1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Copyright (C) 2007 Oracle. All rights reserved.
4 */
5
6 #include <linux/sched.h>
7 #include <linux/sched/signal.h>
8 #include <linux/pagemap.h>
9 #include <linux/writeback.h>
10 #include <linux/blkdev.h>
11 #include <linux/sort.h>
12 #include <linux/rcupdate.h>
13 #include <linux/kthread.h>
14 #include <linux/slab.h>
15 #include <linux/ratelimit.h>
16 #include <linux/percpu_counter.h>
17 #include <linux/lockdep.h>
18 #include <linux/crc32c.h>
19 #include "misc.h"
20 #include "tree-log.h"
21 #include "disk-io.h"
22 #include "print-tree.h"
23 #include "volumes.h"
24 #include "raid56.h"
25 #include "locking.h"
26 #include "free-space-cache.h"
27 #include "free-space-tree.h"
28 #include "sysfs.h"
29 #include "qgroup.h"
30 #include "ref-verify.h"
31 #include "space-info.h"
32 #include "block-rsv.h"
33 #include "delalloc-space.h"
34 #include "block-group.h"
35 #include "discard.h"
36 #include "rcu-string.h"
37 #include "zoned.h"
38 #include "dev-replace.h"
39
40 #undef SCRAMBLE_DELAYED_REFS
41
42
43 static int __btrfs_free_extent(struct btrfs_trans_handle *trans,
44 struct btrfs_delayed_ref_node *node, u64 parent,
45 u64 root_objectid, u64 owner_objectid,
46 u64 owner_offset, int refs_to_drop,
47 struct btrfs_delayed_extent_op *extra_op);
48 static void __run_delayed_extent_op(struct btrfs_delayed_extent_op *extent_op,
49 struct extent_buffer *leaf,
50 struct btrfs_extent_item *ei);
51 static int alloc_reserved_file_extent(struct btrfs_trans_handle *trans,
52 u64 parent, u64 root_objectid,
53 u64 flags, u64 owner, u64 offset,
54 struct btrfs_key *ins, int ref_mod);
55 static int alloc_reserved_tree_block(struct btrfs_trans_handle *trans,
56 struct btrfs_delayed_ref_node *node,
57 struct btrfs_delayed_extent_op *extent_op);
58 static int find_next_key(struct btrfs_path *path, int level,
59 struct btrfs_key *key);
60
block_group_bits(struct btrfs_block_group * cache,u64 bits)61 static int block_group_bits(struct btrfs_block_group *cache, u64 bits)
62 {
63 return (cache->flags & bits) == bits;
64 }
65
btrfs_add_excluded_extent(struct btrfs_fs_info * fs_info,u64 start,u64 num_bytes)66 int btrfs_add_excluded_extent(struct btrfs_fs_info *fs_info,
67 u64 start, u64 num_bytes)
68 {
69 u64 end = start + num_bytes - 1;
70 set_extent_bits(&fs_info->excluded_extents, start, end,
71 EXTENT_UPTODATE);
72 return 0;
73 }
74
btrfs_free_excluded_extents(struct btrfs_block_group * cache)75 void btrfs_free_excluded_extents(struct btrfs_block_group *cache)
76 {
77 struct btrfs_fs_info *fs_info = cache->fs_info;
78 u64 start, end;
79
80 start = cache->start;
81 end = start + cache->length - 1;
82
83 clear_extent_bits(&fs_info->excluded_extents, start, end,
84 EXTENT_UPTODATE);
85 }
86
87 /* simple helper to search for an existing data extent at a given offset */
btrfs_lookup_data_extent(struct btrfs_fs_info * fs_info,u64 start,u64 len)88 int btrfs_lookup_data_extent(struct btrfs_fs_info *fs_info, u64 start, u64 len)
89 {
90 struct btrfs_root *root = btrfs_extent_root(fs_info, start);
91 int ret;
92 struct btrfs_key key;
93 struct btrfs_path *path;
94
95 path = btrfs_alloc_path();
96 if (!path)
97 return -ENOMEM;
98
99 key.objectid = start;
100 key.offset = len;
101 key.type = BTRFS_EXTENT_ITEM_KEY;
102 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
103 btrfs_free_path(path);
104 return ret;
105 }
106
107 /*
108 * helper function to lookup reference count and flags of a tree block.
109 *
110 * the head node for delayed ref is used to store the sum of all the
111 * reference count modifications queued up in the rbtree. the head
112 * node may also store the extent flags to set. This way you can check
113 * to see what the reference count and extent flags would be if all of
114 * the delayed refs are not processed.
115 */
btrfs_lookup_extent_info(struct btrfs_trans_handle * trans,struct btrfs_fs_info * fs_info,u64 bytenr,u64 offset,int metadata,u64 * refs,u64 * flags)116 int btrfs_lookup_extent_info(struct btrfs_trans_handle *trans,
117 struct btrfs_fs_info *fs_info, u64 bytenr,
118 u64 offset, int metadata, u64 *refs, u64 *flags)
119 {
120 struct btrfs_root *extent_root;
121 struct btrfs_delayed_ref_head *head;
122 struct btrfs_delayed_ref_root *delayed_refs;
123 struct btrfs_path *path;
124 struct btrfs_extent_item *ei;
125 struct extent_buffer *leaf;
126 struct btrfs_key key;
127 u32 item_size;
128 u64 num_refs;
129 u64 extent_flags;
130 int ret;
131
132 /*
133 * If we don't have skinny metadata, don't bother doing anything
134 * different
135 */
136 if (metadata && !btrfs_fs_incompat(fs_info, SKINNY_METADATA)) {
137 offset = fs_info->nodesize;
138 metadata = 0;
139 }
140
141 path = btrfs_alloc_path();
142 if (!path)
143 return -ENOMEM;
144
145 if (!trans) {
146 path->skip_locking = 1;
147 path->search_commit_root = 1;
148 }
149
150 search_again:
151 key.objectid = bytenr;
152 key.offset = offset;
153 if (metadata)
154 key.type = BTRFS_METADATA_ITEM_KEY;
155 else
156 key.type = BTRFS_EXTENT_ITEM_KEY;
157
158 extent_root = btrfs_extent_root(fs_info, bytenr);
159 ret = btrfs_search_slot(NULL, extent_root, &key, path, 0, 0);
160 if (ret < 0)
161 goto out_free;
162
163 if (ret > 0 && metadata && key.type == BTRFS_METADATA_ITEM_KEY) {
164 if (path->slots[0]) {
165 path->slots[0]--;
166 btrfs_item_key_to_cpu(path->nodes[0], &key,
167 path->slots[0]);
168 if (key.objectid == bytenr &&
169 key.type == BTRFS_EXTENT_ITEM_KEY &&
170 key.offset == fs_info->nodesize)
171 ret = 0;
172 }
173 }
174
175 if (ret == 0) {
176 leaf = path->nodes[0];
177 item_size = btrfs_item_size(leaf, path->slots[0]);
178 if (item_size >= sizeof(*ei)) {
179 ei = btrfs_item_ptr(leaf, path->slots[0],
180 struct btrfs_extent_item);
181 num_refs = btrfs_extent_refs(leaf, ei);
182 extent_flags = btrfs_extent_flags(leaf, ei);
183 } else {
184 ret = -EINVAL;
185 btrfs_print_v0_err(fs_info);
186 if (trans)
187 btrfs_abort_transaction(trans, ret);
188 else
189 btrfs_handle_fs_error(fs_info, ret, NULL);
190
191 goto out_free;
192 }
193
194 BUG_ON(num_refs == 0);
195 } else {
196 num_refs = 0;
197 extent_flags = 0;
198 ret = 0;
199 }
200
201 if (!trans)
202 goto out;
203
204 delayed_refs = &trans->transaction->delayed_refs;
205 spin_lock(&delayed_refs->lock);
206 head = btrfs_find_delayed_ref_head(delayed_refs, bytenr);
207 if (head) {
208 if (!mutex_trylock(&head->mutex)) {
209 refcount_inc(&head->refs);
210 spin_unlock(&delayed_refs->lock);
211
212 btrfs_release_path(path);
213
214 /*
215 * Mutex was contended, block until it's released and try
216 * again
217 */
218 mutex_lock(&head->mutex);
219 mutex_unlock(&head->mutex);
220 btrfs_put_delayed_ref_head(head);
221 goto search_again;
222 }
223 spin_lock(&head->lock);
224 if (head->extent_op && head->extent_op->update_flags)
225 extent_flags |= head->extent_op->flags_to_set;
226 else
227 BUG_ON(num_refs == 0);
228
229 num_refs += head->ref_mod;
230 spin_unlock(&head->lock);
231 mutex_unlock(&head->mutex);
232 }
233 spin_unlock(&delayed_refs->lock);
234 out:
235 WARN_ON(num_refs == 0);
236 if (refs)
237 *refs = num_refs;
238 if (flags)
239 *flags = extent_flags;
240 out_free:
241 btrfs_free_path(path);
242 return ret;
243 }
244
245 /*
246 * Back reference rules. Back refs have three main goals:
247 *
248 * 1) differentiate between all holders of references to an extent so that
249 * when a reference is dropped we can make sure it was a valid reference
250 * before freeing the extent.
251 *
252 * 2) Provide enough information to quickly find the holders of an extent
253 * if we notice a given block is corrupted or bad.
254 *
255 * 3) Make it easy to migrate blocks for FS shrinking or storage pool
256 * maintenance. This is actually the same as #2, but with a slightly
257 * different use case.
258 *
259 * There are two kinds of back refs. The implicit back refs is optimized
260 * for pointers in non-shared tree blocks. For a given pointer in a block,
261 * back refs of this kind provide information about the block's owner tree
262 * and the pointer's key. These information allow us to find the block by
263 * b-tree searching. The full back refs is for pointers in tree blocks not
264 * referenced by their owner trees. The location of tree block is recorded
265 * in the back refs. Actually the full back refs is generic, and can be
266 * used in all cases the implicit back refs is used. The major shortcoming
267 * of the full back refs is its overhead. Every time a tree block gets
268 * COWed, we have to update back refs entry for all pointers in it.
269 *
270 * For a newly allocated tree block, we use implicit back refs for
271 * pointers in it. This means most tree related operations only involve
272 * implicit back refs. For a tree block created in old transaction, the
273 * only way to drop a reference to it is COW it. So we can detect the
274 * event that tree block loses its owner tree's reference and do the
275 * back refs conversion.
276 *
277 * When a tree block is COWed through a tree, there are four cases:
278 *
279 * The reference count of the block is one and the tree is the block's
280 * owner tree. Nothing to do in this case.
281 *
282 * The reference count of the block is one and the tree is not the
283 * block's owner tree. In this case, full back refs is used for pointers
284 * in the block. Remove these full back refs, add implicit back refs for
285 * every pointers in the new block.
286 *
287 * The reference count of the block is greater than one and the tree is
288 * the block's owner tree. In this case, implicit back refs is used for
289 * pointers in the block. Add full back refs for every pointers in the
290 * block, increase lower level extents' reference counts. The original
291 * implicit back refs are entailed to the new block.
292 *
293 * The reference count of the block is greater than one and the tree is
294 * not the block's owner tree. Add implicit back refs for every pointer in
295 * the new block, increase lower level extents' reference count.
296 *
297 * Back Reference Key composing:
298 *
299 * The key objectid corresponds to the first byte in the extent,
300 * The key type is used to differentiate between types of back refs.
301 * There are different meanings of the key offset for different types
302 * of back refs.
303 *
304 * File extents can be referenced by:
305 *
306 * - multiple snapshots, subvolumes, or different generations in one subvol
307 * - different files inside a single subvolume
308 * - different offsets inside a file (bookend extents in file.c)
309 *
310 * The extent ref structure for the implicit back refs has fields for:
311 *
312 * - Objectid of the subvolume root
313 * - objectid of the file holding the reference
314 * - original offset in the file
315 * - how many bookend extents
316 *
317 * The key offset for the implicit back refs is hash of the first
318 * three fields.
319 *
320 * The extent ref structure for the full back refs has field for:
321 *
322 * - number of pointers in the tree leaf
323 *
324 * The key offset for the implicit back refs is the first byte of
325 * the tree leaf
326 *
327 * When a file extent is allocated, The implicit back refs is used.
328 * the fields are filled in:
329 *
330 * (root_key.objectid, inode objectid, offset in file, 1)
331 *
332 * When a file extent is removed file truncation, we find the
333 * corresponding implicit back refs and check the following fields:
334 *
335 * (btrfs_header_owner(leaf), inode objectid, offset in file)
336 *
337 * Btree extents can be referenced by:
338 *
339 * - Different subvolumes
340 *
341 * Both the implicit back refs and the full back refs for tree blocks
342 * only consist of key. The key offset for the implicit back refs is
343 * objectid of block's owner tree. The key offset for the full back refs
344 * is the first byte of parent block.
345 *
346 * When implicit back refs is used, information about the lowest key and
347 * level of the tree block are required. These information are stored in
348 * tree block info structure.
349 */
350
351 /*
352 * is_data == BTRFS_REF_TYPE_BLOCK, tree block type is required,
353 * is_data == BTRFS_REF_TYPE_DATA, data type is requiried,
354 * is_data == BTRFS_REF_TYPE_ANY, either type is OK.
355 */
btrfs_get_extent_inline_ref_type(const struct extent_buffer * eb,struct btrfs_extent_inline_ref * iref,enum btrfs_inline_ref_type is_data)356 int btrfs_get_extent_inline_ref_type(const struct extent_buffer *eb,
357 struct btrfs_extent_inline_ref *iref,
358 enum btrfs_inline_ref_type is_data)
359 {
360 int type = btrfs_extent_inline_ref_type(eb, iref);
361 u64 offset = btrfs_extent_inline_ref_offset(eb, iref);
362
363 if (type == BTRFS_TREE_BLOCK_REF_KEY ||
364 type == BTRFS_SHARED_BLOCK_REF_KEY ||
365 type == BTRFS_SHARED_DATA_REF_KEY ||
366 type == BTRFS_EXTENT_DATA_REF_KEY) {
367 if (is_data == BTRFS_REF_TYPE_BLOCK) {
368 if (type == BTRFS_TREE_BLOCK_REF_KEY)
369 return type;
370 if (type == BTRFS_SHARED_BLOCK_REF_KEY) {
371 ASSERT(eb->fs_info);
372 /*
373 * Every shared one has parent tree block,
374 * which must be aligned to sector size.
375 */
376 if (offset &&
377 IS_ALIGNED(offset, eb->fs_info->sectorsize))
378 return type;
379 }
380 } else if (is_data == BTRFS_REF_TYPE_DATA) {
381 if (type == BTRFS_EXTENT_DATA_REF_KEY)
382 return type;
383 if (type == BTRFS_SHARED_DATA_REF_KEY) {
384 ASSERT(eb->fs_info);
385 /*
386 * Every shared one has parent tree block,
387 * which must be aligned to sector size.
388 */
389 if (offset &&
390 IS_ALIGNED(offset, eb->fs_info->sectorsize))
391 return type;
392 }
393 } else {
394 ASSERT(is_data == BTRFS_REF_TYPE_ANY);
395 return type;
396 }
397 }
398
399 btrfs_print_leaf((struct extent_buffer *)eb);
400 btrfs_err(eb->fs_info,
401 "eb %llu iref 0x%lx invalid extent inline ref type %d",
402 eb->start, (unsigned long)iref, type);
403 WARN_ON(1);
404
405 return BTRFS_REF_TYPE_INVALID;
406 }
407
hash_extent_data_ref(u64 root_objectid,u64 owner,u64 offset)408 u64 hash_extent_data_ref(u64 root_objectid, u64 owner, u64 offset)
409 {
410 u32 high_crc = ~(u32)0;
411 u32 low_crc = ~(u32)0;
412 __le64 lenum;
413
414 lenum = cpu_to_le64(root_objectid);
415 high_crc = btrfs_crc32c(high_crc, &lenum, sizeof(lenum));
416 lenum = cpu_to_le64(owner);
417 low_crc = btrfs_crc32c(low_crc, &lenum, sizeof(lenum));
418 lenum = cpu_to_le64(offset);
419 low_crc = btrfs_crc32c(low_crc, &lenum, sizeof(lenum));
420
421 return ((u64)high_crc << 31) ^ (u64)low_crc;
422 }
423
hash_extent_data_ref_item(struct extent_buffer * leaf,struct btrfs_extent_data_ref * ref)424 static u64 hash_extent_data_ref_item(struct extent_buffer *leaf,
425 struct btrfs_extent_data_ref *ref)
426 {
427 return hash_extent_data_ref(btrfs_extent_data_ref_root(leaf, ref),
428 btrfs_extent_data_ref_objectid(leaf, ref),
429 btrfs_extent_data_ref_offset(leaf, ref));
430 }
431
match_extent_data_ref(struct extent_buffer * leaf,struct btrfs_extent_data_ref * ref,u64 root_objectid,u64 owner,u64 offset)432 static int match_extent_data_ref(struct extent_buffer *leaf,
433 struct btrfs_extent_data_ref *ref,
434 u64 root_objectid, u64 owner, u64 offset)
435 {
436 if (btrfs_extent_data_ref_root(leaf, ref) != root_objectid ||
437 btrfs_extent_data_ref_objectid(leaf, ref) != owner ||
438 btrfs_extent_data_ref_offset(leaf, ref) != offset)
439 return 0;
440 return 1;
441 }
442
lookup_extent_data_ref(struct btrfs_trans_handle * trans,struct btrfs_path * path,u64 bytenr,u64 parent,u64 root_objectid,u64 owner,u64 offset)443 static noinline int lookup_extent_data_ref(struct btrfs_trans_handle *trans,
444 struct btrfs_path *path,
445 u64 bytenr, u64 parent,
446 u64 root_objectid,
447 u64 owner, u64 offset)
448 {
449 struct btrfs_root *root = btrfs_extent_root(trans->fs_info, bytenr);
450 struct btrfs_key key;
451 struct btrfs_extent_data_ref *ref;
452 struct extent_buffer *leaf;
453 u32 nritems;
454 int ret;
455 int recow;
456 int err = -ENOENT;
457
458 key.objectid = bytenr;
459 if (parent) {
460 key.type = BTRFS_SHARED_DATA_REF_KEY;
461 key.offset = parent;
462 } else {
463 key.type = BTRFS_EXTENT_DATA_REF_KEY;
464 key.offset = hash_extent_data_ref(root_objectid,
465 owner, offset);
466 }
467 again:
468 recow = 0;
469 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
470 if (ret < 0) {
471 err = ret;
472 goto fail;
473 }
474
475 if (parent) {
476 if (!ret)
477 return 0;
478 goto fail;
479 }
480
481 leaf = path->nodes[0];
482 nritems = btrfs_header_nritems(leaf);
483 while (1) {
484 if (path->slots[0] >= nritems) {
485 ret = btrfs_next_leaf(root, path);
486 if (ret < 0)
487 err = ret;
488 if (ret)
489 goto fail;
490
491 leaf = path->nodes[0];
492 nritems = btrfs_header_nritems(leaf);
493 recow = 1;
494 }
495
496 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
497 if (key.objectid != bytenr ||
498 key.type != BTRFS_EXTENT_DATA_REF_KEY)
499 goto fail;
500
501 ref = btrfs_item_ptr(leaf, path->slots[0],
502 struct btrfs_extent_data_ref);
503
504 if (match_extent_data_ref(leaf, ref, root_objectid,
505 owner, offset)) {
506 if (recow) {
507 btrfs_release_path(path);
508 goto again;
509 }
510 err = 0;
511 break;
512 }
513 path->slots[0]++;
514 }
515 fail:
516 return err;
517 }
518
insert_extent_data_ref(struct btrfs_trans_handle * trans,struct btrfs_path * path,u64 bytenr,u64 parent,u64 root_objectid,u64 owner,u64 offset,int refs_to_add)519 static noinline int insert_extent_data_ref(struct btrfs_trans_handle *trans,
520 struct btrfs_path *path,
521 u64 bytenr, u64 parent,
522 u64 root_objectid, u64 owner,
523 u64 offset, int refs_to_add)
524 {
525 struct btrfs_root *root = btrfs_extent_root(trans->fs_info, bytenr);
526 struct btrfs_key key;
527 struct extent_buffer *leaf;
528 u32 size;
529 u32 num_refs;
530 int ret;
531
532 key.objectid = bytenr;
533 if (parent) {
534 key.type = BTRFS_SHARED_DATA_REF_KEY;
535 key.offset = parent;
536 size = sizeof(struct btrfs_shared_data_ref);
537 } else {
538 key.type = BTRFS_EXTENT_DATA_REF_KEY;
539 key.offset = hash_extent_data_ref(root_objectid,
540 owner, offset);
541 size = sizeof(struct btrfs_extent_data_ref);
542 }
543
544 ret = btrfs_insert_empty_item(trans, root, path, &key, size);
545 if (ret && ret != -EEXIST)
546 goto fail;
547
548 leaf = path->nodes[0];
549 if (parent) {
550 struct btrfs_shared_data_ref *ref;
551 ref = btrfs_item_ptr(leaf, path->slots[0],
552 struct btrfs_shared_data_ref);
553 if (ret == 0) {
554 btrfs_set_shared_data_ref_count(leaf, ref, refs_to_add);
555 } else {
556 num_refs = btrfs_shared_data_ref_count(leaf, ref);
557 num_refs += refs_to_add;
558 btrfs_set_shared_data_ref_count(leaf, ref, num_refs);
559 }
560 } else {
561 struct btrfs_extent_data_ref *ref;
562 while (ret == -EEXIST) {
563 ref = btrfs_item_ptr(leaf, path->slots[0],
564 struct btrfs_extent_data_ref);
565 if (match_extent_data_ref(leaf, ref, root_objectid,
566 owner, offset))
567 break;
568 btrfs_release_path(path);
569 key.offset++;
570 ret = btrfs_insert_empty_item(trans, root, path, &key,
571 size);
572 if (ret && ret != -EEXIST)
573 goto fail;
574
575 leaf = path->nodes[0];
576 }
577 ref = btrfs_item_ptr(leaf, path->slots[0],
578 struct btrfs_extent_data_ref);
579 if (ret == 0) {
580 btrfs_set_extent_data_ref_root(leaf, ref,
581 root_objectid);
582 btrfs_set_extent_data_ref_objectid(leaf, ref, owner);
583 btrfs_set_extent_data_ref_offset(leaf, ref, offset);
584 btrfs_set_extent_data_ref_count(leaf, ref, refs_to_add);
585 } else {
586 num_refs = btrfs_extent_data_ref_count(leaf, ref);
587 num_refs += refs_to_add;
588 btrfs_set_extent_data_ref_count(leaf, ref, num_refs);
589 }
590 }
591 btrfs_mark_buffer_dirty(leaf);
592 ret = 0;
593 fail:
594 btrfs_release_path(path);
595 return ret;
596 }
597
remove_extent_data_ref(struct btrfs_trans_handle * trans,struct btrfs_root * root,struct btrfs_path * path,int refs_to_drop)598 static noinline int remove_extent_data_ref(struct btrfs_trans_handle *trans,
599 struct btrfs_root *root,
600 struct btrfs_path *path,
601 int refs_to_drop)
602 {
603 struct btrfs_key key;
604 struct btrfs_extent_data_ref *ref1 = NULL;
605 struct btrfs_shared_data_ref *ref2 = NULL;
606 struct extent_buffer *leaf;
607 u32 num_refs = 0;
608 int ret = 0;
609
610 leaf = path->nodes[0];
611 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
612
613 if (key.type == BTRFS_EXTENT_DATA_REF_KEY) {
614 ref1 = btrfs_item_ptr(leaf, path->slots[0],
615 struct btrfs_extent_data_ref);
616 num_refs = btrfs_extent_data_ref_count(leaf, ref1);
617 } else if (key.type == BTRFS_SHARED_DATA_REF_KEY) {
618 ref2 = btrfs_item_ptr(leaf, path->slots[0],
619 struct btrfs_shared_data_ref);
620 num_refs = btrfs_shared_data_ref_count(leaf, ref2);
621 } else if (unlikely(key.type == BTRFS_EXTENT_REF_V0_KEY)) {
622 btrfs_print_v0_err(trans->fs_info);
623 btrfs_abort_transaction(trans, -EINVAL);
624 return -EINVAL;
625 } else {
626 BUG();
627 }
628
629 BUG_ON(num_refs < refs_to_drop);
630 num_refs -= refs_to_drop;
631
632 if (num_refs == 0) {
633 ret = btrfs_del_item(trans, root, path);
634 } else {
635 if (key.type == BTRFS_EXTENT_DATA_REF_KEY)
636 btrfs_set_extent_data_ref_count(leaf, ref1, num_refs);
637 else if (key.type == BTRFS_SHARED_DATA_REF_KEY)
638 btrfs_set_shared_data_ref_count(leaf, ref2, num_refs);
639 btrfs_mark_buffer_dirty(leaf);
640 }
641 return ret;
642 }
643
extent_data_ref_count(struct btrfs_path * path,struct btrfs_extent_inline_ref * iref)644 static noinline u32 extent_data_ref_count(struct btrfs_path *path,
645 struct btrfs_extent_inline_ref *iref)
646 {
647 struct btrfs_key key;
648 struct extent_buffer *leaf;
649 struct btrfs_extent_data_ref *ref1;
650 struct btrfs_shared_data_ref *ref2;
651 u32 num_refs = 0;
652 int type;
653
654 leaf = path->nodes[0];
655 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
656
657 BUG_ON(key.type == BTRFS_EXTENT_REF_V0_KEY);
658 if (iref) {
659 /*
660 * If type is invalid, we should have bailed out earlier than
661 * this call.
662 */
663 type = btrfs_get_extent_inline_ref_type(leaf, iref, BTRFS_REF_TYPE_DATA);
664 ASSERT(type != BTRFS_REF_TYPE_INVALID);
665 if (type == BTRFS_EXTENT_DATA_REF_KEY) {
666 ref1 = (struct btrfs_extent_data_ref *)(&iref->offset);
667 num_refs = btrfs_extent_data_ref_count(leaf, ref1);
668 } else {
669 ref2 = (struct btrfs_shared_data_ref *)(iref + 1);
670 num_refs = btrfs_shared_data_ref_count(leaf, ref2);
671 }
672 } else if (key.type == BTRFS_EXTENT_DATA_REF_KEY) {
673 ref1 = btrfs_item_ptr(leaf, path->slots[0],
674 struct btrfs_extent_data_ref);
675 num_refs = btrfs_extent_data_ref_count(leaf, ref1);
676 } else if (key.type == BTRFS_SHARED_DATA_REF_KEY) {
677 ref2 = btrfs_item_ptr(leaf, path->slots[0],
678 struct btrfs_shared_data_ref);
679 num_refs = btrfs_shared_data_ref_count(leaf, ref2);
680 } else {
681 WARN_ON(1);
682 }
683 return num_refs;
684 }
685
lookup_tree_block_ref(struct btrfs_trans_handle * trans,struct btrfs_path * path,u64 bytenr,u64 parent,u64 root_objectid)686 static noinline int lookup_tree_block_ref(struct btrfs_trans_handle *trans,
687 struct btrfs_path *path,
688 u64 bytenr, u64 parent,
689 u64 root_objectid)
690 {
691 struct btrfs_root *root = btrfs_extent_root(trans->fs_info, bytenr);
692 struct btrfs_key key;
693 int ret;
694
695 key.objectid = bytenr;
696 if (parent) {
697 key.type = BTRFS_SHARED_BLOCK_REF_KEY;
698 key.offset = parent;
699 } else {
700 key.type = BTRFS_TREE_BLOCK_REF_KEY;
701 key.offset = root_objectid;
702 }
703
704 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
705 if (ret > 0)
706 ret = -ENOENT;
707 return ret;
708 }
709
insert_tree_block_ref(struct btrfs_trans_handle * trans,struct btrfs_path * path,u64 bytenr,u64 parent,u64 root_objectid)710 static noinline int insert_tree_block_ref(struct btrfs_trans_handle *trans,
711 struct btrfs_path *path,
712 u64 bytenr, u64 parent,
713 u64 root_objectid)
714 {
715 struct btrfs_root *root = btrfs_extent_root(trans->fs_info, bytenr);
716 struct btrfs_key key;
717 int ret;
718
719 key.objectid = bytenr;
720 if (parent) {
721 key.type = BTRFS_SHARED_BLOCK_REF_KEY;
722 key.offset = parent;
723 } else {
724 key.type = BTRFS_TREE_BLOCK_REF_KEY;
725 key.offset = root_objectid;
726 }
727
728 ret = btrfs_insert_empty_item(trans, root, path, &key, 0);
729 btrfs_release_path(path);
730 return ret;
731 }
732
extent_ref_type(u64 parent,u64 owner)733 static inline int extent_ref_type(u64 parent, u64 owner)
734 {
735 int type;
736 if (owner < BTRFS_FIRST_FREE_OBJECTID) {
737 if (parent > 0)
738 type = BTRFS_SHARED_BLOCK_REF_KEY;
739 else
740 type = BTRFS_TREE_BLOCK_REF_KEY;
741 } else {
742 if (parent > 0)
743 type = BTRFS_SHARED_DATA_REF_KEY;
744 else
745 type = BTRFS_EXTENT_DATA_REF_KEY;
746 }
747 return type;
748 }
749
find_next_key(struct btrfs_path * path,int level,struct btrfs_key * key)750 static int find_next_key(struct btrfs_path *path, int level,
751 struct btrfs_key *key)
752
753 {
754 for (; level < BTRFS_MAX_LEVEL; level++) {
755 if (!path->nodes[level])
756 break;
757 if (path->slots[level] + 1 >=
758 btrfs_header_nritems(path->nodes[level]))
759 continue;
760 if (level == 0)
761 btrfs_item_key_to_cpu(path->nodes[level], key,
762 path->slots[level] + 1);
763 else
764 btrfs_node_key_to_cpu(path->nodes[level], key,
765 path->slots[level] + 1);
766 return 0;
767 }
768 return 1;
769 }
770
771 /*
772 * look for inline back ref. if back ref is found, *ref_ret is set
773 * to the address of inline back ref, and 0 is returned.
774 *
775 * if back ref isn't found, *ref_ret is set to the address where it
776 * should be inserted, and -ENOENT is returned.
777 *
778 * if insert is true and there are too many inline back refs, the path
779 * points to the extent item, and -EAGAIN is returned.
780 *
781 * NOTE: inline back refs are ordered in the same way that back ref
782 * items in the tree are ordered.
