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 int ret;
91 struct btrfs_key key;
92 struct btrfs_path *path;
93
94 path = btrfs_alloc_path();
95 if (!path)
96 return -ENOMEM;
97
98 key.objectid = start;
99 key.offset = len;
100 key.type = BTRFS_EXTENT_ITEM_KEY;
101 ret = btrfs_search_slot(NULL, fs_info->extent_root, &key, path, 0, 0);
102 btrfs_free_path(path);
103 return ret;
104 }
105
106 /*
107 * helper function to lookup reference count and flags of a tree block.
108 *
109 * the head node for delayed ref is used to store the sum of all the
110 * reference count modifications queued up in the rbtree. the head
111 * node may also store the extent flags to set. This way you can check
112 * to see what the reference count and extent flags would be if all of
113 * the delayed refs are not processed.
114 */
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)115 int btrfs_lookup_extent_info(struct btrfs_trans_handle *trans,
116 struct btrfs_fs_info *fs_info, u64 bytenr,
117 u64 offset, int metadata, u64 *refs, u64 *flags)
118 {
119 struct btrfs_delayed_ref_head *head;
120 struct btrfs_delayed_ref_root *delayed_refs;
121 struct btrfs_path *path;
122 struct btrfs_extent_item *ei;
123 struct extent_buffer *leaf;
124 struct btrfs_key key;
125 u32 item_size;
126 u64 num_refs;
127 u64 extent_flags;
128 int ret;
129
130 /*
131 * If we don't have skinny metadata, don't bother doing anything
132 * different
133 */
134 if (metadata && !btrfs_fs_incompat(fs_info, SKINNY_METADATA)) {
135 offset = fs_info->nodesize;
136 metadata = 0;
137 }
138
139 path = btrfs_alloc_path();
140 if (!path)
141 return -ENOMEM;
142
143 if (!trans) {
144 path->skip_locking = 1;
145 path->search_commit_root = 1;
146 }
147
148 search_again:
149 key.objectid = bytenr;
150 key.offset = offset;
151 if (metadata)
152 key.type = BTRFS_METADATA_ITEM_KEY;
153 else
154 key.type = BTRFS_EXTENT_ITEM_KEY;
155
156 ret = btrfs_search_slot(trans, fs_info->extent_root, &key, path, 0, 0);
157 if (ret < 0)
158 goto out_free;
159
160 if (ret > 0 && metadata && key.type == BTRFS_METADATA_ITEM_KEY) {
161 if (path->slots[0]) {
162 path->slots[0]--;
163 btrfs_item_key_to_cpu(path->nodes[0], &key,
164 path->slots[0]);
165 if (key.objectid == bytenr &&
166 key.type == BTRFS_EXTENT_ITEM_KEY &&
167 key.offset == fs_info->nodesize)
168 ret = 0;
169 }
170 }
171
172 if (ret == 0) {
173 leaf = path->nodes[0];
174 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
175 if (item_size >= sizeof(*ei)) {
176 ei = btrfs_item_ptr(leaf, path->slots[0],
177 struct btrfs_extent_item);
178 num_refs = btrfs_extent_refs(leaf, ei);
179 extent_flags = btrfs_extent_flags(leaf, ei);
180 } else {
181 ret = -EINVAL;
182 btrfs_print_v0_err(fs_info);
183 if (trans)
184 btrfs_abort_transaction(trans, ret);
185 else
186 btrfs_handle_fs_error(fs_info, ret, NULL);
187
188 goto out_free;
189 }
190
191 BUG_ON(num_refs == 0);
192 } else {
193 num_refs = 0;
194 extent_flags = 0;
195 ret = 0;
196 }
197
198 if (!trans)
199 goto out;
200
201 delayed_refs = &trans->transaction->delayed_refs;
202 spin_lock(&delayed_refs->lock);
203 head = btrfs_find_delayed_ref_head(delayed_refs, bytenr);
204 if (head) {
205 if (!mutex_trylock(&head->mutex)) {
206 refcount_inc(&head->refs);
207 spin_unlock(&delayed_refs->lock);
208
209 btrfs_release_path(path);
210
211 /*
212 * Mutex was contended, block until it's released and try
213 * again
214 */
215 mutex_lock(&head->mutex);
216 mutex_unlock(&head->mutex);
217 btrfs_put_delayed_ref_head(head);
218 goto search_again;
219 }
220 spin_lock(&head->lock);
221 if (head->extent_op && head->extent_op->update_flags)
222 extent_flags |= head->extent_op->flags_to_set;
223 else
224 BUG_ON(num_refs == 0);
225
226 num_refs += head->ref_mod;
227 spin_unlock(&head->lock);
228 mutex_unlock(&head->mutex);
229 }
230 spin_unlock(&delayed_refs->lock);
231 out:
232 WARN_ON(num_refs == 0);
233 if (refs)
234 *refs = num_refs;
235 if (flags)
236 *flags = extent_flags;
237 out_free:
238 btrfs_free_path(path);
239 return ret;
240 }
241
242 /*
243 * Back reference rules. Back refs have three main goals:
244 *
245 * 1) differentiate between all holders of references to an extent so that
246 * when a reference is dropped we can make sure it was a valid reference
247 * before freeing the extent.
248 *
249 * 2) Provide enough information to quickly find the holders of an extent
250 * if we notice a given block is corrupted or bad.
251 *
252 * 3) Make it easy to migrate blocks for FS shrinking or storage pool
253 * maintenance. This is actually the same as #2, but with a slightly
254 * different use case.
255 *
256 * There are two kinds of back refs. The implicit back refs is optimized
257 * for pointers in non-shared tree blocks. For a given pointer in a block,
258 * back refs of this kind provide information about the block's owner tree
259 * and the pointer's key. These information allow us to find the block by
260 * b-tree searching. The full back refs is for pointers in tree blocks not
261 * referenced by their owner trees. The location of tree block is recorded
262 * in the back refs. Actually the full back refs is generic, and can be
263 * used in all cases the implicit back refs is used. The major shortcoming
264 * of the full back refs is its overhead. Every time a tree block gets
265 * COWed, we have to update back refs entry for all pointers in it.
266 *
267 * For a newly allocated tree block, we use implicit back refs for
268 * pointers in it. This means most tree related operations only involve
269 * implicit back refs. For a tree block created in old transaction, the
270 * only way to drop a reference to it is COW it. So we can detect the
271 * event that tree block loses its owner tree's reference and do the
272 * back refs conversion.
273 *
274 * When a tree block is COWed through a tree, there are four cases:
275 *
276 * The reference count of the block is one and the tree is the block's
277 * owner tree. Nothing to do in this case.
278 *
279 * The reference count of the block is one and the tree is not the
280 * block's owner tree. In this case, full back refs is used for pointers
281 * in the block. Remove these full back refs, add implicit back refs for
282 * every pointers in the new block.
283 *
284 * The reference count of the block is greater than one and the tree is
285 * the block's owner tree. In this case, implicit back refs is used for
286 * pointers in the block. Add full back refs for every pointers in the
287 * block, increase lower level extents' reference counts. The original
288 * implicit back refs are entailed to the new block.
289 *
290 * The reference count of the block is greater than one and the tree is
291 * not the block's owner tree. Add implicit back refs for every pointer in
292 * the new block, increase lower level extents' reference count.
293 *
294 * Back Reference Key composing:
295 *
296 * The key objectid corresponds to the first byte in the extent,
297 * The key type is used to differentiate between types of back refs.
298 * There are different meanings of the key offset for different types
299 * of back refs.
300 *
301 * File extents can be referenced by:
302 *
303 * - multiple snapshots, subvolumes, or different generations in one subvol
304 * - different files inside a single subvolume
305 * - different offsets inside a file (bookend extents in file.c)
306 *
307 * The extent ref structure for the implicit back refs has fields for:
308 *
309 * - Objectid of the subvolume root
310 * - objectid of the file holding the reference
311 * - original offset in the file
312 * - how many bookend extents
313 *
314 * The key offset for the implicit back refs is hash of the first
315 * three fields.
316 *
317 * The extent ref structure for the full back refs has field for:
318 *
319 * - number of pointers in the tree leaf
320 *
321 * The key offset for the implicit back refs is the first byte of
322 * the tree leaf
323 *
324 * When a file extent is allocated, The implicit back refs is used.
325 * the fields are filled in:
326 *
327 * (root_key.objectid, inode objectid, offset in file, 1)
328 *
329 * When a file extent is removed file truncation, we find the
330 * corresponding implicit back refs and check the following fields:
331 *
332 * (btrfs_header_owner(leaf), inode objectid, offset in file)
333 *
334 * Btree extents can be referenced by:
335 *
336 * - Different subvolumes
337 *
338 * Both the implicit back refs and the full back refs for tree blocks
339 * only consist of key. The key offset for the implicit back refs is
340 * objectid of block's owner tree. The key offset for the full back refs
341 * is the first byte of parent block.
342 *
343 * When implicit back refs is used, information about the lowest key and
344 * level of the tree block are required. These information are stored in
345 * tree block info structure.
346 */
347
348 /*
349 * is_data == BTRFS_REF_TYPE_BLOCK, tree block type is required,
350 * is_data == BTRFS_REF_TYPE_DATA, data type is requiried,
351 * is_data == BTRFS_REF_TYPE_ANY, either type is OK.
352 */
btrfs_get_extent_inline_ref_type(const struct extent_buffer * eb,struct btrfs_extent_inline_ref * iref,enum btrfs_inline_ref_type is_data)353 int btrfs_get_extent_inline_ref_type(const struct extent_buffer *eb,
354 struct btrfs_extent_inline_ref *iref,
355 enum btrfs_inline_ref_type is_data)
356 {
357 int type = btrfs_extent_inline_ref_type(eb, iref);
358 u64 offset = btrfs_extent_inline_ref_offset(eb, iref);
359
360 if (type == BTRFS_TREE_BLOCK_REF_KEY ||
361 type == BTRFS_SHARED_BLOCK_REF_KEY ||
362 type == BTRFS_SHARED_DATA_REF_KEY ||
363 type == BTRFS_EXTENT_DATA_REF_KEY) {
364 if (is_data == BTRFS_REF_TYPE_BLOCK) {
365 if (type == BTRFS_TREE_BLOCK_REF_KEY)
366 return type;
367 if (type == BTRFS_SHARED_BLOCK_REF_KEY) {
368 ASSERT(eb->fs_info);
369 /*
370 * Every shared one has parent tree block,
371 * which must be aligned to sector size.
372 */
373 if (offset &&
374 IS_ALIGNED(offset, eb->fs_info->sectorsize))
375 return type;
376 }
377 } else if (is_data == BTRFS_REF_TYPE_DATA) {
378 if (type == BTRFS_EXTENT_DATA_REF_KEY)
379 return type;
380 if (type == BTRFS_SHARED_DATA_REF_KEY) {
381 ASSERT(eb->fs_info);
382 /*
383 * Every shared one has parent tree block,
384 * which must be aligned to sector size.
385 */
386 if (offset &&
387 IS_ALIGNED(offset, eb->fs_info->sectorsize))
388 return type;
389 }
390 } else {
391 ASSERT(is_data == BTRFS_REF_TYPE_ANY);
392 return type;
393 }
394 }
395
396 btrfs_print_leaf((struct extent_buffer *)eb);
397 btrfs_err(eb->fs_info,
398 "eb %llu iref 0x%lx invalid extent inline ref type %d",
399 eb->start, (unsigned long)iref, type);
400 WARN_ON(1);
401
402 return BTRFS_REF_TYPE_INVALID;
403 }
404
hash_extent_data_ref(u64 root_objectid,u64 owner,u64 offset)405 u64 hash_extent_data_ref(u64 root_objectid, u64 owner, u64 offset)
406 {
407 u32 high_crc = ~(u32)0;
408 u32 low_crc = ~(u32)0;
409 __le64 lenum;
410
411 lenum = cpu_to_le64(root_objectid);
412 high_crc = btrfs_crc32c(high_crc, &lenum, sizeof(lenum));
413 lenum = cpu_to_le64(owner);
414 low_crc = btrfs_crc32c(low_crc, &lenum, sizeof(lenum));
415 lenum = cpu_to_le64(offset);
416 low_crc = btrfs_crc32c(low_crc, &lenum, sizeof(lenum));
417
418 return ((u64)high_crc << 31) ^ (u64)low_crc;
419 }
420
hash_extent_data_ref_item(struct extent_buffer * leaf,struct btrfs_extent_data_ref * ref)421 static u64 hash_extent_data_ref_item(struct extent_buffer *leaf,
422 struct btrfs_extent_data_ref *ref)
423 {
424 return hash_extent_data_ref(btrfs_extent_data_ref_root(leaf, ref),
425 btrfs_extent_data_ref_objectid(leaf, ref),
426 btrfs_extent_data_ref_offset(leaf, ref));
427 }
428
match_extent_data_ref(struct extent_buffer * leaf,struct btrfs_extent_data_ref * ref,u64 root_objectid,u64 owner,u64 offset)429 static int match_extent_data_ref(struct extent_buffer *leaf,
430 struct btrfs_extent_data_ref *ref,
431 u64 root_objectid, u64 owner, u64 offset)
432 {
433 if (btrfs_extent_data_ref_root(leaf, ref) != root_objectid ||
434 btrfs_extent_data_ref_objectid(leaf, ref) != owner ||
435 btrfs_extent_data_ref_offset(leaf, ref) != offset)
436 return 0;
437 return 1;
438 }
439
lookup_extent_data_ref(struct btrfs_trans_handle * trans,struct btrfs_path * path,u64 bytenr,u64 parent,u64 root_objectid,u64 owner,u64 offset)440 static noinline int lookup_extent_data_ref(struct btrfs_trans_handle *trans,
441 struct btrfs_path *path,
442 u64 bytenr, u64 parent,
443 u64 root_objectid,
444 u64 owner, u64 offset)
445 {
446 struct btrfs_root *root = trans->fs_info->extent_root;
447 struct btrfs_key key;
448 struct btrfs_extent_data_ref *ref;
449 struct extent_buffer *leaf;
450 u32 nritems;
451 int ret;
452 int recow;
453 int err = -ENOENT;
454
455 key.objectid = bytenr;
456 if (parent) {
457 key.type = BTRFS_SHARED_DATA_REF_KEY;
458 key.offset = parent;
459 } else {
460 key.type = BTRFS_EXTENT_DATA_REF_KEY;
461 key.offset = hash_extent_data_ref(root_objectid,
462 owner, offset);
463 }
464 again:
465 recow = 0;
466 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
467 if (ret < 0) {
468 err = ret;
469 goto fail;
470 }
471
472 if (parent) {
473 if (!ret)
474 return 0;
475 goto fail;
476 }
477
478 leaf = path->nodes[0];
479 nritems = btrfs_header_nritems(leaf);
480 while (1) {
481 if (path->slots[0] >= nritems) {
482 ret = btrfs_next_leaf(root, path);
483 if (ret < 0)
484 err = ret;
485 if (ret)
486 goto fail;
487
488 leaf = path->nodes[0];
489 nritems = btrfs_header_nritems(leaf);
490 recow = 1;
491 }
492
493 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
494 if (key.objectid != bytenr ||
495 key.type != BTRFS_EXTENT_DATA_REF_KEY)
496 goto fail;
497
498 ref = btrfs_item_ptr(leaf, path->slots[0],
499 struct btrfs_extent_data_ref);
500
501 if (match_extent_data_ref(leaf, ref, root_objectid,
502 owner, offset)) {
503 if (recow) {
504 btrfs_release_path(path);
505 goto again;
506 }
507 err = 0;
508 break;
509 }
510 path->slots[0]++;
511 }
512 fail:
513 return err;
514 }
515
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)516 static noinline int insert_extent_data_ref(struct btrfs_trans_handle *trans,
517 struct btrfs_path *path,
518 u64 bytenr, u64 parent,
519 u64 root_objectid, u64 owner,
520 u64 offset, int refs_to_add)
521 {
522 struct btrfs_root *root = trans->fs_info->extent_root;
523 struct btrfs_key key;
524 struct extent_buffer *leaf;
525 u32 size;
526 u32 num_refs;
527 int ret;
528
529 key.objectid = bytenr;
530 if (parent) {
531 key.type = BTRFS_SHARED_DATA_REF_KEY;
532 key.offset = parent;
533 size = sizeof(struct btrfs_shared_data_ref);
534 } else {
535 key.type = BTRFS_EXTENT_DATA_REF_KEY;
536 key.offset = hash_extent_data_ref(root_objectid,
537 owner, offset);
538 size = sizeof(struct btrfs_extent_data_ref);
539 }
540
541 ret = btrfs_insert_empty_item(trans, root, path, &key, size);
542 if (ret && ret != -EEXIST)
543 goto fail;
544
545 leaf = path->nodes[0];
546 if (parent) {
547 struct btrfs_shared_data_ref *ref;
548 ref = btrfs_item_ptr(leaf, path->slots[0],
549 struct btrfs_shared_data_ref);
550 if (ret == 0) {
551 btrfs_set_shared_data_ref_count(leaf, ref, refs_to_add);
552 } else {
553 num_refs = btrfs_shared_data_ref_count(leaf, ref);
554 num_refs += refs_to_add;
555 btrfs_set_shared_data_ref_count(leaf, ref, num_refs);
556 }
557 } else {
558 struct btrfs_extent_data_ref *ref;
559 while (ret == -EEXIST) {
560 ref = btrfs_item_ptr(leaf, path->slots[0],
561 struct btrfs_extent_data_ref);
562 if (match_extent_data_ref(leaf, ref, root_objectid,
563 owner, offset))
564 break;
565 btrfs_release_path(path);
566 key.offset++;
567 ret = btrfs_insert_empty_item(trans, root, path, &key,
568 size);
569 if (ret && ret != -EEXIST)
570 goto fail;
571
572 leaf = path->nodes[0];
573 }
574 ref = btrfs_item_ptr(leaf, path->slots[0],
575 struct btrfs_extent_data_ref);
576 if (ret == 0) {
577 btrfs_set_extent_data_ref_root(leaf, ref,
578 root_objectid);
579 btrfs_set_extent_data_ref_objectid(leaf, ref, owner);
580 btrfs_set_extent_data_ref_offset(leaf, ref, offset);
581 btrfs_set_extent_data_ref_count(leaf, ref, refs_to_add);
582 } else {
583 num_refs = btrfs_extent_data_ref_count(leaf, ref);
584 num_refs += refs_to_add;
585 btrfs_set_extent_data_ref_count(leaf, ref, num_refs);
586 }
587 }
588 btrfs_mark_buffer_dirty(leaf);
589 ret = 0;
590 fail:
591 btrfs_release_path(path);
592 return ret;
593 }
594
remove_extent_data_ref(struct btrfs_trans_handle * trans,struct btrfs_path * path,int refs_to_drop,int * last_ref)595 static noinline int remove_extent_data_ref(struct btrfs_trans_handle *trans,
596 struct btrfs_path *path,
597 int refs_to_drop, int *last_ref)
598 {
599 struct btrfs_key key;
600 struct btrfs_extent_data_ref *ref1 = NULL;
601 struct btrfs_shared_data_ref *ref2 = NULL;
602 struct extent_buffer *leaf;
603 u32 num_refs = 0;
604 int ret = 0;
605
606 leaf = path->nodes[0];
607 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
608
609 if (key.type == BTRFS_EXTENT_DATA_REF_KEY) {
610 ref1 = btrfs_item_ptr(leaf, path->slots[0],
611 struct btrfs_extent_data_ref);
612 num_refs = btrfs_extent_data_ref_count(leaf, ref1);
613 } else if (key.type == BTRFS_SHARED_DATA_REF_KEY) {
614 ref2 = btrfs_item_ptr(leaf, path->slots[0],
615 struct btrfs_shared_data_ref);
616 num_refs = btrfs_shared_data_ref_count(leaf, ref2);
617 } else if (unlikely(key.type == BTRFS_EXTENT_REF_V0_KEY)) {
618 btrfs_print_v0_err(trans->fs_info);
619 btrfs_abort_transaction(trans, -EINVAL);
620 return -EINVAL;
621 } else {
622 BUG();
623 }
624
625 BUG_ON(num_refs < refs_to_drop);
626 num_refs -= refs_to_drop;
627
628 if (num_refs == 0) {
629 ret = btrfs_del_item(trans, trans->fs_info->extent_root, path);
630 *last_ref = 1;
631 } else {
632 if (key.type == BTRFS_EXTENT_DATA_REF_KEY)
633 btrfs_set_extent_data_ref_count(leaf, ref1, num_refs);
634 else if (key.type == BTRFS_SHARED_DATA_REF_KEY)
635 btrfs_set_shared_data_ref_count(leaf, ref2, num_refs);
636 btrfs_mark_buffer_dirty(leaf);
637 }
638 return ret;
639 }
640
extent_data_ref_count(struct btrfs_path * path,struct btrfs_extent_inline_ref * iref)641 static noinline u32 extent_data_ref_count(struct btrfs_path *path,
642 struct btrfs_extent_inline_ref *iref)
643 {
644 struct btrfs_key key;
645 struct extent_buffer *leaf;
646 struct btrfs_extent_data_ref *ref1;
647 struct btrfs_shared_data_ref *ref2;
648 u32 num_refs = 0;
649 int type;
650
651 leaf = path->nodes[0];
652 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
653
654 BUG_ON(key.type == BTRFS_EXTENT_REF_V0_KEY);
655 if (iref) {
656 /*
657 * If type is invalid, we should have bailed out earlier than
658 * this call.
659 */
660 type = btrfs_get_extent_inline_ref_type(leaf, iref, BTRFS_REF_TYPE_DATA);
661 ASSERT(type != BTRFS_REF_TYPE_INVALID);
662 if (type == BTRFS_EXTENT_DATA_REF_KEY) {
663 ref1 = (struct btrfs_extent_data_ref *)(&iref->offset);
664 num_refs = btrfs_extent_data_ref_count(leaf, ref1);
665 } else {
666 ref2 = (struct btrfs_shared_data_ref *)(iref + 1);
667 num_refs = btrfs_shared_data_ref_count(leaf, ref2);
668 }
669 } else if (key.type == BTRFS_EXTENT_DATA_REF_KEY) {
670 ref1 = btrfs_item_ptr(leaf, path->slots[0],
671 struct btrfs_extent_data_ref);
672 num_refs = btrfs_extent_data_ref_count(leaf, ref1);
673 } else if (key.type == BTRFS_SHARED_DATA_REF_KEY) {
674 ref2 = btrfs_item_ptr(leaf, path->slots[0],
675 struct btrfs_shared_data_ref);
676 num_refs = btrfs_shared_data_ref_count(leaf, ref2);
677 } else {
678 WARN_ON(1);
679 }
680 return num_refs;
681 }
682
lookup_tree_block_ref(struct btrfs_trans_handle * trans,struct btrfs_path * path,u64 bytenr,u64 parent,u64 root_objectid)683 static noinline int lookup_tree_block_ref(struct btrfs_trans_handle *trans,
684 struct btrfs_path *path,
685 u64 bytenr, u64 parent,
686 u64 root_objectid)
687 {
688 struct btrfs_root *root = trans->fs_info->extent_root;
689 struct btrfs_key key;
690 int ret;
691
692 key.objectid = bytenr;
693 if (parent) {
694 key.type = BTRFS_SHARED_BLOCK_REF_KEY;
695 key.offset = parent;
696 } else {
697 key.type = BTRFS_TREE_BLOCK_REF_KEY;
698 key.offset = root_objectid;
699 }
700
701 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
702 if (ret > 0)
703 ret = -ENOENT;
704 return ret;
705 }
706
insert_tree_block_ref(struct btrfs_trans_handle * trans,struct btrfs_path * path,u64 bytenr,u64 parent,u64 root_objectid)707 static noinline int insert_tree_block_ref(struct btrfs_trans_handle *trans,
708 struct btrfs_path *path,
709 u64 bytenr, u64 parent,
710 u64 root_objectid)
711 {
712 struct btrfs_key key;
713 int ret;
714
715 key.objectid = bytenr;
716 if (parent) {
717 key.type = BTRFS_SHARED_BLOCK_REF_KEY;
718 key.offset = parent;
719 } else {
720 key.type = BTRFS_TREE_BLOCK_REF_KEY;
721 key.offset = root_objectid;
722 }
723
724 ret = btrfs_insert_empty_item(trans, trans->fs_info->extent_root,
725 path, &key, 0);
726 btrfs_release_path(path);
727 return ret;
728 }
729
extent_ref_type(u64 parent,u64 owner)730 static inline int extent_ref_type(u64 parent, u64 owner)
731 {
732 int type;
733 if (owner < BTRFS_FIRST_FREE_OBJECTID) {
734 if (parent > 0)
735 type = BTRFS_SHARED_BLOCK_REF_KEY;
736 else
737 type = BTRFS_TREE_BLOCK_REF_KEY;
738 } else {
739 if (parent > 0)
740 type = BTRFS_SHARED_DATA_REF_KEY;
741 else
742 type = BTRFS_EXTENT_DATA_REF_KEY;
743 }
744 return type;
745 }
746
find_next_key(struct btrfs_path * path,int level,struct btrfs_key * key)747 static int find_next_key(struct btrfs_path *path, int level,
748 struct btrfs_key *key)
749
750 {
751 for (; level < BTRFS_MAX_LEVEL; level++) {
752 if (!path->nodes[level])
753 break;
754 if (path->slots[level] + 1 >=
755 btrfs_header_nritems(path->nodes[level]))
756 continue;
757 if (level == 0)
758 btrfs_item_key_to_cpu(path->nodes[level], key,
759 path->slots[level] + 1);
760 else
761 btrfs_node_key_to_cpu(path->nodes[level], key,
762 path->slots[level] + 1);
763 return 0;
764 }
765 return 1;
766 }
767
768 /*
769 * look for inline back ref. if back ref is found, *ref_ret is set
770 * to the address of inline back ref, and 0 is returned.
771 *
772 * if back ref isn't found, *ref_ret is set to the address where it
773 * should be inserted, and -ENOENT is returned.
774 *
775 * if insert is true and there are too many inline back refs, the path
776 * points to the extent item, and -EAGAIN is returned.
777 *
778 * NOTE: inline back refs are ordered in the same way that back ref
779 * items in the tree are ordered.
780 */
781 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)782 int lookup_inline_extent_backref(struct btrfs_trans_handle *trans,
783 struct btrfs_path *path,
784 struct btrfs_extent_inline_ref **ref_ret,
785 u64 bytenr, u64 num_bytes,
786 u64 parent, u64 root_objectid,
787 u64 owner, u64 offset, int insert)
788 {
789 struct btrfs_fs_info *fs_info = trans->fs_info;
790 struct btrfs_root *root = fs_info->extent_root;
791 struct btrfs_key key;
792 struct extent_buffer *leaf;
793 struct btrfs_extent_item *ei;
794 struct btrfs_extent_inline_ref *iref;
795 u64 flags;
796 u64 item_size;
797 unsigned long ptr;
798 unsigned long end;
799 int extra_size;
800 int type;
801 int want;
802 int ret;
803 int err = 0;
804 bool skinny_metadata = btrfs_fs_incompat(fs_info, SKINNY_METADATA);
805 int needed;
806
807 key.objectid = bytenr;
808 key.type = BTRFS_EXTENT_ITEM_KEY;
809 key.offset = num_bytes;
810
811 want = extent_ref_type(parent, owner);
812 if (insert) {
813 extra_size = btrfs_extent_inline_ref_size(want);
814 path->search_for_extension = 1;
815 path->keep_locks = 1;
816 } else
817 extra_size = -1;
818
819 /*
820 * Owner is our level, so we can just add one to get the level for the
821 * block we are interested in.
822 */
823 if (skinny_metadata && owner < BTRFS_FIRST_FREE_OBJECTID) {
824 key.type = BTRFS_METADATA_ITEM_KEY;
825 key.offset = owner;
826 }
827
828 again:
829 ret = btrfs_search_slot(trans, root, &key, path, extra_size, 1);
830 if (ret < 0) {
831 err = ret;
832 goto out;
833 }
834
835 /*
836 * We may be a newly converted file system which still has the old fat
837 * extent entries for metadata, so try and see if we have one of those.
