1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Copyright (C) 2007 Oracle. All rights reserved.
4 */
5
6 #include <linux/fs.h>
7 #include <linux/pagemap.h>
8 #include <linux/time.h>
9 #include <linux/init.h>
10 #include <linux/string.h>
11 #include <linux/backing-dev.h>
12 #include <linux/falloc.h>
13 #include <linux/writeback.h>
14 #include <linux/compat.h>
15 #include <linux/slab.h>
16 #include <linux/btrfs.h>
17 #include <linux/uio.h>
18 #include <linux/iversion.h>
19 #include <linux/fsverity.h>
20 #include "ctree.h"
21 #include "disk-io.h"
22 #include "transaction.h"
23 #include "btrfs_inode.h"
24 #include "print-tree.h"
25 #include "tree-log.h"
26 #include "locking.h"
27 #include "volumes.h"
28 #include "qgroup.h"
29 #include "compression.h"
30 #include "delalloc-space.h"
31 #include "reflink.h"
32 #include "subpage.h"
33
34 static struct kmem_cache *btrfs_inode_defrag_cachep;
35 /*
36 * when auto defrag is enabled we
37 * queue up these defrag structs to remember which
38 * inodes need defragging passes
39 */
40 struct inode_defrag {
41 struct rb_node rb_node;
42 /* objectid */
43 u64 ino;
44 /*
45 * transid where the defrag was added, we search for
46 * extents newer than this
47 */
48 u64 transid;
49
50 /* root objectid */
51 u64 root;
52
53 /* last offset we were able to defrag */
54 u64 last_offset;
55
56 /* if we've wrapped around back to zero once already */
57 int cycled;
58 };
59
__compare_inode_defrag(struct inode_defrag * defrag1,struct inode_defrag * defrag2)60 static int __compare_inode_defrag(struct inode_defrag *defrag1,
61 struct inode_defrag *defrag2)
62 {
63 if (defrag1->root > defrag2->root)
64 return 1;
65 else if (defrag1->root < defrag2->root)
66 return -1;
67 else if (defrag1->ino > defrag2->ino)
68 return 1;
69 else if (defrag1->ino < defrag2->ino)
70 return -1;
71 else
72 return 0;
73 }
74
75 /* pop a record for an inode into the defrag tree. The lock
76 * must be held already
77 *
78 * If you're inserting a record for an older transid than an
79 * existing record, the transid already in the tree is lowered
80 *
81 * If an existing record is found the defrag item you
82 * pass in is freed
83 */
__btrfs_add_inode_defrag(struct btrfs_inode * inode,struct inode_defrag * defrag)84 static int __btrfs_add_inode_defrag(struct btrfs_inode *inode,
85 struct inode_defrag *defrag)
86 {
87 struct btrfs_fs_info *fs_info = inode->root->fs_info;
88 struct inode_defrag *entry;
89 struct rb_node **p;
90 struct rb_node *parent = NULL;
91 int ret;
92
93 p = &fs_info->defrag_inodes.rb_node;
94 while (*p) {
95 parent = *p;
96 entry = rb_entry(parent, struct inode_defrag, rb_node);
97
98 ret = __compare_inode_defrag(defrag, entry);
99 if (ret < 0)
100 p = &parent->rb_left;
101 else if (ret > 0)
102 p = &parent->rb_right;
103 else {
104 /* if we're reinserting an entry for
105 * an old defrag run, make sure to
106 * lower the transid of our existing record
107 */
108 if (defrag->transid < entry->transid)
109 entry->transid = defrag->transid;
110 if (defrag->last_offset > entry->last_offset)
111 entry->last_offset = defrag->last_offset;
112 return -EEXIST;
113 }
114 }
115 set_bit(BTRFS_INODE_IN_DEFRAG, &inode->runtime_flags);
116 rb_link_node(&defrag->rb_node, parent, p);
117 rb_insert_color(&defrag->rb_node, &fs_info->defrag_inodes);
118 return 0;
119 }
120
__need_auto_defrag(struct btrfs_fs_info * fs_info)121 static inline int __need_auto_defrag(struct btrfs_fs_info *fs_info)
122 {
123 if (!btrfs_test_opt(fs_info, AUTO_DEFRAG))
124 return 0;
125
126 if (btrfs_fs_closing(fs_info))
127 return 0;
128
129 return 1;
130 }
131
132 /*
133 * insert a defrag record for this inode if auto defrag is
134 * enabled
135 */
btrfs_add_inode_defrag(struct btrfs_trans_handle * trans,struct btrfs_inode * inode)136 int btrfs_add_inode_defrag(struct btrfs_trans_handle *trans,
137 struct btrfs_inode *inode)
138 {
139 struct btrfs_root *root = inode->root;
140 struct btrfs_fs_info *fs_info = root->fs_info;
141 struct inode_defrag *defrag;
142 u64 transid;
143 int ret;
144
145 if (!__need_auto_defrag(fs_info))
146 return 0;
147
148 if (test_bit(BTRFS_INODE_IN_DEFRAG, &inode->runtime_flags))
149 return 0;
150
151 if (trans)
152 transid = trans->transid;
153 else
154 transid = inode->root->last_trans;
155
156 defrag = kmem_cache_zalloc(btrfs_inode_defrag_cachep, GFP_NOFS);
157 if (!defrag)
158 return -ENOMEM;
159
160 defrag->ino = btrfs_ino(inode);
161 defrag->transid = transid;
162 defrag->root = root->root_key.objectid;
163
164 spin_lock(&fs_info->defrag_inodes_lock);
165 if (!test_bit(BTRFS_INODE_IN_DEFRAG, &inode->runtime_flags)) {
166 /*
167 * If we set IN_DEFRAG flag and evict the inode from memory,
168 * and then re-read this inode, this new inode doesn't have
169 * IN_DEFRAG flag. At the case, we may find the existed defrag.
170 */
171 ret = __btrfs_add_inode_defrag(inode, defrag);
172 if (ret)
173 kmem_cache_free(btrfs_inode_defrag_cachep, defrag);
174 } else {
175 kmem_cache_free(btrfs_inode_defrag_cachep, defrag);
176 }
177 spin_unlock(&fs_info->defrag_inodes_lock);
178 return 0;
179 }
180
181 /*
182 * Requeue the defrag object. If there is a defrag object that points to
183 * the same inode in the tree, we will merge them together (by
184 * __btrfs_add_inode_defrag()) and free the one that we want to requeue.
185 */
btrfs_requeue_inode_defrag(struct btrfs_inode * inode,struct inode_defrag * defrag)186 static void btrfs_requeue_inode_defrag(struct btrfs_inode *inode,
187 struct inode_defrag *defrag)
188 {
189 struct btrfs_fs_info *fs_info = inode->root->fs_info;
190 int ret;
191
192 if (!__need_auto_defrag(fs_info))
193 goto out;
194
195 /*
196 * Here we don't check the IN_DEFRAG flag, because we need merge
197 * them together.
198 */
199 spin_lock(&fs_info->defrag_inodes_lock);
200 ret = __btrfs_add_inode_defrag(inode, defrag);
201 spin_unlock(&fs_info->defrag_inodes_lock);
202 if (ret)
203 goto out;
204 return;
205 out:
206 kmem_cache_free(btrfs_inode_defrag_cachep, defrag);
207 }
208
209 /*
210 * pick the defragable inode that we want, if it doesn't exist, we will get
211 * the next one.
212 */
213 static struct inode_defrag *
btrfs_pick_defrag_inode(struct btrfs_fs_info * fs_info,u64 root,u64 ino)214 btrfs_pick_defrag_inode(struct btrfs_fs_info *fs_info, u64 root, u64 ino)
215 {
216 struct inode_defrag *entry = NULL;
217 struct inode_defrag tmp;
218 struct rb_node *p;
219 struct rb_node *parent = NULL;
220 int ret;
221
222 tmp.ino = ino;
223 tmp.root = root;
224
225 spin_lock(&fs_info->defrag_inodes_lock);
226 p = fs_info->defrag_inodes.rb_node;
227 while (p) {
228 parent = p;
229 entry = rb_entry(parent, struct inode_defrag, rb_node);
230
231 ret = __compare_inode_defrag(&tmp, entry);
232 if (ret < 0)
233 p = parent->rb_left;
234 else if (ret > 0)
235 p = parent->rb_right;
236 else
237 goto out;
238 }
239
240 if (parent && __compare_inode_defrag(&tmp, entry) > 0) {
241 parent = rb_next(parent);
242 if (parent)
243 entry = rb_entry(parent, struct inode_defrag, rb_node);
244 else
245 entry = NULL;
246 }
247 out:
248 if (entry)
249 rb_erase(parent, &fs_info->defrag_inodes);
250 spin_unlock(&fs_info->defrag_inodes_lock);
251 return entry;
252 }
253
btrfs_cleanup_defrag_inodes(struct btrfs_fs_info * fs_info)254 void btrfs_cleanup_defrag_inodes(struct btrfs_fs_info *fs_info)
255 {
256 struct inode_defrag *defrag;
257 struct rb_node *node;
258
259 spin_lock(&fs_info->defrag_inodes_lock);
260 node = rb_first(&fs_info->defrag_inodes);
261 while (node) {
262 rb_erase(node, &fs_info->defrag_inodes);
263 defrag = rb_entry(node, struct inode_defrag, rb_node);
264 kmem_cache_free(btrfs_inode_defrag_cachep, defrag);
265
266 cond_resched_lock(&fs_info->defrag_inodes_lock);
267
268 node = rb_first(&fs_info->defrag_inodes);
269 }
270 spin_unlock(&fs_info->defrag_inodes_lock);
271 }
272
273 #define BTRFS_DEFRAG_BATCH 1024
274
__btrfs_run_defrag_inode(struct btrfs_fs_info * fs_info,struct inode_defrag * defrag)275 static int __btrfs_run_defrag_inode(struct btrfs_fs_info *fs_info,
276 struct inode_defrag *defrag)
277 {
278 struct btrfs_root *inode_root;
279 struct inode *inode;
280 struct btrfs_ioctl_defrag_range_args range;
281 int num_defrag;
282 int ret;
283
284 /* get the inode */
285 inode_root = btrfs_get_fs_root(fs_info, defrag->root, true);
286 if (IS_ERR(inode_root)) {
287 ret = PTR_ERR(inode_root);
288 goto cleanup;
289 }
290
291 inode = btrfs_iget(fs_info->sb, defrag->ino, inode_root);
292 btrfs_put_root(inode_root);
293 if (IS_ERR(inode)) {
294 ret = PTR_ERR(inode);
295 goto cleanup;
296 }
297
298 /* do a chunk of defrag */
299 clear_bit(BTRFS_INODE_IN_DEFRAG, &BTRFS_I(inode)->runtime_flags);
300 memset(&range, 0, sizeof(range));
301 range.len = (u64)-1;
302 range.start = defrag->last_offset;
303
304 sb_start_write(fs_info->sb);
305 num_defrag = btrfs_defrag_file(inode, NULL, &range, defrag->transid,
306 BTRFS_DEFRAG_BATCH);
307 sb_end_write(fs_info->sb);
308 /*
309 * if we filled the whole defrag batch, there
310 * must be more work to do. Queue this defrag
311 * again
312 */
313 if (num_defrag == BTRFS_DEFRAG_BATCH) {
314 defrag->last_offset = range.start;
315 btrfs_requeue_inode_defrag(BTRFS_I(inode), defrag);
316 } else if (defrag->last_offset && !defrag->cycled) {
317 /*
318 * we didn't fill our defrag batch, but
319 * we didn't start at zero. Make sure we loop
320 * around to the start of the file.
321 */
322 defrag->last_offset = 0;
323 defrag->cycled = 1;
324 btrfs_requeue_inode_defrag(BTRFS_I(inode), defrag);
325 } else {
326 kmem_cache_free(btrfs_inode_defrag_cachep, defrag);
327 }
328
329 iput(inode);
330 return 0;
331 cleanup:
332 kmem_cache_free(btrfs_inode_defrag_cachep, defrag);
333 return ret;
334 }
335
336 /*
337 * run through the list of inodes in the FS that need
338 * defragging
339 */
btrfs_run_defrag_inodes(struct btrfs_fs_info * fs_info)340 int btrfs_run_defrag_inodes(struct btrfs_fs_info *fs_info)
341 {
342 struct inode_defrag *defrag;
343 u64 first_ino = 0;
344 u64 root_objectid = 0;
345
346 atomic_inc(&fs_info->defrag_running);
347 while (1) {
348 /* Pause the auto defragger. */
349 if (test_bit(BTRFS_FS_STATE_REMOUNTING,
350 &fs_info->fs_state))
351 break;
352
353 if (!__need_auto_defrag(fs_info))
354 break;
355
356 /* find an inode to defrag */
357 defrag = btrfs_pick_defrag_inode(fs_info, root_objectid,
358 first_ino);
359 if (!defrag) {
360 if (root_objectid || first_ino) {
361 root_objectid = 0;
362 first_ino = 0;
363 continue;
364 } else {
365 break;
366 }
367 }
368
369 first_ino = defrag->ino + 1;
370 root_objectid = defrag->root;
371
372 __btrfs_run_defrag_inode(fs_info, defrag);
373 }
374 atomic_dec(&fs_info->defrag_running);
375
376 /*
377 * during unmount, we use the transaction_wait queue to
378 * wait for the defragger to stop
379 */
380 wake_up(&fs_info->transaction_wait);
381 return 0;
382 }
383
384 /* simple helper to fault in pages and copy. This should go away
385 * and be replaced with calls into generic code.
386 */
btrfs_copy_from_user(loff_t pos,size_t write_bytes,struct page ** prepared_pages,struct iov_iter * i)387 static noinline int btrfs_copy_from_user(loff_t pos, size_t write_bytes,
388 struct page **prepared_pages,
389 struct iov_iter *i)
390 {
391 size_t copied = 0;
392 size_t total_copied = 0;
393 int pg = 0;
394 int offset = offset_in_page(pos);
395
396 while (write_bytes > 0) {
397 size_t count = min_t(size_t,
398 PAGE_SIZE - offset, write_bytes);
399 struct page *page = prepared_pages[pg];
400 /*
401 * Copy data from userspace to the current page
402 */
403 copied = copy_page_from_iter_atomic(page, offset, count, i);
404
405 /* Flush processor's dcache for this page */
406 flush_dcache_page(page);
407
408 /*
409 * if we get a partial write, we can end up with
410 * partially up to date pages. These add
411 * a lot of complexity, so make sure they don't
412 * happen by forcing this copy to be retried.
413 *
414 * The rest of the btrfs_file_write code will fall
415 * back to page at a time copies after we return 0.
416 */
417 if (unlikely(copied < count)) {
418 if (!PageUptodate(page)) {
419 iov_iter_revert(i, copied);
420 copied = 0;
421 }
422 if (!copied)
423 break;
424 }
425
426 write_bytes -= copied;
427 total_copied += copied;
428 offset += copied;
429 if (offset == PAGE_SIZE) {
430 pg++;
431 offset = 0;
432 }
433 }
434 return total_copied;
435 }
436
437 /*
438 * unlocks pages after btrfs_file_write is done with them
439 */
btrfs_drop_pages(struct page ** pages,size_t num_pages)440 static void btrfs_drop_pages(struct page **pages, size_t num_pages)
441 {
442 size_t i;
443 for (i = 0; i < num_pages; i++) {
444 /* page checked is some magic around finding pages that
445 * have been modified without going through btrfs_set_page_dirty
446 * clear it here. There should be no need to mark the pages
447 * accessed as prepare_pages should have marked them accessed
448 * in prepare_pages via find_or_create_page()
449 */
450 ClearPageChecked(pages[i]);
451 unlock_page(pages[i]);
452 put_page(pages[i]);
453 }
454 }
455
456 /*
457 * After btrfs_copy_from_user(), update the following things for delalloc:
458 * - Mark newly dirtied pages as DELALLOC in the io tree.
459 * Used to advise which range is to be written back.
460 * - Mark modified pages as Uptodate/Dirty and not needing COW fixup
461 * - Update inode size for past EOF write
462 */
btrfs_dirty_pages(struct btrfs_inode * inode,struct page ** pages,size_t num_pages,loff_t pos,size_t write_bytes,struct extent_state ** cached,bool noreserve)463 int btrfs_dirty_pages(struct btrfs_inode *inode, struct page **pages,
464 size_t num_pages, loff_t pos, size_t write_bytes,
465 struct extent_state **cached, bool noreserve)
466 {
467 struct btrfs_fs_info *fs_info = inode->root->fs_info;
468 int err = 0;
469 int i;
470 u64 num_bytes;
471 u64 start_pos;
472 u64 end_of_last_block;
473 u64 end_pos = pos + write_bytes;
474 loff_t isize = i_size_read(&inode->vfs_inode);
475 unsigned int extra_bits = 0;
476
477 if (write_bytes == 0)
478 return 0;
479
480 if (noreserve)
481 extra_bits |= EXTENT_NORESERVE;
482
483 start_pos = round_down(pos, fs_info->sectorsize);
484 num_bytes = round_up(write_bytes + pos - start_pos,
485 fs_info->sectorsize);
486 ASSERT(num_bytes <= U32_MAX);
487
488 end_of_last_block = start_pos + num_bytes - 1;
489
490 /*
491 * The pages may have already been dirty, clear out old accounting so
492 * we can set things up properly
493 */
494 clear_extent_bit(&inode->io_tree, start_pos, end_of_last_block,
495 EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG,
496 0, 0, cached);
497
498 err = btrfs_set_extent_delalloc(inode, start_pos, end_of_last_block,
499 extra_bits, cached);
500 if (err)
501 return err;
502
503 for (i = 0; i < num_pages; i++) {
504 struct page *p = pages[i];
505
506 btrfs_page_clamp_set_uptodate(fs_info, p, start_pos, num_bytes);
507 ClearPageChecked(p);
508 btrfs_page_clamp_set_dirty(fs_info, p, start_pos, num_bytes);
509 }
510
511 /*
512 * we've only changed i_size in ram, and we haven't updated
513 * the disk i_size. There is no need to log the inode
514 * at this time.
515 */
516 if (end_pos > isize)
517 i_size_write(&inode->vfs_inode, end_pos);
518 return 0;
519 }
520
521 /*
522 * this drops all the extents in the cache that intersect the range
523 * [start, end]. Existing extents are split as required.
