi, oe->disk_bytenr);
3168 	btrfs_set_stack_file_extent_disk_num_bytes(&stack_fi,
3169 						   oe->disk_num_bytes);
3170 	btrfs_set_stack_file_extent_offset(&stack_fi, oe->offset);
3171 	if (test_bit(BTRFS_ORDERED_TRUNCATED, &oe->flags)) {
3172 		num_bytes = oe->truncated_len;
3173 		ram_bytes = num_bytes;
3174 	}
3175 	btrfs_set_stack_file_extent_num_bytes(&stack_fi, num_bytes);
3176 	btrfs_set_stack_file_extent_ram_bytes(&stack_fi, ram_bytes);
3177 	btrfs_set_stack_file_extent_compression(&stack_fi, oe->compress_type);
3178 	/* Encryption and other encoding is reserved and all 0 */
3179 
3180 	/*
3181 	 * For delalloc, when completing an ordered extent we update the inode's
3182 	 * bytes when clearing the range in the inode's io tree, so pass false
3183 	 * as the argument 'update_inode_bytes' to insert_reserved_file_extent(),
3184 	 * except if the ordered extent was truncated.
3185 	 */
3186 	update_inode_bytes = test_bit(BTRFS_ORDERED_DIRECT, &oe->flags) ||
3187 			     test_bit(BTRFS_ORDERED_ENCODED, &oe->flags) ||
3188 			     test_bit(BTRFS_ORDERED_TRUNCATED, &oe->flags);
3189 
3190 	return insert_reserved_file_extent(trans, BTRFS_I(oe->inode),
3191 					   oe->file_offset, &stack_fi,
3192 					   update_inode_bytes, oe->qgroup_rsv);
3193 }
3194 
3195 /*
3196  * As ordered data IO finishes, this gets called so we can finish
3197  * an ordered extent if the range of bytes in the file it covers are
3198  * fully written.
3199  */
btrfs_finish_ordered_io(struct btrfs_ordered_extent * ordered_extent)3200 int btrfs_finish_ordered_io(struct btrfs_ordered_extent *ordered_extent)
3201 {
3202 	struct btrfs_inode *inode = BTRFS_I(ordered_extent->inode);
3203 	struct btrfs_root *root = inode->root;
3204 	struct btrfs_fs_info *fs_info = root->fs_info;
3205 	struct btrfs_trans_handle *trans = NULL;
3206 	struct extent_io_tree *io_tree = &inode->io_tree;
3207 	struct extent_state *cached_state = NULL;
3208 	u64 start, end;
3209 	int compress_type = 0;
3210 	int ret = 0;
3211 	u64 logical_len = ordered_extent->num_bytes;
3212 	bool freespace_inode;
3213 	bool truncated = false;
3214 	bool clear_reserved_extent = true;
3215 	unsigned int clear_bits = EXTENT_DEFRAG;
3216 
3217 	start = ordered_extent->file_offset;
3218 	end = start + ordered_extent->num_bytes - 1;
3219 
3220 	if (!test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags) &&
3221 	    !test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags) &&
3222 	    !test_bit(BTRFS_ORDERED_DIRECT, &ordered_extent->flags) &&
3223 	    !test_bit(BTRFS_ORDERED_ENCODED, &ordered_extent->flags))
3224 		clear_bits |= EXTENT_DELALLOC_NEW;
3225 
3226 	freespace_inode = btrfs_is_free_space_inode(inode);
3227 	if (!freespace_inode)
3228 		btrfs_lockdep_acquire(fs_info, btrfs_ordered_extent);
3229 
3230 	if (test_bit(BTRFS_ORDERED_IOERR, &ordered_extent->flags)) {
3231 		ret = -EIO;
3232 		goto out;
3233 	}
3234 
3235 	/* A valid bdev implies a write on a sequential zone */
3236 	if (ordered_extent->bdev) {
3237 		btrfs_rewrite_logical_zoned(ordered_extent);
3238 		btrfs_zone_finish_endio(fs_info, ordered_extent->disk_bytenr,
3239 					ordered_extent->disk_num_bytes);
3240 	} else if (btrfs_is_data_reloc_root(inode->root)) {
3241 		btrfs_zone_finish_endio(fs_info, ordered_extent->disk_bytenr,
3242 					ordered_extent->disk_num_bytes);
3243 	}
3244 
3245 	btrfs_free_io_failure_record(inode, start, end);
3246 
3247 	if (test_bit(BTRFS_ORDERED_TRUNCATED, &ordered_extent->flags)) {
3248 		truncated = true;
3249 		logical_len = ordered_extent->truncated_len;
3250 		/* Truncated the entire extent, don't bother adding */
3251 		if (!logical_len)
3252 			goto out;
3253 	}
3254 
3255 	if (test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags)) {
3256 		BUG_ON(!list_empty(&ordered_extent->list)); /* Logic error */
3257 
3258 		btrfs_inode_safe_disk_i_size_write(inode, 0);
3259 		if (freespace_inode)
3260 			trans = btrfs_join_transaction_spacecache(root);
3261 		else
3262 			trans = btrfs_join_transaction(root);
3263 		if (IS_ERR(trans)) {
3264 			ret = PTR_ERR(trans);
3265 			trans = NULL;
3266 			goto out;
3267 		}
3268 		trans->block_rsv = &inode->block_rsv;
3269 		ret = btrfs_update_inode_fallback(trans, root, inode);
3270 		if (ret) /* -ENOMEM or corruption */
3271 			btrfs_abort_transaction(trans, ret);
3272 		goto out;
3273 	}
3274 
3275 	clear_bits |= EXTENT_LOCKED;
3276 	lock_extent(io_tree, start, end, &cached_state);
3277 
3278 	if (freespace_inode)
3279 		trans = btrfs_join_transaction_spacecache(root);
3280 	else
3281 		trans = btrfs_join_transaction(root);
3282 	if (IS_ERR(trans)) {
3283 		ret = PTR_ERR(trans);
3284 		trans = NULL;
3285 		goto out;
3286 	}
3287 
3288 	trans->block_rsv = &inode->block_rsv;
3289 
3290 	if (test_bit(BTRFS_ORDERED_COMPRESSED, &ordered_extent->flags))
3291 		compress_type = ordered_extent->compress_type;
3292 	if (test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags)) {
3293 		BUG_ON(compress_type);
3294 		ret = btrfs_mark_extent_written(trans, inode,
3295 						ordered_extent->file_offset,
3296 						ordered_extent->file_offset +
3297 						logical_len);
3298 		btrfs_zoned_release_data_reloc_bg(fs_info, ordered_extent->disk_bytenr,
3299 						  ordered_extent->disk_num_bytes);
3300 	} else {
3301 		BUG_ON(root == fs_info->tree_root);
3302 		ret = insert_ordered_extent_file_extent(trans, ordered_extent);
3303 		if (!ret) {
3304 			clear_reserved_extent = false;
3305 			btrfs_release_delalloc_bytes(fs_info,
3306 						ordered_extent->disk_bytenr,
3307 						ordered_extent->disk_num_bytes);
3308 		}
3309 	}
3310 	unpin_extent_cache(&inode->extent_tree, ordered_extent->file_offset,
3311 			   ordered_extent->num_bytes, trans->transid);
3312 	if (ret < 0) {
3313 		btrfs_abort_transaction(trans, ret);
3314 		goto out;
3315 	}
3316 
3317 	ret = add_pending_csums(trans, &ordered_extent->list);
3318 	if (ret) {
3319 		btrfs_abort_transaction(trans, ret);
3320 		goto out;
3321 	}
3322 
3323 	/*
3324 	 * If this is a new delalloc range, clear its new delalloc flag to
3325 	 * update the inode's number of bytes. This needs to be done first
3326 	 * before updating the inode item.
3327 	 */
3328 	if ((clear_bits & EXTENT_DELALLOC_NEW) &&
3329 	    !test_bit(BTRFS_ORDERED_TRUNCATED, &ordered_extent->flags))
3330 		clear_extent_bit(&inode->io_tree, start, end,
3331 				 EXTENT_DELALLOC_NEW | EXTENT_ADD_INODE_BYTES,
3332 				 &cached_state);
3333 
3334 	btrfs_inode_safe_disk_i_size_write(inode, 0);
3335 	ret = btrfs_update_inode_fallback(trans, root, inode);
3336 	if (ret) { /* -ENOMEM or corruption */
3337 		btrfs_abort_transaction(trans, ret);
3338 		goto out;
3339 	}
3340 	ret = 0;
3341 out:
3342 	clear_extent_bit(&inode->io_tree, start, end, clear_bits,
3343 			 &cached_state);
3344 
3345 	if (trans)
3346 		btrfs_end_transaction(trans);
3347 
3348 	if (ret || truncated) {
3349 		u64 unwritten_start = start;
3350 
3351 		/*
3352 		 * If we failed to finish this ordered extent for any reason we
3353 		 * need to make sure BTRFS_ORDERED_IOERR is set on the ordered
3354 		 * extent, and mark the inode with the error if it wasn't
3355 		 * already set.  Any error during writeback would have already
3356 		 * set the mapping error, so we need to set it if we're the ones
3357 		 * marking this ordered extent as failed.
3358 		 */
3359 		if (ret && !test_and_set_bit(BTRFS_ORDERED_IOERR,
3360 					     &ordered_extent->flags))
3361 			mapping_set_error(ordered_extent->inode->i_mapping, -EIO);
3362 
3363 		if (truncated)
3364 			unwritten_start += logical_len;
3365 		clear_extent_uptodate(io_tree, unwritten_start, end, NULL);
3366 
3367 		/*
3368 		 * Drop extent maps for the part of the extent we didn't write.
3369 		 *
3370 		 * We have an exception here for the free_space_inode, this is
3371 		 * because when we do btrfs_get_extent() on the free space inode
3372 		 * we will search the commit root.  If this is a new block group
3373 		 * we won't find anything, and we will trip over the assert in
3374 		 * writepage where we do ASSERT(em->block_start !=
3375 		 * EXTENT_MAP_HOLE).
3376 		 *
3377 		 * Theoretically we could also skip this for any NOCOW extent as
3378 		 * we don't mess with the extent map tree in the NOCOW case, but
3379 		 * for now simply skip this if we are the free space inode.
3380 		 */
3381 		if (!btrfs_is_free_space_inode(inode))
3382 			btrfs_drop_extent_map_range(inode, unwritten_start,
3383 						    end, false);
3384 
3385 		/*
3386 		 * If the ordered extent had an IOERR or something else went
3387 		 * wrong we need to return the space for this ordered extent
3388 		 * back to the allocator.  We only free the extent in the
3389 		 * truncated case if we didn't write out the extent at all.
3390 		 *
3391 		 * If we made it past insert_reserved_file_extent before we
3392 		 * errored out then we don't need to do this as the accounting
3393 		 * has already been done.
3394 		 */
3395 		if ((ret || !logical_len) &&
3396 		    clear_reserved_extent &&
3397 		    !test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags) &&
3398 		    !test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags)) {
3399 			/*
3400 			 * Discard the range before returning it back to the
3401 			 * free space pool
3402 			 */
3403 			if (ret && btrfs_test_opt(fs_info, DISCARD_SYNC))
3404 				btrfs_discard_extent(fs_info,
3405 						ordered_extent->disk_bytenr,
3406 						ordered_extent->disk_num_bytes,
3407 						NULL);
3408 			btrfs_free_reserved_extent(fs_info,
3409 					ordered_extent->disk_bytenr,
3410 					ordered_extent->disk_num_bytes, 1);
3411 			/*
3412 			 * Actually free the qgroup rsv which was released when
3413 			 * the ordered extent was created.
3414 			 */
3415 			btrfs_qgroup_free_refroot(fs_info, inode->root->root_key.objectid,
3416 						  ordered_extent->qgroup_rsv,
3417 						  BTRFS_QGROUP_RSV_DATA);
3418 		}
3419 	}
3420 
3421 	/*
3422 	 * This needs to be done to make sure anybody waiting knows we are done
3423 	 * updating everything for this ordered extent.
3424 	 */
3425 	btrfs_remove_ordered_extent(inode, ordered_extent);
3426 
3427 	/* once for us */
3428 	btrfs_put_ordered_extent(ordered_extent);
3429 	/* once for the tree */
3430 	btrfs_put_ordered_extent(ordered_extent);
3431 
3432 	return ret;
3433 }
3434 
btrfs_writepage_endio_finish_ordered(struct btrfs_inode * inode,struct page * page,u64 start,u64 end,bool uptodate)3435 void btrfs_writepage_endio_finish_ordered(struct btrfs_inode *inode,
3436 					  struct page *page, u64 start,
3437 					  u64 end, bool uptodate)
3438 {
3439 	trace_btrfs_writepage_end_io_hook(inode, start, end, uptodate);
3440 
3441 	btrfs_mark_ordered_io_finished(inode, page, start, end + 1 - start, uptodate);
3442 }
3443 
3444 /*
3445  * Verify the checksum for a single sector without any extra action that depend
3446  * on the type of I/O.
3447  */
btrfs_check_sector_csum(struct btrfs_fs_info * fs_info,struct page * page,u32 pgoff,u8 * csum,const u8 * const csum_expected)3448 int btrfs_check_sector_csum(struct btrfs_fs_info *fs_info, struct page *page,
3449 			    u32 pgoff, u8 *csum, const u8 * const csum_expected)
3450 {
3451 	SHASH_DESC_ON_STACK(shash, fs_info->csum_shash);
3452 	char *kaddr;
3453 
3454 	ASSERT(pgoff + fs_info->sectorsize <= PAGE_SIZE);
3455 
3456 	shash->tfm = fs_info->csum_shash;
3457 
3458 	kaddr = kmap_local_page(page) + pgoff;
3459 	crypto_shash_digest(shash, kaddr, fs_info->sectorsize, csum);
3460 	kunmap_local(kaddr);
3461 
3462 	if (memcmp(csum, csum_expected, fs_info->csum_size))
3463 		return -EIO;
3464 	return 0;
3465 }
3466 
btrfs_csum_ptr(const struct btrfs_fs_info * fs_info,u8 * csums,u64 offset)3467 static u8 *btrfs_csum_ptr(const struct btrfs_fs_info *fs_info, u8 *csums, u64 offset)
3468 {
3469 	u64 offset_in_sectors = offset >> fs_info->sectorsize_bits;
3470 
3471 	return csums + offset_in_sectors * fs_info->csum_size;
3472 }
3473 
3474 /*
3475  * check_data_csum - verify checksum of one sector of uncompressed data
3476  * @inode:	inode
3477  * @bbio:	btrfs_bio which contains the csum
3478  * @bio_offset:	offset to the beginning of the bio (in bytes)
3479  * @page:	page where is the data to be verified
3480  * @pgoff:	offset inside the page
3481  *
3482  * The length of such check is always one sector size.
3483  *
3484  * When csum mismatch is detected, we will also report the error and fill the
3485  * corrupted range with zero. (Thus it needs the extra parameters)
3486  */
btrfs_check_data_csum(struct inode * inode,struct btrfs_bio * bbio,u32 bio_offset,struct page * page,u32 pgoff)3487 int btrfs_check_data_csum(struct inode *inode, struct btrfs_bio *bbio,
3488 			  u32 bio_offset, struct page *page, u32 pgoff)
3489 {
3490 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
3491 	u32 len = fs_info->sectorsize;
3492 	u8 *csum_expected;
3493 	u8 csum[BTRFS_CSUM_SIZE];
3494 
3495 	ASSERT(pgoff + len <= PAGE_SIZE);
3496 
3497 	csum_expected = btrfs_csum_ptr(fs_info, bbio->csum, bio_offset);
3498 
3499 	if (btrfs_check_sector_csum(fs_info, page, pgoff, csum, csum_expected))
3500 		goto zeroit;
3501 	return 0;
3502 
3503 zeroit:
3504 	btrfs_print_data_csum_error(BTRFS_I(inode),
3505 				    bbio->file_offset + bio_offset,
3506 				    csum, csum_expected, bbio->mirror_num);
3507 	if (bbio->device)
3508 		btrfs_dev_stat_inc_and_print(bbio->device,
3509 					     BTRFS_DEV_STAT_CORRUPTION_ERRS);
3510 	memzero_page(page, pgoff, len);
3511 	return -EIO;
3512 }
3513 
3514 /*
3515  * When reads are done, we need to check csums to verify the data is correct.
3516  * if there's a match, we allow the bio to finish.  If not, the code in
3517  * extent_io.c will try to find good copies for us.
3518  *
3519  * @bio_offset:	offset to the beginning of the bio (in bytes)
3520  * @start:	file offset of the range start
3521  * @end:	file offset of the range end (inclusive)
3522  *
3523  * Return a bitmap where bit set means a csum mismatch, and bit not set means
3524  * csum match.
3525  */
btrfs_verify_data_csum(struct btrfs_bio * bbio,u32 bio_offset,struct page * page,u64 start,u64 end)3526 unsigned int btrfs_verify_data_csum(struct btrfs_bio *bbio,
3527 				    u32 bio_offset, struct page *page,
3528 				    u64 start, u64 end)
3529 {
3530 	struct inode *inode = page->mapping->host;
3531 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
3532 	struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
3533 	struct btrfs_root *root = BTRFS_I(inode)->root;
3534 	const u32 sectorsize = root->fs_info->sectorsize;
3535 	u32 pg_off;
3536 	unsigned int result = 0;
3537 
3538 	/*
3539 	 * This only happens for NODATASUM or compressed read.
3540 	 * Normally this should be covered by above check for compressed read
3541 	 * or the next check for NODATASUM.  Just do a quicker exit here.
3542 	 */
3543 	if (bbio->csum == NULL)
3544 		return 0;
3545 
3546 	if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM)
3547 		return 0;
3548 
3549 	if (unlikely(test_bit(BTRFS_FS_STATE_NO_CSUMS, &fs_info->fs_state)))
3550 		return 0;
3551 
3552 	ASSERT(page_offset(page) <= start &&
3553 	       end <= page_offset(page) + PAGE_SIZE - 1);
3554 	for (pg_off = offset_in_page(start);
3555 	     pg_off < offset_in_page(end);
3556 	     pg_off += sectorsize, bio_offset += sectorsize) {
3557 		u64 file_offset = pg_off + page_offset(page);
3558 		int ret;
3559 
3560 		if (btrfs_is_data_reloc_root(root) &&
3561 		    test_range_bit(io_tree, file_offset,
3562 				   file_offset + sectorsize - 1,
3563 				   EXTENT_NODATASUM, 1, NULL)) {
3564 			/* Skip the range without csum for data reloc inode */
3565 			clear_extent_bits(io_tree, file_offset,
3566 					  file_offset + sectorsize - 1,
3567 					  EXTENT_NODATASUM);
3568 			continue;
3569 		}
3570 		ret = btrfs_check_data_csum(inode, bbio, bio_offset, page, pg_off);
3571 		if (ret < 0) {
3572 			const int nr_bit = (pg_off - offset_in_page(start)) >>
3573 				     root->fs_info->sectorsize_bits;
3574 
3575 			result |= (1U << nr_bit);
3576 		}
3577 	}
3578 	return result;
3579 }
3580 
3581 /*
3582  * btrfs_add_delayed_iput - perform a delayed iput on @inode
3583  *
3584  * @inode: The inode we want to perform iput on
3585  *
3586  * This function uses the generic vfs_inode::i_count to track whether we should
3587  * just decrement it (in case it's > 1) or if this is the last iput then link
3588  * the inode to the delayed iput machinery. Delayed iputs are processed at
3589  * transaction commit time/superblock commit/cleaner kthread.
3590  */
btrfs_add_delayed_iput(struct inode * inode)3591 void btrfs_add_delayed_iput(struct inode *inode)
3592 {
3593 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
3594 	struct btrfs_inode *binode = BTRFS_I(inode);
3595 
3596 	if (atomic_add_unless(&inode->i_count, -1, 1))
3597 		return;
3598 
3599 	atomic_inc(&fs_info->nr_delayed_iputs);
3600 	spin_lock(&fs_info->delayed_iput_lock);
3601 	ASSERT(list_empty(&binode->delayed_iput));
3602 	list_add_tail(&binode->delayed_iput, &fs_info->delayed_iputs);
3603 	spin_unlock(&fs_info->delayed_iput_lock);
3604 	if (!test_bit(BTRFS_FS_CLEANER_RUNNING, &fs_info->flags))
3605 		wake_up_process(fs_info->cleaner_kthread);
3606 }
3607 
run_delayed_iput_locked(struct btrfs_fs_info * fs_info,struct btrfs_inode * inode)3608 static void run_delayed_iput_locked(struct btrfs_fs_info *fs_info,
3609 				    struct btrfs_inode *inode)
3610 {
3611 	list_del_init(&inode->delayed_iput);
3612 	spin_unlock(&fs_info->delayed_iput_lock);
3613 	iput(&inode->vfs_inode);
3614 	if (atomic_dec_and_test(&fs_info->nr_delayed_iputs))
3615 		wake_up(&fs_info->delayed_iputs_wait);
3616 	spin_lock(&fs_info->delayed_iput_lock);
3617 }
3618 
btrfs_run_delayed_iput(struct btrfs_fs_info * fs_info,struct btrfs_inode * inode)3619 static void btrfs_run_delayed_iput(struct btrfs_fs_info *fs_info,
3620 				   struct btrfs_inode *inode)
3621 {
3622 	if (!list_empty(&inode->delayed_iput)) {
3623 		spin_lock(&fs_info->delayed_iput_lock);
3624 		if (!list_empty(&inode->delayed_iput))
3625 			run_delayed_iput_locked(fs_info, inode);
3626 		spin_unlock(&fs_info->delayed_iput_lock);
3627 	}
3628 }
3629 
btrfs_run_delayed_iputs(struct btrfs_fs_info * fs_info)3630 void btrfs_run_delayed_iputs(struct btrfs_fs_info *fs_info)
3631 {
3632 
3633 	spin_lock(&fs_info->delayed_iput_lock);
3634 	while (!list_empty(&fs_info->delayed_iputs)) {
3635 		struct btrfs_inode *inode;
3636 
3637 		inode = list_first_entry(&fs_info->delayed_iputs,
3638 				struct btrfs_inode, delayed_iput);
3639 		run_delayed_iput_locked(fs_info, inode);
3640 		cond_resched_lock(&fs_info->delayed_iput_lock);
3641 	}
3642 	spin_unlock(&fs_info->delayed_iput_lock);
3643 }
3644 
3645 /*
3646  * Wait for flushing all delayed iputs
3647  *
3648  * @fs_info:  the filesystem
3649  *
3650  * This will wait on any delayed iputs that are currently running with KILLABLE
3651  * set.  Once they are all done running we will return, unless we are killed in
3652  * which case we return EINTR. This helps in user operations like fallocate etc
3653  * that might get blocked on the iputs.
3654  *
3655  * Return EINTR if we were killed, 0 if nothing's pending
3656  */
btrfs_wait_on_delayed_iputs(struct btrfs_fs_info * fs_info)3657 int btrfs_wait_on_delayed_iputs(struct btrfs_fs_info *fs_info)
3658 {
3659 	int ret = wait_event_killable(fs_info->delayed_iputs_wait,
3660 			atomic_read(&fs_info->nr_delayed_iputs) == 0);
3661 	if (ret)
3662 		return -EINTR;
3663 	return 0;
3664 }
3665 
3666 /*
3667  * This creates an orphan entry for the given inode in case something goes wrong
3668  * in the middle of an unlink.
3669  */
btrfs_orphan_add(struct btrfs_trans_handle * trans,struct btrfs_inode * inode)3670 int btrfs_orphan_add(struct btrfs_trans_handle *trans,
3671 		     struct btrfs_inode *inode)
3672 {
3673 	int ret;
3674 
3675 	ret = btrfs_insert_orphan_item(trans, inode->root, btrfs_ino(inode));
3676 	if (ret && ret != -EEXIST) {
3677 		btrfs_abort_transaction(trans, ret);
3678 		return ret;
3679 	}
3680 
3681 	return 0;
3682 }
3683 
3684 /*
3685  * We have done the delete so we can go ahead and remove the orphan item for
3686  * this particular inode.
3687  */
btrfs_orphan_del(struct btrfs_trans_handle * trans,struct btrfs_inode * inode)3688 static int btrfs_orphan_del(struct btrfs_trans_handle *trans,
3689 			    struct btrfs_inode *inode)
3690 {
3691 	return btrfs_del_orphan_item(trans, inode->root, btrfs_ino(inode));
3692 }
3693 
3694 /*
3695  * this cleans up any orphans that may be left on the list from the last use
3696  * of this root.
3697  */
btrfs_orphan_cleanup(struct btrfs_root * root)3698 int btrfs_orphan_cleanup(struct btrfs_root *root)
3699 {
3700 	struct btrfs_fs_info *fs_info = root->fs_info;
3701 	struct btrfs_path *path;
3702 	struct extent_buffer *leaf;
3703 	struct btrfs_key key, found_key;
3704 	struct btrfs_trans_handle *trans;
3705 	struct inode *inode;
3706 	u64 last_objectid = 0;
3707 	int ret = 0, nr_unlink = 0;
3708 
3709 	if (test_and_set_bit(BTRFS_ROOT_ORPHAN_CLEANUP, &root->state))
3710 		return 0;
3711 
3712 	path = btrfs_alloc_path();
3713 	if (!path) {
3714 		ret = -ENOMEM;
3715 		goto out;
3716 	}
3717 	path->reada = READA_BACK;
3718 
3719 	key.objectid = BTRFS_ORPHAN_OBJECTID;
3720 	key.type = BTRFS_ORPHAN_ITEM_KEY;
3721 	key.offset = (u64)-1;
3722 
3723 	while (1) {
3724 		ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3725 		if (ret < 0)
3726 			goto out;
3727 
3728 		/*
3729 		 * if ret == 0 means we found what we were searching for, which
3730 		 * is weird, but possible, so only screw with path if we didn't
3731 		 * find the key and see if we have stuff that matches
3732 		 */
3733 		if (ret > 0) {
3734 			ret = 0;
3735 			if (path->slots[0] == 0)
3736 				break;
3737 			path->slots[0]--;
3738 		}
3739 
3740 		/* pull out the item */
3741 		leaf = path->nodes[0];
3742 		btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
3743 
3744 		/* make sure the item matches what we want */
3745 		if (found_key.objectid != BTRFS_ORPHAN_OBJECTID)
3746 			break;
3747 		if (found_key.type != BTRFS_ORPHAN_ITEM_KEY)
3748 			break;
3749 
3750 		/* release the path since we're done with it */
3751 		btrfs_release_path(path);
3752 
3753 		/*
3754 		 * this is where we are basically btrfs_lookup, without the
3755 		 * crossing root thing.  we store the inode number in the
3756 		 * offset of the orphan item.
3757 		 */
3758 
3759 		if (found_key.offset == last_objectid) {
3760 			btrfs_err(fs_info,
3761 				  "Error removing orphan entry, stopping orphan cleanup");
3762 			ret = -EINVAL;
3763 			goto out;
3764 		}
3765 
3766 		last_objectid = found_key.offset;
3767 
3768 		found_key.objectid = found_key.offset;
3769 		found_key.type = BTRFS_INODE_ITEM_KEY;
3770 		found_key.offset = 0;
3771 		inode = btrfs_iget(fs_info->sb, last_objectid, root);
3772 		ret = PTR_ERR_OR_ZERO(inode);
3773 		if (ret && ret != -ENOENT)
3774 			goto out;
3775 
3776 		if (ret == -ENOENT && root == fs_info->tree_root) {
3777 			struct btrfs_root *dead_root;
3778 			int is_dead_root = 0;
3779 
3780 			/*
3781 			 * This is an orphan in the tree root. Currently these
3782 			 * could come from 2 sources:
3783 			 *  a) a root (snapshot/subvolume) deletion in progress
3784 			 *  b) a free space cache inode
3785 			 * We need to distinguish those two, as the orphan item
3786 			 * for a root must not get deleted before the deletion
3787 			 * of the snapshot/subvolume's tree completes.
3788 			 *
3789 			 * btrfs_find_orphan_roots() ran before us, which has
3790 			 * found all deleted roots and loaded them into
3791 			 * fs_info->fs_roots_radix. So here we can find if an
3792 			 * orphan item corresponds to a deleted root by looking
3793 			 * up the root from that radix tree.
3794 			 */
3795 
3796 			spin_lock(&fs_info->fs_roots_radix_lock);
3797 			dead_root = radix_tree_lookup(&fs_info->fs_roots_radix,
3798 							 (unsigned long)found_key.objectid);
3799 			if (dead_root && btrfs_root_refs(&dead_root->root_item) == 0)
3800 				is_dead_root = 1;
3801 			spin_unlock(&fs_info->fs_roots_radix_lock);
3802 
3803 			if (is_dead_root) {
3804 				/* prevent this orphan from being found again */
3805 				key.offset = found_key.objectid - 1;
3806 				continue;
3807 			}
3808 
3809 		}
3810 
3811 		/*
3812 		 * If we have an inode with links, there are a couple of
3813 		 * possibilities:
3814 		 *
3815 		 * 1. We were halfway through creating fsverity metadata for the
3816 		 * file. In that case, the orphan item represents incomplete
3817 		 * fsverity metadata which must be cleaned up with
3818 		 * btrfs_drop_verity_items and deleting the orphan item.
3819 
3820 		 * 2. Old kernels (before v3.12) used to create an
3821 		 * orphan item for truncate indicating that there were possibly
3822 		 * extent items past i_size that needed to be deleted. In v3.12,
3823 		 * truncate was changed to update i_size in sync with the extent
3824 		 * items, but the (useless) orphan item was still created. Since
3825 		 * v4.18, we don't create the orphan item for truncate at all.
3826 		 *
3827 		 * So, this item could mean that we need to do a truncate, but
3828 		 * only if this filesystem was last used on a pre-v3.12 kernel
3829 		 * and was not cleanly unmounted. The odds of that are quite
3830 		 * slim, and it's a pain to do the truncate now, so just delete
3831 		 * the orphan item.
3832 		 *
3833 		 * It's also possible that this orphan item was supposed to be
3834 		 * deleted but wasn't. The inode number may have been reused,
3835 		 * but either way, we can delete the orphan item.
3836 		 */
3837 		if (ret == -ENOENT || inode->i_nlink) {
3838 			if (!ret) {
3839 				ret = btrfs_drop_verity_items(BTRFS_I(inode));
3840 				iput(inode);
3841 				if (ret)
3842 					goto out;
3843 			}
3844 			trans = btrfs_start_transaction(root, 1);
3845 			if (IS_ERR(trans)) {
3846 				ret = PTR_ERR(trans);
3847 				goto out;
3848 			}
3849 			btrfs_debug(fs_info, "auto deleting %Lu",
3850 				    found_key.objectid);
3851 			ret = btrfs_del_orphan_item(trans, root,
3852 						    found_key.objectid);
3853 			btrfs_end_transaction(trans);
3854 			if (ret)
3855 				goto out;
3856 			continue;
3857 		}
3858 
3859 		nr_unlink++;
3860 
3861 		/* this will do delete_inode and everything for us */
3862 		iput(inode);
3863 	}
3864 	/* release the path since we're done with it */
3865 	btrfs_release_path(path);
3866 
3867 	if (test_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED, &root->state)) {
3868 		trans = btrfs_join_transaction(root);
3869 		if (!IS_ERR(trans))
3870 			btrfs_end_transaction(trans);
3871 	}
3872 
3873 	if (nr_unlink)
3874 		btrfs_debug(fs_info, "unlinked %d orphans", nr_unlink);
3875 
3876 out:
3877 	if (ret)
3878 		btrfs_err(fs_info, "could not do orphan cleanup %d", ret);
3879 	btrfs_free_path(path);
3880 	return ret;
3881 }
3882 
3883 /*
3884  * very simple check to peek ahead in the leaf looking for xattrs.  If we
3885  * don't find any xattrs, we know there can't be any acls.
3886  *
3887  * slot is the slot the inode is in, objectid is the objectid of the inode
3888  */
acls_after_inode_item(struct extent_buffer * leaf,int slot,u64 objectid,int * first_xattr_slot)3889 static noinline int acls_after_inode_item(struct extent_buffer *leaf,
3890 					  int slot, u64 objectid,
3891 					  int *first_xattr_slot)
3892 {
3893 	u32 nritems = btrfs_header_nritems(leaf);
3894 	struct btrfs_key found_key;
3895 	static u64 xattr_access = 0;
3896 	static u64 xattr_default = 0;
3897 	int scanned = 0;
3898 
3899 	if (!xattr_access) {
3900 		xattr_access = btrfs_name_hash(XATTR_NAME_POSIX_ACL_ACCESS,
3901 					strlen(XATTR_NAME_POSIX_ACL_ACCESS));
3902 		xattr_default = btrfs_name_hash(XATTR_NAME_POSIX_ACL_DEFAULT,
3903 					strlen(XATTR_NAME_POSIX_ACL_DEFAULT));
3904 	}
3905 
3906 	slot++;
3907 	*first_xattr_slot = -1;
3908 	while (slot < nritems) {
3909 		btrfs_item_key_to_cpu(leaf, &found_key, slot);
3910 
3911 		/* we found a different objectid, there must not be acls */
3912 		if (found_key.objectid != objectid)
3913 			return 0;
3914 
3915 		/* we found an xattr, assume we've got an acl */
3916 		if (found_key.type == BTRFS_XATTR_ITEM_KEY) {
3917 			if (*first_xattr_slot == -1)
3918 				*first_xattr_slot = slot;
3919 			if (found_key.offset == xattr_access ||
3920 			    found_key.offset == xattr_default)
3921 				return 1;
3922 		}
3923 
3924 		/*
3925 		 * we found a key greater than an xattr key, there can't
3926 		 * be any acls later on
3927 		 */
3928 		if (found_key.type > BTRFS_XATTR_ITEM_KEY)
3929 			return 0;
3930 
3931 		slot++;
3932 		scanned++;
3933 
3934 		/*
3935 		 * it goes inode, inode backrefs, xattrs, extents,
3936 		 * so if there are a ton of hard links to an inode there can
3937 		 * be a lot of backrefs.  Don't waste time searching too hard,
3938 		 * this is just an optimization
3939 		 */
3940 		if (scanned >= 8)
3941 			break;
3942 	}
3943 	/* we hit the end of the leaf before we found an xattr or
3944 	 * something larger than an xattr.  We have to assume the inode
3945 	 * has acls
3946 	 */
3947 	if (*first_xattr_slot == -1)
3948 		*first_xattr_slot = slot;
3949 	return 1;
3950 }
3951 
3952 /*
3953  * read an inode from the btree into the in-memory inode
3954  */
btrfs_read_locked_inode(struct inode * inode,struct btrfs_path * in_path)3955 static int btrfs_read_locked_inode(struct inode *inode,
3956 				   struct btrfs_path *in_path)
3957 {
3958 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
3959 	struct btrfs_path *path = in_path;
3960 	struct extent_buffer *leaf;
3961 	struct btrfs_inode_item *inode_item;
3962 	struct btrfs_root *root = BTRFS_I(inode)->root;
3963 	struct btrfs_key location;
3964 	unsigned long ptr;
3965 	int maybe_acls;
3966 	u32 rdev;
3967 	int ret;
3968 	bool filled = false;
3969 	int first_xattr_slot;
3970 
3971 	ret = btrfs_fill_inode(inode, &rdev);
3972 	if (!ret)
3973 		filled = true;
3974 
3975 	if (!path) {
3976 		path = btrfs_alloc_path();
3977 		if (!path)
3978 			return -ENOMEM;
3979 	}
3980 
3981 	memcpy(&location, &BTRFS_I(inode)->location, sizeof(location));
3982 
3983 	ret = btrfs_lookup_inode(NULL, root, path, &location, 0);
3984 	if (ret) {
3985 		if (path != in_path)
3986 			btrfs_free_path(path);
3987 		return ret;
3988 	}
3989 
3990 	leaf = path->nodes[0];
3991 
3992 	if (filled)
3993 		goto cache_index;
3994 
3995 	inode_item = btrfs_item_ptr(leaf, path->slots[0],
3996 				    struct btrfs_inode_item);
3997 	inode->i_mode = btrfs_inode_mode(leaf, inode_item);
3998 	set_nlink(inode, btrfs_inode_nlink(leaf, inode_item));
3999 	i_uid_write(inode, btrfs_inode_uid(leaf, inode_item));
4000 	i_gid_write(inode, btrfs_inode_gid(leaf, inode_item));
4001 	btrfs_i_size_write(BTRFS_I(inode), btrfs_inode_size(leaf, inode_item));
4002 	btrfs_inode_set_file_extent_range(BTRFS_I(inode), 0,
4003 			round_up(i_size_read(inode), fs_info->sectorsize));
4004 
4005 	inode->i_atime.tv_sec = btrfs_timespec_sec(leaf, &inode_item->atime);
4006 	inode->i_atime.tv_nsec = btrfs_timespec_nsec(leaf, &inode_item->atime);
4007 
4008 	inode->i_mtime.tv_sec = btrfs_timespec_sec(leaf, &inode_item->mtime);
4009 	inode->i_mtime.tv_nsec = btrfs_timespec_nsec(leaf, &inode_item->mtime);
4010 
4011 	inode->i_ctime.tv_sec = btrfs_timespec_sec(leaf, &inode_item->ctime);
4012 	inode->i_ctime.tv_nsec = btrfs_timespec_nsec(leaf, &inode_item->ctime);
4013 
4014 	BTRFS_I(inode)->i_otime.tv_sec =
4015 		btrfs_timespec_sec(leaf, &inode_item->otime);
4016 	BTRFS_I(inode)->i_otime.tv_nsec =
4017 		btrfs_timespec_nsec(leaf, &inode_item->otime);
4018 
4019 	inode_set_bytes(inode, btrfs_inode_nbytes(leaf, inode_item));
4020 	BTRFS_I(inode)->generation = btrfs_inode_generation(leaf, inode_item);
4021 	BTRFS_I(inode)->last_trans = btrfs_inode_transid(leaf, inode_item);
4022 
4023 	inode_set_iversion_queried(inode,
4024 				   btrfs_inode_sequence(leaf, inode_item));
4025 	inode->i_generation = BTRFS_I(inode)->generation;
4026 	inode->i_rdev = 0;
4027 	rdev = btrfs_inode_rdev(leaf, inode_item);
4028 
4029 	BTRFS_I(inode)->index_cnt = (u64)-1;
4030 	btrfs_inode_split_flags(btrfs_inode_flags(leaf, inode_item),
4031 				&BTRFS_I(inode)->flags, &BTRFS_I(inode)->ro_flags);
4032 
4033 cache_index:
4034 	/*
4035 	 * If we were modified in the current generation and evicted from memory
4036 	 * and then re-read we need to do a full sync since we don't have any
4037 	 * idea about which extents were modified before we were evicted from
4038 	 * cache.
4039 	 *
4040 	 * This is required for both inode re-read from disk and delayed inode
4041 	 * in delayed_nodes_tree.
4042 	 */
4043 	if (BTRFS_I(inode)->last_trans == fs_info->generation)
4044 		set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
4045 			&BTRFS_I(inode)->runtime_flags);
4046 
4047 	/*
4048 	 * We don't persist the id of the transaction where an unlink operation
4049 	 * against the inode was last made. So here we assume the inode might
4050 	 * have been evicted, and therefore the exact value of last_unlink_trans
4051 	 * lost, and set it to last_trans to avoid metadata inconsistencies
4052 	 * between the inode and its parent if the inode is fsync'ed and the log
4053 	 * replayed. For example, in the scenario:
4054 	 *
4055 	 * touch mydir/foo
4056 	 * ln mydir/foo mydir/bar
4057 	 * sync
4058 	 * unlink mydir/bar
4059 	 * echo 2 > /proc/sys/vm/drop_caches   # evicts inode
4060 	 * xfs_io -c fsync mydir/foo
4061 	 * <power failure>
4062 	 * mount fs, triggers fsync log replay
4063 	 *
4064 	 * We must make sure that when we fsync our inode foo we also log its
4065 	 * parent inode, otherwise after log replay the parent still has the
4066 	 * dentry with the "bar" name but our inode foo has a link count of 1
4067 	 * and doesn't have an inode ref with the name "bar" anymore.
4068 	 *
4069 	 * Setting last_unlink_trans to last_trans is a pessimistic approach,
4070 	 * but it guarantees correctness at the expense of occasional full
4071 	 * transaction commits on fsync if our inode is a directory, or if our
4072 	 * inode is not a directory, logging its parent unnecessarily.
4073 	 */
4074 	BTRFS_I(inode)->last_unlink_trans = BTRFS_I(inode)->last_trans;
4075 
4076 	/*
4077 	 * Same logic as for last_unlink_trans. We don't persist the generation
4078 	 * of the last transaction where this inode was used for a reflink
4079 	 * operation, so after eviction and reloading the inode we must be
4080 	 * pessimistic and assume the last transaction that modified the inode.
4081 	 */
4082 	BTRFS_I(inode)->last_reflink_trans = BTRFS_I(inode)->last_trans;
4083 
4084 	path->slots[0]++;
4085 	if (inode->i_nlink != 1 ||
4086 	    path->slots[0] >= btrfs_header_nritems(leaf))
4087 		goto cache_acl;
4088 
4089 	btrfs_item_key_to_cpu(leaf, &location, path->slots[0]);
4090 	if (location.objectid != btrfs_ino(BTRFS_I(inode)))
4091 		goto cache_acl;
4092 
4093 	ptr = btrfs_item_ptr_offset(leaf, path->slots[0]);
4094 	if (location.type == BTRFS_INODE_REF_KEY) {
4095 		struct btrfs_inode_ref *ref;
4096 
4097 		ref = (struct btrfs_inode_ref *)ptr;
4098 		BTRFS_I(inode)->dir_index = btrfs_inode_ref_index(leaf, ref);
4099 	} else if (location.type == BTRFS_INODE_EXTREF_KEY) {
4100 		struct btrfs_inode_extref *extref;
4101 
4102 		extref = (struct btrfs_inode_extref *)ptr;
4103 		BTRFS_I(inode)->dir_index = btrfs_inode_extref_index(leaf,
4104 								     extref);
4105 	}
4106 cache_acl:
4107 	/*
4108 	 * try to precache a NULL acl entry for files that don't have
4109 	 * any xattrs or acls
4110 	 */
4111 	maybe_acls = acls_after_inode_item(leaf, path->slots[0],
4112 			btrfs_ino(BTRFS_I(inode)), &first_xattr_slot);
4113 	if (first_xattr_slot != -1) {
4114 		path->slots[0] = first_xattr_slot;
4115 		ret = btrfs_load_inode_props(inode, path);
4116 		if (ret)
4117 			btrfs_err(fs_info,
4118 				  "error loading props for ino %llu (root %llu): %d",
4119 				  btrfs_ino(BTRFS_I(inode)),
4120 				  root->root_key.objectid, ret);
4121 	}
4122 	if (path != in_path)
4123 		btrfs_free_path(path);
4124 
4125 	if (!maybe_acls)
4126 		cache_no_acl(inode);
4127 
4128 	switch (inode->i_mode & S_IFMT) {
4129 	case S_IFREG:
4130 		inode->i_mapping->a_ops = &btrfs_aops;
4131 		inode->i_fop = &btrfs_file_operations;
4132 		inode->i_op = &btrfs_file_inode_operations;
4133 		break;
4134 	case S_IFDIR:
4135 		inode->i_fop = &btrfs_dir_file_operations;
4136 		inode->i_op = &btrfs_dir_inode_operations;
4137 		break;
4138 	case S_IFLNK:
4139 		inode->i_op = &btrfs_symlink_inode_operations;
4140 		inode_nohighmem(inode);
4141 		inode->i_mapping->a_ops = &btrfs_aops;
4142 		break;
4143 	default:
4144 		inode->i_op = &btrfs_special_inode_operations;
4145 		init_special_inode(inode, inode->i_mode, rdev);
4146 		break;
4147 	}
4148 
4149 	btrfs_sync_inode_flags_to_i_flags(inode);
4150 	return 0;
4151 }
4152 
4153 /*
4154  * given a leaf and an inode, copy the inode fields into the leaf
4155  */
fill_inode_item(struct btrfs_trans_handle * trans,struct extent_buffer * leaf,struct btrfs_inode_item * item,struct inode * inode)4156 static void fill_inode_item(struct btrfs_trans_handle *trans,
4157 			    struct extent_buffer *leaf,
4158 			    struct btrfs_inode_item *item,
4159 			    struct inode *inode)
4160 {
4161 	struct btrfs_map_token token;
4162 	u64 flags;
4163 
4164 	btrfs_init_map_token(&token, leaf);
4165 
4166 	btrfs_set_token_inode_uid(&token, item, i_uid_read(inode));
4167 	btrfs_set_token_inode_gid(&token, item, i_gid_read(inode));
4168 	btrfs_set_token_inode_size(&token, item, BTRFS_I(inode)->disk_i_size);
4169 	btrfs_set_token_inode_mode(&token, item, inode->i_mode);
4170 	btrfs_set_token_inode_nlink(&token, item, inode->i_nlink);
4171 
4172 	btrfs_set_token_timespec_sec(&token, &item->atime,
4173 				     inode->i_atime.tv_sec);
4174 	btrfs_set_token_timespec_nsec(&token, &item->atime,
4175 				      inode->i_atime.tv_nsec);
4176 
4177 	btrfs_set_token_timespec_sec(&token, &item->mtime,
4178 				     inode->i_mtime.tv_sec);
4179 	btrfs_set_token_timespec_nsec(&token, &item->mtime,
4180 				      inode->i_mtime.tv_nsec);
4181 
4182 	btrfs_set_token_timespec_sec(&token, &item->ctime,
4183 				     inode->i_ctime.tv_sec);
4184 	btrfs_set_token_timespec_nsec(&token, &item->ctime,
4185 				      inode->i_ctime.tv_nsec);
4186 
4187 	btrfs_set_token_timespec_sec(&token, &item->otime,
4188 				     BTRFS_I(inode)->i_otime.tv_sec);
4189 	btrfs_set_token_timespec_nsec(&token, &item->otime,
4190 				      BTRFS_I(inode)->i_otime.tv_nsec);
4191 
4192 	btrfs_set_token_inode_nbytes(&token, item, inode_get_bytes(inode));
4193 	btrfs_set_token_inode_generation(&token, item,
4194 					 BTRFS_I(inode)->generation);
4195 	btrfs_set_token_inode_sequence(&token, item, inode_peek_iversion(inode));
4196 	btrfs_set_token_inode_transid(&token, item, trans->transid);
4197 	btrfs_set_token_inode_rdev(&token, item, inode->i_rdev);
4198 	flags = btrfs_inode_combine_flags(BTRFS_I(inode)->flags,
4199 					  BTRFS_I(inode)->ro_flags);
4200 	btrfs_set_token_inode_flags(&token, item, flags);
4201 	btrfs_set_token_inode_block_group(&token, item, 0);
4202 }
4203 
4204 /*
4205  * copy everything in the in-memory inode into the btree.