838 */
839 if (ret > 0 && skinny_metadata) {
840 skinny_metadata = false;
841 if (path->slots[0]) {
842 path->slots[0]--;
843 btrfs_item_key_to_cpu(path->nodes[0], &key,
844 path->slots[0]);
845 if (key.objectid == bytenr &&
846 key.type == BTRFS_EXTENT_ITEM_KEY &&
847 key.offset == num_bytes)
848 ret = 0;
849 }
850 if (ret) {
851 key.objectid = bytenr;
852 key.type = BTRFS_EXTENT_ITEM_KEY;
853 key.offset = num_bytes;
854 btrfs_release_path(path);
855 goto again;
856 }
857 }
858
859 if (ret && !insert) {
860 err = -ENOENT;
861 goto out;
862 } else if (WARN_ON(ret)) {
863 err = -EIO;
864 goto out;
865 }
866
867 leaf = path->nodes[0];
868 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
869 if (unlikely(item_size < sizeof(*ei))) {
870 err = -EINVAL;
871 btrfs_print_v0_err(fs_info);
872 btrfs_abort_transaction(trans, err);
873 goto out;
874 }
875
876 ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
877 flags = btrfs_extent_flags(leaf, ei);
878
879 ptr = (unsigned long)(ei + 1);
880 end = (unsigned long)ei + item_size;
881
882 if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK && !skinny_metadata) {
883 ptr += sizeof(struct btrfs_tree_block_info);
884 BUG_ON(ptr > end);
885 }
886
887 if (owner >= BTRFS_FIRST_FREE_OBJECTID)
888 needed = BTRFS_REF_TYPE_DATA;
889 else
890 needed = BTRFS_REF_TYPE_BLOCK;
891
892 err = -ENOENT;
893 while (1) {
894 if (ptr >= end) {
895 WARN_ON(ptr > end);
896 break;
897 }
898 iref = (struct btrfs_extent_inline_ref *)ptr;
899 type = btrfs_get_extent_inline_ref_type(leaf, iref, needed);
900 if (type == BTRFS_REF_TYPE_INVALID) {
901 err = -EUCLEAN;
902 goto out;
903 }
904
905 if (want < type)
906 break;
907 if (want > type) {
908 ptr += btrfs_extent_inline_ref_size(type);
909 continue;
910 }
911
912 if (type == BTRFS_EXTENT_DATA_REF_KEY) {
913 struct btrfs_extent_data_ref *dref;
914 dref = (struct btrfs_extent_data_ref *)(&iref->offset);
915 if (match_extent_data_ref(leaf, dref, root_objectid,
916 owner, offset)) {
917 err = 0;
918 break;
919 }
920 if (hash_extent_data_ref_item(leaf, dref) <
921 hash_extent_data_ref(root_objectid, owner, offset))
922 break;
923 } else {
924 u64 ref_offset;
925 ref_offset = btrfs_extent_inline_ref_offset(leaf, iref);
926 if (parent > 0) {
927 if (parent == ref_offset) {
928 err = 0;
929 break;
930 }
931 if (ref_offset < parent)
932 break;
933 } else {
934 if (root_objectid == ref_offset) {
935 err = 0;
936 break;
937 }
938 if (ref_offset < root_objectid)
939 break;
940 }
941 }
942 ptr += btrfs_extent_inline_ref_size(type);
943 }
944 if (err == -ENOENT && insert) {
945 if (item_size + extra_size >=
946 BTRFS_MAX_EXTENT_ITEM_SIZE(root)) {
947 err = -EAGAIN;
948 goto out;
949 }
950 /*
951 * To add new inline back ref, we have to make sure
952 * there is no corresponding back ref item.
953 * For simplicity, we just do not add new inline back
954 * ref if there is any kind of item for this block
955 */
956 if (find_next_key(path, 0, &key) == 0 &&
957 key.objectid == bytenr &&
958 key.type < BTRFS_BLOCK_GROUP_ITEM_KEY) {
959 err = -EAGAIN;
960 goto out;
961 }
962 }
963 *ref_ret = (struct btrfs_extent_inline_ref *)ptr;
964 out:
965 if (insert) {
966 path->keep_locks = 0;
967 path->search_for_extension = 0;
968 btrfs_unlock_up_safe(path, 1);
969 }
970 return err;
971 }
972
973 /*
974 * helper to add new inline back ref
975 */
976 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)977 void setup_inline_extent_backref(struct btrfs_fs_info *fs_info,
978 struct btrfs_path *path,
979 struct btrfs_extent_inline_ref *iref,
980 u64 parent, u64 root_objectid,
981 u64 owner, u64 offset, int refs_to_add,
982 struct btrfs_delayed_extent_op *extent_op)
983 {
984 struct extent_buffer *leaf;
985 struct btrfs_extent_item *ei;
986 unsigned long ptr;
987 unsigned long end;
988 unsigned long item_offset;
989 u64 refs;
990 int size;
991 int type;
992
993 leaf = path->nodes[0];
994 ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
995 item_offset = (unsigned long)iref - (unsigned long)ei;
996
997 type = extent_ref_type(parent, owner);
998 size = btrfs_extent_inline_ref_size(type);
999
1000 btrfs_extend_item(path, size);
1001
1002 ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
1003 refs = btrfs_extent_refs(leaf, ei);
1004 refs += refs_to_add;
1005 btrfs_set_extent_refs(leaf, ei, refs);
1006 if (extent_op)
1007 __run_delayed_extent_op(extent_op, leaf, ei);
1008
1009 ptr = (unsigned long)ei + item_offset;
1010 end = (unsigned long)ei + btrfs_item_size_nr(leaf, path->slots[0]);
1011 if (ptr < end - size)
1012 memmove_extent_buffer(leaf, ptr + size, ptr,
1013 end - size - ptr);
1014
1015 iref = (struct btrfs_extent_inline_ref *)ptr;
1016 btrfs_set_extent_inline_ref_type(leaf, iref, type);
1017 if (type == BTRFS_EXTENT_DATA_REF_KEY) {
1018 struct btrfs_extent_data_ref *dref;
1019 dref = (struct btrfs_extent_data_ref *)(&iref->offset);
1020 btrfs_set_extent_data_ref_root(leaf, dref, root_objectid);
1021 btrfs_set_extent_data_ref_objectid(leaf, dref, owner);
1022 btrfs_set_extent_data_ref_offset(leaf, dref, offset);
1023 btrfs_set_extent_data_ref_count(leaf, dref, refs_to_add);
1024 } else if (type == BTRFS_SHARED_DATA_REF_KEY) {
1025 struct btrfs_shared_data_ref *sref;
1026 sref = (struct btrfs_shared_data_ref *)(iref + 1);
1027 btrfs_set_shared_data_ref_count(leaf, sref, refs_to_add);
1028 btrfs_set_extent_inline_ref_offset(leaf, iref, parent);
1029 } else if (type == BTRFS_SHARED_BLOCK_REF_KEY) {
1030 btrfs_set_extent_inline_ref_offset(leaf, iref, parent);
1031 } else {
1032 btrfs_set_extent_inline_ref_offset(leaf, iref, root_objectid);
1033 }
1034 btrfs_mark_buffer_dirty(leaf);
1035 }
1036
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)1037 static int lookup_extent_backref(struct btrfs_trans_handle *trans,
1038 struct btrfs_path *path,
1039 struct btrfs_extent_inline_ref **ref_ret,
1040 u64 bytenr, u64 num_bytes, u64 parent,
1041 u64 root_objectid, u64 owner, u64 offset)
1042 {
1043 int ret;
1044
1045 ret = lookup_inline_extent_backref(trans, path, ref_ret, bytenr,
1046 num_bytes, parent, root_objectid,
1047 owner, offset, 0);
1048 if (ret != -ENOENT)
1049 return ret;
1050
1051 btrfs_release_path(path);
1052 *ref_ret = NULL;
1053
1054 if (owner < BTRFS_FIRST_FREE_OBJECTID) {
1055 ret = lookup_tree_block_ref(trans, path, bytenr, parent,
1056 root_objectid);
1057 } else {
1058 ret = lookup_extent_data_ref(trans, path, bytenr, parent,
1059 root_objectid, owner, offset);
1060 }
1061 return ret;
1062 }
1063
1064 /*
1065 * helper to update/remove inline back ref
1066 */
1067 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,int * last_ref)1068 void update_inline_extent_backref(struct btrfs_path *path,
1069 struct btrfs_extent_inline_ref *iref,
1070 int refs_to_mod,
1071 struct btrfs_delayed_extent_op *extent_op,
1072 int *last_ref)
1073 {
1074 struct extent_buffer *leaf = path->nodes[0];
1075 struct btrfs_extent_item *ei;
1076 struct btrfs_extent_data_ref *dref = NULL;
1077 struct btrfs_shared_data_ref *sref = NULL;
1078 unsigned long ptr;
1079 unsigned long end;
1080 u32 item_size;
1081 int size;
1082 int type;
1083 u64 refs;
1084
1085 ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
1086 refs = btrfs_extent_refs(leaf, ei);
1087 WARN_ON(refs_to_mod < 0 && refs + refs_to_mod <= 0);
1088 refs += refs_to_mod;
1089 btrfs_set_extent_refs(leaf, ei, refs);
1090 if (extent_op)
1091 __run_delayed_extent_op(extent_op, leaf, ei);
1092
1093 /*
1094 * If type is invalid, we should have bailed out after
1095 * lookup_inline_extent_backref().
1096 */
1097 type = btrfs_get_extent_inline_ref_type(leaf, iref, BTRFS_REF_TYPE_ANY);
1098 ASSERT(type != BTRFS_REF_TYPE_INVALID);
1099
1100 if (type == BTRFS_EXTENT_DATA_REF_KEY) {
1101 dref = (struct btrfs_extent_data_ref *)(&iref->offset);
1102 refs = btrfs_extent_data_ref_count(leaf, dref);
1103 } else if (type == BTRFS_SHARED_DATA_REF_KEY) {
1104 sref = (struct btrfs_shared_data_ref *)(iref + 1);
1105 refs = btrfs_shared_data_ref_count(leaf, sref);
1106 } else {
1107 refs = 1;
1108 BUG_ON(refs_to_mod != -1);
1109 }
1110
1111 BUG_ON(refs_to_mod < 0 && refs < -refs_to_mod);
1112 refs += refs_to_mod;
1113
1114 if (refs > 0) {
1115 if (type == BTRFS_EXTENT_DATA_REF_KEY)
1116 btrfs_set_extent_data_ref_count(leaf, dref, refs);
1117 else
1118 btrfs_set_shared_data_ref_count(leaf, sref, refs);
1119 } else {
1120 *last_ref = 1;
1121 size = btrfs_extent_inline_ref_size(type);
1122 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
1123 ptr = (unsigned long)iref;
1124 end = (unsigned long)ei + item_size;
1125 if (ptr + size < end)
1126 memmove_extent_buffer(leaf, ptr, ptr + size,
1127 end - ptr - size);
1128 item_size -= size;
1129 btrfs_truncate_item(path, item_size, 1);
1130 }
1131 btrfs_mark_buffer_dirty(leaf);
1132 }
1133
1134 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)1135 int insert_inline_extent_backref(struct btrfs_trans_handle *trans,
1136 struct btrfs_path *path,
1137 u64 bytenr, u64 num_bytes, u64 parent,
1138 u64 root_objectid, u64 owner,
1139 u64 offset, int refs_to_add,
1140 struct btrfs_delayed_extent_op *extent_op)
1141 {
1142 struct btrfs_extent_inline_ref *iref;
1143 int ret;
1144
1145 ret = lookup_inline_extent_backref(trans, path, &iref, bytenr,
1146 num_bytes, parent, root_objectid,
1147 owner, offset, 1);
1148 if (ret == 0) {
1149 /*
1150 * We're adding refs to a tree block we already own, this
1151 * should not happen at all.
1152 */
1153 if (owner < BTRFS_FIRST_FREE_OBJECTID) {
1154 btrfs_crit(trans->fs_info,
1155 "adding refs to an existing tree ref, bytenr %llu num_bytes %llu root_objectid %llu",
1156 bytenr, num_bytes, root_objectid);
1157 if (IS_ENABLED(CONFIG_BTRFS_DEBUG)) {
1158 WARN_ON(1);
1159 btrfs_crit(trans->fs_info,
1160 "path->slots[0]=%d path->nodes[0]:", path->slots[0]);
1161 btrfs_print_leaf(path->nodes[0]);
1162 }
1163 return -EUCLEAN;
1164 }
1165 update_inline_extent_backref(path, iref, refs_to_add,
1166 extent_op, NULL);
1167 } else if (ret == -ENOENT) {
1168 setup_inline_extent_backref(trans->fs_info, path, iref, parent,
1169 root_objectid, owner, offset,
1170 refs_to_add, extent_op);
1171 ret = 0;
1172 }
1173 return ret;
1174 }
1175
remove_extent_backref(struct btrfs_trans_handle * trans,struct btrfs_path * path,struct btrfs_extent_inline_ref * iref,int refs_to_drop,int is_data,int * last_ref)1176 static int remove_extent_backref(struct btrfs_trans_handle *trans,
1177 struct btrfs_path *path,
1178 struct btrfs_extent_inline_ref *iref,
1179 int refs_to_drop, int is_data, int *last_ref)
1180 {
1181 int ret = 0;
1182
1183 BUG_ON(!is_data && refs_to_drop != 1);
1184 if (iref) {
1185 update_inline_extent_backref(path, iref, -refs_to_drop, NULL,
1186 last_ref);
1187 } else if (is_data) {
1188 ret = remove_extent_data_ref(trans, path, refs_to_drop,
1189 last_ref);
1190 } else {
1191 *last_ref = 1;
1192 ret = btrfs_del_item(trans, trans->fs_info->extent_root, path);
1193 }
1194 return ret;
1195 }
1196
btrfs_issue_discard(struct block_device * bdev,u64 start,u64 len,u64 * discarded_bytes)1197 static int btrfs_issue_discard(struct block_device *bdev, u64 start, u64 len,
1198 u64 *discarded_bytes)
1199 {
1200 int j, ret = 0;
1201 u64 bytes_left, end;
1202 u64 aligned_start = ALIGN(start, 1 << 9);
1203
1204 if (WARN_ON(start != aligned_start)) {
1205 len -= aligned_start - start;
1206 len = round_down(len, 1 << 9);
1207 start = aligned_start;
1208 }
1209
1210 *discarded_bytes = 0;
1211
1212 if (!len)
1213 return 0;
1214
1215 end = start + len;
1216 bytes_left = len;
1217
1218 /* Skip any superblocks on this device. */
1219 for (j = 0; j < BTRFS_SUPER_MIRROR_MAX; j++) {
1220 u64 sb_start = btrfs_sb_offset(j);
1221 u64 sb_end = sb_start + BTRFS_SUPER_INFO_SIZE;
1222 u64 size = sb_start - start;
1223
1224 if (!in_range(sb_start, start, bytes_left) &&
1225 !in_range(sb_end, start, bytes_left) &&
1226 !in_range(start, sb_start, BTRFS_SUPER_INFO_SIZE))
1227 continue;
1228
1229 /*
1230 * Superblock spans beginning of range. Adjust start and
1231 * try again.
1232 */
1233 if (sb_start <= start) {
1234 start += sb_end - start;
1235 if (start > end) {
1236 bytes_left = 0;
1237 break;
1238 }
1239 bytes_left = end - start;
1240 continue;
1241 }
1242
1243 if (size) {
1244 ret = blkdev_issue_discard(bdev, start >> 9, size >> 9,
1245 GFP_NOFS, 0);
1246 if (!ret)
1247 *discarded_bytes += size;
1248 else if (ret != -EOPNOTSUPP)
1249 return ret;
1250 }
1251
1252 start = sb_end;
1253 if (start > end) {
1254 bytes_left = 0;
1255 break;
1256 }
1257 bytes_left = end - start;
1258 }
1259
1260 if (bytes_left) {
1261 ret = blkdev_issue_discard(bdev, start >> 9, bytes_left >> 9,
1262 GFP_NOFS, 0);
1263 if (!ret)
1264 *discarded_bytes += bytes_left;
1265 }
1266 return ret;
1267 }
1268
do_discard_extent(struct btrfs_bio_stripe * stripe,u64 * bytes)1269 static int do_discard_extent(struct btrfs_bio_stripe *stripe, u64 *bytes)
1270 {
1271 struct btrfs_device *dev = stripe->dev;
1272 struct btrfs_fs_info *fs_info = dev->fs_info;
1273 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
1274 u64 phys = stripe->physical;
1275 u64 len = stripe->length;
1276 u64 discarded = 0;
1277 int ret = 0;
1278
1279 /* Zone reset on a zoned filesystem */
1280 if (btrfs_can_zone_reset(dev, phys, len)) {
1281 u64 src_disc;
1282
1283 ret = btrfs_reset_device_zone(dev, phys, len, &discarded);
1284 if (ret)
1285 goto out;
1286
1287 if (!btrfs_dev_replace_is_ongoing(dev_replace) ||
1288 dev != dev_replace->srcdev)
1289 goto out;
1290
1291 src_disc = discarded;
1292
1293 /* Send to replace target as well */
1294 ret = btrfs_reset_device_zone(dev_replace->tgtdev, phys, len,
1295 &discarded);
1296 discarded += src_disc;
1297 } else if (blk_queue_discard(bdev_get_queue(stripe->dev->bdev))) {
1298 ret = btrfs_issue_discard(dev->bdev, phys, len, &discarded);
1299 } else {
1300 ret = 0;
1301 *bytes = 0;
1302 }
1303
1304 out:
1305 *bytes = discarded;
1306 return ret;
1307 }
1308
btrfs_discard_extent(struct btrfs_fs_info * fs_info,u64 bytenr,u64 num_bytes,u64 * actual_bytes)1309 int btrfs_discard_extent(struct btrfs_fs_info *fs_info, u64 bytenr,
1310 u64 num_bytes, u64 *actual_bytes)
1311 {
1312 int ret = 0;
1313 u64 discarded_bytes = 0;
1314 u64 end = bytenr + num_bytes;
1315 u64 cur = bytenr;
1316 struct btrfs_bio *bbio = NULL;
1317
1318
1319 /*
1320 * Avoid races with device replace and make sure our bbio has devices
1321 * associated to its stripes that don't go away while we are discarding.
1322 */
1323 btrfs_bio_counter_inc_blocked(fs_info);
1324 while (cur < end) {
1325 struct btrfs_bio_stripe *stripe;
1326 int i;
1327
1328 num_bytes = end - cur;
1329 /* Tell the block device(s) that the sectors can be discarded */
1330 ret = btrfs_map_block(fs_info, BTRFS_MAP_DISCARD, cur,
1331 &num_bytes, &bbio, 0);
1332 /*
1333 * Error can be -ENOMEM, -ENOENT (no such chunk mapping) or
1334 * -EOPNOTSUPP. For any such error, @num_bytes is not updated,
1335 * thus we can't continue anyway.
1336 */
1337 if (ret < 0)
1338 goto out;
1339
1340 stripe = bbio->stripes;
1341 for (i = 0; i < bbio->num_stripes; i++, stripe++) {
1342 u64 bytes;
1343 struct btrfs_device *device = stripe->dev;
1344
1345 if (!device->bdev) {
1346 ASSERT(btrfs_test_opt(fs_info, DEGRADED));
1347 continue;
1348 }
1349
1350 if (!test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state))
1351 continue;
1352
1353 ret = do_discard_extent(stripe, &bytes);
1354 if (!ret) {
1355 discarded_bytes += bytes;
1356 } else if (ret != -EOPNOTSUPP) {
1357 /*
1358 * Logic errors or -ENOMEM, or -EIO, but
1359 * unlikely to happen.
1360 *
1361 * And since there are two loops, explicitly
1362 * go to out to avoid confusion.
1363 */
1364 btrfs_put_bbio(bbio);
1365 goto out;
1366 }
1367
1368 /*
1369 * Just in case we get back EOPNOTSUPP for some reason,
1370 * just ignore the return value so we don't screw up
1371 * people calling discard_extent.
1372 */
1373 ret = 0;
1374 }
1375 btrfs_put_bbio(bbio);
1376 cur += num_bytes;
1377 }
1378 out:
1379 btrfs_bio_counter_dec(fs_info);
1380
1381 if (actual_bytes)
1382 *actual_bytes = discarded_bytes;
1383
1384
1385 if (ret == -EOPNOTSUPP)
1386 ret = 0;
1387 return ret;
1388 }
1389
1390 /* Can return -ENOMEM */
btrfs_inc_extent_ref(struct btrfs_trans_handle * trans,struct btrfs_ref * generic_ref)1391 int btrfs_inc_extent_ref(struct btrfs_trans_handle *trans,
1392 struct btrfs_ref *generic_ref)
1393 {
1394 struct btrfs_fs_info *fs_info = trans->fs_info;
1395 int ret;
1396
1397 ASSERT(generic_ref->type != BTRFS_REF_NOT_SET &&
1398 generic_ref->action);
1399 BUG_ON(generic_ref->type == BTRFS_REF_METADATA &&
1400 generic_ref->tree_ref.root == BTRFS_TREE_LOG_OBJECTID);
1401
1402 if (generic_ref->type == BTRFS_REF_METADATA)
1403 ret = btrfs_add_delayed_tree_ref(trans, generic_ref, NULL);
1404 else
1405 ret = btrfs_add_delayed_data_ref(trans, generic_ref, 0);
1406
1407 btrfs_ref_tree_mod(fs_info, generic_ref);
1408
1409 return ret;
1410 }
1411
1412 /*
1413 * __btrfs_inc_extent_ref - insert backreference for a given extent
1414 *
1415 * The counterpart is in __btrfs_free_extent(), with examples and more details
1416 * how it works.
1417 *
1418 * @trans: Handle of transaction
1419 *
1420 * @node: The delayed ref node used to get the bytenr/length for
1421 * extent whose references are incremented.
1422 *
1423 * @parent: If this is a shared extent (BTRFS_SHARED_DATA_REF_KEY/
1424 * BTRFS_SHARED_BLOCK_REF_KEY) then it holds the logical
1425 * bytenr of the parent block. Since new extents are always
1426 * created with indirect references, this will only be the case
1427 * when relocating a shared extent. In that case, root_objectid
1428 * will be BTRFS_TREE_RELOC_OBJECTID. Otheriwse, parent must
1429 * be 0
1430 *
1431 * @root_objectid: The id of the root where this modification has originated,
1432 * this can be either one of the well-known metadata trees or
1433 * the subvolume id which references this extent.
1434 *
1435 * @owner: For data extents it is the inode number of the owning file.
1436 * For metadata extents this parameter holds the level in the
1437 * tree of the extent.
1438 *
1439 * @offset: For metadata extents the offset is ignored and is currently
1440 * always passed as 0. For data extents it is the fileoffset
1441 * this extent belongs to.
1442 *
1443 * @refs_to_add Number of references to add
1444 *
1445 * @extent_op Pointer to a structure, holding information necessary when
1446 * updating a tree block's flags
1447 *
1448 */
__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)1449 static int __btrfs_inc_extent_ref(struct btrfs_trans_handle *trans,
1450 struct btrfs_delayed_ref_node *node,
1451 u64 parent, u64 root_objectid,
1452 u64 owner, u64 offset, int refs_to_add,
1453 struct btrfs_delayed_extent_op *extent_op)
1454 {
1455 struct btrfs_path *path;
1456 struct extent_buffer *leaf;
1457 struct btrfs_extent_item *item;
1458 struct btrfs_key key;
1459 u64 bytenr = node->bytenr;
1460 u64 num_bytes = node->num_bytes;
1461 u64 refs;
1462 int ret;
1463
1464 path = btrfs_alloc_path();
1465 if (!path)
1466 return -ENOMEM;
1467
1468 /* this will setup the path even if it fails to insert the back ref */
1469 ret = insert_inline_extent_backref(trans, path, bytenr, num_bytes,
1470 parent, root_objectid, owner,
1471 offset, refs_to_add, extent_op);
1472 if ((ret < 0 && ret != -EAGAIN) || !ret)
1473 goto out;
1474
1475 /*
1476 * Ok we had -EAGAIN which means we didn't have space to insert and
1477 * inline extent ref, so just update the reference count and add a
1478 * normal backref.
1479 */
1480 leaf = path->nodes[0];
1481 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
1482 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
1483 refs = btrfs_extent_refs(leaf, item);
1484 btrfs_set_extent_refs(leaf, item, refs + refs_to_add);
1485 if (extent_op)
1486 __run_delayed_extent_op(extent_op, leaf, item);
1487
1488 btrfs_mark_buffer_dirty(leaf);
1489 btrfs_release_path(path);
1490
1491 /* now insert the actual backref */
1492 if (owner < BTRFS_FIRST_FREE_OBJECTID) {
1493 BUG_ON(refs_to_add != 1);
1494 ret = insert_tree_block_ref(trans, path, bytenr, parent,
1495 root_objectid);
1496 } else {
1497 ret = insert_extent_data_ref(trans, path, bytenr, parent,
1498 root_objectid, owner, offset,
1499 refs_to_add);
1500 }
1501 if (ret)
1502 btrfs_abort_transaction(trans, ret);
1503 out:
1504 btrfs_free_path(path);
1505 return ret;
1506 }
1507
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)1508 static int run_delayed_data_ref(struct btrfs_trans_handle *trans,
1509 struct btrfs_delayed_ref_node *node,
1510 struct btrfs_delayed_extent_op *extent_op,
1511 int insert_reserved)
1512 {
1513 int ret = 0;
1514 struct btrfs_delayed_data_ref *ref;
1515 struct btrfs_key ins;
1516 u64 parent = 0;
1517 u64 ref_root = 0;
1518 u64 flags = 0;
1519
1520 ins.objectid = node->bytenr;
1521 ins.offset = node->num_bytes;
1522 ins.type = BTRFS_EXTENT_ITEM_KEY;
1523
1524 ref = btrfs_delayed_node_to_data_ref(node);
1525 trace_run_delayed_data_ref(trans->fs_info, node, ref, node->action);
1526
1527 if (node->type == BTRFS_SHARED_DATA_REF_KEY)
1528 parent = ref->parent;
1529 ref_root = ref->root;
1530
1531 if (node->action == BTRFS_ADD_DELAYED_REF && insert_reserved) {
1532 if (extent_op)
1533 flags |= extent_op->flags_to_set;
1534 ret = alloc_reserved_file_extent(trans, parent, ref_root,
1535 flags, ref->objectid,
1536 ref->offset, &ins,
1537 node->ref_mod);
1538 } else if (node->action == BTRFS_ADD_DELAYED_REF) {
1539 ret = __btrfs_inc_extent_ref(trans, node, parent, ref_root,
1540 ref->objectid, ref->offset,
1541 node->ref_mod, extent_op);
1542 } else if (node->action == BTRFS_DROP_DELAYED_REF) {
1543 ret = __btrfs_free_extent(trans, node, parent,
1544 ref_root, ref->objectid,
1545 ref->offset, node->ref_mod,
1546 extent_op);
1547 } else {
1548 BUG();
1549 }
1550 return ret;
1551 }
1552
__run_delayed_extent_op(struct btrfs_delayed_extent_op * extent_op,struct extent_buffer * leaf,struct btrfs_extent_item * ei)1553 static void __run_delayed_extent_op(struct btrfs_delayed_extent_op *extent_op,
1554 struct extent_buffer *leaf,
1555 struct btrfs_extent_item *ei)
1556 {
1557 u64 flags = btrfs_extent_flags(leaf, ei);
1558 if (extent_op->update_flags) {
1559 flags |= extent_op->flags_to_set;
1560 btrfs_set_extent_flags(leaf, ei, flags);
1561 }
1562
1563 if (extent_op->update_key) {
1564 struct btrfs_tree_block_info *bi;
1565 BUG_ON(!(flags & BTRFS_EXTENT_FLAG_TREE_BLOCK));
1566 bi = (struct btrfs_tree_block_info *)(ei + 1);
1567 btrfs_set_tree_block_key(leaf, bi, &extent_op->key);
1568 }
1569 }
1570
run_delayed_extent_op(struct btrfs_trans_handle * trans,struct btrfs_delayed_ref_head * head,struct btrfs_delayed_extent_op * extent_op)1571 static int run_delayed_extent_op(struct btrfs_trans_handle *trans,
1572 struct btrfs_delayed_ref_head *head,
1573 struct btrfs_delayed_extent_op *extent_op)
1574 {
1575 struct btrfs_fs_info *fs_info = trans->fs_info;
1576 struct btrfs_key key;
1577 struct btrfs_path *path;
1578 struct btrfs_extent_item *ei;
1579 struct extent_buffer *leaf;
1580 u32 item_size;
1581 int ret;
1582 int err = 0;
1583 int metadata = !extent_op->is_data;
1584
1585 if (TRANS_ABORTED(trans))
1586 return 0;
1587
1588 if (metadata && !btrfs_fs_incompat(fs_info, SKINNY_METADATA))
1589 metadata = 0;
1590
1591 path = btrfs_alloc_path();
1592 if (!path)
1593 return -ENOMEM;
1594
1595 key.objectid = head->bytenr;
1596
1597 if (metadata) {
1598 key.type = BTRFS_METADATA_ITEM_KEY;
1599 key.offset = extent_op->level;
1600 } else {
1601 key.type = BTRFS_EXTENT_ITEM_KEY;
1602 key.offset = head->num_bytes;
1603 }
1604
1605 again:
1606 ret = btrfs_search_slot(trans, fs_info->extent_root, &key, path, 0, 1);
1607 if (ret < 0) {
1608 err = ret;
1609 goto out;
1610 }
1611 if (ret > 0) {
1612 if (metadata) {
1613 if (path->slots[0] > 0) {
1614 path->slots[0]--;
1615 btrfs_item_key_to_cpu(path->nodes[0], &key,
1616 path->slots[0]);
1617 if (key.objectid == head->bytenr &&
1618 key.type == BTRFS_EXTENT_ITEM_KEY &&
1619 key.offset == head->num_bytes)
1620 ret = 0;
1621 }
1622 if (ret > 0) {
1623 btrfs_release_path(path);
1624 metadata = 0;
1625
1626 key.objectid = head->bytenr;
1627 key.offset = head->num_bytes;
1628 key.type = BTRFS_EXTENT_ITEM_KEY;
1629 goto again;
1630 }
1631 } else {
1632 err = -EIO;
1633 goto out;
1634 }
1635 }
1636
1637 leaf = path->nodes[0];
1638 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
1639
1640 if (unlikely(item_size < sizeof(*ei))) {
1641 err = -EINVAL;
1642 btrfs_print_v0_err(fs_info);
1643 btrfs_abort_transaction(trans, err);
1644 goto out;
1645 }
1646
1647 ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
1648 __run_delayed_extent_op(extent_op, leaf, ei);
1649
1650 btrfs_mark_buffer_dirty(leaf);
1651 out:
1652 btrfs_free_path(path);
1653 return err;
1654 }
1655
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)1656 static int run_delayed_tree_ref(struct btrfs_trans_handle *trans,
1657 struct btrfs_delayed_ref_node *node,
1658 struct btrfs_delayed_extent_op *extent_op,
1659 int insert_reserved)
1660 {
1661 int ret = 0;
1662 struct btrfs_delayed_tree_ref *ref;
1663 u64 parent = 0;
1664 u64 ref_root = 0;
1665
1666 ref = btrfs_delayed_node_to_tree_ref(node);
1667 trace_run_delayed_tree_ref(trans->fs_info, node, ref, node->action);
1668
1669 if (node->type == BTRFS_SHARED_BLOCK_REF_KEY)
1670 parent = ref->parent;
1671 ref_root = ref->root;
1672
1673 if (node->ref_mod != 1) {
1674 btrfs_err(trans->fs_info,
1675 "btree block(%llu) has %d references rather than 1: action %d ref_root %llu parent %llu",
1676 node->bytenr, node->ref_mod, node->action, ref_root,
1677 parent);
1678 return -EIO;
1679 }
1680 if (node->action == BTRFS_ADD_DELAYED_REF && insert_reserved) {
1681 BUG_ON(!extent_op || !extent_op->update_flags);
1682 ret = alloc_reserved_tree_block(trans, node, extent_op);
1683 } else if (node->action == BTRFS_ADD_DELAYED_REF) {
1684 ret = __btrfs_inc_extent_ref(trans, node, parent, ref_root,
1685 ref->level, 0, 1, extent_op);
1686 } else if (node->action == BTRFS_DROP_DELAYED_REF) {
1687 ret = __btrfs_free_extent(trans, node, parent, ref_root,
1688 ref->level, 0, 1, extent_op);
1689 } else {
1690 BUG();
1691 }
1692 return ret;
1693 }
1694
1695 /* 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)1696 static int run_one_delayed_ref(struct btrfs_trans_handle *trans,
1697 struct btrfs_delayed_ref_node *node,
1698 struct btrfs_delayed_extent_op *extent_op,
1699 int insert_reserved)
1700 {
1701 int ret = 0;
1702
1703 if (TRANS_ABORTED(trans)) {
1704 if (insert_reserved)
1705 btrfs_pin_extent(trans, node->bytenr, node->num_bytes, 1);
1706 return 0;
1707 }
1708
1709 if (node->type == BTRFS_TREE_BLOCK_REF_KEY ||
1710 node->type == BTRFS_SHARED_BLOCK_REF_KEY)
1711 ret = run_delayed_tree_ref(trans, node, extent_op,
1712 insert_reserved);
1713 else if (node->type == BTRFS_EXTENT_DATA_REF_KEY ||
1714 node->type == BTRFS_SHARED_DATA_REF_KEY)
1715 ret = run_delayed_data_ref(trans, node, extent_op,
1716 insert_reserved);
1717 else
1718 BUG();
1719 if (ret && insert_reserved)
1720 btrfs_pin_extent(trans, node->bytenr, node->num_bytes, 1);
1721 return ret;
1722 }
1723
1724 static inline struct btrfs_delayed_ref_node *
select_delayed_ref(struct btrfs_delayed_ref_head * head)1725 select_delayed_ref(struct btrfs_delayed_ref_head *head)
1726 {
1727 struct btrfs_delayed_ref_node *ref;
1728
1729 if (RB_EMPTY_ROOT(&head->ref_tree.rb_root))
1730 return NULL;
1731
1732 /*
1733 * Select a delayed ref of type BTRFS_ADD_DELAYED_REF first.
