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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (C) 2009 Oracle. All rights reserved.
4 */
5
6#include <linux/sched.h>
7#include <linux/slab.h>
8#include <linux/sort.h>
9#include "messages.h"
10#include "ctree.h"
11#include "delayed-ref.h"
12#include "transaction.h"
13#include "qgroup.h"
14#include "space-info.h"
15#include "tree-mod-log.h"
16#include "fs.h"
17
18struct kmem_cache *btrfs_delayed_ref_head_cachep;
19struct kmem_cache *btrfs_delayed_tree_ref_cachep;
20struct kmem_cache *btrfs_delayed_data_ref_cachep;
21struct kmem_cache *btrfs_delayed_extent_op_cachep;
22/*
23 * delayed back reference update tracking. For subvolume trees
24 * we queue up extent allocations and backref maintenance for
25 * delayed processing. This avoids deep call chains where we
26 * add extents in the middle of btrfs_search_slot, and it allows
27 * us to buffer up frequently modified backrefs in an rb tree instead
28 * of hammering updates on the extent allocation tree.
29 */
30
31bool btrfs_check_space_for_delayed_refs(struct btrfs_fs_info *fs_info)
32{
33 struct btrfs_block_rsv *delayed_refs_rsv = &fs_info->delayed_refs_rsv;
34 struct btrfs_block_rsv *global_rsv = &fs_info->global_block_rsv;
35 bool ret = false;
36 u64 reserved;
37
38 spin_lock(&global_rsv->lock);
39 reserved = global_rsv->reserved;
40 spin_unlock(&global_rsv->lock);
41
42 /*
43 * Since the global reserve is just kind of magic we don't really want
44 * to rely on it to save our bacon, so if our size is more than the
45 * delayed_refs_rsv and the global rsv then it's time to think about
46 * bailing.
47 */
48 spin_lock(&delayed_refs_rsv->lock);
49 reserved += delayed_refs_rsv->reserved;
50 if (delayed_refs_rsv->size >= reserved)
51 ret = true;
52 spin_unlock(&delayed_refs_rsv->lock);
53 return ret;
54}
55
56int btrfs_should_throttle_delayed_refs(struct btrfs_trans_handle *trans)
57{
58 u64 num_entries =
59 atomic_read(&trans->transaction->delayed_refs.num_entries);
60 u64 avg_runtime;
61 u64 val;
62
63 smp_mb();
64 avg_runtime = trans->fs_info->avg_delayed_ref_runtime;
65 val = num_entries * avg_runtime;
66 if (val >= NSEC_PER_SEC)
67 return 1;
68 if (val >= NSEC_PER_SEC / 2)
69 return 2;
70
71 return btrfs_check_space_for_delayed_refs(trans->fs_info);
72}
73
74/*
75 * Release a ref head's reservation.
76 *
77 * @fs_info: the filesystem
78 * @nr: number of items to drop
79 *
80 * Drops the delayed ref head's count from the delayed refs rsv and free any
81 * excess reservation we had.
82 */
83void btrfs_delayed_refs_rsv_release(struct btrfs_fs_info *fs_info, int nr)
84{
85 struct btrfs_block_rsv *block_rsv = &fs_info->delayed_refs_rsv;
86 u64 num_bytes = btrfs_calc_insert_metadata_size(fs_info, nr);
87 u64 released = 0;
88
89 /*
90 * We have to check the mount option here because we could be enabling
91 * the free space tree for the first time and don't have the compat_ro
92 * option set yet.
93 *
94 * We need extra reservations if we have the free space tree because
95 * we'll have to modify that tree as well.
96 */
97 if (btrfs_test_opt(fs_info, FREE_SPACE_TREE))
98 num_bytes *= 2;
99
100 released = btrfs_block_rsv_release(fs_info, block_rsv, num_bytes, NULL);
101 if (released)
102 trace_btrfs_space_reservation(fs_info, "delayed_refs_rsv",
103 0, released, 0);
104}
105
106/*
107 * Adjust the size of the delayed refs rsv.
108 *
109 * This is to be called anytime we may have adjusted trans->delayed_ref_updates,
110 * it'll calculate the additional size and add it to the delayed_refs_rsv.