4206  */
btrfs_update_inode_item(struct btrfs_trans_handle * trans,struct btrfs_root * root,struct btrfs_inode * inode)4207 static noinline int btrfs_update_inode_item(struct btrfs_trans_handle *trans,
4208 				struct btrfs_root *root,
4209 				struct btrfs_inode *inode)
4210 {
4211 	struct btrfs_inode_item *inode_item;
4212 	struct btrfs_path *path;
4213 	struct extent_buffer *leaf;
4214 	int ret;
4215 
4216 	path = btrfs_alloc_path();
4217 	if (!path)
4218 		return -ENOMEM;
4219 
4220 	ret = btrfs_lookup_inode(trans, root, path, &inode->location, 1);
4221 	if (ret) {
4222 		if (ret > 0)
4223 			ret = -ENOENT;
4224 		goto failed;
4225 	}
4226 
4227 	leaf = path->nodes[0];
4228 	inode_item = btrfs_item_ptr(leaf, path->slots[0],
4229 				    struct btrfs_inode_item);
4230 
4231 	fill_inode_item(trans, leaf, inode_item, &inode->vfs_inode);
4232 	btrfs_mark_buffer_dirty(leaf);
4233 	btrfs_set_inode_last_trans(trans, inode);
4234 	ret = 0;
4235 failed:
4236 	btrfs_free_path(path);
4237 	return ret;
4238 }
4239 
4240 /*
4241  * copy everything in the in-memory inode into the btree.
4242  */
btrfs_update_inode(struct btrfs_trans_handle * trans,struct btrfs_root * root,struct btrfs_inode * inode)4243 noinline int btrfs_update_inode(struct btrfs_trans_handle *trans,
4244 				struct btrfs_root *root,
4245 				struct btrfs_inode *inode)
4246 {
4247 	struct btrfs_fs_info *fs_info = root->fs_info;
4248 	int ret;
4249 
4250 	/*
4251 	 * If the inode is a free space inode, we can deadlock during commit
4252 	 * if we put it into the delayed code.
4253 	 *
4254 	 * The data relocation inode should also be directly updated
4255 	 * without delay
4256 	 */
4257 	if (!btrfs_is_free_space_inode(inode)
4258 	    && !btrfs_is_data_reloc_root(root)
4259 	    && !test_bit(BTRFS_FS_LOG_RECOVERING, &fs_info->flags)) {
4260 		btrfs_update_root_times(trans, root);
4261 
4262 		ret = btrfs_delayed_update_inode(trans, root, inode);
4263 		if (!ret)
4264 			btrfs_set_inode_last_trans(trans, inode);
4265 		return ret;
4266 	}
4267 
4268 	return btrfs_update_inode_item(trans, root, inode);
4269 }
4270 
btrfs_update_inode_fallback(struct btrfs_trans_handle * trans,struct btrfs_root * root,struct btrfs_inode * inode)4271 int btrfs_update_inode_fallback(struct btrfs_trans_handle *trans,
4272 				struct btrfs_root *root, struct btrfs_inode *inode)
4273 {
4274 	int ret;
4275 
4276 	ret = btrfs_update_inode(trans, root, inode);
4277 	if (ret == -ENOSPC)
4278 		return btrfs_update_inode_item(trans, root, inode);
4279 	return ret;
4280 }
4281 
4282 /*
4283  * unlink helper that gets used here in inode.c and in the tree logging
4284  * recovery code.  It remove a link in a directory with a given name, and
4285  * also drops the back refs in the inode to the directory
4286  */
__btrfs_unlink_inode(struct btrfs_trans_handle * trans,struct btrfs_inode * dir,struct btrfs_inode * inode,const struct fscrypt_str * name,struct btrfs_rename_ctx * rename_ctx)4287 static int __btrfs_unlink_inode(struct btrfs_trans_handle *trans,
4288 				struct btrfs_inode *dir,
4289 				struct btrfs_inode *inode,
4290 				const struct fscrypt_str *name,
4291 				struct btrfs_rename_ctx *rename_ctx)
4292 {
4293 	struct btrfs_root *root = dir->root;
4294 	struct btrfs_fs_info *fs_info = root->fs_info;
4295 	struct btrfs_path *path;
4296 	int ret = 0;
4297 	struct btrfs_dir_item *di;
4298 	u64 index;
4299 	u64 ino = btrfs_ino(inode);
4300 	u64 dir_ino = btrfs_ino(dir);
4301 
4302 	path = btrfs_alloc_path();
4303 	if (!path) {
4304 		ret = -ENOMEM;
4305 		goto out;
4306 	}
4307 
4308 	di = btrfs_lookup_dir_item(trans, root, path, dir_ino, name, -1);
4309 	if (IS_ERR_OR_NULL(di)) {
4310 		ret = di ? PTR_ERR(di) : -ENOENT;
4311 		goto err;
4312 	}
4313 	ret = btrfs_delete_one_dir_name(trans, root, path, di);
4314 	if (ret)
4315 		goto err;
4316 	btrfs_release_path(path);
4317 
4318 	/*
4319 	 * If we don't have dir index, we have to get it by looking up
4320 	 * the inode ref, since we get the inode ref, remove it directly,
4321 	 * it is unnecessary to do delayed deletion.
4322 	 *
4323 	 * But if we have dir index, needn't search inode ref to get it.
4324 	 * Since the inode ref is close to the inode item, it is better
4325 	 * that we delay to delete it, and just do this deletion when
4326 	 * we update the inode item.
4327 	 */
4328 	if (inode->dir_index) {
4329 		ret = btrfs_delayed_delete_inode_ref(inode);
4330 		if (!ret) {
4331 			index = inode->dir_index;
4332 			goto skip_backref;
4333 		}
4334 	}
4335 
4336 	ret = btrfs_del_inode_ref(trans, root, name, ino, dir_ino, &index);
4337 	if (ret) {
4338 		btrfs_info(fs_info,
4339 			"failed to delete reference to %.*s, inode %llu parent %llu",
4340 			name->len, name->name, ino, dir_ino);
4341 		btrfs_abort_transaction(trans, ret);
4342 		goto err;
4343 	}
4344 skip_backref:
4345 	if (rename_ctx)
4346 		rename_ctx->index = index;
4347 
4348 	ret = btrfs_delete_delayed_dir_index(trans, dir, index);
4349 	if (ret) {
4350 		btrfs_abort_transaction(trans, ret);
4351 		goto err;
4352 	}
4353 
4354 	/*
4355 	 * If we are in a rename context, we don't need to update anything in the
4356 	 * log. That will be done later during the rename by btrfs_log_new_name().
4357 	 * Besides that, doing it here would only cause extra unnecessary btree
4358 	 * operations on the log tree, increasing latency for applications.
4359 	 */
4360 	if (!rename_ctx) {
4361 		btrfs_del_inode_ref_in_log(trans, root, name, inode, dir_ino);
4362 		btrfs_del_dir_entries_in_log(trans, root, name, dir, index);
4363 	}
4364 
4365 	/*
4366 	 * If we have a pending delayed iput we could end up with the final iput
4367 	 * being run in btrfs-cleaner context.  If we have enough of these built
4368 	 * up we can end up burning a lot of time in btrfs-cleaner without any
4369 	 * way to throttle the unlinks.  Since we're currently holding a ref on
4370 	 * the inode we can run the delayed iput here without any issues as the
4371 	 * final iput won't be done until after we drop the ref we're currently
4372 	 * holding.
4373 	 */
4374 	btrfs_run_delayed_iput(fs_info, inode);
4375 err:
4376 	btrfs_free_path(path);
4377 	if (ret)
4378 		goto out;
4379 
4380 	btrfs_i_size_write(dir, dir->vfs_inode.i_size - name->len * 2);
4381 	inode_inc_iversion(&inode->vfs_inode);
4382 	inode_inc_iversion(&dir->vfs_inode);
4383 	inode->vfs_inode.i_ctime = current_time(&inode->vfs_inode);
4384 	dir->vfs_inode.i_mtime = inode->vfs_inode.i_ctime;
4385 	dir->vfs_inode.i_ctime = inode->vfs_inode.i_ctime;
4386 	ret = btrfs_update_inode(trans, root, dir);
4387 out:
4388 	return ret;
4389 }
4390 
btrfs_unlink_inode(struct btrfs_trans_handle * trans,struct btrfs_inode * dir,struct btrfs_inode * inode,const struct fscrypt_str * name)4391 int btrfs_unlink_inode(struct btrfs_trans_handle *trans,
4392 		       struct btrfs_inode *dir, struct btrfs_inode *inode,
4393 		       const struct fscrypt_str *name)
4394 {
4395 	int ret;
4396 
4397 	ret = __btrfs_unlink_inode(trans, dir, inode, name, NULL);
4398 	if (!ret) {
4399 		drop_nlink(&inode->vfs_inode);
4400 		ret = btrfs_update_inode(trans, inode->root, inode);
4401 	}
4402 	return ret;
4403 }
4404 
4405 /*
4406  * helper to start transaction for unlink and rmdir.
4407  *
4408  * unlink and rmdir are special in btrfs, they do not always free space, so
4409  * if we cannot make our reservations the normal way try and see if there is
4410  * plenty of slack room in the global reserve to migrate, otherwise we cannot
4411  * allow the unlink to occur.
4412  */
__unlink_start_trans(struct inode * dir)4413 static struct btrfs_trans_handle *__unlink_start_trans(struct inode *dir)
4414 {
4415 	struct btrfs_root *root = BTRFS_I(dir)->root;
4416 
4417 	/*
4418 	 * 1 for the possible orphan item
4419 	 * 1 for the dir item
4420 	 * 1 for the dir index
4421 	 * 1 for the inode ref
4422 	 * 1 for the inode
4423 	 * 1 for the parent inode
4424 	 */
4425 	return btrfs_start_transaction_fallback_global_rsv(root, 6);
4426 }
4427 
btrfs_unlink(struct inode * dir,struct dentry * dentry)4428 static int btrfs_unlink(struct inode *dir, struct dentry *dentry)
4429 {
4430 	struct btrfs_trans_handle *trans;
4431 	struct inode *inode = d_inode(dentry);
4432 	int ret;
4433 	struct fscrypt_name fname;
4434 
4435 	ret = fscrypt_setup_filename(dir, &dentry->d_name, 1, &fname);
4436 	if (ret)
4437 		return ret;
4438 
4439 	/* This needs to handle no-key deletions later on */
4440 
4441 	trans = __unlink_start_trans(dir);
4442 	if (IS_ERR(trans)) {
4443 		ret = PTR_ERR(trans);
4444 		goto fscrypt_free;
4445 	}
4446 
4447 	btrfs_record_unlink_dir(trans, BTRFS_I(dir), BTRFS_I(d_inode(dentry)),
4448 			0);
4449 
4450 	ret = btrfs_unlink_inode(trans, BTRFS_I(dir), BTRFS_I(d_inode(dentry)),
4451 				 &fname.disk_name);
4452 	if (ret)
4453 		goto end_trans;
4454 
4455 	if (inode->i_nlink == 0) {
4456 		ret = btrfs_orphan_add(trans, BTRFS_I(inode));
4457 		if (ret)
4458 			goto end_trans;
4459 	}
4460 
4461 end_trans:
4462 	btrfs_end_transaction(trans);
4463 	btrfs_btree_balance_dirty(BTRFS_I(dir)->root->fs_info);
4464 fscrypt_free:
4465 	fscrypt_free_filename(&fname);
4466 	return ret;
4467 }
4468 
btrfs_unlink_subvol(struct btrfs_trans_handle * trans,struct inode * dir,struct dentry * dentry)4469 static int btrfs_unlink_subvol(struct btrfs_trans_handle *trans,
4470 			       struct inode *dir, struct dentry *dentry)
4471 {
4472 	struct btrfs_root *root = BTRFS_I(dir)->root;
4473 	struct btrfs_inode *inode = BTRFS_I(d_inode(dentry));
4474 	struct btrfs_path *path;
4475 	struct extent_buffer *leaf;
4476 	struct btrfs_dir_item *di;
4477 	struct btrfs_key key;
4478 	u64 index;
4479 	int ret;
4480 	u64 objectid;
4481 	u64 dir_ino = btrfs_ino(BTRFS_I(dir));
4482 	struct fscrypt_name fname;
4483 
4484 	ret = fscrypt_setup_filename(dir, &dentry->d_name, 1, &fname);
4485 	if (ret)
4486 		return ret;
4487 
4488 	/* This needs to handle no-key deletions later on */
4489 
4490 	if (btrfs_ino(inode) == BTRFS_FIRST_FREE_OBJECTID) {
4491 		objectid = inode->root->root_key.objectid;
4492 	} else if (btrfs_ino(inode) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID) {
4493 		objectid = inode->location.objectid;
4494 	} else {
4495 		WARN_ON(1);
4496 		fscrypt_free_filename(&fname);
4497 		return -EINVAL;
4498 	}
4499 
4500 	path = btrfs_alloc_path();
4501 	if (!path) {
4502 		ret = -ENOMEM;
4503 		goto out;
4504 	}
4505 
4506 	di = btrfs_lookup_dir_item(trans, root, path, dir_ino,
4507 				   &fname.disk_name, -1);
4508 	if (IS_ERR_OR_NULL(di)) {
4509 		ret = di ? PTR_ERR(di) : -ENOENT;
4510 		goto out;
4511 	}
4512 
4513 	leaf = path->nodes[0];
4514 	btrfs_dir_item_key_to_cpu(leaf, di, &key);
4515 	WARN_ON(key.type != BTRFS_ROOT_ITEM_KEY || key.objectid != objectid);
4516 	ret = btrfs_delete_one_dir_name(trans, root, path, di);
4517 	if (ret) {
4518 		btrfs_abort_transaction(trans, ret);
4519 		goto out;
4520 	}
4521 	btrfs_release_path(path);
4522 
4523 	/*
4524 	 * This is a placeholder inode for a subvolume we didn't have a
4525 	 * reference to at the time of the snapshot creation.  In the meantime
4526 	 * we could have renamed the real subvol link into our snapshot, so
4527 	 * depending on btrfs_del_root_ref to return -ENOENT here is incorrect.
4528 	 * Instead simply lookup the dir_index_item for this entry so we can
4529 	 * remove it.  Otherwise we know we have a ref to the root and we can
4530 	 * call btrfs_del_root_ref, and it _shouldn't_ fail.
4531 	 */
4532 	if (btrfs_ino(inode) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID) {
4533 		di = btrfs_search_dir_index_item(root, path, dir_ino, &fname.disk_name);
4534 		if (IS_ERR_OR_NULL(di)) {
4535 			if (!di)
4536 				ret = -ENOENT;
4537 			else
4538 				ret = PTR_ERR(di);
4539 			btrfs_abort_transaction(trans, ret);
4540 			goto out;
4541 		}
4542 
4543 		leaf = path->nodes[0];
4544 		btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
4545 		index = key.offset;
4546 		btrfs_release_path(path);
4547 	} else {
4548 		ret = btrfs_del_root_ref(trans, objectid,
4549 					 root->root_key.objectid, dir_ino,
4550 					 &index, &fname.disk_name);
4551 		if (ret) {
4552 			btrfs_abort_transaction(trans, ret);
4553 			goto out;
4554 		}
4555 	}
4556 
4557 	ret = btrfs_delete_delayed_dir_index(trans, BTRFS_I(dir), index);
4558 	if (ret) {
4559 		btrfs_abort_transaction(trans, ret);
4560 		goto out;
4561 	}
4562 
4563 	btrfs_i_size_write(BTRFS_I(dir), dir->i_size - fname.disk_name.len * 2);
4564 	inode_inc_iversion(dir);
4565 	dir->i_mtime = current_time(dir);
4566 	dir->i_ctime = dir->i_mtime;
4567 	ret = btrfs_update_inode_fallback(trans, root, BTRFS_I(dir));
4568 	if (ret)
4569 		btrfs_abort_transaction(trans, ret);
4570 out:
4571 	btrfs_free_path(path);
4572 	fscrypt_free_filename(&fname);
4573 	return ret;
4574 }
4575 
4576 /*
4577  * Helper to check if the subvolume references other subvolumes or if it's
4578  * default.
4579  */
may_destroy_subvol(struct btrfs_root * root)4580 static noinline int may_destroy_subvol(struct btrfs_root *root)
4581 {
4582 	struct btrfs_fs_info *fs_info = root->fs_info;
4583 	struct btrfs_path *path;
4584 	struct btrfs_dir_item *di;
4585 	struct btrfs_key key;
4586 	struct fscrypt_str name = FSTR_INIT("default", 7);
4587 	u64 dir_id;
4588 	int ret;
4589 
4590 	path = btrfs_alloc_path();
4591 	if (!path)
4592 		return -ENOMEM;
4593 
4594 	/* Make sure this root isn't set as the default subvol */
4595 	dir_id = btrfs_super_root_dir(fs_info->super_copy);
4596 	di = btrfs_lookup_dir_item(NULL, fs_info->tree_root, path,
4597 				   dir_id, &name, 0);
4598 	if (di && !IS_ERR(di)) {
4599 		btrfs_dir_item_key_to_cpu(path->nodes[0], di, &key);
4600 		if (key.objectid == root->root_key.objectid) {
4601 			ret = -EPERM;
4602 			btrfs_err(fs_info,
4603 				  "deleting default subvolume %llu is not allowed",
4604 				  key.objectid);
4605 			goto out;
4606 		}
4607 		btrfs_release_path(path);
4608 	}
4609 
4610 	key.objectid = root->root_key.objectid;
4611 	key.type = BTRFS_ROOT_REF_KEY;
4612 	key.offset = (u64)-1;
4613 
4614 	ret = btrfs_search_slot(NULL, fs_info->tree_root, &key, path, 0, 0);
4615 	if (ret < 0)
4616 		goto out;
4617 	BUG_ON(ret == 0);
4618 
4619 	ret = 0;
4620 	if (path->slots[0] > 0) {
4621 		path->slots[0]--;
4622 		btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
4623 		if (key.objectid == root->root_key.objectid &&
4624 		    key.type == BTRFS_ROOT_REF_KEY)
4625 			ret = -ENOTEMPTY;
4626 	}
4627 out:
4628 	btrfs_free_path(path);
4629 	return ret;
4630 }
4631 
4632 /* Delete all dentries for inodes belonging to the root */
btrfs_prune_dentries(struct btrfs_root * root)4633 static void btrfs_prune_dentries(struct btrfs_root *root)
4634 {
4635 	struct btrfs_fs_info *fs_info = root->fs_info;
4636 	struct rb_node *node;
4637 	struct rb_node *prev;
4638 	struct btrfs_inode *entry;
4639 	struct inode *inode;
4640 	u64 objectid = 0;
4641 
4642 	if (!BTRFS_FS_ERROR(fs_info))
4643 		WARN_ON(btrfs_root_refs(&root->root_item) != 0);
4644 
4645 	spin_lock(&root->inode_lock);
4646 again:
4647 	node = root->inode_tree.rb_node;
4648 	prev = NULL;
4649 	while (node) {
4650 		prev = node;
4651 		entry = rb_entry(node, struct btrfs_inode, rb_node);
4652 
4653 		if (objectid < btrfs_ino(entry))
4654 			node = node->rb_left;
4655 		else if (objectid > btrfs_ino(entry))
4656 			node = node->rb_right;
4657 		else
4658 			break;
4659 	}
4660 	if (!node) {
4661 		while (prev) {
4662 			entry = rb_entry(prev, struct btrfs_inode, rb_node);
4663 			if (objectid <= btrfs_ino(entry)) {
4664 				node = prev;
4665 				break;
4666 			}
4667 			prev = rb_next(prev);
4668 		}
4669 	}
4670 	while (node) {
4671 		entry = rb_entry(node, struct btrfs_inode, rb_node);
4672 		objectid = btrfs_ino(entry) + 1;
4673 		inode = igrab(&entry->vfs_inode);
4674 		if (inode) {
4675 			spin_unlock(&root->inode_lock);
4676 			if (atomic_read(&inode->i_count) > 1)
4677 				d_prune_aliases(inode);
4678 			/*
4679 			 * btrfs_drop_inode will have it removed from the inode
4680 			 * cache when its usage count hits zero.
4681 			 */
4682 			iput(inode);
4683 			cond_resched();
4684 			spin_lock(&root->inode_lock);
4685 			goto again;
4686 		}
4687 
4688 		if (cond_resched_lock(&root->inode_lock))
4689 			goto again;
4690 
4691 		node = rb_next(node);
4692 	}
4693 	spin_unlock(&root->inode_lock);
4694 }
4695 
btrfs_delete_subvolume(struct inode * dir,struct dentry * dentry)4696 int btrfs_delete_subvolume(struct inode *dir, struct dentry *dentry)
4697 {
4698 	struct btrfs_fs_info *fs_info = btrfs_sb(dentry->d_sb);
4699 	struct btrfs_root *root = BTRFS_I(dir)->root;
4700 	struct inode *inode = d_inode(dentry);
4701 	struct btrfs_root *dest = BTRFS_I(inode)->root;
4702 	struct btrfs_trans_handle *trans;
4703 	struct btrfs_block_rsv block_rsv;
4704 	u64 root_flags;
4705 	int ret;
4706 
4707 	down_write(&fs_info->subvol_sem);
4708 
4709 	/*
4710 	 * Don't allow to delete a subvolume with send in progress. This is
4711 	 * inside the inode lock so the error handling that has to drop the bit
4712 	 * again is not run concurrently.
4713 	 */
4714 	spin_lock(&dest->root_item_lock);
4715 	if (dest->send_in_progress) {
4716 		spin_unlock(&dest->root_item_lock);
4717 		btrfs_warn(fs_info,
4718 			   "attempt to delete subvolume %llu during send",
4719 			   dest->root_key.objectid);
4720 		ret = -EPERM;
4721 		goto out_up_write;
4722 	}
4723 	if (atomic_read(&dest->nr_swapfiles)) {
4724 		spin_unlock(&dest->root_item_lock);
4725 		btrfs_warn(fs_info,
4726 			   "attempt to delete subvolume %llu with active swapfile",
4727 			   root->root_key.objectid);
4728 		ret = -EPERM;
4729 		goto out_up_write;
4730 	}
4731 	root_flags = btrfs_root_flags(&dest->root_item);
4732 	btrfs_set_root_flags(&dest->root_item,
4733 			     root_flags | BTRFS_ROOT_SUBVOL_DEAD);
4734 	spin_unlock(&dest->root_item_lock);
4735 
4736 	ret = may_destroy_subvol(dest);
4737 	if (ret)
4738 		goto out_undead;
4739 
4740 	btrfs_init_block_rsv(&block_rsv, BTRFS_BLOCK_RSV_TEMP);
4741 	/*
4742 	 * One for dir inode,
4743 	 * two for dir entries,
4744 	 * two for root ref/backref.
4745 	 */
4746 	ret = btrfs_subvolume_reserve_metadata(root, &block_rsv, 5, true);
4747 	if (ret)
4748 		goto out_undead;
4749 
4750 	trans = btrfs_start_transaction(root, 0);
4751 	if (IS_ERR(trans)) {
4752 		ret = PTR_ERR(trans);
4753 		goto out_release;
4754 	}
4755 	trans->block_rsv = &block_rsv;
4756 	trans->bytes_reserved = block_rsv.size;
4757 
4758 	btrfs_record_snapshot_destroy(trans, BTRFS_I(dir));
4759 
4760 	ret = btrfs_unlink_subvol(trans, dir, dentry);
4761 	if (ret) {
4762 		btrfs_abort_transaction(trans, ret);
4763 		goto out_end_trans;
4764 	}
4765 
4766 	ret = btrfs_record_root_in_trans(trans, dest);
4767 	if (ret) {
4768 		btrfs_abort_transaction(trans, ret);
4769 		goto out_end_trans;
4770 	}
4771 
4772 	memset(&dest->root_item.drop_progress, 0,
4773 		sizeof(dest->root_item.drop_progress));
4774 	btrfs_set_root_drop_level(&dest->root_item, 0);
4775 	btrfs_set_root_refs(&dest->root_item, 0);
4776 
4777 	if (!test_and_set_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED, &dest->state)) {
4778 		ret = btrfs_insert_orphan_item(trans,
4779 					fs_info->tree_root,
4780 					dest->root_key.objectid);
4781 		if (ret) {
4782 			btrfs_abort_transaction(trans, ret);
4783 			goto out_end_trans;
4784 		}
4785 	}
4786 
4787 	ret = btrfs_uuid_tree_remove(trans, dest->root_item.uuid,
4788 				  BTRFS_UUID_KEY_SUBVOL,
4789 				  dest->root_key.objectid);
4790 	if (ret && ret != -ENOENT) {
4791 		btrfs_abort_transaction(trans, ret);
4792 		goto out_end_trans;
4793 	}
4794 	if (!btrfs_is_empty_uuid(dest->root_item.received_uuid)) {
4795 		ret = btrfs_uuid_tree_remove(trans,
4796 					  dest->root_item.received_uuid,
4797 					  BTRFS_UUID_KEY_RECEIVED_SUBVOL,
4798 					  dest->root_key.objectid);
4799 		if (ret && ret != -ENOENT) {
4800 			btrfs_abort_transaction(trans, ret);
4801 			goto out_end_trans;
4802 		}
4803 	}
4804 
4805 	free_anon_bdev(dest->anon_dev);
4806 	dest->anon_dev = 0;
4807 out_end_trans:
4808 	trans->block_rsv = NULL;
4809 	trans->bytes_reserved = 0;
4810 	ret = btrfs_end_transaction(trans);
4811 	inode->i_flags |= S_DEAD;
4812 out_release:
4813 	btrfs_subvolume_release_metadata(root, &block_rsv);
4814 out_undead:
4815 	if (ret) {
4816 		spin_lock(&dest->root_item_lock);
4817 		root_flags = btrfs_root_flags(&dest->root_item);
4818 		btrfs_set_root_flags(&dest->root_item,
4819 				root_flags & ~BTRFS_ROOT_SUBVOL_DEAD);
4820 		spin_unlock(&dest->root_item_lock);
4821 	}
4822 out_up_write:
4823 	up_write(&fs_info->subvol_sem);
4824 	if (!ret) {
4825 		d_invalidate(dentry);
4826 		btrfs_prune_dentries(dest);
4827 		ASSERT(dest->send_in_progress == 0);
4828 	}
4829 
4830 	return ret;
4831 }
4832 
btrfs_rmdir(struct inode * dir,struct dentry * dentry)4833 static int btrfs_rmdir(struct inode *dir, struct dentry *dentry)
4834 {
4835 	struct inode *inode = d_inode(dentry);
4836 	struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info;
4837 	int err = 0;
4838 	struct btrfs_trans_handle *trans;
4839 	u64 last_unlink_trans;
4840 	struct fscrypt_name fname;
4841 
4842 	if (inode->i_size > BTRFS_EMPTY_DIR_SIZE)
4843 		return -ENOTEMPTY;
4844 	if (btrfs_ino(BTRFS_I(inode)) == BTRFS_FIRST_FREE_OBJECTID) {
4845 		if (unlikely(btrfs_fs_incompat(fs_info, EXTENT_TREE_V2))) {
4846 			btrfs_err(fs_info,
4847 			"extent tree v2 doesn't support snapshot deletion yet");
4848 			return -EOPNOTSUPP;
4849 		}
4850 		return btrfs_delete_subvolume(dir, dentry);
4851 	}
4852 
4853 	err = fscrypt_setup_filename(dir, &dentry->d_name, 1, &fname);
4854 	if (err)
4855 		return err;
4856 
4857 	/* This needs to handle no-key deletions later on */
4858 
4859 	trans = __unlink_start_trans(dir);
4860 	if (IS_ERR(trans)) {
4861 		err = PTR_ERR(trans);
4862 		goto out_notrans;
4863 	}
4864 
4865 	if (unlikely(btrfs_ino(BTRFS_I(inode)) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)) {
4866 		err = btrfs_unlink_subvol(trans, dir, dentry);
4867 		goto out;
4868 	}
4869 
4870 	err = btrfs_orphan_add(trans, BTRFS_I(inode));
4871 	if (err)
4872 		goto out;
4873 
4874 	last_unlink_trans = BTRFS_I(inode)->last_unlink_trans;
4875 
4876 	/* now the directory is empty */
4877 	err = btrfs_unlink_inode(trans, BTRFS_I(dir), BTRFS_I(d_inode(dentry)),
4878 				 &fname.disk_name);
4879 	if (!err) {
4880 		btrfs_i_size_write(BTRFS_I(inode), 0);
4881 		/*
4882 		 * Propagate the last_unlink_trans value of the deleted dir to
4883 		 * its parent directory. This is to prevent an unrecoverable
4884 		 * log tree in the case we do something like this:
4885 		 * 1) create dir foo
4886 		 * 2) create snapshot under dir foo
4887 		 * 3) delete the snapshot
4888 		 * 4) rmdir foo
4889 		 * 5) mkdir foo
4890 		 * 6) fsync foo or some file inside foo
4891 		 */
4892 		if (last_unlink_trans >= trans->transid)
4893 			BTRFS_I(dir)->last_unlink_trans = last_unlink_trans;
4894 	}
4895 out:
4896 	btrfs_end_transaction(trans);
4897 out_notrans:
4898 	btrfs_btree_balance_dirty(fs_info);
4899 	fscrypt_free_filename(&fname);
4900 
4901 	return err;
4902 }
4903 
4904 /*
4905  * btrfs_truncate_block - read, zero a chunk and write a block
4906  * @inode - inode that we're zeroing
4907  * @from - the offset to start zeroing
4908  * @len - the length to zero, 0 to zero the entire range respective to the
4909  *	offset
4910  * @front - zero up to the offset instead of from the offset on
4911  *
4912  * This will find the block for the "from" offset and cow the block and zero the
4913  * part we want to zero.  This is used with truncate and hole punching.
4914  */
btrfs_truncate_block(struct btrfs_inode * inode,loff_t from,loff_t len,int front)4915 int btrfs_truncate_block(struct btrfs_inode *inode, loff_t from, loff_t len,
4916 			 int front)
4917 {
4918 	struct btrfs_fs_info *fs_info = inode->root->fs_info;
4919 	struct address_space *mapping = inode->vfs_inode.i_mapping;
4920 	struct extent_io_tree *io_tree = &inode->io_tree;
4921 	struct btrfs_ordered_extent *ordered;
4922 	struct extent_state *cached_state = NULL;
4923 	struct extent_changeset *data_reserved = NULL;
4924 	bool only_release_metadata = false;
4925 	u32 blocksize = fs_info->sectorsize;
4926 	pgoff_t index = from >> PAGE_SHIFT;
4927 	unsigned offset = from & (blocksize - 1);
4928 	struct page *page;
4929 	gfp_t mask = btrfs_alloc_write_mask(mapping);
4930 	size_t write_bytes = blocksize;
4931 	int ret = 0;
4932 	u64 block_start;
4933 	u64 block_end;
4934 
4935 	if (IS_ALIGNED(offset, blocksize) &&
4936 	    (!len || IS_ALIGNED(len, blocksize)))
4937 		goto out;
4938 
4939 	block_start = round_down(from, blocksize);
4940 	block_end = block_start + blocksize - 1;
4941 
4942 	ret = btrfs_check_data_free_space(inode, &data_reserved, block_start,
4943 					  blocksize, false);
4944 	if (ret < 0) {
4945 		if (btrfs_check_nocow_lock(inode, block_start, &write_bytes, false) > 0) {
4946 			/* For nocow case, no need to reserve data space */
4947 			only_release_metadata = true;
4948 		} else {
4949 			goto out;
4950 		}
4951 	}
4952 	ret = btrfs_delalloc_reserve_metadata(inode, blocksize, blocksize, false);
4953 	if (ret < 0) {
4954 		if (!only_release_metadata)
4955 			btrfs_free_reserved_data_space(inode, data_reserved,
4956 						       block_start, blocksize);
4957 		goto out;
4958 	}
4959 again:
4960 	page = find_or_create_page(mapping, index, mask);
4961 	if (!page) {
4962 		btrfs_delalloc_release_space(inode, data_reserved, block_start,
4963 					     blocksize, true);
4964 		btrfs_delalloc_release_extents(inode, blocksize);
4965 		ret = -ENOMEM;
4966 		goto out;
4967 	}
4968 
4969 	if (!PageUptodate(page)) {
4970 		ret = btrfs_read_folio(NULL, page_folio(page));
4971 		lock_page(page);
4972 		if (page->mapping != mapping) {
4973 			unlock_page(page);
4974 			put_page(page);
4975 			goto again;
4976 		}
4977 		if (!PageUptodate(page)) {
4978 			ret = -EIO;
4979 			goto out_unlock;
4980 		}
4981 	}
4982 
4983 	/*
4984 	 * We unlock the page after the io is completed and then re-lock it
4985 	 * above.  release_folio() could have come in between that and cleared
4986 	 * PagePrivate(), but left the page in the mapping.  Set the page mapped
4987 	 * here to make sure it's properly set for the subpage stuff.
4988 	 */
4989 	ret = set_page_extent_mapped(page);
4990 	if (ret < 0)
4991 		goto out_unlock;
4992 
4993 	wait_on_page_writeback(page);
4994 
4995 	lock_extent(io_tree, block_start, block_end, &cached_state);
4996 
4997 	ordered = btrfs_lookup_ordered_extent(inode, block_start);
4998 	if (ordered) {
4999 		unlock_extent(io_tree, block_start, block_end, &cached_state);
5000 		unlock_page(page);
5001 		put_page(page);
5002 		btrfs_start_ordered_extent(ordered, 1);
5003 		btrfs_put_ordered_extent(ordered);
5004 		goto again;
5005 	}
5006 
5007 	clear_extent_bit(&inode->io_tree, block_start, block_end,
5008 			 EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG,
5009 			 &cached_state);
5010 
5011 	ret = btrfs_set_extent_delalloc(inode, block_start, block_end, 0,
5012 					&cached_state);
5013 	if (ret) {
5014 		unlock_extent(io_tree, block_start, block_end, &cached_state);
5015 		goto out_unlock;
5016 	}
5017 
5018 	if (offset != blocksize) {
5019 		if (!len)
5020 			len = blocksize - offset;
5021 		if (front)
5022 			memzero_page(page, (block_start - page_offset(page)),
5023 				     offset);
5024 		else
5025 			memzero_page(page, (block_start - page_offset(page)) + offset,
5026 				     len);
5027 	}
5028 	btrfs_page_clear_checked(fs_info, page, block_start,
5029 				 block_end + 1 - block_start);
5030 	btrfs_page_set_dirty(fs_info, page, block_start, block_end + 1 - block_start);
5031 	unlock_extent(io_tree, block_start, block_end, &cached_state);
5032 
5033 	if (only_release_metadata)
5034 		set_extent_bit(&inode->io_tree, block_start, block_end,
5035 			       EXTENT_NORESERVE, NULL, GFP_NOFS);
5036 
5037 out_unlock:
5038 	if (ret) {
5039 		if (only_release_metadata)
5040 			btrfs_delalloc_release_metadata(inode, blocksize, true);
5041 		else
5042 			btrfs_delalloc_release_space(inode, data_reserved,
5043 					block_start, blocksize, true);
5044 	}
5045 	btrfs_delalloc_release_extents(inode, blocksize);
5046 	unlock_page(page);
5047 	put_page(page);
5048 out:
5049 	if (only_release_metadata)
5050 		btrfs_check_nocow_unlock(inode);
5051 	extent_changeset_free(data_reserved);
5052 	return ret;
5053 }
5054 
maybe_insert_hole(struct btrfs_root * root,struct btrfs_inode * inode,u64 offset,u64 len)5055 static int maybe_insert_hole(struct btrfs_root *root, struct btrfs_inode *inode,
5056 			     u64 offset, u64 len)
5057 {
5058 	struct btrfs_fs_info *fs_info = root->fs_info;
5059 	struct btrfs_trans_handle *trans;
5060 	struct btrfs_drop_extents_args drop_args = { 0 };
5061 	int ret;
5062 
5063 	/*
5064 	 * If NO_HOLES is enabled, we don't need to do anything.
5065 	 * Later, up in the call chain, either btrfs_set_inode_last_sub_trans()
5066 	 * or btrfs_update_inode() will be called, which guarantee that the next
5067 	 * fsync will know this inode was changed and needs to be logged.
5068 	 */
5069 	if (btrfs_fs_incompat(fs_info, NO_HOLES))
5070 		return 0;
5071 
5072 	/*
5073 	 * 1 - for the one we're dropping
5074 	 * 1 - for the one we're adding
5075 	 * 1 - for updating the inode.
5076 	 */
5077 	trans = btrfs_start_transaction(root, 3);
5078 	if (IS_ERR(trans))
5079 		return PTR_ERR(trans);
5080 
5081 	drop_args.start = offset;
5082 	drop_args.end = offset + len;
5083 	drop_args.drop_cache = true;
5084 
5085 	ret = btrfs_drop_extents(trans, root, inode, &drop_args);
5086 	if (ret) {
5087 		btrfs_abort_transaction(trans, ret);
5088 		btrfs_end_transaction(trans);
5089 		return ret;
5090 	}
5091 
5092 	ret = btrfs_insert_hole_extent(trans, root, btrfs_ino(inode), offset, len);
5093 	if (ret) {
5094 		btrfs_abort_transaction(trans, ret);
5095 	} else {
5096 		btrfs_update_inode_bytes(inode, 0, drop_args.bytes_found);
5097 		btrfs_update_inode(trans, root, inode);
5098 	}
5099 	btrfs_end_transaction(trans);
5100 	return ret;
5101 }
5102 
5103 /*
5104  * This function puts in dummy file extents for the area we're creating a hole
5105  * for.  So if we are truncating this file to a larger size we need to insert
5106  * these file extents so that btrfs_get_extent will return a EXTENT_MAP_HOLE for
5107  * the range between oldsize and size
5108  */
btrfs_cont_expand(struct btrfs_inode * inode,loff_t oldsize,loff_t size)5109 int btrfs_cont_expand(struct btrfs_inode *inode, loff_t oldsize, loff_t size)
5110 {
5111 	struct btrfs_root *root = inode->root;
5112 	struct btrfs_fs_info *fs_info = root->fs_info;
5113 	struct extent_io_tree *io_tree = &inode->io_tree;
5114 	struct extent_map *em = NULL;
5115 	struct extent_state *cached_state = NULL;
5116 	u64 hole_start = ALIGN(oldsize, fs_info->sectorsize);
5117 	u64 block_end = ALIGN(size, fs_info->sectorsize);
5118 	u64 last_byte;
5119 	u64 cur_offset;
5120 	u64 hole_size;
5121 	int err = 0;
5122 
5123 	/*
5124 	 * If our size started in the middle of a block we need to zero out the
5125 	 * rest of the block before we expand the i_size, otherwise we could
5126 	 * expose stale data.
5127 	 */
5128 	err = btrfs_truncate_block(inode, oldsize, 0, 0);
5129 	if (err)
5130 		return err;
5131 
5132 	if (size <= hole_start)
5133 		return 0;
5134 
5135 	btrfs_lock_and_flush_ordered_range(inode, hole_start, block_end - 1,
5136 					   &cached_state);
5137 	cur_offset = hole_start;
5138 	while (1) {
5139 		em = btrfs_get_extent(inode, NULL, 0, cur_offset,
5140 				      block_end - cur_offset);
5141 		if (IS_ERR(em)) {
5142 			err = PTR_ERR(em);
5143 			em = NULL;
5144 			break;
5145 		}
5146 		last_byte = min(extent_map_end(em), block_end);
5147 		last_byte = ALIGN(last_byte, fs_info->sectorsize);
5148 		hole_size = last_byte - cur_offset;
5149 
5150 		if (!test_bit(EXTENT_FLAG_PREALLOC, &em->flags)) {
5151 			struct extent_map *hole_em;
5152 
5153 			err = maybe_insert_hole(root, inode, cur_offset,
5154 						hole_size);
5155 			if (err)
5156 				break;
5157 
5158 			err = btrfs_inode_set_file_extent_range(inode,
5159 							cur_offset, hole_size);
5160 			if (err)
5161 				break;
5162 
5163 			hole_em = alloc_extent_map();
5164 			if (!hole_em) {
5165 				btrfs_drop_extent_map_range(inode, cur_offset,
5166 						    cur_offset + hole_size - 1,
5167 						    false);
5168 				btrfs_set_inode_full_sync(inode);
5169 				goto next;
5170 			}
5171 			hole_em->start = cur_offset;
5172 			hole_em->len = hole_size;
5173 			hole_em->orig_start = cur_offset;
5174 
5175 			hole_em->block_start = EXTENT_MAP_HOLE;
5176 			hole_em->block_len = 0;
5177 			hole_em->orig_block_len = 0;
5178 			hole_em->ram_bytes = hole_size;
5179 			hole_em->compress_type = BTRFS_COMPRESS_NONE;
5180 			hole_em->generation = fs_info->generation;
5181 
5182 			err = btrfs_replace_extent_map_range(inode, hole_em, true);
5183 			free_extent_map(hole_em);
5184 		} else {
5185 			err = btrfs_inode_set_file_extent_range(inode,
5186 							cur_offset, hole_size);
5187 			if (err)
5188 				break;
5189 		}
5190 next:
5191 		free_extent_map(em);
5192 		em = NULL;
5193 		cur_offset = last_byte;
5194 		if (cur_offset >= block_end)
5195 			break;
5196 	}
5197 	free_extent_map(em);
5198 	unlock_extent(io_tree, hole_start, block_end - 1, &cached_state);
5199 	return err;
5200 }
5201 
btrfs_setsize(struct inode * inode,struct iattr * attr)5202 static int btrfs_setsize(struct inode *inode, struct iattr *attr)
5203 {
5204 	struct btrfs_root *root = BTRFS_I(inode)->root;
5205 	struct btrfs_trans_handle *trans;
5206 	loff_t oldsize = i_size_read(inode);
5207 	loff_t newsize = attr->ia_size;
5208 	int mask = attr->ia_valid;
5209 	int ret;
5210 
5211 	/*
5212 	 * The regular truncate() case without ATTR_CTIME and ATTR_MTIME is a
5213 	 * special case where we need to update the times despite not having
5214 	 * these flags set.  For all other operations the VFS set these flags
5215 	 * explicitly if it wants a timestamp update.
5216 	 */
5217 	if (newsize != oldsize) {
5218 		inode_inc_iversion(inode);
5219 		if (!(mask & (ATTR_CTIME | ATTR_MTIME))) {
5220 			inode->i_mtime = current_time(inode);
5221 			inode->i_ctime = inode->i_mtime;
5222 		}
5223 	}
5224 
5225 	if (newsize > oldsize) {
5226 		/*
5227 		 * Don't do an expanding truncate while snapshotting is ongoing.
5228 		 * This is to ensure the snapshot captures a fully consistent
5229 		 * state of this file - if the snapshot captures this expanding
5230 		 * truncation, it must capture all writes that happened before
5231 		 * this truncation.