1734 * This is to prevent a ref count from going down to zero, which deletes
1735 * the extent item from the extent tree, when there still are references
1736 * to add, which would fail because they would not find the extent item.
1737 */
1738 if (!list_empty(&head->ref_add_list))
1739 return list_first_entry(&head->ref_add_list,
1740 struct btrfs_delayed_ref_node, add_list);
1741
1742 ref = rb_entry(rb_first_cached(&head->ref_tree),
1743 struct btrfs_delayed_ref_node, ref_node);
1744 ASSERT(list_empty(&ref->add_list));
1745 return ref;
1746 }
1747
unselect_delayed_ref_head(struct btrfs_delayed_ref_root * delayed_refs,struct btrfs_delayed_ref_head * head)1748 static void unselect_delayed_ref_head(struct btrfs_delayed_ref_root *delayed_refs,
1749 struct btrfs_delayed_ref_head *head)
1750 {
1751 spin_lock(&delayed_refs->lock);
1752 head->processing = 0;
1753 delayed_refs->num_heads_ready++;
1754 spin_unlock(&delayed_refs->lock);
1755 btrfs_delayed_ref_unlock(head);
1756 }
1757
cleanup_extent_op(struct btrfs_delayed_ref_head * head)1758 static struct btrfs_delayed_extent_op *cleanup_extent_op(
1759 struct btrfs_delayed_ref_head *head)
1760 {
1761 struct btrfs_delayed_extent_op *extent_op = head->extent_op;
1762
1763 if (!extent_op)
1764 return NULL;
1765
1766 if (head->must_insert_reserved) {
1767 head->extent_op = NULL;
1768 btrfs_free_delayed_extent_op(extent_op);
1769 return NULL;
1770 }
1771 return extent_op;
1772 }
1773
run_and_cleanup_extent_op(struct btrfs_trans_handle * trans,struct btrfs_delayed_ref_head * head)1774 static int run_and_cleanup_extent_op(struct btrfs_trans_handle *trans,
1775 struct btrfs_delayed_ref_head *head)
1776 {
1777 struct btrfs_delayed_extent_op *extent_op;
1778 int ret;
1779
1780 extent_op = cleanup_extent_op(head);
1781 if (!extent_op)
1782 return 0;
1783 head->extent_op = NULL;
1784 spin_unlock(&head->lock);
1785 ret = run_delayed_extent_op(trans, head, extent_op);
1786 btrfs_free_delayed_extent_op(extent_op);
1787 return ret ? ret : 1;
1788 }
1789
btrfs_cleanup_ref_head_accounting(struct btrfs_fs_info * fs_info,struct btrfs_delayed_ref_root * delayed_refs,struct btrfs_delayed_ref_head * head)1790 void btrfs_cleanup_ref_head_accounting(struct btrfs_fs_info *fs_info,
1791 struct btrfs_delayed_ref_root *delayed_refs,
1792 struct btrfs_delayed_ref_head *head)
1793 {
1794 int nr_items = 1; /* Dropping this ref head update. */
1795
1796 /*
1797 * We had csum deletions accounted for in our delayed refs rsv, we need
1798 * to drop the csum leaves for this update from our delayed_refs_rsv.
1799 */
1800 if (head->total_ref_mod < 0 && head->is_data) {
1801 spin_lock(&delayed_refs->lock);
1802 delayed_refs->pending_csums -= head->num_bytes;
1803 spin_unlock(&delayed_refs->lock);
1804 nr_items += btrfs_csum_bytes_to_leaves(fs_info, head->num_bytes);
1805 }
1806
1807 /*
1808 * We were dropping refs, or had a new ref and dropped it, and thus must
1809 * adjust down our total_bytes_pinned, the space may or may not have
1810 * been pinned and so is accounted for properly in the pinned space by
1811 * now.
1812 */
1813 if (head->total_ref_mod < 0 ||
1814 (head->total_ref_mod == 0 && head->must_insert_reserved)) {
1815 u64 flags = btrfs_ref_head_to_space_flags(head);
1816
1817 btrfs_mod_total_bytes_pinned(fs_info, flags, -head->num_bytes);
1818 }
1819
1820 btrfs_delayed_refs_rsv_release(fs_info, nr_items);
1821 }
1822
cleanup_ref_head(struct btrfs_trans_handle * trans,struct btrfs_delayed_ref_head * head)1823 static int cleanup_ref_head(struct btrfs_trans_handle *trans,
1824 struct btrfs_delayed_ref_head *head)
1825 {
1826
1827 struct btrfs_fs_info *fs_info = trans->fs_info;
1828 struct btrfs_delayed_ref_root *delayed_refs;
1829 int ret;
1830
1831 delayed_refs = &trans->transaction->delayed_refs;
1832
1833 ret = run_and_cleanup_extent_op(trans, head);
1834 if (ret < 0) {
1835 unselect_delayed_ref_head(delayed_refs, head);
1836 btrfs_debug(fs_info, "run_delayed_extent_op returned %d", ret);
1837 return ret;
1838 } else if (ret) {
1839 return ret;
1840 }
1841
1842 /*
1843 * Need to drop our head ref lock and re-acquire the delayed ref lock
1844 * and then re-check to make sure nobody got added.
1845 */
1846 spin_unlock(&head->lock);
1847 spin_lock(&delayed_refs->lock);
1848 spin_lock(&head->lock);
1849 if (!RB_EMPTY_ROOT(&head->ref_tree.rb_root) || head->extent_op) {
1850 spin_unlock(&head->lock);
1851 spin_unlock(&delayed_refs->lock);
1852 return 1;
1853 }
1854 btrfs_delete_ref_head(delayed_refs, head);
1855 spin_unlock(&head->lock);
1856 spin_unlock(&delayed_refs->lock);
1857
1858 if (head->must_insert_reserved) {
1859 btrfs_pin_extent(trans, head->bytenr, head->num_bytes, 1);
1860 if (head->is_data) {
1861 ret = btrfs_del_csums(trans, fs_info->csum_root,
1862 head->bytenr, head->num_bytes);
1863 }
1864 }
1865
1866 btrfs_cleanup_ref_head_accounting(fs_info, delayed_refs, head);
1867
1868 trace_run_delayed_ref_head(fs_info, head, 0);
1869 btrfs_delayed_ref_unlock(head);
1870 btrfs_put_delayed_ref_head(head);
1871 return 0;
1872 }
1873
btrfs_obtain_ref_head(struct btrfs_trans_handle * trans)1874 static struct btrfs_delayed_ref_head *btrfs_obtain_ref_head(
1875 struct btrfs_trans_handle *trans)
1876 {
1877 struct btrfs_delayed_ref_root *delayed_refs =
1878 &trans->transaction->delayed_refs;
1879 struct btrfs_delayed_ref_head *head = NULL;
1880 int ret;
1881
1882 spin_lock(&delayed_refs->lock);
1883 head = btrfs_select_ref_head(delayed_refs);
1884 if (!head) {
1885 spin_unlock(&delayed_refs->lock);
1886 return head;
1887 }
1888
1889 /*
1890 * Grab the lock that says we are going to process all the refs for
1891 * this head
1892 */
1893 ret = btrfs_delayed_ref_lock(delayed_refs, head);
1894 spin_unlock(&delayed_refs->lock);
1895
1896 /*
1897 * We may have dropped the spin lock to get the head mutex lock, and
1898 * that might have given someone else time to free the head. If that's
1899 * true, it has been removed from our list and we can move on.
1900 */
1901 if (ret == -EAGAIN)
1902 head = ERR_PTR(-EAGAIN);
1903
1904 return head;
1905 }
1906
btrfs_run_delayed_refs_for_head(struct btrfs_trans_handle * trans,struct btrfs_delayed_ref_head * locked_ref,unsigned long * run_refs)1907 static int btrfs_run_delayed_refs_for_head(struct btrfs_trans_handle *trans,
1908 struct btrfs_delayed_ref_head *locked_ref,
1909 unsigned long *run_refs)
1910 {
1911 struct btrfs_fs_info *fs_info = trans->fs_info;
1912 struct btrfs_delayed_ref_root *delayed_refs;
1913 struct btrfs_delayed_extent_op *extent_op;
1914 struct btrfs_delayed_ref_node *ref;
1915 int must_insert_reserved = 0;
1916 int ret;
1917
1918 delayed_refs = &trans->transaction->delayed_refs;
1919
1920 lockdep_assert_held(&locked_ref->mutex);
1921 lockdep_assert_held(&locked_ref->lock);
1922
1923 while ((ref = select_delayed_ref(locked_ref))) {
1924 if (ref->seq &&
1925 btrfs_check_delayed_seq(fs_info, ref->seq)) {
1926 spin_unlock(&locked_ref->lock);
1927 unselect_delayed_ref_head(delayed_refs, locked_ref);
1928 return -EAGAIN;
1929 }
1930
1931 (*run_refs)++;
1932 ref->in_tree = 0;
1933 rb_erase_cached(&ref->ref_node, &locked_ref->ref_tree);
1934 RB_CLEAR_NODE(&ref->ref_node);
1935 if (!list_empty(&ref->add_list))
1936 list_del(&ref->add_list);
1937 /*
1938 * When we play the delayed ref, also correct the ref_mod on
1939 * head
1940 */
1941 switch (ref->action) {
1942 case BTRFS_ADD_DELAYED_REF:
1943 case BTRFS_ADD_DELAYED_EXTENT:
1944 locked_ref->ref_mod -= ref->ref_mod;
1945 break;
1946 case BTRFS_DROP_DELAYED_REF:
1947 locked_ref->ref_mod += ref->ref_mod;
1948 break;
1949 default:
1950 WARN_ON(1);
1951 }
1952 atomic_dec(&delayed_refs->num_entries);
1953
1954 /*
1955 * Record the must_insert_reserved flag before we drop the
1956 * spin lock.
1957 */
1958 must_insert_reserved = locked_ref->must_insert_reserved;
1959 locked_ref->must_insert_reserved = 0;
1960
1961 extent_op = locked_ref->extent_op;
1962 locked_ref->extent_op = NULL;
1963 spin_unlock(&locked_ref->lock);
1964
1965 ret = run_one_delayed_ref(trans, ref, extent_op,
1966 must_insert_reserved);
1967
1968 btrfs_free_delayed_extent_op(extent_op);
1969 if (ret) {
1970 unselect_delayed_ref_head(delayed_refs, locked_ref);
1971 btrfs_put_delayed_ref(ref);
1972 btrfs_debug(fs_info, "run_one_delayed_ref returned %d",
1973 ret);
1974 return ret;
1975 }
1976
1977 btrfs_put_delayed_ref(ref);
1978 cond_resched();
1979
1980 spin_lock(&locked_ref->lock);
1981 btrfs_merge_delayed_refs(trans, delayed_refs, locked_ref);
1982 }
1983
1984 return 0;
1985 }
1986
1987 /*
1988 * Returns 0 on success or if called with an already aborted transaction.
1989 * Returns -ENOMEM or -EIO on failure and will abort the transaction.
1990 */
__btrfs_run_delayed_refs(struct btrfs_trans_handle * trans,unsigned long nr)1991 static noinline int __btrfs_run_delayed_refs(struct btrfs_trans_handle *trans,
1992 unsigned long nr)
1993 {
1994 struct btrfs_fs_info *fs_info = trans->fs_info;
1995 struct btrfs_delayed_ref_root *delayed_refs;
1996 struct btrfs_delayed_ref_head *locked_ref = NULL;
1997 ktime_t start = ktime_get();
1998 int ret;
1999 unsigned long count = 0;
2000 unsigned long actual_count = 0;
2001
2002 delayed_refs = &trans->transaction->delayed_refs;
2003 do {
2004 if (!locked_ref) {
2005 locked_ref = btrfs_obtain_ref_head(trans);
2006 if (IS_ERR_OR_NULL(locked_ref)) {
2007 if (PTR_ERR(locked_ref) == -EAGAIN) {
2008 continue;
2009 } else {
2010 break;
2011 }
2012 }
2013 count++;
2014 }
2015 /*
2016 * We need to try and merge add/drops of the same ref since we
2017 * can run into issues with relocate dropping the implicit ref
2018 * and then it being added back again before the drop can
2019 * finish. If we merged anything we need to re-loop so we can
2020 * get a good ref.
2021 * Or we can get node references of the same type that weren't
2022 * merged when created due to bumps in the tree mod seq, and
2023 * we need to merge them to prevent adding an inline extent
2024 * backref before dropping it (triggering a BUG_ON at
2025 * insert_inline_extent_backref()).
2026 */
2027 spin_lock(&locked_ref->lock);
2028 btrfs_merge_delayed_refs(trans, delayed_refs, locked_ref);
2029
2030 ret = btrfs_run_delayed_refs_for_head(trans, locked_ref,
2031 &actual_count);
2032 if (ret < 0 && ret != -EAGAIN) {
2033 /*
2034 * Error, btrfs_run_delayed_refs_for_head already
2035 * unlocked everything so just bail out
2036 */
2037 return ret;
2038 } else if (!ret) {
2039 /*
2040 * Success, perform the usual cleanup of a processed
2041 * head
2042 */
2043 ret = cleanup_ref_head(trans, locked_ref);
2044 if (ret > 0 ) {
2045 /* We dropped our lock, we need to loop. */
2046 ret = 0;
2047 continue;
2048 } else if (ret) {
2049 return ret;
2050 }
2051 }
2052
2053 /*
2054 * Either success case or btrfs_run_delayed_refs_for_head
2055 * returned -EAGAIN, meaning we need to select another head
2056 */
2057
2058 locked_ref = NULL;
2059 cond_resched();
2060 } while ((nr != -1 && count < nr) || locked_ref);
2061
2062 /*
2063 * We don't want to include ref heads since we can have empty ref heads
2064 * and those will drastically skew our runtime down since we just do
2065 * accounting, no actual extent tree updates.
2066 */
2067 if (actual_count > 0) {
2068 u64 runtime = ktime_to_ns(ktime_sub(ktime_get(), start));
2069 u64 avg;
2070
2071 /*
2072 * We weigh the current average higher than our current runtime
2073 * to avoid large swings in the average.
2074 */
2075 spin_lock(&delayed_refs->lock);
2076 avg = fs_info->avg_delayed_ref_runtime * 3 + runtime;
2077 fs_info->avg_delayed_ref_runtime = avg >> 2; /* div by 4 */
2078 spin_unlock(&delayed_refs->lock);
2079 }
2080 return 0;
2081 }
2082
2083 #ifdef SCRAMBLE_DELAYED_REFS
2084 /*
2085 * Normally delayed refs get processed in ascending bytenr order. This
2086 * correlates in most cases to the order added. To expose dependencies on this
2087 * order, we start to process the tree in the middle instead of the beginning
2088 */
find_middle(struct rb_root * root)2089 static u64 find_middle(struct rb_root *root)
2090 {
2091 struct rb_node *n = root->rb_node;
2092 struct btrfs_delayed_ref_node *entry;
2093 int alt = 1;
2094 u64 middle;
2095 u64 first = 0, last = 0;
2096
2097 n = rb_first(root);
2098 if (n) {
2099 entry = rb_entry(n, struct btrfs_delayed_ref_node, rb_node);
2100 first = entry->bytenr;
2101 }
2102 n = rb_last(root);
2103 if (n) {
2104 entry = rb_entry(n, struct btrfs_delayed_ref_node, rb_node);
2105 last = entry->bytenr;
2106 }
2107 n = root->rb_node;
2108
2109 while (n) {
2110 entry = rb_entry(n, struct btrfs_delayed_ref_node, rb_node);
2111 WARN_ON(!entry->in_tree);
2112
2113 middle = entry->bytenr;
2114
2115 if (alt)
2116 n = n->rb_left;
2117 else
2118 n = n->rb_right;
2119
2120 alt = 1 - alt;
2121 }
2122 return middle;
2123 }
2124 #endif
2125
2126 /*
2127 * this starts processing the delayed reference count updates and
2128 * extent insertions we have queued up so far. count can be
2129 * 0, which means to process everything in the tree at the start
2130 * of the run (but not newly added entries), or it can be some target
2131 * number you'd like to process.
2132 *
2133 * Returns 0 on success or if called with an aborted transaction
2134 * Returns <0 on error and aborts the transaction
2135 */
btrfs_run_delayed_refs(struct btrfs_trans_handle * trans,unsigned long count)2136 int btrfs_run_delayed_refs(struct btrfs_trans_handle *trans,
2137 unsigned long count)
2138 {
2139 struct btrfs_fs_info *fs_info = trans->fs_info;
2140 struct rb_node *node;
2141 struct btrfs_delayed_ref_root *delayed_refs;
2142 struct btrfs_delayed_ref_head *head;
2143 int ret;
2144 int run_all = count == (unsigned long)-1;
2145
2146 /* We'll clean this up in btrfs_cleanup_transaction */
2147 if (TRANS_ABORTED(trans))
2148 return 0;
2149
2150 if (test_bit(BTRFS_FS_CREATING_FREE_SPACE_TREE, &fs_info->flags))
2151 return 0;
2152
2153 delayed_refs = &trans->transaction->delayed_refs;
2154 if (count == 0)
2155 count = delayed_refs->num_heads_ready;
2156
2157 again:
2158 #ifdef SCRAMBLE_DELAYED_REFS
2159 delayed_refs->run_delayed_start = find_middle(&delayed_refs->root);
2160 #endif
2161 ret = __btrfs_run_delayed_refs(trans, count);
2162 if (ret < 0) {
2163 btrfs_abort_transaction(trans, ret);
2164 return ret;
2165 }
2166
2167 if (run_all) {
2168 btrfs_create_pending_block_groups(trans);
2169
2170 spin_lock(&delayed_refs->lock);
2171 node = rb_first_cached(&delayed_refs->href_root);
2172 if (!node) {
2173 spin_unlock(&delayed_refs->lock);
2174 goto out;
2175 }
2176 head = rb_entry(node, struct btrfs_delayed_ref_head,
2177 href_node);
2178 refcount_inc(&head->refs);
2179 spin_unlock(&delayed_refs->lock);
2180
2181 /* Mutex was contended, block until it's released and retry. */
2182 mutex_lock(&head->mutex);
2183 mutex_unlock(&head->mutex);
2184
2185 btrfs_put_delayed_ref_head(head);
2186 cond_resched();
2187 goto again;
2188 }
2189 out:
2190 return 0;
2191 }
2192
btrfs_set_disk_extent_flags(struct btrfs_trans_handle * trans,struct extent_buffer * eb,u64 flags,int level,int is_data)2193 int btrfs_set_disk_extent_flags(struct btrfs_trans_handle *trans,
2194 struct extent_buffer *eb, u64 flags,
2195 int level, int is_data)
2196 {
2197 struct btrfs_delayed_extent_op *extent_op;
2198 int ret;
2199
2200 extent_op = btrfs_alloc_delayed_extent_op();
2201 if (!extent_op)
2202 return -ENOMEM;
2203
2204 extent_op->flags_to_set = flags;
2205 extent_op->update_flags = true;
2206 extent_op->update_key = false;
2207 extent_op->is_data = is_data ? true : false;
2208 extent_op->level = level;
2209
2210 ret = btrfs_add_delayed_extent_op(trans, eb->start, eb->len, extent_op);
2211 if (ret)
2212 btrfs_free_delayed_extent_op(extent_op);
2213 return ret;
2214 }
2215
check_delayed_ref(struct btrfs_root * root,struct btrfs_path * path,u64 objectid,u64 offset,u64 bytenr)2216 static noinline int check_delayed_ref(struct btrfs_root *root,
2217 struct btrfs_path *path,
2218 u64 objectid, u64 offset, u64 bytenr)
2219 {
2220 struct btrfs_delayed_ref_head *head;
2221 struct btrfs_delayed_ref_node *ref;
2222 struct btrfs_delayed_data_ref *data_ref;
2223 struct btrfs_delayed_ref_root *delayed_refs;
2224 struct btrfs_transaction *cur_trans;
2225 struct rb_node *node;
2226 int ret = 0;
2227
2228 spin_lock(&root->fs_info->trans_lock);
2229 cur_trans = root->fs_info->running_transaction;
2230 if (cur_trans)
2231 refcount_inc(&cur_trans->use_count);
2232 spin_unlock(&root->fs_info->trans_lock);
2233 if (!cur_trans)
2234 return 0;
2235
2236 delayed_refs = &cur_trans->delayed_refs;
2237 spin_lock(&delayed_refs->lock);
2238 head = btrfs_find_delayed_ref_head(delayed_refs, bytenr);
2239 if (!head) {
2240 spin_unlock(&delayed_refs->lock);
2241 btrfs_put_transaction(cur_trans);
2242 return 0;
2243 }
2244
2245 if (!mutex_trylock(&head->mutex)) {
2246 refcount_inc(&head->refs);
2247 spin_unlock(&delayed_refs->lock);
2248
2249 btrfs_release_path(path);
2250
2251 /*
2252 * Mutex was contended, block until it's released and let
2253 * caller try again
2254 */
2255 mutex_lock(&head->mutex);
2256 mutex_unlock(&head->mutex);
2257 btrfs_put_delayed_ref_head(head);
2258 btrfs_put_transaction(cur_trans);
2259 return -EAGAIN;
2260 }
2261 spin_unlock(&delayed_refs->lock);
2262
2263 spin_lock(&head->lock);
2264 /*
2265 * XXX: We should replace this with a proper search function in the
2266 * future.
2267 */
2268 for (node = rb_first_cached(&head->ref_tree); node;
2269 node = rb_next(node)) {
2270 ref = rb_entry(node, struct btrfs_delayed_ref_node, ref_node);
2271 /* If it's a shared ref we know a cross reference exists */
2272 if (ref->type != BTRFS_EXTENT_DATA_REF_KEY) {
2273 ret = 1;
2274 break;
2275 }
2276
2277 data_ref = btrfs_delayed_node_to_data_ref(ref);
2278
2279 /*
2280 * If our ref doesn't match the one we're currently looking at
2281 * then we have a cross reference.
2282 */
2283 if (data_ref->root != root->root_key.objectid ||
2284 data_ref->objectid != objectid ||
2285 data_ref->offset != offset) {
2286 ret = 1;
2287 break;
2288 }
2289 }
2290 spin_unlock(&head->lock);
2291 mutex_unlock(&head->mutex);
2292 btrfs_put_transaction(cur_trans);
2293 return ret;
2294 }
2295
check_committed_ref(struct btrfs_root * root,struct btrfs_path * path,u64 objectid,u64 offset,u64 bytenr,bool strict)2296 static noinline int check_committed_ref(struct btrfs_root *root,
2297 struct btrfs_path *path,
2298 u64 objectid, u64 offset, u64 bytenr,
2299 bool strict)
2300 {
2301 struct btrfs_fs_info *fs_info = root->fs_info;
2302 struct btrfs_root *extent_root = fs_info->extent_root;
2303 struct extent_buffer *leaf;
2304 struct btrfs_extent_data_ref *ref;
2305 struct btrfs_extent_inline_ref *iref;
2306 struct btrfs_extent_item *ei;
2307 struct btrfs_key key;
2308 u32 item_size;
2309 int type;
2310 int ret;
2311
2312 key.objectid = bytenr;
2313 key.offset = (u64)-1;
2314 key.type = BTRFS_EXTENT_ITEM_KEY;
2315
2316 ret = btrfs_search_slot(NULL, extent_root, &key, path, 0, 0);
2317 if (ret < 0)
2318 goto out;
2319 BUG_ON(ret == 0); /* Corruption */
2320
2321 ret = -ENOENT;
2322 if (path->slots[0] == 0)
2323 goto out;
2324
2325 path->slots[0]--;
2326 leaf = path->nodes[0];
2327 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
2328
2329 if (key.objectid != bytenr || key.type != BTRFS_EXTENT_ITEM_KEY)
2330 goto out;
2331
2332 ret = 1;
2333 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
2334 ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
2335
2336 /* If extent item has more than 1 inline ref then it's shared */
2337 if (item_size != sizeof(*ei) +
2338 btrfs_extent_inline_ref_size(BTRFS_EXTENT_DATA_REF_KEY))
2339 goto out;
2340
2341 /*
2342 * If extent created before last snapshot => it's shared unless the
2343 * snapshot has been deleted. Use the heuristic if strict is false.