783 */
784 static noinline_for_stack
lookup_inline_extent_backref(struct btrfs_trans_handle * trans,struct btrfs_path * path,struct btrfs_extent_inline_ref ** ref_ret,u64 bytenr,u64 num_bytes,u64 parent,u64 root_objectid,u64 owner,u64 offset,int insert)785 int lookup_inline_extent_backref(struct btrfs_trans_handle *trans,
786 struct btrfs_path *path,
787 struct btrfs_extent_inline_ref **ref_ret,
788 u64 bytenr, u64 num_bytes,
789 u64 parent, u64 root_objectid,
790 u64 owner, u64 offset, int insert)
791 {
792 struct btrfs_fs_info *fs_info = trans->fs_info;
793 struct btrfs_root *root = btrfs_extent_root(fs_info, bytenr);
794 struct btrfs_key key;
795 struct extent_buffer *leaf;
796 struct btrfs_extent_item *ei;
797 struct btrfs_extent_inline_ref *iref;
798 u64 flags;
799 u64 item_size;
800 unsigned long ptr;
801 unsigned long end;
802 int extra_size;
803 int type;
804 int want;
805 int ret;
806 int err = 0;
807 bool skinny_metadata = btrfs_fs_incompat(fs_info, SKINNY_METADATA);
808 int needed;
809
810 key.objectid = bytenr;
811 key.type = BTRFS_EXTENT_ITEM_KEY;
812 key.offset = num_bytes;
813
814 want = extent_ref_type(parent, owner);
815 if (insert) {
816 extra_size = btrfs_extent_inline_ref_size(want);
817 path->search_for_extension = 1;
818 path->keep_locks = 1;
819 } else
820 extra_size = -1;
821
822 /*
823 * Owner is our level, so we can just add one to get the level for the
824 * block we are interested in.
825 */
826 if (skinny_metadata && owner < BTRFS_FIRST_FREE_OBJECTID) {
827 key.type = BTRFS_METADATA_ITEM_KEY;
828 key.offset = owner;
829 }
830
831 again:
832 ret = btrfs_search_slot(trans, root, &key, path, extra_size, 1);
833 if (ret < 0) {
834 err = ret;
835 goto out;
836 }
837
838 /*
839 * We may be a newly converted file system which still has the old fat
840 * extent entries for metadata, so try and see if we have one of those.
841 */
842 if (ret > 0 && skinny_metadata) {
843 skinny_metadata = false;
844 if (path->slots[0]) {
845 path->slots[0]--;
846 btrfs_item_key_to_cpu(path->nodes[0], &key,
847 path->slots[0]);
848 if (key.objectid == bytenr &&
849 key.type == BTRFS_EXTENT_ITEM_KEY &&
850 key.offset == num_bytes)
851 ret = 0;
852 }
853 if (ret) {
854 key.objectid = bytenr;
855 key.type = BTRFS_EXTENT_ITEM_KEY;
856 key.offset = num_bytes;
857 btrfs_release_path(path);
858 goto again;
859 }
860 }
861
862 if (ret && !insert) {
863 err = -ENOENT;
864 goto out;
865 } else if (WARN_ON(ret)) {
866 err = -EIO;
867 goto out;
868 }
869
870 leaf = path->nodes[0];
871 item_size = btrfs_item_size(leaf, path->slots[0]);
872 if (unlikely(item_size < sizeof(*ei))) {
873 err = -EINVAL;
874 btrfs_print_v0_err(fs_info);
875 btrfs_abort_transaction(trans, err);
876 goto out;
877 }
878
879 ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
880 flags = btrfs_extent_flags(leaf, ei);
881
882 ptr = (unsigned long)(ei + 1);
883 end = (unsigned long)ei + item_size;
884
885 if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK && !skinny_metadata) {
886 ptr += sizeof(struct btrfs_tree_block_info);
887 BUG_ON(ptr > end);
888 }
889
890 if (owner >= BTRFS_FIRST_FREE_OBJECTID)
891 needed = BTRFS_REF_TYPE_DATA;
892 else
893 needed = BTRFS_REF_TYPE_BLOCK;
894
895 err = -ENOENT;
896 while (1) {
897 if (ptr >= end) {
898 if (ptr > end) {
899 err = -EUCLEAN;
900 btrfs_print_leaf(path->nodes[0]);
901 btrfs_crit(fs_info,
902 "overrun extent record at slot %d while looking for inline extent for root %llu owner %llu offset %llu parent %llu",
903 path->slots[0], root_objectid, owner, offset, parent);
904 }
905 break;
906 }
907 iref = (struct btrfs_extent_inline_ref *)ptr;
908 type = btrfs_get_extent_inline_ref_type(leaf, iref, needed);
909 if (type == BTRFS_REF_TYPE_INVALID) {
910 err = -EUCLEAN;
911 goto out;
912 }
913
914 if (want < type)
915 break;
916 if (want > type) {
917 ptr += btrfs_extent_inline_ref_size(type);
918 continue;
919 }
920
921 if (type == BTRFS_EXTENT_DATA_REF_KEY) {
922 struct btrfs_extent_data_ref *dref;
923 dref = (struct btrfs_extent_data_ref *)(&iref->offset);
924 if (match_extent_data_ref(leaf, dref, root_objectid,
925 owner, offset)) {
926 err = 0;
927 break;
928 }
929 if (hash_extent_data_ref_item(leaf, dref) <
930 hash_extent_data_ref(root_objectid, owner, offset))
931 break;
932 } else {
933 u64 ref_offset;
934 ref_offset = btrfs_extent_inline_ref_offset(leaf, iref);
935 if (parent > 0) {
936 if (parent == ref_offset) {
937 err = 0;
938 break;
939 }
940 if (ref_offset < parent)
941 break;
942 } else {
943 if (root_objectid == ref_offset) {
944 err = 0;
945 break;
946 }
947 if (ref_offset < root_objectid)
948 break;
949 }
950 }
951 ptr += btrfs_extent_inline_ref_size(type);
952 }
953 if (err == -ENOENT && insert) {
954 if (item_size + extra_size >=
955 BTRFS_MAX_EXTENT_ITEM_SIZE(root)) {
956 err = -EAGAIN;
957 goto out;
958 }
959 /*
960 * To add new inline back ref, we have to make sure
961 * there is no corresponding back ref item.
962 * For simplicity, we just do not add new inline back
963 * ref if there is any kind of item for this block
964 */
965 if (find_next_key(path, 0, &key) == 0 &&
966 key.objectid == bytenr &&
967 key.type < BTRFS_BLOCK_GROUP_ITEM_KEY) {
968 err = -EAGAIN;
969 goto out;
970 }
971 }
972 *ref_ret = (struct btrfs_extent_inline_ref *)ptr;
973 out:
974 if (insert) {
975 path->keep_locks = 0;
976 path->search_for_extension = 0;
977 btrfs_unlock_up_safe(path, 1);
978 }
979 return err;
980 }
981
982 /*
983 * helper to add new inline back ref
984 */
985 static noinline_for_stack
setup_inline_extent_backref(struct btrfs_fs_info * fs_info,struct btrfs_path * path,struct btrfs_extent_inline_ref * iref,u64 parent,u64 root_objectid,u64 owner,u64 offset,int refs_to_add,struct btrfs_delayed_extent_op * extent_op)986 void setup_inline_extent_backref(struct btrfs_fs_info *fs_info,
987 struct btrfs_path *path,
988 struct btrfs_extent_inline_ref *iref,
989 u64 parent, u64 root_objectid,
990 u64 owner, u64 offset, int refs_to_add,
991 struct btrfs_delayed_extent_op *extent_op)
992 {
993 struct extent_buffer *leaf;
994 struct btrfs_extent_item *ei;
995 unsigned long ptr;
996 unsigned long end;
997 unsigned long item_offset;
998 u64 refs;
999 int size;
1000 int type;
1001
1002 leaf = path->nodes[0];
1003 ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
1004 item_offset = (unsigned long)iref - (unsigned long)ei;
1005
1006 type = extent_ref_type(parent, owner);
1007 size = btrfs_extent_inline_ref_size(type);
1008
1009 btrfs_extend_item(path, size);
1010
1011 ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
1012 refs = btrfs_extent_refs(leaf, ei);
1013 refs += refs_to_add;
1014 btrfs_set_extent_refs(leaf, ei, refs);
1015 if (extent_op)
1016 __run_delayed_extent_op(extent_op, leaf, ei);
1017
1018 ptr = (unsigned long)ei + item_offset;
1019 end = (unsigned long)ei + btrfs_item_size(leaf, path->slots[0]);
1020 if (ptr < end - size)
1021 memmove_extent_buffer(leaf, ptr + size, ptr,
1022 end - size - ptr);
1023
1024 iref = (struct btrfs_extent_inline_ref *)ptr;
1025 btrfs_set_extent_inline_ref_type(leaf, iref, type);
1026 if (type == BTRFS_EXTENT_DATA_REF_KEY) {
1027 struct btrfs_extent_data_ref *dref;
1028 dref = (struct btrfs_extent_data_ref *)(&iref->offset);
1029 btrfs_set_extent_data_ref_root(leaf, dref, root_objectid);
1030 btrfs_set_extent_data_ref_objectid(leaf, dref, owner);
1031 btrfs_set_extent_data_ref_offset(leaf, dref, offset);
1032 btrfs_set_extent_data_ref_count(leaf, dref, refs_to_add);
1033 } else if (type == BTRFS_SHARED_DATA_REF_KEY) {
1034 struct btrfs_shared_data_ref *sref;
1035 sref = (struct btrfs_shared_data_ref *)(iref + 1);
1036 btrfs_set_shared_data_ref_count(leaf, sref, refs_to_add);
1037 btrfs_set_extent_inline_ref_offset(leaf, iref, parent);
1038 } else if (type == BTRFS_SHARED_BLOCK_REF_KEY) {
1039 btrfs_set_extent_inline_ref_offset(leaf, iref, parent);
1040 } else {
1041 btrfs_set_extent_inline_ref_offset(leaf, iref, root_objectid);
1042 }
1043 btrfs_mark_buffer_dirty(leaf);
1044 }
1045
lookup_extent_backref(struct btrfs_trans_handle * trans,struct btrfs_path * path,struct btrfs_extent_inline_ref ** ref_ret,u64 bytenr,u64 num_bytes,u64 parent,u64 root_objectid,u64 owner,u64 offset)1046 static int lookup_extent_backref(struct btrfs_trans_handle *trans,
1047 struct btrfs_path *path,
1048 struct btrfs_extent_inline_ref **ref_ret,
1049 u64 bytenr, u64 num_bytes, u64 parent,
1050 u64 root_objectid, u64 owner, u64 offset)
1051 {
1052 int ret;
1053
1054 ret = lookup_inline_extent_backref(trans, path, ref_ret, bytenr,
1055 num_bytes, parent, root_objectid,
1056 owner, offset, 0);
1057 if (ret != -ENOENT)
1058 return ret;
1059
1060 btrfs_release_path(path);
1061 *ref_ret = NULL;
1062
1063 if (owner < BTRFS_FIRST_FREE_OBJECTID) {
1064 ret = lookup_tree_block_ref(trans, path, bytenr, parent,
1065 root_objectid);
1066 } else {
1067 ret = lookup_extent_data_ref(trans, path, bytenr, parent,
1068 root_objectid, owner, offset);
1069 }
1070 return ret;
1071 }
1072
1073 /*
1074 * helper to update/remove inline back ref
1075 */
1076 static noinline_for_stack
update_inline_extent_backref(struct btrfs_path * path,struct btrfs_extent_inline_ref * iref,int refs_to_mod,struct btrfs_delayed_extent_op * extent_op)1077 void update_inline_extent_backref(struct btrfs_path *path,
1078 struct btrfs_extent_inline_ref *iref,
1079 int refs_to_mod,
1080 struct btrfs_delayed_extent_op *extent_op)
1081 {
1082 struct extent_buffer *leaf = path->nodes[0];
1083 struct btrfs_extent_item *ei;
1084 struct btrfs_extent_data_ref *dref = NULL;
1085 struct btrfs_shared_data_ref *sref = NULL;
1086 unsigned long ptr;
1087 unsigned long end;
1088 u32 item_size;
1089 int size;
1090 int type;
1091 u64 refs;
1092
1093 ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
1094 refs = btrfs_extent_refs(leaf, ei);
1095 WARN_ON(refs_to_mod < 0 && refs + refs_to_mod <= 0);
1096 refs += refs_to_mod;
1097 btrfs_set_extent_refs(leaf, ei, refs);
1098 if (extent_op)
1099 __run_delayed_extent_op(extent_op, leaf, ei);
1100
1101 /*
1102 * If type is invalid, we should have bailed out after
1103 * lookup_inline_extent_backref().
1104 */
1105 type = btrfs_get_extent_inline_ref_type(leaf, iref, BTRFS_REF_TYPE_ANY);
1106 ASSERT(type != BTRFS_REF_TYPE_INVALID);
1107
1108 if (type == BTRFS_EXTENT_DATA_REF_KEY) {
1109 dref = (struct btrfs_extent_data_ref *)(&iref->offset);
1110 refs = btrfs_extent_data_ref_count(leaf, dref);
1111 } else if (type == BTRFS_SHARED_DATA_REF_KEY) {
1112 sref = (struct btrfs_shared_data_ref *)(iref + 1);
1113 refs = btrfs_shared_data_ref_count(leaf, sref);
1114 } else {
1115 refs = 1;
1116 BUG_ON(refs_to_mod != -1);
1117 }
1118
1119 BUG_ON(refs_to_mod < 0 && refs < -refs_to_mod);
1120 refs += refs_to_mod;
1121
1122 if (refs > 0) {
1123 if (type == BTRFS_EXTENT_DATA_REF_KEY)
1124 btrfs_set_extent_data_ref_count(leaf, dref, refs);
1125 else
1126 btrfs_set_shared_data_ref_count(leaf, sref, refs);
1127 } else {
1128 size = btrfs_extent_inline_ref_size(type);
1129 item_size = btrfs_item_size(leaf, path->slots[0]);
1130 ptr = (unsigned long)iref;
1131 end = (unsigned long)ei + item_size;
1132 if (ptr + size < end)
1133 memmove_extent_buffer(leaf, ptr, ptr + size,
1134 end - ptr - size);
1135 item_size -= size;
1136 btrfs_truncate_item(path, item_size, 1);
1137 }
1138 btrfs_mark_buffer_dirty(leaf);
1139 }
1140
1141 static noinline_for_stack
insert_inline_extent_backref(struct btrfs_trans_handle * trans,struct btrfs_path * path,u64 bytenr,u64 num_bytes,u64 parent,u64 root_objectid,u64 owner,u64 offset,int refs_to_add,struct btrfs_delayed_extent_op * extent_op)1142 int insert_inline_extent_backref(struct btrfs_trans_handle *trans,
1143 struct btrfs_path *path,
1144 u64 bytenr, u64 num_bytes, u64 parent,
1145 u64 root_objectid, u64 owner,
1146 u64 offset, int refs_to_add,
1147 struct btrfs_delayed_extent_op *extent_op)
1148 {
1149 struct btrfs_extent_inline_ref *iref;
1150 int ret;
1151
1152 ret = lookup_inline_extent_backref(trans, path, &iref, bytenr,
1153 num_bytes, parent, root_objectid,
1154 owner, offset, 1);
1155 if (ret == 0) {
1156 /*
1157 * We're adding refs to a tree block we already own, this
1158 * should not happen at all.
1159 */
1160 if (owner < BTRFS_FIRST_FREE_OBJECTID) {
1161 btrfs_crit(trans->fs_info,
1162 "adding refs to an existing tree ref, bytenr %llu num_bytes %llu root_objectid %llu",
1163 bytenr, num_bytes, root_objectid);
1164 if (IS_ENABLED(CONFIG_BTRFS_DEBUG)) {
1165 WARN_ON(1);
1166 btrfs_crit(trans->fs_info,
1167 "path->slots[0]=%d path->nodes[0]:", path->slots[0]);
1168 btrfs_print_leaf(path->nodes[0]);
1169 }
1170 return -EUCLEAN;
1171 }
1172 update_inline_extent_backref(path, iref, refs_to_add, extent_op);
1173 } else if (ret == -ENOENT) {
1174 setup_inline_extent_backref(trans->fs_info, path, iref, parent,
1175 root_objectid, owner, offset,
1176 refs_to_add, extent_op);
1177 ret = 0;
1178 }
1179 return ret;
1180 }
1181
remove_extent_backref(struct btrfs_trans_handle * trans,struct btrfs_root * root,struct btrfs_path * path,struct btrfs_extent_inline_ref * iref,int refs_to_drop,int is_data)1182 static int remove_extent_backref(struct btrfs_trans_handle *trans,
1183 struct btrfs_root *root,
1184 struct btrfs_path *path,
1185 struct btrfs_extent_inline_ref *iref,
1186 int refs_to_drop, int is_data)
1187 {
1188 int ret = 0;
1189
1190 BUG_ON(!is_data && refs_to_drop != 1);
1191 if (iref)
1192 update_inline_extent_backref(path, iref, -refs_to_drop, NULL);
1193 else if (is_data)
1194 ret = remove_extent_data_ref(trans, root, path, refs_to_drop);
1195 else
1196 ret = btrfs_del_item(trans, root, path);
1197 return ret;
1198 }
1199
btrfs_issue_discard(struct block_device * bdev,u64 start,u64 len,u64 * discarded_bytes)1200 static int btrfs_issue_discard(struct block_device *bdev, u64 start, u64 len,
1201 u64 *discarded_bytes)
1202 {
1203 int j, ret = 0;
1204 u64 bytes_left, end;
1205 u64 aligned_start = ALIGN(start, 1 << 9);
1206
1207 if (WARN_ON(start != aligned_start)) {
1208 len -= aligned_start - start;
1209 len = round_down(len, 1 << 9);
1210 start = aligned_start;
1211 }
1212
1213 *discarded_bytes = 0;
1214
1215 if (!len)
1216 return 0;
1217
1218 end = start + len;
1219 bytes_left = len;
1220
1221 /* Skip any superblocks on this device. */
1222 for (j = 0; j < BTRFS_SUPER_MIRROR_MAX; j++) {
1223 u64 sb_start = btrfs_sb_offset(j);
1224 u64 sb_end = sb_start + BTRFS_SUPER_INFO_SIZE;
1225 u64 size = sb_start - start;
1226
1227 if (!in_range(sb_start, start, bytes_left) &&
1228 !in_range(sb_end, start, bytes_left) &&
1229 !in_range(start, sb_start, BTRFS_SUPER_INFO_SIZE))
1230 continue;
1231
1232 /*
1233 * Superblock spans beginning of range. Adjust start and
1234 * try again.
1235 */
1236 if (sb_start <= start) {
1237 start += sb_end - start;
1238 if (start > end) {
1239 bytes_left = 0;
1240 break;
1241 }
1242 bytes_left = end - start;
1243 continue;
1244 }
1245
1246 if (size) {
1247 ret = blkdev_issue_discard(bdev, start >> 9, size >> 9,
1248 GFP_NOFS);
1249 if (!ret)
1250 *discarded_bytes += size;
1251 else if (ret != -EOPNOTSUPP)
1252 return ret;
1253 }
1254
1255 start = sb_end;
1256 if (start > end) {
1257 bytes_left = 0;
1258 break;
1259 }
1260 bytes_left = end - start;
1261 }
1262
1263 if (bytes_left) {
1264 ret = blkdev_issue_discard(bdev, start >> 9, bytes_left >> 9,
1265 GFP_NOFS);
1266 if (!ret)
1267 *discarded_bytes += bytes_left;
1268 }
1269 return ret;
1270 }
1271
do_discard_extent(struct btrfs_discard_stripe * stripe,u64 * bytes)1272 static int do_discard_extent(struct btrfs_discard_stripe *stripe, u64 *bytes)
1273 {
1274 struct btrfs_device *dev = stripe->dev;
1275 struct btrfs_fs_info *fs_info = dev->fs_info;
1276 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
1277 u64 phys = stripe->physical;
1278 u64 len = stripe->length;
1279 u64 discarded = 0;
1280 int ret = 0;
1281
1282 /* Zone reset on a zoned filesystem */
1283 if (btrfs_can_zone_reset(dev, phys, len)) {
1284 u64 src_disc;
1285
1286 ret = btrfs_reset_device_zone(dev, phys, len, &discarded);
1287 if (ret)
1288 goto out;
1289
1290 if (!btrfs_dev_replace_is_ongoing(dev_replace) ||
1291 dev != dev_replace->srcdev)
1292 goto out;
1293
1294 src_disc = discarded;
1295
1296 /* Send to replace target as well */
1297 ret = btrfs_reset_device_zone(dev_replace->tgtdev, phys, len,
1298 &discarded);
1299 discarded += src_disc;
1300 } else if (bdev_max_discard_sectors(stripe->dev->bdev)) {
1301 ret = btrfs_issue_discard(dev->bdev, phys, len, &discarded);
1302 } else {
1303 ret = 0;
1304 *bytes = 0;
1305 }
1306
1307 out:
1308 *bytes = discarded;
1309 return ret;
1310 }
1311
btrfs_discard_extent(struct btrfs_fs_info * fs_info,u64 bytenr,u64 num_bytes,u64 * actual_bytes)1312 int btrfs_discard_extent(struct btrfs_fs_info *fs_info, u64 bytenr,
1313 u64 num_bytes, u64 *actual_bytes)
1314 {
1315 int ret = 0;
1316 u64 discarded_bytes = 0;
1317 u64 end = bytenr + num_bytes;
1318 u64 cur = bytenr;
1319
1320 /*
1321 * Avoid races with device replace and make sure the devices in the
1322 * stripes don't go away while we are discarding.
1323 */
1324 btrfs_bio_counter_inc_blocked(fs_info);
1325 while (cur < end) {
1326 struct btrfs_discard_stripe *stripes;
1327 unsigned int num_stripes;
1328 int i;
1329
1330 num_bytes = end - cur;
1331 stripes = btrfs_map_discard(fs_info, cur, &num_bytes, &num_stripes);
1332 if (IS_ERR(stripes)) {
1333 ret = PTR_ERR(stripes);
1334 if (ret == -EOPNOTSUPP)
1335 ret = 0;
1336 break;
1337 }
1338
1339 for (i = 0; i < num_stripes; i++) {
1340 struct btrfs_discard_stripe *stripe = stripes + i;
1341 u64 bytes;
1342
1343 if (!stripe->dev->bdev) {
1344 ASSERT(btrfs_test_opt(fs_info, DEGRADED));
1345 continue;
1346 }
1347
1348 if (!test_bit(BTRFS_DEV_STATE_WRITEABLE,
1349 &stripe->dev->dev_state))
1350 continue;
1351
1352 ret = do_discard_extent(stripe, &bytes);
1353 if (ret) {
1354 /*
1355 * Keep going if discard is not supported by the
1356 * device.
1357 */
1358 if (ret != -EOPNOTSUPP)
1359 break;
1360 ret = 0;
1361 } else {
1362 discarded_bytes += bytes;
1363 }
1364 }
1365 kfree(stripes);
1366 if (ret)
1367 break;
1368 cur += num_bytes;
1369 }
1370 btrfs_bio_counter_dec(fs_info);
1371 if (actual_bytes)
1372 *actual_bytes = discarded_bytes;
1373 return ret;
1374 }
1375
1376 /* Can return -ENOMEM */
btrfs_inc_extent_ref(struct btrfs_trans_handle * trans,struct btrfs_ref * generic_ref)1377 int btrfs_inc_extent_ref(struct btrfs_trans_handle *trans,
1378 struct btrfs_ref *generic_ref)
1379 {
1380 struct btrfs_fs_info *fs_info = trans->fs_info;
1381 int ret;
1382
1383 ASSERT(generic_ref->type != BTRFS_REF_NOT_SET &&
1384 generic_ref->action);
1385 BUG_ON(generic_ref->type == BTRFS_REF_METADATA &&
1386 generic_ref->tree_ref.owning_root == BTRFS_TREE_LOG_OBJECTID);
1387
1388 if (generic_ref->type == BTRFS_REF_METADATA)
1389 ret = btrfs_add_delayed_tree_ref(trans, generic_ref, NULL);
1390 else
1391 ret = btrfs_add_delayed_data_ref(trans, generic_ref, 0);
1392
1393 btrfs_ref_tree_mod(fs_info, generic_ref);
1394
1395 return ret;
1396 }
1397
1398 /*
1399 * __btrfs_inc_extent_ref - insert backreference for a given extent
1400 *
1401 * The counterpart is in __btrfs_free_extent(), with examples and more details
1402 * how it works.
1403 *
1404 * @trans: Handle of transaction
1405 *
1406 * @node: The delayed ref node used to get the bytenr/length for
1407 * extent whose references are incremented.
1408 *
1409 * @parent: If this is a shared extent (BTRFS_SHARED_DATA_REF_KEY/
1410 * BTRFS_SHARED_BLOCK_REF_KEY) then it holds the logical
1411 * bytenr of the parent block. Since new extents are always
1412 * created with indirect references, this will only be the case
1413 * when relocating a shared extent. In that case, root_objectid
1414 * will be BTRFS_TREE_RELOC_OBJECTID. Otherwise, parent must
1415 * be 0
1416 *
1417 * @root_objectid: The id of the root where this modification has originated,
1418 * this can be either one of the well-known metadata trees or
1419 * the subvolume id which references this extent.
1420 *
1421 * @owner: For data extents it is the inode number of the owning file.
1422 * For metadata extents this parameter holds the level in the
1423 * tree of the extent.
1424 *
1425 * @offset: For metadata extents the offset is ignored and is currently
1426 * always passed as 0. For data extents it is the fileoffset
1427 * this extent belongs to.
1428 *
1429 * @refs_to_add Number of references to add
1430 *
1431 * @extent_op Pointer to a structure, holding information necessary when
1432 * updating a tree block's flags
1433 *
1434 */
__btrfs_inc_extent_ref(struct btrfs_trans_handle * trans,struct btrfs_delayed_ref_node * node,u64 parent,u64 root_objectid,u64 owner,u64 offset,int refs_to_add,struct btrfs_delayed_extent_op * extent_op)1435 static int __btrfs_inc_extent_ref(struct btrfs_trans_handle *trans,
1436 struct btrfs_delayed_ref_node *node,
1437 u64 parent, u64 root_objectid,
1438 u64 owner, u64 offset, int refs_to_add,
1439 struct btrfs_delayed_extent_op *extent_op)
1440 {
1441 struct btrfs_path *path;
1442 struct extent_buffer *leaf;
1443 struct btrfs_extent_item *item;
1444 struct btrfs_key key;
1445 u64 bytenr = node->bytenr;
1446 u64 num_bytes = node->num_bytes;
1447 u64 refs;
1448 int ret;
1449
1450 path = btrfs_alloc_path();
1451 if (!path)
1452 return -ENOMEM;
1453
1454 /* this will setup the path even if it fails to insert the back ref */
1455 ret = insert_inline_extent_backref(trans, path, bytenr, num_bytes,
1456 parent, root_objectid, owner,
1457 offset, refs_to_add, extent_op);
1458 if ((ret < 0 && ret != -EAGAIN) || !ret)
1459 goto out;
1460
1461 /*
1462 * Ok we had -EAGAIN which means we didn't have space to insert and
1463 * inline extent ref, so just update the reference count and add a
1464 * normal backref.