5232 		 */
5233 		btrfs_drew_write_lock(&root->snapshot_lock);
5234 		ret = btrfs_cont_expand(BTRFS_I(inode), oldsize, newsize);
5235 		if (ret) {
5236 			btrfs_drew_write_unlock(&root->snapshot_lock);
5237 			return ret;
5238 		}
5239 
5240 		trans = btrfs_start_transaction(root, 1);
5241 		if (IS_ERR(trans)) {
5242 			btrfs_drew_write_unlock(&root->snapshot_lock);
5243 			return PTR_ERR(trans);
5244 		}
5245 
5246 		i_size_write(inode, newsize);
5247 		btrfs_inode_safe_disk_i_size_write(BTRFS_I(inode), 0);
5248 		pagecache_isize_extended(inode, oldsize, newsize);
5249 		ret = btrfs_update_inode(trans, root, BTRFS_I(inode));
5250 		btrfs_drew_write_unlock(&root->snapshot_lock);
5251 		btrfs_end_transaction(trans);
5252 	} else {
5253 		struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5254 
5255 		if (btrfs_is_zoned(fs_info)) {
5256 			ret = btrfs_wait_ordered_range(inode,
5257 					ALIGN(newsize, fs_info->sectorsize),
5258 					(u64)-1);
5259 			if (ret)
5260 				return ret;
5261 		}
5262 
5263 		/*
5264 		 * We're truncating a file that used to have good data down to
5265 		 * zero. Make sure any new writes to the file get on disk
5266 		 * on close.
5267 		 */
5268 		if (newsize == 0)
5269 			set_bit(BTRFS_INODE_FLUSH_ON_CLOSE,
5270 				&BTRFS_I(inode)->runtime_flags);
5271 
5272 		truncate_setsize(inode, newsize);
5273 
5274 		inode_dio_wait(inode);
5275 
5276 		ret = btrfs_truncate(inode, newsize == oldsize);
5277 		if (ret && inode->i_nlink) {
5278 			int err;
5279 
5280 			/*
5281 			 * Truncate failed, so fix up the in-memory size. We
5282 			 * adjusted disk_i_size down as we removed extents, so
5283 			 * wait for disk_i_size to be stable and then update the
5284 			 * in-memory size to match.
5285 			 */
5286 			err = btrfs_wait_ordered_range(inode, 0, (u64)-1);
5287 			if (err)
5288 				return err;
5289 			i_size_write(inode, BTRFS_I(inode)->disk_i_size);
5290 		}
5291 	}
5292 
5293 	return ret;
5294 }
5295 
btrfs_setattr(struct user_namespace * mnt_userns,struct dentry * dentry,struct iattr * attr)5296 static int btrfs_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
5297 			 struct iattr *attr)
5298 {
5299 	struct inode *inode = d_inode(dentry);
5300 	struct btrfs_root *root = BTRFS_I(inode)->root;
5301 	int err;
5302 
5303 	if (btrfs_root_readonly(root))
5304 		return -EROFS;
5305 
5306 	err = setattr_prepare(mnt_userns, dentry, attr);
5307 	if (err)
5308 		return err;
5309 
5310 	if (S_ISREG(inode->i_mode) && (attr->ia_valid & ATTR_SIZE)) {
5311 		err = btrfs_setsize(inode, attr);
5312 		if (err)
5313 			return err;
5314 	}
5315 
5316 	if (attr->ia_valid) {
5317 		setattr_copy(mnt_userns, inode, attr);
5318 		inode_inc_iversion(inode);
5319 		err = btrfs_dirty_inode(inode);
5320 
5321 		if (!err && attr->ia_valid & ATTR_MODE)
5322 			err = posix_acl_chmod(mnt_userns, inode, inode->i_mode);
5323 	}
5324 
5325 	return err;
5326 }
5327 
5328 /*
5329  * While truncating the inode pages during eviction, we get the VFS
5330  * calling btrfs_invalidate_folio() against each folio of the inode. This
5331  * is slow because the calls to btrfs_invalidate_folio() result in a
5332  * huge amount of calls to lock_extent() and clear_extent_bit(),
5333  * which keep merging and splitting extent_state structures over and over,
5334  * wasting lots of time.
5335  *
5336  * Therefore if the inode is being evicted, let btrfs_invalidate_folio()
5337  * skip all those expensive operations on a per folio basis and do only
5338  * the ordered io finishing, while we release here the extent_map and
5339  * extent_state structures, without the excessive merging and splitting.
5340  */
evict_inode_truncate_pages(struct inode * inode)5341 static void evict_inode_truncate_pages(struct inode *inode)
5342 {
5343 	struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
5344 	struct rb_node *node;
5345 
5346 	ASSERT(inode->i_state & I_FREEING);
5347 	truncate_inode_pages_final(&inode->i_data);
5348 
5349 	btrfs_drop_extent_map_range(BTRFS_I(inode), 0, (u64)-1, false);
5350 
5351 	/*
5352 	 * Keep looping until we have no more ranges in the io tree.
5353 	 * We can have ongoing bios started by readahead that have
5354 	 * their endio callback (extent_io.c:end_bio_extent_readpage)
5355 	 * still in progress (unlocked the pages in the bio but did not yet
5356 	 * unlocked the ranges in the io tree). Therefore this means some
5357 	 * ranges can still be locked and eviction started because before
5358 	 * submitting those bios, which are executed by a separate task (work
5359 	 * queue kthread), inode references (inode->i_count) were not taken
5360 	 * (which would be dropped in the end io callback of each bio).
5361 	 * Therefore here we effectively end up waiting for those bios and
5362 	 * anyone else holding locked ranges without having bumped the inode's
5363 	 * reference count - if we don't do it, when they access the inode's
5364 	 * io_tree to unlock a range it may be too late, leading to an
5365 	 * use-after-free issue.
5366 	 */
5367 	spin_lock(&io_tree->lock);
5368 	while (!RB_EMPTY_ROOT(&io_tree->state)) {
5369 		struct extent_state *state;
5370 		struct extent_state *cached_state = NULL;
5371 		u64 start;
5372 		u64 end;
5373 		unsigned state_flags;
5374 
5375 		node = rb_first(&io_tree->state);
5376 		state = rb_entry(node, struct extent_state, rb_node);
5377 		start = state->start;
5378 		end = state->end;
5379 		state_flags = state->state;
5380 		spin_unlock(&io_tree->lock);
5381 
5382 		lock_extent(io_tree, start, end, &cached_state);
5383 
5384 		/*
5385 		 * If still has DELALLOC flag, the extent didn't reach disk,
5386 		 * and its reserved space won't be freed by delayed_ref.
5387 		 * So we need to free its reserved space here.
5388 		 * (Refer to comment in btrfs_invalidate_folio, case 2)
5389 		 *
5390 		 * Note, end is the bytenr of last byte, so we need + 1 here.
5391 		 */
5392 		if (state_flags & EXTENT_DELALLOC)
5393 			btrfs_qgroup_free_data(BTRFS_I(inode), NULL, start,
5394 					       end - start + 1, NULL);
5395 
5396 		clear_extent_bit(io_tree, start, end,
5397 				 EXTENT_CLEAR_ALL_BITS | EXTENT_DO_ACCOUNTING,
5398 				 &cached_state);
5399 
5400 		cond_resched();
5401 		spin_lock(&io_tree->lock);
5402 	}
5403 	spin_unlock(&io_tree->lock);
5404 }
5405 
evict_refill_and_join(struct btrfs_root * root,struct btrfs_block_rsv * rsv)5406 static struct btrfs_trans_handle *evict_refill_and_join(struct btrfs_root *root,
5407 							struct btrfs_block_rsv *rsv)
5408 {
5409 	struct btrfs_fs_info *fs_info = root->fs_info;
5410 	struct btrfs_trans_handle *trans;
5411 	u64 delayed_refs_extra = btrfs_calc_insert_metadata_size(fs_info, 1);
5412 	int ret;
5413 
5414 	/*
5415 	 * Eviction should be taking place at some place safe because of our
5416 	 * delayed iputs.  However the normal flushing code will run delayed
5417 	 * iputs, so we cannot use FLUSH_ALL otherwise we'll deadlock.
5418 	 *
5419 	 * We reserve the delayed_refs_extra here again because we can't use
5420 	 * btrfs_start_transaction(root, 0) for the same deadlocky reason as
5421 	 * above.  We reserve our extra bit here because we generate a ton of
5422 	 * delayed refs activity by truncating.
5423 	 *
5424 	 * BTRFS_RESERVE_FLUSH_EVICT will steal from the global_rsv if it can,
5425 	 * if we fail to make this reservation we can re-try without the
5426 	 * delayed_refs_extra so we can make some forward progress.
5427 	 */
5428 	ret = btrfs_block_rsv_refill(fs_info, rsv, rsv->size + delayed_refs_extra,
5429 				     BTRFS_RESERVE_FLUSH_EVICT);
5430 	if (ret) {
5431 		ret = btrfs_block_rsv_refill(fs_info, rsv, rsv->size,
5432 					     BTRFS_RESERVE_FLUSH_EVICT);
5433 		if (ret) {
5434 			btrfs_warn(fs_info,
5435 				   "could not allocate space for delete; will truncate on mount");
5436 			return ERR_PTR(-ENOSPC);
5437 		}
5438 		delayed_refs_extra = 0;
5439 	}
5440 
5441 	trans = btrfs_join_transaction(root);
5442 	if (IS_ERR(trans))
5443 		return trans;
5444 
5445 	if (delayed_refs_extra) {
5446 		trans->block_rsv = &fs_info->trans_block_rsv;
5447 		trans->bytes_reserved = delayed_refs_extra;
5448 		btrfs_block_rsv_migrate(rsv, trans->block_rsv,
5449 					delayed_refs_extra, 1);
5450 	}
5451 	return trans;
5452 }
5453 
btrfs_evict_inode(struct inode * inode)5454 void btrfs_evict_inode(struct inode *inode)
5455 {
5456 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5457 	struct btrfs_trans_handle *trans;
5458 	struct btrfs_root *root = BTRFS_I(inode)->root;
5459 	struct btrfs_block_rsv *rsv;
5460 	int ret;
5461 
5462 	trace_btrfs_inode_evict(inode);
5463 
5464 	if (!root) {
5465 		fsverity_cleanup_inode(inode);
5466 		clear_inode(inode);
5467 		return;
5468 	}
5469 
5470 	evict_inode_truncate_pages(inode);
5471 
5472 	if (inode->i_nlink &&
5473 	    ((btrfs_root_refs(&root->root_item) != 0 &&
5474 	      root->root_key.objectid != BTRFS_ROOT_TREE_OBJECTID) ||
5475 	     btrfs_is_free_space_inode(BTRFS_I(inode))))
5476 		goto no_delete;
5477 
5478 	if (is_bad_inode(inode))
5479 		goto no_delete;
5480 
5481 	btrfs_free_io_failure_record(BTRFS_I(inode), 0, (u64)-1);
5482 
5483 	if (test_bit(BTRFS_FS_LOG_RECOVERING, &fs_info->flags))
5484 		goto no_delete;
5485 
5486 	if (inode->i_nlink > 0) {
5487 		BUG_ON(btrfs_root_refs(&root->root_item) != 0 &&
5488 		       root->root_key.objectid != BTRFS_ROOT_TREE_OBJECTID);
5489 		goto no_delete;
5490 	}
5491 
5492 	/*
5493 	 * This makes sure the inode item in tree is uptodate and the space for
5494 	 * the inode update is released.
5495 	 */
5496 	ret = btrfs_commit_inode_delayed_inode(BTRFS_I(inode));
5497 	if (ret)
5498 		goto no_delete;
5499 
5500 	/*
5501 	 * This drops any pending insert or delete operations we have for this
5502 	 * inode.  We could have a delayed dir index deletion queued up, but
5503 	 * we're removing the inode completely so that'll be taken care of in
5504 	 * the truncate.
5505 	 */
5506 	btrfs_kill_delayed_inode_items(BTRFS_I(inode));
5507 
5508 	rsv = btrfs_alloc_block_rsv(fs_info, BTRFS_BLOCK_RSV_TEMP);
5509 	if (!rsv)
5510 		goto no_delete;
5511 	rsv->size = btrfs_calc_metadata_size(fs_info, 1);
5512 	rsv->failfast = true;
5513 
5514 	btrfs_i_size_write(BTRFS_I(inode), 0);
5515 
5516 	while (1) {
5517 		struct btrfs_truncate_control control = {
5518 			.inode = BTRFS_I(inode),
5519 			.ino = btrfs_ino(BTRFS_I(inode)),
5520 			.new_size = 0,
5521 			.min_type = 0,
5522 		};
5523 
5524 		trans = evict_refill_and_join(root, rsv);
5525 		if (IS_ERR(trans))
5526 			goto free_rsv;
5527 
5528 		trans->block_rsv = rsv;
5529 
5530 		ret = btrfs_truncate_inode_items(trans, root, &control);
5531 		trans->block_rsv = &fs_info->trans_block_rsv;
5532 		btrfs_end_transaction(trans);
5533 		btrfs_btree_balance_dirty(fs_info);
5534 		if (ret && ret != -ENOSPC && ret != -EAGAIN)
5535 			goto free_rsv;
5536 		else if (!ret)
5537 			break;
5538 	}
5539 
5540 	/*
5541 	 * Errors here aren't a big deal, it just means we leave orphan items in
5542 	 * the tree. They will be cleaned up on the next mount. If the inode
5543 	 * number gets reused, cleanup deletes the orphan item without doing
5544 	 * anything, and unlink reuses the existing orphan item.
5545 	 *
5546 	 * If it turns out that we are dropping too many of these, we might want
5547 	 * to add a mechanism for retrying these after a commit.
5548 	 */
5549 	trans = evict_refill_and_join(root, rsv);
5550 	if (!IS_ERR(trans)) {
5551 		trans->block_rsv = rsv;
5552 		btrfs_orphan_del(trans, BTRFS_I(inode));
5553 		trans->block_rsv = &fs_info->trans_block_rsv;
5554 		btrfs_end_transaction(trans);
5555 	}
5556 
5557 free_rsv:
5558 	btrfs_free_block_rsv(fs_info, rsv);
5559 no_delete:
5560 	/*
5561 	 * If we didn't successfully delete, the orphan item will still be in
5562 	 * the tree and we'll retry on the next mount. Again, we might also want
5563 	 * to retry these periodically in the future.
5564 	 */
5565 	btrfs_remove_delayed_node(BTRFS_I(inode));
5566 	fsverity_cleanup_inode(inode);
5567 	clear_inode(inode);
5568 }
5569 
5570 /*
5571  * Return the key found in the dir entry in the location pointer, fill @type
5572  * with BTRFS_FT_*, and return 0.
5573  *
5574  * If no dir entries were found, returns -ENOENT.
5575  * If found a corrupted location in dir entry, returns -EUCLEAN.
5576  */
btrfs_inode_by_name(struct inode * dir,struct dentry * dentry,struct btrfs_key * location,u8 * type)5577 static int btrfs_inode_by_name(struct inode *dir, struct dentry *dentry,
5578 			       struct btrfs_key *location, u8 *type)
5579 {
5580 	struct btrfs_dir_item *di;
5581 	struct btrfs_path *path;
5582 	struct btrfs_root *root = BTRFS_I(dir)->root;
5583 	int ret = 0;
5584 	struct fscrypt_name fname;
5585 
5586 	path = btrfs_alloc_path();
5587 	if (!path)
5588 		return -ENOMEM;
5589 
5590 	ret = fscrypt_setup_filename(dir, &dentry->d_name, 1, &fname);
5591 	if (ret)
5592 		goto out;
5593 
5594 	/* This needs to handle no-key deletions later on */
5595 
5596 	di = btrfs_lookup_dir_item(NULL, root, path, btrfs_ino(BTRFS_I(dir)),
5597 				   &fname.disk_name, 0);
5598 	if (IS_ERR_OR_NULL(di)) {
5599 		ret = di ? PTR_ERR(di) : -ENOENT;
5600 		goto out;
5601 	}
5602 
5603 	btrfs_dir_item_key_to_cpu(path->nodes[0], di, location);
5604 	if (location->type != BTRFS_INODE_ITEM_KEY &&
5605 	    location->type != BTRFS_ROOT_ITEM_KEY) {
5606 		ret = -EUCLEAN;
5607 		btrfs_warn(root->fs_info,
5608 "%s gets something invalid in DIR_ITEM (name %s, directory ino %llu, location(%llu %u %llu))",
5609 			   __func__, fname.disk_name.name, btrfs_ino(BTRFS_I(dir)),
5610 			   location->objectid, location->type, location->offset);
5611 	}
5612 	if (!ret)
5613 		*type = btrfs_dir_type(path->nodes[0], di);
5614 out:
5615 	fscrypt_free_filename(&fname);
5616 	btrfs_free_path(path);
5617 	return ret;
5618 }
5619 
5620 /*
5621  * when we hit a tree root in a directory, the btrfs part of the inode
5622  * needs to be changed to reflect the root directory of the tree root.  This
5623  * is kind of like crossing a mount point.
5624  */
fixup_tree_root_location(struct btrfs_fs_info * fs_info,struct inode * dir,struct dentry * dentry,struct btrfs_key * location,struct btrfs_root ** sub_root)5625 static int fixup_tree_root_location(struct btrfs_fs_info *fs_info,
5626 				    struct inode *dir,
5627 				    struct dentry *dentry,
5628 				    struct btrfs_key *location,
5629 				    struct btrfs_root **sub_root)
5630 {
5631 	struct btrfs_path *path;
5632 	struct btrfs_root *new_root;
5633 	struct btrfs_root_ref *ref;
5634 	struct extent_buffer *leaf;
5635 	struct btrfs_key key;
5636 	int ret;
5637 	int err = 0;
5638 	struct fscrypt_name fname;
5639 
5640 	ret = fscrypt_setup_filename(dir, &dentry->d_name, 0, &fname);
5641 	if (ret)
5642 		return ret;
5643 
5644 	path = btrfs_alloc_path();
5645 	if (!path) {
5646 		err = -ENOMEM;
5647 		goto out;
5648 	}
5649 
5650 	err = -ENOENT;
5651 	key.objectid = BTRFS_I(dir)->root->root_key.objectid;
5652 	key.type = BTRFS_ROOT_REF_KEY;
5653 	key.offset = location->objectid;
5654 
5655 	ret = btrfs_search_slot(NULL, fs_info->tree_root, &key, path, 0, 0);
5656 	if (ret) {
5657 		if (ret < 0)
5658 			err = ret;
5659 		goto out;
5660 	}
5661 
5662 	leaf = path->nodes[0];
5663 	ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_root_ref);
5664 	if (btrfs_root_ref_dirid(leaf, ref) != btrfs_ino(BTRFS_I(dir)) ||
5665 	    btrfs_root_ref_name_len(leaf, ref) != fname.disk_name.len)
5666 		goto out;
5667 
5668 	ret = memcmp_extent_buffer(leaf, fname.disk_name.name,
5669 				   (unsigned long)(ref + 1), fname.disk_name.len);
5670 	if (ret)
5671 		goto out;
5672 
5673 	btrfs_release_path(path);
5674 
5675 	new_root = btrfs_get_fs_root(fs_info, location->objectid, true);
5676 	if (IS_ERR(new_root)) {
5677 		err = PTR_ERR(new_root);
5678 		goto out;
5679 	}
5680 
5681 	*sub_root = new_root;
5682 	location->objectid = btrfs_root_dirid(&new_root->root_item);
5683 	location->type = BTRFS_INODE_ITEM_KEY;
5684 	location->offset = 0;
5685 	err = 0;
5686 out:
5687 	btrfs_free_path(path);
5688 	fscrypt_free_filename(&fname);
5689 	return err;
5690 }
5691 
inode_tree_add(struct inode * inode)5692 static void inode_tree_add(struct inode *inode)
5693 {
5694 	struct btrfs_root *root = BTRFS_I(inode)->root;
5695 	struct btrfs_inode *entry;
5696 	struct rb_node **p;
5697 	struct rb_node *parent;
5698 	struct rb_node *new = &BTRFS_I(inode)->rb_node;
5699 	u64 ino = btrfs_ino(BTRFS_I(inode));
5700 
5701 	if (inode_unhashed(inode))
5702 		return;
5703 	parent = NULL;
5704 	spin_lock(&root->inode_lock);
5705 	p = &root->inode_tree.rb_node;
5706 	while (*p) {
5707 		parent = *p;
5708 		entry = rb_entry(parent, struct btrfs_inode, rb_node);
5709 
5710 		if (ino < btrfs_ino(entry))
5711 			p = &parent->rb_left;
5712 		else if (ino > btrfs_ino(entry))
5713 			p = &parent->rb_right;
5714 		else {
5715 			WARN_ON(!(entry->vfs_inode.i_state &
5716 				  (I_WILL_FREE | I_FREEING)));
5717 			rb_replace_node(parent, new, &root->inode_tree);
5718 			RB_CLEAR_NODE(parent);
5719 			spin_unlock(&root->inode_lock);
5720 			return;
5721 		}
5722 	}
5723 	rb_link_node(new, parent, p);
5724 	rb_insert_color(new, &root->inode_tree);
5725 	spin_unlock(&root->inode_lock);
5726 }
5727 
inode_tree_del(struct btrfs_inode * inode)5728 static void inode_tree_del(struct btrfs_inode *inode)
5729 {
5730 	struct btrfs_root *root = inode->root;
5731 	int empty = 0;
5732 
5733 	spin_lock(&root->inode_lock);
5734 	if (!RB_EMPTY_NODE(&inode->rb_node)) {
5735 		rb_erase(&inode->rb_node, &root->inode_tree);
5736 		RB_CLEAR_NODE(&inode->rb_node);
5737 		empty = RB_EMPTY_ROOT(&root->inode_tree);
5738 	}
5739 	spin_unlock(&root->inode_lock);
5740 
5741 	if (empty && btrfs_root_refs(&root->root_item) == 0) {
5742 		spin_lock(&root->inode_lock);
5743 		empty = RB_EMPTY_ROOT(&root->inode_tree);
5744 		spin_unlock(&root->inode_lock);
5745 		if (empty)
5746 			btrfs_add_dead_root(root);
5747 	}
5748 }
5749 
5750 
btrfs_init_locked_inode(struct inode * inode,void * p)5751 static int btrfs_init_locked_inode(struct inode *inode, void *p)
5752 {
5753 	struct btrfs_iget_args *args = p;
5754 
5755 	inode->i_ino = args->ino;
5756 	BTRFS_I(inode)->location.objectid = args->ino;
5757 	BTRFS_I(inode)->location.type = BTRFS_INODE_ITEM_KEY;
5758 	BTRFS_I(inode)->location.offset = 0;
5759 	BTRFS_I(inode)->root = btrfs_grab_root(args->root);
5760 	BUG_ON(args->root && !BTRFS_I(inode)->root);
5761 
5762 	if (args->root && args->root == args->root->fs_info->tree_root &&
5763 	    args->ino != BTRFS_BTREE_INODE_OBJECTID)
5764 		set_bit(BTRFS_INODE_FREE_SPACE_INODE,
5765 			&BTRFS_I(inode)->runtime_flags);
5766 	return 0;
5767 }
5768 
btrfs_find_actor(struct inode * inode,void * opaque)5769 static int btrfs_find_actor(struct inode *inode, void *opaque)
5770 {
5771 	struct btrfs_iget_args *args = opaque;
5772 
5773 	return args->ino == BTRFS_I(inode)->location.objectid &&
5774 		args->root == BTRFS_I(inode)->root;
5775 }
5776 
btrfs_iget_locked(struct super_block * s,u64 ino,struct btrfs_root * root)5777 static struct inode *btrfs_iget_locked(struct super_block *s, u64 ino,
5778 				       struct btrfs_root *root)
5779 {
5780 	struct inode *inode;
5781 	struct btrfs_iget_args args;
5782 	unsigned long hashval = btrfs_inode_hash(ino, root);
5783 
5784 	args.ino = ino;
5785 	args.root = root;
5786 
5787 	inode = iget5_locked(s, hashval, btrfs_find_actor,
5788 			     btrfs_init_locked_inode,
5789 			     (void *)&args);
5790 	return inode;
5791 }
5792 
5793 /*
5794  * Get an inode object given its inode number and corresponding root.
5795  * Path can be preallocated to prevent recursing back to iget through
5796  * allocator. NULL is also valid but may require an additional allocation
5797  * later.
5798  */
btrfs_iget_path(struct super_block * s,u64 ino,struct btrfs_root * root,struct btrfs_path * path)5799 struct inode *btrfs_iget_path(struct super_block *s, u64 ino,
5800 			      struct btrfs_root *root, struct btrfs_path *path)
5801 {
5802 	struct inode *inode;
5803 
5804 	inode = btrfs_iget_locked(s, ino, root);
5805 	if (!inode)
5806 		return ERR_PTR(-ENOMEM);
5807 
5808 	if (inode->i_state & I_NEW) {
5809 		int ret;
5810 
5811 		ret = btrfs_read_locked_inode(inode, path);
5812 		if (!ret) {
5813 			inode_tree_add(inode);
5814 			unlock_new_inode(inode);
5815 		} else {
5816 			iget_failed(inode);
5817 			/*
5818 			 * ret > 0 can come from btrfs_search_slot called by
5819 			 * btrfs_read_locked_inode, this means the inode item
5820 			 * was not found.
5821 			 */
5822 			if (ret > 0)
5823 				ret = -ENOENT;
5824 			inode = ERR_PTR(ret);
5825 		}
5826 	}
5827 
5828 	return inode;
5829 }
5830 
btrfs_iget(struct super_block * s,u64 ino,struct btrfs_root * root)5831 struct inode *btrfs_iget(struct super_block *s, u64 ino, struct btrfs_root *root)
5832 {
5833 	return btrfs_iget_path(s, ino, root, NULL);
5834 }
5835 
new_simple_dir(struct super_block * s,struct btrfs_key * key,struct btrfs_root * root)5836 static struct inode *new_simple_dir(struct super_block *s,
5837 				    struct btrfs_key *key,
5838 				    struct btrfs_root *root)
5839 {
5840 	struct inode *inode = new_inode(s);
5841 
5842 	if (!inode)
5843 		return ERR_PTR(-ENOMEM);
5844 
5845 	BTRFS_I(inode)->root = btrfs_grab_root(root);
5846 	memcpy(&BTRFS_I(inode)->location, key, sizeof(*key));
5847 	set_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags);
5848 
5849 	inode->i_ino = BTRFS_EMPTY_SUBVOL_DIR_OBJECTID;
5850 	/*
5851 	 * We only need lookup, the rest is read-only and there's no inode
5852 	 * associated with the dentry
5853 	 */
5854 	inode->i_op = &simple_dir_inode_operations;
5855 	inode->i_opflags &= ~IOP_XATTR;
5856 	inode->i_fop = &simple_dir_operations;
5857 	inode->i_mode = S_IFDIR | S_IRUGO | S_IWUSR | S_IXUGO;
5858 	inode->i_mtime = current_time(inode);
5859 	inode->i_atime = inode->i_mtime;
5860 	inode->i_ctime = inode->i_mtime;
5861 	BTRFS_I(inode)->i_otime = inode->i_mtime;
5862 
5863 	return inode;
5864 }
5865 
5866 static_assert(BTRFS_FT_UNKNOWN == FT_UNKNOWN);
5867 static_assert(BTRFS_FT_REG_FILE == FT_REG_FILE);
5868 static_assert(BTRFS_FT_DIR == FT_DIR);
5869 static_assert(BTRFS_FT_CHRDEV == FT_CHRDEV);
5870 static_assert(BTRFS_FT_BLKDEV == FT_BLKDEV);
5871 static_assert(BTRFS_FT_FIFO == FT_FIFO);
5872 static_assert(BTRFS_FT_SOCK == FT_SOCK);
5873 static_assert(BTRFS_FT_SYMLINK == FT_SYMLINK);
5874 
btrfs_inode_type(struct inode * inode)5875 static inline u8 btrfs_inode_type(struct inode *inode)
5876 {
5877 	return fs_umode_to_ftype(inode->i_mode);
5878 }
5879 
btrfs_lookup_dentry(struct inode * dir,struct dentry * dentry)5880 struct inode *btrfs_lookup_dentry(struct inode *dir, struct dentry *dentry)
5881 {
5882 	struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
5883 	struct inode *inode;
5884 	struct btrfs_root *root = BTRFS_I(dir)->root;
5885 	struct btrfs_root *sub_root = root;
5886 	struct btrfs_key location;
5887 	u8 di_type = 0;
5888 	int ret = 0;
5889 
5890 	if (dentry->d_name.len > BTRFS_NAME_LEN)
5891 		return ERR_PTR(-ENAMETOOLONG);
5892 
5893 	ret = btrfs_inode_by_name(dir, dentry, &location, &di_type);
5894 	if (ret < 0)
5895 		return ERR_PTR(ret);
5896 
5897 	if (location.type == BTRFS_INODE_ITEM_KEY) {
5898 		inode = btrfs_iget(dir->i_sb, location.objectid, root);
5899 		if (IS_ERR(inode))
5900 			return inode;
5901 
5902 		/* Do extra check against inode mode with di_type */
5903 		if (btrfs_inode_type(inode) != di_type) {
5904 			btrfs_crit(fs_info,
5905 "inode mode mismatch with dir: inode mode=0%o btrfs type=%u dir type=%u",
5906 				  inode->i_mode, btrfs_inode_type(inode),
5907 				  di_type);
5908 			iput(inode);
5909 			return ERR_PTR(-EUCLEAN);
5910 		}
5911 		return inode;
5912 	}
5913 
5914 	ret = fixup_tree_root_location(fs_info, dir, dentry,
5915 				       &location, &sub_root);
5916 	if (ret < 0) {
5917 		if (ret != -ENOENT)
5918 			inode = ERR_PTR(ret);
5919 		else
5920 			inode = new_simple_dir(dir->i_sb, &location, root);
5921 	} else {
5922 		inode = btrfs_iget(dir->i_sb, location.objectid, sub_root);
5923 		btrfs_put_root(sub_root);
5924 
5925 		if (IS_ERR(inode))
5926 			return inode;
5927 
5928 		down_read(&fs_info->cleanup_work_sem);
5929 		if (!sb_rdonly(inode->i_sb))
5930 			ret = btrfs_orphan_cleanup(sub_root);
5931 		up_read(&fs_info->cleanup_work_sem);
5932 		if (ret) {
5933 			iput(inode);
5934 			inode = ERR_PTR(ret);
5935 		}
5936 	}
5937 
5938 	return inode;
5939 }
5940 
btrfs_dentry_delete(const struct dentry * dentry)5941 static int btrfs_dentry_delete(const struct dentry *dentry)
5942 {
5943 	struct btrfs_root *root;
5944 	struct inode *inode = d_inode(dentry);
5945 
5946 	if (!inode && !IS_ROOT(dentry))
5947 		inode = d_inode(dentry->d_parent);
5948 
5949 	if (inode) {
5950 		root = BTRFS_I(inode)->root;
5951 		if (btrfs_root_refs(&root->root_item) == 0)
5952 			return 1;
5953 
5954 		if (btrfs_ino(BTRFS_I(inode)) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)
5955 			return 1;
5956 	}
5957 	return 0;
5958 }
5959 
btrfs_lookup(struct inode * dir,struct dentry * dentry,unsigned int flags)5960 static struct dentry *btrfs_lookup(struct inode *dir, struct dentry *dentry,
5961 				   unsigned int flags)
5962 {
5963 	struct inode *inode = btrfs_lookup_dentry(dir, dentry);
5964 
5965 	if (inode == ERR_PTR(-ENOENT))
5966 		inode = NULL;
5967 	return d_splice_alias(inode, dentry);
5968 }
5969 
5970 /*
5971  * Find the highest existing sequence number in a directory and then set the
5972  * in-memory index_cnt variable to the first free sequence number.
5973  */
btrfs_set_inode_index_count(struct btrfs_inode * inode)5974 static int btrfs_set_inode_index_count(struct btrfs_inode *inode)
5975 {
5976 	struct btrfs_root *root = inode->root;
5977 	struct btrfs_key key, found_key;
5978 	struct btrfs_path *path;
5979 	struct extent_buffer *leaf;
5980 	int ret;
5981 
5982 	key.objectid = btrfs_ino(inode);
5983 	key.type = BTRFS_DIR_INDEX_KEY;
5984 	key.offset = (u64)-1;
5985 
5986 	path = btrfs_alloc_path();
5987 	if (!path)
5988 		return -ENOMEM;
5989 
5990 	ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
5991 	if (ret < 0)
5992 		goto out;
5993 	/* FIXME: we should be able to handle this */
5994 	if (ret == 0)
5995 		goto out;
5996 	ret = 0;
5997 
5998 	if (path->slots[0] == 0) {
5999 		inode->index_cnt = BTRFS_DIR_START_INDEX;
6000 		goto out;
6001 	}
6002 
6003 	path->slots[0]--;
6004 
6005 	leaf = path->nodes[0];
6006 	btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
6007 
6008 	if (found_key.objectid != btrfs_ino(inode) ||
6009 	    found_key.type != BTRFS_DIR_INDEX_KEY) {
6010 		inode->index_cnt = BTRFS_DIR_START_INDEX;
6011 		goto out;
6012 	}
6013 
6014 	inode->index_cnt = found_key.offset + 1;
6015 out:
6016 	btrfs_free_path(path);
6017 	return ret;
6018 }
6019 
btrfs_get_dir_last_index(struct btrfs_inode * dir,u64 * index)6020 static int btrfs_get_dir_last_index(struct btrfs_inode *dir, u64 *index)
6021 {
6022 	int ret = 0;
6023 
6024 	btrfs_inode_lock(&dir->vfs_inode, 0);
6025 	if (dir->index_cnt == (u64)-1) {
6026 		ret = btrfs_inode_delayed_dir_index_count(dir);
6027 		if (ret) {
6028 			ret = btrfs_set_inode_index_count(dir);
6029 			if (ret)
6030 				goto out;
6031 		}
6032 	}
6033 
6034 	/* index_cnt is the index number of next new entry, so decrement it. */
6035 	*index = dir->index_cnt - 1;
6036 out:
6037 	btrfs_inode_unlock(&dir->vfs_inode, 0);
6038 
6039 	return ret;
6040 }
6041 
6042 /*
6043  * All this infrastructure exists because dir_emit can fault, and we are holding
6044  * the tree lock when doing readdir.  For now just allocate a buffer and copy
6045  * our information into that, and then dir_emit from the buffer.  This is
6046  * similar to what NFS does, only we don't keep the buffer around in pagecache
6047  * because I'm afraid I'll mess that up.  Long term we need to make filldir do
6048  * copy_to_user_inatomic so we don't have to worry about page faulting under the
6049  * tree lock.
6050  */
btrfs_opendir(struct inode * inode,struct file * file)6051 static int btrfs_opendir(struct inode *inode, struct file *file)
6052 {
6053 	struct btrfs_file_private *private;
6054 	u64 last_index;
6055 	int ret;
6056 
6057 	ret = btrfs_get_dir_last_index(BTRFS_I(inode), &last_index);
6058 	if (ret)
6059 		return ret;
6060 
6061 	private = kzalloc(sizeof(struct btrfs_file_private), GFP_KERNEL);
6062 	if (!private)
6063 		return -ENOMEM;
6064 	private->last_index = last_index;
6065 	private->filldir_buf = kzalloc(PAGE_SIZE, GFP_KERNEL);
6066 	if (!private->filldir_buf) {
6067 		kfree(private);
6068 		return -ENOMEM;
6069 	}
6070 	file->private_data = private;
6071 	return 0;
6072 }
6073 
btrfs_dir_llseek(struct file * file,loff_t offset,int whence)6074 static loff_t btrfs_dir_llseek(struct file *file, loff_t offset, int whence)
6075 {
6076 	struct btrfs_file_private *private = file->private_data;
6077 	int ret;
6078 
6079 	ret = btrfs_get_dir_last_index(BTRFS_I(file_inode(file)),
6080 				       &private->last_index);
6081 	if (ret)
6082 		return ret;
6083 
6084 	return generic_file_llseek(file, offset, whence);
6085 }
6086 
6087 struct dir_entry {
6088 	u64 ino;
6089 	u64 offset;
6090 	unsigned type;
6091 	int name_len;
6092 };
6093 
btrfs_filldir(void * addr,int entries,struct dir_context * ctx)6094 static int btrfs_filldir(void *addr, int entries, struct dir_context *ctx)
6095 {
6096 	while (entries--) {
6097 		struct dir_entry *entry = addr;
6098 		char *name = (char *)(entry + 1);
6099 
6100 		ctx->pos = get_unaligned(&entry->offset);
6101 		if (!dir_emit(ctx, name, get_unaligned(&entry->name_len),
6102 					 get_unaligned(&entry->ino),
6103 					 get_unaligned(&entry->type)))
6104 			return 1;
6105 		addr += sizeof(struct dir_entry) +
6106 			get_unaligned(&entry->name_len);
6107 		ctx->pos++;
6108 	}
6109 	return 0;
6110 }
6111 
btrfs_real_readdir(struct file * file,struct dir_context * ctx)6112 static int btrfs_real_readdir(struct file *file, struct dir_context *ctx)
6113 {
6114 	struct inode *inode = file_inode(file);
6115 	struct btrfs_root *root = BTRFS_I(inode)->root;
6116 	struct btrfs_file_private *private = file->private_data;
6117 	struct btrfs_dir_item *di;
6118 	struct btrfs_key key;
6119 	struct btrfs_key found_key;
6120 	struct btrfs_path *path;
6121 	void *addr;
6122 	struct list_head ins_list;
6123 	struct list_head del_list;
6124 	int ret;
6125 	char *name_ptr;
6126 	int name_len;
6127 	int entries = 0;
6128 	int total_len = 0;
6129 	bool put = false;
6130 	struct btrfs_key location;
6131 
6132 	if (!dir_emit_dots(file, ctx))
6133 		return 0;
6134 
6135 	path = btrfs_alloc_path();
6136 	if (!path)
6137 		return -ENOMEM;
6138 
6139 	addr = private->filldir_buf;
6140 	path->reada = READA_FORWARD;
6141 
6142 	INIT_LIST_HEAD(&ins_list);
6143 	INIT_LIST_HEAD(&del_list);
6144 	put = btrfs_readdir_get_delayed_items(inode, private->last_index,
6145 					      &ins_list, &del_list);
6146 
6147 again:
6148 	key.type = BTRFS_DIR_INDEX_KEY;
6149 	key.offset = ctx->pos;
6150 	key.objectid = btrfs_ino(BTRFS_I(inode));
6151 
6152 	btrfs_for_each_slot(root, &key, &found_key, path, ret) {
6153 		struct dir_entry *entry;
6154 		struct extent_buffer *leaf = path->nodes[0];
6155 
6156 		if (found_key.objectid != key.objectid)
6157 			break;
6158 		if (found_key.type != BTRFS_DIR_INDEX_KEY)
6159 			break;
6160 		if (found_key.offset < ctx->pos)
6161 			continue;
6162 		if (found_key.offset > private->last_index)
6163 			break;
6164 		if (btrfs_should_delete_dir_index(&del_list, found_key.offset))
6165 			continue;
6166 		di = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dir_item);
6167 		name_len = btrfs_dir_name_len(leaf, di);
6168 		if ((total_len + sizeof(struct dir_entry) + name_len) >=
6169 		    PAGE_SIZE) {
6170 			btrfs_release_path(path);
6171 			ret = btrfs_filldir(private->filldir_buf, entries, ctx);
6172 			if (ret)
6173 				goto nopos;
6174 			addr = private->filldir_buf;
6175 			entries = 0;
6176 			total_len = 0;
6177 			goto again;
6178 		}
6179 
6180 		entry = addr;
6181 		put_unaligned(name_len, &entry->name_len);
6182 		name_ptr = (char *)(entry + 1);
6183 		read_extent_buffer(leaf, name_ptr, (unsigned long)(di + 1),
6184 				   name_len);
6185 		put_unaligned(fs_ftype_to_dtype(btrfs_dir_type(leaf, di)),
6186 				&entry->type);
6187 		btrfs_dir_item_key_to_cpu(leaf, di, &location);
6188 		put_unaligned(location.objectid, &entry->ino);
6189 		put_unaligned(found_key.offset, &entry->offset);
6190 		entries++;
6191 		addr += sizeof(struct dir_entry) + name_len;
6192 		total_len += sizeof(struct dir_entry) + name_len;
6193 	}
6194 	/* Catch error encountered during iteration */
6195 	if (ret < 0)
6196 		goto err;
6197 
6198 	btrfs_release_path(path);
6199 
6200 	ret = btrfs_filldir(private->filldir_buf, entries, ctx);
6201 	if (ret)
6202 		goto nopos;
6203 
6204 	ret = btrfs_readdir_delayed_dir_index(ctx, &ins_list);
6205 	if (ret)
6206 		goto nopos;
6207 
6208 	/*
6209 	 * Stop new entries from being returned after we return the last
6210 	 * entry.
6211 	 *
6212 	 * New directory entries are assigned a strictly increasing
6213 	 * offset.  This means that new entries created during readdir
6214 	 * are *guaranteed* to be seen in the future by that readdir.
6215 	 * This has broken buggy programs which operate on names as
6216 	 * they're returned by readdir.  Until we re-use freed offsets
6217 	 * we have this hack to stop new entries from being returned
6218 	 * under the assumption that they'll never reach this huge
6219 	 * offset.
6220 	 *
6221 	 * This is being careful not to overflow 32bit loff_t unless the
6222 	 * last entry requires it because doing so has broken 32bit apps
6223 	 * in the past.
6224 	 */
6225 	if (ctx->pos >= INT_MAX)
6226 		ctx->pos = LLONG_MAX;
6227 	else
6228 		ctx->pos = INT_MAX;
6229 nopos:
6230 	ret = 0;
6231 err:
6232 	if (put)
6233 		btrfs_readdir_put_delayed_items(inode, &ins_list, &del_list);
6234 	btrfs_free_path(path);
6235 	return ret;
6236 }
6237 
6238 /*
6239  * This is somewhat expensive, updating the tree every time the
6240  * inode changes.  But, it is most likely to find the inode in cache.
6241  * FIXME, needs more benchmarking...there are no reasons other than performance
6242  * to keep or drop this code.
6243  */
btrfs_dirty_inode(struct inode * inode)6244 static int btrfs_dirty_inode(struct inode *inode)
6245 {
6246 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
6247 	struct btrfs_root *root = BTRFS_I(inode)->root;
6248 	struct btrfs_trans_handle *trans;
6249 	int ret;
6250 
6251 	if (test_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags))
6252 		return 0;
6253 
6254 	trans = btrfs_join_transaction(root);
6255 	if (IS_ERR(trans))
6256 		return PTR_ERR(trans);
6257 
6258 	ret = btrfs_update_inode(trans, root, BTRFS_I(inode));
6259 	if (ret && (ret == -ENOSPC || ret == -EDQUOT)) {
6260 		/* whoops, lets try again with the full transaction */
6261 		btrfs_end_transaction(trans);
6262 		trans = btrfs_start_transaction(root, 1);
6263 		if (IS_ERR(trans))
6264 			return PTR_ERR(trans);
6265 
6266 		ret = btrfs_update_inode(trans, root, BTRFS_I(inode));
6267 	}
6268 	btrfs_end_transaction(trans);
6269 	if (BTRFS_I(inode)->delayed_node)
6270 		btrfs_balance_delayed_items(fs_info);
6271 
6272 	return ret;
6273 }
6274 
6275 /*
6276  * This is a copy of file_update_time.  We need this so we can return error on
6277  * ENOSPC for updating the inode in the case of file write and mmap writes.
6278  */
btrfs_update_time(struct inode * inode,struct timespec64 * now,int flags)6279 static int btrfs_update_time(struct inode *inode, struct timespec64 *now,
6280 			     int flags)
6281 {
6282 	struct btrfs_root *root = BTRFS_I(inode)->root;
6283 	bool dirty = flags & ~S_VERSION;
6284 
6285 	if (btrfs_root_readonly(root))
6286 		return -EROFS;
6287 
6288 	if (flags & S_VERSION)
6289 		dirty |= inode_maybe_inc_iversion(inode, dirty);
6290 	if (flags & S_CTIME)
6291 		inode->i_ctime = *now;
6292 	if (flags & S_MTIME)
6293 		inode->i_mtime = *now;
6294 	if (flags & S_ATIME)
6295 		inode->i_atime = *now;
6296 	return dirty ? btrfs_dirty_inode(inode) : 0;
6297 }
6298 
6299 /*
6300  * helper to find a free sequence number in a given directory.  This current
6301  * code is very simple, later versions will do smarter things in the btree
6302  */
btrfs_set_inode_index(struct btrfs_inode * dir,u64 * index)6303 int btrfs_set_inode_index(struct btrfs_inode *dir, u64 *index)
6304 {
6305 	int ret = 0;
6306 
6307 	if (dir->index_cnt == (u64)-1) {
6308 		ret = btrfs_inode_delayed_dir_index_count(dir);
6309 		if (ret) {
6310 			ret = btrfs_set_inode_index_count(dir);
6311 			if (ret)
6312 				return ret;
6313 		}
6314 	}
6315 
6316 	*index = dir->index_cnt;
6317 	dir->index_cnt++;
6318 
6319 	return ret;
6320 }
6321 
btrfs_insert_inode_locked(struct inode * inode)6322 static int btrfs_insert_inode_locked(struct inode *inode)
6323 {
6324 	struct btrfs_iget_args args;
6325 
6326 	args.ino = BTRFS_I(inode)->location.objectid;
6327 	args.root = BTRFS_I(inode)->root;
6328 
6329 	return insert_inode_locked4(inode,
6330 		   btrfs_inode_hash(inode->i_ino, BTRFS_I(inode)->root),
6331 		   btrfs_find_actor, &args);
6332 }
6333 
btrfs_new_inode_prepare(struct btrfs_new_inode_args * args,unsigned int * trans_num_items)6334 int btrfs_new_inode_prepare(struct btrfs_new_inode_args *args,
6335 			    unsigned int *trans_num_items)
6336 {
6337 	struct inode *dir = args->dir;
6338 	struct inode *inode = args->inode;
6339 	int ret;
6340 
6341 	if (!args->orphan) {
6342 		ret = fscrypt_setup_filename(dir, &args->dentry->d_name, 0,
6343 					     &args->fname);
6344 		if (ret)
6345 			return ret;
6346 	}
6347 
6348 	ret = posix_acl_create(dir, &inode->i_mode, &args->default_acl, &args->acl);
6349 	if (ret) {
6350 		fscrypt_free_filename(&args->fname);
6351 		return ret;
6352 	}
6353 
6354 	/* 1 to add inode item */
6355 	*trans_num_items = 1;
6356 	/* 1 to add compression property */
6357 	if (BTRFS_I(dir)->prop_compress)
6358 		(*trans_num_items)++;
6359 	/* 1 to add default ACL xattr */
6360 	if (args->default_acl)
6361 		(*trans_num_items)++;
6362 	/* 1 to add access ACL xattr */
6363 	if (args->acl)
6364 		(*trans_num_items)++;
6365 #ifdef CONFIG_SECURITY
6366 	/* 1 to add LSM xattr */
6367 	if (dir->i_security)
6368 		(*trans_num_items)++;
6369 #endif
6370 	if (args->orphan) {
6371 		/* 1 to add orphan item */
6372 		(*trans_num_items)++;
6373 	} else {
6374 		/*
6375 		 * 1 to add dir item
6376 		 * 1 to add dir index
6377 		 * 1 to update parent inode item
6378 		 *
6379 		 * No need for 1 unit for the inode ref item because it is
6380 		 * inserted in a batch together with the inode item at
6381 		 * btrfs_create_new_inode().