2344 */
2345 if (!strict &&
2346 (btrfs_extent_generation(leaf, ei) <=
2347 btrfs_root_last_snapshot(&root->root_item)))
2348 goto out;
2349
2350 iref = (struct btrfs_extent_inline_ref *)(ei + 1);
2351
2352 /* If this extent has SHARED_DATA_REF then it's shared */
2353 type = btrfs_get_extent_inline_ref_type(leaf, iref, BTRFS_REF_TYPE_DATA);
2354 if (type != BTRFS_EXTENT_DATA_REF_KEY)
2355 goto out;
2356
2357 ref = (struct btrfs_extent_data_ref *)(&iref->offset);
2358 if (btrfs_extent_refs(leaf, ei) !=
2359 btrfs_extent_data_ref_count(leaf, ref) ||
2360 btrfs_extent_data_ref_root(leaf, ref) !=
2361 root->root_key.objectid ||
2362 btrfs_extent_data_ref_objectid(leaf, ref) != objectid ||
2363 btrfs_extent_data_ref_offset(leaf, ref) != offset)
2364 goto out;
2365
2366 ret = 0;
2367 out:
2368 return ret;
2369 }
2370
btrfs_cross_ref_exist(struct btrfs_root * root,u64 objectid,u64 offset,u64 bytenr,bool strict)2371 int btrfs_cross_ref_exist(struct btrfs_root *root, u64 objectid, u64 offset,
2372 u64 bytenr, bool strict)
2373 {
2374 struct btrfs_path *path;
2375 int ret;
2376
2377 path = btrfs_alloc_path();
2378 if (!path)
2379 return -ENOMEM;
2380
2381 do {
2382 ret = check_committed_ref(root, path, objectid,
2383 offset, bytenr, strict);
2384 if (ret && ret != -ENOENT)
2385 goto out;
2386
2387 ret = check_delayed_ref(root, path, objectid, offset, bytenr);
2388 } while (ret == -EAGAIN);
2389
2390 out:
2391 btrfs_free_path(path);
2392 if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID)
2393 WARN_ON(ret > 0);
2394 return ret;
2395 }
2396
__btrfs_mod_ref(struct btrfs_trans_handle * trans,struct btrfs_root * root,struct extent_buffer * buf,int full_backref,int inc)2397 static int __btrfs_mod_ref(struct btrfs_trans_handle *trans,
2398 struct btrfs_root *root,
2399 struct extent_buffer *buf,
2400 int full_backref, int inc)
2401 {
2402 struct btrfs_fs_info *fs_info = root->fs_info;
2403 u64 bytenr;
2404 u64 num_bytes;
2405 u64 parent;
2406 u64 ref_root;
2407 u32 nritems;
2408 struct btrfs_key key;
2409 struct btrfs_file_extent_item *fi;
2410 struct btrfs_ref generic_ref = { 0 };
2411 bool for_reloc = btrfs_header_flag(buf, BTRFS_HEADER_FLAG_RELOC);
2412 int i;
2413 int action;
2414 int level;
2415 int ret = 0;
2416
2417 if (btrfs_is_testing(fs_info))
2418 return 0;
2419
2420 ref_root = btrfs_header_owner(buf);
2421 nritems = btrfs_header_nritems(buf);
2422 level = btrfs_header_level(buf);
2423
2424 if (!test_bit(BTRFS_ROOT_SHAREABLE, &root->state) && level == 0)
2425 return 0;
2426
2427 if (full_backref)
2428 parent = buf->start;
2429 else
2430 parent = 0;
2431 if (inc)
2432 action = BTRFS_ADD_DELAYED_REF;
2433 else
2434 action = BTRFS_DROP_DELAYED_REF;
2435
2436 for (i = 0; i < nritems; i++) {
2437 if (level == 0) {
2438 btrfs_item_key_to_cpu(buf, &key, i);
2439 if (key.type != BTRFS_EXTENT_DATA_KEY)
2440 continue;
2441 fi = btrfs_item_ptr(buf, i,
2442 struct btrfs_file_extent_item);
2443 if (btrfs_file_extent_type(buf, fi) ==
2444 BTRFS_FILE_EXTENT_INLINE)
2445 continue;
2446 bytenr = btrfs_file_extent_disk_bytenr(buf, fi);
2447 if (bytenr == 0)
2448 continue;
2449
2450 num_bytes = btrfs_file_extent_disk_num_bytes(buf, fi);
2451 key.offset -= btrfs_file_extent_offset(buf, fi);
2452 btrfs_init_generic_ref(&generic_ref, action, bytenr,
2453 num_bytes, parent);
2454 generic_ref.real_root = root->root_key.objectid;
2455 btrfs_init_data_ref(&generic_ref, ref_root, key.objectid,
2456 key.offset);
2457 generic_ref.skip_qgroup = for_reloc;
2458 if (inc)
2459 ret = btrfs_inc_extent_ref(trans, &generic_ref);
2460 else
2461 ret = btrfs_free_extent(trans, &generic_ref);
2462 if (ret)
2463 goto fail;
2464 } else {
2465 bytenr = btrfs_node_blockptr(buf, i);
2466 num_bytes = fs_info->nodesize;
2467 btrfs_init_generic_ref(&generic_ref, action, bytenr,
2468 num_bytes, parent);
2469 generic_ref.real_root = root->root_key.objectid;
2470 btrfs_init_tree_ref(&generic_ref, level - 1, ref_root);
2471 generic_ref.skip_qgroup = for_reloc;
2472 if (inc)
2473 ret = btrfs_inc_extent_ref(trans, &generic_ref);
2474 else
2475 ret = btrfs_free_extent(trans, &generic_ref);
2476 if (ret)
2477 goto fail;
2478 }
2479 }
2480 return 0;
2481 fail:
2482 return ret;
2483 }
2484
btrfs_inc_ref(struct btrfs_trans_handle * trans,struct btrfs_root * root,struct extent_buffer * buf,int full_backref)2485 int btrfs_inc_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
2486 struct extent_buffer *buf, int full_backref)
2487 {
2488 return __btrfs_mod_ref(trans, root, buf, full_backref, 1);
2489 }
2490
btrfs_dec_ref(struct btrfs_trans_handle * trans,struct btrfs_root * root,struct extent_buffer * buf,int full_backref)2491 int btrfs_dec_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
2492 struct extent_buffer *buf, int full_backref)
2493 {
2494 return __btrfs_mod_ref(trans, root, buf, full_backref, 0);
2495 }
2496
get_alloc_profile_by_root(struct btrfs_root * root,int data)2497 static u64 get_alloc_profile_by_root(struct btrfs_root *root, int data)
2498 {
2499 struct btrfs_fs_info *fs_info = root->fs_info;
2500 u64 flags;
2501 u64 ret;
2502
2503 if (data)
2504 flags = BTRFS_BLOCK_GROUP_DATA;
2505 else if (root == fs_info->chunk_root)
2506 flags = BTRFS_BLOCK_GROUP_SYSTEM;
2507 else
2508 flags = BTRFS_BLOCK_GROUP_METADATA;
2509
2510 ret = btrfs_get_alloc_profile(fs_info, flags);
2511 return ret;
2512 }
2513
first_logical_byte(struct btrfs_fs_info * fs_info,u64 search_start)2514 static u64 first_logical_byte(struct btrfs_fs_info *fs_info, u64 search_start)
2515 {
2516 struct btrfs_block_group *cache;
2517 u64 bytenr;
2518
2519 spin_lock(&fs_info->block_group_cache_lock);
2520 bytenr = fs_info->first_logical_byte;
2521 spin_unlock(&fs_info->block_group_cache_lock);
2522
2523 if (bytenr < (u64)-1)
2524 return bytenr;
2525
2526 cache = btrfs_lookup_first_block_group(fs_info, search_start);
2527 if (!cache)
2528 return 0;
2529
2530 bytenr = cache->start;
2531 btrfs_put_block_group(cache);
2532
2533 return bytenr;
2534 }
2535
pin_down_extent(struct btrfs_trans_handle * trans,struct btrfs_block_group * cache,u64 bytenr,u64 num_bytes,int reserved)2536 static int pin_down_extent(struct btrfs_trans_handle *trans,
2537 struct btrfs_block_group *cache,
2538 u64 bytenr, u64 num_bytes, int reserved)
2539 {
2540 struct btrfs_fs_info *fs_info = cache->fs_info;
2541
2542 spin_lock(&cache->space_info->lock);
2543 spin_lock(&cache->lock);
2544 cache->pinned += num_bytes;
2545 btrfs_space_info_update_bytes_pinned(fs_info, cache->space_info,
2546 num_bytes);
2547 if (reserved) {
2548 cache->reserved -= num_bytes;
2549 cache->space_info->bytes_reserved -= num_bytes;
2550 }
2551 spin_unlock(&cache->lock);
2552 spin_unlock(&cache->space_info->lock);
2553
2554 __btrfs_mod_total_bytes_pinned(cache->space_info, num_bytes);
2555 set_extent_dirty(&trans->transaction->pinned_extents, bytenr,
2556 bytenr + num_bytes - 1, GFP_NOFS | __GFP_NOFAIL);
2557 return 0;
2558 }
2559
btrfs_pin_extent(struct btrfs_trans_handle * trans,u64 bytenr,u64 num_bytes,int reserved)2560 int btrfs_pin_extent(struct btrfs_trans_handle *trans,
2561 u64 bytenr, u64 num_bytes, int reserved)
2562 {
2563 struct btrfs_block_group *cache;
2564
2565 cache = btrfs_lookup_block_group(trans->fs_info, bytenr);
2566 BUG_ON(!cache); /* Logic error */
2567
2568 pin_down_extent(trans, cache, bytenr, num_bytes, reserved);
2569
2570 btrfs_put_block_group(cache);
2571 return 0;
2572 }
2573
2574 /*
2575 * this function must be called within transaction
2576 */
btrfs_pin_extent_for_log_replay(struct btrfs_trans_handle * trans,u64 bytenr,u64 num_bytes)2577 int btrfs_pin_extent_for_log_replay(struct btrfs_trans_handle *trans,
2578 u64 bytenr, u64 num_bytes)
2579 {
2580 struct btrfs_block_group *cache;
2581 int ret;
2582
2583 cache = btrfs_lookup_block_group(trans->fs_info, bytenr);
2584 if (!cache)
2585 return -EINVAL;
2586
2587 /*
2588 * pull in the free space cache (if any) so that our pin
2589 * removes the free space from the cache. We have load_only set
2590 * to one because the slow code to read in the free extents does check
2591 * the pinned extents.
2592 */
2593 btrfs_cache_block_group(cache, 1);
2594 /*
2595 * Make sure we wait until the cache is completely built in case it is
2596 * missing or is invalid and therefore needs to be rebuilt.
2597 */
2598 ret = btrfs_wait_block_group_cache_done(cache);
2599 if (ret)
2600 goto out;
2601
2602 pin_down_extent(trans, cache, bytenr, num_bytes, 0);
2603
2604 /* remove us from the free space cache (if we're there at all) */
2605 ret = btrfs_remove_free_space(cache, bytenr, num_bytes);
2606 out:
2607 btrfs_put_block_group(cache);
2608 return ret;
2609 }
2610
__exclude_logged_extent(struct btrfs_fs_info * fs_info,u64 start,u64 num_bytes)2611 static int __exclude_logged_extent(struct btrfs_fs_info *fs_info,
2612 u64 start, u64 num_bytes)
2613 {
2614 int ret;
2615 struct btrfs_block_group *block_group;
2616
2617 block_group = btrfs_lookup_block_group(fs_info, start);
2618 if (!block_group)
2619 return -EINVAL;
2620
2621 btrfs_cache_block_group(block_group, 1);
2622 /*
2623 * Make sure we wait until the cache is completely built in case it is
2624 * missing or is invalid and therefore needs to be rebuilt.
2625 */
2626 ret = btrfs_wait_block_group_cache_done(block_group);
2627 if (ret)
2628 goto out;
2629
2630 ret = btrfs_remove_free_space(block_group, start, num_bytes);
2631 out:
2632 btrfs_put_block_group(block_group);
2633 return ret;
2634 }
2635
btrfs_exclude_logged_extents(struct extent_buffer * eb)2636 int btrfs_exclude_logged_extents(struct extent_buffer *eb)
2637 {
2638 struct btrfs_fs_info *fs_info = eb->fs_info;
2639 struct btrfs_file_extent_item *item;
2640 struct btrfs_key key;
2641 int found_type;
2642 int i;
2643 int ret = 0;
2644
2645 if (!btrfs_fs_incompat(fs_info, MIXED_GROUPS))
2646 return 0;
2647
2648 for (i = 0; i < btrfs_header_nritems(eb); i++) {
2649 btrfs_item_key_to_cpu(eb, &key, i);
2650 if (key.type != BTRFS_EXTENT_DATA_KEY)
2651 continue;
2652 item = btrfs_item_ptr(eb, i, struct btrfs_file_extent_item);
2653 found_type = btrfs_file_extent_type(eb, item);
2654 if (found_type == BTRFS_FILE_EXTENT_INLINE)
2655 continue;
2656 if (btrfs_file_extent_disk_bytenr(eb, item) == 0)
2657 continue;
2658 key.objectid = btrfs_file_extent_disk_bytenr(eb, item);
2659 key.offset = btrfs_file_extent_disk_num_bytes(eb, item);
2660 ret = __exclude_logged_extent(fs_info, key.objectid, key.offset);
2661 if (ret)
2662 break;
2663 }
2664
2665 return ret;
2666 }
2667
2668 static void
btrfs_inc_block_group_reservations(struct btrfs_block_group * bg)2669 btrfs_inc_block_group_reservations(struct btrfs_block_group *bg)
2670 {
2671 atomic_inc(&bg->reservations);
2672 }
2673
2674 /*
2675 * Returns the free cluster for the given space info and sets empty_cluster to
2676 * what it should be based on the mount options.
2677 */
2678 static struct btrfs_free_cluster *
fetch_cluster_info(struct btrfs_fs_info * fs_info,struct btrfs_space_info * space_info,u64 * empty_cluster)2679 fetch_cluster_info(struct btrfs_fs_info *fs_info,
2680 struct btrfs_space_info *space_info, u64 *empty_cluster)
2681 {
2682 struct btrfs_free_cluster *ret = NULL;
2683
2684 *empty_cluster = 0;
2685 if (btrfs_mixed_space_info(space_info))
2686 return ret;
2687
2688 if (space_info->flags & BTRFS_BLOCK_GROUP_METADATA) {
2689 ret = &fs_info->meta_alloc_cluster;
2690 if (btrfs_test_opt(fs_info, SSD))
2691 *empty_cluster = SZ_2M;
2692 else
2693 *empty_cluster = SZ_64K;
2694 } else if ((space_info->flags & BTRFS_BLOCK_GROUP_DATA) &&
2695 btrfs_test_opt(fs_info, SSD_SPREAD)) {
2696 *empty_cluster = SZ_2M;
2697 ret = &fs_info->data_alloc_cluster;
2698 }
2699
2700 return ret;
2701 }
2702
unpin_extent_range(struct btrfs_fs_info * fs_info,u64 start,u64 end,const bool return_free_space)2703 static int unpin_extent_range(struct btrfs_fs_info *fs_info,
2704 u64 start, u64 end,
2705 const bool return_free_space)
2706 {
2707 struct btrfs_block_group *cache = NULL;
2708 struct btrfs_space_info *space_info;
2709 struct btrfs_block_rsv *global_rsv = &fs_info->global_block_rsv;
2710 struct btrfs_free_cluster *cluster = NULL;
2711 u64 len;
2712 u64 total_unpinned = 0;
2713 u64 empty_cluster = 0;
2714 bool readonly;
2715
2716 while (start <= end) {
2717 readonly = false;
2718 if (!cache ||
2719 start >= cache->start + cache->length) {
2720 if (cache)
2721 btrfs_put_block_group(cache);
2722 total_unpinned = 0;
2723 cache = btrfs_lookup_block_group(fs_info, start);
2724 BUG_ON(!cache); /* Logic error */
2725
2726 cluster = fetch_cluster_info(fs_info,
2727 cache->space_info,
2728 &empty_cluster);
2729 empty_cluster <<= 1;
2730 }
2731
2732 len = cache->start + cache->length - start;
2733 len = min(len, end + 1 - start);
2734
2735 down_read(&fs_info->commit_root_sem);
2736 if (start < cache->last_byte_to_unpin && return_free_space) {
2737 u64 add_len = min(len, cache->last_byte_to_unpin - start);
2738
2739 btrfs_add_free_space(cache, start, add_len);
2740 }
2741 up_read(&fs_info->commit_root_sem);
2742
2743 start += len;
2744 total_unpinned += len;
2745 space_info = cache->space_info;
2746
2747 /*
2748 * If this space cluster has been marked as fragmented and we've
2749 * unpinned enough in this block group to potentially allow a
2750 * cluster to be created inside of it go ahead and clear the
2751 * fragmented check.
2752 */
2753 if (cluster && cluster->fragmented &&
2754 total_unpinned > empty_cluster) {
2755 spin_lock(&cluster->lock);
2756 cluster->fragmented = 0;
2757 spin_unlock(&cluster->lock);
2758 }
2759
2760 spin_lock(&space_info->lock);
2761 spin_lock(&cache->lock);
2762 cache->pinned -= len;
2763 btrfs_space_info_update_bytes_pinned(fs_info, space_info, -len);
2764 space_info->max_extent_size = 0;
2765 __btrfs_mod_total_bytes_pinned(space_info, -len);
2766 if (cache->ro) {
2767 space_info->bytes_readonly += len;
2768 readonly = true;
2769 } else if (btrfs_is_zoned(fs_info)) {
2770 /* Need reset before reusing in a zoned block group */
2771 space_info->bytes_zone_unusable += len;
2772 readonly = true;
2773 }
2774 spin_unlock(&cache->lock);
2775 if (!readonly && return_free_space &&
2776 global_rsv->space_info == space_info) {
2777 u64 to_add = len;
2778
2779 spin_lock(&global_rsv->lock);
2780 if (!global_rsv->full) {
2781 to_add = min(len, global_rsv->size -
2782 global_rsv->reserved);
2783 global_rsv->reserved += to_add;
2784 btrfs_space_info_update_bytes_may_use(fs_info,
2785 space_info, to_add);
2786 if (global_rsv->reserved >= global_rsv->size)
2787 global_rsv->full = 1;
2788 len -= to_add;
2789 }
2790 spin_unlock(&global_rsv->lock);
2791 }
2792 /* Add to any tickets we may have */
2793 if (!readonly && return_free_space && len)
2794 btrfs_try_granting_tickets(fs_info, space_info);
2795 spin_unlock(&space_info->lock);
2796 }
2797
2798 if (cache)
2799 btrfs_put_block_group(cache);
2800 return 0;
2801 }
2802
btrfs_finish_extent_commit(struct btrfs_trans_handle * trans)2803 int btrfs_finish_extent_commit(struct btrfs_trans_handle *trans)
2804 {
2805 struct btrfs_fs_info *fs_info = trans->fs_info;
2806 struct btrfs_block_group *block_group, *tmp;
2807 struct list_head *deleted_bgs;
2808 struct extent_io_tree *unpin;
2809 u64 start;
2810 u64 end;
2811 int ret;
2812
2813 unpin = &trans->transaction->pinned_extents;
2814
2815 while (!TRANS_ABORTED(trans)) {
2816 struct extent_state *cached_state = NULL;
2817
2818 mutex_lock(&fs_info->unused_bg_unpin_mutex);
2819 ret = find_first_extent_bit(unpin, 0, &start, &end,
2820 EXTENT_DIRTY, &cached_state);
2821 if (ret) {
2822 mutex_unlock(&fs_info->unused_bg_unpin_mutex);
2823 break;
2824 }
2825
2826 if (btrfs_test_opt(fs_info, DISCARD_SYNC))
2827 ret = btrfs_discard_extent(fs_info, start,
2828 end + 1 - start, NULL);
2829
2830 clear_extent_dirty(unpin, start, end, &cached_state);
2831 unpin_extent_range(fs_info, start, end, true);
2832 mutex_unlock(&fs_info->unused_bg_unpin_mutex);
2833 free_extent_state(cached_state);
2834 cond_resched();
2835 }
2836
2837 if (btrfs_test_opt(fs_info, DISCARD_ASYNC)) {
2838 btrfs_discard_calc_delay(&fs_info->discard_ctl);
2839 btrfs_discard_schedule_work(&fs_info->discard_ctl, true);
2840 }
2841
2842 /*
2843 * Transaction is finished. We don't need the lock anymore. We
2844 * do need to clean up the block groups in case of a transaction
2845 * abort.
2846 */
2847 deleted_bgs = &trans->transaction->deleted_bgs;
2848 list_for_each_entry_safe(block_group, tmp, deleted_bgs, bg_list) {
2849 u64 trimmed = 0;
2850
2851 ret = -EROFS;
2852 if (!TRANS_ABORTED(trans))
2853 ret = btrfs_discard_extent(fs_info,
2854 block_group->start,
2855 block_group->length,
2856 &trimmed);
2857
2858 list_del_init(&block_group->bg_list);
2859 btrfs_unfreeze_block_group(block_group);
2860 btrfs_put_block_group(block_group);
2861
2862 if (ret) {
2863 const char *errstr = btrfs_decode_error(ret);
2864 btrfs_warn(fs_info,
2865 "discard failed while removing blockgroup: errno=%d %s",
2866 ret, errstr);
2867 }
2868 }
2869
2870 return 0;
2871 }
2872
2873 /*
2874 * Drop one or more refs of @node.
2875 *
2876 * 1. Locate the extent refs.
2877 * It's either inline in EXTENT/METADATA_ITEM or in keyed SHARED_* item.
2878 * Locate it, then reduce the refs number or remove the ref line completely.
2879 *
2880 * 2. Update the refs count in EXTENT/METADATA_ITEM
2881 *
2882 * Inline backref case:
2883 *
2884 * in extent tree we have:
2885 *
2886 * item 0 key (13631488 EXTENT_ITEM 1048576) itemoff 16201 itemsize 82
2887 * refs 2 gen 6 flags DATA
2888 * extent data backref root FS_TREE objectid 258 offset 0 count 1
2889 * extent data backref root FS_TREE objectid 257 offset 0 count 1
2890 *
2891 * This function gets called with:
2892 *
2893 * node->bytenr = 13631488
2894 * node->num_bytes = 1048576
2895 * root_objectid = FS_TREE
2896 * owner_objectid = 257
2897 * owner_offset = 0
2898 * refs_to_drop = 1
2899 *
2900 * Then we should get some like:
2901 *
2902 * item 0 key (13631488 EXTENT_ITEM 1048576) itemoff 16201 itemsize 82
2903 * refs 1 gen 6 flags DATA
2904 * extent data backref root FS_TREE objectid 258 offset 0 count 1
2905 *
2906 * Keyed backref case:
2907 *
2908 * in extent tree we have:
2909 *
2910 * item 0 key (13631488 EXTENT_ITEM 1048576) itemoff 3971 itemsize 24
2911 * refs 754 gen 6 flags DATA
2912 * [...]
2913 * item 2 key (13631488 EXTENT_DATA_REF <HASH>) itemoff 3915 itemsize 28
2914 * extent data backref root FS_TREE objectid 866 offset 0 count 1
2915 *
2916 * This function get called with:
2917 *
2918 * node->bytenr = 13631488
2919 * node->num_bytes = 1048576
2920 * root_objectid = FS_TREE
2921 * owner_objectid = 866
2922 * owner_offset = 0
2923 * refs_to_drop = 1
2924 *
2925 * Then we should get some like:
2926 *
2927 * item 0 key (13631488 EXTENT_ITEM 1048576) itemoff 3971 itemsize 24
2928 * refs 753 gen 6 flags DATA
2929 *
2930 * And that (13631488 EXTENT_DATA_REF <HASH>) gets removed.
2931 */
__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)2932 static int __btrfs_free_extent(struct btrfs_trans_handle *trans,
2933 struct btrfs_delayed_ref_node *node, u64 parent,
2934 u64 root_objectid, u64 owner_objectid,
2935 u64 owner_offset, int refs_to_drop,
2936 struct btrfs_delayed_extent_op *extent_op)
2937 {
2938 struct btrfs_fs_info *info = trans->fs_info;
2939 struct btrfs_key key;
2940 struct btrfs_path *path;
2941 struct btrfs_root *extent_root = info->extent_root;
2942 struct extent_buffer *leaf;
2943 struct btrfs_extent_item *ei;
2944 struct btrfs_extent_inline_ref *iref;
2945 int ret;
2946 int is_data;
2947 int extent_slot = 0;
2948 int found_extent = 0;
2949 int num_to_del = 1;
2950 u32 item_size;
2951 u64 refs;
2952 u64 bytenr = node->bytenr;
2953 u64 num_bytes = node->num_bytes;
2954 int last_ref = 0;
2955 bool skinny_metadata = btrfs_fs_incompat(info, SKINNY_METADATA);
2956
2957 path = btrfs_alloc_path();
2958 if (!path)
2959 return -ENOMEM;
2960
2961 is_data = owner_objectid >= BTRFS_FIRST_FREE_OBJECTID;
2962
2963 if (!is_data && refs_to_drop != 1) {
2964 btrfs_crit(info,
2965 "invalid refs_to_drop, dropping more than 1 refs for tree block %llu refs_to_drop %u",
2966 node->bytenr, refs_to_drop);
2967 ret = -EINVAL;
2968 btrfs_abort_transaction(trans, ret);
2969 goto out;
2970 }
2971
2972 if (is_data)
2973 skinny_metadata = false;
2974
2975 ret = lookup_extent_backref(trans, path, &iref, bytenr, num_bytes,
2976 parent, root_objectid, owner_objectid,
2977 owner_offset);
2978 if (ret == 0) {
2979 /*
2980 * Either the inline backref or the SHARED_DATA_REF/
2981 * SHARED_BLOCK_REF is found
2982 *
2983 * Here is a quick path to locate EXTENT/METADATA_ITEM.
2984 * It's possible the EXTENT/METADATA_ITEM is near current slot.
2985 */
2986 extent_slot = path->slots[0];
2987 while (extent_slot >= 0) {
2988 btrfs_item_key_to_cpu(path->nodes[0], &key,
2989 extent_slot);
2990 if (key.objectid != bytenr)
2991 break;
2992 if (key.type == BTRFS_EXTENT_ITEM_KEY &&
2993 key.offset == num_bytes) {
2994 found_extent = 1;
2995 break;
2996 }
2997 if (key.type == BTRFS_METADATA_ITEM_KEY &&
2998 key.offset == owner_objectid) {
2999 found_extent = 1;
3000 break;
3001 }
3002
3003 /* Quick path didn't find the EXTEMT/METADATA_ITEM */
3004 if (path->slots[0] - extent_slot > 5)
3005 break;
3006 extent_slot--;
3007 }
3008
3009 if (!found_extent) {
3010 if (iref) {
3011 btrfs_crit(info,
3012 "invalid iref, no EXTENT/METADATA_ITEM found but has inline extent ref");
3013 btrfs_abort_transaction(trans, -EUCLEAN);
3014 goto err_dump;
3015 }
3016 /* Must be SHARED_* item, remove the backref first */
3017 ret = remove_extent_backref(trans, path, NULL,
3018 refs_to_drop,
3019 is_data, &last_ref);
3020 if (ret) {
3021 btrfs_abort_transaction(trans, ret);
3022 goto out;
3023 }
3024 btrfs_release_path(path);
3025
3026 /* Slow path to locate EXTENT/METADATA_ITEM */
3027 key.objectid = bytenr;
3028 key.type = BTRFS_EXTENT_ITEM_KEY;
3029 key.offset = num_bytes;
3030
3031 if (!is_data && skinny_metadata) {
3032 key.type = BTRFS_METADATA_ITEM_KEY;
3033 key.offset = owner_objectid;
3034 }
3035
3036 ret = btrfs_search_slot(trans, extent_root,
3037 &key, path, -1, 1);
3038 if (ret > 0 && skinny_metadata && path->slots[0]) {
3039 /*
3040 * Couldn't find our skinny metadata item,
3041 * see if we have ye olde extent item.
