1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Copyright (C) 2008 Red Hat. All rights reserved.
4 */
5
6 #include <linux/pagemap.h>
7 #include <linux/sched.h>
8 #include <linux/sched/signal.h>
9 #include <linux/slab.h>
10 #include <linux/math64.h>
11 #include <linux/ratelimit.h>
12 #include <linux/error-injection.h>
13 #include <linux/sched/mm.h>
14 #include "ctree.h"
15 #include "free-space-cache.h"
16 #include "transaction.h"
17 #include "disk-io.h"
18 #include "extent_io.h"
19 #include "inode-map.h"
20 #include "volumes.h"
21 #include "space-info.h"
22 #include "delalloc-space.h"
23 #include "block-group.h"
24
25 #define BITS_PER_BITMAP (PAGE_SIZE * 8UL)
26 #define MAX_CACHE_BYTES_PER_GIG SZ_32K
27
28 struct btrfs_trim_range {
29 u64 start;
30 u64 bytes;
31 struct list_head list;
32 };
33
34 static int link_free_space(struct btrfs_free_space_ctl *ctl,
35 struct btrfs_free_space *info);
36 static void unlink_free_space(struct btrfs_free_space_ctl *ctl,
37 struct btrfs_free_space *info);
38 static int btrfs_wait_cache_io_root(struct btrfs_root *root,
39 struct btrfs_trans_handle *trans,
40 struct btrfs_io_ctl *io_ctl,
41 struct btrfs_path *path);
42
__lookup_free_space_inode(struct btrfs_root * root,struct btrfs_path * path,u64 offset)43 static struct inode *__lookup_free_space_inode(struct btrfs_root *root,
44 struct btrfs_path *path,
45 u64 offset)
46 {
47 struct btrfs_fs_info *fs_info = root->fs_info;
48 struct btrfs_key key;
49 struct btrfs_key location;
50 struct btrfs_disk_key disk_key;
51 struct btrfs_free_space_header *header;
52 struct extent_buffer *leaf;
53 struct inode *inode = NULL;
54 unsigned nofs_flag;
55 int ret;
56
57 key.objectid = BTRFS_FREE_SPACE_OBJECTID;
58 key.offset = offset;
59 key.type = 0;
60
61 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
62 if (ret < 0)
63 return ERR_PTR(ret);
64 if (ret > 0) {
65 btrfs_release_path(path);
66 return ERR_PTR(-ENOENT);
67 }
68
69 leaf = path->nodes[0];
70 header = btrfs_item_ptr(leaf, path->slots[0],
71 struct btrfs_free_space_header);
72 btrfs_free_space_key(leaf, header, &disk_key);
73 btrfs_disk_key_to_cpu(&location, &disk_key);
74 btrfs_release_path(path);
75
76 /*
77 * We are often under a trans handle at this point, so we need to make
78 * sure NOFS is set to keep us from deadlocking.
79 */
80 nofs_flag = memalloc_nofs_save();
81 inode = btrfs_iget_path(fs_info->sb, &location, root, NULL, path);
82 btrfs_release_path(path);
83 memalloc_nofs_restore(nofs_flag);
84 if (IS_ERR(inode))
85 return inode;
86
87 mapping_set_gfp_mask(inode->i_mapping,
88 mapping_gfp_constraint(inode->i_mapping,
89 ~(__GFP_FS | __GFP_HIGHMEM)));
90
91 return inode;
92 }
93
lookup_free_space_inode(struct btrfs_block_group_cache * block_group,struct btrfs_path * path)94 struct inode *lookup_free_space_inode(
95 struct btrfs_block_group_cache *block_group,
96 struct btrfs_path *path)
97 {
98 struct btrfs_fs_info *fs_info = block_group->fs_info;
99 struct inode *inode = NULL;
100 u32 flags = BTRFS_INODE_NODATASUM | BTRFS_INODE_NODATACOW;
101
102 spin_lock(&block_group->lock);
103 if (block_group->inode)
104 inode = igrab(block_group->inode);
105 spin_unlock(&block_group->lock);
106 if (inode)
107 return inode;
108
109 inode = __lookup_free_space_inode(fs_info->tree_root, path,
110 block_group->key.objectid);
111 if (IS_ERR(inode))
112 return inode;
113
114 spin_lock(&block_group->lock);
115 if (!((BTRFS_I(inode)->flags & flags) == flags)) {
116 btrfs_info(fs_info, "Old style space inode found, converting.");
117 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATASUM |
118 BTRFS_INODE_NODATACOW;
119 block_group->disk_cache_state = BTRFS_DC_CLEAR;
120 }
121
122 if (!block_group->iref) {
123 block_group->inode = igrab(inode);
124 block_group->iref = 1;
125 }
126 spin_unlock(&block_group->lock);
127
128 return inode;
129 }
130
__create_free_space_inode(struct btrfs_root * root,struct btrfs_trans_handle * trans,struct btrfs_path * path,u64 ino,u64 offset)131 static int __create_free_space_inode(struct btrfs_root *root,
132 struct btrfs_trans_handle *trans,
133 struct btrfs_path *path,
134 u64 ino, u64 offset)
135 {
136 struct btrfs_key key;
137 struct btrfs_disk_key disk_key;
138 struct btrfs_free_space_header *header;
139 struct btrfs_inode_item *inode_item;
140 struct extent_buffer *leaf;
141 u64 flags = BTRFS_INODE_NOCOMPRESS | BTRFS_INODE_PREALLOC;
142 int ret;
143
144 ret = btrfs_insert_empty_inode(trans, root, path, ino);
145 if (ret)
146 return ret;
147
148 /* We inline crc's for the free disk space cache */
149 if (ino != BTRFS_FREE_INO_OBJECTID)
150 flags |= BTRFS_INODE_NODATASUM | BTRFS_INODE_NODATACOW;
151
152 leaf = path->nodes[0];
153 inode_item = btrfs_item_ptr(leaf, path->slots[0],
154 struct btrfs_inode_item);
155 btrfs_item_key(leaf, &disk_key, path->slots[0]);
156 memzero_extent_buffer(leaf, (unsigned long)inode_item,
157 sizeof(*inode_item));
158 btrfs_set_inode_generation(leaf, inode_item, trans->transid);
159 btrfs_set_inode_size(leaf, inode_item, 0);
160 btrfs_set_inode_nbytes(leaf, inode_item, 0);
161 btrfs_set_inode_uid(leaf, inode_item, 0);
162 btrfs_set_inode_gid(leaf, inode_item, 0);
163 btrfs_set_inode_mode(leaf, inode_item, S_IFREG | 0600);
164 btrfs_set_inode_flags(leaf, inode_item, flags);
165 btrfs_set_inode_nlink(leaf, inode_item, 1);
166 btrfs_set_inode_transid(leaf, inode_item, trans->transid);
167 btrfs_set_inode_block_group(leaf, inode_item, offset);
168 btrfs_mark_buffer_dirty(leaf);
169 btrfs_release_path(path);
170
171 key.objectid = BTRFS_FREE_SPACE_OBJECTID;
172 key.offset = offset;
173 key.type = 0;
174 ret = btrfs_insert_empty_item(trans, root, path, &key,
175 sizeof(struct btrfs_free_space_header));
176 if (ret < 0) {
177 btrfs_release_path(path);
178 return ret;
179 }
180
181 leaf = path->nodes[0];
182 header = btrfs_item_ptr(leaf, path->slots[0],
183 struct btrfs_free_space_header);
184 memzero_extent_buffer(leaf, (unsigned long)header, sizeof(*header));
185 btrfs_set_free_space_key(leaf, header, &disk_key);
186 btrfs_mark_buffer_dirty(leaf);
187 btrfs_release_path(path);
188
189 return 0;
190 }
191
create_free_space_inode(struct btrfs_trans_handle * trans,struct btrfs_block_group_cache * block_group,struct btrfs_path * path)192 int create_free_space_inode(struct btrfs_trans_handle *trans,
193 struct btrfs_block_group_cache *block_group,
194 struct btrfs_path *path)
195 {
196 int ret;
197 u64 ino;
198
199 ret = btrfs_find_free_objectid(trans->fs_info->tree_root, &ino);
200 if (ret < 0)
201 return ret;
202
203 return __create_free_space_inode(trans->fs_info->tree_root, trans, path,
204 ino, block_group->key.objectid);
205 }
206
btrfs_check_trunc_cache_free_space(struct btrfs_fs_info * fs_info,struct btrfs_block_rsv * rsv)207 int btrfs_check_trunc_cache_free_space(struct btrfs_fs_info *fs_info,
208 struct btrfs_block_rsv *rsv)
209 {
210 u64 needed_bytes;
211 int ret;
212
213 /* 1 for slack space, 1 for updating the inode */
214 needed_bytes = btrfs_calc_insert_metadata_size(fs_info, 1) +
215 btrfs_calc_metadata_size(fs_info, 1);
216
217 spin_lock(&rsv->lock);
218 if (rsv->reserved < needed_bytes)
219 ret = -ENOSPC;
220 else
221 ret = 0;
222 spin_unlock(&rsv->lock);
223 return ret;
224 }
225
btrfs_truncate_free_space_cache(struct btrfs_trans_handle * trans,struct btrfs_block_group_cache * block_group,struct inode * inode)226 int btrfs_truncate_free_space_cache(struct btrfs_trans_handle *trans,
227 struct btrfs_block_group_cache *block_group,
228 struct inode *inode)
229 {
230 struct btrfs_root *root = BTRFS_I(inode)->root;
231 int ret = 0;
232 bool locked = false;
233
234 if (block_group) {
235 struct btrfs_path *path = btrfs_alloc_path();
236
237 if (!path) {
238 ret = -ENOMEM;
239 goto fail;
240 }
241 locked = true;
242 mutex_lock(&trans->transaction->cache_write_mutex);
243 if (!list_empty(&block_group->io_list)) {
244 list_del_init(&block_group->io_list);
245
246 btrfs_wait_cache_io(trans, block_group, path);
247 btrfs_put_block_group(block_group);
248 }
249
250 /*
251 * now that we've truncated the cache away, its no longer
252 * setup or written
253 */
254 spin_lock(&block_group->lock);
255 block_group->disk_cache_state = BTRFS_DC_CLEAR;
256 spin_unlock(&block_group->lock);
257 btrfs_free_path(path);
258 }
259
260 btrfs_i_size_write(BTRFS_I(inode), 0);
261 truncate_pagecache(inode, 0);
262
263 /*
264 * We skip the throttling logic for free space cache inodes, so we don't
265 * need to check for -EAGAIN.
266 */
267 ret = btrfs_truncate_inode_items(trans, root, inode,
268 0, BTRFS_EXTENT_DATA_KEY);
269 if (ret)
270 goto fail;
271
272 ret = btrfs_update_inode(trans, root, inode);
273
274 fail:
275 if (locked)
276 mutex_unlock(&trans->transaction->cache_write_mutex);
277 if (ret)
278 btrfs_abort_transaction(trans, ret);
279
280 return ret;
281 }
282
readahead_cache(struct inode * inode)283 static void readahead_cache(struct inode *inode)
284 {
285 struct file_ra_state *ra;
286 unsigned long last_index;
287
288 ra = kzalloc(sizeof(*ra), GFP_NOFS);
289 if (!ra)
290 return;
291
292 file_ra_state_init(ra, inode->i_mapping);
293 last_index = (i_size_read(inode) - 1) >> PAGE_SHIFT;
294
295 page_cache_sync_readahead(inode->i_mapping, ra, NULL, 0, last_index);
296
297 kfree(ra);
298 }
299
io_ctl_init(struct btrfs_io_ctl * io_ctl,struct inode * inode,int write)300 static int io_ctl_init(struct btrfs_io_ctl *io_ctl, struct inode *inode,
301 int write)
302 {
303 int num_pages;
304 int check_crcs = 0;
305
306 num_pages = DIV_ROUND_UP(i_size_read(inode), PAGE_SIZE);
307
308 if (btrfs_ino(BTRFS_I(inode)) != BTRFS_FREE_INO_OBJECTID)
309 check_crcs = 1;
310
311 /* Make sure we can fit our crcs and generation into the first page */
312 if (write && check_crcs &&
313 (num_pages * sizeof(u32) + sizeof(u64)) > PAGE_SIZE)
314 return -ENOSPC;
315
316 memset(io_ctl, 0, sizeof(struct btrfs_io_ctl));
317
318 io_ctl->pages = kcalloc(num_pages, sizeof(struct page *), GFP_NOFS);
319 if (!io_ctl->pages)
320 return -ENOMEM;
321
322 io_ctl->num_pages = num_pages;
323 io_ctl->fs_info = btrfs_sb(inode->i_sb);
324 io_ctl->check_crcs = check_crcs;
325 io_ctl->inode = inode;
326
327 return 0;
328 }
329 ALLOW_ERROR_INJECTION(io_ctl_init, ERRNO);
330
io_ctl_free(struct btrfs_io_ctl * io_ctl)331 static void io_ctl_free(struct btrfs_io_ctl *io_ctl)
332 {
333 kfree(io_ctl->pages);
334 io_ctl->pages = NULL;
335 }
336
io_ctl_unmap_page(struct btrfs_io_ctl * io_ctl)337 static void io_ctl_unmap_page(struct btrfs_io_ctl *io_ctl)
338 {
339 if (io_ctl->cur) {
340 io_ctl->cur = NULL;
341 io_ctl->orig = NULL;
342 }
343 }
344
io_ctl_map_page(struct btrfs_io_ctl * io_ctl,int clear)345 static void io_ctl_map_page(struct btrfs_io_ctl *io_ctl, int clear)
346 {
347 ASSERT(io_ctl->index < io_ctl->num_pages);
348 io_ctl->page = io_ctl->pages[io_ctl->index++];
349 io_ctl->cur = page_address(io_ctl->page);
350 io_ctl->orig = io_ctl->cur;
351 io_ctl->size = PAGE_SIZE;
352 if (clear)
353 clear_page(io_ctl->cur);
354 }
355
io_ctl_drop_pages(struct btrfs_io_ctl * io_ctl)356 static void io_ctl_drop_pages(struct btrfs_io_ctl *io_ctl)
357 {
358 int i;
359
360 io_ctl_unmap_page(io_ctl);
361
362 for (i = 0; i < io_ctl->num_pages; i++) {
363 if (io_ctl->pages[i]) {
364 ClearPageChecked(io_ctl->pages[i]);
365 unlock_page(io_ctl->pages[i]);
366 put_page(io_ctl->pages[i]);
367 }
368 }
369 }
370
io_ctl_prepare_pages(struct btrfs_io_ctl * io_ctl,struct inode * inode,int uptodate)371 static int io_ctl_prepare_pages(struct btrfs_io_ctl *io_ctl, struct inode *inode,
372 int uptodate)
373 {
374 struct page *page;
375 gfp_t mask = btrfs_alloc_write_mask(inode->i_mapping);
376 int i;
377
378 for (i = 0; i < io_ctl->num_pages; i++) {
379 page = find_or_create_page(inode->i_mapping, i, mask);
380 if (!page) {
381 io_ctl_drop_pages(io_ctl);
382 return -ENOMEM;
383 }
384 io_ctl->pages[i] = page;
385 if (uptodate && !PageUptodate(page)) {
386 btrfs_readpage(NULL, page);
387 lock_page(page);
388 if (page->mapping != inode->i_mapping) {
389 btrfs_err(BTRFS_I(inode)->root->fs_info,
390 "free space cache page truncated");
391 io_ctl_drop_pages(io_ctl);
392 return -EIO;
393 }
394 if (!PageUptodate(page)) {
395 btrfs_err(BTRFS_I(inode)->root->fs_info,
396 "error reading free space cache");
397 io_ctl_drop_pages(io_ctl);
398 return -EIO;
399 }
400 }
401 }
402
403 for (i = 0; i < io_ctl->num_pages; i++) {
404 clear_page_dirty_for_io(io_ctl->pages[i]);
405 set_page_extent_mapped(io_ctl->pages[i]);
406 }
407
408 return 0;
409 }
410
io_ctl_set_generation(struct btrfs_io_ctl * io_ctl,u64 generation)411 static void io_ctl_set_generation(struct btrfs_io_ctl *io_ctl, u64 generation)
412 {
413 __le64 *val;
414
415 io_ctl_map_page(io_ctl, 1);
416
417 /*
418 * Skip the csum areas. If we don't check crcs then we just have a
419 * 64bit chunk at the front of the first page.
420 */
421 if (io_ctl->check_crcs) {
422 io_ctl->cur += (sizeof(u32) * io_ctl->num_pages);
423 io_ctl->size -= sizeof(u64) + (sizeof(u32) * io_ctl->num_pages);
424 } else {
425 io_ctl->cur += sizeof(u64);
426 io_ctl->size -= sizeof(u64) * 2;
427 }
428
429 val = io_ctl->cur;
430 *val = cpu_to_le64(generation);
431 io_ctl->cur += sizeof(u64);
432 }
433
io_ctl_check_generation(struct btrfs_io_ctl * io_ctl,u64 generation)434 static int io_ctl_check_generation(struct btrfs_io_ctl *io_ctl, u64 generation)
435 {
436 __le64 *gen;
437
438 /*
439 * Skip the crc area. If we don't check crcs then we just have a 64bit
440 * chunk at the front of the first page.