6382 		 */
6383 		*trans_num_items += 3;
6384 	}
6385 	return 0;
6386 }
6387 
btrfs_new_inode_args_destroy(struct btrfs_new_inode_args * args)6388 void btrfs_new_inode_args_destroy(struct btrfs_new_inode_args *args)
6389 {
6390 	posix_acl_release(args->acl);
6391 	posix_acl_release(args->default_acl);
6392 	fscrypt_free_filename(&args->fname);
6393 }
6394 
6395 /*
6396  * Inherit flags from the parent inode.
6397  *
6398  * Currently only the compression flags and the cow flags are inherited.
6399  */
btrfs_inherit_iflags(struct inode * inode,struct inode * dir)6400 static void btrfs_inherit_iflags(struct inode *inode, struct inode *dir)
6401 {
6402 	unsigned int flags;
6403 
6404 	flags = BTRFS_I(dir)->flags;
6405 
6406 	if (flags & BTRFS_INODE_NOCOMPRESS) {
6407 		BTRFS_I(inode)->flags &= ~BTRFS_INODE_COMPRESS;
6408 		BTRFS_I(inode)->flags |= BTRFS_INODE_NOCOMPRESS;
6409 	} else if (flags & BTRFS_INODE_COMPRESS) {
6410 		BTRFS_I(inode)->flags &= ~BTRFS_INODE_NOCOMPRESS;
6411 		BTRFS_I(inode)->flags |= BTRFS_INODE_COMPRESS;
6412 	}
6413 
6414 	if (flags & BTRFS_INODE_NODATACOW) {
6415 		BTRFS_I(inode)->flags |= BTRFS_INODE_NODATACOW;
6416 		if (S_ISREG(inode->i_mode))
6417 			BTRFS_I(inode)->flags |= BTRFS_INODE_NODATASUM;
6418 	}
6419 
6420 	btrfs_sync_inode_flags_to_i_flags(inode);
6421 }
6422 
btrfs_create_new_inode(struct btrfs_trans_handle * trans,struct btrfs_new_inode_args * args)6423 int btrfs_create_new_inode(struct btrfs_trans_handle *trans,
6424 			   struct btrfs_new_inode_args *args)
6425 {
6426 	struct inode *dir = args->dir;
6427 	struct inode *inode = args->inode;
6428 	const struct fscrypt_str *name = args->orphan ? NULL : &args->fname.disk_name;
6429 	struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
6430 	struct btrfs_root *root;
6431 	struct btrfs_inode_item *inode_item;
6432 	struct btrfs_key *location;
6433 	struct btrfs_path *path;
6434 	u64 objectid;
6435 	struct btrfs_inode_ref *ref;
6436 	struct btrfs_key key[2];
6437 	u32 sizes[2];
6438 	struct btrfs_item_batch batch;
6439 	unsigned long ptr;
6440 	int ret;
6441 
6442 	path = btrfs_alloc_path();
6443 	if (!path)
6444 		return -ENOMEM;
6445 
6446 	if (!args->subvol)
6447 		BTRFS_I(inode)->root = btrfs_grab_root(BTRFS_I(dir)->root);
6448 	root = BTRFS_I(inode)->root;
6449 
6450 	ret = btrfs_get_free_objectid(root, &objectid);
6451 	if (ret)
6452 		goto out;
6453 	inode->i_ino = objectid;
6454 
6455 	if (args->orphan) {
6456 		/*
6457 		 * O_TMPFILE, set link count to 0, so that after this point, we
6458 		 * fill in an inode item with the correct link count.
6459 		 */
6460 		set_nlink(inode, 0);
6461 	} else {
6462 		trace_btrfs_inode_request(dir);
6463 
6464 		ret = btrfs_set_inode_index(BTRFS_I(dir), &BTRFS_I(inode)->dir_index);
6465 		if (ret)
6466 			goto out;
6467 	}
6468 	/* index_cnt is ignored for everything but a dir. */
6469 	BTRFS_I(inode)->index_cnt = BTRFS_DIR_START_INDEX;
6470 	BTRFS_I(inode)->generation = trans->transid;
6471 	inode->i_generation = BTRFS_I(inode)->generation;
6472 
6473 	/*
6474 	 * Subvolumes don't inherit flags from their parent directory.
6475 	 * Originally this was probably by accident, but we probably can't
6476 	 * change it now without compatibility issues.
6477 	 */
6478 	if (!args->subvol)
6479 		btrfs_inherit_iflags(inode, dir);
6480 
6481 	if (S_ISREG(inode->i_mode)) {
6482 		if (btrfs_test_opt(fs_info, NODATASUM))
6483 			BTRFS_I(inode)->flags |= BTRFS_INODE_NODATASUM;
6484 		if (btrfs_test_opt(fs_info, NODATACOW))
6485 			BTRFS_I(inode)->flags |= BTRFS_INODE_NODATACOW |
6486 				BTRFS_INODE_NODATASUM;
6487 	}
6488 
6489 	location = &BTRFS_I(inode)->location;
6490 	location->objectid = objectid;
6491 	location->offset = 0;
6492 	location->type = BTRFS_INODE_ITEM_KEY;
6493 
6494 	ret = btrfs_insert_inode_locked(inode);
6495 	if (ret < 0) {
6496 		if (!args->orphan)
6497 			BTRFS_I(dir)->index_cnt--;
6498 		goto out;
6499 	}
6500 
6501 	/*
6502 	 * We could have gotten an inode number from somebody who was fsynced
6503 	 * and then removed in this same transaction, so let's just set full
6504 	 * sync since it will be a full sync anyway and this will blow away the
6505 	 * old info in the log.
6506 	 */
6507 	btrfs_set_inode_full_sync(BTRFS_I(inode));
6508 
6509 	key[0].objectid = objectid;
6510 	key[0].type = BTRFS_INODE_ITEM_KEY;
6511 	key[0].offset = 0;
6512 
6513 	sizes[0] = sizeof(struct btrfs_inode_item);
6514 
6515 	if (!args->orphan) {
6516 		/*
6517 		 * Start new inodes with an inode_ref. This is slightly more
6518 		 * efficient for small numbers of hard links since they will
6519 		 * be packed into one item. Extended refs will kick in if we
6520 		 * add more hard links than can fit in the ref item.
6521 		 */
6522 		key[1].objectid = objectid;
6523 		key[1].type = BTRFS_INODE_REF_KEY;
6524 		if (args->subvol) {
6525 			key[1].offset = objectid;
6526 			sizes[1] = 2 + sizeof(*ref);
6527 		} else {
6528 			key[1].offset = btrfs_ino(BTRFS_I(dir));
6529 			sizes[1] = name->len + sizeof(*ref);
6530 		}
6531 	}
6532 
6533 	batch.keys = &key[0];
6534 	batch.data_sizes = &sizes[0];
6535 	batch.total_data_size = sizes[0] + (args->orphan ? 0 : sizes[1]);
6536 	batch.nr = args->orphan ? 1 : 2;
6537 	ret = btrfs_insert_empty_items(trans, root, path, &batch);
6538 	if (ret != 0) {
6539 		btrfs_abort_transaction(trans, ret);
6540 		goto discard;
6541 	}
6542 
6543 	inode->i_mtime = current_time(inode);
6544 	inode->i_atime = inode->i_mtime;
6545 	inode->i_ctime = inode->i_mtime;
6546 	BTRFS_I(inode)->i_otime = inode->i_mtime;
6547 
6548 	/*
6549 	 * We're going to fill the inode item now, so at this point the inode
6550 	 * must be fully initialized.
6551 	 */
6552 
6553 	inode_item = btrfs_item_ptr(path->nodes[0], path->slots[0],
6554 				  struct btrfs_inode_item);
6555 	memzero_extent_buffer(path->nodes[0], (unsigned long)inode_item,
6556 			     sizeof(*inode_item));
6557 	fill_inode_item(trans, path->nodes[0], inode_item, inode);
6558 
6559 	if (!args->orphan) {
6560 		ref = btrfs_item_ptr(path->nodes[0], path->slots[0] + 1,
6561 				     struct btrfs_inode_ref);
6562 		ptr = (unsigned long)(ref + 1);
6563 		if (args->subvol) {
6564 			btrfs_set_inode_ref_name_len(path->nodes[0], ref, 2);
6565 			btrfs_set_inode_ref_index(path->nodes[0], ref, 0);
6566 			write_extent_buffer(path->nodes[0], "..", ptr, 2);
6567 		} else {
6568 			btrfs_set_inode_ref_name_len(path->nodes[0], ref,
6569 						     name->len);
6570 			btrfs_set_inode_ref_index(path->nodes[0], ref,
6571 						  BTRFS_I(inode)->dir_index);
6572 			write_extent_buffer(path->nodes[0], name->name, ptr,
6573 					    name->len);
6574 		}
6575 	}
6576 
6577 	btrfs_mark_buffer_dirty(path->nodes[0]);
6578 	/*
6579 	 * We don't need the path anymore, plus inheriting properties, adding
6580 	 * ACLs, security xattrs, orphan item or adding the link, will result in
6581 	 * allocating yet another path. So just free our path.
6582 	 */
6583 	btrfs_free_path(path);
6584 	path = NULL;
6585 
6586 	if (args->subvol) {
6587 		struct inode *parent;
6588 
6589 		/*
6590 		 * Subvolumes inherit properties from their parent subvolume,
6591 		 * not the directory they were created in.
6592 		 */
6593 		parent = btrfs_iget(fs_info->sb, BTRFS_FIRST_FREE_OBJECTID,
6594 				    BTRFS_I(dir)->root);
6595 		if (IS_ERR(parent)) {
6596 			ret = PTR_ERR(parent);
6597 		} else {
6598 			ret = btrfs_inode_inherit_props(trans, inode, parent);
6599 			iput(parent);
6600 		}
6601 	} else {
6602 		ret = btrfs_inode_inherit_props(trans, inode, dir);
6603 	}
6604 	if (ret) {
6605 		btrfs_err(fs_info,
6606 			  "error inheriting props for ino %llu (root %llu): %d",
6607 			  btrfs_ino(BTRFS_I(inode)), root->root_key.objectid,
6608 			  ret);
6609 	}
6610 
6611 	/*
6612 	 * Subvolumes don't inherit ACLs or get passed to the LSM. This is
6613 	 * probably a bug.
6614 	 */
6615 	if (!args->subvol) {
6616 		ret = btrfs_init_inode_security(trans, args);
6617 		if (ret) {
6618 			btrfs_abort_transaction(trans, ret);
6619 			goto discard;
6620 		}
6621 	}
6622 
6623 	inode_tree_add(inode);
6624 
6625 	trace_btrfs_inode_new(inode);
6626 	btrfs_set_inode_last_trans(trans, BTRFS_I(inode));
6627 
6628 	btrfs_update_root_times(trans, root);
6629 
6630 	if (args->orphan) {
6631 		ret = btrfs_orphan_add(trans, BTRFS_I(inode));
6632 	} else {
6633 		ret = btrfs_add_link(trans, BTRFS_I(dir), BTRFS_I(inode), name,
6634 				     0, BTRFS_I(inode)->dir_index);
6635 	}
6636 	if (ret) {
6637 		btrfs_abort_transaction(trans, ret);
6638 		goto discard;
6639 	}
6640 
6641 	return 0;
6642 
6643 discard:
6644 	/*
6645 	 * discard_new_inode() calls iput(), but the caller owns the reference
6646 	 * to the inode.
6647 	 */
6648 	ihold(inode);
6649 	discard_new_inode(inode);
6650 out:
6651 	btrfs_free_path(path);
6652 	return ret;
6653 }
6654 
6655 /*
6656  * utility function to add 'inode' into 'parent_inode' with
6657  * a give name and a given sequence number.
6658  * if 'add_backref' is true, also insert a backref from the
6659  * inode to the parent directory.
6660  */
btrfs_add_link(struct btrfs_trans_handle * trans,struct btrfs_inode * parent_inode,struct btrfs_inode * inode,const struct fscrypt_str * name,int add_backref,u64 index)6661 int btrfs_add_link(struct btrfs_trans_handle *trans,
6662 		   struct btrfs_inode *parent_inode, struct btrfs_inode *inode,
6663 		   const struct fscrypt_str *name, int add_backref, u64 index)
6664 {
6665 	int ret = 0;
6666 	struct btrfs_key key;
6667 	struct btrfs_root *root = parent_inode->root;
6668 	u64 ino = btrfs_ino(inode);
6669 	u64 parent_ino = btrfs_ino(parent_inode);
6670 
6671 	if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
6672 		memcpy(&key, &inode->root->root_key, sizeof(key));
6673 	} else {
6674 		key.objectid = ino;
6675 		key.type = BTRFS_INODE_ITEM_KEY;
6676 		key.offset = 0;
6677 	}
6678 
6679 	if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
6680 		ret = btrfs_add_root_ref(trans, key.objectid,
6681 					 root->root_key.objectid, parent_ino,
6682 					 index, name);
6683 	} else if (add_backref) {
6684 		ret = btrfs_insert_inode_ref(trans, root, name,
6685 					     ino, parent_ino, index);
6686 	}
6687 
6688 	/* Nothing to clean up yet */
6689 	if (ret)
6690 		return ret;
6691 
6692 	ret = btrfs_insert_dir_item(trans, name, parent_inode, &key,
6693 				    btrfs_inode_type(&inode->vfs_inode), index);
6694 	if (ret == -EEXIST || ret == -EOVERFLOW)
6695 		goto fail_dir_item;
6696 	else if (ret) {
6697 		btrfs_abort_transaction(trans, ret);
6698 		return ret;
6699 	}
6700 
6701 	btrfs_i_size_write(parent_inode, parent_inode->vfs_inode.i_size +
6702 			   name->len * 2);
6703 	inode_inc_iversion(&parent_inode->vfs_inode);
6704 	/*
6705 	 * If we are replaying a log tree, we do not want to update the mtime
6706 	 * and ctime of the parent directory with the current time, since the
6707 	 * log replay procedure is responsible for setting them to their correct
6708 	 * values (the ones it had when the fsync was done).
6709 	 */
6710 	if (!test_bit(BTRFS_FS_LOG_RECOVERING, &root->fs_info->flags)) {
6711 		struct timespec64 now = current_time(&parent_inode->vfs_inode);
6712 
6713 		parent_inode->vfs_inode.i_mtime = now;
6714 		parent_inode->vfs_inode.i_ctime = now;
6715 	}
6716 	ret = btrfs_update_inode(trans, root, parent_inode);
6717 	if (ret)
6718 		btrfs_abort_transaction(trans, ret);
6719 	return ret;
6720 
6721 fail_dir_item:
6722 	if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
6723 		u64 local_index;
6724 		int err;
6725 		err = btrfs_del_root_ref(trans, key.objectid,
6726 					 root->root_key.objectid, parent_ino,
6727 					 &local_index, name);
6728 		if (err)
6729 			btrfs_abort_transaction(trans, err);
6730 	} else if (add_backref) {
6731 		u64 local_index;
6732 		int err;
6733 
6734 		err = btrfs_del_inode_ref(trans, root, name, ino, parent_ino,
6735 					  &local_index);
6736 		if (err)
6737 			btrfs_abort_transaction(trans, err);
6738 	}
6739 
6740 	/* Return the original error code */
6741 	return ret;
6742 }
6743 
btrfs_create_common(struct inode * dir,struct dentry * dentry,struct inode * inode)6744 static int btrfs_create_common(struct inode *dir, struct dentry *dentry,
6745 			       struct inode *inode)
6746 {
6747 	struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
6748 	struct btrfs_root *root = BTRFS_I(dir)->root;
6749 	struct btrfs_new_inode_args new_inode_args = {
6750 		.dir = dir,
6751 		.dentry = dentry,
6752 		.inode = inode,
6753 	};
6754 	unsigned int trans_num_items;
6755 	struct btrfs_trans_handle *trans;
6756 	int err;
6757 
6758 	err = btrfs_new_inode_prepare(&new_inode_args, &trans_num_items);
6759 	if (err)
6760 		goto out_inode;
6761 
6762 	trans = btrfs_start_transaction(root, trans_num_items);
6763 	if (IS_ERR(trans)) {
6764 		err = PTR_ERR(trans);
6765 		goto out_new_inode_args;
6766 	}
6767 
6768 	err = btrfs_create_new_inode(trans, &new_inode_args);
6769 	if (!err)
6770 		d_instantiate_new(dentry, inode);
6771 
6772 	btrfs_end_transaction(trans);
6773 	btrfs_btree_balance_dirty(fs_info);
6774 out_new_inode_args:
6775 	btrfs_new_inode_args_destroy(&new_inode_args);
6776 out_inode:
6777 	if (err)
6778 		iput(inode);
6779 	return err;
6780 }
6781 
btrfs_mknod(struct user_namespace * mnt_userns,struct inode * dir,struct dentry * dentry,umode_t mode,dev_t rdev)6782 static int btrfs_mknod(struct user_namespace *mnt_userns, struct inode *dir,
6783 		       struct dentry *dentry, umode_t mode, dev_t rdev)
6784 {
6785 	struct inode *inode;
6786 
6787 	inode = new_inode(dir->i_sb);
6788 	if (!inode)
6789 		return -ENOMEM;
6790 	inode_init_owner(mnt_userns, inode, dir, mode);
6791 	inode->i_op = &btrfs_special_inode_operations;
6792 	init_special_inode(inode, inode->i_mode, rdev);
6793 	return btrfs_create_common(dir, dentry, inode);
6794 }
6795 
btrfs_create(struct user_namespace * mnt_userns,struct inode * dir,struct dentry * dentry,umode_t mode,bool excl)6796 static int btrfs_create(struct user_namespace *mnt_userns, struct inode *dir,
6797 			struct dentry *dentry, umode_t mode, bool excl)
6798 {
6799 	struct inode *inode;
6800 
6801 	inode = new_inode(dir->i_sb);
6802 	if (!inode)
6803 		return -ENOMEM;
6804 	inode_init_owner(mnt_userns, inode, dir, mode);
6805 	inode->i_fop = &btrfs_file_operations;
6806 	inode->i_op = &btrfs_file_inode_operations;
6807 	inode->i_mapping->a_ops = &btrfs_aops;
6808 	return btrfs_create_common(dir, dentry, inode);
6809 }
6810 
btrfs_link(struct dentry * old_dentry,struct inode * dir,struct dentry * dentry)6811 static int btrfs_link(struct dentry *old_dentry, struct inode *dir,
6812 		      struct dentry *dentry)
6813 {
6814 	struct btrfs_trans_handle *trans = NULL;
6815 	struct btrfs_root *root = BTRFS_I(dir)->root;
6816 	struct inode *inode = d_inode(old_dentry);
6817 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
6818 	struct fscrypt_name fname;
6819 	u64 index;
6820 	int err;
6821 	int drop_inode = 0;
6822 
6823 	/* do not allow sys_link's with other subvols of the same device */
6824 	if (root->root_key.objectid != BTRFS_I(inode)->root->root_key.objectid)
6825 		return -EXDEV;
6826 
6827 	if (inode->i_nlink >= BTRFS_LINK_MAX)
6828 		return -EMLINK;
6829 
6830 	err = fscrypt_setup_filename(dir, &dentry->d_name, 0, &fname);
6831 	if (err)
6832 		goto fail;
6833 
6834 	err = btrfs_set_inode_index(BTRFS_I(dir), &index);
6835 	if (err)
6836 		goto fail;
6837 
6838 	/*
6839 	 * 2 items for inode and inode ref
6840 	 * 2 items for dir items
6841 	 * 1 item for parent inode
6842 	 * 1 item for orphan item deletion if O_TMPFILE
6843 	 */
6844 	trans = btrfs_start_transaction(root, inode->i_nlink ? 5 : 6);
6845 	if (IS_ERR(trans)) {
6846 		err = PTR_ERR(trans);
6847 		trans = NULL;
6848 		goto fail;
6849 	}
6850 
6851 	/* There are several dir indexes for this inode, clear the cache. */
6852 	BTRFS_I(inode)->dir_index = 0ULL;
6853 	inc_nlink(inode);
6854 	inode_inc_iversion(inode);
6855 	inode->i_ctime = current_time(inode);
6856 	ihold(inode);
6857 	set_bit(BTRFS_INODE_COPY_EVERYTHING, &BTRFS_I(inode)->runtime_flags);
6858 
6859 	err = btrfs_add_link(trans, BTRFS_I(dir), BTRFS_I(inode),
6860 			     &fname.disk_name, 1, index);
6861 
6862 	if (err) {
6863 		drop_inode = 1;
6864 	} else {
6865 		struct dentry *parent = dentry->d_parent;
6866 
6867 		err = btrfs_update_inode(trans, root, BTRFS_I(inode));
6868 		if (err)
6869 			goto fail;
6870 		if (inode->i_nlink == 1) {
6871 			/*
6872 			 * If new hard link count is 1, it's a file created
6873 			 * with open(2) O_TMPFILE flag.
6874 			 */
6875 			err = btrfs_orphan_del(trans, BTRFS_I(inode));
6876 			if (err)
6877 				goto fail;
6878 		}
6879 		d_instantiate(dentry, inode);
6880 		btrfs_log_new_name(trans, old_dentry, NULL, 0, parent);
6881 	}
6882 
6883 fail:
6884 	fscrypt_free_filename(&fname);
6885 	if (trans)
6886 		btrfs_end_transaction(trans);
6887 	if (drop_inode) {
6888 		inode_dec_link_count(inode);
6889 		iput(inode);
6890 	}
6891 	btrfs_btree_balance_dirty(fs_info);
6892 	return err;
6893 }
6894 
btrfs_mkdir(struct user_namespace * mnt_userns,struct inode * dir,struct dentry * dentry,umode_t mode)6895 static int btrfs_mkdir(struct user_namespace *mnt_userns, struct inode *dir,
6896 		       struct dentry *dentry, umode_t mode)
6897 {
6898 	struct inode *inode;
6899 
6900 	inode = new_inode(dir->i_sb);
6901 	if (!inode)
6902 		return -ENOMEM;
6903 	inode_init_owner(mnt_userns, inode, dir, S_IFDIR | mode);
6904 	inode->i_op = &btrfs_dir_inode_operations;
6905 	inode->i_fop = &btrfs_dir_file_operations;
6906 	return btrfs_create_common(dir, dentry, inode);
6907 }
6908 
uncompress_inline(struct btrfs_path * path,struct page * page,size_t pg_offset,u64 extent_offset,struct btrfs_file_extent_item * item)6909 static noinline int uncompress_inline(struct btrfs_path *path,
6910 				      struct page *page,
6911 				      size_t pg_offset, u64 extent_offset,
6912 				      struct btrfs_file_extent_item *item)
6913 {
6914 	int ret;
6915 	struct extent_buffer *leaf = path->nodes[0];
6916 	char *tmp;
6917 	size_t max_size;
6918 	unsigned long inline_size;
6919 	unsigned long ptr;
6920 	int compress_type;
6921 
6922 	WARN_ON(pg_offset != 0);
6923 	compress_type = btrfs_file_extent_compression(leaf, item);
6924 	max_size = btrfs_file_extent_ram_bytes(leaf, item);
6925 	inline_size = btrfs_file_extent_inline_item_len(leaf, path->slots[0]);
6926 	tmp = kmalloc(inline_size, GFP_NOFS);
6927 	if (!tmp)
6928 		return -ENOMEM;
6929 	ptr = btrfs_file_extent_inline_start(item);
6930 
6931 	read_extent_buffer(leaf, tmp, ptr, inline_size);
6932 
6933 	max_size = min_t(unsigned long, PAGE_SIZE, max_size);
6934 	ret = btrfs_decompress(compress_type, tmp, page,
6935 			       extent_offset, inline_size, max_size);
6936 
6937 	/*
6938 	 * decompression code contains a memset to fill in any space between the end
6939 	 * of the uncompressed data and the end of max_size in case the decompressed
6940 	 * data ends up shorter than ram_bytes.  That doesn't cover the hole between
6941 	 * the end of an inline extent and the beginning of the next block, so we
6942 	 * cover that region here.
6943 	 */
6944 
6945 	if (max_size + pg_offset < PAGE_SIZE)
6946 		memzero_page(page,  pg_offset + max_size,
6947 			     PAGE_SIZE - max_size - pg_offset);
6948 	kfree(tmp);
6949 	return ret;
6950 }
6951 
6952 /**
6953  * btrfs_get_extent - Lookup the first extent overlapping a range in a file.
6954  * @inode:	file to search in
6955  * @page:	page to read extent data into if the extent is inline
6956  * @pg_offset:	offset into @page to copy to
6957  * @start:	file offset
6958  * @len:	length of range starting at @start
6959  *
6960  * This returns the first &struct extent_map which overlaps with the given
6961  * range, reading it from the B-tree and caching it if necessary. Note that
6962  * there may be more extents which overlap the given range after the returned
6963  * extent_map.
6964  *
6965  * If @page is not NULL and the extent is inline, this also reads the extent
6966  * data directly into the page and marks the extent up to date in the io_tree.
6967  *
6968  * Return: ERR_PTR on error, non-NULL extent_map on success.
6969  */
btrfs_get_extent(struct btrfs_inode * inode,struct page * page,size_t pg_offset,u64 start,u64 len)6970 struct extent_map *btrfs_get_extent(struct btrfs_inode *inode,
6971 				    struct page *page, size_t pg_offset,
6972 				    u64 start, u64 len)
6973 {
6974 	struct btrfs_fs_info *fs_info = inode->root->fs_info;
6975 	int ret = 0;
6976 	u64 extent_start = 0;
6977 	u64 extent_end = 0;
6978 	u64 objectid = btrfs_ino(inode);
6979 	int extent_type = -1;
6980 	struct btrfs_path *path = NULL;
6981 	struct btrfs_root *root = inode->root;
6982 	struct btrfs_file_extent_item *item;
6983 	struct extent_buffer *leaf;
6984 	struct btrfs_key found_key;
6985 	struct extent_map *em = NULL;
6986 	struct extent_map_tree *em_tree = &inode->extent_tree;
6987 
6988 	read_lock(&em_tree->lock);
6989 	em = lookup_extent_mapping(em_tree, start, len);
6990 	read_unlock(&em_tree->lock);
6991 
6992 	if (em) {
6993 		if (em->start > start || em->start + em->len <= start)
6994 			free_extent_map(em);
6995 		else if (em->block_start == EXTENT_MAP_INLINE && page)
6996 			free_extent_map(em);
6997 		else
6998 			goto out;
6999 	}
7000 	em = alloc_extent_map();
7001 	if (!em) {
7002 		ret = -ENOMEM;
7003 		goto out;
7004 	}
7005 	em->start = EXTENT_MAP_HOLE;
7006 	em->orig_start = EXTENT_MAP_HOLE;
7007 	em->len = (u64)-1;
7008 	em->block_len = (u64)-1;
7009 
7010 	path = btrfs_alloc_path();
7011 	if (!path) {
7012 		ret = -ENOMEM;
7013 		goto out;
7014 	}
7015 
7016 	/* Chances are we'll be called again, so go ahead and do readahead */
7017 	path->reada = READA_FORWARD;
7018 
7019 	/*
7020 	 * The same explanation in load_free_space_cache applies here as well,
7021 	 * we only read when we're loading the free space cache, and at that
7022 	 * point the commit_root has everything we need.
7023 	 */
7024 	if (btrfs_is_free_space_inode(inode)) {
7025 		path->search_commit_root = 1;
7026 		path->skip_locking = 1;
7027 	}
7028 
7029 	ret = btrfs_lookup_file_extent(NULL, root, path, objectid, start, 0);
7030 	if (ret < 0) {
7031 		goto out;
7032 	} else if (ret > 0) {
7033 		if (path->slots[0] == 0)
7034 			goto not_found;
7035 		path->slots[0]--;
7036 		ret = 0;
7037 	}
7038 
7039 	leaf = path->nodes[0];
7040 	item = btrfs_item_ptr(leaf, path->slots[0],
7041 			      struct btrfs_file_extent_item);
7042 	btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
7043 	if (found_key.objectid != objectid ||
7044 	    found_key.type != BTRFS_EXTENT_DATA_KEY) {
7045 		/*
7046 		 * If we backup past the first extent we want to move forward
7047 		 * and see if there is an extent in front of us, otherwise we'll
7048 		 * say there is a hole for our whole search range which can
7049 		 * cause problems.
7050 		 */
7051 		extent_end = start;
7052 		goto next;
7053 	}
7054 
7055 	extent_type = btrfs_file_extent_type(leaf, item);
7056 	extent_start = found_key.offset;
7057 	extent_end = btrfs_file_extent_end(path);
7058 	if (extent_type == BTRFS_FILE_EXTENT_REG ||
7059 	    extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
7060 		/* Only regular file could have regular/prealloc extent */
7061 		if (!S_ISREG(inode->vfs_inode.i_mode)) {
7062 			ret = -EUCLEAN;
7063 			btrfs_crit(fs_info,
7064 		"regular/prealloc extent found for non-regular inode %llu",
7065 				   btrfs_ino(inode));
7066 			goto out;
7067 		}
7068 		trace_btrfs_get_extent_show_fi_regular(inode, leaf, item,
7069 						       extent_start);
7070 	} else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
7071 		trace_btrfs_get_extent_show_fi_inline(inode, leaf, item,
7072 						      path->slots[0],
7073 						      extent_start);
7074 	}
7075 next:
7076 	if (start >= extent_end) {
7077 		path->slots[0]++;
7078 		if (path->slots[0] >= btrfs_header_nritems(leaf)) {
7079 			ret = btrfs_next_leaf(root, path);
7080 			if (ret < 0)
7081 				goto out;
7082 			else if (ret > 0)
7083 				goto not_found;
7084 
7085 			leaf = path->nodes[0];
7086 		}
7087 		btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
7088 		if (found_key.objectid != objectid ||
7089 		    found_key.type != BTRFS_EXTENT_DATA_KEY)
7090 			goto not_found;
7091 		if (start + len <= found_key.offset)
7092 			goto not_found;
7093 		if (start > found_key.offset)
7094 			goto next;
7095 
7096 		/* New extent overlaps with existing one */
7097 		em->start = start;
7098 		em->orig_start = start;
7099 		em->len = found_key.offset - start;
7100 		em->block_start = EXTENT_MAP_HOLE;
7101 		goto insert;
7102 	}
7103 
7104 	btrfs_extent_item_to_extent_map(inode, path, item, !page, em);
7105 
7106 	if (extent_type == BTRFS_FILE_EXTENT_REG ||
7107 	    extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
7108 		goto insert;
7109 	} else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
7110 		unsigned long ptr;
7111 		char *map;
7112 		size_t size;
7113 		size_t extent_offset;
7114 		size_t copy_size;
7115 
7116 		if (!page)
7117 			goto out;
7118 
7119 		size = btrfs_file_extent_ram_bytes(leaf, item);
7120 		extent_offset = page_offset(page) + pg_offset - extent_start;
7121 		copy_size = min_t(u64, PAGE_SIZE - pg_offset,
7122 				  size - extent_offset);
7123 		em->start = extent_start + extent_offset;
7124 		em->len = ALIGN(copy_size, fs_info->sectorsize);
7125 		em->orig_block_len = em->len;
7126 		em->orig_start = em->start;
7127 		ptr = btrfs_file_extent_inline_start(item) + extent_offset;
7128 
7129 		if (!PageUptodate(page)) {
7130 			if (btrfs_file_extent_compression(leaf, item) !=
7131 			    BTRFS_COMPRESS_NONE) {
7132 				ret = uncompress_inline(path, page, pg_offset,
7133 							extent_offset, item);
7134 				if (ret)
7135 					goto out;
7136 			} else {
7137 				map = kmap_local_page(page);
7138 				read_extent_buffer(leaf, map + pg_offset, ptr,
7139 						   copy_size);
7140 				if (pg_offset + copy_size < PAGE_SIZE) {
7141 					memset(map + pg_offset + copy_size, 0,
7142 					       PAGE_SIZE - pg_offset -
7143 					       copy_size);
7144 				}
7145 				kunmap_local(map);
7146 			}
7147 			flush_dcache_page(page);
7148 		}
7149 		goto insert;
7150 	}
7151 not_found:
7152 	em->start = start;
7153 	em->orig_start = start;
7154 	em->len = len;
7155 	em->block_start = EXTENT_MAP_HOLE;
7156 insert:
7157 	ret = 0;
7158 	btrfs_release_path(path);
7159 	if (em->start > start || extent_map_end(em) <= start) {
7160 		btrfs_err(fs_info,
7161 			  "bad extent! em: [%llu %llu] passed [%llu %llu]",
7162 			  em->start, em->len, start, len);
7163 		ret = -EIO;
7164 		goto out;
7165 	}
7166 
7167 	write_lock(&em_tree->lock);
7168 	ret = btrfs_add_extent_mapping(fs_info, em_tree, &em, start, len);
7169 	write_unlock(&em_tree->lock);
7170 out:
7171 	btrfs_free_path(path);
7172 
7173 	trace_btrfs_get_extent(root, inode, em);
7174 
7175 	if (ret) {
7176 		free_extent_map(em);
7177 		return ERR_PTR(ret);
7178 	}
7179 	return em;
7180 }
7181 
btrfs_create_dio_extent(struct btrfs_inode * inode,const u64 start,const u64 len,const u64 orig_start,const u64 block_start,const u64 block_len,const u64 orig_block_len,const u64 ram_bytes,const int type)7182 static struct extent_map *btrfs_create_dio_extent(struct btrfs_inode *inode,
7183 						  const u64 start,
7184 						  const u64 len,
7185 						  const u64 orig_start,
7186 						  const u64 block_start,
7187 						  const u64 block_len,
7188 						  const u64 orig_block_len,
7189 						  const u64 ram_bytes,
7190 						  const int type)
7191 {
7192 	struct extent_map *em = NULL;
7193 	int ret;
7194 
7195 	if (type != BTRFS_ORDERED_NOCOW) {
7196 		em = create_io_em(inode, start, len, orig_start, block_start,
7197 				  block_len, orig_block_len, ram_bytes,
7198 				  BTRFS_COMPRESS_NONE, /* compress_type */
7199 				  type);
7200 		if (IS_ERR(em))
7201 			goto out;
7202 	}
7203 	ret = btrfs_add_ordered_extent(inode, start, len, len, block_start,
7204 				       block_len, 0,
7205 				       (1 << type) |
7206 				       (1 << BTRFS_ORDERED_DIRECT),
7207 				       BTRFS_COMPRESS_NONE);
7208 	if (ret) {
7209 		if (em) {
7210 			free_extent_map(em);
7211 			btrfs_drop_extent_map_range(inode, start,
7212 						    start + len - 1, false);
7213 		}
7214 		em = ERR_PTR(ret);
7215 	}
7216  out:
7217 
7218 	return em;
7219 }
7220 
btrfs_new_extent_direct(struct btrfs_inode * inode,u64 start,u64 len)7221 static struct extent_map *btrfs_new_extent_direct(struct btrfs_inode *inode,
7222 						  u64 start, u64 len)
7223 {
7224 	struct btrfs_root *root = inode->root;
7225 	struct btrfs_fs_info *fs_info = root->fs_info;
7226 	struct extent_map *em;
7227 	struct btrfs_key ins;
7228 	u64 alloc_hint;
7229 	int ret;
7230 
7231 	alloc_hint = get_extent_allocation_hint(inode, start, len);
7232 again:
7233 	ret = btrfs_reserve_extent(root, len, len, fs_info->sectorsize,
7234 				   0, alloc_hint, &ins, 1, 1);
7235 	if (ret == -EAGAIN) {
7236 		ASSERT(btrfs_is_zoned(fs_info));
7237 		wait_on_bit_io(&inode->root->fs_info->flags, BTRFS_FS_NEED_ZONE_FINISH,
7238 			       TASK_UNINTERRUPTIBLE);
7239 		goto again;
7240 	}
7241 	if (ret)
7242 		return ERR_PTR(ret);
7243 
7244 	em = btrfs_create_dio_extent(inode, start, ins.offset, start,
7245 				     ins.objectid, ins.offset, ins.offset,
7246 				     ins.offset, BTRFS_ORDERED_REGULAR);
7247 	btrfs_dec_block_group_reservations(fs_info, ins.objectid);
7248 	if (IS_ERR(em))
7249 		btrfs_free_reserved_extent(fs_info, ins.objectid, ins.offset,
7250 					   1);
7251 
7252 	return em;
7253 }
7254 
btrfs_extent_readonly(struct btrfs_fs_info * fs_info,u64 bytenr)7255 static bool btrfs_extent_readonly(struct btrfs_fs_info *fs_info, u64 bytenr)
7256 {
7257 	struct btrfs_block_group *block_group;
7258 	bool readonly = false;
7259 
7260 	block_group = btrfs_lookup_block_group(fs_info, bytenr);
7261 	if (!block_group || block_group->ro)
7262 		readonly = true;
7263 	if (block_group)
7264 		btrfs_put_block_group(block_group);
7265 	return readonly;
7266 }
7267 
7268 /*
7269  * Check if we can do nocow write into the range [@offset, @offset + @len)
7270  *
7271  * @offset:	File offset
7272  * @len:	The length to write, will be updated to the nocow writeable
7273  *		range
7274  * @orig_start:	(optional) Return the original file offset of the file extent
7275  * @orig_len:	(optional) Return the original on-disk length of the file extent
7276  * @ram_bytes:	(optional) Return the ram_bytes of the file extent
7277  * @strict:	if true, omit optimizations that might force us into unnecessary
7278  *		cow. e.g., don't trust generation number.
7279  *
7280  * Return:
7281  * >0	and update @len if we can do nocow write
7282  *  0	if we can't do nocow write
7283  * <0	if error happened
7284  *
7285  * NOTE: This only checks the file extents, caller is responsible to wait for
7286  *	 any ordered extents.
7287  */
can_nocow_extent(struct inode * inode,u64 offset,u64 * len,u64 * orig_start,u64 * orig_block_len,u64 * ram_bytes,bool nowait,bool strict)7288 noinline int can_nocow_extent(struct inode *inode, u64 offset, u64 *len,
7289 			      u64 *orig_start, u64 *orig_block_len,
7290 			      u64 *ram_bytes, bool nowait, bool strict)
7291 {
7292 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
7293 	struct can_nocow_file_extent_args nocow_args = { 0 };
7294 	struct btrfs_path *path;
7295 	int ret;
7296 	struct extent_buffer *leaf;
7297 	struct btrfs_root *root = BTRFS_I(inode)->root;
7298 	struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
7299 	struct btrfs_file_extent_item *fi;
7300 	struct btrfs_key key;
7301 	int found_type;
7302 
7303 	path = btrfs_alloc_path();
7304 	if (!path)
7305 		return -ENOMEM;
7306 	path->nowait = nowait;
7307 
7308 	ret = btrfs_lookup_file_extent(NULL, root, path,
7309 			btrfs_ino(BTRFS_I(inode)), offset, 0);
7310 	if (ret < 0)
7311 		goto out;
7312 
7313 	if (ret == 1) {
7314 		if (path->slots[0] == 0) {
7315 			/* can't find the item, must cow */
7316 			ret = 0;
7317 			goto out;
7318 		}
7319 		path->slots[0]--;
7320 	}
7321 	ret = 0;
7322 	leaf = path->nodes[0];
7323 	btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
7324 	if (key.objectid != btrfs_ino(BTRFS_I(inode)) ||
7325 	    key.type != BTRFS_EXTENT_DATA_KEY) {
7326 		/* not our file or wrong item type, must cow */
7327 		goto out;
7328 	}
7329 
7330 	if (key.offset > offset) {
7331 		/* Wrong offset, must cow */
7332 		goto out;
7333 	}
7334 
7335 	if (btrfs_file_extent_end(path) <= offset)
7336 		goto out;
7337 
7338 	fi = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_file_extent_item);
7339 	found_type = btrfs_file_extent_type(leaf, fi);
7340 	if (ram_bytes)
7341 		*ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi);
7342 
7343 	nocow_args.start = offset;
7344 	nocow_args.end = offset + *len - 1;
7345 	nocow_args.strict = strict;
7346 	nocow_args.free_path = true;
7347 
7348 	ret = can_nocow_file_extent(path, &key, BTRFS_I(inode), &nocow_args);
7349 	/* can_nocow_file_extent() has freed the path. */
7350 	path = NULL;
7351 
7352 	if (ret != 1) {
7353 		/* Treat errors as not being able to NOCOW. */
7354 		ret = 0;
7355 		goto out;
7356 	}
7357 
7358 	ret = 0;
7359 	if (btrfs_extent_readonly(fs_info, nocow_args.disk_bytenr))
7360 		goto out;
7361 
7362 	if (!(BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW) &&
7363 	    found_type == BTRFS_FILE_EXTENT_PREALLOC) {
7364 		u64 range_end;
7365 
7366 		range_end = round_up(offset + nocow_args.num_bytes,
7367 				     root->fs_info->sectorsize) - 1;
7368 		ret = test_range_bit(io_tree, offset, range_end,
7369 				     EXTENT_DELALLOC, 0, NULL);
7370 		if (ret) {
7371 			ret = -EAGAIN;
7372 			goto out;
7373 		}
7374 	}
7375 
7376 	if (orig_start)
7377 		*orig_start = key.offset - nocow_args.extent_offset;
7378 	if (orig_block_len)
7379 		*orig_block_len = nocow_args.disk_num_bytes;
7380 
7381 	*len = nocow_args.num_bytes;
7382 	ret = 1;
7383 out:
7384 	btrfs_free_path(path);
7385 	return ret;
7386 }
7387 
lock_extent_direct(struct inode * inode,u64 lockstart,u64 lockend,struct extent_state ** cached_state,unsigned int iomap_flags)7388 static int lock_extent_direct(struct inode *inode, u64 lockstart, u64 lockend,
7389 			      struct extent_state **cached_state,
7390 			      unsigned int iomap_flags)
7391 {
7392 	const bool writing = (iomap_flags & IOMAP_WRITE);
7393 	const bool nowait = (iomap_flags & IOMAP_NOWAIT);
7394 	struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
7395 	struct btrfs_ordered_extent *ordered;
7396 	int ret = 0;
7397 
7398 	while (1) {
7399 		if (nowait) {
7400 			if (!try_lock_extent(io_tree, lockstart, lockend))
7401 				return -EAGAIN;
7402 		} else {
7403 			lock_extent(io_tree, lockstart, lockend, cached_state);
7404 		}
7405 		/*
7406 		 * We're concerned with the entire range that we're going to be
7407 		 * doing DIO to, so we need to make sure there's no ordered
7408 		 * extents in this range.
7409 		 */
7410 		ordered = btrfs_lookup_ordered_range(BTRFS_I(inode), lockstart,
7411 						     lockend - lockstart + 1);
7412 
7413 		/*
7414 		 * We need to make sure there are no buffered pages in this
7415 		 * range either, we could have raced between the invalidate in
7416 		 * generic_file_direct_write and locking the extent.  The
7417 		 * invalidate needs to happen so that reads after a write do not
7418 		 * get stale data.
7419 		 */
7420 		if (!ordered &&
7421 		    (!writing || !filemap_range_has_page(inode->i_mapping,
7422 							 lockstart, lockend)))
7423 			break;
7424 
7425 		unlock_extent(io_tree, lockstart, lockend, cached_state);
7426 
7427 		if (ordered) {
7428 			if (nowait) {
7429 				btrfs_put_ordered_extent(ordered);
7430 				ret = -EAGAIN;
7431 				break;
7432 			}
7433 			/*
7434 			 * If we are doing a DIO read and the ordered extent we
7435 			 * found is for a buffered write, we can not wait for it
7436 			 * to complete and retry, because if we do so we can
7437 			 * deadlock with concurrent buffered writes on page
7438 			 * locks. This happens only if our DIO read covers more
7439 			 * than one extent map, if at this point has already
7440 			 * created an ordered extent for a previous extent map
7441 			 * and locked its range in the inode's io tree, and a
7442 			 * concurrent write against that previous extent map's
7443 			 * range and this range started (we unlock the ranges
7444 			 * in the io tree only when the bios complete and
7445 			 * buffered writes always lock pages before attempting
7446 			 * to lock range in the io tree).