524 */
btrfs_drop_extent_cache(struct btrfs_inode * inode,u64 start,u64 end,int skip_pinned)525 void btrfs_drop_extent_cache(struct btrfs_inode *inode, u64 start, u64 end,
526 int skip_pinned)
527 {
528 struct extent_map *em;
529 struct extent_map *split = NULL;
530 struct extent_map *split2 = NULL;
531 struct extent_map_tree *em_tree = &inode->extent_tree;
532 u64 len = end - start + 1;
533 u64 gen;
534 int ret;
535 int testend = 1;
536 unsigned long flags;
537 int compressed = 0;
538 bool modified;
539
540 WARN_ON(end < start);
541 if (end == (u64)-1) {
542 len = (u64)-1;
543 testend = 0;
544 }
545 while (1) {
546 int no_splits = 0;
547
548 modified = false;
549 if (!split)
550 split = alloc_extent_map();
551 if (!split2)
552 split2 = alloc_extent_map();
553 if (!split || !split2)
554 no_splits = 1;
555
556 write_lock(&em_tree->lock);
557 em = lookup_extent_mapping(em_tree, start, len);
558 if (!em) {
559 write_unlock(&em_tree->lock);
560 break;
561 }
562 flags = em->flags;
563 gen = em->generation;
564 if (skip_pinned && test_bit(EXTENT_FLAG_PINNED, &em->flags)) {
565 if (testend && em->start + em->len >= start + len) {
566 free_extent_map(em);
567 write_unlock(&em_tree->lock);
568 break;
569 }
570 start = em->start + em->len;
571 if (testend)
572 len = start + len - (em->start + em->len);
573 free_extent_map(em);
574 write_unlock(&em_tree->lock);
575 continue;
576 }
577 compressed = test_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
578 clear_bit(EXTENT_FLAG_PINNED, &em->flags);
579 clear_bit(EXTENT_FLAG_LOGGING, &flags);
580 modified = !list_empty(&em->list);
581 if (no_splits)
582 goto next;
583
584 if (em->start < start) {
585 split->start = em->start;
586 split->len = start - em->start;
587
588 if (em->block_start < EXTENT_MAP_LAST_BYTE) {
589 split->orig_start = em->orig_start;
590 split->block_start = em->block_start;
591
592 if (compressed)
593 split->block_len = em->block_len;
594 else
595 split->block_len = split->len;
596 split->orig_block_len = max(split->block_len,
597 em->orig_block_len);
598 split->ram_bytes = em->ram_bytes;
599 } else {
600 split->orig_start = split->start;
601 split->block_len = 0;
602 split->block_start = em->block_start;
603 split->orig_block_len = 0;
604 split->ram_bytes = split->len;
605 }
606
607 split->generation = gen;
608 split->flags = flags;
609 split->compress_type = em->compress_type;
610 replace_extent_mapping(em_tree, em, split, modified);
611 free_extent_map(split);
612 split = split2;
613 split2 = NULL;
614 }
615 if (testend && em->start + em->len > start + len) {
616 u64 diff = start + len - em->start;
617
618 split->start = start + len;
619 split->len = em->start + em->len - (start + len);
620 split->flags = flags;
621 split->compress_type = em->compress_type;
622 split->generation = gen;
623
624 if (em->block_start < EXTENT_MAP_LAST_BYTE) {
625 split->orig_block_len = max(em->block_len,
626 em->orig_block_len);
627
628 split->ram_bytes = em->ram_bytes;
629 if (compressed) {
630 split->block_len = em->block_len;
631 split->block_start = em->block_start;
632 split->orig_start = em->orig_start;
633 } else {
634 split->block_len = split->len;
635 split->block_start = em->block_start
636 + diff;
637 split->orig_start = em->orig_start;
638 }
639 } else {
640 split->ram_bytes = split->len;
641 split->orig_start = split->start;
642 split->block_len = 0;
643 split->block_start = em->block_start;
644 split->orig_block_len = 0;
645 }
646
647 if (extent_map_in_tree(em)) {
648 replace_extent_mapping(em_tree, em, split,
649 modified);
650 } else {
651 ret = add_extent_mapping(em_tree, split,
652 modified);
653 ASSERT(ret == 0); /* Logic error */
654 }
655 free_extent_map(split);
656 split = NULL;
657 }
658 next:
659 if (extent_map_in_tree(em))
660 remove_extent_mapping(em_tree, em);
661 write_unlock(&em_tree->lock);
662
663 /* once for us */
664 free_extent_map(em);
665 /* once for the tree*/
666 free_extent_map(em);
667 }
668 if (split)
669 free_extent_map(split);
670 if (split2)
671 free_extent_map(split2);
672 }
673
674 /*
675 * this is very complex, but the basic idea is to drop all extents
676 * in the range start - end. hint_block is filled in with a block number
677 * that would be a good hint to the block allocator for this file.
678 *
679 * If an extent intersects the range but is not entirely inside the range
680 * it is either truncated or split. Anything entirely inside the range
681 * is deleted from the tree.
682 *
683 * Note: the VFS' inode number of bytes is not updated, it's up to the caller
684 * to deal with that. We set the field 'bytes_found' of the arguments structure
685 * with the number of allocated bytes found in the target range, so that the
686 * caller can update the inode's number of bytes in an atomic way when
687 * replacing extents in a range to avoid races with stat(2).
688 */
btrfs_drop_extents(struct btrfs_trans_handle * trans,struct btrfs_root * root,struct btrfs_inode * inode,struct btrfs_drop_extents_args * args)689 int btrfs_drop_extents(struct btrfs_trans_handle *trans,
690 struct btrfs_root *root, struct btrfs_inode *inode,
691 struct btrfs_drop_extents_args *args)
692 {
693 struct btrfs_fs_info *fs_info = root->fs_info;
694 struct extent_buffer *leaf;
695 struct btrfs_file_extent_item *fi;
696 struct btrfs_ref ref = { 0 };
697 struct btrfs_key key;
698 struct btrfs_key new_key;
699 u64 ino = btrfs_ino(inode);
700 u64 search_start = args->start;
701 u64 disk_bytenr = 0;
702 u64 num_bytes = 0;
703 u64 extent_offset = 0;
704 u64 extent_end = 0;
705 u64 last_end = args->start;
706 int del_nr = 0;
707 int del_slot = 0;
708 int extent_type;
709 int recow;
710 int ret;
711 int modify_tree = -1;
712 int update_refs;
713 int found = 0;
714 int leafs_visited = 0;
715 struct btrfs_path *path = args->path;
716
717 args->bytes_found = 0;
718 args->extent_inserted = false;
719
720 /* Must always have a path if ->replace_extent is true */
721 ASSERT(!(args->replace_extent && !args->path));
722
723 if (!path) {
724 path = btrfs_alloc_path();
725 if (!path) {
726 ret = -ENOMEM;
727 goto out;
728 }
729 }
730
731 if (args->drop_cache)
732 btrfs_drop_extent_cache(inode, args->start, args->end - 1, 0);
733
734 if (args->start >= inode->disk_i_size && !args->replace_extent)
735 modify_tree = 0;
736
737 update_refs = (root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID);
738 while (1) {
739 recow = 0;
740 ret = btrfs_lookup_file_extent(trans, root, path, ino,
741 search_start, modify_tree);
742 if (ret < 0)
743 break;
744 if (ret > 0 && path->slots[0] > 0 && search_start == args->start) {
745 leaf = path->nodes[0];
746 btrfs_item_key_to_cpu(leaf, &key, path->slots[0] - 1);
747 if (key.objectid == ino &&
748 key.type == BTRFS_EXTENT_DATA_KEY)
749 path->slots[0]--;
750 }
751 ret = 0;
752 leafs_visited++;
753 next_slot:
754 leaf = path->nodes[0];
755 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
756 BUG_ON(del_nr > 0);
757 ret = btrfs_next_leaf(root, path);
758 if (ret < 0)
759 break;
760 if (ret > 0) {
761 ret = 0;
762 break;
763 }
764 leafs_visited++;
765 leaf = path->nodes[0];
766 recow = 1;
767 }
768
769 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
770
771 if (key.objectid > ino)
772 break;
773 if (WARN_ON_ONCE(key.objectid < ino) ||
774 key.type < BTRFS_EXTENT_DATA_KEY) {
775 ASSERT(del_nr == 0);
776 path->slots[0]++;
777 goto next_slot;
778 }
779 if (key.type > BTRFS_EXTENT_DATA_KEY || key.offset >= args->end)
780 break;
781
782 fi = btrfs_item_ptr(leaf, path->slots[0],
783 struct btrfs_file_extent_item);
784 extent_type = btrfs_file_extent_type(leaf, fi);
785
786 if (extent_type == BTRFS_FILE_EXTENT_REG ||
787 extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
788 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
789 num_bytes = btrfs_file_extent_disk_num_bytes(leaf, fi);
790 extent_offset = btrfs_file_extent_offset(leaf, fi);
791 extent_end = key.offset +
792 btrfs_file_extent_num_bytes(leaf, fi);
793 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
794 extent_end = key.offset +
795 btrfs_file_extent_ram_bytes(leaf, fi);
796 } else {
797 /* can't happen */
798 BUG();
799 }
800
801 /*
802 * Don't skip extent items representing 0 byte lengths. They
803 * used to be created (bug) if while punching holes we hit
804 * -ENOSPC condition. So if we find one here, just ensure we
805 * delete it, otherwise we would insert a new file extent item
806 * with the same key (offset) as that 0 bytes length file
807 * extent item in the call to setup_items_for_insert() later
808 * in this function.
809 */
810 if (extent_end == key.offset && extent_end >= search_start) {
811 last_end = extent_end;
812 goto delete_extent_item;
813 }
814
815 if (extent_end <= search_start) {
816 path->slots[0]++;
817 goto next_slot;
818 }
819
820 found = 1;
821 search_start = max(key.offset, args->start);
822 if (recow || !modify_tree) {
823 modify_tree = -1;
824 btrfs_release_path(path);
825 continue;
826 }
827
828 /*
829 * | - range to drop - |
830 * | -------- extent -------- |
831 */
832 if (args->start > key.offset && args->end < extent_end) {
833 BUG_ON(del_nr > 0);
834 if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
835 ret = -EOPNOTSUPP;
836 break;
837 }
838
839 memcpy(&new_key, &key, sizeof(new_key));
840 new_key.offset = args->start;
841 ret = btrfs_duplicate_item(trans, root, path,
842 &new_key);
843 if (ret == -EAGAIN) {
844 btrfs_release_path(path);
845 continue;
846 }
847 if (ret < 0)
848 break;
849
850 leaf = path->nodes[0];
851 fi = btrfs_item_ptr(leaf, path->slots[0] - 1,
852 struct btrfs_file_extent_item);
853 btrfs_set_file_extent_num_bytes(leaf, fi,
854 args->start - key.offset);
855
856 fi = btrfs_item_ptr(leaf, path->slots[0],
857 struct btrfs_file_extent_item);
858
859 extent_offset += args->start - key.offset;
860 btrfs_set_file_extent_offset(leaf, fi, extent_offset);
861 btrfs_set_file_extent_num_bytes(leaf, fi,
862 extent_end - args->start);
863 btrfs_mark_buffer_dirty(leaf);
864
865 if (update_refs && disk_bytenr > 0) {
866 btrfs_init_generic_ref(&ref,
867 BTRFS_ADD_DELAYED_REF,
868 disk_bytenr, num_bytes, 0);
869 btrfs_init_data_ref(&ref,
870 root->root_key.objectid,
871 new_key.objectid,
872 args->start - extent_offset,
873 0, false);
874 ret = btrfs_inc_extent_ref(trans, &ref);
875 if (ret) {
876 btrfs_abort_transaction(trans, ret);
877 break;
878 }
879 }
880 key.offset = args->start;
881 }
882 /*
883 * From here on out we will have actually dropped something, so
884 * last_end can be updated.
885 */
886 last_end = extent_end;
887
888 /*
889 * | ---- range to drop ----- |
890 * | -------- extent -------- |
891 */
892 if (args->start <= key.offset && args->end < extent_end) {
893 if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
894 ret = -EOPNOTSUPP;
895 break;
896 }
897
898 memcpy(&new_key, &key, sizeof(new_key));
899 new_key.offset = args->end;
900 btrfs_set_item_key_safe(fs_info, path, &new_key);
901
902 extent_offset += args->end - key.offset;
903 btrfs_set_file_extent_offset(leaf, fi, extent_offset);
904 btrfs_set_file_extent_num_bytes(leaf, fi,
905 extent_end - args->end);
906 btrfs_mark_buffer_dirty(leaf);
907 if (update_refs && disk_bytenr > 0)
908 args->bytes_found += args->end - key.offset;
909 break;
910 }
911
912 search_start = extent_end;
913 /*
914 * | ---- range to drop ----- |
915 * | -------- extent -------- |
916 */
917 if (args->start > key.offset && args->end >= extent_end) {
918 BUG_ON(del_nr > 0);
919 if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
920 ret = -EOPNOTSUPP;
921 break;
922 }
923
924 btrfs_set_file_extent_num_bytes(leaf, fi,
925 args->start - key.offset);
926 btrfs_mark_buffer_dirty(leaf);
927 if (update_refs && disk_bytenr > 0)
928 args->bytes_found += extent_end - args->start;
929 if (args->end == extent_end)
930 break;
931
932 path->slots[0]++;
933 goto next_slot;
934 }
935
936 /*
937 * | ---- range to drop ----- |
938 * | ------ extent ------ |
939 */
940 if (args->start <= key.offset && args->end >= extent_end) {
941 delete_extent_item:
942 if (del_nr == 0) {
943 del_slot = path->slots[0];
944 del_nr = 1;
945 } else {
946 BUG_ON(del_slot + del_nr != path->slots[0]);
947 del_nr++;
948 }
949
950 if (update_refs &&
951 extent_type == BTRFS_FILE_EXTENT_INLINE) {
952 args->bytes_found += extent_end - key.offset;
953 extent_end = ALIGN(extent_end,
954 fs_info->sectorsize);
955 } else if (update_refs && disk_bytenr > 0) {
956 btrfs_init_generic_ref(&ref,
957 BTRFS_DROP_DELAYED_REF,
958 disk_bytenr, num_bytes, 0);
959 btrfs_init_data_ref(&ref,
960 root->root_key.objectid,
961 key.objectid,
962 key.offset - extent_offset, 0,
963 false);
964 ret = btrfs_free_extent(trans, &ref);
965 if (ret) {
966 btrfs_abort_transaction(trans, ret);
967 break;
968 }
969 args->bytes_found += extent_end - key.offset;
970 }
971
972 if (args->end == extent_end)
973 break;
974
975 if (path->slots[0] + 1 < btrfs_header_nritems(leaf)) {
976 path->slots[0]++;
977 goto next_slot;
978 }
979
980 ret = btrfs_del_items(trans, root, path, del_slot,
981 del_nr);
982 if (ret) {
983 btrfs_abort_transaction(trans, ret);
984 break;
985 }
986
987 del_nr = 0;
988 del_slot = 0;
989
990 btrfs_release_path(path);
991 continue;
992 }
993
994 BUG();
995 }
996
997 if (!ret && del_nr > 0) {
998 /*
999 * Set path->slots[0] to first slot, so that after the delete
1000 * if items are move off from our leaf to its immediate left or
1001 * right neighbor leafs, we end up with a correct and adjusted
1002 * path->slots[0] for our insertion (if args->replace_extent).
1003 */
1004 path->slots[0] = del_slot;
1005 ret = btrfs_del_items(trans, root, path, del_slot, del_nr);
1006 if (ret)
1007 btrfs_abort_transaction(trans, ret);
1008 }
1009
1010 leaf = path->nodes[0];
1011 /*
1012 * If btrfs_del_items() was called, it might have deleted a leaf, in
1013 * which case it unlocked our path, so check path->locks[0] matches a
1014 * write lock.
1015 */
1016 if (!ret && args->replace_extent && leafs_visited == 1 &&
1017 path->locks[0] == BTRFS_WRITE_LOCK &&
1018 btrfs_leaf_free_space(leaf) >=
1019 sizeof(struct btrfs_item) + args->extent_item_size) {
1020
1021 key.objectid = ino;
1022 key.type = BTRFS_EXTENT_DATA_KEY;
1023 key.offset = args->start;
1024 if (!del_nr && path->slots[0] < btrfs_header_nritems(leaf)) {
1025 struct btrfs_key slot_key;
1026
1027 btrfs_item_key_to_cpu(leaf, &slot_key, path->slots[0]);
1028 if (btrfs_comp_cpu_keys(&key, &slot_key) > 0)
1029 path->slots[0]++;
1030 }
1031 setup_items_for_insert(root, path, &key,
1032 &args->extent_item_size, 1);
1033 args->extent_inserted = true;
1034 }
1035
1036 if (!args->path)
1037 btrfs_free_path(path);
1038 else if (!args->extent_inserted)
1039 btrfs_release_path(path);
1040 out:
1041 args->drop_end = found ? min(args->end, last_end) : args->end;
1042
1043 return ret;
1044 }
1045
extent_mergeable(struct extent_buffer * leaf,int slot,u64 objectid,u64 bytenr,u64 orig_offset,u64 * start,u64 * end)1046 static int extent_mergeable(struct extent_buffer *leaf, int slot,
1047 u64 objectid, u64 bytenr, u64 orig_offset,
1048 u64 *start, u64 *end)
1049 {
1050 struct btrfs_file_extent_item *fi;
1051 struct btrfs_key key;
1052 u64 extent_end;
1053
1054 if (slot < 0 || slot >= btrfs_header_nritems(leaf))
1055 return 0;
1056
1057 btrfs_item_key_to_cpu(leaf, &key, slot);
1058 if (key.objectid != objectid || key.type != BTRFS_EXTENT_DATA_KEY)
1059 return 0;
1060
1061 fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
1062 if (btrfs_file_extent_type(leaf, fi) != BTRFS_FILE_EXTENT_REG ||
1063 btrfs_file_extent_disk_bytenr(leaf, fi) != bytenr ||
1064 btrfs_file_extent_offset(leaf, fi) != key.offset - orig_offset ||
1065 btrfs_file_extent_compression(leaf, fi) ||
1066 btrfs_file_extent_encryption(leaf, fi) ||
1067 btrfs_file_extent_other_encoding(leaf, fi))
1068 return 0;
1069
1070 extent_end = key.offset + btrfs_file_extent_num_bytes(leaf, fi);
1071 if ((*start && *start != key.offset) || (*end && *end != extent_end))
1072 return 0;
1073
1074 *start = key.offset;
1075 *end = extent_end;
1076 return 1;
1077 }
1078
1079 /*
1080 * Mark extent in the range start - end as written.
