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 "ctree.h"
20 #include "extent-tree.h"
21 #include "tree-log.h"
22 #include "disk-io.h"
23 #include "print-tree.h"
24 #include "volumes.h"
25 #include "raid56.h"
26 #include "locking.h"
27 #include "free-space-cache.h"
28 #include "free-space-tree.h"
29 #include "sysfs.h"
30 #include "qgroup.h"
31 #include "ref-verify.h"
32 #include "space-info.h"
33 #include "block-rsv.h"
34 #include "delalloc-space.h"
35 #include "discard.h"
36 #include "rcu-string.h"
37 #include "zoned.h"
38 #include "dev-replace.h"
39 #include "fs.h"
40 #include "accessors.h"
41 #include "root-tree.h"
42 #include "file-item.h"
43 #include "orphan.h"
44 #include "tree-checker.h"
45 #include "raid-stripe-tree.h"
46
47 #undef SCRAMBLE_DELAYED_REFS
48
49
50 static int __btrfs_free_extent(struct btrfs_trans_handle *trans,
51 struct btrfs_delayed_ref_head *href,
52 struct btrfs_delayed_ref_node *node, u64 parent,
53 u64 root_objectid, u64 owner_objectid,
54 u64 owner_offset,
55 struct btrfs_delayed_extent_op *extra_op);
56 static void __run_delayed_extent_op(struct btrfs_delayed_extent_op *extent_op,
57 struct extent_buffer *leaf,
58 struct btrfs_extent_item *ei);
59 static int alloc_reserved_file_extent(struct btrfs_trans_handle *trans,
60 u64 parent, u64 root_objectid,
61 u64 flags, u64 owner, u64 offset,
62 struct btrfs_key *ins, int ref_mod, u64 oref_root);
63 static int alloc_reserved_tree_block(struct btrfs_trans_handle *trans,
64 struct btrfs_delayed_ref_node *node,
65 struct btrfs_delayed_extent_op *extent_op);
66 static int find_next_key(struct btrfs_path *path, int level,
67 struct btrfs_key *key);
68
block_group_bits(struct btrfs_block_group * cache,u64 bits)69 static int block_group_bits(struct btrfs_block_group *cache, u64 bits)
70 {
71 return (cache->flags & bits) == bits;
72 }
73
74 /* 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)75 int btrfs_lookup_data_extent(struct btrfs_fs_info *fs_info, u64 start, u64 len)
76 {
77 struct btrfs_root *root = btrfs_extent_root(fs_info, start);
78 int ret;
79 struct btrfs_key key;
80 struct btrfs_path *path;
81
82 path = btrfs_alloc_path();
83 if (!path)
84 return -ENOMEM;
85
86 key.objectid = start;
87 key.offset = len;
88 key.type = BTRFS_EXTENT_ITEM_KEY;
89 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
90 btrfs_free_path(path);
91 return ret;
92 }
93
94 /*
95 * helper function to lookup reference count and flags of a tree block.
96 *
97 * the head node for delayed ref is used to store the sum of all the
98 * reference count modifications queued up in the rbtree. the head
99 * node may also store the extent flags to set. This way you can check
100 * to see what the reference count and extent flags would be if all of
101 * the delayed refs are not processed.
102 */
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,u64 * owning_root)103 int btrfs_lookup_extent_info(struct btrfs_trans_handle *trans,
104 struct btrfs_fs_info *fs_info, u64 bytenr,
105 u64 offset, int metadata, u64 *refs, u64 *flags,
106 u64 *owning_root)
107 {
108 struct btrfs_root *extent_root;
109 struct btrfs_delayed_ref_head *head;
110 struct btrfs_delayed_ref_root *delayed_refs;
111 struct btrfs_path *path;
112 struct btrfs_extent_item *ei;
113 struct extent_buffer *leaf;
114 struct btrfs_key key;
115 u32 item_size;
116 u64 num_refs;
117 u64 extent_flags;
118 u64 owner = 0;
119 int ret;
120
121 /*
122 * If we don't have skinny metadata, don't bother doing anything
123 * different
124 */
125 if (metadata && !btrfs_fs_incompat(fs_info, SKINNY_METADATA)) {
126 offset = fs_info->nodesize;
127 metadata = 0;
128 }
129
130 path = btrfs_alloc_path();
131 if (!path)
132 return -ENOMEM;
133
134 if (!trans) {
135 path->skip_locking = 1;
136 path->search_commit_root = 1;
137 }
138
139 search_again:
140 key.objectid = bytenr;
141 key.offset = offset;
142 if (metadata)
143 key.type = BTRFS_METADATA_ITEM_KEY;
144 else
145 key.type = BTRFS_EXTENT_ITEM_KEY;
146
147 extent_root = btrfs_extent_root(fs_info, bytenr);
148 ret = btrfs_search_slot(NULL, extent_root, &key, path, 0, 0);
149 if (ret < 0)
150 goto out_free;
151
152 if (ret > 0 && metadata && key.type == BTRFS_METADATA_ITEM_KEY) {
153 if (path->slots[0]) {
154 path->slots[0]--;
155 btrfs_item_key_to_cpu(path->nodes[0], &key,
156 path->slots[0]);
157 if (key.objectid == bytenr &&
158 key.type == BTRFS_EXTENT_ITEM_KEY &&
159 key.offset == fs_info->nodesize)
160 ret = 0;
161 }
162 }
163
164 if (ret == 0) {
165 leaf = path->nodes[0];
166 item_size = btrfs_item_size(leaf, path->slots[0]);
167 if (item_size >= sizeof(*ei)) {
168 ei = btrfs_item_ptr(leaf, path->slots[0],
169 struct btrfs_extent_item);
170 num_refs = btrfs_extent_refs(leaf, ei);
171 extent_flags = btrfs_extent_flags(leaf, ei);
172 owner = btrfs_get_extent_owner_root(fs_info, leaf,
173 path->slots[0]);
174 } else {
175 ret = -EUCLEAN;
176 btrfs_err(fs_info,
177 "unexpected extent item size, has %u expect >= %zu",
178 item_size, sizeof(*ei));
179 if (trans)
180 btrfs_abort_transaction(trans, ret);
181 else
182 btrfs_handle_fs_error(fs_info, ret, NULL);
183
184 goto out_free;
185 }
186
187 BUG_ON(num_refs == 0);
188 } else {
189 num_refs = 0;
190 extent_flags = 0;
191 ret = 0;
192 }
193
194 if (!trans)
195 goto out;
196
197 delayed_refs = &trans->transaction->delayed_refs;
198 spin_lock(&delayed_refs->lock);
199 head = btrfs_find_delayed_ref_head(delayed_refs, bytenr);
200 if (head) {
201 if (!mutex_trylock(&head->mutex)) {
202 refcount_inc(&head->refs);
203 spin_unlock(&delayed_refs->lock);
204
205 btrfs_release_path(path);
206
207 /*
208 * Mutex was contended, block until it's released and try
209 * again
210 */
211 mutex_lock(&head->mutex);
212 mutex_unlock(&head->mutex);
213 btrfs_put_delayed_ref_head(head);
214 goto search_again;
215 }
216 spin_lock(&head->lock);
217 if (head->extent_op && head->extent_op->update_flags)
218 extent_flags |= head->extent_op->flags_to_set;
219 else
220 BUG_ON(num_refs == 0);
221
222 num_refs += head->ref_mod;
223 spin_unlock(&head->lock);
224 mutex_unlock(&head->mutex);
225 }
226 spin_unlock(&delayed_refs->lock);
227 out:
228 WARN_ON(num_refs == 0);
229 if (refs)
230 *refs = num_refs;
231 if (flags)
232 *flags = extent_flags;
233 if (owning_root)
234 *owning_root = owner;
235 out_free:
236 btrfs_free_path(path);
237 return ret;
238 }
239
240 /*
241 * Back reference rules. Back refs have three main goals:
242 *
243 * 1) differentiate between all holders of references to an extent so that
244 * when a reference is dropped we can make sure it was a valid reference
245 * before freeing the extent.
246 *
247 * 2) Provide enough information to quickly find the holders of an extent
248 * if we notice a given block is corrupted or bad.
249 *
250 * 3) Make it easy to migrate blocks for FS shrinking or storage pool
251 * maintenance. This is actually the same as #2, but with a slightly
252 * different use case.
253 *
254 * There are two kinds of back refs. The implicit back refs is optimized
255 * for pointers in non-shared tree blocks. For a given pointer in a block,
256 * back refs of this kind provide information about the block's owner tree
257 * and the pointer's key. These information allow us to find the block by
258 * b-tree searching. The full back refs is for pointers in tree blocks not
259 * referenced by their owner trees. The location of tree block is recorded
260 * in the back refs. Actually the full back refs is generic, and can be
261 * used in all cases the implicit back refs is used. The major shortcoming
262 * of the full back refs is its overhead. Every time a tree block gets
263 * COWed, we have to update back refs entry for all pointers in it.
264 *
265 * For a newly allocated tree block, we use implicit back refs for
266 * pointers in it. This means most tree related operations only involve
267 * implicit back refs. For a tree block created in old transaction, the
268 * only way to drop a reference to it is COW it. So we can detect the
269 * event that tree block loses its owner tree's reference and do the
270 * back refs conversion.
271 *
272 * When a tree block is COWed through a tree, there are four cases:
273 *
274 * The reference count of the block is one and the tree is the block's
275 * owner tree. Nothing to do in this case.
276 *
277 * The reference count of the block is one and the tree is not the
278 * block's owner tree. In this case, full back refs is used for pointers
279 * in the block. Remove these full back refs, add implicit back refs for
280 * every pointers in the new block.
281 *
282 * The reference count of the block is greater than one and the tree is
283 * the block's owner tree. In this case, implicit back refs is used for
284 * pointers in the block. Add full back refs for every pointers in the
285 * block, increase lower level extents' reference counts. The original
286 * implicit back refs are entailed to the new block.
287 *
288 * The reference count of the block is greater than one and the tree is
289 * not the block's owner tree. Add implicit back refs for every pointer in
290 * the new block, increase lower level extents' reference count.
291 *
292 * Back Reference Key composing:
293 *
294 * The key objectid corresponds to the first byte in the extent,
295 * The key type is used to differentiate between types of back refs.
296 * There are different meanings of the key offset for different types
297 * of back refs.
298 *
299 * File extents can be referenced by:
300 *
301 * - multiple snapshots, subvolumes, or different generations in one subvol
302 * - different files inside a single subvolume
303 * - different offsets inside a file (bookend extents in file.c)
304 *
305 * The extent ref structure for the implicit back refs has fields for:
306 *
307 * - Objectid of the subvolume root
308 * - objectid of the file holding the reference
309 * - original offset in the file
310 * - how many bookend extents
311 *
312 * The key offset for the implicit back refs is hash of the first
313 * three fields.
314 *
315 * The extent ref structure for the full back refs has field for:
316 *
317 * - number of pointers in the tree leaf
318 *
319 * The key offset for the implicit back refs is the first byte of
320 * the tree leaf
321 *
322 * When a file extent is allocated, The implicit back refs is used.
323 * the fields are filled in:
324 *
325 * (root_key.objectid, inode objectid, offset in file, 1)
326 *
327 * When a file extent is removed file truncation, we find the
328 * corresponding implicit back refs and check the following fields:
329 *
330 * (btrfs_header_owner(leaf), inode objectid, offset in file)
331 *
332 * Btree extents can be referenced by:
333 *
334 * - Different subvolumes
335 *
336 * Both the implicit back refs and the full back refs for tree blocks
337 * only consist of key. The key offset for the implicit back refs is
338 * objectid of block's owner tree. The key offset for the full back refs
339 * is the first byte of parent block.
340 *
341 * When implicit back refs is used, information about the lowest key and
342 * level of the tree block are required. These information are stored in
343 * tree block info structure.
344 */
345
346 /*
347 * is_data == BTRFS_REF_TYPE_BLOCK, tree block type is required,
348 * is_data == BTRFS_REF_TYPE_DATA, data type is requiried,
349 * is_data == BTRFS_REF_TYPE_ANY, either type is OK.
350 */
btrfs_get_extent_inline_ref_type(const struct extent_buffer * eb,struct btrfs_extent_inline_ref * iref,enum btrfs_inline_ref_type is_data)351 int btrfs_get_extent_inline_ref_type(const struct extent_buffer *eb,
352 struct btrfs_extent_inline_ref *iref,
353 enum btrfs_inline_ref_type is_data)
354 {
355 struct btrfs_fs_info *fs_info = eb->fs_info;
356 int type = btrfs_extent_inline_ref_type(eb, iref);
357 u64 offset = btrfs_extent_inline_ref_offset(eb, iref);
358
359 if (type == BTRFS_EXTENT_OWNER_REF_KEY) {
360 ASSERT(btrfs_fs_incompat(fs_info, SIMPLE_QUOTA));
361 return type;
362 }
363
364 if (type == BTRFS_TREE_BLOCK_REF_KEY ||
365 type == BTRFS_SHARED_BLOCK_REF_KEY ||
366 type == BTRFS_SHARED_DATA_REF_KEY ||
367 type == BTRFS_EXTENT_DATA_REF_KEY) {
368 if (is_data == BTRFS_REF_TYPE_BLOCK) {
369 if (type == BTRFS_TREE_BLOCK_REF_KEY)
370 return type;
371 if (type == BTRFS_SHARED_BLOCK_REF_KEY) {
372 ASSERT(fs_info);
373 /*
374 * Every shared one has parent tree block,
375 * which must be aligned to sector size.
376 */
377 if (offset && IS_ALIGNED(offset, fs_info->sectorsize))
378 return type;
379 }
380 } else if (is_data == BTRFS_REF_TYPE_DATA) {
381 if (type == BTRFS_EXTENT_DATA_REF_KEY)
382 return type;
383 if (type == BTRFS_SHARED_DATA_REF_KEY) {
384 ASSERT(fs_info);
385 /*
386 * Every shared one has parent tree block,
387 * which must be aligned to sector size.
388 */
389 if (offset &&
390 IS_ALIGNED(offset, fs_info->sectorsize))
391 return type;
392 }
393 } else {
394 ASSERT(is_data == BTRFS_REF_TYPE_ANY);
395 return type;
396 }
397 }
398
399 WARN_ON(1);
400 btrfs_print_leaf(eb);
401 btrfs_err(fs_info,
402 "eb %llu iref 0x%lx invalid extent inline ref type %d",
403 eb->start, (unsigned long)iref, type);
404
405 return BTRFS_REF_TYPE_INVALID;
406 }
407
hash_extent_data_ref(u64 root_objectid,u64 owner,u64 offset)408 u64 hash_extent_data_ref(u64 root_objectid, u64 owner, u64 offset)
409 {
410 u32 high_crc = ~(u32)0;
411 u32 low_crc = ~(u32)0;
412 __le64 lenum;
413
414 lenum = cpu_to_le64(root_objectid);
415 high_crc = crc32c(high_crc, &lenum, sizeof(lenum));
416 lenum = cpu_to_le64(owner);
417 low_crc = crc32c(low_crc, &lenum, sizeof(lenum));
418 lenum = cpu_to_le64(offset);
419 low_crc = crc32c(low_crc, &lenum, sizeof(lenum));
420
421 return ((u64)high_crc << 31) ^ (u64)low_crc;
422 }
423
hash_extent_data_ref_item(struct extent_buffer * leaf,struct btrfs_extent_data_ref * ref)424 static u64 hash_extent_data_ref_item(struct extent_buffer *leaf,
425 struct btrfs_extent_data_ref *ref)
426 {
427 return hash_extent_data_ref(btrfs_extent_data_ref_root(leaf, ref),
428 btrfs_extent_data_ref_objectid(leaf, ref),
429 btrfs_extent_data_ref_offset(leaf, ref));
430 }
431
match_extent_data_ref(struct extent_buffer * leaf,struct btrfs_extent_data_ref * ref,u64 root_objectid,u64 owner,u64 offset)432 static int match_extent_data_ref(struct extent_buffer *leaf,
433 struct btrfs_extent_data_ref *ref,
434 u64 root_objectid, u64 owner, u64 offset)
435 {
436 if (btrfs_extent_data_ref_root(leaf, ref) != root_objectid ||
437 btrfs_extent_data_ref_objectid(leaf, ref) != owner ||
438 btrfs_extent_data_ref_offset(leaf, ref) != offset)
439 return 0;
440 return 1;
441 }
442
lookup_extent_data_ref(struct btrfs_trans_handle * trans,struct btrfs_path * path,u64 bytenr,u64 parent,u64 root_objectid,u64 owner,u64 offset)443 static noinline int lookup_extent_data_ref(struct btrfs_trans_handle *trans,
444 struct btrfs_path *path,
445 u64 bytenr, u64 parent,
446 u64 root_objectid,
447 u64 owner, u64 offset)
448 {
449 struct btrfs_root *root = btrfs_extent_root(trans->fs_info, bytenr);
450 struct btrfs_key key;
451 struct btrfs_extent_data_ref *ref;
452 struct extent_buffer *leaf;
453 u32 nritems;
454 int ret;
455 int recow;
456 int err = -ENOENT;
457
458 key.objectid = bytenr;
459 if (parent) {
460 key.type = BTRFS_SHARED_DATA_REF_KEY;
461 key.offset = parent;
462 } else {
463 key.type = BTRFS_EXTENT_DATA_REF_KEY;
464 key.offset = hash_extent_data_ref(root_objectid,
465 owner, offset);
466 }
467 again:
468 recow = 0;
469 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
470 if (ret < 0) {
471 err = ret;
472 goto fail;
473 }
474
475 if (parent) {
476 if (!ret)
477 return 0;
478 goto fail;
479 }
480
481 leaf = path->nodes[0];
482 nritems = btrfs_header_nritems(leaf);
483 while (1) {
484 if (path->slots[0] >= nritems) {
485 ret = btrfs_next_leaf(root, path);
486 if (ret < 0)
487 err = ret;
488 if (ret)
489 goto fail;
490
491 leaf = path->nodes[0];
492 nritems = btrfs_header_nritems(leaf);
493 recow = 1;
494 }
495
496 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
497 if (key.objectid != bytenr ||
498 key.type != BTRFS_EXTENT_DATA_REF_KEY)
499 goto fail;
500
501 ref = btrfs_item_ptr(leaf, path->slots[0],
502 struct btrfs_extent_data_ref);
503
504 if (match_extent_data_ref(leaf, ref, root_objectid,
505 owner, offset)) {
506 if (recow) {
507 btrfs_release_path(path);
508 goto again;
509 }
510 err = 0;
511 break;
512 }
513 path->slots[0]++;
514 }
515 fail:
516 return err;
517 }
518
insert_extent_data_ref(struct btrfs_trans_handle * trans,struct btrfs_path * path,u64 bytenr,u64 parent,u64 root_objectid,u64 owner,u64 offset,int refs_to_add)519 static noinline int insert_extent_data_ref(struct btrfs_trans_handle *trans,
520 struct btrfs_path *path,
521 u64 bytenr, u64 parent,
522 u64 root_objectid, u64 owner,
523 u64 offset, int refs_to_add)
524 {
525 struct btrfs_root *root = btrfs_extent_root(trans->fs_info, bytenr);
526 struct btrfs_key key;
527 struct extent_buffer *leaf;
528 u32 size;
529 u32 num_refs;
530 int ret;
531
532 key.objectid = bytenr;
533 if (parent) {
534 key.type = BTRFS_SHARED_DATA_REF_KEY;
535 key.offset = parent;
536 size = sizeof(struct btrfs_shared_data_ref);
537 } else {
538 key.type = BTRFS_EXTENT_DATA_REF_KEY;
539 key.offset = hash_extent_data_ref(root_objectid,
540 owner, offset);
541 size = sizeof(struct btrfs_extent_data_ref);
542 }
543
544 ret = btrfs_insert_empty_item(trans, root, path, &key, size);
545 if (ret && ret != -EEXIST)
546 goto fail;
547
548 leaf = path->nodes[0];
549 if (parent) {
550 struct btrfs_shared_data_ref *ref;
551 ref = btrfs_item_ptr(leaf, path->slots[0],
552 struct btrfs_shared_data_ref);
553 if (ret == 0) {
554 btrfs_set_shared_data_ref_count(leaf, ref, refs_to_add);
555 } else {
556 num_refs = btrfs_shared_data_ref_count(leaf, ref);
557 num_refs += refs_to_add;
558 btrfs_set_shared_data_ref_count(leaf, ref, num_refs);
559 }
560 } else {
561 struct btrfs_extent_data_ref *ref;
562 while (ret == -EEXIST) {
563 ref = btrfs_item_ptr(leaf, path->slots[0],
564 struct btrfs_extent_data_ref);
565 if (match_extent_data_ref(leaf, ref, root_objectid,
566 owner, offset))
567 break;
568 btrfs_release_path(path);
569 key.offset++;
570 ret = btrfs_insert_empty_item(trans, root, path, &key,
571 size);
572 if (ret && ret != -EEXIST)
573 goto fail;
574
575 leaf = path->nodes[0];
576 }
577 ref = btrfs_item_ptr(leaf, path->slots[0],
578 struct btrfs_extent_data_ref);
579 if (ret == 0) {
580 btrfs_set_extent_data_ref_root(leaf, ref,
581 root_objectid);
582 btrfs_set_extent_data_ref_objectid(leaf, ref, owner);
583 btrfs_set_extent_data_ref_offset(leaf, ref, offset);
584 btrfs_set_extent_data_ref_count(leaf, ref, refs_to_add);
585 } else {
586 num_refs = btrfs_extent_data_ref_count(leaf, ref);
587 num_refs += refs_to_add;
588 btrfs_set_extent_data_ref_count(leaf, ref, num_refs);
589 }
590 }
591 btrfs_mark_buffer_dirty(trans, leaf);
592 ret = 0;
593 fail:
594 btrfs_release_path(path);
595 return ret;
596 }
597
remove_extent_data_ref(struct btrfs_trans_handle * trans,struct btrfs_root * root,struct btrfs_path * path,int refs_to_drop)598 static noinline int remove_extent_data_ref(struct btrfs_trans_handle *trans,
599 struct btrfs_root *root,
600 struct btrfs_path *path,
601 int refs_to_drop)
602 {
603 struct btrfs_key key;
604 struct btrfs_extent_data_ref *ref1 = NULL;
605 struct btrfs_shared_data_ref *ref2 = NULL;
606 struct extent_buffer *leaf;
607 u32 num_refs = 0;
608 int ret = 0;
609
610 leaf = path->nodes[0];
611 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
612
613 if (key.type == BTRFS_EXTENT_DATA_REF_KEY) {
614 ref1 = btrfs_item_ptr(leaf, path->slots[0],
615 struct btrfs_extent_data_ref);
616 num_refs = btrfs_extent_data_ref_count(leaf, ref1);
617 } else if (key.type == BTRFS_SHARED_DATA_REF_KEY) {
618 ref2 = btrfs_item_ptr(leaf, path->slots[0],
619 struct btrfs_shared_data_ref);
620 num_refs = btrfs_shared_data_ref_count(leaf, ref2);
621 } else {
622 btrfs_err(trans->fs_info,
623 "unrecognized backref key (%llu %u %llu)",
624 key.objectid, key.type, key.offset);
625 btrfs_abort_transaction(trans, -EUCLEAN);
626 return -EUCLEAN;
627 }
628
629 BUG_ON(num_refs < refs_to_drop);
630 num_refs -= refs_to_drop;
631
632 if (num_refs == 0) {
633 ret = btrfs_del_item(trans, root, path);
634 } else {
635 if (key.type == BTRFS_EXTENT_DATA_REF_KEY)
636 btrfs_set_extent_data_ref_count(leaf, ref1, num_refs);
637 else if (key.type == BTRFS_SHARED_DATA_REF_KEY)
638 btrfs_set_shared_data_ref_count(leaf, ref2, num_refs);
639 btrfs_mark_buffer_dirty(trans, leaf);
640 }
641 return ret;
642 }
643
extent_data_ref_count(struct btrfs_path * path,struct btrfs_extent_inline_ref * iref)644 static noinline u32 extent_data_ref_count(struct btrfs_path *path,
645 struct btrfs_extent_inline_ref *iref)
646 {
647 struct btrfs_key key;
648 struct extent_buffer *leaf;
649 struct btrfs_extent_data_ref *ref1;
650 struct btrfs_shared_data_ref *ref2;
651 u32 num_refs = 0;
652 int type;
653
654 leaf = path->nodes[0];
655 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
656
657 if (iref) {
658 /*
659 * If type is invalid, we should have bailed out earlier than
660 * this call.
661 */
662 type = btrfs_get_extent_inline_ref_type(leaf, iref, BTRFS_REF_TYPE_DATA);
663 ASSERT(type != BTRFS_REF_TYPE_INVALID);
664 if (type == BTRFS_EXTENT_DATA_REF_KEY) {
665 ref1 = (struct btrfs_extent_data_ref *)(&iref->offset);
666 num_refs = btrfs_extent_data_ref_count(leaf, ref1);
667 } else {
668 ref2 = (struct btrfs_shared_data_ref *)(iref + 1);
669 num_refs = btrfs_shared_data_ref_count(leaf, ref2);
670 }
671 } else if (key.type == BTRFS_EXTENT_DATA_REF_KEY) {
672 ref1 = btrfs_item_ptr(leaf, path->slots[0],
673 struct btrfs_extent_data_ref);
674 num_refs = btrfs_extent_data_ref_count(leaf, ref1);
675 } else if (key.type == BTRFS_SHARED_DATA_REF_KEY) {
676 ref2 = btrfs_item_ptr(leaf, path->slots[0],
677 struct btrfs_shared_data_ref);
678 num_refs = btrfs_shared_data_ref_count(leaf, ref2);
679 } else {
680 WARN_ON(1);
681 }
682 return num_refs;
683 }
684
lookup_tree_block_ref(struct btrfs_trans_handle * trans,struct btrfs_path * path,u64 bytenr,u64 parent,u64 root_objectid)685 static noinline int lookup_tree_block_ref(struct btrfs_trans_handle *trans,
686 struct btrfs_path *path,
687 u64 bytenr, u64 parent,
688 u64 root_objectid)
689 {
690 struct btrfs_root *root = btrfs_extent_root(trans->fs_info, bytenr);
691 struct btrfs_key key;
692 int ret;
693
694 key.objectid = bytenr;
695 if (parent) {
696 key.type = BTRFS_SHARED_BLOCK_REF_KEY;
697 key.offset = parent;
698 } else {
699 key.type = BTRFS_TREE_BLOCK_REF_KEY;
700 key.offset = root_objectid;
701 }
702
703 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
704 if (ret > 0)
705 ret = -ENOENT;
706 return ret;
707 }
708
insert_tree_block_ref(struct btrfs_trans_handle * trans,struct btrfs_path * path,u64 bytenr,u64 parent,u64 root_objectid)709 static noinline int insert_tree_block_ref(struct btrfs_trans_handle *trans,
710 struct btrfs_path *path,
711 u64 bytenr, u64 parent,
712 u64 root_objectid)
713 {
714 struct btrfs_root *root = btrfs_extent_root(trans->fs_info, bytenr);
715 struct btrfs_key key;
716 int ret;
717
718 key.objectid = bytenr;
719 if (parent) {
720 key.type = BTRFS_SHARED_BLOCK_REF_KEY;
721 key.offset = parent;
722 } else {
723 key.type = BTRFS_TREE_BLOCK_REF_KEY;
724 key.offset = root_objectid;
725 }
726
727 ret = btrfs_insert_empty_item(trans, root, path, &key, 0);
728 btrfs_release_path(path);
729 return ret;
730 }
731
extent_ref_type(u64 parent,u64 owner)732 static inline int extent_ref_type(u64 parent, u64 owner)
733 {
734 int type;
735 if (owner < BTRFS_FIRST_FREE_OBJECTID) {
736 if (parent > 0)
737 type = BTRFS_SHARED_BLOCK_REF_KEY;
738 else
739 type = BTRFS_TREE_BLOCK_REF_KEY;
740 } else {
741 if (parent > 0)
742 type = BTRFS_SHARED_DATA_REF_KEY;
743 else
744 type = BTRFS_EXTENT_DATA_REF_KEY;
745 }
746 return type;
747 }
748
find_next_key(struct btrfs_path * path,int level,struct btrfs_key * key)749 static int find_next_key(struct btrfs_path *path, int level,
750 struct btrfs_key *key)
751
752 {
753 for (; level < BTRFS_MAX_LEVEL; level++) {
754 if (!path->nodes[level])
755 break;
756 if (path->slots[level] + 1 >=
757 btrfs_header_nritems(path->nodes[level]))
758 continue;
759 if (level == 0)
760 btrfs_item_key_to_cpu(path->nodes[level], key,
761 path->slots[level] + 1);
762 else
763 btrfs_node_key_to_cpu(path->nodes[level], key,
764 path->slots[level] + 1);
765 return 0;
766 }
767 return 1;
768 }
769
770 /*
771 * look for inline back ref. if back ref is found, *ref_ret is set
772 * to the address of inline back ref, and 0 is returned.
773 *
774 * if back ref isn't found, *ref_ret is set to the address where it
775 * should be inserted, and -ENOENT is returned.
776 *
777 * if insert is true and there are too many inline back refs, the path
778 * points to the extent item, and -EAGAIN is returned.
779 *
780 * NOTE: inline back refs are ordered in the same way that back ref
781 * items in the tree are ordered.
782 */
783 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)784 int lookup_inline_extent_backref(struct btrfs_trans_handle *trans,
785 struct btrfs_path *path,
786 struct btrfs_extent_inline_ref **ref_ret,
787 u64 bytenr, u64 num_bytes,
788 u64 parent, u64 root_objectid,
789 u64 owner, u64 offset, int insert)
790 {
791 struct btrfs_fs_info *fs_info = trans->fs_info;
792 struct btrfs_root *root = btrfs_extent_root(fs_info, bytenr);
793 struct btrfs_key key;
794 struct extent_buffer *leaf;
795 struct btrfs_extent_item *ei;
796 struct btrfs_extent_inline_ref *iref;
797 u64 flags;
798 u64 item_size;
799 unsigned long ptr;
800 unsigned long end;
801 int extra_size;
802 int type;
803 int want;
804 int ret;
805 bool skinny_metadata = btrfs_fs_incompat(fs_info, SKINNY_METADATA);
806 int needed;
807
808 key.objectid = bytenr;
809 key.type = BTRFS_EXTENT_ITEM_KEY;
810 key.offset = num_bytes;
811
812 want = extent_ref_type(parent, owner);
813 if (insert) {
814 extra_size = btrfs_extent_inline_ref_size(want);
815 path->search_for_extension = 1;
816 path->keep_locks = 1;
817 } else
818 extra_size = -1;
819
820 /*
821 * Owner is our level, so we can just add one to get the level for the
822 * block we are interested in.
823 */
824 if (skinny_metadata && owner < BTRFS_FIRST_FREE_OBJECTID) {
825 key.type = BTRFS_METADATA_ITEM_KEY;
826 key.offset = owner;
827 }
828
829 again:
830 ret = btrfs_search_slot(trans, root, &key, path, extra_size, 1);
831 if (ret < 0)
832 goto out;
833
834 /*
835 * We may be a newly converted file system which still has the old fat
836 * extent entries for metadata, so try and see if we have one of those.