7447 			 */
7448 			if (writing ||
7449 			    test_bit(BTRFS_ORDERED_DIRECT, &ordered->flags))
7450 				btrfs_start_ordered_extent(ordered, 1);
7451 			else
7452 				ret = nowait ? -EAGAIN : -ENOTBLK;
7453 			btrfs_put_ordered_extent(ordered);
7454 		} else {
7455 			/*
7456 			 * We could trigger writeback for this range (and wait
7457 			 * for it to complete) and then invalidate the pages for
7458 			 * this range (through invalidate_inode_pages2_range()),
7459 			 * but that can lead us to a deadlock with a concurrent
7460 			 * call to readahead (a buffered read or a defrag call
7461 			 * triggered a readahead) on a page lock due to an
7462 			 * ordered dio extent we created before but did not have
7463 			 * yet a corresponding bio submitted (whence it can not
7464 			 * complete), which makes readahead wait for that
7465 			 * ordered extent to complete while holding a lock on
7466 			 * that page.
7467 			 */
7468 			ret = nowait ? -EAGAIN : -ENOTBLK;
7469 		}
7470 
7471 		if (ret)
7472 			break;
7473 
7474 		cond_resched();
7475 	}
7476 
7477 	return ret;
7478 }
7479 
7480 /* The callers of this must take lock_extent() */
create_io_em(struct btrfs_inode * inode,u64 start,u64 len,u64 orig_start,u64 block_start,u64 block_len,u64 orig_block_len,u64 ram_bytes,int compress_type,int type)7481 static struct extent_map *create_io_em(struct btrfs_inode *inode, u64 start,
7482 				       u64 len, u64 orig_start, u64 block_start,
7483 				       u64 block_len, u64 orig_block_len,
7484 				       u64 ram_bytes, int compress_type,
7485 				       int type)
7486 {
7487 	struct extent_map *em;
7488 	int ret;
7489 
7490 	ASSERT(type == BTRFS_ORDERED_PREALLOC ||
7491 	       type == BTRFS_ORDERED_COMPRESSED ||
7492 	       type == BTRFS_ORDERED_NOCOW ||
7493 	       type == BTRFS_ORDERED_REGULAR);
7494 
7495 	em = alloc_extent_map();
7496 	if (!em)
7497 		return ERR_PTR(-ENOMEM);
7498 
7499 	em->start = start;
7500 	em->orig_start = orig_start;
7501 	em->len = len;
7502 	em->block_len = block_len;
7503 	em->block_start = block_start;
7504 	em->orig_block_len = orig_block_len;
7505 	em->ram_bytes = ram_bytes;
7506 	em->generation = -1;
7507 	set_bit(EXTENT_FLAG_PINNED, &em->flags);
7508 	if (type == BTRFS_ORDERED_PREALLOC) {
7509 		set_bit(EXTENT_FLAG_FILLING, &em->flags);
7510 	} else if (type == BTRFS_ORDERED_COMPRESSED) {
7511 		set_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
7512 		em->compress_type = compress_type;
7513 	}
7514 
7515 	ret = btrfs_replace_extent_map_range(inode, em, true);
7516 	if (ret) {
7517 		free_extent_map(em);
7518 		return ERR_PTR(ret);
7519 	}
7520 
7521 	/* em got 2 refs now, callers needs to do free_extent_map once. */
7522 	return em;
7523 }
7524 
7525 
btrfs_get_blocks_direct_write(struct extent_map ** map,struct inode * inode,struct btrfs_dio_data * dio_data,u64 start,u64 * lenp,unsigned int iomap_flags)7526 static int btrfs_get_blocks_direct_write(struct extent_map **map,
7527 					 struct inode *inode,
7528 					 struct btrfs_dio_data *dio_data,
7529 					 u64 start, u64 *lenp,
7530 					 unsigned int iomap_flags)
7531 {
7532 	const bool nowait = (iomap_flags & IOMAP_NOWAIT);
7533 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
7534 	struct extent_map *em = *map;
7535 	int type;
7536 	u64 block_start, orig_start, orig_block_len, ram_bytes;
7537 	struct btrfs_block_group *bg;
7538 	bool can_nocow = false;
7539 	bool space_reserved = false;
7540 	u64 len = *lenp;
7541 	u64 prev_len;
7542 	int ret = 0;
7543 
7544 	/*
7545 	 * We don't allocate a new extent in the following cases
7546 	 *
7547 	 * 1) The inode is marked as NODATACOW. In this case we'll just use the
7548 	 * existing extent.
7549 	 * 2) The extent is marked as PREALLOC. We're good to go here and can
7550 	 * just use the extent.
7551 	 *
7552 	 */
7553 	if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags) ||
7554 	    ((BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW) &&
7555 	     em->block_start != EXTENT_MAP_HOLE)) {
7556 		if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
7557 			type = BTRFS_ORDERED_PREALLOC;
7558 		else
7559 			type = BTRFS_ORDERED_NOCOW;
7560 		len = min(len, em->len - (start - em->start));
7561 		block_start = em->block_start + (start - em->start);
7562 
7563 		if (can_nocow_extent(inode, start, &len, &orig_start,
7564 				     &orig_block_len, &ram_bytes, false, false) == 1) {
7565 			bg = btrfs_inc_nocow_writers(fs_info, block_start);
7566 			if (bg)
7567 				can_nocow = true;
7568 		}
7569 	}
7570 
7571 	prev_len = len;
7572 	if (can_nocow) {
7573 		struct extent_map *em2;
7574 
7575 		/* We can NOCOW, so only need to reserve metadata space. */
7576 		ret = btrfs_delalloc_reserve_metadata(BTRFS_I(inode), len, len,
7577 						      nowait);
7578 		if (ret < 0) {
7579 			/* Our caller expects us to free the input extent map. */
7580 			free_extent_map(em);
7581 			*map = NULL;
7582 			btrfs_dec_nocow_writers(bg);
7583 			if (nowait && (ret == -ENOSPC || ret == -EDQUOT))
7584 				ret = -EAGAIN;
7585 			goto out;
7586 		}
7587 		space_reserved = true;
7588 
7589 		em2 = btrfs_create_dio_extent(BTRFS_I(inode), start, len,
7590 					      orig_start, block_start,
7591 					      len, orig_block_len,
7592 					      ram_bytes, type);
7593 		btrfs_dec_nocow_writers(bg);
7594 		if (type == BTRFS_ORDERED_PREALLOC) {
7595 			free_extent_map(em);
7596 			*map = em2;
7597 			em = em2;
7598 		}
7599 
7600 		if (IS_ERR(em2)) {
7601 			ret = PTR_ERR(em2);
7602 			goto out;
7603 		}
7604 
7605 		dio_data->nocow_done = true;
7606 	} else {
7607 		/* Our caller expects us to free the input extent map. */
7608 		free_extent_map(em);
7609 		*map = NULL;
7610 
7611 		if (nowait) {
7612 			ret = -EAGAIN;
7613 			goto out;
7614 		}
7615 
7616 		/*
7617 		 * If we could not allocate data space before locking the file
7618 		 * range and we can't do a NOCOW write, then we have to fail.
7619 		 */
7620 		if (!dio_data->data_space_reserved) {
7621 			ret = -ENOSPC;
7622 			goto out;
7623 		}
7624 
7625 		/*
7626 		 * We have to COW and we have already reserved data space before,
7627 		 * so now we reserve only metadata.
7628 		 */
7629 		ret = btrfs_delalloc_reserve_metadata(BTRFS_I(inode), len, len,
7630 						      false);
7631 		if (ret < 0)
7632 			goto out;
7633 		space_reserved = true;
7634 
7635 		em = btrfs_new_extent_direct(BTRFS_I(inode), start, len);
7636 		if (IS_ERR(em)) {
7637 			ret = PTR_ERR(em);
7638 			goto out;
7639 		}
7640 		*map = em;
7641 		len = min(len, em->len - (start - em->start));
7642 		if (len < prev_len)
7643 			btrfs_delalloc_release_metadata(BTRFS_I(inode),
7644 							prev_len - len, true);
7645 	}
7646 
7647 	/*
7648 	 * We have created our ordered extent, so we can now release our reservation
7649 	 * for an outstanding extent.
7650 	 */
7651 	btrfs_delalloc_release_extents(BTRFS_I(inode), prev_len);
7652 
7653 	/*
7654 	 * Need to update the i_size under the extent lock so buffered
7655 	 * readers will get the updated i_size when we unlock.
7656 	 */
7657 	if (start + len > i_size_read(inode))
7658 		i_size_write(inode, start + len);
7659 out:
7660 	if (ret && space_reserved) {
7661 		btrfs_delalloc_release_extents(BTRFS_I(inode), len);
7662 		btrfs_delalloc_release_metadata(BTRFS_I(inode), len, true);
7663 	}
7664 	*lenp = len;
7665 	return ret;
7666 }
7667 
btrfs_dio_iomap_begin(struct inode * inode,loff_t start,loff_t length,unsigned int flags,struct iomap * iomap,struct iomap * srcmap)7668 static int btrfs_dio_iomap_begin(struct inode *inode, loff_t start,
7669 		loff_t length, unsigned int flags, struct iomap *iomap,
7670 		struct iomap *srcmap)
7671 {
7672 	struct iomap_iter *iter = container_of(iomap, struct iomap_iter, iomap);
7673 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
7674 	struct extent_map *em;
7675 	struct extent_state *cached_state = NULL;
7676 	struct btrfs_dio_data *dio_data = iter->private;
7677 	u64 lockstart, lockend;
7678 	const bool write = !!(flags & IOMAP_WRITE);
7679 	int ret = 0;
7680 	u64 len = length;
7681 	const u64 data_alloc_len = length;
7682 	bool unlock_extents = false;
7683 
7684 	/*
7685 	 * We could potentially fault if we have a buffer > PAGE_SIZE, and if
7686 	 * we're NOWAIT we may submit a bio for a partial range and return
7687 	 * EIOCBQUEUED, which would result in an errant short read.
7688 	 *
7689 	 * The best way to handle this would be to allow for partial completions
7690 	 * of iocb's, so we could submit the partial bio, return and fault in
7691 	 * the rest of the pages, and then submit the io for the rest of the
7692 	 * range.  However we don't have that currently, so simply return
7693 	 * -EAGAIN at this point so that the normal path is used.
7694 	 */
7695 	if (!write && (flags & IOMAP_NOWAIT) && length > PAGE_SIZE)
7696 		return -EAGAIN;
7697 
7698 	/*
7699 	 * Cap the size of reads to that usually seen in buffered I/O as we need
7700 	 * to allocate a contiguous array for the checksums.
7701 	 */
7702 	if (!write)
7703 		len = min_t(u64, len, fs_info->sectorsize * BTRFS_MAX_BIO_SECTORS);
7704 
7705 	lockstart = start;
7706 	lockend = start + len - 1;
7707 
7708 	/*
7709 	 * iomap_dio_rw() only does filemap_write_and_wait_range(), which isn't
7710 	 * enough if we've written compressed pages to this area, so we need to
7711 	 * flush the dirty pages again to make absolutely sure that any
7712 	 * outstanding dirty pages are on disk - the first flush only starts
7713 	 * compression on the data, while keeping the pages locked, so by the
7714 	 * time the second flush returns we know bios for the compressed pages
7715 	 * were submitted and finished, and the pages no longer under writeback.
7716 	 *
7717 	 * If we have a NOWAIT request and we have any pages in the range that
7718 	 * are locked, likely due to compression still in progress, we don't want
7719 	 * to block on page locks. We also don't want to block on pages marked as
7720 	 * dirty or under writeback (same as for the non-compression case).
7721 	 * iomap_dio_rw() did the same check, but after that and before we got
7722 	 * here, mmap'ed writes may have happened or buffered reads started
7723 	 * (readpage() and readahead(), which lock pages), as we haven't locked
7724 	 * the file range yet.
7725 	 */
7726 	if (test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
7727 		     &BTRFS_I(inode)->runtime_flags)) {
7728 		if (flags & IOMAP_NOWAIT) {
7729 			if (filemap_range_needs_writeback(inode->i_mapping,
7730 							  lockstart, lockend))
7731 				return -EAGAIN;
7732 		} else {
7733 			ret = filemap_fdatawrite_range(inode->i_mapping, start,
7734 						       start + length - 1);
7735 			if (ret)
7736 				return ret;
7737 		}
7738 	}
7739 
7740 	memset(dio_data, 0, sizeof(*dio_data));
7741 
7742 	/*
7743 	 * We always try to allocate data space and must do it before locking
7744 	 * the file range, to avoid deadlocks with concurrent writes to the same
7745 	 * range if the range has several extents and the writes don't expand the
7746 	 * current i_size (the inode lock is taken in shared mode). If we fail to
7747 	 * allocate data space here we continue and later, after locking the
7748 	 * file range, we fail with ENOSPC only if we figure out we can not do a
7749 	 * NOCOW write.
7750 	 */
7751 	if (write && !(flags & IOMAP_NOWAIT)) {
7752 		ret = btrfs_check_data_free_space(BTRFS_I(inode),
7753 						  &dio_data->data_reserved,
7754 						  start, data_alloc_len, false);
7755 		if (!ret)
7756 			dio_data->data_space_reserved = true;
7757 		else if (ret && !(BTRFS_I(inode)->flags &
7758 				  (BTRFS_INODE_NODATACOW | BTRFS_INODE_PREALLOC)))
7759 			goto err;
7760 	}
7761 
7762 	/*
7763 	 * If this errors out it's because we couldn't invalidate pagecache for
7764 	 * this range and we need to fallback to buffered IO, or we are doing a
7765 	 * NOWAIT read/write and we need to block.
7766 	 */
7767 	ret = lock_extent_direct(inode, lockstart, lockend, &cached_state, flags);
7768 	if (ret < 0)
7769 		goto err;
7770 
7771 	em = btrfs_get_extent(BTRFS_I(inode), NULL, 0, start, len);
7772 	if (IS_ERR(em)) {
7773 		ret = PTR_ERR(em);
7774 		goto unlock_err;
7775 	}
7776 
7777 	/*
7778 	 * Ok for INLINE and COMPRESSED extents we need to fallback on buffered
7779 	 * io.  INLINE is special, and we could probably kludge it in here, but
7780 	 * it's still buffered so for safety lets just fall back to the generic
7781 	 * buffered path.
7782 	 *
7783 	 * For COMPRESSED we _have_ to read the entire extent in so we can
7784 	 * decompress it, so there will be buffering required no matter what we
7785 	 * do, so go ahead and fallback to buffered.
7786 	 *
7787 	 * We return -ENOTBLK because that's what makes DIO go ahead and go back
7788 	 * to buffered IO.  Don't blame me, this is the price we pay for using
7789 	 * the generic code.
7790 	 */
7791 	if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags) ||
7792 	    em->block_start == EXTENT_MAP_INLINE) {
7793 		free_extent_map(em);
7794 		/*
7795 		 * If we are in a NOWAIT context, return -EAGAIN in order to
7796 		 * fallback to buffered IO. This is not only because we can
7797 		 * block with buffered IO (no support for NOWAIT semantics at
7798 		 * the moment) but also to avoid returning short reads to user
7799 		 * space - this happens if we were able to read some data from
7800 		 * previous non-compressed extents and then when we fallback to
7801 		 * buffered IO, at btrfs_file_read_iter() by calling
7802 		 * filemap_read(), we fail to fault in pages for the read buffer,
7803 		 * in which case filemap_read() returns a short read (the number
7804 		 * of bytes previously read is > 0, so it does not return -EFAULT).
7805 		 */
7806 		ret = (flags & IOMAP_NOWAIT) ? -EAGAIN : -ENOTBLK;
7807 		goto unlock_err;
7808 	}
7809 
7810 	len = min(len, em->len - (start - em->start));
7811 
7812 	/*
7813 	 * If we have a NOWAIT request and the range contains multiple extents
7814 	 * (or a mix of extents and holes), then we return -EAGAIN to make the
7815 	 * caller fallback to a context where it can do a blocking (without
7816 	 * NOWAIT) request. This way we avoid doing partial IO and returning
7817 	 * success to the caller, which is not optimal for writes and for reads
7818 	 * it can result in unexpected behaviour for an application.
7819 	 *
7820 	 * When doing a read, because we use IOMAP_DIO_PARTIAL when calling
7821 	 * iomap_dio_rw(), we can end up returning less data then what the caller
7822 	 * asked for, resulting in an unexpected, and incorrect, short read.
7823 	 * That is, the caller asked to read N bytes and we return less than that,
7824 	 * which is wrong unless we are crossing EOF. This happens if we get a
7825 	 * page fault error when trying to fault in pages for the buffer that is
7826 	 * associated to the struct iov_iter passed to iomap_dio_rw(), and we
7827 	 * have previously submitted bios for other extents in the range, in
7828 	 * which case iomap_dio_rw() may return us EIOCBQUEUED if not all of
7829 	 * those bios have completed by the time we get the page fault error,
7830 	 * which we return back to our caller - we should only return EIOCBQUEUED
7831 	 * after we have submitted bios for all the extents in the range.
7832 	 */
7833 	if ((flags & IOMAP_NOWAIT) && len < length) {
7834 		free_extent_map(em);
7835 		ret = -EAGAIN;
7836 		goto unlock_err;
7837 	}
7838 
7839 	if (write) {
7840 		ret = btrfs_get_blocks_direct_write(&em, inode, dio_data,
7841 						    start, &len, flags);
7842 		if (ret < 0)
7843 			goto unlock_err;
7844 		unlock_extents = true;
7845 		/* Recalc len in case the new em is smaller than requested */
7846 		len = min(len, em->len - (start - em->start));
7847 		if (dio_data->data_space_reserved) {
7848 			u64 release_offset;
7849 			u64 release_len = 0;
7850 
7851 			if (dio_data->nocow_done) {
7852 				release_offset = start;
7853 				release_len = data_alloc_len;
7854 			} else if (len < data_alloc_len) {
7855 				release_offset = start + len;
7856 				release_len = data_alloc_len - len;
7857 			}
7858 
7859 			if (release_len > 0)
7860 				btrfs_free_reserved_data_space(BTRFS_I(inode),
7861 							       dio_data->data_reserved,
7862 							       release_offset,
7863 							       release_len);
7864 		}
7865 	} else {
7866 		/*
7867 		 * We need to unlock only the end area that we aren't using.
7868 		 * The rest is going to be unlocked by the endio routine.
7869 		 */
7870 		lockstart = start + len;
7871 		if (lockstart < lockend)
7872 			unlock_extents = true;
7873 	}
7874 
7875 	if (unlock_extents)
7876 		unlock_extent(&BTRFS_I(inode)->io_tree, lockstart, lockend,
7877 			      &cached_state);
7878 	else
7879 		free_extent_state(cached_state);
7880 
7881 	/*
7882 	 * Translate extent map information to iomap.
7883 	 * We trim the extents (and move the addr) even though iomap code does
7884 	 * that, since we have locked only the parts we are performing I/O in.
7885 	 */
7886 	if ((em->block_start == EXTENT_MAP_HOLE) ||
7887 	    (test_bit(EXTENT_FLAG_PREALLOC, &em->flags) && !write)) {
7888 		iomap->addr = IOMAP_NULL_ADDR;
7889 		iomap->type = IOMAP_HOLE;
7890 	} else {
7891 		iomap->addr = em->block_start + (start - em->start);
7892 		iomap->type = IOMAP_MAPPED;
7893 	}
7894 	iomap->offset = start;
7895 	iomap->bdev = fs_info->fs_devices->latest_dev->bdev;
7896 	iomap->length = len;
7897 
7898 	if (write && btrfs_use_zone_append(BTRFS_I(inode), em->block_start))
7899 		iomap->flags |= IOMAP_F_ZONE_APPEND;
7900 
7901 	free_extent_map(em);
7902 
7903 	return 0;
7904 
7905 unlock_err:
7906 	unlock_extent(&BTRFS_I(inode)->io_tree, lockstart, lockend,
7907 		      &cached_state);
7908 err:
7909 	if (dio_data->data_space_reserved) {
7910 		btrfs_free_reserved_data_space(BTRFS_I(inode),
7911 					       dio_data->data_reserved,
7912 					       start, data_alloc_len);
7913 		extent_changeset_free(dio_data->data_reserved);
7914 	}
7915 
7916 	return ret;
7917 }
7918 
btrfs_dio_iomap_end(struct inode * inode,loff_t pos,loff_t length,ssize_t written,unsigned int flags,struct iomap * iomap)7919 static int btrfs_dio_iomap_end(struct inode *inode, loff_t pos, loff_t length,
7920 		ssize_t written, unsigned int flags, struct iomap *iomap)
7921 {
7922 	struct iomap_iter *iter = container_of(iomap, struct iomap_iter, iomap);
7923 	struct btrfs_dio_data *dio_data = iter->private;
7924 	size_t submitted = dio_data->submitted;
7925 	const bool write = !!(flags & IOMAP_WRITE);
7926 	int ret = 0;
7927 
7928 	if (!write && (iomap->type == IOMAP_HOLE)) {
7929 		/* If reading from a hole, unlock and return */
7930 		unlock_extent(&BTRFS_I(inode)->io_tree, pos, pos + length - 1,
7931 			      NULL);
7932 		return 0;
7933 	}
7934 
7935 	if (submitted < length) {
7936 		pos += submitted;
7937 		length -= submitted;
7938 		if (write)
7939 			btrfs_mark_ordered_io_finished(BTRFS_I(inode), NULL,
7940 						       pos, length, false);
7941 		else
7942 			unlock_extent(&BTRFS_I(inode)->io_tree, pos,
7943 				      pos + length - 1, NULL);
7944 		ret = -ENOTBLK;
7945 	}
7946 
7947 	if (write)
7948 		extent_changeset_free(dio_data->data_reserved);
7949 	return ret;
7950 }
7951 
btrfs_dio_private_put(struct btrfs_dio_private * dip)7952 static void btrfs_dio_private_put(struct btrfs_dio_private *dip)
7953 {
7954 	/*
7955 	 * This implies a barrier so that stores to dio_bio->bi_status before
7956 	 * this and loads of dio_bio->bi_status after this are fully ordered.
7957 	 */
7958 	if (!refcount_dec_and_test(&dip->refs))
7959 		return;
7960 
7961 	if (btrfs_op(&dip->bio) == BTRFS_MAP_WRITE) {
7962 		btrfs_mark_ordered_io_finished(BTRFS_I(dip->inode), NULL,
7963 					       dip->file_offset, dip->bytes,
7964 					       !dip->bio.bi_status);
7965 	} else {
7966 		unlock_extent(&BTRFS_I(dip->inode)->io_tree,
7967 			      dip->file_offset,
7968 			      dip->file_offset + dip->bytes - 1, NULL);
7969 	}
7970 
7971 	kfree(dip->csums);
7972 	bio_endio(&dip->bio);
7973 }
7974 
submit_dio_repair_bio(struct inode * inode,struct bio * bio,int mirror_num,enum btrfs_compression_type compress_type)7975 static void submit_dio_repair_bio(struct inode *inode, struct bio *bio,
7976 				  int mirror_num,
7977 				  enum btrfs_compression_type compress_type)
7978 {
7979 	struct btrfs_dio_private *dip = btrfs_bio(bio)->private;
7980 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
7981 
7982 	BUG_ON(bio_op(bio) == REQ_OP_WRITE);
7983 
7984 	refcount_inc(&dip->refs);
7985 	btrfs_submit_bio(fs_info, bio, mirror_num);
7986 }
7987 
btrfs_check_read_dio_bio(struct btrfs_dio_private * dip,struct btrfs_bio * bbio,const bool uptodate)7988 static blk_status_t btrfs_check_read_dio_bio(struct btrfs_dio_private *dip,
7989 					     struct btrfs_bio *bbio,
7990 					     const bool uptodate)
7991 {
7992 	struct inode *inode = dip->inode;
7993 	struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info;
7994 	const bool csum = !(BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM);
7995 	blk_status_t err = BLK_STS_OK;
7996 	struct bvec_iter iter;
7997 	struct bio_vec bv;
7998 	u32 offset;
7999 
8000 	btrfs_bio_for_each_sector(fs_info, bv, bbio, iter, offset) {
8001 		u64 start = bbio->file_offset + offset;
8002 
8003 		if (uptodate &&
8004 		    (!csum || !btrfs_check_data_csum(inode, bbio, offset, bv.bv_page,
8005 					       bv.bv_offset))) {
8006 			btrfs_clean_io_failure(BTRFS_I(inode), start,
8007 					       bv.bv_page, bv.bv_offset);
8008 		} else {
8009 			int ret;
8010 
8011 			ret = btrfs_repair_one_sector(inode, bbio, offset,
8012 					bv.bv_page, bv.bv_offset,
8013 					submit_dio_repair_bio);
8014 			if (ret)
8015 				err = errno_to_blk_status(ret);
8016 		}
8017 	}
8018 
8019 	return err;
8020 }
8021 
btrfs_submit_bio_start_direct_io(struct inode * inode,struct bio * bio,u64 dio_file_offset)8022 static blk_status_t btrfs_submit_bio_start_direct_io(struct inode *inode,
8023 						     struct bio *bio,
8024 						     u64 dio_file_offset)
8025 {
8026 	return btrfs_csum_one_bio(BTRFS_I(inode), bio, dio_file_offset, false);
8027 }
8028 
btrfs_end_dio_bio(struct btrfs_bio * bbio)8029 static void btrfs_end_dio_bio(struct btrfs_bio *bbio)
8030 {
8031 	struct btrfs_dio_private *dip = bbio->private;
8032 	struct bio *bio = &bbio->bio;
8033 	blk_status_t err = bio->bi_status;
8034 
8035 	if (err)
8036 		btrfs_warn(BTRFS_I(dip->inode)->root->fs_info,
8037 			   "direct IO failed ino %llu rw %d,%u sector %#Lx len %u err no %d",
8038 			   btrfs_ino(BTRFS_I(dip->inode)), bio_op(bio),
8039 			   bio->bi_opf, bio->bi_iter.bi_sector,
8040 			   bio->bi_iter.bi_size, err);
8041 
8042 	if (bio_op(bio) == REQ_OP_READ)
8043 		err = btrfs_check_read_dio_bio(dip, bbio, !err);
8044 
8045 	if (err)
8046 		dip->bio.bi_status = err;
8047 
8048 	btrfs_record_physical_zoned(dip->inode, bbio->file_offset, bio);
8049 
8050 	bio_put(bio);
8051 	btrfs_dio_private_put(dip);
8052 }
8053 
btrfs_submit_dio_bio(struct bio * bio,struct inode * inode,u64 file_offset,int async_submit)8054 static void btrfs_submit_dio_bio(struct bio *bio, struct inode *inode,
8055 				 u64 file_offset, int async_submit)
8056 {
8057 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
8058 	struct btrfs_dio_private *dip = btrfs_bio(bio)->private;
8059 	blk_status_t ret;
8060 
8061 	/* Save the original iter for read repair */
8062 	if (btrfs_op(bio) == BTRFS_MAP_READ)
8063 		btrfs_bio(bio)->iter = bio->bi_iter;
8064 
8065 	if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM)
8066 		goto map;
8067 
8068 	if (btrfs_op(bio) == BTRFS_MAP_WRITE) {
8069 		/* Check btrfs_submit_data_write_bio() for async submit rules */
8070 		if (async_submit && !atomic_read(&BTRFS_I(inode)->sync_writers) &&
8071 		    btrfs_wq_submit_bio(inode, bio, 0, file_offset,
8072 					btrfs_submit_bio_start_direct_io))
8073 			return;
8074 
8075 		/*
8076 		 * If we aren't doing async submit, calculate the csum of the
8077 		 * bio now.
8078 		 */
8079 		ret = btrfs_csum_one_bio(BTRFS_I(inode), bio, file_offset, false);
8080 		if (ret) {
8081 			btrfs_bio_end_io(btrfs_bio(bio), ret);
8082 			return;
8083 		}
8084 	} else {
8085 		btrfs_bio(bio)->csum = btrfs_csum_ptr(fs_info, dip->csums,
8086 						      file_offset - dip->file_offset);
8087 	}
8088 map:
8089 	btrfs_submit_bio(fs_info, bio, 0);
8090 }
8091 
btrfs_submit_direct(const struct iomap_iter * iter,struct bio * dio_bio,loff_t file_offset)8092 static void btrfs_submit_direct(const struct iomap_iter *iter,
8093 		struct bio *dio_bio, loff_t file_offset)
8094 {
8095 	struct btrfs_dio_private *dip =
8096 		container_of(dio_bio, struct btrfs_dio_private, bio);
8097 	struct inode *inode = iter->inode;
8098 	const bool write = (btrfs_op(dio_bio) == BTRFS_MAP_WRITE);
8099 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
8100 	const bool raid56 = (btrfs_data_alloc_profile(fs_info) &
8101 			     BTRFS_BLOCK_GROUP_RAID56_MASK);
8102 	struct bio *bio;
8103 	u64 start_sector;
8104 	int async_submit = 0;
8105 	u64 submit_len;
8106 	u64 clone_offset = 0;
8107 	u64 clone_len;
8108 	u64 logical;
8109 	int ret;
8110 	blk_status_t status;
8111 	struct btrfs_io_geometry geom;
8112 	struct btrfs_dio_data *dio_data = iter->private;
8113 	struct extent_map *em = NULL;
8114 
8115 	dip->inode = inode;
8116 	dip->file_offset = file_offset;
8117 	dip->bytes = dio_bio->bi_iter.bi_size;
8118 	refcount_set(&dip->refs, 1);
8119 	dip->csums = NULL;
8120 
8121 	if (!write && !(BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM)) {
8122 		unsigned int nr_sectors =
8123 			(dio_bio->bi_iter.bi_size >> fs_info->sectorsize_bits);
8124 
8125 		/*
8126 		 * Load the csums up front to reduce csum tree searches and
8127 		 * contention when submitting bios.
8128 		 */
8129 		status = BLK_STS_RESOURCE;
8130 		dip->csums = kcalloc(nr_sectors, fs_info->csum_size, GFP_NOFS);
8131 		if (!dip->csums)
8132 			goto out_err;
8133 
8134 		status = btrfs_lookup_bio_sums(inode, dio_bio, dip->csums);
8135 		if (status != BLK_STS_OK)
8136 			goto out_err;
8137 	}
8138 
8139 	start_sector = dio_bio->bi_iter.bi_sector;
8140 	submit_len = dio_bio->bi_iter.bi_size;
8141 
8142 	do {
8143 		logical = start_sector << 9;
8144 		em = btrfs_get_chunk_map(fs_info, logical, submit_len);
8145 		if (IS_ERR(em)) {
8146 			status = errno_to_blk_status(PTR_ERR(em));
8147 			em = NULL;
8148 			goto out_err_em;
8149 		}
8150 		ret = btrfs_get_io_geometry(fs_info, em, btrfs_op(dio_bio),
8151 					    logical, &geom);
8152 		if (ret) {
8153 			status = errno_to_blk_status(ret);
8154 			goto out_err_em;
8155 		}
8156 
8157 		clone_len = min(submit_len, geom.len);
8158 		ASSERT(clone_len <= UINT_MAX);
8159 
8160 		/*
8161 		 * This will never fail as it's passing GPF_NOFS and
8162 		 * the allocation is backed by btrfs_bioset.
8163 		 */
8164 		bio = btrfs_bio_clone_partial(dio_bio, clone_offset, clone_len,
8165 					      btrfs_end_dio_bio, dip);
8166 		btrfs_bio(bio)->file_offset = file_offset;
8167 
8168 		if (bio_op(bio) == REQ_OP_ZONE_APPEND) {
8169 			status = extract_ordered_extent(BTRFS_I(inode), bio,
8170 							file_offset);
8171 			if (status) {
8172 				bio_put(bio);
8173 				goto out_err;
8174 			}
8175 		}
8176 
8177 		ASSERT(submit_len >= clone_len);
8178 		submit_len -= clone_len;
8179 
8180 		/*
8181 		 * Increase the count before we submit the bio so we know
8182 		 * the end IO handler won't happen before we increase the
8183 		 * count. Otherwise, the dip might get freed before we're
8184 		 * done setting it up.
8185 		 *
8186 		 * We transfer the initial reference to the last bio, so we
8187 		 * don't need to increment the reference count for the last one.
8188 		 */
8189 		if (submit_len > 0) {
8190 			refcount_inc(&dip->refs);
8191 			/*
8192 			 * If we are submitting more than one bio, submit them
8193 			 * all asynchronously. The exception is RAID 5 or 6, as
8194 			 * asynchronous checksums make it difficult to collect
8195 			 * full stripe writes.
8196 			 */
8197 			if (!raid56)
8198 				async_submit = 1;
8199 		}
8200 
8201 		btrfs_submit_dio_bio(bio, inode, file_offset, async_submit);
8202 
8203 		dio_data->submitted += clone_len;
8204 		clone_offset += clone_len;
8205 		start_sector += clone_len >> 9;
8206 		file_offset += clone_len;
8207 
8208 		free_extent_map(em);
8209 	} while (submit_len > 0);
8210 	return;
8211 
8212 out_err_em:
8213 	free_extent_map(em);
8214 out_err:
8215 	dio_bio->bi_status = status;
8216 	btrfs_dio_private_put(dip);
8217 }
8218 
8219 static const struct iomap_ops btrfs_dio_iomap_ops = {
8220 	.iomap_begin            = btrfs_dio_iomap_begin,
8221 	.iomap_end              = btrfs_dio_iomap_end,
8222 };
8223 
8224 static const struct iomap_dio_ops btrfs_dio_ops = {
8225 	.submit_io		= btrfs_submit_direct,
8226 	.bio_set		= &btrfs_dio_bioset,
8227 };
8228 
btrfs_dio_read(struct kiocb * iocb,struct iov_iter * iter,size_t done_before)8229 ssize_t btrfs_dio_read(struct kiocb *iocb, struct iov_iter *iter, size_t done_before)
8230 {
8231 	struct btrfs_dio_data data;
8232 
8233 	return iomap_dio_rw(iocb, iter, &btrfs_dio_iomap_ops, &btrfs_dio_ops,
8234 			    IOMAP_DIO_PARTIAL, &data, done_before);
8235 }
8236 
btrfs_dio_write(struct kiocb * iocb,struct iov_iter * iter,size_t done_before)8237 struct iomap_dio *btrfs_dio_write(struct kiocb *iocb, struct iov_iter *iter,
8238 				  size_t done_before)
8239 {
8240 	struct btrfs_dio_data data;
8241 
8242 	return __iomap_dio_rw(iocb, iter, &btrfs_dio_iomap_ops, &btrfs_dio_ops,
8243 			    IOMAP_DIO_PARTIAL, &data, done_before);
8244 }
8245 
btrfs_fiemap(struct inode * inode,struct fiemap_extent_info * fieinfo,u64 start,u64 len)8246 static int btrfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
8247 			u64 start, u64 len)
8248 {
8249 	int	ret;
8250 
8251 	ret = fiemap_prep(inode, fieinfo, start, &len, 0);
8252 	if (ret)
8253 		return ret;
8254 
8255 	/*
8256 	 * fiemap_prep() called filemap_write_and_wait() for the whole possible
8257 	 * file range (0 to LLONG_MAX), but that is not enough if we have
8258 	 * compression enabled. The first filemap_fdatawrite_range() only kicks
8259 	 * in the compression of data (in an async thread) and will return
8260 	 * before the compression is done and writeback is started. A second
8261 	 * filemap_fdatawrite_range() is needed to wait for the compression to
8262 	 * complete and writeback to start. We also need to wait for ordered
8263 	 * extents to complete, because our fiemap implementation uses mainly
8264 	 * file extent items to list the extents, searching for extent maps
8265 	 * only for file ranges with holes or prealloc extents to figure out
8266 	 * if we have delalloc in those ranges.
8267 	 */
8268 	if (fieinfo->fi_flags & FIEMAP_FLAG_SYNC) {
8269 		ret = btrfs_wait_ordered_range(inode, 0, LLONG_MAX);
8270 		if (ret)
8271 			return ret;
8272 	}
8273 
8274 	return extent_fiemap(BTRFS_I(inode), fieinfo, start, len);
8275 }
8276 
btrfs_writepages(struct address_space * mapping,struct writeback_control * wbc)8277 static int btrfs_writepages(struct address_space *mapping,
8278 			    struct writeback_control *wbc)
8279 {
8280 	return extent_writepages(mapping, wbc);
8281 }
8282 
btrfs_readahead(struct readahead_control * rac)8283 static void btrfs_readahead(struct readahead_control *rac)
8284 {
8285 	extent_readahead(rac);
8286 }
8287 
8288 /*
8289  * For release_folio() and invalidate_folio() we have a race window where
8290  * folio_end_writeback() is called but the subpage spinlock is not yet released.
8291  * If we continue to release/invalidate the page, we could cause use-after-free
8292  * for subpage spinlock.  So this function is to spin and wait for subpage
8293  * spinlock.
8294  */
wait_subpage_spinlock(struct page * page)8295 static void wait_subpage_spinlock(struct page *page)
8296 {
8297 	struct btrfs_fs_info *fs_info = btrfs_sb(page->mapping->host->i_sb);
8298 	struct btrfs_subpage *subpage;
8299 
8300 	if (!btrfs_is_subpage(fs_info, page))
8301 		return;
8302 
8303 	ASSERT(PagePrivate(page) && page->private);
8304 	subpage = (struct btrfs_subpage *)page->private;
8305 
8306 	/*
8307 	 * This may look insane as we just acquire the spinlock and release it,
8308 	 * without doing anything.  But we just want to make sure no one is
8309 	 * still holding the subpage spinlock.
8310 	 * And since the page is not dirty nor writeback, and we have page
8311 	 * locked, the only possible way to hold a spinlock is from the endio
8312 	 * function to clear page writeback.
8313 	 *
8314 	 * Here we just acquire the spinlock so that all existing callers
8315 	 * should exit and we're safe to release/invalidate the page.
8316 	 */
8317 	spin_lock_irq(&subpage->lock);
8318 	spin_unlock_irq(&subpage->lock);
8319 }
8320 
__btrfs_release_folio(struct folio * folio,gfp_t gfp_flags)8321 static bool __btrfs_release_folio(struct folio *folio, gfp_t gfp_flags)
8322 {
8323 	int ret = try_release_extent_mapping(&folio->page, gfp_flags);
8324 
8325 	if (ret == 1) {
8326 		wait_subpage_spinlock(&folio->page);
8327 		clear_page_extent_mapped(&folio->page);
8328 	}
8329 	return ret;
8330 }
8331 
btrfs_release_folio(struct folio * folio,gfp_t gfp_flags)8332 static bool btrfs_release_folio(struct folio *folio, gfp_t gfp_flags)
8333 {
8334 	if (folio_test_writeback(folio) || folio_test_dirty(folio))
8335 		return false;
8336 	return __btrfs_release_folio(folio, gfp_flags);
8337 }
8338 
8339 #ifdef CONFIG_MIGRATION
btrfs_migrate_folio(struct address_space * mapping,struct folio * dst,struct folio * src,enum migrate_mode mode)8340 static int btrfs_migrate_folio(struct address_space *mapping,
8341 			     struct folio *dst, struct folio *src,
8342 			     enum migrate_mode mode)
8343 {
8344 	int ret = filemap_migrate_folio(mapping, dst, src, mode);
8345 
8346 	if (ret != MIGRATEPAGE_SUCCESS)
8347 		return ret;
8348 
8349 	if (folio_test_ordered(src)) {
8350 		folio_clear_ordered(src);
8351 		folio_set_ordered(dst);
8352 	}
8353 
8354 	return MIGRATEPAGE_SUCCESS;
8355 }
8356 #else
8357 #define btrfs_migrate_folio NULL
8358 #endif
8359 
btrfs_invalidate_folio(struct folio * folio,size_t offset,size_t length)8360 static void btrfs_invalidate_folio(struct folio *folio, size_t offset,
8361 				 size_t length)
8362 {
8363 	struct btrfs_inode *inode = BTRFS_I(folio->mapping->host);
8364 	struct btrfs_fs_info *fs_info = inode->root->fs_info;
8365 	struct extent_io_tree *tree = &inode->io_tree;
8366 	struct extent_state *cached_state = NULL;
8367 	u64 page_start = folio_pos(folio);
8368 	u64 page_end = page_start + folio_size(folio) - 1;
8369 	u64 cur;
8370 	int inode_evicting = inode->vfs_inode.i_state & I_FREEING;
8371 
8372 	/*
8373 	 * We have folio locked so no new ordered extent can be created on this
8374 	 * page, nor bio can be submitted for this folio.
8375 	 *
8376 	 * But already submitted bio can still be finished on this folio.
8377 	 * Furthermore, endio function won't skip folio which has Ordered
8378 	 * (Private2) already cleared, so it's possible for endio and
8379 	 * invalidate_folio to do the same ordered extent accounting twice
8380 	 * on one folio.
8381 	 *
8382 	 * So here we wait for any submitted bios to finish, so that we won't
8383 	 * do double ordered extent accounting on the same folio.
8384 	 */
8385 	folio_wait_writeback(folio);
8386 	wait_subpage_spinlock(&folio->page);
8387 
8388 	/*
8389 	 * For subpage case, we have call sites like
8390 	 * btrfs_punch_hole_lock_range() which passes range not aligned to
8391 	 * sectorsize.
8392 	 * If the range doesn't cover the full folio, we don't need to and
8393 	 * shouldn't clear page extent mapped, as folio->private can still
8394 	 * record subpage dirty bits for other part of the range.
8395 	 *
8396 	 * For cases that invalidate the full folio even the range doesn't
8397 	 * cover the full folio, like invalidating the last folio, we're
8398 	 * still safe to wait for ordered extent to finish.
8399 	 */
8400 	if (!(offset == 0 && length == folio_size(folio))) {
8401 		btrfs_release_folio(folio, GFP_NOFS);
8402 		return;
8403 	}
8404 
8405 	if (!inode_evicting)
8406 		lock_extent(tree, page_start, page_end, &cached_state);
8407 
8408 	cur = page_start;
8409 	while (cur < page_end) {
8410 		struct btrfs_ordered_extent *ordered;
8411 		u64 range_end;
8412 		u32 range_len;
8413 		u32 extra_flags = 0;
8414 
8415 		ordered = btrfs_lookup_first_ordered_range(inode, cur,
8416 							   page_end + 1 - cur);
8417 		if (!ordered) {
8418 			range_end = page_end;
8419 			/*
8420 			 * No ordered extent covering this range, we are safe
8421 			 * to delete all extent states in the range.
8422 			 */
8423 			extra_flags = EXTENT_CLEAR_ALL_BITS;
8424 			goto next;
8425 		}
8426 		if (ordered->file_offset > cur) {
8427 			/*
8428 			 * There is a range between [cur, oe->file_offset) not
8429 			 * covered by any ordered extent.
8430 			 * We are safe to delete all extent states, and handle
8431 			 * the ordered extent in the next iteration.
8432 			 */
8433 			range_end = ordered->file_offset - 1;
8434 			extra_flags = EXTENT_CLEAR_ALL_BITS;
8435 			goto next;
8436 		}
8437 
8438 		range_end = min(ordered->file_offset + ordered->num_bytes - 1,
8439 				page_end);
8440 		ASSERT(range_end + 1 - cur < U32_MAX);
8441 		range_len = range_end + 1 - cur;
8442 		if (!btrfs_page_test_ordered(fs_info, &folio->page, cur, range_len)) {
8443 			/*
8444 			 * If Ordered (Private2) is cleared, it means endio has
8445 			 * already been executed for the range.
8446 			 * We can't delete the extent states as
8447 			 * btrfs_finish_ordered_io() may still use some of them.
8448 			 */
8449 			goto next;
8450 		}
8451 		btrfs_page_clear_ordered(fs_info, &folio->page, cur, range_len);
8452 
8453 		/*
8454 		 * IO on this page will never be started, so we need to account
8455 		 * for any ordered extents now. Don't clear EXTENT_DELALLOC_NEW
8456 		 * here, must leave that up for the ordered extent completion.
8457 		 *
8458 		 * This will also unlock the range for incoming
8459 		 * btrfs_finish_ordered_io().
8460 		 */
8461 		if (!inode_evicting)
8462 			clear_extent_bit(tree, cur, range_end,
8463 					 EXTENT_DELALLOC |
8464 					 EXTENT_LOCKED | EXTENT_DO_ACCOUNTING |
8465 					 EXTENT_DEFRAG, &cached_state);
8466 
8467 		spin_lock_irq(&inode->ordered_tree.lock);
8468 		set_bit(BTRFS_ORDERED_TRUNCATED, &ordered->flags);
8469 		ordered->truncated_len = min(ordered->truncated_len,
8470 					     cur - ordered->file_offset);
8471 		spin_unlock_irq(&inode->ordered_tree.lock);
8472 
8473 		/*
8474 		 * If the ordered extent has finished, we're safe to delete all
8475 		 * the extent states of the range, otherwise
8476 		 * btrfs_finish_ordered_io() will get executed by endio for
8477 		 * other pages, so we can't delete extent states.