1081 *
1082 * This changes extent type from 'pre-allocated' to 'regular'. If only
1083 * part of extent is marked as written, the extent will be split into
1084 * two or three.
1085 */
btrfs_mark_extent_written(struct btrfs_trans_handle * trans,struct btrfs_inode * inode,u64 start,u64 end)1086 int btrfs_mark_extent_written(struct btrfs_trans_handle *trans,
1087 struct btrfs_inode *inode, u64 start, u64 end)
1088 {
1089 struct btrfs_fs_info *fs_info = trans->fs_info;
1090 struct btrfs_root *root = inode->root;
1091 struct extent_buffer *leaf;
1092 struct btrfs_path *path;
1093 struct btrfs_file_extent_item *fi;
1094 struct btrfs_ref ref = { 0 };
1095 struct btrfs_key key;
1096 struct btrfs_key new_key;
1097 u64 bytenr;
1098 u64 num_bytes;
1099 u64 extent_end;
1100 u64 orig_offset;
1101 u64 other_start;
1102 u64 other_end;
1103 u64 split;
1104 int del_nr = 0;
1105 int del_slot = 0;
1106 int recow;
1107 int ret = 0;
1108 u64 ino = btrfs_ino(inode);
1109
1110 path = btrfs_alloc_path();
1111 if (!path)
1112 return -ENOMEM;
1113 again:
1114 recow = 0;
1115 split = start;
1116 key.objectid = ino;
1117 key.type = BTRFS_EXTENT_DATA_KEY;
1118 key.offset = split;
1119
1120 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1121 if (ret < 0)
1122 goto out;
1123 if (ret > 0 && path->slots[0] > 0)
1124 path->slots[0]--;
1125
1126 leaf = path->nodes[0];
1127 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
1128 if (key.objectid != ino ||
1129 key.type != BTRFS_EXTENT_DATA_KEY) {
1130 ret = -EINVAL;
1131 btrfs_abort_transaction(trans, ret);
1132 goto out;
1133 }
1134 fi = btrfs_item_ptr(leaf, path->slots[0],
1135 struct btrfs_file_extent_item);
1136 if (btrfs_file_extent_type(leaf, fi) != BTRFS_FILE_EXTENT_PREALLOC) {
1137 ret = -EINVAL;
1138 btrfs_abort_transaction(trans, ret);
1139 goto out;
1140 }
1141 extent_end = key.offset + btrfs_file_extent_num_bytes(leaf, fi);
1142 if (key.offset > start || extent_end < end) {
1143 ret = -EINVAL;
1144 btrfs_abort_transaction(trans, ret);
1145 goto out;
1146 }
1147
1148 bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
1149 num_bytes = btrfs_file_extent_disk_num_bytes(leaf, fi);
1150 orig_offset = key.offset - btrfs_file_extent_offset(leaf, fi);
1151 memcpy(&new_key, &key, sizeof(new_key));
1152
1153 if (start == key.offset && end < extent_end) {
1154 other_start = 0;
1155 other_end = start;
1156 if (extent_mergeable(leaf, path->slots[0] - 1,
1157 ino, bytenr, orig_offset,
1158 &other_start, &other_end)) {
1159 new_key.offset = end;
1160 btrfs_set_item_key_safe(fs_info, path, &new_key);
1161 fi = btrfs_item_ptr(leaf, path->slots[0],
1162 struct btrfs_file_extent_item);
1163 btrfs_set_file_extent_generation(leaf, fi,
1164 trans->transid);
1165 btrfs_set_file_extent_num_bytes(leaf, fi,
1166 extent_end - end);
1167 btrfs_set_file_extent_offset(leaf, fi,
1168 end - orig_offset);
1169 fi = btrfs_item_ptr(leaf, path->slots[0] - 1,
1170 struct btrfs_file_extent_item);
1171 btrfs_set_file_extent_generation(leaf, fi,
1172 trans->transid);
1173 btrfs_set_file_extent_num_bytes(leaf, fi,
1174 end - other_start);
1175 btrfs_mark_buffer_dirty(leaf);
1176 goto out;
1177 }
1178 }
1179
1180 if (start > key.offset && end == extent_end) {
1181 other_start = end;
1182 other_end = 0;
1183 if (extent_mergeable(leaf, path->slots[0] + 1,
1184 ino, bytenr, orig_offset,
1185 &other_start, &other_end)) {
1186 fi = btrfs_item_ptr(leaf, path->slots[0],
1187 struct btrfs_file_extent_item);
1188 btrfs_set_file_extent_num_bytes(leaf, fi,
1189 start - key.offset);
1190 btrfs_set_file_extent_generation(leaf, fi,
1191 trans->transid);
1192 path->slots[0]++;
1193 new_key.offset = start;
1194 btrfs_set_item_key_safe(fs_info, path, &new_key);
1195
1196 fi = btrfs_item_ptr(leaf, path->slots[0],
1197 struct btrfs_file_extent_item);
1198 btrfs_set_file_extent_generation(leaf, fi,
1199 trans->transid);
1200 btrfs_set_file_extent_num_bytes(leaf, fi,
1201 other_end - start);
1202 btrfs_set_file_extent_offset(leaf, fi,
1203 start - orig_offset);
1204 btrfs_mark_buffer_dirty(leaf);
1205 goto out;
1206 }
1207 }
1208
1209 while (start > key.offset || end < extent_end) {
1210 if (key.offset == start)
1211 split = end;
1212
1213 new_key.offset = split;
1214 ret = btrfs_duplicate_item(trans, root, path, &new_key);
1215 if (ret == -EAGAIN) {
1216 btrfs_release_path(path);
1217 goto again;
1218 }
1219 if (ret < 0) {
1220 btrfs_abort_transaction(trans, ret);
1221 goto out;
1222 }
1223
1224 leaf = path->nodes[0];
1225 fi = btrfs_item_ptr(leaf, path->slots[0] - 1,
1226 struct btrfs_file_extent_item);
1227 btrfs_set_file_extent_generation(leaf, fi, trans->transid);
1228 btrfs_set_file_extent_num_bytes(leaf, fi,
1229 split - key.offset);
1230
1231 fi = btrfs_item_ptr(leaf, path->slots[0],
1232 struct btrfs_file_extent_item);
1233
1234 btrfs_set_file_extent_generation(leaf, fi, trans->transid);
1235 btrfs_set_file_extent_offset(leaf, fi, split - orig_offset);
1236 btrfs_set_file_extent_num_bytes(leaf, fi,
1237 extent_end - split);
1238 btrfs_mark_buffer_dirty(leaf);
1239
1240 btrfs_init_generic_ref(&ref, BTRFS_ADD_DELAYED_REF, bytenr,
1241 num_bytes, 0);
1242 btrfs_init_data_ref(&ref, root->root_key.objectid, ino,
1243 orig_offset, 0, false);
1244 ret = btrfs_inc_extent_ref(trans, &ref);
1245 if (ret) {
1246 btrfs_abort_transaction(trans, ret);
1247 goto out;
1248 }
1249
1250 if (split == start) {
1251 key.offset = start;
1252 } else {
1253 if (start != key.offset) {
1254 ret = -EINVAL;
1255 btrfs_abort_transaction(trans, ret);
1256 goto out;
1257 }
1258 path->slots[0]--;
1259 extent_end = end;
1260 }
1261 recow = 1;
1262 }
1263
1264 other_start = end;
1265 other_end = 0;
1266 btrfs_init_generic_ref(&ref, BTRFS_DROP_DELAYED_REF, bytenr,
1267 num_bytes, 0);
1268 btrfs_init_data_ref(&ref, root->root_key.objectid, ino, orig_offset,
1269 0, false);
1270 if (extent_mergeable(leaf, path->slots[0] + 1,
1271 ino, bytenr, orig_offset,
1272 &other_start, &other_end)) {
1273 if (recow) {
1274 btrfs_release_path(path);
1275 goto again;
1276 }
1277 extent_end = other_end;
1278 del_slot = path->slots[0] + 1;
1279 del_nr++;
1280 ret = btrfs_free_extent(trans, &ref);
1281 if (ret) {
1282 btrfs_abort_transaction(trans, ret);
1283 goto out;
1284 }
1285 }
1286 other_start = 0;
1287 other_end = start;
1288 if (extent_mergeable(leaf, path->slots[0] - 1,
1289 ino, bytenr, orig_offset,
1290 &other_start, &other_end)) {
1291 if (recow) {
1292 btrfs_release_path(path);
1293 goto again;
1294 }
1295 key.offset = other_start;
1296 del_slot = path->slots[0];
1297 del_nr++;
1298 ret = btrfs_free_extent(trans, &ref);
1299 if (ret) {
1300 btrfs_abort_transaction(trans, ret);
1301 goto out;
1302 }
1303 }
1304 if (del_nr == 0) {
1305 fi = btrfs_item_ptr(leaf, path->slots[0],
1306 struct btrfs_file_extent_item);
1307 btrfs_set_file_extent_type(leaf, fi,
1308 BTRFS_FILE_EXTENT_REG);
1309 btrfs_set_file_extent_generation(leaf, fi, trans->transid);
1310 btrfs_mark_buffer_dirty(leaf);
1311 } else {
1312 fi = btrfs_item_ptr(leaf, del_slot - 1,
1313 struct btrfs_file_extent_item);
1314 btrfs_set_file_extent_type(leaf, fi,
1315 BTRFS_FILE_EXTENT_REG);
1316 btrfs_set_file_extent_generation(leaf, fi, trans->transid);
1317 btrfs_set_file_extent_num_bytes(leaf, fi,
1318 extent_end - key.offset);
1319 btrfs_mark_buffer_dirty(leaf);
1320
1321 ret = btrfs_del_items(trans, root, path, del_slot, del_nr);
1322 if (ret < 0) {
1323 btrfs_abort_transaction(trans, ret);
1324 goto out;
1325 }
1326 }
1327 out:
1328 btrfs_free_path(path);
1329 return ret;
1330 }
1331
1332 /*
1333 * on error we return an unlocked page and the error value
1334 * on success we return a locked page and 0
1335 */
prepare_uptodate_page(struct inode * inode,struct page * page,u64 pos,bool force_uptodate)1336 static int prepare_uptodate_page(struct inode *inode,
1337 struct page *page, u64 pos,
1338 bool force_uptodate)
1339 {
1340 int ret = 0;
1341
1342 if (((pos & (PAGE_SIZE - 1)) || force_uptodate) &&
1343 !PageUptodate(page)) {
1344 ret = btrfs_readpage(NULL, page);
1345 if (ret)
1346 return ret;
1347 lock_page(page);
1348 if (!PageUptodate(page)) {
1349 unlock_page(page);
1350 return -EIO;
1351 }
1352
1353 /*
1354 * Since btrfs_readpage() will unlock the page before it
1355 * returns, there is a window where btrfs_releasepage() can be
1356 * called to release the page. Here we check both inode
1357 * mapping and PagePrivate() to make sure the page was not
1358 * released.
1359 *
1360 * The private flag check is essential for subpage as we need
1361 * to store extra bitmap using page->private.
1362 */
1363 if (page->mapping != inode->i_mapping || !PagePrivate(page)) {
1364 unlock_page(page);
1365 return -EAGAIN;
1366 }
1367 }
1368 return 0;
1369 }
1370
1371 /*
1372 * this just gets pages into the page cache and locks them down.
1373 */
prepare_pages(struct inode * inode,struct page ** pages,size_t num_pages,loff_t pos,size_t write_bytes,bool force_uptodate)1374 static noinline int prepare_pages(struct inode *inode, struct page **pages,
1375 size_t num_pages, loff_t pos,
1376 size_t write_bytes, bool force_uptodate)
1377 {
1378 int i;
1379 unsigned long index = pos >> PAGE_SHIFT;
1380 gfp_t mask = btrfs_alloc_write_mask(inode->i_mapping);
1381 int err = 0;
1382 int faili;
1383
1384 for (i = 0; i < num_pages; i++) {
1385 again:
1386 pages[i] = find_or_create_page(inode->i_mapping, index + i,
1387 mask | __GFP_WRITE);
1388 if (!pages[i]) {
1389 faili = i - 1;
1390 err = -ENOMEM;
1391 goto fail;
1392 }
1393
1394 err = set_page_extent_mapped(pages[i]);
1395 if (err < 0) {
1396 faili = i;
1397 goto fail;
1398 }
1399
1400 if (i == 0)
1401 err = prepare_uptodate_page(inode, pages[i], pos,
1402 force_uptodate);
1403 if (!err && i == num_pages - 1)
1404 err = prepare_uptodate_page(inode, pages[i],
1405 pos + write_bytes, false);
1406 if (err) {
1407 put_page(pages[i]);
1408 if (err == -EAGAIN) {
1409 err = 0;
1410 goto again;
1411 }
1412 faili = i - 1;
1413 goto fail;
1414 }
1415 wait_on_page_writeback(pages[i]);
1416 }
1417
1418 return 0;
1419 fail:
1420 while (faili >= 0) {
1421 unlock_page(pages[faili]);
1422 put_page(pages[faili]);
1423 faili--;
1424 }
1425 return err;
1426
1427 }
1428
1429 /*
1430 * This function locks the extent and properly waits for data=ordered extents
1431 * to finish before allowing the pages to be modified if need.
1432 *
1433 * The return value:
1434 * 1 - the extent is locked
1435 * 0 - the extent is not locked, and everything is OK
1436 * -EAGAIN - need re-prepare the pages
1437 * the other < 0 number - Something wrong happens
1438 */
1439 static noinline int
lock_and_cleanup_extent_if_need(struct btrfs_inode * inode,struct page ** pages,size_t num_pages,loff_t pos,size_t write_bytes,u64 * lockstart,u64 * lockend,struct extent_state ** cached_state)1440 lock_and_cleanup_extent_if_need(struct btrfs_inode *inode, struct page **pages,
1441 size_t num_pages, loff_t pos,
1442 size_t write_bytes,
1443 u64 *lockstart, u64 *lockend,
1444 struct extent_state **cached_state)
1445 {
1446 struct btrfs_fs_info *fs_info = inode->root->fs_info;
1447 u64 start_pos;
1448 u64 last_pos;
1449 int i;
1450 int ret = 0;
1451
1452 start_pos = round_down(pos, fs_info->sectorsize);
1453 last_pos = round_up(pos + write_bytes, fs_info->sectorsize) - 1;
1454
1455 if (start_pos < inode->vfs_inode.i_size) {
1456 struct btrfs_ordered_extent *ordered;
1457
1458 lock_extent_bits(&inode->io_tree, start_pos, last_pos,
1459 cached_state);
1460 ordered = btrfs_lookup_ordered_range(inode, start_pos,
1461 last_pos - start_pos + 1);
1462 if (ordered &&
1463 ordered->file_offset + ordered->num_bytes > start_pos &&
1464 ordered->file_offset <= last_pos) {
1465 unlock_extent_cached(&inode->io_tree, start_pos,
1466 last_pos, cached_state);
1467 for (i = 0; i < num_pages; i++) {
1468 unlock_page(pages[i]);
1469 put_page(pages[i]);
1470 }
1471 btrfs_start_ordered_extent(ordered, 1);
1472 btrfs_put_ordered_extent(ordered);
1473 return -EAGAIN;
1474 }
1475 if (ordered)
1476 btrfs_put_ordered_extent(ordered);
1477
1478 *lockstart = start_pos;
1479 *lockend = last_pos;
1480 ret = 1;
1481 }
1482
1483 /*
1484 * We should be called after prepare_pages() which should have locked
1485 * all pages in the range.
1486 */
1487 for (i = 0; i < num_pages; i++)
1488 WARN_ON(!PageLocked(pages[i]));
1489
1490 return ret;
1491 }
1492
check_can_nocow(struct btrfs_inode * inode,loff_t pos,size_t * write_bytes,bool nowait)1493 static int check_can_nocow(struct btrfs_inode *inode, loff_t pos,
1494 size_t *write_bytes, bool nowait)
1495 {
1496 struct btrfs_fs_info *fs_info = inode->root->fs_info;
1497 struct btrfs_root *root = inode->root;
1498 u64 lockstart, lockend;
1499 u64 num_bytes;
1500 int ret;
1501
1502 if (!(inode->flags & (BTRFS_INODE_NODATACOW | BTRFS_INODE_PREALLOC)))
1503 return 0;
1504
1505 if (!nowait && !btrfs_drew_try_write_lock(&root->snapshot_lock))
1506 return -EAGAIN;
1507
1508 lockstart = round_down(pos, fs_info->sectorsize);
1509 lockend = round_up(pos + *write_bytes,
1510 fs_info->sectorsize) - 1;
1511 num_bytes = lockend - lockstart + 1;
1512
1513 if (nowait) {
1514 struct btrfs_ordered_extent *ordered;
1515
1516 if (!try_lock_extent(&inode->io_tree, lockstart, lockend))
1517 return -EAGAIN;
1518
1519 ordered = btrfs_lookup_ordered_range(inode, lockstart,
1520 num_bytes);
1521 if (ordered) {
1522 btrfs_put_ordered_extent(ordered);
1523 ret = -EAGAIN;
1524 goto out_unlock;
1525 }
1526 } else {
1527 btrfs_lock_and_flush_ordered_range(inode, lockstart,
1528 lockend, NULL);
1529 }
1530
1531 ret = can_nocow_extent(&inode->vfs_inode, lockstart, &num_bytes,
1532 NULL, NULL, NULL, false);
1533 if (ret <= 0) {
1534 ret = 0;
1535 if (!nowait)
1536 btrfs_drew_write_unlock(&root->snapshot_lock);
1537 } else {
1538 *write_bytes = min_t(size_t, *write_bytes ,
1539 num_bytes - pos + lockstart);
1540 }
1541 out_unlock:
1542 unlock_extent(&inode->io_tree, lockstart, lockend);
1543
1544 return ret;
1545 }
1546
check_nocow_nolock(struct btrfs_inode * inode,loff_t pos,size_t * write_bytes)1547 static int check_nocow_nolock(struct btrfs_inode *inode, loff_t pos,
1548 size_t *write_bytes)
1549 {
1550 return check_can_nocow(inode, pos, write_bytes, true);
1551 }
1552
1553 /*
1554 * Check if we can do nocow write into the range [@pos, @pos + @write_bytes)
1555 *
1556 * @pos: File offset
1557 * @write_bytes: The length to write, will be updated to the nocow writeable
1558 * range
1559 *
1560 * This function will flush ordered extents in the range to ensure proper
1561 * nocow checks.