837 */
838 if (ret > 0 && skinny_metadata) {
839 skinny_metadata = false;
840 if (path->slots[0]) {
841 path->slots[0]--;
842 btrfs_item_key_to_cpu(path->nodes[0], &key,
843 path->slots[0]);
844 if (key.objectid == bytenr &&
845 key.type == BTRFS_EXTENT_ITEM_KEY &&
846 key.offset == num_bytes)
847 ret = 0;
848 }
849 if (ret) {
850 key.objectid = bytenr;
851 key.type = BTRFS_EXTENT_ITEM_KEY;
852 key.offset = num_bytes;
853 btrfs_release_path(path);
854 goto again;
855 }
856 }
857
858 if (ret && !insert) {
859 ret = -ENOENT;
860 goto out;
861 } else if (WARN_ON(ret)) {
862 btrfs_print_leaf(path->nodes[0]);
863 btrfs_err(fs_info,
864 "extent item not found for insert, bytenr %llu num_bytes %llu parent %llu root_objectid %llu owner %llu offset %llu",
865 bytenr, num_bytes, parent, root_objectid, owner,
866 offset);
867 ret = -EUCLEAN;
868 goto out;
869 }
870
871 leaf = path->nodes[0];
872 item_size = btrfs_item_size(leaf, path->slots[0]);
873 if (unlikely(item_size < sizeof(*ei))) {
874 ret = -EUCLEAN;
875 btrfs_err(fs_info,
876 "unexpected extent item size, has %llu expect >= %zu",
877 item_size, sizeof(*ei));
878 btrfs_abort_transaction(trans, ret);
879 goto out;
880 }
881
882 ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
883 flags = btrfs_extent_flags(leaf, ei);
884
885 ptr = (unsigned long)(ei + 1);
886 end = (unsigned long)ei + item_size;
887
888 if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK && !skinny_metadata) {
889 ptr += sizeof(struct btrfs_tree_block_info);
890 BUG_ON(ptr > end);
891 }
892
893 if (owner >= BTRFS_FIRST_FREE_OBJECTID)
894 needed = BTRFS_REF_TYPE_DATA;
895 else
896 needed = BTRFS_REF_TYPE_BLOCK;
897
898 ret = -ENOENT;
899 while (ptr < end) {
900 iref = (struct btrfs_extent_inline_ref *)ptr;
901 type = btrfs_get_extent_inline_ref_type(leaf, iref, needed);
902 if (type == BTRFS_EXTENT_OWNER_REF_KEY) {
903 ASSERT(btrfs_fs_incompat(fs_info, SIMPLE_QUOTA));
904 ptr += btrfs_extent_inline_ref_size(type);
905 continue;
906 }
907 if (type == BTRFS_REF_TYPE_INVALID) {
908 ret = -EUCLEAN;
909 goto out;
910 }
911
912 if (want < type)
913 break;
914 if (want > type) {
915 ptr += btrfs_extent_inline_ref_size(type);
916 continue;
917 }
918
919 if (type == BTRFS_EXTENT_DATA_REF_KEY) {
920 struct btrfs_extent_data_ref *dref;
921 dref = (struct btrfs_extent_data_ref *)(&iref->offset);
922 if (match_extent_data_ref(leaf, dref, root_objectid,
923 owner, offset)) {
924 ret = 0;
925 break;
926 }
927 if (hash_extent_data_ref_item(leaf, dref) <
928 hash_extent_data_ref(root_objectid, owner, offset))
929 break;
930 } else {
931 u64 ref_offset;
932 ref_offset = btrfs_extent_inline_ref_offset(leaf, iref);
933 if (parent > 0) {
934 if (parent == ref_offset) {
935 ret = 0;
936 break;
937 }
938 if (ref_offset < parent)
939 break;
940 } else {
941 if (root_objectid == ref_offset) {
942 ret = 0;
943 break;
944 }
945 if (ref_offset < root_objectid)
946 break;
947 }
948 }
949 ptr += btrfs_extent_inline_ref_size(type);
950 }
951
952 if (unlikely(ptr > end)) {
953 ret = -EUCLEAN;
954 btrfs_print_leaf(path->nodes[0]);
955 btrfs_crit(fs_info,
956 "overrun extent record at slot %d while looking for inline extent for root %llu owner %llu offset %llu parent %llu",
957 path->slots[0], root_objectid, owner, offset, parent);
958 goto out;
959 }
960
961 if (ret == -ENOENT && insert) {
962 if (item_size + extra_size >=
963 BTRFS_MAX_EXTENT_ITEM_SIZE(root)) {
964 ret = -EAGAIN;
965 goto out;
966 }
967 /*
968 * To add new inline back ref, we have to make sure
969 * there is no corresponding back ref item.
970 * For simplicity, we just do not add new inline back
971 * ref if there is any kind of item for this block
972 */
973 if (find_next_key(path, 0, &key) == 0 &&
974 key.objectid == bytenr &&
975 key.type < BTRFS_BLOCK_GROUP_ITEM_KEY) {
976 ret = -EAGAIN;
977 goto out;
978 }
979 }
980 *ref_ret = (struct btrfs_extent_inline_ref *)ptr;
981 out:
982 if (insert) {
983 path->keep_locks = 0;
984 path->search_for_extension = 0;
985 btrfs_unlock_up_safe(path, 1);
986 }
987 return ret;
988 }
989
990 /*
991 * helper to add new inline back ref
992 */
993 static noinline_for_stack
setup_inline_extent_backref(struct btrfs_trans_handle * trans,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)994 void setup_inline_extent_backref(struct btrfs_trans_handle *trans,
995 struct btrfs_path *path,
996 struct btrfs_extent_inline_ref *iref,
997 u64 parent, u64 root_objectid,
998 u64 owner, u64 offset, int refs_to_add,
999 struct btrfs_delayed_extent_op *extent_op)
1000 {
1001 struct extent_buffer *leaf;
1002 struct btrfs_extent_item *ei;
1003 unsigned long ptr;
1004 unsigned long end;
1005 unsigned long item_offset;
1006 u64 refs;
1007 int size;
1008 int type;
1009
1010 leaf = path->nodes[0];
1011 ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
1012 item_offset = (unsigned long)iref - (unsigned long)ei;
1013
1014 type = extent_ref_type(parent, owner);
1015 size = btrfs_extent_inline_ref_size(type);
1016
1017 btrfs_extend_item(trans, path, size);
1018
1019 ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
1020 refs = btrfs_extent_refs(leaf, ei);
1021 refs += refs_to_add;
1022 btrfs_set_extent_refs(leaf, ei, refs);
1023 if (extent_op)
1024 __run_delayed_extent_op(extent_op, leaf, ei);
1025
1026 ptr = (unsigned long)ei + item_offset;
1027 end = (unsigned long)ei + btrfs_item_size(leaf, path->slots[0]);
1028 if (ptr < end - size)
1029 memmove_extent_buffer(leaf, ptr + size, ptr,
1030 end - size - ptr);
1031
1032 iref = (struct btrfs_extent_inline_ref *)ptr;
1033 btrfs_set_extent_inline_ref_type(leaf, iref, type);
1034 if (type == BTRFS_EXTENT_DATA_REF_KEY) {
1035 struct btrfs_extent_data_ref *dref;
1036 dref = (struct btrfs_extent_data_ref *)(&iref->offset);
1037 btrfs_set_extent_data_ref_root(leaf, dref, root_objectid);
1038 btrfs_set_extent_data_ref_objectid(leaf, dref, owner);
1039 btrfs_set_extent_data_ref_offset(leaf, dref, offset);
1040 btrfs_set_extent_data_ref_count(leaf, dref, refs_to_add);
1041 } else if (type == BTRFS_SHARED_DATA_REF_KEY) {
1042 struct btrfs_shared_data_ref *sref;
1043 sref = (struct btrfs_shared_data_ref *)(iref + 1);
1044 btrfs_set_shared_data_ref_count(leaf, sref, refs_to_add);
1045 btrfs_set_extent_inline_ref_offset(leaf, iref, parent);
1046 } else if (type == BTRFS_SHARED_BLOCK_REF_KEY) {
1047 btrfs_set_extent_inline_ref_offset(leaf, iref, parent);
1048 } else {
1049 btrfs_set_extent_inline_ref_offset(leaf, iref, root_objectid);
1050 }
1051 btrfs_mark_buffer_dirty(trans, leaf);
1052 }
1053
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)1054 static int lookup_extent_backref(struct btrfs_trans_handle *trans,
1055 struct btrfs_path *path,
1056 struct btrfs_extent_inline_ref **ref_ret,
1057 u64 bytenr, u64 num_bytes, u64 parent,
1058 u64 root_objectid, u64 owner, u64 offset)
1059 {
1060 int ret;
1061
1062 ret = lookup_inline_extent_backref(trans, path, ref_ret, bytenr,
1063 num_bytes, parent, root_objectid,
1064 owner, offset, 0);
1065 if (ret != -ENOENT)
1066 return ret;
1067
1068 btrfs_release_path(path);
1069 *ref_ret = NULL;
1070
1071 if (owner < BTRFS_FIRST_FREE_OBJECTID) {
1072 ret = lookup_tree_block_ref(trans, path, bytenr, parent,
1073 root_objectid);
1074 } else {
1075 ret = lookup_extent_data_ref(trans, path, bytenr, parent,
1076 root_objectid, owner, offset);
1077 }
1078 return ret;
1079 }
1080
1081 /*
1082 * helper to update/remove inline back ref
1083 */
update_inline_extent_backref(struct btrfs_trans_handle * trans,struct btrfs_path * path,struct btrfs_extent_inline_ref * iref,int refs_to_mod,struct btrfs_delayed_extent_op * extent_op)1084 static noinline_for_stack int update_inline_extent_backref(
1085 struct btrfs_trans_handle *trans,
1086 struct btrfs_path *path,
1087 struct btrfs_extent_inline_ref *iref,
1088 int refs_to_mod,
1089 struct btrfs_delayed_extent_op *extent_op)
1090 {
1091 struct extent_buffer *leaf = path->nodes[0];
1092 struct btrfs_fs_info *fs_info = leaf->fs_info;
1093 struct btrfs_extent_item *ei;
1094 struct btrfs_extent_data_ref *dref = NULL;
1095 struct btrfs_shared_data_ref *sref = NULL;
1096 unsigned long ptr;
1097 unsigned long end;
1098 u32 item_size;
1099 int size;
1100 int type;
1101 u64 refs;
1102
1103 ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
1104 refs = btrfs_extent_refs(leaf, ei);
1105 if (unlikely(refs_to_mod < 0 && refs + refs_to_mod <= 0)) {
1106 struct btrfs_key key;
1107 u32 extent_size;
1108
1109 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
1110 if (key.type == BTRFS_METADATA_ITEM_KEY)
1111 extent_size = fs_info->nodesize;
1112 else
1113 extent_size = key.offset;
1114 btrfs_print_leaf(leaf);
1115 btrfs_err(fs_info,
1116 "invalid refs_to_mod for extent %llu num_bytes %u, has %d expect >= -%llu",
1117 key.objectid, extent_size, refs_to_mod, refs);
1118 return -EUCLEAN;
1119 }
1120 refs += refs_to_mod;
1121 btrfs_set_extent_refs(leaf, ei, refs);
1122 if (extent_op)
1123 __run_delayed_extent_op(extent_op, leaf, ei);
1124
1125 type = btrfs_get_extent_inline_ref_type(leaf, iref, BTRFS_REF_TYPE_ANY);
1126 /*
1127 * Function btrfs_get_extent_inline_ref_type() has already printed
1128 * error messages.
1129 */
1130 if (unlikely(type == BTRFS_REF_TYPE_INVALID))
1131 return -EUCLEAN;
1132
1133 if (type == BTRFS_EXTENT_DATA_REF_KEY) {
1134 dref = (struct btrfs_extent_data_ref *)(&iref->offset);
1135 refs = btrfs_extent_data_ref_count(leaf, dref);
1136 } else if (type == BTRFS_SHARED_DATA_REF_KEY) {
1137 sref = (struct btrfs_shared_data_ref *)(iref + 1);
1138 refs = btrfs_shared_data_ref_count(leaf, sref);
1139 } else {
1140 refs = 1;
1141 /*
1142 * For tree blocks we can only drop one ref for it, and tree
1143 * blocks should not have refs > 1.
1144 *
1145 * Furthermore if we're inserting a new inline backref, we
1146 * won't reach this path either. That would be
1147 * setup_inline_extent_backref().
1148 */
1149 if (unlikely(refs_to_mod != -1)) {
1150 struct btrfs_key key;
1151
1152 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
1153
1154 btrfs_print_leaf(leaf);
1155 btrfs_err(fs_info,
1156 "invalid refs_to_mod for tree block %llu, has %d expect -1",
1157 key.objectid, refs_to_mod);
1158 return -EUCLEAN;
1159 }
1160 }
1161
1162 if (unlikely(refs_to_mod < 0 && refs < -refs_to_mod)) {
1163 struct btrfs_key key;
1164 u32 extent_size;
1165
1166 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
1167 if (key.type == BTRFS_METADATA_ITEM_KEY)
1168 extent_size = fs_info->nodesize;
1169 else
1170 extent_size = key.offset;
1171 btrfs_print_leaf(leaf);
1172 btrfs_err(fs_info,
1173 "invalid refs_to_mod for backref entry, iref %lu extent %llu num_bytes %u, has %d expect >= -%llu",
1174 (unsigned long)iref, key.objectid, extent_size,
1175 refs_to_mod, refs);
1176 return -EUCLEAN;
1177 }
1178 refs += refs_to_mod;
1179
1180 if (refs > 0) {
1181 if (type == BTRFS_EXTENT_DATA_REF_KEY)
1182 btrfs_set_extent_data_ref_count(leaf, dref, refs);
1183 else
1184 btrfs_set_shared_data_ref_count(leaf, sref, refs);
1185 } else {
1186 size = btrfs_extent_inline_ref_size(type);
1187 item_size = btrfs_item_size(leaf, path->slots[0]);
1188 ptr = (unsigned long)iref;
1189 end = (unsigned long)ei + item_size;
1190 if (ptr + size < end)
1191 memmove_extent_buffer(leaf, ptr, ptr + size,
1192 end - ptr - size);
1193 item_size -= size;
1194 btrfs_truncate_item(trans, path, item_size, 1);
1195 }
1196 btrfs_mark_buffer_dirty(trans, leaf);
1197 return 0;
1198 }
1199
1200 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)1201 int insert_inline_extent_backref(struct btrfs_trans_handle *trans,
1202 struct btrfs_path *path,
1203 u64 bytenr, u64 num_bytes, u64 parent,
1204 u64 root_objectid, u64 owner,
1205 u64 offset, int refs_to_add,
1206 struct btrfs_delayed_extent_op *extent_op)
1207 {
1208 struct btrfs_extent_inline_ref *iref;
1209 int ret;
1210
1211 ret = lookup_inline_extent_backref(trans, path, &iref, bytenr,
1212 num_bytes, parent, root_objectid,
1213 owner, offset, 1);
1214 if (ret == 0) {
1215 /*
1216 * We're adding refs to a tree block we already own, this
1217 * should not happen at all.
1218 */
1219 if (owner < BTRFS_FIRST_FREE_OBJECTID) {
1220 btrfs_print_leaf(path->nodes[0]);
1221 btrfs_crit(trans->fs_info,
1222 "adding refs to an existing tree ref, bytenr %llu num_bytes %llu root_objectid %llu slot %u",
1223 bytenr, num_bytes, root_objectid, path->slots[0]);
1224 return -EUCLEAN;
1225 }
1226 ret = update_inline_extent_backref(trans, path, iref,
1227 refs_to_add, extent_op);
1228 } else if (ret == -ENOENT) {
1229 setup_inline_extent_backref(trans, path, iref, parent,
1230 root_objectid, owner, offset,
1231 refs_to_add, extent_op);
1232 ret = 0;
1233 }
1234 return ret;
1235 }
1236
remove_extent_backref(struct btrfs_trans_handle * trans,struct btrfs_root * root,struct btrfs_path * path,struct btrfs_extent_inline_ref * iref,int refs_to_drop,int is_data)1237 static int remove_extent_backref(struct btrfs_trans_handle *trans,
1238 struct btrfs_root *root,
1239 struct btrfs_path *path,
1240 struct btrfs_extent_inline_ref *iref,
1241 int refs_to_drop, int is_data)
1242 {
1243 int ret = 0;
1244
1245 BUG_ON(!is_data && refs_to_drop != 1);
1246 if (iref)
1247 ret = update_inline_extent_backref(trans, path, iref,
1248 -refs_to_drop, NULL);
1249 else if (is_data)
1250 ret = remove_extent_data_ref(trans, root, path, refs_to_drop);
1251 else
1252 ret = btrfs_del_item(trans, root, path);
1253 return ret;
1254 }
1255
btrfs_issue_discard(struct block_device * bdev,u64 start,u64 len,u64 * discarded_bytes)1256 static int btrfs_issue_discard(struct block_device *bdev, u64 start, u64 len,
1257 u64 *discarded_bytes)
1258 {
1259 int j, ret = 0;
1260 u64 bytes_left, end;
1261 u64 aligned_start = ALIGN(start, 1 << SECTOR_SHIFT);
1262
1263 /* Adjust the range to be aligned to 512B sectors if necessary. */
1264 if (start != aligned_start) {
1265 len -= aligned_start - start;
1266 len = round_down(len, 1 << SECTOR_SHIFT);
1267 start = aligned_start;
1268 }
1269
1270 *discarded_bytes = 0;
1271
1272 if (!len)
1273 return 0;
1274
1275 end = start + len;
1276 bytes_left = len;
1277
1278 /* Skip any superblocks on this device. */
1279 for (j = 0; j < BTRFS_SUPER_MIRROR_MAX; j++) {
1280 u64 sb_start = btrfs_sb_offset(j);
1281 u64 sb_end = sb_start + BTRFS_SUPER_INFO_SIZE;
1282 u64 size = sb_start - start;
1283
1284 if (!in_range(sb_start, start, bytes_left) &&
1285 !in_range(sb_end, start, bytes_left) &&
1286 !in_range(start, sb_start, BTRFS_SUPER_INFO_SIZE))
1287 continue;
1288
1289 /*
1290 * Superblock spans beginning of range. Adjust start and
1291 * try again.
1292 */
1293 if (sb_start <= start) {
1294 start += sb_end - start;
1295 if (start > end) {
1296 bytes_left = 0;
1297 break;
1298 }
1299 bytes_left = end - start;
1300 continue;
1301 }
1302
1303 if (size) {
1304 ret = blkdev_issue_discard(bdev, start >> SECTOR_SHIFT,
1305 size >> SECTOR_SHIFT,
1306 GFP_NOFS);
1307 if (!ret)
1308 *discarded_bytes += size;
1309 else if (ret != -EOPNOTSUPP)
1310 return ret;
1311 }
1312
1313 start = sb_end;
1314 if (start > end) {
1315 bytes_left = 0;
1316 break;
1317 }
1318 bytes_left = end - start;
1319 }
1320
1321 if (bytes_left) {
1322 ret = blkdev_issue_discard(bdev, start >> SECTOR_SHIFT,
1323 bytes_left >> SECTOR_SHIFT,
1324 GFP_NOFS);
1325 if (!ret)
1326 *discarded_bytes += bytes_left;
1327 }
1328 return ret;
1329 }
1330
do_discard_extent(struct btrfs_discard_stripe * stripe,u64 * bytes)1331 static int do_discard_extent(struct btrfs_discard_stripe *stripe, u64 *bytes)
1332 {
1333 struct btrfs_device *dev = stripe->dev;
1334 struct btrfs_fs_info *fs_info = dev->fs_info;
1335 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
1336 u64 phys = stripe->physical;
1337 u64 len = stripe->length;
1338 u64 discarded = 0;
1339 int ret = 0;
1340
1341 /* Zone reset on a zoned filesystem */
1342 if (btrfs_can_zone_reset(dev, phys, len)) {
1343 u64 src_disc;
1344
1345 ret = btrfs_reset_device_zone(dev, phys, len, &discarded);
1346 if (ret)
1347 goto out;
1348
1349 if (!btrfs_dev_replace_is_ongoing(dev_replace) ||
1350 dev != dev_replace->srcdev)
1351 goto out;
1352
1353 src_disc = discarded;
1354
1355 /* Send to replace target as well */
1356 ret = btrfs_reset_device_zone(dev_replace->tgtdev, phys, len,
1357 &discarded);
1358 discarded += src_disc;
1359 } else if (bdev_max_discard_sectors(stripe->dev->bdev)) {
1360 ret = btrfs_issue_discard(dev->bdev, phys, len, &discarded);
1361 } else {
1362 ret = 0;
1363 *bytes = 0;
1364 }
1365
1366 out:
1367 *bytes = discarded;
1368 return ret;
1369 }
1370
btrfs_discard_extent(struct btrfs_fs_info * fs_info,u64 bytenr,u64 num_bytes,u64 * actual_bytes)1371 int btrfs_discard_extent(struct btrfs_fs_info *fs_info, u64 bytenr,
1372 u64 num_bytes, u64 *actual_bytes)
1373 {
1374 int ret = 0;
1375 u64 discarded_bytes = 0;
1376 u64 end = bytenr + num_bytes;
1377 u64 cur = bytenr;
1378
1379 /*
1380 * Avoid races with device replace and make sure the devices in the
1381 * stripes don't go away while we are discarding.
1382 */
1383 btrfs_bio_counter_inc_blocked(fs_info);
1384 while (cur < end) {
1385 struct btrfs_discard_stripe *stripes;
1386 unsigned int num_stripes;
1387 int i;
1388
1389 num_bytes = end - cur;
1390 stripes = btrfs_map_discard(fs_info, cur, &num_bytes, &num_stripes);
1391 if (IS_ERR(stripes)) {
1392 ret = PTR_ERR(stripes);
1393 if (ret == -EOPNOTSUPP)
1394 ret = 0;
1395 break;
1396 }
1397
1398 for (i = 0; i < num_stripes; i++) {
1399 struct btrfs_discard_stripe *stripe = stripes + i;
1400 u64 bytes;
1401
1402 if (!stripe->dev->bdev) {
1403 ASSERT(btrfs_test_opt(fs_info, DEGRADED));
1404 continue;
1405 }
1406
1407 if (!test_bit(BTRFS_DEV_STATE_WRITEABLE,
1408 &stripe->dev->dev_state))
1409 continue;
1410
1411 ret = do_discard_extent(stripe, &bytes);
1412 if (ret) {
1413 /*
1414 * Keep going if discard is not supported by the
1415 * device.
1416 */
1417 if (ret != -EOPNOTSUPP)
1418 break;
1419 ret = 0;
1420 } else {
1421 discarded_bytes += bytes;
1422 }
1423 }
1424 kfree(stripes);
1425 if (ret)
1426 break;
1427 cur += num_bytes;
1428 }
1429 btrfs_bio_counter_dec(fs_info);
1430 if (actual_bytes)
1431 *actual_bytes = discarded_bytes;
1432 return ret;
1433 }
1434
1435 /* Can return -ENOMEM */
btrfs_inc_extent_ref(struct btrfs_trans_handle * trans,struct btrfs_ref * generic_ref)1436 int btrfs_inc_extent_ref(struct btrfs_trans_handle *trans,
1437 struct btrfs_ref *generic_ref)
1438 {
1439 struct btrfs_fs_info *fs_info = trans->fs_info;
1440 int ret;
1441
1442 ASSERT(generic_ref->type != BTRFS_REF_NOT_SET &&
1443 generic_ref->action);
1444 BUG_ON(generic_ref->type == BTRFS_REF_METADATA &&
1445 generic_ref->tree_ref.ref_root == BTRFS_TREE_LOG_OBJECTID);
1446
1447 if (generic_ref->type == BTRFS_REF_METADATA)
1448 ret = btrfs_add_delayed_tree_ref(trans, generic_ref, NULL);
1449 else
1450 ret = btrfs_add_delayed_data_ref(trans, generic_ref, 0);
1451
1452 btrfs_ref_tree_mod(fs_info, generic_ref);
1453
1454 return ret;
1455 }
1456
1457 /*
1458 * Insert backreference for a given extent.
1459 *
1460 * The counterpart is in __btrfs_free_extent(), with examples and more details
1461 * how it works.
1462 *
1463 * @trans: Handle of transaction
1464 *
1465 * @node: The delayed ref node used to get the bytenr/length for
1466 * extent whose references are incremented.
1467 *
1468 * @parent: If this is a shared extent (BTRFS_SHARED_DATA_REF_KEY/
1469 * BTRFS_SHARED_BLOCK_REF_KEY) then it holds the logical
1470 * bytenr of the parent block. Since new extents are always
1471 * created with indirect references, this will only be the case
1472 * when relocating a shared extent. In that case, root_objectid
1473 * will be BTRFS_TREE_RELOC_OBJECTID. Otherwise, parent must
1474 * be 0
1475 *
1476 * @root_objectid: The id of the root where this modification has originated,
1477 * this can be either one of the well-known metadata trees or
1478 * the subvolume id which references this extent.
1479 *
1480 * @owner: For data extents it is the inode number of the owning file.
1481 * For metadata extents this parameter holds the level in the
1482 * tree of the extent.
1483 *
1484 * @offset: For metadata extents the offset is ignored and is currently
1485 * always passed as 0. For data extents it is the fileoffset
1486 * this extent belongs to.
1487 *
1488 * @extent_op Pointer to a structure, holding information necessary when
1489 * updating a tree block's flags
1490 *
1491 */
__btrfs_inc_extent_ref(struct btrfs_trans_handle * trans,struct btrfs_delayed_ref_node * node,u64 parent,u64 root_objectid,u64 owner,u64 offset,struct btrfs_delayed_extent_op * extent_op)1492 static int __btrfs_inc_extent_ref(struct btrfs_trans_handle *trans,
1493 struct btrfs_delayed_ref_node *node,
1494 u64 parent, u64 root_objectid,
1495 u64 owner, u64 offset,
1496 struct btrfs_delayed_extent_op *extent_op)
1497 {
1498 struct btrfs_path *path;
1499 struct extent_buffer *leaf;
1500 struct btrfs_extent_item *item;
1501 struct btrfs_key key;
1502 u64 bytenr = node->bytenr;
1503 u64 num_bytes = node->num_bytes;
1504 u64 refs;
1505 int refs_to_add = node->ref_mod;
1506 int ret;
1507
1508 path = btrfs_alloc_path();
1509 if (!path)
1510 return -ENOMEM;
1511
1512 /* this will setup the path even if it fails to insert the back ref */
1513 ret = insert_inline_extent_backref(trans, path, bytenr, num_bytes,
1514 parent, root_objectid, owner,
1515 offset, refs_to_add, extent_op);
1516 if ((ret < 0 && ret != -EAGAIN) || !ret)
1517 goto out;
1518
1519 /*
1520 * Ok we had -EAGAIN which means we didn't have space to insert and
1521 * inline extent ref, so just update the reference count and add a
1522 * normal backref.
1523 */
1524 leaf = path->nodes[0];
1525 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
1526 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
1527 refs = btrfs_extent_refs(leaf, item);
1528 btrfs_set_extent_refs(leaf, item, refs + refs_to_add);
1529 if (extent_op)
1530 __run_delayed_extent_op(extent_op, leaf, item);
1531
1532 btrfs_mark_buffer_dirty(trans, leaf);
1533 btrfs_release_path(path);
1534
1535 /* now insert the actual backref */
1536 if (owner < BTRFS_FIRST_FREE_OBJECTID)
1537 ret = insert_tree_block_ref(trans, path, bytenr, parent,
1538 root_objectid);
1539 else
1540 ret = insert_extent_data_ref(trans, path, bytenr, parent,
1541 root_objectid, owner, offset,
1542 refs_to_add);
1543
1544 if (ret)
1545 btrfs_abort_transaction(trans, ret);
1546 out:
1547 btrfs_free_path(path);
1548 return ret;
1549 }
1550
free_head_ref_squota_rsv(struct btrfs_fs_info * fs_info,struct btrfs_delayed_ref_head * href)1551 static void free_head_ref_squota_rsv(struct btrfs_fs_info *fs_info,
1552 struct btrfs_delayed_ref_head *href)
1553 {
1554 u64 root = href->owning_root;
1555
1556 /*
1557 * Don't check must_insert_reserved, as this is called from contexts
1558 * where it has already been unset.