1465 */
1466 leaf = path->nodes[0];
1467 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
1468 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
1469 refs = btrfs_extent_refs(leaf, item);
1470 btrfs_set_extent_refs(leaf, item, refs + refs_to_add);
1471 if (extent_op)
1472 __run_delayed_extent_op(extent_op, leaf, item);
1473
1474 btrfs_mark_buffer_dirty(leaf);
1475 btrfs_release_path(path);
1476
1477 /* now insert the actual backref */
1478 if (owner < BTRFS_FIRST_FREE_OBJECTID) {
1479 BUG_ON(refs_to_add != 1);
1480 ret = insert_tree_block_ref(trans, path, bytenr, parent,
1481 root_objectid);
1482 } else {
1483 ret = insert_extent_data_ref(trans, path, bytenr, parent,
1484 root_objectid, owner, offset,
1485 refs_to_add);
1486 }
1487 if (ret)
1488 btrfs_abort_transaction(trans, ret);
1489 out:
1490 btrfs_free_path(path);
1491 return ret;
1492 }
1493
run_delayed_data_ref(struct btrfs_trans_handle * trans,struct btrfs_delayed_ref_node * node,struct btrfs_delayed_extent_op * extent_op,int insert_reserved)1494 static int run_delayed_data_ref(struct btrfs_trans_handle *trans,
1495 struct btrfs_delayed_ref_node *node,
1496 struct btrfs_delayed_extent_op *extent_op,
1497 int insert_reserved)
1498 {
1499 int ret = 0;
1500 struct btrfs_delayed_data_ref *ref;
1501 struct btrfs_key ins;
1502 u64 parent = 0;
1503 u64 ref_root = 0;
1504 u64 flags = 0;
1505
1506 ins.objectid = node->bytenr;
1507 ins.offset = node->num_bytes;
1508 ins.type = BTRFS_EXTENT_ITEM_KEY;
1509
1510 ref = btrfs_delayed_node_to_data_ref(node);
1511 trace_run_delayed_data_ref(trans->fs_info, node, ref, node->action);
1512
1513 if (node->type == BTRFS_SHARED_DATA_REF_KEY)
1514 parent = ref->parent;
1515 ref_root = ref->root;
1516
1517 if (node->action == BTRFS_ADD_DELAYED_REF && insert_reserved) {
1518 if (extent_op)
1519 flags |= extent_op->flags_to_set;
1520 ret = alloc_reserved_file_extent(trans, parent, ref_root,
1521 flags, ref->objectid,
1522 ref->offset, &ins,
1523 node->ref_mod);
1524 } else if (node->action == BTRFS_ADD_DELAYED_REF) {
1525 ret = __btrfs_inc_extent_ref(trans, node, parent, ref_root,
1526 ref->objectid, ref->offset,
1527 node->ref_mod, extent_op);
1528 } else if (node->action == BTRFS_DROP_DELAYED_REF) {
1529 ret = __btrfs_free_extent(trans, node, parent,
1530 ref_root, ref->objectid,
1531 ref->offset, node->ref_mod,
1532 extent_op);
1533 } else {
1534 BUG();
1535 }
1536 return ret;
1537 }
1538
__run_delayed_extent_op(struct btrfs_delayed_extent_op * extent_op,struct extent_buffer * leaf,struct btrfs_extent_item * ei)1539 static void __run_delayed_extent_op(struct btrfs_delayed_extent_op *extent_op,
1540 struct extent_buffer *leaf,
1541 struct btrfs_extent_item *ei)
1542 {
1543 u64 flags = btrfs_extent_flags(leaf, ei);
1544 if (extent_op->update_flags) {
1545 flags |= extent_op->flags_to_set;
1546 btrfs_set_extent_flags(leaf, ei, flags);
1547 }
1548
1549 if (extent_op->update_key) {
1550 struct btrfs_tree_block_info *bi;
1551 BUG_ON(!(flags & BTRFS_EXTENT_FLAG_TREE_BLOCK));
1552 bi = (struct btrfs_tree_block_info *)(ei + 1);
1553 btrfs_set_tree_block_key(leaf, bi, &extent_op->key);
1554 }
1555 }
1556
run_delayed_extent_op(struct btrfs_trans_handle * trans,struct btrfs_delayed_ref_head * head,struct btrfs_delayed_extent_op * extent_op)1557 static int run_delayed_extent_op(struct btrfs_trans_handle *trans,
1558 struct btrfs_delayed_ref_head *head,
1559 struct btrfs_delayed_extent_op *extent_op)
1560 {
1561 struct btrfs_fs_info *fs_info = trans->fs_info;
1562 struct btrfs_root *root;
1563 struct btrfs_key key;
1564 struct btrfs_path *path;
1565 struct btrfs_extent_item *ei;
1566 struct extent_buffer *leaf;
1567 u32 item_size;
1568 int ret;
1569 int err = 0;
1570 int metadata = 1;
1571
1572 if (TRANS_ABORTED(trans))
1573 return 0;
1574
1575 if (!btrfs_fs_incompat(fs_info, SKINNY_METADATA))
1576 metadata = 0;
1577
1578 path = btrfs_alloc_path();
1579 if (!path)
1580 return -ENOMEM;
1581
1582 key.objectid = head->bytenr;
1583
1584 if (metadata) {
1585 key.type = BTRFS_METADATA_ITEM_KEY;
1586 key.offset = extent_op->level;
1587 } else {
1588 key.type = BTRFS_EXTENT_ITEM_KEY;
1589 key.offset = head->num_bytes;
1590 }
1591
1592 root = btrfs_extent_root(fs_info, key.objectid);
1593 again:
1594 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
1595 if (ret < 0) {
1596 err = ret;
1597 goto out;
1598 }
1599 if (ret > 0) {
1600 if (metadata) {
1601 if (path->slots[0] > 0) {
1602 path->slots[0]--;
1603 btrfs_item_key_to_cpu(path->nodes[0], &key,
1604 path->slots[0]);
1605 if (key.objectid == head->bytenr &&
1606 key.type == BTRFS_EXTENT_ITEM_KEY &&
1607 key.offset == head->num_bytes)
1608 ret = 0;
1609 }
1610 if (ret > 0) {
1611 btrfs_release_path(path);
1612 metadata = 0;
1613
1614 key.objectid = head->bytenr;
1615 key.offset = head->num_bytes;
1616 key.type = BTRFS_EXTENT_ITEM_KEY;
1617 goto again;
1618 }
1619 } else {
1620 err = -EIO;
1621 goto out;
1622 }
1623 }
1624
1625 leaf = path->nodes[0];
1626 item_size = btrfs_item_size(leaf, path->slots[0]);
1627
1628 if (unlikely(item_size < sizeof(*ei))) {
1629 err = -EINVAL;
1630 btrfs_print_v0_err(fs_info);
1631 btrfs_abort_transaction(trans, err);
1632 goto out;
1633 }
1634
1635 ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
1636 __run_delayed_extent_op(extent_op, leaf, ei);
1637
1638 btrfs_mark_buffer_dirty(leaf);
1639 out:
1640 btrfs_free_path(path);
1641 return err;
1642 }
1643
run_delayed_tree_ref(struct btrfs_trans_handle * trans,struct btrfs_delayed_ref_node * node,struct btrfs_delayed_extent_op * extent_op,int insert_reserved)1644 static int run_delayed_tree_ref(struct btrfs_trans_handle *trans,
1645 struct btrfs_delayed_ref_node *node,
1646 struct btrfs_delayed_extent_op *extent_op,
1647 int insert_reserved)
1648 {
1649 int ret = 0;
1650 struct btrfs_delayed_tree_ref *ref;
1651 u64 parent = 0;
1652 u64 ref_root = 0;
1653
1654 ref = btrfs_delayed_node_to_tree_ref(node);
1655 trace_run_delayed_tree_ref(trans->fs_info, node, ref, node->action);
1656
1657 if (node->type == BTRFS_SHARED_BLOCK_REF_KEY)
1658 parent = ref->parent;
1659 ref_root = ref->root;
1660
1661 if (node->ref_mod != 1) {
1662 btrfs_err(trans->fs_info,
1663 "btree block(%llu) has %d references rather than 1: action %d ref_root %llu parent %llu",
1664 node->bytenr, node->ref_mod, node->action, ref_root,
1665 parent);
1666 return -EIO;
1667 }
1668 if (node->action == BTRFS_ADD_DELAYED_REF && insert_reserved) {
1669 BUG_ON(!extent_op || !extent_op->update_flags);
1670 ret = alloc_reserved_tree_block(trans, node, extent_op);
1671 } else if (node->action == BTRFS_ADD_DELAYED_REF) {
1672 ret = __btrfs_inc_extent_ref(trans, node, parent, ref_root,
1673 ref->level, 0, 1, extent_op);
1674 } else if (node->action == BTRFS_DROP_DELAYED_REF) {
1675 ret = __btrfs_free_extent(trans, node, parent, ref_root,
1676 ref->level, 0, 1, extent_op);
1677 } else {
1678 BUG();
1679 }
1680 return ret;
1681 }
1682
1683 /* helper function to actually process a single delayed ref entry */
run_one_delayed_ref(struct btrfs_trans_handle * trans,struct btrfs_delayed_ref_node * node,struct btrfs_delayed_extent_op * extent_op,int insert_reserved)1684 static int run_one_delayed_ref(struct btrfs_trans_handle *trans,
1685 struct btrfs_delayed_ref_node *node,
1686 struct btrfs_delayed_extent_op *extent_op,
1687 int insert_reserved)
1688 {
1689 int ret = 0;
1690
1691 if (TRANS_ABORTED(trans)) {
1692 if (insert_reserved)
1693 btrfs_pin_extent(trans, node->bytenr, node->num_bytes, 1);
1694 return 0;
1695 }
1696
1697 if (node->type == BTRFS_TREE_BLOCK_REF_KEY ||
1698 node->type == BTRFS_SHARED_BLOCK_REF_KEY)
1699 ret = run_delayed_tree_ref(trans, node, extent_op,
1700 insert_reserved);
1701 else if (node->type == BTRFS_EXTENT_DATA_REF_KEY ||
1702 node->type == BTRFS_SHARED_DATA_REF_KEY)
1703 ret = run_delayed_data_ref(trans, node, extent_op,
1704 insert_reserved);
1705 else
1706 BUG();
1707 if (ret && insert_reserved)
1708 btrfs_pin_extent(trans, node->bytenr, node->num_bytes, 1);
1709 return ret;
1710 }
1711
1712 static inline struct btrfs_delayed_ref_node *
select_delayed_ref(struct btrfs_delayed_ref_head * head)1713 select_delayed_ref(struct btrfs_delayed_ref_head *head)
1714 {
1715 struct btrfs_delayed_ref_node *ref;
1716
1717 if (RB_EMPTY_ROOT(&head->ref_tree.rb_root))
1718 return NULL;
1719
1720 /*
1721 * Select a delayed ref of type BTRFS_ADD_DELAYED_REF first.
1722 * This is to prevent a ref count from going down to zero, which deletes
1723 * the extent item from the extent tree, when there still are references
1724 * to add, which would fail because they would not find the extent item.
1725 */
1726 if (!list_empty(&head->ref_add_list))
1727 return list_first_entry(&head->ref_add_list,
1728 struct btrfs_delayed_ref_node, add_list);
1729
1730 ref = rb_entry(rb_first_cached(&head->ref_tree),
1731 struct btrfs_delayed_ref_node, ref_node);
1732 ASSERT(list_empty(&ref->add_list));
1733 return ref;
1734 }
1735
unselect_delayed_ref_head(struct btrfs_delayed_ref_root * delayed_refs,struct btrfs_delayed_ref_head * head)1736 static void unselect_delayed_ref_head(struct btrfs_delayed_ref_root *delayed_refs,
1737 struct btrfs_delayed_ref_head *head)
1738 {
1739 spin_lock(&delayed_refs->lock);
1740 head->processing = 0;
1741 delayed_refs->num_heads_ready++;
1742 spin_unlock(&delayed_refs->lock);
1743 btrfs_delayed_ref_unlock(head);
1744 }
1745
cleanup_extent_op(struct btrfs_delayed_ref_head * head)1746 static struct btrfs_delayed_extent_op *cleanup_extent_op(
1747 struct btrfs_delayed_ref_head *head)
1748 {
1749 struct btrfs_delayed_extent_op *extent_op = head->extent_op;
1750
1751 if (!extent_op)
1752 return NULL;
1753
1754 if (head->must_insert_reserved) {
1755 head->extent_op = NULL;
1756 btrfs_free_delayed_extent_op(extent_op);
1757 return NULL;
1758 }
1759 return extent_op;
1760 }
1761
run_and_cleanup_extent_op(struct btrfs_trans_handle * trans,struct btrfs_delayed_ref_head * head)1762 static int run_and_cleanup_extent_op(struct btrfs_trans_handle *trans,
1763 struct btrfs_delayed_ref_head *head)
1764 {
1765 struct btrfs_delayed_extent_op *extent_op;
1766 int ret;
1767
1768 extent_op = cleanup_extent_op(head);
1769 if (!extent_op)
1770 return 0;
1771 head->extent_op = NULL;
1772 spin_unlock(&head->lock);
1773 ret = run_delayed_extent_op(trans, head, extent_op);
1774 btrfs_free_delayed_extent_op(extent_op);
1775 return ret ? ret : 1;
1776 }
1777
btrfs_cleanup_ref_head_accounting(struct btrfs_fs_info * fs_info,struct btrfs_delayed_ref_root * delayed_refs,struct btrfs_delayed_ref_head * head)1778 void btrfs_cleanup_ref_head_accounting(struct btrfs_fs_info *fs_info,
1779 struct btrfs_delayed_ref_root *delayed_refs,
1780 struct btrfs_delayed_ref_head *head)
1781 {
1782 int nr_items = 1; /* Dropping this ref head update. */
1783
1784 /*
1785 * We had csum deletions accounted for in our delayed refs rsv, we need
1786 * to drop the csum leaves for this update from our delayed_refs_rsv.
1787 */
1788 if (head->total_ref_mod < 0 && head->is_data) {
1789 spin_lock(&delayed_refs->lock);
1790 delayed_refs->pending_csums -= head->num_bytes;
1791 spin_unlock(&delayed_refs->lock);
1792 nr_items += btrfs_csum_bytes_to_leaves(fs_info, head->num_bytes);
1793 }
1794
1795 btrfs_delayed_refs_rsv_release(fs_info, nr_items);
1796 }
1797
cleanup_ref_head(struct btrfs_trans_handle * trans,struct btrfs_delayed_ref_head * head)1798 static int cleanup_ref_head(struct btrfs_trans_handle *trans,
1799 struct btrfs_delayed_ref_head *head)
1800 {
1801
1802 struct btrfs_fs_info *fs_info = trans->fs_info;
1803 struct btrfs_delayed_ref_root *delayed_refs;
1804 int ret;
1805
1806 delayed_refs = &trans->transaction->delayed_refs;
1807
1808 ret = run_and_cleanup_extent_op(trans, head);
1809 if (ret < 0) {
1810 unselect_delayed_ref_head(delayed_refs, head);
1811 btrfs_debug(fs_info, "run_delayed_extent_op returned %d", ret);
1812 return ret;
1813 } else if (ret) {
1814 return ret;
1815 }
1816
1817 /*
1818 * Need to drop our head ref lock and re-acquire the delayed ref lock
1819 * and then re-check to make sure nobody got added.
1820 */
1821 spin_unlock(&head->lock);
1822 spin_lock(&delayed_refs->lock);
1823 spin_lock(&head->lock);
1824 if (!RB_EMPTY_ROOT(&head->ref_tree.rb_root) || head->extent_op) {
1825 spin_unlock(&head->lock);
1826 spin_unlock(&delayed_refs->lock);
1827 return 1;
1828 }
1829 btrfs_delete_ref_head(delayed_refs, head);
1830 spin_unlock(&head->lock);
1831 spin_unlock(&delayed_refs->lock);
1832
1833 if (head->must_insert_reserved) {
1834 btrfs_pin_extent(trans, head->bytenr, head->num_bytes, 1);
1835 if (head->is_data) {
1836 struct btrfs_root *csum_root;
1837
1838 csum_root = btrfs_csum_root(fs_info, head->bytenr);
1839 ret = btrfs_del_csums(trans, csum_root, head->bytenr,
1840 head->num_bytes);
1841 }
1842 }
1843
1844 btrfs_cleanup_ref_head_accounting(fs_info, delayed_refs, head);
1845
1846 trace_run_delayed_ref_head(fs_info, head, 0);
1847 btrfs_delayed_ref_unlock(head);
1848 btrfs_put_delayed_ref_head(head);
1849 return ret;
1850 }
1851
btrfs_obtain_ref_head(struct btrfs_trans_handle * trans)1852 static struct btrfs_delayed_ref_head *btrfs_obtain_ref_head(
1853 struct btrfs_trans_handle *trans)
1854 {
1855 struct btrfs_delayed_ref_root *delayed_refs =
1856 &trans->transaction->delayed_refs;
1857 struct btrfs_delayed_ref_head *head = NULL;
1858 int ret;
1859
1860 spin_lock(&delayed_refs->lock);
1861 head = btrfs_select_ref_head(delayed_refs);
1862 if (!head) {
1863 spin_unlock(&delayed_refs->lock);
1864 return head;
1865 }
1866
1867 /*
1868 * Grab the lock that says we are going to process all the refs for
1869 * this head
1870 */
1871 ret = btrfs_delayed_ref_lock(delayed_refs, head);
1872 spin_unlock(&delayed_refs->lock);
1873
1874 /*
1875 * We may have dropped the spin lock to get the head mutex lock, and
1876 * that might have given someone else time to free the head. If that's
1877 * true, it has been removed from our list and we can move on.
1878 */
1879 if (ret == -EAGAIN)
1880 head = ERR_PTR(-EAGAIN);
1881
1882 return head;
1883 }
1884
btrfs_run_delayed_refs_for_head(struct btrfs_trans_handle * trans,struct btrfs_delayed_ref_head * locked_ref,unsigned long * run_refs)1885 static int btrfs_run_delayed_refs_for_head(struct btrfs_trans_handle *trans,
1886 struct btrfs_delayed_ref_head *locked_ref,
1887 unsigned long *run_refs)
1888 {
1889 struct btrfs_fs_info *fs_info = trans->fs_info;
1890 struct btrfs_delayed_ref_root *delayed_refs;
1891 struct btrfs_delayed_extent_op *extent_op;
1892 struct btrfs_delayed_ref_node *ref;
1893 int must_insert_reserved = 0;
1894 int ret;
1895
1896 delayed_refs = &trans->transaction->delayed_refs;
1897
1898 lockdep_assert_held(&locked_ref->mutex);
1899 lockdep_assert_held(&locked_ref->lock);
1900
1901 while ((ref = select_delayed_ref(locked_ref))) {
1902 if (ref->seq &&
1903 btrfs_check_delayed_seq(fs_info, ref->seq)) {
1904 spin_unlock(&locked_ref->lock);
1905 unselect_delayed_ref_head(delayed_refs, locked_ref);
1906 return -EAGAIN;
1907 }
1908
1909 (*run_refs)++;
1910 ref->in_tree = 0;
1911 rb_erase_cached(&ref->ref_node, &locked_ref->ref_tree);
1912 RB_CLEAR_NODE(&ref->ref_node);
1913 if (!list_empty(&ref->add_list))
1914 list_del(&ref->add_list);
1915 /*
1916 * When we play the delayed ref, also correct the ref_mod on
1917 * head
1918 */
1919 switch (ref->action) {
1920 case BTRFS_ADD_DELAYED_REF:
1921 case BTRFS_ADD_DELAYED_EXTENT:
1922 locked_ref->ref_mod -= ref->ref_mod;
1923 break;
1924 case BTRFS_DROP_DELAYED_REF:
1925 locked_ref->ref_mod += ref->ref_mod;
1926 break;
1927 default:
1928 WARN_ON(1);
1929 }
1930 atomic_dec(&delayed_refs->num_entries);
1931
1932 /*
1933 * Record the must_insert_reserved flag before we drop the
1934 * spin lock.
1935 */
1936 must_insert_reserved = locked_ref->must_insert_reserved;
1937 locked_ref->must_insert_reserved = 0;
1938
1939 extent_op = locked_ref->extent_op;
1940 locked_ref->extent_op = NULL;
1941 spin_unlock(&locked_ref->lock);
1942
1943 ret = run_one_delayed_ref(trans, ref, extent_op,
1944 must_insert_reserved);
1945
1946 btrfs_free_delayed_extent_op(extent_op);
1947 if (ret) {
1948 unselect_delayed_ref_head(delayed_refs, locked_ref);
1949 btrfs_put_delayed_ref(ref);
1950 btrfs_debug(fs_info, "run_one_delayed_ref returned %d",
1951 ret);
1952 return ret;
1953 }
1954
1955 btrfs_put_delayed_ref(ref);
1956 cond_resched();
1957
1958 spin_lock(&locked_ref->lock);
1959 btrfs_merge_delayed_refs(trans, delayed_refs, locked_ref);
1960 }
1961
1962 return 0;
1963 }
1964
1965 /*
1966 * Returns 0 on success or if called with an already aborted transaction.
1967 * Returns -ENOMEM or -EIO on failure and will abort the transaction.
1968 */
__btrfs_run_delayed_refs(struct btrfs_trans_handle * trans,unsigned long nr)1969 static noinline int __btrfs_run_delayed_refs(struct btrfs_trans_handle *trans,
1970 unsigned long nr)
1971 {
1972 struct btrfs_fs_info *fs_info = trans->fs_info;
1973 struct btrfs_delayed_ref_root *delayed_refs;
1974 struct btrfs_delayed_ref_head *locked_ref = NULL;
1975 ktime_t start = ktime_get();
1976 int ret;
1977 unsigned long count = 0;
1978 unsigned long actual_count = 0;
1979
1980 delayed_refs = &trans->transaction->delayed_refs;
1981 do {
1982 if (!locked_ref) {
1983 locked_ref = btrfs_obtain_ref_head(trans);
1984 if (IS_ERR_OR_NULL(locked_ref)) {
1985 if (PTR_ERR(locked_ref) == -EAGAIN) {
1986 continue;
1987 } else {
1988 break;
1989 }
1990 }
1991 count++;
1992 }
1993 /*
1994 * We need to try and merge add/drops of the same ref since we
1995 * can run into issues with relocate dropping the implicit ref
1996 * and then it being added back again before the drop can
1997 * finish. If we merged anything we need to re-loop so we can
1998 * get a good ref.
1999 * Or we can get node references of the same type that weren't
2000 * merged when created due to bumps in the tree mod seq, and
2001 * we need to merge them to prevent adding an inline extent
2002 * backref before dropping it (triggering a BUG_ON at
2003 * insert_inline_extent_backref()).
2004 */
2005 spin_lock(&locked_ref->lock);
2006 btrfs_merge_delayed_refs(trans, delayed_refs, locked_ref);
2007
2008 ret = btrfs_run_delayed_refs_for_head(trans, locked_ref,
2009 &actual_count);
2010 if (ret < 0 && ret != -EAGAIN) {
2011 /*
2012 * Error, btrfs_run_delayed_refs_for_head already
2013 * unlocked everything so just bail out
2014 */
2015 return ret;
2016 } else if (!ret) {
2017 /*
2018 * Success, perform the usual cleanup of a processed
2019 * head
2020 */
2021 ret = cleanup_ref_head(trans, locked_ref);
2022 if (ret > 0 ) {
2023 /* We dropped our lock, we need to loop. */
2024 ret = 0;
2025 continue;
2026 } else if (ret) {
2027 return ret;
2028 }
2029 }
2030
2031 /*
2032 * Either success case or btrfs_run_delayed_refs_for_head
2033 * returned -EAGAIN, meaning we need to select another head
2034 */
2035
2036 locked_ref = NULL;
2037 cond_resched();
2038 } while ((nr != -1 && count < nr) || locked_ref);
2039
2040 /*
2041 * We don't want to include ref heads since we can have empty ref heads
2042 * and those will drastically skew our runtime down since we just do
2043 * accounting, no actual extent tree updates.
2044 */
2045 if (actual_count > 0) {
2046 u64 runtime = ktime_to_ns(ktime_sub(ktime_get(), start));
2047 u64 avg;
2048
2049 /*
2050 * We weigh the current average higher than our current runtime
2051 * to avoid large swings in the average.
2052 */
2053 spin_lock(&delayed_refs->lock);
2054 avg = fs_info->avg_delayed_ref_runtime * 3 + runtime;
2055 fs_info->avg_delayed_ref_runtime = avg >> 2; /* div by 4 */
2056 spin_unlock(&delayed_refs->lock);
2057 }
2058 return 0;
2059 }
2060
2061 #ifdef SCRAMBLE_DELAYED_REFS
2062 /*
2063 * Normally delayed refs get processed in ascending bytenr order. This
2064 * correlates in most cases to the order added. To expose dependencies on this
2065 * order, we start to process the tree in the middle instead of the beginning
2066 */
find_middle(struct rb_root * root)2067 static u64 find_middle(struct rb_root *root)
2068 {
2069 struct rb_node *n = root->rb_node;
2070 struct btrfs_delayed_ref_node *entry;
2071 int alt = 1;
2072 u64 middle;
2073 u64 first = 0, last = 0;
2074
2075 n = rb_first(root);
2076 if (n) {
2077 entry = rb_entry(n, struct btrfs_delayed_ref_node, rb_node);
2078 first = entry->bytenr;
2079 }
2080 n = rb_last(root);
2081 if (n) {
2082 entry = rb_entry(n, struct btrfs_delayed_ref_node, rb_node);
2083 last = entry->bytenr;
2084 }
2085 n = root->rb_node;
2086
2087 while (n) {
2088 entry = rb_entry(n, struct btrfs_delayed_ref_node, rb_node);
2089 WARN_ON(!entry->in_tree);
2090
2091 middle = entry->bytenr;
2092
2093 if (alt)
2094 n = n->rb_left;
2095 else
2096 n = n->rb_right;
2097
2098 alt = 1 - alt;
2099 }
2100 return middle;
2101 }
2102 #endif
2103
2104 /*
2105 * this starts processing the delayed reference count updates and
2106 * extent insertions we have queued up so far. count can be
2107 * 0, which means to process everything in the tree at the start
2108 * of the run (but not newly added entries), or it can be some target
2109 * number you'd like to process.
2110 *
2111 * Returns 0 on success or if called with an aborted transaction
2112 * Returns <0 on error and aborts the transaction
2113 */
btrfs_run_delayed_refs(struct btrfs_trans_handle * trans,unsigned long count)2114 int btrfs_run_delayed_refs(struct btrfs_trans_handle *trans,
2115 unsigned long count)
2116 {
2117 struct btrfs_fs_info *fs_info = trans->fs_info;
2118 struct rb_node *node;
2119 struct btrfs_delayed_ref_root *delayed_refs;
2120 struct btrfs_delayed_ref_head *head;
2121 int ret;
2122 int run_all = count == (unsigned long)-1;
2123
2124 /* We'll clean this up in btrfs_cleanup_transaction */
2125 if (TRANS_ABORTED(trans))
2126 return 0;
2127
2128 if (test_bit(BTRFS_FS_CREATING_FREE_SPACE_TREE, &fs_info->flags))
2129 return 0;
2130
2131 delayed_refs = &trans->transaction->delayed_refs;
2132 if (count == 0)
2133 count = delayed_refs->num_heads_ready;
2134
2135 again:
2136 #ifdef SCRAMBLE_DELAYED_REFS
2137 delayed_refs->run_delayed_start = find_middle(&delayed_refs->root);
2138 #endif
2139 ret = __btrfs_run_delayed_refs(trans, count);
2140 if (ret < 0) {
2141 btrfs_abort_transaction(trans, ret);
2142 return ret;
2143 }
2144
2145 if (run_all) {
2146 btrfs_create_pending_block_groups(trans);
2147
2148 spin_lock(&delayed_refs->lock);
2149 node = rb_first_cached(&delayed_refs->href_root);
2150 if (!node) {
2151 spin_unlock(&delayed_refs->lock);
2152 goto out;
2153 }
2154 head = rb_entry(node, struct btrfs_delayed_ref_head,
2155 href_node);
2156 refcount_inc(&head->refs);
2157 spin_unlock(&delayed_refs->lock);
2158
2159 /* Mutex was contended, block until it's released and retry. */
2160 mutex_lock(&head->mutex);
2161 mutex_unlock(&head->mutex);
2162
2163 btrfs_put_delayed_ref_head(head);
2164 cond_resched();
2165 goto again;
2166 }
2167 out:
2168 return 0;
2169 }
2170
btrfs_set_disk_extent_flags(struct btrfs_trans_handle * trans,struct extent_buffer * eb,u64 flags,int level)2171 int btrfs_set_disk_extent_flags(struct btrfs_trans_handle *trans,
2172 struct extent_buffer *eb, u64 flags,
2173 int level)
2174 {
2175 struct btrfs_delayed_extent_op *extent_op;
2176 int ret;
2177
2178 extent_op = btrfs_alloc_delayed_extent_op();
2179 if (!extent_op)
2180 return -ENOMEM;
2181
2182 extent_op->flags_to_set = flags;
2183 extent_op->update_flags = true;
2184 extent_op->update_key = false;
2185 extent_op->level = level;
2186
2187 ret = btrfs_add_delayed_extent_op(trans, eb->start, eb->len, extent_op);
2188 if (ret)
2189 btrfs_free_delayed_extent_op(extent_op);
2190 return ret;
2191 }
2192
check_delayed_ref(struct btrfs_root * root,struct btrfs_path * path,u64 objectid,u64 offset,u64 bytenr)2193 static noinline int check_delayed_ref(struct btrfs_root *root,
2194 struct btrfs_path *path,
2195 u64 objectid, u64 offset, u64 bytenr)
2196 {
2197 struct btrfs_delayed_ref_head *head;
2198 struct btrfs_delayed_ref_node *ref;
2199 struct btrfs_delayed_data_ref *data_ref;
2200 struct btrfs_delayed_ref_root *delayed_refs;
2201 struct btrfs_transaction *cur_trans;
2202 struct rb_node *node;
2203 int ret = 0;
2204
2205 spin_lock(&root->fs_info->trans_lock);
2206 cur_trans = root->fs_info->running_transaction;
2207 if (cur_trans)
2208 refcount_inc(&cur_trans->use_count);
2209 spin_unlock(&root->fs_info->trans_lock);
2210 if (!cur_trans)
2211 return 0;
2212
2213 delayed_refs = &cur_trans->delayed_refs;
2214 spin_lock(&delayed_refs->lock);
2215 head = btrfs_find_delayed_ref_head(delayed_refs, bytenr);
2216 if (!head) {
2217 spin_unlock(&delayed_refs->lock);
2218 btrfs_put_transaction(cur_trans);
2219 return 0;
2220 }
2221
2222 if (!mutex_trylock(&head->mutex)) {
2223 if (path->nowait) {
2224 spin_unlock(&delayed_refs->lock);
2225 btrfs_put_transaction(cur_trans);
2226 return -EAGAIN;
2227 }
2228
2229 refcount_inc(&head->refs);
2230 spin_unlock(&delayed_refs->lock);
2231
2232 btrfs_release_path(path);
2233
2234 /*
2235 * Mutex was contended, block until it's released and let
2236 * caller try again
2237 */
2238 mutex_lock(&head->mutex);
2239 mutex_unlock(&head->mutex);
2240 btrfs_put_delayed_ref_head(head);
2241 btrfs_put_transaction(cur_trans);
2242 return -EAGAIN;
2243 }
2244 spin_unlock(&delayed_refs->lock);
2245
2246 spin_lock(&head->lock);
2247 /*
2248 * XXX: We should replace this with a proper search function in the
2249 * future.
2250 */
2251 for (node = rb_first_cached(&head->ref_tree); node;
2252 node = rb_next(node)) {
2253 ref = rb_entry(node, struct btrfs_delayed_ref_node, ref_node);
2254 /* If it's a shared ref we know a cross reference exists */
2255 if (ref->type != BTRFS_EXTENT_DATA_REF_KEY) {
2256 ret = 1;
2257 break;
2258 }
2259
2260 data_ref = btrfs_delayed_node_to_data_ref(ref);
2261
2262 /*
2263 * If our ref doesn't match the one we're currently looking at
2264 * then we have a cross reference.
2265 */
2266 if (data_ref->root != root->root_key.objectid ||
2267 data_ref->objectid != objectid ||
2268 data_ref->offset != offset) {
2269 ret = 1;
2270 break;
2271 }
2272 }
2273 spin_unlock(&head->lock);
2274 mutex_unlock(&head->mutex);
2275 btrfs_put_transaction(cur_trans);
2276 return ret;
2277 }
2278
check_committed_ref(struct btrfs_root * root,struct btrfs_path * path,u64 objectid,u64 offset,u64 bytenr,bool strict)2279 static noinline int check_committed_ref(struct btrfs_root *root,
2280 struct btrfs_path *path,
2281 u64 objectid, u64 offset, u64 bytenr,
2282 bool strict)
2283 {
2284 struct btrfs_fs_info *fs_info = root->fs_info;
2285 struct btrfs_root *extent_root = btrfs_extent_root(fs_info, bytenr);
2286 struct extent_buffer *leaf;
2287 struct btrfs_extent_data_ref *ref;
2288 struct btrfs_extent_inline_ref *iref;
2289 struct btrfs_extent_item *ei;
2290 struct btrfs_key key;
2291 u32 item_size;
2292 int type;
2293 int ret;
2294
2295 key.objectid = bytenr;
2296 key.offset = (u64)-1;
2297 key.type = BTRFS_EXTENT_ITEM_KEY;
2298
2299 ret = btrfs_search_slot(NULL, extent_root, &key, path, 0, 0);
2300 if (ret < 0)
2301 goto out;
2302 BUG_ON(ret == 0); /* Corruption */
2303
2304 ret = -ENOENT;
2305 if (path->slots[0] == 0)
2306 goto out;
2307
2308 path->slots[0]--;
2309 leaf = path->nodes[0];
2310 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
2311
2312 if (key.objectid != bytenr || key.type != BTRFS_EXTENT_ITEM_KEY)
2313 goto out;
2314
2315 ret = 1;
2316 item_size = btrfs_item_size(leaf, path->slots[0]);
2317 ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
2318
2319 /* If extent item has more than 1 inline ref then it's shared */
2320 if (item_size != sizeof(*ei) +
2321 btrfs_extent_inline_ref_size(BTRFS_EXTENT_DATA_REF_KEY))
2322 goto out;
2323
2324 /*
2325 * If extent created before last snapshot => it's shared unless the
2326 * snapshot has been deleted. Use the heuristic if strict is false.