8478 		 */
8479 		if (btrfs_dec_test_ordered_pending(inode, &ordered,
8480 						   cur, range_end + 1 - cur)) {
8481 			btrfs_finish_ordered_io(ordered);
8482 			/*
8483 			 * The ordered extent has finished, now we're again
8484 			 * safe to delete all extent states of the range.
8485 			 */
8486 			extra_flags = EXTENT_CLEAR_ALL_BITS;
8487 		}
8488 next:
8489 		if (ordered)
8490 			btrfs_put_ordered_extent(ordered);
8491 		/*
8492 		 * Qgroup reserved space handler
8493 		 * Sector(s) here will be either:
8494 		 *
8495 		 * 1) Already written to disk or bio already finished
8496 		 *    Then its QGROUP_RESERVED bit in io_tree is already cleared.
8497 		 *    Qgroup will be handled by its qgroup_record then.
8498 		 *    btrfs_qgroup_free_data() call will do nothing here.
8499 		 *
8500 		 * 2) Not written to disk yet
8501 		 *    Then btrfs_qgroup_free_data() call will clear the
8502 		 *    QGROUP_RESERVED bit of its io_tree, and free the qgroup
8503 		 *    reserved data space.
8504 		 *    Since the IO will never happen for this page.
8505 		 */
8506 		btrfs_qgroup_free_data(inode, NULL, cur, range_end + 1 - cur, NULL);
8507 		if (!inode_evicting) {
8508 			clear_extent_bit(tree, cur, range_end, EXTENT_LOCKED |
8509 				 EXTENT_DELALLOC | EXTENT_UPTODATE |
8510 				 EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG |
8511 				 extra_flags, &cached_state);
8512 		}
8513 		cur = range_end + 1;
8514 	}
8515 	/*
8516 	 * We have iterated through all ordered extents of the page, the page
8517 	 * should not have Ordered (Private2) anymore, or the above iteration
8518 	 * did something wrong.
8519 	 */
8520 	ASSERT(!folio_test_ordered(folio));
8521 	btrfs_page_clear_checked(fs_info, &folio->page, folio_pos(folio), folio_size(folio));
8522 	if (!inode_evicting)
8523 		__btrfs_release_folio(folio, GFP_NOFS);
8524 	clear_page_extent_mapped(&folio->page);
8525 }
8526 
8527 /*
8528  * btrfs_page_mkwrite() is not allowed to change the file size as it gets
8529  * called from a page fault handler when a page is first dirtied. Hence we must
8530  * be careful to check for EOF conditions here. We set the page up correctly
8531  * for a written page which means we get ENOSPC checking when writing into
8532  * holes and correct delalloc and unwritten extent mapping on filesystems that
8533  * support these features.
8534  *
8535  * We are not allowed to take the i_mutex here so we have to play games to
8536  * protect against truncate races as the page could now be beyond EOF.  Because
8537  * truncate_setsize() writes the inode size before removing pages, once we have
8538  * the page lock we can determine safely if the page is beyond EOF. If it is not
8539  * beyond EOF, then the page is guaranteed safe against truncation until we
8540  * unlock the page.
8541  */
btrfs_page_mkwrite(struct vm_fault * vmf)8542 vm_fault_t btrfs_page_mkwrite(struct vm_fault *vmf)
8543 {
8544 	struct page *page = vmf->page;
8545 	struct inode *inode = file_inode(vmf->vma->vm_file);
8546 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
8547 	struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
8548 	struct btrfs_ordered_extent *ordered;
8549 	struct extent_state *cached_state = NULL;
8550 	struct extent_changeset *data_reserved = NULL;
8551 	unsigned long zero_start;
8552 	loff_t size;
8553 	vm_fault_t ret;
8554 	int ret2;
8555 	int reserved = 0;
8556 	u64 reserved_space;
8557 	u64 page_start;
8558 	u64 page_end;
8559 	u64 end;
8560 
8561 	reserved_space = PAGE_SIZE;
8562 
8563 	sb_start_pagefault(inode->i_sb);
8564 	page_start = page_offset(page);
8565 	page_end = page_start + PAGE_SIZE - 1;
8566 	end = page_end;
8567 
8568 	/*
8569 	 * Reserving delalloc space after obtaining the page lock can lead to
8570 	 * deadlock. For example, if a dirty page is locked by this function
8571 	 * and the call to btrfs_delalloc_reserve_space() ends up triggering
8572 	 * dirty page write out, then the btrfs_writepages() function could
8573 	 * end up waiting indefinitely to get a lock on the page currently
8574 	 * being processed by btrfs_page_mkwrite() function.
8575 	 */
8576 	ret2 = btrfs_delalloc_reserve_space(BTRFS_I(inode), &data_reserved,
8577 					    page_start, reserved_space);
8578 	if (!ret2) {
8579 		ret2 = file_update_time(vmf->vma->vm_file);
8580 		reserved = 1;
8581 	}
8582 	if (ret2) {
8583 		ret = vmf_error(ret2);
8584 		if (reserved)
8585 			goto out;
8586 		goto out_noreserve;
8587 	}
8588 
8589 	ret = VM_FAULT_NOPAGE; /* make the VM retry the fault */
8590 again:
8591 	down_read(&BTRFS_I(inode)->i_mmap_lock);
8592 	lock_page(page);
8593 	size = i_size_read(inode);
8594 
8595 	if ((page->mapping != inode->i_mapping) ||
8596 	    (page_start >= size)) {
8597 		/* page got truncated out from underneath us */
8598 		goto out_unlock;
8599 	}
8600 	wait_on_page_writeback(page);
8601 
8602 	lock_extent(io_tree, page_start, page_end, &cached_state);
8603 	ret2 = set_page_extent_mapped(page);
8604 	if (ret2 < 0) {
8605 		ret = vmf_error(ret2);
8606 		unlock_extent(io_tree, page_start, page_end, &cached_state);
8607 		goto out_unlock;
8608 	}
8609 
8610 	/*
8611 	 * we can't set the delalloc bits if there are pending ordered
8612 	 * extents.  Drop our locks and wait for them to finish
8613 	 */
8614 	ordered = btrfs_lookup_ordered_range(BTRFS_I(inode), page_start,
8615 			PAGE_SIZE);
8616 	if (ordered) {
8617 		unlock_extent(io_tree, page_start, page_end, &cached_state);
8618 		unlock_page(page);
8619 		up_read(&BTRFS_I(inode)->i_mmap_lock);
8620 		btrfs_start_ordered_extent(ordered, 1);
8621 		btrfs_put_ordered_extent(ordered);
8622 		goto again;
8623 	}
8624 
8625 	if (page->index == ((size - 1) >> PAGE_SHIFT)) {
8626 		reserved_space = round_up(size - page_start,
8627 					  fs_info->sectorsize);
8628 		if (reserved_space < PAGE_SIZE) {
8629 			end = page_start + reserved_space - 1;
8630 			btrfs_delalloc_release_space(BTRFS_I(inode),
8631 					data_reserved, page_start,
8632 					PAGE_SIZE - reserved_space, true);
8633 		}
8634 	}
8635 
8636 	/*
8637 	 * page_mkwrite gets called when the page is firstly dirtied after it's
8638 	 * faulted in, but write(2) could also dirty a page and set delalloc
8639 	 * bits, thus in this case for space account reason, we still need to
8640 	 * clear any delalloc bits within this page range since we have to
8641 	 * reserve data&meta space before lock_page() (see above comments).
8642 	 */
8643 	clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start, end,
8644 			  EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING |
8645 			  EXTENT_DEFRAG, &cached_state);
8646 
8647 	ret2 = btrfs_set_extent_delalloc(BTRFS_I(inode), page_start, end, 0,
8648 					&cached_state);
8649 	if (ret2) {
8650 		unlock_extent(io_tree, page_start, page_end, &cached_state);
8651 		ret = VM_FAULT_SIGBUS;
8652 		goto out_unlock;
8653 	}
8654 
8655 	/* page is wholly or partially inside EOF */
8656 	if (page_start + PAGE_SIZE > size)
8657 		zero_start = offset_in_page(size);
8658 	else
8659 		zero_start = PAGE_SIZE;
8660 
8661 	if (zero_start != PAGE_SIZE)
8662 		memzero_page(page, zero_start, PAGE_SIZE - zero_start);
8663 
8664 	btrfs_page_clear_checked(fs_info, page, page_start, PAGE_SIZE);
8665 	btrfs_page_set_dirty(fs_info, page, page_start, end + 1 - page_start);
8666 	btrfs_page_set_uptodate(fs_info, page, page_start, end + 1 - page_start);
8667 
8668 	btrfs_set_inode_last_sub_trans(BTRFS_I(inode));
8669 
8670 	unlock_extent(io_tree, page_start, page_end, &cached_state);
8671 	up_read(&BTRFS_I(inode)->i_mmap_lock);
8672 
8673 	btrfs_delalloc_release_extents(BTRFS_I(inode), PAGE_SIZE);
8674 	sb_end_pagefault(inode->i_sb);
8675 	extent_changeset_free(data_reserved);
8676 	return VM_FAULT_LOCKED;
8677 
8678 out_unlock:
8679 	unlock_page(page);
8680 	up_read(&BTRFS_I(inode)->i_mmap_lock);
8681 out:
8682 	btrfs_delalloc_release_extents(BTRFS_I(inode), PAGE_SIZE);
8683 	btrfs_delalloc_release_space(BTRFS_I(inode), data_reserved, page_start,
8684 				     reserved_space, (ret != 0));
8685 out_noreserve:
8686 	sb_end_pagefault(inode->i_sb);
8687 	extent_changeset_free(data_reserved);
8688 	return ret;
8689 }
8690 
btrfs_truncate(struct inode * inode,bool skip_writeback)8691 static int btrfs_truncate(struct inode *inode, bool skip_writeback)
8692 {
8693 	struct btrfs_truncate_control control = {
8694 		.inode = BTRFS_I(inode),
8695 		.ino = btrfs_ino(BTRFS_I(inode)),
8696 		.min_type = BTRFS_EXTENT_DATA_KEY,
8697 		.clear_extent_range = true,
8698 	};
8699 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
8700 	struct btrfs_root *root = BTRFS_I(inode)->root;
8701 	struct btrfs_block_rsv *rsv;
8702 	int ret;
8703 	struct btrfs_trans_handle *trans;
8704 	u64 mask = fs_info->sectorsize - 1;
8705 	u64 min_size = btrfs_calc_metadata_size(fs_info, 1);
8706 
8707 	if (!skip_writeback) {
8708 		ret = btrfs_wait_ordered_range(inode, inode->i_size & (~mask),
8709 					       (u64)-1);
8710 		if (ret)
8711 			return ret;
8712 	}
8713 
8714 	/*
8715 	 * Yes ladies and gentlemen, this is indeed ugly.  We have a couple of
8716 	 * things going on here:
8717 	 *
8718 	 * 1) We need to reserve space to update our inode.
8719 	 *
8720 	 * 2) We need to have something to cache all the space that is going to
8721 	 * be free'd up by the truncate operation, but also have some slack
8722 	 * space reserved in case it uses space during the truncate (thank you
8723 	 * very much snapshotting).
8724 	 *
8725 	 * And we need these to be separate.  The fact is we can use a lot of
8726 	 * space doing the truncate, and we have no earthly idea how much space
8727 	 * we will use, so we need the truncate reservation to be separate so it
8728 	 * doesn't end up using space reserved for updating the inode.  We also
8729 	 * need to be able to stop the transaction and start a new one, which
8730 	 * means we need to be able to update the inode several times, and we
8731 	 * have no idea of knowing how many times that will be, so we can't just
8732 	 * reserve 1 item for the entirety of the operation, so that has to be
8733 	 * done separately as well.
8734 	 *
8735 	 * So that leaves us with
8736 	 *
8737 	 * 1) rsv - for the truncate reservation, which we will steal from the
8738 	 * transaction reservation.
8739 	 * 2) fs_info->trans_block_rsv - this will have 1 items worth left for
8740 	 * updating the inode.
8741 	 */
8742 	rsv = btrfs_alloc_block_rsv(fs_info, BTRFS_BLOCK_RSV_TEMP);
8743 	if (!rsv)
8744 		return -ENOMEM;
8745 	rsv->size = min_size;
8746 	rsv->failfast = true;
8747 
8748 	/*
8749 	 * 1 for the truncate slack space
8750 	 * 1 for updating the inode.
8751 	 */
8752 	trans = btrfs_start_transaction(root, 2);
8753 	if (IS_ERR(trans)) {
8754 		ret = PTR_ERR(trans);
8755 		goto out;
8756 	}
8757 
8758 	/* Migrate the slack space for the truncate to our reserve */
8759 	ret = btrfs_block_rsv_migrate(&fs_info->trans_block_rsv, rsv,
8760 				      min_size, false);
8761 	BUG_ON(ret);
8762 
8763 	trans->block_rsv = rsv;
8764 
8765 	while (1) {
8766 		struct extent_state *cached_state = NULL;
8767 		const u64 new_size = inode->i_size;
8768 		const u64 lock_start = ALIGN_DOWN(new_size, fs_info->sectorsize);
8769 
8770 		control.new_size = new_size;
8771 		lock_extent(&BTRFS_I(inode)->io_tree, lock_start, (u64)-1,
8772 				 &cached_state);
8773 		/*
8774 		 * We want to drop from the next block forward in case this new
8775 		 * size is not block aligned since we will be keeping the last
8776 		 * block of the extent just the way it is.
8777 		 */
8778 		btrfs_drop_extent_map_range(BTRFS_I(inode),
8779 					    ALIGN(new_size, fs_info->sectorsize),
8780 					    (u64)-1, false);
8781 
8782 		ret = btrfs_truncate_inode_items(trans, root, &control);
8783 
8784 		inode_sub_bytes(inode, control.sub_bytes);
8785 		btrfs_inode_safe_disk_i_size_write(BTRFS_I(inode), control.last_size);
8786 
8787 		unlock_extent(&BTRFS_I(inode)->io_tree, lock_start, (u64)-1,
8788 			      &cached_state);
8789 
8790 		trans->block_rsv = &fs_info->trans_block_rsv;
8791 		if (ret != -ENOSPC && ret != -EAGAIN)
8792 			break;
8793 
8794 		ret = btrfs_update_inode(trans, root, BTRFS_I(inode));
8795 		if (ret)
8796 			break;
8797 
8798 		btrfs_end_transaction(trans);
8799 		btrfs_btree_balance_dirty(fs_info);
8800 
8801 		trans = btrfs_start_transaction(root, 2);
8802 		if (IS_ERR(trans)) {
8803 			ret = PTR_ERR(trans);
8804 			trans = NULL;
8805 			break;
8806 		}
8807 
8808 		btrfs_block_rsv_release(fs_info, rsv, -1, NULL);
8809 		ret = btrfs_block_rsv_migrate(&fs_info->trans_block_rsv,
8810 					      rsv, min_size, false);
8811 		BUG_ON(ret);	/* shouldn't happen */
8812 		trans->block_rsv = rsv;
8813 	}
8814 
8815 	/*
8816 	 * We can't call btrfs_truncate_block inside a trans handle as we could
8817 	 * deadlock with freeze, if we got BTRFS_NEED_TRUNCATE_BLOCK then we
8818 	 * know we've truncated everything except the last little bit, and can
8819 	 * do btrfs_truncate_block and then update the disk_i_size.
8820 	 */
8821 	if (ret == BTRFS_NEED_TRUNCATE_BLOCK) {
8822 		btrfs_end_transaction(trans);
8823 		btrfs_btree_balance_dirty(fs_info);
8824 
8825 		ret = btrfs_truncate_block(BTRFS_I(inode), inode->i_size, 0, 0);
8826 		if (ret)
8827 			goto out;
8828 		trans = btrfs_start_transaction(root, 1);
8829 		if (IS_ERR(trans)) {
8830 			ret = PTR_ERR(trans);
8831 			goto out;
8832 		}
8833 		btrfs_inode_safe_disk_i_size_write(BTRFS_I(inode), 0);
8834 	}
8835 
8836 	if (trans) {
8837 		int ret2;
8838 
8839 		trans->block_rsv = &fs_info->trans_block_rsv;
8840 		ret2 = btrfs_update_inode(trans, root, BTRFS_I(inode));
8841 		if (ret2 && !ret)
8842 			ret = ret2;
8843 
8844 		ret2 = btrfs_end_transaction(trans);
8845 		if (ret2 && !ret)
8846 			ret = ret2;
8847 		btrfs_btree_balance_dirty(fs_info);
8848 	}
8849 out:
8850 	btrfs_free_block_rsv(fs_info, rsv);
8851 	/*
8852 	 * So if we truncate and then write and fsync we normally would just
8853 	 * write the extents that changed, which is a problem if we need to
8854 	 * first truncate that entire inode.  So set this flag so we write out
8855 	 * all of the extents in the inode to the sync log so we're completely
8856 	 * safe.
8857 	 *
8858 	 * If no extents were dropped or trimmed we don't need to force the next
8859 	 * fsync to truncate all the inode's items from the log and re-log them
8860 	 * all. This means the truncate operation did not change the file size,
8861 	 * or changed it to a smaller size but there was only an implicit hole
8862 	 * between the old i_size and the new i_size, and there were no prealloc
8863 	 * extents beyond i_size to drop.
8864 	 */
8865 	if (control.extents_found > 0)
8866 		btrfs_set_inode_full_sync(BTRFS_I(inode));
8867 
8868 	return ret;
8869 }
8870 
btrfs_new_subvol_inode(struct user_namespace * mnt_userns,struct inode * dir)8871 struct inode *btrfs_new_subvol_inode(struct user_namespace *mnt_userns,
8872 				     struct inode *dir)
8873 {
8874 	struct inode *inode;
8875 
8876 	inode = new_inode(dir->i_sb);
8877 	if (inode) {
8878 		/*
8879 		 * Subvolumes don't inherit the sgid bit or the parent's gid if
8880 		 * the parent's sgid bit is set. This is probably a bug.
8881 		 */
8882 		inode_init_owner(mnt_userns, inode, NULL,
8883 				 S_IFDIR | (~current_umask() & S_IRWXUGO));
8884 		inode->i_op = &btrfs_dir_inode_operations;
8885 		inode->i_fop = &btrfs_dir_file_operations;
8886 	}
8887 	return inode;
8888 }
8889 
btrfs_alloc_inode(struct super_block * sb)8890 struct inode *btrfs_alloc_inode(struct super_block *sb)
8891 {
8892 	struct btrfs_fs_info *fs_info = btrfs_sb(sb);
8893 	struct btrfs_inode *ei;
8894 	struct inode *inode;
8895 
8896 	ei = alloc_inode_sb(sb, btrfs_inode_cachep, GFP_KERNEL);
8897 	if (!ei)
8898 		return NULL;
8899 
8900 	ei->root = NULL;
8901 	ei->generation = 0;
8902 	ei->last_trans = 0;
8903 	ei->last_sub_trans = 0;
8904 	ei->logged_trans = 0;
8905 	ei->delalloc_bytes = 0;
8906 	ei->new_delalloc_bytes = 0;
8907 	ei->defrag_bytes = 0;
8908 	ei->disk_i_size = 0;
8909 	ei->flags = 0;
8910 	ei->ro_flags = 0;
8911 	ei->csum_bytes = 0;
8912 	ei->index_cnt = (u64)-1;
8913 	ei->dir_index = 0;
8914 	ei->last_unlink_trans = 0;
8915 	ei->last_reflink_trans = 0;
8916 	ei->last_log_commit = 0;
8917 
8918 	spin_lock_init(&ei->lock);
8919 	spin_lock_init(&ei->io_failure_lock);
8920 	ei->outstanding_extents = 0;
8921 	if (sb->s_magic != BTRFS_TEST_MAGIC)
8922 		btrfs_init_metadata_block_rsv(fs_info, &ei->block_rsv,
8923 					      BTRFS_BLOCK_RSV_DELALLOC);
8924 	ei->runtime_flags = 0;
8925 	ei->prop_compress = BTRFS_COMPRESS_NONE;
8926 	ei->defrag_compress = BTRFS_COMPRESS_NONE;
8927 
8928 	ei->delayed_node = NULL;
8929 
8930 	ei->i_otime.tv_sec = 0;
8931 	ei->i_otime.tv_nsec = 0;
8932 
8933 	inode = &ei->vfs_inode;
8934 	extent_map_tree_init(&ei->extent_tree);
8935 	extent_io_tree_init(fs_info, &ei->io_tree, IO_TREE_INODE_IO, inode);
8936 	extent_io_tree_init(fs_info, &ei->file_extent_tree,
8937 			    IO_TREE_INODE_FILE_EXTENT, NULL);
8938 	ei->io_failure_tree = RB_ROOT;
8939 	atomic_set(&ei->sync_writers, 0);
8940 	mutex_init(&ei->log_mutex);
8941 	btrfs_ordered_inode_tree_init(&ei->ordered_tree);
8942 	INIT_LIST_HEAD(&ei->delalloc_inodes);
8943 	INIT_LIST_HEAD(&ei->delayed_iput);
8944 	RB_CLEAR_NODE(&ei->rb_node);
8945 	init_rwsem(&ei->i_mmap_lock);
8946 
8947 	return inode;
8948 }
8949 
8950 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
btrfs_test_destroy_inode(struct inode * inode)8951 void btrfs_test_destroy_inode(struct inode *inode)
8952 {
8953 	btrfs_drop_extent_map_range(BTRFS_I(inode), 0, (u64)-1, false);
8954 	kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
8955 }
8956 #endif
8957 
btrfs_free_inode(struct inode * inode)8958 void btrfs_free_inode(struct inode *inode)
8959 {
8960 	kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
8961 }
8962 
btrfs_destroy_inode(struct inode * vfs_inode)8963 void btrfs_destroy_inode(struct inode *vfs_inode)
8964 {
8965 	struct btrfs_ordered_extent *ordered;
8966 	struct btrfs_inode *inode = BTRFS_I(vfs_inode);
8967 	struct btrfs_root *root = inode->root;
8968 	bool freespace_inode;
8969 
8970 	WARN_ON(!hlist_empty(&vfs_inode->i_dentry));
8971 	WARN_ON(vfs_inode->i_data.nrpages);
8972 	WARN_ON(inode->block_rsv.reserved);
8973 	WARN_ON(inode->block_rsv.size);
8974 	WARN_ON(inode->outstanding_extents);
8975 	if (!S_ISDIR(vfs_inode->i_mode)) {
8976 		WARN_ON(inode->delalloc_bytes);
8977 		WARN_ON(inode->new_delalloc_bytes);
8978 	}
8979 	WARN_ON(inode->csum_bytes);
8980 	WARN_ON(inode->defrag_bytes);
8981 
8982 	/*
8983 	 * This can happen where we create an inode, but somebody else also
8984 	 * created the same inode and we need to destroy the one we already
8985 	 * created.
8986 	 */
8987 	if (!root)
8988 		return;
8989 
8990 	/*
8991 	 * If this is a free space inode do not take the ordered extents lockdep
8992 	 * map.
8993 	 */
8994 	freespace_inode = btrfs_is_free_space_inode(inode);
8995 
8996 	while (1) {
8997 		ordered = btrfs_lookup_first_ordered_extent(inode, (u64)-1);
8998 		if (!ordered)
8999 			break;
9000 		else {
9001 			btrfs_err(root->fs_info,
9002 				  "found ordered extent %llu %llu on inode cleanup",
9003 				  ordered->file_offset, ordered->num_bytes);
9004 
9005 			if (!freespace_inode)
9006 				btrfs_lockdep_acquire(root->fs_info, btrfs_ordered_extent);
9007 
9008 			btrfs_remove_ordered_extent(inode, ordered);
9009 			btrfs_put_ordered_extent(ordered);
9010 			btrfs_put_ordered_extent(ordered);
9011 		}
9012 	}
9013 	btrfs_qgroup_check_reserved_leak(inode);
9014 	inode_tree_del(inode);
9015 	btrfs_drop_extent_map_range(inode, 0, (u64)-1, false);
9016 	btrfs_inode_clear_file_extent_range(inode, 0, (u64)-1);
9017 	btrfs_put_root(inode->root);
9018 }
9019 
btrfs_drop_inode(struct inode * inode)9020 int btrfs_drop_inode(struct inode *inode)
9021 {
9022 	struct btrfs_root *root = BTRFS_I(inode)->root;
9023 
9024 	if (root == NULL)
9025 		return 1;
9026 
9027 	/* the snap/subvol tree is on deleting */
9028 	if (btrfs_root_refs(&root->root_item) == 0)
9029 		return 1;
9030 	else
9031 		return generic_drop_inode(inode);
9032 }
9033 
init_once(void * foo)9034 static void init_once(void *foo)
9035 {
9036 	struct btrfs_inode *ei = foo;
9037 
9038 	inode_init_once(&ei->vfs_inode);
9039 }
9040 
btrfs_destroy_cachep(void)9041 void __cold btrfs_destroy_cachep(void)
9042 {
9043 	/*
9044 	 * Make sure all delayed rcu free inodes are flushed before we
9045 	 * destroy cache.
9046 	 */
9047 	rcu_barrier();
9048 	bioset_exit(&btrfs_dio_bioset);
9049 	kmem_cache_destroy(btrfs_inode_cachep);
9050 	kmem_cache_destroy(btrfs_trans_handle_cachep);
9051 	kmem_cache_destroy(btrfs_path_cachep);
9052 	kmem_cache_destroy(btrfs_free_space_cachep);
9053 	kmem_cache_destroy(btrfs_free_space_bitmap_cachep);
9054 }
9055 
btrfs_init_cachep(void)9056 int __init btrfs_init_cachep(void)
9057 {
9058 	btrfs_inode_cachep = kmem_cache_create("btrfs_inode",
9059 			sizeof(struct btrfs_inode), 0,
9060 			SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD | SLAB_ACCOUNT,
9061 			init_once);
9062 	if (!btrfs_inode_cachep)
9063 		goto fail;
9064 
9065 	btrfs_trans_handle_cachep = kmem_cache_create("btrfs_trans_handle",
9066 			sizeof(struct btrfs_trans_handle), 0,
9067 			SLAB_TEMPORARY | SLAB_MEM_SPREAD, NULL);
9068 	if (!btrfs_trans_handle_cachep)
9069 		goto fail;
9070 
9071 	btrfs_path_cachep = kmem_cache_create("btrfs_path",
9072 			sizeof(struct btrfs_path), 0,
9073 			SLAB_MEM_SPREAD, NULL);
9074 	if (!btrfs_path_cachep)
9075 		goto fail;
9076 
9077 	btrfs_free_space_cachep = kmem_cache_create("btrfs_free_space",
9078 			sizeof(struct btrfs_free_space), 0,
9079 			SLAB_MEM_SPREAD, NULL);
9080 	if (!btrfs_free_space_cachep)
9081 		goto fail;
9082 
9083 	btrfs_free_space_bitmap_cachep = kmem_cache_create("btrfs_free_space_bitmap",
9084 							PAGE_SIZE, PAGE_SIZE,
9085 							SLAB_MEM_SPREAD, NULL);
9086 	if (!btrfs_free_space_bitmap_cachep)
9087 		goto fail;
9088 
9089 	if (bioset_init(&btrfs_dio_bioset, BIO_POOL_SIZE,
9090 			offsetof(struct btrfs_dio_private, bio),
9091 			BIOSET_NEED_BVECS))
9092 		goto fail;
9093 
9094 	return 0;
9095 fail:
9096 	btrfs_destroy_cachep();
9097 	return -ENOMEM;
9098 }
9099 
btrfs_getattr(struct user_namespace * mnt_userns,const struct path * path,struct kstat * stat,u32 request_mask,unsigned int flags)9100 static int btrfs_getattr(struct user_namespace *mnt_userns,
9101 			 const struct path *path, struct kstat *stat,
9102 			 u32 request_mask, unsigned int flags)
9103 {
9104 	u64 delalloc_bytes;
9105 	u64 inode_bytes;
9106 	struct inode *inode = d_inode(path->dentry);
9107 	u32 blocksize = inode->i_sb->s_blocksize;
9108 	u32 bi_flags = BTRFS_I(inode)->flags;
9109 	u32 bi_ro_flags = BTRFS_I(inode)->ro_flags;
9110 
9111 	stat->result_mask |= STATX_BTIME;
9112 	stat->btime.tv_sec = BTRFS_I(inode)->i_otime.tv_sec;
9113 	stat->btime.tv_nsec = BTRFS_I(inode)->i_otime.tv_nsec;
9114 	if (bi_flags & BTRFS_INODE_APPEND)
9115 		stat->attributes |= STATX_ATTR_APPEND;
9116 	if (bi_flags & BTRFS_INODE_COMPRESS)
9117 		stat->attributes |= STATX_ATTR_COMPRESSED;
9118 	if (bi_flags & BTRFS_INODE_IMMUTABLE)
9119 		stat->attributes |= STATX_ATTR_IMMUTABLE;
9120 	if (bi_flags & BTRFS_INODE_NODUMP)
9121 		stat->attributes |= STATX_ATTR_NODUMP;
9122 	if (bi_ro_flags & BTRFS_INODE_RO_VERITY)
9123 		stat->attributes |= STATX_ATTR_VERITY;
9124 
9125 	stat->attributes_mask |= (STATX_ATTR_APPEND |
9126 				  STATX_ATTR_COMPRESSED |
9127 				  STATX_ATTR_IMMUTABLE |
9128 				  STATX_ATTR_NODUMP);
9129 
9130 	generic_fillattr(mnt_userns, inode, stat);
9131 	stat->dev = BTRFS_I(inode)->root->anon_dev;
9132 
9133 	spin_lock(&BTRFS_I(inode)->lock);
9134 	delalloc_bytes = BTRFS_I(inode)->new_delalloc_bytes;
9135 	inode_bytes = inode_get_bytes(inode);
9136 	spin_unlock(&BTRFS_I(inode)->lock);
9137 	stat->blocks = (ALIGN(inode_bytes, blocksize) +
9138 			ALIGN(delalloc_bytes, blocksize)) >> 9;
9139 	return 0;
9140 }
9141 
btrfs_rename_exchange(struct inode * old_dir,struct dentry * old_dentry,struct inode * new_dir,struct dentry * new_dentry)9142 static int btrfs_rename_exchange(struct inode *old_dir,
9143 			      struct dentry *old_dentry,
9144 			      struct inode *new_dir,
9145 			      struct dentry *new_dentry)
9146 {
9147 	struct btrfs_fs_info *fs_info = btrfs_sb(old_dir->i_sb);
9148 	struct btrfs_trans_handle *trans;
9149 	unsigned int trans_num_items;
9150 	struct btrfs_root *root = BTRFS_I(old_dir)->root;
9151 	struct btrfs_root *dest = BTRFS_I(new_dir)->root;
9152 	struct inode *new_inode = new_dentry->d_inode;
9153 	struct inode *old_inode = old_dentry->d_inode;
9154 	struct timespec64 ctime = current_time(old_inode);
9155 	struct btrfs_rename_ctx old_rename_ctx;
9156 	struct btrfs_rename_ctx new_rename_ctx;
9157 	u64 old_ino = btrfs_ino(BTRFS_I(old_inode));
9158 	u64 new_ino = btrfs_ino(BTRFS_I(new_inode));
9159 	u64 old_idx = 0;
9160 	u64 new_idx = 0;
9161 	int ret;
9162 	int ret2;
9163 	bool need_abort = false;
9164 	struct fscrypt_name old_fname, new_fname;
9165 	struct fscrypt_str *old_name, *new_name;
9166 
9167 	/*
9168 	 * For non-subvolumes allow exchange only within one subvolume, in the
9169 	 * same inode namespace. Two subvolumes (represented as directory) can
9170 	 * be exchanged as they're a logical link and have a fixed inode number.
9171 	 */
9172 	if (root != dest &&
9173 	    (old_ino != BTRFS_FIRST_FREE_OBJECTID ||
9174 	     new_ino != BTRFS_FIRST_FREE_OBJECTID))
9175 		return -EXDEV;
9176 
9177 	ret = fscrypt_setup_filename(old_dir, &old_dentry->d_name, 0, &old_fname);
9178 	if (ret)
9179 		return ret;
9180 
9181 	ret = fscrypt_setup_filename(new_dir, &new_dentry->d_name, 0, &new_fname);
9182 	if (ret) {
9183 		fscrypt_free_filename(&old_fname);
9184 		return ret;
9185 	}
9186 
9187 	old_name = &old_fname.disk_name;
9188 	new_name = &new_fname.disk_name;
9189 
9190 	/* close the race window with snapshot create/destroy ioctl */
9191 	if (old_ino == BTRFS_FIRST_FREE_OBJECTID ||
9192 	    new_ino == BTRFS_FIRST_FREE_OBJECTID)
9193 		down_read(&fs_info->subvol_sem);
9194 
9195 	/*
9196 	 * For each inode:
9197 	 * 1 to remove old dir item
9198 	 * 1 to remove old dir index
9199 	 * 1 to add new dir item
9200 	 * 1 to add new dir index
9201 	 * 1 to update parent inode
9202 	 *
9203 	 * If the parents are the same, we only need to account for one
9204 	 */
9205 	trans_num_items = (old_dir == new_dir ? 9 : 10);
9206 	if (old_ino == BTRFS_FIRST_FREE_OBJECTID) {
9207 		/*
9208 		 * 1 to remove old root ref
9209 		 * 1 to remove old root backref
9210 		 * 1 to add new root ref
9211 		 * 1 to add new root backref
9212 		 */
9213 		trans_num_items += 4;
9214 	} else {
9215 		/*
9216 		 * 1 to update inode item
9217 		 * 1 to remove old inode ref
9218 		 * 1 to add new inode ref
9219 		 */
9220 		trans_num_items += 3;
9221 	}
9222 	if (new_ino == BTRFS_FIRST_FREE_OBJECTID)
9223 		trans_num_items += 4;
9224 	else
9225 		trans_num_items += 3;
9226 	trans = btrfs_start_transaction(root, trans_num_items);
9227 	if (IS_ERR(trans)) {
9228 		ret = PTR_ERR(trans);
9229 		goto out_notrans;
9230 	}
9231 
9232 	if (dest != root) {
9233 		ret = btrfs_record_root_in_trans(trans, dest);
9234 		if (ret)
9235 			goto out_fail;
9236 	}
9237 
9238 	/*
9239 	 * We need to find a free sequence number both in the source and
9240 	 * in the destination directory for the exchange.
9241 	 */
9242 	ret = btrfs_set_inode_index(BTRFS_I(new_dir), &old_idx);
9243 	if (ret)
9244 		goto out_fail;
9245 	ret = btrfs_set_inode_index(BTRFS_I(old_dir), &new_idx);
9246 	if (ret)
9247 		goto out_fail;
9248 
9249 	BTRFS_I(old_inode)->dir_index = 0ULL;
9250 	BTRFS_I(new_inode)->dir_index = 0ULL;
9251 
9252 	/* Reference for the source. */
9253 	if (old_ino == BTRFS_FIRST_FREE_OBJECTID) {
9254 		/* force full log commit if subvolume involved. */
9255 		btrfs_set_log_full_commit(trans);
9256 	} else {
9257 		ret = btrfs_insert_inode_ref(trans, dest, new_name, old_ino,
9258 					     btrfs_ino(BTRFS_I(new_dir)),
9259 					     old_idx);
9260 		if (ret)
9261 			goto out_fail;
9262 		need_abort = true;
9263 	}
9264 
9265 	/* And now for the dest. */
9266 	if (new_ino == BTRFS_FIRST_FREE_OBJECTID) {
9267 		/* force full log commit if subvolume involved. */
9268 		btrfs_set_log_full_commit(trans);
9269 	} else {
9270 		ret = btrfs_insert_inode_ref(trans, root, old_name, new_ino,
9271 					     btrfs_ino(BTRFS_I(old_dir)),
9272 					     new_idx);
9273 		if (ret) {
9274 			if (need_abort)
9275 				btrfs_abort_transaction(trans, ret);
9276 			goto out_fail;
9277 		}
9278 	}
9279 
9280 	/* Update inode version and ctime/mtime. */
9281 	inode_inc_iversion(old_dir);
9282 	inode_inc_iversion(new_dir);
9283 	inode_inc_iversion(old_inode);
9284 	inode_inc_iversion(new_inode);
9285 	old_dir->i_mtime = ctime;
9286 	old_dir->i_ctime = ctime;
9287 	new_dir->i_mtime = ctime;
9288 	new_dir->i_ctime = ctime;
9289 	old_inode->i_ctime = ctime;
9290 	new_inode->i_ctime = ctime;
9291 
9292 	if (old_dentry->d_parent != new_dentry->d_parent) {
9293 		btrfs_record_unlink_dir(trans, BTRFS_I(old_dir),
9294 				BTRFS_I(old_inode), 1);
9295 		btrfs_record_unlink_dir(trans, BTRFS_I(new_dir),
9296 				BTRFS_I(new_inode), 1);
9297 	}
9298 
9299 	/* src is a subvolume */
9300 	if (old_ino == BTRFS_FIRST_FREE_OBJECTID) {
9301 		ret = btrfs_unlink_subvol(trans, old_dir, old_dentry);
9302 	} else { /* src is an inode */
9303 		ret = __btrfs_unlink_inode(trans, BTRFS_I(old_dir),
9304 					   BTRFS_I(old_dentry->d_inode),
9305 					   old_name, &old_rename_ctx);
9306 		if (!ret)
9307 			ret = btrfs_update_inode(trans, root, BTRFS_I(old_inode));
9308 	}
9309 	if (ret) {
9310 		btrfs_abort_transaction(trans, ret);
9311 		goto out_fail;
9312 	}
9313 
9314 	/* dest is a subvolume */
9315 	if (new_ino == BTRFS_FIRST_FREE_OBJECTID) {
9316 		ret = btrfs_unlink_subvol(trans, new_dir, new_dentry);
9317 	} else { /* dest is an inode */
9318 		ret = __btrfs_unlink_inode(trans, BTRFS_I(new_dir),
9319 					   BTRFS_I(new_dentry->d_inode),
9320 					   new_name, &new_rename_ctx);
9321 		if (!ret)
9322 			ret = btrfs_update_inode(trans, dest, BTRFS_I(new_inode));
9323 	}
9324 	if (ret) {
9325 		btrfs_abort_transaction(trans, ret);
9326 		goto out_fail;
9327 	}
9328 
9329 	ret = btrfs_add_link(trans, BTRFS_I(new_dir), BTRFS_I(old_inode),
9330 			     new_name, 0, old_idx);
9331 	if (ret) {
9332 		btrfs_abort_transaction(trans, ret);
9333 		goto out_fail;
9334 	}
9335 
9336 	ret = btrfs_add_link(trans, BTRFS_I(old_dir), BTRFS_I(new_inode),
9337 			     old_name, 0, new_idx);
9338 	if (ret) {
9339 		btrfs_abort_transaction(trans, ret);
9340 		goto out_fail;
9341 	}
9342 
9343 	if (old_inode->i_nlink == 1)
9344 		BTRFS_I(old_inode)->dir_index = old_idx;
9345 	if (new_inode->i_nlink == 1)
9346 		BTRFS_I(new_inode)->dir_index = new_idx;
9347 
9348 	/*
9349 	 * Now pin the logs of the roots. We do it to ensure that no other task
9350 	 * can sync the logs while we are in progress with the rename, because
9351 	 * that could result in an inconsistency in case any of the inodes that
9352 	 * are part of this rename operation were logged before.