1559 */
1560 if (btrfs_qgroup_mode(fs_info) != BTRFS_QGROUP_MODE_SIMPLE ||
1561 !href->is_data || !is_fstree(root))
1562 return;
1563
1564 btrfs_qgroup_free_refroot(fs_info, root, href->reserved_bytes,
1565 BTRFS_QGROUP_RSV_DATA);
1566 }
1567
run_delayed_data_ref(struct btrfs_trans_handle * trans,struct btrfs_delayed_ref_head * href,struct btrfs_delayed_ref_node * node,struct btrfs_delayed_extent_op * extent_op,bool insert_reserved)1568 static int run_delayed_data_ref(struct btrfs_trans_handle *trans,
1569 struct btrfs_delayed_ref_head *href,
1570 struct btrfs_delayed_ref_node *node,
1571 struct btrfs_delayed_extent_op *extent_op,
1572 bool insert_reserved)
1573 {
1574 int ret = 0;
1575 struct btrfs_delayed_data_ref *ref;
1576 u64 parent = 0;
1577 u64 flags = 0;
1578
1579 ref = btrfs_delayed_node_to_data_ref(node);
1580 trace_run_delayed_data_ref(trans->fs_info, node, ref, node->action);
1581
1582 if (node->type == BTRFS_SHARED_DATA_REF_KEY)
1583 parent = ref->parent;
1584
1585 if (node->action == BTRFS_ADD_DELAYED_REF && insert_reserved) {
1586 struct btrfs_key key;
1587 struct btrfs_squota_delta delta = {
1588 .root = href->owning_root,
1589 .num_bytes = node->num_bytes,
1590 .is_data = true,
1591 .is_inc = true,
1592 .generation = trans->transid,
1593 };
1594
1595 if (extent_op)
1596 flags |= extent_op->flags_to_set;
1597
1598 key.objectid = node->bytenr;
1599 key.type = BTRFS_EXTENT_ITEM_KEY;
1600 key.offset = node->num_bytes;
1601
1602 ret = alloc_reserved_file_extent(trans, parent, ref->root,
1603 flags, ref->objectid,
1604 ref->offset, &key,
1605 node->ref_mod, href->owning_root);
1606 free_head_ref_squota_rsv(trans->fs_info, href);
1607 if (!ret)
1608 ret = btrfs_record_squota_delta(trans->fs_info, &delta);
1609 } else if (node->action == BTRFS_ADD_DELAYED_REF) {
1610 ret = __btrfs_inc_extent_ref(trans, node, parent, ref->root,
1611 ref->objectid, ref->offset,
1612 extent_op);
1613 } else if (node->action == BTRFS_DROP_DELAYED_REF) {
1614 ret = __btrfs_free_extent(trans, href, node, parent,
1615 ref->root, ref->objectid,
1616 ref->offset, extent_op);
1617 } else {
1618 BUG();
1619 }
1620 return ret;
1621 }
1622
__run_delayed_extent_op(struct btrfs_delayed_extent_op * extent_op,struct extent_buffer * leaf,struct btrfs_extent_item * ei)1623 static void __run_delayed_extent_op(struct btrfs_delayed_extent_op *extent_op,
1624 struct extent_buffer *leaf,
1625 struct btrfs_extent_item *ei)
1626 {
1627 u64 flags = btrfs_extent_flags(leaf, ei);
1628 if (extent_op->update_flags) {
1629 flags |= extent_op->flags_to_set;
1630 btrfs_set_extent_flags(leaf, ei, flags);
1631 }
1632
1633 if (extent_op->update_key) {
1634 struct btrfs_tree_block_info *bi;
1635 BUG_ON(!(flags & BTRFS_EXTENT_FLAG_TREE_BLOCK));
1636 bi = (struct btrfs_tree_block_info *)(ei + 1);
1637 btrfs_set_tree_block_key(leaf, bi, &extent_op->key);
1638 }
1639 }
1640
run_delayed_extent_op(struct btrfs_trans_handle * trans,struct btrfs_delayed_ref_head * head,struct btrfs_delayed_extent_op * extent_op)1641 static int run_delayed_extent_op(struct btrfs_trans_handle *trans,
1642 struct btrfs_delayed_ref_head *head,
1643 struct btrfs_delayed_extent_op *extent_op)
1644 {
1645 struct btrfs_fs_info *fs_info = trans->fs_info;
1646 struct btrfs_root *root;
1647 struct btrfs_key key;
1648 struct btrfs_path *path;
1649 struct btrfs_extent_item *ei;
1650 struct extent_buffer *leaf;
1651 u32 item_size;
1652 int ret;
1653 int metadata = 1;
1654
1655 if (TRANS_ABORTED(trans))
1656 return 0;
1657
1658 if (!btrfs_fs_incompat(fs_info, SKINNY_METADATA))
1659 metadata = 0;
1660
1661 path = btrfs_alloc_path();
1662 if (!path)
1663 return -ENOMEM;
1664
1665 key.objectid = head->bytenr;
1666
1667 if (metadata) {
1668 key.type = BTRFS_METADATA_ITEM_KEY;
1669 key.offset = extent_op->level;
1670 } else {
1671 key.type = BTRFS_EXTENT_ITEM_KEY;
1672 key.offset = head->num_bytes;
1673 }
1674
1675 root = btrfs_extent_root(fs_info, key.objectid);
1676 again:
1677 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
1678 if (ret < 0) {
1679 goto out;
1680 } else if (ret > 0) {
1681 if (metadata) {
1682 if (path->slots[0] > 0) {
1683 path->slots[0]--;
1684 btrfs_item_key_to_cpu(path->nodes[0], &key,
1685 path->slots[0]);
1686 if (key.objectid == head->bytenr &&
1687 key.type == BTRFS_EXTENT_ITEM_KEY &&
1688 key.offset == head->num_bytes)
1689 ret = 0;
1690 }
1691 if (ret > 0) {
1692 btrfs_release_path(path);
1693 metadata = 0;
1694
1695 key.objectid = head->bytenr;
1696 key.offset = head->num_bytes;
1697 key.type = BTRFS_EXTENT_ITEM_KEY;
1698 goto again;
1699 }
1700 } else {
1701 ret = -EUCLEAN;
1702 btrfs_err(fs_info,
1703 "missing extent item for extent %llu num_bytes %llu level %d",
1704 head->bytenr, head->num_bytes, extent_op->level);
1705 goto out;
1706 }
1707 }
1708
1709 leaf = path->nodes[0];
1710 item_size = btrfs_item_size(leaf, path->slots[0]);
1711
1712 if (unlikely(item_size < sizeof(*ei))) {
1713 ret = -EUCLEAN;
1714 btrfs_err(fs_info,
1715 "unexpected extent item size, has %u expect >= %zu",
1716 item_size, sizeof(*ei));
1717 btrfs_abort_transaction(trans, ret);
1718 goto out;
1719 }
1720
1721 ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
1722 __run_delayed_extent_op(extent_op, leaf, ei);
1723
1724 btrfs_mark_buffer_dirty(trans, leaf);
1725 out:
1726 btrfs_free_path(path);
1727 return ret;
1728 }
1729
run_delayed_tree_ref(struct btrfs_trans_handle * trans,struct btrfs_delayed_ref_head * href,struct btrfs_delayed_ref_node * node,struct btrfs_delayed_extent_op * extent_op,bool insert_reserved)1730 static int run_delayed_tree_ref(struct btrfs_trans_handle *trans,
1731 struct btrfs_delayed_ref_head *href,
1732 struct btrfs_delayed_ref_node *node,
1733 struct btrfs_delayed_extent_op *extent_op,
1734 bool insert_reserved)
1735 {
1736 int ret = 0;
1737 struct btrfs_fs_info *fs_info = trans->fs_info;
1738 struct btrfs_delayed_tree_ref *ref;
1739 u64 parent = 0;
1740 u64 ref_root = 0;
1741
1742 ref = btrfs_delayed_node_to_tree_ref(node);
1743 trace_run_delayed_tree_ref(trans->fs_info, node, ref, node->action);
1744
1745 if (node->type == BTRFS_SHARED_BLOCK_REF_KEY)
1746 parent = ref->parent;
1747 ref_root = ref->root;
1748
1749 if (unlikely(node->ref_mod != 1)) {
1750 btrfs_err(trans->fs_info,
1751 "btree block %llu has %d references rather than 1: action %d ref_root %llu parent %llu",
1752 node->bytenr, node->ref_mod, node->action, ref_root,
1753 parent);
1754 return -EUCLEAN;
1755 }
1756 if (node->action == BTRFS_ADD_DELAYED_REF && insert_reserved) {
1757 struct btrfs_squota_delta delta = {
1758 .root = href->owning_root,
1759 .num_bytes = fs_info->nodesize,
1760 .is_data = false,
1761 .is_inc = true,
1762 .generation = trans->transid,
1763 };
1764
1765 BUG_ON(!extent_op || !extent_op->update_flags);
1766 ret = alloc_reserved_tree_block(trans, node, extent_op);
1767 if (!ret)
1768 btrfs_record_squota_delta(fs_info, &delta);
1769 } else if (node->action == BTRFS_ADD_DELAYED_REF) {
1770 ret = __btrfs_inc_extent_ref(trans, node, parent, ref_root,
1771 ref->level, 0, extent_op);
1772 } else if (node->action == BTRFS_DROP_DELAYED_REF) {
1773 ret = __btrfs_free_extent(trans, href, node, parent, ref_root,
1774 ref->level, 0, extent_op);
1775 } else {
1776 BUG();
1777 }
1778 return ret;
1779 }
1780
1781 /* helper function to actually process a single delayed ref entry */
run_one_delayed_ref(struct btrfs_trans_handle * trans,struct btrfs_delayed_ref_head * href,struct btrfs_delayed_ref_node * node,struct btrfs_delayed_extent_op * extent_op,bool insert_reserved)1782 static int run_one_delayed_ref(struct btrfs_trans_handle *trans,
1783 struct btrfs_delayed_ref_head *href,
1784 struct btrfs_delayed_ref_node *node,
1785 struct btrfs_delayed_extent_op *extent_op,
1786 bool insert_reserved)
1787 {
1788 int ret = 0;
1789
1790 if (TRANS_ABORTED(trans)) {
1791 if (insert_reserved) {
1792 btrfs_pin_extent(trans, node->bytenr, node->num_bytes, 1);
1793 free_head_ref_squota_rsv(trans->fs_info, href);
1794 }
1795 return 0;
1796 }
1797
1798 if (node->type == BTRFS_TREE_BLOCK_REF_KEY ||
1799 node->type == BTRFS_SHARED_BLOCK_REF_KEY)
1800 ret = run_delayed_tree_ref(trans, href, node, extent_op,
1801 insert_reserved);
1802 else if (node->type == BTRFS_EXTENT_DATA_REF_KEY ||
1803 node->type == BTRFS_SHARED_DATA_REF_KEY)
1804 ret = run_delayed_data_ref(trans, href, node, extent_op,
1805 insert_reserved);
1806 else if (node->type == BTRFS_EXTENT_OWNER_REF_KEY)
1807 ret = 0;
1808 else
1809 BUG();
1810 if (ret && insert_reserved)
1811 btrfs_pin_extent(trans, node->bytenr, node->num_bytes, 1);
1812 if (ret < 0)
1813 btrfs_err(trans->fs_info,
1814 "failed to run delayed ref for logical %llu num_bytes %llu type %u action %u ref_mod %d: %d",
1815 node->bytenr, node->num_bytes, node->type,
1816 node->action, node->ref_mod, ret);
1817 return ret;
1818 }
1819
1820 static inline struct btrfs_delayed_ref_node *
select_delayed_ref(struct btrfs_delayed_ref_head * head)1821 select_delayed_ref(struct btrfs_delayed_ref_head *head)
1822 {
1823 struct btrfs_delayed_ref_node *ref;
1824
1825 if (RB_EMPTY_ROOT(&head->ref_tree.rb_root))
1826 return NULL;
1827
1828 /*
1829 * Select a delayed ref of type BTRFS_ADD_DELAYED_REF first.
1830 * This is to prevent a ref count from going down to zero, which deletes
1831 * the extent item from the extent tree, when there still are references
1832 * to add, which would fail because they would not find the extent item.
1833 */
1834 if (!list_empty(&head->ref_add_list))
1835 return list_first_entry(&head->ref_add_list,
1836 struct btrfs_delayed_ref_node, add_list);
1837
1838 ref = rb_entry(rb_first_cached(&head->ref_tree),
1839 struct btrfs_delayed_ref_node, ref_node);
1840 ASSERT(list_empty(&ref->add_list));
1841 return ref;
1842 }
1843
unselect_delayed_ref_head(struct btrfs_delayed_ref_root * delayed_refs,struct btrfs_delayed_ref_head * head)1844 static void unselect_delayed_ref_head(struct btrfs_delayed_ref_root *delayed_refs,
1845 struct btrfs_delayed_ref_head *head)
1846 {
1847 spin_lock(&delayed_refs->lock);
1848 head->processing = false;
1849 delayed_refs->num_heads_ready++;
1850 spin_unlock(&delayed_refs->lock);
1851 btrfs_delayed_ref_unlock(head);
1852 }
1853
cleanup_extent_op(struct btrfs_delayed_ref_head * head)1854 static struct btrfs_delayed_extent_op *cleanup_extent_op(
1855 struct btrfs_delayed_ref_head *head)
1856 {
1857 struct btrfs_delayed_extent_op *extent_op = head->extent_op;
1858
1859 if (!extent_op)
1860 return NULL;
1861
1862 if (head->must_insert_reserved) {
1863 head->extent_op = NULL;
1864 btrfs_free_delayed_extent_op(extent_op);
1865 return NULL;
1866 }
1867 return extent_op;
1868 }
1869
run_and_cleanup_extent_op(struct btrfs_trans_handle * trans,struct btrfs_delayed_ref_head * head)1870 static int run_and_cleanup_extent_op(struct btrfs_trans_handle *trans,
1871 struct btrfs_delayed_ref_head *head)
1872 {
1873 struct btrfs_delayed_extent_op *extent_op;
1874 int ret;
1875
1876 extent_op = cleanup_extent_op(head);
1877 if (!extent_op)
1878 return 0;
1879 head->extent_op = NULL;
1880 spin_unlock(&head->lock);
1881 ret = run_delayed_extent_op(trans, head, extent_op);
1882 btrfs_free_delayed_extent_op(extent_op);
1883 return ret ? ret : 1;
1884 }
1885
btrfs_cleanup_ref_head_accounting(struct btrfs_fs_info * fs_info,struct btrfs_delayed_ref_root * delayed_refs,struct btrfs_delayed_ref_head * head)1886 u64 btrfs_cleanup_ref_head_accounting(struct btrfs_fs_info *fs_info,
1887 struct btrfs_delayed_ref_root *delayed_refs,
1888 struct btrfs_delayed_ref_head *head)
1889 {
1890 u64 ret = 0;
1891
1892 /*
1893 * We had csum deletions accounted for in our delayed refs rsv, we need
1894 * to drop the csum leaves for this update from our delayed_refs_rsv.
1895 */
1896 if (head->total_ref_mod < 0 && head->is_data) {
1897 int nr_csums;
1898
1899 spin_lock(&delayed_refs->lock);
1900 delayed_refs->pending_csums -= head->num_bytes;
1901 spin_unlock(&delayed_refs->lock);
1902 nr_csums = btrfs_csum_bytes_to_leaves(fs_info, head->num_bytes);
1903
1904 btrfs_delayed_refs_rsv_release(fs_info, 0, nr_csums);
1905
1906 ret = btrfs_calc_delayed_ref_csum_bytes(fs_info, nr_csums);
1907 }
1908 /* must_insert_reserved can be set only if we didn't run the head ref. */
1909 if (head->must_insert_reserved)
1910 free_head_ref_squota_rsv(fs_info, head);
1911
1912 return ret;
1913 }
1914
cleanup_ref_head(struct btrfs_trans_handle * trans,struct btrfs_delayed_ref_head * head,u64 * bytes_released)1915 static int cleanup_ref_head(struct btrfs_trans_handle *trans,
1916 struct btrfs_delayed_ref_head *head,
1917 u64 *bytes_released)
1918 {
1919
1920 struct btrfs_fs_info *fs_info = trans->fs_info;
1921 struct btrfs_delayed_ref_root *delayed_refs;
1922 int ret;
1923
1924 delayed_refs = &trans->transaction->delayed_refs;
1925
1926 ret = run_and_cleanup_extent_op(trans, head);
1927 if (ret < 0) {
1928 unselect_delayed_ref_head(delayed_refs, head);
1929 btrfs_debug(fs_info, "run_delayed_extent_op returned %d", ret);
1930 return ret;
1931 } else if (ret) {
1932 return ret;
1933 }
1934
1935 /*
1936 * Need to drop our head ref lock and re-acquire the delayed ref lock
1937 * and then re-check to make sure nobody got added.
1938 */
1939 spin_unlock(&head->lock);
1940 spin_lock(&delayed_refs->lock);
1941 spin_lock(&head->lock);
1942 if (!RB_EMPTY_ROOT(&head->ref_tree.rb_root) || head->extent_op) {
1943 spin_unlock(&head->lock);
1944 spin_unlock(&delayed_refs->lock);
1945 return 1;
1946 }
1947 btrfs_delete_ref_head(delayed_refs, head);
1948 spin_unlock(&head->lock);
1949 spin_unlock(&delayed_refs->lock);
1950
1951 if (head->must_insert_reserved) {
1952 btrfs_pin_extent(trans, head->bytenr, head->num_bytes, 1);
1953 if (head->is_data) {
1954 struct btrfs_root *csum_root;
1955
1956 csum_root = btrfs_csum_root(fs_info, head->bytenr);
1957 ret = btrfs_del_csums(trans, csum_root, head->bytenr,
1958 head->num_bytes);
1959 }
1960 }
1961
1962 *bytes_released += btrfs_cleanup_ref_head_accounting(fs_info, delayed_refs, head);
1963
1964 trace_run_delayed_ref_head(fs_info, head, 0);
1965 btrfs_delayed_ref_unlock(head);
1966 btrfs_put_delayed_ref_head(head);
1967 return ret;
1968 }
1969
btrfs_obtain_ref_head(struct btrfs_trans_handle * trans)1970 static struct btrfs_delayed_ref_head *btrfs_obtain_ref_head(
1971 struct btrfs_trans_handle *trans)
1972 {
1973 struct btrfs_delayed_ref_root *delayed_refs =
1974 &trans->transaction->delayed_refs;
1975 struct btrfs_delayed_ref_head *head = NULL;
1976 int ret;
1977
1978 spin_lock(&delayed_refs->lock);
1979 head = btrfs_select_ref_head(delayed_refs);
1980 if (!head) {
1981 spin_unlock(&delayed_refs->lock);
1982 return head;
1983 }
1984
1985 /*
1986 * Grab the lock that says we are going to process all the refs for
1987 * this head
1988 */
1989 ret = btrfs_delayed_ref_lock(delayed_refs, head);
1990 spin_unlock(&delayed_refs->lock);
1991
1992 /*
1993 * We may have dropped the spin lock to get the head mutex lock, and
1994 * that might have given someone else time to free the head. If that's
1995 * true, it has been removed from our list and we can move on.
1996 */
1997 if (ret == -EAGAIN)
1998 head = ERR_PTR(-EAGAIN);
1999
2000 return head;
2001 }
2002
btrfs_run_delayed_refs_for_head(struct btrfs_trans_handle * trans,struct btrfs_delayed_ref_head * locked_ref,u64 * bytes_released)2003 static int btrfs_run_delayed_refs_for_head(struct btrfs_trans_handle *trans,
2004 struct btrfs_delayed_ref_head *locked_ref,
2005 u64 *bytes_released)
2006 {
2007 struct btrfs_fs_info *fs_info = trans->fs_info;
2008 struct btrfs_delayed_ref_root *delayed_refs;
2009 struct btrfs_delayed_extent_op *extent_op;
2010 struct btrfs_delayed_ref_node *ref;
2011 bool must_insert_reserved;
2012 int ret;
2013
2014 delayed_refs = &trans->transaction->delayed_refs;
2015
2016 lockdep_assert_held(&locked_ref->mutex);
2017 lockdep_assert_held(&locked_ref->lock);
2018
2019 while ((ref = select_delayed_ref(locked_ref))) {
2020 if (ref->seq &&
2021 btrfs_check_delayed_seq(fs_info, ref->seq)) {
2022 spin_unlock(&locked_ref->lock);
2023 unselect_delayed_ref_head(delayed_refs, locked_ref);
2024 return -EAGAIN;
2025 }
2026
2027 rb_erase_cached(&ref->ref_node, &locked_ref->ref_tree);
2028 RB_CLEAR_NODE(&ref->ref_node);
2029 if (!list_empty(&ref->add_list))
2030 list_del(&ref->add_list);
2031 /*
2032 * When we play the delayed ref, also correct the ref_mod on
2033 * head
2034 */
2035 switch (ref->action) {
2036 case BTRFS_ADD_DELAYED_REF:
2037 case BTRFS_ADD_DELAYED_EXTENT:
2038 locked_ref->ref_mod -= ref->ref_mod;
2039 break;
2040 case BTRFS_DROP_DELAYED_REF:
2041 locked_ref->ref_mod += ref->ref_mod;
2042 break;
2043 default:
2044 WARN_ON(1);
2045 }
2046 atomic_dec(&delayed_refs->num_entries);
2047
2048 /*
2049 * Record the must_insert_reserved flag before we drop the
2050 * spin lock.
2051 */
2052 must_insert_reserved = locked_ref->must_insert_reserved;
2053 /*
2054 * Unsetting this on the head ref relinquishes ownership of
2055 * the rsv_bytes, so it is critical that every possible code
2056 * path from here forward frees all reserves including qgroup
2057 * reserve.
2058 */
2059 locked_ref->must_insert_reserved = false;
2060
2061 extent_op = locked_ref->extent_op;
2062 locked_ref->extent_op = NULL;
2063 spin_unlock(&locked_ref->lock);
2064
2065 ret = run_one_delayed_ref(trans, locked_ref, ref, extent_op,
2066 must_insert_reserved);
2067 btrfs_delayed_refs_rsv_release(fs_info, 1, 0);
2068 *bytes_released += btrfs_calc_delayed_ref_bytes(fs_info, 1);
2069
2070 btrfs_free_delayed_extent_op(extent_op);
2071 if (ret) {
2072 unselect_delayed_ref_head(delayed_refs, locked_ref);
2073 btrfs_put_delayed_ref(ref);
2074 return ret;
2075 }
2076
2077 btrfs_put_delayed_ref(ref);
2078 cond_resched();
2079
2080 spin_lock(&locked_ref->lock);
2081 btrfs_merge_delayed_refs(fs_info, delayed_refs, locked_ref);
2082 }
2083
2084 return 0;
2085 }
2086
2087 /*
2088 * Returns 0 on success or if called with an already aborted transaction.
2089 * Returns -ENOMEM or -EIO on failure and will abort the transaction.
2090 */
__btrfs_run_delayed_refs(struct btrfs_trans_handle * trans,u64 min_bytes)2091 static noinline int __btrfs_run_delayed_refs(struct btrfs_trans_handle *trans,
2092 u64 min_bytes)
2093 {
2094 struct btrfs_fs_info *fs_info = trans->fs_info;
2095 struct btrfs_delayed_ref_root *delayed_refs;
2096 struct btrfs_delayed_ref_head *locked_ref = NULL;
2097 int ret;
2098 unsigned long count = 0;
2099 unsigned long max_count = 0;
2100 u64 bytes_processed = 0;
2101
2102 delayed_refs = &trans->transaction->delayed_refs;
2103 if (min_bytes == 0) {
2104 max_count = delayed_refs->num_heads_ready;
2105 min_bytes = U64_MAX;
2106 }
2107
2108 do {
2109 if (!locked_ref) {
2110 locked_ref = btrfs_obtain_ref_head(trans);
2111 if (IS_ERR_OR_NULL(locked_ref)) {
2112 if (PTR_ERR(locked_ref) == -EAGAIN) {
2113 continue;
2114 } else {
2115 break;
2116 }
2117 }
2118 count++;
2119 }
2120 /*
2121 * We need to try and merge add/drops of the same ref since we
2122 * can run into issues with relocate dropping the implicit ref
2123 * and then it being added back again before the drop can
2124 * finish. If we merged anything we need to re-loop so we can
2125 * get a good ref.
2126 * Or we can get node references of the same type that weren't
2127 * merged when created due to bumps in the tree mod seq, and
2128 * we need to merge them to prevent adding an inline extent
2129 * backref before dropping it (triggering a BUG_ON at
2130 * insert_inline_extent_backref()).
2131 */
2132 spin_lock(&locked_ref->lock);
2133 btrfs_merge_delayed_refs(fs_info, delayed_refs, locked_ref);
2134
2135 ret = btrfs_run_delayed_refs_for_head(trans, locked_ref, &bytes_processed);
2136 if (ret < 0 && ret != -EAGAIN) {
2137 /*
2138 * Error, btrfs_run_delayed_refs_for_head already
2139 * unlocked everything so just bail out
2140 */
2141 return ret;
2142 } else if (!ret) {
2143 /*
2144 * Success, perform the usual cleanup of a processed
2145 * head
2146 */
2147 ret = cleanup_ref_head(trans, locked_ref, &bytes_processed);
2148 if (ret > 0 ) {
2149 /* We dropped our lock, we need to loop. */
2150 ret = 0;
2151 continue;
2152 } else if (ret) {
2153 return ret;
2154 }
2155 }
2156
2157 /*
2158 * Either success case or btrfs_run_delayed_refs_for_head
2159 * returned -EAGAIN, meaning we need to select another head
2160 */
2161
2162 locked_ref = NULL;
2163 cond_resched();
2164 } while ((min_bytes != U64_MAX && bytes_processed < min_bytes) ||
2165 (max_count > 0 && count < max_count) ||
2166 locked_ref);
2167
2168 return 0;
2169 }
2170
2171 #ifdef SCRAMBLE_DELAYED_REFS
2172 /*
2173 * Normally delayed refs get processed in ascending bytenr order. This
2174 * correlates in most cases to the order added. To expose dependencies on this
2175 * order, we start to process the tree in the middle instead of the beginning
2176 */
find_middle(struct rb_root * root)2177 static u64 find_middle(struct rb_root *root)
2178 {
2179 struct rb_node *n = root->rb_node;
2180 struct btrfs_delayed_ref_node *entry;
2181 int alt = 1;
2182 u64 middle;
2183 u64 first = 0, last = 0;
2184
2185 n = rb_first(root);
2186 if (n) {
2187 entry = rb_entry(n, struct btrfs_delayed_ref_node, rb_node);
2188 first = entry->bytenr;
2189 }
2190 n = rb_last(root);
2191 if (n) {
2192 entry = rb_entry(n, struct btrfs_delayed_ref_node, rb_node);
2193 last = entry->bytenr;
2194 }
2195 n = root->rb_node;
2196
2197 while (n) {
2198 entry = rb_entry(n, struct btrfs_delayed_ref_node, rb_node);
2199 WARN_ON(!entry->in_tree);
2200
2201 middle = entry->bytenr;
2202
2203 if (alt)
2204 n = n->rb_left;
2205 else
2206 n = n->rb_right;
2207
2208 alt = 1 - alt;
2209 }
2210 return middle;
2211 }
2212 #endif
2213
2214 /*
2215 * Start processing the delayed reference count updates and extent insertions
2216 * we have queued up so far.
2217 *
2218 * @trans: Transaction handle.
2219 * @min_bytes: How many bytes of delayed references to process. After this
2220 * many bytes we stop processing delayed references if there are
2221 * any more. If 0 it means to run all existing delayed references,
2222 * but not new ones added after running all existing ones.
2223 * Use (u64)-1 (U64_MAX) to run all existing delayed references
2224 * plus any new ones that are added.
2225 *
2226 * Returns 0 on success or if called with an aborted transaction
2227 * Returns <0 on error and aborts the transaction
2228 */
btrfs_run_delayed_refs(struct btrfs_trans_handle * trans,u64 min_bytes)2229 int btrfs_run_delayed_refs(struct btrfs_trans_handle *trans, u64 min_bytes)
2230 {
2231 struct btrfs_fs_info *fs_info = trans->fs_info;
2232 struct btrfs_delayed_ref_root *delayed_refs;
2233 int ret;
2234
2235 /* We'll clean this up in btrfs_cleanup_transaction */
2236 if (TRANS_ABORTED(trans))
2237 return 0;
2238
2239 if (test_bit(BTRFS_FS_CREATING_FREE_SPACE_TREE, &fs_info->flags))
2240 return 0;
2241
2242 delayed_refs = &trans->transaction->delayed_refs;
2243 again:
2244 #ifdef SCRAMBLE_DELAYED_REFS
2245 delayed_refs->run_delayed_start = find_middle(&delayed_refs->root);
2246 #endif
2247 ret = __btrfs_run_delayed_refs(trans, min_bytes);
2248 if (ret < 0) {
2249 btrfs_abort_transaction(trans, ret);
2250 return ret;
2251 }
2252
2253 if (min_bytes == U64_MAX) {
2254 btrfs_create_pending_block_groups(trans);
2255
2256 spin_lock(&delayed_refs->lock);
2257 if (RB_EMPTY_ROOT(&delayed_refs->href_root.rb_root)) {
2258 spin_unlock(&delayed_refs->lock);
2259 return 0;
2260 }
2261 spin_unlock(&delayed_refs->lock);
2262
2263 cond_resched();
2264 goto again;
2265 }
2266
2267 return 0;
2268 }
2269
btrfs_set_disk_extent_flags(struct btrfs_trans_handle * trans,struct extent_buffer * eb,u64 flags)2270 int btrfs_set_disk_extent_flags(struct btrfs_trans_handle *trans,
2271 struct extent_buffer *eb, u64 flags)
2272 {
2273 struct btrfs_delayed_extent_op *extent_op;
2274 int level = btrfs_header_level(eb);
2275 int ret;
2276
2277 extent_op = btrfs_alloc_delayed_extent_op();
2278 if (!extent_op)
2279 return -ENOMEM;
2280
2281 extent_op->flags_to_set = flags;
2282 extent_op->update_flags = true;
2283 extent_op->update_key = false;
2284 extent_op->level = level;
2285
2286 ret = btrfs_add_delayed_extent_op(trans, eb->start, eb->len, extent_op);
2287 if (ret)
2288 btrfs_free_delayed_extent_op(extent_op);
2289 return ret;
2290 }
2291
check_delayed_ref(struct btrfs_root * root,struct btrfs_path * path,u64 objectid,u64 offset,u64 bytenr)2292 static noinline int check_delayed_ref(struct btrfs_root *root,
2293 struct btrfs_path *path,
2294 u64 objectid, u64 offset, u64 bytenr)
2295 {
2296 struct btrfs_delayed_ref_head *head;
2297 struct btrfs_delayed_ref_node *ref;
2298 struct btrfs_delayed_data_ref *data_ref;
2299 struct btrfs_delayed_ref_root *delayed_refs;
2300 struct btrfs_transaction *cur_trans;
2301 struct rb_node *node;
2302 int ret = 0;
2303
2304 spin_lock(&root->fs_info->trans_lock);
2305 cur_trans = root->fs_info->running_transaction;
2306 if (cur_trans)
2307 refcount_inc(&cur_trans->use_count);
2308 spin_unlock(&root->fs_info->trans_lock);
2309 if (!cur_trans)
2310 return 0;
2311
2312 delayed_refs = &cur_trans->delayed_refs;
2313 spin_lock(&delayed_refs->lock);
2314 head = btrfs_find_delayed_ref_head(delayed_refs, bytenr);
2315 if (!head) {
2316 spin_unlock(&delayed_refs->lock);
2317 btrfs_put_transaction(cur_trans);
2318 return 0;
2319 }
2320
2321 if (!mutex_trylock(&head->mutex)) {
2322 if (path->nowait) {
2323 spin_unlock(&delayed_refs->lock);
2324 btrfs_put_transaction(cur_trans);
2325 return -EAGAIN;
2326 }
2327
2328 refcount_inc(&head->refs);
2329 spin_unlock(&delayed_refs->lock);
2330
2331 btrfs_release_path(path);
2332
2333 /*
2334 * Mutex was contended, block until it's released and let
2335 * caller try again
2336 */
2337 mutex_lock(&head->mutex);
2338 mutex_unlock(&head->mutex);
2339 btrfs_put_delayed_ref_head(head);
2340 btrfs_put_transaction(cur_trans);
2341 return -EAGAIN;
2342 }
2343 spin_unlock(&delayed_refs->lock);
2344
2345 spin_lock(&head->lock);
2346 /*
2347 * XXX: We should replace this with a proper search function in the
2348 * future.
2349 */
2350 for (node = rb_first_cached(&head->ref_tree); node;
2351 node = rb_next(node)) {
2352 ref = rb_entry(node, struct btrfs_delayed_ref_node, ref_node);
2353 /* If it's a shared ref we know a cross reference exists */
2354 if (ref->type != BTRFS_EXTENT_DATA_REF_KEY) {
2355 ret = 1;
2356 break;
2357 }
2358
2359 data_ref = btrfs_delayed_node_to_data_ref(ref);
2360
2361 /*
2362 * If our ref doesn't match the one we're currently looking at
2363 * then we have a cross reference.
2364 */
2365 if (data_ref->root != root->root_key.objectid ||
2366 data_ref->objectid != objectid ||
2367 data_ref->offset != offset) {
2368 ret = 1;
2369 break;
2370 }
2371 }
2372 spin_unlock(&head->lock);
2373 mutex_unlock(&head->mutex);
2374 btrfs_put_transaction(cur_trans);
2375 return ret;
2376 }
2377
check_committed_ref(struct btrfs_root * root,struct btrfs_path * path,u64 objectid,u64 offset,u64 bytenr,bool strict)2378 static noinline int check_committed_ref(struct btrfs_root *root,
2379 struct btrfs_path *path,
2380 u64 objectid, u64 offset, u64 bytenr,
2381 bool strict)
2382 {
2383 struct btrfs_fs_info *fs_info = root->fs_info;
2384 struct btrfs_root *extent_root = btrfs_extent_root(fs_info, bytenr);
2385 struct extent_buffer *leaf;
2386 struct btrfs_extent_data_ref *ref;
2387 struct btrfs_extent_inline_ref *iref;
2388 struct btrfs_extent_item *ei;
2389 struct btrfs_key key;
2390 u32 item_size;
2391 u32 expected_size;
2392 int type;
2393 int ret;
2394
2395 key.objectid = bytenr;
2396 key.offset = (u64)-1;
2397 key.type = BTRFS_EXTENT_ITEM_KEY;
2398
2399 ret = btrfs_search_slot(NULL, extent_root, &key, path, 0, 0);
2400 if (ret < 0)
2401 goto out;
2402 BUG_ON(ret == 0); /* Corruption */
2403
2404 ret = -ENOENT;
2405 if (path->slots[0] == 0)
2406 goto out;
2407
2408 path->slots[0]--;
2409 leaf = path->nodes[0];
2410 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
2411
2412 if (key.objectid != bytenr || key.type != BTRFS_EXTENT_ITEM_KEY)
2413 goto out;
2414
2415 ret = 1;
2416 item_size = btrfs_item_size(leaf, path->slots[0]);
2417 ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
2418 expected_size = sizeof(*ei) + btrfs_extent_inline_ref_size(BTRFS_EXTENT_DATA_REF_KEY);
2419
2420 /* No inline refs; we need to bail before checking for owner ref. */
2421 if (item_size == sizeof(*ei))
2422 goto out;
2423
2424 /* Check for an owner ref; skip over it to the real inline refs. */
2425 iref = (struct btrfs_extent_inline_ref *)(ei + 1);
2426 type = btrfs_get_extent_inline_ref_type(leaf, iref, BTRFS_REF_TYPE_DATA);
2427 if (btrfs_fs_incompat(fs_info, SIMPLE_QUOTA) && type == BTRFS_EXTENT_OWNER_REF_KEY) {
2428 expected_size += btrfs_extent_inline_ref_size(BTRFS_EXTENT_OWNER_REF_KEY);
2429 iref = (struct btrfs_extent_inline_ref *)(iref + 1);
2430 }
2431
2432 /* If extent item has more than 1 inline ref then it's shared */
2433 if (item_size != expected_size)
2434 goto out;
2435
2436 /*
2437 * If extent created before last snapshot => it's shared unless the
2438 * snapshot has been deleted. Use the heuristic if strict is false.