3042 */
3043 path->slots[0]--;
3044 btrfs_item_key_to_cpu(path->nodes[0], &key,
3045 path->slots[0]);
3046 if (key.objectid == bytenr &&
3047 key.type == BTRFS_EXTENT_ITEM_KEY &&
3048 key.offset == num_bytes)
3049 ret = 0;
3050 }
3051
3052 if (ret > 0 && skinny_metadata) {
3053 skinny_metadata = false;
3054 key.objectid = bytenr;
3055 key.type = BTRFS_EXTENT_ITEM_KEY;
3056 key.offset = num_bytes;
3057 btrfs_release_path(path);
3058 ret = btrfs_search_slot(trans, extent_root,
3059 &key, path, -1, 1);
3060 }
3061
3062 if (ret) {
3063 btrfs_err(info,
3064 "umm, got %d back from search, was looking for %llu",
3065 ret, bytenr);
3066 if (ret > 0)
3067 btrfs_print_leaf(path->nodes[0]);
3068 }
3069 if (ret < 0) {
3070 btrfs_abort_transaction(trans, ret);
3071 goto out;
3072 }
3073 extent_slot = path->slots[0];
3074 }
3075 } else if (WARN_ON(ret == -ENOENT)) {
3076 btrfs_print_leaf(path->nodes[0]);
3077 btrfs_err(info,
3078 "unable to find ref byte nr %llu parent %llu root %llu owner %llu offset %llu",
3079 bytenr, parent, root_objectid, owner_objectid,
3080 owner_offset);
3081 btrfs_abort_transaction(trans, ret);
3082 goto out;
3083 } else {
3084 btrfs_abort_transaction(trans, ret);
3085 goto out;
3086 }
3087
3088 leaf = path->nodes[0];
3089 item_size = btrfs_item_size_nr(leaf, extent_slot);
3090 if (unlikely(item_size < sizeof(*ei))) {
3091 ret = -EINVAL;
3092 btrfs_print_v0_err(info);
3093 btrfs_abort_transaction(trans, ret);
3094 goto out;
3095 }
3096 ei = btrfs_item_ptr(leaf, extent_slot,
3097 struct btrfs_extent_item);
3098 if (owner_objectid < BTRFS_FIRST_FREE_OBJECTID &&
3099 key.type == BTRFS_EXTENT_ITEM_KEY) {
3100 struct btrfs_tree_block_info *bi;
3101 if (item_size < sizeof(*ei) + sizeof(*bi)) {
3102 btrfs_crit(info,
3103 "invalid extent item size for key (%llu, %u, %llu) owner %llu, has %u expect >= %zu",
3104 key.objectid, key.type, key.offset,
3105 owner_objectid, item_size,
3106 sizeof(*ei) + sizeof(*bi));
3107 btrfs_abort_transaction(trans, -EUCLEAN);
3108 goto err_dump;
3109 }
3110 bi = (struct btrfs_tree_block_info *)(ei + 1);
3111 WARN_ON(owner_objectid != btrfs_tree_block_level(leaf, bi));
3112 }
3113
3114 refs = btrfs_extent_refs(leaf, ei);
3115 if (refs < refs_to_drop) {
3116 btrfs_crit(info,
3117 "trying to drop %d refs but we only have %llu for bytenr %llu",
3118 refs_to_drop, refs, bytenr);
3119 btrfs_abort_transaction(trans, -EUCLEAN);
3120 goto err_dump;
3121 }
3122 refs -= refs_to_drop;
3123
3124 if (refs > 0) {
3125 if (extent_op)
3126 __run_delayed_extent_op(extent_op, leaf, ei);
3127 /*
3128 * In the case of inline back ref, reference count will
3129 * be updated by remove_extent_backref
3130 */
3131 if (iref) {
3132 if (!found_extent) {
3133 btrfs_crit(info,
3134 "invalid iref, got inlined extent ref but no EXTENT/METADATA_ITEM found");
3135 btrfs_abort_transaction(trans, -EUCLEAN);
3136 goto err_dump;
3137 }
3138 } else {
3139 btrfs_set_extent_refs(leaf, ei, refs);
3140 btrfs_mark_buffer_dirty(leaf);
3141 }
3142 if (found_extent) {
3143 ret = remove_extent_backref(trans, path, iref,
3144 refs_to_drop, is_data,
3145 &last_ref);
3146 if (ret) {
3147 btrfs_abort_transaction(trans, ret);
3148 goto out;
3149 }
3150 }
3151 } else {
3152 /* In this branch refs == 1 */
3153 if (found_extent) {
3154 if (is_data && refs_to_drop !=
3155 extent_data_ref_count(path, iref)) {
3156 btrfs_crit(info,
3157 "invalid refs_to_drop, current refs %u refs_to_drop %u",
3158 extent_data_ref_count(path, iref),
3159 refs_to_drop);
3160 btrfs_abort_transaction(trans, -EUCLEAN);
3161 goto err_dump;
3162 }
3163 if (iref) {
3164 if (path->slots[0] != extent_slot) {
3165 btrfs_crit(info,
3166 "invalid iref, extent item key (%llu %u %llu) doesn't have wanted iref",
3167 key.objectid, key.type,
3168 key.offset);
3169 btrfs_abort_transaction(trans, -EUCLEAN);
3170 goto err_dump;
3171 }
3172 } else {
3173 /*
3174 * No inline ref, we must be at SHARED_* item,
3175 * And it's single ref, it must be:
3176 * | extent_slot ||extent_slot + 1|
3177 * [ EXTENT/METADATA_ITEM ][ SHARED_* ITEM ]
3178 */
3179 if (path->slots[0] != extent_slot + 1) {
3180 btrfs_crit(info,
3181 "invalid SHARED_* item, previous item is not EXTENT/METADATA_ITEM");
3182 btrfs_abort_transaction(trans, -EUCLEAN);
3183 goto err_dump;
3184 }
3185 path->slots[0] = extent_slot;
3186 num_to_del = 2;
3187 }
3188 }
3189
3190 last_ref = 1;
3191 ret = btrfs_del_items(trans, extent_root, path, path->slots[0],
3192 num_to_del);
3193 if (ret) {
3194 btrfs_abort_transaction(trans, ret);
3195 goto out;
3196 }
3197 btrfs_release_path(path);
3198
3199 if (is_data) {
3200 ret = btrfs_del_csums(trans, info->csum_root, bytenr,
3201 num_bytes);
3202 if (ret) {
3203 btrfs_abort_transaction(trans, ret);
3204 goto out;
3205 }
3206 }
3207
3208 ret = add_to_free_space_tree(trans, bytenr, num_bytes);
3209 if (ret) {
3210 btrfs_abort_transaction(trans, ret);
3211 goto out;
3212 }
3213
3214 ret = btrfs_update_block_group(trans, bytenr, num_bytes, 0);
3215 if (ret) {
3216 btrfs_abort_transaction(trans, ret);
3217 goto out;
3218 }
3219 }
3220 btrfs_release_path(path);
3221
3222 out:
3223 btrfs_free_path(path);
3224 return ret;
3225 err_dump:
3226 /*
3227 * Leaf dump can take up a lot of log buffer, so we only do full leaf
3228 * dump for debug build.
3229 */
3230 if (IS_ENABLED(CONFIG_BTRFS_DEBUG)) {
3231 btrfs_crit(info, "path->slots[0]=%d extent_slot=%d",
3232 path->slots[0], extent_slot);
3233 btrfs_print_leaf(path->nodes[0]);
3234 }
3235
3236 btrfs_free_path(path);
3237 return -EUCLEAN;
3238 }
3239
3240 /*
3241 * when we free an block, it is possible (and likely) that we free the last
3242 * delayed ref for that extent as well. This searches the delayed ref tree for
3243 * a given extent, and if there are no other delayed refs to be processed, it
3244 * removes it from the tree.
3245 */
check_ref_cleanup(struct btrfs_trans_handle * trans,u64 bytenr)3246 static noinline int check_ref_cleanup(struct btrfs_trans_handle *trans,
3247 u64 bytenr)
3248 {
3249 struct btrfs_delayed_ref_head *head;
3250 struct btrfs_delayed_ref_root *delayed_refs;
3251 int ret = 0;
3252
3253 delayed_refs = &trans->transaction->delayed_refs;
3254 spin_lock(&delayed_refs->lock);
3255 head = btrfs_find_delayed_ref_head(delayed_refs, bytenr);
3256 if (!head)
3257 goto out_delayed_unlock;
3258
3259 spin_lock(&head->lock);
3260 if (!RB_EMPTY_ROOT(&head->ref_tree.rb_root))
3261 goto out;
3262
3263 if (cleanup_extent_op(head) != NULL)
3264 goto out;
3265
3266 /*
3267 * waiting for the lock here would deadlock. If someone else has it
3268 * locked they are already in the process of dropping it anyway
3269 */
3270 if (!mutex_trylock(&head->mutex))
3271 goto out;
3272
3273 btrfs_delete_ref_head(delayed_refs, head);
3274 head->processing = 0;
3275
3276 spin_unlock(&head->lock);
3277 spin_unlock(&delayed_refs->lock);
3278
3279 BUG_ON(head->extent_op);
3280 if (head->must_insert_reserved)
3281 ret = 1;
3282
3283 btrfs_cleanup_ref_head_accounting(trans->fs_info, delayed_refs, head);
3284 mutex_unlock(&head->mutex);
3285 btrfs_put_delayed_ref_head(head);
3286 return ret;
3287 out:
3288 spin_unlock(&head->lock);
3289
3290 out_delayed_unlock:
3291 spin_unlock(&delayed_refs->lock);
3292 return 0;
3293 }
3294
btrfs_free_tree_block(struct btrfs_trans_handle * trans,struct btrfs_root * root,struct extent_buffer * buf,u64 parent,int last_ref)3295 void btrfs_free_tree_block(struct btrfs_trans_handle *trans,
3296 struct btrfs_root *root,
3297 struct extent_buffer *buf,
3298 u64 parent, int last_ref)
3299 {
3300 struct btrfs_fs_info *fs_info = root->fs_info;
3301 struct btrfs_ref generic_ref = { 0 };
3302 int ret;
3303
3304 btrfs_init_generic_ref(&generic_ref, BTRFS_DROP_DELAYED_REF,
3305 buf->start, buf->len, parent);
3306 btrfs_init_tree_ref(&generic_ref, btrfs_header_level(buf),
3307 root->root_key.objectid);
3308
3309 if (root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID) {
3310 btrfs_ref_tree_mod(fs_info, &generic_ref);
3311 ret = btrfs_add_delayed_tree_ref(trans, &generic_ref, NULL);
3312 BUG_ON(ret); /* -ENOMEM */
3313 }
3314
3315 if (last_ref && btrfs_header_generation(buf) == trans->transid) {
3316 struct btrfs_block_group *cache;
3317 bool must_pin = false;
3318
3319 if (root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID) {
3320 ret = check_ref_cleanup(trans, buf->start);
3321 if (!ret) {
3322 btrfs_redirty_list_add(trans->transaction, buf);
3323 goto out;
3324 }
3325 }
3326
3327 cache = btrfs_lookup_block_group(fs_info, buf->start);
3328
3329 if (btrfs_header_flag(buf, BTRFS_HEADER_FLAG_WRITTEN)) {
3330 pin_down_extent(trans, cache, buf->start, buf->len, 1);
3331 btrfs_put_block_group(cache);
3332 goto out;
3333 }
3334
3335 /*
3336 * If this is a leaf and there are tree mod log users, we may
3337 * have recorded mod log operations that point to this leaf.
3338 * So we must make sure no one reuses this leaf's extent before
3339 * mod log operations are applied to a node, otherwise after
3340 * rewinding a node using the mod log operations we get an
3341 * inconsistent btree, as the leaf's extent may now be used as
3342 * a node or leaf for another different btree.
3343 * We are safe from races here because at this point no other
3344 * node or root points to this extent buffer, so if after this
3345 * check a new tree mod log user joins, it will not be able to
3346 * find a node pointing to this leaf and record operations that
3347 * point to this leaf.
3348 */
3349 if (btrfs_header_level(buf) == 0 &&
3350 test_bit(BTRFS_FS_TREE_MOD_LOG_USERS, &fs_info->flags))
3351 must_pin = true;
3352
3353 if (must_pin || btrfs_is_zoned(fs_info)) {
3354 btrfs_redirty_list_add(trans->transaction, buf);
3355 pin_down_extent(trans, cache, buf->start, buf->len, 1);
3356 btrfs_put_block_group(cache);
3357 goto out;
3358 }
3359
3360 WARN_ON(test_bit(EXTENT_BUFFER_DIRTY, &buf->bflags));
3361
3362 btrfs_add_free_space(cache, buf->start, buf->len);
3363 btrfs_free_reserved_bytes(cache, buf->len, 0);
3364 btrfs_put_block_group(cache);
3365 trace_btrfs_reserved_extent_free(fs_info, buf->start, buf->len);
3366 }
3367 out:
3368 if (last_ref) {
3369 /*
3370 * Deleting the buffer, clear the corrupt flag since it doesn't
3371 * matter anymore.
3372 */
3373 clear_bit(EXTENT_BUFFER_CORRUPT, &buf->bflags);
3374 }
3375 }
3376
3377 /* Can return -ENOMEM */
btrfs_free_extent(struct btrfs_trans_handle * trans,struct btrfs_ref * ref)3378 int btrfs_free_extent(struct btrfs_trans_handle *trans, struct btrfs_ref *ref)
3379 {
3380 struct btrfs_fs_info *fs_info = trans->fs_info;
3381 int ret;
3382
3383 if (btrfs_is_testing(fs_info))
3384 return 0;
3385
3386 /*
3387 * tree log blocks never actually go into the extent allocation
3388 * tree, just update pinning info and exit early.
3389 */
3390 if ((ref->type == BTRFS_REF_METADATA &&
3391 ref->tree_ref.root == BTRFS_TREE_LOG_OBJECTID) ||
3392 (ref->type == BTRFS_REF_DATA &&
3393 ref->data_ref.ref_root == BTRFS_TREE_LOG_OBJECTID)) {
3394 /* unlocks the pinned mutex */
3395 btrfs_pin_extent(trans, ref->bytenr, ref->len, 1);
3396 ret = 0;
3397 } else if (ref->type == BTRFS_REF_METADATA) {
3398 ret = btrfs_add_delayed_tree_ref(trans, ref, NULL);
3399 } else {
3400 ret = btrfs_add_delayed_data_ref(trans, ref, 0);
3401 }
3402
3403 if (!((ref->type == BTRFS_REF_METADATA &&
3404 ref->tree_ref.root == BTRFS_TREE_LOG_OBJECTID) ||
3405 (ref->type == BTRFS_REF_DATA &&
3406 ref->data_ref.ref_root == BTRFS_TREE_LOG_OBJECTID)))
3407 btrfs_ref_tree_mod(fs_info, ref);
3408
3409 return ret;
3410 }
3411
3412 enum btrfs_loop_type {
3413 LOOP_CACHING_NOWAIT,
3414 LOOP_CACHING_WAIT,
3415 LOOP_ALLOC_CHUNK,
3416 LOOP_NO_EMPTY_SIZE,
3417 };
3418
3419 static inline void
btrfs_lock_block_group(struct btrfs_block_group * cache,int delalloc)3420 btrfs_lock_block_group(struct btrfs_block_group *cache,
3421 int delalloc)
3422 {
3423 if (delalloc)
3424 down_read(&cache->data_rwsem);
3425 }
3426
btrfs_grab_block_group(struct btrfs_block_group * cache,int delalloc)3427 static inline void btrfs_grab_block_group(struct btrfs_block_group *cache,
3428 int delalloc)
3429 {
3430 btrfs_get_block_group(cache);
3431 if (delalloc)
3432 down_read(&cache->data_rwsem);
3433 }
3434
btrfs_lock_cluster(struct btrfs_block_group * block_group,struct btrfs_free_cluster * cluster,int delalloc)3435 static struct btrfs_block_group *btrfs_lock_cluster(
3436 struct btrfs_block_group *block_group,
3437 struct btrfs_free_cluster *cluster,
3438 int delalloc)
3439 __acquires(&cluster->refill_lock)
3440 {
3441 struct btrfs_block_group *used_bg = NULL;
3442
3443 spin_lock(&cluster->refill_lock);
3444 while (1) {
3445 used_bg = cluster->block_group;
3446 if (!used_bg)
3447 return NULL;
3448
3449 if (used_bg == block_group)
3450 return used_bg;
3451
3452 btrfs_get_block_group(used_bg);
3453
3454 if (!delalloc)
3455 return used_bg;
3456
3457 if (down_read_trylock(&used_bg->data_rwsem))
3458 return used_bg;
3459
3460 spin_unlock(&cluster->refill_lock);
3461
3462 /* We should only have one-level nested. */
3463 down_read_nested(&used_bg->data_rwsem, SINGLE_DEPTH_NESTING);
3464
3465 spin_lock(&cluster->refill_lock);
3466 if (used_bg == cluster->block_group)
3467 return used_bg;
3468
3469 up_read(&used_bg->data_rwsem);
3470 btrfs_put_block_group(used_bg);
3471 }
3472 }
3473
3474 static inline void
btrfs_release_block_group(struct btrfs_block_group * cache,int delalloc)3475 btrfs_release_block_group(struct btrfs_block_group *cache,
3476 int delalloc)
3477 {
3478 if (delalloc)
3479 up_read(&cache->data_rwsem);
3480 btrfs_put_block_group(cache);
3481 }
3482
3483 enum btrfs_extent_allocation_policy {
3484 BTRFS_EXTENT_ALLOC_CLUSTERED,
3485 BTRFS_EXTENT_ALLOC_ZONED,
3486 };
3487
3488 /*
3489 * Structure used internally for find_free_extent() function. Wraps needed
3490 * parameters.
3491 */
3492 struct find_free_extent_ctl {
3493 /* Basic allocation info */
3494 u64 num_bytes;
3495 u64 empty_size;
3496 u64 flags;
3497 int delalloc;
3498
3499 /* Where to start the search inside the bg */
3500 u64 search_start;
3501
3502 /* For clustered allocation */
3503 u64 empty_cluster;
3504 struct btrfs_free_cluster *last_ptr;
3505 bool use_cluster;
3506
3507 bool have_caching_bg;
3508 bool orig_have_caching_bg;
3509
3510 /* Allocation is called for tree-log */
3511 bool for_treelog;
3512
3513 /* RAID index, converted from flags */
3514 int index;
3515
3516 /*
3517 * Current loop number, check find_free_extent_update_loop() for details
3518 */
3519 int loop;
3520
3521 /*
3522 * Whether we're refilling a cluster, if true we need to re-search
3523 * current block group but don't try to refill the cluster again.
3524 */
3525 bool retry_clustered;
3526
3527 /*
3528 * Whether we're updating free space cache, if true we need to re-search
3529 * current block group but don't try updating free space cache again.
3530 */
3531 bool retry_unclustered;
3532
3533 /* If current block group is cached */
3534 int cached;
3535
3536 /* Max contiguous hole found */
3537 u64 max_extent_size;
3538
3539 /* Total free space from free space cache, not always contiguous */
3540 u64 total_free_space;
3541
3542 /* Found result */
3543 u64 found_offset;
3544
3545 /* Hint where to start looking for an empty space */
3546 u64 hint_byte;
3547
3548 /* Allocation policy */
3549 enum btrfs_extent_allocation_policy policy;
3550 };
3551
3552
3553 /*
3554 * Helper function for find_free_extent().
3555 *
3556 * Return -ENOENT to inform caller that we need fallback to unclustered mode.
3557 * Return -EAGAIN to inform caller that we need to re-search this block group
3558 * Return >0 to inform caller that we find nothing
3559 * Return 0 means we have found a location and set ffe_ctl->found_offset.
3560 */
find_free_extent_clustered(struct btrfs_block_group * bg,struct find_free_extent_ctl * ffe_ctl,struct btrfs_block_group ** cluster_bg_ret)3561 static int find_free_extent_clustered(struct btrfs_block_group *bg,
3562 struct find_free_extent_ctl *ffe_ctl,
3563 struct btrfs_block_group **cluster_bg_ret)
3564 {
3565 struct btrfs_block_group *cluster_bg;
3566 struct btrfs_free_cluster *last_ptr = ffe_ctl->last_ptr;
3567 u64 aligned_cluster;
3568 u64 offset;
3569 int ret;
3570
3571 cluster_bg = btrfs_lock_cluster(bg, last_ptr, ffe_ctl->delalloc);
3572 if (!cluster_bg)
3573 goto refill_cluster;
3574 if (cluster_bg != bg && (cluster_bg->ro ||
3575 !block_group_bits(cluster_bg, ffe_ctl->flags)))
3576 goto release_cluster;
3577
3578 offset = btrfs_alloc_from_cluster(cluster_bg, last_ptr,
3579 ffe_ctl->num_bytes, cluster_bg->start,
3580 &ffe_ctl->max_extent_size);
3581 if (offset) {
3582 /* We have a block, we're done */
3583 spin_unlock(&last_ptr->refill_lock);
3584 trace_btrfs_reserve_extent_cluster(cluster_bg,
3585 ffe_ctl->search_start, ffe_ctl->num_bytes);
3586 *cluster_bg_ret = cluster_bg;
3587 ffe_ctl->found_offset = offset;
3588 return 0;
3589 }
3590 WARN_ON(last_ptr->block_group != cluster_bg);
3591
3592 release_cluster:
3593 /*
3594 * If we are on LOOP_NO_EMPTY_SIZE, we can't set up a new clusters, so
3595 * lets just skip it and let the allocator find whatever block it can
3596 * find. If we reach this point, we will have tried the cluster
3597 * allocator plenty of times and not have found anything, so we are
3598 * likely way too fragmented for the clustering stuff to find anything.
3599 *
3600 * However, if the cluster is taken from the current block group,
3601 * release the cluster first, so that we stand a better chance of
3602 * succeeding in the unclustered allocation.
3603 */
3604 if (ffe_ctl->loop >= LOOP_NO_EMPTY_SIZE && cluster_bg != bg) {
3605 spin_unlock(&last_ptr->refill_lock);
3606 btrfs_release_block_group(cluster_bg, ffe_ctl->delalloc);
3607 return -ENOENT;
3608 }
3609
3610 /* This cluster didn't work out, free it and start over */
3611 btrfs_return_cluster_to_free_space(NULL, last_ptr);
3612
3613 if (cluster_bg != bg)
3614 btrfs_release_block_group(cluster_bg, ffe_ctl->delalloc);
3615
3616 refill_cluster:
3617 if (ffe_ctl->loop >= LOOP_NO_EMPTY_SIZE) {
3618 spin_unlock(&last_ptr->refill_lock);
3619 return -ENOENT;
3620 }
3621
3622 aligned_cluster = max_t(u64,
3623 ffe_ctl->empty_cluster + ffe_ctl->empty_size,
3624 bg->full_stripe_len);
3625 ret = btrfs_find_space_cluster(bg, last_ptr, ffe_ctl->search_start,
3626 ffe_ctl->num_bytes, aligned_cluster);
3627 if (ret == 0) {
3628 /* Now pull our allocation out of this cluster */
3629 offset = btrfs_alloc_from_cluster(bg, last_ptr,
3630 ffe_ctl->num_bytes, ffe_ctl->search_start,
3631 &ffe_ctl->max_extent_size);
3632 if (offset) {
3633 /* We found one, proceed */
3634 spin_unlock(&last_ptr->refill_lock);
3635 trace_btrfs_reserve_extent_cluster(bg,
3636 ffe_ctl->search_start,
3637 ffe_ctl->num_bytes);
3638 ffe_ctl->found_offset = offset;
3639 return 0;
3640 }
3641 } else if (!ffe_ctl->cached && ffe_ctl->loop > LOOP_CACHING_NOWAIT &&
3642 !ffe_ctl->retry_clustered) {
3643 spin_unlock(&last_ptr->refill_lock);
3644
3645 ffe_ctl->retry_clustered = true;
3646 btrfs_wait_block_group_cache_progress(bg, ffe_ctl->num_bytes +
3647 ffe_ctl->empty_cluster + ffe_ctl->empty_size);
3648 return -EAGAIN;
3649 }
3650 /*
3651 * At this point we either didn't find a cluster or we weren't able to
3652 * allocate a block from our cluster. Free the cluster we've been
3653 * trying to use, and go to the next block group.
3654 */
3655 btrfs_return_cluster_to_free_space(NULL, last_ptr);
3656 spin_unlock(&last_ptr->refill_lock);
3657 return 1;
3658 }
3659
3660 /*
3661 * Return >0 to inform caller that we find nothing
3662 * Return 0 when we found an free extent and set ffe_ctrl->found_offset
3663 * Return -EAGAIN to inform caller that we need to re-search this block group
3664 */
find_free_extent_unclustered(struct btrfs_block_group * bg,struct find_free_extent_ctl * ffe_ctl)3665 static int find_free_extent_unclustered(struct btrfs_block_group *bg,
3666 struct find_free_extent_ctl *ffe_ctl)
3667 {
3668 struct btrfs_free_cluster *last_ptr = ffe_ctl->last_ptr;
3669 u64 offset;
3670
3671 /*
3672 * We are doing an unclustered allocation, set the fragmented flag so
3673 * we don't bother trying to setup a cluster again until we get more
3674 * space.
3675 */
3676 if (unlikely(last_ptr)) {
3677 spin_lock(&last_ptr->lock);
3678 last_ptr->fragmented = 1;
3679 spin_unlock(&last_ptr->lock);
3680 }
3681 if (ffe_ctl->cached) {
3682 struct btrfs_free_space_ctl *free_space_ctl;
3683
3684 free_space_ctl = bg->free_space_ctl;
3685 spin_lock(&free_space_ctl->tree_lock);
3686 if (free_space_ctl->free_space <
3687 ffe_ctl->num_bytes + ffe_ctl->empty_cluster +
3688 ffe_ctl->empty_size) {
3689 ffe_ctl->total_free_space = max_t(u64,
3690 ffe_ctl->total_free_space,
3691 free_space_ctl->free_space);
3692 spin_unlock(&free_space_ctl->tree_lock);
3693 return 1;
3694 }
3695 spin_unlock(&free_space_ctl->tree_lock);
3696 }
3697
3698 offset = btrfs_find_space_for_alloc(bg, ffe_ctl->search_start,
3699 ffe_ctl->num_bytes, ffe_ctl->empty_size,
3700 &ffe_ctl->max_extent_size);
3701
3702 /*
3703 * If we didn't find a chunk, and we haven't failed on this block group
3704 * before, and this block group is in the middle of caching and we are
3705 * ok with waiting, then go ahead and wait for progress to be made, and
3706 * set @retry_unclustered to true.
3707 *
3708 * If @retry_unclustered is true then we've already waited on this
3709 * block group once and should move on to the next block group.
3710 */
3711 if (!offset && !ffe_ctl->retry_unclustered && !ffe_ctl->cached &&
3712 ffe_ctl->loop > LOOP_CACHING_NOWAIT) {
3713 btrfs_wait_block_group_cache_progress(bg, ffe_ctl->num_bytes +
3714 ffe_ctl->empty_size);
3715 ffe_ctl->retry_unclustered = true;
3716 return -EAGAIN;
3717 } else if (!offset) {
3718 return 1;
3719 }
3720 ffe_ctl->found_offset = offset;
3721 return 0;
3722 }
3723
do_allocation_clustered(struct btrfs_block_group * block_group,struct find_free_extent_ctl * ffe_ctl,struct btrfs_block_group ** bg_ret)3724 static int do_allocation_clustered(struct btrfs_block_group *block_group,
3725 struct find_free_extent_ctl *ffe_ctl,
3726 struct btrfs_block_group **bg_ret)
3727 {
3728 int ret;
3729
3730 /* We want to try and use the cluster allocator, so lets look there */
3731 if (ffe_ctl->last_ptr && ffe_ctl->use_cluster) {
3732 ret = find_free_extent_clustered(block_group, ffe_ctl, bg_ret);
3733 if (ret >= 0 || ret == -EAGAIN)
3734 return ret;
3735 /* ret == -ENOENT case falls through */
3736 }
3737
3738 return find_free_extent_unclustered(block_group, ffe_ctl);
3739 }
3740
3741 /*
3742 * Tree-log block group locking
3743 * ============================
3744 *
3745 * fs_info::treelog_bg_lock protects the fs_info::treelog_bg which
3746 * indicates the starting address of a block group, which is reserved only
3747 * for tree-log metadata.
3748 *
3749 * Lock nesting
3750 * ============
3751 *
3752 * space_info::lock
3753 * block_group::lock
3754 * fs_info::treelog_bg_lock
3755 */
3756
3757 /*
3758 * Simple allocator for sequential-only block group. It only allows sequential
3759 * allocation. No need to play with trees. This function also reserves the
3760 * bytes as in btrfs_add_reserved_bytes.
3761 */
do_allocation_zoned(struct btrfs_block_group * block_group,struct find_free_extent_ctl * ffe_ctl,struct btrfs_block_group ** bg_ret)3762 static int do_allocation_zoned(struct btrfs_block_group *block_group,
3763 struct find_free_extent_ctl *ffe_ctl,
3764 struct btrfs_block_group **bg_ret)
3765 {
3766 struct btrfs_fs_info *fs_info = block_group->fs_info;
3767 struct btrfs_space_info *space_info = block_group->space_info;
3768 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
3769 u64 start = block_group->start;
3770 u64 num_bytes = ffe_ctl->num_bytes;
3771 u64 avail;
3772 u64 bytenr = block_group->start;
3773 u64 log_bytenr;
3774 int ret = 0;
3775 bool skip;
3776
3777 ASSERT(btrfs_is_zoned(block_group->fs_info));
3778
3779 /*
3780 * Do not allow non-tree-log blocks in the dedicated tree-log block
3781 * group, and vice versa.
3782 */
3783 spin_lock(&fs_info->treelog_bg_lock);
3784 log_bytenr = fs_info->treelog_bg;
3785 skip = log_bytenr && ((ffe_ctl->for_treelog && bytenr != log_bytenr) ||
3786 (!ffe_ctl->for_treelog && bytenr == log_bytenr));
3787 spin_unlock(&fs_info->treelog_bg_lock);
3788 if (skip)
3789 return 1;
3790
3791 spin_lock(&space_info->lock);
3792 spin_lock(&block_group->lock);
3793 spin_lock(&fs_info->treelog_bg_lock);
3794
3795 ASSERT(!ffe_ctl->for_treelog ||
3796 block_group->start == fs_info->treelog_bg ||
3797 fs_info->treelog_bg == 0);
3798
3799 if (block_group->ro) {
3800 ret = 1;
3801 goto out;
3802 }
3803
3804 /*
3805 * Do not allow currently using block group to be tree-log dedicated
3806 * block group.