9353 	 */
9354 	if (old_ino != BTRFS_FIRST_FREE_OBJECTID)
9355 		btrfs_pin_log_trans(root);
9356 	if (new_ino != BTRFS_FIRST_FREE_OBJECTID)
9357 		btrfs_pin_log_trans(dest);
9358 
9359 	/* Do the log updates for all inodes. */
9360 	if (old_ino != BTRFS_FIRST_FREE_OBJECTID)
9361 		btrfs_log_new_name(trans, old_dentry, BTRFS_I(old_dir),
9362 				   old_rename_ctx.index, new_dentry->d_parent);
9363 	if (new_ino != BTRFS_FIRST_FREE_OBJECTID)
9364 		btrfs_log_new_name(trans, new_dentry, BTRFS_I(new_dir),
9365 				   new_rename_ctx.index, old_dentry->d_parent);
9366 
9367 	/* Now unpin the logs. */
9368 	if (old_ino != BTRFS_FIRST_FREE_OBJECTID)
9369 		btrfs_end_log_trans(root);
9370 	if (new_ino != BTRFS_FIRST_FREE_OBJECTID)
9371 		btrfs_end_log_trans(dest);
9372 out_fail:
9373 	ret2 = btrfs_end_transaction(trans);
9374 	ret = ret ? ret : ret2;
9375 out_notrans:
9376 	if (new_ino == BTRFS_FIRST_FREE_OBJECTID ||
9377 	    old_ino == BTRFS_FIRST_FREE_OBJECTID)
9378 		up_read(&fs_info->subvol_sem);
9379 
9380 	fscrypt_free_filename(&new_fname);
9381 	fscrypt_free_filename(&old_fname);
9382 	return ret;
9383 }
9384 
new_whiteout_inode(struct user_namespace * mnt_userns,struct inode * dir)9385 static struct inode *new_whiteout_inode(struct user_namespace *mnt_userns,
9386 					struct inode *dir)
9387 {
9388 	struct inode *inode;
9389 
9390 	inode = new_inode(dir->i_sb);
9391 	if (inode) {
9392 		inode_init_owner(mnt_userns, inode, dir,
9393 				 S_IFCHR | WHITEOUT_MODE);
9394 		inode->i_op = &btrfs_special_inode_operations;
9395 		init_special_inode(inode, inode->i_mode, WHITEOUT_DEV);
9396 	}
9397 	return inode;
9398 }
9399 
btrfs_rename(struct user_namespace * mnt_userns,struct inode * old_dir,struct dentry * old_dentry,struct inode * new_dir,struct dentry * new_dentry,unsigned int flags)9400 static int btrfs_rename(struct user_namespace *mnt_userns,
9401 			struct inode *old_dir, struct dentry *old_dentry,
9402 			struct inode *new_dir, struct dentry *new_dentry,
9403 			unsigned int flags)
9404 {
9405 	struct btrfs_fs_info *fs_info = btrfs_sb(old_dir->i_sb);
9406 	struct btrfs_new_inode_args whiteout_args = {
9407 		.dir = old_dir,
9408 		.dentry = old_dentry,
9409 	};
9410 	struct btrfs_trans_handle *trans;
9411 	unsigned int trans_num_items;
9412 	struct btrfs_root *root = BTRFS_I(old_dir)->root;
9413 	struct btrfs_root *dest = BTRFS_I(new_dir)->root;
9414 	struct inode *new_inode = d_inode(new_dentry);
9415 	struct inode *old_inode = d_inode(old_dentry);
9416 	struct btrfs_rename_ctx rename_ctx;
9417 	u64 index = 0;
9418 	int ret;
9419 	int ret2;
9420 	u64 old_ino = btrfs_ino(BTRFS_I(old_inode));
9421 	struct fscrypt_name old_fname, new_fname;
9422 
9423 	if (btrfs_ino(BTRFS_I(new_dir)) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)
9424 		return -EPERM;
9425 
9426 	/* we only allow rename subvolume link between subvolumes */
9427 	if (old_ino != BTRFS_FIRST_FREE_OBJECTID && root != dest)
9428 		return -EXDEV;
9429 
9430 	if (old_ino == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID ||
9431 	    (new_inode && btrfs_ino(BTRFS_I(new_inode)) == BTRFS_FIRST_FREE_OBJECTID))
9432 		return -ENOTEMPTY;
9433 
9434 	if (S_ISDIR(old_inode->i_mode) && new_inode &&
9435 	    new_inode->i_size > BTRFS_EMPTY_DIR_SIZE)
9436 		return -ENOTEMPTY;
9437 
9438 	ret = fscrypt_setup_filename(old_dir, &old_dentry->d_name, 0, &old_fname);
9439 	if (ret)
9440 		return ret;
9441 
9442 	ret = fscrypt_setup_filename(new_dir, &new_dentry->d_name, 0, &new_fname);
9443 	if (ret) {
9444 		fscrypt_free_filename(&old_fname);
9445 		return ret;
9446 	}
9447 
9448 	/* check for collisions, even if the  name isn't there */
9449 	ret = btrfs_check_dir_item_collision(dest, new_dir->i_ino, &new_fname.disk_name);
9450 	if (ret) {
9451 		if (ret == -EEXIST) {
9452 			/* we shouldn't get
9453 			 * eexist without a new_inode */
9454 			if (WARN_ON(!new_inode)) {
9455 				goto out_fscrypt_names;
9456 			}
9457 		} else {
9458 			/* maybe -EOVERFLOW */
9459 			goto out_fscrypt_names;
9460 		}
9461 	}
9462 	ret = 0;
9463 
9464 	/*
9465 	 * we're using rename to replace one file with another.  Start IO on it
9466 	 * now so  we don't add too much work to the end of the transaction
9467 	 */
9468 	if (new_inode && S_ISREG(old_inode->i_mode) && new_inode->i_size)
9469 		filemap_flush(old_inode->i_mapping);
9470 
9471 	if (flags & RENAME_WHITEOUT) {
9472 		whiteout_args.inode = new_whiteout_inode(mnt_userns, old_dir);
9473 		if (!whiteout_args.inode) {
9474 			ret = -ENOMEM;
9475 			goto out_fscrypt_names;
9476 		}
9477 		ret = btrfs_new_inode_prepare(&whiteout_args, &trans_num_items);
9478 		if (ret)
9479 			goto out_whiteout_inode;
9480 	} else {
9481 		/* 1 to update the old parent inode. */
9482 		trans_num_items = 1;
9483 	}
9484 
9485 	if (old_ino == BTRFS_FIRST_FREE_OBJECTID) {
9486 		/* Close the race window with snapshot create/destroy ioctl */
9487 		down_read(&fs_info->subvol_sem);
9488 		/*
9489 		 * 1 to remove old root ref
9490 		 * 1 to remove old root backref
9491 		 * 1 to add new root ref
9492 		 * 1 to add new root backref
9493 		 */
9494 		trans_num_items += 4;
9495 	} else {
9496 		/*
9497 		 * 1 to update inode
9498 		 * 1 to remove old inode ref
9499 		 * 1 to add new inode ref
9500 		 */
9501 		trans_num_items += 3;
9502 	}
9503 	/*
9504 	 * 1 to remove old dir item
9505 	 * 1 to remove old dir index
9506 	 * 1 to add new dir item
9507 	 * 1 to add new dir index
9508 	 */
9509 	trans_num_items += 4;
9510 	/* 1 to update new parent inode if it's not the same as the old parent */
9511 	if (new_dir != old_dir)
9512 		trans_num_items++;
9513 	if (new_inode) {
9514 		/*
9515 		 * 1 to update inode
9516 		 * 1 to remove inode ref
9517 		 * 1 to remove dir item
9518 		 * 1 to remove dir index
9519 		 * 1 to possibly add orphan item
9520 		 */
9521 		trans_num_items += 5;
9522 	}
9523 	trans = btrfs_start_transaction(root, trans_num_items);
9524 	if (IS_ERR(trans)) {
9525 		ret = PTR_ERR(trans);
9526 		goto out_notrans;
9527 	}
9528 
9529 	if (dest != root) {
9530 		ret = btrfs_record_root_in_trans(trans, dest);
9531 		if (ret)
9532 			goto out_fail;
9533 	}
9534 
9535 	ret = btrfs_set_inode_index(BTRFS_I(new_dir), &index);
9536 	if (ret)
9537 		goto out_fail;
9538 
9539 	BTRFS_I(old_inode)->dir_index = 0ULL;
9540 	if (unlikely(old_ino == BTRFS_FIRST_FREE_OBJECTID)) {
9541 		/* force full log commit if subvolume involved. */
9542 		btrfs_set_log_full_commit(trans);
9543 	} else {
9544 		ret = btrfs_insert_inode_ref(trans, dest, &new_fname.disk_name,
9545 					     old_ino, btrfs_ino(BTRFS_I(new_dir)),
9546 					     index);
9547 		if (ret)
9548 			goto out_fail;
9549 	}
9550 
9551 	inode_inc_iversion(old_dir);
9552 	inode_inc_iversion(new_dir);
9553 	inode_inc_iversion(old_inode);
9554 	old_dir->i_mtime = current_time(old_dir);
9555 	old_dir->i_ctime = old_dir->i_mtime;
9556 	new_dir->i_mtime = old_dir->i_mtime;
9557 	new_dir->i_ctime = old_dir->i_mtime;
9558 	old_inode->i_ctime = old_dir->i_mtime;
9559 
9560 	if (old_dentry->d_parent != new_dentry->d_parent)
9561 		btrfs_record_unlink_dir(trans, BTRFS_I(old_dir),
9562 				BTRFS_I(old_inode), 1);
9563 
9564 	if (unlikely(old_ino == BTRFS_FIRST_FREE_OBJECTID)) {
9565 		ret = btrfs_unlink_subvol(trans, old_dir, old_dentry);
9566 	} else {
9567 		ret = __btrfs_unlink_inode(trans, BTRFS_I(old_dir),
9568 					   BTRFS_I(d_inode(old_dentry)),
9569 					   &old_fname.disk_name, &rename_ctx);
9570 		if (!ret)
9571 			ret = btrfs_update_inode(trans, root, BTRFS_I(old_inode));
9572 	}
9573 	if (ret) {
9574 		btrfs_abort_transaction(trans, ret);
9575 		goto out_fail;
9576 	}
9577 
9578 	if (new_inode) {
9579 		inode_inc_iversion(new_inode);
9580 		new_inode->i_ctime = current_time(new_inode);
9581 		if (unlikely(btrfs_ino(BTRFS_I(new_inode)) ==
9582 			     BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)) {
9583 			ret = btrfs_unlink_subvol(trans, new_dir, new_dentry);
9584 			BUG_ON(new_inode->i_nlink == 0);
9585 		} else {
9586 			ret = btrfs_unlink_inode(trans, BTRFS_I(new_dir),
9587 						 BTRFS_I(d_inode(new_dentry)),
9588 						 &new_fname.disk_name);
9589 		}
9590 		if (!ret && new_inode->i_nlink == 0)
9591 			ret = btrfs_orphan_add(trans,
9592 					BTRFS_I(d_inode(new_dentry)));
9593 		if (ret) {
9594 			btrfs_abort_transaction(trans, ret);
9595 			goto out_fail;
9596 		}
9597 	}
9598 
9599 	ret = btrfs_add_link(trans, BTRFS_I(new_dir), BTRFS_I(old_inode),
9600 			     &new_fname.disk_name, 0, index);
9601 	if (ret) {
9602 		btrfs_abort_transaction(trans, ret);
9603 		goto out_fail;
9604 	}
9605 
9606 	if (old_inode->i_nlink == 1)
9607 		BTRFS_I(old_inode)->dir_index = index;
9608 
9609 	if (old_ino != BTRFS_FIRST_FREE_OBJECTID)
9610 		btrfs_log_new_name(trans, old_dentry, BTRFS_I(old_dir),
9611 				   rename_ctx.index, new_dentry->d_parent);
9612 
9613 	if (flags & RENAME_WHITEOUT) {
9614 		ret = btrfs_create_new_inode(trans, &whiteout_args);
9615 		if (ret) {
9616 			btrfs_abort_transaction(trans, ret);
9617 			goto out_fail;
9618 		} else {
9619 			unlock_new_inode(whiteout_args.inode);
9620 			iput(whiteout_args.inode);
9621 			whiteout_args.inode = NULL;
9622 		}
9623 	}
9624 out_fail:
9625 	ret2 = btrfs_end_transaction(trans);
9626 	ret = ret ? ret : ret2;
9627 out_notrans:
9628 	if (old_ino == BTRFS_FIRST_FREE_OBJECTID)
9629 		up_read(&fs_info->subvol_sem);
9630 	if (flags & RENAME_WHITEOUT)
9631 		btrfs_new_inode_args_destroy(&whiteout_args);
9632 out_whiteout_inode:
9633 	if (flags & RENAME_WHITEOUT)
9634 		iput(whiteout_args.inode);
9635 out_fscrypt_names:
9636 	fscrypt_free_filename(&old_fname);
9637 	fscrypt_free_filename(&new_fname);
9638 	return ret;
9639 }
9640 
btrfs_rename2(struct user_namespace * mnt_userns,struct inode * old_dir,struct dentry * old_dentry,struct inode * new_dir,struct dentry * new_dentry,unsigned int flags)9641 static int btrfs_rename2(struct user_namespace *mnt_userns, struct inode *old_dir,
9642 			 struct dentry *old_dentry, struct inode *new_dir,
9643 			 struct dentry *new_dentry, unsigned int flags)
9644 {
9645 	int ret;
9646 
9647 	if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE | RENAME_WHITEOUT))
9648 		return -EINVAL;
9649 
9650 	if (flags & RENAME_EXCHANGE)
9651 		ret = btrfs_rename_exchange(old_dir, old_dentry, new_dir,
9652 					    new_dentry);
9653 	else
9654 		ret = btrfs_rename(mnt_userns, old_dir, old_dentry, new_dir,
9655 				   new_dentry, flags);
9656 
9657 	btrfs_btree_balance_dirty(BTRFS_I(new_dir)->root->fs_info);
9658 
9659 	return ret;
9660 }
9661 
9662 struct btrfs_delalloc_work {
9663 	struct inode *inode;
9664 	struct completion completion;
9665 	struct list_head list;
9666 	struct btrfs_work work;
9667 };
9668 
btrfs_run_delalloc_work(struct btrfs_work * work)9669 static void btrfs_run_delalloc_work(struct btrfs_work *work)
9670 {
9671 	struct btrfs_delalloc_work *delalloc_work;
9672 	struct inode *inode;
9673 
9674 	delalloc_work = container_of(work, struct btrfs_delalloc_work,
9675 				     work);
9676 	inode = delalloc_work->inode;
9677 	filemap_flush(inode->i_mapping);
9678 	if (test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
9679 				&BTRFS_I(inode)->runtime_flags))
9680 		filemap_flush(inode->i_mapping);
9681 
9682 	iput(inode);
9683 	complete(&delalloc_work->completion);
9684 }
9685 
btrfs_alloc_delalloc_work(struct inode * inode)9686 static struct btrfs_delalloc_work *btrfs_alloc_delalloc_work(struct inode *inode)
9687 {
9688 	struct btrfs_delalloc_work *work;
9689 
9690 	work = kmalloc(sizeof(*work), GFP_NOFS);
9691 	if (!work)
9692 		return NULL;
9693 
9694 	init_completion(&work->completion);
9695 	INIT_LIST_HEAD(&work->list);
9696 	work->inode = inode;
9697 	btrfs_init_work(&work->work, btrfs_run_delalloc_work, NULL, NULL);
9698 
9699 	return work;
9700 }
9701 
9702 /*
9703  * some fairly slow code that needs optimization. This walks the list
9704  * of all the inodes with pending delalloc and forces them to disk.
9705  */
start_delalloc_inodes(struct btrfs_root * root,struct writeback_control * wbc,bool snapshot,bool in_reclaim_context)9706 static int start_delalloc_inodes(struct btrfs_root *root,
9707 				 struct writeback_control *wbc, bool snapshot,
9708 				 bool in_reclaim_context)
9709 {
9710 	struct btrfs_inode *binode;
9711 	struct inode *inode;
9712 	struct btrfs_delalloc_work *work, *next;
9713 	struct list_head works;
9714 	struct list_head splice;
9715 	int ret = 0;
9716 	bool full_flush = wbc->nr_to_write == LONG_MAX;
9717 
9718 	INIT_LIST_HEAD(&works);
9719 	INIT_LIST_HEAD(&splice);
9720 
9721 	mutex_lock(&root->delalloc_mutex);
9722 	spin_lock(&root->delalloc_lock);
9723 	list_splice_init(&root->delalloc_inodes, &splice);
9724 	while (!list_empty(&splice)) {
9725 		binode = list_entry(splice.next, struct btrfs_inode,
9726 				    delalloc_inodes);
9727 
9728 		list_move_tail(&binode->delalloc_inodes,
9729 			       &root->delalloc_inodes);
9730 
9731 		if (in_reclaim_context &&
9732 		    test_bit(BTRFS_INODE_NO_DELALLOC_FLUSH, &binode->runtime_flags))
9733 			continue;
9734 
9735 		inode = igrab(&binode->vfs_inode);
9736 		if (!inode) {
9737 			cond_resched_lock(&root->delalloc_lock);
9738 			continue;
9739 		}
9740 		spin_unlock(&root->delalloc_lock);
9741 
9742 		if (snapshot)
9743 			set_bit(BTRFS_INODE_SNAPSHOT_FLUSH,
9744 				&binode->runtime_flags);
9745 		if (full_flush) {
9746 			work = btrfs_alloc_delalloc_work(inode);
9747 			if (!work) {
9748 				iput(inode);
9749 				ret = -ENOMEM;
9750 				goto out;
9751 			}
9752 			list_add_tail(&work->list, &works);
9753 			btrfs_queue_work(root->fs_info->flush_workers,
9754 					 &work->work);
9755 		} else {
9756 			ret = filemap_fdatawrite_wbc(inode->i_mapping, wbc);
9757 			btrfs_add_delayed_iput(inode);
9758 			if (ret || wbc->nr_to_write <= 0)
9759 				goto out;
9760 		}
9761 		cond_resched();
9762 		spin_lock(&root->delalloc_lock);
9763 	}
9764 	spin_unlock(&root->delalloc_lock);
9765 
9766 out:
9767 	list_for_each_entry_safe(work, next, &works, list) {
9768 		list_del_init(&work->list);
9769 		wait_for_completion(&work->completion);
9770 		kfree(work);
9771 	}
9772 
9773 	if (!list_empty(&splice)) {
9774 		spin_lock(&root->delalloc_lock);
9775 		list_splice_tail(&splice, &root->delalloc_inodes);
9776 		spin_unlock(&root->delalloc_lock);
9777 	}
9778 	mutex_unlock(&root->delalloc_mutex);
9779 	return ret;
9780 }
9781 
btrfs_start_delalloc_snapshot(struct btrfs_root * root,bool in_reclaim_context)9782 int btrfs_start_delalloc_snapshot(struct btrfs_root *root, bool in_reclaim_context)
9783 {
9784 	struct writeback_control wbc = {
9785 		.nr_to_write = LONG_MAX,
9786 		.sync_mode = WB_SYNC_NONE,
9787 		.range_start = 0,
9788 		.range_end = LLONG_MAX,
9789 	};
9790 	struct btrfs_fs_info *fs_info = root->fs_info;
9791 
9792 	if (BTRFS_FS_ERROR(fs_info))
9793 		return -EROFS;
9794 
9795 	return start_delalloc_inodes(root, &wbc, true, in_reclaim_context);
9796 }
9797 
btrfs_start_delalloc_roots(struct btrfs_fs_info * fs_info,long nr,bool in_reclaim_context)9798 int btrfs_start_delalloc_roots(struct btrfs_fs_info *fs_info, long nr,
9799 			       bool in_reclaim_context)
9800 {
9801 	struct writeback_control wbc = {
9802 		.nr_to_write = nr,
9803 		.sync_mode = WB_SYNC_NONE,
9804 		.range_start = 0,
9805 		.range_end = LLONG_MAX,
9806 	};
9807 	struct btrfs_root *root;
9808 	struct list_head splice;
9809 	int ret;
9810 
9811 	if (BTRFS_FS_ERROR(fs_info))
9812 		return -EROFS;
9813 
9814 	INIT_LIST_HEAD(&splice);
9815 
9816 	mutex_lock(&fs_info->delalloc_root_mutex);
9817 	spin_lock(&fs_info->delalloc_root_lock);
9818 	list_splice_init(&fs_info->delalloc_roots, &splice);
9819 	while (!list_empty(&splice)) {
9820 		/*
9821 		 * Reset nr_to_write here so we know that we're doing a full
9822 		 * flush.
9823 		 */
9824 		if (nr == LONG_MAX)
9825 			wbc.nr_to_write = LONG_MAX;
9826 
9827 		root = list_first_entry(&splice, struct btrfs_root,
9828 					delalloc_root);
9829 		root = btrfs_grab_root(root);
9830 		BUG_ON(!root);
9831 		list_move_tail(&root->delalloc_root,
9832 			       &fs_info->delalloc_roots);
9833 		spin_unlock(&fs_info->delalloc_root_lock);
9834 
9835 		ret = start_delalloc_inodes(root, &wbc, false, in_reclaim_context);
9836 		btrfs_put_root(root);
9837 		if (ret < 0 || wbc.nr_to_write <= 0)
9838 			goto out;
9839 		spin_lock(&fs_info->delalloc_root_lock);
9840 	}
9841 	spin_unlock(&fs_info->delalloc_root_lock);
9842 
9843 	ret = 0;
9844 out:
9845 	if (!list_empty(&splice)) {
9846 		spin_lock(&fs_info->delalloc_root_lock);
9847 		list_splice_tail(&splice, &fs_info->delalloc_roots);
9848 		spin_unlock(&fs_info->delalloc_root_lock);
9849 	}
9850 	mutex_unlock(&fs_info->delalloc_root_mutex);
9851 	return ret;
9852 }
9853 
btrfs_symlink(struct user_namespace * mnt_userns,struct inode * dir,struct dentry * dentry,const char * symname)9854 static int btrfs_symlink(struct user_namespace *mnt_userns, struct inode *dir,
9855 			 struct dentry *dentry, const char *symname)
9856 {
9857 	struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
9858 	struct btrfs_trans_handle *trans;
9859 	struct btrfs_root *root = BTRFS_I(dir)->root;
9860 	struct btrfs_path *path;
9861 	struct btrfs_key key;
9862 	struct inode *inode;
9863 	struct btrfs_new_inode_args new_inode_args = {
9864 		.dir = dir,
9865 		.dentry = dentry,
9866 	};
9867 	unsigned int trans_num_items;
9868 	int err;
9869 	int name_len;
9870 	int datasize;
9871 	unsigned long ptr;
9872 	struct btrfs_file_extent_item *ei;
9873 	struct extent_buffer *leaf;
9874 
9875 	name_len = strlen(symname);
9876 	if (name_len > BTRFS_MAX_INLINE_DATA_SIZE(fs_info))
9877 		return -ENAMETOOLONG;
9878 
9879 	inode = new_inode(dir->i_sb);
9880 	if (!inode)
9881 		return -ENOMEM;
9882 	inode_init_owner(mnt_userns, inode, dir, S_IFLNK | S_IRWXUGO);
9883 	inode->i_op = &btrfs_symlink_inode_operations;
9884 	inode_nohighmem(inode);
9885 	inode->i_mapping->a_ops = &btrfs_aops;
9886 	btrfs_i_size_write(BTRFS_I(inode), name_len);
9887 	inode_set_bytes(inode, name_len);
9888 
9889 	new_inode_args.inode = inode;
9890 	err = btrfs_new_inode_prepare(&new_inode_args, &trans_num_items);
9891 	if (err)
9892 		goto out_inode;
9893 	/* 1 additional item for the inline extent */
9894 	trans_num_items++;
9895 
9896 	trans = btrfs_start_transaction(root, trans_num_items);
9897 	if (IS_ERR(trans)) {
9898 		err = PTR_ERR(trans);
9899 		goto out_new_inode_args;
9900 	}
9901 
9902 	err = btrfs_create_new_inode(trans, &new_inode_args);
9903 	if (err)
9904 		goto out;
9905 
9906 	path = btrfs_alloc_path();
9907 	if (!path) {
9908 		err = -ENOMEM;
9909 		btrfs_abort_transaction(trans, err);
9910 		discard_new_inode(inode);
9911 		inode = NULL;
9912 		goto out;
9913 	}
9914 	key.objectid = btrfs_ino(BTRFS_I(inode));
9915 	key.offset = 0;
9916 	key.type = BTRFS_EXTENT_DATA_KEY;
9917 	datasize = btrfs_file_extent_calc_inline_size(name_len);
9918 	err = btrfs_insert_empty_item(trans, root, path, &key,
9919 				      datasize);
9920 	if (err) {
9921 		btrfs_abort_transaction(trans, err);
9922 		btrfs_free_path(path);
9923 		discard_new_inode(inode);
9924 		inode = NULL;
9925 		goto out;
9926 	}
9927 	leaf = path->nodes[0];
9928 	ei = btrfs_item_ptr(leaf, path->slots[0],
9929 			    struct btrfs_file_extent_item);
9930 	btrfs_set_file_extent_generation(leaf, ei, trans->transid);
9931 	btrfs_set_file_extent_type(leaf, ei,
9932 				   BTRFS_FILE_EXTENT_INLINE);
9933 	btrfs_set_file_extent_encryption(leaf, ei, 0);
9934 	btrfs_set_file_extent_compression(leaf, ei, 0);
9935 	btrfs_set_file_extent_other_encoding(leaf, ei, 0);
9936 	btrfs_set_file_extent_ram_bytes(leaf, ei, name_len);
9937 
9938 	ptr = btrfs_file_extent_inline_start(ei);
9939 	write_extent_buffer(leaf, symname, ptr, name_len);
9940 	btrfs_mark_buffer_dirty(leaf);
9941 	btrfs_free_path(path);
9942 
9943 	d_instantiate_new(dentry, inode);
9944 	err = 0;
9945 out:
9946 	btrfs_end_transaction(trans);
9947 	btrfs_btree_balance_dirty(fs_info);
9948 out_new_inode_args:
9949 	btrfs_new_inode_args_destroy(&new_inode_args);
9950 out_inode:
9951 	if (err)
9952 		iput(inode);
9953 	return err;
9954 }
9955 
insert_prealloc_file_extent(struct btrfs_trans_handle * trans_in,struct btrfs_inode * inode,struct btrfs_key * ins,u64 file_offset)9956 static struct btrfs_trans_handle *insert_prealloc_file_extent(
9957 				       struct btrfs_trans_handle *trans_in,
9958 				       struct btrfs_inode *inode,
9959 				       struct btrfs_key *ins,
9960 				       u64 file_offset)
9961 {
9962 	struct btrfs_file_extent_item stack_fi;
9963 	struct btrfs_replace_extent_info extent_info;
9964 	struct btrfs_trans_handle *trans = trans_in;
9965 	struct btrfs_path *path;
9966 	u64 start = ins->objectid;
9967 	u64 len = ins->offset;
9968 	u64 qgroup_released = 0;
9969 	int ret;
9970 
9971 	memset(&stack_fi, 0, sizeof(stack_fi));
9972 
9973 	btrfs_set_stack_file_extent_type(&stack_fi, BTRFS_FILE_EXTENT_PREALLOC);
9974 	btrfs_set_stack_file_extent_disk_bytenr(&stack_fi, start);
9975 	btrfs_set_stack_file_extent_disk_num_bytes(&stack_fi, len);
9976 	btrfs_set_stack_file_extent_num_bytes(&stack_fi, len);
9977 	btrfs_set_stack_file_extent_ram_bytes(&stack_fi, len);
9978 	btrfs_set_stack_file_extent_compression(&stack_fi, BTRFS_COMPRESS_NONE);
9979 	/* Encryption and other encoding is reserved and all 0 */
9980 
9981 	ret = btrfs_qgroup_release_data(inode, file_offset, len, &qgroup_released);
9982 	if (ret < 0)
9983 		return ERR_PTR(ret);
9984 
9985 	if (trans) {
9986 		ret = insert_reserved_file_extent(trans, inode,
9987 						  file_offset, &stack_fi,
9988 						  true, qgroup_released);
9989 		if (ret)
9990 			goto free_qgroup;
9991 		return trans;
9992 	}
9993 
9994 	extent_info.disk_offset = start;
9995 	extent_info.disk_len = len;
9996 	extent_info.data_offset = 0;
9997 	extent_info.data_len = len;
9998 	extent_info.file_offset = file_offset;
9999 	extent_info.extent_buf = (char *)&stack_fi;
10000 	extent_info.is_new_extent = true;
10001 	extent_info.update_times = true;
10002 	extent_info.qgroup_reserved = qgroup_released;
10003 	extent_info.insertions = 0;
10004 
10005 	path = btrfs_alloc_path();
10006 	if (!path) {
10007 		ret = -ENOMEM;
10008 		goto free_qgroup;
10009 	}
10010 
10011 	ret = btrfs_replace_file_extents(inode, path, file_offset,
10012 				     file_offset + len - 1, &extent_info,
10013 				     &trans);
10014 	btrfs_free_path(path);
10015 	if (ret)
10016 		goto free_qgroup;
10017 	return trans;
10018 
10019 free_qgroup:
10020 	/*
10021 	 * We have released qgroup data range at the beginning of the function,
10022 	 * and normally qgroup_released bytes will be freed when committing
10023 	 * transaction.
10024 	 * But if we error out early, we have to free what we have released
10025 	 * or we leak qgroup data reservation.
10026 	 */
10027 	btrfs_qgroup_free_refroot(inode->root->fs_info,
10028 			inode->root->root_key.objectid, qgroup_released,
10029 			BTRFS_QGROUP_RSV_DATA);
10030 	return ERR_PTR(ret);
10031 }
10032 
__btrfs_prealloc_file_range(struct inode * inode,int mode,u64 start,u64 num_bytes,u64 min_size,loff_t actual_len,u64 * alloc_hint,struct btrfs_trans_handle * trans)10033 static int __btrfs_prealloc_file_range(struct inode *inode, int mode,
10034 				       u64 start, u64 num_bytes, u64 min_size,
10035 				       loff_t actual_len, u64 *alloc_hint,
10036 				       struct btrfs_trans_handle *trans)
10037 {
10038 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
10039 	struct extent_map *em;
10040 	struct btrfs_root *root = BTRFS_I(inode)->root;
10041 	struct btrfs_key ins;
10042 	u64 cur_offset = start;
10043 	u64 clear_offset = start;
10044 	u64 i_size;
10045 	u64 cur_bytes;
10046 	u64 last_alloc = (u64)-1;
10047 	int ret = 0;
10048 	bool own_trans = true;
10049 	u64 end = start + num_bytes - 1;
10050 
10051 	if (trans)
10052 		own_trans = false;
10053 	while (num_bytes > 0) {
10054 		cur_bytes = min_t(u64, num_bytes, SZ_256M);
10055 		cur_bytes = max(cur_bytes, min_size);
10056 		/*
10057 		 * If we are severely fragmented we could end up with really
10058 		 * small allocations, so if the allocator is returning small
10059 		 * chunks lets make its job easier by only searching for those
10060 		 * sized chunks.
10061 		 */
10062 		cur_bytes = min(cur_bytes, last_alloc);
10063 		ret = btrfs_reserve_extent(root, cur_bytes, cur_bytes,
10064 				min_size, 0, *alloc_hint, &ins, 1, 0);
10065 		if (ret)
10066 			break;
10067 
10068 		/*
10069 		 * We've reserved this space, and thus converted it from
10070 		 * ->bytes_may_use to ->bytes_reserved.  Any error that happens
10071 		 * from here on out we will only need to clear our reservation
10072 		 * for the remaining unreserved area, so advance our
10073 		 * clear_offset by our extent size.
10074 		 */
10075 		clear_offset += ins.offset;
10076 
10077 		last_alloc = ins.offset;
10078 		trans = insert_prealloc_file_extent(trans, BTRFS_I(inode),
10079 						    &ins, cur_offset);
10080 		/*
10081 		 * Now that we inserted the prealloc extent we can finally
10082 		 * decrement the number of reservations in the block group.
10083 		 * If we did it before, we could race with relocation and have
10084 		 * relocation miss the reserved extent, making it fail later.
10085 		 */
10086 		btrfs_dec_block_group_reservations(fs_info, ins.objectid);
10087 		if (IS_ERR(trans)) {
10088 			ret = PTR_ERR(trans);
10089 			btrfs_free_reserved_extent(fs_info, ins.objectid,
10090 						   ins.offset, 0);
10091 			break;
10092 		}
10093 
10094 		em = alloc_extent_map();
10095 		if (!em) {
10096 			btrfs_drop_extent_map_range(BTRFS_I(inode), cur_offset,
10097 					    cur_offset + ins.offset - 1, false);
10098 			btrfs_set_inode_full_sync(BTRFS_I(inode));
10099 			goto next;
10100 		}
10101 
10102 		em->start = cur_offset;
10103 		em->orig_start = cur_offset;
10104 		em->len = ins.offset;
10105 		em->block_start = ins.objectid;
10106 		em->block_len = ins.offset;
10107 		em->orig_block_len = ins.offset;
10108 		em->ram_bytes = ins.offset;
10109 		set_bit(EXTENT_FLAG_PREALLOC, &em->flags);
10110 		em->generation = trans->transid;
10111 
10112 		ret = btrfs_replace_extent_map_range(BTRFS_I(inode), em, true);
10113 		free_extent_map(em);
10114 next:
10115 		num_bytes -= ins.offset;
10116 		cur_offset += ins.offset;
10117 		*alloc_hint = ins.objectid + ins.offset;
10118 
10119 		inode_inc_iversion(inode);
10120 		inode->i_ctime = current_time(inode);
10121 		BTRFS_I(inode)->flags |= BTRFS_INODE_PREALLOC;
10122 		if (!(mode & FALLOC_FL_KEEP_SIZE) &&
10123 		    (actual_len > inode->i_size) &&
10124 		    (cur_offset > inode->i_size)) {
10125 			if (cur_offset > actual_len)
10126 				i_size = actual_len;
10127 			else
10128 				i_size = cur_offset;
10129 			i_size_write(inode, i_size);
10130 			btrfs_inode_safe_disk_i_size_write(BTRFS_I(inode), 0);
10131 		}
10132 
10133 		ret = btrfs_update_inode(trans, root, BTRFS_I(inode));
10134 
10135 		if (ret) {
10136 			btrfs_abort_transaction(trans, ret);
10137 			if (own_trans)
10138 				btrfs_end_transaction(trans);
10139 			break;
10140 		}
10141 
10142 		if (own_trans) {
10143 			btrfs_end_transaction(trans);
10144 			trans = NULL;
10145 		}
10146 	}
10147 	if (clear_offset < end)
10148 		btrfs_free_reserved_data_space(BTRFS_I(inode), NULL, clear_offset,
10149 			end - clear_offset + 1);
10150 	return ret;
10151 }
10152 
btrfs_prealloc_file_range(struct inode * inode,int mode,u64 start,u64 num_bytes,u64 min_size,loff_t actual_len,u64 * alloc_hint)10153 int btrfs_prealloc_file_range(struct inode *inode, int mode,
10154 			      u64 start, u64 num_bytes, u64 min_size,
10155 			      loff_t actual_len, u64 *alloc_hint)
10156 {
10157 	return __btrfs_prealloc_file_range(inode, mode, start, num_bytes,
10158 					   min_size, actual_len, alloc_hint,
10159 					   NULL);
10160 }
10161 
btrfs_prealloc_file_range_trans(struct inode * inode,struct btrfs_trans_handle * trans,int mode,u64 start,u64 num_bytes,u64 min_size,loff_t actual_len,u64 * alloc_hint)10162 int btrfs_prealloc_file_range_trans(struct inode *inode,
10163 				    struct btrfs_trans_handle *trans, int mode,
10164 				    u64 start, u64 num_bytes, u64 min_size,
10165 				    loff_t actual_len, u64 *alloc_hint)
10166 {
10167 	return __btrfs_prealloc_file_range(inode, mode, start, num_bytes,
10168 					   min_size, actual_len, alloc_hint, trans);
10169 }
10170 
btrfs_permission(struct user_namespace * mnt_userns,struct inode * inode,int mask)10171 static int btrfs_permission(struct user_namespace *mnt_userns,
10172 			    struct inode *inode, int mask)
10173 {
10174 	struct btrfs_root *root = BTRFS_I(inode)->root;
10175 	umode_t mode = inode->i_mode;
10176 
10177 	if (mask & MAY_WRITE &&
10178 	    (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode))) {
10179 		if (btrfs_root_readonly(root))
10180 			return -EROFS;
10181 		if (BTRFS_I(inode)->flags & BTRFS_INODE_READONLY)
10182 			return -EACCES;
10183 	}
10184 	return generic_permission(mnt_userns, inode, mask);
10185 }
10186 
btrfs_tmpfile(struct user_namespace * mnt_userns,struct inode * dir,struct file * file,umode_t mode)10187 static int btrfs_tmpfile(struct user_namespace *mnt_userns, struct inode *dir,
10188 			 struct file *file, umode_t mode)
10189 {
10190 	struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
10191 	struct btrfs_trans_handle *trans;
10192 	struct btrfs_root *root = BTRFS_I(dir)->root;
10193 	struct inode *inode;
10194 	struct btrfs_new_inode_args new_inode_args = {
10195 		.dir = dir,
10196 		.dentry = file->f_path.dentry,
10197 		.orphan = true,
10198 	};
10199 	unsigned int trans_num_items;
10200 	int ret;
10201 
10202 	inode = new_inode(dir->i_sb);
10203 	if (!inode)
10204 		return -ENOMEM;
10205 	inode_init_owner(mnt_userns, inode, dir, mode);
10206 	inode->i_fop = &btrfs_file_operations;
10207 	inode->i_op = &btrfs_file_inode_operations;
10208 	inode->i_mapping->a_ops = &btrfs_aops;
10209 
10210 	new_inode_args.inode = inode;
10211 	ret = btrfs_new_inode_prepare(&new_inode_args, &trans_num_items);
10212 	if (ret)
10213 		goto out_inode;
10214 
10215 	trans = btrfs_start_transaction(root, trans_num_items);
10216 	if (IS_ERR(trans)) {
10217 		ret = PTR_ERR(trans);
10218 		goto out_new_inode_args;
10219 	}
10220 
10221 	ret = btrfs_create_new_inode(trans, &new_inode_args);
10222 
10223 	/*
10224 	 * We set number of links to 0 in btrfs_create_new_inode(), and here we
10225 	 * set it to 1 because d_tmpfile() will issue a warning if the count is
10226 	 * 0, through:
10227 	 *
10228 	 *    d_tmpfile() -> inode_dec_link_count() -> drop_nlink()
10229 	 */
10230 	set_nlink(inode, 1);
10231 
10232 	if (!ret) {
10233 		d_tmpfile(file, inode);
10234 		unlock_new_inode(inode);
10235 		mark_inode_dirty(inode);
10236 	}
10237 
10238 	btrfs_end_transaction(trans);
10239 	btrfs_btree_balance_dirty(fs_info);
10240 out_new_inode_args:
10241 	btrfs_new_inode_args_destroy(&new_inode_args);
10242 out_inode:
10243 	if (ret)
10244 		iput(inode);
10245 	return finish_open_simple(file, ret);
10246 }
10247 
btrfs_set_range_writeback(struct btrfs_inode * inode,u64 start,u64 end)10248 void btrfs_set_range_writeback(struct btrfs_inode *inode, u64 start, u64 end)
10249 {
10250 	struct btrfs_fs_info *fs_info = inode->root->fs_info;
10251 	unsigned long index = start >> PAGE_SHIFT;
10252 	unsigned long end_index = end >> PAGE_SHIFT;
10253 	struct page *page;
10254 	u32 len;
10255 
10256 	ASSERT(end + 1 - start <= U32_MAX);
10257 	len = end + 1 - start;
10258 	while (index <= end_index) {
10259 		page = find_get_page(inode->vfs_inode.i_mapping, index);
10260 		ASSERT(page); /* Pages should be in the extent_io_tree */
10261 
10262 		btrfs_page_set_writeback(fs_info, page, start, len);
10263 		put_page(page);
10264 		index++;
10265 	}
10266 }
10267 
btrfs_encoded_io_compression_from_extent(struct btrfs_fs_info * fs_info,int compress_type)10268 int btrfs_encoded_io_compression_from_extent(struct btrfs_fs_info *fs_info,
10269 					     int compress_type)
10270 {
10271 	switch (compress_type) {
10272 	case BTRFS_COMPRESS_NONE:
10273 		return BTRFS_ENCODED_IO_COMPRESSION_NONE;
10274 	case BTRFS_COMPRESS_ZLIB:
10275 		return BTRFS_ENCODED_IO_COMPRESSION_ZLIB;
10276 	case BTRFS_COMPRESS_LZO:
10277 		/*
10278 		 * The LZO format depends on the sector size. 64K is the maximum
10279 		 * sector size that we support.
10280 		 */
10281 		if (fs_info->sectorsize < SZ_4K || fs_info->sectorsize > SZ_64K)
10282 			return -EINVAL;
10283 		return BTRFS_ENCODED_IO_COMPRESSION_LZO_4K +
10284 		       (fs_info->sectorsize_bits - 12);
10285 	case BTRFS_COMPRESS_ZSTD:
10286 		return BTRFS_ENCODED_IO_COMPRESSION_ZSTD;
10287 	default:
10288 		return -EUCLEAN;
10289 	}
10290 }
10291 
btrfs_encoded_read_inline(struct kiocb * iocb,struct iov_iter * iter,u64 start,u64 lockend,struct extent_state ** cached_state,u64 extent_start,size_t count,struct btrfs_ioctl_encoded_io_args * encoded,bool * unlocked)10292 static ssize_t btrfs_encoded_read_inline(
10293 				struct kiocb *iocb,
10294 				struct iov_iter *iter, u64 start,
10295 				u64 lockend,
10296 				struct extent_state **cached_state,
10297 				u64 extent_start, size_t count,
10298 				struct btrfs_ioctl_encoded_io_args *encoded,
10299 				bool *unlocked)
10300 {
10301 	struct btrfs_inode *inode = BTRFS_I(file_inode(iocb->ki_filp));
10302 	struct btrfs_root *root = inode->root;
10303 	struct btrfs_fs_info *fs_info = root->fs_info;
10304 	struct extent_io_tree *io_tree = &inode->io_tree;
10305 	struct btrfs_path *path;
10306 	struct extent_buffer *leaf;
10307 	struct btrfs_file_extent_item *item;
10308 	u64 ram_bytes;
10309 	unsigned long ptr;
10310 	void *tmp;
10311 	ssize_t ret;
10312 
10313 	path = btrfs_alloc_path();
10314 	if (!path) {
10315 		ret = -ENOMEM;
10316 		goto out;
10317 	}
10318 	ret = btrfs_lookup_file_extent(NULL, root, path, btrfs_ino(inode),
10319 				       extent_start, 0);
10320 	if (ret) {
10321 		if (ret > 0) {
10322 			/* The extent item disappeared? */
10323 			ret = -EIO;
10324 		}
10325 		goto out;
10326 	}
10327 	leaf = path->nodes[0];
10328 	item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_file_extent_item);
10329 
10330 	ram_bytes = btrfs_file_extent_ram_bytes(leaf, item);
10331 	ptr = btrfs_file_extent_inline_start(item);
10332 
10333 	encoded->len = min_t(u64, extent_start + ram_bytes,
10334 			     inode->vfs_inode.i_size) - iocb->ki_pos;
10335 	ret = btrfs_encoded_io_compression_from_extent(fs_info,
10336 				 btrfs_file_extent_compression(leaf, item));
10337 	if (ret < 0)
10338 		goto out;
10339 	encoded->compression = ret;
10340 	if (encoded->compression) {
10341 		size_t inline_size;
10342 
10343 		inline_size = btrfs_file_extent_inline_item_len(leaf,
10344 								path->slots[0]);
10345 		if (inline_size > count) {
10346 			ret = -ENOBUFS;
10347 			goto out;
10348 		}
10349 		count = inline_size;
10350 		encoded->unencoded_len = ram_bytes;
10351 		encoded->unencoded_offset = iocb->ki_pos - extent_start;
10352 	} else {
10353 		count = min_t(u64, count, encoded->len);
10354 		encoded->len = count;
10355 		encoded->unencoded_len = count;
10356 		ptr += iocb->ki_pos - extent_start;
10357 	}
10358 
10359 	tmp = kmalloc(count, GFP_NOFS);
10360 	if (!tmp) {
10361 		ret = -ENOMEM;
10362 		goto out;
10363 	}
10364 	read_extent_buffer(leaf, tmp, ptr, count);
10365 	btrfs_release_path(path);
10366 	unlock_extent(io_tree, start, lockend, cached_state);
10367 	btrfs_inode_unlock(&inode->vfs_inode, BTRFS_ILOCK_SHARED);
10368 	*unlocked = true;
10369 
10370 	ret = copy_to_iter(tmp, count, iter);
10371 	if (ret != count)
10372 		ret = -EFAULT;
10373 	kfree(tmp);
10374 out:
10375 	btrfs_free_path(path);
10376 	return ret;
10377 }
10378 
10379 struct btrfs_encoded_read_private {
10380 	struct btrfs_inode *inode;
10381 	u64 file_offset;
10382 	wait_queue_head_t wait;
10383 	atomic_t pending;
10384 	blk_status_t status;
10385 	bool skip_csum;
10386 };
10387 
submit_encoded_read_bio(struct btrfs_inode * inode,struct bio * bio,int mirror_num)10388 static blk_status_t submit_encoded_read_bio(struct btrfs_inode *inode,
10389 					    struct bio *bio, int mirror_num)
10390 {
10391 	struct btrfs_encoded_read_private *priv = btrfs_bio(bio)->private;
10392 	struct btrfs_fs_info *fs_info = inode->root->fs_info;
10393 	blk_status_t ret;
10394 
10395 	if (!priv->skip_csum) {
10396 		ret = btrfs_lookup_bio_sums(&inode->vfs_inode, bio, NULL);
10397 		if (ret)
10398 			return ret;
10399 	}
10400 
10401 	atomic_inc(&priv->pending);
10402 	btrfs_submit_bio(fs_info, bio, mirror_num);
10403 	return BLK_STS_OK;
10404 }
10405 
btrfs_encoded_read_verify_csum(struct btrfs_bio * bbio)10406 static blk_status_t btrfs_encoded_read_verify_csum(struct btrfs_bio *bbio)
10407 {
10408 	const bool uptodate = (bbio->bio.bi_status == BLK_STS_OK);
10409 	struct btrfs_encoded_read_private *priv = bbio->private;
10410 	struct btrfs_inode *inode = priv->inode;
10411 	struct btrfs_fs_info *fs_info = inode->root->fs_info;
10412 	u32 sectorsize = fs_info->sectorsize;
10413 	struct bio_vec *bvec;
10414 	struct bvec_iter_all iter_all;
10415 	u32 bio_offset = 0;
10416 
10417 	if (priv->skip_csum || !uptodate)
10418 		return bbio->bio.bi_status;
10419 
10420 	bio_for_each_segment_all(bvec, &bbio->bio, iter_all) {
10421 		unsigned int i, nr_sectors, pgoff;
10422 
10423 		nr_sectors = BTRFS_BYTES_TO_BLKS(fs_info, bvec->bv_len);
10424 		pgoff = bvec->bv_offset;
10425 		for (i = 0; i < nr_sectors; i++) {
10426 			ASSERT(pgoff < PAGE_SIZE);
10427 			if (btrfs_check_data_csum(&inode->vfs_inode, bbio, bio_offset,
10428 					    bvec->bv_page, pgoff))
10429 				return BLK_STS_IOERR;
10430 			bio_offset += sectorsize;
10431 			pgoff += sectorsize;
10432 		}
10433 	}
10434 	return BLK_STS_OK;
10435 }
10436 
btrfs_encoded_read_endio(struct btrfs_bio * bbio)10437 static void btrfs_encoded_read_endio(struct btrfs_bio *bbio)
10438 {
10439 	struct btrfs_encoded_read_private *priv = bbio->private;
10440 	blk_status_t status;
10441 
10442 	status = btrfs_encoded_read_verify_csum(bbio);
10443 	if (status) {
10444 		/*
10445 		 * The memory barrier implied by the atomic_dec_return() here
10446 		 * pairs with the memory barrier implied by the
10447 		 * atomic_dec_return() or io_wait_event() in
10448 		 * btrfs_encoded_read_regular_fill_pages() to ensure that this
10449 		 * write is observed before the load of status in
10450 		 * btrfs_encoded_read_regular_fill_pages().
10451 		 */
10452 		WRITE_ONCE(priv->status, status);
10453 	}
10454 	if (!atomic_dec_return(&priv->pending))
10455 		wake_up(&priv->wait);
10456 	btrfs_bio_free_csum(bbio);
10457 	bio_put(&bbio->bio);
10458 }
10459 
btrfs_encoded_read_regular_fill_pages(struct btrfs_inode * inode,u64 file_offset,u64 disk_bytenr,u64 disk_io_size,struct page ** pages)10460 int btrfs_encoded_read_regular_fill_pages(struct btrfs_inode *inode,
10461 					  u64 file_offset, u64 disk_bytenr,
10462 					  u64 disk_io_size, struct page **pages)
10463 {
10464 	struct btrfs_fs_info *fs_info = inode->root->fs_info;
10465 	struct btrfs_encoded_read_private priv = {
10466 		.inode = inode,
10467 		.file_offset = file_offset,
10468 		.pending = ATOMIC_INIT(1),
10469 		.skip_csum = (inode->flags & BTRFS_INODE_NODATASUM),
10470 	};
10471 	unsigned long i = 0;
10472 	u64 cur = 0;
10473 	int ret;
10474 
10475 	init_waitqueue_head(&priv.wait);
10476 	/*
10477 	 * Submit bios for the extent, splitting due to bio or stripe limits as
10478 	 * necessary.