2327 */
2328 if (!strict &&
2329 (btrfs_extent_generation(leaf, ei) <=
2330 btrfs_root_last_snapshot(&root->root_item)))
2331 goto out;
2332
2333 iref = (struct btrfs_extent_inline_ref *)(ei + 1);
2334
2335 /* If this extent has SHARED_DATA_REF then it's shared */
2336 type = btrfs_get_extent_inline_ref_type(leaf, iref, BTRFS_REF_TYPE_DATA);
2337 if (type != BTRFS_EXTENT_DATA_REF_KEY)
2338 goto out;
2339
2340 ref = (struct btrfs_extent_data_ref *)(&iref->offset);
2341 if (btrfs_extent_refs(leaf, ei) !=
2342 btrfs_extent_data_ref_count(leaf, ref) ||
2343 btrfs_extent_data_ref_root(leaf, ref) !=
2344 root->root_key.objectid ||
2345 btrfs_extent_data_ref_objectid(leaf, ref) != objectid ||
2346 btrfs_extent_data_ref_offset(leaf, ref) != offset)
2347 goto out;
2348
2349 ret = 0;
2350 out:
2351 return ret;
2352 }
2353
btrfs_cross_ref_exist(struct btrfs_root * root,u64 objectid,u64 offset,u64 bytenr,bool strict,struct btrfs_path * path)2354 int btrfs_cross_ref_exist(struct btrfs_root *root, u64 objectid, u64 offset,
2355 u64 bytenr, bool strict, struct btrfs_path *path)
2356 {
2357 int ret;
2358
2359 do {
2360 ret = check_committed_ref(root, path, objectid,
2361 offset, bytenr, strict);
2362 if (ret && ret != -ENOENT)
2363 goto out;
2364
2365 ret = check_delayed_ref(root, path, objectid, offset, bytenr);
2366 } while (ret == -EAGAIN);
2367
2368 out:
2369 btrfs_release_path(path);
2370 if (btrfs_is_data_reloc_root(root))
2371 WARN_ON(ret > 0);
2372 return ret;
2373 }
2374
__btrfs_mod_ref(struct btrfs_trans_handle * trans,struct btrfs_root * root,struct extent_buffer * buf,int full_backref,int inc)2375 static int __btrfs_mod_ref(struct btrfs_trans_handle *trans,
2376 struct btrfs_root *root,
2377 struct extent_buffer *buf,
2378 int full_backref, int inc)
2379 {
2380 struct btrfs_fs_info *fs_info = root->fs_info;
2381 u64 bytenr;
2382 u64 num_bytes;
2383 u64 parent;
2384 u64 ref_root;
2385 u32 nritems;
2386 struct btrfs_key key;
2387 struct btrfs_file_extent_item *fi;
2388 struct btrfs_ref generic_ref = { 0 };
2389 bool for_reloc = btrfs_header_flag(buf, BTRFS_HEADER_FLAG_RELOC);
2390 int i;
2391 int action;
2392 int level;
2393 int ret = 0;
2394
2395 if (btrfs_is_testing(fs_info))
2396 return 0;
2397
2398 ref_root = btrfs_header_owner(buf);
2399 nritems = btrfs_header_nritems(buf);
2400 level = btrfs_header_level(buf);
2401
2402 if (!test_bit(BTRFS_ROOT_SHAREABLE, &root->state) && level == 0)
2403 return 0;
2404
2405 if (full_backref)
2406 parent = buf->start;
2407 else
2408 parent = 0;
2409 if (inc)
2410 action = BTRFS_ADD_DELAYED_REF;
2411 else
2412 action = BTRFS_DROP_DELAYED_REF;
2413
2414 for (i = 0; i < nritems; i++) {
2415 if (level == 0) {
2416 btrfs_item_key_to_cpu(buf, &key, i);
2417 if (key.type != BTRFS_EXTENT_DATA_KEY)
2418 continue;
2419 fi = btrfs_item_ptr(buf, i,
2420 struct btrfs_file_extent_item);
2421 if (btrfs_file_extent_type(buf, fi) ==
2422 BTRFS_FILE_EXTENT_INLINE)
2423 continue;
2424 bytenr = btrfs_file_extent_disk_bytenr(buf, fi);
2425 if (bytenr == 0)
2426 continue;
2427
2428 num_bytes = btrfs_file_extent_disk_num_bytes(buf, fi);
2429 key.offset -= btrfs_file_extent_offset(buf, fi);
2430 btrfs_init_generic_ref(&generic_ref, action, bytenr,
2431 num_bytes, parent);
2432 btrfs_init_data_ref(&generic_ref, ref_root, key.objectid,
2433 key.offset, root->root_key.objectid,
2434 for_reloc);
2435 if (inc)
2436 ret = btrfs_inc_extent_ref(trans, &generic_ref);
2437 else
2438 ret = btrfs_free_extent(trans, &generic_ref);
2439 if (ret)
2440 goto fail;
2441 } else {
2442 bytenr = btrfs_node_blockptr(buf, i);
2443 num_bytes = fs_info->nodesize;
2444 btrfs_init_generic_ref(&generic_ref, action, bytenr,
2445 num_bytes, parent);
2446 btrfs_init_tree_ref(&generic_ref, level - 1, ref_root,
2447 root->root_key.objectid, for_reloc);
2448 if (inc)
2449 ret = btrfs_inc_extent_ref(trans, &generic_ref);
2450 else
2451 ret = btrfs_free_extent(trans, &generic_ref);
2452 if (ret)
2453 goto fail;
2454 }
2455 }
2456 return 0;
2457 fail:
2458 return ret;
2459 }
2460
btrfs_inc_ref(struct btrfs_trans_handle * trans,struct btrfs_root * root,struct extent_buffer * buf,int full_backref)2461 int btrfs_inc_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
2462 struct extent_buffer *buf, int full_backref)
2463 {
2464 return __btrfs_mod_ref(trans, root, buf, full_backref, 1);
2465 }
2466
btrfs_dec_ref(struct btrfs_trans_handle * trans,struct btrfs_root * root,struct extent_buffer * buf,int full_backref)2467 int btrfs_dec_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
2468 struct extent_buffer *buf, int full_backref)
2469 {
2470 return __btrfs_mod_ref(trans, root, buf, full_backref, 0);
2471 }
2472
get_alloc_profile_by_root(struct btrfs_root * root,int data)2473 static u64 get_alloc_profile_by_root(struct btrfs_root *root, int data)
2474 {
2475 struct btrfs_fs_info *fs_info = root->fs_info;
2476 u64 flags;
2477 u64 ret;
2478
2479 if (data)
2480 flags = BTRFS_BLOCK_GROUP_DATA;
2481 else if (root == fs_info->chunk_root)
2482 flags = BTRFS_BLOCK_GROUP_SYSTEM;
2483 else
2484 flags = BTRFS_BLOCK_GROUP_METADATA;
2485
2486 ret = btrfs_get_alloc_profile(fs_info, flags);
2487 return ret;
2488 }
2489
first_logical_byte(struct btrfs_fs_info * fs_info)2490 static u64 first_logical_byte(struct btrfs_fs_info *fs_info)
2491 {
2492 struct rb_node *leftmost;
2493 u64 bytenr = 0;
2494
2495 read_lock(&fs_info->block_group_cache_lock);
2496 /* Get the block group with the lowest logical start address. */
2497 leftmost = rb_first_cached(&fs_info->block_group_cache_tree);
2498 if (leftmost) {
2499 struct btrfs_block_group *bg;
2500
2501 bg = rb_entry(leftmost, struct btrfs_block_group, cache_node);
2502 bytenr = bg->start;
2503 }
2504 read_unlock(&fs_info->block_group_cache_lock);
2505
2506 return bytenr;
2507 }
2508
pin_down_extent(struct btrfs_trans_handle * trans,struct btrfs_block_group * cache,u64 bytenr,u64 num_bytes,int reserved)2509 static int pin_down_extent(struct btrfs_trans_handle *trans,
2510 struct btrfs_block_group *cache,
2511 u64 bytenr, u64 num_bytes, int reserved)
2512 {
2513 struct btrfs_fs_info *fs_info = cache->fs_info;
2514
2515 spin_lock(&cache->space_info->lock);
2516 spin_lock(&cache->lock);
2517 cache->pinned += num_bytes;
2518 btrfs_space_info_update_bytes_pinned(fs_info, cache->space_info,
2519 num_bytes);
2520 if (reserved) {
2521 cache->reserved -= num_bytes;
2522 cache->space_info->bytes_reserved -= num_bytes;
2523 }
2524 spin_unlock(&cache->lock);
2525 spin_unlock(&cache->space_info->lock);
2526
2527 set_extent_dirty(&trans->transaction->pinned_extents, bytenr,
2528 bytenr + num_bytes - 1, GFP_NOFS | __GFP_NOFAIL);
2529 return 0;
2530 }
2531
btrfs_pin_extent(struct btrfs_trans_handle * trans,u64 bytenr,u64 num_bytes,int reserved)2532 int btrfs_pin_extent(struct btrfs_trans_handle *trans,
2533 u64 bytenr, u64 num_bytes, int reserved)
2534 {
2535 struct btrfs_block_group *cache;
2536
2537 cache = btrfs_lookup_block_group(trans->fs_info, bytenr);
2538 BUG_ON(!cache); /* Logic error */
2539
2540 pin_down_extent(trans, cache, bytenr, num_bytes, reserved);
2541
2542 btrfs_put_block_group(cache);
2543 return 0;
2544 }
2545
2546 /*
2547 * this function must be called within transaction
2548 */
btrfs_pin_extent_for_log_replay(struct btrfs_trans_handle * trans,u64 bytenr,u64 num_bytes)2549 int btrfs_pin_extent_for_log_replay(struct btrfs_trans_handle *trans,
2550 u64 bytenr, u64 num_bytes)
2551 {
2552 struct btrfs_block_group *cache;
2553 int ret;
2554
2555 cache = btrfs_lookup_block_group(trans->fs_info, bytenr);
2556 if (!cache)
2557 return -EINVAL;
2558
2559 /*
2560 * Fully cache the free space first so that our pin removes the free space
2561 * from the cache.
2562 */
2563 ret = btrfs_cache_block_group(cache, true);
2564 if (ret)
2565 goto out;
2566
2567 pin_down_extent(trans, cache, bytenr, num_bytes, 0);
2568
2569 /* remove us from the free space cache (if we're there at all) */
2570 ret = btrfs_remove_free_space(cache, bytenr, num_bytes);
2571 out:
2572 btrfs_put_block_group(cache);
2573 return ret;
2574 }
2575
__exclude_logged_extent(struct btrfs_fs_info * fs_info,u64 start,u64 num_bytes)2576 static int __exclude_logged_extent(struct btrfs_fs_info *fs_info,
2577 u64 start, u64 num_bytes)
2578 {
2579 int ret;
2580 struct btrfs_block_group *block_group;
2581
2582 block_group = btrfs_lookup_block_group(fs_info, start);
2583 if (!block_group)
2584 return -EINVAL;
2585
2586 ret = btrfs_cache_block_group(block_group, true);
2587 if (ret)
2588 goto out;
2589
2590 ret = btrfs_remove_free_space(block_group, start, num_bytes);
2591 out:
2592 btrfs_put_block_group(block_group);
2593 return ret;
2594 }
2595
btrfs_exclude_logged_extents(struct extent_buffer * eb)2596 int btrfs_exclude_logged_extents(struct extent_buffer *eb)
2597 {
2598 struct btrfs_fs_info *fs_info = eb->fs_info;
2599 struct btrfs_file_extent_item *item;
2600 struct btrfs_key key;
2601 int found_type;
2602 int i;
2603 int ret = 0;
2604
2605 if (!btrfs_fs_incompat(fs_info, MIXED_GROUPS))
2606 return 0;
2607
2608 for (i = 0; i < btrfs_header_nritems(eb); i++) {
2609 btrfs_item_key_to_cpu(eb, &key, i);
2610 if (key.type != BTRFS_EXTENT_DATA_KEY)
2611 continue;
2612 item = btrfs_item_ptr(eb, i, struct btrfs_file_extent_item);
2613 found_type = btrfs_file_extent_type(eb, item);
2614 if (found_type == BTRFS_FILE_EXTENT_INLINE)
2615 continue;
2616 if (btrfs_file_extent_disk_bytenr(eb, item) == 0)
2617 continue;
2618 key.objectid = btrfs_file_extent_disk_bytenr(eb, item);
2619 key.offset = btrfs_file_extent_disk_num_bytes(eb, item);
2620 ret = __exclude_logged_extent(fs_info, key.objectid, key.offset);
2621 if (ret)
2622 break;
2623 }
2624
2625 return ret;
2626 }
2627
2628 static void
btrfs_inc_block_group_reservations(struct btrfs_block_group * bg)2629 btrfs_inc_block_group_reservations(struct btrfs_block_group *bg)
2630 {
2631 atomic_inc(&bg->reservations);
2632 }
2633
2634 /*
2635 * Returns the free cluster for the given space info and sets empty_cluster to
2636 * what it should be based on the mount options.
2637 */
2638 static struct btrfs_free_cluster *
fetch_cluster_info(struct btrfs_fs_info * fs_info,struct btrfs_space_info * space_info,u64 * empty_cluster)2639 fetch_cluster_info(struct btrfs_fs_info *fs_info,
2640 struct btrfs_space_info *space_info, u64 *empty_cluster)
2641 {
2642 struct btrfs_free_cluster *ret = NULL;
2643
2644 *empty_cluster = 0;
2645 if (btrfs_mixed_space_info(space_info))
2646 return ret;
2647
2648 if (space_info->flags & BTRFS_BLOCK_GROUP_METADATA) {
2649 ret = &fs_info->meta_alloc_cluster;
2650 if (btrfs_test_opt(fs_info, SSD))
2651 *empty_cluster = SZ_2M;
2652 else
2653 *empty_cluster = SZ_64K;
2654 } else if ((space_info->flags & BTRFS_BLOCK_GROUP_DATA) &&
2655 btrfs_test_opt(fs_info, SSD_SPREAD)) {
2656 *empty_cluster = SZ_2M;
2657 ret = &fs_info->data_alloc_cluster;
2658 }
2659
2660 return ret;
2661 }
2662
unpin_extent_range(struct btrfs_fs_info * fs_info,u64 start,u64 end,const bool return_free_space)2663 static int unpin_extent_range(struct btrfs_fs_info *fs_info,
2664 u64 start, u64 end,
2665 const bool return_free_space)
2666 {
2667 struct btrfs_block_group *cache = NULL;
2668 struct btrfs_space_info *space_info;
2669 struct btrfs_block_rsv *global_rsv = &fs_info->global_block_rsv;
2670 struct btrfs_free_cluster *cluster = NULL;
2671 u64 len;
2672 u64 total_unpinned = 0;
2673 u64 empty_cluster = 0;
2674 bool readonly;
2675
2676 while (start <= end) {
2677 readonly = false;
2678 if (!cache ||
2679 start >= cache->start + cache->length) {
2680 if (cache)
2681 btrfs_put_block_group(cache);
2682 total_unpinned = 0;
2683 cache = btrfs_lookup_block_group(fs_info, start);
2684 BUG_ON(!cache); /* Logic error */
2685
2686 cluster = fetch_cluster_info(fs_info,
2687 cache->space_info,
2688 &empty_cluster);
2689 empty_cluster <<= 1;
2690 }
2691
2692 len = cache->start + cache->length - start;
2693 len = min(len, end + 1 - start);
2694
2695 if (return_free_space)
2696 btrfs_add_free_space(cache, start, len);
2697
2698 start += len;
2699 total_unpinned += len;
2700 space_info = cache->space_info;
2701
2702 /*
2703 * If this space cluster has been marked as fragmented and we've
2704 * unpinned enough in this block group to potentially allow a
2705 * cluster to be created inside of it go ahead and clear the
2706 * fragmented check.
2707 */
2708 if (cluster && cluster->fragmented &&
2709 total_unpinned > empty_cluster) {
2710 spin_lock(&cluster->lock);
2711 cluster->fragmented = 0;
2712 spin_unlock(&cluster->lock);
2713 }
2714
2715 spin_lock(&space_info->lock);
2716 spin_lock(&cache->lock);
2717 cache->pinned -= len;
2718 btrfs_space_info_update_bytes_pinned(fs_info, space_info, -len);
2719 space_info->max_extent_size = 0;
2720 if (cache->ro) {
2721 space_info->bytes_readonly += len;
2722 readonly = true;
2723 } else if (btrfs_is_zoned(fs_info)) {
2724 /* Need reset before reusing in a zoned block group */
2725 space_info->bytes_zone_unusable += len;
2726 readonly = true;
2727 }
2728 spin_unlock(&cache->lock);
2729 if (!readonly && return_free_space &&
2730 global_rsv->space_info == space_info) {
2731 spin_lock(&global_rsv->lock);
2732 if (!global_rsv->full) {
2733 u64 to_add = min(len, global_rsv->size -
2734 global_rsv->reserved);
2735
2736 global_rsv->reserved += to_add;
2737 btrfs_space_info_update_bytes_may_use(fs_info,
2738 space_info, to_add);
2739 if (global_rsv->reserved >= global_rsv->size)
2740 global_rsv->full = 1;
2741 len -= to_add;
2742 }
2743 spin_unlock(&global_rsv->lock);
2744 }
2745 /* Add to any tickets we may have */
2746 if (!readonly && return_free_space && len)
2747 btrfs_try_granting_tickets(fs_info, space_info);
2748 spin_unlock(&space_info->lock);
2749 }
2750
2751 if (cache)
2752 btrfs_put_block_group(cache);
2753 return 0;
2754 }
2755
btrfs_finish_extent_commit(struct btrfs_trans_handle * trans)2756 int btrfs_finish_extent_commit(struct btrfs_trans_handle *trans)
2757 {
2758 struct btrfs_fs_info *fs_info = trans->fs_info;
2759 struct btrfs_block_group *block_group, *tmp;
2760 struct list_head *deleted_bgs;
2761 struct extent_io_tree *unpin;
2762 u64 start;
2763 u64 end;
2764 int ret;
2765
2766 unpin = &trans->transaction->pinned_extents;
2767
2768 while (!TRANS_ABORTED(trans)) {
2769 struct extent_state *cached_state = NULL;
2770
2771 mutex_lock(&fs_info->unused_bg_unpin_mutex);
2772 ret = find_first_extent_bit(unpin, 0, &start, &end,
2773 EXTENT_DIRTY, &cached_state);
2774 if (ret) {
2775 mutex_unlock(&fs_info->unused_bg_unpin_mutex);
2776 break;
2777 }
2778
2779 if (btrfs_test_opt(fs_info, DISCARD_SYNC))
2780 ret = btrfs_discard_extent(fs_info, start,
2781 end + 1 - start, NULL);
2782
2783 clear_extent_dirty(unpin, start, end, &cached_state);
2784 unpin_extent_range(fs_info, start, end, true);
2785 mutex_unlock(&fs_info->unused_bg_unpin_mutex);
2786 free_extent_state(cached_state);
2787 cond_resched();
2788 }
2789
2790 if (btrfs_test_opt(fs_info, DISCARD_ASYNC)) {
2791 btrfs_discard_calc_delay(&fs_info->discard_ctl);
2792 btrfs_discard_schedule_work(&fs_info->discard_ctl, true);
2793 }
2794
2795 /*
2796 * Transaction is finished. We don't need the lock anymore. We
2797 * do need to clean up the block groups in case of a transaction
2798 * abort.
2799 */
2800 deleted_bgs = &trans->transaction->deleted_bgs;
2801 list_for_each_entry_safe(block_group, tmp, deleted_bgs, bg_list) {
2802 u64 trimmed = 0;
2803
2804 ret = -EROFS;
2805 if (!TRANS_ABORTED(trans))
2806 ret = btrfs_discard_extent(fs_info,
2807 block_group->start,
2808 block_group->length,
2809 &trimmed);
2810
2811 list_del_init(&block_group->bg_list);
2812 btrfs_unfreeze_block_group(block_group);
2813 btrfs_put_block_group(block_group);
2814
2815 if (ret) {
2816 const char *errstr = btrfs_decode_error(ret);
2817 btrfs_warn(fs_info,
2818 "discard failed while removing blockgroup: errno=%d %s",
2819 ret, errstr);
2820 }
2821 }
2822
2823 return 0;
2824 }
2825
do_free_extent_accounting(struct btrfs_trans_handle * trans,u64 bytenr,u64 num_bytes,bool is_data)2826 static int do_free_extent_accounting(struct btrfs_trans_handle *trans,
2827 u64 bytenr, u64 num_bytes, bool is_data)
2828 {
2829 int ret;
2830
2831 if (is_data) {
2832 struct btrfs_root *csum_root;
2833
2834 csum_root = btrfs_csum_root(trans->fs_info, bytenr);
2835 ret = btrfs_del_csums(trans, csum_root, bytenr, num_bytes);
2836 if (ret) {
2837 btrfs_abort_transaction(trans, ret);
2838 return ret;
2839 }
2840 }
2841
2842 ret = add_to_free_space_tree(trans, bytenr, num_bytes);
2843 if (ret) {
2844 btrfs_abort_transaction(trans, ret);
2845 return ret;
2846 }
2847
2848 ret = btrfs_update_block_group(trans, bytenr, num_bytes, false);
2849 if (ret)
2850 btrfs_abort_transaction(trans, ret);
2851
2852 return ret;
2853 }
2854
2855 /*
2856 * Drop one or more refs of @node.
2857 *
2858 * 1. Locate the extent refs.
2859 * It's either inline in EXTENT/METADATA_ITEM or in keyed SHARED_* item.
2860 * Locate it, then reduce the refs number or remove the ref line completely.
2861 *
2862 * 2. Update the refs count in EXTENT/METADATA_ITEM
2863 *
2864 * Inline backref case:
2865 *
2866 * in extent tree we have:
2867 *
2868 * item 0 key (13631488 EXTENT_ITEM 1048576) itemoff 16201 itemsize 82
2869 * refs 2 gen 6 flags DATA
2870 * extent data backref root FS_TREE objectid 258 offset 0 count 1
2871 * extent data backref root FS_TREE objectid 257 offset 0 count 1
2872 *
2873 * This function gets called with:
2874 *
2875 * node->bytenr = 13631488
2876 * node->num_bytes = 1048576
2877 * root_objectid = FS_TREE
2878 * owner_objectid = 257
2879 * owner_offset = 0
2880 * refs_to_drop = 1
2881 *
2882 * Then we should get some like:
2883 *
2884 * item 0 key (13631488 EXTENT_ITEM 1048576) itemoff 16201 itemsize 82
2885 * refs 1 gen 6 flags DATA
2886 * extent data backref root FS_TREE objectid 258 offset 0 count 1
2887 *
2888 * Keyed backref case:
2889 *
2890 * in extent tree we have:
2891 *
2892 * item 0 key (13631488 EXTENT_ITEM 1048576) itemoff 3971 itemsize 24
2893 * refs 754 gen 6 flags DATA
2894 * [...]
2895 * item 2 key (13631488 EXTENT_DATA_REF <HASH>) itemoff 3915 itemsize 28
2896 * extent data backref root FS_TREE objectid 866 offset 0 count 1
2897 *
2898 * This function get called with:
2899 *
2900 * node->bytenr = 13631488
2901 * node->num_bytes = 1048576
2902 * root_objectid = FS_TREE
2903 * owner_objectid = 866
2904 * owner_offset = 0
2905 * refs_to_drop = 1
2906 *
2907 * Then we should get some like:
2908 *
2909 * item 0 key (13631488 EXTENT_ITEM 1048576) itemoff 3971 itemsize 24
2910 * refs 753 gen 6 flags DATA
2911 *
2912 * And that (13631488 EXTENT_DATA_REF <HASH>) gets removed.
2913 */
__btrfs_free_extent(struct btrfs_trans_handle * trans,struct btrfs_delayed_ref_node * node,u64 parent,u64 root_objectid,u64 owner_objectid,u64 owner_offset,int refs_to_drop,struct btrfs_delayed_extent_op * extent_op)2914 static int __btrfs_free_extent(struct btrfs_trans_handle *trans,
2915 struct btrfs_delayed_ref_node *node, u64 parent,
2916 u64 root_objectid, u64 owner_objectid,
2917 u64 owner_offset, int refs_to_drop,
2918 struct btrfs_delayed_extent_op *extent_op)
2919 {
2920 struct btrfs_fs_info *info = trans->fs_info;
2921 struct btrfs_key key;
2922 struct btrfs_path *path;
2923 struct btrfs_root *extent_root;
2924 struct extent_buffer *leaf;
2925 struct btrfs_extent_item *ei;
2926 struct btrfs_extent_inline_ref *iref;
2927 int ret;
2928 int is_data;
2929 int extent_slot = 0;
2930 int found_extent = 0;
2931 int num_to_del = 1;
2932 u32 item_size;
2933 u64 refs;
2934 u64 bytenr = node->bytenr;
2935 u64 num_bytes = node->num_bytes;
2936 bool skinny_metadata = btrfs_fs_incompat(info, SKINNY_METADATA);
2937
2938 extent_root = btrfs_extent_root(info, bytenr);
2939 ASSERT(extent_root);
2940
2941 path = btrfs_alloc_path();
2942 if (!path)
2943 return -ENOMEM;
2944
2945 is_data = owner_objectid >= BTRFS_FIRST_FREE_OBJECTID;
2946
2947 if (!is_data && refs_to_drop != 1) {
2948 btrfs_crit(info,
2949 "invalid refs_to_drop, dropping more than 1 refs for tree block %llu refs_to_drop %u",
2950 node->bytenr, refs_to_drop);
2951 ret = -EINVAL;
2952 btrfs_abort_transaction(trans, ret);
2953 goto out;
2954 }
2955
2956 if (is_data)
2957 skinny_metadata = false;
2958
2959 ret = lookup_extent_backref(trans, path, &iref, bytenr, num_bytes,
2960 parent, root_objectid, owner_objectid,
2961 owner_offset);
2962 if (ret == 0) {
2963 /*
2964 * Either the inline backref or the SHARED_DATA_REF/
2965 * SHARED_BLOCK_REF is found
2966 *
2967 * Here is a quick path to locate EXTENT/METADATA_ITEM.
2968 * It's possible the EXTENT/METADATA_ITEM is near current slot.
2969 */
2970 extent_slot = path->slots[0];
2971 while (extent_slot >= 0) {
2972 btrfs_item_key_to_cpu(path->nodes[0], &key,
2973 extent_slot);
2974 if (key.objectid != bytenr)
2975 break;
2976 if (key.type == BTRFS_EXTENT_ITEM_KEY &&
2977 key.offset == num_bytes) {
2978 found_extent = 1;
2979 break;
2980 }
2981 if (key.type == BTRFS_METADATA_ITEM_KEY &&
2982 key.offset == owner_objectid) {
2983 found_extent = 1;
2984 break;
2985 }
2986
2987 /* Quick path didn't find the EXTEMT/METADATA_ITEM */
2988 if (path->slots[0] - extent_slot > 5)
2989 break;
2990 extent_slot--;
2991 }
2992
2993 if (!found_extent) {
2994 if (iref) {
2995 btrfs_crit(info,
2996 "invalid iref, no EXTENT/METADATA_ITEM found but has inline extent ref");
2997 btrfs_abort_transaction(trans, -EUCLEAN);
2998 goto err_dump;
2999 }
3000 /* Must be SHARED_* item, remove the backref first */
3001 ret = remove_extent_backref(trans, extent_root, path,
3002 NULL, refs_to_drop, is_data);
3003 if (ret) {
3004 btrfs_abort_transaction(trans, ret);
3005 goto out;
3006 }
3007 btrfs_release_path(path);
3008
3009 /* Slow path to locate EXTENT/METADATA_ITEM */
3010 key.objectid = bytenr;
3011 key.type = BTRFS_EXTENT_ITEM_KEY;
3012 key.offset = num_bytes;
3013
3014 if (!is_data && skinny_metadata) {
3015 key.type = BTRFS_METADATA_ITEM_KEY;
3016 key.offset = owner_objectid;
3017 }
3018
3019 ret = btrfs_search_slot(trans, extent_root,
3020 &key, path, -1, 1);
3021 if (ret > 0 && skinny_metadata && path->slots[0]) {
3022 /*
3023 * Couldn't find our skinny metadata item,
3024 * see if we have ye olde extent item.
3025 */
3026 path->slots[0]--;
3027 btrfs_item_key_to_cpu(path->nodes[0], &key,
3028 path->slots[0]);
3029 if (key.objectid == bytenr &&
3030 key.type == BTRFS_EXTENT_ITEM_KEY &&
3031 key.offset == num_bytes)
3032 ret = 0;
3033 }
3034
3035 if (ret > 0 && skinny_metadata) {
3036 skinny_metadata = false;
3037 key.objectid = bytenr;
3038 key.type = BTRFS_EXTENT_ITEM_KEY;
3039 key.offset = num_bytes;
3040 btrfs_release_path(path);
3041 ret = btrfs_search_slot(trans, extent_root,
3042 &key, path, -1, 1);
3043 }
3044
3045 if (ret) {
3046 btrfs_err(info,
3047 "umm, got %d back from search, was looking for %llu",
3048 ret, bytenr);
3049 if (ret > 0)
3050 btrfs_print_leaf(path->nodes[0]);
3051 }
3052 if (ret < 0) {
3053 btrfs_abort_transaction(trans, ret);
3054 goto out;
3055 }
3056 extent_slot = path->slots[0];
3057 }
3058 } else if (WARN_ON(ret == -ENOENT)) {
3059 btrfs_print_leaf(path->nodes[0]);
3060 btrfs_err(info,
3061 "unable to find ref byte nr %llu parent %llu root %llu owner %llu offset %llu",
3062 bytenr, parent, root_objectid, owner_objectid,
3063 owner_offset);
3064 btrfs_abort_transaction(trans, ret);
3065 goto out;
3066 } else {
3067 btrfs_abort_transaction(trans, ret);
3068 goto out;
3069 }
3070
3071 leaf = path->nodes[0];
3072 item_size = btrfs_item_size(leaf, extent_slot);
3073 if (unlikely(item_size < sizeof(*ei))) {
3074 ret = -EINVAL;
3075 btrfs_print_v0_err(info);
3076 btrfs_abort_transaction(trans, ret);
3077 goto out;
3078 }
3079 ei = btrfs_item_ptr(leaf, extent_slot,
3080 struct btrfs_extent_item);
3081 if (owner_objectid < BTRFS_FIRST_FREE_OBJECTID &&
3082 key.type == BTRFS_EXTENT_ITEM_KEY) {
3083 struct btrfs_tree_block_info *bi;
3084 if (item_size < sizeof(*ei) + sizeof(*bi)) {
3085 btrfs_crit(info,
3086 "invalid extent item size for key (%llu, %u, %llu) owner %llu, has %u expect >= %zu",
3087 key.objectid, key.type, key.offset,
3088 owner_objectid, item_size,
3089 sizeof(*ei) + sizeof(*bi));
3090 btrfs_abort_transaction(trans, -EUCLEAN);
3091 goto err_dump;
3092 }
3093 bi = (struct btrfs_tree_block_info *)(ei + 1);
3094 WARN_ON(owner_objectid != btrfs_tree_block_level(leaf, bi));
3095 }
3096
3097 refs = btrfs_extent_refs(leaf, ei);
3098 if (refs < refs_to_drop) {
3099 btrfs_crit(info,
3100 "trying to drop %d refs but we only have %llu for bytenr %llu",
3101 refs_to_drop, refs, bytenr);
3102 btrfs_abort_transaction(trans, -EUCLEAN);
3103 goto err_dump;
3104 }
3105 refs -= refs_to_drop;
3106
3107 if (refs > 0) {
3108 if (extent_op)
3109 __run_delayed_extent_op(extent_op, leaf, ei);
3110 /*
3111 * In the case of inline back ref, reference count will
3112 * be updated by remove_extent_backref
3113 */
3114 if (iref) {
3115 if (!found_extent) {
3116 btrfs_crit(info,
3117 "invalid iref, got inlined extent ref but no EXTENT/METADATA_ITEM found");
3118 btrfs_abort_transaction(trans, -EUCLEAN);
3119 goto err_dump;
3120 }
3121 } else {
3122 btrfs_set_extent_refs(leaf, ei, refs);
3123 btrfs_mark_buffer_dirty(leaf);
3124 }
3125 if (found_extent) {
3126 ret = remove_extent_backref(trans, extent_root, path,
3127 iref, refs_to_drop, is_data);
3128 if (ret) {
3129 btrfs_abort_transaction(trans, ret);
3130 goto out;
3131 }
3132 }
3133 } else {
3134 /* In this branch refs == 1 */
3135 if (found_extent) {
3136 if (is_data && refs_to_drop !=
3137 extent_data_ref_count(path, iref)) {
3138 btrfs_crit(info,
3139 "invalid refs_to_drop, current refs %u refs_to_drop %u",
3140 extent_data_ref_count(path, iref),
3141 refs_to_drop);
3142 btrfs_abort_transaction(trans, -EUCLEAN);
3143 goto err_dump;
3144 }
3145 if (iref) {
3146 if (path->slots[0] != extent_slot) {
3147 btrfs_crit(info,
3148 "invalid iref, extent item key (%llu %u %llu) doesn't have wanted iref",
3149 key.objectid, key.type,
3150 key.offset);
3151 btrfs_abort_transaction(trans, -EUCLEAN);
3152 goto err_dump;
3153 }
3154 } else {
3155 /*
3156 * No inline ref, we must be at SHARED_* item,
3157 * And it's single ref, it must be:
3158 * | extent_slot ||extent_slot + 1|
3159 * [ EXTENT/METADATA_ITEM ][ SHARED_* ITEM ]
3160 */
3161 if (path->slots[0] != extent_slot + 1) {
3162 btrfs_crit(info,
3163 "invalid SHARED_* item, previous item is not EXTENT/METADATA_ITEM");
3164 btrfs_abort_transaction(trans, -EUCLEAN);
3165 goto err_dump;
3166 }
3167 path->slots[0] = extent_slot;
3168 num_to_del = 2;
3169 }
3170 }
3171
3172 ret = btrfs_del_items(trans, extent_root, path, path->slots[0],
3173 num_to_del);
3174 if (ret) {
3175 btrfs_abort_transaction(trans, ret);
3176 goto out;
3177 }
3178 btrfs_release_path(path);
3179
3180 ret = do_free_extent_accounting(trans, bytenr, num_bytes, is_data);
3181 }
3182 btrfs_release_path(path);
3183
3184 out:
3185 btrfs_free_path(path);
3186 return ret;
3187 err_dump:
3188 /*
3189 * Leaf dump can take up a lot of log buffer, so we only do full leaf
3190 * dump for debug build.