1562 *
1563 * Return:
1564 * >0 and update @write_bytes if we can do nocow write
1565 * 0 if we can't do nocow write
1566 * -EAGAIN if we can't get the needed lock or there are ordered extents
1567 * for * (nowait == true) case
1568 * <0 if other error happened
1569 *
1570 * NOTE: Callers need to release the lock by btrfs_check_nocow_unlock().
1571 */
btrfs_check_nocow_lock(struct btrfs_inode * inode,loff_t pos,size_t * write_bytes)1572 int btrfs_check_nocow_lock(struct btrfs_inode *inode, loff_t pos,
1573 size_t *write_bytes)
1574 {
1575 return check_can_nocow(inode, pos, write_bytes, false);
1576 }
1577
btrfs_check_nocow_unlock(struct btrfs_inode * inode)1578 void btrfs_check_nocow_unlock(struct btrfs_inode *inode)
1579 {
1580 btrfs_drew_write_unlock(&inode->root->snapshot_lock);
1581 }
1582
update_time_for_write(struct inode * inode)1583 static void update_time_for_write(struct inode *inode)
1584 {
1585 struct timespec64 now;
1586
1587 if (IS_NOCMTIME(inode))
1588 return;
1589
1590 now = current_time(inode);
1591 if (!timespec64_equal(&inode->i_mtime, &now))
1592 inode->i_mtime = now;
1593
1594 if (!timespec64_equal(&inode->i_ctime, &now))
1595 inode->i_ctime = now;
1596
1597 if (IS_I_VERSION(inode))
1598 inode_inc_iversion(inode);
1599 }
1600
btrfs_write_check(struct kiocb * iocb,struct iov_iter * from,size_t count)1601 static int btrfs_write_check(struct kiocb *iocb, struct iov_iter *from,
1602 size_t count)
1603 {
1604 struct file *file = iocb->ki_filp;
1605 struct inode *inode = file_inode(file);
1606 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1607 loff_t pos = iocb->ki_pos;
1608 int ret;
1609 loff_t oldsize;
1610 loff_t start_pos;
1611
1612 if (iocb->ki_flags & IOCB_NOWAIT) {
1613 size_t nocow_bytes = count;
1614
1615 /* We will allocate space in case nodatacow is not set, so bail */
1616 if (check_nocow_nolock(BTRFS_I(inode), pos, &nocow_bytes) <= 0)
1617 return -EAGAIN;
1618 /*
1619 * There are holes in the range or parts of the range that must
1620 * be COWed (shared extents, RO block groups, etc), so just bail
1621 * out.
1622 */
1623 if (nocow_bytes < count)
1624 return -EAGAIN;
1625 }
1626
1627 current->backing_dev_info = inode_to_bdi(inode);
1628 ret = file_remove_privs(file);
1629 if (ret)
1630 return ret;
1631
1632 /*
1633 * We reserve space for updating the inode when we reserve space for the
1634 * extent we are going to write, so we will enospc out there. We don't
1635 * need to start yet another transaction to update the inode as we will
1636 * update the inode when we finish writing whatever data we write.
1637 */
1638 update_time_for_write(inode);
1639
1640 start_pos = round_down(pos, fs_info->sectorsize);
1641 oldsize = i_size_read(inode);
1642 if (start_pos > oldsize) {
1643 /* Expand hole size to cover write data, preventing empty gap */
1644 loff_t end_pos = round_up(pos + count, fs_info->sectorsize);
1645
1646 ret = btrfs_cont_expand(BTRFS_I(inode), oldsize, end_pos);
1647 if (ret) {
1648 current->backing_dev_info = NULL;
1649 return ret;
1650 }
1651 }
1652
1653 return 0;
1654 }
1655
btrfs_buffered_write(struct kiocb * iocb,struct iov_iter * i)1656 static noinline ssize_t btrfs_buffered_write(struct kiocb *iocb,
1657 struct iov_iter *i)
1658 {
1659 struct file *file = iocb->ki_filp;
1660 loff_t pos;
1661 struct inode *inode = file_inode(file);
1662 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1663 struct page **pages = NULL;
1664 struct extent_changeset *data_reserved = NULL;
1665 u64 release_bytes = 0;
1666 u64 lockstart;
1667 u64 lockend;
1668 size_t num_written = 0;
1669 int nrptrs;
1670 ssize_t ret;
1671 bool only_release_metadata = false;
1672 bool force_page_uptodate = false;
1673 loff_t old_isize = i_size_read(inode);
1674 unsigned int ilock_flags = 0;
1675
1676 if (iocb->ki_flags & IOCB_NOWAIT)
1677 ilock_flags |= BTRFS_ILOCK_TRY;
1678
1679 ret = btrfs_inode_lock(inode, ilock_flags);
1680 if (ret < 0)
1681 return ret;
1682
1683 ret = generic_write_checks(iocb, i);
1684 if (ret <= 0)
1685 goto out;
1686
1687 ret = btrfs_write_check(iocb, i, ret);
1688 if (ret < 0)
1689 goto out;
1690
1691 pos = iocb->ki_pos;
1692 nrptrs = min(DIV_ROUND_UP(iov_iter_count(i), PAGE_SIZE),
1693 PAGE_SIZE / (sizeof(struct page *)));
1694 nrptrs = min(nrptrs, current->nr_dirtied_pause - current->nr_dirtied);
1695 nrptrs = max(nrptrs, 8);
1696 pages = kmalloc_array(nrptrs, sizeof(struct page *), GFP_KERNEL);
1697 if (!pages) {
1698 ret = -ENOMEM;
1699 goto out;
1700 }
1701
1702 while (iov_iter_count(i) > 0) {
1703 struct extent_state *cached_state = NULL;
1704 size_t offset = offset_in_page(pos);
1705 size_t sector_offset;
1706 size_t write_bytes = min(iov_iter_count(i),
1707 nrptrs * (size_t)PAGE_SIZE -
1708 offset);
1709 size_t num_pages;
1710 size_t reserve_bytes;
1711 size_t dirty_pages;
1712 size_t copied;
1713 size_t dirty_sectors;
1714 size_t num_sectors;
1715 int extents_locked;
1716
1717 /*
1718 * Fault pages before locking them in prepare_pages
1719 * to avoid recursive lock
1720 */
1721 if (unlikely(fault_in_iov_iter_readable(i, write_bytes))) {
1722 ret = -EFAULT;
1723 break;
1724 }
1725
1726 only_release_metadata = false;
1727 sector_offset = pos & (fs_info->sectorsize - 1);
1728
1729 extent_changeset_release(data_reserved);
1730 ret = btrfs_check_data_free_space(BTRFS_I(inode),
1731 &data_reserved, pos,
1732 write_bytes);
1733 if (ret < 0) {
1734 /*
1735 * If we don't have to COW at the offset, reserve
1736 * metadata only. write_bytes may get smaller than
1737 * requested here.
1738 */
1739 if (btrfs_check_nocow_lock(BTRFS_I(inode), pos,
1740 &write_bytes) > 0)
1741 only_release_metadata = true;
1742 else
1743 break;
1744 }
1745
1746 num_pages = DIV_ROUND_UP(write_bytes + offset, PAGE_SIZE);
1747 WARN_ON(num_pages > nrptrs);
1748 reserve_bytes = round_up(write_bytes + sector_offset,
1749 fs_info->sectorsize);
1750 WARN_ON(reserve_bytes == 0);
1751 ret = btrfs_delalloc_reserve_metadata(BTRFS_I(inode),
1752 reserve_bytes);
1753 if (ret) {
1754 if (!only_release_metadata)
1755 btrfs_free_reserved_data_space(BTRFS_I(inode),
1756 data_reserved, pos,
1757 write_bytes);
1758 else
1759 btrfs_check_nocow_unlock(BTRFS_I(inode));
1760 break;
1761 }
1762
1763 release_bytes = reserve_bytes;
1764 again:
1765 /*
1766 * This is going to setup the pages array with the number of
1767 * pages we want, so we don't really need to worry about the
1768 * contents of pages from loop to loop
1769 */
1770 ret = prepare_pages(inode, pages, num_pages,
1771 pos, write_bytes,
1772 force_page_uptodate);
1773 if (ret) {
1774 btrfs_delalloc_release_extents(BTRFS_I(inode),
1775 reserve_bytes);
1776 break;
1777 }
1778
1779 extents_locked = lock_and_cleanup_extent_if_need(
1780 BTRFS_I(inode), pages,
1781 num_pages, pos, write_bytes, &lockstart,
1782 &lockend, &cached_state);
1783 if (extents_locked < 0) {
1784 if (extents_locked == -EAGAIN)
1785 goto again;
1786 btrfs_delalloc_release_extents(BTRFS_I(inode),
1787 reserve_bytes);
1788 ret = extents_locked;
1789 break;
1790 }
1791
1792 copied = btrfs_copy_from_user(pos, write_bytes, pages, i);
1793
1794 num_sectors = BTRFS_BYTES_TO_BLKS(fs_info, reserve_bytes);
1795 dirty_sectors = round_up(copied + sector_offset,
1796 fs_info->sectorsize);
1797 dirty_sectors = BTRFS_BYTES_TO_BLKS(fs_info, dirty_sectors);
1798
1799 /*
1800 * if we have trouble faulting in the pages, fall
1801 * back to one page at a time
1802 */
1803 if (copied < write_bytes)
1804 nrptrs = 1;
1805
1806 if (copied == 0) {
1807 force_page_uptodate = true;
1808 dirty_sectors = 0;
1809 dirty_pages = 0;
1810 } else {
1811 force_page_uptodate = false;
1812 dirty_pages = DIV_ROUND_UP(copied + offset,
1813 PAGE_SIZE);
1814 }
1815
1816 if (num_sectors > dirty_sectors) {
1817 /* release everything except the sectors we dirtied */
1818 release_bytes -= dirty_sectors << fs_info->sectorsize_bits;
1819 if (only_release_metadata) {
1820 btrfs_delalloc_release_metadata(BTRFS_I(inode),
1821 release_bytes, true);
1822 } else {
1823 u64 __pos;
1824
1825 __pos = round_down(pos,
1826 fs_info->sectorsize) +
1827 (dirty_pages << PAGE_SHIFT);
1828 btrfs_delalloc_release_space(BTRFS_I(inode),
1829 data_reserved, __pos,
1830 release_bytes, true);
1831 }
1832 }
1833
1834 release_bytes = round_up(copied + sector_offset,
1835 fs_info->sectorsize);
1836
1837 ret = btrfs_dirty_pages(BTRFS_I(inode), pages,
1838 dirty_pages, pos, copied,
1839 &cached_state, only_release_metadata);
1840
1841 /*
1842 * If we have not locked the extent range, because the range's
1843 * start offset is >= i_size, we might still have a non-NULL
1844 * cached extent state, acquired while marking the extent range
1845 * as delalloc through btrfs_dirty_pages(). Therefore free any
1846 * possible cached extent state to avoid a memory leak.
1847 */
1848 if (extents_locked)
1849 unlock_extent_cached(&BTRFS_I(inode)->io_tree,
1850 lockstart, lockend, &cached_state);
1851 else
1852 free_extent_state(cached_state);
1853
1854 btrfs_delalloc_release_extents(BTRFS_I(inode), reserve_bytes);
1855 if (ret) {
1856 btrfs_drop_pages(pages, num_pages);
1857 break;
1858 }
1859
1860 release_bytes = 0;
1861 if (only_release_metadata)
1862 btrfs_check_nocow_unlock(BTRFS_I(inode));
1863
1864 btrfs_drop_pages(pages, num_pages);
1865
1866 cond_resched();
1867
1868 balance_dirty_pages_ratelimited(inode->i_mapping);
1869
1870 pos += copied;
1871 num_written += copied;
1872 }
1873
1874 kfree(pages);
1875
1876 if (release_bytes) {
1877 if (only_release_metadata) {
1878 btrfs_check_nocow_unlock(BTRFS_I(inode));
1879 btrfs_delalloc_release_metadata(BTRFS_I(inode),
1880 release_bytes, true);
1881 } else {
1882 btrfs_delalloc_release_space(BTRFS_I(inode),
1883 data_reserved,
1884 round_down(pos, fs_info->sectorsize),
1885 release_bytes, true);
1886 }
1887 }
1888
1889 extent_changeset_free(data_reserved);
1890 if (num_written > 0) {
1891 pagecache_isize_extended(inode, old_isize, iocb->ki_pos);
1892 iocb->ki_pos += num_written;
1893 }
1894 out:
1895 btrfs_inode_unlock(inode, ilock_flags);
1896 return num_written ? num_written : ret;
1897 }
1898
check_direct_IO(struct btrfs_fs_info * fs_info,const struct iov_iter * iter,loff_t offset)1899 static ssize_t check_direct_IO(struct btrfs_fs_info *fs_info,
1900 const struct iov_iter *iter, loff_t offset)
1901 {
1902 const u32 blocksize_mask = fs_info->sectorsize - 1;
1903
1904 if (offset & blocksize_mask)
1905 return -EINVAL;
1906
1907 if (iov_iter_alignment(iter) & blocksize_mask)
1908 return -EINVAL;
1909
1910 return 0;
1911 }
1912
btrfs_direct_write(struct kiocb * iocb,struct iov_iter * from)1913 static ssize_t btrfs_direct_write(struct kiocb *iocb, struct iov_iter *from)
1914 {
1915 struct file *file = iocb->ki_filp;
1916 struct inode *inode = file_inode(file);
1917 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1918 loff_t pos;
1919 ssize_t written = 0;
1920 ssize_t written_buffered;
1921 size_t prev_left = 0;
1922 loff_t endbyte;
1923 ssize_t err;
1924 unsigned int ilock_flags = 0;
1925 struct iomap_dio *dio;
1926
1927 if (iocb->ki_flags & IOCB_NOWAIT)
1928 ilock_flags |= BTRFS_ILOCK_TRY;
1929
1930 /* If the write DIO is within EOF, use a shared lock */
1931 if (iocb->ki_pos + iov_iter_count(from) <= i_size_read(inode))
1932 ilock_flags |= BTRFS_ILOCK_SHARED;
1933
1934 relock:
1935 err = btrfs_inode_lock(inode, ilock_flags);
1936 if (err < 0)
1937 return err;
1938
1939 err = generic_write_checks(iocb, from);
1940 if (err <= 0) {
1941 btrfs_inode_unlock(inode, ilock_flags);
1942 return err;
1943 }
1944
1945 err = btrfs_write_check(iocb, from, err);
1946 if (err < 0) {
1947 btrfs_inode_unlock(inode, ilock_flags);
1948 goto out;
1949 }
1950
1951 pos = iocb->ki_pos;
1952 /*
1953 * Re-check since file size may have changed just before taking the
1954 * lock or pos may have changed because of O_APPEND in generic_write_check()
1955 */
1956 if ((ilock_flags & BTRFS_ILOCK_SHARED) &&
1957 pos + iov_iter_count(from) > i_size_read(inode)) {
1958 btrfs_inode_unlock(inode, ilock_flags);
1959 ilock_flags &= ~BTRFS_ILOCK_SHARED;
1960 goto relock;
1961 }
1962
1963 if (check_direct_IO(fs_info, from, pos)) {
1964 btrfs_inode_unlock(inode, ilock_flags);
1965 goto buffered;
1966 }
1967
1968 /*
1969 * The iov_iter can be mapped to the same file range we are writing to.
1970 * If that's the case, then we will deadlock in the iomap code, because
1971 * it first calls our callback btrfs_dio_iomap_begin(), which will create
1972 * an ordered extent, and after that it will fault in the pages that the
1973 * iov_iter refers to. During the fault in we end up in the readahead
1974 * pages code (starting at btrfs_readahead()), which will lock the range,
1975 * find that ordered extent and then wait for it to complete (at
1976 * btrfs_lock_and_flush_ordered_range()), resulting in a deadlock since
1977 * obviously the ordered extent can never complete as we didn't submit
1978 * yet the respective bio(s). This always happens when the buffer is
1979 * memory mapped to the same file range, since the iomap DIO code always
1980 * invalidates pages in the target file range (after starting and waiting
1981 * for any writeback).
1982 *
1983 * So here we disable page faults in the iov_iter and then retry if we
1984 * got -EFAULT, faulting in the pages before the retry.
1985 */
1986 from->nofault = true;
1987 dio = __iomap_dio_rw(iocb, from, &btrfs_dio_iomap_ops, &btrfs_dio_ops,
1988 IOMAP_DIO_PARTIAL, written);
1989 from->nofault = false;
1990
1991 /*
1992 * iomap_dio_complete() will call btrfs_sync_file() if we have a dsync
1993 * iocb, and that needs to lock the inode. So unlock it before calling
1994 * iomap_dio_complete() to avoid a deadlock.
1995 */
1996 btrfs_inode_unlock(inode, ilock_flags);
1997
1998 if (IS_ERR_OR_NULL(dio))
1999 err = PTR_ERR_OR_ZERO(dio);
2000 else
2001 err = iomap_dio_complete(dio);
2002
2003 /* No increment (+=) because iomap returns a cumulative value. */
2004 if (err > 0)
2005 written = err;
2006
2007 if (iov_iter_count(from) > 0 && (err == -EFAULT || err > 0)) {
2008 const size_t left = iov_iter_count(from);
2009 /*
2010 * We have more data left to write. Try to fault in as many as
2011 * possible of the remainder pages and retry. We do this without
2012 * releasing and locking again the inode, to prevent races with
2013 * truncate.
2014 *
2015 * Also, in case the iov refers to pages in the file range of the
2016 * file we want to write to (due to a mmap), we could enter an
2017 * infinite loop if we retry after faulting the pages in, since
2018 * iomap will invalidate any pages in the range early on, before
2019 * it tries to fault in the pages of the iov. So we keep track of
2020 * how much was left of iov in the previous EFAULT and fallback
2021 * to buffered IO in case we haven't made any progress.