111 */
112void btrfs_update_delayed_refs_rsv(struct btrfs_trans_handle *trans)
113{
114 struct btrfs_fs_info *fs_info = trans->fs_info;
115 struct btrfs_block_rsv *delayed_rsv = &fs_info->delayed_refs_rsv;
116 u64 num_bytes;
117
118 if (!trans->delayed_ref_updates)
119 return;
120
121 num_bytes = btrfs_calc_insert_metadata_size(fs_info,
122 trans->delayed_ref_updates);
123 /*
124 * We have to check the mount option here because we could be enabling
125 * the free space tree for the first time and don't have the compat_ro
126 * option set yet.
127 *
128 * We need extra reservations if we have the free space tree because
129 * we'll have to modify that tree as well.
130 */
131 if (btrfs_test_opt(fs_info, FREE_SPACE_TREE))
132 num_bytes *= 2;
133
134 spin_lock(&delayed_rsv->lock);
135 delayed_rsv->size += num_bytes;
136 delayed_rsv->full = false;
137 spin_unlock(&delayed_rsv->lock);
138 trans->delayed_ref_updates = 0;
139}
140
141/*
142 * Transfer bytes to our delayed refs rsv.
143 *
144 * @fs_info: the filesystem
145 * @src: source block rsv to transfer from
146 * @num_bytes: number of bytes to transfer
147 *
148 * This transfers up to the num_bytes amount from the src rsv to the
149 * delayed_refs_rsv. Any extra bytes are returned to the space info.
150 */
151void btrfs_migrate_to_delayed_refs_rsv(struct btrfs_fs_info *fs_info,
152 struct btrfs_block_rsv *src,
153 u64 num_bytes)
154{
155 struct btrfs_block_rsv *delayed_refs_rsv = &fs_info->delayed_refs_rsv;
156 u64 to_free = 0;
157
158 spin_lock(&src->lock);
159 src->reserved -= num_bytes;
160 src->size -= num_bytes;
161 spin_unlock(&src->lock);
162
163 spin_lock(&delayed_refs_rsv->lock);
164 if (delayed_refs_rsv->size > delayed_refs_rsv->reserved) {
165 u64 delta = delayed_refs_rsv->size -
166 delayed_refs_rsv->reserved;
167 if (num_bytes > delta) {
168 to_free = num_bytes - delta;
169 num_bytes = delta;
170 }
171 } else {
172 to_free = num_bytes;
173 num_bytes = 0;
174 }
175
176 if (num_bytes)
177 delayed_refs_rsv->reserved += num_bytes;
178 if (delayed_refs_rsv->reserved >= delayed_refs_rsv->size)
179 delayed_refs_rsv->full = true;
180 spin_unlock(&delayed_refs_rsv->lock);
181
182 if (num_bytes)
183 trace_btrfs_space_reservation(fs_info, "delayed_refs_rsv",
184 0, num_bytes, 1);
185 if (to_free)
186 btrfs_space_info_free_bytes_may_use(fs_info,
187 delayed_refs_rsv->space_info, to_free);
188}
189
190/*
191 * Refill based on our delayed refs usage.
192 *
193 * @fs_info: the filesystem
194 * @flush: control how we can flush for this reservation.
195 *
196 * This will refill the delayed block_rsv up to 1 items size worth of space and
197 * will return -ENOSPC if we can't make the reservation.