3191 */
3192 if (IS_ENABLED(CONFIG_BTRFS_DEBUG)) {
3193 btrfs_crit(info, "path->slots[0]=%d extent_slot=%d",
3194 path->slots[0], extent_slot);
3195 btrfs_print_leaf(path->nodes[0]);
3196 }
3197
3198 btrfs_free_path(path);
3199 return -EUCLEAN;
3200 }
3201
3202 /*
3203 * when we free an block, it is possible (and likely) that we free the last
3204 * delayed ref for that extent as well. This searches the delayed ref tree for
3205 * a given extent, and if there are no other delayed refs to be processed, it
3206 * removes it from the tree.
3207 */
check_ref_cleanup(struct btrfs_trans_handle * trans,u64 bytenr)3208 static noinline int check_ref_cleanup(struct btrfs_trans_handle *trans,
3209 u64 bytenr)
3210 {
3211 struct btrfs_delayed_ref_head *head;
3212 struct btrfs_delayed_ref_root *delayed_refs;
3213 int ret = 0;
3214
3215 delayed_refs = &trans->transaction->delayed_refs;
3216 spin_lock(&delayed_refs->lock);
3217 head = btrfs_find_delayed_ref_head(delayed_refs, bytenr);
3218 if (!head)
3219 goto out_delayed_unlock;
3220
3221 spin_lock(&head->lock);
3222 if (!RB_EMPTY_ROOT(&head->ref_tree.rb_root))
3223 goto out;
3224
3225 if (cleanup_extent_op(head) != NULL)
3226 goto out;
3227
3228 /*
3229 * waiting for the lock here would deadlock. If someone else has it
3230 * locked they are already in the process of dropping it anyway
3231 */
3232 if (!mutex_trylock(&head->mutex))
3233 goto out;
3234
3235 btrfs_delete_ref_head(delayed_refs, head);
3236 head->processing = 0;
3237
3238 spin_unlock(&head->lock);
3239 spin_unlock(&delayed_refs->lock);
3240
3241 BUG_ON(head->extent_op);
3242 if (head->must_insert_reserved)
3243 ret = 1;
3244
3245 btrfs_cleanup_ref_head_accounting(trans->fs_info, delayed_refs, head);
3246 mutex_unlock(&head->mutex);
3247 btrfs_put_delayed_ref_head(head);
3248 return ret;
3249 out:
3250 spin_unlock(&head->lock);
3251
3252 out_delayed_unlock:
3253 spin_unlock(&delayed_refs->lock);
3254 return 0;
3255 }
3256
btrfs_free_tree_block(struct btrfs_trans_handle * trans,u64 root_id,struct extent_buffer * buf,u64 parent,int last_ref)3257 void btrfs_free_tree_block(struct btrfs_trans_handle *trans,
3258 u64 root_id,
3259 struct extent_buffer *buf,
3260 u64 parent, int last_ref)
3261 {
3262 struct btrfs_fs_info *fs_info = trans->fs_info;
3263 struct btrfs_ref generic_ref = { 0 };
3264 int ret;
3265
3266 btrfs_init_generic_ref(&generic_ref, BTRFS_DROP_DELAYED_REF,
3267 buf->start, buf->len, parent);
3268 btrfs_init_tree_ref(&generic_ref, btrfs_header_level(buf),
3269 root_id, 0, false);
3270
3271 if (root_id != BTRFS_TREE_LOG_OBJECTID) {
3272 btrfs_ref_tree_mod(fs_info, &generic_ref);
3273 ret = btrfs_add_delayed_tree_ref(trans, &generic_ref, NULL);
3274 BUG_ON(ret); /* -ENOMEM */
3275 }
3276
3277 if (last_ref && btrfs_header_generation(buf) == trans->transid) {
3278 struct btrfs_block_group *cache;
3279 bool must_pin = false;
3280
3281 if (root_id != BTRFS_TREE_LOG_OBJECTID) {
3282 ret = check_ref_cleanup(trans, buf->start);
3283 if (!ret) {
3284 btrfs_redirty_list_add(trans->transaction, buf);
3285 goto out;
3286 }
3287 }
3288
3289 cache = btrfs_lookup_block_group(fs_info, buf->start);
3290
3291 if (btrfs_header_flag(buf, BTRFS_HEADER_FLAG_WRITTEN)) {
3292 pin_down_extent(trans, cache, buf->start, buf->len, 1);
3293 btrfs_put_block_group(cache);
3294 goto out;
3295 }
3296
3297 /*
3298 * If there are tree mod log users we may have recorded mod log
3299 * operations for this node. If we re-allocate this node we
3300 * could replay operations on this node that happened when it
3301 * existed in a completely different root. For example if it
3302 * was part of root A, then was reallocated to root B, and we
3303 * are doing a btrfs_old_search_slot(root b), we could replay
3304 * operations that happened when the block was part of root A,
3305 * giving us an inconsistent view of the btree.
3306 *
3307 * We are safe from races here because at this point no other
3308 * node or root points to this extent buffer, so if after this
3309 * check a new tree mod log user joins we will not have an
3310 * existing log of operations on this node that we have to
3311 * contend with.
3312 */
3313 if (test_bit(BTRFS_FS_TREE_MOD_LOG_USERS, &fs_info->flags))
3314 must_pin = true;
3315
3316 if (must_pin || btrfs_is_zoned(fs_info)) {
3317 btrfs_redirty_list_add(trans->transaction, buf);
3318 pin_down_extent(trans, cache, buf->start, buf->len, 1);
3319 btrfs_put_block_group(cache);
3320 goto out;
3321 }
3322
3323 WARN_ON(test_bit(EXTENT_BUFFER_DIRTY, &buf->bflags));
3324
3325 btrfs_add_free_space(cache, buf->start, buf->len);
3326 btrfs_free_reserved_bytes(cache, buf->len, 0);
3327 btrfs_put_block_group(cache);
3328 trace_btrfs_reserved_extent_free(fs_info, buf->start, buf->len);
3329 }
3330 out:
3331 if (last_ref) {
3332 /*
3333 * Deleting the buffer, clear the corrupt flag since it doesn't
3334 * matter anymore.
3335 */
3336 clear_bit(EXTENT_BUFFER_CORRUPT, &buf->bflags);
3337 }
3338 }
3339
3340 /* Can return -ENOMEM */
btrfs_free_extent(struct btrfs_trans_handle * trans,struct btrfs_ref * ref)3341 int btrfs_free_extent(struct btrfs_trans_handle *trans, struct btrfs_ref *ref)
3342 {
3343 struct btrfs_fs_info *fs_info = trans->fs_info;
3344 int ret;
3345
3346 if (btrfs_is_testing(fs_info))
3347 return 0;
3348
3349 /*
3350 * tree log blocks never actually go into the extent allocation
3351 * tree, just update pinning info and exit early.
3352 */
3353 if ((ref->type == BTRFS_REF_METADATA &&
3354 ref->tree_ref.owning_root == BTRFS_TREE_LOG_OBJECTID) ||
3355 (ref->type == BTRFS_REF_DATA &&
3356 ref->data_ref.owning_root == BTRFS_TREE_LOG_OBJECTID)) {
3357 /* unlocks the pinned mutex */
3358 btrfs_pin_extent(trans, ref->bytenr, ref->len, 1);
3359 ret = 0;
3360 } else if (ref->type == BTRFS_REF_METADATA) {
3361 ret = btrfs_add_delayed_tree_ref(trans, ref, NULL);
3362 } else {
3363 ret = btrfs_add_delayed_data_ref(trans, ref, 0);
3364 }
3365
3366 if (!((ref->type == BTRFS_REF_METADATA &&
3367 ref->tree_ref.owning_root == BTRFS_TREE_LOG_OBJECTID) ||
3368 (ref->type == BTRFS_REF_DATA &&
3369 ref->data_ref.owning_root == BTRFS_TREE_LOG_OBJECTID)))
3370 btrfs_ref_tree_mod(fs_info, ref);
3371
3372 return ret;
3373 }
3374
3375 enum btrfs_loop_type {
3376 LOOP_CACHING_NOWAIT,
3377 LOOP_CACHING_WAIT,
3378 LOOP_ALLOC_CHUNK,
3379 LOOP_NO_EMPTY_SIZE,
3380 };
3381
3382 static inline void
btrfs_lock_block_group(struct btrfs_block_group * cache,int delalloc)3383 btrfs_lock_block_group(struct btrfs_block_group *cache,
3384 int delalloc)
3385 {
3386 if (delalloc)
3387 down_read(&cache->data_rwsem);
3388 }
3389
btrfs_grab_block_group(struct btrfs_block_group * cache,int delalloc)3390 static inline void btrfs_grab_block_group(struct btrfs_block_group *cache,
3391 int delalloc)
3392 {
3393 btrfs_get_block_group(cache);
3394 if (delalloc)
3395 down_read(&cache->data_rwsem);
3396 }
3397
btrfs_lock_cluster(struct btrfs_block_group * block_group,struct btrfs_free_cluster * cluster,int delalloc)3398 static struct btrfs_block_group *btrfs_lock_cluster(
3399 struct btrfs_block_group *block_group,
3400 struct btrfs_free_cluster *cluster,
3401 int delalloc)
3402 __acquires(&cluster->refill_lock)
3403 {
3404 struct btrfs_block_group *used_bg = NULL;
3405
3406 spin_lock(&cluster->refill_lock);
3407 while (1) {
3408 used_bg = cluster->block_group;
3409 if (!used_bg)
3410 return NULL;
3411
3412 if (used_bg == block_group)
3413 return used_bg;
3414
3415 btrfs_get_block_group(used_bg);
3416
3417 if (!delalloc)
3418 return used_bg;
3419
3420 if (down_read_trylock(&used_bg->data_rwsem))
3421 return used_bg;
3422
3423 spin_unlock(&cluster->refill_lock);
3424
3425 /* We should only have one-level nested. */
3426 down_read_nested(&used_bg->data_rwsem, SINGLE_DEPTH_NESTING);
3427
3428 spin_lock(&cluster->refill_lock);
3429 if (used_bg == cluster->block_group)
3430 return used_bg;
3431
3432 up_read(&used_bg->data_rwsem);
3433 btrfs_put_block_group(used_bg);
3434 }
3435 }
3436
3437 static inline void
btrfs_release_block_group(struct btrfs_block_group * cache,int delalloc)3438 btrfs_release_block_group(struct btrfs_block_group *cache,
3439 int delalloc)
3440 {
3441 if (delalloc)
3442 up_read(&cache->data_rwsem);
3443 btrfs_put_block_group(cache);
3444 }
3445
3446 enum btrfs_extent_allocation_policy {
3447 BTRFS_EXTENT_ALLOC_CLUSTERED,
3448 BTRFS_EXTENT_ALLOC_ZONED,
3449 };
3450
3451 /*
3452 * Structure used internally for find_free_extent() function. Wraps needed
3453 * parameters.
3454 */
3455 struct find_free_extent_ctl {
3456 /* Basic allocation info */
3457 u64 ram_bytes;
3458 u64 num_bytes;
3459 u64 min_alloc_size;
3460 u64 empty_size;
3461 u64 flags;
3462 int delalloc;
3463
3464 /* Where to start the search inside the bg */
3465 u64 search_start;
3466
3467 /* For clustered allocation */
3468 u64 empty_cluster;
3469 struct btrfs_free_cluster *last_ptr;
3470 bool use_cluster;
3471
3472 bool have_caching_bg;
3473 bool orig_have_caching_bg;
3474
3475 /* Allocation is called for tree-log */
3476 bool for_treelog;
3477
3478 /* Allocation is called for data relocation */
3479 bool for_data_reloc;
3480
3481 /* RAID index, converted from flags */
3482 int index;
3483
3484 /*
3485 * Current loop number, check find_free_extent_update_loop() for details
3486 */
3487 int loop;
3488
3489 /*
3490 * Whether we're refilling a cluster, if true we need to re-search
3491 * current block group but don't try to refill the cluster again.
3492 */
3493 bool retry_clustered;
3494
3495 /*
3496 * Whether we're updating free space cache, if true we need to re-search
3497 * current block group but don't try updating free space cache again.
3498 */
3499 bool retry_unclustered;
3500
3501 /* If current block group is cached */
3502 int cached;
3503
3504 /* Max contiguous hole found */
3505 u64 max_extent_size;
3506
3507 /* Total free space from free space cache, not always contiguous */
3508 u64 total_free_space;
3509
3510 /* Found result */
3511 u64 found_offset;
3512
3513 /* Hint where to start looking for an empty space */
3514 u64 hint_byte;
3515
3516 /* Allocation policy */
3517 enum btrfs_extent_allocation_policy policy;
3518 };
3519
3520
3521 /*
3522 * Helper function for find_free_extent().
3523 *
3524 * Return -ENOENT to inform caller that we need fallback to unclustered mode.
3525 * Return -EAGAIN to inform caller that we need to re-search this block group
3526 * Return >0 to inform caller that we find nothing
3527 * Return 0 means we have found a location and set ffe_ctl->found_offset.
3528 */
find_free_extent_clustered(struct btrfs_block_group * bg,struct find_free_extent_ctl * ffe_ctl,struct btrfs_block_group ** cluster_bg_ret)3529 static int find_free_extent_clustered(struct btrfs_block_group *bg,
3530 struct find_free_extent_ctl *ffe_ctl,
3531 struct btrfs_block_group **cluster_bg_ret)
3532 {
3533 struct btrfs_block_group *cluster_bg;
3534 struct btrfs_free_cluster *last_ptr = ffe_ctl->last_ptr;
3535 u64 aligned_cluster;
3536 u64 offset;
3537 int ret;
3538
3539 cluster_bg = btrfs_lock_cluster(bg, last_ptr, ffe_ctl->delalloc);
3540 if (!cluster_bg)
3541 goto refill_cluster;
3542 if (cluster_bg != bg && (cluster_bg->ro ||
3543 !block_group_bits(cluster_bg, ffe_ctl->flags)))
3544 goto release_cluster;
3545
3546 offset = btrfs_alloc_from_cluster(cluster_bg, last_ptr,
3547 ffe_ctl->num_bytes, cluster_bg->start,
3548 &ffe_ctl->max_extent_size);
3549 if (offset) {
3550 /* We have a block, we're done */
3551 spin_unlock(&last_ptr->refill_lock);
3552 trace_btrfs_reserve_extent_cluster(cluster_bg,
3553 ffe_ctl->search_start, ffe_ctl->num_bytes);
3554 *cluster_bg_ret = cluster_bg;
3555 ffe_ctl->found_offset = offset;
3556 return 0;
3557 }
3558 WARN_ON(last_ptr->block_group != cluster_bg);
3559
3560 release_cluster:
3561 /*
3562 * If we are on LOOP_NO_EMPTY_SIZE, we can't set up a new clusters, so
3563 * lets just skip it and let the allocator find whatever block it can
3564 * find. If we reach this point, we will have tried the cluster
3565 * allocator plenty of times and not have found anything, so we are
3566 * likely way too fragmented for the clustering stuff to find anything.
3567 *
3568 * However, if the cluster is taken from the current block group,
3569 * release the cluster first, so that we stand a better chance of
3570 * succeeding in the unclustered allocation.
3571 */
3572 if (ffe_ctl->loop >= LOOP_NO_EMPTY_SIZE && cluster_bg != bg) {
3573 spin_unlock(&last_ptr->refill_lock);
3574 btrfs_release_block_group(cluster_bg, ffe_ctl->delalloc);
3575 return -ENOENT;
3576 }
3577
3578 /* This cluster didn't work out, free it and start over */
3579 btrfs_return_cluster_to_free_space(NULL, last_ptr);
3580
3581 if (cluster_bg != bg)
3582 btrfs_release_block_group(cluster_bg, ffe_ctl->delalloc);
3583
3584 refill_cluster:
3585 if (ffe_ctl->loop >= LOOP_NO_EMPTY_SIZE) {
3586 spin_unlock(&last_ptr->refill_lock);
3587 return -ENOENT;
3588 }
3589
3590 aligned_cluster = max_t(u64,
3591 ffe_ctl->empty_cluster + ffe_ctl->empty_size,
3592 bg->full_stripe_len);
3593 ret = btrfs_find_space_cluster(bg, last_ptr, ffe_ctl->search_start,
3594 ffe_ctl->num_bytes, aligned_cluster);
3595 if (ret == 0) {
3596 /* Now pull our allocation out of this cluster */
3597 offset = btrfs_alloc_from_cluster(bg, last_ptr,
3598 ffe_ctl->num_bytes, ffe_ctl->search_start,
3599 &ffe_ctl->max_extent_size);
3600 if (offset) {
3601 /* We found one, proceed */
3602 spin_unlock(&last_ptr->refill_lock);
3603 trace_btrfs_reserve_extent_cluster(bg,
3604 ffe_ctl->search_start,
3605 ffe_ctl->num_bytes);
3606 ffe_ctl->found_offset = offset;
3607 return 0;
3608 }
3609 } else if (!ffe_ctl->cached && ffe_ctl->loop > LOOP_CACHING_NOWAIT &&
3610 !ffe_ctl->retry_clustered) {
3611 spin_unlock(&last_ptr->refill_lock);
3612
3613 ffe_ctl->retry_clustered = true;
3614 btrfs_wait_block_group_cache_progress(bg, ffe_ctl->num_bytes +
3615 ffe_ctl->empty_cluster + ffe_ctl->empty_size);
3616 return -EAGAIN;
3617 }
3618 /*
3619 * At this point we either didn't find a cluster or we weren't able to
3620 * allocate a block from our cluster. Free the cluster we've been
3621 * trying to use, and go to the next block group.
3622 */
3623 btrfs_return_cluster_to_free_space(NULL, last_ptr);
3624 spin_unlock(&last_ptr->refill_lock);
3625 return 1;
3626 }
3627
3628 /*
3629 * Return >0 to inform caller that we find nothing
3630 * Return 0 when we found an free extent and set ffe_ctrl->found_offset
3631 * Return -EAGAIN to inform caller that we need to re-search this block group
3632 */
find_free_extent_unclustered(struct btrfs_block_group * bg,struct find_free_extent_ctl * ffe_ctl)3633 static int find_free_extent_unclustered(struct btrfs_block_group *bg,
3634 struct find_free_extent_ctl *ffe_ctl)
3635 {
3636 struct btrfs_free_cluster *last_ptr = ffe_ctl->last_ptr;
3637 u64 offset;
3638
3639 /*
3640 * We are doing an unclustered allocation, set the fragmented flag so
3641 * we don't bother trying to setup a cluster again until we get more
3642 * space.
3643 */
3644 if (unlikely(last_ptr)) {
3645 spin_lock(&last_ptr->lock);
3646 last_ptr->fragmented = 1;
3647 spin_unlock(&last_ptr->lock);
3648 }
3649 if (ffe_ctl->cached) {
3650 struct btrfs_free_space_ctl *free_space_ctl;
3651
3652 free_space_ctl = bg->free_space_ctl;
3653 spin_lock(&free_space_ctl->tree_lock);
3654 if (free_space_ctl->free_space <
3655 ffe_ctl->num_bytes + ffe_ctl->empty_cluster +
3656 ffe_ctl->empty_size) {
3657 ffe_ctl->total_free_space = max_t(u64,
3658 ffe_ctl->total_free_space,
3659 free_space_ctl->free_space);
3660 spin_unlock(&free_space_ctl->tree_lock);
3661 return 1;
3662 }
3663 spin_unlock(&free_space_ctl->tree_lock);
3664 }
3665
3666 offset = btrfs_find_space_for_alloc(bg, ffe_ctl->search_start,
3667 ffe_ctl->num_bytes, ffe_ctl->empty_size,
3668 &ffe_ctl->max_extent_size);
3669
3670 /*
3671 * If we didn't find a chunk, and we haven't failed on this block group
3672 * before, and this block group is in the middle of caching and we are
3673 * ok with waiting, then go ahead and wait for progress to be made, and
3674 * set @retry_unclustered to true.
3675 *
3676 * If @retry_unclustered is true then we've already waited on this
3677 * block group once and should move on to the next block group.
3678 */
3679 if (!offset && !ffe_ctl->retry_unclustered && !ffe_ctl->cached &&
3680 ffe_ctl->loop > LOOP_CACHING_NOWAIT) {
3681 btrfs_wait_block_group_cache_progress(bg, ffe_ctl->num_bytes +
3682 ffe_ctl->empty_size);
3683 ffe_ctl->retry_unclustered = true;
3684 return -EAGAIN;
3685 } else if (!offset) {
3686 return 1;
3687 }
3688 ffe_ctl->found_offset = offset;
3689 return 0;
3690 }
3691
do_allocation_clustered(struct btrfs_block_group * block_group,struct find_free_extent_ctl * ffe_ctl,struct btrfs_block_group ** bg_ret)3692 static int do_allocation_clustered(struct btrfs_block_group *block_group,
3693 struct find_free_extent_ctl *ffe_ctl,
3694 struct btrfs_block_group **bg_ret)
3695 {
3696 int ret;
3697
3698 /* We want to try and use the cluster allocator, so lets look there */
3699 if (ffe_ctl->last_ptr && ffe_ctl->use_cluster) {
3700 ret = find_free_extent_clustered(block_group, ffe_ctl, bg_ret);
3701 if (ret >= 0 || ret == -EAGAIN)
3702 return ret;
3703 /* ret == -ENOENT case falls through */
3704 }
3705
3706 return find_free_extent_unclustered(block_group, ffe_ctl);
3707 }
3708
3709 /*
3710 * Tree-log block group locking
3711 * ============================
3712 *
3713 * fs_info::treelog_bg_lock protects the fs_info::treelog_bg which
3714 * indicates the starting address of a block group, which is reserved only
3715 * for tree-log metadata.
3716 *
3717 * Lock nesting
3718 * ============
3719 *
3720 * space_info::lock
3721 * block_group::lock
3722 * fs_info::treelog_bg_lock
3723 */
3724
3725 /*
3726 * Simple allocator for sequential-only block group. It only allows sequential
3727 * allocation. No need to play with trees. This function also reserves the
3728 * bytes as in btrfs_add_reserved_bytes.
3729 */
do_allocation_zoned(struct btrfs_block_group * block_group,struct find_free_extent_ctl * ffe_ctl,struct btrfs_block_group ** bg_ret)3730 static int do_allocation_zoned(struct btrfs_block_group *block_group,
3731 struct find_free_extent_ctl *ffe_ctl,
3732 struct btrfs_block_group **bg_ret)
3733 {
3734 struct btrfs_fs_info *fs_info = block_group->fs_info;
3735 struct btrfs_space_info *space_info = block_group->space_info;
3736 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
3737 u64 start = block_group->start;
3738 u64 num_bytes = ffe_ctl->num_bytes;
3739 u64 avail;
3740 u64 bytenr = block_group->start;
3741 u64 log_bytenr;
3742 u64 data_reloc_bytenr;
3743 int ret = 0;
3744 bool skip = false;
3745
3746 ASSERT(btrfs_is_zoned(block_group->fs_info));
3747
3748 /*
3749 * Do not allow non-tree-log blocks in the dedicated tree-log block
3750 * group, and vice versa.
3751 */
3752 spin_lock(&fs_info->treelog_bg_lock);
3753 log_bytenr = fs_info->treelog_bg;
3754 if (log_bytenr && ((ffe_ctl->for_treelog && bytenr != log_bytenr) ||
3755 (!ffe_ctl->for_treelog && bytenr == log_bytenr)))
3756 skip = true;
3757 spin_unlock(&fs_info->treelog_bg_lock);
3758 if (skip)
3759 return 1;
3760
3761 /*
3762 * Do not allow non-relocation blocks in the dedicated relocation block
3763 * group, and vice versa.
3764 */
3765 spin_lock(&fs_info->relocation_bg_lock);
3766 data_reloc_bytenr = fs_info->data_reloc_bg;
3767 if (data_reloc_bytenr &&
3768 ((ffe_ctl->for_data_reloc && bytenr != data_reloc_bytenr) ||
3769 (!ffe_ctl->for_data_reloc && bytenr == data_reloc_bytenr)))
3770 skip = true;
3771 spin_unlock(&fs_info->relocation_bg_lock);
3772 if (skip)
3773 return 1;
3774
3775 /* Check RO and no space case before trying to activate it */
3776 spin_lock(&block_group->lock);
3777 if (block_group->ro || btrfs_zoned_bg_is_full(block_group)) {
3778 ret = 1;
3779 /*
3780 * May need to clear fs_info->{treelog,data_reloc}_bg.
3781 * Return the error after taking the locks.
3782 */
3783 }
3784 spin_unlock(&block_group->lock);
3785
3786 if (!ret && !btrfs_zone_activate(block_group)) {
3787 ret = 1;
3788 /*
3789 * May need to clear fs_info->{treelog,data_reloc}_bg.
3790 * Return the error after taking the locks.
3791 */
3792 }
3793
3794 spin_lock(&space_info->lock);
3795 spin_lock(&block_group->lock);
3796 spin_lock(&fs_info->treelog_bg_lock);
3797 spin_lock(&fs_info->relocation_bg_lock);
3798
3799 if (ret)
3800 goto out;
3801
3802 ASSERT(!ffe_ctl->for_treelog ||
3803 block_group->start == fs_info->treelog_bg ||
3804 fs_info->treelog_bg == 0);
3805 ASSERT(!ffe_ctl->for_data_reloc ||
3806 block_group->start == fs_info->data_reloc_bg ||
3807 fs_info->data_reloc_bg == 0);
3808
3809 if (block_group->ro ||
3810 test_bit(BLOCK_GROUP_FLAG_ZONED_DATA_RELOC, &block_group->runtime_flags)) {
3811 ret = 1;
3812 goto out;
3813 }
3814
3815 /*
3816 * Do not allow currently using block group to be tree-log dedicated
3817 * block group.
3818 */
3819 if (ffe_ctl->for_treelog && !fs_info->treelog_bg &&
3820 (block_group->used || block_group->reserved)) {
3821 ret = 1;
3822 goto out;
3823 }
3824
3825 /*
3826 * Do not allow currently used block group to be the data relocation
3827 * dedicated block group.
3828 */
3829 if (ffe_ctl->for_data_reloc && !fs_info->data_reloc_bg &&
3830 (block_group->used || block_group->reserved)) {
3831 ret = 1;
3832 goto out;
3833 }
3834
3835 WARN_ON_ONCE(block_group->alloc_offset > block_group->zone_capacity);
3836 avail = block_group->zone_capacity - block_group->alloc_offset;
3837 if (avail < num_bytes) {
3838 if (ffe_ctl->max_extent_size < avail) {
3839 /*
3840 * With sequential allocator, free space is always
3841 * contiguous
3842 */
3843 ffe_ctl->max_extent_size = avail;
3844 ffe_ctl->total_free_space = avail;
3845 }
3846 ret = 1;
3847 goto out;
3848 }
3849
3850 if (ffe_ctl->for_treelog && !fs_info->treelog_bg)
3851 fs_info->treelog_bg = block_group->start;
3852
3853 if (ffe_ctl->for_data_reloc && !fs_info->data_reloc_bg)
3854 fs_info->data_reloc_bg = block_group->start;
3855
3856 ffe_ctl->found_offset = start + block_group->alloc_offset;
3857 block_group->alloc_offset += num_bytes;
3858 spin_lock(&ctl->tree_lock);
3859 ctl->free_space -= num_bytes;
3860 spin_unlock(&ctl->tree_lock);
3861
3862 /*
3863 * We do not check if found_offset is aligned to stripesize. The
3864 * address is anyway rewritten when using zone append writing.
3865 */
3866
3867 ffe_ctl->search_start = ffe_ctl->found_offset;
3868
3869 out:
3870 if (ret && ffe_ctl->for_treelog)
3871 fs_info->treelog_bg = 0;
3872 if (ret && ffe_ctl->for_data_reloc &&
3873 fs_info->data_reloc_bg == block_group->start) {
3874 /*
3875 * Do not allow further allocations from this block group.
3876 * Compared to increasing the ->ro, setting the
3877 * ->zoned_data_reloc_ongoing flag still allows nocow
3878 * writers to come in. See btrfs_inc_nocow_writers().
3879 *
3880 * We need to disable an allocation to avoid an allocation of
3881 * regular (non-relocation data) extent. With mix of relocation
3882 * extents and regular extents, we can dispatch WRITE commands
3883 * (for relocation extents) and ZONE APPEND commands (for
3884 * regular extents) at the same time to the same zone, which
3885 * easily break the write pointer.