2022 */
2023 if (left == prev_left) {
2024 err = -ENOTBLK;
2025 } else {
2026 fault_in_iov_iter_readable(from, left);
2027 prev_left = left;
2028 goto relock;
2029 }
2030 }
2031
2032 /* If 'err' is -ENOTBLK then it means we must fallback to buffered IO. */
2033 if ((err < 0 && err != -ENOTBLK) || !iov_iter_count(from))
2034 goto out;
2035
2036 buffered:
2037 pos = iocb->ki_pos;
2038 written_buffered = btrfs_buffered_write(iocb, from);
2039 if (written_buffered < 0) {
2040 err = written_buffered;
2041 goto out;
2042 }
2043 /*
2044 * Ensure all data is persisted. We want the next direct IO read to be
2045 * able to read what was just written.
2046 */
2047 endbyte = pos + written_buffered - 1;
2048 err = btrfs_fdatawrite_range(inode, pos, endbyte);
2049 if (err)
2050 goto out;
2051 err = filemap_fdatawait_range(inode->i_mapping, pos, endbyte);
2052 if (err)
2053 goto out;
2054 written += written_buffered;
2055 iocb->ki_pos = pos + written_buffered;
2056 invalidate_mapping_pages(file->f_mapping, pos >> PAGE_SHIFT,
2057 endbyte >> PAGE_SHIFT);
2058 out:
2059 return err < 0 ? err : written;
2060 }
2061
btrfs_file_write_iter(struct kiocb * iocb,struct iov_iter * from)2062 static ssize_t btrfs_file_write_iter(struct kiocb *iocb,
2063 struct iov_iter *from)
2064 {
2065 struct file *file = iocb->ki_filp;
2066 struct btrfs_inode *inode = BTRFS_I(file_inode(file));
2067 ssize_t num_written = 0;
2068 const bool sync = iocb->ki_flags & IOCB_DSYNC;
2069
2070 /*
2071 * If the fs flips readonly due to some impossible error, although we
2072 * have opened a file as writable, we have to stop this write operation
2073 * to ensure consistency.
2074 */
2075 if (test_bit(BTRFS_FS_STATE_ERROR, &inode->root->fs_info->fs_state))
2076 return -EROFS;
2077
2078 if (!(iocb->ki_flags & IOCB_DIRECT) &&
2079 (iocb->ki_flags & IOCB_NOWAIT))
2080 return -EOPNOTSUPP;
2081
2082 if (sync)
2083 atomic_inc(&inode->sync_writers);
2084
2085 if (iocb->ki_flags & IOCB_DIRECT)
2086 num_written = btrfs_direct_write(iocb, from);
2087 else
2088 num_written = btrfs_buffered_write(iocb, from);
2089
2090 btrfs_set_inode_last_sub_trans(inode);
2091
2092 if (num_written > 0)
2093 num_written = generic_write_sync(iocb, num_written);
2094
2095 if (sync)
2096 atomic_dec(&inode->sync_writers);
2097
2098 current->backing_dev_info = NULL;
2099 return num_written;
2100 }
2101
btrfs_release_file(struct inode * inode,struct file * filp)2102 int btrfs_release_file(struct inode *inode, struct file *filp)
2103 {
2104 struct btrfs_file_private *private = filp->private_data;
2105
2106 if (private && private->filldir_buf)
2107 kfree(private->filldir_buf);
2108 kfree(private);
2109 filp->private_data = NULL;
2110
2111 /*
2112 * Set by setattr when we are about to truncate a file from a non-zero
2113 * size to a zero size. This tries to flush down new bytes that may
2114 * have been written if the application were using truncate to replace
2115 * a file in place.
2116 */
2117 if (test_and_clear_bit(BTRFS_INODE_FLUSH_ON_CLOSE,
2118 &BTRFS_I(inode)->runtime_flags))
2119 filemap_flush(inode->i_mapping);
2120 return 0;
2121 }
2122
start_ordered_ops(struct inode * inode,loff_t start,loff_t end)2123 static int start_ordered_ops(struct inode *inode, loff_t start, loff_t end)
2124 {
2125 int ret;
2126 struct blk_plug plug;
2127
2128 /*
2129 * This is only called in fsync, which would do synchronous writes, so
2130 * a plug can merge adjacent IOs as much as possible. Esp. in case of
2131 * multiple disks using raid profile, a large IO can be split to
2132 * several segments of stripe length (currently 64K).
2133 */
2134 blk_start_plug(&plug);
2135 atomic_inc(&BTRFS_I(inode)->sync_writers);
2136 ret = btrfs_fdatawrite_range(inode, start, end);
2137 atomic_dec(&BTRFS_I(inode)->sync_writers);
2138 blk_finish_plug(&plug);
2139
2140 return ret;
2141 }
2142
skip_inode_logging(const struct btrfs_log_ctx * ctx)2143 static inline bool skip_inode_logging(const struct btrfs_log_ctx *ctx)
2144 {
2145 struct btrfs_inode *inode = BTRFS_I(ctx->inode);
2146 struct btrfs_fs_info *fs_info = inode->root->fs_info;
2147
2148 if (btrfs_inode_in_log(inode, fs_info->generation) &&
2149 list_empty(&ctx->ordered_extents))
2150 return true;
2151
2152 /*
2153 * If we are doing a fast fsync we can not bail out if the inode's
2154 * last_trans is <= then the last committed transaction, because we only
2155 * update the last_trans of the inode during ordered extent completion,
2156 * and for a fast fsync we don't wait for that, we only wait for the
2157 * writeback to complete.
2158 */
2159 if (inode->last_trans <= fs_info->last_trans_committed &&
2160 (test_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &inode->runtime_flags) ||
2161 list_empty(&ctx->ordered_extents)))
2162 return true;
2163
2164 return false;
2165 }
2166
2167 /*
2168 * fsync call for both files and directories. This logs the inode into
2169 * the tree log instead of forcing full commits whenever possible.
2170 *
2171 * It needs to call filemap_fdatawait so that all ordered extent updates are
2172 * in the metadata btree are up to date for copying to the log.
2173 *
2174 * It drops the inode mutex before doing the tree log commit. This is an
2175 * important optimization for directories because holding the mutex prevents
2176 * new operations on the dir while we write to disk.
2177 */
btrfs_sync_file(struct file * file,loff_t start,loff_t end,int datasync)2178 int btrfs_sync_file(struct file *file, loff_t start, loff_t end, int datasync)
2179 {
2180 struct dentry *dentry = file_dentry(file);
2181 struct inode *inode = d_inode(dentry);
2182 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2183 struct btrfs_root *root = BTRFS_I(inode)->root;
2184 struct btrfs_trans_handle *trans;
2185 struct btrfs_log_ctx ctx;
2186 int ret = 0, err;
2187 u64 len;
2188 bool full_sync;
2189
2190 trace_btrfs_sync_file(file, datasync);
2191
2192 btrfs_init_log_ctx(&ctx, inode);
2193
2194 /*
2195 * Always set the range to a full range, otherwise we can get into
2196 * several problems, from missing file extent items to represent holes
2197 * when not using the NO_HOLES feature, to log tree corruption due to
2198 * races between hole detection during logging and completion of ordered
2199 * extents outside the range, to missing checksums due to ordered extents
2200 * for which we flushed only a subset of their pages.
2201 */
2202 start = 0;
2203 end = LLONG_MAX;
2204 len = (u64)LLONG_MAX + 1;
2205
2206 /*
2207 * We write the dirty pages in the range and wait until they complete
2208 * out of the ->i_mutex. If so, we can flush the dirty pages by
2209 * multi-task, and make the performance up. See
2210 * btrfs_wait_ordered_range for an explanation of the ASYNC check.
2211 */
2212 ret = start_ordered_ops(inode, start, end);
2213 if (ret)
2214 goto out;
2215
2216 btrfs_inode_lock(inode, BTRFS_ILOCK_MMAP);
2217
2218 atomic_inc(&root->log_batch);
2219
2220 /*
2221 * Always check for the full sync flag while holding the inode's lock,
2222 * to avoid races with other tasks. The flag must be either set all the
2223 * time during logging or always off all the time while logging.
2224 */
2225 full_sync = test_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
2226 &BTRFS_I(inode)->runtime_flags);
2227
2228 /*
2229 * Before we acquired the inode's lock and the mmap lock, someone may
2230 * have dirtied more pages in the target range. We need to make sure
2231 * that writeback for any such pages does not start while we are logging
2232 * the inode, because if it does, any of the following might happen when
2233 * we are not doing a full inode sync:
2234 *
2235 * 1) We log an extent after its writeback finishes but before its
2236 * checksums are added to the csum tree, leading to -EIO errors
2237 * when attempting to read the extent after a log replay.
2238 *
2239 * 2) We can end up logging an extent before its writeback finishes.
2240 * Therefore after the log replay we will have a file extent item
2241 * pointing to an unwritten extent (and no data checksums as well).
2242 *
2243 * So trigger writeback for any eventual new dirty pages and then we
2244 * wait for all ordered extents to complete below.
2245 */
2246 ret = start_ordered_ops(inode, start, end);
2247 if (ret) {
2248 btrfs_inode_unlock(inode, BTRFS_ILOCK_MMAP);
2249 goto out;
2250 }
2251
2252 /*
2253 * We have to do this here to avoid the priority inversion of waiting on
2254 * IO of a lower priority task while holding a transaction open.
2255 *
2256 * For a full fsync we wait for the ordered extents to complete while
2257 * for a fast fsync we wait just for writeback to complete, and then
2258 * attach the ordered extents to the transaction so that a transaction
2259 * commit waits for their completion, to avoid data loss if we fsync,
2260 * the current transaction commits before the ordered extents complete
2261 * and a power failure happens right after that.
2262 *
2263 * For zoned filesystem, if a write IO uses a ZONE_APPEND command, the
2264 * logical address recorded in the ordered extent may change. We need
2265 * to wait for the IO to stabilize the logical address.
2266 */
2267 if (full_sync || btrfs_is_zoned(fs_info)) {
2268 ret = btrfs_wait_ordered_range(inode, start, len);
2269 } else {
2270 /*
2271 * Get our ordered extents as soon as possible to avoid doing
2272 * checksum lookups in the csum tree, and use instead the
2273 * checksums attached to the ordered extents.
2274 */
2275 btrfs_get_ordered_extents_for_logging(BTRFS_I(inode),
2276 &ctx.ordered_extents);
2277 ret = filemap_fdatawait_range(inode->i_mapping, start, end);
2278 }
2279
2280 if (ret)
2281 goto out_release_extents;
2282
2283 atomic_inc(&root->log_batch);
2284
2285 smp_mb();
2286 if (skip_inode_logging(&ctx)) {
2287 /*
2288 * We've had everything committed since the last time we were
2289 * modified so clear this flag in case it was set for whatever
2290 * reason, it's no longer relevant.
2291 */
2292 clear_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
2293 &BTRFS_I(inode)->runtime_flags);
2294 /*
2295 * An ordered extent might have started before and completed
2296 * already with io errors, in which case the inode was not
2297 * updated and we end up here. So check the inode's mapping
2298 * for any errors that might have happened since we last
2299 * checked called fsync.
2300 */
2301 ret = filemap_check_wb_err(inode->i_mapping, file->f_wb_err);
2302 goto out_release_extents;
2303 }
2304
2305 /*
2306 * We use start here because we will need to wait on the IO to complete
2307 * in btrfs_sync_log, which could require joining a transaction (for
2308 * example checking cross references in the nocow path). If we use join
2309 * here we could get into a situation where we're waiting on IO to
2310 * happen that is blocked on a transaction trying to commit. With start
2311 * we inc the extwriter counter, so we wait for all extwriters to exit
2312 * before we start blocking joiners. This comment is to keep somebody
2313 * from thinking they are super smart and changing this to
2314 * btrfs_join_transaction *cough*Josef*cough*.
2315 */
2316 trans = btrfs_start_transaction(root, 0);
2317 if (IS_ERR(trans)) {
2318 ret = PTR_ERR(trans);
2319 goto out_release_extents;
2320 }
2321 trans->in_fsync = true;
2322
2323 ret = btrfs_log_dentry_safe(trans, dentry, &ctx);
2324 btrfs_release_log_ctx_extents(&ctx);
2325 if (ret < 0) {
2326 /* Fallthrough and commit/free transaction. */
2327 ret = 1;
2328 }
2329
2330 /* we've logged all the items and now have a consistent
2331 * version of the file in the log. It is possible that
2332 * someone will come in and modify the file, but that's
2333 * fine because the log is consistent on disk, and we
2334 * have references to all of the file's extents
2335 *
2336 * It is possible that someone will come in and log the
2337 * file again, but that will end up using the synchronization
2338 * inside btrfs_sync_log to keep things safe.
2339 */
2340 btrfs_inode_unlock(inode, BTRFS_ILOCK_MMAP);
2341
2342 if (ret == BTRFS_NO_LOG_SYNC) {
2343 ret = btrfs_end_transaction(trans);
2344 goto out;
2345 }
2346
2347 /* We successfully logged the inode, attempt to sync the log. */
2348 if (!ret) {
2349 ret = btrfs_sync_log(trans, root, &ctx);
2350 if (!ret) {
2351 ret = btrfs_end_transaction(trans);
2352 goto out;
2353 }
2354 }
2355
2356 /*
2357 * At this point we need to commit the transaction because we had
2358 * btrfs_need_log_full_commit() or some other error.
2359 *
2360 * If we didn't do a full sync we have to stop the trans handle, wait on
2361 * the ordered extents, start it again and commit the transaction. If
2362 * we attempt to wait on the ordered extents here we could deadlock with
2363 * something like fallocate() that is holding the extent lock trying to
2364 * start a transaction while some other thread is trying to commit the
2365 * transaction while we (fsync) are currently holding the transaction
2366 * open.
2367 */
2368 if (!full_sync) {
2369 ret = btrfs_end_transaction(trans);
2370 if (ret)
2371 goto out;
2372 ret = btrfs_wait_ordered_range(inode, start, len);
2373 if (ret)
2374 goto out;
2375
2376 /*
2377 * This is safe to use here because we're only interested in
2378 * making sure the transaction that had the ordered extents is
2379 * committed. We aren't waiting on anything past this point,
2380 * we're purely getting the transaction and committing it.
2381 */
2382 trans = btrfs_attach_transaction_barrier(root);
2383 if (IS_ERR(trans)) {
2384 ret = PTR_ERR(trans);
2385
2386 /*
2387 * We committed the transaction and there's no currently
2388 * running transaction, this means everything we care
2389 * about made it to disk and we are done.
2390 */
2391 if (ret == -ENOENT)
2392 ret = 0;
2393 goto out;
2394 }
2395 }
2396
2397 ret = btrfs_commit_transaction(trans);
2398 out:
2399 ASSERT(list_empty(&ctx.list));
2400 err = file_check_and_advance_wb_err(file);
2401 if (!ret)
2402 ret = err;
2403 return ret > 0 ? -EIO : ret;
2404
2405 out_release_extents:
2406 btrfs_release_log_ctx_extents(&ctx);
2407 btrfs_inode_unlock(inode, BTRFS_ILOCK_MMAP);
2408 goto out;
2409 }
2410
2411 static const struct vm_operations_struct btrfs_file_vm_ops = {
2412 .fault = filemap_fault,
2413 .map_pages = filemap_map_pages,
2414 .page_mkwrite = btrfs_page_mkwrite,
2415 .speculative = true,
2416 };
2417
btrfs_file_mmap(struct file * filp,struct vm_area_struct * vma)2418 static int btrfs_file_mmap(struct file *filp, struct vm_area_struct *vma)
2419 {
2420 struct address_space *mapping = filp->f_mapping;
2421
2422 if (!mapping->a_ops->readpage)
2423 return -ENOEXEC;
2424
2425 file_accessed(filp);
2426 vma->vm_ops = &btrfs_file_vm_ops;
2427
2428 return 0;
2429 }
2430
hole_mergeable(struct btrfs_inode * inode,struct extent_buffer * leaf,int slot,u64 start,u64 end)2431 static int hole_mergeable(struct btrfs_inode *inode, struct extent_buffer *leaf,
2432 int slot, u64 start, u64 end)
2433 {
2434 struct btrfs_file_extent_item *fi;
2435 struct btrfs_key key;
2436
2437 if (slot < 0 || slot >= btrfs_header_nritems(leaf))
2438 return 0;
2439
2440 btrfs_item_key_to_cpu(leaf, &key, slot);
2441 if (key.objectid != btrfs_ino(inode) ||
2442 key.type != BTRFS_EXTENT_DATA_KEY)
2443 return 0;
2444
2445 fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
2446
2447 if (btrfs_file_extent_type(leaf, fi) != BTRFS_FILE_EXTENT_REG)
2448 return 0;
2449
2450 if (btrfs_file_extent_disk_bytenr(leaf, fi))
2451 return 0;
2452
2453 if (key.offset == end)
2454 return 1;
2455 if (key.offset + btrfs_file_extent_num_bytes(leaf, fi) == start)
2456 return 1;
2457 return 0;
2458 }
2459
fill_holes(struct btrfs_trans_handle * trans,struct btrfs_inode * inode,struct btrfs_path * path,u64 offset,u64 end)2460 static int fill_holes(struct btrfs_trans_handle *trans,
2461 struct btrfs_inode *inode,
2462 struct btrfs_path *path, u64 offset, u64 end)
2463 {
2464 struct btrfs_fs_info *fs_info = trans->fs_info;
2465 struct btrfs_root *root = inode->root;
2466 struct extent_buffer *leaf;
2467 struct btrfs_file_extent_item *fi;
2468 struct extent_map *hole_em;
2469 struct extent_map_tree *em_tree = &inode->extent_tree;
2470 struct btrfs_key key;
2471 int ret;
2472
2473 if (btrfs_fs_incompat(fs_info, NO_HOLES))
2474 goto out;
2475
2476 key.objectid = btrfs_ino(inode);
2477 key.type = BTRFS_EXTENT_DATA_KEY;
2478 key.offset = offset;
2479
2480 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
2481 if (ret <= 0) {
2482 /*
2483 * We should have dropped this offset, so if we find it then
2484 * something has gone horribly wrong.