2439 */
2440 if (!strict &&
2441 (btrfs_extent_generation(leaf, ei) <=
2442 btrfs_root_last_snapshot(&root->root_item)))
2443 goto out;
2444
2445 /* If this extent has SHARED_DATA_REF then it's shared */
2446 type = btrfs_get_extent_inline_ref_type(leaf, iref, BTRFS_REF_TYPE_DATA);
2447 if (type != BTRFS_EXTENT_DATA_REF_KEY)
2448 goto out;
2449
2450 ref = (struct btrfs_extent_data_ref *)(&iref->offset);
2451 if (btrfs_extent_refs(leaf, ei) !=
2452 btrfs_extent_data_ref_count(leaf, ref) ||
2453 btrfs_extent_data_ref_root(leaf, ref) !=
2454 root->root_key.objectid ||
2455 btrfs_extent_data_ref_objectid(leaf, ref) != objectid ||
2456 btrfs_extent_data_ref_offset(leaf, ref) != offset)
2457 goto out;
2458
2459 ret = 0;
2460 out:
2461 return ret;
2462 }
2463
btrfs_cross_ref_exist(struct btrfs_root * root,u64 objectid,u64 offset,u64 bytenr,bool strict,struct btrfs_path * path)2464 int btrfs_cross_ref_exist(struct btrfs_root *root, u64 objectid, u64 offset,
2465 u64 bytenr, bool strict, struct btrfs_path *path)
2466 {
2467 int ret;
2468
2469 do {
2470 ret = check_committed_ref(root, path, objectid,
2471 offset, bytenr, strict);
2472 if (ret && ret != -ENOENT)
2473 goto out;
2474
2475 ret = check_delayed_ref(root, path, objectid, offset, bytenr);
2476 } while (ret == -EAGAIN);
2477
2478 out:
2479 btrfs_release_path(path);
2480 if (btrfs_is_data_reloc_root(root))
2481 WARN_ON(ret > 0);
2482 return ret;
2483 }
2484
__btrfs_mod_ref(struct btrfs_trans_handle * trans,struct btrfs_root * root,struct extent_buffer * buf,int full_backref,int inc)2485 static int __btrfs_mod_ref(struct btrfs_trans_handle *trans,
2486 struct btrfs_root *root,
2487 struct extent_buffer *buf,
2488 int full_backref, int inc)
2489 {
2490 struct btrfs_fs_info *fs_info = root->fs_info;
2491 u64 bytenr;
2492 u64 num_bytes;
2493 u64 parent;
2494 u64 ref_root;
2495 u32 nritems;
2496 struct btrfs_key key;
2497 struct btrfs_file_extent_item *fi;
2498 struct btrfs_ref generic_ref = { 0 };
2499 bool for_reloc = btrfs_header_flag(buf, BTRFS_HEADER_FLAG_RELOC);
2500 int i;
2501 int action;
2502 int level;
2503 int ret = 0;
2504
2505 if (btrfs_is_testing(fs_info))
2506 return 0;
2507
2508 ref_root = btrfs_header_owner(buf);
2509 nritems = btrfs_header_nritems(buf);
2510 level = btrfs_header_level(buf);
2511
2512 if (!test_bit(BTRFS_ROOT_SHAREABLE, &root->state) && level == 0)
2513 return 0;
2514
2515 if (full_backref)
2516 parent = buf->start;
2517 else
2518 parent = 0;
2519 if (inc)
2520 action = BTRFS_ADD_DELAYED_REF;
2521 else
2522 action = BTRFS_DROP_DELAYED_REF;
2523
2524 for (i = 0; i < nritems; i++) {
2525 if (level == 0) {
2526 btrfs_item_key_to_cpu(buf, &key, i);
2527 if (key.type != BTRFS_EXTENT_DATA_KEY)
2528 continue;
2529 fi = btrfs_item_ptr(buf, i,
2530 struct btrfs_file_extent_item);
2531 if (btrfs_file_extent_type(buf, fi) ==
2532 BTRFS_FILE_EXTENT_INLINE)
2533 continue;
2534 bytenr = btrfs_file_extent_disk_bytenr(buf, fi);
2535 if (bytenr == 0)
2536 continue;
2537
2538 num_bytes = btrfs_file_extent_disk_num_bytes(buf, fi);
2539 key.offset -= btrfs_file_extent_offset(buf, fi);
2540 btrfs_init_generic_ref(&generic_ref, action, bytenr,
2541 num_bytes, parent, ref_root);
2542 btrfs_init_data_ref(&generic_ref, ref_root, key.objectid,
2543 key.offset, root->root_key.objectid,
2544 for_reloc);
2545 if (inc)
2546 ret = btrfs_inc_extent_ref(trans, &generic_ref);
2547 else
2548 ret = btrfs_free_extent(trans, &generic_ref);
2549 if (ret)
2550 goto fail;
2551 } else {
2552 bytenr = btrfs_node_blockptr(buf, i);
2553 num_bytes = fs_info->nodesize;
2554 /* We don't know the owning_root, use 0. */
2555 btrfs_init_generic_ref(&generic_ref, action, bytenr,
2556 num_bytes, parent, 0);
2557 btrfs_init_tree_ref(&generic_ref, level - 1, ref_root,
2558 root->root_key.objectid, for_reloc);
2559 if (inc)
2560 ret = btrfs_inc_extent_ref(trans, &generic_ref);
2561 else
2562 ret = btrfs_free_extent(trans, &generic_ref);
2563 if (ret)
2564 goto fail;
2565 }
2566 }
2567 return 0;
2568 fail:
2569 return ret;
2570 }
2571
btrfs_inc_ref(struct btrfs_trans_handle * trans,struct btrfs_root * root,struct extent_buffer * buf,int full_backref)2572 int btrfs_inc_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
2573 struct extent_buffer *buf, int full_backref)
2574 {
2575 return __btrfs_mod_ref(trans, root, buf, full_backref, 1);
2576 }
2577
btrfs_dec_ref(struct btrfs_trans_handle * trans,struct btrfs_root * root,struct extent_buffer * buf,int full_backref)2578 int btrfs_dec_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
2579 struct extent_buffer *buf, int full_backref)
2580 {
2581 return __btrfs_mod_ref(trans, root, buf, full_backref, 0);
2582 }
2583
get_alloc_profile_by_root(struct btrfs_root * root,int data)2584 static u64 get_alloc_profile_by_root(struct btrfs_root *root, int data)
2585 {
2586 struct btrfs_fs_info *fs_info = root->fs_info;
2587 u64 flags;
2588 u64 ret;
2589
2590 if (data)
2591 flags = BTRFS_BLOCK_GROUP_DATA;
2592 else if (root == fs_info->chunk_root)
2593 flags = BTRFS_BLOCK_GROUP_SYSTEM;
2594 else
2595 flags = BTRFS_BLOCK_GROUP_METADATA;
2596
2597 ret = btrfs_get_alloc_profile(fs_info, flags);
2598 return ret;
2599 }
2600
first_logical_byte(struct btrfs_fs_info * fs_info)2601 static u64 first_logical_byte(struct btrfs_fs_info *fs_info)
2602 {
2603 struct rb_node *leftmost;
2604 u64 bytenr = 0;
2605
2606 read_lock(&fs_info->block_group_cache_lock);
2607 /* Get the block group with the lowest logical start address. */
2608 leftmost = rb_first_cached(&fs_info->block_group_cache_tree);
2609 if (leftmost) {
2610 struct btrfs_block_group *bg;
2611
2612 bg = rb_entry(leftmost, struct btrfs_block_group, cache_node);
2613 bytenr = bg->start;
2614 }
2615 read_unlock(&fs_info->block_group_cache_lock);
2616
2617 return bytenr;
2618 }
2619
pin_down_extent(struct btrfs_trans_handle * trans,struct btrfs_block_group * cache,u64 bytenr,u64 num_bytes,int reserved)2620 static int pin_down_extent(struct btrfs_trans_handle *trans,
2621 struct btrfs_block_group *cache,
2622 u64 bytenr, u64 num_bytes, int reserved)
2623 {
2624 struct btrfs_fs_info *fs_info = cache->fs_info;
2625
2626 spin_lock(&cache->space_info->lock);
2627 spin_lock(&cache->lock);
2628 cache->pinned += num_bytes;
2629 btrfs_space_info_update_bytes_pinned(fs_info, cache->space_info,
2630 num_bytes);
2631 if (reserved) {
2632 cache->reserved -= num_bytes;
2633 cache->space_info->bytes_reserved -= num_bytes;
2634 }
2635 spin_unlock(&cache->lock);
2636 spin_unlock(&cache->space_info->lock);
2637
2638 set_extent_bit(&trans->transaction->pinned_extents, bytenr,
2639 bytenr + num_bytes - 1, EXTENT_DIRTY, NULL);
2640 return 0;
2641 }
2642
btrfs_pin_extent(struct btrfs_trans_handle * trans,u64 bytenr,u64 num_bytes,int reserved)2643 int btrfs_pin_extent(struct btrfs_trans_handle *trans,
2644 u64 bytenr, u64 num_bytes, int reserved)
2645 {
2646 struct btrfs_block_group *cache;
2647
2648 cache = btrfs_lookup_block_group(trans->fs_info, bytenr);
2649 BUG_ON(!cache); /* Logic error */
2650
2651 pin_down_extent(trans, cache, bytenr, num_bytes, reserved);
2652
2653 btrfs_put_block_group(cache);
2654 return 0;
2655 }
2656
btrfs_pin_extent_for_log_replay(struct btrfs_trans_handle * trans,const struct extent_buffer * eb)2657 int btrfs_pin_extent_for_log_replay(struct btrfs_trans_handle *trans,
2658 const struct extent_buffer *eb)
2659 {
2660 struct btrfs_block_group *cache;
2661 int ret;
2662
2663 cache = btrfs_lookup_block_group(trans->fs_info, eb->start);
2664 if (!cache)
2665 return -EINVAL;
2666
2667 /*
2668 * Fully cache the free space first so that our pin removes the free space
2669 * from the cache.
2670 */
2671 ret = btrfs_cache_block_group(cache, true);
2672 if (ret)
2673 goto out;
2674
2675 pin_down_extent(trans, cache, eb->start, eb->len, 0);
2676
2677 /* remove us from the free space cache (if we're there at all) */
2678 ret = btrfs_remove_free_space(cache, eb->start, eb->len);
2679 out:
2680 btrfs_put_block_group(cache);
2681 return ret;
2682 }
2683
__exclude_logged_extent(struct btrfs_fs_info * fs_info,u64 start,u64 num_bytes)2684 static int __exclude_logged_extent(struct btrfs_fs_info *fs_info,
2685 u64 start, u64 num_bytes)
2686 {
2687 int ret;
2688 struct btrfs_block_group *block_group;
2689
2690 block_group = btrfs_lookup_block_group(fs_info, start);
2691 if (!block_group)
2692 return -EINVAL;
2693
2694 ret = btrfs_cache_block_group(block_group, true);
2695 if (ret)
2696 goto out;
2697
2698 ret = btrfs_remove_free_space(block_group, start, num_bytes);
2699 out:
2700 btrfs_put_block_group(block_group);
2701 return ret;
2702 }
2703
btrfs_exclude_logged_extents(struct extent_buffer * eb)2704 int btrfs_exclude_logged_extents(struct extent_buffer *eb)
2705 {
2706 struct btrfs_fs_info *fs_info = eb->fs_info;
2707 struct btrfs_file_extent_item *item;
2708 struct btrfs_key key;
2709 int found_type;
2710 int i;
2711 int ret = 0;
2712
2713 if (!btrfs_fs_incompat(fs_info, MIXED_GROUPS))
2714 return 0;
2715
2716 for (i = 0; i < btrfs_header_nritems(eb); i++) {
2717 btrfs_item_key_to_cpu(eb, &key, i);
2718 if (key.type != BTRFS_EXTENT_DATA_KEY)
2719 continue;
2720 item = btrfs_item_ptr(eb, i, struct btrfs_file_extent_item);
2721 found_type = btrfs_file_extent_type(eb, item);
2722 if (found_type == BTRFS_FILE_EXTENT_INLINE)
2723 continue;
2724 if (btrfs_file_extent_disk_bytenr(eb, item) == 0)
2725 continue;
2726 key.objectid = btrfs_file_extent_disk_bytenr(eb, item);
2727 key.offset = btrfs_file_extent_disk_num_bytes(eb, item);
2728 ret = __exclude_logged_extent(fs_info, key.objectid, key.offset);
2729 if (ret)
2730 break;
2731 }
2732
2733 return ret;
2734 }
2735
2736 static void
btrfs_inc_block_group_reservations(struct btrfs_block_group * bg)2737 btrfs_inc_block_group_reservations(struct btrfs_block_group *bg)
2738 {
2739 atomic_inc(&bg->reservations);
2740 }
2741
2742 /*
2743 * Returns the free cluster for the given space info and sets empty_cluster to
2744 * what it should be based on the mount options.
2745 */
2746 static struct btrfs_free_cluster *
fetch_cluster_info(struct btrfs_fs_info * fs_info,struct btrfs_space_info * space_info,u64 * empty_cluster)2747 fetch_cluster_info(struct btrfs_fs_info *fs_info,
2748 struct btrfs_space_info *space_info, u64 *empty_cluster)
2749 {
2750 struct btrfs_free_cluster *ret = NULL;
2751
2752 *empty_cluster = 0;
2753 if (btrfs_mixed_space_info(space_info))
2754 return ret;
2755
2756 if (space_info->flags & BTRFS_BLOCK_GROUP_METADATA) {
2757 ret = &fs_info->meta_alloc_cluster;
2758 if (btrfs_test_opt(fs_info, SSD))
2759 *empty_cluster = SZ_2M;
2760 else
2761 *empty_cluster = SZ_64K;
2762 } else if ((space_info->flags & BTRFS_BLOCK_GROUP_DATA) &&
2763 btrfs_test_opt(fs_info, SSD_SPREAD)) {
2764 *empty_cluster = SZ_2M;
2765 ret = &fs_info->data_alloc_cluster;
2766 }
2767
2768 return ret;
2769 }
2770
unpin_extent_range(struct btrfs_fs_info * fs_info,u64 start,u64 end,const bool return_free_space)2771 static int unpin_extent_range(struct btrfs_fs_info *fs_info,
2772 u64 start, u64 end,
2773 const bool return_free_space)
2774 {
2775 struct btrfs_block_group *cache = NULL;
2776 struct btrfs_space_info *space_info;
2777 struct btrfs_block_rsv *global_rsv = &fs_info->global_block_rsv;
2778 struct btrfs_free_cluster *cluster = NULL;
2779 u64 len;
2780 u64 total_unpinned = 0;
2781 u64 empty_cluster = 0;
2782 bool readonly;
2783
2784 while (start <= end) {
2785 readonly = false;
2786 if (!cache ||
2787 start >= cache->start + cache->length) {
2788 if (cache)
2789 btrfs_put_block_group(cache);
2790 total_unpinned = 0;
2791 cache = btrfs_lookup_block_group(fs_info, start);
2792 BUG_ON(!cache); /* Logic error */
2793
2794 cluster = fetch_cluster_info(fs_info,
2795 cache->space_info,
2796 &empty_cluster);
2797 empty_cluster <<= 1;
2798 }
2799
2800 len = cache->start + cache->length - start;
2801 len = min(len, end + 1 - start);
2802
2803 if (return_free_space)
2804 btrfs_add_free_space(cache, start, len);
2805
2806 start += len;
2807 total_unpinned += len;
2808 space_info = cache->space_info;
2809
2810 /*
2811 * If this space cluster has been marked as fragmented and we've
2812 * unpinned enough in this block group to potentially allow a
2813 * cluster to be created inside of it go ahead and clear the
2814 * fragmented check.
2815 */
2816 if (cluster && cluster->fragmented &&
2817 total_unpinned > empty_cluster) {
2818 spin_lock(&cluster->lock);
2819 cluster->fragmented = 0;
2820 spin_unlock(&cluster->lock);
2821 }
2822
2823 spin_lock(&space_info->lock);
2824 spin_lock(&cache->lock);
2825 cache->pinned -= len;
2826 btrfs_space_info_update_bytes_pinned(fs_info, space_info, -len);
2827 space_info->max_extent_size = 0;
2828 if (cache->ro) {
2829 space_info->bytes_readonly += len;
2830 readonly = true;
2831 } else if (btrfs_is_zoned(fs_info)) {
2832 /* Need reset before reusing in a zoned block group */
2833 space_info->bytes_zone_unusable += len;
2834 readonly = true;
2835 }
2836 spin_unlock(&cache->lock);
2837 if (!readonly && return_free_space &&
2838 global_rsv->space_info == space_info) {
2839 spin_lock(&global_rsv->lock);
2840 if (!global_rsv->full) {
2841 u64 to_add = min(len, global_rsv->size -
2842 global_rsv->reserved);
2843
2844 global_rsv->reserved += to_add;
2845 btrfs_space_info_update_bytes_may_use(fs_info,
2846 space_info, to_add);
2847 if (global_rsv->reserved >= global_rsv->size)
2848 global_rsv->full = 1;
2849 len -= to_add;
2850 }
2851 spin_unlock(&global_rsv->lock);
2852 }
2853 /* Add to any tickets we may have */
2854 if (!readonly && return_free_space && len)
2855 btrfs_try_granting_tickets(fs_info, space_info);
2856 spin_unlock(&space_info->lock);
2857 }
2858
2859 if (cache)
2860 btrfs_put_block_group(cache);
2861 return 0;
2862 }
2863
btrfs_finish_extent_commit(struct btrfs_trans_handle * trans)2864 int btrfs_finish_extent_commit(struct btrfs_trans_handle *trans)
2865 {
2866 struct btrfs_fs_info *fs_info = trans->fs_info;
2867 struct btrfs_block_group *block_group, *tmp;
2868 struct list_head *deleted_bgs;
2869 struct extent_io_tree *unpin;
2870 u64 start;
2871 u64 end;
2872 int ret;
2873
2874 unpin = &trans->transaction->pinned_extents;
2875
2876 while (!TRANS_ABORTED(trans)) {
2877 struct extent_state *cached_state = NULL;
2878
2879 mutex_lock(&fs_info->unused_bg_unpin_mutex);
2880 if (!find_first_extent_bit(unpin, 0, &start, &end,
2881 EXTENT_DIRTY, &cached_state)) {
2882 mutex_unlock(&fs_info->unused_bg_unpin_mutex);
2883 break;
2884 }
2885
2886 if (btrfs_test_opt(fs_info, DISCARD_SYNC))
2887 ret = btrfs_discard_extent(fs_info, start,
2888 end + 1 - start, NULL);
2889
2890 clear_extent_dirty(unpin, start, end, &cached_state);
2891 unpin_extent_range(fs_info, start, end, true);
2892 mutex_unlock(&fs_info->unused_bg_unpin_mutex);
2893 free_extent_state(cached_state);
2894 cond_resched();
2895 }
2896
2897 if (btrfs_test_opt(fs_info, DISCARD_ASYNC)) {
2898 btrfs_discard_calc_delay(&fs_info->discard_ctl);
2899 btrfs_discard_schedule_work(&fs_info->discard_ctl, true);
2900 }
2901
2902 /*
2903 * Transaction is finished. We don't need the lock anymore. We
2904 * do need to clean up the block groups in case of a transaction
2905 * abort.
2906 */
2907 deleted_bgs = &trans->transaction->deleted_bgs;
2908 list_for_each_entry_safe(block_group, tmp, deleted_bgs, bg_list) {
2909 u64 trimmed = 0;
2910
2911 ret = -EROFS;
2912 if (!TRANS_ABORTED(trans))
2913 ret = btrfs_discard_extent(fs_info,
2914 block_group->start,
2915 block_group->length,
2916 &trimmed);
2917
2918 list_del_init(&block_group->bg_list);
2919 btrfs_unfreeze_block_group(block_group);
2920 btrfs_put_block_group(block_group);
2921
2922 if (ret) {
2923 const char *errstr = btrfs_decode_error(ret);
2924 btrfs_warn(fs_info,
2925 "discard failed while removing blockgroup: errno=%d %s",
2926 ret, errstr);
2927 }
2928 }
2929
2930 return 0;
2931 }
2932
2933 /*
2934 * Parse an extent item's inline extents looking for a simple quotas owner ref.
2935 *
2936 * @fs_info: the btrfs_fs_info for this mount
2937 * @leaf: a leaf in the extent tree containing the extent item
2938 * @slot: the slot in the leaf where the extent item is found
2939 *
2940 * Returns the objectid of the root that originally allocated the extent item
2941 * if the inline owner ref is expected and present, otherwise 0.
2942 *
2943 * If an extent item has an owner ref item, it will be the first inline ref
2944 * item. Therefore the logic is to check whether there are any inline ref
2945 * items, then check the type of the first one.
2946 */
btrfs_get_extent_owner_root(struct btrfs_fs_info * fs_info,struct extent_buffer * leaf,int slot)2947 u64 btrfs_get_extent_owner_root(struct btrfs_fs_info *fs_info,
2948 struct extent_buffer *leaf, int slot)
2949 {
2950 struct btrfs_extent_item *ei;
2951 struct btrfs_extent_inline_ref *iref;
2952 struct btrfs_extent_owner_ref *oref;
2953 unsigned long ptr;
2954 unsigned long end;
2955 int type;
2956
2957 if (!btrfs_fs_incompat(fs_info, SIMPLE_QUOTA))
2958 return 0;
2959
2960 ei = btrfs_item_ptr(leaf, slot, struct btrfs_extent_item);
2961 ptr = (unsigned long)(ei + 1);
2962 end = (unsigned long)ei + btrfs_item_size(leaf, slot);
2963
2964 /* No inline ref items of any kind, can't check type. */
2965 if (ptr == end)
2966 return 0;
2967
2968 iref = (struct btrfs_extent_inline_ref *)ptr;
2969 type = btrfs_get_extent_inline_ref_type(leaf, iref, BTRFS_REF_TYPE_ANY);
2970
2971 /* We found an owner ref, get the root out of it. */
2972 if (type == BTRFS_EXTENT_OWNER_REF_KEY) {
2973 oref = (struct btrfs_extent_owner_ref *)(&iref->offset);
2974 return btrfs_extent_owner_ref_root_id(leaf, oref);
2975 }
2976
2977 /* We have inline refs, but not an owner ref. */
2978 return 0;
2979 }
2980
do_free_extent_accounting(struct btrfs_trans_handle * trans,u64 bytenr,struct btrfs_squota_delta * delta)2981 static int do_free_extent_accounting(struct btrfs_trans_handle *trans,
2982 u64 bytenr, struct btrfs_squota_delta *delta)
2983 {
2984 int ret;
2985 u64 num_bytes = delta->num_bytes;
2986
2987 if (delta->is_data) {
2988 struct btrfs_root *csum_root;
2989
2990 csum_root = btrfs_csum_root(trans->fs_info, bytenr);
2991 ret = btrfs_del_csums(trans, csum_root, bytenr, num_bytes);
2992 if (ret) {
2993 btrfs_abort_transaction(trans, ret);
2994 return ret;
2995 }
2996
2997 ret = btrfs_delete_raid_extent(trans, bytenr, num_bytes);
2998 if (ret) {
2999 btrfs_abort_transaction(trans, ret);
3000 return ret;
3001 }
3002 }
3003
3004 ret = btrfs_record_squota_delta(trans->fs_info, delta);
3005 if (ret) {
3006 btrfs_abort_transaction(trans, ret);
3007 return ret;
3008 }
3009
3010 ret = add_to_free_space_tree(trans, bytenr, num_bytes);
3011 if (ret) {
3012 btrfs_abort_transaction(trans, ret);
3013 return ret;
3014 }
3015
3016 ret = btrfs_update_block_group(trans, bytenr, num_bytes, false);
3017 if (ret)
3018 btrfs_abort_transaction(trans, ret);
3019
3020 return ret;
3021 }
3022
3023 #define abort_and_dump(trans, path, fmt, args...) \
3024 ({ \
3025 btrfs_abort_transaction(trans, -EUCLEAN); \
3026 btrfs_print_leaf(path->nodes[0]); \
3027 btrfs_crit(trans->fs_info, fmt, ##args); \
3028 })
3029
3030 /*
3031 * Drop one or more refs of @node.
3032 *
3033 * 1. Locate the extent refs.
3034 * It's either inline in EXTENT/METADATA_ITEM or in keyed SHARED_* item.
3035 * Locate it, then reduce the refs number or remove the ref line completely.
3036 *
3037 * 2. Update the refs count in EXTENT/METADATA_ITEM
3038 *
3039 * Inline backref case:
3040 *
3041 * in extent tree we have:
3042 *
3043 * item 0 key (13631488 EXTENT_ITEM 1048576) itemoff 16201 itemsize 82
3044 * refs 2 gen 6 flags DATA
3045 * extent data backref root FS_TREE objectid 258 offset 0 count 1
3046 * extent data backref root FS_TREE objectid 257 offset 0 count 1
3047 *
3048 * This function gets called with:
3049 *
3050 * node->bytenr = 13631488
3051 * node->num_bytes = 1048576
3052 * root_objectid = FS_TREE
3053 * owner_objectid = 257
3054 * owner_offset = 0
3055 * refs_to_drop = 1
3056 *
3057 * Then we should get some like:
3058 *
3059 * item 0 key (13631488 EXTENT_ITEM 1048576) itemoff 16201 itemsize 82
3060 * refs 1 gen 6 flags DATA
3061 * extent data backref root FS_TREE objectid 258 offset 0 count 1
3062 *
3063 * Keyed backref case:
3064 *
3065 * in extent tree we have:
3066 *
3067 * item 0 key (13631488 EXTENT_ITEM 1048576) itemoff 3971 itemsize 24
3068 * refs 754 gen 6 flags DATA
3069 * [...]
3070 * item 2 key (13631488 EXTENT_DATA_REF <HASH>) itemoff 3915 itemsize 28
3071 * extent data backref root FS_TREE objectid 866 offset 0 count 1
3072 *
3073 * This function get called with:
3074 *
3075 * node->bytenr = 13631488
3076 * node->num_bytes = 1048576
3077 * root_objectid = FS_TREE
3078 * owner_objectid = 866
3079 * owner_offset = 0
3080 * refs_to_drop = 1
3081 *
3082 * Then we should get some like:
3083 *
3084 * item 0 key (13631488 EXTENT_ITEM 1048576) itemoff 3971 itemsize 24
3085 * refs 753 gen 6 flags DATA
3086 *
3087 * And that (13631488 EXTENT_DATA_REF <HASH>) gets removed.
3088 */
__btrfs_free_extent(struct btrfs_trans_handle * trans,struct btrfs_delayed_ref_head * href,struct btrfs_delayed_ref_node * node,u64 parent,u64 root_objectid,u64 owner_objectid,u64 owner_offset,struct btrfs_delayed_extent_op * extent_op)3089 static int __btrfs_free_extent(struct btrfs_trans_handle *trans,
3090 struct btrfs_delayed_ref_head *href,
3091 struct btrfs_delayed_ref_node *node, u64 parent,
3092 u64 root_objectid, u64 owner_objectid,
3093 u64 owner_offset,
3094 struct btrfs_delayed_extent_op *extent_op)
3095 {
3096 struct btrfs_fs_info *info = trans->fs_info;
3097 struct btrfs_key key;
3098 struct btrfs_path *path;
3099 struct btrfs_root *extent_root;
3100 struct extent_buffer *leaf;
3101 struct btrfs_extent_item *ei;
3102 struct btrfs_extent_inline_ref *iref;
3103 int ret;
3104 int is_data;
3105 int extent_slot = 0;
3106 int found_extent = 0;
3107 int num_to_del = 1;
3108 int refs_to_drop = node->ref_mod;
3109 u32 item_size;
3110 u64 refs;
3111 u64 bytenr = node->bytenr;
3112 u64 num_bytes = node->num_bytes;
3113 bool skinny_metadata = btrfs_fs_incompat(info, SKINNY_METADATA);
3114 u64 delayed_ref_root = href->owning_root;
3115
3116 extent_root = btrfs_extent_root(info, bytenr);
3117 ASSERT(extent_root);
3118
3119 path = btrfs_alloc_path();
3120 if (!path)
3121 return -ENOMEM;
3122
3123 is_data = owner_objectid >= BTRFS_FIRST_FREE_OBJECTID;
3124
3125 if (!is_data && refs_to_drop != 1) {
3126 btrfs_crit(info,
3127 "invalid refs_to_drop, dropping more than 1 refs for tree block %llu refs_to_drop %u",
3128 node->bytenr, refs_to_drop);
3129 ret = -EINVAL;
3130 btrfs_abort_transaction(trans, ret);
3131 goto out;
3132 }
3133
3134 if (is_data)
3135 skinny_metadata = false;
3136
3137 ret = lookup_extent_backref(trans, path, &iref, bytenr, num_bytes,
3138 parent, root_objectid, owner_objectid,
3139 owner_offset);
3140 if (ret == 0) {
3141 /*
3142 * Either the inline backref or the SHARED_DATA_REF/
3143 * SHARED_BLOCK_REF is found
3144 *
3145 * Here is a quick path to locate EXTENT/METADATA_ITEM.
3146 * It's possible the EXTENT/METADATA_ITEM is near current slot.
3147 */
3148 extent_slot = path->slots[0];
3149 while (extent_slot >= 0) {
3150 btrfs_item_key_to_cpu(path->nodes[0], &key,
3151 extent_slot);
3152 if (key.objectid != bytenr)
3153 break;
3154 if (key.type == BTRFS_EXTENT_ITEM_KEY &&
3155 key.offset == num_bytes) {
3156 found_extent = 1;
3157 break;
3158 }
3159 if (key.type == BTRFS_METADATA_ITEM_KEY &&
3160 key.offset == owner_objectid) {
3161 found_extent = 1;
3162 break;
3163 }
3164
3165 /* Quick path didn't find the EXTEMT/METADATA_ITEM */
3166 if (path->slots[0] - extent_slot > 5)
3167 break;
3168 extent_slot--;
3169 }
3170
3171 if (!found_extent) {
3172 if (iref) {
3173 abort_and_dump(trans, path,
3174 "invalid iref slot %u, no EXTENT/METADATA_ITEM found but has inline extent ref",
3175 path->slots[0]);
3176 ret = -EUCLEAN;
3177 goto out;
3178 }
3179 /* Must be SHARED_* item, remove the backref first */
3180 ret = remove_extent_backref(trans, extent_root, path,
3181 NULL, refs_to_drop, is_data);
3182 if (ret) {
3183 btrfs_abort_transaction(trans, ret);
3184 goto out;
3185 }
3186 btrfs_release_path(path);
3187
3188 /* Slow path to locate EXTENT/METADATA_ITEM */
3189 key.objectid = bytenr;
3190 key.type = BTRFS_EXTENT_ITEM_KEY;
3191 key.offset = num_bytes;
3192
3193 if (!is_data && skinny_metadata) {
3194 key.type = BTRFS_METADATA_ITEM_KEY;
3195 key.offset = owner_objectid;
3196 }
3197
3198 ret = btrfs_search_slot(trans, extent_root,
3199 &key, path, -1, 1);
3200 if (ret > 0 && skinny_metadata && path->slots[0]) {
3201 /*
3202 * Couldn't find our skinny metadata item,
3203 * see if we have ye olde extent item.