441 */
442 if (io_ctl->check_crcs) {
443 io_ctl->cur += sizeof(u32) * io_ctl->num_pages;
444 io_ctl->size -= sizeof(u64) +
445 (sizeof(u32) * io_ctl->num_pages);
446 } else {
447 io_ctl->cur += sizeof(u64);
448 io_ctl->size -= sizeof(u64) * 2;
449 }
450
451 gen = io_ctl->cur;
452 if (le64_to_cpu(*gen) != generation) {
453 btrfs_err_rl(io_ctl->fs_info,
454 "space cache generation (%llu) does not match inode (%llu)",
455 *gen, generation);
456 io_ctl_unmap_page(io_ctl);
457 return -EIO;
458 }
459 io_ctl->cur += sizeof(u64);
460 return 0;
461 }
462
io_ctl_set_crc(struct btrfs_io_ctl * io_ctl,int index)463 static void io_ctl_set_crc(struct btrfs_io_ctl *io_ctl, int index)
464 {
465 u32 *tmp;
466 u32 crc = ~(u32)0;
467 unsigned offset = 0;
468
469 if (!io_ctl->check_crcs) {
470 io_ctl_unmap_page(io_ctl);
471 return;
472 }
473
474 if (index == 0)
475 offset = sizeof(u32) * io_ctl->num_pages;
476
477 crc = btrfs_crc32c(crc, io_ctl->orig + offset, PAGE_SIZE - offset);
478 btrfs_crc32c_final(crc, (u8 *)&crc);
479 io_ctl_unmap_page(io_ctl);
480 tmp = page_address(io_ctl->pages[0]);
481 tmp += index;
482 *tmp = crc;
483 }
484
io_ctl_check_crc(struct btrfs_io_ctl * io_ctl,int index)485 static int io_ctl_check_crc(struct btrfs_io_ctl *io_ctl, int index)
486 {
487 u32 *tmp, val;
488 u32 crc = ~(u32)0;
489 unsigned offset = 0;
490
491 if (!io_ctl->check_crcs) {
492 io_ctl_map_page(io_ctl, 0);
493 return 0;
494 }
495
496 if (index == 0)
497 offset = sizeof(u32) * io_ctl->num_pages;
498
499 tmp = page_address(io_ctl->pages[0]);
500 tmp += index;
501 val = *tmp;
502
503 io_ctl_map_page(io_ctl, 0);
504 crc = btrfs_crc32c(crc, io_ctl->orig + offset, PAGE_SIZE - offset);
505 btrfs_crc32c_final(crc, (u8 *)&crc);
506 if (val != crc) {
507 btrfs_err_rl(io_ctl->fs_info,
508 "csum mismatch on free space cache");
509 io_ctl_unmap_page(io_ctl);
510 return -EIO;
511 }
512
513 return 0;
514 }
515
io_ctl_add_entry(struct btrfs_io_ctl * io_ctl,u64 offset,u64 bytes,void * bitmap)516 static int io_ctl_add_entry(struct btrfs_io_ctl *io_ctl, u64 offset, u64 bytes,
517 void *bitmap)
518 {
519 struct btrfs_free_space_entry *entry;
520
521 if (!io_ctl->cur)
522 return -ENOSPC;
523
524 entry = io_ctl->cur;
525 entry->offset = cpu_to_le64(offset);
526 entry->bytes = cpu_to_le64(bytes);
527 entry->type = (bitmap) ? BTRFS_FREE_SPACE_BITMAP :
528 BTRFS_FREE_SPACE_EXTENT;
529 io_ctl->cur += sizeof(struct btrfs_free_space_entry);
530 io_ctl->size -= sizeof(struct btrfs_free_space_entry);
531
532 if (io_ctl->size >= sizeof(struct btrfs_free_space_entry))
533 return 0;
534
535 io_ctl_set_crc(io_ctl, io_ctl->index - 1);
536
537 /* No more pages to map */
538 if (io_ctl->index >= io_ctl->num_pages)
539 return 0;
540
541 /* map the next page */
542 io_ctl_map_page(io_ctl, 1);
543 return 0;
544 }
545
io_ctl_add_bitmap(struct btrfs_io_ctl * io_ctl,void * bitmap)546 static int io_ctl_add_bitmap(struct btrfs_io_ctl *io_ctl, void *bitmap)
547 {
548 if (!io_ctl->cur)
549 return -ENOSPC;
550
551 /*
552 * If we aren't at the start of the current page, unmap this one and
553 * map the next one if there is any left.
554 */
555 if (io_ctl->cur != io_ctl->orig) {
556 io_ctl_set_crc(io_ctl, io_ctl->index - 1);
557 if (io_ctl->index >= io_ctl->num_pages)
558 return -ENOSPC;
559 io_ctl_map_page(io_ctl, 0);
560 }
561
562 copy_page(io_ctl->cur, bitmap);
563 io_ctl_set_crc(io_ctl, io_ctl->index - 1);
564 if (io_ctl->index < io_ctl->num_pages)
565 io_ctl_map_page(io_ctl, 0);
566 return 0;
567 }
568
io_ctl_zero_remaining_pages(struct btrfs_io_ctl * io_ctl)569 static void io_ctl_zero_remaining_pages(struct btrfs_io_ctl *io_ctl)
570 {
571 /*
572 * If we're not on the boundary we know we've modified the page and we
573 * need to crc the page.
574 */
575 if (io_ctl->cur != io_ctl->orig)
576 io_ctl_set_crc(io_ctl, io_ctl->index - 1);
577 else
578 io_ctl_unmap_page(io_ctl);
579
580 while (io_ctl->index < io_ctl->num_pages) {
581 io_ctl_map_page(io_ctl, 1);
582 io_ctl_set_crc(io_ctl, io_ctl->index - 1);
583 }
584 }
585
io_ctl_read_entry(struct btrfs_io_ctl * io_ctl,struct btrfs_free_space * entry,u8 * type)586 static int io_ctl_read_entry(struct btrfs_io_ctl *io_ctl,
587 struct btrfs_free_space *entry, u8 *type)
588 {
589 struct btrfs_free_space_entry *e;
590 int ret;
591
592 if (!io_ctl->cur) {
593 ret = io_ctl_check_crc(io_ctl, io_ctl->index);
594 if (ret)
595 return ret;
596 }
597
598 e = io_ctl->cur;
599 entry->offset = le64_to_cpu(e->offset);
600 entry->bytes = le64_to_cpu(e->bytes);
601 *type = e->type;
602 io_ctl->cur += sizeof(struct btrfs_free_space_entry);
603 io_ctl->size -= sizeof(struct btrfs_free_space_entry);
604
605 if (io_ctl->size >= sizeof(struct btrfs_free_space_entry))
606 return 0;
607
608 io_ctl_unmap_page(io_ctl);
609
610 return 0;
611 }
612
io_ctl_read_bitmap(struct btrfs_io_ctl * io_ctl,struct btrfs_free_space * entry)613 static int io_ctl_read_bitmap(struct btrfs_io_ctl *io_ctl,
614 struct btrfs_free_space *entry)
615 {
616 int ret;
617
618 ret = io_ctl_check_crc(io_ctl, io_ctl->index);
619 if (ret)
620 return ret;
621
622 copy_page(entry->bitmap, io_ctl->cur);
623 io_ctl_unmap_page(io_ctl);
624
625 return 0;
626 }
627
628 /*
629 * Since we attach pinned extents after the fact we can have contiguous sections
630 * of free space that are split up in entries. This poses a problem with the
631 * tree logging stuff since it could have allocated across what appears to be 2
632 * entries since we would have merged the entries when adding the pinned extents
633 * back to the free space cache. So run through the space cache that we just
634 * loaded and merge contiguous entries. This will make the log replay stuff not
635 * blow up and it will make for nicer allocator behavior.
636 */
merge_space_tree(struct btrfs_free_space_ctl * ctl)637 static void merge_space_tree(struct btrfs_free_space_ctl *ctl)
638 {
639 struct btrfs_free_space *e, *prev = NULL;
640 struct rb_node *n;
641
642 again:
643 spin_lock(&ctl->tree_lock);
644 for (n = rb_first(&ctl->free_space_offset); n; n = rb_next(n)) {
645 e = rb_entry(n, struct btrfs_free_space, offset_index);
646 if (!prev)
647 goto next;
648 if (e->bitmap || prev->bitmap)
649 goto next;
650 if (prev->offset + prev->bytes == e->offset) {
651 unlink_free_space(ctl, prev);
652 unlink_free_space(ctl, e);
653 prev->bytes += e->bytes;
654 kmem_cache_free(btrfs_free_space_cachep, e);
655 link_free_space(ctl, prev);
656 prev = NULL;
657 spin_unlock(&ctl->tree_lock);
658 goto again;
659 }
660 next:
661 prev = e;
662 }
663 spin_unlock(&ctl->tree_lock);
664 }
665
__load_free_space_cache(struct btrfs_root * root,struct inode * inode,struct btrfs_free_space_ctl * ctl,struct btrfs_path * path,u64 offset)666 static int __load_free_space_cache(struct btrfs_root *root, struct inode *inode,
667 struct btrfs_free_space_ctl *ctl,
668 struct btrfs_path *path, u64 offset)
669 {
670 struct btrfs_fs_info *fs_info = root->fs_info;
671 struct btrfs_free_space_header *header;
672 struct extent_buffer *leaf;
673 struct btrfs_io_ctl io_ctl;
674 struct btrfs_key key;
675 struct btrfs_free_space *e, *n;
676 LIST_HEAD(bitmaps);
677 u64 num_entries;
678 u64 num_bitmaps;
679 u64 generation;
680 u8 type;
681 int ret = 0;
682
683 /* Nothing in the space cache, goodbye */
684 if (!i_size_read(inode))
685 return 0;
686
687 key.objectid = BTRFS_FREE_SPACE_OBJECTID;
688 key.offset = offset;
689 key.type = 0;
690
691 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
692 if (ret < 0)
693 return 0;
694 else if (ret > 0) {
695 btrfs_release_path(path);
696 return 0;
697 }
698
699 ret = -1;
700
701 leaf = path->nodes[0];
702 header = btrfs_item_ptr(leaf, path->slots[0],
703 struct btrfs_free_space_header);
704 num_entries = btrfs_free_space_entries(leaf, header);
705 num_bitmaps = btrfs_free_space_bitmaps(leaf, header);
706 generation = btrfs_free_space_generation(leaf, header);
707 btrfs_release_path(path);
708
709 if (!BTRFS_I(inode)->generation) {
710 btrfs_info(fs_info,
711 "the free space cache file (%llu) is invalid, skip it",
712 offset);
713 return 0;
714 }
715
716 if (BTRFS_I(inode)->generation != generation) {
717 btrfs_err(fs_info,
718 "free space inode generation (%llu) did not match free space cache generation (%llu)",
719 BTRFS_I(inode)->generation, generation);
720 return 0;
721 }
722
723 if (!num_entries)
724 return 0;
725
726 ret = io_ctl_init(&io_ctl, inode, 0);
727 if (ret)
728 return ret;
729
730 readahead_cache(inode);
731
732 ret = io_ctl_prepare_pages(&io_ctl, inode, 1);
733 if (ret)
734 goto out;
735
736 ret = io_ctl_check_crc(&io_ctl, 0);
737 if (ret)
738 goto free_cache;
739
740 ret = io_ctl_check_generation(&io_ctl, generation);
741 if (ret)
742 goto free_cache;
743
744 while (num_entries) {
745 e = kmem_cache_zalloc(btrfs_free_space_cachep,
746 GFP_NOFS);
747 if (!e) {
748 ret = -ENOMEM;
749 goto free_cache;
750 }
751
752 ret = io_ctl_read_entry(&io_ctl, e, &type);
753 if (ret) {
754 kmem_cache_free(btrfs_free_space_cachep, e);
755 goto free_cache;
756 }
757
758 if (!e->bytes) {
759 ret = -1;
760 kmem_cache_free(btrfs_free_space_cachep, e);
761 goto free_cache;
762 }
763
764 if (type == BTRFS_FREE_SPACE_EXTENT) {
765 spin_lock(&ctl->tree_lock);
766 ret = link_free_space(ctl, e);
767 spin_unlock(&ctl->tree_lock);
768 if (ret) {
769 btrfs_err(fs_info,
770 "Duplicate entries in free space cache, dumping");
771 kmem_cache_free(btrfs_free_space_cachep, e);
772 goto free_cache;
773 }
774 } else {
775 ASSERT(num_bitmaps);
776 num_bitmaps--;
777 e->bitmap = kmem_cache_zalloc(
778 btrfs_free_space_bitmap_cachep, GFP_NOFS);
779 if (!e->bitmap) {
780 ret = -ENOMEM;
781 kmem_cache_free(
782 btrfs_free_space_cachep, e);
783 goto free_cache;
784 }
785 spin_lock(&ctl->tree_lock);
786 ret = link_free_space(ctl, e);
787 if (ret) {
788 spin_unlock(&ctl->tree_lock);
789 btrfs_err(fs_info,
790 "Duplicate entries in free space cache, dumping");
791 kmem_cache_free(btrfs_free_space_cachep, e);
792 goto free_cache;
793 }
794 ctl->total_bitmaps++;
795 ctl->op->recalc_thresholds(ctl);
796 spin_unlock(&ctl->tree_lock);
797 list_add_tail(&e->list, &bitmaps);
798 }
799
800 num_entries--;
801 }
802
803 io_ctl_unmap_page(&io_ctl);
804
805 /*
806 * We add the bitmaps at the end of the entries in order that
807 * the bitmap entries are added to the cache.
808 */
809 list_for_each_entry_safe(e, n, &bitmaps, list) {
810 list_del_init(&e->list);
811 ret = io_ctl_read_bitmap(&io_ctl, e);
812 if (ret)
813 goto free_cache;
814 }
815
816 io_ctl_drop_pages(&io_ctl);
817 merge_space_tree(ctl);
818 ret = 1;
819 out:
820 io_ctl_free(&io_ctl);
821 return ret;
822 free_cache:
823 io_ctl_drop_pages(&io_ctl);
824 __btrfs_remove_free_space_cache(ctl);
825 goto out;
826 }
827
load_free_space_cache(struct btrfs_block_group_cache * block_group)828 int load_free_space_cache(struct btrfs_block_group_cache *block_group)
829 {
830 struct btrfs_fs_info *fs_info = block_group->fs_info;
831 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
832 struct inode *inode;
833 struct btrfs_path *path;
834 int ret = 0;
835 bool matched;
836 u64 used = btrfs_block_group_used(&block_group->item);
837
838 /*
839 * If this block group has been marked to be cleared for one reason or
840 * another then we can't trust the on disk cache, so just return.
841 */
842 spin_lock(&block_group->lock);
843 if (block_group->disk_cache_state != BTRFS_DC_WRITTEN) {
844 spin_unlock(&block_group->lock);
845 return 0;
846 }
847 spin_unlock(&block_group->lock);
848
849 path = btrfs_alloc_path();
850 if (!path)
851 return 0;
852 path->search_commit_root = 1;
853 path->skip_locking = 1;
854
855 /*
856 * We must pass a path with search_commit_root set to btrfs_iget in
857 * order to avoid a deadlock when allocating extents for the tree root.
858 *
859 * When we are COWing an extent buffer from the tree root, when looking
860 * for a free extent, at extent-tree.c:find_free_extent(), we can find
861 * block group without its free space cache loaded. When we find one
862 * we must load its space cache which requires reading its free space
863 * cache's inode item from the root tree. If this inode item is located
864 * in the same leaf that we started COWing before, then we end up in
865 * deadlock on the extent buffer (trying to read lock it when we
866 * previously write locked it).
867 *
868 * It's safe to read the inode item using the commit root because
869 * block groups, once loaded, stay in memory forever (until they are
870 * removed) as well as their space caches once loaded. New block groups
871 * once created get their ->cached field set to BTRFS_CACHE_FINISHED so
872 * we will never try to read their inode item while the fs is mounted.
873 */
874 inode = lookup_free_space_inode(block_group, path);
875 if (IS_ERR(inode)) {
876 btrfs_free_path(path);
877 return 0;
878 }
879
880 /* We may have converted the inode and made the cache invalid. */
881 spin_lock(&block_group->lock);
882 if (block_group->disk_cache_state != BTRFS_DC_WRITTEN) {
883 spin_unlock(&block_group->lock);
884 btrfs_free_path(path);
885 goto out;
886 }
887 spin_unlock(&block_group->lock);
888
889 ret = __load_free_space_cache(fs_info->tree_root, inode, ctl,
890 path, block_group->key.objectid);
891 btrfs_free_path(path);
892 if (ret <= 0)
893 goto out;
894
895 spin_lock(&ctl->tree_lock);
896 matched = (ctl->free_space == (block_group->key.offset - used -
897 block_group->bytes_super));
898 spin_unlock(&ctl->tree_lock);
899
900 if (!matched) {
901 __btrfs_remove_free_space_cache(ctl);
902 btrfs_warn(fs_info,
903 "block group %llu has wrong amount of free space",
904 block_group->key.objectid);
905 ret = -1;
906 }
907 out:
908 if (ret < 0) {
909 /* This cache is bogus, make sure it gets cleared */
910 spin_lock(&block_group->lock);
911 block_group->disk_cache_state = BTRFS_DC_CLEAR;
912 spin_unlock(&block_group->lock);
913 ret = 0;
914
915 btrfs_warn(fs_info,
916 "failed to load free space cache for block group %llu, rebuilding it now",
917 block_group->key.objectid);
918 }
919
920 iput(inode);
921 return ret;
922 }
923
924 static noinline_for_stack
write_cache_extent_entries(struct btrfs_io_ctl * io_ctl,struct btrfs_free_space_ctl * ctl,struct btrfs_block_group_cache * block_group,int * entries,int * bitmaps,struct list_head * bitmap_list)925 int write_cache_extent_entries(struct btrfs_io_ctl *io_ctl,
926 struct btrfs_free_space_ctl *ctl,
927 struct btrfs_block_group_cache *block_group,
928 int *entries, int *bitmaps,
929 struct list_head *bitmap_list)
930 {
931 int ret;
932 struct btrfs_free_cluster *cluster = NULL;
933 struct btrfs_free_cluster *cluster_locked = NULL;
934 struct rb_node *node = rb_first(&ctl->free_space_offset);
935 struct btrfs_trim_range *trim_entry;
936
937 /* Get the cluster for this block_group if it exists */
938 if (block_group && !list_empty(&block_group->cluster_list)) {
939 cluster = list_entry(block_group->cluster_list.next,
940 struct btrfs_free_cluster,
941 block_group_list);
942 }
943
944 if (!node && cluster) {
945 cluster_locked = cluster;
946 spin_lock(&cluster_locked->lock);
947 node = rb_first(&cluster->root);
948 cluster = NULL;
949 }
950
951 /* Write out the extent entries */
952 while (node) {
953 struct btrfs_free_space *e;
954
955 e = rb_entry(node, struct btrfs_free_space, offset_index);
956 *entries += 1;
957
958 ret = io_ctl_add_entry(io_ctl, e->offset, e->bytes,
959 e->bitmap);
960 if (ret)
961 goto fail;
962
963 if (e->bitmap) {
964 list_add_tail(&e->list, bitmap_list);
965 *bitmaps += 1;
966 }
967 node = rb_next(node);
968 if (!node && cluster) {
969 node = rb_first(&cluster->root);
970 cluster_locked = cluster;
971 spin_lock(&cluster_locked->lock);
972 cluster = NULL;
973 }
974 }
975 if (cluster_locked) {
976 spin_unlock(&cluster_locked->lock);
977 cluster_locked = NULL;
978 }
979
980 /*
981 * Make sure we don't miss any range that was removed from our rbtree
982 * because trimming is running. Otherwise after a umount+mount (or crash
983 * after committing the transaction) we would leak free space and get
984 * an inconsistent free space cache report from fsck.