2485 */
2486 if (ret == 0)
2487 ret = -EINVAL;
2488 return ret;
2489 }
2490
2491 leaf = path->nodes[0];
2492 if (hole_mergeable(inode, leaf, path->slots[0] - 1, offset, end)) {
2493 u64 num_bytes;
2494
2495 path->slots[0]--;
2496 fi = btrfs_item_ptr(leaf, path->slots[0],
2497 struct btrfs_file_extent_item);
2498 num_bytes = btrfs_file_extent_num_bytes(leaf, fi) +
2499 end - offset;
2500 btrfs_set_file_extent_num_bytes(leaf, fi, num_bytes);
2501 btrfs_set_file_extent_ram_bytes(leaf, fi, num_bytes);
2502 btrfs_set_file_extent_offset(leaf, fi, 0);
2503 btrfs_mark_buffer_dirty(leaf);
2504 goto out;
2505 }
2506
2507 if (hole_mergeable(inode, leaf, path->slots[0], offset, end)) {
2508 u64 num_bytes;
2509
2510 key.offset = offset;
2511 btrfs_set_item_key_safe(fs_info, path, &key);
2512 fi = btrfs_item_ptr(leaf, path->slots[0],
2513 struct btrfs_file_extent_item);
2514 num_bytes = btrfs_file_extent_num_bytes(leaf, fi) + end -
2515 offset;
2516 btrfs_set_file_extent_num_bytes(leaf, fi, num_bytes);
2517 btrfs_set_file_extent_ram_bytes(leaf, fi, num_bytes);
2518 btrfs_set_file_extent_offset(leaf, fi, 0);
2519 btrfs_mark_buffer_dirty(leaf);
2520 goto out;
2521 }
2522 btrfs_release_path(path);
2523
2524 ret = btrfs_insert_file_extent(trans, root, btrfs_ino(inode),
2525 offset, 0, 0, end - offset, 0, end - offset, 0, 0, 0);
2526 if (ret)
2527 return ret;
2528
2529 out:
2530 btrfs_release_path(path);
2531
2532 hole_em = alloc_extent_map();
2533 if (!hole_em) {
2534 btrfs_drop_extent_cache(inode, offset, end - 1, 0);
2535 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &inode->runtime_flags);
2536 } else {
2537 hole_em->start = offset;
2538 hole_em->len = end - offset;
2539 hole_em->ram_bytes = hole_em->len;
2540 hole_em->orig_start = offset;
2541
2542 hole_em->block_start = EXTENT_MAP_HOLE;
2543 hole_em->block_len = 0;
2544 hole_em->orig_block_len = 0;
2545 hole_em->compress_type = BTRFS_COMPRESS_NONE;
2546 hole_em->generation = trans->transid;
2547
2548 do {
2549 btrfs_drop_extent_cache(inode, offset, end - 1, 0);
2550 write_lock(&em_tree->lock);
2551 ret = add_extent_mapping(em_tree, hole_em, 1);
2552 write_unlock(&em_tree->lock);
2553 } while (ret == -EEXIST);
2554 free_extent_map(hole_em);
2555 if (ret)
2556 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
2557 &inode->runtime_flags);
2558 }
2559
2560 return 0;
2561 }
2562
2563 /*
2564 * Find a hole extent on given inode and change start/len to the end of hole
2565 * extent.(hole/vacuum extent whose em->start <= start &&
2566 * em->start + em->len > start)
2567 * When a hole extent is found, return 1 and modify start/len.
2568 */
find_first_non_hole(struct btrfs_inode * inode,u64 * start,u64 * len)2569 static int find_first_non_hole(struct btrfs_inode *inode, u64 *start, u64 *len)
2570 {
2571 struct btrfs_fs_info *fs_info = inode->root->fs_info;
2572 struct extent_map *em;
2573 int ret = 0;
2574
2575 em = btrfs_get_extent(inode, NULL, 0,
2576 round_down(*start, fs_info->sectorsize),
2577 round_up(*len, fs_info->sectorsize));
2578 if (IS_ERR(em))
2579 return PTR_ERR(em);
2580
2581 /* Hole or vacuum extent(only exists in no-hole mode) */
2582 if (em->block_start == EXTENT_MAP_HOLE) {
2583 ret = 1;
2584 *len = em->start + em->len > *start + *len ?
2585 0 : *start + *len - em->start - em->len;
2586 *start = em->start + em->len;
2587 }
2588 free_extent_map(em);
2589 return ret;
2590 }
2591
btrfs_punch_hole_lock_range(struct inode * inode,const u64 lockstart,const u64 lockend,struct extent_state ** cached_state)2592 static int btrfs_punch_hole_lock_range(struct inode *inode,
2593 const u64 lockstart,
2594 const u64 lockend,
2595 struct extent_state **cached_state)
2596 {
2597 /*
2598 * For subpage case, if the range is not at page boundary, we could
2599 * have pages at the leading/tailing part of the range.
2600 * This could lead to dead loop since filemap_range_has_page()
2601 * will always return true.
2602 * So here we need to do extra page alignment for
2603 * filemap_range_has_page().
2604 */
2605 const u64 page_lockstart = round_up(lockstart, PAGE_SIZE);
2606 const u64 page_lockend = round_down(lockend + 1, PAGE_SIZE) - 1;
2607
2608 while (1) {
2609 struct btrfs_ordered_extent *ordered;
2610 int ret;
2611
2612 truncate_pagecache_range(inode, lockstart, lockend);
2613
2614 lock_extent_bits(&BTRFS_I(inode)->io_tree, lockstart, lockend,
2615 cached_state);
2616 ordered = btrfs_lookup_first_ordered_extent(BTRFS_I(inode),
2617 lockend);
2618
2619 /*
2620 * We need to make sure we have no ordered extents in this range
2621 * and nobody raced in and read a page in this range, if we did
2622 * we need to try again.
2623 */
2624 if ((!ordered ||
2625 (ordered->file_offset + ordered->num_bytes <= lockstart ||
2626 ordered->file_offset > lockend)) &&
2627 !filemap_range_has_page(inode->i_mapping,
2628 page_lockstart, page_lockend)) {
2629 if (ordered)
2630 btrfs_put_ordered_extent(ordered);
2631 break;
2632 }
2633 if (ordered)
2634 btrfs_put_ordered_extent(ordered);
2635 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart,
2636 lockend, cached_state);
2637 ret = btrfs_wait_ordered_range(inode, lockstart,
2638 lockend - lockstart + 1);
2639 if (ret)
2640 return ret;
2641 }
2642 return 0;
2643 }
2644
btrfs_insert_replace_extent(struct btrfs_trans_handle * trans,struct btrfs_inode * inode,struct btrfs_path * path,struct btrfs_replace_extent_info * extent_info,const u64 replace_len,const u64 bytes_to_drop)2645 static int btrfs_insert_replace_extent(struct btrfs_trans_handle *trans,
2646 struct btrfs_inode *inode,
2647 struct btrfs_path *path,
2648 struct btrfs_replace_extent_info *extent_info,
2649 const u64 replace_len,
2650 const u64 bytes_to_drop)
2651 {
2652 struct btrfs_fs_info *fs_info = trans->fs_info;
2653 struct btrfs_root *root = inode->root;
2654 struct btrfs_file_extent_item *extent;
2655 struct extent_buffer *leaf;
2656 struct btrfs_key key;
2657 int slot;
2658 struct btrfs_ref ref = { 0 };
2659 int ret;
2660
2661 if (replace_len == 0)
2662 return 0;
2663
2664 if (extent_info->disk_offset == 0 &&
2665 btrfs_fs_incompat(fs_info, NO_HOLES)) {
2666 btrfs_update_inode_bytes(inode, 0, bytes_to_drop);
2667 return 0;
2668 }
2669
2670 key.objectid = btrfs_ino(inode);
2671 key.type = BTRFS_EXTENT_DATA_KEY;
2672 key.offset = extent_info->file_offset;
2673 ret = btrfs_insert_empty_item(trans, root, path, &key,
2674 sizeof(struct btrfs_file_extent_item));
2675 if (ret)
2676 return ret;
2677 leaf = path->nodes[0];
2678 slot = path->slots[0];
2679 write_extent_buffer(leaf, extent_info->extent_buf,
2680 btrfs_item_ptr_offset(leaf, slot),
2681 sizeof(struct btrfs_file_extent_item));
2682 extent = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
2683 ASSERT(btrfs_file_extent_type(leaf, extent) != BTRFS_FILE_EXTENT_INLINE);
2684 btrfs_set_file_extent_offset(leaf, extent, extent_info->data_offset);
2685 btrfs_set_file_extent_num_bytes(leaf, extent, replace_len);
2686 if (extent_info->is_new_extent)
2687 btrfs_set_file_extent_generation(leaf, extent, trans->transid);
2688 btrfs_mark_buffer_dirty(leaf);
2689 btrfs_release_path(path);
2690
2691 ret = btrfs_inode_set_file_extent_range(inode, extent_info->file_offset,
2692 replace_len);
2693 if (ret)
2694 return ret;
2695
2696 /* If it's a hole, nothing more needs to be done. */
2697 if (extent_info->disk_offset == 0) {
2698 btrfs_update_inode_bytes(inode, 0, bytes_to_drop);
2699 return 0;
2700 }
2701
2702 btrfs_update_inode_bytes(inode, replace_len, bytes_to_drop);
2703
2704 if (extent_info->is_new_extent && extent_info->insertions == 0) {
2705 key.objectid = extent_info->disk_offset;
2706 key.type = BTRFS_EXTENT_ITEM_KEY;
2707 key.offset = extent_info->disk_len;
2708 ret = btrfs_alloc_reserved_file_extent(trans, root,
2709 btrfs_ino(inode),
2710 extent_info->file_offset,
2711 extent_info->qgroup_reserved,
2712 &key);
2713 } else {
2714 u64 ref_offset;
2715
2716 btrfs_init_generic_ref(&ref, BTRFS_ADD_DELAYED_REF,
2717 extent_info->disk_offset,
2718 extent_info->disk_len, 0);
2719 ref_offset = extent_info->file_offset - extent_info->data_offset;
2720 btrfs_init_data_ref(&ref, root->root_key.objectid,
2721 btrfs_ino(inode), ref_offset, 0, false);
2722 ret = btrfs_inc_extent_ref(trans, &ref);
2723 }
2724
2725 extent_info->insertions++;
2726
2727 return ret;
2728 }
2729
2730 /*
2731 * The respective range must have been previously locked, as well as the inode.
2732 * The end offset is inclusive (last byte of the range).
2733 * @extent_info is NULL for fallocate's hole punching and non-NULL when replacing
2734 * the file range with an extent.
2735 * When not punching a hole, we don't want to end up in a state where we dropped
2736 * extents without inserting a new one, so we must abort the transaction to avoid
2737 * a corruption.
2738 */
btrfs_replace_file_extents(struct btrfs_inode * inode,struct btrfs_path * path,const u64 start,const u64 end,struct btrfs_replace_extent_info * extent_info,struct btrfs_trans_handle ** trans_out)2739 int btrfs_replace_file_extents(struct btrfs_inode *inode,
2740 struct btrfs_path *path, const u64 start,
2741 const u64 end,
2742 struct btrfs_replace_extent_info *extent_info,
2743 struct btrfs_trans_handle **trans_out)
2744 {
2745 struct btrfs_drop_extents_args drop_args = { 0 };
2746 struct btrfs_root *root = inode->root;
2747 struct btrfs_fs_info *fs_info = root->fs_info;
2748 u64 min_size = btrfs_calc_insert_metadata_size(fs_info, 1);
2749 u64 ino_size = round_up(inode->vfs_inode.i_size, fs_info->sectorsize);
2750 struct btrfs_trans_handle *trans = NULL;
2751 struct btrfs_block_rsv *rsv;
2752 unsigned int rsv_count;
2753 u64 cur_offset;
2754 u64 len = end - start;
2755 int ret = 0;
2756
2757 if (end <= start)
2758 return -EINVAL;
2759
2760 rsv = btrfs_alloc_block_rsv(fs_info, BTRFS_BLOCK_RSV_TEMP);
2761 if (!rsv) {
2762 ret = -ENOMEM;
2763 goto out;
2764 }
2765 rsv->size = btrfs_calc_insert_metadata_size(fs_info, 1);
2766 rsv->failfast = 1;
2767
2768 /*
2769 * 1 - update the inode
2770 * 1 - removing the extents in the range
2771 * 1 - adding the hole extent if no_holes isn't set or if we are
2772 * replacing the range with a new extent
2773 */
2774 if (!btrfs_fs_incompat(fs_info, NO_HOLES) || extent_info)
2775 rsv_count = 3;
2776 else
2777 rsv_count = 2;
2778
2779 trans = btrfs_start_transaction(root, rsv_count);
2780 if (IS_ERR(trans)) {
2781 ret = PTR_ERR(trans);
2782 trans = NULL;
2783 goto out_free;
2784 }
2785
2786 ret = btrfs_block_rsv_migrate(&fs_info->trans_block_rsv, rsv,
2787 min_size, false);
2788 BUG_ON(ret);
2789 trans->block_rsv = rsv;
2790
2791 cur_offset = start;
2792 drop_args.path = path;
2793 drop_args.end = end + 1;
2794 drop_args.drop_cache = true;
2795 while (cur_offset < end) {
2796 drop_args.start = cur_offset;
2797 ret = btrfs_drop_extents(trans, root, inode, &drop_args);
2798 /* If we are punching a hole decrement the inode's byte count */
2799 if (!extent_info)
2800 btrfs_update_inode_bytes(inode, 0,
2801 drop_args.bytes_found);
2802 if (ret != -ENOSPC) {
2803 /*
2804 * The only time we don't want to abort is if we are
2805 * attempting to clone a partial inline extent, in which
2806 * case we'll get EOPNOTSUPP. However if we aren't
2807 * clone we need to abort no matter what, because if we
2808 * got EOPNOTSUPP via prealloc then we messed up and
2809 * need to abort.
2810 */
2811 if (ret &&
2812 (ret != -EOPNOTSUPP ||
2813 (extent_info && extent_info->is_new_extent)))
2814 btrfs_abort_transaction(trans, ret);
2815 break;
2816 }
2817
2818 trans->block_rsv = &fs_info->trans_block_rsv;
2819
2820 if (!extent_info && cur_offset < drop_args.drop_end &&
2821 cur_offset < ino_size) {
2822 ret = fill_holes(trans, inode, path, cur_offset,
2823 drop_args.drop_end);
2824 if (ret) {
2825 /*
2826 * If we failed then we didn't insert our hole
2827 * entries for the area we dropped, so now the
2828 * fs is corrupted, so we must abort the
2829 * transaction.
2830 */
2831 btrfs_abort_transaction(trans, ret);
2832 break;
2833 }
2834 } else if (!extent_info && cur_offset < drop_args.drop_end) {
2835 /*
2836 * We are past the i_size here, but since we didn't
2837 * insert holes we need to clear the mapped area so we
2838 * know to not set disk_i_size in this area until a new
2839 * file extent is inserted here.
2840 */
2841 ret = btrfs_inode_clear_file_extent_range(inode,
2842 cur_offset,
2843 drop_args.drop_end - cur_offset);
2844 if (ret) {
2845 /*
2846 * We couldn't clear our area, so we could
2847 * presumably adjust up and corrupt the fs, so
2848 * we need to abort.
2849 */
2850 btrfs_abort_transaction(trans, ret);
2851 break;
2852 }
2853 }
2854
2855 if (extent_info &&
2856 drop_args.drop_end > extent_info->file_offset) {
2857 u64 replace_len = drop_args.drop_end -
2858 extent_info->file_offset;
2859
2860 ret = btrfs_insert_replace_extent(trans, inode, path,
2861 extent_info, replace_len,
2862 drop_args.bytes_found);
2863 if (ret) {
2864 btrfs_abort_transaction(trans, ret);
2865 break;
2866 }
2867 extent_info->data_len -= replace_len;
2868 extent_info->data_offset += replace_len;
2869 extent_info->file_offset += replace_len;
2870 }
2871
2872 ret = btrfs_update_inode(trans, root, inode);
2873 if (ret)
2874 break;
2875
2876 btrfs_end_transaction(trans);
2877 btrfs_btree_balance_dirty(fs_info);
2878
2879 trans = btrfs_start_transaction(root, rsv_count);
2880 if (IS_ERR(trans)) {
2881 ret = PTR_ERR(trans);
2882 trans = NULL;
2883 break;
2884 }
2885
2886 ret = btrfs_block_rsv_migrate(&fs_info->trans_block_rsv,
2887 rsv, min_size, false);
2888 BUG_ON(ret); /* shouldn't happen */
2889 trans->block_rsv = rsv;
2890
2891 cur_offset = drop_args.drop_end;
2892 len = end - cur_offset;
2893 if (!extent_info && len) {
2894 ret = find_first_non_hole(inode, &cur_offset, &len);
2895 if (unlikely(ret < 0))
2896 break;
2897 if (ret && !len) {
2898 ret = 0;
2899 break;
2900 }
2901 }
2902 }
2903
2904 /*
2905 * If we were cloning, force the next fsync to be a full one since we
2906 * we replaced (or just dropped in the case of cloning holes when
2907 * NO_HOLES is enabled) file extent items and did not setup new extent
2908 * maps for the replacement extents (or holes).
2909 */
2910 if (extent_info && !extent_info->is_new_extent)
2911 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &inode->runtime_flags);
2912
2913 if (ret)
2914 goto out_trans;
2915
2916 trans->block_rsv = &fs_info->trans_block_rsv;
2917 /*
2918 * If we are using the NO_HOLES feature we might have had already an
2919 * hole that overlaps a part of the region [lockstart, lockend] and
2920 * ends at (or beyond) lockend. Since we have no file extent items to
2921 * represent holes, drop_end can be less than lockend and so we must
2922 * make sure we have an extent map representing the existing hole (the
2923 * call to __btrfs_drop_extents() might have dropped the existing extent
2924 * map representing the existing hole), otherwise the fast fsync path
2925 * will not record the existence of the hole region
2926 * [existing_hole_start, lockend].
2927 */
2928 if (drop_args.drop_end <= end)
2929 drop_args.drop_end = end + 1;
2930 /*
2931 * Don't insert file hole extent item if it's for a range beyond eof
2932 * (because it's useless) or if it represents a 0 bytes range (when
2933 * cur_offset == drop_end).