3204 */
3205 path->slots[0]--;
3206 btrfs_item_key_to_cpu(path->nodes[0], &key,
3207 path->slots[0]);
3208 if (key.objectid == bytenr &&
3209 key.type == BTRFS_EXTENT_ITEM_KEY &&
3210 key.offset == num_bytes)
3211 ret = 0;
3212 }
3213
3214 if (ret > 0 && skinny_metadata) {
3215 skinny_metadata = false;
3216 key.objectid = bytenr;
3217 key.type = BTRFS_EXTENT_ITEM_KEY;
3218 key.offset = num_bytes;
3219 btrfs_release_path(path);
3220 ret = btrfs_search_slot(trans, extent_root,
3221 &key, path, -1, 1);
3222 }
3223
3224 if (ret) {
3225 if (ret > 0)
3226 btrfs_print_leaf(path->nodes[0]);
3227 btrfs_err(info,
3228 "umm, got %d back from search, was looking for %llu, slot %d",
3229 ret, bytenr, path->slots[0]);
3230 }
3231 if (ret < 0) {
3232 btrfs_abort_transaction(trans, ret);
3233 goto out;
3234 }
3235 extent_slot = path->slots[0];
3236 }
3237 } else if (WARN_ON(ret == -ENOENT)) {
3238 abort_and_dump(trans, path,
3239 "unable to find ref byte nr %llu parent %llu root %llu owner %llu offset %llu slot %d",
3240 bytenr, parent, root_objectid, owner_objectid,
3241 owner_offset, path->slots[0]);
3242 goto out;
3243 } else {
3244 btrfs_abort_transaction(trans, ret);
3245 goto out;
3246 }
3247
3248 leaf = path->nodes[0];
3249 item_size = btrfs_item_size(leaf, extent_slot);
3250 if (unlikely(item_size < sizeof(*ei))) {
3251 ret = -EUCLEAN;
3252 btrfs_err(trans->fs_info,
3253 "unexpected extent item size, has %u expect >= %zu",
3254 item_size, sizeof(*ei));
3255 btrfs_abort_transaction(trans, ret);
3256 goto out;
3257 }
3258 ei = btrfs_item_ptr(leaf, extent_slot,
3259 struct btrfs_extent_item);
3260 if (owner_objectid < BTRFS_FIRST_FREE_OBJECTID &&
3261 key.type == BTRFS_EXTENT_ITEM_KEY) {
3262 struct btrfs_tree_block_info *bi;
3263
3264 if (item_size < sizeof(*ei) + sizeof(*bi)) {
3265 abort_and_dump(trans, path,
3266 "invalid extent item size for key (%llu, %u, %llu) slot %u owner %llu, has %u expect >= %zu",
3267 key.objectid, key.type, key.offset,
3268 path->slots[0], owner_objectid, item_size,
3269 sizeof(*ei) + sizeof(*bi));
3270 ret = -EUCLEAN;
3271 goto out;
3272 }
3273 bi = (struct btrfs_tree_block_info *)(ei + 1);
3274 WARN_ON(owner_objectid != btrfs_tree_block_level(leaf, bi));
3275 }
3276
3277 refs = btrfs_extent_refs(leaf, ei);
3278 if (refs < refs_to_drop) {
3279 abort_and_dump(trans, path,
3280 "trying to drop %d refs but we only have %llu for bytenr %llu slot %u",
3281 refs_to_drop, refs, bytenr, path->slots[0]);
3282 ret = -EUCLEAN;
3283 goto out;
3284 }
3285 refs -= refs_to_drop;
3286
3287 if (refs > 0) {
3288 if (extent_op)
3289 __run_delayed_extent_op(extent_op, leaf, ei);
3290 /*
3291 * In the case of inline back ref, reference count will
3292 * be updated by remove_extent_backref
3293 */
3294 if (iref) {
3295 if (!found_extent) {
3296 abort_and_dump(trans, path,
3297 "invalid iref, got inlined extent ref but no EXTENT/METADATA_ITEM found, slot %u",
3298 path->slots[0]);
3299 ret = -EUCLEAN;
3300 goto out;
3301 }
3302 } else {
3303 btrfs_set_extent_refs(leaf, ei, refs);
3304 btrfs_mark_buffer_dirty(trans, leaf);
3305 }
3306 if (found_extent) {
3307 ret = remove_extent_backref(trans, extent_root, path,
3308 iref, refs_to_drop, is_data);
3309 if (ret) {
3310 btrfs_abort_transaction(trans, ret);
3311 goto out;
3312 }
3313 }
3314 } else {
3315 struct btrfs_squota_delta delta = {
3316 .root = delayed_ref_root,
3317 .num_bytes = num_bytes,
3318 .is_data = is_data,
3319 .is_inc = false,
3320 .generation = btrfs_extent_generation(leaf, ei),
3321 };
3322
3323 /* In this branch refs == 1 */
3324 if (found_extent) {
3325 if (is_data && refs_to_drop !=
3326 extent_data_ref_count(path, iref)) {
3327 abort_and_dump(trans, path,
3328 "invalid refs_to_drop, current refs %u refs_to_drop %u slot %u",
3329 extent_data_ref_count(path, iref),
3330 refs_to_drop, path->slots[0]);
3331 ret = -EUCLEAN;
3332 goto out;
3333 }
3334 if (iref) {
3335 if (path->slots[0] != extent_slot) {
3336 abort_and_dump(trans, path,
3337 "invalid iref, extent item key (%llu %u %llu) slot %u doesn't have wanted iref",
3338 key.objectid, key.type,
3339 key.offset, path->slots[0]);
3340 ret = -EUCLEAN;
3341 goto out;
3342 }
3343 } else {
3344 /*
3345 * No inline ref, we must be at SHARED_* item,
3346 * And it's single ref, it must be:
3347 * | extent_slot ||extent_slot + 1|
3348 * [ EXTENT/METADATA_ITEM ][ SHARED_* ITEM ]
3349 */
3350 if (path->slots[0] != extent_slot + 1) {
3351 abort_and_dump(trans, path,
3352 "invalid SHARED_* item slot %u, previous item is not EXTENT/METADATA_ITEM",
3353 path->slots[0]);
3354 ret = -EUCLEAN;
3355 goto out;
3356 }
3357 path->slots[0] = extent_slot;
3358 num_to_del = 2;
3359 }
3360 }
3361 /*
3362 * We can't infer the data owner from the delayed ref, so we need
3363 * to try to get it from the owning ref item.
3364 *
3365 * If it is not present, then that extent was not written under
3366 * simple quotas mode, so we don't need to account for its deletion.
3367 */
3368 if (is_data)
3369 delta.root = btrfs_get_extent_owner_root(trans->fs_info,
3370 leaf, extent_slot);
3371
3372 ret = btrfs_del_items(trans, extent_root, path, path->slots[0],
3373 num_to_del);
3374 if (ret) {
3375 btrfs_abort_transaction(trans, ret);
3376 goto out;
3377 }
3378 btrfs_release_path(path);
3379
3380 ret = do_free_extent_accounting(trans, bytenr, &delta);
3381 }
3382 btrfs_release_path(path);
3383
3384 out:
3385 btrfs_free_path(path);
3386 return ret;
3387 }
3388
3389 /*
3390 * when we free an block, it is possible (and likely) that we free the last
3391 * delayed ref for that extent as well. This searches the delayed ref tree for
3392 * a given extent, and if there are no other delayed refs to be processed, it
3393 * removes it from the tree.
3394 */
check_ref_cleanup(struct btrfs_trans_handle * trans,u64 bytenr)3395 static noinline int check_ref_cleanup(struct btrfs_trans_handle *trans,
3396 u64 bytenr)
3397 {
3398 struct btrfs_delayed_ref_head *head;
3399 struct btrfs_delayed_ref_root *delayed_refs;
3400 int ret = 0;
3401
3402 delayed_refs = &trans->transaction->delayed_refs;
3403 spin_lock(&delayed_refs->lock);
3404 head = btrfs_find_delayed_ref_head(delayed_refs, bytenr);
3405 if (!head)
3406 goto out_delayed_unlock;
3407
3408 spin_lock(&head->lock);
3409 if (!RB_EMPTY_ROOT(&head->ref_tree.rb_root))
3410 goto out;
3411
3412 if (cleanup_extent_op(head) != NULL)
3413 goto out;
3414
3415 /*
3416 * waiting for the lock here would deadlock. If someone else has it
3417 * locked they are already in the process of dropping it anyway
3418 */
3419 if (!mutex_trylock(&head->mutex))
3420 goto out;
3421
3422 btrfs_delete_ref_head(delayed_refs, head);
3423 head->processing = false;
3424
3425 spin_unlock(&head->lock);
3426 spin_unlock(&delayed_refs->lock);
3427
3428 BUG_ON(head->extent_op);
3429 if (head->must_insert_reserved)
3430 ret = 1;
3431
3432 btrfs_cleanup_ref_head_accounting(trans->fs_info, delayed_refs, head);
3433 mutex_unlock(&head->mutex);
3434 btrfs_put_delayed_ref_head(head);
3435 return ret;
3436 out:
3437 spin_unlock(&head->lock);
3438
3439 out_delayed_unlock:
3440 spin_unlock(&delayed_refs->lock);
3441 return 0;
3442 }
3443
btrfs_free_tree_block(struct btrfs_trans_handle * trans,u64 root_id,struct extent_buffer * buf,u64 parent,int last_ref)3444 void btrfs_free_tree_block(struct btrfs_trans_handle *trans,
3445 u64 root_id,
3446 struct extent_buffer *buf,
3447 u64 parent, int last_ref)
3448 {
3449 struct btrfs_fs_info *fs_info = trans->fs_info;
3450 struct btrfs_ref generic_ref = { 0 };
3451 struct btrfs_block_group *bg;
3452 int ret;
3453
3454 btrfs_init_generic_ref(&generic_ref, BTRFS_DROP_DELAYED_REF,
3455 buf->start, buf->len, parent, btrfs_header_owner(buf));
3456 btrfs_init_tree_ref(&generic_ref, btrfs_header_level(buf),
3457 root_id, 0, false);
3458
3459 if (root_id != BTRFS_TREE_LOG_OBJECTID) {
3460 btrfs_ref_tree_mod(fs_info, &generic_ref);
3461 ret = btrfs_add_delayed_tree_ref(trans, &generic_ref, NULL);
3462 BUG_ON(ret); /* -ENOMEM */
3463 }
3464
3465 if (!last_ref)
3466 return;
3467
3468 if (btrfs_header_generation(buf) != trans->transid)
3469 goto out;
3470
3471 if (root_id != BTRFS_TREE_LOG_OBJECTID) {
3472 ret = check_ref_cleanup(trans, buf->start);
3473 if (!ret)
3474 goto out;
3475 }
3476
3477 bg = btrfs_lookup_block_group(fs_info, buf->start);
3478
3479 if (btrfs_header_flag(buf, BTRFS_HEADER_FLAG_WRITTEN)) {
3480 pin_down_extent(trans, bg, buf->start, buf->len, 1);
3481 btrfs_put_block_group(bg);
3482 goto out;
3483 }
3484
3485 /*
3486 * If there are tree mod log users we may have recorded mod log
3487 * operations for this node. If we re-allocate this node we
3488 * could replay operations on this node that happened when it
3489 * existed in a completely different root. For example if it
3490 * was part of root A, then was reallocated to root B, and we
3491 * are doing a btrfs_old_search_slot(root b), we could replay
3492 * operations that happened when the block was part of root A,
3493 * giving us an inconsistent view of the btree.
3494 *
3495 * We are safe from races here because at this point no other
3496 * node or root points to this extent buffer, so if after this
3497 * check a new tree mod log user joins we will not have an
3498 * existing log of operations on this node that we have to
3499 * contend with.
3500 */
3501
3502 if (test_bit(BTRFS_FS_TREE_MOD_LOG_USERS, &fs_info->flags)
3503 || btrfs_is_zoned(fs_info)) {
3504 pin_down_extent(trans, bg, buf->start, buf->len, 1);
3505 btrfs_put_block_group(bg);
3506 goto out;
3507 }
3508
3509 WARN_ON(test_bit(EXTENT_BUFFER_DIRTY, &buf->bflags));
3510
3511 btrfs_add_free_space(bg, buf->start, buf->len);
3512 btrfs_free_reserved_bytes(bg, buf->len, 0);
3513 btrfs_put_block_group(bg);
3514 trace_btrfs_reserved_extent_free(fs_info, buf->start, buf->len);
3515
3516 out:
3517
3518 /*
3519 * Deleting the buffer, clear the corrupt flag since it doesn't
3520 * matter anymore.
3521 */
3522 clear_bit(EXTENT_BUFFER_CORRUPT, &buf->bflags);
3523 }
3524
3525 /* Can return -ENOMEM */
btrfs_free_extent(struct btrfs_trans_handle * trans,struct btrfs_ref * ref)3526 int btrfs_free_extent(struct btrfs_trans_handle *trans, struct btrfs_ref *ref)
3527 {
3528 struct btrfs_fs_info *fs_info = trans->fs_info;
3529 int ret;
3530
3531 if (btrfs_is_testing(fs_info))
3532 return 0;
3533
3534 /*
3535 * tree log blocks never actually go into the extent allocation
3536 * tree, just update pinning info and exit early.
3537 */
3538 if ((ref->type == BTRFS_REF_METADATA &&
3539 ref->tree_ref.ref_root == BTRFS_TREE_LOG_OBJECTID) ||
3540 (ref->type == BTRFS_REF_DATA &&
3541 ref->data_ref.ref_root == BTRFS_TREE_LOG_OBJECTID)) {
3542 btrfs_pin_extent(trans, ref->bytenr, ref->len, 1);
3543 ret = 0;
3544 } else if (ref->type == BTRFS_REF_METADATA) {
3545 ret = btrfs_add_delayed_tree_ref(trans, ref, NULL);
3546 } else {
3547 ret = btrfs_add_delayed_data_ref(trans, ref, 0);
3548 }
3549
3550 if (!((ref->type == BTRFS_REF_METADATA &&
3551 ref->tree_ref.ref_root == BTRFS_TREE_LOG_OBJECTID) ||
3552 (ref->type == BTRFS_REF_DATA &&
3553 ref->data_ref.ref_root == BTRFS_TREE_LOG_OBJECTID)))
3554 btrfs_ref_tree_mod(fs_info, ref);
3555
3556 return ret;
3557 }
3558
3559 enum btrfs_loop_type {
3560 /*
3561 * Start caching block groups but do not wait for progress or for them
3562 * to be done.
3563 */
3564 LOOP_CACHING_NOWAIT,
3565
3566 /*
3567 * Wait for the block group free_space >= the space we're waiting for if
3568 * the block group isn't cached.
3569 */
3570 LOOP_CACHING_WAIT,
3571
3572 /*
3573 * Allow allocations to happen from block groups that do not yet have a
3574 * size classification.
3575 */
3576 LOOP_UNSET_SIZE_CLASS,
3577
3578 /*
3579 * Allocate a chunk and then retry the allocation.
3580 */
3581 LOOP_ALLOC_CHUNK,
3582
3583 /*
3584 * Ignore the size class restrictions for this allocation.
3585 */
3586 LOOP_WRONG_SIZE_CLASS,
3587
3588 /*
3589 * Ignore the empty size, only try to allocate the number of bytes
3590 * needed for this allocation.
3591 */
3592 LOOP_NO_EMPTY_SIZE,
3593 };
3594
3595 static inline void
btrfs_lock_block_group(struct btrfs_block_group * cache,int delalloc)3596 btrfs_lock_block_group(struct btrfs_block_group *cache,
3597 int delalloc)
3598 {
3599 if (delalloc)
3600 down_read(&cache->data_rwsem);
3601 }
3602
btrfs_grab_block_group(struct btrfs_block_group * cache,int delalloc)3603 static inline void btrfs_grab_block_group(struct btrfs_block_group *cache,
3604 int delalloc)
3605 {
3606 btrfs_get_block_group(cache);
3607 if (delalloc)
3608 down_read(&cache->data_rwsem);
3609 }
3610
btrfs_lock_cluster(struct btrfs_block_group * block_group,struct btrfs_free_cluster * cluster,int delalloc)3611 static struct btrfs_block_group *btrfs_lock_cluster(
3612 struct btrfs_block_group *block_group,
3613 struct btrfs_free_cluster *cluster,
3614 int delalloc)
3615 __acquires(&cluster->refill_lock)
3616 {
3617 struct btrfs_block_group *used_bg = NULL;
3618
3619 spin_lock(&cluster->refill_lock);
3620 while (1) {
3621 used_bg = cluster->block_group;
3622 if (!used_bg)
3623 return NULL;
3624
3625 if (used_bg == block_group)
3626 return used_bg;
3627
3628 btrfs_get_block_group(used_bg);
3629
3630 if (!delalloc)
3631 return used_bg;
3632
3633 if (down_read_trylock(&used_bg->data_rwsem))
3634 return used_bg;
3635
3636 spin_unlock(&cluster->refill_lock);
3637
3638 /* We should only have one-level nested. */
3639 down_read_nested(&used_bg->data_rwsem, SINGLE_DEPTH_NESTING);
3640
3641 spin_lock(&cluster->refill_lock);
3642 if (used_bg == cluster->block_group)
3643 return used_bg;
3644
3645 up_read(&used_bg->data_rwsem);
3646 btrfs_put_block_group(used_bg);
3647 }
3648 }
3649
3650 static inline void
btrfs_release_block_group(struct btrfs_block_group * cache,int delalloc)3651 btrfs_release_block_group(struct btrfs_block_group *cache,
3652 int delalloc)
3653 {
3654 if (delalloc)
3655 up_read(&cache->data_rwsem);
3656 btrfs_put_block_group(cache);
3657 }
3658
3659 /*
3660 * Helper function for find_free_extent().
3661 *
3662 * Return -ENOENT to inform caller that we need fallback to unclustered mode.
3663 * Return >0 to inform caller that we find nothing
3664 * Return 0 means we have found a location and set ffe_ctl->found_offset.
3665 */
find_free_extent_clustered(struct btrfs_block_group * bg,struct find_free_extent_ctl * ffe_ctl,struct btrfs_block_group ** cluster_bg_ret)3666 static int find_free_extent_clustered(struct btrfs_block_group *bg,
3667 struct find_free_extent_ctl *ffe_ctl,
3668 struct btrfs_block_group **cluster_bg_ret)
3669 {
3670 struct btrfs_block_group *cluster_bg;
3671 struct btrfs_free_cluster *last_ptr = ffe_ctl->last_ptr;
3672 u64 aligned_cluster;
3673 u64 offset;
3674 int ret;
3675
3676 cluster_bg = btrfs_lock_cluster(bg, last_ptr, ffe_ctl->delalloc);
3677 if (!cluster_bg)
3678 goto refill_cluster;
3679 if (cluster_bg != bg && (cluster_bg->ro ||
3680 !block_group_bits(cluster_bg, ffe_ctl->flags)))
3681 goto release_cluster;
3682
3683 offset = btrfs_alloc_from_cluster(cluster_bg, last_ptr,
3684 ffe_ctl->num_bytes, cluster_bg->start,
3685 &ffe_ctl->max_extent_size);
3686 if (offset) {
3687 /* We have a block, we're done */
3688 spin_unlock(&last_ptr->refill_lock);
3689 trace_btrfs_reserve_extent_cluster(cluster_bg, ffe_ctl);
3690 *cluster_bg_ret = cluster_bg;
3691 ffe_ctl->found_offset = offset;
3692 return 0;
3693 }
3694 WARN_ON(last_ptr->block_group != cluster_bg);
3695
3696 release_cluster:
3697 /*
3698 * If we are on LOOP_NO_EMPTY_SIZE, we can't set up a new clusters, so
3699 * lets just skip it and let the allocator find whatever block it can
3700 * find. If we reach this point, we will have tried the cluster
3701 * allocator plenty of times and not have found anything, so we are
3702 * likely way too fragmented for the clustering stuff to find anything.
3703 *
3704 * However, if the cluster is taken from the current block group,
3705 * release the cluster first, so that we stand a better chance of
3706 * succeeding in the unclustered allocation.
3707 */
3708 if (ffe_ctl->loop >= LOOP_NO_EMPTY_SIZE && cluster_bg != bg) {
3709 spin_unlock(&last_ptr->refill_lock);
3710 btrfs_release_block_group(cluster_bg, ffe_ctl->delalloc);
3711 return -ENOENT;
3712 }
3713
3714 /* This cluster didn't work out, free it and start over */
3715 btrfs_return_cluster_to_free_space(NULL, last_ptr);
3716
3717 if (cluster_bg != bg)
3718 btrfs_release_block_group(cluster_bg, ffe_ctl->delalloc);
3719
3720 refill_cluster:
3721 if (ffe_ctl->loop >= LOOP_NO_EMPTY_SIZE) {
3722 spin_unlock(&last_ptr->refill_lock);
3723 return -ENOENT;
3724 }
3725
3726 aligned_cluster = max_t(u64,
3727 ffe_ctl->empty_cluster + ffe_ctl->empty_size,
3728 bg->full_stripe_len);
3729 ret = btrfs_find_space_cluster(bg, last_ptr, ffe_ctl->search_start,
3730 ffe_ctl->num_bytes, aligned_cluster);
3731 if (ret == 0) {
3732 /* Now pull our allocation out of this cluster */
3733 offset = btrfs_alloc_from_cluster(bg, last_ptr,
3734 ffe_ctl->num_bytes, ffe_ctl->search_start,
3735 &ffe_ctl->max_extent_size);
3736 if (offset) {
3737 /* We found one, proceed */
3738 spin_unlock(&last_ptr->refill_lock);
3739 ffe_ctl->found_offset = offset;
3740 trace_btrfs_reserve_extent_cluster(bg, ffe_ctl);
3741 return 0;
3742 }
3743 }
3744 /*
3745 * At this point we either didn't find a cluster or we weren't able to
3746 * allocate a block from our cluster. Free the cluster we've been
3747 * trying to use, and go to the next block group.
3748 */
3749 btrfs_return_cluster_to_free_space(NULL, last_ptr);
3750 spin_unlock(&last_ptr->refill_lock);
3751 return 1;
3752 }
3753
3754 /*
3755 * Return >0 to inform caller that we find nothing
3756 * Return 0 when we found an free extent and set ffe_ctrl->found_offset
3757 */
find_free_extent_unclustered(struct btrfs_block_group * bg,struct find_free_extent_ctl * ffe_ctl)3758 static int find_free_extent_unclustered(struct btrfs_block_group *bg,
3759 struct find_free_extent_ctl *ffe_ctl)
3760 {
3761 struct btrfs_free_cluster *last_ptr = ffe_ctl->last_ptr;
3762 u64 offset;
3763
3764 /*
3765 * We are doing an unclustered allocation, set the fragmented flag so
3766 * we don't bother trying to setup a cluster again until we get more
3767 * space.
3768 */
3769 if (unlikely(last_ptr)) {
3770 spin_lock(&last_ptr->lock);
3771 last_ptr->fragmented = 1;
3772 spin_unlock(&last_ptr->lock);
3773 }
3774 if (ffe_ctl->cached) {
3775 struct btrfs_free_space_ctl *free_space_ctl;
3776
3777 free_space_ctl = bg->free_space_ctl;
3778 spin_lock(&free_space_ctl->tree_lock);
3779 if (free_space_ctl->free_space <
3780 ffe_ctl->num_bytes + ffe_ctl->empty_cluster +
3781 ffe_ctl->empty_size) {
3782 ffe_ctl->total_free_space = max_t(u64,
3783 ffe_ctl->total_free_space,
3784 free_space_ctl->free_space);
3785 spin_unlock(&free_space_ctl->tree_lock);
3786 return 1;
3787 }
3788 spin_unlock(&free_space_ctl->tree_lock);
3789 }
3790
3791 offset = btrfs_find_space_for_alloc(bg, ffe_ctl->search_start,
3792 ffe_ctl->num_bytes, ffe_ctl->empty_size,
3793 &ffe_ctl->max_extent_size);
3794 if (!offset)
3795 return 1;
3796 ffe_ctl->found_offset = offset;
3797 return 0;
3798 }
3799
do_allocation_clustered(struct btrfs_block_group * block_group,struct find_free_extent_ctl * ffe_ctl,struct btrfs_block_group ** bg_ret)3800 static int do_allocation_clustered(struct btrfs_block_group *block_group,
3801 struct find_free_extent_ctl *ffe_ctl,
3802 struct btrfs_block_group **bg_ret)
3803 {
3804 int ret;
3805
3806 /* We want to try and use the cluster allocator, so lets look there */
3807 if (ffe_ctl->last_ptr && ffe_ctl->use_cluster) {
3808 ret = find_free_extent_clustered(block_group, ffe_ctl, bg_ret);
3809 if (ret >= 0)
3810 return ret;
3811 /* ret == -ENOENT case falls through */
3812 }
3813
3814 return find_free_extent_unclustered(block_group, ffe_ctl);
3815 }
3816
3817 /*
3818 * Tree-log block group locking
3819 * ============================
3820 *
3821 * fs_info::treelog_bg_lock protects the fs_info::treelog_bg which
3822 * indicates the starting address of a block group, which is reserved only
3823 * for tree-log metadata.
3824 *
3825 * Lock nesting
3826 * ============
3827 *
3828 * space_info::lock
3829 * block_group::lock
3830 * fs_info::treelog_bg_lock
3831 */
3832
3833 /*
3834 * Simple allocator for sequential-only block group. It only allows sequential
3835 * allocation. No need to play with trees. This function also reserves the
3836 * bytes as in btrfs_add_reserved_bytes.
3837 */
do_allocation_zoned(struct btrfs_block_group * block_group,struct find_free_extent_ctl * ffe_ctl,struct btrfs_block_group ** bg_ret)3838 static int do_allocation_zoned(struct btrfs_block_group *block_group,
3839 struct find_free_extent_ctl *ffe_ctl,
3840 struct btrfs_block_group **bg_ret)
3841 {
3842 struct btrfs_fs_info *fs_info = block_group->fs_info;
3843 struct btrfs_space_info *space_info = block_group->space_info;
3844 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
3845 u64 start = block_group->start;
3846 u64 num_bytes = ffe_ctl->num_bytes;
3847 u64 avail;
3848 u64 bytenr = block_group->start;
3849 u64 log_bytenr;
3850 u64 data_reloc_bytenr;
3851 int ret = 0;
3852 bool skip = false;
3853
3854 ASSERT(btrfs_is_zoned(block_group->fs_info));
3855
3856 /*
3857 * Do not allow non-tree-log blocks in the dedicated tree-log block
3858 * group, and vice versa.
3859 */
3860 spin_lock(&fs_info->treelog_bg_lock);
3861 log_bytenr = fs_info->treelog_bg;
3862 if (log_bytenr && ((ffe_ctl->for_treelog && bytenr != log_bytenr) ||
3863 (!ffe_ctl->for_treelog && bytenr == log_bytenr)))
3864 skip = true;
3865 spin_unlock(&fs_info->treelog_bg_lock);
3866 if (skip)
3867 return 1;
3868
3869 /*
3870 * Do not allow non-relocation blocks in the dedicated relocation block
3871 * group, and vice versa.
3872 */
3873 spin_lock(&fs_info->relocation_bg_lock);
3874 data_reloc_bytenr = fs_info->data_reloc_bg;
3875 if (data_reloc_bytenr &&
3876 ((ffe_ctl->for_data_reloc && bytenr != data_reloc_bytenr) ||
3877 (!ffe_ctl->for_data_reloc && bytenr == data_reloc_bytenr)))
3878 skip = true;
3879 spin_unlock(&fs_info->relocation_bg_lock);
3880 if (skip)
3881 return 1;
3882
3883 /* Check RO and no space case before trying to activate it */
3884 spin_lock(&block_group->lock);
3885 if (block_group->ro || btrfs_zoned_bg_is_full(block_group)) {
3886 ret = 1;
3887 /*
3888 * May need to clear fs_info->{treelog,data_reloc}_bg.
3889 * Return the error after taking the locks.
3890 */
3891 }
3892 spin_unlock(&block_group->lock);
3893
3894 /* Metadata block group is activated at write time. */
3895 if (!ret && (block_group->flags & BTRFS_BLOCK_GROUP_DATA) &&
3896 !btrfs_zone_activate(block_group)) {
3897 ret = 1;
3898 /*
3899 * May need to clear fs_info->{treelog,data_reloc}_bg.
3900 * Return the error after taking the locks.
3901 */
3902 }
3903
3904 spin_lock(&space_info->lock);
3905 spin_lock(&block_group->lock);
3906 spin_lock(&fs_info->treelog_bg_lock);
3907 spin_lock(&fs_info->relocation_bg_lock);
3908
3909 if (ret)
3910 goto out;
3911
3912 ASSERT(!ffe_ctl->for_treelog ||
3913 block_group->start == fs_info->treelog_bg ||
3914 fs_info->treelog_bg == 0);
3915 ASSERT(!ffe_ctl->for_data_reloc ||
3916 block_group->start == fs_info->data_reloc_bg ||
3917 fs_info->data_reloc_bg == 0);
3918
3919 if (block_group->ro ||
3920 (!ffe_ctl->for_data_reloc &&
3921 test_bit(BLOCK_GROUP_FLAG_ZONED_DATA_RELOC, &block_group->runtime_flags))) {
3922 ret = 1;
3923 goto out;
3924 }
3925
3926 /*
3927 * Do not allow currently using block group to be tree-log dedicated
3928 * block group.
3929 */
3930 if (ffe_ctl->for_treelog && !fs_info->treelog_bg &&
3931 (block_group->used || block_group->reserved)) {
3932 ret = 1;
3933 goto out;
3934 }
3935
3936 /*
3937 * Do not allow currently used block group to be the data relocation
3938 * dedicated block group.
3939 */
3940 if (ffe_ctl->for_data_reloc && !fs_info->data_reloc_bg &&
3941 (block_group->used || block_group->reserved)) {
3942 ret = 1;
3943 goto out;
3944 }
3945
3946 WARN_ON_ONCE(block_group->alloc_offset > block_group->zone_capacity);
3947 avail = block_group->zone_capacity - block_group->alloc_offset;
3948 if (avail < num_bytes) {
3949 if (ffe_ctl->max_extent_size < avail) {
3950 /*
3951 * With sequential allocator, free space is always
3952 * contiguous
3953 */
3954 ffe_ctl->max_extent_size = avail;
3955 ffe_ctl->total_free_space = avail;
3956 }
3957 ret = 1;
3958 goto out;
3959 }
3960
3961 if (ffe_ctl->for_treelog && !fs_info->treelog_bg)
3962 fs_info->treelog_bg = block_group->start;
3963
3964 if (ffe_ctl->for_data_reloc) {
3965 if (!fs_info->data_reloc_bg)
3966 fs_info->data_reloc_bg = block_group->start;
3967 /*
3968 * Do not allow allocations from this block group, unless it is
3969 * for data relocation. Compared to increasing the ->ro, setting
3970 * the ->zoned_data_reloc_ongoing flag still allows nocow
3971 * writers to come in. See btrfs_inc_nocow_writers().
3972 *
3973 * We need to disable an allocation to avoid an allocation of
3974 * regular (non-relocation data) extent. With mix of relocation
3975 * extents and regular extents, we can dispatch WRITE commands
3976 * (for relocation extents) and ZONE APPEND commands (for
3977 * regular extents) at the same time to the same zone, which
3978 * easily break the write pointer.
3979 *
3980 * Also, this flag avoids this block group to be zone finished.
3981 */
3982 set_bit(BLOCK_GROUP_FLAG_ZONED_DATA_RELOC, &block_group->runtime_flags);
3983 }
3984
3985 ffe_ctl->found_offset = start + block_group->alloc_offset;
3986 block_group->alloc_offset += num_bytes;
3987 spin_lock(&ctl->tree_lock);
3988 ctl->free_space -= num_bytes;
3989 spin_unlock(&ctl->tree_lock);
3990
3991 /*
3992 * We do not check if found_offset is aligned to stripesize. The
3993 * address is anyway rewritten when using zone append writing.