198 */
199int btrfs_delayed_refs_rsv_refill(struct btrfs_fs_info *fs_info,
200 enum btrfs_reserve_flush_enum flush)
201{
202 struct btrfs_block_rsv *block_rsv = &fs_info->delayed_refs_rsv;
203 u64 limit = btrfs_calc_insert_metadata_size(fs_info, 1);
204 u64 num_bytes = 0;
205 int ret = -ENOSPC;
206
207 spin_lock(&block_rsv->lock);
208 if (block_rsv->reserved < block_rsv->size) {
209 num_bytes = block_rsv->size - block_rsv->reserved;
210 num_bytes = min(num_bytes, limit);
211 }
212 spin_unlock(&block_rsv->lock);
213
214 if (!num_bytes)
215 return 0;
216
217 ret = btrfs_reserve_metadata_bytes(fs_info, block_rsv, num_bytes, flush);
218 if (ret)
219 return ret;
220 btrfs_block_rsv_add_bytes(block_rsv, num_bytes, 0);
221 trace_btrfs_space_reservation(fs_info, "delayed_refs_rsv",
222 0, num_bytes, 1);
223 return 0;
224}
225
226/*
227 * compare two delayed tree backrefs with same bytenr and type
228 */
229static int comp_tree_refs(struct btrfs_delayed_tree_ref *ref1,
230 struct btrfs_delayed_tree_ref *ref2)
231{
232 if (ref1->node.type == BTRFS_TREE_BLOCK_REF_KEY) {
233 if (ref1->root < ref2->root)
234 return -1;
235 if (ref1->root > ref2->root)
236 return 1;
237 } else {
238 if (ref1->parent < ref2->parent)
239 return -1;
240 if (ref1->parent > ref2->parent)
241 return 1;
242 }
243 return 0;
244}
245
246/*
247 * compare two delayed data backrefs with same bytenr and type
248 */
249static int comp_data_refs(struct btrfs_delayed_data_ref *ref1,
250 struct btrfs_delayed_data_ref *ref2)
251{
252 if (ref1->node.type == BTRFS_EXTENT_DATA_REF_KEY) {
253 if (ref1->root < ref2->root)
254 return -1;
255 if (ref1->root > ref2->root)
256 return 1;
257 if (ref1->objectid < ref2->objectid)
258 return -1;
259 if (ref1->objectid > ref2->objectid)
260 return 1;
261 if (ref1->offset < ref2->offset)
262 return -1;
263 if (ref1->offset > ref2->offset)
264 return 1;
265 } else {
266 if (ref1->parent < ref2->parent)
267 return -1;
268 if (ref1->parent > ref2->parent)
269 return 1;
270 }
271 return 0;
272}
273
274static int comp_refs(struct btrfs_delayed_ref_node *ref1,
275 struct btrfs_delayed_ref_node *ref2,
276 bool check_seq)
277{
278 int ret = 0;
279
280 if (ref1->type < ref2->type)
281 return -1;
282 if (ref1->type > ref2->type)
283 return 1;
284 if (ref1->type == BTRFS_TREE_BLOCK_REF_KEY ||
285 ref1->type == BTRFS_SHARED_BLOCK_REF_KEY)
286 ret = comp_tree_refs(btrfs_delayed_node_to_tree_ref(ref1),
287 btrfs_delayed_node_to_tree_ref(ref2));
288 else
289 ret = comp_data_refs(btrfs_delayed_node_to_data_ref(ref1),
290 btrfs_delayed_node_to_data_ref(ref2));
291 if (ret)
292 return ret;
293 if (check_seq) {
294 if (ref1->seq < ref2->seq)
295 return -1;
296 if (ref1->seq > ref2->seq)
297 return 1;
298 }
299 return 0;
300}
301
302/* insert a new ref to head ref rbtree */
303static struct btrfs_delayed_ref_head *htree_insert(struct rb_root_cached *root,
304 struct rb_node *node)
305{
306 struct rb_node **p = &root->rb_root.rb_node;
307 struct rb_node *parent_node = NULL;
308 struct btrfs_delayed_ref_head *entry;
309 struct btrfs_delayed_ref_head *ins;
310 u64 bytenr;
311 bool leftmost = true;
312
313 ins = rb_entry(node, struct btrfs_delayed_ref_head, href_node);
314 bytenr = ins->bytenr;
315 while (*p) {
316 parent_node = *p;
317 entry = rb_entry(parent_node, struct btrfs_delayed_ref_head,
318 href_node);
319
320 if (bytenr < entry->bytenr) {
321 p = &(*p)->rb_left;
322 } else if (bytenr > entry->bytenr) {
323 p = &(*p)->rb_right;
324 leftmost = false;
325 } else {
326 return entry;
327 }
328 }
329
330 rb_link_node(node, parent_node, p);
331 rb_insert_color_cached(node, root, leftmost);
332 return NULL;
333}
334
335static struct btrfs_delayed_ref_node* tree_insert(struct rb_root_cached *root,
336 struct btrfs_delayed_ref_node *ins)
337{
338 struct rb_node **p = &root->rb_root.rb_node;
339 struct rb_node *node = &ins->ref_node;
340 struct rb_node *parent_node = NULL;
341 struct btrfs_delayed_ref_node *entry;