985 */
986 list_for_each_entry(trim_entry, &ctl->trimming_ranges, list) {
987 ret = io_ctl_add_entry(io_ctl, trim_entry->start,
988 trim_entry->bytes, NULL);
989 if (ret)
990 goto fail;
991 *entries += 1;
992 }
993
994 return 0;
995 fail:
996 if (cluster_locked)
997 spin_unlock(&cluster_locked->lock);
998 return -ENOSPC;
999 }
1000
1001 static noinline_for_stack int
update_cache_item(struct btrfs_trans_handle * trans,struct btrfs_root * root,struct inode * inode,struct btrfs_path * path,u64 offset,int entries,int bitmaps)1002 update_cache_item(struct btrfs_trans_handle *trans,
1003 struct btrfs_root *root,
1004 struct inode *inode,
1005 struct btrfs_path *path, u64 offset,
1006 int entries, int bitmaps)
1007 {
1008 struct btrfs_key key;
1009 struct btrfs_free_space_header *header;
1010 struct extent_buffer *leaf;
1011 int ret;
1012
1013 key.objectid = BTRFS_FREE_SPACE_OBJECTID;
1014 key.offset = offset;
1015 key.type = 0;
1016
1017 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
1018 if (ret < 0) {
1019 clear_extent_bit(&BTRFS_I(inode)->io_tree, 0, inode->i_size - 1,
1020 EXTENT_DELALLOC, 0, 0, NULL);
1021 goto fail;
1022 }
1023 leaf = path->nodes[0];
1024 if (ret > 0) {
1025 struct btrfs_key found_key;
1026 ASSERT(path->slots[0]);
1027 path->slots[0]--;
1028 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
1029 if (found_key.objectid != BTRFS_FREE_SPACE_OBJECTID ||
1030 found_key.offset != offset) {
1031 clear_extent_bit(&BTRFS_I(inode)->io_tree, 0,
1032 inode->i_size - 1, EXTENT_DELALLOC, 0,
1033 0, NULL);
1034 btrfs_release_path(path);
1035 goto fail;
1036 }
1037 }
1038
1039 BTRFS_I(inode)->generation = trans->transid;
1040 header = btrfs_item_ptr(leaf, path->slots[0],
1041 struct btrfs_free_space_header);
1042 btrfs_set_free_space_entries(leaf, header, entries);
1043 btrfs_set_free_space_bitmaps(leaf, header, bitmaps);
1044 btrfs_set_free_space_generation(leaf, header, trans->transid);
1045 btrfs_mark_buffer_dirty(leaf);
1046 btrfs_release_path(path);
1047
1048 return 0;
1049
1050 fail:
1051 return -1;
1052 }
1053
write_pinned_extent_entries(struct btrfs_block_group_cache * block_group,struct btrfs_io_ctl * io_ctl,int * entries)1054 static noinline_for_stack int write_pinned_extent_entries(
1055 struct btrfs_block_group_cache *block_group,
1056 struct btrfs_io_ctl *io_ctl,
1057 int *entries)
1058 {
1059 u64 start, extent_start, extent_end, len;
1060 struct extent_io_tree *unpin = NULL;
1061 int ret;
1062
1063 if (!block_group)
1064 return 0;
1065
1066 /*
1067 * We want to add any pinned extents to our free space cache
1068 * so we don't leak the space
1069 *
1070 * We shouldn't have switched the pinned extents yet so this is the
1071 * right one
1072 */
1073 unpin = block_group->fs_info->pinned_extents;
1074
1075 start = block_group->key.objectid;
1076
1077 while (start < block_group->key.objectid + block_group->key.offset) {
1078 ret = find_first_extent_bit(unpin, start,
1079 &extent_start, &extent_end,
1080 EXTENT_DIRTY, NULL);
1081 if (ret)
1082 return 0;
1083
1084 /* This pinned extent is out of our range */
1085 if (extent_start >= block_group->key.objectid +
1086 block_group->key.offset)
1087 return 0;
1088
1089 extent_start = max(extent_start, start);
1090 extent_end = min(block_group->key.objectid +
1091 block_group->key.offset, extent_end + 1);
1092 len = extent_end - extent_start;
1093
1094 *entries += 1;
1095 ret = io_ctl_add_entry(io_ctl, extent_start, len, NULL);
1096 if (ret)
1097 return -ENOSPC;
1098
1099 start = extent_end;
1100 }
1101
1102 return 0;
1103 }
1104
1105 static noinline_for_stack int
write_bitmap_entries(struct btrfs_io_ctl * io_ctl,struct list_head * bitmap_list)1106 write_bitmap_entries(struct btrfs_io_ctl *io_ctl, struct list_head *bitmap_list)
1107 {
1108 struct btrfs_free_space *entry, *next;
1109 int ret;
1110
1111 /* Write out the bitmaps */
1112 list_for_each_entry_safe(entry, next, bitmap_list, list) {
1113 ret = io_ctl_add_bitmap(io_ctl, entry->bitmap);
1114 if (ret)
1115 return -ENOSPC;
1116 list_del_init(&entry->list);
1117 }
1118
1119 return 0;
1120 }
1121
flush_dirty_cache(struct inode * inode)1122 static int flush_dirty_cache(struct inode *inode)
1123 {
1124 int ret;
1125
1126 ret = btrfs_wait_ordered_range(inode, 0, (u64)-1);
1127 if (ret)
1128 clear_extent_bit(&BTRFS_I(inode)->io_tree, 0, inode->i_size - 1,
1129 EXTENT_DELALLOC, 0, 0, NULL);
1130
1131 return ret;
1132 }
1133
1134 static void noinline_for_stack
cleanup_bitmap_list(struct list_head * bitmap_list)1135 cleanup_bitmap_list(struct list_head *bitmap_list)
1136 {
1137 struct btrfs_free_space *entry, *next;
1138
1139 list_for_each_entry_safe(entry, next, bitmap_list, list)
1140 list_del_init(&entry->list);
1141 }
1142
1143 static void noinline_for_stack
cleanup_write_cache_enospc(struct inode * inode,struct btrfs_io_ctl * io_ctl,struct extent_state ** cached_state)1144 cleanup_write_cache_enospc(struct inode *inode,
1145 struct btrfs_io_ctl *io_ctl,
1146 struct extent_state **cached_state)
1147 {
1148 io_ctl_drop_pages(io_ctl);
1149 unlock_extent_cached(&BTRFS_I(inode)->io_tree, 0,
1150 i_size_read(inode) - 1, cached_state);
1151 }
1152
__btrfs_wait_cache_io(struct btrfs_root * root,struct btrfs_trans_handle * trans,struct btrfs_block_group_cache * block_group,struct btrfs_io_ctl * io_ctl,struct btrfs_path * path,u64 offset)1153 static int __btrfs_wait_cache_io(struct btrfs_root *root,
1154 struct btrfs_trans_handle *trans,
1155 struct btrfs_block_group_cache *block_group,
1156 struct btrfs_io_ctl *io_ctl,
1157 struct btrfs_path *path, u64 offset)
1158 {
1159 int ret;
1160 struct inode *inode = io_ctl->inode;
1161
1162 if (!inode)
1163 return 0;
1164
1165 /* Flush the dirty pages in the cache file. */
1166 ret = flush_dirty_cache(inode);
1167 if (ret)
1168 goto out;
1169
1170 /* Update the cache item to tell everyone this cache file is valid. */
1171 ret = update_cache_item(trans, root, inode, path, offset,
1172 io_ctl->entries, io_ctl->bitmaps);
1173 out:
1174 if (ret) {
1175 invalidate_inode_pages2(inode->i_mapping);
1176 BTRFS_I(inode)->generation = 0;
1177 if (block_group) {
1178 #ifdef DEBUG
1179 btrfs_err(root->fs_info,
1180 "failed to write free space cache for block group %llu",
1181 block_group->key.objectid);
1182 #endif
1183 }
1184 }
1185 btrfs_update_inode(trans, root, inode);
1186
1187 if (block_group) {
1188 /* the dirty list is protected by the dirty_bgs_lock */
1189 spin_lock(&trans->transaction->dirty_bgs_lock);
1190
1191 /* the disk_cache_state is protected by the block group lock */
1192 spin_lock(&block_group->lock);
1193
1194 /*
1195 * only mark this as written if we didn't get put back on
1196 * the dirty list while waiting for IO. Otherwise our
1197 * cache state won't be right, and we won't get written again
1198 */
1199 if (!ret && list_empty(&block_group->dirty_list))
1200 block_group->disk_cache_state = BTRFS_DC_WRITTEN;
1201 else if (ret)
1202 block_group->disk_cache_state = BTRFS_DC_ERROR;
1203
1204 spin_unlock(&block_group->lock);
1205 spin_unlock(&trans->transaction->dirty_bgs_lock);
1206 io_ctl->inode = NULL;
1207 iput(inode);
1208 }
1209
1210 return ret;
1211
1212 }
1213
btrfs_wait_cache_io_root(struct btrfs_root * root,struct btrfs_trans_handle * trans,struct btrfs_io_ctl * io_ctl,struct btrfs_path * path)1214 static int btrfs_wait_cache_io_root(struct btrfs_root *root,
1215 struct btrfs_trans_handle *trans,
1216 struct btrfs_io_ctl *io_ctl,
1217 struct btrfs_path *path)
1218 {
1219 return __btrfs_wait_cache_io(root, trans, NULL, io_ctl, path, 0);
1220 }
1221
btrfs_wait_cache_io(struct btrfs_trans_handle * trans,struct btrfs_block_group_cache * block_group,struct btrfs_path * path)1222 int btrfs_wait_cache_io(struct btrfs_trans_handle *trans,
1223 struct btrfs_block_group_cache *block_group,
1224 struct btrfs_path *path)
1225 {
1226 return __btrfs_wait_cache_io(block_group->fs_info->tree_root, trans,
1227 block_group, &block_group->io_ctl,
1228 path, block_group->key.objectid);
1229 }
1230
1231 /**
1232 * __btrfs_write_out_cache - write out cached info to an inode
1233 * @root - the root the inode belongs to
1234 * @ctl - the free space cache we are going to write out
1235 * @block_group - the block_group for this cache if it belongs to a block_group
1236 * @trans - the trans handle
1237 *
1238 * This function writes out a free space cache struct to disk for quick recovery
1239 * on mount. This will return 0 if it was successful in writing the cache out,
1240 * or an errno if it was not.
1241 */
__btrfs_write_out_cache(struct btrfs_root * root,struct inode * inode,struct btrfs_free_space_ctl * ctl,struct btrfs_block_group_cache * block_group,struct btrfs_io_ctl * io_ctl,struct btrfs_trans_handle * trans)1242 static int __btrfs_write_out_cache(struct btrfs_root *root, struct inode *inode,
1243 struct btrfs_free_space_ctl *ctl,
1244 struct btrfs_block_group_cache *block_group,
1245 struct btrfs_io_ctl *io_ctl,
1246 struct btrfs_trans_handle *trans)
1247 {
1248 struct extent_state *cached_state = NULL;
1249 LIST_HEAD(bitmap_list);
1250 int entries = 0;
1251 int bitmaps = 0;
1252 int ret;
1253 int must_iput = 0;
1254
1255 if (!i_size_read(inode))
1256 return -EIO;
1257
1258 WARN_ON(io_ctl->pages);
1259 ret = io_ctl_init(io_ctl, inode, 1);
1260 if (ret)
1261 return ret;
1262
1263 if (block_group && (block_group->flags & BTRFS_BLOCK_GROUP_DATA)) {
1264 down_write(&block_group->data_rwsem);
1265 spin_lock(&block_group->lock);
1266 if (block_group->delalloc_bytes) {
1267 block_group->disk_cache_state = BTRFS_DC_WRITTEN;
1268 spin_unlock(&block_group->lock);
1269 up_write(&block_group->data_rwsem);
1270 BTRFS_I(inode)->generation = 0;
1271 ret = 0;
1272 must_iput = 1;
1273 goto out;
1274 }
1275 spin_unlock(&block_group->lock);
1276 }
1277
1278 /* Lock all pages first so we can lock the extent safely. */
1279 ret = io_ctl_prepare_pages(io_ctl, inode, 0);
1280 if (ret)
1281 goto out_unlock;
1282
1283 lock_extent_bits(&BTRFS_I(inode)->io_tree, 0, i_size_read(inode) - 1,
1284 &cached_state);
1285
1286 io_ctl_set_generation(io_ctl, trans->transid);
1287
1288 mutex_lock(&ctl->cache_writeout_mutex);
1289 /* Write out the extent entries in the free space cache */
1290 spin_lock(&ctl->tree_lock);
1291 ret = write_cache_extent_entries(io_ctl, ctl,
1292 block_group, &entries, &bitmaps,
1293 &bitmap_list);
1294 if (ret)
1295 goto out_nospc_locked;
1296
1297 /*
1298 * Some spaces that are freed in the current transaction are pinned,
1299 * they will be added into free space cache after the transaction is
1300 * committed, we shouldn't lose them.
1301 *
1302 * If this changes while we are working we'll get added back to
1303 * the dirty list and redo it. No locking needed
1304 */
1305 ret = write_pinned_extent_entries(block_group, io_ctl, &entries);
1306 if (ret)
1307 goto out_nospc_locked;
1308
1309 /*
1310 * At last, we write out all the bitmaps and keep cache_writeout_mutex
1311 * locked while doing it because a concurrent trim can be manipulating
1312 * or freeing the bitmap.