10479 	 */
10480 	while (cur < disk_io_size) {
10481 		struct extent_map *em;
10482 		struct btrfs_io_geometry geom;
10483 		struct bio *bio = NULL;
10484 		u64 remaining;
10485 
10486 		em = btrfs_get_chunk_map(fs_info, disk_bytenr + cur,
10487 					 disk_io_size - cur);
10488 		if (IS_ERR(em)) {
10489 			ret = PTR_ERR(em);
10490 		} else {
10491 			ret = btrfs_get_io_geometry(fs_info, em, BTRFS_MAP_READ,
10492 						    disk_bytenr + cur, &geom);
10493 			free_extent_map(em);
10494 		}
10495 		if (ret) {
10496 			WRITE_ONCE(priv.status, errno_to_blk_status(ret));
10497 			break;
10498 		}
10499 		remaining = min(geom.len, disk_io_size - cur);
10500 		while (bio || remaining) {
10501 			size_t bytes = min_t(u64, remaining, PAGE_SIZE);
10502 
10503 			if (!bio) {
10504 				bio = btrfs_bio_alloc(BIO_MAX_VECS, REQ_OP_READ,
10505 						      btrfs_encoded_read_endio,
10506 						      &priv);
10507 				bio->bi_iter.bi_sector =
10508 					(disk_bytenr + cur) >> SECTOR_SHIFT;
10509 			}
10510 
10511 			if (!bytes ||
10512 			    bio_add_page(bio, pages[i], bytes, 0) < bytes) {
10513 				blk_status_t status;
10514 
10515 				status = submit_encoded_read_bio(inode, bio, 0);
10516 				if (status) {
10517 					WRITE_ONCE(priv.status, status);
10518 					bio_put(bio);
10519 					goto out;
10520 				}
10521 				bio = NULL;
10522 				continue;
10523 			}
10524 
10525 			i++;
10526 			cur += bytes;
10527 			remaining -= bytes;
10528 		}
10529 	}
10530 
10531 out:
10532 	if (atomic_dec_return(&priv.pending))
10533 		io_wait_event(priv.wait, !atomic_read(&priv.pending));
10534 	/* See btrfs_encoded_read_endio() for ordering. */
10535 	return blk_status_to_errno(READ_ONCE(priv.status));
10536 }
10537 
btrfs_encoded_read_regular(struct kiocb * iocb,struct iov_iter * iter,u64 start,u64 lockend,struct extent_state ** cached_state,u64 disk_bytenr,u64 disk_io_size,size_t count,bool compressed,bool * unlocked)10538 static ssize_t btrfs_encoded_read_regular(struct kiocb *iocb,
10539 					  struct iov_iter *iter,
10540 					  u64 start, u64 lockend,
10541 					  struct extent_state **cached_state,
10542 					  u64 disk_bytenr, u64 disk_io_size,
10543 					  size_t count, bool compressed,
10544 					  bool *unlocked)
10545 {
10546 	struct btrfs_inode *inode = BTRFS_I(file_inode(iocb->ki_filp));
10547 	struct extent_io_tree *io_tree = &inode->io_tree;
10548 	struct page **pages;
10549 	unsigned long nr_pages, i;
10550 	u64 cur;
10551 	size_t page_offset;
10552 	ssize_t ret;
10553 
10554 	nr_pages = DIV_ROUND_UP(disk_io_size, PAGE_SIZE);
10555 	pages = kcalloc(nr_pages, sizeof(struct page *), GFP_NOFS);
10556 	if (!pages)
10557 		return -ENOMEM;
10558 	ret = btrfs_alloc_page_array(nr_pages, pages);
10559 	if (ret) {
10560 		ret = -ENOMEM;
10561 		goto out;
10562 		}
10563 
10564 	ret = btrfs_encoded_read_regular_fill_pages(inode, start, disk_bytenr,
10565 						    disk_io_size, pages);
10566 	if (ret)
10567 		goto out;
10568 
10569 	unlock_extent(io_tree, start, lockend, cached_state);
10570 	btrfs_inode_unlock(&inode->vfs_inode, BTRFS_ILOCK_SHARED);
10571 	*unlocked = true;
10572 
10573 	if (compressed) {
10574 		i = 0;
10575 		page_offset = 0;
10576 	} else {
10577 		i = (iocb->ki_pos - start) >> PAGE_SHIFT;
10578 		page_offset = (iocb->ki_pos - start) & (PAGE_SIZE - 1);
10579 	}
10580 	cur = 0;
10581 	while (cur < count) {
10582 		size_t bytes = min_t(size_t, count - cur,
10583 				     PAGE_SIZE - page_offset);
10584 
10585 		if (copy_page_to_iter(pages[i], page_offset, bytes,
10586 				      iter) != bytes) {
10587 			ret = -EFAULT;
10588 			goto out;
10589 		}
10590 		i++;
10591 		cur += bytes;
10592 		page_offset = 0;
10593 	}
10594 	ret = count;
10595 out:
10596 	for (i = 0; i < nr_pages; i++) {
10597 		if (pages[i])
10598 			__free_page(pages[i]);
10599 	}
10600 	kfree(pages);
10601 	return ret;
10602 }
10603 
btrfs_encoded_read(struct kiocb * iocb,struct iov_iter * iter,struct btrfs_ioctl_encoded_io_args * encoded)10604 ssize_t btrfs_encoded_read(struct kiocb *iocb, struct iov_iter *iter,
10605 			   struct btrfs_ioctl_encoded_io_args *encoded)
10606 {
10607 	struct btrfs_inode *inode = BTRFS_I(file_inode(iocb->ki_filp));
10608 	struct btrfs_fs_info *fs_info = inode->root->fs_info;
10609 	struct extent_io_tree *io_tree = &inode->io_tree;
10610 	ssize_t ret;
10611 	size_t count = iov_iter_count(iter);
10612 	u64 start, lockend, disk_bytenr, disk_io_size;
10613 	struct extent_state *cached_state = NULL;
10614 	struct extent_map *em;
10615 	bool unlocked = false;
10616 
10617 	file_accessed(iocb->ki_filp);
10618 
10619 	btrfs_inode_lock(&inode->vfs_inode, BTRFS_ILOCK_SHARED);
10620 
10621 	if (iocb->ki_pos >= inode->vfs_inode.i_size) {
10622 		btrfs_inode_unlock(&inode->vfs_inode, BTRFS_ILOCK_SHARED);
10623 		return 0;
10624 	}
10625 	start = ALIGN_DOWN(iocb->ki_pos, fs_info->sectorsize);
10626 	/*
10627 	 * We don't know how long the extent containing iocb->ki_pos is, but if
10628 	 * it's compressed we know that it won't be longer than this.
10629 	 */
10630 	lockend = start + BTRFS_MAX_UNCOMPRESSED - 1;
10631 
10632 	for (;;) {
10633 		struct btrfs_ordered_extent *ordered;
10634 
10635 		ret = btrfs_wait_ordered_range(&inode->vfs_inode, start,
10636 					       lockend - start + 1);
10637 		if (ret)
10638 			goto out_unlock_inode;
10639 		lock_extent(io_tree, start, lockend, &cached_state);
10640 		ordered = btrfs_lookup_ordered_range(inode, start,
10641 						     lockend - start + 1);
10642 		if (!ordered)
10643 			break;
10644 		btrfs_put_ordered_extent(ordered);
10645 		unlock_extent(io_tree, start, lockend, &cached_state);
10646 		cond_resched();
10647 	}
10648 
10649 	em = btrfs_get_extent(inode, NULL, 0, start, lockend - start + 1);
10650 	if (IS_ERR(em)) {
10651 		ret = PTR_ERR(em);
10652 		goto out_unlock_extent;
10653 	}
10654 
10655 	if (em->block_start == EXTENT_MAP_INLINE) {
10656 		u64 extent_start = em->start;
10657 
10658 		/*
10659 		 * For inline extents we get everything we need out of the
10660 		 * extent item.
10661 		 */
10662 		free_extent_map(em);
10663 		em = NULL;
10664 		ret = btrfs_encoded_read_inline(iocb, iter, start, lockend,
10665 						&cached_state, extent_start,
10666 						count, encoded, &unlocked);
10667 		goto out;
10668 	}
10669 
10670 	/*
10671 	 * We only want to return up to EOF even if the extent extends beyond
10672 	 * that.
10673 	 */
10674 	encoded->len = min_t(u64, extent_map_end(em),
10675 			     inode->vfs_inode.i_size) - iocb->ki_pos;
10676 	if (em->block_start == EXTENT_MAP_HOLE ||
10677 	    test_bit(EXTENT_FLAG_PREALLOC, &em->flags)) {
10678 		disk_bytenr = EXTENT_MAP_HOLE;
10679 		count = min_t(u64, count, encoded->len);
10680 		encoded->len = count;
10681 		encoded->unencoded_len = count;
10682 	} else if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) {
10683 		disk_bytenr = em->block_start;
10684 		/*
10685 		 * Bail if the buffer isn't large enough to return the whole
10686 		 * compressed extent.
10687 		 */
10688 		if (em->block_len > count) {
10689 			ret = -ENOBUFS;
10690 			goto out_em;
10691 		}
10692 		disk_io_size = em->block_len;
10693 		count = em->block_len;
10694 		encoded->unencoded_len = em->ram_bytes;
10695 		encoded->unencoded_offset = iocb->ki_pos - em->orig_start;
10696 		ret = btrfs_encoded_io_compression_from_extent(fs_info,
10697 							     em->compress_type);
10698 		if (ret < 0)
10699 			goto out_em;
10700 		encoded->compression = ret;
10701 	} else {
10702 		disk_bytenr = em->block_start + (start - em->start);
10703 		if (encoded->len > count)
10704 			encoded->len = count;
10705 		/*
10706 		 * Don't read beyond what we locked. This also limits the page
10707 		 * allocations that we'll do.
10708 		 */
10709 		disk_io_size = min(lockend + 1, iocb->ki_pos + encoded->len) - start;
10710 		count = start + disk_io_size - iocb->ki_pos;
10711 		encoded->len = count;
10712 		encoded->unencoded_len = count;
10713 		disk_io_size = ALIGN(disk_io_size, fs_info->sectorsize);
10714 	}
10715 	free_extent_map(em);
10716 	em = NULL;
10717 
10718 	if (disk_bytenr == EXTENT_MAP_HOLE) {
10719 		unlock_extent(io_tree, start, lockend, &cached_state);
10720 		btrfs_inode_unlock(&inode->vfs_inode, BTRFS_ILOCK_SHARED);
10721 		unlocked = true;
10722 		ret = iov_iter_zero(count, iter);
10723 		if (ret != count)
10724 			ret = -EFAULT;
10725 	} else {
10726 		ret = btrfs_encoded_read_regular(iocb, iter, start, lockend,
10727 						 &cached_state, disk_bytenr,
10728 						 disk_io_size, count,
10729 						 encoded->compression,
10730 						 &unlocked);
10731 	}
10732 
10733 out:
10734 	if (ret >= 0)
10735 		iocb->ki_pos += encoded->len;
10736 out_em:
10737 	free_extent_map(em);
10738 out_unlock_extent:
10739 	if (!unlocked)
10740 		unlock_extent(io_tree, start, lockend, &cached_state);
10741 out_unlock_inode:
10742 	if (!unlocked)
10743 		btrfs_inode_unlock(&inode->vfs_inode, BTRFS_ILOCK_SHARED);
10744 	return ret;
10745 }
10746 
btrfs_do_encoded_write(struct kiocb * iocb,struct iov_iter * from,const struct btrfs_ioctl_encoded_io_args * encoded)10747 ssize_t btrfs_do_encoded_write(struct kiocb *iocb, struct iov_iter *from,
10748 			       const struct btrfs_ioctl_encoded_io_args *encoded)
10749 {
10750 	struct btrfs_inode *inode = BTRFS_I(file_inode(iocb->ki_filp));
10751 	struct btrfs_root *root = inode->root;
10752 	struct btrfs_fs_info *fs_info = root->fs_info;
10753 	struct extent_io_tree *io_tree = &inode->io_tree;
10754 	struct extent_changeset *data_reserved = NULL;
10755 	struct extent_state *cached_state = NULL;
10756 	int compression;
10757 	size_t orig_count;
10758 	u64 start, end;
10759 	u64 num_bytes, ram_bytes, disk_num_bytes;
10760 	unsigned long nr_pages, i;
10761 	struct page **pages;
10762 	struct btrfs_key ins;
10763 	bool extent_reserved = false;
10764 	struct extent_map *em;
10765 	ssize_t ret;
10766 
10767 	switch (encoded->compression) {
10768 	case BTRFS_ENCODED_IO_COMPRESSION_ZLIB:
10769 		compression = BTRFS_COMPRESS_ZLIB;
10770 		break;
10771 	case BTRFS_ENCODED_IO_COMPRESSION_ZSTD:
10772 		compression = BTRFS_COMPRESS_ZSTD;
10773 		break;
10774 	case BTRFS_ENCODED_IO_COMPRESSION_LZO_4K:
10775 	case BTRFS_ENCODED_IO_COMPRESSION_LZO_8K:
10776 	case BTRFS_ENCODED_IO_COMPRESSION_LZO_16K:
10777 	case BTRFS_ENCODED_IO_COMPRESSION_LZO_32K:
10778 	case BTRFS_ENCODED_IO_COMPRESSION_LZO_64K:
10779 		/* The sector size must match for LZO. */
10780 		if (encoded->compression -
10781 		    BTRFS_ENCODED_IO_COMPRESSION_LZO_4K + 12 !=
10782 		    fs_info->sectorsize_bits)
10783 			return -EINVAL;
10784 		compression = BTRFS_COMPRESS_LZO;
10785 		break;
10786 	default:
10787 		return -EINVAL;
10788 	}
10789 	if (encoded->encryption != BTRFS_ENCODED_IO_ENCRYPTION_NONE)
10790 		return -EINVAL;
10791 
10792 	/*
10793 	 * Compressed extents should always have checksums, so error out if we
10794 	 * have a NOCOW file or inode was created while mounted with NODATASUM.
10795 	 */
10796 	if (inode->flags & BTRFS_INODE_NODATASUM)
10797 		return -EINVAL;
10798 
10799 	orig_count = iov_iter_count(from);
10800 
10801 	/* The extent size must be sane. */
10802 	if (encoded->unencoded_len > BTRFS_MAX_UNCOMPRESSED ||
10803 	    orig_count > BTRFS_MAX_COMPRESSED || orig_count == 0)
10804 		return -EINVAL;
10805 
10806 	/*
10807 	 * The compressed data must be smaller than the decompressed data.
10808 	 *
10809 	 * It's of course possible for data to compress to larger or the same
10810 	 * size, but the buffered I/O path falls back to no compression for such
10811 	 * data, and we don't want to break any assumptions by creating these
10812 	 * extents.
10813 	 *
10814 	 * Note that this is less strict than the current check we have that the
10815 	 * compressed data must be at least one sector smaller than the
10816 	 * decompressed data. We only want to enforce the weaker requirement
10817 	 * from old kernels that it is at least one byte smaller.
10818 	 */
10819 	if (orig_count >= encoded->unencoded_len)
10820 		return -EINVAL;
10821 
10822 	/* The extent must start on a sector boundary. */
10823 	start = iocb->ki_pos;
10824 	if (!IS_ALIGNED(start, fs_info->sectorsize))
10825 		return -EINVAL;
10826 
10827 	/*
10828 	 * The extent must end on a sector boundary. However, we allow a write
10829 	 * which ends at or extends i_size to have an unaligned length; we round
10830 	 * up the extent size and set i_size to the unaligned end.
10831 	 */
10832 	if (start + encoded->len < inode->vfs_inode.i_size &&
10833 	    !IS_ALIGNED(start + encoded->len, fs_info->sectorsize))
10834 		return -EINVAL;
10835 
10836 	/* Finally, the offset in the unencoded data must be sector-aligned. */
10837 	if (!IS_ALIGNED(encoded->unencoded_offset, fs_info->sectorsize))
10838 		return -EINVAL;
10839 
10840 	num_bytes = ALIGN(encoded->len, fs_info->sectorsize);
10841 	ram_bytes = ALIGN(encoded->unencoded_len, fs_info->sectorsize);
10842 	end = start + num_bytes - 1;
10843 
10844 	/*
10845 	 * If the extent cannot be inline, the compressed data on disk must be
10846 	 * sector-aligned. For convenience, we extend it with zeroes if it
10847 	 * isn't.
10848 	 */
10849 	disk_num_bytes = ALIGN(orig_count, fs_info->sectorsize);
10850 	nr_pages = DIV_ROUND_UP(disk_num_bytes, PAGE_SIZE);
10851 	pages = kvcalloc(nr_pages, sizeof(struct page *), GFP_KERNEL_ACCOUNT);
10852 	if (!pages)
10853 		return -ENOMEM;
10854 	for (i = 0; i < nr_pages; i++) {
10855 		size_t bytes = min_t(size_t, PAGE_SIZE, iov_iter_count(from));
10856 		char *kaddr;
10857 
10858 		pages[i] = alloc_page(GFP_KERNEL_ACCOUNT);
10859 		if (!pages[i]) {
10860 			ret = -ENOMEM;
10861 			goto out_pages;
10862 		}
10863 		kaddr = kmap_local_page(pages[i]);
10864 		if (copy_from_iter(kaddr, bytes, from) != bytes) {
10865 			kunmap_local(kaddr);
10866 			ret = -EFAULT;
10867 			goto out_pages;
10868 		}
10869 		if (bytes < PAGE_SIZE)
10870 			memset(kaddr + bytes, 0, PAGE_SIZE - bytes);
10871 		kunmap_local(kaddr);
10872 	}
10873 
10874 	for (;;) {
10875 		struct btrfs_ordered_extent *ordered;
10876 
10877 		ret = btrfs_wait_ordered_range(&inode->vfs_inode, start, num_bytes);
10878 		if (ret)
10879 			goto out_pages;
10880 		ret = invalidate_inode_pages2_range(inode->vfs_inode.i_mapping,
10881 						    start >> PAGE_SHIFT,
10882 						    end >> PAGE_SHIFT);
10883 		if (ret)
10884 			goto out_pages;
10885 		lock_extent(io_tree, start, end, &cached_state);
10886 		ordered = btrfs_lookup_ordered_range(inode, start, num_bytes);
10887 		if (!ordered &&
10888 		    !filemap_range_has_page(inode->vfs_inode.i_mapping, start, end))
10889 			break;
10890 		if (ordered)
10891 			btrfs_put_ordered_extent(ordered);
10892 		unlock_extent(io_tree, start, end, &cached_state);
10893 		cond_resched();
10894 	}
10895 
10896 	/*
10897 	 * We don't use the higher-level delalloc space functions because our
10898 	 * num_bytes and disk_num_bytes are different.
10899 	 */
10900 	ret = btrfs_alloc_data_chunk_ondemand(inode, disk_num_bytes);
10901 	if (ret)
10902 		goto out_unlock;
10903 	ret = btrfs_qgroup_reserve_data(inode, &data_reserved, start, num_bytes);
10904 	if (ret)
10905 		goto out_free_data_space;
10906 	ret = btrfs_delalloc_reserve_metadata(inode, num_bytes, disk_num_bytes,
10907 					      false);
10908 	if (ret)
10909 		goto out_qgroup_free_data;
10910 
10911 	/* Try an inline extent first. */
10912 	if (start == 0 && encoded->unencoded_len == encoded->len &&
10913 	    encoded->unencoded_offset == 0) {
10914 		ret = cow_file_range_inline(inode, encoded->len, orig_count,
10915 					    compression, pages, true);
10916 		if (ret <= 0) {
10917 			if (ret == 0)
10918 				ret = orig_count;
10919 			goto out_delalloc_release;
10920 		}
10921 	}
10922 
10923 	ret = btrfs_reserve_extent(root, disk_num_bytes, disk_num_bytes,
10924 				   disk_num_bytes, 0, 0, &ins, 1, 1);
10925 	if (ret)
10926 		goto out_delalloc_release;
10927 	extent_reserved = true;
10928 
10929 	em = create_io_em(inode, start, num_bytes,
10930 			  start - encoded->unencoded_offset, ins.objectid,
10931 			  ins.offset, ins.offset, ram_bytes, compression,
10932 			  BTRFS_ORDERED_COMPRESSED);
10933 	if (IS_ERR(em)) {
10934 		ret = PTR_ERR(em);
10935 		goto out_free_reserved;
10936 	}
10937 	free_extent_map(em);
10938 
10939 	ret = btrfs_add_ordered_extent(inode, start, num_bytes, ram_bytes,
10940 				       ins.objectid, ins.offset,
10941 				       encoded->unencoded_offset,
10942 				       (1 << BTRFS_ORDERED_ENCODED) |
10943 				       (1 << BTRFS_ORDERED_COMPRESSED),
10944 				       compression);
10945 	if (ret) {
10946 		btrfs_drop_extent_map_range(inode, start, end, false);
10947 		goto out_free_reserved;
10948 	}
10949 	btrfs_dec_block_group_reservations(fs_info, ins.objectid);
10950 
10951 	if (start + encoded->len > inode->vfs_inode.i_size)
10952 		i_size_write(&inode->vfs_inode, start + encoded->len);
10953 
10954 	unlock_extent(io_tree, start, end, &cached_state);
10955 
10956 	btrfs_delalloc_release_extents(inode, num_bytes);
10957 
10958 	if (btrfs_submit_compressed_write(inode, start, num_bytes, ins.objectid,
10959 					  ins.offset, pages, nr_pages, 0, NULL,
10960 					  false)) {
10961 		btrfs_writepage_endio_finish_ordered(inode, pages[0], start, end, 0);
10962 		ret = -EIO;
10963 		goto out_pages;
10964 	}
10965 	ret = orig_count;
10966 	goto out;
10967 
10968 out_free_reserved:
10969 	btrfs_dec_block_group_reservations(fs_info, ins.objectid);
10970 	btrfs_free_reserved_extent(fs_info, ins.objectid, ins.offset, 1);
10971 out_delalloc_release:
10972 	btrfs_delalloc_release_extents(inode, num_bytes);
10973 	btrfs_delalloc_release_metadata(inode, disk_num_bytes, ret < 0);
10974 out_qgroup_free_data:
10975 	if (ret < 0)
10976 		btrfs_qgroup_free_data(inode, data_reserved, start, num_bytes, NULL);
10977 out_free_data_space:
10978 	/*
10979 	 * If btrfs_reserve_extent() succeeded, then we already decremented
10980 	 * bytes_may_use.
10981 	 */
10982 	if (!extent_reserved)
10983 		btrfs_free_reserved_data_space_noquota(fs_info, disk_num_bytes);
10984 out_unlock:
10985 	unlock_extent(io_tree, start, end, &cached_state);
10986 out_pages:
10987 	for (i = 0; i < nr_pages; i++) {
10988 		if (pages[i])
10989 			__free_page(pages[i]);
10990 	}
10991 	kvfree(pages);
10992 out:
10993 	if (ret >= 0)
10994 		iocb->ki_pos += encoded->len;
10995 	return ret;
10996 }
10997 
10998 #ifdef CONFIG_SWAP
10999 /*
11000  * Add an entry indicating a block group or device which is pinned by a
11001  * swapfile. Returns 0 on success, 1 if there is already an entry for it, or a
11002  * negative errno on failure.
11003  */
btrfs_add_swapfile_pin(struct inode * inode,void * ptr,bool is_block_group)11004 static int btrfs_add_swapfile_pin(struct inode *inode, void *ptr,
11005 				  bool is_block_group)
11006 {
11007 	struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info;
11008 	struct btrfs_swapfile_pin *sp, *entry;
11009 	struct rb_node **p;
11010 	struct rb_node *parent = NULL;
11011 
11012 	sp = kmalloc(sizeof(*sp), GFP_NOFS);
11013 	if (!sp)
11014 		return -ENOMEM;
11015 	sp->ptr = ptr;
11016 	sp->inode = inode;
11017 	sp->is_block_group = is_block_group;
11018 	sp->bg_extent_count = 1;
11019 
11020 	spin_lock(&fs_info->swapfile_pins_lock);
11021 	p = &fs_info->swapfile_pins.rb_node;
11022 	while (*p) {
11023 		parent = *p;
11024 		entry = rb_entry(parent, struct btrfs_swapfile_pin, node);
11025 		if (sp->ptr < entry->ptr ||
11026 		    (sp->ptr == entry->ptr && sp->inode < entry->inode)) {
11027 			p = &(*p)->rb_left;
11028 		} else if (sp->ptr > entry->ptr ||
11029 			   (sp->ptr == entry->ptr && sp->inode > entry->inode)) {
11030 			p = &(*p)->rb_right;
11031 		} else {
11032 			if (is_block_group)
11033 				entry->bg_extent_count++;
11034 			spin_unlock(&fs_info->swapfile_pins_lock);
11035 			kfree(sp);
11036 			return 1;
11037 		}
11038 	}
11039 	rb_link_node(&sp->node, parent, p);
11040 	rb_insert_color(&sp->node, &fs_info->swapfile_pins);
11041 	spin_unlock(&fs_info->swapfile_pins_lock);
11042 	return 0;
11043 }
11044 
11045 /* Free all of the entries pinned by this swapfile. */
btrfs_free_swapfile_pins(struct inode * inode)11046 static void btrfs_free_swapfile_pins(struct inode *inode)
11047 {
11048 	struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info;
11049 	struct btrfs_swapfile_pin *sp;
11050 	struct rb_node *node, *next;
11051 
11052 	spin_lock(&fs_info->swapfile_pins_lock);
11053 	node = rb_first(&fs_info->swapfile_pins);
11054 	while (node) {
11055 		next = rb_next(node);
11056 		sp = rb_entry(node, struct btrfs_swapfile_pin, node);
11057 		if (sp->inode == inode) {
11058 			rb_erase(&sp->node, &fs_info->swapfile_pins);
11059 			if (sp->is_block_group) {
11060 				btrfs_dec_block_group_swap_extents(sp->ptr,
11061 							   sp->bg_extent_count);
11062 				btrfs_put_block_group(sp->ptr);
11063 			}
11064 			kfree(sp);
11065 		}
11066 		node = next;
11067 	}
11068 	spin_unlock(&fs_info->swapfile_pins_lock);
11069 }
11070 
11071 struct btrfs_swap_info {
11072 	u64 start;
11073 	u64 block_start;
11074 	u64 block_len;
11075 	u64 lowest_ppage;
11076 	u64 highest_ppage;
11077 	unsigned long nr_pages;
11078 	int nr_extents;
11079 };
11080 
btrfs_add_swap_extent(struct swap_info_struct * sis,struct btrfs_swap_info * bsi)11081 static int btrfs_add_swap_extent(struct swap_info_struct *sis,
11082 				 struct btrfs_swap_info *bsi)
11083 {
11084 	unsigned long nr_pages;
11085 	unsigned long max_pages;
11086 	u64 first_ppage, first_ppage_reported, next_ppage;
11087 	int ret;
11088 
11089 	/*
11090 	 * Our swapfile may have had its size extended after the swap header was
11091 	 * written. In that case activating the swapfile should not go beyond
11092 	 * the max size set in the swap header.
11093 	 */
11094 	if (bsi->nr_pages >= sis->max)
11095 		return 0;
11096 
11097 	max_pages = sis->max - bsi->nr_pages;
11098 	first_ppage = ALIGN(bsi->block_start, PAGE_SIZE) >> PAGE_SHIFT;
11099 	next_ppage = ALIGN_DOWN(bsi->block_start + bsi->block_len,
11100 				PAGE_SIZE) >> PAGE_SHIFT;
11101 
11102 	if (first_ppage >= next_ppage)
11103 		return 0;
11104 	nr_pages = next_ppage - first_ppage;
11105 	nr_pages = min(nr_pages, max_pages);
11106 
11107 	first_ppage_reported = first_ppage;
11108 	if (bsi->start == 0)
11109 		first_ppage_reported++;
11110 	if (bsi->lowest_ppage > first_ppage_reported)
11111 		bsi->lowest_ppage = first_ppage_reported;
11112 	if (bsi->highest_ppage < (next_ppage - 1))
11113 		bsi->highest_ppage = next_ppage - 1;
11114 
11115 	ret = add_swap_extent(sis, bsi->nr_pages, nr_pages, first_ppage);
11116 	if (ret < 0)
11117 		return ret;
11118 	bsi->nr_extents += ret;
11119 	bsi->nr_pages += nr_pages;
11120 	return 0;
11121 }
11122 
btrfs_swap_deactivate(struct file * file)11123 static void btrfs_swap_deactivate(struct file *file)
11124 {
11125 	struct inode *inode = file_inode(file);
11126 
11127 	btrfs_free_swapfile_pins(inode);
11128 	atomic_dec(&BTRFS_I(inode)->root->nr_swapfiles);
11129 }
11130 
btrfs_swap_activate(struct swap_info_struct * sis,struct file * file,sector_t * span)11131 static int btrfs_swap_activate(struct swap_info_struct *sis, struct file *file,
11132 			       sector_t *span)
11133 {
11134 	struct inode *inode = file_inode(file);
11135 	struct btrfs_root *root = BTRFS_I(inode)->root;
11136 	struct btrfs_fs_info *fs_info = root->fs_info;
11137 	struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
11138 	struct extent_state *cached_state = NULL;
11139 	struct extent_map *em = NULL;
11140 	struct btrfs_device *device = NULL;
11141 	struct btrfs_swap_info bsi = {
11142 		.lowest_ppage = (sector_t)-1ULL,
11143 	};
11144 	int ret = 0;
11145 	u64 isize;
11146 	u64 start;
11147 
11148 	/*
11149 	 * If the swap file was just created, make sure delalloc is done. If the
11150 	 * file changes again after this, the user is doing something stupid and
11151 	 * we don't really care.
11152 	 */
11153 	ret = btrfs_wait_ordered_range(inode, 0, (u64)-1);
11154 	if (ret)
11155 		return ret;
11156 
11157 	/*
11158 	 * The inode is locked, so these flags won't change after we check them.
11159 	 */
11160 	if (BTRFS_I(inode)->flags & BTRFS_INODE_COMPRESS) {
11161 		btrfs_warn(fs_info, "swapfile must not be compressed");
11162 		return -EINVAL;
11163 	}
11164 	if (!(BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW)) {
11165 		btrfs_warn(fs_info, "swapfile must not be copy-on-write");
11166 		return -EINVAL;
11167 	}
11168 	if (!(BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM)) {
11169 		btrfs_warn(fs_info, "swapfile must not be checksummed");
11170 		return -EINVAL;
11171 	}
11172 
11173 	/*
11174 	 * Balance or device remove/replace/resize can move stuff around from
11175 	 * under us. The exclop protection makes sure they aren't running/won't
11176 	 * run concurrently while we are mapping the swap extents, and
11177 	 * fs_info->swapfile_pins prevents them from running while the swap
11178 	 * file is active and moving the extents. Note that this also prevents
11179 	 * a concurrent device add which isn't actually necessary, but it's not
11180 	 * really worth the trouble to allow it.
11181 	 */
11182 	if (!btrfs_exclop_start(fs_info, BTRFS_EXCLOP_SWAP_ACTIVATE)) {
11183 		btrfs_warn(fs_info,
11184 	   "cannot activate swapfile while exclusive operation is running");
11185 		return -EBUSY;
11186 	}
11187 
11188 	/*
11189 	 * Prevent snapshot creation while we are activating the swap file.
11190 	 * We do not want to race with snapshot creation. If snapshot creation
11191 	 * already started before we bumped nr_swapfiles from 0 to 1 and
11192 	 * completes before the first write into the swap file after it is
11193 	 * activated, than that write would fallback to COW.
11194 	 */
11195 	if (!btrfs_drew_try_write_lock(&root->snapshot_lock)) {
11196 		btrfs_exclop_finish(fs_info);
11197 		btrfs_warn(fs_info,
11198 	   "cannot activate swapfile because snapshot creation is in progress");
11199 		return -EINVAL;
11200 	}
11201 	/*
11202 	 * Snapshots can create extents which require COW even if NODATACOW is
11203 	 * set. We use this counter to prevent snapshots. We must increment it
11204 	 * before walking the extents because we don't want a concurrent
11205 	 * snapshot to run after we've already checked the extents.
11206 	 *
11207 	 * It is possible that subvolume is marked for deletion but still not
11208 	 * removed yet. To prevent this race, we check the root status before
11209 	 * activating the swapfile.
11210 	 */
11211 	spin_lock(&root->root_item_lock);
11212 	if (btrfs_root_dead(root)) {
11213 		spin_unlock(&root->root_item_lock);
11214 
11215 		btrfs_exclop_finish(fs_info);
11216 		btrfs_warn(fs_info,
11217 		"cannot activate swapfile because subvolume %llu is being deleted",
11218 			root->root_key.objectid);
11219 		return -EPERM;
11220 	}
11221 	atomic_inc(&root->nr_swapfiles);
11222 	spin_unlock(&root->root_item_lock);
11223 
11224 	isize = ALIGN_DOWN(inode->i_size, fs_info->sectorsize);
11225 
11226 	lock_extent(io_tree, 0, isize - 1, &cached_state);
11227 	start = 0;
11228 	while (start < isize) {
11229 		u64 logical_block_start, physical_block_start;
11230 		struct btrfs_block_group *bg;
11231 		u64 len = isize - start;
11232 
11233 		em = btrfs_get_extent(BTRFS_I(inode), NULL, 0, start, len);
11234 		if (IS_ERR(em)) {
11235 			ret = PTR_ERR(em);
11236 			goto out;
11237 		}
11238 
11239 		if (em->block_start == EXTENT_MAP_HOLE) {
11240 			btrfs_warn(fs_info, "swapfile must not have holes");
11241 			ret = -EINVAL;
11242 			goto out;
11243 		}
11244 		if (em->block_start == EXTENT_MAP_INLINE) {
11245 			/*
11246 			 * It's unlikely we'll ever actually find ourselves
11247 			 * here, as a file small enough to fit inline won't be
11248 			 * big enough to store more than the swap header, but in
11249 			 * case something changes in the future, let's catch it
11250 			 * here rather than later.
11251 			 */
11252 			btrfs_warn(fs_info, "swapfile must not be inline");
11253 			ret = -EINVAL;
11254 			goto out;
11255 		}
11256 		if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) {
11257 			btrfs_warn(fs_info, "swapfile must not be compressed");
11258 			ret = -EINVAL;
11259 			goto out;
11260 		}
11261 
11262 		logical_block_start = em->block_start + (start - em->start);
11263 		len = min(len, em->len - (start - em->start));
11264 		free_extent_map(em);
11265 		em = NULL;
11266 
11267 		ret = can_nocow_extent(inode, start, &len, NULL, NULL, NULL, false, true);
11268 		if (ret < 0) {
11269 			goto out;
11270 		} else if (ret) {
11271 			ret = 0;
11272 		} else {
11273 			btrfs_warn(fs_info,
11274 				   "swapfile must not be copy-on-write");
11275 			ret = -EINVAL;
11276 			goto out;
11277 		}
11278 
11279 		em = btrfs_get_chunk_map(fs_info, logical_block_start, len);
11280 		if (IS_ERR(em)) {
11281 			ret = PTR_ERR(em);
11282 			goto out;
11283 		}
11284 
11285 		if (em->map_lookup->type & BTRFS_BLOCK_GROUP_PROFILE_MASK) {
11286 			btrfs_warn(fs_info,
11287 				   "swapfile must have single data profile");
11288 			ret = -EINVAL;
11289 			goto out;
11290 		}
11291 
11292 		if (device == NULL) {
11293 			device = em->map_lookup->stripes[0].dev;
11294 			ret = btrfs_add_swapfile_pin(inode, device, false);
11295 			if (ret == 1)
11296 				ret = 0;
11297 			else if (ret)
11298 				goto out;
11299 		} else if (device != em->map_lookup->stripes[0].dev) {
11300 			btrfs_warn(fs_info, "swapfile must be on one device");
11301 			ret = -EINVAL;
11302 			goto out;
11303 		}
11304 
11305 		physical_block_start = (em->map_lookup->stripes[0].physical +
11306 					(logical_block_start - em->start));
11307 		len = min(len, em->len - (logical_block_start - em->start));
11308 		free_extent_map(em);
11309 		em = NULL;
11310 
11311 		bg = btrfs_lookup_block_group(fs_info, logical_block_start);
11312 		if (!bg) {
11313 			btrfs_warn(fs_info,
11314 			   "could not find block group containing swapfile");
11315 			ret = -EINVAL;
11316 			goto out;
11317 		}
11318 
11319 		if (!btrfs_inc_block_group_swap_extents(bg)) {
11320 			btrfs_warn(fs_info,
11321 			   "block group for swapfile at %llu is read-only%s",
11322 			   bg->start,
11323 			   atomic_read(&fs_info->scrubs_running) ?
11324 				       " (scrub running)" : "");
11325 			btrfs_put_block_group(bg);
11326 			ret = -EINVAL;
11327 			goto out;
11328 		}
11329 
11330 		ret = btrfs_add_swapfile_pin(inode, bg, true);
11331 		if (ret) {
11332 			btrfs_put_block_group(bg);
11333 			if (ret == 1)
11334 				ret = 0;
11335 			else
11336 				goto out;
11337 		}
11338 
11339 		if (bsi.block_len &&
11340 		    bsi.block_start + bsi.block_len == physical_block_start) {
11341 			bsi.block_len += len;
11342 		} else {
11343 			if (bsi.block_len) {
11344 				ret = btrfs_add_swap_extent(sis, &bsi);
11345 				if (ret)
11346 					goto out;
11347 			}
11348 			bsi.start = start;
11349 			bsi.block_start = physical_block_start;
11350 			bsi.block_len = len;
11351 		}
11352 
11353 		start += len;
11354 	}
11355 
11356 	if (bsi.block_len)
11357 		ret = btrfs_add_swap_extent(sis, &bsi);
11358 
11359 out:
11360 	if (!IS_ERR_OR_NULL(em))
11361 		free_extent_map(em);
11362 
11363 	unlock_extent(io_tree, 0, isize - 1, &cached_state);
11364 
11365 	if (ret)
11366 		btrfs_swap_deactivate(file);
11367 
11368 	btrfs_drew_write_unlock(&root->snapshot_lock);
11369 
11370 	btrfs_exclop_finish(fs_info);
11371 
11372 	if (ret)
11373 		return ret;
11374 
11375 	if (device)
11376 		sis->bdev = device->bdev;
11377 	*span = bsi.highest_ppage - bsi.lowest_ppage + 1;
11378 	sis->max = bsi.nr_pages;
11379 	sis->pages = bsi.nr_pages - 1;
11380 	sis->highest_bit = bsi.nr_pages - 1;
11381 	return bsi.nr_extents;
11382 }
11383 #else
btrfs_swap_deactivate(struct file * file)11384 static void btrfs_swap_deactivate(struct file *file)
11385 {
11386 }
11387 
btrfs_swap_activate(struct swap_info_struct * sis,struct file * file,sector_t * span)11388 static int btrfs_swap_activate(struct swap_info_struct *sis, struct file *file,
11389 			       sector_t *span)
11390 {
11391 	return -EOPNOTSUPP;
11392 }
11393 #endif
11394 
11395 /*
11396  * Update the number of bytes used in the VFS' inode. When we replace extents in
11397  * a range (clone, dedupe, fallocate's zero range), we must update the number of
11398  * bytes used by the inode in an atomic manner, so that concurrent stat(2) calls
11399  * always get a correct value.
11400  */
btrfs_update_inode_bytes(struct btrfs_inode * inode,const u64 add_bytes,const u64 del_bytes)11401 void btrfs_update_inode_bytes(struct btrfs_inode *inode,
11402 			      const u64 add_bytes,
11403 			      const u64 del_bytes)
11404 {
11405 	if (add_bytes == del_bytes)
11406 		return;
11407 
11408 	spin_lock(&inode->lock);
11409 	if (del_bytes > 0)
11410 		inode_sub_bytes(&inode->vfs_inode, del_bytes);
11411 	if (add_bytes > 0)
11412 		inode_add_bytes(&inode->vfs_inode, add_bytes);
11413 	spin_unlock(&inode->lock);
11414 }
11415 
11416 /**
11417  * Verify that there are no ordered extents for a given file range.
11418  *
11419  * @inode:   The target inode.
11420  * @start:   Start offset of the file range, should be sector size aligned.
11421  * @end:     End offset (inclusive) of the file range, its value +1 should be
11422  *           sector size aligned.
11423  *
11424  * This should typically be used for cases where we locked an inode's VFS lock in
11425  * exclusive mode, we have also locked the inode's i_mmap_lock in exclusive mode,
11426  * we have flushed all delalloc in the range, we have waited for all ordered
11427  * extents in the range to complete and finally we have locked the file range in
11428  * the inode's io_tree.
11429  */
btrfs_assert_inode_range_clean(struct btrfs_inode * inode,u64 start,u64 end)11430 void btrfs_assert_inode_range_clean(struct btrfs_inode *inode, u64 start, u64 end)
11431 {
11432 	struct btrfs_root *root = inode->root;
11433 	struct btrfs_ordered_extent *ordered;
11434 
11435 	if (!IS_ENABLED(CONFIG_BTRFS_ASSERT))
11436 		return;
11437 
11438 	ordered = btrfs_lookup_first_ordered_range(inode, start, end + 1 - start);
11439 	if (ordered) {
11440 		btrfs_err(root->fs_info,
11441 "found unexpected ordered extent in file range [%llu, %llu] for inode %llu root %llu (ordered range [%llu, %llu])",
11442 			  start, end, btrfs_ino(inode), root->root_key.objectid,
11443 			  ordered->file_offset,
11444 			  ordered->file_offset + ordered->num_bytes - 1);
11445 		btrfs_put_ordered_extent(ordered);
11446 	}
11447 
11448 	ASSERT(ordered == NULL);
11449 }
11450 
11451 static const struct inode_operations btrfs_dir_inode_operations = {
11452 	.getattr	= btrfs_getattr,
11453 	.lookup		= btrfs_lookup,
11454 	.create		= btrfs_create,
11455 	.unlink		= btrfs_unlink,
11456 	.link		= btrfs_link,
11457 	.mkdir		= btrfs_mkdir,
11458 	.rmdir		= btrfs_rmdir,
11459 	.rename		= btrfs_rename2,
11460 	.symlink	= btrfs_symlink,
11461 	.setattr	= btrfs_setattr,
11462 	.mknod		= btrfs_mknod,
11463 	.listxattr	= btrfs_listxattr,
11464 	.permission	= btrfs_permission,
11465 	.get_acl	= btrfs_get_acl,
11466 	.set_acl	= btrfs_set_acl,
11467 	.update_time	= btrfs_update_time,
11468 	.tmpfile        = btrfs_tmpfile,
11469 	.fileattr_get	= btrfs_fileattr_get,
11470 	.fileattr_set	= btrfs_fileattr_set,
11471 };
11472 
11473 static const struct file_operations btrfs_dir_file_operations = {
11474 	.llseek		= btrfs_dir_llseek,
11475 	.read		= generic_read_dir,
11476 	.iterate_shared	= btrfs_real_readdir,
11477 	.open		= btrfs_opendir,
11478 	.unlocked_ioctl	= btrfs_ioctl,
11479 #ifdef CONFIG_COMPAT
11480 	.compat_ioctl	= btrfs_compat_ioctl,
11481 #endif
11482 	.release        = btrfs_release_file,
11483 	.fsync		= btrfs_sync_file,
11484 };
11485 
11486 /*
11487  * btrfs doesn't support the bmap operation because swapfiles
11488  * use bmap to make a mapping of extents in the file.  They assume
11489  * these extents won't change over the life of the file and they
11490  * use the bmap result to do IO directly to the drive.
11491  *
11492  * the btrfs bmap call would return logical addresses that aren't
11493  * suitable for IO and they also will change frequently as COW
11494  * operations happen.  So, swapfile + btrfs == corruption.
11495  *
11496  * For now we're avoiding this by dropping bmap.
11497  */
11498 static const struct address_space_operations btrfs_aops = {
11499 	.read_folio	= btrfs_read_folio,
11500 	.writepages	= btrfs_writepages,
11501 	.readahead	= btrfs_readahead,
11502 	.direct_IO	= noop_direct_IO,
11503 	.invalidate_folio = btrfs_invalidate_folio,
11504 	.release_folio	= btrfs_release_folio,
11505 	.migrate_folio	= btrfs_migrate_folio,
11506 	.dirty_folio	= filemap_dirty_folio,
11507 	.error_remove_page = generic_error_remove_page,
11508 	.swap_activate	= btrfs_swap_activate,
11509 	.swap_deactivate = btrfs_swap_deactivate,
11510 };
11511 
11512 static const struct inode_operations btrfs_file_inode_operations = {
11513 	.getattr	= btrfs_getattr,
11514 	.setattr	= btrfs_setattr,
11515 	.listxattr      = btrfs_listxattr,
11516 	.permission	= btrfs_permission,
11517 	.fiemap		= btrfs_fiemap,
11518 	.get_acl	= btrfs_get_acl,
11519 	.set_acl	= btrfs_set_acl,
11520 	.update_time	= btrfs_update_time,
11521 	.fileattr_get	= btrfs_fileattr_get,
11522 	.fileattr_set	= btrfs_fileattr_set,
11523 };
11524 static const struct inode_operations btrfs_special_inode_operations = {
11525 	.getattr	= btrfs_getattr,
11526 	.setattr	= btrfs_setattr,
11527 	.permission	= btrfs_permission,
11528 	.listxattr	= btrfs_listxattr,
11529 	.get_acl	= btrfs_get_acl,
11530 	.set_acl	= btrfs_set_acl,
11531 	.update_time	= btrfs_update_time,
11532 };
11533 static const struct inode_operations btrfs_symlink_inode_operations = {
11534 	.get_link	= page_get_link,
11535 	.getattr	= btrfs_getattr,
11536 	.setattr	= btrfs_setattr,
11537 	.permission	= btrfs_permission,
11538 	.listxattr	= btrfs_listxattr,
11539 	.update_time	= btrfs_update_time,
11540 };
11541 
11542 const struct dentry_operations btrfs_dentry_operations = {
11543 	.d_delete	= btrfs_dentry_delete,
11544 };
11545