3994 */
3995
3996 ffe_ctl->search_start = ffe_ctl->found_offset;
3997
3998 out:
3999 if (ret && ffe_ctl->for_treelog)
4000 fs_info->treelog_bg = 0;
4001 if (ret && ffe_ctl->for_data_reloc)
4002 fs_info->data_reloc_bg = 0;
4003 spin_unlock(&fs_info->relocation_bg_lock);
4004 spin_unlock(&fs_info->treelog_bg_lock);
4005 spin_unlock(&block_group->lock);
4006 spin_unlock(&space_info->lock);
4007 return ret;
4008 }
4009
do_allocation(struct btrfs_block_group * block_group,struct find_free_extent_ctl * ffe_ctl,struct btrfs_block_group ** bg_ret)4010 static int do_allocation(struct btrfs_block_group *block_group,
4011 struct find_free_extent_ctl *ffe_ctl,
4012 struct btrfs_block_group **bg_ret)
4013 {
4014 switch (ffe_ctl->policy) {
4015 case BTRFS_EXTENT_ALLOC_CLUSTERED:
4016 return do_allocation_clustered(block_group, ffe_ctl, bg_ret);
4017 case BTRFS_EXTENT_ALLOC_ZONED:
4018 return do_allocation_zoned(block_group, ffe_ctl, bg_ret);
4019 default:
4020 BUG();
4021 }
4022 }
4023
release_block_group(struct btrfs_block_group * block_group,struct find_free_extent_ctl * ffe_ctl,int delalloc)4024 static void release_block_group(struct btrfs_block_group *block_group,
4025 struct find_free_extent_ctl *ffe_ctl,
4026 int delalloc)
4027 {
4028 switch (ffe_ctl->policy) {
4029 case BTRFS_EXTENT_ALLOC_CLUSTERED:
4030 ffe_ctl->retry_uncached = false;
4031 break;
4032 case BTRFS_EXTENT_ALLOC_ZONED:
4033 /* Nothing to do */
4034 break;
4035 default:
4036 BUG();
4037 }
4038
4039 BUG_ON(btrfs_bg_flags_to_raid_index(block_group->flags) !=
4040 ffe_ctl->index);
4041 btrfs_release_block_group(block_group, delalloc);
4042 }
4043
found_extent_clustered(struct find_free_extent_ctl * ffe_ctl,struct btrfs_key * ins)4044 static void found_extent_clustered(struct find_free_extent_ctl *ffe_ctl,
4045 struct btrfs_key *ins)
4046 {
4047 struct btrfs_free_cluster *last_ptr = ffe_ctl->last_ptr;
4048
4049 if (!ffe_ctl->use_cluster && last_ptr) {
4050 spin_lock(&last_ptr->lock);
4051 last_ptr->window_start = ins->objectid;
4052 spin_unlock(&last_ptr->lock);
4053 }
4054 }
4055
found_extent(struct find_free_extent_ctl * ffe_ctl,struct btrfs_key * ins)4056 static void found_extent(struct find_free_extent_ctl *ffe_ctl,
4057 struct btrfs_key *ins)
4058 {
4059 switch (ffe_ctl->policy) {
4060 case BTRFS_EXTENT_ALLOC_CLUSTERED:
4061 found_extent_clustered(ffe_ctl, ins);
4062 break;
4063 case BTRFS_EXTENT_ALLOC_ZONED:
4064 /* Nothing to do */
4065 break;
4066 default:
4067 BUG();
4068 }
4069 }
4070
can_allocate_chunk_zoned(struct btrfs_fs_info * fs_info,struct find_free_extent_ctl * ffe_ctl)4071 static int can_allocate_chunk_zoned(struct btrfs_fs_info *fs_info,
4072 struct find_free_extent_ctl *ffe_ctl)
4073 {
4074 /* Block group's activeness is not a requirement for METADATA block groups. */
4075 if (!(ffe_ctl->flags & BTRFS_BLOCK_GROUP_DATA))
4076 return 0;
4077
4078 /* If we can activate new zone, just allocate a chunk and use it */
4079 if (btrfs_can_activate_zone(fs_info->fs_devices, ffe_ctl->flags))
4080 return 0;
4081
4082 /*
4083 * We already reached the max active zones. Try to finish one block
4084 * group to make a room for a new block group. This is only possible
4085 * for a data block group because btrfs_zone_finish() may need to wait
4086 * for a running transaction which can cause a deadlock for metadata
4087 * allocation.
4088 */
4089 if (ffe_ctl->flags & BTRFS_BLOCK_GROUP_DATA) {
4090 int ret = btrfs_zone_finish_one_bg(fs_info);
4091
4092 if (ret == 1)
4093 return 0;
4094 else if (ret < 0)
4095 return ret;
4096 }
4097
4098 /*
4099 * If we have enough free space left in an already active block group
4100 * and we can't activate any other zone now, do not allow allocating a
4101 * new chunk and let find_free_extent() retry with a smaller size.
4102 */
4103 if (ffe_ctl->max_extent_size >= ffe_ctl->min_alloc_size)
4104 return -ENOSPC;
4105
4106 /*
4107 * Even min_alloc_size is not left in any block groups. Since we cannot
4108 * activate a new block group, allocating it may not help. Let's tell a
4109 * caller to try again and hope it progress something by writing some
4110 * parts of the region. That is only possible for data block groups,
4111 * where a part of the region can be written.
4112 */
4113 if (ffe_ctl->flags & BTRFS_BLOCK_GROUP_DATA)
4114 return -EAGAIN;
4115
4116 /*
4117 * We cannot activate a new block group and no enough space left in any
4118 * block groups. So, allocating a new block group may not help. But,
4119 * there is nothing to do anyway, so let's go with it.
4120 */
4121 return 0;
4122 }
4123
can_allocate_chunk(struct btrfs_fs_info * fs_info,struct find_free_extent_ctl * ffe_ctl)4124 static int can_allocate_chunk(struct btrfs_fs_info *fs_info,
4125 struct find_free_extent_ctl *ffe_ctl)
4126 {
4127 switch (ffe_ctl->policy) {
4128 case BTRFS_EXTENT_ALLOC_CLUSTERED:
4129 return 0;
4130 case BTRFS_EXTENT_ALLOC_ZONED:
4131 return can_allocate_chunk_zoned(fs_info, ffe_ctl);
4132 default:
4133 BUG();
4134 }
4135 }
4136
4137 /*
4138 * Return >0 means caller needs to re-search for free extent
4139 * Return 0 means we have the needed free extent.
4140 * Return <0 means we failed to locate any free extent.
4141 */
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)4142 static int find_free_extent_update_loop(struct btrfs_fs_info *fs_info,
4143 struct btrfs_key *ins,
4144 struct find_free_extent_ctl *ffe_ctl,
4145 bool full_search)
4146 {
4147 struct btrfs_root *root = fs_info->chunk_root;
4148 int ret;
4149
4150 if ((ffe_ctl->loop == LOOP_CACHING_NOWAIT) &&
4151 ffe_ctl->have_caching_bg && !ffe_ctl->orig_have_caching_bg)
4152 ffe_ctl->orig_have_caching_bg = true;
4153
4154 if (ins->objectid) {
4155 found_extent(ffe_ctl, ins);
4156 return 0;
4157 }
4158
4159 if (ffe_ctl->loop >= LOOP_CACHING_WAIT && ffe_ctl->have_caching_bg)
4160 return 1;
4161
4162 ffe_ctl->index++;
4163 if (ffe_ctl->index < BTRFS_NR_RAID_TYPES)
4164 return 1;
4165
4166 /* See the comments for btrfs_loop_type for an explanation of the phases. */
4167 if (ffe_ctl->loop < LOOP_NO_EMPTY_SIZE) {
4168 ffe_ctl->index = 0;
4169 /*
4170 * We want to skip the LOOP_CACHING_WAIT step if we don't have
4171 * any uncached bgs and we've already done a full search
4172 * through.
4173 */
4174 if (ffe_ctl->loop == LOOP_CACHING_NOWAIT &&
4175 (!ffe_ctl->orig_have_caching_bg && full_search))
4176 ffe_ctl->loop++;
4177 ffe_ctl->loop++;
4178
4179 if (ffe_ctl->loop == LOOP_ALLOC_CHUNK) {
4180 struct btrfs_trans_handle *trans;
4181 int exist = 0;
4182
4183 /* Check if allocation policy allows to create a new chunk */
4184 ret = can_allocate_chunk(fs_info, ffe_ctl);
4185 if (ret)
4186 return ret;
4187
4188 trans = current->journal_info;
4189 if (trans)
4190 exist = 1;
4191 else
4192 trans = btrfs_join_transaction(root);
4193
4194 if (IS_ERR(trans)) {
4195 ret = PTR_ERR(trans);
4196 return ret;
4197 }
4198
4199 ret = btrfs_chunk_alloc(trans, ffe_ctl->flags,
4200 CHUNK_ALLOC_FORCE_FOR_EXTENT);
4201
4202 /* Do not bail out on ENOSPC since we can do more. */
4203 if (ret == -ENOSPC) {
4204 ret = 0;
4205 ffe_ctl->loop++;
4206 }
4207 else if (ret < 0)
4208 btrfs_abort_transaction(trans, ret);
4209 else
4210 ret = 0;
4211 if (!exist)
4212 btrfs_end_transaction(trans);
4213 if (ret)
4214 return ret;
4215 }
4216
4217 if (ffe_ctl->loop == LOOP_NO_EMPTY_SIZE) {
4218 if (ffe_ctl->policy != BTRFS_EXTENT_ALLOC_CLUSTERED)
4219 return -ENOSPC;
4220
4221 /*
4222 * Don't loop again if we already have no empty_size and
4223 * no empty_cluster.
4224 */
4225 if (ffe_ctl->empty_size == 0 &&
4226 ffe_ctl->empty_cluster == 0)
4227 return -ENOSPC;
4228 ffe_ctl->empty_size = 0;
4229 ffe_ctl->empty_cluster = 0;
4230 }
4231 return 1;
4232 }
4233 return -ENOSPC;
4234 }
4235
find_free_extent_check_size_class(struct find_free_extent_ctl * ffe_ctl,struct btrfs_block_group * bg)4236 static bool find_free_extent_check_size_class(struct find_free_extent_ctl *ffe_ctl,
4237 struct btrfs_block_group *bg)
4238 {
4239 if (ffe_ctl->policy == BTRFS_EXTENT_ALLOC_ZONED)
4240 return true;
4241 if (!btrfs_block_group_should_use_size_class(bg))
4242 return true;
4243 if (ffe_ctl->loop >= LOOP_WRONG_SIZE_CLASS)
4244 return true;
4245 if (ffe_ctl->loop >= LOOP_UNSET_SIZE_CLASS &&
4246 bg->size_class == BTRFS_BG_SZ_NONE)
4247 return true;
4248 return ffe_ctl->size_class == bg->size_class;
4249 }
4250
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)4251 static int prepare_allocation_clustered(struct btrfs_fs_info *fs_info,
4252 struct find_free_extent_ctl *ffe_ctl,
4253 struct btrfs_space_info *space_info,
4254 struct btrfs_key *ins)
4255 {
4256 /*
4257 * If our free space is heavily fragmented we may not be able to make
4258 * big contiguous allocations, so instead of doing the expensive search
4259 * for free space, simply return ENOSPC with our max_extent_size so we
4260 * can go ahead and search for a more manageable chunk.
4261 *
4262 * If our max_extent_size is large enough for our allocation simply
4263 * disable clustering since we will likely not be able to find enough
4264 * space to create a cluster and induce latency trying.
4265 */
4266 if (space_info->max_extent_size) {
4267 spin_lock(&space_info->lock);
4268 if (space_info->max_extent_size &&
4269 ffe_ctl->num_bytes > space_info->max_extent_size) {
4270 ins->offset = space_info->max_extent_size;
4271 spin_unlock(&space_info->lock);
4272 return -ENOSPC;
4273 } else if (space_info->max_extent_size) {
4274 ffe_ctl->use_cluster = false;
4275 }
4276 spin_unlock(&space_info->lock);
4277 }
4278
4279 ffe_ctl->last_ptr = fetch_cluster_info(fs_info, space_info,
4280 &ffe_ctl->empty_cluster);
4281 if (ffe_ctl->last_ptr) {
4282 struct btrfs_free_cluster *last_ptr = ffe_ctl->last_ptr;
4283
4284 spin_lock(&last_ptr->lock);
4285 if (last_ptr->block_group)
4286 ffe_ctl->hint_byte = last_ptr->window_start;
4287 if (last_ptr->fragmented) {
4288 /*
4289 * We still set window_start so we can keep track of the
4290 * last place we found an allocation to try and save
4291 * some time.
4292 */
4293 ffe_ctl->hint_byte = last_ptr->window_start;
4294 ffe_ctl->use_cluster = false;
4295 }
4296 spin_unlock(&last_ptr->lock);
4297 }
4298
4299 return 0;
4300 }
4301
prepare_allocation_zoned(struct btrfs_fs_info * fs_info,struct find_free_extent_ctl * ffe_ctl)4302 static int prepare_allocation_zoned(struct btrfs_fs_info *fs_info,
4303 struct find_free_extent_ctl *ffe_ctl)
4304 {
4305 if (ffe_ctl->for_treelog) {
4306 spin_lock(&fs_info->treelog_bg_lock);
4307 if (fs_info->treelog_bg)
4308 ffe_ctl->hint_byte = fs_info->treelog_bg;
4309 spin_unlock(&fs_info->treelog_bg_lock);
4310 } else if (ffe_ctl->for_data_reloc) {
4311 spin_lock(&fs_info->relocation_bg_lock);
4312 if (fs_info->data_reloc_bg)
4313 ffe_ctl->hint_byte = fs_info->data_reloc_bg;
4314 spin_unlock(&fs_info->relocation_bg_lock);
4315 } else if (ffe_ctl->flags & BTRFS_BLOCK_GROUP_DATA) {
4316 struct btrfs_block_group *block_group;
4317
4318 spin_lock(&fs_info->zone_active_bgs_lock);
4319 list_for_each_entry(block_group, &fs_info->zone_active_bgs, active_bg_list) {
4320 /*
4321 * No lock is OK here because avail is monotinically
4322 * decreasing, and this is just a hint.
4323 */
4324 u64 avail = block_group->zone_capacity - block_group->alloc_offset;
4325
4326 if (block_group_bits(block_group, ffe_ctl->flags) &&
4327 avail >= ffe_ctl->num_bytes) {
4328 ffe_ctl->hint_byte = block_group->start;
4329 break;
4330 }
4331 }
4332 spin_unlock(&fs_info->zone_active_bgs_lock);
4333 }
4334
4335 return 0;
4336 }
4337
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)4338 static int prepare_allocation(struct btrfs_fs_info *fs_info,
4339 struct find_free_extent_ctl *ffe_ctl,
4340 struct btrfs_space_info *space_info,
4341 struct btrfs_key *ins)
4342 {
4343 switch (ffe_ctl->policy) {
4344 case BTRFS_EXTENT_ALLOC_CLUSTERED:
4345 return prepare_allocation_clustered(fs_info, ffe_ctl,
4346 space_info, ins);
4347 case BTRFS_EXTENT_ALLOC_ZONED:
4348 return prepare_allocation_zoned(fs_info, ffe_ctl);
4349 default:
4350 BUG();
4351 }
4352 }
4353
4354 /*
4355 * walks the btree of allocated extents and find a hole of a given size.
4356 * The key ins is changed to record the hole:
4357 * ins->objectid == start position
4358 * ins->flags = BTRFS_EXTENT_ITEM_KEY
4359 * ins->offset == the size of the hole.
4360 * Any available blocks before search_start are skipped.
4361 *
4362 * If there is no suitable free space, we will record the max size of
4363 * the free space extent currently.
4364 *
4365 * The overall logic and call chain:
4366 *
4367 * find_free_extent()
4368 * |- Iterate through all block groups
4369 * | |- Get a valid block group
4370 * | |- Try to do clustered allocation in that block group
4371 * | |- Try to do unclustered allocation in that block group
4372 * | |- Check if the result is valid
4373 * | | |- If valid, then exit
4374 * | |- Jump to next block group
4375 * |
4376 * |- Push harder to find free extents
4377 * |- If not found, re-iterate all block groups
4378 */
find_free_extent(struct btrfs_root * root,struct btrfs_key * ins,struct find_free_extent_ctl * ffe_ctl)4379 static noinline int find_free_extent(struct btrfs_root *root,
4380 struct btrfs_key *ins,
4381 struct find_free_extent_ctl *ffe_ctl)
4382 {
4383 struct btrfs_fs_info *fs_info = root->fs_info;
4384 int ret = 0;
4385 int cache_block_group_error = 0;
4386 struct btrfs_block_group *block_group = NULL;
4387 struct btrfs_space_info *space_info;
4388 bool full_search = false;
4389
4390 WARN_ON(ffe_ctl->num_bytes < fs_info->sectorsize);
4391
4392 ffe_ctl->search_start = 0;
4393 /* For clustered allocation */
4394 ffe_ctl->empty_cluster = 0;
4395 ffe_ctl->last_ptr = NULL;
4396 ffe_ctl->use_cluster = true;
4397 ffe_ctl->have_caching_bg = false;
4398 ffe_ctl->orig_have_caching_bg = false;
4399 ffe_ctl->index = btrfs_bg_flags_to_raid_index(ffe_ctl->flags);
4400 ffe_ctl->loop = 0;
4401 ffe_ctl->retry_uncached = false;
4402 ffe_ctl->cached = 0;
4403 ffe_ctl->max_extent_size = 0;
4404 ffe_ctl->total_free_space = 0;
4405 ffe_ctl->found_offset = 0;
4406 ffe_ctl->policy = BTRFS_EXTENT_ALLOC_CLUSTERED;
4407 ffe_ctl->size_class = btrfs_calc_block_group_size_class(ffe_ctl->num_bytes);
4408
4409 if (btrfs_is_zoned(fs_info))
4410 ffe_ctl->policy = BTRFS_EXTENT_ALLOC_ZONED;
4411
4412 ins->type = BTRFS_EXTENT_ITEM_KEY;
4413 ins->objectid = 0;
4414 ins->offset = 0;
4415
4416 trace_find_free_extent(root, ffe_ctl);
4417
4418 space_info = btrfs_find_space_info(fs_info, ffe_ctl->flags);
4419 if (!space_info) {
4420 btrfs_err(fs_info, "No space info for %llu", ffe_ctl->flags);
4421 return -ENOSPC;
4422 }
4423
4424 ret = prepare_allocation(fs_info, ffe_ctl, space_info, ins);
4425 if (ret < 0)
4426 return ret;
4427
4428 ffe_ctl->search_start = max(ffe_ctl->search_start,
4429 first_logical_byte(fs_info));
4430 ffe_ctl->search_start = max(ffe_ctl->search_start, ffe_ctl->hint_byte);
4431 if (ffe_ctl->search_start == ffe_ctl->hint_byte) {
4432 block_group = btrfs_lookup_block_group(fs_info,
4433 ffe_ctl->search_start);
4434 /*
4435 * we don't want to use the block group if it doesn't match our
4436 * allocation bits, or if its not cached.
4437 *
4438 * However if we are re-searching with an ideal block group
4439 * picked out then we don't care that the block group is cached.
4440 */
4441 if (block_group && block_group_bits(block_group, ffe_ctl->flags) &&
4442 block_group->cached != BTRFS_CACHE_NO) {
4443 down_read(&space_info->groups_sem);
4444 if (list_empty(&block_group->list) ||
4445 block_group->ro) {
4446 /*
4447 * someone is removing this block group,
4448 * we can't jump into the have_block_group
4449 * target because our list pointers are not
4450 * valid
4451 */
4452 btrfs_put_block_group(block_group);
4453 up_read(&space_info->groups_sem);
4454 } else {
4455 ffe_ctl->index = btrfs_bg_flags_to_raid_index(
4456 block_group->flags);
4457 btrfs_lock_block_group(block_group,
4458 ffe_ctl->delalloc);
4459 ffe_ctl->hinted = true;
4460 goto have_block_group;
4461 }
4462 } else if (block_group) {
4463 btrfs_put_block_group(block_group);
4464 }
4465 }
4466 search:
4467 trace_find_free_extent_search_loop(root, ffe_ctl);
4468 ffe_ctl->have_caching_bg = false;
4469 if (ffe_ctl->index == btrfs_bg_flags_to_raid_index(ffe_ctl->flags) ||
4470 ffe_ctl->index == 0)
4471 full_search = true;
4472 down_read(&space_info->groups_sem);
4473 list_for_each_entry(block_group,
4474 &space_info->block_groups[ffe_ctl->index], list) {
4475 struct btrfs_block_group *bg_ret;
4476
4477 ffe_ctl->hinted = false;
4478 /* If the block group is read-only, we can skip it entirely. */
4479 if (unlikely(block_group->ro)) {
4480 if (ffe_ctl->for_treelog)
4481 btrfs_clear_treelog_bg(block_group);
4482 if (ffe_ctl->for_data_reloc)
4483 btrfs_clear_data_reloc_bg(block_group);
4484 continue;
4485 }
4486
4487 btrfs_grab_block_group(block_group, ffe_ctl->delalloc);
4488 ffe_ctl->search_start = block_group->start;
4489
4490 /*
4491 * this can happen if we end up cycling through all the
4492 * raid types, but we want to make sure we only allocate
4493 * for the proper type.
4494 */
4495 if (!block_group_bits(block_group, ffe_ctl->flags)) {
4496 u64 extra = BTRFS_BLOCK_GROUP_DUP |
4497 BTRFS_BLOCK_GROUP_RAID1_MASK |
4498 BTRFS_BLOCK_GROUP_RAID56_MASK |
4499 BTRFS_BLOCK_GROUP_RAID10;
4500
4501 /*
4502 * if they asked for extra copies and this block group
4503 * doesn't provide them, bail. This does allow us to
4504 * fill raid0 from raid1.
4505 */
4506 if ((ffe_ctl->flags & extra) && !(block_group->flags & extra))
4507 goto loop;
4508
4509 /*
4510 * This block group has different flags than we want.
4511 * It's possible that we have MIXED_GROUP flag but no
4512 * block group is mixed. Just skip such block group.
4513 */
4514 btrfs_release_block_group(block_group, ffe_ctl->delalloc);
4515 continue;
4516 }
4517
4518 have_block_group:
4519 trace_find_free_extent_have_block_group(root, ffe_ctl, block_group);
4520 ffe_ctl->cached = btrfs_block_group_done(block_group);
4521 if (unlikely(!ffe_ctl->cached)) {
4522 ffe_ctl->have_caching_bg = true;
4523 ret = btrfs_cache_block_group(block_group, false);
4524
4525 /*
4526 * If we get ENOMEM here or something else we want to
4527 * try other block groups, because it may not be fatal.
4528 * However if we can't find anything else we need to
4529 * save our return here so that we return the actual
4530 * error that caused problems, not ENOSPC.
4531 */
4532 if (ret < 0) {
4533 if (!cache_block_group_error)
4534 cache_block_group_error = ret;
4535 ret = 0;
4536 goto loop;
4537 }
4538 ret = 0;
4539 }
4540
4541 if (unlikely(block_group->cached == BTRFS_CACHE_ERROR)) {
4542 if (!cache_block_group_error)
4543 cache_block_group_error = -EIO;
4544 goto loop;
4545 }
4546
4547 if (!find_free_extent_check_size_class(ffe_ctl, block_group))
4548 goto loop;
4549
4550 bg_ret = NULL;
4551 ret = do_allocation(block_group, ffe_ctl, &bg_ret);
4552 if (ret > 0)
4553 goto loop;
4554
4555 if (bg_ret && bg_ret != block_group) {
4556 btrfs_release_block_group(block_group, ffe_ctl->delalloc);
4557 block_group = bg_ret;
4558 }
4559
4560 /* Checks */
4561 ffe_ctl->search_start = round_up(ffe_ctl->found_offset,
4562 fs_info->stripesize);
4563
4564 /* move on to the next group */
4565 if (ffe_ctl->search_start + ffe_ctl->num_bytes >
4566 block_group->start + block_group->length) {
4567 btrfs_add_free_space_unused(block_group,
4568 ffe_ctl->found_offset,
4569 ffe_ctl->num_bytes);
4570 goto loop;
4571 }
4572
4573 if (ffe_ctl->found_offset < ffe_ctl->search_start)
4574 btrfs_add_free_space_unused(block_group,
4575 ffe_ctl->found_offset,
4576 ffe_ctl->search_start - ffe_ctl->found_offset);
4577
4578 ret = btrfs_add_reserved_bytes(block_group, ffe_ctl->ram_bytes,
4579 ffe_ctl->num_bytes,
4580 ffe_ctl->delalloc,
4581 ffe_ctl->loop >= LOOP_WRONG_SIZE_CLASS);
4582 if (ret == -EAGAIN) {
4583 btrfs_add_free_space_unused(block_group,
4584 ffe_ctl->found_offset,
4585 ffe_ctl->num_bytes);
4586 goto loop;
4587 }
4588 btrfs_inc_block_group_reservations(block_group);
4589
4590 /* we are all good, lets return */
4591 ins->objectid = ffe_ctl->search_start;
4592 ins->offset = ffe_ctl->num_bytes;
4593
4594 trace_btrfs_reserve_extent(block_group, ffe_ctl);
4595 btrfs_release_block_group(block_group, ffe_ctl->delalloc);
4596 break;
4597 loop:
4598 if (!ffe_ctl->cached && ffe_ctl->loop > LOOP_CACHING_NOWAIT &&
4599 !ffe_ctl->retry_uncached) {
4600 ffe_ctl->retry_uncached = true;
4601 btrfs_wait_block_group_cache_progress(block_group,
4602 ffe_ctl->num_bytes +
4603 ffe_ctl->empty_cluster +
4604 ffe_ctl->empty_size);
4605 goto have_block_group;
4606 }
4607 release_block_group(block_group, ffe_ctl, ffe_ctl->delalloc);
4608 cond_resched();
4609 }
4610 up_read(&space_info->groups_sem);
4611
4612 ret = find_free_extent_update_loop(fs_info, ins, ffe_ctl, full_search);
4613 if (ret > 0)
4614 goto search;
4615
4616 if (ret == -ENOSPC && !cache_block_group_error) {
4617 /*
4618 * Use ffe_ctl->total_free_space as fallback if we can't find
4619 * any contiguous hole.
4620 */
4621 if (!ffe_ctl->max_extent_size)
4622 ffe_ctl->max_extent_size = ffe_ctl->total_free_space;
4623 spin_lock(&space_info->lock);
4624 space_info->max_extent_size = ffe_ctl->max_extent_size;
4625 spin_unlock(&space_info->lock);
4626 ins->offset = ffe_ctl->max_extent_size;
4627 } else if (ret == -ENOSPC) {
4628 ret = cache_block_group_error;
4629 }
4630 return ret;
4631 }
4632
4633 /*
4634 * Entry point to the extent allocator. Tries to find a hole that is at least
4635 * as big as @num_bytes.
4636 *
4637 * @root - The root that will contain this extent
4638 *
4639 * @ram_bytes - The amount of space in ram that @num_bytes take. This
4640 * is used for accounting purposes. This value differs
4641 * from @num_bytes only in the case of compressed extents.
4642 *
4643 * @num_bytes - Number of bytes to allocate on-disk.
4644 *
4645 * @min_alloc_size - Indicates the minimum amount of space that the
4646 * allocator should try to satisfy. In some cases
4647 * @num_bytes may be larger than what is required and if
4648 * the filesystem is fragmented then allocation fails.
4649 * However, the presence of @min_alloc_size gives a
4650 * chance to try and satisfy the smaller allocation.
4651 *
4652 * @empty_size - A hint that you plan on doing more COW. This is the
4653 * size in bytes the allocator should try to find free
4654 * next to the block it returns. This is just a hint and
4655 * may be ignored by the allocator.
4656 *
4657 * @hint_byte - Hint to the allocator to start searching above the byte
4658 * address passed. It might be ignored.
4659 *
4660 * @ins - This key is modified to record the found hole. It will
4661 * have the following values:
4662 * ins->objectid == start position
4663 * ins->flags = BTRFS_EXTENT_ITEM_KEY
4664 * ins->offset == the size of the hole.
4665 *
4666 * @is_data - Boolean flag indicating whether an extent is
4667 * allocated for data (true) or metadata (false)
4668 *
4669 * @delalloc - Boolean flag indicating whether this allocation is for
4670 * delalloc or not. If 'true' data_rwsem of block groups
4671 * is going to be acquired.
4672 *
4673 *
4674 * Returns 0 when an allocation succeeded or < 0 when an error occurred. In
4675 * case -ENOSPC is returned then @ins->offset will contain the size of the
4676 * largest available hole the allocator managed to find.