1313 */
1314 ret = write_bitmap_entries(io_ctl, &bitmap_list);
1315 spin_unlock(&ctl->tree_lock);
1316 mutex_unlock(&ctl->cache_writeout_mutex);
1317 if (ret)
1318 goto out_nospc;
1319
1320 /* Zero out the rest of the pages just to make sure */
1321 io_ctl_zero_remaining_pages(io_ctl);
1322
1323 /* Everything is written out, now we dirty the pages in the file. */
1324 ret = btrfs_dirty_pages(inode, io_ctl->pages, io_ctl->num_pages, 0,
1325 i_size_read(inode), &cached_state);
1326 if (ret)
1327 goto out_nospc;
1328
1329 if (block_group && (block_group->flags & BTRFS_BLOCK_GROUP_DATA))
1330 up_write(&block_group->data_rwsem);
1331 /*
1332 * Release the pages and unlock the extent, we will flush
1333 * them out later
1334 */
1335 io_ctl_drop_pages(io_ctl);
1336 io_ctl_free(io_ctl);
1337
1338 unlock_extent_cached(&BTRFS_I(inode)->io_tree, 0,
1339 i_size_read(inode) - 1, &cached_state);
1340
1341 /*
1342 * at this point the pages are under IO and we're happy,
1343 * The caller is responsible for waiting on them and updating
1344 * the cache and the inode
1345 */
1346 io_ctl->entries = entries;
1347 io_ctl->bitmaps = bitmaps;
1348
1349 ret = btrfs_fdatawrite_range(inode, 0, (u64)-1);
1350 if (ret)
1351 goto out;
1352
1353 return 0;
1354
1355 out:
1356 io_ctl->inode = NULL;
1357 io_ctl_free(io_ctl);
1358 if (ret) {
1359 invalidate_inode_pages2(inode->i_mapping);
1360 BTRFS_I(inode)->generation = 0;
1361 }
1362 btrfs_update_inode(trans, root, inode);
1363 if (must_iput)
1364 iput(inode);
1365 return ret;
1366
1367 out_nospc_locked:
1368 cleanup_bitmap_list(&bitmap_list);
1369 spin_unlock(&ctl->tree_lock);
1370 mutex_unlock(&ctl->cache_writeout_mutex);
1371
1372 out_nospc:
1373 cleanup_write_cache_enospc(inode, io_ctl, &cached_state);
1374
1375 out_unlock:
1376 if (block_group && (block_group->flags & BTRFS_BLOCK_GROUP_DATA))
1377 up_write(&block_group->data_rwsem);
1378
1379 goto out;
1380 }
1381
btrfs_write_out_cache(struct btrfs_trans_handle * trans,struct btrfs_block_group_cache * block_group,struct btrfs_path * path)1382 int btrfs_write_out_cache(struct btrfs_trans_handle *trans,
1383 struct btrfs_block_group_cache *block_group,
1384 struct btrfs_path *path)
1385 {
1386 struct btrfs_fs_info *fs_info = trans->fs_info;
1387 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
1388 struct inode *inode;
1389 int ret = 0;
1390
1391 spin_lock(&block_group->lock);
1392 if (block_group->disk_cache_state < BTRFS_DC_SETUP) {
1393 spin_unlock(&block_group->lock);
1394 return 0;
1395 }
1396 spin_unlock(&block_group->lock);
1397
1398 inode = lookup_free_space_inode(block_group, path);
1399 if (IS_ERR(inode))
1400 return 0;
1401
1402 ret = __btrfs_write_out_cache(fs_info->tree_root, inode, ctl,
1403 block_group, &block_group->io_ctl, trans);
1404 if (ret) {
1405 #ifdef DEBUG
1406 btrfs_err(fs_info,
1407 "failed to write free space cache for block group %llu",
1408 block_group->key.objectid);
1409 #endif
1410 spin_lock(&block_group->lock);
1411 block_group->disk_cache_state = BTRFS_DC_ERROR;
1412 spin_unlock(&block_group->lock);
1413
1414 block_group->io_ctl.inode = NULL;
1415 iput(inode);
1416 }
1417
1418 /*
1419 * if ret == 0 the caller is expected to call btrfs_wait_cache_io
1420 * to wait for IO and put the inode
1421 */
1422
1423 return ret;
1424 }
1425
offset_to_bit(u64 bitmap_start,u32 unit,u64 offset)1426 static inline unsigned long offset_to_bit(u64 bitmap_start, u32 unit,
1427 u64 offset)
1428 {
1429 ASSERT(offset >= bitmap_start);
1430 offset -= bitmap_start;
1431 return (unsigned long)(div_u64(offset, unit));
1432 }
1433
bytes_to_bits(u64 bytes,u32 unit)1434 static inline unsigned long bytes_to_bits(u64 bytes, u32 unit)
1435 {
1436 return (unsigned long)(div_u64(bytes, unit));
1437 }
1438
offset_to_bitmap(struct btrfs_free_space_ctl * ctl,u64 offset)1439 static inline u64 offset_to_bitmap(struct btrfs_free_space_ctl *ctl,
1440 u64 offset)
1441 {
1442 u64 bitmap_start;
1443 u64 bytes_per_bitmap;
1444
1445 bytes_per_bitmap = BITS_PER_BITMAP * ctl->unit;
1446 bitmap_start = offset - ctl->start;
1447 bitmap_start = div64_u64(bitmap_start, bytes_per_bitmap);
1448 bitmap_start *= bytes_per_bitmap;
1449 bitmap_start += ctl->start;
1450
1451 return bitmap_start;
1452 }
1453
tree_insert_offset(struct rb_root * root,u64 offset,struct rb_node * node,int bitmap)1454 static int tree_insert_offset(struct rb_root *root, u64 offset,
1455 struct rb_node *node, int bitmap)
1456 {
1457 struct rb_node **p = &root->rb_node;
1458 struct rb_node *parent = NULL;
1459 struct btrfs_free_space *info;
1460
1461 while (*p) {
1462 parent = *p;
1463 info = rb_entry(parent, struct btrfs_free_space, offset_index);
1464
1465 if (offset < info->offset) {
1466 p = &(*p)->rb_left;
1467 } else if (offset > info->offset) {
1468 p = &(*p)->rb_right;
1469 } else {
1470 /*
1471 * we could have a bitmap entry and an extent entry
1472 * share the same offset. If this is the case, we want
1473 * the extent entry to always be found first if we do a
1474 * linear search through the tree, since we want to have
1475 * the quickest allocation time, and allocating from an
1476 * extent is faster than allocating from a bitmap. So
1477 * if we're inserting a bitmap and we find an entry at
1478 * this offset, we want to go right, or after this entry
1479 * logically. If we are inserting an extent and we've
1480 * found a bitmap, we want to go left, or before
1481 * logically.
1482 */
1483 if (bitmap) {
1484 if (info->bitmap) {
1485 WARN_ON_ONCE(1);
1486 return -EEXIST;
1487 }
1488 p = &(*p)->rb_right;
1489 } else {
1490 if (!info->bitmap) {
1491 WARN_ON_ONCE(1);
1492 return -EEXIST;
1493 }
1494 p = &(*p)->rb_left;
1495 }
1496 }
1497 }
1498
1499 rb_link_node(node, parent, p);
1500 rb_insert_color(node, root);
1501
1502 return 0;
1503 }
1504
1505 /*
1506 * searches the tree for the given offset.
1507 *
1508 * fuzzy - If this is set, then we are trying to make an allocation, and we just
1509 * want a section that has at least bytes size and comes at or after the given
1510 * offset.
1511 */
1512 static struct btrfs_free_space *
tree_search_offset(struct btrfs_free_space_ctl * ctl,u64 offset,int bitmap_only,int fuzzy)1513 tree_search_offset(struct btrfs_free_space_ctl *ctl,
1514 u64 offset, int bitmap_only, int fuzzy)
1515 {
1516 struct rb_node *n = ctl->free_space_offset.rb_node;
1517 struct btrfs_free_space *entry, *prev = NULL;
1518
1519 /* find entry that is closest to the 'offset' */
1520 while (1) {
1521 if (!n) {
1522 entry = NULL;
1523 break;
1524 }
1525
1526 entry = rb_entry(n, struct btrfs_free_space, offset_index);
1527 prev = entry;
1528
1529 if (offset < entry->offset)
1530 n = n->rb_left;
1531 else if (offset > entry->offset)
1532 n = n->rb_right;
1533 else
1534 break;
1535 }
1536
1537 if (bitmap_only) {
1538 if (!entry)
1539 return NULL;
1540 if (entry->bitmap)
1541 return entry;
1542
1543 /*
1544 * bitmap entry and extent entry may share same offset,
1545 * in that case, bitmap entry comes after extent entry.
1546 */
1547 n = rb_next(n);
1548 if (!n)
1549 return NULL;
1550 entry = rb_entry(n, struct btrfs_free_space, offset_index);
1551 if (entry->offset != offset)
1552 return NULL;
1553
1554 WARN_ON(!entry->bitmap);
1555 return entry;
1556 } else if (entry) {
1557 if (entry->bitmap) {
1558 /*
1559 * if previous extent entry covers the offset,
1560 * we should return it instead of the bitmap entry
1561 */
1562 n = rb_prev(&entry->offset_index);
1563 if (n) {
1564 prev = rb_entry(n, struct btrfs_free_space,
1565 offset_index);
1566 if (!prev->bitmap &&
1567 prev->offset + prev->bytes > offset)
1568 entry = prev;
1569 }
1570 }
1571 return entry;
1572 }
1573
1574 if (!prev)
1575 return NULL;
1576
1577 /* find last entry before the 'offset' */
1578 entry = prev;
1579 if (entry->offset > offset) {
1580 n = rb_prev(&entry->offset_index);
1581 if (n) {
1582 entry = rb_entry(n, struct btrfs_free_space,
1583 offset_index);
1584 ASSERT(entry->offset <= offset);
1585 } else {
1586 if (fuzzy)
1587 return entry;
1588 else
1589 return NULL;
1590 }
1591 }
1592
1593 if (entry->bitmap) {
1594 n = rb_prev(&entry->offset_index);
1595 if (n) {
1596 prev = rb_entry(n, struct btrfs_free_space,
1597 offset_index);
1598 if (!prev->bitmap &&
1599 prev->offset + prev->bytes > offset)
1600 return prev;
1601 }
1602 if (entry->offset + BITS_PER_BITMAP * ctl->unit > offset)
1603 return entry;
1604 } else if (entry->offset + entry->bytes > offset)
1605 return entry;
1606
1607 if (!fuzzy)
1608 return NULL;
1609
1610 while (1) {
1611 if (entry->bitmap) {
1612 if (entry->offset + BITS_PER_BITMAP *
1613 ctl->unit > offset)
1614 break;
1615 } else {
1616 if (entry->offset + entry->bytes > offset)
1617 break;
1618 }
1619
1620 n = rb_next(&entry->offset_index);
1621 if (!n)
1622 return NULL;
1623 entry = rb_entry(n, struct btrfs_free_space, offset_index);
1624 }
1625 return entry;
1626 }
1627
1628 static inline void
__unlink_free_space(struct btrfs_free_space_ctl * ctl,struct btrfs_free_space * info)1629 __unlink_free_space(struct btrfs_free_space_ctl *ctl,
1630 struct btrfs_free_space *info)
1631 {
1632 rb_erase(&info->offset_index, &ctl->free_space_offset);
1633 ctl->free_extents--;
1634 }
1635
unlink_free_space(struct btrfs_free_space_ctl * ctl,struct btrfs_free_space * info)1636 static void unlink_free_space(struct btrfs_free_space_ctl *ctl,
1637 struct btrfs_free_space *info)
1638 {
1639 __unlink_free_space(ctl, info);
1640 ctl->free_space -= info->bytes;
1641 }
1642
link_free_space(struct btrfs_free_space_ctl * ctl,struct btrfs_free_space * info)1643 static int link_free_space(struct btrfs_free_space_ctl *ctl,
1644 struct btrfs_free_space *info)
1645 {
1646 int ret = 0;
1647
1648 ASSERT(info->bytes || info->bitmap);
1649 ret = tree_insert_offset(&ctl->free_space_offset, info->offset,
1650 &info->offset_index, (info->bitmap != NULL));
1651 if (ret)
1652 return ret;
1653
1654 ctl->free_space += info->bytes;
1655 ctl->free_extents++;
1656 return ret;
1657 }
1658
recalculate_thresholds(struct btrfs_free_space_ctl * ctl)1659 static void recalculate_thresholds(struct btrfs_free_space_ctl *ctl)
1660 {
1661 struct btrfs_block_group_cache *block_group = ctl->private;
1662 u64 max_bytes;
1663 u64 bitmap_bytes;
1664 u64 extent_bytes;
1665 u64 size = block_group->key.offset;
1666 u64 bytes_per_bg = BITS_PER_BITMAP * ctl->unit;
1667 u64 max_bitmaps = div64_u64(size + bytes_per_bg - 1, bytes_per_bg);
1668
1669 max_bitmaps = max_t(u64, max_bitmaps, 1);
1670
1671 ASSERT(ctl->total_bitmaps <= max_bitmaps);
1672
1673 /*
1674 * The goal is to keep the total amount of memory used per 1gb of space
1675 * at or below 32k, so we need to adjust how much memory we allow to be
1676 * used by extent based free space tracking
1677 */
1678 if (size < SZ_1G)
1679 max_bytes = MAX_CACHE_BYTES_PER_GIG;
1680 else
1681 max_bytes = MAX_CACHE_BYTES_PER_GIG * div_u64(size, SZ_1G);
1682
1683 /*
1684 * we want to account for 1 more bitmap than what we have so we can make
1685 * sure we don't go over our overall goal of MAX_CACHE_BYTES_PER_GIG as
1686 * we add more bitmaps.
1687 */
1688 bitmap_bytes = (ctl->total_bitmaps + 1) * ctl->unit;
1689
1690 if (bitmap_bytes >= max_bytes) {
1691 ctl->extents_thresh = 0;
1692 return;
1693 }
1694
1695 /*
1696 * we want the extent entry threshold to always be at most 1/2 the max
1697 * bytes we can have, or whatever is less than that.
1698 */
1699 extent_bytes = max_bytes - bitmap_bytes;
1700 extent_bytes = min_t(u64, extent_bytes, max_bytes >> 1);
1701
1702 ctl->extents_thresh =
1703 div_u64(extent_bytes, sizeof(struct btrfs_free_space));
1704 }
1705
__bitmap_clear_bits(struct btrfs_free_space_ctl * ctl,struct btrfs_free_space * info,u64 offset,u64 bytes)1706 static inline void __bitmap_clear_bits(struct btrfs_free_space_ctl *ctl,
1707 struct btrfs_free_space *info,
1708 u64 offset, u64 bytes)
1709 {
1710 unsigned long start, count;
1711
1712 start = offset_to_bit(info->offset, ctl->unit, offset);
1713 count = bytes_to_bits(bytes, ctl->unit);
1714 ASSERT(start + count <= BITS_PER_BITMAP);
1715
1716 bitmap_clear(info->bitmap, start, count);
1717
1718 info->bytes -= bytes;
1719 if (info->max_extent_size > ctl->unit)
1720 info->max_extent_size = 0;
1721 }
1722
bitmap_clear_bits(struct btrfs_free_space_ctl * ctl,struct btrfs_free_space * info,u64 offset,u64 bytes)1723 static void bitmap_clear_bits(struct btrfs_free_space_ctl *ctl,
1724 struct btrfs_free_space *info, u64 offset,
1725 u64 bytes)
1726 {
1727 __bitmap_clear_bits(ctl, info, offset, bytes);
1728 ctl->free_space -= bytes;
1729 }
1730
bitmap_set_bits(struct btrfs_free_space_ctl * ctl,struct btrfs_free_space * info,u64 offset,u64 bytes)1731 static void bitmap_set_bits(struct btrfs_free_space_ctl *ctl,
1732 struct btrfs_free_space *info, u64 offset,
1733 u64 bytes)
1734 {
1735 unsigned long start, count;
1736
1737 start = offset_to_bit(info->offset, ctl->unit, offset);
1738 count = bytes_to_bits(bytes, ctl->unit);
1739 ASSERT(start + count <= BITS_PER_BITMAP);
1740
1741 bitmap_set(info->bitmap, start, count);
1742
1743 info->bytes += bytes;
1744 ctl->free_space += bytes;
1745 }
1746
1747 /*
1748 * If we can not find suitable extent, we will use bytes to record
1749 * the size of the max extent.
1750 */
search_bitmap(struct btrfs_free_space_ctl * ctl,struct btrfs_free_space * bitmap_info,u64 * offset,u64 * bytes,bool for_alloc)1751 static int search_bitmap(struct btrfs_free_space_ctl *ctl,
1752 struct btrfs_free_space *bitmap_info, u64 *offset,
1753 u64 *bytes, bool for_alloc)
1754 {
1755 unsigned long found_bits = 0;
1756 unsigned long max_bits = 0;
1757 unsigned long bits, i;
1758 unsigned long next_zero;
1759 unsigned long extent_bits;
1760
1761 /*
1762 * Skip searching the bitmap if we don't have a contiguous section that
1763 * is large enough for this allocation.
1764 */
1765 if (for_alloc &&
1766 bitmap_info->max_extent_size &&
1767 bitmap_info->max_extent_size < *bytes) {
1768 *bytes = bitmap_info->max_extent_size;
1769 return -1;
1770 }
1771
1772 i = offset_to_bit(bitmap_info->offset, ctl->unit,
1773 max_t(u64, *offset, bitmap_info->offset));
1774 bits = bytes_to_bits(*bytes, ctl->unit);
1775
1776 for_each_set_bit_from(i, bitmap_info->bitmap, BITS_PER_BITMAP) {
1777 if (for_alloc && bits == 1) {
1778 found_bits = 1;
1779 break;
1780 }
1781 next_zero = find_next_zero_bit(bitmap_info->bitmap,
1782 BITS_PER_BITMAP, i);
1783 extent_bits = next_zero - i;
1784 if (extent_bits >= bits) {
1785 found_bits = extent_bits;
1786 break;
1787 } else if (extent_bits > max_bits) {
1788 max_bits = extent_bits;
1789 }
1790 i = next_zero;
1791 }
1792
1793 if (found_bits) {
1794 *offset = (u64)(i * ctl->unit) + bitmap_info->offset;
1795 *bytes = (u64)(found_bits) * ctl->unit;
1796 return 0;
1797 }
1798
1799 *bytes = (u64)(max_bits) * ctl->unit;
1800 bitmap_info->max_extent_size = *bytes;
1801 return -1;
1802 }
1803
get_max_extent_size(struct btrfs_free_space * entry)1804 static inline u64 get_max_extent_size(struct btrfs_free_space *entry)
1805 {
1806 if (entry->bitmap)
1807 return entry->max_extent_size;
1808 return entry->bytes;
1809 }
1810
1811 /* Cache the size of the max extent in bytes */
1812 static struct btrfs_free_space *
find_free_space(struct btrfs_free_space_ctl * ctl,u64 * offset,u64 * bytes,unsigned long align,u64 * max_extent_size)1813 find_free_space(struct btrfs_free_space_ctl *ctl, u64 *offset, u64 *bytes,
1814 unsigned long align, u64 *max_extent_size)
1815 {
1816 struct btrfs_free_space *entry;
1817 struct rb_node *node;
1818 u64 tmp;
1819 u64 align_off;
1820 int ret;
1821
1822 if (!ctl->free_space_offset.rb_node)
1823 goto out;
1824
1825 entry = tree_search_offset(ctl, offset_to_bitmap(ctl, *offset), 0, 1);
1826 if (!entry)
1827 goto out;
1828
1829 for (node = &entry->offset_index; node; node = rb_next(node)) {
1830 entry = rb_entry(node, struct btrfs_free_space, offset_index);
1831 if (entry->bytes < *bytes) {
1832 *max_extent_size = max(get_max_extent_size(entry),
1833 *max_extent_size);
1834 continue;
1835 }
1836
1837 /* make sure the space returned is big enough
1838 * to match our requested alignment
1839 */
1840 if (*bytes >= align) {
1841 tmp = entry->offset - ctl->start + align - 1;
1842 tmp = div64_u64(tmp, align);
1843 tmp = tmp * align + ctl->start;
1844 align_off = tmp - entry->offset;
1845 } else {
1846 align_off = 0;
1847 tmp = entry->offset;
1848 }
1849
1850 if (entry->bytes < *bytes + align_off) {
1851 *max_extent_size = max(get_max_extent_size(entry),
1852 *max_extent_size);
1853 continue;
1854 }
1855
1856 if (entry->bitmap) {
1857 u64 size = *bytes;
1858
1859 ret = search_bitmap(ctl, entry, &tmp, &size, true);
1860 if (!ret) {
1861 *offset = tmp;
1862 *bytes = size;
1863 return entry;
1864 } else {
1865 *max_extent_size =
1866 max(get_max_extent_size(entry),
1867 *max_extent_size);
1868 }
1869 continue;
1870 }
1871
1872 *offset = tmp;
1873 *bytes = entry->bytes - align_off;
1874 return entry;
1875 }
1876 out:
1877 return NULL;
1878 }
1879
add_new_bitmap(struct btrfs_free_space_ctl * ctl,struct btrfs_free_space * info,u64 offset)1880 static void add_new_bitmap(struct btrfs_free_space_ctl *ctl,
1881 struct btrfs_free_space *info, u64 offset)
1882 {
1883 info->offset = offset_to_bitmap(ctl, offset);
1884 info->bytes = 0;
1885 INIT_LIST_HEAD(&info->list);
1886 link_free_space(ctl, info);
1887 ctl->total_bitmaps++;
1888
1889 ctl->op->recalc_thresholds(ctl);
1890 }
1891
free_bitmap(struct btrfs_free_space_ctl * ctl,struct btrfs_free_space * bitmap_info)1892 static void free_bitmap(struct btrfs_free_space_ctl *ctl,
1893 struct btrfs_free_space *bitmap_info)
1894 {
1895 unlink_free_space(ctl, bitmap_info);
1896 kmem_cache_free(btrfs_free_space_bitmap_cachep, bitmap_info->bitmap);
1897 kmem_cache_free(btrfs_free_space_cachep, bitmap_info);
1898 ctl->total_bitmaps--;
1899 ctl->op->recalc_thresholds(ctl);
1900 }
1901
remove_from_bitmap(struct btrfs_free_space_ctl * ctl,struct btrfs_free_space * bitmap_info,u64 * offset,u64 * bytes)1902 static noinline int remove_from_bitmap(struct btrfs_free_space_ctl *ctl,
1903 struct btrfs_free_space *bitmap_info,
1904 u64 *offset, u64 *bytes)
1905 {
1906 u64 end;
1907 u64 search_start, search_bytes;
1908 int ret;
1909
1910 again:
1911 end = bitmap_info->offset + (u64)(BITS_PER_BITMAP * ctl->unit) - 1;
1912
1913 /*
1914 * We need to search for bits in this bitmap. We could only cover some
1915 * of the extent in this bitmap thanks to how we add space, so we need
1916 * to search for as much as it as we can and clear that amount, and then
1917 * go searching for the next bit.