3886 */
3887 set_bit(BLOCK_GROUP_FLAG_ZONED_DATA_RELOC, &block_group->runtime_flags);
3888 fs_info->data_reloc_bg = 0;
3889 }
3890 spin_unlock(&fs_info->relocation_bg_lock);
3891 spin_unlock(&fs_info->treelog_bg_lock);
3892 spin_unlock(&block_group->lock);
3893 spin_unlock(&space_info->lock);
3894 return ret;
3895 }
3896
do_allocation(struct btrfs_block_group * block_group,struct find_free_extent_ctl * ffe_ctl,struct btrfs_block_group ** bg_ret)3897 static int do_allocation(struct btrfs_block_group *block_group,
3898 struct find_free_extent_ctl *ffe_ctl,
3899 struct btrfs_block_group **bg_ret)
3900 {
3901 switch (ffe_ctl->policy) {
3902 case BTRFS_EXTENT_ALLOC_CLUSTERED:
3903 return do_allocation_clustered(block_group, ffe_ctl, bg_ret);
3904 case BTRFS_EXTENT_ALLOC_ZONED:
3905 return do_allocation_zoned(block_group, ffe_ctl, bg_ret);
3906 default:
3907 BUG();
3908 }
3909 }
3910
release_block_group(struct btrfs_block_group * block_group,struct find_free_extent_ctl * ffe_ctl,int delalloc)3911 static void release_block_group(struct btrfs_block_group *block_group,
3912 struct find_free_extent_ctl *ffe_ctl,
3913 int delalloc)
3914 {
3915 switch (ffe_ctl->policy) {
3916 case BTRFS_EXTENT_ALLOC_CLUSTERED:
3917 ffe_ctl->retry_clustered = false;
3918 ffe_ctl->retry_unclustered = false;
3919 break;
3920 case BTRFS_EXTENT_ALLOC_ZONED:
3921 /* Nothing to do */
3922 break;
3923 default:
3924 BUG();
3925 }
3926
3927 BUG_ON(btrfs_bg_flags_to_raid_index(block_group->flags) !=
3928 ffe_ctl->index);
3929 btrfs_release_block_group(block_group, delalloc);
3930 }
3931
found_extent_clustered(struct find_free_extent_ctl * ffe_ctl,struct btrfs_key * ins)3932 static void found_extent_clustered(struct find_free_extent_ctl *ffe_ctl,
3933 struct btrfs_key *ins)
3934 {
3935 struct btrfs_free_cluster *last_ptr = ffe_ctl->last_ptr;
3936
3937 if (!ffe_ctl->use_cluster && last_ptr) {
3938 spin_lock(&last_ptr->lock);
3939 last_ptr->window_start = ins->objectid;
3940 spin_unlock(&last_ptr->lock);
3941 }
3942 }
3943
found_extent(struct find_free_extent_ctl * ffe_ctl,struct btrfs_key * ins)3944 static void found_extent(struct find_free_extent_ctl *ffe_ctl,
3945 struct btrfs_key *ins)
3946 {
3947 switch (ffe_ctl->policy) {
3948 case BTRFS_EXTENT_ALLOC_CLUSTERED:
3949 found_extent_clustered(ffe_ctl, ins);
3950 break;
3951 case BTRFS_EXTENT_ALLOC_ZONED:
3952 /* Nothing to do */
3953 break;
3954 default:
3955 BUG();
3956 }
3957 }
3958
can_allocate_chunk_zoned(struct btrfs_fs_info * fs_info,struct find_free_extent_ctl * ffe_ctl)3959 static int can_allocate_chunk_zoned(struct btrfs_fs_info *fs_info,
3960 struct find_free_extent_ctl *ffe_ctl)
3961 {
3962 /* If we can activate new zone, just allocate a chunk and use it */
3963 if (btrfs_can_activate_zone(fs_info->fs_devices, ffe_ctl->flags))
3964 return 0;
3965
3966 /*
3967 * We already reached the max active zones. Try to finish one block
3968 * group to make a room for a new block group. This is only possible
3969 * for a data block group because btrfs_zone_finish() may need to wait
3970 * for a running transaction which can cause a deadlock for metadata
3971 * allocation.
3972 */
3973 if (ffe_ctl->flags & BTRFS_BLOCK_GROUP_DATA) {
3974 int ret = btrfs_zone_finish_one_bg(fs_info);
3975
3976 if (ret == 1)
3977 return 0;
3978 else if (ret < 0)
3979 return ret;
3980 }
3981
3982 /*
3983 * If we have enough free space left in an already active block group
3984 * and we can't activate any other zone now, do not allow allocating a
3985 * new chunk and let find_free_extent() retry with a smaller size.
3986 */
3987 if (ffe_ctl->max_extent_size >= ffe_ctl->min_alloc_size)
3988 return -ENOSPC;
3989
3990 /*
3991 * Even min_alloc_size is not left in any block groups. Since we cannot
3992 * activate a new block group, allocating it may not help. Let's tell a
3993 * caller to try again and hope it progress something by writing some
3994 * parts of the region. That is only possible for data block groups,
3995 * where a part of the region can be written.
3996 */
3997 if (ffe_ctl->flags & BTRFS_BLOCK_GROUP_DATA)
3998 return -EAGAIN;
3999
4000 /*
4001 * We cannot activate a new block group and no enough space left in any
4002 * block groups. So, allocating a new block group may not help. But,
4003 * there is nothing to do anyway, so let's go with it.
4004 */
4005 return 0;
4006 }
4007
can_allocate_chunk(struct btrfs_fs_info * fs_info,struct find_free_extent_ctl * ffe_ctl)4008 static int can_allocate_chunk(struct btrfs_fs_info *fs_info,
4009 struct find_free_extent_ctl *ffe_ctl)
4010 {
4011 switch (ffe_ctl->policy) {
4012 case BTRFS_EXTENT_ALLOC_CLUSTERED:
4013 return 0;
4014 case BTRFS_EXTENT_ALLOC_ZONED:
4015 return can_allocate_chunk_zoned(fs_info, ffe_ctl);
4016 default:
4017 BUG();
4018 }
4019 }
4020
chunk_allocation_failed(struct find_free_extent_ctl * ffe_ctl)4021 static int chunk_allocation_failed(struct find_free_extent_ctl *ffe_ctl)
4022 {
4023 switch (ffe_ctl->policy) {
4024 case BTRFS_EXTENT_ALLOC_CLUSTERED:
4025 /*
4026 * If we can't allocate a new chunk we've already looped through
4027 * at least once, move on to the NO_EMPTY_SIZE case.
4028 */
4029 ffe_ctl->loop = LOOP_NO_EMPTY_SIZE;
4030 return 0;
4031 case BTRFS_EXTENT_ALLOC_ZONED:
4032 /* Give up here */
4033 return -ENOSPC;
4034 default:
4035 BUG();
4036 }
4037 }
4038
4039 /*
4040 * Return >0 means caller needs to re-search for free extent
4041 * Return 0 means we have the needed free extent.
4042 * Return <0 means we failed to locate any free extent.
4043 */
find_free_extent_update_loop(struct btrfs_fs_info * fs_info,struct btrfs_key * ins,struct find_free_extent_ctl * ffe_ctl,bool full_search)4044 static int find_free_extent_update_loop(struct btrfs_fs_info *fs_info,
4045 struct btrfs_key *ins,
4046 struct find_free_extent_ctl *ffe_ctl,
4047 bool full_search)
4048 {
4049 struct btrfs_root *root = fs_info->chunk_root;
4050 int ret;
4051
4052 if ((ffe_ctl->loop == LOOP_CACHING_NOWAIT) &&
4053 ffe_ctl->have_caching_bg && !ffe_ctl->orig_have_caching_bg)
4054 ffe_ctl->orig_have_caching_bg = true;
4055
4056 if (ins->objectid) {
4057 found_extent(ffe_ctl, ins);
4058 return 0;
4059 }
4060
4061 if (ffe_ctl->loop >= LOOP_CACHING_WAIT && ffe_ctl->have_caching_bg)
4062 return 1;
4063
4064 ffe_ctl->index++;
4065 if (ffe_ctl->index < BTRFS_NR_RAID_TYPES)
4066 return 1;
4067
4068 /*
4069 * LOOP_CACHING_NOWAIT, search partially cached block groups, kicking
4070 * caching kthreads as we move along
4071 * LOOP_CACHING_WAIT, search everything, and wait if our bg is caching
4072 * LOOP_ALLOC_CHUNK, force a chunk allocation and try again
4073 * LOOP_NO_EMPTY_SIZE, set empty_size and empty_cluster to 0 and try
4074 * again
4075 */
4076 if (ffe_ctl->loop < LOOP_NO_EMPTY_SIZE) {
4077 ffe_ctl->index = 0;
4078 if (ffe_ctl->loop == LOOP_CACHING_NOWAIT) {
4079 /*
4080 * We want to skip the LOOP_CACHING_WAIT step if we
4081 * don't have any uncached bgs and we've already done a
4082 * full search through.
4083 */
4084 if (ffe_ctl->orig_have_caching_bg || !full_search)
4085 ffe_ctl->loop = LOOP_CACHING_WAIT;
4086 else
4087 ffe_ctl->loop = LOOP_ALLOC_CHUNK;
4088 } else {
4089 ffe_ctl->loop++;
4090 }
4091
4092 if (ffe_ctl->loop == LOOP_ALLOC_CHUNK) {
4093 struct btrfs_trans_handle *trans;
4094 int exist = 0;
4095
4096 /*Check if allocation policy allows to create a new chunk */
4097 ret = can_allocate_chunk(fs_info, ffe_ctl);
4098 if (ret)
4099 return ret;
4100
4101 trans = current->journal_info;
4102 if (trans)
4103 exist = 1;
4104 else
4105 trans = btrfs_join_transaction(root);
4106
4107 if (IS_ERR(trans)) {
4108 ret = PTR_ERR(trans);
4109 return ret;
4110 }
4111
4112 ret = btrfs_chunk_alloc(trans, ffe_ctl->flags,
4113 CHUNK_ALLOC_FORCE_FOR_EXTENT);
4114
4115 /* Do not bail out on ENOSPC since we can do more. */
4116 if (ret == -ENOSPC)
4117 ret = chunk_allocation_failed(ffe_ctl);
4118 else if (ret < 0)
4119 btrfs_abort_transaction(trans, ret);
4120 else
4121 ret = 0;
4122 if (!exist)
4123 btrfs_end_transaction(trans);
4124 if (ret)
4125 return ret;
4126 }
4127
4128 if (ffe_ctl->loop == LOOP_NO_EMPTY_SIZE) {
4129 if (ffe_ctl->policy != BTRFS_EXTENT_ALLOC_CLUSTERED)
4130 return -ENOSPC;
4131
4132 /*
4133 * Don't loop again if we already have no empty_size and
4134 * no empty_cluster.
4135 */
4136 if (ffe_ctl->empty_size == 0 &&
4137 ffe_ctl->empty_cluster == 0)
4138 return -ENOSPC;
4139 ffe_ctl->empty_size = 0;
4140 ffe_ctl->empty_cluster = 0;
4141 }
4142 return 1;
4143 }
4144 return -ENOSPC;
4145 }
4146
prepare_allocation_clustered(struct btrfs_fs_info * fs_info,struct find_free_extent_ctl * ffe_ctl,struct btrfs_space_info * space_info,struct btrfs_key * ins)4147 static int prepare_allocation_clustered(struct btrfs_fs_info *fs_info,
4148 struct find_free_extent_ctl *ffe_ctl,
4149 struct btrfs_space_info *space_info,
4150 struct btrfs_key *ins)
4151 {
4152 /*
4153 * If our free space is heavily fragmented we may not be able to make
4154 * big contiguous allocations, so instead of doing the expensive search
4155 * for free space, simply return ENOSPC with our max_extent_size so we
4156 * can go ahead and search for a more manageable chunk.
4157 *
4158 * If our max_extent_size is large enough for our allocation simply
4159 * disable clustering since we will likely not be able to find enough
4160 * space to create a cluster and induce latency trying.
4161 */
4162 if (space_info->max_extent_size) {
4163 spin_lock(&space_info->lock);
4164 if (space_info->max_extent_size &&
4165 ffe_ctl->num_bytes > space_info->max_extent_size) {
4166 ins->offset = space_info->max_extent_size;
4167 spin_unlock(&space_info->lock);
4168 return -ENOSPC;
4169 } else if (space_info->max_extent_size) {
4170 ffe_ctl->use_cluster = false;
4171 }
4172 spin_unlock(&space_info->lock);
4173 }
4174
4175 ffe_ctl->last_ptr = fetch_cluster_info(fs_info, space_info,
4176 &ffe_ctl->empty_cluster);
4177 if (ffe_ctl->last_ptr) {
4178 struct btrfs_free_cluster *last_ptr = ffe_ctl->last_ptr;
4179
4180 spin_lock(&last_ptr->lock);
4181 if (last_ptr->block_group)
4182 ffe_ctl->hint_byte = last_ptr->window_start;
4183 if (last_ptr->fragmented) {
4184 /*
4185 * We still set window_start so we can keep track of the
4186 * last place we found an allocation to try and save
4187 * some time.
4188 */
4189 ffe_ctl->hint_byte = last_ptr->window_start;
4190 ffe_ctl->use_cluster = false;
4191 }
4192 spin_unlock(&last_ptr->lock);
4193 }
4194
4195 return 0;
4196 }
4197
prepare_allocation(struct btrfs_fs_info * fs_info,struct find_free_extent_ctl * ffe_ctl,struct btrfs_space_info * space_info,struct btrfs_key * ins)4198 static int prepare_allocation(struct btrfs_fs_info *fs_info,
4199 struct find_free_extent_ctl *ffe_ctl,
4200 struct btrfs_space_info *space_info,
4201 struct btrfs_key *ins)
4202 {
4203 switch (ffe_ctl->policy) {
4204 case BTRFS_EXTENT_ALLOC_CLUSTERED:
4205 return prepare_allocation_clustered(fs_info, ffe_ctl,
4206 space_info, ins);
4207 case BTRFS_EXTENT_ALLOC_ZONED:
4208 if (ffe_ctl->for_treelog) {
4209 spin_lock(&fs_info->treelog_bg_lock);
4210 if (fs_info->treelog_bg)
4211 ffe_ctl->hint_byte = fs_info->treelog_bg;
4212 spin_unlock(&fs_info->treelog_bg_lock);
4213 }
4214 if (ffe_ctl->for_data_reloc) {
4215 spin_lock(&fs_info->relocation_bg_lock);
4216 if (fs_info->data_reloc_bg)
4217 ffe_ctl->hint_byte = fs_info->data_reloc_bg;
4218 spin_unlock(&fs_info->relocation_bg_lock);
4219 }
4220 return 0;
4221 default:
4222 BUG();
4223 }
4224 }
4225
4226 /*
4227 * walks the btree of allocated extents and find a hole of a given size.
4228 * The key ins is changed to record the hole:
4229 * ins->objectid == start position
4230 * ins->flags = BTRFS_EXTENT_ITEM_KEY
4231 * ins->offset == the size of the hole.
4232 * Any available blocks before search_start are skipped.
4233 *
4234 * If there is no suitable free space, we will record the max size of
4235 * the free space extent currently.
4236 *
4237 * The overall logic and call chain:
4238 *
4239 * find_free_extent()
4240 * |- Iterate through all block groups
4241 * | |- Get a valid block group
4242 * | |- Try to do clustered allocation in that block group
4243 * | |- Try to do unclustered allocation in that block group
4244 * | |- Check if the result is valid
4245 * | | |- If valid, then exit
4246 * | |- Jump to next block group
4247 * |
4248 * |- Push harder to find free extents
4249 * |- If not found, re-iterate all block groups
4250 */
find_free_extent(struct btrfs_root * root,struct btrfs_key * ins,struct find_free_extent_ctl * ffe_ctl)4251 static noinline int find_free_extent(struct btrfs_root *root,
4252 struct btrfs_key *ins,
4253 struct find_free_extent_ctl *ffe_ctl)
4254 {
4255 struct btrfs_fs_info *fs_info = root->fs_info;
4256 int ret = 0;
4257 int cache_block_group_error = 0;
4258 struct btrfs_block_group *block_group = NULL;
4259 struct btrfs_space_info *space_info;
4260 bool full_search = false;
4261
4262 WARN_ON(ffe_ctl->num_bytes < fs_info->sectorsize);
4263
4264 ffe_ctl->search_start = 0;
4265 /* For clustered allocation */
4266 ffe_ctl->empty_cluster = 0;
4267 ffe_ctl->last_ptr = NULL;
4268 ffe_ctl->use_cluster = true;
4269 ffe_ctl->have_caching_bg = false;
4270 ffe_ctl->orig_have_caching_bg = false;
4271 ffe_ctl->index = btrfs_bg_flags_to_raid_index(ffe_ctl->flags);
4272 ffe_ctl->loop = 0;
4273 /* For clustered allocation */
4274 ffe_ctl->retry_clustered = false;
4275 ffe_ctl->retry_unclustered = false;
4276 ffe_ctl->cached = 0;
4277 ffe_ctl->max_extent_size = 0;
4278 ffe_ctl->total_free_space = 0;
4279 ffe_ctl->found_offset = 0;
4280 ffe_ctl->policy = BTRFS_EXTENT_ALLOC_CLUSTERED;
4281
4282 if (btrfs_is_zoned(fs_info))
4283 ffe_ctl->policy = BTRFS_EXTENT_ALLOC_ZONED;
4284
4285 ins->type = BTRFS_EXTENT_ITEM_KEY;
4286 ins->objectid = 0;
4287 ins->offset = 0;
4288
4289 trace_find_free_extent(root, ffe_ctl->num_bytes, ffe_ctl->empty_size,
4290 ffe_ctl->flags);
4291
4292 space_info = btrfs_find_space_info(fs_info, ffe_ctl->flags);
4293 if (!space_info) {
4294 btrfs_err(fs_info, "No space info for %llu", ffe_ctl->flags);
4295 return -ENOSPC;
4296 }
4297
4298 ret = prepare_allocation(fs_info, ffe_ctl, space_info, ins);
4299 if (ret < 0)
4300 return ret;
4301
4302 ffe_ctl->search_start = max(ffe_ctl->search_start,
4303 first_logical_byte(fs_info));
4304 ffe_ctl->search_start = max(ffe_ctl->search_start, ffe_ctl->hint_byte);
4305 if (ffe_ctl->search_start == ffe_ctl->hint_byte) {
4306 block_group = btrfs_lookup_block_group(fs_info,
4307 ffe_ctl->search_start);
4308 /*
4309 * we don't want to use the block group if it doesn't match our
4310 * allocation bits, or if its not cached.
4311 *
4312 * However if we are re-searching with an ideal block group
4313 * picked out then we don't care that the block group is cached.
4314 */
4315 if (block_group && block_group_bits(block_group, ffe_ctl->flags) &&
4316 block_group->cached != BTRFS_CACHE_NO) {
4317 down_read(&space_info->groups_sem);
4318 if (list_empty(&block_group->list) ||
4319 block_group->ro) {
4320 /*
4321 * someone is removing this block group,
4322 * we can't jump into the have_block_group
4323 * target because our list pointers are not
4324 * valid
4325 */
4326 btrfs_put_block_group(block_group);
4327 up_read(&space_info->groups_sem);
4328 } else {
4329 ffe_ctl->index = btrfs_bg_flags_to_raid_index(
4330 block_group->flags);
4331 btrfs_lock_block_group(block_group,
4332 ffe_ctl->delalloc);
4333 goto have_block_group;
4334 }
4335 } else if (block_group) {
4336 btrfs_put_block_group(block_group);
4337 }
4338 }
4339 search:
4340 ffe_ctl->have_caching_bg = false;
4341 if (ffe_ctl->index == btrfs_bg_flags_to_raid_index(ffe_ctl->flags) ||
4342 ffe_ctl->index == 0)
4343 full_search = true;
4344 down_read(&space_info->groups_sem);
4345 list_for_each_entry(block_group,
4346 &space_info->block_groups[ffe_ctl->index], list) {
4347 struct btrfs_block_group *bg_ret;
4348
4349 /* If the block group is read-only, we can skip it entirely. */
4350 if (unlikely(block_group->ro)) {
4351 if (ffe_ctl->for_treelog)
4352 btrfs_clear_treelog_bg(block_group);
4353 if (ffe_ctl->for_data_reloc)
4354 btrfs_clear_data_reloc_bg(block_group);
4355 continue;
4356 }
4357
4358 btrfs_grab_block_group(block_group, ffe_ctl->delalloc);
4359 ffe_ctl->search_start = block_group->start;
4360
4361 /*
4362 * this can happen if we end up cycling through all the
4363 * raid types, but we want to make sure we only allocate
4364 * for the proper type.
4365 */
4366 if (!block_group_bits(block_group, ffe_ctl->flags)) {
4367 u64 extra = BTRFS_BLOCK_GROUP_DUP |
4368 BTRFS_BLOCK_GROUP_RAID1_MASK |
4369 BTRFS_BLOCK_GROUP_RAID56_MASK |
4370 BTRFS_BLOCK_GROUP_RAID10;
4371
4372 /*
4373 * if they asked for extra copies and this block group
4374 * doesn't provide them, bail. This does allow us to
4375 * fill raid0 from raid1.
4376 */
4377 if ((ffe_ctl->flags & extra) && !(block_group->flags & extra))
4378 goto loop;
4379
4380 /*
4381 * This block group has different flags than we want.
4382 * It's possible that we have MIXED_GROUP flag but no
4383 * block group is mixed. Just skip such block group.
4384 */
4385 btrfs_release_block_group(block_group, ffe_ctl->delalloc);
4386 continue;
4387 }
4388
4389 have_block_group:
4390 ffe_ctl->cached = btrfs_block_group_done(block_group);
4391 if (unlikely(!ffe_ctl->cached)) {
4392 ffe_ctl->have_caching_bg = true;
4393 ret = btrfs_cache_block_group(block_group, false);
4394
4395 /*
4396 * If we get ENOMEM here or something else we want to
4397 * try other block groups, because it may not be fatal.
4398 * However if we can't find anything else we need to
4399 * save our return here so that we return the actual
4400 * error that caused problems, not ENOSPC.
4401 */
4402 if (ret < 0) {
4403 if (!cache_block_group_error)
4404 cache_block_group_error = ret;
4405 ret = 0;
4406 goto loop;
4407 }
4408 ret = 0;
4409 }
4410
4411 if (unlikely(block_group->cached == BTRFS_CACHE_ERROR))
4412 goto loop;
4413
4414 bg_ret = NULL;
4415 ret = do_allocation(block_group, ffe_ctl, &bg_ret);
4416 if (ret == 0) {
4417 if (bg_ret && bg_ret != block_group) {
4418 btrfs_release_block_group(block_group,
4419 ffe_ctl->delalloc);
4420 block_group = bg_ret;
4421 }
4422 } else if (ret == -EAGAIN) {
4423 goto have_block_group;
4424 } else if (ret > 0) {
4425 goto loop;
4426 }
4427
4428 /* Checks */
4429 ffe_ctl->search_start = round_up(ffe_ctl->found_offset,
4430 fs_info->stripesize);
4431
4432 /* move on to the next group */
4433 if (ffe_ctl->search_start + ffe_ctl->num_bytes >
4434 block_group->start + block_group->length) {
4435 btrfs_add_free_space_unused(block_group,
4436 ffe_ctl->found_offset,
4437 ffe_ctl->num_bytes);
4438 goto loop;
4439 }
4440
4441 if (ffe_ctl->found_offset < ffe_ctl->search_start)
4442 btrfs_add_free_space_unused(block_group,
4443 ffe_ctl->found_offset,
4444 ffe_ctl->search_start - ffe_ctl->found_offset);
4445
4446 ret = btrfs_add_reserved_bytes(block_group, ffe_ctl->ram_bytes,
4447 ffe_ctl->num_bytes,
4448 ffe_ctl->delalloc);
4449 if (ret == -EAGAIN) {
4450 btrfs_add_free_space_unused(block_group,
4451 ffe_ctl->found_offset,
4452 ffe_ctl->num_bytes);
4453 goto loop;
4454 }
4455 btrfs_inc_block_group_reservations(block_group);
4456
4457 /* we are all good, lets return */
4458 ins->objectid = ffe_ctl->search_start;
4459 ins->offset = ffe_ctl->num_bytes;
4460
4461 trace_btrfs_reserve_extent(block_group, ffe_ctl->search_start,
4462 ffe_ctl->num_bytes);
4463 btrfs_release_block_group(block_group, ffe_ctl->delalloc);
4464 break;
4465 loop:
4466 release_block_group(block_group, ffe_ctl, ffe_ctl->delalloc);
4467 cond_resched();
4468 }
4469 up_read(&space_info->groups_sem);
4470
4471 ret = find_free_extent_update_loop(fs_info, ins, ffe_ctl, full_search);
4472 if (ret > 0)
4473 goto search;
4474
4475 if (ret == -ENOSPC && !cache_block_group_error) {
4476 /*
4477 * Use ffe_ctl->total_free_space as fallback if we can't find
4478 * any contiguous hole.
4479 */
4480 if (!ffe_ctl->max_extent_size)
4481 ffe_ctl->max_extent_size = ffe_ctl->total_free_space;
4482 spin_lock(&space_info->lock);
4483 space_info->max_extent_size = ffe_ctl->max_extent_size;
4484 spin_unlock(&space_info->lock);
4485 ins->offset = ffe_ctl->max_extent_size;
4486 } else if (ret == -ENOSPC) {
4487 ret = cache_block_group_error;
4488 }
4489 return ret;
4490 }
4491
4492 /*
4493 * btrfs_reserve_extent - entry point to the extent allocator. Tries to find a
4494 * hole that is at least as big as @num_bytes.
4495 *
4496 * @root - The root that will contain this extent
4497 *
4498 * @ram_bytes - The amount of space in ram that @num_bytes take. This
4499 * is used for accounting purposes. This value differs
4500 * from @num_bytes only in the case of compressed extents.
4501 *
4502 * @num_bytes - Number of bytes to allocate on-disk.
4503 *
4504 * @min_alloc_size - Indicates the minimum amount of space that the
4505 * allocator should try to satisfy. In some cases
4506 * @num_bytes may be larger than what is required and if
4507 * the filesystem is fragmented then allocation fails.
4508 * However, the presence of @min_alloc_size gives a
4509 * chance to try and satisfy the smaller allocation.
4510 *
4511 * @empty_size - A hint that you plan on doing more COW. This is the
4512 * size in bytes the allocator should try to find free
4513 * next to the block it returns. This is just a hint and
4514 * may be ignored by the allocator.
4515 *
4516 * @hint_byte - Hint to the allocator to start searching above the byte
4517 * address passed. It might be ignored.
4518 *
4519 * @ins - This key is modified to record the found hole. It will
4520 * have the following values:
4521 * ins->objectid == start position
4522 * ins->flags = BTRFS_EXTENT_ITEM_KEY
4523 * ins->offset == the size of the hole.
4524 *
4525 * @is_data - Boolean flag indicating whether an extent is
4526 * allocated for data (true) or metadata (false)
4527 *
4528 * @delalloc - Boolean flag indicating whether this allocation is for
4529 * delalloc or not. If 'true' data_rwsem of block groups
4530 * is going to be acquired.
4531 *
4532 *
4533 * Returns 0 when an allocation succeeded or < 0 when an error occurred. In
4534 * case -ENOSPC is returned then @ins->offset will contain the size of the
4535 * largest available hole the allocator managed to find.