4677 */
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)4678 int btrfs_reserve_extent(struct btrfs_root *root, u64 ram_bytes,
4679 u64 num_bytes, u64 min_alloc_size,
4680 u64 empty_size, u64 hint_byte,
4681 struct btrfs_key *ins, int is_data, int delalloc)
4682 {
4683 struct btrfs_fs_info *fs_info = root->fs_info;
4684 struct find_free_extent_ctl ffe_ctl = {};
4685 bool final_tried = num_bytes == min_alloc_size;
4686 u64 flags;
4687 int ret;
4688 bool for_treelog = (root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID);
4689 bool for_data_reloc = (btrfs_is_data_reloc_root(root) && is_data);
4690
4691 flags = get_alloc_profile_by_root(root, is_data);
4692 again:
4693 WARN_ON(num_bytes < fs_info->sectorsize);
4694
4695 ffe_ctl.ram_bytes = ram_bytes;
4696 ffe_ctl.num_bytes = num_bytes;
4697 ffe_ctl.min_alloc_size = min_alloc_size;
4698 ffe_ctl.empty_size = empty_size;
4699 ffe_ctl.flags = flags;
4700 ffe_ctl.delalloc = delalloc;
4701 ffe_ctl.hint_byte = hint_byte;
4702 ffe_ctl.for_treelog = for_treelog;
4703 ffe_ctl.for_data_reloc = for_data_reloc;
4704
4705 ret = find_free_extent(root, ins, &ffe_ctl);
4706 if (!ret && !is_data) {
4707 btrfs_dec_block_group_reservations(fs_info, ins->objectid);
4708 } else if (ret == -ENOSPC) {
4709 if (!final_tried && ins->offset) {
4710 num_bytes = min(num_bytes >> 1, ins->offset);
4711 num_bytes = round_down(num_bytes,
4712 fs_info->sectorsize);
4713 num_bytes = max(num_bytes, min_alloc_size);
4714 ram_bytes = num_bytes;
4715 if (num_bytes == min_alloc_size)
4716 final_tried = true;
4717 goto again;
4718 } else if (btrfs_test_opt(fs_info, ENOSPC_DEBUG)) {
4719 struct btrfs_space_info *sinfo;
4720
4721 sinfo = btrfs_find_space_info(fs_info, flags);
4722 btrfs_err(fs_info,
4723 "allocation failed flags %llu, wanted %llu tree-log %d, relocation: %d",
4724 flags, num_bytes, for_treelog, for_data_reloc);
4725 if (sinfo)
4726 btrfs_dump_space_info(fs_info, sinfo,
4727 num_bytes, 1);
4728 }
4729 }
4730
4731 return ret;
4732 }
4733
btrfs_free_reserved_extent(struct btrfs_fs_info * fs_info,u64 start,u64 len,int delalloc)4734 int btrfs_free_reserved_extent(struct btrfs_fs_info *fs_info,
4735 u64 start, u64 len, int delalloc)
4736 {
4737 struct btrfs_block_group *cache;
4738
4739 cache = btrfs_lookup_block_group(fs_info, start);
4740 if (!cache) {
4741 btrfs_err(fs_info, "Unable to find block group for %llu",
4742 start);
4743 return -ENOSPC;
4744 }
4745
4746 btrfs_add_free_space(cache, start, len);
4747 btrfs_free_reserved_bytes(cache, len, delalloc);
4748 trace_btrfs_reserved_extent_free(fs_info, start, len);
4749
4750 btrfs_put_block_group(cache);
4751 return 0;
4752 }
4753
btrfs_pin_reserved_extent(struct btrfs_trans_handle * trans,const struct extent_buffer * eb)4754 int btrfs_pin_reserved_extent(struct btrfs_trans_handle *trans,
4755 const struct extent_buffer *eb)
4756 {
4757 struct btrfs_block_group *cache;
4758 int ret = 0;
4759
4760 cache = btrfs_lookup_block_group(trans->fs_info, eb->start);
4761 if (!cache) {
4762 btrfs_err(trans->fs_info, "unable to find block group for %llu",
4763 eb->start);
4764 return -ENOSPC;
4765 }
4766
4767 ret = pin_down_extent(trans, cache, eb->start, eb->len, 1);
4768 btrfs_put_block_group(cache);
4769 return ret;
4770 }
4771
alloc_reserved_extent(struct btrfs_trans_handle * trans,u64 bytenr,u64 num_bytes)4772 static int alloc_reserved_extent(struct btrfs_trans_handle *trans, u64 bytenr,
4773 u64 num_bytes)
4774 {
4775 struct btrfs_fs_info *fs_info = trans->fs_info;
4776 int ret;
4777
4778 ret = remove_from_free_space_tree(trans, bytenr, num_bytes);
4779 if (ret)
4780 return ret;
4781
4782 ret = btrfs_update_block_group(trans, bytenr, num_bytes, true);
4783 if (ret) {
4784 ASSERT(!ret);
4785 btrfs_err(fs_info, "update block group failed for %llu %llu",
4786 bytenr, num_bytes);
4787 return ret;
4788 }
4789
4790 trace_btrfs_reserved_extent_alloc(fs_info, bytenr, num_bytes);
4791 return 0;
4792 }
4793
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,u64 oref_root)4794 static int alloc_reserved_file_extent(struct btrfs_trans_handle *trans,
4795 u64 parent, u64 root_objectid,
4796 u64 flags, u64 owner, u64 offset,
4797 struct btrfs_key *ins, int ref_mod, u64 oref_root)
4798 {
4799 struct btrfs_fs_info *fs_info = trans->fs_info;
4800 struct btrfs_root *extent_root;
4801 int ret;
4802 struct btrfs_extent_item *extent_item;
4803 struct btrfs_extent_owner_ref *oref;
4804 struct btrfs_extent_inline_ref *iref;
4805 struct btrfs_path *path;
4806 struct extent_buffer *leaf;
4807 int type;
4808 u32 size;
4809 const bool simple_quota = (btrfs_qgroup_mode(fs_info) == BTRFS_QGROUP_MODE_SIMPLE);
4810
4811 if (parent > 0)
4812 type = BTRFS_SHARED_DATA_REF_KEY;
4813 else
4814 type = BTRFS_EXTENT_DATA_REF_KEY;
4815
4816 size = sizeof(*extent_item);
4817 if (simple_quota)
4818 size += btrfs_extent_inline_ref_size(BTRFS_EXTENT_OWNER_REF_KEY);
4819 size += btrfs_extent_inline_ref_size(type);
4820
4821 path = btrfs_alloc_path();
4822 if (!path)
4823 return -ENOMEM;
4824
4825 extent_root = btrfs_extent_root(fs_info, ins->objectid);
4826 ret = btrfs_insert_empty_item(trans, extent_root, path, ins, size);
4827 if (ret) {
4828 btrfs_free_path(path);
4829 return ret;
4830 }
4831
4832 leaf = path->nodes[0];
4833 extent_item = btrfs_item_ptr(leaf, path->slots[0],
4834 struct btrfs_extent_item);
4835 btrfs_set_extent_refs(leaf, extent_item, ref_mod);
4836 btrfs_set_extent_generation(leaf, extent_item, trans->transid);
4837 btrfs_set_extent_flags(leaf, extent_item,
4838 flags | BTRFS_EXTENT_FLAG_DATA);
4839
4840 iref = (struct btrfs_extent_inline_ref *)(extent_item + 1);
4841 if (simple_quota) {
4842 btrfs_set_extent_inline_ref_type(leaf, iref, BTRFS_EXTENT_OWNER_REF_KEY);
4843 oref = (struct btrfs_extent_owner_ref *)(&iref->offset);
4844 btrfs_set_extent_owner_ref_root_id(leaf, oref, oref_root);
4845 iref = (struct btrfs_extent_inline_ref *)(oref + 1);
4846 }
4847 btrfs_set_extent_inline_ref_type(leaf, iref, type);
4848
4849 if (parent > 0) {
4850 struct btrfs_shared_data_ref *ref;
4851 ref = (struct btrfs_shared_data_ref *)(iref + 1);
4852 btrfs_set_extent_inline_ref_offset(leaf, iref, parent);
4853 btrfs_set_shared_data_ref_count(leaf, ref, ref_mod);
4854 } else {
4855 struct btrfs_extent_data_ref *ref;
4856 ref = (struct btrfs_extent_data_ref *)(&iref->offset);
4857 btrfs_set_extent_data_ref_root(leaf, ref, root_objectid);
4858 btrfs_set_extent_data_ref_objectid(leaf, ref, owner);
4859 btrfs_set_extent_data_ref_offset(leaf, ref, offset);
4860 btrfs_set_extent_data_ref_count(leaf, ref, ref_mod);
4861 }
4862
4863 btrfs_mark_buffer_dirty(trans, path->nodes[0]);
4864 btrfs_free_path(path);
4865
4866 return alloc_reserved_extent(trans, ins->objectid, ins->offset);
4867 }
4868
alloc_reserved_tree_block(struct btrfs_trans_handle * trans,struct btrfs_delayed_ref_node * node,struct btrfs_delayed_extent_op * extent_op)4869 static int alloc_reserved_tree_block(struct btrfs_trans_handle *trans,
4870 struct btrfs_delayed_ref_node *node,
4871 struct btrfs_delayed_extent_op *extent_op)
4872 {
4873 struct btrfs_fs_info *fs_info = trans->fs_info;
4874 struct btrfs_root *extent_root;
4875 int ret;
4876 struct btrfs_extent_item *extent_item;
4877 struct btrfs_key extent_key;
4878 struct btrfs_tree_block_info *block_info;
4879 struct btrfs_extent_inline_ref *iref;
4880 struct btrfs_path *path;
4881 struct extent_buffer *leaf;
4882 struct btrfs_delayed_tree_ref *ref;
4883 u32 size = sizeof(*extent_item) + sizeof(*iref);
4884 u64 flags = extent_op->flags_to_set;
4885 bool skinny_metadata = btrfs_fs_incompat(fs_info, SKINNY_METADATA);
4886
4887 ref = btrfs_delayed_node_to_tree_ref(node);
4888
4889 extent_key.objectid = node->bytenr;
4890 if (skinny_metadata) {
4891 extent_key.offset = ref->level;
4892 extent_key.type = BTRFS_METADATA_ITEM_KEY;
4893 } else {
4894 extent_key.offset = node->num_bytes;
4895 extent_key.type = BTRFS_EXTENT_ITEM_KEY;
4896 size += sizeof(*block_info);
4897 }
4898
4899 path = btrfs_alloc_path();
4900 if (!path)
4901 return -ENOMEM;
4902
4903 extent_root = btrfs_extent_root(fs_info, extent_key.objectid);
4904 ret = btrfs_insert_empty_item(trans, extent_root, path, &extent_key,
4905 size);
4906 if (ret) {
4907 btrfs_free_path(path);
4908 return ret;
4909 }
4910
4911 leaf = path->nodes[0];
4912 extent_item = btrfs_item_ptr(leaf, path->slots[0],
4913 struct btrfs_extent_item);
4914 btrfs_set_extent_refs(leaf, extent_item, 1);
4915 btrfs_set_extent_generation(leaf, extent_item, trans->transid);
4916 btrfs_set_extent_flags(leaf, extent_item,
4917 flags | BTRFS_EXTENT_FLAG_TREE_BLOCK);
4918
4919 if (skinny_metadata) {
4920 iref = (struct btrfs_extent_inline_ref *)(extent_item + 1);
4921 } else {
4922 block_info = (struct btrfs_tree_block_info *)(extent_item + 1);
4923 btrfs_set_tree_block_key(leaf, block_info, &extent_op->key);
4924 btrfs_set_tree_block_level(leaf, block_info, ref->level);
4925 iref = (struct btrfs_extent_inline_ref *)(block_info + 1);
4926 }
4927
4928 if (node->type == BTRFS_SHARED_BLOCK_REF_KEY) {
4929 btrfs_set_extent_inline_ref_type(leaf, iref,
4930 BTRFS_SHARED_BLOCK_REF_KEY);
4931 btrfs_set_extent_inline_ref_offset(leaf, iref, ref->parent);
4932 } else {
4933 btrfs_set_extent_inline_ref_type(leaf, iref,
4934 BTRFS_TREE_BLOCK_REF_KEY);
4935 btrfs_set_extent_inline_ref_offset(leaf, iref, ref->root);
4936 }
4937
4938 btrfs_mark_buffer_dirty(trans, leaf);
4939 btrfs_free_path(path);
4940
4941 return alloc_reserved_extent(trans, node->bytenr, fs_info->nodesize);
4942 }
4943
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)4944 int btrfs_alloc_reserved_file_extent(struct btrfs_trans_handle *trans,
4945 struct btrfs_root *root, u64 owner,
4946 u64 offset, u64 ram_bytes,
4947 struct btrfs_key *ins)
4948 {
4949 struct btrfs_ref generic_ref = { 0 };
4950 u64 root_objectid = root->root_key.objectid;
4951 u64 owning_root = root_objectid;
4952
4953 BUG_ON(root_objectid == BTRFS_TREE_LOG_OBJECTID);
4954
4955 if (btrfs_is_data_reloc_root(root) && is_fstree(root->relocation_src_root))
4956 owning_root = root->relocation_src_root;
4957
4958 btrfs_init_generic_ref(&generic_ref, BTRFS_ADD_DELAYED_EXTENT,
4959 ins->objectid, ins->offset, 0, owning_root);
4960 btrfs_init_data_ref(&generic_ref, root_objectid, owner,
4961 offset, 0, false);
4962 btrfs_ref_tree_mod(root->fs_info, &generic_ref);
4963
4964 return btrfs_add_delayed_data_ref(trans, &generic_ref, ram_bytes);
4965 }
4966
4967 /*
4968 * this is used by the tree logging recovery code. It records that
4969 * an extent has been allocated and makes sure to clear the free
4970 * space cache bits as well
4971 */
btrfs_alloc_logged_file_extent(struct btrfs_trans_handle * trans,u64 root_objectid,u64 owner,u64 offset,struct btrfs_key * ins)4972 int btrfs_alloc_logged_file_extent(struct btrfs_trans_handle *trans,
4973 u64 root_objectid, u64 owner, u64 offset,
4974 struct btrfs_key *ins)
4975 {
4976 struct btrfs_fs_info *fs_info = trans->fs_info;
4977 int ret;
4978 struct btrfs_block_group *block_group;
4979 struct btrfs_space_info *space_info;
4980 struct btrfs_squota_delta delta = {
4981 .root = root_objectid,
4982 .num_bytes = ins->offset,
4983 .generation = trans->transid,
4984 .is_data = true,
4985 .is_inc = true,
4986 };
4987
4988 /*
4989 * Mixed block groups will exclude before processing the log so we only
4990 * need to do the exclude dance if this fs isn't mixed.
4991 */
4992 if (!btrfs_fs_incompat(fs_info, MIXED_GROUPS)) {
4993 ret = __exclude_logged_extent(fs_info, ins->objectid,
4994 ins->offset);
4995 if (ret)
4996 return ret;
4997 }
4998
4999 block_group = btrfs_lookup_block_group(fs_info, ins->objectid);
5000 if (!block_group)
5001 return -EINVAL;
5002
5003 space_info = block_group->space_info;
5004 spin_lock(&space_info->lock);
5005 spin_lock(&block_group->lock);
5006 space_info->bytes_reserved += ins->offset;
5007 block_group->reserved += ins->offset;
5008 spin_unlock(&block_group->lock);
5009 spin_unlock(&space_info->lock);
5010
5011 ret = alloc_reserved_file_extent(trans, 0, root_objectid, 0, owner,
5012 offset, ins, 1, root_objectid);
5013 if (ret)
5014 btrfs_pin_extent(trans, ins->objectid, ins->offset, 1);
5015 ret = btrfs_record_squota_delta(fs_info, &delta);
5016 btrfs_put_block_group(block_group);
5017 return ret;
5018 }
5019
5020 #ifdef CONFIG_BTRFS_DEBUG
5021 /*
5022 * Extra safety check in case the extent tree is corrupted and extent allocator
5023 * chooses to use a tree block which is already used and locked.
5024 */
check_eb_lock_owner(const struct extent_buffer * eb)5025 static bool check_eb_lock_owner(const struct extent_buffer *eb)
5026 {
5027 if (eb->lock_owner == current->pid) {
5028 btrfs_err_rl(eb->fs_info,
5029 "tree block %llu owner %llu already locked by pid=%d, extent tree corruption detected",
5030 eb->start, btrfs_header_owner(eb), current->pid);
5031 return true;
5032 }
5033 return false;
5034 }
5035 #else
check_eb_lock_owner(struct extent_buffer * eb)5036 static bool check_eb_lock_owner(struct extent_buffer *eb)
5037 {
5038 return false;
5039 }
5040 #endif
5041
5042 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)5043 btrfs_init_new_buffer(struct btrfs_trans_handle *trans, struct btrfs_root *root,
5044 u64 bytenr, int level, u64 owner,
5045 enum btrfs_lock_nesting nest)
5046 {
5047 struct btrfs_fs_info *fs_info = root->fs_info;
5048 struct extent_buffer *buf;
5049 u64 lockdep_owner = owner;
5050
5051 buf = btrfs_find_create_tree_block(fs_info, bytenr, owner, level);
5052 if (IS_ERR(buf))
5053 return buf;
5054
5055 if (check_eb_lock_owner(buf)) {
5056 free_extent_buffer(buf);
5057 return ERR_PTR(-EUCLEAN);
5058 }
5059
5060 /*
5061 * The reloc trees are just snapshots, so we need them to appear to be
5062 * just like any other fs tree WRT lockdep.
5063 *
5064 * The exception however is in replace_path() in relocation, where we
5065 * hold the lock on the original fs root and then search for the reloc
5066 * root. At that point we need to make sure any reloc root buffers are
5067 * set to the BTRFS_TREE_RELOC_OBJECTID lockdep class in order to make
5068 * lockdep happy.
5069 */
5070 if (lockdep_owner == BTRFS_TREE_RELOC_OBJECTID &&
5071 !test_bit(BTRFS_ROOT_RESET_LOCKDEP_CLASS, &root->state))
5072 lockdep_owner = BTRFS_FS_TREE_OBJECTID;
5073
5074 /* btrfs_clear_buffer_dirty() accesses generation field. */
5075 btrfs_set_header_generation(buf, trans->transid);
5076
5077 /*
5078 * This needs to stay, because we could allocate a freed block from an
5079 * old tree into a new tree, so we need to make sure this new block is
5080 * set to the appropriate level and owner.
5081 */
5082 btrfs_set_buffer_lockdep_class(lockdep_owner, buf, level);
5083
5084 __btrfs_tree_lock(buf, nest);
5085 btrfs_clear_buffer_dirty(trans, buf);
5086 clear_bit(EXTENT_BUFFER_STALE, &buf->bflags);
5087 clear_bit(EXTENT_BUFFER_ZONED_ZEROOUT, &buf->bflags);
5088
5089 set_extent_buffer_uptodate(buf);
5090
5091 memzero_extent_buffer(buf, 0, sizeof(struct btrfs_header));
5092 btrfs_set_header_level(buf, level);
5093 btrfs_set_header_bytenr(buf, buf->start);
5094 btrfs_set_header_generation(buf, trans->transid);
5095 btrfs_set_header_backref_rev(buf, BTRFS_MIXED_BACKREF_REV);
5096 btrfs_set_header_owner(buf, owner);
5097 write_extent_buffer_fsid(buf, fs_info->fs_devices->metadata_uuid);
5098 write_extent_buffer_chunk_tree_uuid(buf, fs_info->chunk_tree_uuid);
5099 if (root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID) {
5100 buf->log_index = root->log_transid % 2;
5101 /*
5102 * we allow two log transactions at a time, use different
5103 * EXTENT bit to differentiate dirty pages.
5104 */
5105 if (buf->log_index == 0)
5106 set_extent_bit(&root->dirty_log_pages, buf->start,
5107 buf->start + buf->len - 1,
5108 EXTENT_DIRTY, NULL);
5109 else
5110 set_extent_bit(&root->dirty_log_pages, buf->start,
5111 buf->start + buf->len - 1,
5112 EXTENT_NEW, NULL);
5113 } else {
5114 buf->log_index = -1;
5115 set_extent_bit(&trans->transaction->dirty_pages, buf->start,
5116 buf->start + buf->len - 1, EXTENT_DIRTY, NULL);
5117 }
5118 /* this returns a buffer locked for blocking */
5119 return buf;
5120 }
5121
5122 /*
5123 * finds a free extent and does all the dirty work required for allocation
5124 * returns the tree buffer or an ERR_PTR on error.
5125 */
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,u64 reloc_src_root,enum btrfs_lock_nesting nest)5126 struct extent_buffer *btrfs_alloc_tree_block(struct btrfs_trans_handle *trans,
5127 struct btrfs_root *root,
5128 u64 parent, u64 root_objectid,
5129 const struct btrfs_disk_key *key,
5130 int level, u64 hint,
5131 u64 empty_size,
5132 u64 reloc_src_root,
5133 enum btrfs_lock_nesting nest)
5134 {
5135 struct btrfs_fs_info *fs_info = root->fs_info;
5136 struct btrfs_key ins;
5137 struct btrfs_block_rsv *block_rsv;
5138 struct extent_buffer *buf;
5139 struct btrfs_delayed_extent_op *extent_op;
5140 struct btrfs_ref generic_ref = { 0 };
5141 u64 flags = 0;
5142 int ret;
5143 u32 blocksize = fs_info->nodesize;
5144 bool skinny_metadata = btrfs_fs_incompat(fs_info, SKINNY_METADATA);
5145 u64 owning_root;
5146
5147 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
5148 if (btrfs_is_testing(fs_info)) {
5149 buf = btrfs_init_new_buffer(trans, root, root->alloc_bytenr,
5150 level, root_objectid, nest);
5151 if (!IS_ERR(buf))
5152 root->alloc_bytenr += blocksize;
5153 return buf;
5154 }
5155 #endif
5156
5157 block_rsv = btrfs_use_block_rsv(trans, root, blocksize);
5158 if (IS_ERR(block_rsv))
5159 return ERR_CAST(block_rsv);
5160
5161 ret = btrfs_reserve_extent(root, blocksize, blocksize, blocksize,
5162 empty_size, hint, &ins, 0, 0);
5163 if (ret)
5164 goto out_unuse;
5165
5166 buf = btrfs_init_new_buffer(trans, root, ins.objectid, level,
5167 root_objectid, nest);
5168 if (IS_ERR(buf)) {
5169 ret = PTR_ERR(buf);
5170 goto out_free_reserved;
5171 }
5172 owning_root = btrfs_header_owner(buf);
5173
5174 if (root_objectid == BTRFS_TREE_RELOC_OBJECTID) {
5175 if (parent == 0)
5176 parent = ins.objectid;
5177 flags |= BTRFS_BLOCK_FLAG_FULL_BACKREF;
5178 owning_root = reloc_src_root;
5179 } else
5180 BUG_ON(parent > 0);
5181
5182 if (root_objectid != BTRFS_TREE_LOG_OBJECTID) {
5183 extent_op = btrfs_alloc_delayed_extent_op();
5184 if (!extent_op) {
5185 ret = -ENOMEM;
5186 goto out_free_buf;
5187 }
5188 if (key)
5189 memcpy(&extent_op->key, key, sizeof(extent_op->key));
5190 else
5191 memset(&extent_op->key, 0, sizeof(extent_op->key));
5192 extent_op->flags_to_set = flags;
5193 extent_op->update_key = skinny_metadata ? false : true;
5194 extent_op->update_flags = true;
5195 extent_op->level = level;
5196
5197 btrfs_init_generic_ref(&generic_ref, BTRFS_ADD_DELAYED_EXTENT,
5198 ins.objectid, ins.offset, parent, owning_root);
5199 btrfs_init_tree_ref(&generic_ref, level, root_objectid,
5200 root->root_key.objectid, false);
5201 btrfs_ref_tree_mod(fs_info, &generic_ref);
5202 ret = btrfs_add_delayed_tree_ref(trans, &generic_ref, extent_op);
5203 if (ret)
5204 goto out_free_delayed;
5205 }
5206 return buf;
5207
5208 out_free_delayed:
5209 btrfs_free_delayed_extent_op(extent_op);
5210 out_free_buf:
5211 btrfs_tree_unlock(buf);
5212 free_extent_buffer(buf);
5213 out_free_reserved:
5214 btrfs_free_reserved_extent(fs_info, ins.objectid, ins.offset, 0);
5215 out_unuse:
5216 btrfs_unuse_block_rsv(fs_info, block_rsv, blocksize);
5217 return ERR_PTR(ret);
5218 }
5219
5220 struct walk_control {
5221 u64 refs[BTRFS_MAX_LEVEL];
5222 u64 flags[BTRFS_MAX_LEVEL];
5223 struct btrfs_key update_progress;
5224 struct btrfs_key drop_progress;
5225 int drop_level;
5226 int stage;
5227 int level;
5228 int shared_level;
5229 int update_ref;
5230 int keep_locks;
5231 int reada_slot;
5232 int reada_count;
5233 int restarted;
5234 };
5235
5236 #define DROP_REFERENCE 1
5237 #define UPDATE_BACKREF 2
5238
reada_walk_down(struct btrfs_trans_handle * trans,struct btrfs_root * root,struct walk_control * wc,struct btrfs_path * path)5239 static noinline void reada_walk_down(struct btrfs_trans_handle *trans,
5240 struct btrfs_root *root,
5241 struct walk_control *wc,
5242 struct btrfs_path *path)
5243 {
5244 struct btrfs_fs_info *fs_info = root->fs_info;
5245 u64 bytenr;
5246 u64 generation;
5247 u64 refs;
5248 u64 flags;
5249 u32 nritems;
5250 struct btrfs_key key;
5251 struct extent_buffer *eb;
5252 int ret;
5253 int slot;
5254 int nread = 0;
5255
5256 if (path->slots[wc->level] < wc->reada_slot) {
5257 wc->reada_count = wc->reada_count * 2 / 3;
5258 wc->reada_count = max(wc->reada_count, 2);
5259 } else {
5260 wc->reada_count = wc->reada_count * 3 / 2;
5261 wc->reada_count = min_t(int, wc->reada_count,
5262 BTRFS_NODEPTRS_PER_BLOCK(fs_info));
5263 }
5264
5265 eb = path->nodes[wc->level];
5266 nritems = btrfs_header_nritems(eb);
5267
5268 for (slot = path->slots[wc->level]; slot < nritems; slot++) {
5269 if (nread >= wc->reada_count)
5270 break;
5271
5272 cond_resched();
5273 bytenr = btrfs_node_blockptr(eb, slot);
5274 generation = btrfs_node_ptr_generation(eb, slot);
5275
5276 if (slot == path->slots[wc->level])
5277 goto reada;
5278
5279 if (wc->stage == UPDATE_BACKREF &&
5280 generation <= root->root_key.offset)
5281 continue;
5282
5283 /* We don't lock the tree block, it's OK to be racy here */
5284 ret = btrfs_lookup_extent_info(trans, fs_info, bytenr,
5285 wc->level - 1, 1, &refs,
5286 &flags, NULL);
5287 /* We don't care about errors in readahead. */
5288 if (ret < 0)
5289 continue;
5290 BUG_ON(refs == 0);
5291
5292 if (wc->stage == DROP_REFERENCE) {
5293 if (refs == 1)
5294 goto reada;
5295
5296 if (wc->level == 1 &&
5297 (flags & BTRFS_BLOCK_FLAG_FULL_BACKREF))
5298 continue;
5299 if (!wc->update_ref ||
5300 generation <= root->root_key.offset)
5301 continue;
5302 btrfs_node_key_to_cpu(eb, &key, slot);
5303 ret = btrfs_comp_cpu_keys(&key,
5304 &wc->update_progress);
5305 if (ret < 0)
5306 continue;
5307 } else {
5308 if (wc->level == 1 &&
5309 (flags & BTRFS_BLOCK_FLAG_FULL_BACKREF))
5310 continue;
5311 }
5312 reada:
5313 btrfs_readahead_node_child(eb, slot);
5314 nread++;
5315 }
5316 wc->reada_slot = slot;
5317 }
5318
5319 /*
5320 * helper to process tree block while walking down the tree.
5321 *
5322 * when wc->stage == UPDATE_BACKREF, this function updates
5323 * back refs for pointers in the block.
5324 *
5325 * NOTE: return value 1 means we should stop walking down.
5326 */
walk_down_proc(struct btrfs_trans_handle * trans,struct btrfs_root * root,struct btrfs_path * path,struct walk_control * wc,int lookup_info)5327 static noinline int walk_down_proc(struct btrfs_trans_handle *trans,
5328 struct btrfs_root *root,
5329 struct btrfs_path *path,
5330 struct walk_control *wc, int lookup_info)
5331 {
5332 struct btrfs_fs_info *fs_info = root->fs_info;
5333 int level = wc->level;
5334 struct extent_buffer *eb = path->nodes[level];
5335 u64 flag = BTRFS_BLOCK_FLAG_FULL_BACKREF;
5336 int ret;
5337
5338 if (wc->stage == UPDATE_BACKREF &&
5339 btrfs_header_owner(eb) != root->root_key.objectid)
5340 return 1;
5341
5342 /*
5343 * when reference count of tree block is 1, it won't increase
5344 * again. once full backref flag is set, we never clear it.
5345 */
5346 if (lookup_info &&
5347 ((wc->stage == DROP_REFERENCE && wc->refs[level] != 1) ||
5348 (wc->stage == UPDATE_BACKREF && !(wc->flags[level] & flag)))) {
5349 BUG_ON(!path->locks[level]);
5350 ret = btrfs_lookup_extent_info(trans, fs_info,
5351 eb->start, level, 1,
5352 &wc->refs[level],
5353 &wc->flags[level],
5354 NULL);
5355 BUG_ON(ret == -ENOMEM);
5356 if (ret)
5357 return ret;
5358 BUG_ON(wc->refs[level] == 0);
5359 }
5360
5361 if (wc->stage == DROP_REFERENCE) {
5362 if (wc->refs[level] > 1)
5363 return 1;
5364
5365 if (path->locks[level] && !wc->keep_locks) {
5366 btrfs_tree_unlock_rw(eb, path->locks[level]);
5367 path->locks[level] = 0;
5368 }
5369 return 0;
5370 }
5371
5372 /* wc->stage == UPDATE_BACKREF */
5373 if (!(wc->flags[level] & flag)) {
5374 BUG_ON(!path->locks[level]);
5375 ret = btrfs_inc_ref(trans, root, eb, 1);
5376 BUG_ON(ret); /* -ENOMEM */
5377 ret = btrfs_dec_ref(trans, root, eb, 0);
5378 BUG_ON(ret); /* -ENOMEM */
5379 ret = btrfs_set_disk_extent_flags(trans, eb, flag);
5380 BUG_ON(ret); /* -ENOMEM */
5381 wc->flags[level] |= flag;
5382 }
5383
5384 /*
5385 * the block is shared by multiple trees, so it's not good to
5386 * keep the tree lock
5387 */
5388 if (path->locks[level] && level > 0) {
5389 btrfs_tree_unlock_rw(eb, path->locks[level]);
5390 path->locks[level] = 0;
5391 }
5392 return 0;
5393 }
5394
5395 /*
5396 * This is used to verify a ref exists for this root to deal with a bug where we
5397 * would have a drop_progress key that hadn't been updated properly.
5398 */
check_ref_exists(struct btrfs_trans_handle * trans,struct btrfs_root * root,u64 bytenr,u64 parent,int level)5399 static int check_ref_exists(struct btrfs_trans_handle *trans,
5400 struct btrfs_root *root, u64 bytenr, u64 parent,
5401 int level)
5402 {
5403 struct btrfs_path *path;
5404 struct btrfs_extent_inline_ref *iref;
5405 int ret;
5406
5407 path = btrfs_alloc_path();
5408 if (!path)
5409 return -ENOMEM;
5410
5411 ret = lookup_extent_backref(trans, path, &iref, bytenr,
5412 root->fs_info->nodesize, parent,
5413 root->root_key.objectid, level, 0);
5414 btrfs_free_path(path);
5415 if (ret == -ENOENT)
5416 return 0;
5417 if (ret < 0)
5418 return ret;
5419 return 1;
5420 }
5421
5422 /*
5423 * helper to process tree block pointer.
5424 *
5425 * when wc->stage == DROP_REFERENCE, this function checks
5426 * reference count of the block pointed to. if the block
5427 * is shared and we need update back refs for the subtree
5428 * rooted at the block, this function changes wc->stage to
5429 * UPDATE_BACKREF. if the block is shared and there is no
5430 * need to update back, this function drops the reference
5431 * to the block.
5432 *
5433 * NOTE: return value 1 means we should stop walking down.