1918 */
1919 search_start = *offset;
1920 search_bytes = ctl->unit;
1921 search_bytes = min(search_bytes, end - search_start + 1);
1922 ret = search_bitmap(ctl, bitmap_info, &search_start, &search_bytes,
1923 false);
1924 if (ret < 0 || search_start != *offset)
1925 return -EINVAL;
1926
1927 /* We may have found more bits than what we need */
1928 search_bytes = min(search_bytes, *bytes);
1929
1930 /* Cannot clear past the end of the bitmap */
1931 search_bytes = min(search_bytes, end - search_start + 1);
1932
1933 bitmap_clear_bits(ctl, bitmap_info, search_start, search_bytes);
1934 *offset += search_bytes;
1935 *bytes -= search_bytes;
1936
1937 if (*bytes) {
1938 struct rb_node *next = rb_next(&bitmap_info->offset_index);
1939 if (!bitmap_info->bytes)
1940 free_bitmap(ctl, bitmap_info);
1941
1942 /*
1943 * no entry after this bitmap, but we still have bytes to
1944 * remove, so something has gone wrong.
1945 */
1946 if (!next)
1947 return -EINVAL;
1948
1949 bitmap_info = rb_entry(next, struct btrfs_free_space,
1950 offset_index);
1951
1952 /*
1953 * if the next entry isn't a bitmap we need to return to let the
1954 * extent stuff do its work.
1955 */
1956 if (!bitmap_info->bitmap)
1957 return -EAGAIN;
1958
1959 /*
1960 * Ok the next item is a bitmap, but it may not actually hold
1961 * the information for the rest of this free space stuff, so
1962 * look for it, and if we don't find it return so we can try
1963 * everything over again.
1964 */
1965 search_start = *offset;
1966 search_bytes = ctl->unit;
1967 ret = search_bitmap(ctl, bitmap_info, &search_start,
1968 &search_bytes, false);
1969 if (ret < 0 || search_start != *offset)
1970 return -EAGAIN;
1971
1972 goto again;
1973 } else if (!bitmap_info->bytes)
1974 free_bitmap(ctl, bitmap_info);
1975
1976 return 0;
1977 }
1978
add_bytes_to_bitmap(struct btrfs_free_space_ctl * ctl,struct btrfs_free_space * info,u64 offset,u64 bytes)1979 static u64 add_bytes_to_bitmap(struct btrfs_free_space_ctl *ctl,
1980 struct btrfs_free_space *info, u64 offset,
1981 u64 bytes)
1982 {
1983 u64 bytes_to_set = 0;
1984 u64 end;
1985
1986 end = info->offset + (u64)(BITS_PER_BITMAP * ctl->unit);
1987
1988 bytes_to_set = min(end - offset, bytes);
1989
1990 bitmap_set_bits(ctl, info, offset, bytes_to_set);
1991
1992 /*
1993 * We set some bytes, we have no idea what the max extent size is
1994 * anymore.
1995 */
1996 info->max_extent_size = 0;
1997
1998 return bytes_to_set;
1999
2000 }
2001
use_bitmap(struct btrfs_free_space_ctl * ctl,struct btrfs_free_space * info)2002 static bool use_bitmap(struct btrfs_free_space_ctl *ctl,
2003 struct btrfs_free_space *info)
2004 {
2005 struct btrfs_block_group_cache *block_group = ctl->private;
2006 struct btrfs_fs_info *fs_info = block_group->fs_info;
2007 bool forced = false;
2008
2009 #ifdef CONFIG_BTRFS_DEBUG
2010 if (btrfs_should_fragment_free_space(block_group))
2011 forced = true;
2012 #endif
2013
2014 /*
2015 * If we are below the extents threshold then we can add this as an
2016 * extent, and don't have to deal with the bitmap
2017 */
2018 if (!forced && ctl->free_extents < ctl->extents_thresh) {
2019 /*
2020 * If this block group has some small extents we don't want to
2021 * use up all of our free slots in the cache with them, we want
2022 * to reserve them to larger extents, however if we have plenty
2023 * of cache left then go ahead an dadd them, no sense in adding
2024 * the overhead of a bitmap if we don't have to.
2025 */
2026 if (info->bytes <= fs_info->sectorsize * 4) {
2027 if (ctl->free_extents * 2 <= ctl->extents_thresh)
2028 return false;
2029 } else {
2030 return false;
2031 }
2032 }
2033
2034 /*
2035 * The original block groups from mkfs can be really small, like 8
2036 * megabytes, so don't bother with a bitmap for those entries. However
2037 * some block groups can be smaller than what a bitmap would cover but
2038 * are still large enough that they could overflow the 32k memory limit,
2039 * so allow those block groups to still be allowed to have a bitmap
2040 * entry.
2041 */
2042 if (((BITS_PER_BITMAP * ctl->unit) >> 1) > block_group->key.offset)
2043 return false;
2044
2045 return true;
2046 }
2047
2048 static const struct btrfs_free_space_op free_space_op = {
2049 .recalc_thresholds = recalculate_thresholds,
2050 .use_bitmap = use_bitmap,
2051 };
2052
insert_into_bitmap(struct btrfs_free_space_ctl * ctl,struct btrfs_free_space * info)2053 static int insert_into_bitmap(struct btrfs_free_space_ctl *ctl,
2054 struct btrfs_free_space *info)
2055 {
2056 struct btrfs_free_space *bitmap_info;
2057 struct btrfs_block_group_cache *block_group = NULL;
2058 int added = 0;
2059 u64 bytes, offset, bytes_added;
2060 int ret;
2061
2062 bytes = info->bytes;
2063 offset = info->offset;
2064
2065 if (!ctl->op->use_bitmap(ctl, info))
2066 return 0;
2067
2068 if (ctl->op == &free_space_op)
2069 block_group = ctl->private;
2070 again:
2071 /*
2072 * Since we link bitmaps right into the cluster we need to see if we
2073 * have a cluster here, and if so and it has our bitmap we need to add
2074 * the free space to that bitmap.
2075 */
2076 if (block_group && !list_empty(&block_group->cluster_list)) {
2077 struct btrfs_free_cluster *cluster;
2078 struct rb_node *node;
2079 struct btrfs_free_space *entry;
2080
2081 cluster = list_entry(block_group->cluster_list.next,
2082 struct btrfs_free_cluster,
2083 block_group_list);
2084 spin_lock(&cluster->lock);
2085 node = rb_first(&cluster->root);
2086 if (!node) {
2087 spin_unlock(&cluster->lock);
2088 goto no_cluster_bitmap;
2089 }
2090
2091 entry = rb_entry(node, struct btrfs_free_space, offset_index);
2092 if (!entry->bitmap) {
2093 spin_unlock(&cluster->lock);
2094 goto no_cluster_bitmap;
2095 }
2096
2097 if (entry->offset == offset_to_bitmap(ctl, offset)) {
2098 bytes_added = add_bytes_to_bitmap(ctl, entry,
2099 offset, bytes);
2100 bytes -= bytes_added;
2101 offset += bytes_added;
2102 }
2103 spin_unlock(&cluster->lock);
2104 if (!bytes) {
2105 ret = 1;
2106 goto out;
2107 }
2108 }
2109
2110 no_cluster_bitmap:
2111 bitmap_info = tree_search_offset(ctl, offset_to_bitmap(ctl, offset),
2112 1, 0);
2113 if (!bitmap_info) {
2114 ASSERT(added == 0);
2115 goto new_bitmap;
2116 }
2117
2118 bytes_added = add_bytes_to_bitmap(ctl, bitmap_info, offset, bytes);
2119 bytes -= bytes_added;
2120 offset += bytes_added;
2121 added = 0;
2122
2123 if (!bytes) {
2124 ret = 1;
2125 goto out;
2126 } else
2127 goto again;
2128
2129 new_bitmap:
2130 if (info && info->bitmap) {
2131 add_new_bitmap(ctl, info, offset);
2132 added = 1;
2133 info = NULL;
2134 goto again;
2135 } else {
2136 spin_unlock(&ctl->tree_lock);
2137
2138 /* no pre-allocated info, allocate a new one */
2139 if (!info) {
2140 info = kmem_cache_zalloc(btrfs_free_space_cachep,
2141 GFP_NOFS);
2142 if (!info) {
2143 spin_lock(&ctl->tree_lock);
2144 ret = -ENOMEM;
2145 goto out;
2146 }
2147 }
2148
2149 /* allocate the bitmap */
2150 info->bitmap = kmem_cache_zalloc(btrfs_free_space_bitmap_cachep,
2151 GFP_NOFS);
2152 spin_lock(&ctl->tree_lock);
2153 if (!info->bitmap) {
2154 ret = -ENOMEM;
2155 goto out;
2156 }
2157 goto again;
2158 }
2159
2160 out:
2161 if (info) {
2162 if (info->bitmap)
2163 kmem_cache_free(btrfs_free_space_bitmap_cachep,
2164 info->bitmap);
2165 kmem_cache_free(btrfs_free_space_cachep, info);
2166 }
2167
2168 return ret;
2169 }
2170
try_merge_free_space(struct btrfs_free_space_ctl * ctl,struct btrfs_free_space * info,bool update_stat)2171 static bool try_merge_free_space(struct btrfs_free_space_ctl *ctl,
2172 struct btrfs_free_space *info, bool update_stat)
2173 {
2174 struct btrfs_free_space *left_info = NULL;
2175 struct btrfs_free_space *right_info;
2176 bool merged = false;
2177 u64 offset = info->offset;
2178 u64 bytes = info->bytes;
2179
2180 /*
2181 * first we want to see if there is free space adjacent to the range we
2182 * are adding, if there is remove that struct and add a new one to
2183 * cover the entire range
2184 */
2185 right_info = tree_search_offset(ctl, offset + bytes, 0, 0);
2186 if (right_info && rb_prev(&right_info->offset_index))
2187 left_info = rb_entry(rb_prev(&right_info->offset_index),
2188 struct btrfs_free_space, offset_index);
2189 else if (!right_info)
2190 left_info = tree_search_offset(ctl, offset - 1, 0, 0);
2191
2192 if (right_info && !right_info->bitmap) {
2193 if (update_stat)
2194 unlink_free_space(ctl, right_info);
2195 else
2196 __unlink_free_space(ctl, right_info);
2197 info->bytes += right_info->bytes;
2198 kmem_cache_free(btrfs_free_space_cachep, right_info);
2199 merged = true;
2200 }
2201
2202 if (left_info && !left_info->bitmap &&
2203 left_info->offset + left_info->bytes == offset) {
2204 if (update_stat)
2205 unlink_free_space(ctl, left_info);
2206 else
2207 __unlink_free_space(ctl, left_info);
2208 info->offset = left_info->offset;
2209 info->bytes += left_info->bytes;
2210 kmem_cache_free(btrfs_free_space_cachep, left_info);
2211 merged = true;
2212 }
2213
2214 return merged;
2215 }
2216
steal_from_bitmap_to_end(struct btrfs_free_space_ctl * ctl,struct btrfs_free_space * info,bool update_stat)2217 static bool steal_from_bitmap_to_end(struct btrfs_free_space_ctl *ctl,
2218 struct btrfs_free_space *info,
2219 bool update_stat)
2220 {
2221 struct btrfs_free_space *bitmap;
2222 unsigned long i;
2223 unsigned long j;
2224 const u64 end = info->offset + info->bytes;
2225 const u64 bitmap_offset = offset_to_bitmap(ctl, end);
2226 u64 bytes;
2227
2228 bitmap = tree_search_offset(ctl, bitmap_offset, 1, 0);
2229 if (!bitmap)
2230 return false;
2231
2232 i = offset_to_bit(bitmap->offset, ctl->unit, end);
2233 j = find_next_zero_bit(bitmap->bitmap, BITS_PER_BITMAP, i);
2234 if (j == i)
2235 return false;
2236 bytes = (j - i) * ctl->unit;
2237 info->bytes += bytes;
2238
2239 if (update_stat)
2240 bitmap_clear_bits(ctl, bitmap, end, bytes);
2241 else
2242 __bitmap_clear_bits(ctl, bitmap, end, bytes);
2243
2244 if (!bitmap->bytes)
2245 free_bitmap(ctl, bitmap);
2246
2247 return true;
2248 }
2249
steal_from_bitmap_to_front(struct btrfs_free_space_ctl * ctl,struct btrfs_free_space * info,bool update_stat)2250 static bool steal_from_bitmap_to_front(struct btrfs_free_space_ctl *ctl,
2251 struct btrfs_free_space *info,
2252 bool update_stat)
2253 {
2254 struct btrfs_free_space *bitmap;
2255 u64 bitmap_offset;
2256 unsigned long i;
2257 unsigned long j;
2258 unsigned long prev_j;
2259 u64 bytes;
2260
2261 bitmap_offset = offset_to_bitmap(ctl, info->offset);
2262 /* If we're on a boundary, try the previous logical bitmap. */
2263 if (bitmap_offset == info->offset) {
2264 if (info->offset == 0)
2265 return false;
2266 bitmap_offset = offset_to_bitmap(ctl, info->offset - 1);
2267 }
2268
2269 bitmap = tree_search_offset(ctl, bitmap_offset, 1, 0);
2270 if (!bitmap)
2271 return false;
2272
2273 i = offset_to_bit(bitmap->offset, ctl->unit, info->offset) - 1;
2274 j = 0;
2275 prev_j = (unsigned long)-1;
2276 for_each_clear_bit_from(j, bitmap->bitmap, BITS_PER_BITMAP) {
2277 if (j > i)
2278 break;
2279 prev_j = j;
2280 }
2281 if (prev_j == i)
2282 return false;
2283
2284 if (prev_j == (unsigned long)-1)
2285 bytes = (i + 1) * ctl->unit;
2286 else
2287 bytes = (i - prev_j) * ctl->unit;
2288
2289 info->offset -= bytes;
2290 info->bytes += bytes;
2291
2292 if (update_stat)
2293 bitmap_clear_bits(ctl, bitmap, info->offset, bytes);
2294 else
2295 __bitmap_clear_bits(ctl, bitmap, info->offset, bytes);
2296
2297 if (!bitmap->bytes)
2298 free_bitmap(ctl, bitmap);
2299
2300 return true;
2301 }
2302
2303 /*
2304 * We prefer always to allocate from extent entries, both for clustered and
2305 * non-clustered allocation requests. So when attempting to add a new extent
2306 * entry, try to see if there's adjacent free space in bitmap entries, and if
2307 * there is, migrate that space from the bitmaps to the extent.
2308 * Like this we get better chances of satisfying space allocation requests
2309 * because we attempt to satisfy them based on a single cache entry, and never
2310 * on 2 or more entries - even if the entries represent a contiguous free space
2311 * region (e.g. 1 extent entry + 1 bitmap entry starting where the extent entry
2312 * ends).
2313 */
steal_from_bitmap(struct btrfs_free_space_ctl * ctl,struct btrfs_free_space * info,bool update_stat)2314 static void steal_from_bitmap(struct btrfs_free_space_ctl *ctl,
2315 struct btrfs_free_space *info,
2316 bool update_stat)
2317 {
2318 /*
2319 * Only work with disconnected entries, as we can change their offset,
2320 * and must be extent entries.