3807 */
3808 if (ffe_ctl->for_treelog && !fs_info->treelog_bg &&
3809 (block_group->used || block_group->reserved)) {
3810 ret = 1;
3811 goto out;
3812 }
3813
3814 avail = block_group->length - block_group->alloc_offset;
3815 if (avail < num_bytes) {
3816 if (ffe_ctl->max_extent_size < avail) {
3817 /*
3818 * With sequential allocator, free space is always
3819 * contiguous
3820 */
3821 ffe_ctl->max_extent_size = avail;
3822 ffe_ctl->total_free_space = avail;
3823 }
3824 ret = 1;
3825 goto out;
3826 }
3827
3828 if (ffe_ctl->for_treelog && !fs_info->treelog_bg)
3829 fs_info->treelog_bg = block_group->start;
3830
3831 ffe_ctl->found_offset = start + block_group->alloc_offset;
3832 block_group->alloc_offset += num_bytes;
3833 spin_lock(&ctl->tree_lock);
3834 ctl->free_space -= num_bytes;
3835 spin_unlock(&ctl->tree_lock);
3836
3837 /*
3838 * We do not check if found_offset is aligned to stripesize. The
3839 * address is anyway rewritten when using zone append writing.
3840 */
3841
3842 ffe_ctl->search_start = ffe_ctl->found_offset;
3843
3844 out:
3845 if (ret && ffe_ctl->for_treelog)
3846 fs_info->treelog_bg = 0;
3847 spin_unlock(&fs_info->treelog_bg_lock);
3848 spin_unlock(&block_group->lock);
3849 spin_unlock(&space_info->lock);
3850 return ret;
3851 }
3852
do_allocation(struct btrfs_block_group * block_group,struct find_free_extent_ctl * ffe_ctl,struct btrfs_block_group ** bg_ret)3853 static int do_allocation(struct btrfs_block_group *block_group,
3854 struct find_free_extent_ctl *ffe_ctl,
3855 struct btrfs_block_group **bg_ret)
3856 {
3857 switch (ffe_ctl->policy) {
3858 case BTRFS_EXTENT_ALLOC_CLUSTERED:
3859 return do_allocation_clustered(block_group, ffe_ctl, bg_ret);
3860 case BTRFS_EXTENT_ALLOC_ZONED:
3861 return do_allocation_zoned(block_group, ffe_ctl, bg_ret);
3862 default:
3863 BUG();
3864 }
3865 }
3866
release_block_group(struct btrfs_block_group * block_group,struct find_free_extent_ctl * ffe_ctl,int delalloc)3867 static void release_block_group(struct btrfs_block_group *block_group,
3868 struct find_free_extent_ctl *ffe_ctl,
3869 int delalloc)
3870 {
3871 switch (ffe_ctl->policy) {
3872 case BTRFS_EXTENT_ALLOC_CLUSTERED:
3873 ffe_ctl->retry_clustered = false;
3874 ffe_ctl->retry_unclustered = false;
3875 break;
3876 case BTRFS_EXTENT_ALLOC_ZONED:
3877 /* Nothing to do */
3878 break;
3879 default:
3880 BUG();
3881 }
3882
3883 BUG_ON(btrfs_bg_flags_to_raid_index(block_group->flags) !=
3884 ffe_ctl->index);
3885 btrfs_release_block_group(block_group, delalloc);
3886 }
3887
found_extent_clustered(struct find_free_extent_ctl * ffe_ctl,struct btrfs_key * ins)3888 static void found_extent_clustered(struct find_free_extent_ctl *ffe_ctl,
3889 struct btrfs_key *ins)
3890 {
3891 struct btrfs_free_cluster *last_ptr = ffe_ctl->last_ptr;
3892
3893 if (!ffe_ctl->use_cluster && last_ptr) {
3894 spin_lock(&last_ptr->lock);
3895 last_ptr->window_start = ins->objectid;
3896 spin_unlock(&last_ptr->lock);
3897 }
3898 }
3899
found_extent(struct find_free_extent_ctl * ffe_ctl,struct btrfs_key * ins)3900 static void found_extent(struct find_free_extent_ctl *ffe_ctl,
3901 struct btrfs_key *ins)
3902 {
3903 switch (ffe_ctl->policy) {
3904 case BTRFS_EXTENT_ALLOC_CLUSTERED:
3905 found_extent_clustered(ffe_ctl, ins);
3906 break;
3907 case BTRFS_EXTENT_ALLOC_ZONED:
3908 /* Nothing to do */
3909 break;
3910 default:
3911 BUG();
3912 }
3913 }
3914
chunk_allocation_failed(struct find_free_extent_ctl * ffe_ctl)3915 static int chunk_allocation_failed(struct find_free_extent_ctl *ffe_ctl)
3916 {
3917 switch (ffe_ctl->policy) {
3918 case BTRFS_EXTENT_ALLOC_CLUSTERED:
3919 /*
3920 * If we can't allocate a new chunk we've already looped through
3921 * at least once, move on to the NO_EMPTY_SIZE case.
3922 */
3923 ffe_ctl->loop = LOOP_NO_EMPTY_SIZE;
3924 return 0;
3925 case BTRFS_EXTENT_ALLOC_ZONED:
3926 /* Give up here */
3927 return -ENOSPC;
3928 default:
3929 BUG();
3930 }
3931 }
3932
3933 /*
3934 * Return >0 means caller needs to re-search for free extent
3935 * Return 0 means we have the needed free extent.
3936 * Return <0 means we failed to locate any free extent.
3937 */
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)3938 static int find_free_extent_update_loop(struct btrfs_fs_info *fs_info,
3939 struct btrfs_key *ins,
3940 struct find_free_extent_ctl *ffe_ctl,
3941 bool full_search)
3942 {
3943 struct btrfs_root *root = fs_info->extent_root;
3944 int ret;
3945
3946 if ((ffe_ctl->loop == LOOP_CACHING_NOWAIT) &&
3947 ffe_ctl->have_caching_bg && !ffe_ctl->orig_have_caching_bg)
3948 ffe_ctl->orig_have_caching_bg = true;
3949
3950 if (!ins->objectid && ffe_ctl->loop >= LOOP_CACHING_WAIT &&
3951 ffe_ctl->have_caching_bg)
3952 return 1;
3953
3954 if (!ins->objectid && ++(ffe_ctl->index) < BTRFS_NR_RAID_TYPES)
3955 return 1;
3956
3957 if (ins->objectid) {
3958 found_extent(ffe_ctl, ins);
3959 return 0;
3960 }
3961
3962 /*
3963 * LOOP_CACHING_NOWAIT, search partially cached block groups, kicking
3964 * caching kthreads as we move along
3965 * LOOP_CACHING_WAIT, search everything, and wait if our bg is caching
3966 * LOOP_ALLOC_CHUNK, force a chunk allocation and try again
3967 * LOOP_NO_EMPTY_SIZE, set empty_size and empty_cluster to 0 and try
3968 * again
3969 */
3970 if (ffe_ctl->loop < LOOP_NO_EMPTY_SIZE) {
3971 ffe_ctl->index = 0;
3972 if (ffe_ctl->loop == LOOP_CACHING_NOWAIT) {
3973 /*
3974 * We want to skip the LOOP_CACHING_WAIT step if we
3975 * don't have any uncached bgs and we've already done a
3976 * full search through.
3977 */
3978 if (ffe_ctl->orig_have_caching_bg || !full_search)
3979 ffe_ctl->loop = LOOP_CACHING_WAIT;
3980 else
3981 ffe_ctl->loop = LOOP_ALLOC_CHUNK;
3982 } else {
3983 ffe_ctl->loop++;
3984 }
3985
3986 if (ffe_ctl->loop == LOOP_ALLOC_CHUNK) {
3987 struct btrfs_trans_handle *trans;
3988 int exist = 0;
3989
3990 trans = current->journal_info;
3991 if (trans)
3992 exist = 1;
3993 else
3994 trans = btrfs_join_transaction(root);
3995
3996 if (IS_ERR(trans)) {
3997 ret = PTR_ERR(trans);
3998 return ret;
3999 }
4000
4001 ret = btrfs_chunk_alloc(trans, ffe_ctl->flags,
4002 CHUNK_ALLOC_FORCE);
4003
4004 /* Do not bail out on ENOSPC since we can do more. */
4005 if (ret == -ENOSPC)
4006 ret = chunk_allocation_failed(ffe_ctl);
4007 else if (ret < 0)
4008 btrfs_abort_transaction(trans, ret);
4009 else
4010 ret = 0;
4011 if (!exist)
4012 btrfs_end_transaction(trans);
4013 if (ret)
4014 return ret;
4015 }
4016
4017 if (ffe_ctl->loop == LOOP_NO_EMPTY_SIZE) {
4018 if (ffe_ctl->policy != BTRFS_EXTENT_ALLOC_CLUSTERED)
4019 return -ENOSPC;
4020
4021 /*
4022 * Don't loop again if we already have no empty_size and
4023 * no empty_cluster.
4024 */
4025 if (ffe_ctl->empty_size == 0 &&
4026 ffe_ctl->empty_cluster == 0)
4027 return -ENOSPC;
4028 ffe_ctl->empty_size = 0;
4029 ffe_ctl->empty_cluster = 0;
4030 }
4031 return 1;
4032 }
4033 return -ENOSPC;
4034 }
4035
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)4036 static int prepare_allocation_clustered(struct btrfs_fs_info *fs_info,
4037 struct find_free_extent_ctl *ffe_ctl,
4038 struct btrfs_space_info *space_info,
4039 struct btrfs_key *ins)
4040 {
4041 /*
4042 * If our free space is heavily fragmented we may not be able to make
4043 * big contiguous allocations, so instead of doing the expensive search
4044 * for free space, simply return ENOSPC with our max_extent_size so we
4045 * can go ahead and search for a more manageable chunk.
4046 *
4047 * If our max_extent_size is large enough for our allocation simply
4048 * disable clustering since we will likely not be able to find enough
4049 * space to create a cluster and induce latency trying.
4050 */
4051 if (space_info->max_extent_size) {
4052 spin_lock(&space_info->lock);
4053 if (space_info->max_extent_size &&
4054 ffe_ctl->num_bytes > space_info->max_extent_size) {
4055 ins->offset = space_info->max_extent_size;
4056 spin_unlock(&space_info->lock);
4057 return -ENOSPC;
4058 } else if (space_info->max_extent_size) {
4059 ffe_ctl->use_cluster = false;
4060 }
4061 spin_unlock(&space_info->lock);
4062 }
4063
4064 ffe_ctl->last_ptr = fetch_cluster_info(fs_info, space_info,
4065 &ffe_ctl->empty_cluster);
4066 if (ffe_ctl->last_ptr) {
4067 struct btrfs_free_cluster *last_ptr = ffe_ctl->last_ptr;
4068
4069 spin_lock(&last_ptr->lock);
4070 if (last_ptr->block_group)
4071 ffe_ctl->hint_byte = last_ptr->window_start;
4072 if (last_ptr->fragmented) {
4073 /*
4074 * We still set window_start so we can keep track of the
4075 * last place we found an allocation to try and save
4076 * some time.
4077 */
4078 ffe_ctl->hint_byte = last_ptr->window_start;
4079 ffe_ctl->use_cluster = false;
4080 }
4081 spin_unlock(&last_ptr->lock);
4082 }
4083
4084 return 0;
4085 }
4086
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)4087 static int prepare_allocation(struct btrfs_fs_info *fs_info,
4088 struct find_free_extent_ctl *ffe_ctl,
4089 struct btrfs_space_info *space_info,
4090 struct btrfs_key *ins)
4091 {
4092 switch (ffe_ctl->policy) {
4093 case BTRFS_EXTENT_ALLOC_CLUSTERED:
4094 return prepare_allocation_clustered(fs_info, ffe_ctl,
4095 space_info, ins);
4096 case BTRFS_EXTENT_ALLOC_ZONED:
4097 if (ffe_ctl->for_treelog) {
4098 spin_lock(&fs_info->treelog_bg_lock);
4099 if (fs_info->treelog_bg)
4100 ffe_ctl->hint_byte = fs_info->treelog_bg;
4101 spin_unlock(&fs_info->treelog_bg_lock);
4102 }
4103 return 0;
4104 default:
4105 BUG();
4106 }
4107 }
4108
4109 /*
4110 * walks the btree of allocated extents and find a hole of a given size.
4111 * The key ins is changed to record the hole:
4112 * ins->objectid == start position
4113 * ins->flags = BTRFS_EXTENT_ITEM_KEY
4114 * ins->offset == the size of the hole.
4115 * Any available blocks before search_start are skipped.
4116 *
4117 * If there is no suitable free space, we will record the max size of
4118 * the free space extent currently.
4119 *
4120 * The overall logic and call chain:
4121 *
4122 * find_free_extent()
4123 * |- Iterate through all block groups
4124 * | |- Get a valid block group
4125 * | |- Try to do clustered allocation in that block group
4126 * | |- Try to do unclustered allocation in that block group
4127 * | |- Check if the result is valid
4128 * | | |- If valid, then exit
4129 * | |- Jump to next block group
4130 * |
4131 * |- Push harder to find free extents
4132 * |- If not found, re-iterate all block groups
4133 */
find_free_extent(struct btrfs_root * root,u64 ram_bytes,u64 num_bytes,u64 empty_size,u64 hint_byte_orig,struct btrfs_key * ins,u64 flags,int delalloc)4134 static noinline int find_free_extent(struct btrfs_root *root,
4135 u64 ram_bytes, u64 num_bytes, u64 empty_size,
4136 u64 hint_byte_orig, struct btrfs_key *ins,
4137 u64 flags, int delalloc)
4138 {
4139 struct btrfs_fs_info *fs_info = root->fs_info;
4140 int ret = 0;
4141 int cache_block_group_error = 0;
4142 struct btrfs_block_group *block_group = NULL;
4143 struct find_free_extent_ctl ffe_ctl = {0};
4144 struct btrfs_space_info *space_info;
4145 bool full_search = false;
4146 bool for_treelog = (root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID);
4147
4148 WARN_ON(num_bytes < fs_info->sectorsize);
4149
4150 ffe_ctl.num_bytes = num_bytes;
4151 ffe_ctl.empty_size = empty_size;
4152 ffe_ctl.flags = flags;
4153 ffe_ctl.search_start = 0;
4154 ffe_ctl.delalloc = delalloc;
4155 ffe_ctl.index = btrfs_bg_flags_to_raid_index(flags);
4156 ffe_ctl.have_caching_bg = false;
4157 ffe_ctl.orig_have_caching_bg = false;
4158 ffe_ctl.found_offset = 0;
4159 ffe_ctl.hint_byte = hint_byte_orig;
4160 ffe_ctl.for_treelog = for_treelog;
4161 ffe_ctl.policy = BTRFS_EXTENT_ALLOC_CLUSTERED;
4162
4163 /* For clustered allocation */
4164 ffe_ctl.retry_clustered = false;
4165 ffe_ctl.retry_unclustered = false;
4166 ffe_ctl.last_ptr = NULL;
4167 ffe_ctl.use_cluster = true;
4168
4169 if (btrfs_is_zoned(fs_info))
4170 ffe_ctl.policy = BTRFS_EXTENT_ALLOC_ZONED;
4171
4172 ins->type = BTRFS_EXTENT_ITEM_KEY;
4173 ins->objectid = 0;
4174 ins->offset = 0;
4175
4176 trace_find_free_extent(root, num_bytes, empty_size, flags);
4177
4178 space_info = btrfs_find_space_info(fs_info, flags);
4179 if (!space_info) {
4180 btrfs_err(fs_info, "No space info for %llu", flags);
4181 return -ENOSPC;
4182 }
4183
4184 ret = prepare_allocation(fs_info, &ffe_ctl, space_info, ins);
4185 if (ret < 0)
4186 return ret;
4187
4188 ffe_ctl.search_start = max(ffe_ctl.search_start,
4189 first_logical_byte(fs_info, 0));
4190 ffe_ctl.search_start = max(ffe_ctl.search_start, ffe_ctl.hint_byte);
4191 if (ffe_ctl.search_start == ffe_ctl.hint_byte) {
4192 block_group = btrfs_lookup_block_group(fs_info,
4193 ffe_ctl.search_start);
4194 /*
4195 * we don't want to use the block group if it doesn't match our
4196 * allocation bits, or if its not cached.
4197 *
4198 * However if we are re-searching with an ideal block group
4199 * picked out then we don't care that the block group is cached.
4200 */
4201 if (block_group && block_group_bits(block_group, flags) &&
4202 block_group->cached != BTRFS_CACHE_NO) {
4203 down_read(&space_info->groups_sem);
4204 if (list_empty(&block_group->list) ||
4205 block_group->ro) {
4206 /*
4207 * someone is removing this block group,
4208 * we can't jump into the have_block_group
4209 * target because our list pointers are not
4210 * valid
4211 */
4212 btrfs_put_block_group(block_group);
4213 up_read(&space_info->groups_sem);
4214 } else {
4215 ffe_ctl.index = btrfs_bg_flags_to_raid_index(
4216 block_group->flags);
4217 btrfs_lock_block_group(block_group, delalloc);
4218 goto have_block_group;
4219 }
4220 } else if (block_group) {
4221 btrfs_put_block_group(block_group);
4222 }
4223 }
4224 search:
4225 ffe_ctl.have_caching_bg = false;
4226 if (ffe_ctl.index == btrfs_bg_flags_to_raid_index(flags) ||
4227 ffe_ctl.index == 0)
4228 full_search = true;
4229 down_read(&space_info->groups_sem);
4230 list_for_each_entry(block_group,
4231 &space_info->block_groups[ffe_ctl.index], list) {
4232 struct btrfs_block_group *bg_ret;
4233
4234 /* If the block group is read-only, we can skip it entirely. */
4235 if (unlikely(block_group->ro)) {
4236 if (for_treelog)
4237 btrfs_clear_treelog_bg(block_group);
4238 continue;
4239 }
4240
4241 btrfs_grab_block_group(block_group, delalloc);
4242 ffe_ctl.search_start = block_group->start;
4243
4244 /*
4245 * this can happen if we end up cycling through all the
4246 * raid types, but we want to make sure we only allocate
4247 * for the proper type.
4248 */
4249 if (!block_group_bits(block_group, flags)) {
4250 u64 extra = BTRFS_BLOCK_GROUP_DUP |
4251 BTRFS_BLOCK_GROUP_RAID1_MASK |
4252 BTRFS_BLOCK_GROUP_RAID56_MASK |
4253 BTRFS_BLOCK_GROUP_RAID10;
4254
4255 /*
4256 * if they asked for extra copies and this block group
4257 * doesn't provide them, bail. This does allow us to
4258 * fill raid0 from raid1.
4259 */
4260 if ((flags & extra) && !(block_group->flags & extra))
4261 goto loop;
4262
4263 /*
4264 * This block group has different flags than we want.
4265 * It's possible that we have MIXED_GROUP flag but no
4266 * block group is mixed. Just skip such block group.
4267 */
4268 btrfs_release_block_group(block_group, delalloc);
4269 continue;
4270 }
4271
4272 have_block_group:
4273 ffe_ctl.cached = btrfs_block_group_done(block_group);
4274 if (unlikely(!ffe_ctl.cached)) {
4275 ffe_ctl.have_caching_bg = true;
4276 ret = btrfs_cache_block_group(block_group, 0);
4277
4278 /*
4279 * If we get ENOMEM here or something else we want to
4280 * try other block groups, because it may not be fatal.
4281 * However if we can't find anything else we need to
4282 * save our return here so that we return the actual
4283 * error that caused problems, not ENOSPC.
4284 */
4285 if (ret < 0) {
4286 if (!cache_block_group_error)
4287 cache_block_group_error = ret;
4288 ret = 0;
4289 goto loop;
4290 }
4291 ret = 0;
4292 }
4293
4294 if (unlikely(block_group->cached == BTRFS_CACHE_ERROR))
4295 goto loop;
4296
4297 bg_ret = NULL;
4298 ret = do_allocation(block_group, &ffe_ctl, &bg_ret);
4299 if (ret == 0) {
4300 if (bg_ret && bg_ret != block_group) {
4301 btrfs_release_block_group(block_group, delalloc);
4302 block_group = bg_ret;
4303 }
4304 } else if (ret == -EAGAIN) {
4305 goto have_block_group;
4306 } else if (ret > 0) {
4307 goto loop;
4308 }
4309
4310 /* Checks */
4311 ffe_ctl.search_start = round_up(ffe_ctl.found_offset,
4312 fs_info->stripesize);
4313
4314 /* move on to the next group */
4315 if (ffe_ctl.search_start + num_bytes >
4316 block_group->start + block_group->length) {
4317 btrfs_add_free_space_unused(block_group,
4318 ffe_ctl.found_offset, num_bytes);
4319 goto loop;
4320 }
4321
4322 if (ffe_ctl.found_offset < ffe_ctl.search_start)
4323 btrfs_add_free_space_unused(block_group,
4324 ffe_ctl.found_offset,
4325 ffe_ctl.search_start - ffe_ctl.found_offset);
4326
4327 ret = btrfs_add_reserved_bytes(block_group, ram_bytes,
4328 num_bytes, delalloc);
4329 if (ret == -EAGAIN) {
4330 btrfs_add_free_space_unused(block_group,
4331 ffe_ctl.found_offset, num_bytes);
4332 goto loop;
4333 }
4334 btrfs_inc_block_group_reservations(block_group);
4335
4336 /* we are all good, lets return */
4337 ins->objectid = ffe_ctl.search_start;
4338 ins->offset = num_bytes;
4339
4340 trace_btrfs_reserve_extent(block_group, ffe_ctl.search_start,
4341 num_bytes);
4342 btrfs_release_block_group(block_group, delalloc);
4343 break;
4344 loop:
4345 release_block_group(block_group, &ffe_ctl, delalloc);
4346 cond_resched();
4347 }
4348 up_read(&space_info->groups_sem);
4349
4350 ret = find_free_extent_update_loop(fs_info, ins, &ffe_ctl, full_search);
4351 if (ret > 0)
4352 goto search;
4353
4354 if (ret == -ENOSPC && !cache_block_group_error) {
4355 /*
4356 * Use ffe_ctl->total_free_space as fallback if we can't find
4357 * any contiguous hole.
4358 */
4359 if (!ffe_ctl.max_extent_size)
4360 ffe_ctl.max_extent_size = ffe_ctl.total_free_space;
4361 spin_lock(&space_info->lock);
4362 space_info->max_extent_size = ffe_ctl.max_extent_size;
4363 spin_unlock(&space_info->lock);
4364 ins->offset = ffe_ctl.max_extent_size;
4365 } else if (ret == -ENOSPC) {
4366 ret = cache_block_group_error;
4367 }
4368 return ret;
4369 }
4370
4371 /*
4372 * btrfs_reserve_extent - entry point to the extent allocator. Tries to find a
4373 * hole that is at least as big as @num_bytes.
4374 *
4375 * @root - The root that will contain this extent
4376 *
4377 * @ram_bytes - The amount of space in ram that @num_bytes take. This
4378 * is used for accounting purposes. This value differs
4379 * from @num_bytes only in the case of compressed extents.
4380 *
4381 * @num_bytes - Number of bytes to allocate on-disk.
4382 *
4383 * @min_alloc_size - Indicates the minimum amount of space that the
4384 * allocator should try to satisfy. In some cases
4385 * @num_bytes may be larger than what is required and if
4386 * the filesystem is fragmented then allocation fails.
4387 * However, the presence of @min_alloc_size gives a
4388 * chance to try and satisfy the smaller allocation.
4389 *
4390 * @empty_size - A hint that you plan on doing more COW. This is the
4391 * size in bytes the allocator should try to find free
4392 * next to the block it returns. This is just a hint and
4393 * may be ignored by the allocator.
4394 *
4395 * @hint_byte - Hint to the allocator to start searching above the byte
4396 * address passed. It might be ignored.
4397 *
4398 * @ins - This key is modified to record the found hole. It will
4399 * have the following values:
4400 * ins->objectid == start position
4401 * ins->flags = BTRFS_EXTENT_ITEM_KEY
4402 * ins->offset == the size of the hole.
4403 *
4404 * @is_data - Boolean flag indicating whether an extent is
4405 * allocated for data (true) or metadata (false)
4406 *
4407 * @delalloc - Boolean flag indicating whether this allocation is for
4408 * delalloc or not. If 'true' data_rwsem of block groups
4409 * is going to be acquired.
4410 *
4411 *
4412 * Returns 0 when an allocation succeeded or < 0 when an error occurred. In
4413 * case -ENOSPC is returned then @ins->offset will contain the size of the
4414 * largest available hole the allocator managed to find.