2934 */
2935 if (!extent_info && cur_offset < ino_size &&
2936 cur_offset < drop_args.drop_end) {
2937 ret = fill_holes(trans, inode, path, cur_offset,
2938 drop_args.drop_end);
2939 if (ret) {
2940 /* Same comment as above. */
2941 btrfs_abort_transaction(trans, ret);
2942 goto out_trans;
2943 }
2944 } else if (!extent_info && cur_offset < drop_args.drop_end) {
2945 /* See the comment in the loop above for the reasoning here. */
2946 ret = btrfs_inode_clear_file_extent_range(inode, cur_offset,
2947 drop_args.drop_end - cur_offset);
2948 if (ret) {
2949 btrfs_abort_transaction(trans, ret);
2950 goto out_trans;
2951 }
2952
2953 }
2954 if (extent_info) {
2955 ret = btrfs_insert_replace_extent(trans, inode, path,
2956 extent_info, extent_info->data_len,
2957 drop_args.bytes_found);
2958 if (ret) {
2959 btrfs_abort_transaction(trans, ret);
2960 goto out_trans;
2961 }
2962 }
2963
2964 out_trans:
2965 if (!trans)
2966 goto out_free;
2967
2968 trans->block_rsv = &fs_info->trans_block_rsv;
2969 if (ret)
2970 btrfs_end_transaction(trans);
2971 else
2972 *trans_out = trans;
2973 out_free:
2974 btrfs_free_block_rsv(fs_info, rsv);
2975 out:
2976 return ret;
2977 }
2978
btrfs_punch_hole(struct file * file,loff_t offset,loff_t len)2979 static int btrfs_punch_hole(struct file *file, loff_t offset, loff_t len)
2980 {
2981 struct inode *inode = file_inode(file);
2982 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2983 struct btrfs_root *root = BTRFS_I(inode)->root;
2984 struct extent_state *cached_state = NULL;
2985 struct btrfs_path *path;
2986 struct btrfs_trans_handle *trans = NULL;
2987 u64 lockstart;
2988 u64 lockend;
2989 u64 tail_start;
2990 u64 tail_len;
2991 u64 orig_start = offset;
2992 int ret = 0;
2993 bool same_block;
2994 u64 ino_size;
2995 bool truncated_block = false;
2996 bool updated_inode = false;
2997
2998 ret = btrfs_wait_ordered_range(inode, offset, len);
2999 if (ret)
3000 return ret;
3001
3002 btrfs_inode_lock(inode, BTRFS_ILOCK_MMAP);
3003 ino_size = round_up(inode->i_size, fs_info->sectorsize);
3004 ret = find_first_non_hole(BTRFS_I(inode), &offset, &len);
3005 if (ret < 0)
3006 goto out_only_mutex;
3007 if (ret && !len) {
3008 /* Already in a large hole */
3009 ret = 0;
3010 goto out_only_mutex;
3011 }
3012
3013 ret = file_modified(file);
3014 if (ret)
3015 goto out_only_mutex;
3016
3017 lockstart = round_up(offset, btrfs_inode_sectorsize(BTRFS_I(inode)));
3018 lockend = round_down(offset + len,
3019 btrfs_inode_sectorsize(BTRFS_I(inode))) - 1;
3020 same_block = (BTRFS_BYTES_TO_BLKS(fs_info, offset))
3021 == (BTRFS_BYTES_TO_BLKS(fs_info, offset + len - 1));
3022 /*
3023 * We needn't truncate any block which is beyond the end of the file
3024 * because we are sure there is no data there.
3025 */
3026 /*
3027 * Only do this if we are in the same block and we aren't doing the
3028 * entire block.
3029 */
3030 if (same_block && len < fs_info->sectorsize) {
3031 if (offset < ino_size) {
3032 truncated_block = true;
3033 ret = btrfs_truncate_block(BTRFS_I(inode), offset, len,
3034 0);
3035 } else {
3036 ret = 0;
3037 }
3038 goto out_only_mutex;
3039 }
3040
3041 /* zero back part of the first block */
3042 if (offset < ino_size) {
3043 truncated_block = true;
3044 ret = btrfs_truncate_block(BTRFS_I(inode), offset, 0, 0);
3045 if (ret) {
3046 btrfs_inode_unlock(inode, BTRFS_ILOCK_MMAP);
3047 return ret;
3048 }
3049 }
3050
3051 /* Check the aligned pages after the first unaligned page,
3052 * if offset != orig_start, which means the first unaligned page
3053 * including several following pages are already in holes,
3054 * the extra check can be skipped */
3055 if (offset == orig_start) {
3056 /* after truncate page, check hole again */
3057 len = offset + len - lockstart;
3058 offset = lockstart;
3059 ret = find_first_non_hole(BTRFS_I(inode), &offset, &len);
3060 if (ret < 0)
3061 goto out_only_mutex;
3062 if (ret && !len) {
3063 ret = 0;
3064 goto out_only_mutex;
3065 }
3066 lockstart = offset;
3067 }
3068
3069 /* Check the tail unaligned part is in a hole */
3070 tail_start = lockend + 1;
3071 tail_len = offset + len - tail_start;
3072 if (tail_len) {
3073 ret = find_first_non_hole(BTRFS_I(inode), &tail_start, &tail_len);
3074 if (unlikely(ret < 0))
3075 goto out_only_mutex;
3076 if (!ret) {
3077 /* zero the front end of the last page */
3078 if (tail_start + tail_len < ino_size) {
3079 truncated_block = true;
3080 ret = btrfs_truncate_block(BTRFS_I(inode),
3081 tail_start + tail_len,
3082 0, 1);
3083 if (ret)
3084 goto out_only_mutex;
3085 }
3086 }
3087 }
3088
3089 if (lockend < lockstart) {
3090 ret = 0;
3091 goto out_only_mutex;
3092 }
3093
3094 ret = btrfs_punch_hole_lock_range(inode, lockstart, lockend,
3095 &cached_state);
3096 if (ret)
3097 goto out_only_mutex;
3098
3099 path = btrfs_alloc_path();
3100 if (!path) {
3101 ret = -ENOMEM;
3102 goto out;
3103 }
3104
3105 ret = btrfs_replace_file_extents(BTRFS_I(inode), path, lockstart,
3106 lockend, NULL, &trans);
3107 btrfs_free_path(path);
3108 if (ret)
3109 goto out;
3110
3111 ASSERT(trans != NULL);
3112 inode_inc_iversion(inode);
3113 inode->i_mtime = inode->i_ctime = current_time(inode);
3114 ret = btrfs_update_inode(trans, root, BTRFS_I(inode));
3115 updated_inode = true;
3116 btrfs_end_transaction(trans);
3117 btrfs_btree_balance_dirty(fs_info);
3118 out:
3119 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart, lockend,
3120 &cached_state);
3121 out_only_mutex:
3122 if (!updated_inode && truncated_block && !ret) {
3123 /*
3124 * If we only end up zeroing part of a page, we still need to
3125 * update the inode item, so that all the time fields are
3126 * updated as well as the necessary btrfs inode in memory fields
3127 * for detecting, at fsync time, if the inode isn't yet in the
3128 * log tree or it's there but not up to date.
3129 */
3130 struct timespec64 now = current_time(inode);
3131
3132 inode_inc_iversion(inode);
3133 inode->i_mtime = now;
3134 inode->i_ctime = now;
3135 trans = btrfs_start_transaction(root, 1);
3136 if (IS_ERR(trans)) {
3137 ret = PTR_ERR(trans);
3138 } else {
3139 int ret2;
3140
3141 ret = btrfs_update_inode(trans, root, BTRFS_I(inode));
3142 ret2 = btrfs_end_transaction(trans);
3143 if (!ret)
3144 ret = ret2;
3145 }
3146 }
3147 btrfs_inode_unlock(inode, BTRFS_ILOCK_MMAP);
3148 return ret;
3149 }
3150
3151 /* Helper structure to record which range is already reserved */
3152 struct falloc_range {
3153 struct list_head list;
3154 u64 start;
3155 u64 len;
3156 };
3157
3158 /*
3159 * Helper function to add falloc range
3160 *
3161 * Caller should have locked the larger range of extent containing
3162 * [start, len)
3163 */
add_falloc_range(struct list_head * head,u64 start,u64 len)3164 static int add_falloc_range(struct list_head *head, u64 start, u64 len)
3165 {
3166 struct falloc_range *range = NULL;
3167
3168 if (!list_empty(head)) {
3169 /*
3170 * As fallocate iterates by bytenr order, we only need to check
3171 * the last range.
3172 */
3173 range = list_last_entry(head, struct falloc_range, list);
3174 if (range->start + range->len == start) {
3175 range->len += len;
3176 return 0;
3177 }
3178 }
3179
3180 range = kmalloc(sizeof(*range), GFP_KERNEL);
3181 if (!range)
3182 return -ENOMEM;
3183 range->start = start;
3184 range->len = len;
3185 list_add_tail(&range->list, head);
3186 return 0;
3187 }
3188
btrfs_fallocate_update_isize(struct inode * inode,const u64 end,const int mode)3189 static int btrfs_fallocate_update_isize(struct inode *inode,
3190 const u64 end,
3191 const int mode)
3192 {
3193 struct btrfs_trans_handle *trans;
3194 struct btrfs_root *root = BTRFS_I(inode)->root;
3195 int ret;
3196 int ret2;
3197
3198 if (mode & FALLOC_FL_KEEP_SIZE || end <= i_size_read(inode))
3199 return 0;
3200
3201 trans = btrfs_start_transaction(root, 1);
3202 if (IS_ERR(trans))
3203 return PTR_ERR(trans);
3204
3205 inode->i_ctime = current_time(inode);
3206 i_size_write(inode, end);
3207 btrfs_inode_safe_disk_i_size_write(BTRFS_I(inode), 0);
3208 ret = btrfs_update_inode(trans, root, BTRFS_I(inode));
3209 ret2 = btrfs_end_transaction(trans);
3210
3211 return ret ? ret : ret2;
3212 }
3213
3214 enum {
3215 RANGE_BOUNDARY_WRITTEN_EXTENT,
3216 RANGE_BOUNDARY_PREALLOC_EXTENT,
3217 RANGE_BOUNDARY_HOLE,
3218 };
3219
btrfs_zero_range_check_range_boundary(struct btrfs_inode * inode,u64 offset)3220 static int btrfs_zero_range_check_range_boundary(struct btrfs_inode *inode,
3221 u64 offset)
3222 {
3223 const u64 sectorsize = btrfs_inode_sectorsize(inode);
3224 struct extent_map *em;
3225 int ret;
3226
3227 offset = round_down(offset, sectorsize);
3228 em = btrfs_get_extent(inode, NULL, 0, offset, sectorsize);
3229 if (IS_ERR(em))
3230 return PTR_ERR(em);
3231
3232 if (em->block_start == EXTENT_MAP_HOLE)
3233 ret = RANGE_BOUNDARY_HOLE;
3234 else if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
3235 ret = RANGE_BOUNDARY_PREALLOC_EXTENT;
3236 else
3237 ret = RANGE_BOUNDARY_WRITTEN_EXTENT;
3238
3239 free_extent_map(em);
3240 return ret;
3241 }
3242
btrfs_zero_range(struct inode * inode,loff_t offset,loff_t len,const int mode)3243 static int btrfs_zero_range(struct inode *inode,
3244 loff_t offset,
3245 loff_t len,
3246 const int mode)
3247 {
3248 struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info;
3249 struct extent_map *em;
3250 struct extent_changeset *data_reserved = NULL;
3251 int ret;
3252 u64 alloc_hint = 0;
3253 const u64 sectorsize = btrfs_inode_sectorsize(BTRFS_I(inode));
3254 u64 alloc_start = round_down(offset, sectorsize);
3255 u64 alloc_end = round_up(offset + len, sectorsize);
3256 u64 bytes_to_reserve = 0;
3257 bool space_reserved = false;
3258
3259 inode_dio_wait(inode);
3260
3261 em = btrfs_get_extent(BTRFS_I(inode), NULL, 0, alloc_start,
3262 alloc_end - alloc_start);
3263 if (IS_ERR(em)) {
3264 ret = PTR_ERR(em);
3265 goto out;
3266 }
3267
3268 /*
3269 * Avoid hole punching and extent allocation for some cases. More cases
3270 * could be considered, but these are unlikely common and we keep things
3271 * as simple as possible for now. Also, intentionally, if the target
3272 * range contains one or more prealloc extents together with regular
3273 * extents and holes, we drop all the existing extents and allocate a
3274 * new prealloc extent, so that we get a larger contiguous disk extent.
3275 */
3276 if (em->start <= alloc_start &&
3277 test_bit(EXTENT_FLAG_PREALLOC, &em->flags)) {
3278 const u64 em_end = em->start + em->len;
3279
3280 if (em_end >= offset + len) {
3281 /*
3282 * The whole range is already a prealloc extent,
3283 * do nothing except updating the inode's i_size if
3284 * needed.
3285 */
3286 free_extent_map(em);
3287 ret = btrfs_fallocate_update_isize(inode, offset + len,
3288 mode);
3289 goto out;
3290 }
3291 /*
3292 * Part of the range is already a prealloc extent, so operate
3293 * only on the remaining part of the range.
3294 */
3295 alloc_start = em_end;
3296 ASSERT(IS_ALIGNED(alloc_start, sectorsize));
3297 len = offset + len - alloc_start;
3298 offset = alloc_start;
3299 alloc_hint = em->block_start + em->len;
3300 }
3301 free_extent_map(em);
3302
3303 if (BTRFS_BYTES_TO_BLKS(fs_info, offset) ==
3304 BTRFS_BYTES_TO_BLKS(fs_info, offset + len - 1)) {
3305 em = btrfs_get_extent(BTRFS_I(inode), NULL, 0, alloc_start,
3306 sectorsize);
3307 if (IS_ERR(em)) {
3308 ret = PTR_ERR(em);
3309 goto out;
3310 }
3311
3312 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags)) {
3313 free_extent_map(em);
3314 ret = btrfs_fallocate_update_isize(inode, offset + len,
3315 mode);
3316 goto out;
3317 }
3318 if (len < sectorsize && em->block_start != EXTENT_MAP_HOLE) {
3319 free_extent_map(em);
3320 ret = btrfs_truncate_block(BTRFS_I(inode), offset, len,
3321 0);
3322 if (!ret)
3323 ret = btrfs_fallocate_update_isize(inode,
3324 offset + len,
3325 mode);
3326 return ret;
3327 }
3328 free_extent_map(em);
3329 alloc_start = round_down(offset, sectorsize);
3330 alloc_end = alloc_start + sectorsize;
3331 goto reserve_space;
3332 }
3333
3334 alloc_start = round_up(offset, sectorsize);
3335 alloc_end = round_down(offset + len, sectorsize);
3336
3337 /*
3338 * For unaligned ranges, check the pages at the boundaries, they might
3339 * map to an extent, in which case we need to partially zero them, or
3340 * they might map to a hole, in which case we need our allocation range
3341 * to cover them.
3342 */
3343 if (!IS_ALIGNED(offset, sectorsize)) {
3344 ret = btrfs_zero_range_check_range_boundary(BTRFS_I(inode),
3345 offset);
3346 if (ret < 0)
3347 goto out;
3348 if (ret == RANGE_BOUNDARY_HOLE) {
3349 alloc_start = round_down(offset, sectorsize);
3350 ret = 0;
3351 } else if (ret == RANGE_BOUNDARY_WRITTEN_EXTENT) {
3352 ret = btrfs_truncate_block(BTRFS_I(inode), offset, 0, 0);
3353 if (ret)
3354 goto out;
3355 } else {
3356 ret = 0;
3357 }
3358 }
3359
3360 if (!IS_ALIGNED(offset + len, sectorsize)) {
3361 ret = btrfs_zero_range_check_range_boundary(BTRFS_I(inode),
3362 offset + len);
3363 if (ret < 0)
3364 goto out;
3365 if (ret == RANGE_BOUNDARY_HOLE) {
3366 alloc_end = round_up(offset + len, sectorsize);
3367 ret = 0;
3368 } else if (ret == RANGE_BOUNDARY_WRITTEN_EXTENT) {
3369 ret = btrfs_truncate_block(BTRFS_I(inode), offset + len,
3370 0, 1);
3371 if (ret)
3372 goto out;
3373 } else {
3374 ret = 0;
3375 }
3376 }
3377
3378 reserve_space:
3379 if (alloc_start < alloc_end) {
3380 struct extent_state *cached_state = NULL;
3381 const u64 lockstart = alloc_start;
3382 const u64 lockend = alloc_end - 1;
3383
3384 bytes_to_reserve = alloc_end - alloc_start;
3385 ret = btrfs_alloc_data_chunk_ondemand(BTRFS_I(inode),
3386 bytes_to_reserve);
3387 if (ret < 0)
3388 goto out;
3389 space_reserved = true;
3390 ret = btrfs_punch_hole_lock_range(inode, lockstart, lockend,
3391 &cached_state);
3392 if (ret)
3393 goto out;
3394 ret = btrfs_qgroup_reserve_data(BTRFS_I(inode), &data_reserved,
3395 alloc_start, bytes_to_reserve);
3396 if (ret) {
3397 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart,
3398 lockend, &cached_state);
3399 goto out;
3400 }
3401 ret = btrfs_prealloc_file_range(inode, mode, alloc_start,
3402 alloc_end - alloc_start,
3403 i_blocksize(inode),
3404 offset + len, &alloc_hint);
3405 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart,
3406 lockend, &cached_state);
3407 /* btrfs_prealloc_file_range releases reserved space on error */
3408 if (ret) {
3409 space_reserved = false;
3410 goto out;
3411 }
3412 }
3413 ret = btrfs_fallocate_update_isize(inode, offset + len, mode);
3414 out:
3415 if (ret && space_reserved)
3416 btrfs_free_reserved_data_space(BTRFS_I(inode), data_reserved,
3417 alloc_start, bytes_to_reserve);
3418 extent_changeset_free(data_reserved);
3419
3420 return ret;
3421 }
3422
btrfs_fallocate(struct file * file,int mode,loff_t offset,loff_t len)3423 static long btrfs_fallocate(struct file *file, int mode,
3424 loff_t offset, loff_t len)
3425 {
3426 struct inode *inode = file_inode(file);
3427 struct extent_state *cached_state = NULL;
3428 struct extent_changeset *data_reserved = NULL;
3429 struct falloc_range *range;
3430 struct falloc_range *tmp;
3431 struct list_head reserve_list;
3432 u64 cur_offset;
3433 u64 last_byte;
3434 u64 alloc_start;
3435 u64 alloc_end;
3436 u64 alloc_hint = 0;
3437 u64 locked_end;
3438 u64 actual_end = 0;
3439 struct extent_map *em;
3440 int blocksize = btrfs_inode_sectorsize(BTRFS_I(inode));
3441 int ret;
3442
3443 /* Do not allow fallocate in ZONED mode */
3444 if (btrfs_is_zoned(btrfs_sb(inode->i_sb)))
3445 return -EOPNOTSUPP;
3446
3447 alloc_start = round_down(offset, blocksize);
3448 alloc_end = round_up(offset + len, blocksize);
3449 cur_offset = alloc_start;
3450
3451 /* Make sure we aren't being give some crap mode */
3452 if (mode & ~(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE |
3453 FALLOC_FL_ZERO_RANGE))
3454 return -EOPNOTSUPP;
3455
3456 if (mode & FALLOC_FL_PUNCH_HOLE)
3457 return btrfs_punch_hole(file, offset, len);
3458
3459 /*
3460 * Only trigger disk allocation, don't trigger qgroup reserve
3461 *
3462 * For qgroup space, it will be checked later.