2321 */
2322 ASSERT(!info->bitmap);
2323 ASSERT(RB_EMPTY_NODE(&info->offset_index));
2324
2325 if (ctl->total_bitmaps > 0) {
2326 bool stole_end;
2327 bool stole_front = false;
2328
2329 stole_end = steal_from_bitmap_to_end(ctl, info, update_stat);
2330 if (ctl->total_bitmaps > 0)
2331 stole_front = steal_from_bitmap_to_front(ctl, info,
2332 update_stat);
2333
2334 if (stole_end || stole_front)
2335 try_merge_free_space(ctl, info, update_stat);
2336 }
2337 }
2338
__btrfs_add_free_space(struct btrfs_fs_info * fs_info,struct btrfs_free_space_ctl * ctl,u64 offset,u64 bytes)2339 int __btrfs_add_free_space(struct btrfs_fs_info *fs_info,
2340 struct btrfs_free_space_ctl *ctl,
2341 u64 offset, u64 bytes)
2342 {
2343 struct btrfs_free_space *info;
2344 int ret = 0;
2345
2346 info = kmem_cache_zalloc(btrfs_free_space_cachep, GFP_NOFS);
2347 if (!info)
2348 return -ENOMEM;
2349
2350 info->offset = offset;
2351 info->bytes = bytes;
2352 RB_CLEAR_NODE(&info->offset_index);
2353
2354 spin_lock(&ctl->tree_lock);
2355
2356 if (try_merge_free_space(ctl, info, true))
2357 goto link;
2358
2359 /*
2360 * There was no extent directly to the left or right of this new
2361 * extent then we know we're going to have to allocate a new extent, so
2362 * before we do that see if we need to drop this into a bitmap
2363 */
2364 ret = insert_into_bitmap(ctl, info);
2365 if (ret < 0) {
2366 goto out;
2367 } else if (ret) {
2368 ret = 0;
2369 goto out;
2370 }
2371 link:
2372 /*
2373 * Only steal free space from adjacent bitmaps if we're sure we're not
2374 * going to add the new free space to existing bitmap entries - because
2375 * that would mean unnecessary work that would be reverted. Therefore
2376 * attempt to steal space from bitmaps if we're adding an extent entry.
2377 */
2378 steal_from_bitmap(ctl, info, true);
2379
2380 ret = link_free_space(ctl, info);
2381 if (ret)
2382 kmem_cache_free(btrfs_free_space_cachep, info);
2383 out:
2384 spin_unlock(&ctl->tree_lock);
2385
2386 if (ret) {
2387 btrfs_crit(fs_info, "unable to add free space :%d", ret);
2388 ASSERT(ret != -EEXIST);
2389 }
2390
2391 return ret;
2392 }
2393
btrfs_add_free_space(struct btrfs_block_group_cache * block_group,u64 bytenr,u64 size)2394 int btrfs_add_free_space(struct btrfs_block_group_cache *block_group,
2395 u64 bytenr, u64 size)
2396 {
2397 return __btrfs_add_free_space(block_group->fs_info,
2398 block_group->free_space_ctl,
2399 bytenr, size);
2400 }
2401
btrfs_remove_free_space(struct btrfs_block_group_cache * block_group,u64 offset,u64 bytes)2402 int btrfs_remove_free_space(struct btrfs_block_group_cache *block_group,
2403 u64 offset, u64 bytes)
2404 {
2405 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2406 struct btrfs_free_space *info;
2407 int ret;
2408 bool re_search = false;
2409
2410 spin_lock(&ctl->tree_lock);
2411
2412 again:
2413 ret = 0;
2414 if (!bytes)
2415 goto out_lock;
2416
2417 info = tree_search_offset(ctl, offset, 0, 0);
2418 if (!info) {
2419 /*
2420 * oops didn't find an extent that matched the space we wanted
2421 * to remove, look for a bitmap instead
2422 */
2423 info = tree_search_offset(ctl, offset_to_bitmap(ctl, offset),
2424 1, 0);
2425 if (!info) {
2426 /*
2427 * If we found a partial bit of our free space in a
2428 * bitmap but then couldn't find the other part this may
2429 * be a problem, so WARN about it.
2430 */
2431 WARN_ON(re_search);
2432 goto out_lock;
2433 }
2434 }
2435
2436 re_search = false;
2437 if (!info->bitmap) {
2438 unlink_free_space(ctl, info);
2439 if (offset == info->offset) {
2440 u64 to_free = min(bytes, info->bytes);
2441
2442 info->bytes -= to_free;
2443 info->offset += to_free;
2444 if (info->bytes) {
2445 ret = link_free_space(ctl, info);
2446 WARN_ON(ret);
2447 } else {
2448 kmem_cache_free(btrfs_free_space_cachep, info);
2449 }
2450
2451 offset += to_free;
2452 bytes -= to_free;
2453 goto again;
2454 } else {
2455 u64 old_end = info->bytes + info->offset;
2456
2457 info->bytes = offset - info->offset;
2458 ret = link_free_space(ctl, info);
2459 WARN_ON(ret);
2460 if (ret)
2461 goto out_lock;
2462
2463 /* Not enough bytes in this entry to satisfy us */
2464 if (old_end < offset + bytes) {
2465 bytes -= old_end - offset;
2466 offset = old_end;
2467 goto again;
2468 } else if (old_end == offset + bytes) {
2469 /* all done */
2470 goto out_lock;
2471 }
2472 spin_unlock(&ctl->tree_lock);
2473
2474 ret = btrfs_add_free_space(block_group, offset + bytes,
2475 old_end - (offset + bytes));
2476 WARN_ON(ret);
2477 goto out;
2478 }
2479 }
2480
2481 ret = remove_from_bitmap(ctl, info, &offset, &bytes);
2482 if (ret == -EAGAIN) {
2483 re_search = true;
2484 goto again;
2485 }
2486 out_lock:
2487 spin_unlock(&ctl->tree_lock);
2488 out:
2489 return ret;
2490 }
2491
btrfs_dump_free_space(struct btrfs_block_group_cache * block_group,u64 bytes)2492 void btrfs_dump_free_space(struct btrfs_block_group_cache *block_group,
2493 u64 bytes)
2494 {
2495 struct btrfs_fs_info *fs_info = block_group->fs_info;
2496 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2497 struct btrfs_free_space *info;
2498 struct rb_node *n;
2499 int count = 0;
2500
2501 spin_lock(&ctl->tree_lock);
2502 for (n = rb_first(&ctl->free_space_offset); n; n = rb_next(n)) {
2503 info = rb_entry(n, struct btrfs_free_space, offset_index);
2504 if (info->bytes >= bytes && !block_group->ro)
2505 count++;
2506 btrfs_crit(fs_info, "entry offset %llu, bytes %llu, bitmap %s",
2507 info->offset, info->bytes,
2508 (info->bitmap) ? "yes" : "no");
2509 }
2510 spin_unlock(&ctl->tree_lock);
2511 btrfs_info(fs_info, "block group has cluster?: %s",
2512 list_empty(&block_group->cluster_list) ? "no" : "yes");
2513 btrfs_info(fs_info,
2514 "%d blocks of free space at or bigger than bytes is", count);
2515 }
2516
btrfs_init_free_space_ctl(struct btrfs_block_group_cache * block_group)2517 void btrfs_init_free_space_ctl(struct btrfs_block_group_cache *block_group)
2518 {
2519 struct btrfs_fs_info *fs_info = block_group->fs_info;
2520 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2521
2522 spin_lock_init(&ctl->tree_lock);
2523 ctl->unit = fs_info->sectorsize;
2524 ctl->start = block_group->key.objectid;
2525 ctl->private = block_group;
2526 ctl->op = &free_space_op;
2527 INIT_LIST_HEAD(&ctl->trimming_ranges);
2528 mutex_init(&ctl->cache_writeout_mutex);
2529
2530 /*
2531 * we only want to have 32k of ram per block group for keeping
2532 * track of free space, and if we pass 1/2 of that we want to
2533 * start converting things over to using bitmaps
2534 */
2535 ctl->extents_thresh = (SZ_32K / 2) / sizeof(struct btrfs_free_space);
2536 }
2537
2538 /*
2539 * for a given cluster, put all of its extents back into the free
2540 * space cache. If the block group passed doesn't match the block group
2541 * pointed to by the cluster, someone else raced in and freed the
2542 * cluster already. In that case, we just return without changing anything
2543 */
2544 static int
__btrfs_return_cluster_to_free_space(struct btrfs_block_group_cache * block_group,struct btrfs_free_cluster * cluster)2545 __btrfs_return_cluster_to_free_space(
2546 struct btrfs_block_group_cache *block_group,
2547 struct btrfs_free_cluster *cluster)
2548 {
2549 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2550 struct btrfs_free_space *entry;
2551 struct rb_node *node;
2552
2553 spin_lock(&cluster->lock);
2554 if (cluster->block_group != block_group)
2555 goto out;
2556
2557 cluster->block_group = NULL;
2558 cluster->window_start = 0;
2559 list_del_init(&cluster->block_group_list);
2560
2561 node = rb_first(&cluster->root);
2562 while (node) {
2563 bool bitmap;
2564
2565 entry = rb_entry(node, struct btrfs_free_space, offset_index);
2566 node = rb_next(&entry->offset_index);
2567 rb_erase(&entry->offset_index, &cluster->root);
2568 RB_CLEAR_NODE(&entry->offset_index);
2569
2570 bitmap = (entry->bitmap != NULL);
2571 if (!bitmap) {
2572 try_merge_free_space(ctl, entry, false);
2573 steal_from_bitmap(ctl, entry, false);
2574 }
2575 tree_insert_offset(&ctl->free_space_offset,
2576 entry->offset, &entry->offset_index, bitmap);
2577 }
2578 cluster->root = RB_ROOT;
2579
2580 out:
2581 spin_unlock(&cluster->lock);
2582 btrfs_put_block_group(block_group);
2583 return 0;
2584 }
2585
__btrfs_remove_free_space_cache_locked(struct btrfs_free_space_ctl * ctl)2586 static void __btrfs_remove_free_space_cache_locked(
2587 struct btrfs_free_space_ctl *ctl)
2588 {
2589 struct btrfs_free_space *info;
2590 struct rb_node *node;
2591
2592 while ((node = rb_last(&ctl->free_space_offset)) != NULL) {
2593 info = rb_entry(node, struct btrfs_free_space, offset_index);
2594 if (!info->bitmap) {
2595 unlink_free_space(ctl, info);
2596 kmem_cache_free(btrfs_free_space_cachep, info);
2597 } else {
2598 free_bitmap(ctl, info);
2599 }
2600
2601 cond_resched_lock(&ctl->tree_lock);
2602 }
2603 }
2604
__btrfs_remove_free_space_cache(struct btrfs_free_space_ctl * ctl)2605 void __btrfs_remove_free_space_cache(struct btrfs_free_space_ctl *ctl)
2606 {
2607 spin_lock(&ctl->tree_lock);
2608 __btrfs_remove_free_space_cache_locked(ctl);
2609 spin_unlock(&ctl->tree_lock);
2610 }
2611
btrfs_remove_free_space_cache(struct btrfs_block_group_cache * block_group)2612 void btrfs_remove_free_space_cache(struct btrfs_block_group_cache *block_group)
2613 {
2614 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2615 struct btrfs_free_cluster *cluster;
2616 struct list_head *head;
2617
2618 spin_lock(&ctl->tree_lock);
2619 while ((head = block_group->cluster_list.next) !=
2620 &block_group->cluster_list) {
2621 cluster = list_entry(head, struct btrfs_free_cluster,
2622 block_group_list);
2623
2624 WARN_ON(cluster->block_group != block_group);
2625 __btrfs_return_cluster_to_free_space(block_group, cluster);
2626
2627 cond_resched_lock(&ctl->tree_lock);
2628 }
2629 __btrfs_remove_free_space_cache_locked(ctl);
2630 spin_unlock(&ctl->tree_lock);
2631
2632 }
2633
btrfs_find_space_for_alloc(struct btrfs_block_group_cache * block_group,u64 offset,u64 bytes,u64 empty_size,u64 * max_extent_size)2634 u64 btrfs_find_space_for_alloc(struct btrfs_block_group_cache *block_group,
2635 u64 offset, u64 bytes, u64 empty_size,
2636 u64 *max_extent_size)
2637 {
2638 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2639 struct btrfs_free_space *entry = NULL;
2640 u64 bytes_search = bytes + empty_size;
2641 u64 ret = 0;
2642 u64 align_gap = 0;
2643 u64 align_gap_len = 0;
2644
2645 spin_lock(&ctl->tree_lock);
2646 entry = find_free_space(ctl, &offset, &bytes_search,
2647 block_group->full_stripe_len, max_extent_size);
2648 if (!entry)
2649 goto out;
2650
2651 ret = offset;
2652 if (entry->bitmap) {
2653 bitmap_clear_bits(ctl, entry, offset, bytes);
2654 if (!entry->bytes)
2655 free_bitmap(ctl, entry);
2656 } else {
2657 unlink_free_space(ctl, entry);
2658 align_gap_len = offset - entry->offset;
2659 align_gap = entry->offset;
2660
2661 entry->offset = offset + bytes;
2662 WARN_ON(entry->bytes < bytes + align_gap_len);
2663
2664 entry->bytes -= bytes + align_gap_len;
2665 if (!entry->bytes)
2666 kmem_cache_free(btrfs_free_space_cachep, entry);
2667 else
2668 link_free_space(ctl, entry);
2669 }
2670 out:
2671 spin_unlock(&ctl->tree_lock);
2672
2673 if (align_gap_len)
2674 __btrfs_add_free_space(block_group->fs_info, ctl,
2675 align_gap, align_gap_len);
2676 return ret;
2677 }
2678
2679 /*
2680 * given a cluster, put all of its extents back into the free space
2681 * cache. If a block group is passed, this function will only free
2682 * a cluster that belongs to the passed block group.
2683 *
2684 * Otherwise, it'll get a reference on the block group pointed to by the
2685 * cluster and remove the cluster from it.
2686 */
btrfs_return_cluster_to_free_space(struct btrfs_block_group_cache * block_group,struct btrfs_free_cluster * cluster)2687 int btrfs_return_cluster_to_free_space(
2688 struct btrfs_block_group_cache *block_group,
2689 struct btrfs_free_cluster *cluster)
2690 {
2691 struct btrfs_free_space_ctl *ctl;
2692 int ret;
2693
2694 /* first, get a safe pointer to the block group */
2695 spin_lock(&cluster->lock);
2696 if (!block_group) {
2697 block_group = cluster->block_group;
2698 if (!block_group) {
2699 spin_unlock(&cluster->lock);
2700 return 0;
2701 }
2702 } else if (cluster->block_group != block_group) {
2703 /* someone else has already freed it don't redo their work */
2704 spin_unlock(&cluster->lock);
2705 return 0;
2706 }
2707 atomic_inc(&block_group->count);
2708 spin_unlock(&cluster->lock);
2709
2710 ctl = block_group->free_space_ctl;
2711
2712 /* now return any extents the cluster had on it */
2713 spin_lock(&ctl->tree_lock);
2714 ret = __btrfs_return_cluster_to_free_space(block_group, cluster);
2715 spin_unlock(&ctl->tree_lock);
2716
2717 /* finally drop our ref */
2718 btrfs_put_block_group(block_group);
2719 return ret;
2720 }
2721
btrfs_alloc_from_bitmap(struct btrfs_block_group_cache * block_group,struct btrfs_free_cluster * cluster,struct btrfs_free_space * entry,u64 bytes,u64 min_start,u64 * max_extent_size)2722 static u64 btrfs_alloc_from_bitmap(struct btrfs_block_group_cache *block_group,
2723 struct btrfs_free_cluster *cluster,
2724 struct btrfs_free_space *entry,
2725 u64 bytes, u64 min_start,
2726 u64 *max_extent_size)
2727 {
2728 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2729 int err;
2730 u64 search_start = cluster->window_start;
2731 u64 search_bytes = bytes;
2732 u64 ret = 0;
2733
2734 search_start = min_start;
2735 search_bytes = bytes;
2736
2737 err = search_bitmap(ctl, entry, &search_start, &search_bytes, true);
2738 if (err) {
2739 *max_extent_size = max(get_max_extent_size(entry),
2740 *max_extent_size);
2741 return 0;
2742 }
2743
2744 ret = search_start;
2745 __bitmap_clear_bits(ctl, entry, ret, bytes);
2746
2747 return ret;
2748 }
2749
2750 /*
2751 * given a cluster, try to allocate 'bytes' from it, returns 0
2752 * if it couldn't find anything suitably large, or a logical disk offset
2753 * if things worked out
2754 */
btrfs_alloc_from_cluster(struct btrfs_block_group_cache * block_group,struct btrfs_free_cluster * cluster,u64 bytes,u64 min_start,u64 * max_extent_size)2755 u64 btrfs_alloc_from_cluster(struct btrfs_block_group_cache *block_group,
2756 struct btrfs_free_cluster *cluster, u64 bytes,
2757 u64 min_start, u64 *max_extent_size)
2758 {
2759 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2760 struct btrfs_free_space *entry = NULL;
2761 struct rb_node *node;
2762 u64 ret = 0;
2763
2764 spin_lock(&cluster->lock);
2765 if (bytes > cluster->max_size)
2766 goto out;
2767
2768 if (cluster->block_group != block_group)
2769 goto out;
2770
2771 node = rb_first(&cluster->root);
2772 if (!node)
2773 goto out;
2774
2775 entry = rb_entry(node, struct btrfs_free_space, offset_index);
2776 while (1) {
2777 if (entry->bytes < bytes)
2778 *max_extent_size = max(get_max_extent_size(entry),
2779 *max_extent_size);
2780
2781 if (entry->bytes < bytes ||
2782 (!entry->bitmap && entry->offset < min_start)) {
2783 node = rb_next(&entry->offset_index);
2784 if (!node)
2785 break;
2786 entry = rb_entry(node, struct btrfs_free_space,
2787 offset_index);
2788 continue;
2789 }
2790
2791 if (entry->bitmap) {
2792 ret = btrfs_alloc_from_bitmap(block_group,
2793 cluster, entry, bytes,
2794 cluster->window_start,
2795 max_extent_size);
2796 if (ret == 0) {
2797 node = rb_next(&entry->offset_index);
2798 if (!node)
2799 break;
2800 entry = rb_entry(node, struct btrfs_free_space,
2801 offset_index);
2802 continue;
2803 }
2804 cluster->window_start += bytes;
2805 } else {
2806 ret = entry->offset;
2807
2808 entry->offset += bytes;
2809 entry->bytes -= bytes;
2810 }
2811
2812 if (entry->bytes == 0)
2813 rb_erase(&entry->offset_index, &cluster->root);
2814 break;
2815 }
2816 out:
2817 spin_unlock(&cluster->lock);
2818
2819 if (!ret)
2820 return 0;
2821
2822 spin_lock(&ctl->tree_lock);
2823
2824 ctl->free_space -= bytes;
2825 if (entry->bytes == 0) {
2826 ctl->free_extents--;
2827 if (entry->bitmap) {
2828 kmem_cache_free(btrfs_free_space_bitmap_cachep,
2829 entry->bitmap);
2830 ctl->total_bitmaps--;
2831 ctl->op->recalc_thresholds(ctl);
2832 }
2833 kmem_cache_free(btrfs_free_space_cachep, entry);
2834 }
2835
2836 spin_unlock(&ctl->tree_lock);
2837
2838 return ret;
2839 }
2840
btrfs_bitmap_cluster(struct btrfs_block_group_cache * block_group,struct btrfs_free_space * entry,struct btrfs_free_cluster * cluster,u64 offset,u64 bytes,u64 cont1_bytes,u64 min_bytes)2841 static int btrfs_bitmap_cluster(struct btrfs_block_group_cache *block_group,
2842 struct btrfs_free_space *entry,
2843 struct btrfs_free_cluster *cluster,
2844 u64 offset, u64 bytes,
2845 u64 cont1_bytes, u64 min_bytes)
2846 {
2847 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2848 unsigned long next_zero;
2849 unsigned long i;
2850 unsigned long want_bits;
2851 unsigned long min_bits;
2852 unsigned long found_bits;
2853 unsigned long max_bits = 0;
2854 unsigned long start = 0;
2855 unsigned long total_found = 0;
2856 int ret;
2857
2858 i = offset_to_bit(entry->offset, ctl->unit,
2859 max_t(u64, offset, entry->offset));
2860 want_bits = bytes_to_bits(bytes, ctl->unit);
2861 min_bits = bytes_to_bits(min_bytes, ctl->unit);
2862
2863 /*
2864 * Don't bother looking for a cluster in this bitmap if it's heavily
2865 * fragmented.