4415 */
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)4416 int btrfs_reserve_extent(struct btrfs_root *root, u64 ram_bytes,
4417 u64 num_bytes, u64 min_alloc_size,
4418 u64 empty_size, u64 hint_byte,
4419 struct btrfs_key *ins, int is_data, int delalloc)
4420 {
4421 struct btrfs_fs_info *fs_info = root->fs_info;
4422 bool final_tried = num_bytes == min_alloc_size;
4423 u64 flags;
4424 int ret;
4425 bool for_treelog = (root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID);
4426
4427 flags = get_alloc_profile_by_root(root, is_data);
4428 again:
4429 WARN_ON(num_bytes < fs_info->sectorsize);
4430 ret = find_free_extent(root, ram_bytes, num_bytes, empty_size,
4431 hint_byte, ins, flags, delalloc);
4432 if (!ret && !is_data) {
4433 btrfs_dec_block_group_reservations(fs_info, ins->objectid);
4434 } else if (ret == -ENOSPC) {
4435 if (!final_tried && ins->offset) {
4436 num_bytes = min(num_bytes >> 1, ins->offset);
4437 num_bytes = round_down(num_bytes,
4438 fs_info->sectorsize);
4439 num_bytes = max(num_bytes, min_alloc_size);
4440 ram_bytes = num_bytes;
4441 if (num_bytes == min_alloc_size)
4442 final_tried = true;
4443 goto again;
4444 } else if (btrfs_test_opt(fs_info, ENOSPC_DEBUG)) {
4445 struct btrfs_space_info *sinfo;
4446
4447 sinfo = btrfs_find_space_info(fs_info, flags);
4448 btrfs_err(fs_info,
4449 "allocation failed flags %llu, wanted %llu tree-log %d",
4450 flags, num_bytes, for_treelog);
4451 if (sinfo)
4452 btrfs_dump_space_info(fs_info, sinfo,
4453 num_bytes, 1);
4454 }
4455 }
4456
4457 return ret;
4458 }
4459
btrfs_free_reserved_extent(struct btrfs_fs_info * fs_info,u64 start,u64 len,int delalloc)4460 int btrfs_free_reserved_extent(struct btrfs_fs_info *fs_info,
4461 u64 start, u64 len, int delalloc)
4462 {
4463 struct btrfs_block_group *cache;
4464
4465 cache = btrfs_lookup_block_group(fs_info, start);
4466 if (!cache) {
4467 btrfs_err(fs_info, "Unable to find block group for %llu",
4468 start);
4469 return -ENOSPC;
4470 }
4471
4472 btrfs_add_free_space(cache, start, len);
4473 btrfs_free_reserved_bytes(cache, len, delalloc);
4474 trace_btrfs_reserved_extent_free(fs_info, start, len);
4475
4476 btrfs_put_block_group(cache);
4477 return 0;
4478 }
4479
btrfs_pin_reserved_extent(struct btrfs_trans_handle * trans,u64 start,u64 len)4480 int btrfs_pin_reserved_extent(struct btrfs_trans_handle *trans, u64 start,
4481 u64 len)
4482 {
4483 struct btrfs_block_group *cache;
4484 int ret = 0;
4485
4486 cache = btrfs_lookup_block_group(trans->fs_info, start);
4487 if (!cache) {
4488 btrfs_err(trans->fs_info, "unable to find block group for %llu",
4489 start);
4490 return -ENOSPC;
4491 }
4492
4493 ret = pin_down_extent(trans, cache, start, len, 1);
4494 btrfs_put_block_group(cache);
4495 return ret;
4496 }
4497
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)4498 static int alloc_reserved_file_extent(struct btrfs_trans_handle *trans,
4499 u64 parent, u64 root_objectid,
4500 u64 flags, u64 owner, u64 offset,
4501 struct btrfs_key *ins, int ref_mod)
4502 {
4503 struct btrfs_fs_info *fs_info = trans->fs_info;
4504 int ret;
4505 struct btrfs_extent_item *extent_item;
4506 struct btrfs_extent_inline_ref *iref;
4507 struct btrfs_path *path;
4508 struct extent_buffer *leaf;
4509 int type;
4510 u32 size;
4511
4512 if (parent > 0)
4513 type = BTRFS_SHARED_DATA_REF_KEY;
4514 else
4515 type = BTRFS_EXTENT_DATA_REF_KEY;
4516
4517 size = sizeof(*extent_item) + btrfs_extent_inline_ref_size(type);
4518
4519 path = btrfs_alloc_path();
4520 if (!path)
4521 return -ENOMEM;
4522
4523 ret = btrfs_insert_empty_item(trans, fs_info->extent_root, path,
4524 ins, size);
4525 if (ret) {
4526 btrfs_free_path(path);
4527 return ret;
4528 }
4529
4530 leaf = path->nodes[0];
4531 extent_item = btrfs_item_ptr(leaf, path->slots[0],
4532 struct btrfs_extent_item);
4533 btrfs_set_extent_refs(leaf, extent_item, ref_mod);
4534 btrfs_set_extent_generation(leaf, extent_item, trans->transid);
4535 btrfs_set_extent_flags(leaf, extent_item,
4536 flags | BTRFS_EXTENT_FLAG_DATA);
4537
4538 iref = (struct btrfs_extent_inline_ref *)(extent_item + 1);
4539 btrfs_set_extent_inline_ref_type(leaf, iref, type);
4540 if (parent > 0) {
4541 struct btrfs_shared_data_ref *ref;
4542 ref = (struct btrfs_shared_data_ref *)(iref + 1);
4543 btrfs_set_extent_inline_ref_offset(leaf, iref, parent);
4544 btrfs_set_shared_data_ref_count(leaf, ref, ref_mod);
4545 } else {
4546 struct btrfs_extent_data_ref *ref;
4547 ref = (struct btrfs_extent_data_ref *)(&iref->offset);
4548 btrfs_set_extent_data_ref_root(leaf, ref, root_objectid);
4549 btrfs_set_extent_data_ref_objectid(leaf, ref, owner);
4550 btrfs_set_extent_data_ref_offset(leaf, ref, offset);
4551 btrfs_set_extent_data_ref_count(leaf, ref, ref_mod);
4552 }
4553
4554 btrfs_mark_buffer_dirty(path->nodes[0]);
4555 btrfs_free_path(path);
4556
4557 ret = remove_from_free_space_tree(trans, ins->objectid, ins->offset);
4558 if (ret)
4559 return ret;
4560
4561 ret = btrfs_update_block_group(trans, ins->objectid, ins->offset, 1);
4562 if (ret) { /* -ENOENT, logic error */
4563 btrfs_err(fs_info, "update block group failed for %llu %llu",
4564 ins->objectid, ins->offset);
4565 BUG();
4566 }
4567 trace_btrfs_reserved_extent_alloc(fs_info, ins->objectid, ins->offset);
4568 return ret;
4569 }
4570
alloc_reserved_tree_block(struct btrfs_trans_handle * trans,struct btrfs_delayed_ref_node * node,struct btrfs_delayed_extent_op * extent_op)4571 static int alloc_reserved_tree_block(struct btrfs_trans_handle *trans,
4572 struct btrfs_delayed_ref_node *node,
4573 struct btrfs_delayed_extent_op *extent_op)
4574 {
4575 struct btrfs_fs_info *fs_info = trans->fs_info;
4576 int ret;
4577 struct btrfs_extent_item *extent_item;
4578 struct btrfs_key extent_key;
4579 struct btrfs_tree_block_info *block_info;
4580 struct btrfs_extent_inline_ref *iref;
4581 struct btrfs_path *path;
4582 struct extent_buffer *leaf;
4583 struct btrfs_delayed_tree_ref *ref;
4584 u32 size = sizeof(*extent_item) + sizeof(*iref);
4585 u64 num_bytes;
4586 u64 flags = extent_op->flags_to_set;
4587 bool skinny_metadata = btrfs_fs_incompat(fs_info, SKINNY_METADATA);
4588
4589 ref = btrfs_delayed_node_to_tree_ref(node);
4590
4591 extent_key.objectid = node->bytenr;
4592 if (skinny_metadata) {
4593 extent_key.offset = ref->level;
4594 extent_key.type = BTRFS_METADATA_ITEM_KEY;
4595 num_bytes = fs_info->nodesize;
4596 } else {
4597 extent_key.offset = node->num_bytes;
4598 extent_key.type = BTRFS_EXTENT_ITEM_KEY;
4599 size += sizeof(*block_info);
4600 num_bytes = node->num_bytes;
4601 }
4602
4603 path = btrfs_alloc_path();
4604 if (!path)
4605 return -ENOMEM;
4606
4607 ret = btrfs_insert_empty_item(trans, fs_info->extent_root, path,
4608 &extent_key, size);
4609 if (ret) {
4610 btrfs_free_path(path);
4611 return ret;
4612 }
4613
4614 leaf = path->nodes[0];
4615 extent_item = btrfs_item_ptr(leaf, path->slots[0],
4616 struct btrfs_extent_item);
4617 btrfs_set_extent_refs(leaf, extent_item, 1);
4618 btrfs_set_extent_generation(leaf, extent_item, trans->transid);
4619 btrfs_set_extent_flags(leaf, extent_item,
4620 flags | BTRFS_EXTENT_FLAG_TREE_BLOCK);
4621
4622 if (skinny_metadata) {
4623 iref = (struct btrfs_extent_inline_ref *)(extent_item + 1);
4624 } else {
4625 block_info = (struct btrfs_tree_block_info *)(extent_item + 1);
4626 btrfs_set_tree_block_key(leaf, block_info, &extent_op->key);
4627 btrfs_set_tree_block_level(leaf, block_info, ref->level);
4628 iref = (struct btrfs_extent_inline_ref *)(block_info + 1);
4629 }
4630
4631 if (node->type == BTRFS_SHARED_BLOCK_REF_KEY) {
4632 btrfs_set_extent_inline_ref_type(leaf, iref,
4633 BTRFS_SHARED_BLOCK_REF_KEY);
4634 btrfs_set_extent_inline_ref_offset(leaf, iref, ref->parent);
4635 } else {
4636 btrfs_set_extent_inline_ref_type(leaf, iref,
4637 BTRFS_TREE_BLOCK_REF_KEY);
4638 btrfs_set_extent_inline_ref_offset(leaf, iref, ref->root);
4639 }
4640
4641 btrfs_mark_buffer_dirty(leaf);
4642 btrfs_free_path(path);
4643
4644 ret = remove_from_free_space_tree(trans, extent_key.objectid,
4645 num_bytes);
4646 if (ret)
4647 return ret;
4648
4649 ret = btrfs_update_block_group(trans, extent_key.objectid,
4650 fs_info->nodesize, 1);
4651 if (ret) { /* -ENOENT, logic error */
4652 btrfs_err(fs_info, "update block group failed for %llu %llu",
4653 extent_key.objectid, extent_key.offset);
4654 BUG();
4655 }
4656
4657 trace_btrfs_reserved_extent_alloc(fs_info, extent_key.objectid,
4658 fs_info->nodesize);
4659 return ret;
4660 }
4661
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)4662 int btrfs_alloc_reserved_file_extent(struct btrfs_trans_handle *trans,
4663 struct btrfs_root *root, u64 owner,
4664 u64 offset, u64 ram_bytes,
4665 struct btrfs_key *ins)
4666 {
4667 struct btrfs_ref generic_ref = { 0 };
4668
4669 BUG_ON(root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID);
4670
4671 btrfs_init_generic_ref(&generic_ref, BTRFS_ADD_DELAYED_EXTENT,
4672 ins->objectid, ins->offset, 0);
4673 btrfs_init_data_ref(&generic_ref, root->root_key.objectid, owner, offset);
4674 btrfs_ref_tree_mod(root->fs_info, &generic_ref);
4675
4676 return btrfs_add_delayed_data_ref(trans, &generic_ref, ram_bytes);
4677 }
4678
4679 /*
4680 * this is used by the tree logging recovery code. It records that
4681 * an extent has been allocated and makes sure to clear the free
4682 * space cache bits as well
4683 */
btrfs_alloc_logged_file_extent(struct btrfs_trans_handle * trans,u64 root_objectid,u64 owner,u64 offset,struct btrfs_key * ins)4684 int btrfs_alloc_logged_file_extent(struct btrfs_trans_handle *trans,
4685 u64 root_objectid, u64 owner, u64 offset,
4686 struct btrfs_key *ins)
4687 {
4688 struct btrfs_fs_info *fs_info = trans->fs_info;
4689 int ret;
4690 struct btrfs_block_group *block_group;
4691 struct btrfs_space_info *space_info;
4692
4693 /*
4694 * Mixed block groups will exclude before processing the log so we only
4695 * need to do the exclude dance if this fs isn't mixed.
4696 */
4697 if (!btrfs_fs_incompat(fs_info, MIXED_GROUPS)) {
4698 ret = __exclude_logged_extent(fs_info, ins->objectid,
4699 ins->offset);
4700 if (ret)
4701 return ret;
4702 }
4703
4704 block_group = btrfs_lookup_block_group(fs_info, ins->objectid);
4705 if (!block_group)
4706 return -EINVAL;
4707
4708 space_info = block_group->space_info;
4709 spin_lock(&space_info->lock);
4710 spin_lock(&block_group->lock);
4711 space_info->bytes_reserved += ins->offset;
4712 block_group->reserved += ins->offset;
4713 spin_unlock(&block_group->lock);
4714 spin_unlock(&space_info->lock);
4715
4716 ret = alloc_reserved_file_extent(trans, 0, root_objectid, 0, owner,
4717 offset, ins, 1);
4718 if (ret)
4719 btrfs_pin_extent(trans, ins->objectid, ins->offset, 1);
4720 btrfs_put_block_group(block_group);
4721 return ret;
4722 }
4723
4724 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)4725 btrfs_init_new_buffer(struct btrfs_trans_handle *trans, struct btrfs_root *root,
4726 u64 bytenr, int level, u64 owner,
4727 enum btrfs_lock_nesting nest)
4728 {
4729 struct btrfs_fs_info *fs_info = root->fs_info;
4730 struct extent_buffer *buf;
4731
4732 buf = btrfs_find_create_tree_block(fs_info, bytenr, owner, level);
4733 if (IS_ERR(buf))
4734 return buf;
4735
4736 /*
4737 * Extra safety check in case the extent tree is corrupted and extent
4738 * allocator chooses to use a tree block which is already used and
4739 * locked.
4740 */
4741 if (buf->lock_owner == current->pid) {
4742 btrfs_err_rl(fs_info,
4743 "tree block %llu owner %llu already locked by pid=%d, extent tree corruption detected",
4744 buf->start, btrfs_header_owner(buf), current->pid);
4745 free_extent_buffer(buf);
4746 return ERR_PTR(-EUCLEAN);
4747 }
4748
4749 /*
4750 * This needs to stay, because we could allocate a freed block from an
4751 * old tree into a new tree, so we need to make sure this new block is
4752 * set to the appropriate level and owner.
4753 */
4754 btrfs_set_buffer_lockdep_class(owner, buf, level);
4755 __btrfs_tree_lock(buf, nest);
4756 btrfs_clean_tree_block(buf);
4757 clear_bit(EXTENT_BUFFER_STALE, &buf->bflags);
4758 clear_bit(EXTENT_BUFFER_NO_CHECK, &buf->bflags);
4759
4760 set_extent_buffer_uptodate(buf);
4761
4762 memzero_extent_buffer(buf, 0, sizeof(struct btrfs_header));
4763 btrfs_set_header_level(buf, level);
4764 btrfs_set_header_bytenr(buf, buf->start);
4765 btrfs_set_header_generation(buf, trans->transid);
4766 btrfs_set_header_backref_rev(buf, BTRFS_MIXED_BACKREF_REV);
4767 btrfs_set_header_owner(buf, owner);
4768 write_extent_buffer_fsid(buf, fs_info->fs_devices->metadata_uuid);
4769 write_extent_buffer_chunk_tree_uuid(buf, fs_info->chunk_tree_uuid);
4770 if (root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID) {
4771 buf->log_index = root->log_transid % 2;
4772 /*
4773 * we allow two log transactions at a time, use different
4774 * EXTENT bit to differentiate dirty pages.
4775 */
4776 if (buf->log_index == 0)
4777 set_extent_dirty(&root->dirty_log_pages, buf->start,
4778 buf->start + buf->len - 1, GFP_NOFS);
4779 else
4780 set_extent_new(&root->dirty_log_pages, buf->start,
4781 buf->start + buf->len - 1);
4782 } else {
4783 buf->log_index = -1;
4784 set_extent_dirty(&trans->transaction->dirty_pages, buf->start,
4785 buf->start + buf->len - 1, GFP_NOFS);
4786 }
4787 trans->dirty = true;
4788 /* this returns a buffer locked for blocking */
4789 return buf;
4790 }
4791
4792 /*
4793 * finds a free extent and does all the dirty work required for allocation
4794 * returns the tree buffer or an ERR_PTR on error.
4795 */
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)4796 struct extent_buffer *btrfs_alloc_tree_block(struct btrfs_trans_handle *trans,
4797 struct btrfs_root *root,
4798 u64 parent, u64 root_objectid,
4799 const struct btrfs_disk_key *key,
4800 int level, u64 hint,
4801 u64 empty_size,
4802 enum btrfs_lock_nesting nest)
4803 {
4804 struct btrfs_fs_info *fs_info = root->fs_info;
4805 struct btrfs_key ins;
4806 struct btrfs_block_rsv *block_rsv;
4807 struct extent_buffer *buf;
4808 struct btrfs_delayed_extent_op *extent_op;
4809 struct btrfs_ref generic_ref = { 0 };
4810 u64 flags = 0;
4811 int ret;
4812 u32 blocksize = fs_info->nodesize;
4813 bool skinny_metadata = btrfs_fs_incompat(fs_info, SKINNY_METADATA);
4814
4815 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
4816 if (btrfs_is_testing(fs_info)) {
4817 buf = btrfs_init_new_buffer(trans, root, root->alloc_bytenr,
4818 level, root_objectid, nest);
4819 if (!IS_ERR(buf))
4820 root->alloc_bytenr += blocksize;
4821 return buf;
4822 }
4823 #endif
4824
4825 block_rsv = btrfs_use_block_rsv(trans, root, blocksize);
4826 if (IS_ERR(block_rsv))
4827 return ERR_CAST(block_rsv);
4828
4829 ret = btrfs_reserve_extent(root, blocksize, blocksize, blocksize,
4830 empty_size, hint, &ins, 0, 0);
4831 if (ret)
4832 goto out_unuse;
4833
4834 buf = btrfs_init_new_buffer(trans, root, ins.objectid, level,
4835 root_objectid, nest);
4836 if (IS_ERR(buf)) {
4837 ret = PTR_ERR(buf);
4838 goto out_free_reserved;
4839 }
4840
4841 if (root_objectid == BTRFS_TREE_RELOC_OBJECTID) {
4842 if (parent == 0)
4843 parent = ins.objectid;
4844 flags |= BTRFS_BLOCK_FLAG_FULL_BACKREF;
4845 } else
4846 BUG_ON(parent > 0);
4847
4848 if (root_objectid != BTRFS_TREE_LOG_OBJECTID) {
4849 extent_op = btrfs_alloc_delayed_extent_op();
4850 if (!extent_op) {
4851 ret = -ENOMEM;
4852 goto out_free_buf;
4853 }
4854 if (key)
4855 memcpy(&extent_op->key, key, sizeof(extent_op->key));
4856 else
4857 memset(&extent_op->key, 0, sizeof(extent_op->key));
4858 extent_op->flags_to_set = flags;
4859 extent_op->update_key = skinny_metadata ? false : true;
4860 extent_op->update_flags = true;
4861 extent_op->is_data = false;
4862 extent_op->level = level;
4863
4864 btrfs_init_generic_ref(&generic_ref, BTRFS_ADD_DELAYED_EXTENT,
4865 ins.objectid, ins.offset, parent);
4866 generic_ref.real_root = root->root_key.objectid;
4867 btrfs_init_tree_ref(&generic_ref, level, root_objectid);
4868 btrfs_ref_tree_mod(fs_info, &generic_ref);
4869 ret = btrfs_add_delayed_tree_ref(trans, &generic_ref, extent_op);
4870 if (ret)
4871 goto out_free_delayed;
4872 }
4873 return buf;
4874
4875 out_free_delayed:
4876 btrfs_free_delayed_extent_op(extent_op);
4877 out_free_buf:
4878 free_extent_buffer(buf);
4879 out_free_reserved:
4880 btrfs_free_reserved_extent(fs_info, ins.objectid, ins.offset, 0);
4881 out_unuse:
4882 btrfs_unuse_block_rsv(fs_info, block_rsv, blocksize);
4883 return ERR_PTR(ret);
4884 }
4885
4886 struct walk_control {
4887 u64 refs[BTRFS_MAX_LEVEL];
4888 u64 flags[BTRFS_MAX_LEVEL];
4889 struct btrfs_key update_progress;
4890 struct btrfs_key drop_progress;
4891 int drop_level;
4892 int stage;
4893 int level;
4894 int shared_level;
4895 int update_ref;
4896 int keep_locks;
4897 int reada_slot;
4898 int reada_count;
4899 int restarted;
4900 };
4901
4902 #define DROP_REFERENCE 1
4903 #define UPDATE_BACKREF 2
4904
reada_walk_down(struct btrfs_trans_handle * trans,struct btrfs_root * root,struct walk_control * wc,struct btrfs_path * path)4905 static noinline void reada_walk_down(struct btrfs_trans_handle *trans,
4906 struct btrfs_root *root,
4907 struct walk_control *wc,
4908 struct btrfs_path *path)
4909 {
4910 struct btrfs_fs_info *fs_info = root->fs_info;
4911 u64 bytenr;
4912 u64 generation;
4913 u64 refs;
4914 u64 flags;
4915 u32 nritems;
4916 struct btrfs_key key;
4917 struct extent_buffer *eb;
4918 int ret;
4919 int slot;
4920 int nread = 0;
4921
4922 if (path->slots[wc->level] < wc->reada_slot) {
4923 wc->reada_count = wc->reada_count * 2 / 3;
4924 wc->reada_count = max(wc->reada_count, 2);
4925 } else {
4926 wc->reada_count = wc->reada_count * 3 / 2;
4927 wc->reada_count = min_t(int, wc->reada_count,
4928 BTRFS_NODEPTRS_PER_BLOCK(fs_info));
4929 }
4930
4931 eb = path->nodes[wc->level];
4932 nritems = btrfs_header_nritems(eb);
4933
4934 for (slot = path->slots[wc->level]; slot < nritems; slot++) {
4935 if (nread >= wc->reada_count)
4936 break;
4937
4938 cond_resched();
4939 bytenr = btrfs_node_blockptr(eb, slot);
4940 generation = btrfs_node_ptr_generation(eb, slot);
4941
4942 if (slot == path->slots[wc->level])
4943 goto reada;
4944
4945 if (wc->stage == UPDATE_BACKREF &&
4946 generation <= root->root_key.offset)
4947 continue;
4948
4949 /* We don't lock the tree block, it's OK to be racy here */
4950 ret = btrfs_lookup_extent_info(trans, fs_info, bytenr,
4951 wc->level - 1, 1, &refs,
4952 &flags);
4953 /* We don't care about errors in readahead. */
4954 if (ret < 0)
4955 continue;
4956 BUG_ON(refs == 0);
4957
4958 if (wc->stage == DROP_REFERENCE) {
4959 if (refs == 1)
4960 goto reada;
4961
4962 if (wc->level == 1 &&
4963 (flags & BTRFS_BLOCK_FLAG_FULL_BACKREF))
4964 continue;
4965 if (!wc->update_ref ||
4966 generation <= root->root_key.offset)
4967 continue;
4968 btrfs_node_key_to_cpu(eb, &key, slot);
4969 ret = btrfs_comp_cpu_keys(&key,
4970 &wc->update_progress);
4971 if (ret < 0)
4972 continue;
4973 } else {
4974 if (wc->level == 1 &&
4975 (flags & BTRFS_BLOCK_FLAG_FULL_BACKREF))
4976 continue;
4977 }
4978 reada:
4979 btrfs_readahead_node_child(eb, slot);
4980 nread++;
4981 }
4982 wc->reada_slot = slot;
4983 }
4984
4985 /*
4986 * helper to process tree block while walking down the tree.
4987 *
4988 * when wc->stage == UPDATE_BACKREF, this function updates
4989 * back refs for pointers in the block.
4990 *
4991 * NOTE: return value 1 means we should stop walking down.
4992 */
walk_down_proc(struct btrfs_trans_handle * trans,struct btrfs_root * root,struct btrfs_path * path,struct walk_control * wc,int lookup_info)4993 static noinline int walk_down_proc(struct btrfs_trans_handle *trans,
4994 struct btrfs_root *root,
4995 struct btrfs_path *path,
4996 struct walk_control *wc, int lookup_info)
4997 {
4998 struct btrfs_fs_info *fs_info = root->fs_info;
4999 int level = wc->level;
5000 struct extent_buffer *eb = path->nodes[level];
5001 u64 flag = BTRFS_BLOCK_FLAG_FULL_BACKREF;
5002 int ret;
5003
5004 if (wc->stage == UPDATE_BACKREF &&
5005 btrfs_header_owner(eb) != root->root_key.objectid)
5006 return 1;
5007
5008 /*
5009 * when reference count of tree block is 1, it won't increase
5010 * again. once full backref flag is set, we never clear it.
5011 */
5012 if (lookup_info &&
5013 ((wc->stage == DROP_REFERENCE && wc->refs[level] != 1) ||
5014 (wc->stage == UPDATE_BACKREF && !(wc->flags[level] & flag)))) {
5015 BUG_ON(!path->locks[level]);
5016 ret = btrfs_lookup_extent_info(trans, fs_info,
5017 eb->start, level, 1,
5018 &wc->refs[level],
5019 &wc->flags[level]);
5020 BUG_ON(ret == -ENOMEM);
5021 if (ret)
5022 return ret;
5023 BUG_ON(wc->refs[level] == 0);
5024 }
5025
5026 if (wc->stage == DROP_REFERENCE) {
5027 if (wc->refs[level] > 1)
5028 return 1;
5029
5030 if (path->locks[level] && !wc->keep_locks) {
5031 btrfs_tree_unlock_rw(eb, path->locks[level]);
5032 path->locks[level] = 0;
5033 }
5034 return 0;
5035 }
5036
5037 /* wc->stage == UPDATE_BACKREF */
5038 if (!(wc->flags[level] & flag)) {
5039 BUG_ON(!path->locks[level]);
5040 ret = btrfs_inc_ref(trans, root, eb, 1);
5041 BUG_ON(ret); /* -ENOMEM */
5042 ret = btrfs_dec_ref(trans, root, eb, 0);
5043 BUG_ON(ret); /* -ENOMEM */
5044 ret = btrfs_set_disk_extent_flags(trans, eb, flag,
5045 btrfs_header_level(eb), 0);
5046 BUG_ON(ret); /* -ENOMEM */
5047 wc->flags[level] |= flag;
5048 }
5049
5050 /*
5051 * the block is shared by multiple trees, so it's not good to
5052 * keep the tree lock
5053 */
5054 if (path->locks[level] && level > 0) {
5055 btrfs_tree_unlock_rw(eb, path->locks[level]);
5056 path->locks[level] = 0;
5057 }
5058 return 0;
5059 }
5060
5061 /*
5062 * This is used to verify a ref exists for this root to deal with a bug where we
5063 * would have a drop_progress key that hadn't been updated properly.
5064 */
check_ref_exists(struct btrfs_trans_handle * trans,struct btrfs_root * root,u64 bytenr,u64 parent,int level)5065 static int check_ref_exists(struct btrfs_trans_handle *trans,
5066 struct btrfs_root *root, u64 bytenr, u64 parent,
5067 int level)
5068 {
5069 struct btrfs_path *path;
5070 struct btrfs_extent_inline_ref *iref;
5071 int ret;
5072
5073 path = btrfs_alloc_path();
5074 if (!path)
5075 return -ENOMEM;
5076
5077 ret = lookup_extent_backref(trans, path, &iref, bytenr,
5078 root->fs_info->nodesize, parent,
5079 root->root_key.objectid, level, 0);
5080 btrfs_free_path(path);
5081 if (ret == -ENOENT)
5082 return 0;
5083 if (ret < 0)
5084 return ret;
5085 return 1;
5086 }
5087
5088 /*
5089 * helper to process tree block pointer.
5090 *
5091 * when wc->stage == DROP_REFERENCE, this function checks
5092 * reference count of the block pointed to. if the block
5093 * is shared and we need update back refs for the subtree
5094 * rooted at the block, this function changes wc->stage to
5095 * UPDATE_BACKREF. if the block is shared and there is no
5096 * need to update back, this function drops the reference
5097 * to the block.
5098 *
5099 * NOTE: return value 1 means we should stop walking down.
5100 */
do_walk_down(struct btrfs_trans_handle * trans,struct btrfs_root * root,struct btrfs_path * path,struct walk_control * wc,int * lookup_info)5101 static noinline int do_walk_down(struct btrfs_trans_handle *trans,
5102 struct btrfs_root *root,
5103 struct btrfs_path *path,
5104 struct walk_control *wc, int *lookup_info)
5105 {
5106 struct btrfs_fs_info *fs_info = root->fs_info;
5107 u64 bytenr;
5108 u64 generation;
5109 u64 parent;
5110 struct btrfs_key key;
5111 struct btrfs_key first_key;
5112 struct btrfs_ref ref = { 0 };
5113 struct extent_buffer *next;
5114 int level = wc->level;
5115 int reada = 0;
5116 int ret = 0;
5117 bool need_account = false;
5118
5119 generation = btrfs_node_ptr_generation(path->nodes[level],
5120 path->slots[level]);
5121 /*
5122 * if the lower level block was created before the snapshot
5123 * was created, we know there is no need to update back refs
5124 * for the subtree
5125 */
5126 if (wc->stage == UPDATE_BACKREF &&
5127 generation <= root->root_key.offset) {
5128 *lookup_info = 1;
5129 return 1;
5130 }
5131
5132 bytenr = btrfs_node_blockptr(path->nodes[level], path->slots[level]);
5133 btrfs_node_key_to_cpu(path->nodes[level], &first_key,
5134 path->slots[level]);
5135
5136 next = find_extent_buffer(fs_info, bytenr);
5137 if (!next) {
5138 next = btrfs_find_create_tree_block(fs_info, bytenr,
5139 root->root_key.objectid, level - 1);
5140 if (IS_ERR(next))
5141 return PTR_ERR(next);
5142 reada = 1;
5143 }
5144 btrfs_tree_lock(next);
5145
5146 ret = btrfs_lookup_extent_info(trans, fs_info, bytenr, level - 1, 1,
5147 &wc->refs[level - 1],
5148 &wc->flags[level - 1]);
5149 if (ret < 0)
5150 goto out_unlock;
5151
5152 if (unlikely(wc->refs[level - 1] == 0)) {
5153 btrfs_err(fs_info, "Missing references.");
5154 ret = -EIO;
5155 goto out_unlock;
5156 }
5157 *lookup_info = 0;
5158
5159 if (wc->stage == DROP_REFERENCE) {
5160 if (wc->refs[level - 1] > 1) {
5161 need_account = true;
5162 if (level == 1 &&
5163 (wc->flags[0] & BTRFS_BLOCK_FLAG_FULL_BACKREF))
5164 goto skip;
5165
5166 if (!wc->update_ref ||
5167 generation <= root->root_key.offset)
5168 goto skip;
5169
5170 btrfs_node_key_to_cpu(path->nodes[level], &key,
5171 path->slots[level]);
5172 ret = btrfs_comp_cpu_keys(&key, &wc->update_progress);
5173 if (ret < 0)
5174 goto skip;
5175
5176 wc->stage = UPDATE_BACKREF;
5177 wc->shared_level = level - 1;
5178 }
5179 } else {
5180 if (level == 1 &&
5181 (wc->flags[0] & BTRFS_BLOCK_FLAG_FULL_BACKREF))
5182 goto skip;
5183 }
5184
5185 if (!btrfs_buffer_uptodate(next, generation, 0)) {
5186 btrfs_tree_unlock(next);
5187 free_extent_buffer(next);
5188 next = NULL;
5189 *lookup_info = 1;
5190 }
5191
5192 if (!next) {
5193 if (reada && level == 1)
5194 reada_walk_down(trans, root, wc, path);
5195 next = read_tree_block(fs_info, bytenr, root->root_key.objectid,
5196 generation, level - 1, &first_key);
5197 if (IS_ERR(next)) {
5198 return PTR_ERR(next);
5199 } else if (!extent_buffer_uptodate(next)) {
5200 free_extent_buffer(next);
5201 return -EIO;
5202 }
5203 btrfs_tree_lock(next);
5204 }
5205
5206 level--;
5207 ASSERT(level == btrfs_header_level(next));
5208 if (level != btrfs_header_level(next)) {
5209 btrfs_err(root->fs_info, "mismatched level");
5210 ret = -EIO;
5211 goto out_unlock;
5212 }
5213 path->nodes[level] = next;
5214 path->slots[level] = 0;
5215 path->locks[level] = BTRFS_WRITE_LOCK;
5216 wc->level = level;
5217 if (wc->level == 1)
5218 wc->reada_slot = 0;
5219 return 0;
5220 skip:
5221 wc->refs[level - 1] = 0;
5222 wc->flags[level - 1] = 0;
5223 if (wc->stage == DROP_REFERENCE) {
5224 if (wc->flags[level] & BTRFS_BLOCK_FLAG_FULL_BACKREF) {
5225 parent = path->nodes[level]->start;
5226 } else {
5227 ASSERT(root->root_key.objectid ==
5228 btrfs_header_owner(path->nodes[level]));
5229 if (root->root_key.objectid !=
5230 btrfs_header_owner(path->nodes[level])) {
5231 btrfs_err(root->fs_info,
5232 "mismatched block owner");
5233 ret = -EIO;
5234 goto out_unlock;
5235 }
5236 parent = 0;
5237 }
5238
5239 /*
5240 * If we had a drop_progress we need to verify the refs are set
5241 * as expected. If we find our ref then we know that from here
5242 * on out everything should be correct, and we can clear the
5243 * ->restarted flag.