4536 */
btrfs_reserve_extent(struct btrfs_root * root,u64 ram_bytes,u64 num_bytes,u64 min_alloc_size,u64 empty_size,u64 hint_byte,struct btrfs_key * ins,int is_data,int delalloc)4537 int btrfs_reserve_extent(struct btrfs_root *root, u64 ram_bytes,
4538 u64 num_bytes, u64 min_alloc_size,
4539 u64 empty_size, u64 hint_byte,
4540 struct btrfs_key *ins, int is_data, int delalloc)
4541 {
4542 struct btrfs_fs_info *fs_info = root->fs_info;
4543 struct find_free_extent_ctl ffe_ctl = {};
4544 bool final_tried = num_bytes == min_alloc_size;
4545 u64 flags;
4546 int ret;
4547 bool for_treelog = (root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID);
4548 bool for_data_reloc = (btrfs_is_data_reloc_root(root) && is_data);
4549
4550 flags = get_alloc_profile_by_root(root, is_data);
4551 again:
4552 WARN_ON(num_bytes < fs_info->sectorsize);
4553
4554 ffe_ctl.ram_bytes = ram_bytes;
4555 ffe_ctl.num_bytes = num_bytes;
4556 ffe_ctl.min_alloc_size = min_alloc_size;
4557 ffe_ctl.empty_size = empty_size;
4558 ffe_ctl.flags = flags;
4559 ffe_ctl.delalloc = delalloc;
4560 ffe_ctl.hint_byte = hint_byte;
4561 ffe_ctl.for_treelog = for_treelog;
4562 ffe_ctl.for_data_reloc = for_data_reloc;
4563
4564 ret = find_free_extent(root, ins, &ffe_ctl);
4565 if (!ret && !is_data) {
4566 btrfs_dec_block_group_reservations(fs_info, ins->objectid);
4567 } else if (ret == -ENOSPC) {
4568 if (!final_tried && ins->offset) {
4569 num_bytes = min(num_bytes >> 1, ins->offset);
4570 num_bytes = round_down(num_bytes,
4571 fs_info->sectorsize);
4572 num_bytes = max(num_bytes, min_alloc_size);
4573 ram_bytes = num_bytes;
4574 if (num_bytes == min_alloc_size)
4575 final_tried = true;
4576 goto again;
4577 } else if (btrfs_test_opt(fs_info, ENOSPC_DEBUG)) {
4578 struct btrfs_space_info *sinfo;
4579
4580 sinfo = btrfs_find_space_info(fs_info, flags);
4581 btrfs_err(fs_info,
4582 "allocation failed flags %llu, wanted %llu tree-log %d, relocation: %d",
4583 flags, num_bytes, for_treelog, for_data_reloc);
4584 if (sinfo)
4585 btrfs_dump_space_info(fs_info, sinfo,
4586 num_bytes, 1);
4587 }
4588 }
4589
4590 return ret;
4591 }
4592
btrfs_free_reserved_extent(struct btrfs_fs_info * fs_info,u64 start,u64 len,int delalloc)4593 int btrfs_free_reserved_extent(struct btrfs_fs_info *fs_info,
4594 u64 start, u64 len, int delalloc)
4595 {
4596 struct btrfs_block_group *cache;
4597
4598 cache = btrfs_lookup_block_group(fs_info, start);
4599 if (!cache) {
4600 btrfs_err(fs_info, "Unable to find block group for %llu",
4601 start);
4602 return -ENOSPC;
4603 }
4604
4605 btrfs_add_free_space(cache, start, len);
4606 btrfs_free_reserved_bytes(cache, len, delalloc);
4607 trace_btrfs_reserved_extent_free(fs_info, start, len);
4608
4609 btrfs_put_block_group(cache);
4610 return 0;
4611 }
4612
btrfs_pin_reserved_extent(struct btrfs_trans_handle * trans,u64 start,u64 len)4613 int btrfs_pin_reserved_extent(struct btrfs_trans_handle *trans, u64 start,
4614 u64 len)
4615 {
4616 struct btrfs_block_group *cache;
4617 int ret = 0;
4618
4619 cache = btrfs_lookup_block_group(trans->fs_info, start);
4620 if (!cache) {
4621 btrfs_err(trans->fs_info, "unable to find block group for %llu",
4622 start);
4623 return -ENOSPC;
4624 }
4625
4626 ret = pin_down_extent(trans, cache, start, len, 1);
4627 btrfs_put_block_group(cache);
4628 return ret;
4629 }
4630
alloc_reserved_extent(struct btrfs_trans_handle * trans,u64 bytenr,u64 num_bytes)4631 static int alloc_reserved_extent(struct btrfs_trans_handle *trans, u64 bytenr,
4632 u64 num_bytes)
4633 {
4634 struct btrfs_fs_info *fs_info = trans->fs_info;
4635 int ret;
4636
4637 ret = remove_from_free_space_tree(trans, bytenr, num_bytes);
4638 if (ret)
4639 return ret;
4640
4641 ret = btrfs_update_block_group(trans, bytenr, num_bytes, true);
4642 if (ret) {
4643 ASSERT(!ret);
4644 btrfs_err(fs_info, "update block group failed for %llu %llu",
4645 bytenr, num_bytes);
4646 return ret;
4647 }
4648
4649 trace_btrfs_reserved_extent_alloc(fs_info, bytenr, num_bytes);
4650 return 0;
4651 }
4652
alloc_reserved_file_extent(struct btrfs_trans_handle * trans,u64 parent,u64 root_objectid,u64 flags,u64 owner,u64 offset,struct btrfs_key * ins,int ref_mod)4653 static int alloc_reserved_file_extent(struct btrfs_trans_handle *trans,
4654 u64 parent, u64 root_objectid,
4655 u64 flags, u64 owner, u64 offset,
4656 struct btrfs_key *ins, int ref_mod)
4657 {
4658 struct btrfs_fs_info *fs_info = trans->fs_info;
4659 struct btrfs_root *extent_root;
4660 int ret;
4661 struct btrfs_extent_item *extent_item;
4662 struct btrfs_extent_inline_ref *iref;
4663 struct btrfs_path *path;
4664 struct extent_buffer *leaf;
4665 int type;
4666 u32 size;
4667
4668 if (parent > 0)
4669 type = BTRFS_SHARED_DATA_REF_KEY;
4670 else
4671 type = BTRFS_EXTENT_DATA_REF_KEY;
4672
4673 size = sizeof(*extent_item) + btrfs_extent_inline_ref_size(type);
4674
4675 path = btrfs_alloc_path();
4676 if (!path)
4677 return -ENOMEM;
4678
4679 extent_root = btrfs_extent_root(fs_info, ins->objectid);
4680 ret = btrfs_insert_empty_item(trans, extent_root, path, ins, size);
4681 if (ret) {
4682 btrfs_free_path(path);
4683 return ret;
4684 }
4685
4686 leaf = path->nodes[0];
4687 extent_item = btrfs_item_ptr(leaf, path->slots[0],
4688 struct btrfs_extent_item);
4689 btrfs_set_extent_refs(leaf, extent_item, ref_mod);
4690 btrfs_set_extent_generation(leaf, extent_item, trans->transid);
4691 btrfs_set_extent_flags(leaf, extent_item,
4692 flags | BTRFS_EXTENT_FLAG_DATA);
4693
4694 iref = (struct btrfs_extent_inline_ref *)(extent_item + 1);
4695 btrfs_set_extent_inline_ref_type(leaf, iref, type);
4696 if (parent > 0) {
4697 struct btrfs_shared_data_ref *ref;
4698 ref = (struct btrfs_shared_data_ref *)(iref + 1);
4699 btrfs_set_extent_inline_ref_offset(leaf, iref, parent);
4700 btrfs_set_shared_data_ref_count(leaf, ref, ref_mod);
4701 } else {
4702 struct btrfs_extent_data_ref *ref;
4703 ref = (struct btrfs_extent_data_ref *)(&iref->offset);
4704 btrfs_set_extent_data_ref_root(leaf, ref, root_objectid);
4705 btrfs_set_extent_data_ref_objectid(leaf, ref, owner);
4706 btrfs_set_extent_data_ref_offset(leaf, ref, offset);
4707 btrfs_set_extent_data_ref_count(leaf, ref, ref_mod);
4708 }
4709
4710 btrfs_mark_buffer_dirty(path->nodes[0]);
4711 btrfs_free_path(path);
4712
4713 return alloc_reserved_extent(trans, ins->objectid, ins->offset);
4714 }
4715
alloc_reserved_tree_block(struct btrfs_trans_handle * trans,struct btrfs_delayed_ref_node * node,struct btrfs_delayed_extent_op * extent_op)4716 static int alloc_reserved_tree_block(struct btrfs_trans_handle *trans,
4717 struct btrfs_delayed_ref_node *node,
4718 struct btrfs_delayed_extent_op *extent_op)
4719 {
4720 struct btrfs_fs_info *fs_info = trans->fs_info;
4721 struct btrfs_root *extent_root;
4722 int ret;
4723 struct btrfs_extent_item *extent_item;
4724 struct btrfs_key extent_key;
4725 struct btrfs_tree_block_info *block_info;
4726 struct btrfs_extent_inline_ref *iref;
4727 struct btrfs_path *path;
4728 struct extent_buffer *leaf;
4729 struct btrfs_delayed_tree_ref *ref;
4730 u32 size = sizeof(*extent_item) + sizeof(*iref);
4731 u64 flags = extent_op->flags_to_set;
4732 bool skinny_metadata = btrfs_fs_incompat(fs_info, SKINNY_METADATA);
4733
4734 ref = btrfs_delayed_node_to_tree_ref(node);
4735
4736 extent_key.objectid = node->bytenr;
4737 if (skinny_metadata) {
4738 extent_key.offset = ref->level;
4739 extent_key.type = BTRFS_METADATA_ITEM_KEY;
4740 } else {
4741 extent_key.offset = node->num_bytes;
4742 extent_key.type = BTRFS_EXTENT_ITEM_KEY;
4743 size += sizeof(*block_info);
4744 }
4745
4746 path = btrfs_alloc_path();
4747 if (!path)
4748 return -ENOMEM;
4749
4750 extent_root = btrfs_extent_root(fs_info, extent_key.objectid);
4751 ret = btrfs_insert_empty_item(trans, extent_root, path, &extent_key,
4752 size);
4753 if (ret) {
4754 btrfs_free_path(path);
4755 return ret;
4756 }
4757
4758 leaf = path->nodes[0];
4759 extent_item = btrfs_item_ptr(leaf, path->slots[0],
4760 struct btrfs_extent_item);
4761 btrfs_set_extent_refs(leaf, extent_item, 1);
4762 btrfs_set_extent_generation(leaf, extent_item, trans->transid);
4763 btrfs_set_extent_flags(leaf, extent_item,
4764 flags | BTRFS_EXTENT_FLAG_TREE_BLOCK);
4765
4766 if (skinny_metadata) {
4767 iref = (struct btrfs_extent_inline_ref *)(extent_item + 1);
4768 } else {
4769 block_info = (struct btrfs_tree_block_info *)(extent_item + 1);
4770 btrfs_set_tree_block_key(leaf, block_info, &extent_op->key);
4771 btrfs_set_tree_block_level(leaf, block_info, ref->level);
4772 iref = (struct btrfs_extent_inline_ref *)(block_info + 1);
4773 }
4774
4775 if (node->type == BTRFS_SHARED_BLOCK_REF_KEY) {
4776 btrfs_set_extent_inline_ref_type(leaf, iref,
4777 BTRFS_SHARED_BLOCK_REF_KEY);
4778 btrfs_set_extent_inline_ref_offset(leaf, iref, ref->parent);
4779 } else {
4780 btrfs_set_extent_inline_ref_type(leaf, iref,
4781 BTRFS_TREE_BLOCK_REF_KEY);
4782 btrfs_set_extent_inline_ref_offset(leaf, iref, ref->root);
4783 }
4784
4785 btrfs_mark_buffer_dirty(leaf);
4786 btrfs_free_path(path);
4787
4788 return alloc_reserved_extent(trans, node->bytenr, fs_info->nodesize);
4789 }
4790
btrfs_alloc_reserved_file_extent(struct btrfs_trans_handle * trans,struct btrfs_root * root,u64 owner,u64 offset,u64 ram_bytes,struct btrfs_key * ins)4791 int btrfs_alloc_reserved_file_extent(struct btrfs_trans_handle *trans,
4792 struct btrfs_root *root, u64 owner,
4793 u64 offset, u64 ram_bytes,
4794 struct btrfs_key *ins)
4795 {
4796 struct btrfs_ref generic_ref = { 0 };
4797
4798 BUG_ON(root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID);
4799
4800 btrfs_init_generic_ref(&generic_ref, BTRFS_ADD_DELAYED_EXTENT,
4801 ins->objectid, ins->offset, 0);
4802 btrfs_init_data_ref(&generic_ref, root->root_key.objectid, owner,
4803 offset, 0, false);
4804 btrfs_ref_tree_mod(root->fs_info, &generic_ref);
4805
4806 return btrfs_add_delayed_data_ref(trans, &generic_ref, ram_bytes);
4807 }
4808
4809 /*
4810 * this is used by the tree logging recovery code. It records that
4811 * an extent has been allocated and makes sure to clear the free
4812 * space cache bits as well
4813 */
btrfs_alloc_logged_file_extent(struct btrfs_trans_handle * trans,u64 root_objectid,u64 owner,u64 offset,struct btrfs_key * ins)4814 int btrfs_alloc_logged_file_extent(struct btrfs_trans_handle *trans,
4815 u64 root_objectid, u64 owner, u64 offset,
4816 struct btrfs_key *ins)
4817 {
4818 struct btrfs_fs_info *fs_info = trans->fs_info;
4819 int ret;
4820 struct btrfs_block_group *block_group;
4821 struct btrfs_space_info *space_info;
4822
4823 /*
4824 * Mixed block groups will exclude before processing the log so we only
4825 * need to do the exclude dance if this fs isn't mixed.
4826 */
4827 if (!btrfs_fs_incompat(fs_info, MIXED_GROUPS)) {
4828 ret = __exclude_logged_extent(fs_info, ins->objectid,
4829 ins->offset);
4830 if (ret)
4831 return ret;
4832 }
4833
4834 block_group = btrfs_lookup_block_group(fs_info, ins->objectid);
4835 if (!block_group)
4836 return -EINVAL;
4837
4838 space_info = block_group->space_info;
4839 spin_lock(&space_info->lock);
4840 spin_lock(&block_group->lock);
4841 space_info->bytes_reserved += ins->offset;
4842 block_group->reserved += ins->offset;
4843 spin_unlock(&block_group->lock);
4844 spin_unlock(&space_info->lock);
4845
4846 ret = alloc_reserved_file_extent(trans, 0, root_objectid, 0, owner,
4847 offset, ins, 1);
4848 if (ret)
4849 btrfs_pin_extent(trans, ins->objectid, ins->offset, 1);
4850 btrfs_put_block_group(block_group);
4851 return ret;
4852 }
4853
4854 static struct extent_buffer *
btrfs_init_new_buffer(struct btrfs_trans_handle * trans,struct btrfs_root * root,u64 bytenr,int level,u64 owner,enum btrfs_lock_nesting nest)4855 btrfs_init_new_buffer(struct btrfs_trans_handle *trans, struct btrfs_root *root,
4856 u64 bytenr, int level, u64 owner,
4857 enum btrfs_lock_nesting nest)
4858 {
4859 struct btrfs_fs_info *fs_info = root->fs_info;
4860 struct extent_buffer *buf;
4861 u64 lockdep_owner = owner;
4862
4863 buf = btrfs_find_create_tree_block(fs_info, bytenr, owner, level);
4864 if (IS_ERR(buf))
4865 return buf;
4866
4867 /*
4868 * Extra safety check in case the extent tree is corrupted and extent
4869 * allocator chooses to use a tree block which is already used and
4870 * locked.
4871 */
4872 if (buf->lock_owner == current->pid) {
4873 btrfs_err_rl(fs_info,
4874 "tree block %llu owner %llu already locked by pid=%d, extent tree corruption detected",
4875 buf->start, btrfs_header_owner(buf), current->pid);
4876 free_extent_buffer(buf);
4877 return ERR_PTR(-EUCLEAN);
4878 }
4879
4880 /*
4881 * The reloc trees are just snapshots, so we need them to appear to be
4882 * just like any other fs tree WRT lockdep.
4883 *
4884 * The exception however is in replace_path() in relocation, where we
4885 * hold the lock on the original fs root and then search for the reloc
4886 * root. At that point we need to make sure any reloc root buffers are
4887 * set to the BTRFS_TREE_RELOC_OBJECTID lockdep class in order to make
4888 * lockdep happy.
4889 */
4890 if (lockdep_owner == BTRFS_TREE_RELOC_OBJECTID &&
4891 !test_bit(BTRFS_ROOT_RESET_LOCKDEP_CLASS, &root->state))
4892 lockdep_owner = BTRFS_FS_TREE_OBJECTID;
4893
4894 /* btrfs_clean_tree_block() accesses generation field. */
4895 btrfs_set_header_generation(buf, trans->transid);
4896
4897 /*
4898 * This needs to stay, because we could allocate a freed block from an
4899 * old tree into a new tree, so we need to make sure this new block is
4900 * set to the appropriate level and owner.
4901 */
4902 btrfs_set_buffer_lockdep_class(lockdep_owner, buf, level);
4903
4904 __btrfs_tree_lock(buf, nest);
4905 btrfs_clean_tree_block(buf);
4906 clear_bit(EXTENT_BUFFER_STALE, &buf->bflags);
4907 clear_bit(EXTENT_BUFFER_NO_CHECK, &buf->bflags);
4908
4909 set_extent_buffer_uptodate(buf);
4910
4911 memzero_extent_buffer(buf, 0, sizeof(struct btrfs_header));
4912 btrfs_set_header_level(buf, level);
4913 btrfs_set_header_bytenr(buf, buf->start);
4914 btrfs_set_header_generation(buf, trans->transid);
4915 btrfs_set_header_backref_rev(buf, BTRFS_MIXED_BACKREF_REV);
4916 btrfs_set_header_owner(buf, owner);
4917 write_extent_buffer_fsid(buf, fs_info->fs_devices->metadata_uuid);
4918 write_extent_buffer_chunk_tree_uuid(buf, fs_info->chunk_tree_uuid);
4919 if (root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID) {
4920 buf->log_index = root->log_transid % 2;
4921 /*
4922 * we allow two log transactions at a time, use different
4923 * EXTENT bit to differentiate dirty pages.
4924 */
4925 if (buf->log_index == 0)
4926 set_extent_dirty(&root->dirty_log_pages, buf->start,
4927 buf->start + buf->len - 1, GFP_NOFS);
4928 else
4929 set_extent_new(&root->dirty_log_pages, buf->start,
4930 buf->start + buf->len - 1);
4931 } else {
4932 buf->log_index = -1;
4933 set_extent_dirty(&trans->transaction->dirty_pages, buf->start,
4934 buf->start + buf->len - 1, GFP_NOFS);
4935 }
4936 /* this returns a buffer locked for blocking */
4937 return buf;
4938 }
4939
4940 /*
4941 * finds a free extent and does all the dirty work required for allocation
4942 * returns the tree buffer or an ERR_PTR on error.
4943 */
btrfs_alloc_tree_block(struct btrfs_trans_handle * trans,struct btrfs_root * root,u64 parent,u64 root_objectid,const struct btrfs_disk_key * key,int level,u64 hint,u64 empty_size,enum btrfs_lock_nesting nest)4944 struct extent_buffer *btrfs_alloc_tree_block(struct btrfs_trans_handle *trans,
4945 struct btrfs_root *root,
4946 u64 parent, u64 root_objectid,
4947 const struct btrfs_disk_key *key,
4948 int level, u64 hint,
4949 u64 empty_size,
4950 enum btrfs_lock_nesting nest)
4951 {
4952 struct btrfs_fs_info *fs_info = root->fs_info;
4953 struct btrfs_key ins;
4954 struct btrfs_block_rsv *block_rsv;
4955 struct extent_buffer *buf;
4956 struct btrfs_delayed_extent_op *extent_op;
4957 struct btrfs_ref generic_ref = { 0 };
4958 u64 flags = 0;
4959 int ret;
4960 u32 blocksize = fs_info->nodesize;
4961 bool skinny_metadata = btrfs_fs_incompat(fs_info, SKINNY_METADATA);
4962
4963 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
4964 if (btrfs_is_testing(fs_info)) {
4965 buf = btrfs_init_new_buffer(trans, root, root->alloc_bytenr,
4966 level, root_objectid, nest);
4967 if (!IS_ERR(buf))
4968 root->alloc_bytenr += blocksize;
4969 return buf;
4970 }
4971 #endif
4972
4973 block_rsv = btrfs_use_block_rsv(trans, root, blocksize);
4974 if (IS_ERR(block_rsv))
4975 return ERR_CAST(block_rsv);
4976
4977 ret = btrfs_reserve_extent(root, blocksize, blocksize, blocksize,
4978 empty_size, hint, &ins, 0, 0);
4979 if (ret)
4980 goto out_unuse;
4981
4982 buf = btrfs_init_new_buffer(trans, root, ins.objectid, level,
4983 root_objectid, nest);
4984 if (IS_ERR(buf)) {
4985 ret = PTR_ERR(buf);
4986 goto out_free_reserved;
4987 }
4988
4989 if (root_objectid == BTRFS_TREE_RELOC_OBJECTID) {
4990 if (parent == 0)
4991 parent = ins.objectid;
4992 flags |= BTRFS_BLOCK_FLAG_FULL_BACKREF;
4993 } else
4994 BUG_ON(parent > 0);
4995
4996 if (root_objectid != BTRFS_TREE_LOG_OBJECTID) {
4997 extent_op = btrfs_alloc_delayed_extent_op();
4998 if (!extent_op) {
4999 ret = -ENOMEM;
5000 goto out_free_buf;
5001 }
5002 if (key)
5003 memcpy(&extent_op->key, key, sizeof(extent_op->key));
5004 else
5005 memset(&extent_op->key, 0, sizeof(extent_op->key));
5006 extent_op->flags_to_set = flags;
5007 extent_op->update_key = skinny_metadata ? false : true;
5008 extent_op->update_flags = true;
5009 extent_op->level = level;
5010
5011 btrfs_init_generic_ref(&generic_ref, BTRFS_ADD_DELAYED_EXTENT,
5012 ins.objectid, ins.offset, parent);
5013 btrfs_init_tree_ref(&generic_ref, level, root_objectid,
5014 root->root_key.objectid, false);
5015 btrfs_ref_tree_mod(fs_info, &generic_ref);
5016 ret = btrfs_add_delayed_tree_ref(trans, &generic_ref, extent_op);
5017 if (ret)
5018 goto out_free_delayed;
5019 }
5020 return buf;
5021
5022 out_free_delayed:
5023 btrfs_free_delayed_extent_op(extent_op);
5024 out_free_buf:
5025 btrfs_tree_unlock(buf);
5026 free_extent_buffer(buf);
5027 out_free_reserved:
5028 btrfs_free_reserved_extent(fs_info, ins.objectid, ins.offset, 0);
5029 out_unuse:
5030 btrfs_unuse_block_rsv(fs_info, block_rsv, blocksize);
5031 return ERR_PTR(ret);
5032 }
5033
5034 struct walk_control {
5035 u64 refs[BTRFS_MAX_LEVEL];
5036 u64 flags[BTRFS_MAX_LEVEL];
5037 struct btrfs_key update_progress;
5038 struct btrfs_key drop_progress;
5039 int drop_level;
5040 int stage;
5041 int level;
5042 int shared_level;
5043 int update_ref;
5044 int keep_locks;
5045 int reada_slot;
5046 int reada_count;
5047 int restarted;
5048 };
5049
5050 #define DROP_REFERENCE 1
5051 #define UPDATE_BACKREF 2
5052
reada_walk_down(struct btrfs_trans_handle * trans,struct btrfs_root * root,struct walk_control * wc,struct btrfs_path * path)5053 static noinline void reada_walk_down(struct btrfs_trans_handle *trans,
5054 struct btrfs_root *root,
5055 struct walk_control *wc,
5056 struct btrfs_path *path)
5057 {
5058 struct btrfs_fs_info *fs_info = root->fs_info;
5059 u64 bytenr;
5060 u64 generation;
5061 u64 refs;
5062 u64 flags;
5063 u32 nritems;
5064 struct btrfs_key key;
5065 struct extent_buffer *eb;
5066 int ret;
5067 int slot;
5068 int nread = 0;
5069
5070 if (path->slots[wc->level] < wc->reada_slot) {
5071 wc->reada_count = wc->reada_count * 2 / 3;
5072 wc->reada_count = max(wc->reada_count, 2);
5073 } else {
5074 wc->reada_count = wc->reada_count * 3 / 2;
5075 wc->reada_count = min_t(int, wc->reada_count,
5076 BTRFS_NODEPTRS_PER_BLOCK(fs_info));
5077 }
5078
5079 eb = path->nodes[wc->level];
5080 nritems = btrfs_header_nritems(eb);
5081
5082 for (slot = path->slots[wc->level]; slot < nritems; slot++) {
5083 if (nread >= wc->reada_count)
5084 break;
5085
5086 cond_resched();
5087 bytenr = btrfs_node_blockptr(eb, slot);
5088 generation = btrfs_node_ptr_generation(eb, slot);
5089
5090 if (slot == path->slots[wc->level])
5091 goto reada;
5092
5093 if (wc->stage == UPDATE_BACKREF &&
5094 generation <= root->root_key.offset)
5095 continue;
5096
5097 /* We don't lock the tree block, it's OK to be racy here */
5098 ret = btrfs_lookup_extent_info(trans, fs_info, bytenr,
5099 wc->level - 1, 1, &refs,
5100 &flags);
5101 /* We don't care about errors in readahead. */
5102 if (ret < 0)
5103 continue;
5104 BUG_ON(refs == 0);
5105
5106 if (wc->stage == DROP_REFERENCE) {
5107 if (refs == 1)
5108 goto reada;
5109
5110 if (wc->level == 1 &&
5111 (flags & BTRFS_BLOCK_FLAG_FULL_BACKREF))
5112 continue;
5113 if (!wc->update_ref ||
5114 generation <= root->root_key.offset)
5115 continue;
5116 btrfs_node_key_to_cpu(eb, &key, slot);
5117 ret = btrfs_comp_cpu_keys(&key,
5118 &wc->update_progress);
5119 if (ret < 0)
5120 continue;
5121 } else {
5122 if (wc->level == 1 &&
5123 (flags & BTRFS_BLOCK_FLAG_FULL_BACKREF))
5124 continue;
5125 }
5126 reada:
5127 btrfs_readahead_node_child(eb, slot);
5128 nread++;
5129 }
5130 wc->reada_slot = slot;
5131 }
5132
5133 /*
5134 * helper to process tree block while walking down the tree.
5135 *
5136 * when wc->stage == UPDATE_BACKREF, this function updates
5137 * back refs for pointers in the block.
5138 *
5139 * NOTE: return value 1 means we should stop walking down.
5140 */
walk_down_proc(struct btrfs_trans_handle * trans,struct btrfs_root * root,struct btrfs_path * path,struct walk_control * wc,int lookup_info)5141 static noinline int walk_down_proc(struct btrfs_trans_handle *trans,
5142 struct btrfs_root *root,
5143 struct btrfs_path *path,
5144 struct walk_control *wc, int lookup_info)
5145 {
5146 struct btrfs_fs_info *fs_info = root->fs_info;
5147 int level = wc->level;
5148 struct extent_buffer *eb = path->nodes[level];
5149 u64 flag = BTRFS_BLOCK_FLAG_FULL_BACKREF;
5150 int ret;
5151
5152 if (wc->stage == UPDATE_BACKREF &&
5153 btrfs_header_owner(eb) != root->root_key.objectid)
5154 return 1;
5155
5156 /*
5157 * when reference count of tree block is 1, it won't increase
5158 * again. once full backref flag is set, we never clear it.
5159 */
5160 if (lookup_info &&
5161 ((wc->stage == DROP_REFERENCE && wc->refs[level] != 1) ||
5162 (wc->stage == UPDATE_BACKREF && !(wc->flags[level] & flag)))) {
5163 BUG_ON(!path->locks[level]);
5164 ret = btrfs_lookup_extent_info(trans, fs_info,
5165 eb->start, level, 1,
5166 &wc->refs[level],
5167 &wc->flags[level]);
5168 BUG_ON(ret == -ENOMEM);
5169 if (ret)
5170 return ret;
5171 BUG_ON(wc->refs[level] == 0);
5172 }
5173
5174 if (wc->stage == DROP_REFERENCE) {
5175 if (wc->refs[level] > 1)
5176 return 1;
5177
5178 if (path->locks[level] && !wc->keep_locks) {
5179 btrfs_tree_unlock_rw(eb, path->locks[level]);
5180 path->locks[level] = 0;
5181 }
5182 return 0;
5183 }
5184
5185 /* wc->stage == UPDATE_BACKREF */
5186 if (!(wc->flags[level] & flag)) {
5187 BUG_ON(!path->locks[level]);
5188 ret = btrfs_inc_ref(trans, root, eb, 1);
5189 BUG_ON(ret); /* -ENOMEM */
5190 ret = btrfs_dec_ref(trans, root, eb, 0);
5191 BUG_ON(ret); /* -ENOMEM */
5192 ret = btrfs_set_disk_extent_flags(trans, eb, flag,
5193 btrfs_header_level(eb));
5194 BUG_ON(ret); /* -ENOMEM */
5195 wc->flags[level] |= flag;
5196 }
5197
5198 /*
5199 * the block is shared by multiple trees, so it's not good to
5200 * keep the tree lock
5201 */
5202 if (path->locks[level] && level > 0) {
5203 btrfs_tree_unlock_rw(eb, path->locks[level]);
5204 path->locks[level] = 0;
5205 }
5206 return 0;
5207 }
5208
5209 /*
5210 * This is used to verify a ref exists for this root to deal with a bug where we
5211 * would have a drop_progress key that hadn't been updated properly.
5212 */
check_ref_exists(struct btrfs_trans_handle * trans,struct btrfs_root * root,u64 bytenr,u64 parent,int level)5213 static int check_ref_exists(struct btrfs_trans_handle *trans,
5214 struct btrfs_root *root, u64 bytenr, u64 parent,
5215 int level)
5216 {
5217 struct btrfs_path *path;
5218 struct btrfs_extent_inline_ref *iref;
5219 int ret;
5220
5221 path = btrfs_alloc_path();
5222 if (!path)
5223 return -ENOMEM;
5224
5225 ret = lookup_extent_backref(trans, path, &iref, bytenr,
5226 root->fs_info->nodesize, parent,
5227 root->root_key.objectid, level, 0);
5228 btrfs_free_path(path);
5229 if (ret == -ENOENT)
5230 return 0;
5231 if (ret < 0)
5232 return ret;
5233 return 1;
5234 }
5235
5236 /*
5237 * helper to process tree block pointer.
5238 *
5239 * when wc->stage == DROP_REFERENCE, this function checks
5240 * reference count of the block pointed to. if the block
5241 * is shared and we need update back refs for the subtree
5242 * rooted at the block, this function changes wc->stage to
5243 * UPDATE_BACKREF. if the block is shared and there is no
5244 * need to update back, this function drops the reference
5245 * to the block.
5246 *
5247 * NOTE: return value 1 means we should stop walking down.
5248 */
do_walk_down(struct btrfs_trans_handle * trans,struct btrfs_root * root,struct btrfs_path * path,struct walk_control * wc,int * lookup_info)5249 static noinline int do_walk_down(struct btrfs_trans_handle *trans,
5250 struct btrfs_root *root,
5251 struct btrfs_path *path,
5252 struct walk_control *wc, int *lookup_info)
5253 {
5254 struct btrfs_fs_info *fs_info = root->fs_info;
5255 u64 bytenr;
5256 u64 generation;
5257 u64 parent;
5258 struct btrfs_key key;
5259 struct btrfs_key first_key;
5260 struct btrfs_ref ref = { 0 };
5261 struct extent_buffer *next;
5262 int level = wc->level;
5263 int reada = 0;
5264 int ret = 0;
5265 bool need_account = false;
5266
5267 generation = btrfs_node_ptr_generation(path->nodes[level],
5268 path->slots[level]);
5269 /*
5270 * if the lower level block was created before the snapshot
5271 * was created, we know there is no need to update back refs
5272 * for the subtree
5273 */
5274 if (wc->stage == UPDATE_BACKREF &&
5275 generation <= root->root_key.offset) {
5276 *lookup_info = 1;
5277 return 1;
5278 }
5279
5280 bytenr = btrfs_node_blockptr(path->nodes[level], path->slots[level]);
5281 btrfs_node_key_to_cpu(path->nodes[level], &first_key,
5282 path->slots[level]);
5283
5284 next = find_extent_buffer(fs_info, bytenr);
5285 if (!next) {
5286 next = btrfs_find_create_tree_block(fs_info, bytenr,
5287 root->root_key.objectid, level - 1);
5288 if (IS_ERR(next))
5289 return PTR_ERR(next);
5290 reada = 1;
5291 }
5292 btrfs_tree_lock(next);
5293
5294 ret = btrfs_lookup_extent_info(trans, fs_info, bytenr, level - 1, 1,
5295 &wc->refs[level - 1],
5296 &wc->flags[level - 1]);
5297 if (ret < 0)
5298 goto out_unlock;
5299
5300 if (unlikely(wc->refs[level - 1] == 0)) {
5301 btrfs_err(fs_info, "Missing references.");
5302 ret = -EIO;
5303 goto out_unlock;
5304 }
5305 *lookup_info = 0;
5306
5307 if (wc->stage == DROP_REFERENCE) {
5308 if (wc->refs[level - 1] > 1) {
5309 need_account = true;
5310 if (level == 1 &&
5311 (wc->flags[0] & BTRFS_BLOCK_FLAG_FULL_BACKREF))
5312 goto skip;
5313
5314 if (!wc->update_ref ||
5315 generation <= root->root_key.offset)
5316 goto skip;
5317
5318 btrfs_node_key_to_cpu(path->nodes[level], &key,
5319 path->slots[level]);
5320 ret = btrfs_comp_cpu_keys(&key, &wc->update_progress);
5321 if (ret < 0)
5322 goto skip;
5323
5324 wc->stage = UPDATE_BACKREF;
5325 wc->shared_level = level - 1;
5326 }
5327 } else {
5328 if (level == 1 &&
5329 (wc->flags[0] & BTRFS_BLOCK_FLAG_FULL_BACKREF))
5330 goto skip;
5331 }
5332
5333 if (!btrfs_buffer_uptodate(next, generation, 0)) {
5334 btrfs_tree_unlock(next);
5335 free_extent_buffer(next);
5336 next = NULL;
5337 *lookup_info = 1;
5338 }
5339
5340 if (!next) {
5341 if (reada && level == 1)
5342 reada_walk_down(trans, root, wc, path);
5343 next = read_tree_block(fs_info, bytenr, root->root_key.objectid,
5344 generation, level - 1, &first_key);
5345 if (IS_ERR(next)) {
5346 return PTR_ERR(next);
5347 } else if (!extent_buffer_uptodate(next)) {
5348 free_extent_buffer(next);
5349 return -EIO;
5350 }
5351 btrfs_tree_lock(next);
5352 }
5353
5354 level--;
5355 ASSERT(level == btrfs_header_level(next));
5356 if (level != btrfs_header_level(next)) {
5357 btrfs_err(root->fs_info, "mismatched level");
5358 ret = -EIO;
5359 goto out_unlock;
5360 }
5361 path->nodes[level] = next;
5362 path->slots[level] = 0;
5363 path->locks[level] = BTRFS_WRITE_LOCK;
5364 wc->level = level;
5365 if (wc->level == 1)
5366 wc->reada_slot = 0;
5367 return 0;
5368 skip:
5369 wc->refs[level - 1] = 0;
5370 wc->flags[level - 1] = 0;
5371 if (wc->stage == DROP_REFERENCE) {
5372 if (wc->flags[level] & BTRFS_BLOCK_FLAG_FULL_BACKREF) {
5373 parent = path->nodes[level]->start;
5374 } else {
5375 ASSERT(root->root_key.objectid ==
5376 btrfs_header_owner(path->nodes[level]));
5377 if (root->root_key.objectid !=
5378 btrfs_header_owner(path->nodes[level])) {
5379 btrfs_err(root->fs_info,
5380 "mismatched block owner");
5381 ret = -EIO;
5382 goto out_unlock;
5383 }
5384 parent = 0;
5385 }
5386
5387 /*
5388 * If we had a drop_progress we need to verify the refs are set
5389 * as expected. If we find our ref then we know that from here
5390 * on out everything should be correct, and we can clear the
5391 * ->restarted flag.