5434 */
do_walk_down(struct btrfs_trans_handle * trans,struct btrfs_root * root,struct btrfs_path * path,struct walk_control * wc,int * lookup_info)5435 static noinline int do_walk_down(struct btrfs_trans_handle *trans,
5436 struct btrfs_root *root,
5437 struct btrfs_path *path,
5438 struct walk_control *wc, int *lookup_info)
5439 {
5440 struct btrfs_fs_info *fs_info = root->fs_info;
5441 u64 bytenr;
5442 u64 generation;
5443 u64 parent;
5444 u64 owner_root = 0;
5445 struct btrfs_tree_parent_check check = { 0 };
5446 struct btrfs_key key;
5447 struct btrfs_ref ref = { 0 };
5448 struct extent_buffer *next;
5449 int level = wc->level;
5450 int reada = 0;
5451 int ret = 0;
5452 bool need_account = false;
5453
5454 generation = btrfs_node_ptr_generation(path->nodes[level],
5455 path->slots[level]);
5456 /*
5457 * if the lower level block was created before the snapshot
5458 * was created, we know there is no need to update back refs
5459 * for the subtree
5460 */
5461 if (wc->stage == UPDATE_BACKREF &&
5462 generation <= root->root_key.offset) {
5463 *lookup_info = 1;
5464 return 1;
5465 }
5466
5467 bytenr = btrfs_node_blockptr(path->nodes[level], path->slots[level]);
5468
5469 check.level = level - 1;
5470 check.transid = generation;
5471 check.owner_root = root->root_key.objectid;
5472 check.has_first_key = true;
5473 btrfs_node_key_to_cpu(path->nodes[level], &check.first_key,
5474 path->slots[level]);
5475
5476 next = find_extent_buffer(fs_info, bytenr);
5477 if (!next) {
5478 next = btrfs_find_create_tree_block(fs_info, bytenr,
5479 root->root_key.objectid, level - 1);
5480 if (IS_ERR(next))
5481 return PTR_ERR(next);
5482 reada = 1;
5483 }
5484 btrfs_tree_lock(next);
5485
5486 ret = btrfs_lookup_extent_info(trans, fs_info, bytenr, level - 1, 1,
5487 &wc->refs[level - 1],
5488 &wc->flags[level - 1],
5489 &owner_root);
5490 if (ret < 0)
5491 goto out_unlock;
5492
5493 if (unlikely(wc->refs[level - 1] == 0)) {
5494 btrfs_err(fs_info, "Missing references.");
5495 ret = -EIO;
5496 goto out_unlock;
5497 }
5498 *lookup_info = 0;
5499
5500 if (wc->stage == DROP_REFERENCE) {
5501 if (wc->refs[level - 1] > 1) {
5502 need_account = true;
5503 if (level == 1 &&
5504 (wc->flags[0] & BTRFS_BLOCK_FLAG_FULL_BACKREF))
5505 goto skip;
5506
5507 if (!wc->update_ref ||
5508 generation <= root->root_key.offset)
5509 goto skip;
5510
5511 btrfs_node_key_to_cpu(path->nodes[level], &key,
5512 path->slots[level]);
5513 ret = btrfs_comp_cpu_keys(&key, &wc->update_progress);
5514 if (ret < 0)
5515 goto skip;
5516
5517 wc->stage = UPDATE_BACKREF;
5518 wc->shared_level = level - 1;
5519 }
5520 } else {
5521 if (level == 1 &&
5522 (wc->flags[0] & BTRFS_BLOCK_FLAG_FULL_BACKREF))
5523 goto skip;
5524 }
5525
5526 if (!btrfs_buffer_uptodate(next, generation, 0)) {
5527 btrfs_tree_unlock(next);
5528 free_extent_buffer(next);
5529 next = NULL;
5530 *lookup_info = 1;
5531 }
5532
5533 if (!next) {
5534 if (reada && level == 1)
5535 reada_walk_down(trans, root, wc, path);
5536 next = read_tree_block(fs_info, bytenr, &check);
5537 if (IS_ERR(next)) {
5538 return PTR_ERR(next);
5539 } else if (!extent_buffer_uptodate(next)) {
5540 free_extent_buffer(next);
5541 return -EIO;
5542 }
5543 btrfs_tree_lock(next);
5544 }
5545
5546 level--;
5547 ASSERT(level == btrfs_header_level(next));
5548 if (level != btrfs_header_level(next)) {
5549 btrfs_err(root->fs_info, "mismatched level");
5550 ret = -EIO;
5551 goto out_unlock;
5552 }
5553 path->nodes[level] = next;
5554 path->slots[level] = 0;
5555 path->locks[level] = BTRFS_WRITE_LOCK;
5556 wc->level = level;
5557 if (wc->level == 1)
5558 wc->reada_slot = 0;
5559 return 0;
5560 skip:
5561 wc->refs[level - 1] = 0;
5562 wc->flags[level - 1] = 0;
5563 if (wc->stage == DROP_REFERENCE) {
5564 if (wc->flags[level] & BTRFS_BLOCK_FLAG_FULL_BACKREF) {
5565 parent = path->nodes[level]->start;
5566 } else {
5567 ASSERT(root->root_key.objectid ==
5568 btrfs_header_owner(path->nodes[level]));
5569 if (root->root_key.objectid !=
5570 btrfs_header_owner(path->nodes[level])) {
5571 btrfs_err(root->fs_info,
5572 "mismatched block owner");
5573 ret = -EIO;
5574 goto out_unlock;
5575 }
5576 parent = 0;
5577 }
5578
5579 /*
5580 * If we had a drop_progress we need to verify the refs are set
5581 * as expected. If we find our ref then we know that from here
5582 * on out everything should be correct, and we can clear the
5583 * ->restarted flag.
5584 */
5585 if (wc->restarted) {
5586 ret = check_ref_exists(trans, root, bytenr, parent,
5587 level - 1);
5588 if (ret < 0)
5589 goto out_unlock;
5590 if (ret == 0)
5591 goto no_delete;
5592 ret = 0;
5593 wc->restarted = 0;
5594 }
5595
5596 /*
5597 * Reloc tree doesn't contribute to qgroup numbers, and we have
5598 * already accounted them at merge time (replace_path),
5599 * thus we could skip expensive subtree trace here.
5600 */
5601 if (root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID &&
5602 need_account) {
5603 ret = btrfs_qgroup_trace_subtree(trans, next,
5604 generation, level - 1);
5605 if (ret) {
5606 btrfs_err_rl(fs_info,
5607 "Error %d accounting shared subtree. Quota is out of sync, rescan required.",
5608 ret);
5609 }
5610 }
5611
5612 /*
5613 * We need to update the next key in our walk control so we can
5614 * update the drop_progress key accordingly. We don't care if
5615 * find_next_key doesn't find a key because that means we're at
5616 * the end and are going to clean up now.
5617 */
5618 wc->drop_level = level;
5619 find_next_key(path, level, &wc->drop_progress);
5620
5621 btrfs_init_generic_ref(&ref, BTRFS_DROP_DELAYED_REF, bytenr,
5622 fs_info->nodesize, parent, owner_root);
5623 btrfs_init_tree_ref(&ref, level - 1, root->root_key.objectid,
5624 0, false);
5625 ret = btrfs_free_extent(trans, &ref);
5626 if (ret)
5627 goto out_unlock;
5628 }
5629 no_delete:
5630 *lookup_info = 1;
5631 ret = 1;
5632
5633 out_unlock:
5634 btrfs_tree_unlock(next);
5635 free_extent_buffer(next);
5636
5637 return ret;
5638 }
5639
5640 /*
5641 * helper to process tree block while walking up the tree.
5642 *
5643 * when wc->stage == DROP_REFERENCE, this function drops
5644 * reference count on the block.
5645 *
5646 * when wc->stage == UPDATE_BACKREF, this function changes
5647 * wc->stage back to DROP_REFERENCE if we changed wc->stage
5648 * to UPDATE_BACKREF previously while processing the block.
5649 *
5650 * NOTE: return value 1 means we should stop walking up.
5651 */
walk_up_proc(struct btrfs_trans_handle * trans,struct btrfs_root * root,struct btrfs_path * path,struct walk_control * wc)5652 static noinline int walk_up_proc(struct btrfs_trans_handle *trans,
5653 struct btrfs_root *root,
5654 struct btrfs_path *path,
5655 struct walk_control *wc)
5656 {
5657 struct btrfs_fs_info *fs_info = root->fs_info;
5658 int ret;
5659 int level = wc->level;
5660 struct extent_buffer *eb = path->nodes[level];
5661 u64 parent = 0;
5662
5663 if (wc->stage == UPDATE_BACKREF) {
5664 BUG_ON(wc->shared_level < level);
5665 if (level < wc->shared_level)
5666 goto out;
5667
5668 ret = find_next_key(path, level + 1, &wc->update_progress);
5669 if (ret > 0)
5670 wc->update_ref = 0;
5671
5672 wc->stage = DROP_REFERENCE;
5673 wc->shared_level = -1;
5674 path->slots[level] = 0;
5675
5676 /*
5677 * check reference count again if the block isn't locked.
5678 * we should start walking down the tree again if reference
5679 * count is one.
5680 */
5681 if (!path->locks[level]) {
5682 BUG_ON(level == 0);
5683 btrfs_tree_lock(eb);
5684 path->locks[level] = BTRFS_WRITE_LOCK;
5685
5686 ret = btrfs_lookup_extent_info(trans, fs_info,
5687 eb->start, level, 1,
5688 &wc->refs[level],
5689 &wc->flags[level],
5690 NULL);
5691 if (ret < 0) {
5692 btrfs_tree_unlock_rw(eb, path->locks[level]);
5693 path->locks[level] = 0;
5694 return ret;
5695 }
5696 BUG_ON(wc->refs[level] == 0);
5697 if (wc->refs[level] == 1) {
5698 btrfs_tree_unlock_rw(eb, path->locks[level]);
5699 path->locks[level] = 0;
5700 return 1;
5701 }
5702 }
5703 }
5704
5705 /* wc->stage == DROP_REFERENCE */
5706 BUG_ON(wc->refs[level] > 1 && !path->locks[level]);
5707
5708 if (wc->refs[level] == 1) {
5709 if (level == 0) {
5710 if (wc->flags[level] & BTRFS_BLOCK_FLAG_FULL_BACKREF)
5711 ret = btrfs_dec_ref(trans, root, eb, 1);
5712 else
5713 ret = btrfs_dec_ref(trans, root, eb, 0);
5714 BUG_ON(ret); /* -ENOMEM */
5715 if (is_fstree(root->root_key.objectid)) {
5716 ret = btrfs_qgroup_trace_leaf_items(trans, eb);
5717 if (ret) {
5718 btrfs_err_rl(fs_info,
5719 "error %d accounting leaf items, quota is out of sync, rescan required",
5720 ret);
5721 }
5722 }
5723 }
5724 /* Make block locked assertion in btrfs_clear_buffer_dirty happy. */
5725 if (!path->locks[level]) {
5726 btrfs_tree_lock(eb);
5727 path->locks[level] = BTRFS_WRITE_LOCK;
5728 }
5729 btrfs_clear_buffer_dirty(trans, eb);
5730 }
5731
5732 if (eb == root->node) {
5733 if (wc->flags[level] & BTRFS_BLOCK_FLAG_FULL_BACKREF)
5734 parent = eb->start;
5735 else if (root->root_key.objectid != btrfs_header_owner(eb))
5736 goto owner_mismatch;
5737 } else {
5738 if (wc->flags[level + 1] & BTRFS_BLOCK_FLAG_FULL_BACKREF)
5739 parent = path->nodes[level + 1]->start;
5740 else if (root->root_key.objectid !=
5741 btrfs_header_owner(path->nodes[level + 1]))
5742 goto owner_mismatch;
5743 }
5744
5745 btrfs_free_tree_block(trans, btrfs_root_id(root), eb, parent,
5746 wc->refs[level] == 1);
5747 out:
5748 wc->refs[level] = 0;
5749 wc->flags[level] = 0;
5750 return 0;
5751
5752 owner_mismatch:
5753 btrfs_err_rl(fs_info, "unexpected tree owner, have %llu expect %llu",
5754 btrfs_header_owner(eb), root->root_key.objectid);
5755 return -EUCLEAN;
5756 }
5757
walk_down_tree(struct btrfs_trans_handle * trans,struct btrfs_root * root,struct btrfs_path * path,struct walk_control * wc)5758 static noinline int walk_down_tree(struct btrfs_trans_handle *trans,
5759 struct btrfs_root *root,
5760 struct btrfs_path *path,
5761 struct walk_control *wc)
5762 {
5763 int level = wc->level;
5764 int lookup_info = 1;
5765 int ret = 0;
5766
5767 while (level >= 0) {
5768 ret = walk_down_proc(trans, root, path, wc, lookup_info);
5769 if (ret)
5770 break;
5771
5772 if (level == 0)
5773 break;
5774
5775 if (path->slots[level] >=
5776 btrfs_header_nritems(path->nodes[level]))
5777 break;
5778
5779 ret = do_walk_down(trans, root, path, wc, &lookup_info);
5780 if (ret > 0) {
5781 path->slots[level]++;
5782 continue;
5783 } else if (ret < 0)
5784 break;
5785 level = wc->level;
5786 }
5787 return (ret == 1) ? 0 : ret;
5788 }
5789
walk_up_tree(struct btrfs_trans_handle * trans,struct btrfs_root * root,struct btrfs_path * path,struct walk_control * wc,int max_level)5790 static noinline int walk_up_tree(struct btrfs_trans_handle *trans,
5791 struct btrfs_root *root,
5792 struct btrfs_path *path,
5793 struct walk_control *wc, int max_level)
5794 {
5795 int level = wc->level;
5796 int ret;
5797
5798 path->slots[level] = btrfs_header_nritems(path->nodes[level]);
5799 while (level < max_level && path->nodes[level]) {
5800 wc->level = level;
5801 if (path->slots[level] + 1 <
5802 btrfs_header_nritems(path->nodes[level])) {
5803 path->slots[level]++;
5804 return 0;
5805 } else {
5806 ret = walk_up_proc(trans, root, path, wc);
5807 if (ret > 0)
5808 return 0;
5809 if (ret < 0)
5810 return ret;
5811
5812 if (path->locks[level]) {
5813 btrfs_tree_unlock_rw(path->nodes[level],
5814 path->locks[level]);
5815 path->locks[level] = 0;
5816 }
5817 free_extent_buffer(path->nodes[level]);
5818 path->nodes[level] = NULL;
5819 level++;
5820 }
5821 }
5822 return 1;
5823 }
5824
5825 /*
5826 * drop a subvolume tree.
5827 *
5828 * this function traverses the tree freeing any blocks that only
5829 * referenced by the tree.
5830 *
5831 * when a shared tree block is found. this function decreases its
5832 * reference count by one. if update_ref is true, this function
5833 * also make sure backrefs for the shared block and all lower level
5834 * blocks are properly updated.
5835 *
5836 * If called with for_reloc == 0, may exit early with -EAGAIN
5837 */
btrfs_drop_snapshot(struct btrfs_root * root,int update_ref,int for_reloc)5838 int btrfs_drop_snapshot(struct btrfs_root *root, int update_ref, int for_reloc)
5839 {
5840 const bool is_reloc_root = (root->root_key.objectid ==
5841 BTRFS_TREE_RELOC_OBJECTID);
5842 struct btrfs_fs_info *fs_info = root->fs_info;
5843 struct btrfs_path *path;
5844 struct btrfs_trans_handle *trans;
5845 struct btrfs_root *tree_root = fs_info->tree_root;
5846 struct btrfs_root_item *root_item = &root->root_item;
5847 struct walk_control *wc;
5848 struct btrfs_key key;
5849 int err = 0;
5850 int ret;
5851 int level;
5852 bool root_dropped = false;
5853 bool unfinished_drop = false;
5854
5855 btrfs_debug(fs_info, "Drop subvolume %llu", root->root_key.objectid);
5856
5857 path = btrfs_alloc_path();
5858 if (!path) {
5859 err = -ENOMEM;
5860 goto out;
5861 }
5862
5863 wc = kzalloc(sizeof(*wc), GFP_NOFS);
5864 if (!wc) {
5865 btrfs_free_path(path);
5866 err = -ENOMEM;
5867 goto out;
5868 }
5869
5870 /*
5871 * Use join to avoid potential EINTR from transaction start. See
5872 * wait_reserve_ticket and the whole reservation callchain.
5873 */
5874 if (for_reloc)
5875 trans = btrfs_join_transaction(tree_root);
5876 else
5877 trans = btrfs_start_transaction(tree_root, 0);
5878 if (IS_ERR(trans)) {
5879 err = PTR_ERR(trans);
5880 goto out_free;
5881 }
5882
5883 err = btrfs_run_delayed_items(trans);
5884 if (err)
5885 goto out_end_trans;
5886
5887 /*
5888 * This will help us catch people modifying the fs tree while we're
5889 * dropping it. It is unsafe to mess with the fs tree while it's being
5890 * dropped as we unlock the root node and parent nodes as we walk down
5891 * the tree, assuming nothing will change. If something does change
5892 * then we'll have stale information and drop references to blocks we've
5893 * already dropped.
5894 */
5895 set_bit(BTRFS_ROOT_DELETING, &root->state);
5896 unfinished_drop = test_bit(BTRFS_ROOT_UNFINISHED_DROP, &root->state);
5897
5898 if (btrfs_disk_key_objectid(&root_item->drop_progress) == 0) {
5899 level = btrfs_header_level(root->node);
5900 path->nodes[level] = btrfs_lock_root_node(root);
5901 path->slots[level] = 0;
5902 path->locks[level] = BTRFS_WRITE_LOCK;
5903 memset(&wc->update_progress, 0,
5904 sizeof(wc->update_progress));
5905 } else {
5906 btrfs_disk_key_to_cpu(&key, &root_item->drop_progress);
5907 memcpy(&wc->update_progress, &key,
5908 sizeof(wc->update_progress));
5909
5910 level = btrfs_root_drop_level(root_item);
5911 BUG_ON(level == 0);
5912 path->lowest_level = level;
5913 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
5914 path->lowest_level = 0;
5915 if (ret < 0) {
5916 err = ret;
5917 goto out_end_trans;
5918 }
5919 WARN_ON(ret > 0);
5920
5921 /*
5922 * unlock our path, this is safe because only this
5923 * function is allowed to delete this snapshot
5924 */
5925 btrfs_unlock_up_safe(path, 0);
5926
5927 level = btrfs_header_level(root->node);
5928 while (1) {
5929 btrfs_tree_lock(path->nodes[level]);
5930 path->locks[level] = BTRFS_WRITE_LOCK;
5931
5932 ret = btrfs_lookup_extent_info(trans, fs_info,
5933 path->nodes[level]->start,
5934 level, 1, &wc->refs[level],
5935 &wc->flags[level], NULL);
5936 if (ret < 0) {
5937 err = ret;
5938 goto out_end_trans;
5939 }
5940 BUG_ON(wc->refs[level] == 0);
5941
5942 if (level == btrfs_root_drop_level(root_item))
5943 break;
5944
5945 btrfs_tree_unlock(path->nodes[level]);
5946 path->locks[level] = 0;
5947 WARN_ON(wc->refs[level] != 1);
5948 level--;
5949 }
5950 }
5951
5952 wc->restarted = test_bit(BTRFS_ROOT_DEAD_TREE, &root->state);
5953 wc->level = level;
5954 wc->shared_level = -1;
5955 wc->stage = DROP_REFERENCE;
5956 wc->update_ref = update_ref;
5957 wc->keep_locks = 0;
5958 wc->reada_count = BTRFS_NODEPTRS_PER_BLOCK(fs_info);
5959
5960 while (1) {
5961
5962 ret = walk_down_tree(trans, root, path, wc);
5963 if (ret < 0) {
5964 btrfs_abort_transaction(trans, ret);
5965 err = ret;
5966 break;
5967 }
5968
5969 ret = walk_up_tree(trans, root, path, wc, BTRFS_MAX_LEVEL);
5970 if (ret < 0) {
5971 btrfs_abort_transaction(trans, ret);
5972 err = ret;
5973 break;
5974 }
5975
5976 if (ret > 0) {
5977 BUG_ON(wc->stage != DROP_REFERENCE);
5978 break;
5979 }
5980
5981 if (wc->stage == DROP_REFERENCE) {
5982 wc->drop_level = wc->level;
5983 btrfs_node_key_to_cpu(path->nodes[wc->drop_level],
5984 &wc->drop_progress,
5985 path->slots[wc->drop_level]);
5986 }
5987 btrfs_cpu_key_to_disk(&root_item->drop_progress,
5988 &wc->drop_progress);
5989 btrfs_set_root_drop_level(root_item, wc->drop_level);
5990
5991 BUG_ON(wc->level == 0);
5992 if (btrfs_should_end_transaction(trans) ||
5993 (!for_reloc && btrfs_need_cleaner_sleep(fs_info))) {
5994 ret = btrfs_update_root(trans, tree_root,
5995 &root->root_key,
5996 root_item);
5997 if (ret) {
5998 btrfs_abort_transaction(trans, ret);
5999 err = ret;
6000 goto out_end_trans;
6001 }
6002
6003 if (!is_reloc_root)
6004 btrfs_set_last_root_drop_gen(fs_info, trans->transid);
6005
6006 btrfs_end_transaction_throttle(trans);
6007 if (!for_reloc && btrfs_need_cleaner_sleep(fs_info)) {
6008 btrfs_debug(fs_info,
6009 "drop snapshot early exit");
6010 err = -EAGAIN;
6011 goto out_free;
6012 }
6013
6014 /*
6015 * Use join to avoid potential EINTR from transaction
6016 * start. See wait_reserve_ticket and the whole
6017 * reservation callchain.
6018 */
6019 if (for_reloc)
6020 trans = btrfs_join_transaction(tree_root);
6021 else
6022 trans = btrfs_start_transaction(tree_root, 0);
6023 if (IS_ERR(trans)) {
6024 err = PTR_ERR(trans);
6025 goto out_free;
6026 }
6027 }
6028 }
6029 btrfs_release_path(path);
6030 if (err)
6031 goto out_end_trans;
6032
6033 ret = btrfs_del_root(trans, &root->root_key);
6034 if (ret) {
6035 btrfs_abort_transaction(trans, ret);
6036 err = ret;
6037 goto out_end_trans;
6038 }
6039
6040 if (!is_reloc_root) {
6041 ret = btrfs_find_root(tree_root, &root->root_key, path,
6042 NULL, NULL);
6043 if (ret < 0) {
6044 btrfs_abort_transaction(trans, ret);
6045 err = ret;
6046 goto out_end_trans;
6047 } else if (ret > 0) {
6048 /* if we fail to delete the orphan item this time
6049 * around, it'll get picked up the next time.
6050 *
6051 * The most common failure here is just -ENOENT.
6052 */
6053 btrfs_del_orphan_item(trans, tree_root,
6054 root->root_key.objectid);
6055 }
6056 }
6057
6058 /*
6059 * This subvolume is going to be completely dropped, and won't be
6060 * recorded as dirty roots, thus pertrans meta rsv will not be freed at
6061 * commit transaction time. So free it here manually.
6062 */
6063 btrfs_qgroup_convert_reserved_meta(root, INT_MAX);
6064 btrfs_qgroup_free_meta_all_pertrans(root);
6065
6066 if (test_bit(BTRFS_ROOT_IN_RADIX, &root->state))
6067 btrfs_add_dropped_root(trans, root);
6068 else
6069 btrfs_put_root(root);
6070 root_dropped = true;
6071 out_end_trans:
6072 if (!is_reloc_root)
6073 btrfs_set_last_root_drop_gen(fs_info, trans->transid);
6074
6075 btrfs_end_transaction_throttle(trans);
6076 out_free:
6077 kfree(wc);
6078 btrfs_free_path(path);
6079 out:
6080 /*
6081 * We were an unfinished drop root, check to see if there are any
6082 * pending, and if not clear and wake up any waiters.
6083 */
6084 if (!err && unfinished_drop)
6085 btrfs_maybe_wake_unfinished_drop(fs_info);
6086
6087 /*
6088 * So if we need to stop dropping the snapshot for whatever reason we
6089 * need to make sure to add it back to the dead root list so that we
6090 * keep trying to do the work later. This also cleans up roots if we
6091 * don't have it in the radix (like when we recover after a power fail
6092 * or unmount) so we don't leak memory.
6093 */
6094 if (!for_reloc && !root_dropped)
6095 btrfs_add_dead_root(root);
6096 return err;
6097 }
6098
6099 /*
6100 * drop subtree rooted at tree block 'node'.
6101 *
6102 * NOTE: this function will unlock and release tree block 'node'
6103 * only used by relocation code
6104 */
btrfs_drop_subtree(struct btrfs_trans_handle * trans,struct btrfs_root * root,struct extent_buffer * node,struct extent_buffer * parent)6105 int btrfs_drop_subtree(struct btrfs_trans_handle *trans,
6106 struct btrfs_root *root,
6107 struct extent_buffer *node,
6108 struct extent_buffer *parent)
6109 {
6110 struct btrfs_fs_info *fs_info = root->fs_info;
6111 struct btrfs_path *path;
6112 struct walk_control *wc;
6113 int level;
6114 int parent_level;
6115 int ret = 0;
6116 int wret;
6117
6118 BUG_ON(root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID);
6119
6120 path = btrfs_alloc_path();
6121 if (!path)
6122 return -ENOMEM;
6123
6124 wc = kzalloc(sizeof(*wc), GFP_NOFS);
6125 if (!wc) {
6126 btrfs_free_path(path);
6127 return -ENOMEM;
6128 }
6129
6130 btrfs_assert_tree_write_locked(parent);
6131 parent_level = btrfs_header_level(parent);
6132 atomic_inc(&parent->refs);
6133 path->nodes[parent_level] = parent;
6134 path->slots[parent_level] = btrfs_header_nritems(parent);
6135
6136 btrfs_assert_tree_write_locked(node);
6137 level = btrfs_header_level(node);
6138 path->nodes[level] = node;
6139 path->slots[level] = 0;
6140 path->locks[level] = BTRFS_WRITE_LOCK;
6141
6142 wc->refs[parent_level] = 1;
6143 wc->flags[parent_level] = BTRFS_BLOCK_FLAG_FULL_BACKREF;
6144 wc->level = level;
6145 wc->shared_level = -1;
6146 wc->stage = DROP_REFERENCE;
6147 wc->update_ref = 0;
6148 wc->keep_locks = 1;
6149 wc->reada_count = BTRFS_NODEPTRS_PER_BLOCK(fs_info);
6150
6151 while (1) {
6152 wret = walk_down_tree(trans, root, path, wc);
6153 if (wret < 0) {
6154 ret = wret;
6155 break;
6156 }
6157
6158 wret = walk_up_tree(trans, root, path, wc, parent_level);
6159 if (wret < 0)
6160 ret = wret;
6161 if (wret != 0)
6162 break;
6163 }
6164
6165 kfree(wc);
6166 btrfs_free_path(path);
6167 return ret;
6168 }
6169
btrfs_error_unpin_extent_range(struct btrfs_fs_info * fs_info,u64 start,u64 end)6170 int btrfs_error_unpin_extent_range(struct btrfs_fs_info *fs_info,
6171 u64 start, u64 end)
6172 {
6173 return unpin_extent_range(fs_info, start, end, false);
6174 }
6175
6176 /*
6177 * It used to be that old block groups would be left around forever.
6178 * Iterating over them would be enough to trim unused space. Since we
6179 * now automatically remove them, we also need to iterate over unallocated
6180 * space.
6181 *
6182 * We don't want a transaction for this since the discard may take a
6183 * substantial amount of time. We don't require that a transaction be
6184 * running, but we do need to take a running transaction into account
6185 * to ensure that we're not discarding chunks that were released or
6186 * allocated in the current transaction.
6187 *
6188 * Holding the chunks lock will prevent other threads from allocating
6189 * or releasing chunks, but it won't prevent a running transaction
6190 * from committing and releasing the memory that the pending chunks
6191 * list head uses. For that, we need to take a reference to the
6192 * transaction and hold the commit root sem. We only need to hold
6193 * it while performing the free space search since we have already
6194 * held back allocations.
6195 */
btrfs_trim_free_extents(struct btrfs_device * device,u64 * trimmed)6196 static int btrfs_trim_free_extents(struct btrfs_device *device, u64 *trimmed)
6197 {
6198 u64 start = BTRFS_DEVICE_RANGE_RESERVED, len = 0, end = 0;
6199 int ret;
6200
6201 *trimmed = 0;
6202
6203 /* Discard not supported = nothing to do. */
6204 if (!bdev_max_discard_sectors(device->bdev))
6205 return 0;
6206
6207 /* Not writable = nothing to do. */
6208 if (!test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state))
6209 return 0;
6210
6211 /* No free space = nothing to do. */
6212 if (device->total_bytes <= device->bytes_used)
6213 return 0;
6214
6215 ret = 0;
6216
6217 while (1) {
6218 struct btrfs_fs_info *fs_info = device->fs_info;
6219 u64 bytes;
6220
6221 ret = mutex_lock_interruptible(&fs_info->chunk_mutex);
6222 if (ret)
6223 break;
6224
6225 find_first_clear_extent_bit(&device->alloc_state, start,
6226 &start, &end,
6227 CHUNK_TRIMMED | CHUNK_ALLOCATED);
6228
6229 /* Check if there are any CHUNK_* bits left */
6230 if (start > device->total_bytes) {
6231 WARN_ON(IS_ENABLED(CONFIG_BTRFS_DEBUG));
6232 btrfs_warn_in_rcu(fs_info,
6233 "ignoring attempt to trim beyond device size: offset %llu length %llu device %s device size %llu",
6234 start, end - start + 1,
6235 btrfs_dev_name(device),
6236 device->total_bytes);
6237 mutex_unlock(&fs_info->chunk_mutex);
6238 ret = 0;
6239 break;
6240 }
6241
6242 /* Ensure we skip the reserved space on each device. */
6243 start = max_t(u64, start, BTRFS_DEVICE_RANGE_RESERVED);
6244
6245 /*
6246 * If find_first_clear_extent_bit find a range that spans the
6247 * end of the device it will set end to -1, in this case it's up
6248 * to the caller to trim the value to the size of the device.
6249 */
6250 end = min(end, device->total_bytes - 1);
6251
6252 len = end - start + 1;
6253
6254 /* We didn't find any extents */
6255 if (!len) {
6256 mutex_unlock(&fs_info->chunk_mutex);
6257 ret = 0;
6258 break;
6259 }
6260
6261 ret = btrfs_issue_discard(device->bdev, start, len,
6262 &bytes);
6263 if (!ret)
6264 set_extent_bit(&device->alloc_state, start,
6265 start + bytes - 1, CHUNK_TRIMMED, NULL);
6266 mutex_unlock(&fs_info->chunk_mutex);
6267
6268 if (ret)
6269 break;
6270
6271 start += len;
6272 *trimmed += bytes;
6273
6274 if (fatal_signal_pending(current)) {
6275 ret = -ERESTARTSYS;
6276 break;
6277 }
6278
6279 cond_resched();
6280 }
6281
6282 return ret;
6283 }
6284
6285 /*
6286 * Trim the whole filesystem by:
6287 * 1) trimming the free space in each block group
6288 * 2) trimming the unallocated space on each device
6289 *
6290 * This will also continue trimming even if a block group or device encounters
6291 * an error. The return value will be the last error, or 0 if nothing bad
6292 * happens.
6293 */
btrfs_trim_fs(struct btrfs_fs_info * fs_info,struct fstrim_range * range)6294 int btrfs_trim_fs(struct btrfs_fs_info *fs_info, struct fstrim_range *range)
6295 {
6296 struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
6297 struct btrfs_block_group *cache = NULL;
6298 struct btrfs_device *device;
6299 u64 group_trimmed;
6300 u64 range_end = U64_MAX;
6301 u64 start;
6302 u64 end;
6303 u64 trimmed = 0;
6304 u64 bg_failed = 0;
6305 u64 dev_failed = 0;
6306 int bg_ret = 0;
6307 int dev_ret = 0;
6308 int ret = 0;
6309
6310 if (range->start == U64_MAX)
6311 return -EINVAL;
6312
6313 /*
6314 * Check range overflow if range->len is set.
6315 * The default range->len is U64_MAX.
6316 */
6317 if (range->len != U64_MAX &&
6318 check_add_overflow(range->start, range->len, &range_end))
6319 return -EINVAL;
6320
6321 cache = btrfs_lookup_first_block_group(fs_info, range->start);
6322 for (; cache; cache = btrfs_next_block_group(cache)) {
6323 if (cache->start >= range_end) {
6324 btrfs_put_block_group(cache);
6325 break;
6326 }
6327
6328 start = max(range->start, cache->start);
6329 end = min(range_end, cache->start + cache->length);
6330
6331 if (end - start >= range->minlen) {
6332 if (!btrfs_block_group_done(cache)) {
6333 ret = btrfs_cache_block_group(cache, true);
6334 if (ret) {
6335 bg_failed++;
6336 bg_ret = ret;
6337 continue;
6338 }
6339 }
6340 ret = btrfs_trim_block_group(cache,
6341 &group_trimmed,
6342 start,
6343 end,
6344 range->minlen);
6345
6346 trimmed += group_trimmed;
6347 if (ret) {
6348 bg_failed++;
6349 bg_ret = ret;
6350 continue;
6351 }
6352 }
6353 }
6354
6355 if (bg_failed)
6356 btrfs_warn(fs_info,
6357 "failed to trim %llu block group(s), last error %d",
6358 bg_failed, bg_ret);
6359
6360 mutex_lock(&fs_devices->device_list_mutex);
6361 list_for_each_entry(device, &fs_devices->devices, dev_list) {
6362 if (test_bit(BTRFS_DEV_STATE_MISSING, &device->dev_state))
6363 continue;
6364
6365 ret = btrfs_trim_free_extents(device, &group_trimmed);
6366 if (ret) {
6367 dev_failed++;
6368 dev_ret = ret;
6369 break;
6370 }
6371
6372 trimmed += group_trimmed;
6373 }
6374 mutex_unlock(&fs_devices->device_list_mutex);
6375
6376 if (dev_failed)
6377 btrfs_warn(fs_info,
6378 "failed to trim %llu device(s), last error %d",
6379 dev_failed, dev_ret);
6380 range->len = trimmed;
6381 if (bg_ret)
6382 return bg_ret;
6383 return dev_ret;
6384 }
6385