5244 */
5245 if (wc->restarted) {
5246 ret = check_ref_exists(trans, root, bytenr, parent,
5247 level - 1);
5248 if (ret < 0)
5249 goto out_unlock;
5250 if (ret == 0)
5251 goto no_delete;
5252 ret = 0;
5253 wc->restarted = 0;
5254 }
5255
5256 /*
5257 * Reloc tree doesn't contribute to qgroup numbers, and we have
5258 * already accounted them at merge time (replace_path),
5259 * thus we could skip expensive subtree trace here.
5260 */
5261 if (root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID &&
5262 need_account) {
5263 ret = btrfs_qgroup_trace_subtree(trans, next,
5264 generation, level - 1);
5265 if (ret) {
5266 btrfs_err_rl(fs_info,
5267 "Error %d accounting shared subtree. Quota is out of sync, rescan required.",
5268 ret);
5269 }
5270 }
5271
5272 /*
5273 * We need to update the next key in our walk control so we can
5274 * update the drop_progress key accordingly. We don't care if
5275 * find_next_key doesn't find a key because that means we're at
5276 * the end and are going to clean up now.
5277 */
5278 wc->drop_level = level;
5279 find_next_key(path, level, &wc->drop_progress);
5280
5281 btrfs_init_generic_ref(&ref, BTRFS_DROP_DELAYED_REF, bytenr,
5282 fs_info->nodesize, parent);
5283 btrfs_init_tree_ref(&ref, level - 1, root->root_key.objectid);
5284 ret = btrfs_free_extent(trans, &ref);
5285 if (ret)
5286 goto out_unlock;
5287 }
5288 no_delete:
5289 *lookup_info = 1;
5290 ret = 1;
5291
5292 out_unlock:
5293 btrfs_tree_unlock(next);
5294 free_extent_buffer(next);
5295
5296 return ret;
5297 }
5298
5299 /*
5300 * helper to process tree block while walking up the tree.
5301 *
5302 * when wc->stage == DROP_REFERENCE, this function drops
5303 * reference count on the block.
5304 *
5305 * when wc->stage == UPDATE_BACKREF, this function changes
5306 * wc->stage back to DROP_REFERENCE if we changed wc->stage
5307 * to UPDATE_BACKREF previously while processing the block.
5308 *
5309 * NOTE: return value 1 means we should stop walking up.
5310 */
walk_up_proc(struct btrfs_trans_handle * trans,struct btrfs_root * root,struct btrfs_path * path,struct walk_control * wc)5311 static noinline int walk_up_proc(struct btrfs_trans_handle *trans,
5312 struct btrfs_root *root,
5313 struct btrfs_path *path,
5314 struct walk_control *wc)
5315 {
5316 struct btrfs_fs_info *fs_info = root->fs_info;
5317 int ret;
5318 int level = wc->level;
5319 struct extent_buffer *eb = path->nodes[level];
5320 u64 parent = 0;
5321
5322 if (wc->stage == UPDATE_BACKREF) {
5323 BUG_ON(wc->shared_level < level);
5324 if (level < wc->shared_level)
5325 goto out;
5326
5327 ret = find_next_key(path, level + 1, &wc->update_progress);
5328 if (ret > 0)
5329 wc->update_ref = 0;
5330
5331 wc->stage = DROP_REFERENCE;
5332 wc->shared_level = -1;
5333 path->slots[level] = 0;
5334
5335 /*
5336 * check reference count again if the block isn't locked.
5337 * we should start walking down the tree again if reference
5338 * count is one.
5339 */
5340 if (!path->locks[level]) {
5341 BUG_ON(level == 0);
5342 btrfs_tree_lock(eb);
5343 path->locks[level] = BTRFS_WRITE_LOCK;
5344
5345 ret = btrfs_lookup_extent_info(trans, fs_info,
5346 eb->start, level, 1,
5347 &wc->refs[level],
5348 &wc->flags[level]);
5349 if (ret < 0) {
5350 btrfs_tree_unlock_rw(eb, path->locks[level]);
5351 path->locks[level] = 0;
5352 return ret;
5353 }
5354 BUG_ON(wc->refs[level] == 0);
5355 if (wc->refs[level] == 1) {
5356 btrfs_tree_unlock_rw(eb, path->locks[level]);
5357 path->locks[level] = 0;
5358 return 1;
5359 }
5360 }
5361 }
5362
5363 /* wc->stage == DROP_REFERENCE */
5364 BUG_ON(wc->refs[level] > 1 && !path->locks[level]);
5365
5366 if (wc->refs[level] == 1) {
5367 if (level == 0) {
5368 if (wc->flags[level] & BTRFS_BLOCK_FLAG_FULL_BACKREF)
5369 ret = btrfs_dec_ref(trans, root, eb, 1);
5370 else
5371 ret = btrfs_dec_ref(trans, root, eb, 0);
5372 BUG_ON(ret); /* -ENOMEM */
5373 if (is_fstree(root->root_key.objectid)) {
5374 ret = btrfs_qgroup_trace_leaf_items(trans, eb);
5375 if (ret) {
5376 btrfs_err_rl(fs_info,
5377 "error %d accounting leaf items, quota is out of sync, rescan required",
5378 ret);
5379 }
5380 }
5381 }
5382 /* make block locked assertion in btrfs_clean_tree_block happy */
5383 if (!path->locks[level] &&
5384 btrfs_header_generation(eb) == trans->transid) {
5385 btrfs_tree_lock(eb);
5386 path->locks[level] = BTRFS_WRITE_LOCK;
5387 }
5388 btrfs_clean_tree_block(eb);
5389 }
5390
5391 if (eb == root->node) {
5392 if (wc->flags[level] & BTRFS_BLOCK_FLAG_FULL_BACKREF)
5393 parent = eb->start;
5394 else if (root->root_key.objectid != btrfs_header_owner(eb))
5395 goto owner_mismatch;
5396 } else {
5397 if (wc->flags[level + 1] & BTRFS_BLOCK_FLAG_FULL_BACKREF)
5398 parent = path->nodes[level + 1]->start;
5399 else if (root->root_key.objectid !=
5400 btrfs_header_owner(path->nodes[level + 1]))
5401 goto owner_mismatch;
5402 }
5403
5404 btrfs_free_tree_block(trans, root, eb, parent, wc->refs[level] == 1);
5405 out:
5406 wc->refs[level] = 0;
5407 wc->flags[level] = 0;
5408 return 0;
5409
5410 owner_mismatch:
5411 btrfs_err_rl(fs_info, "unexpected tree owner, have %llu expect %llu",
5412 btrfs_header_owner(eb), root->root_key.objectid);
5413 return -EUCLEAN;
5414 }
5415
walk_down_tree(struct btrfs_trans_handle * trans,struct btrfs_root * root,struct btrfs_path * path,struct walk_control * wc)5416 static noinline int walk_down_tree(struct btrfs_trans_handle *trans,
5417 struct btrfs_root *root,
5418 struct btrfs_path *path,
5419 struct walk_control *wc)
5420 {
5421 int level = wc->level;
5422 int lookup_info = 1;
5423 int ret;
5424
5425 while (level >= 0) {
5426 ret = walk_down_proc(trans, root, path, wc, lookup_info);
5427 if (ret > 0)
5428 break;
5429
5430 if (level == 0)
5431 break;
5432
5433 if (path->slots[level] >=
5434 btrfs_header_nritems(path->nodes[level]))
5435 break;
5436
5437 ret = do_walk_down(trans, root, path, wc, &lookup_info);
5438 if (ret > 0) {
5439 path->slots[level]++;
5440 continue;
5441 } else if (ret < 0)
5442 return ret;
5443 level = wc->level;
5444 }
5445 return 0;
5446 }
5447
walk_up_tree(struct btrfs_trans_handle * trans,struct btrfs_root * root,struct btrfs_path * path,struct walk_control * wc,int max_level)5448 static noinline int walk_up_tree(struct btrfs_trans_handle *trans,
5449 struct btrfs_root *root,
5450 struct btrfs_path *path,
5451 struct walk_control *wc, int max_level)
5452 {
5453 int level = wc->level;
5454 int ret;
5455
5456 path->slots[level] = btrfs_header_nritems(path->nodes[level]);
5457 while (level < max_level && path->nodes[level]) {
5458 wc->level = level;
5459 if (path->slots[level] + 1 <
5460 btrfs_header_nritems(path->nodes[level])) {
5461 path->slots[level]++;
5462 return 0;
5463 } else {
5464 ret = walk_up_proc(trans, root, path, wc);
5465 if (ret > 0)
5466 return 0;
5467 if (ret < 0)
5468 return ret;
5469
5470 if (path->locks[level]) {
5471 btrfs_tree_unlock_rw(path->nodes[level],
5472 path->locks[level]);
5473 path->locks[level] = 0;
5474 }
5475 free_extent_buffer(path->nodes[level]);
5476 path->nodes[level] = NULL;
5477 level++;
5478 }
5479 }
5480 return 1;
5481 }
5482
5483 /*
5484 * drop a subvolume tree.
5485 *
5486 * this function traverses the tree freeing any blocks that only
5487 * referenced by the tree.
5488 *
5489 * when a shared tree block is found. this function decreases its
5490 * reference count by one. if update_ref is true, this function
5491 * also make sure backrefs for the shared block and all lower level
5492 * blocks are properly updated.
5493 *
5494 * If called with for_reloc == 0, may exit early with -EAGAIN
5495 */
btrfs_drop_snapshot(struct btrfs_root * root,int update_ref,int for_reloc)5496 int btrfs_drop_snapshot(struct btrfs_root *root, int update_ref, int for_reloc)
5497 {
5498 struct btrfs_fs_info *fs_info = root->fs_info;
5499 struct btrfs_path *path;
5500 struct btrfs_trans_handle *trans;
5501 struct btrfs_root *tree_root = fs_info->tree_root;
5502 struct btrfs_root_item *root_item = &root->root_item;
5503 struct walk_control *wc;
5504 struct btrfs_key key;
5505 int err = 0;
5506 int ret;
5507 int level;
5508 bool root_dropped = false;
5509
5510 btrfs_debug(fs_info, "Drop subvolume %llu", root->root_key.objectid);
5511
5512 path = btrfs_alloc_path();
5513 if (!path) {
5514 err = -ENOMEM;
5515 goto out;
5516 }
5517
5518 wc = kzalloc(sizeof(*wc), GFP_NOFS);
5519 if (!wc) {
5520 btrfs_free_path(path);
5521 err = -ENOMEM;
5522 goto out;
5523 }
5524
5525 /*
5526 * Use join to avoid potential EINTR from transaction start. See
5527 * wait_reserve_ticket and the whole reservation callchain.
5528 */
5529 if (for_reloc)
5530 trans = btrfs_join_transaction(tree_root);
5531 else
5532 trans = btrfs_start_transaction(tree_root, 0);
5533 if (IS_ERR(trans)) {
5534 err = PTR_ERR(trans);
5535 goto out_free;
5536 }
5537
5538 err = btrfs_run_delayed_items(trans);
5539 if (err)
5540 goto out_end_trans;
5541
5542 /*
5543 * This will help us catch people modifying the fs tree while we're
5544 * dropping it. It is unsafe to mess with the fs tree while it's being
5545 * dropped as we unlock the root node and parent nodes as we walk down
5546 * the tree, assuming nothing will change. If something does change
5547 * then we'll have stale information and drop references to blocks we've
5548 * already dropped.
5549 */
5550 set_bit(BTRFS_ROOT_DELETING, &root->state);
5551 if (btrfs_disk_key_objectid(&root_item->drop_progress) == 0) {
5552 level = btrfs_header_level(root->node);
5553 path->nodes[level] = btrfs_lock_root_node(root);
5554 path->slots[level] = 0;
5555 path->locks[level] = BTRFS_WRITE_LOCK;
5556 memset(&wc->update_progress, 0,
5557 sizeof(wc->update_progress));
5558 } else {
5559 btrfs_disk_key_to_cpu(&key, &root_item->drop_progress);
5560 memcpy(&wc->update_progress, &key,
5561 sizeof(wc->update_progress));
5562
5563 level = btrfs_root_drop_level(root_item);
5564 BUG_ON(level == 0);
5565 path->lowest_level = level;
5566 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
5567 path->lowest_level = 0;
5568 if (ret < 0) {
5569 err = ret;
5570 goto out_end_trans;
5571 }
5572 WARN_ON(ret > 0);
5573
5574 /*
5575 * unlock our path, this is safe because only this
5576 * function is allowed to delete this snapshot
5577 */
5578 btrfs_unlock_up_safe(path, 0);
5579
5580 level = btrfs_header_level(root->node);
5581 while (1) {
5582 btrfs_tree_lock(path->nodes[level]);
5583 path->locks[level] = BTRFS_WRITE_LOCK;
5584
5585 ret = btrfs_lookup_extent_info(trans, fs_info,
5586 path->nodes[level]->start,
5587 level, 1, &wc->refs[level],
5588 &wc->flags[level]);
5589 if (ret < 0) {
5590 err = ret;
5591 goto out_end_trans;
5592 }
5593 BUG_ON(wc->refs[level] == 0);
5594
5595 if (level == btrfs_root_drop_level(root_item))
5596 break;
5597
5598 btrfs_tree_unlock(path->nodes[level]);
5599 path->locks[level] = 0;
5600 WARN_ON(wc->refs[level] != 1);
5601 level--;
5602 }
5603 }
5604
5605 wc->restarted = test_bit(BTRFS_ROOT_DEAD_TREE, &root->state);
5606 wc->level = level;
5607 wc->shared_level = -1;
5608 wc->stage = DROP_REFERENCE;
5609 wc->update_ref = update_ref;
5610 wc->keep_locks = 0;
5611 wc->reada_count = BTRFS_NODEPTRS_PER_BLOCK(fs_info);
5612
5613 while (1) {
5614
5615 ret = walk_down_tree(trans, root, path, wc);
5616 if (ret < 0) {
5617 err = ret;
5618 break;
5619 }
5620
5621 ret = walk_up_tree(trans, root, path, wc, BTRFS_MAX_LEVEL);
5622 if (ret < 0) {
5623 err = ret;
5624 break;
5625 }
5626
5627 if (ret > 0) {
5628 BUG_ON(wc->stage != DROP_REFERENCE);
5629 break;
5630 }
5631
5632 if (wc->stage == DROP_REFERENCE) {
5633 wc->drop_level = wc->level;
5634 btrfs_node_key_to_cpu(path->nodes[wc->drop_level],
5635 &wc->drop_progress,
5636 path->slots[wc->drop_level]);
5637 }
5638 btrfs_cpu_key_to_disk(&root_item->drop_progress,
5639 &wc->drop_progress);
5640 btrfs_set_root_drop_level(root_item, wc->drop_level);
5641
5642 BUG_ON(wc->level == 0);
5643 if (btrfs_should_end_transaction(trans) ||
5644 (!for_reloc && btrfs_need_cleaner_sleep(fs_info))) {
5645 ret = btrfs_update_root(trans, tree_root,
5646 &root->root_key,
5647 root_item);
5648 if (ret) {
5649 btrfs_abort_transaction(trans, ret);
5650 err = ret;
5651 goto out_end_trans;
5652 }
5653
5654 btrfs_end_transaction_throttle(trans);
5655 if (!for_reloc && btrfs_need_cleaner_sleep(fs_info)) {
5656 btrfs_debug(fs_info,
5657 "drop snapshot early exit");
5658 err = -EAGAIN;
5659 goto out_free;
5660 }
5661
5662 /*
5663 * Use join to avoid potential EINTR from transaction
5664 * start. See wait_reserve_ticket and the whole
5665 * reservation callchain.
5666 */
5667 if (for_reloc)
5668 trans = btrfs_join_transaction(tree_root);
5669 else
5670 trans = btrfs_start_transaction(tree_root, 0);
5671 if (IS_ERR(trans)) {
5672 err = PTR_ERR(trans);
5673 goto out_free;
5674 }
5675 }
5676 }
5677 btrfs_release_path(path);
5678 if (err)
5679 goto out_end_trans;
5680
5681 ret = btrfs_del_root(trans, &root->root_key);
5682 if (ret) {
5683 btrfs_abort_transaction(trans, ret);
5684 err = ret;
5685 goto out_end_trans;
5686 }
5687
5688 if (root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID) {
5689 ret = btrfs_find_root(tree_root, &root->root_key, path,
5690 NULL, NULL);
5691 if (ret < 0) {
5692 btrfs_abort_transaction(trans, ret);
5693 err = ret;
5694 goto out_end_trans;
5695 } else if (ret > 0) {
5696 /* if we fail to delete the orphan item this time
5697 * around, it'll get picked up the next time.
5698 *
5699 * The most common failure here is just -ENOENT.
5700 */
5701 btrfs_del_orphan_item(trans, tree_root,
5702 root->root_key.objectid);
5703 }
5704 }
5705
5706 /*
5707 * This subvolume is going to be completely dropped, and won't be
5708 * recorded as dirty roots, thus pertrans meta rsv will not be freed at
5709 * commit transaction time. So free it here manually.
5710 */
5711 btrfs_qgroup_convert_reserved_meta(root, INT_MAX);
5712 btrfs_qgroup_free_meta_all_pertrans(root);
5713
5714 if (test_bit(BTRFS_ROOT_IN_RADIX, &root->state))
5715 btrfs_add_dropped_root(trans, root);
5716 else
5717 btrfs_put_root(root);
5718 root_dropped = true;
5719 out_end_trans:
5720 btrfs_end_transaction_throttle(trans);
5721 out_free:
5722 kfree(wc);
5723 btrfs_free_path(path);
5724 out:
5725 /*
5726 * So if we need to stop dropping the snapshot for whatever reason we
5727 * need to make sure to add it back to the dead root list so that we
5728 * keep trying to do the work later. This also cleans up roots if we
5729 * don't have it in the radix (like when we recover after a power fail
5730 * or unmount) so we don't leak memory.
5731 */
5732 if (!for_reloc && !root_dropped)
5733 btrfs_add_dead_root(root);
5734 return err;
5735 }
5736
5737 /*
5738 * drop subtree rooted at tree block 'node'.
5739 *
5740 * NOTE: this function will unlock and release tree block 'node'
5741 * only used by relocation code
5742 */
btrfs_drop_subtree(struct btrfs_trans_handle * trans,struct btrfs_root * root,struct extent_buffer * node,struct extent_buffer * parent)5743 int btrfs_drop_subtree(struct btrfs_trans_handle *trans,
5744 struct btrfs_root *root,
5745 struct extent_buffer *node,
5746 struct extent_buffer *parent)
5747 {
5748 struct btrfs_fs_info *fs_info = root->fs_info;
5749 struct btrfs_path *path;
5750 struct walk_control *wc;
5751 int level;
5752 int parent_level;
5753 int ret = 0;
5754 int wret;
5755
5756 BUG_ON(root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID);
5757
5758 path = btrfs_alloc_path();
5759 if (!path)
5760 return -ENOMEM;
5761
5762 wc = kzalloc(sizeof(*wc), GFP_NOFS);
5763 if (!wc) {
5764 btrfs_free_path(path);
5765 return -ENOMEM;
5766 }
5767
5768 btrfs_assert_tree_locked(parent);
5769 parent_level = btrfs_header_level(parent);
5770 atomic_inc(&parent->refs);
5771 path->nodes[parent_level] = parent;
5772 path->slots[parent_level] = btrfs_header_nritems(parent);
5773
5774 btrfs_assert_tree_locked(node);
5775 level = btrfs_header_level(node);
5776 path->nodes[level] = node;
5777 path->slots[level] = 0;
5778 path->locks[level] = BTRFS_WRITE_LOCK;
5779
5780 wc->refs[parent_level] = 1;
5781 wc->flags[parent_level] = BTRFS_BLOCK_FLAG_FULL_BACKREF;
5782 wc->level = level;
5783 wc->shared_level = -1;
5784 wc->stage = DROP_REFERENCE;
5785 wc->update_ref = 0;
5786 wc->keep_locks = 1;
5787 wc->reada_count = BTRFS_NODEPTRS_PER_BLOCK(fs_info);
5788
5789 while (1) {
5790 wret = walk_down_tree(trans, root, path, wc);
5791 if (wret < 0) {
5792 ret = wret;
5793 break;
5794 }
5795
5796 wret = walk_up_tree(trans, root, path, wc, parent_level);
5797 if (wret < 0)
5798 ret = wret;
5799 if (wret != 0)
5800 break;
5801 }
5802
5803 kfree(wc);
5804 btrfs_free_path(path);
5805 return ret;
5806 }
5807
5808 /*
5809 * helper to account the unused space of all the readonly block group in the
5810 * space_info. takes mirrors into account.
5811 */
btrfs_account_ro_block_groups_free_space(struct btrfs_space_info * sinfo)5812 u64 btrfs_account_ro_block_groups_free_space(struct btrfs_space_info *sinfo)
5813 {
5814 struct btrfs_block_group *block_group;
5815 u64 free_bytes = 0;
5816 int factor;
5817
5818 /* It's df, we don't care if it's racy */
5819 if (list_empty(&sinfo->ro_bgs))
5820 return 0;
5821
5822 spin_lock(&sinfo->lock);
5823 list_for_each_entry(block_group, &sinfo->ro_bgs, ro_list) {
5824 spin_lock(&block_group->lock);
5825
5826 if (!block_group->ro) {
5827 spin_unlock(&block_group->lock);
5828 continue;
5829 }
5830
5831 factor = btrfs_bg_type_to_factor(block_group->flags);
5832 free_bytes += (block_group->length -
5833 block_group->used) * factor;
5834
5835 spin_unlock(&block_group->lock);
5836 }
5837 spin_unlock(&sinfo->lock);
5838
5839 return free_bytes;
5840 }
5841
btrfs_error_unpin_extent_range(struct btrfs_fs_info * fs_info,u64 start,u64 end)5842 int btrfs_error_unpin_extent_range(struct btrfs_fs_info *fs_info,
5843 u64 start, u64 end)
5844 {
5845 return unpin_extent_range(fs_info, start, end, false);
5846 }
5847
5848 /*
5849 * It used to be that old block groups would be left around forever.
5850 * Iterating over them would be enough to trim unused space. Since we
5851 * now automatically remove them, we also need to iterate over unallocated
5852 * space.
5853 *
5854 * We don't want a transaction for this since the discard may take a
5855 * substantial amount of time. We don't require that a transaction be
5856 * running, but we do need to take a running transaction into account
5857 * to ensure that we're not discarding chunks that were released or
5858 * allocated in the current transaction.
5859 *
5860 * Holding the chunks lock will prevent other threads from allocating
5861 * or releasing chunks, but it won't prevent a running transaction
5862 * from committing and releasing the memory that the pending chunks
5863 * list head uses. For that, we need to take a reference to the
5864 * transaction and hold the commit root sem. We only need to hold
5865 * it while performing the free space search since we have already
5866 * held back allocations.
5867 */
btrfs_trim_free_extents(struct btrfs_device * device,u64 * trimmed)5868 static int btrfs_trim_free_extents(struct btrfs_device *device, u64 *trimmed)
5869 {
5870 u64 start = SZ_1M, len = 0, end = 0;
5871 int ret;
5872
5873 *trimmed = 0;
5874
5875 /* Discard not supported = nothing to do. */
5876 if (!blk_queue_discard(bdev_get_queue(device->bdev)))
5877 return 0;
5878
5879 /* Not writable = nothing to do. */
5880 if (!test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state))
5881 return 0;
5882
5883 /* No free space = nothing to do. */
5884 if (device->total_bytes <= device->bytes_used)
5885 return 0;
5886
5887 ret = 0;
5888
5889 while (1) {
5890 struct btrfs_fs_info *fs_info = device->fs_info;
5891 u64 bytes;
5892
5893 ret = mutex_lock_interruptible(&fs_info->chunk_mutex);
5894 if (ret)
5895 break;
5896
5897 find_first_clear_extent_bit(&device->alloc_state, start,
5898 &start, &end,
5899 CHUNK_TRIMMED | CHUNK_ALLOCATED);
5900
5901 /* Check if there are any CHUNK_* bits left */
5902 if (start > device->total_bytes) {
5903 WARN_ON(IS_ENABLED(CONFIG_BTRFS_DEBUG));
5904 btrfs_warn_in_rcu(fs_info,
5905 "ignoring attempt to trim beyond device size: offset %llu length %llu device %s device size %llu",
5906 start, end - start + 1,
5907 rcu_str_deref(device->name),
5908 device->total_bytes);
5909 mutex_unlock(&fs_info->chunk_mutex);
5910 ret = 0;
5911 break;
5912 }
5913
5914 /* Ensure we skip the reserved area in the first 1M */
5915 start = max_t(u64, start, SZ_1M);
5916
5917 /*
5918 * If find_first_clear_extent_bit find a range that spans the
5919 * end of the device it will set end to -1, in this case it's up
5920 * to the caller to trim the value to the size of the device.
5921 */
5922 end = min(end, device->total_bytes - 1);
5923
5924 len = end - start + 1;
5925
5926 /* We didn't find any extents */
5927 if (!len) {
5928 mutex_unlock(&fs_info->chunk_mutex);
5929 ret = 0;
5930 break;
5931 }
5932
5933 ret = btrfs_issue_discard(device->bdev, start, len,
5934 &bytes);
5935 if (!ret)
5936 set_extent_bits(&device->alloc_state, start,
5937 start + bytes - 1,
5938 CHUNK_TRIMMED);
5939 mutex_unlock(&fs_info->chunk_mutex);
5940
5941 if (ret)
5942 break;
5943
5944 start += len;
5945 *trimmed += bytes;
5946
5947 if (fatal_signal_pending(current)) {
5948 ret = -ERESTARTSYS;
5949 break;
5950 }
5951
5952 cond_resched();
5953 }
5954
5955 return ret;
5956 }
5957
5958 /*
5959 * Trim the whole filesystem by:
5960 * 1) trimming the free space in each block group
5961 * 2) trimming the unallocated space on each device
5962 *
5963 * This will also continue trimming even if a block group or device encounters
5964 * an error. The return value will be the last error, or 0 if nothing bad
5965 * happens.
5966 */
btrfs_trim_fs(struct btrfs_fs_info * fs_info,struct fstrim_range * range)5967 int btrfs_trim_fs(struct btrfs_fs_info *fs_info, struct fstrim_range *range)
5968 {
5969 struct btrfs_block_group *cache = NULL;
5970 struct btrfs_device *device;
5971 struct list_head *devices;
5972 u64 group_trimmed;
5973 u64 range_end = U64_MAX;
5974 u64 start;
5975 u64 end;
5976 u64 trimmed = 0;
5977 u64 bg_failed = 0;
5978 u64 dev_failed = 0;
5979 int bg_ret = 0;
5980 int dev_ret = 0;
5981 int ret = 0;
5982
5983 /*
5984 * Check range overflow if range->len is set.
5985 * The default range->len is U64_MAX.
5986 */
5987 if (range->len != U64_MAX &&
5988 check_add_overflow(range->start, range->len, &range_end))
5989 return -EINVAL;
5990
5991 cache = btrfs_lookup_first_block_group(fs_info, range->start);
5992 for (; cache; cache = btrfs_next_block_group(cache)) {
5993 if (cache->start >= range_end) {
5994 btrfs_put_block_group(cache);
5995 break;
5996 }
5997
5998 start = max(range->start, cache->start);
5999 end = min(range_end, cache->start + cache->length);
6000
6001 if (end - start >= range->minlen) {
6002 if (!btrfs_block_group_done(cache)) {
6003 ret = btrfs_cache_block_group(cache, 0);
6004 if (ret) {
6005 bg_failed++;
6006 bg_ret = ret;
6007 continue;
6008 }
6009 ret = btrfs_wait_block_group_cache_done(cache);
6010 if (ret) {
6011 bg_failed++;
6012 bg_ret = ret;
6013 continue;
6014 }
6015 }
6016 ret = btrfs_trim_block_group(cache,
6017 &group_trimmed,
6018 start,
6019 end,
6020 range->minlen);
6021
6022 trimmed += group_trimmed;
6023 if (ret) {
6024 bg_failed++;
6025 bg_ret = ret;
6026 continue;
6027 }
6028 }
6029 }
6030
6031 if (bg_failed)
6032 btrfs_warn(fs_info,
6033 "failed to trim %llu block group(s), last error %d",
6034 bg_failed, bg_ret);
6035 mutex_lock(&fs_info->fs_devices->device_list_mutex);
6036 devices = &fs_info->fs_devices->devices;
6037 list_for_each_entry(device, devices, dev_list) {
6038 ret = btrfs_trim_free_extents(device, &group_trimmed);
6039 if (ret) {
6040 dev_failed++;
6041 dev_ret = ret;
6042 break;
6043 }
6044
6045 trimmed += group_trimmed;
6046 }
6047 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
6048
6049 if (dev_failed)
6050 btrfs_warn(fs_info,
6051 "failed to trim %llu device(s), last error %d",
6052 dev_failed, dev_ret);
6053 range->len = trimmed;
6054 if (bg_ret)
6055 return bg_ret;
6056 return dev_ret;
6057 }
6058