2866 */
2867 if (entry->max_extent_size &&
2868 entry->max_extent_size < cont1_bytes)
2869 return -ENOSPC;
2870 again:
2871 found_bits = 0;
2872 for_each_set_bit_from(i, entry->bitmap, BITS_PER_BITMAP) {
2873 next_zero = find_next_zero_bit(entry->bitmap,
2874 BITS_PER_BITMAP, i);
2875 if (next_zero - i >= min_bits) {
2876 found_bits = next_zero - i;
2877 if (found_bits > max_bits)
2878 max_bits = found_bits;
2879 break;
2880 }
2881 if (next_zero - i > max_bits)
2882 max_bits = next_zero - i;
2883 i = next_zero;
2884 }
2885
2886 if (!found_bits) {
2887 entry->max_extent_size = (u64)max_bits * ctl->unit;
2888 return -ENOSPC;
2889 }
2890
2891 if (!total_found) {
2892 start = i;
2893 cluster->max_size = 0;
2894 }
2895
2896 total_found += found_bits;
2897
2898 if (cluster->max_size < found_bits * ctl->unit)
2899 cluster->max_size = found_bits * ctl->unit;
2900
2901 if (total_found < want_bits || cluster->max_size < cont1_bytes) {
2902 i = next_zero + 1;
2903 goto again;
2904 }
2905
2906 cluster->window_start = start * ctl->unit + entry->offset;
2907 rb_erase(&entry->offset_index, &ctl->free_space_offset);
2908 ret = tree_insert_offset(&cluster->root, entry->offset,
2909 &entry->offset_index, 1);
2910 ASSERT(!ret); /* -EEXIST; Logic error */
2911
2912 trace_btrfs_setup_cluster(block_group, cluster,
2913 total_found * ctl->unit, 1);
2914 return 0;
2915 }
2916
2917 /*
2918 * This searches the block group for just extents to fill the cluster with.
2919 * Try to find a cluster with at least bytes total bytes, at least one
2920 * extent of cont1_bytes, and other clusters of at least min_bytes.
2921 */
2922 static noinline int
setup_cluster_no_bitmap(struct btrfs_block_group_cache * block_group,struct btrfs_free_cluster * cluster,struct list_head * bitmaps,u64 offset,u64 bytes,u64 cont1_bytes,u64 min_bytes)2923 setup_cluster_no_bitmap(struct btrfs_block_group_cache *block_group,
2924 struct btrfs_free_cluster *cluster,
2925 struct list_head *bitmaps, u64 offset, u64 bytes,
2926 u64 cont1_bytes, u64 min_bytes)
2927 {
2928 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2929 struct btrfs_free_space *first = NULL;
2930 struct btrfs_free_space *entry = NULL;
2931 struct btrfs_free_space *last;
2932 struct rb_node *node;
2933 u64 window_free;
2934 u64 max_extent;
2935 u64 total_size = 0;
2936
2937 entry = tree_search_offset(ctl, offset, 0, 1);
2938 if (!entry)
2939 return -ENOSPC;
2940
2941 /*
2942 * We don't want bitmaps, so just move along until we find a normal
2943 * extent entry.
2944 */
2945 while (entry->bitmap || entry->bytes < min_bytes) {
2946 if (entry->bitmap && list_empty(&entry->list))
2947 list_add_tail(&entry->list, bitmaps);
2948 node = rb_next(&entry->offset_index);
2949 if (!node)
2950 return -ENOSPC;
2951 entry = rb_entry(node, struct btrfs_free_space, offset_index);
2952 }
2953
2954 window_free = entry->bytes;
2955 max_extent = entry->bytes;
2956 first = entry;
2957 last = entry;
2958
2959 for (node = rb_next(&entry->offset_index); node;
2960 node = rb_next(&entry->offset_index)) {
2961 entry = rb_entry(node, struct btrfs_free_space, offset_index);
2962
2963 if (entry->bitmap) {
2964 if (list_empty(&entry->list))
2965 list_add_tail(&entry->list, bitmaps);
2966 continue;
2967 }
2968
2969 if (entry->bytes < min_bytes)
2970 continue;
2971
2972 last = entry;
2973 window_free += entry->bytes;
2974 if (entry->bytes > max_extent)
2975 max_extent = entry->bytes;
2976 }
2977
2978 if (window_free < bytes || max_extent < cont1_bytes)
2979 return -ENOSPC;
2980
2981 cluster->window_start = first->offset;
2982
2983 node = &first->offset_index;
2984
2985 /*
2986 * now we've found our entries, pull them out of the free space
2987 * cache and put them into the cluster rbtree
2988 */
2989 do {
2990 int ret;
2991
2992 entry = rb_entry(node, struct btrfs_free_space, offset_index);
2993 node = rb_next(&entry->offset_index);
2994 if (entry->bitmap || entry->bytes < min_bytes)
2995 continue;
2996
2997 rb_erase(&entry->offset_index, &ctl->free_space_offset);
2998 ret = tree_insert_offset(&cluster->root, entry->offset,
2999 &entry->offset_index, 0);
3000 total_size += entry->bytes;
3001 ASSERT(!ret); /* -EEXIST; Logic error */
3002 } while (node && entry != last);
3003
3004 cluster->max_size = max_extent;
3005 trace_btrfs_setup_cluster(block_group, cluster, total_size, 0);
3006 return 0;
3007 }
3008
3009 /*
3010 * This specifically looks for bitmaps that may work in the cluster, we assume
3011 * that we have already failed to find extents that will work.
3012 */
3013 static noinline int
setup_cluster_bitmap(struct btrfs_block_group_cache * block_group,struct btrfs_free_cluster * cluster,struct list_head * bitmaps,u64 offset,u64 bytes,u64 cont1_bytes,u64 min_bytes)3014 setup_cluster_bitmap(struct btrfs_block_group_cache *block_group,
3015 struct btrfs_free_cluster *cluster,
3016 struct list_head *bitmaps, u64 offset, u64 bytes,
3017 u64 cont1_bytes, u64 min_bytes)
3018 {
3019 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
3020 struct btrfs_free_space *entry = NULL;
3021 int ret = -ENOSPC;
3022 u64 bitmap_offset = offset_to_bitmap(ctl, offset);
3023
3024 if (ctl->total_bitmaps == 0)
3025 return -ENOSPC;
3026
3027 /*
3028 * The bitmap that covers offset won't be in the list unless offset
3029 * is just its start offset.
3030 */
3031 if (!list_empty(bitmaps))
3032 entry = list_first_entry(bitmaps, struct btrfs_free_space, list);
3033
3034 if (!entry || entry->offset != bitmap_offset) {
3035 entry = tree_search_offset(ctl, bitmap_offset, 1, 0);
3036 if (entry && list_empty(&entry->list))
3037 list_add(&entry->list, bitmaps);
3038 }
3039
3040 list_for_each_entry(entry, bitmaps, list) {
3041 if (entry->bytes < bytes)
3042 continue;
3043 ret = btrfs_bitmap_cluster(block_group, entry, cluster, offset,
3044 bytes, cont1_bytes, min_bytes);
3045 if (!ret)
3046 return 0;
3047 }
3048
3049 /*
3050 * The bitmaps list has all the bitmaps that record free space
3051 * starting after offset, so no more search is required.
3052 */
3053 return -ENOSPC;
3054 }
3055
3056 /*
3057 * here we try to find a cluster of blocks in a block group. The goal
3058 * is to find at least bytes+empty_size.
3059 * We might not find them all in one contiguous area.
3060 *
3061 * returns zero and sets up cluster if things worked out, otherwise
3062 * it returns -enospc
3063 */
btrfs_find_space_cluster(struct btrfs_block_group_cache * block_group,struct btrfs_free_cluster * cluster,u64 offset,u64 bytes,u64 empty_size)3064 int btrfs_find_space_cluster(struct btrfs_block_group_cache *block_group,
3065 struct btrfs_free_cluster *cluster,
3066 u64 offset, u64 bytes, u64 empty_size)
3067 {
3068 struct btrfs_fs_info *fs_info = block_group->fs_info;
3069 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
3070 struct btrfs_free_space *entry, *tmp;
3071 LIST_HEAD(bitmaps);
3072 u64 min_bytes;
3073 u64 cont1_bytes;
3074 int ret;
3075
3076 /*
3077 * Choose the minimum extent size we'll require for this
3078 * cluster. For SSD_SPREAD, don't allow any fragmentation.
3079 * For metadata, allow allocates with smaller extents. For
3080 * data, keep it dense.
3081 */
3082 if (btrfs_test_opt(fs_info, SSD_SPREAD)) {
3083 cont1_bytes = min_bytes = bytes + empty_size;
3084 } else if (block_group->flags & BTRFS_BLOCK_GROUP_METADATA) {
3085 cont1_bytes = bytes;
3086 min_bytes = fs_info->sectorsize;
3087 } else {
3088 cont1_bytes = max(bytes, (bytes + empty_size) >> 2);
3089 min_bytes = fs_info->sectorsize;
3090 }
3091
3092 spin_lock(&ctl->tree_lock);
3093
3094 /*
3095 * If we know we don't have enough space to make a cluster don't even
3096 * bother doing all the work to try and find one.
3097 */
3098 if (ctl->free_space < bytes) {
3099 spin_unlock(&ctl->tree_lock);
3100 return -ENOSPC;
3101 }
3102
3103 spin_lock(&cluster->lock);
3104
3105 /* someone already found a cluster, hooray */
3106 if (cluster->block_group) {
3107 ret = 0;
3108 goto out;
3109 }
3110
3111 trace_btrfs_find_cluster(block_group, offset, bytes, empty_size,
3112 min_bytes);
3113
3114 ret = setup_cluster_no_bitmap(block_group, cluster, &bitmaps, offset,
3115 bytes + empty_size,
3116 cont1_bytes, min_bytes);
3117 if (ret)
3118 ret = setup_cluster_bitmap(block_group, cluster, &bitmaps,
3119 offset, bytes + empty_size,
3120 cont1_bytes, min_bytes);
3121
3122 /* Clear our temporary list */
3123 list_for_each_entry_safe(entry, tmp, &bitmaps, list)
3124 list_del_init(&entry->list);
3125
3126 if (!ret) {
3127 atomic_inc(&block_group->count);
3128 list_add_tail(&cluster->block_group_list,
3129 &block_group->cluster_list);
3130 cluster->block_group = block_group;
3131 } else {
3132 trace_btrfs_failed_cluster_setup(block_group);
3133 }
3134 out:
3135 spin_unlock(&cluster->lock);
3136 spin_unlock(&ctl->tree_lock);
3137
3138 return ret;
3139 }
3140
3141 /*
3142 * simple code to zero out a cluster
3143 */
btrfs_init_free_cluster(struct btrfs_free_cluster * cluster)3144 void btrfs_init_free_cluster(struct btrfs_free_cluster *cluster)
3145 {
3146 spin_lock_init(&cluster->lock);
3147 spin_lock_init(&cluster->refill_lock);
3148 cluster->root = RB_ROOT;
3149 cluster->max_size = 0;
3150 cluster->fragmented = false;
3151 INIT_LIST_HEAD(&cluster->block_group_list);
3152 cluster->block_group = NULL;
3153 }
3154
do_trimming(struct btrfs_block_group_cache * block_group,u64 * total_trimmed,u64 start,u64 bytes,u64 reserved_start,u64 reserved_bytes,struct btrfs_trim_range * trim_entry)3155 static int do_trimming(struct btrfs_block_group_cache *block_group,
3156 u64 *total_trimmed, u64 start, u64 bytes,
3157 u64 reserved_start, u64 reserved_bytes,
3158 struct btrfs_trim_range *trim_entry)
3159 {
3160 struct btrfs_space_info *space_info = block_group->space_info;
3161 struct btrfs_fs_info *fs_info = block_group->fs_info;
3162 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
3163 int ret;
3164 int update = 0;
3165 u64 trimmed = 0;
3166
3167 spin_lock(&space_info->lock);
3168 spin_lock(&block_group->lock);
3169 if (!block_group->ro) {
3170 block_group->reserved += reserved_bytes;
3171 space_info->bytes_reserved += reserved_bytes;
3172 update = 1;
3173 }
3174 spin_unlock(&block_group->lock);
3175 spin_unlock(&space_info->lock);
3176
3177 ret = btrfs_discard_extent(fs_info, start, bytes, &trimmed);
3178 if (!ret)
3179 *total_trimmed += trimmed;
3180
3181 mutex_lock(&ctl->cache_writeout_mutex);
3182 btrfs_add_free_space(block_group, reserved_start, reserved_bytes);
3183 list_del(&trim_entry->list);
3184 mutex_unlock(&ctl->cache_writeout_mutex);
3185
3186 if (update) {
3187 spin_lock(&space_info->lock);
3188 spin_lock(&block_group->lock);
3189 if (block_group->ro)
3190 space_info->bytes_readonly += reserved_bytes;
3191 block_group->reserved -= reserved_bytes;
3192 space_info->bytes_reserved -= reserved_bytes;
3193 spin_unlock(&block_group->lock);
3194 spin_unlock(&space_info->lock);
3195 }
3196
3197 return ret;
3198 }
3199
trim_no_bitmap(struct btrfs_block_group_cache * block_group,u64 * total_trimmed,u64 start,u64 end,u64 minlen)3200 static int trim_no_bitmap(struct btrfs_block_group_cache *block_group,
3201 u64 *total_trimmed, u64 start, u64 end, u64 minlen)
3202 {
3203 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
3204 struct btrfs_free_space *entry;
3205 struct rb_node *node;
3206 int ret = 0;
3207 u64 extent_start;
3208 u64 extent_bytes;
3209 u64 bytes;
3210
3211 while (start < end) {
3212 struct btrfs_trim_range trim_entry;
3213
3214 mutex_lock(&ctl->cache_writeout_mutex);
3215 spin_lock(&ctl->tree_lock);
3216
3217 if (ctl->free_space < minlen) {
3218 spin_unlock(&ctl->tree_lock);
3219 mutex_unlock(&ctl->cache_writeout_mutex);
3220 break;
3221 }
3222
3223 entry = tree_search_offset(ctl, start, 0, 1);
3224 if (!entry) {
3225 spin_unlock(&ctl->tree_lock);
3226 mutex_unlock(&ctl->cache_writeout_mutex);
3227 break;
3228 }
3229
3230 /* skip bitmaps */
3231 while (entry->bitmap) {
3232 node = rb_next(&entry->offset_index);
3233 if (!node) {
3234 spin_unlock(&ctl->tree_lock);
3235 mutex_unlock(&ctl->cache_writeout_mutex);
3236 goto out;
3237 }
3238 entry = rb_entry(node, struct btrfs_free_space,
3239 offset_index);
3240 }
3241
3242 if (entry->offset >= end) {
3243 spin_unlock(&ctl->tree_lock);
3244 mutex_unlock(&ctl->cache_writeout_mutex);
3245 break;
3246 }
3247
3248 extent_start = entry->offset;
3249 extent_bytes = entry->bytes;
3250 start = max(start, extent_start);
3251 bytes = min(extent_start + extent_bytes, end) - start;
3252 if (bytes < minlen) {
3253 spin_unlock(&ctl->tree_lock);
3254 mutex_unlock(&ctl->cache_writeout_mutex);
3255 goto next;
3256 }
3257
3258 unlink_free_space(ctl, entry);
3259 kmem_cache_free(btrfs_free_space_cachep, entry);
3260
3261 spin_unlock(&ctl->tree_lock);
3262 trim_entry.start = extent_start;
3263 trim_entry.bytes = extent_bytes;
3264 list_add_tail(&trim_entry.list, &ctl->trimming_ranges);
3265 mutex_unlock(&ctl->cache_writeout_mutex);
3266
3267 ret = do_trimming(block_group, total_trimmed, start, bytes,
3268 extent_start, extent_bytes, &trim_entry);
3269 if (ret)
3270 break;
3271 next:
3272 start += bytes;
3273
3274 if (fatal_signal_pending(current)) {
3275 ret = -ERESTARTSYS;
3276 break;
3277 }
3278
3279 cond_resched();
3280 }
3281 out:
3282 return ret;
3283 }
3284
trim_bitmaps(struct btrfs_block_group_cache * block_group,u64 * total_trimmed,u64 start,u64 end,u64 minlen)3285 static int trim_bitmaps(struct btrfs_block_group_cache *block_group,
3286 u64 *total_trimmed, u64 start, u64 end, u64 minlen)
3287 {
3288 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
3289 struct btrfs_free_space *entry;
3290 int ret = 0;
3291 int ret2;
3292 u64 bytes;
3293 u64 offset = offset_to_bitmap(ctl, start);
3294
3295 while (offset < end) {
3296 bool next_bitmap = false;
3297 struct btrfs_trim_range trim_entry;
3298
3299 mutex_lock(&ctl->cache_writeout_mutex);
3300 spin_lock(&ctl->tree_lock);
3301
3302 if (ctl->free_space < minlen) {
3303 spin_unlock(&ctl->tree_lock);
3304 mutex_unlock(&ctl->cache_writeout_mutex);
3305 break;
3306 }
3307
3308 entry = tree_search_offset(ctl, offset, 1, 0);
3309 if (!entry) {
3310 spin_unlock(&ctl->tree_lock);
3311 mutex_unlock(&ctl->cache_writeout_mutex);
3312 next_bitmap = true;
3313 goto next;
3314 }
3315
3316 bytes = minlen;
3317 ret2 = search_bitmap(ctl, entry, &start, &bytes, false);
3318 if (ret2 || start >= end) {
3319 spin_unlock(&ctl->tree_lock);
3320 mutex_unlock(&ctl->cache_writeout_mutex);
3321 next_bitmap = true;
3322 goto next;
3323 }
3324
3325 bytes = min(bytes, end - start);
3326 if (bytes < minlen) {
3327 spin_unlock(&ctl->tree_lock);
3328 mutex_unlock(&ctl->cache_writeout_mutex);
3329 goto next;
3330 }
3331
3332 bitmap_clear_bits(ctl, entry, start, bytes);
3333 if (entry->bytes == 0)
3334 free_bitmap(ctl, entry);
3335
3336 spin_unlock(&ctl->tree_lock);
3337 trim_entry.start = start;
3338 trim_entry.bytes = bytes;
3339 list_add_tail(&trim_entry.list, &ctl->trimming_ranges);
3340 mutex_unlock(&ctl->cache_writeout_mutex);
3341
3342 ret = do_trimming(block_group, total_trimmed, start, bytes,
3343 start, bytes, &trim_entry);
3344 if (ret)
3345 break;
3346 next:
3347 if (next_bitmap) {
3348 offset += BITS_PER_BITMAP * ctl->unit;
3349 } else {
3350 start += bytes;
3351 if (start >= offset + BITS_PER_BITMAP * ctl->unit)
3352 offset += BITS_PER_BITMAP * ctl->unit;
3353 }
3354
3355 if (fatal_signal_pending(current)) {
3356 ret = -ERESTARTSYS;
3357 break;
3358 }
3359
3360 cond_resched();
3361 }
3362
3363 return ret;
3364 }
3365
btrfs_get_block_group_trimming(struct btrfs_block_group_cache * cache)3366 void btrfs_get_block_group_trimming(struct btrfs_block_group_cache *cache)
3367 {
3368 atomic_inc(&cache->trimming);
3369 }
3370
btrfs_put_block_group_trimming(struct btrfs_block_group_cache * block_group)3371 void btrfs_put_block_group_trimming(struct btrfs_block_group_cache *block_group)
3372 {
3373 struct btrfs_fs_info *fs_info = block_group->fs_info;
3374 struct extent_map_tree *em_tree;
3375 struct extent_map *em;
3376 bool cleanup;
3377
3378 spin_lock(&block_group->lock);
3379 cleanup = (atomic_dec_and_test(&block_group->trimming) &&
3380 block_group->removed);
3381 spin_unlock(&block_group->lock);
3382
3383 if (cleanup) {
3384 mutex_lock(&fs_info->chunk_mutex);
3385 em_tree = &fs_info->mapping_tree;
3386 write_lock(&em_tree->lock);
3387 em = lookup_extent_mapping(em_tree, block_group->key.objectid,
3388 1);
3389 BUG_ON(!em); /* logic error, can't happen */
3390 remove_extent_mapping(em_tree, em);
3391 write_unlock(&em_tree->lock);
3392 mutex_unlock(&fs_info->chunk_mutex);
3393
3394 /* once for us and once for the tree */
3395 free_extent_map(em);
3396 free_extent_map(em);
3397
3398 /*
3399 * We've left one free space entry and other tasks trimming
3400 * this block group have left 1 entry each one. Free them.