3463 */
3464 if (!(mode & FALLOC_FL_ZERO_RANGE)) {
3465 ret = btrfs_alloc_data_chunk_ondemand(BTRFS_I(inode),
3466 alloc_end - alloc_start);
3467 if (ret < 0)
3468 return ret;
3469 }
3470
3471 btrfs_inode_lock(inode, BTRFS_ILOCK_MMAP);
3472
3473 if (!(mode & FALLOC_FL_KEEP_SIZE) && offset + len > inode->i_size) {
3474 ret = inode_newsize_ok(inode, offset + len);
3475 if (ret)
3476 goto out;
3477 }
3478
3479 ret = file_modified(file);
3480 if (ret)
3481 goto out;
3482
3483 /*
3484 * TODO: Move these two operations after we have checked
3485 * accurate reserved space, or fallocate can still fail but
3486 * with page truncated or size expanded.
3487 *
3488 * But that's a minor problem and won't do much harm BTW.
3489 */
3490 if (alloc_start > inode->i_size) {
3491 ret = btrfs_cont_expand(BTRFS_I(inode), i_size_read(inode),
3492 alloc_start);
3493 if (ret)
3494 goto out;
3495 } else if (offset + len > inode->i_size) {
3496 /*
3497 * If we are fallocating from the end of the file onward we
3498 * need to zero out the end of the block if i_size lands in the
3499 * middle of a block.
3500 */
3501 ret = btrfs_truncate_block(BTRFS_I(inode), inode->i_size, 0, 0);
3502 if (ret)
3503 goto out;
3504 }
3505
3506 /*
3507 * wait for ordered IO before we have any locks. We'll loop again
3508 * below with the locks held.
3509 */
3510 ret = btrfs_wait_ordered_range(inode, alloc_start,
3511 alloc_end - alloc_start);
3512 if (ret)
3513 goto out;
3514
3515 if (mode & FALLOC_FL_ZERO_RANGE) {
3516 ret = btrfs_zero_range(inode, offset, len, mode);
3517 btrfs_inode_unlock(inode, BTRFS_ILOCK_MMAP);
3518 return ret;
3519 }
3520
3521 locked_end = alloc_end - 1;
3522 while (1) {
3523 struct btrfs_ordered_extent *ordered;
3524
3525 /* the extent lock is ordered inside the running
3526 * transaction
3527 */
3528 lock_extent_bits(&BTRFS_I(inode)->io_tree, alloc_start,
3529 locked_end, &cached_state);
3530 ordered = btrfs_lookup_first_ordered_extent(BTRFS_I(inode),
3531 locked_end);
3532
3533 if (ordered &&
3534 ordered->file_offset + ordered->num_bytes > alloc_start &&
3535 ordered->file_offset < alloc_end) {
3536 btrfs_put_ordered_extent(ordered);
3537 unlock_extent_cached(&BTRFS_I(inode)->io_tree,
3538 alloc_start, locked_end,
3539 &cached_state);
3540 /*
3541 * we can't wait on the range with the transaction
3542 * running or with the extent lock held
3543 */
3544 ret = btrfs_wait_ordered_range(inode, alloc_start,
3545 alloc_end - alloc_start);
3546 if (ret)
3547 goto out;
3548 } else {
3549 if (ordered)
3550 btrfs_put_ordered_extent(ordered);
3551 break;
3552 }
3553 }
3554
3555 /* First, check if we exceed the qgroup limit */
3556 INIT_LIST_HEAD(&reserve_list);
3557 while (cur_offset < alloc_end) {
3558 em = btrfs_get_extent(BTRFS_I(inode), NULL, 0, cur_offset,
3559 alloc_end - cur_offset);
3560 if (IS_ERR(em)) {
3561 ret = PTR_ERR(em);
3562 break;
3563 }
3564 last_byte = min(extent_map_end(em), alloc_end);
3565 actual_end = min_t(u64, extent_map_end(em), offset + len);
3566 last_byte = ALIGN(last_byte, blocksize);
3567 if (em->block_start == EXTENT_MAP_HOLE ||
3568 (cur_offset >= inode->i_size &&
3569 !test_bit(EXTENT_FLAG_PREALLOC, &em->flags))) {
3570 ret = add_falloc_range(&reserve_list, cur_offset,
3571 last_byte - cur_offset);
3572 if (ret < 0) {
3573 free_extent_map(em);
3574 break;
3575 }
3576 ret = btrfs_qgroup_reserve_data(BTRFS_I(inode),
3577 &data_reserved, cur_offset,
3578 last_byte - cur_offset);
3579 if (ret < 0) {
3580 cur_offset = last_byte;
3581 free_extent_map(em);
3582 break;
3583 }
3584 } else {
3585 /*
3586 * Do not need to reserve unwritten extent for this
3587 * range, free reserved data space first, otherwise
3588 * it'll result in false ENOSPC error.
3589 */
3590 btrfs_free_reserved_data_space(BTRFS_I(inode),
3591 data_reserved, cur_offset,
3592 last_byte - cur_offset);
3593 }
3594 free_extent_map(em);
3595 cur_offset = last_byte;
3596 }
3597
3598 /*
3599 * If ret is still 0, means we're OK to fallocate.
3600 * Or just cleanup the list and exit.
3601 */
3602 list_for_each_entry_safe(range, tmp, &reserve_list, list) {
3603 if (!ret)
3604 ret = btrfs_prealloc_file_range(inode, mode,
3605 range->start,
3606 range->len, i_blocksize(inode),
3607 offset + len, &alloc_hint);
3608 else
3609 btrfs_free_reserved_data_space(BTRFS_I(inode),
3610 data_reserved, range->start,
3611 range->len);
3612 list_del(&range->list);
3613 kfree(range);
3614 }
3615 if (ret < 0)
3616 goto out_unlock;
3617
3618 /*
3619 * We didn't need to allocate any more space, but we still extended the
3620 * size of the file so we need to update i_size and the inode item.
3621 */
3622 ret = btrfs_fallocate_update_isize(inode, actual_end, mode);
3623 out_unlock:
3624 unlock_extent_cached(&BTRFS_I(inode)->io_tree, alloc_start, locked_end,
3625 &cached_state);
3626 out:
3627 btrfs_inode_unlock(inode, BTRFS_ILOCK_MMAP);
3628 /* Let go of our reservation. */
3629 if (ret != 0 && !(mode & FALLOC_FL_ZERO_RANGE))
3630 btrfs_free_reserved_data_space(BTRFS_I(inode), data_reserved,
3631 cur_offset, alloc_end - cur_offset);
3632 extent_changeset_free(data_reserved);
3633 return ret;
3634 }
3635
find_desired_extent(struct btrfs_inode * inode,loff_t offset,int whence)3636 static loff_t find_desired_extent(struct btrfs_inode *inode, loff_t offset,
3637 int whence)
3638 {
3639 struct btrfs_fs_info *fs_info = inode->root->fs_info;
3640 struct extent_map *em = NULL;
3641 struct extent_state *cached_state = NULL;
3642 loff_t i_size = inode->vfs_inode.i_size;
3643 u64 lockstart;
3644 u64 lockend;
3645 u64 start;
3646 u64 len;
3647 int ret = 0;
3648
3649 if (i_size == 0 || offset >= i_size)
3650 return -ENXIO;
3651
3652 /*
3653 * offset can be negative, in this case we start finding DATA/HOLE from
3654 * the very start of the file.
3655 */
3656 start = max_t(loff_t, 0, offset);
3657
3658 lockstart = round_down(start, fs_info->sectorsize);
3659 lockend = round_up(i_size, fs_info->sectorsize);
3660 if (lockend <= lockstart)
3661 lockend = lockstart + fs_info->sectorsize;
3662 lockend--;
3663 len = lockend - lockstart + 1;
3664
3665 lock_extent_bits(&inode->io_tree, lockstart, lockend, &cached_state);
3666
3667 while (start < i_size) {
3668 em = btrfs_get_extent_fiemap(inode, start, len);
3669 if (IS_ERR(em)) {
3670 ret = PTR_ERR(em);
3671 em = NULL;
3672 break;
3673 }
3674
3675 if (whence == SEEK_HOLE &&
3676 (em->block_start == EXTENT_MAP_HOLE ||
3677 test_bit(EXTENT_FLAG_PREALLOC, &em->flags)))
3678 break;
3679 else if (whence == SEEK_DATA &&
3680 (em->block_start != EXTENT_MAP_HOLE &&
3681 !test_bit(EXTENT_FLAG_PREALLOC, &em->flags)))
3682 break;
3683
3684 start = em->start + em->len;
3685 free_extent_map(em);
3686 em = NULL;
3687 cond_resched();
3688 }
3689 free_extent_map(em);
3690 unlock_extent_cached(&inode->io_tree, lockstart, lockend,
3691 &cached_state);
3692 if (ret) {
3693 offset = ret;
3694 } else {
3695 if (whence == SEEK_DATA && start >= i_size)
3696 offset = -ENXIO;
3697 else
3698 offset = min_t(loff_t, start, i_size);
3699 }
3700
3701 return offset;
3702 }
3703
btrfs_file_llseek(struct file * file,loff_t offset,int whence)3704 static loff_t btrfs_file_llseek(struct file *file, loff_t offset, int whence)
3705 {
3706 struct inode *inode = file->f_mapping->host;
3707
3708 switch (whence) {
3709 default:
3710 return generic_file_llseek(file, offset, whence);
3711 case SEEK_DATA:
3712 case SEEK_HOLE:
3713 btrfs_inode_lock(inode, BTRFS_ILOCK_SHARED);
3714 offset = find_desired_extent(BTRFS_I(inode), offset, whence);
3715 btrfs_inode_unlock(inode, BTRFS_ILOCK_SHARED);
3716 break;
3717 }
3718
3719 if (offset < 0)
3720 return offset;
3721
3722 return vfs_setpos(file, offset, inode->i_sb->s_maxbytes);
3723 }
3724
btrfs_file_open(struct inode * inode,struct file * filp)3725 static int btrfs_file_open(struct inode *inode, struct file *filp)
3726 {
3727 int ret;
3728
3729 filp->f_mode |= FMODE_NOWAIT | FMODE_BUF_RASYNC;
3730
3731 ret = fsverity_file_open(inode, filp);
3732 if (ret)
3733 return ret;
3734 return generic_file_open(inode, filp);
3735 }
3736
check_direct_read(struct btrfs_fs_info * fs_info,const struct iov_iter * iter,loff_t offset)3737 static int check_direct_read(struct btrfs_fs_info *fs_info,
3738 const struct iov_iter *iter, loff_t offset)
3739 {
3740 int ret;
3741 int i, seg;
3742
3743 ret = check_direct_IO(fs_info, iter, offset);
3744 if (ret < 0)
3745 return ret;
3746
3747 if (!iter_is_iovec(iter))
3748 return 0;
3749
3750 for (seg = 0; seg < iter->nr_segs; seg++)
3751 for (i = seg + 1; i < iter->nr_segs; i++)
3752 if (iter->iov[seg].iov_base == iter->iov[i].iov_base)
3753 return -EINVAL;
3754 return 0;
3755 }
3756
btrfs_direct_read(struct kiocb * iocb,struct iov_iter * to)3757 static ssize_t btrfs_direct_read(struct kiocb *iocb, struct iov_iter *to)
3758 {
3759 struct inode *inode = file_inode(iocb->ki_filp);
3760 size_t prev_left = 0;
3761 ssize_t read = 0;
3762 ssize_t ret;
3763
3764 if (fsverity_active(inode))
3765 return 0;
3766
3767 if (check_direct_read(btrfs_sb(inode->i_sb), to, iocb->ki_pos))
3768 return 0;
3769
3770 btrfs_inode_lock(inode, BTRFS_ILOCK_SHARED);
3771 again:
3772 /*
3773 * This is similar to what we do for direct IO writes, see the comment
3774 * at btrfs_direct_write(), but we also disable page faults in addition
3775 * to disabling them only at the iov_iter level. This is because when
3776 * reading from a hole or prealloc extent, iomap calls iov_iter_zero(),
3777 * which can still trigger page fault ins despite having set ->nofault
3778 * to true of our 'to' iov_iter.
3779 *
3780 * The difference to direct IO writes is that we deadlock when trying
3781 * to lock the extent range in the inode's tree during he page reads
3782 * triggered by the fault in (while for writes it is due to waiting for
3783 * our own ordered extent). This is because for direct IO reads,
3784 * btrfs_dio_iomap_begin() returns with the extent range locked, which
3785 * is only unlocked in the endio callback (end_bio_extent_readpage()).
3786 */
3787 pagefault_disable();
3788 to->nofault = true;
3789 ret = iomap_dio_rw(iocb, to, &btrfs_dio_iomap_ops, &btrfs_dio_ops,
3790 IOMAP_DIO_PARTIAL, read);
3791 to->nofault = false;
3792 pagefault_enable();
3793
3794 /* No increment (+=) because iomap returns a cumulative value. */
3795 if (ret > 0)
3796 read = ret;
3797
3798 if (iov_iter_count(to) > 0 && (ret == -EFAULT || ret > 0)) {
3799 const size_t left = iov_iter_count(to);
3800
3801 if (left == prev_left) {
3802 /*
3803 * We didn't make any progress since the last attempt,
3804 * fallback to a buffered read for the remainder of the
3805 * range. This is just to avoid any possibility of looping
3806 * for too long.
3807 */
3808 ret = read;
3809 } else {
3810 /*
3811 * We made some progress since the last retry or this is
3812 * the first time we are retrying. Fault in as many pages
3813 * as possible and retry.
3814 */
3815 fault_in_iov_iter_writeable(to, left);
3816 prev_left = left;
3817 goto again;
3818 }
3819 }
3820 btrfs_inode_unlock(inode, BTRFS_ILOCK_SHARED);
3821 return ret < 0 ? ret : read;
3822 }
3823
btrfs_file_read_iter(struct kiocb * iocb,struct iov_iter * to)3824 static ssize_t btrfs_file_read_iter(struct kiocb *iocb, struct iov_iter *to)
3825 {
3826 ssize_t ret = 0;
3827
3828 if (iocb->ki_flags & IOCB_DIRECT) {
3829 ret = btrfs_direct_read(iocb, to);
3830 if (ret < 0 || !iov_iter_count(to) ||
3831 iocb->ki_pos >= i_size_read(file_inode(iocb->ki_filp)))
3832 return ret;
3833 }
3834
3835 return filemap_read(iocb, to, ret);
3836 }
3837
3838 const struct file_operations btrfs_file_operations = {
3839 .llseek = btrfs_file_llseek,
3840 .read_iter = btrfs_file_read_iter,
3841 .splice_read = generic_file_splice_read,
3842 .write_iter = btrfs_file_write_iter,
3843 .splice_write = iter_file_splice_write,
3844 .mmap = btrfs_file_mmap,
3845 .open = btrfs_file_open,
3846 .release = btrfs_release_file,
3847 .fsync = btrfs_sync_file,
3848 .fallocate = btrfs_fallocate,
3849 .unlocked_ioctl = btrfs_ioctl,
3850 #ifdef CONFIG_COMPAT
3851 .compat_ioctl = btrfs_compat_ioctl,
3852 #endif
3853 .remap_file_range = btrfs_remap_file_range,
3854 };
3855
btrfs_auto_defrag_exit(void)3856 void __cold btrfs_auto_defrag_exit(void)
3857 {
3858 kmem_cache_destroy(btrfs_inode_defrag_cachep);
3859 }
3860
btrfs_auto_defrag_init(void)3861 int __init btrfs_auto_defrag_init(void)
3862 {
3863 btrfs_inode_defrag_cachep = kmem_cache_create("btrfs_inode_defrag",
3864 sizeof(struct inode_defrag), 0,
3865 SLAB_MEM_SPREAD,
3866 NULL);
3867 if (!btrfs_inode_defrag_cachep)
3868 return -ENOMEM;
3869
3870 return 0;
3871 }
3872
btrfs_fdatawrite_range(struct inode * inode,loff_t start,loff_t end)3873 int btrfs_fdatawrite_range(struct inode *inode, loff_t start, loff_t end)
3874 {
3875 int ret;
3876
3877 /*
3878 * So with compression we will find and lock a dirty page and clear the
3879 * first one as dirty, setup an async extent, and immediately return
3880 * with the entire range locked but with nobody actually marked with
3881 * writeback. So we can't just filemap_write_and_wait_range() and
3882 * expect it to work since it will just kick off a thread to do the
3883 * actual work. So we need to call filemap_fdatawrite_range _again_
3884 * since it will wait on the page lock, which won't be unlocked until
3885 * after the pages have been marked as writeback and so we're good to go
3886 * from there. We have to do this otherwise we'll miss the ordered
3887 * extents and that results in badness. Please Josef, do not think you
3888 * know better and pull this out at some point in the future, it is
3889 * right and you are wrong.
3890 */
3891 ret = filemap_fdatawrite_range(inode->i_mapping, start, end);
3892 if (!ret && test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
3893 &BTRFS_I(inode)->runtime_flags))
3894 ret = filemap_fdatawrite_range(inode->i_mapping, start, end);
3895
3896 return ret;
3897 }
3898