342 bool leftmost = true;
343
344 while (*p) {
345 int comp;
346
347 parent_node = *p;
348 entry = rb_entry(parent_node, struct btrfs_delayed_ref_node,
349 ref_node);
350 comp = comp_refs(ins, entry, true);
351 if (comp < 0) {
352 p = &(*p)->rb_left;
353 } else if (comp > 0) {
354 p = &(*p)->rb_right;
355 leftmost = false;
356 } else {
357 return entry;
358 }
359 }
360
361 rb_link_node(node, parent_node, p);
362 rb_insert_color_cached(node, root, leftmost);
363 return NULL;
364}
365
366static struct btrfs_delayed_ref_head *find_first_ref_head(
367 struct btrfs_delayed_ref_root *dr)
368{
369 struct rb_node *n;
370 struct btrfs_delayed_ref_head *entry;
371
372 n = rb_first_cached(&dr->href_root);
373 if (!n)
374 return NULL;
375
376 entry = rb_entry(n, struct btrfs_delayed_ref_head, href_node);
377
378 return entry;
379}
380
381/*
382 * Find a head entry based on bytenr. This returns the delayed ref head if it
383 * was able to find one, or NULL if nothing was in that spot. If return_bigger
384 * is given, the next bigger entry is returned if no exact match is found.
385 */
386static struct btrfs_delayed_ref_head *find_ref_head(
387 struct btrfs_delayed_ref_root *dr, u64 bytenr,
388 bool return_bigger)
389{
390 struct rb_root *root = &dr->href_root.rb_root;
391 struct rb_node *n;
392 struct btrfs_delayed_ref_head *entry;
393
394 n = root->rb_node;
395 entry = NULL;
396 while (n) {
397 entry = rb_entry(n, struct btrfs_delayed_ref_head, href_node);
398
399 if (bytenr < entry->bytenr)
400 n = n->rb_left;
401 else if (bytenr > entry->bytenr)
402 n = n->rb_right;
403 else
404 return entry;
405 }
406 if (entry && return_bigger) {
407 if (bytenr > entry->bytenr) {
408 n = rb_next(&entry->href_node);
409 if (!n)
410 return NULL;
411 entry = rb_entry(n, struct btrfs_delayed_ref_head,
412 href_node);
413 }
414 return entry;
415 }
416 return NULL;
417}
418
419int btrfs_delayed_ref_lock(struct btrfs_delayed_ref_root *delayed_refs,
420 struct btrfs_delayed_ref_head *head)
421{
422 lockdep_assert_held(&delayed_refs->lock);
423 if (mutex_trylock(&head->mutex))
424 return 0;
425
426 refcount_inc(&head->refs);
427 spin_unlock(&delayed_refs->lock);
428
429 mutex_lock(&head->mutex);
430 spin_lock(&delayed_refs->lock);
431 if (RB_EMPTY_NODE(&head->href_node)) {
432 mutex_unlock(&head->mutex);
433 btrfs_put_delayed_ref_head(head);
434 return -EAGAIN;
435 }
436 btrfs_put_delayed_ref_head(head);
437 return 0;
438}
439
440static inline void drop_delayed_ref(struct btrfs_trans_handle *trans,
441 struct btrfs_delayed_ref_root *delayed_refs,
442 struct btrfs_delayed_ref_head *head,
443 struct btrfs_delayed_ref_node *ref)
444{
445 lockdep_assert_held(&head->lock);
446 rb_erase_cached(&ref->ref_node, &head->ref_tree);
447 RB_CLEAR_NODE(&ref->ref_node);
448 if (!list_empty(&ref->add_list))
449 list_del(&ref->add_list);
450 ref->in_tree = 0;
451 btrfs_put_delayed_ref(ref);
452 atomic_dec(&delayed_refs->num_entries);
453}
454
455static bool merge_ref(struct btrfs_trans_handle *trans,
456 struct btrfs_delayed_ref_root *delayed_refs,
457 struct btrfs_delayed_ref_head *head,
458 struct btrfs_delayed_ref_node *ref,
459 u64 seq)
460{
461 struct btrfs_delayed_ref_node *next;
462 struct rb_node *node = rb_next(&ref->ref_node);
463 bool done = false;
464
465 while (!done && node) {
466 int mod;
467
468 next = rb_entry(node, struct btrfs_delayed_ref_node, ref_node);
469 node = rb_next(node);
470 if (seq && next->seq >= seq)
471 break;
472 if (comp_refs(ref, next, false))
473 break;
474
475 if (ref->action == next->action) {
476 mod = next->ref_mod;
477 } else {
478 if (ref->ref_mod < next->ref_mod) {
479 swap(ref, next);
480 done = true;
481 }
482 mod = -next->ref_mod;
483 }
484
485 drop_delayed_ref(trans, delayed_refs, head, next);
486 ref->ref_mod += mod;
487 if (ref->ref_mod == 0) {
488 drop_delayed_ref(trans, delayed_refs, head, ref);
489 done = true;
490 } else {
491 /*
492 * Can't have multiples of the same ref on a tree block.