3401 */
3402 __btrfs_remove_free_space_cache(block_group->free_space_ctl);
3403 }
3404 }
3405
btrfs_trim_block_group(struct btrfs_block_group_cache * block_group,u64 * trimmed,u64 start,u64 end,u64 minlen)3406 int btrfs_trim_block_group(struct btrfs_block_group_cache *block_group,
3407 u64 *trimmed, u64 start, u64 end, u64 minlen)
3408 {
3409 int ret;
3410
3411 *trimmed = 0;
3412
3413 spin_lock(&block_group->lock);
3414 if (block_group->removed) {
3415 spin_unlock(&block_group->lock);
3416 return 0;
3417 }
3418 btrfs_get_block_group_trimming(block_group);
3419 spin_unlock(&block_group->lock);
3420
3421 ret = trim_no_bitmap(block_group, trimmed, start, end, minlen);
3422 if (ret)
3423 goto out;
3424
3425 ret = trim_bitmaps(block_group, trimmed, start, end, minlen);
3426 out:
3427 btrfs_put_block_group_trimming(block_group);
3428 return ret;
3429 }
3430
3431 /*
3432 * Find the left-most item in the cache tree, and then return the
3433 * smallest inode number in the item.
3434 *
3435 * Note: the returned inode number may not be the smallest one in
3436 * the tree, if the left-most item is a bitmap.
3437 */
btrfs_find_ino_for_alloc(struct btrfs_root * fs_root)3438 u64 btrfs_find_ino_for_alloc(struct btrfs_root *fs_root)
3439 {
3440 struct btrfs_free_space_ctl *ctl = fs_root->free_ino_ctl;
3441 struct btrfs_free_space *entry = NULL;
3442 u64 ino = 0;
3443
3444 spin_lock(&ctl->tree_lock);
3445
3446 if (RB_EMPTY_ROOT(&ctl->free_space_offset))
3447 goto out;
3448
3449 entry = rb_entry(rb_first(&ctl->free_space_offset),
3450 struct btrfs_free_space, offset_index);
3451
3452 if (!entry->bitmap) {
3453 ino = entry->offset;
3454
3455 unlink_free_space(ctl, entry);
3456 entry->offset++;
3457 entry->bytes--;
3458 if (!entry->bytes)
3459 kmem_cache_free(btrfs_free_space_cachep, entry);
3460 else
3461 link_free_space(ctl, entry);
3462 } else {
3463 u64 offset = 0;
3464 u64 count = 1;
3465 int ret;
3466
3467 ret = search_bitmap(ctl, entry, &offset, &count, true);
3468 /* Logic error; Should be empty if it can't find anything */
3469 ASSERT(!ret);
3470
3471 ino = offset;
3472 bitmap_clear_bits(ctl, entry, offset, 1);
3473 if (entry->bytes == 0)
3474 free_bitmap(ctl, entry);
3475 }
3476 out:
3477 spin_unlock(&ctl->tree_lock);
3478
3479 return ino;
3480 }
3481
lookup_free_ino_inode(struct btrfs_root * root,struct btrfs_path * path)3482 struct inode *lookup_free_ino_inode(struct btrfs_root *root,
3483 struct btrfs_path *path)
3484 {
3485 struct inode *inode = NULL;
3486
3487 spin_lock(&root->ino_cache_lock);
3488 if (root->ino_cache_inode)
3489 inode = igrab(root->ino_cache_inode);
3490 spin_unlock(&root->ino_cache_lock);
3491 if (inode)
3492 return inode;
3493
3494 inode = __lookup_free_space_inode(root, path, 0);
3495 if (IS_ERR(inode))
3496 return inode;
3497
3498 spin_lock(&root->ino_cache_lock);
3499 if (!btrfs_fs_closing(root->fs_info))
3500 root->ino_cache_inode = igrab(inode);
3501 spin_unlock(&root->ino_cache_lock);
3502
3503 return inode;
3504 }
3505
create_free_ino_inode(struct btrfs_root * root,struct btrfs_trans_handle * trans,struct btrfs_path * path)3506 int create_free_ino_inode(struct btrfs_root *root,
3507 struct btrfs_trans_handle *trans,
3508 struct btrfs_path *path)
3509 {
3510 return __create_free_space_inode(root, trans, path,
3511 BTRFS_FREE_INO_OBJECTID, 0);
3512 }
3513
load_free_ino_cache(struct btrfs_fs_info * fs_info,struct btrfs_root * root)3514 int load_free_ino_cache(struct btrfs_fs_info *fs_info, struct btrfs_root *root)
3515 {
3516 struct btrfs_free_space_ctl *ctl = root->free_ino_ctl;
3517 struct btrfs_path *path;
3518 struct inode *inode;
3519 int ret = 0;
3520 u64 root_gen = btrfs_root_generation(&root->root_item);
3521
3522 if (!btrfs_test_opt(fs_info, INODE_MAP_CACHE))
3523 return 0;
3524
3525 /*
3526 * If we're unmounting then just return, since this does a search on the
3527 * normal root and not the commit root and we could deadlock.
3528 */
3529 if (btrfs_fs_closing(fs_info))
3530 return 0;
3531
3532 path = btrfs_alloc_path();
3533 if (!path)
3534 return 0;
3535
3536 inode = lookup_free_ino_inode(root, path);
3537 if (IS_ERR(inode))
3538 goto out;
3539
3540 if (root_gen != BTRFS_I(inode)->generation)
3541 goto out_put;
3542
3543 ret = __load_free_space_cache(root, inode, ctl, path, 0);
3544
3545 if (ret < 0)
3546 btrfs_err(fs_info,
3547 "failed to load free ino cache for root %llu",
3548 root->root_key.objectid);
3549 out_put:
3550 iput(inode);
3551 out:
3552 btrfs_free_path(path);
3553 return ret;
3554 }
3555
btrfs_write_out_ino_cache(struct btrfs_root * root,struct btrfs_trans_handle * trans,struct btrfs_path * path,struct inode * inode)3556 int btrfs_write_out_ino_cache(struct btrfs_root *root,
3557 struct btrfs_trans_handle *trans,
3558 struct btrfs_path *path,
3559 struct inode *inode)
3560 {
3561 struct btrfs_fs_info *fs_info = root->fs_info;
3562 struct btrfs_free_space_ctl *ctl = root->free_ino_ctl;
3563 int ret;
3564 struct btrfs_io_ctl io_ctl;
3565 bool release_metadata = true;
3566
3567 if (!btrfs_test_opt(fs_info, INODE_MAP_CACHE))
3568 return 0;
3569
3570 memset(&io_ctl, 0, sizeof(io_ctl));
3571 ret = __btrfs_write_out_cache(root, inode, ctl, NULL, &io_ctl, trans);
3572 if (!ret) {
3573 /*
3574 * At this point writepages() didn't error out, so our metadata
3575 * reservation is released when the writeback finishes, at
3576 * inode.c:btrfs_finish_ordered_io(), regardless of it finishing
3577 * with or without an error.
3578 */
3579 release_metadata = false;
3580 ret = btrfs_wait_cache_io_root(root, trans, &io_ctl, path);
3581 }
3582
3583 if (ret) {
3584 if (release_metadata)
3585 btrfs_delalloc_release_metadata(BTRFS_I(inode),
3586 inode->i_size, true);
3587 #ifdef DEBUG
3588 btrfs_err(fs_info,
3589 "failed to write free ino cache for root %llu",
3590 root->root_key.objectid);
3591 #endif
3592 }
3593
3594 return ret;
3595 }
3596
3597 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
3598 /*
3599 * Use this if you need to make a bitmap or extent entry specifically, it
3600 * doesn't do any of the merging that add_free_space does, this acts a lot like
3601 * how the free space cache loading stuff works, so you can get really weird
3602 * configurations.
3603 */
test_add_free_space_entry(struct btrfs_block_group_cache * cache,u64 offset,u64 bytes,bool bitmap)3604 int test_add_free_space_entry(struct btrfs_block_group_cache *cache,
3605 u64 offset, u64 bytes, bool bitmap)
3606 {
3607 struct btrfs_free_space_ctl *ctl = cache->free_space_ctl;
3608 struct btrfs_free_space *info = NULL, *bitmap_info;
3609 void *map = NULL;
3610 u64 bytes_added;
3611 int ret;
3612
3613 again:
3614 if (!info) {
3615 info = kmem_cache_zalloc(btrfs_free_space_cachep, GFP_NOFS);
3616 if (!info)
3617 return -ENOMEM;
3618 }
3619
3620 if (!bitmap) {
3621 spin_lock(&ctl->tree_lock);
3622 info->offset = offset;
3623 info->bytes = bytes;
3624 info->max_extent_size = 0;
3625 ret = link_free_space(ctl, info);
3626 spin_unlock(&ctl->tree_lock);
3627 if (ret)
3628 kmem_cache_free(btrfs_free_space_cachep, info);
3629 return ret;
3630 }
3631
3632 if (!map) {
3633 map = kmem_cache_zalloc(btrfs_free_space_bitmap_cachep, GFP_NOFS);
3634 if (!map) {
3635 kmem_cache_free(btrfs_free_space_cachep, info);
3636 return -ENOMEM;
3637 }
3638 }
3639
3640 spin_lock(&ctl->tree_lock);
3641 bitmap_info = tree_search_offset(ctl, offset_to_bitmap(ctl, offset),
3642 1, 0);
3643 if (!bitmap_info) {
3644 info->bitmap = map;
3645 map = NULL;
3646 add_new_bitmap(ctl, info, offset);
3647 bitmap_info = info;
3648 info = NULL;
3649 }
3650
3651 bytes_added = add_bytes_to_bitmap(ctl, bitmap_info, offset, bytes);
3652
3653 bytes -= bytes_added;
3654 offset += bytes_added;
3655 spin_unlock(&ctl->tree_lock);
3656
3657 if (bytes)
3658 goto again;
3659
3660 if (info)
3661 kmem_cache_free(btrfs_free_space_cachep, info);
3662 if (map)
3663 kmem_cache_free(btrfs_free_space_bitmap_cachep, map);
3664 return 0;
3665 }
3666
3667 /*
3668 * Checks to see if the given range is in the free space cache. This is really
3669 * just used to check the absence of space, so if there is free space in the
3670 * range at all we will return 1.
3671 */
test_check_exists(struct btrfs_block_group_cache * cache,u64 offset,u64 bytes)3672 int test_check_exists(struct btrfs_block_group_cache *cache,
3673 u64 offset, u64 bytes)
3674 {
3675 struct btrfs_free_space_ctl *ctl = cache->free_space_ctl;
3676 struct btrfs_free_space *info;
3677 int ret = 0;
3678
3679 spin_lock(&ctl->tree_lock);
3680 info = tree_search_offset(ctl, offset, 0, 0);
3681 if (!info) {
3682 info = tree_search_offset(ctl, offset_to_bitmap(ctl, offset),
3683 1, 0);
3684 if (!info)
3685 goto out;
3686 }
3687
3688 have_info:
3689 if (info->bitmap) {
3690 u64 bit_off, bit_bytes;
3691 struct rb_node *n;
3692 struct btrfs_free_space *tmp;
3693
3694 bit_off = offset;
3695 bit_bytes = ctl->unit;
3696 ret = search_bitmap(ctl, info, &bit_off, &bit_bytes, false);
3697 if (!ret) {
3698 if (bit_off == offset) {
3699 ret = 1;
3700 goto out;
3701 } else if (bit_off > offset &&
3702 offset + bytes > bit_off) {
3703 ret = 1;
3704 goto out;
3705 }
3706 }
3707
3708 n = rb_prev(&info->offset_index);
3709 while (n) {
3710 tmp = rb_entry(n, struct btrfs_free_space,
3711 offset_index);
3712 if (tmp->offset + tmp->bytes < offset)
3713 break;
3714 if (offset + bytes < tmp->offset) {
3715 n = rb_prev(&tmp->offset_index);
3716 continue;
3717 }
3718 info = tmp;
3719 goto have_info;
3720 }
3721
3722 n = rb_next(&info->offset_index);
3723 while (n) {
3724 tmp = rb_entry(n, struct btrfs_free_space,
3725 offset_index);
3726 if (offset + bytes < tmp->offset)
3727 break;
3728 if (tmp->offset + tmp->bytes < offset) {
3729 n = rb_next(&tmp->offset_index);
3730 continue;
3731 }
3732 info = tmp;
3733 goto have_info;
3734 }
3735
3736 ret = 0;
3737 goto out;
3738 }
3739
3740 if (info->offset == offset) {
3741 ret = 1;
3742 goto out;
3743 }
3744
3745 if (offset > info->offset && offset < info->offset + info->bytes)
3746 ret = 1;
3747 out:
3748 spin_unlock(&ctl->tree_lock);
3749 return ret;
3750 }
3751 #endif /* CONFIG_BTRFS_FS_RUN_SANITY_TESTS */
3752