5392 */
5393 if (wc->restarted) {
5394 ret = check_ref_exists(trans, root, bytenr, parent,
5395 level - 1);
5396 if (ret < 0)
5397 goto out_unlock;
5398 if (ret == 0)
5399 goto no_delete;
5400 ret = 0;
5401 wc->restarted = 0;
5402 }
5403
5404 /*
5405 * Reloc tree doesn't contribute to qgroup numbers, and we have
5406 * already accounted them at merge time (replace_path),
5407 * thus we could skip expensive subtree trace here.
5408 */
5409 if (root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID &&
5410 need_account) {
5411 ret = btrfs_qgroup_trace_subtree(trans, next,
5412 generation, level - 1);
5413 if (ret) {
5414 btrfs_err_rl(fs_info,
5415 "Error %d accounting shared subtree. Quota is out of sync, rescan required.",
5416 ret);
5417 }
5418 }
5419
5420 /*
5421 * We need to update the next key in our walk control so we can
5422 * update the drop_progress key accordingly. We don't care if
5423 * find_next_key doesn't find a key because that means we're at
5424 * the end and are going to clean up now.
5425 */
5426 wc->drop_level = level;
5427 find_next_key(path, level, &wc->drop_progress);
5428
5429 btrfs_init_generic_ref(&ref, BTRFS_DROP_DELAYED_REF, bytenr,
5430 fs_info->nodesize, parent);
5431 btrfs_init_tree_ref(&ref, level - 1, root->root_key.objectid,
5432 0, false);
5433 ret = btrfs_free_extent(trans, &ref);
5434 if (ret)
5435 goto out_unlock;
5436 }
5437 no_delete:
5438 *lookup_info = 1;
5439 ret = 1;
5440
5441 out_unlock:
5442 btrfs_tree_unlock(next);
5443 free_extent_buffer(next);
5444
5445 return ret;
5446 }
5447
5448 /*
5449 * helper to process tree block while walking up the tree.
5450 *
5451 * when wc->stage == DROP_REFERENCE, this function drops
5452 * reference count on the block.
5453 *
5454 * when wc->stage == UPDATE_BACKREF, this function changes
5455 * wc->stage back to DROP_REFERENCE if we changed wc->stage
5456 * to UPDATE_BACKREF previously while processing the block.
5457 *
5458 * NOTE: return value 1 means we should stop walking up.
5459 */
walk_up_proc(struct btrfs_trans_handle * trans,struct btrfs_root * root,struct btrfs_path * path,struct walk_control * wc)5460 static noinline int walk_up_proc(struct btrfs_trans_handle *trans,
5461 struct btrfs_root *root,
5462 struct btrfs_path *path,
5463 struct walk_control *wc)
5464 {
5465 struct btrfs_fs_info *fs_info = root->fs_info;
5466 int ret;
5467 int level = wc->level;
5468 struct extent_buffer *eb = path->nodes[level];
5469 u64 parent = 0;
5470
5471 if (wc->stage == UPDATE_BACKREF) {
5472 BUG_ON(wc->shared_level < level);
5473 if (level < wc->shared_level)
5474 goto out;
5475
5476 ret = find_next_key(path, level + 1, &wc->update_progress);
5477 if (ret > 0)
5478 wc->update_ref = 0;
5479
5480 wc->stage = DROP_REFERENCE;
5481 wc->shared_level = -1;
5482 path->slots[level] = 0;
5483
5484 /*
5485 * check reference count again if the block isn't locked.
5486 * we should start walking down the tree again if reference
5487 * count is one.
5488 */
5489 if (!path->locks[level]) {
5490 BUG_ON(level == 0);
5491 btrfs_tree_lock(eb);
5492 path->locks[level] = BTRFS_WRITE_LOCK;
5493
5494 ret = btrfs_lookup_extent_info(trans, fs_info,
5495 eb->start, level, 1,
5496 &wc->refs[level],
5497 &wc->flags[level]);
5498 if (ret < 0) {
5499 btrfs_tree_unlock_rw(eb, path->locks[level]);
5500 path->locks[level] = 0;
5501 return ret;
5502 }
5503 BUG_ON(wc->refs[level] == 0);
5504 if (wc->refs[level] == 1) {
5505 btrfs_tree_unlock_rw(eb, path->locks[level]);
5506 path->locks[level] = 0;
5507 return 1;
5508 }
5509 }
5510 }
5511
5512 /* wc->stage == DROP_REFERENCE */
5513 BUG_ON(wc->refs[level] > 1 && !path->locks[level]);
5514
5515 if (wc->refs[level] == 1) {
5516 if (level == 0) {
5517 if (wc->flags[level] & BTRFS_BLOCK_FLAG_FULL_BACKREF)
5518 ret = btrfs_dec_ref(trans, root, eb, 1);
5519 else
5520 ret = btrfs_dec_ref(trans, root, eb, 0);
5521 BUG_ON(ret); /* -ENOMEM */
5522 if (is_fstree(root->root_key.objectid)) {
5523 ret = btrfs_qgroup_trace_leaf_items(trans, eb);
5524 if (ret) {
5525 btrfs_err_rl(fs_info,
5526 "error %d accounting leaf items, quota is out of sync, rescan required",
5527 ret);
5528 }
5529 }
5530 }
5531 /* make block locked assertion in btrfs_clean_tree_block happy */
5532 if (!path->locks[level] &&
5533 btrfs_header_generation(eb) == trans->transid) {
5534 btrfs_tree_lock(eb);
5535 path->locks[level] = BTRFS_WRITE_LOCK;
5536 }
5537 btrfs_clean_tree_block(eb);
5538 }
5539
5540 if (eb == root->node) {
5541 if (wc->flags[level] & BTRFS_BLOCK_FLAG_FULL_BACKREF)
5542 parent = eb->start;
5543 else if (root->root_key.objectid != btrfs_header_owner(eb))
5544 goto owner_mismatch;
5545 } else {
5546 if (wc->flags[level + 1] & BTRFS_BLOCK_FLAG_FULL_BACKREF)
5547 parent = path->nodes[level + 1]->start;
5548 else if (root->root_key.objectid !=
5549 btrfs_header_owner(path->nodes[level + 1]))
5550 goto owner_mismatch;
5551 }
5552
5553 btrfs_free_tree_block(trans, btrfs_root_id(root), eb, parent,
5554 wc->refs[level] == 1);
5555 out:
5556 wc->refs[level] = 0;
5557 wc->flags[level] = 0;
5558 return 0;
5559
5560 owner_mismatch:
5561 btrfs_err_rl(fs_info, "unexpected tree owner, have %llu expect %llu",
5562 btrfs_header_owner(eb), root->root_key.objectid);
5563 return -EUCLEAN;
5564 }
5565
walk_down_tree(struct btrfs_trans_handle * trans,struct btrfs_root * root,struct btrfs_path * path,struct walk_control * wc)5566 static noinline int walk_down_tree(struct btrfs_trans_handle *trans,
5567 struct btrfs_root *root,
5568 struct btrfs_path *path,
5569 struct walk_control *wc)
5570 {
5571 int level = wc->level;
5572 int lookup_info = 1;
5573 int ret;
5574
5575 while (level >= 0) {
5576 ret = walk_down_proc(trans, root, path, wc, lookup_info);
5577 if (ret > 0)
5578 break;
5579
5580 if (level == 0)
5581 break;
5582
5583 if (path->slots[level] >=
5584 btrfs_header_nritems(path->nodes[level]))
5585 break;
5586
5587 ret = do_walk_down(trans, root, path, wc, &lookup_info);
5588 if (ret > 0) {
5589 path->slots[level]++;
5590 continue;
5591 } else if (ret < 0)
5592 return ret;
5593 level = wc->level;
5594 }
5595 return 0;
5596 }
5597
walk_up_tree(struct btrfs_trans_handle * trans,struct btrfs_root * root,struct btrfs_path * path,struct walk_control * wc,int max_level)5598 static noinline int walk_up_tree(struct btrfs_trans_handle *trans,
5599 struct btrfs_root *root,
5600 struct btrfs_path *path,
5601 struct walk_control *wc, int max_level)
5602 {
5603 int level = wc->level;
5604 int ret;
5605
5606 path->slots[level] = btrfs_header_nritems(path->nodes[level]);
5607 while (level < max_level && path->nodes[level]) {
5608 wc->level = level;
5609 if (path->slots[level] + 1 <
5610 btrfs_header_nritems(path->nodes[level])) {
5611 path->slots[level]++;
5612 return 0;
5613 } else {
5614 ret = walk_up_proc(trans, root, path, wc);
5615 if (ret > 0)
5616 return 0;
5617 if (ret < 0)
5618 return ret;
5619
5620 if (path->locks[level]) {
5621 btrfs_tree_unlock_rw(path->nodes[level],
5622 path->locks[level]);
5623 path->locks[level] = 0;
5624 }
5625 free_extent_buffer(path->nodes[level]);
5626 path->nodes[level] = NULL;
5627 level++;
5628 }
5629 }
5630 return 1;
5631 }
5632
5633 /*
5634 * drop a subvolume tree.
5635 *
5636 * this function traverses the tree freeing any blocks that only
5637 * referenced by the tree.
5638 *
5639 * when a shared tree block is found. this function decreases its
5640 * reference count by one. if update_ref is true, this function
5641 * also make sure backrefs for the shared block and all lower level
5642 * blocks are properly updated.
5643 *
5644 * If called with for_reloc == 0, may exit early with -EAGAIN
5645 */
btrfs_drop_snapshot(struct btrfs_root * root,int update_ref,int for_reloc)5646 int btrfs_drop_snapshot(struct btrfs_root *root, int update_ref, int for_reloc)
5647 {
5648 const bool is_reloc_root = (root->root_key.objectid ==
5649 BTRFS_TREE_RELOC_OBJECTID);
5650 struct btrfs_fs_info *fs_info = root->fs_info;
5651 struct btrfs_path *path;
5652 struct btrfs_trans_handle *trans;
5653 struct btrfs_root *tree_root = fs_info->tree_root;
5654 struct btrfs_root_item *root_item = &root->root_item;
5655 struct walk_control *wc;
5656 struct btrfs_key key;
5657 int err = 0;
5658 int ret;
5659 int level;
5660 bool root_dropped = false;
5661 bool unfinished_drop = false;
5662
5663 btrfs_debug(fs_info, "Drop subvolume %llu", root->root_key.objectid);
5664
5665 path = btrfs_alloc_path();
5666 if (!path) {
5667 err = -ENOMEM;
5668 goto out;
5669 }
5670
5671 wc = kzalloc(sizeof(*wc), GFP_NOFS);
5672 if (!wc) {
5673 btrfs_free_path(path);
5674 err = -ENOMEM;
5675 goto out;
5676 }
5677
5678 /*
5679 * Use join to avoid potential EINTR from transaction start. See
5680 * wait_reserve_ticket and the whole reservation callchain.
5681 */
5682 if (for_reloc)
5683 trans = btrfs_join_transaction(tree_root);
5684 else
5685 trans = btrfs_start_transaction(tree_root, 0);
5686 if (IS_ERR(trans)) {
5687 err = PTR_ERR(trans);
5688 goto out_free;
5689 }
5690
5691 err = btrfs_run_delayed_items(trans);
5692 if (err)
5693 goto out_end_trans;
5694
5695 /*
5696 * This will help us catch people modifying the fs tree while we're
5697 * dropping it. It is unsafe to mess with the fs tree while it's being
5698 * dropped as we unlock the root node and parent nodes as we walk down
5699 * the tree, assuming nothing will change. If something does change
5700 * then we'll have stale information and drop references to blocks we've
5701 * already dropped.
5702 */
5703 set_bit(BTRFS_ROOT_DELETING, &root->state);
5704 unfinished_drop = test_bit(BTRFS_ROOT_UNFINISHED_DROP, &root->state);
5705
5706 if (btrfs_disk_key_objectid(&root_item->drop_progress) == 0) {
5707 level = btrfs_header_level(root->node);
5708 path->nodes[level] = btrfs_lock_root_node(root);
5709 path->slots[level] = 0;
5710 path->locks[level] = BTRFS_WRITE_LOCK;
5711 memset(&wc->update_progress, 0,
5712 sizeof(wc->update_progress));
5713 } else {
5714 btrfs_disk_key_to_cpu(&key, &root_item->drop_progress);
5715 memcpy(&wc->update_progress, &key,
5716 sizeof(wc->update_progress));
5717
5718 level = btrfs_root_drop_level(root_item);
5719 BUG_ON(level == 0);
5720 path->lowest_level = level;
5721 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
5722 path->lowest_level = 0;
5723 if (ret < 0) {
5724 err = ret;
5725 goto out_end_trans;
5726 }
5727 WARN_ON(ret > 0);
5728
5729 /*
5730 * unlock our path, this is safe because only this
5731 * function is allowed to delete this snapshot
5732 */
5733 btrfs_unlock_up_safe(path, 0);
5734
5735 level = btrfs_header_level(root->node);
5736 while (1) {
5737 btrfs_tree_lock(path->nodes[level]);
5738 path->locks[level] = BTRFS_WRITE_LOCK;
5739
5740 ret = btrfs_lookup_extent_info(trans, fs_info,
5741 path->nodes[level]->start,
5742 level, 1, &wc->refs[level],
5743 &wc->flags[level]);
5744 if (ret < 0) {
5745 err = ret;
5746 goto out_end_trans;
5747 }
5748 BUG_ON(wc->refs[level] == 0);
5749
5750 if (level == btrfs_root_drop_level(root_item))
5751 break;
5752
5753 btrfs_tree_unlock(path->nodes[level]);
5754 path->locks[level] = 0;
5755 WARN_ON(wc->refs[level] != 1);
5756 level--;
5757 }
5758 }
5759
5760 wc->restarted = test_bit(BTRFS_ROOT_DEAD_TREE, &root->state);
5761 wc->level = level;
5762 wc->shared_level = -1;
5763 wc->stage = DROP_REFERENCE;
5764 wc->update_ref = update_ref;
5765 wc->keep_locks = 0;
5766 wc->reada_count = BTRFS_NODEPTRS_PER_BLOCK(fs_info);
5767
5768 while (1) {
5769
5770 ret = walk_down_tree(trans, root, path, wc);
5771 if (ret < 0) {
5772 err = ret;
5773 break;
5774 }
5775
5776 ret = walk_up_tree(trans, root, path, wc, BTRFS_MAX_LEVEL);
5777 if (ret < 0) {
5778 err = ret;
5779 break;
5780 }
5781
5782 if (ret > 0) {
5783 BUG_ON(wc->stage != DROP_REFERENCE);
5784 break;
5785 }
5786
5787 if (wc->stage == DROP_REFERENCE) {
5788 wc->drop_level = wc->level;
5789 btrfs_node_key_to_cpu(path->nodes[wc->drop_level],
5790 &wc->drop_progress,
5791 path->slots[wc->drop_level]);
5792 }
5793 btrfs_cpu_key_to_disk(&root_item->drop_progress,
5794 &wc->drop_progress);
5795 btrfs_set_root_drop_level(root_item, wc->drop_level);
5796
5797 BUG_ON(wc->level == 0);
5798 if (btrfs_should_end_transaction(trans) ||
5799 (!for_reloc && btrfs_need_cleaner_sleep(fs_info))) {
5800 ret = btrfs_update_root(trans, tree_root,
5801 &root->root_key,
5802 root_item);
5803 if (ret) {
5804 btrfs_abort_transaction(trans, ret);
5805 err = ret;
5806 goto out_end_trans;
5807 }
5808
5809 if (!is_reloc_root)
5810 btrfs_set_last_root_drop_gen(fs_info, trans->transid);
5811
5812 btrfs_end_transaction_throttle(trans);
5813 if (!for_reloc && btrfs_need_cleaner_sleep(fs_info)) {
5814 btrfs_debug(fs_info,
5815 "drop snapshot early exit");
5816 err = -EAGAIN;
5817 goto out_free;
5818 }
5819
5820 /*
5821 * Use join to avoid potential EINTR from transaction
5822 * start. See wait_reserve_ticket and the whole
5823 * reservation callchain.
5824 */
5825 if (for_reloc)
5826 trans = btrfs_join_transaction(tree_root);
5827 else
5828 trans = btrfs_start_transaction(tree_root, 0);
5829 if (IS_ERR(trans)) {
5830 err = PTR_ERR(trans);
5831 goto out_free;
5832 }
5833 }
5834 }
5835 btrfs_release_path(path);
5836 if (err)
5837 goto out_end_trans;
5838
5839 ret = btrfs_del_root(trans, &root->root_key);
5840 if (ret) {
5841 btrfs_abort_transaction(trans, ret);
5842 err = ret;
5843 goto out_end_trans;
5844 }
5845
5846 if (!is_reloc_root) {
5847 ret = btrfs_find_root(tree_root, &root->root_key, path,
5848 NULL, NULL);
5849 if (ret < 0) {
5850 btrfs_abort_transaction(trans, ret);
5851 err = ret;
5852 goto out_end_trans;
5853 } else if (ret > 0) {
5854 /* if we fail to delete the orphan item this time
5855 * around, it'll get picked up the next time.
5856 *
5857 * The most common failure here is just -ENOENT.
5858 */
5859 btrfs_del_orphan_item(trans, tree_root,
5860 root->root_key.objectid);
5861 }
5862 }
5863
5864 /*
5865 * This subvolume is going to be completely dropped, and won't be
5866 * recorded as dirty roots, thus pertrans meta rsv will not be freed at
5867 * commit transaction time. So free it here manually.
5868 */
5869 btrfs_qgroup_convert_reserved_meta(root, INT_MAX);
5870 btrfs_qgroup_free_meta_all_pertrans(root);
5871
5872 if (test_bit(BTRFS_ROOT_IN_RADIX, &root->state))
5873 btrfs_add_dropped_root(trans, root);
5874 else
5875 btrfs_put_root(root);
5876 root_dropped = true;
5877 out_end_trans:
5878 if (!is_reloc_root)
5879 btrfs_set_last_root_drop_gen(fs_info, trans->transid);
5880
5881 btrfs_end_transaction_throttle(trans);
5882 out_free:
5883 kfree(wc);
5884 btrfs_free_path(path);
5885 out:
5886 /*
5887 * We were an unfinished drop root, check to see if there are any
5888 * pending, and if not clear and wake up any waiters.
5889 */
5890 if (!err && unfinished_drop)
5891 btrfs_maybe_wake_unfinished_drop(fs_info);
5892
5893 /*
5894 * So if we need to stop dropping the snapshot for whatever reason we
5895 * need to make sure to add it back to the dead root list so that we
5896 * keep trying to do the work later. This also cleans up roots if we
5897 * don't have it in the radix (like when we recover after a power fail
5898 * or unmount) so we don't leak memory.
5899 */
5900 if (!for_reloc && !root_dropped)
5901 btrfs_add_dead_root(root);
5902 return err;
5903 }
5904
5905 /*
5906 * drop subtree rooted at tree block 'node'.
5907 *
5908 * NOTE: this function will unlock and release tree block 'node'
5909 * only used by relocation code
5910 */
btrfs_drop_subtree(struct btrfs_trans_handle * trans,struct btrfs_root * root,struct extent_buffer * node,struct extent_buffer * parent)5911 int btrfs_drop_subtree(struct btrfs_trans_handle *trans,
5912 struct btrfs_root *root,
5913 struct extent_buffer *node,
5914 struct extent_buffer *parent)
5915 {
5916 struct btrfs_fs_info *fs_info = root->fs_info;
5917 struct btrfs_path *path;
5918 struct walk_control *wc;
5919 int level;
5920 int parent_level;
5921 int ret = 0;
5922 int wret;
5923
5924 BUG_ON(root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID);
5925
5926 path = btrfs_alloc_path();
5927 if (!path)
5928 return -ENOMEM;
5929
5930 wc = kzalloc(sizeof(*wc), GFP_NOFS);
5931 if (!wc) {
5932 btrfs_free_path(path);
5933 return -ENOMEM;
5934 }
5935
5936 btrfs_assert_tree_write_locked(parent);
5937 parent_level = btrfs_header_level(parent);
5938 atomic_inc(&parent->refs);
5939 path->nodes[parent_level] = parent;
5940 path->slots[parent_level] = btrfs_header_nritems(parent);
5941
5942 btrfs_assert_tree_write_locked(node);
5943 level = btrfs_header_level(node);
5944 path->nodes[level] = node;
5945 path->slots[level] = 0;
5946 path->locks[level] = BTRFS_WRITE_LOCK;
5947
5948 wc->refs[parent_level] = 1;
5949 wc->flags[parent_level] = BTRFS_BLOCK_FLAG_FULL_BACKREF;
5950 wc->level = level;
5951 wc->shared_level = -1;
5952 wc->stage = DROP_REFERENCE;
5953 wc->update_ref = 0;
5954 wc->keep_locks = 1;
5955 wc->reada_count = BTRFS_NODEPTRS_PER_BLOCK(fs_info);
5956
5957 while (1) {
5958 wret = walk_down_tree(trans, root, path, wc);
5959 if (wret < 0) {
5960 ret = wret;
5961 break;
5962 }
5963
5964 wret = walk_up_tree(trans, root, path, wc, parent_level);
5965 if (wret < 0)
5966 ret = wret;
5967 if (wret != 0)
5968 break;
5969 }
5970
5971 kfree(wc);
5972 btrfs_free_path(path);
5973 return ret;
5974 }
5975
5976 /*
5977 * helper to account the unused space of all the readonly block group in the
5978 * space_info. takes mirrors into account.
5979 */
btrfs_account_ro_block_groups_free_space(struct btrfs_space_info * sinfo)5980 u64 btrfs_account_ro_block_groups_free_space(struct btrfs_space_info *sinfo)
5981 {
5982 struct btrfs_block_group *block_group;
5983 u64 free_bytes = 0;
5984 int factor;
5985
5986 /* It's df, we don't care if it's racy */
5987 if (list_empty(&sinfo->ro_bgs))
5988 return 0;
5989
5990 spin_lock(&sinfo->lock);
5991 list_for_each_entry(block_group, &sinfo->ro_bgs, ro_list) {
5992 spin_lock(&block_group->lock);
5993
5994 if (!block_group->ro) {
5995 spin_unlock(&block_group->lock);
5996 continue;
5997 }
5998
5999 factor = btrfs_bg_type_to_factor(block_group->flags);
6000 free_bytes += (block_group->length -
6001 block_group->used) * factor;
6002
6003 spin_unlock(&block_group->lock);
6004 }
6005 spin_unlock(&sinfo->lock);
6006
6007 return free_bytes;
6008 }
6009
btrfs_error_unpin_extent_range(struct btrfs_fs_info * fs_info,u64 start,u64 end)6010 int btrfs_error_unpin_extent_range(struct btrfs_fs_info *fs_info,
6011 u64 start, u64 end)
6012 {
6013 return unpin_extent_range(fs_info, start, end, false);
6014 }
6015
6016 /*
6017 * It used to be that old block groups would be left around forever.
6018 * Iterating over them would be enough to trim unused space. Since we
6019 * now automatically remove them, we also need to iterate over unallocated
6020 * space.
6021 *
6022 * We don't want a transaction for this since the discard may take a
6023 * substantial amount of time. We don't require that a transaction be
6024 * running, but we do need to take a running transaction into account
6025 * to ensure that we're not discarding chunks that were released or
6026 * allocated in the current transaction.
6027 *
6028 * Holding the chunks lock will prevent other threads from allocating
6029 * or releasing chunks, but it won't prevent a running transaction
6030 * from committing and releasing the memory that the pending chunks
6031 * list head uses. For that, we need to take a reference to the
6032 * transaction and hold the commit root sem. We only need to hold
6033 * it while performing the free space search since we have already
6034 * held back allocations.
6035 */
btrfs_trim_free_extents(struct btrfs_device * device,u64 * trimmed)6036 static int btrfs_trim_free_extents(struct btrfs_device *device, u64 *trimmed)
6037 {
6038 u64 start = BTRFS_DEVICE_RANGE_RESERVED, len = 0, end = 0;
6039 int ret;
6040
6041 *trimmed = 0;
6042
6043 /* Discard not supported = nothing to do. */
6044 if (!bdev_max_discard_sectors(device->bdev))
6045 return 0;
6046
6047 /* Not writable = nothing to do. */
6048 if (!test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state))
6049 return 0;
6050
6051 /* No free space = nothing to do. */
6052 if (device->total_bytes <= device->bytes_used)
6053 return 0;
6054
6055 ret = 0;
6056
6057 while (1) {
6058 struct btrfs_fs_info *fs_info = device->fs_info;
6059 u64 bytes;
6060
6061 ret = mutex_lock_interruptible(&fs_info->chunk_mutex);
6062 if (ret)
6063 break;
6064
6065 find_first_clear_extent_bit(&device->alloc_state, start,
6066 &start, &end,
6067 CHUNK_TRIMMED | CHUNK_ALLOCATED);
6068
6069 /* Check if there are any CHUNK_* bits left */
6070 if (start > device->total_bytes) {
6071 WARN_ON(IS_ENABLED(CONFIG_BTRFS_DEBUG));
6072 btrfs_warn_in_rcu(fs_info,
6073 "ignoring attempt to trim beyond device size: offset %llu length %llu device %s device size %llu",
6074 start, end - start + 1,
6075 rcu_str_deref(device->name),
6076 device->total_bytes);
6077 mutex_unlock(&fs_info->chunk_mutex);
6078 ret = 0;
6079 break;
6080 }
6081
6082 /* Ensure we skip the reserved space on each device. */
6083 start = max_t(u64, start, BTRFS_DEVICE_RANGE_RESERVED);
6084
6085 /*
6086 * If find_first_clear_extent_bit find a range that spans the
6087 * end of the device it will set end to -1, in this case it's up
6088 * to the caller to trim the value to the size of the device.
6089 */
6090 end = min(end, device->total_bytes - 1);
6091
6092 len = end - start + 1;
6093
6094 /* We didn't find any extents */
6095 if (!len) {
6096 mutex_unlock(&fs_info->chunk_mutex);
6097 ret = 0;
6098 break;
6099 }
6100
6101 ret = btrfs_issue_discard(device->bdev, start, len,
6102 &bytes);
6103 if (!ret)
6104 set_extent_bits(&device->alloc_state, start,
6105 start + bytes - 1,
6106 CHUNK_TRIMMED);
6107 mutex_unlock(&fs_info->chunk_mutex);
6108
6109 if (ret)
6110 break;
6111
6112 start += len;
6113 *trimmed += bytes;
6114
6115 if (fatal_signal_pending(current)) {
6116 ret = -ERESTARTSYS;
6117 break;
6118 }
6119
6120 cond_resched();
6121 }
6122
6123 return ret;
6124 }
6125
6126 /*
6127 * Trim the whole filesystem by:
6128 * 1) trimming the free space in each block group
6129 * 2) trimming the unallocated space on each device
6130 *
6131 * This will also continue trimming even if a block group or device encounters
6132 * an error. The return value will be the last error, or 0 if nothing bad
6133 * happens.
6134 */
btrfs_trim_fs(struct btrfs_fs_info * fs_info,struct fstrim_range * range)6135 int btrfs_trim_fs(struct btrfs_fs_info *fs_info, struct fstrim_range *range)
6136 {
6137 struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
6138 struct btrfs_block_group *cache = NULL;
6139 struct btrfs_device *device;
6140 u64 group_trimmed;
6141 u64 range_end = U64_MAX;
6142 u64 start;
6143 u64 end;
6144 u64 trimmed = 0;
6145 u64 bg_failed = 0;
6146 u64 dev_failed = 0;
6147 int bg_ret = 0;
6148 int dev_ret = 0;
6149 int ret = 0;
6150
6151 if (range->start == U64_MAX)
6152 return -EINVAL;
6153
6154 /*
6155 * Check range overflow if range->len is set.
6156 * The default range->len is U64_MAX.
6157 */
6158 if (range->len != U64_MAX &&
6159 check_add_overflow(range->start, range->len, &range_end))
6160 return -EINVAL;
6161
6162 cache = btrfs_lookup_first_block_group(fs_info, range->start);
6163 for (; cache; cache = btrfs_next_block_group(cache)) {
6164 if (cache->start >= range_end) {
6165 btrfs_put_block_group(cache);
6166 break;
6167 }
6168
6169 start = max(range->start, cache->start);
6170 end = min(range_end, cache->start + cache->length);
6171
6172 if (end - start >= range->minlen) {
6173 if (!btrfs_block_group_done(cache)) {
6174 ret = btrfs_cache_block_group(cache, true);
6175 if (ret) {
6176 bg_failed++;
6177 bg_ret = ret;
6178 continue;
6179 }
6180 }
6181 ret = btrfs_trim_block_group(cache,
6182 &group_trimmed,
6183 start,
6184 end,
6185 range->minlen);
6186
6187 trimmed += group_trimmed;
6188 if (ret) {
6189 bg_failed++;
6190 bg_ret = ret;
6191 continue;
6192 }
6193 }
6194 }
6195
6196 if (bg_failed)
6197 btrfs_warn(fs_info,
6198 "failed to trim %llu block group(s), last error %d",
6199 bg_failed, bg_ret);
6200
6201 mutex_lock(&fs_devices->device_list_mutex);
6202 list_for_each_entry(device, &fs_devices->devices, dev_list) {
6203 if (test_bit(BTRFS_DEV_STATE_MISSING, &device->dev_state))
6204 continue;
6205
6206 ret = btrfs_trim_free_extents(device, &group_trimmed);
6207 if (ret) {
6208 dev_failed++;
6209 dev_ret = ret;
6210 break;
6211 }
6212
6213 trimmed += group_trimmed;
6214 }
6215 mutex_unlock(&fs_devices->device_list_mutex);
6216
6217 if (dev_failed)
6218 btrfs_warn(fs_info,
6219 "failed to trim %llu device(s), last error %d",
6220 dev_failed, dev_ret);
6221 range->len = trimmed;
6222 if (bg_ret)
6223 return bg_ret;
6224 return dev_ret;
6225 }
6226