493 */
494 WARN_ON(ref->type == BTRFS_TREE_BLOCK_REF_KEY ||
495 ref->type == BTRFS_SHARED_BLOCK_REF_KEY);
496 }
497 }
498
499 return done;
500}
501
502void btrfs_merge_delayed_refs(struct btrfs_trans_handle *trans,
503 struct btrfs_delayed_ref_root *delayed_refs,
504 struct btrfs_delayed_ref_head *head)
505{
506 struct btrfs_fs_info *fs_info = trans->fs_info;
507 struct btrfs_delayed_ref_node *ref;
508 struct rb_node *node;
509 u64 seq = 0;
510
511 lockdep_assert_held(&head->lock);
512
513 if (RB_EMPTY_ROOT(&head->ref_tree.rb_root))
514 return;
515
516 /* We don't have too many refs to merge for data. */
517 if (head->is_data)
518 return;
519
520 seq = btrfs_tree_mod_log_lowest_seq(fs_info);
521again:
522 for (node = rb_first_cached(&head->ref_tree); node;
523 node = rb_next(node)) {
524 ref = rb_entry(node, struct btrfs_delayed_ref_node, ref_node);
525 if (seq && ref->seq >= seq)
526 continue;
527 if (merge_ref(trans, delayed_refs, head, ref, seq))
528 goto again;
529 }
530}
531
532int btrfs_check_delayed_seq(struct btrfs_fs_info *fs_info, u64 seq)
533{
534 int ret = 0;
535 u64 min_seq = btrfs_tree_mod_log_lowest_seq(fs_info);
536
537 if (min_seq != 0 && seq >= min_seq) {
538 btrfs_debug(fs_info,
539 "holding back delayed_ref %llu, lowest is %llu",
540 seq, min_seq);
541 ret = 1;
542 }
543
544 return ret;
545}
546
547struct btrfs_delayed_ref_head *btrfs_select_ref_head(
548 struct btrfs_delayed_ref_root *delayed_refs)
549{
550 struct btrfs_delayed_ref_head *head;
551
552again:
553 head = find_ref_head(delayed_refs, delayed_refs->run_delayed_start,
554 true);
555 if (!head && delayed_refs->run_delayed_start != 0) {
556 delayed_refs->run_delayed_start = 0;
557 head = find_first_ref_head(delayed_refs);
558 }
559 if (!head)
560 return NULL;
561
562 while (head->processing) {
563 struct rb_node *node;
564
565 node = rb_next(&head->href_node);
566 if (!node) {
567 if (delayed_refs->run_delayed_start == 0)
568 return NULL;
569 delayed_refs->run_delayed_start = 0;
570 goto again;
571 }
572 head = rb_entry(node, struct btrfs_delayed_ref_head,
573 href_node);
574 }
575
576 head->processing = 1;
577 WARN_ON(delayed_refs->num_heads_ready == 0);
578 delayed_refs->num_heads_ready--;
579 delayed_refs->run_delayed_start = head->bytenr +
580 head->num_bytes;
581 return head;
582}
583
584void btrfs_delete_ref_head(struct btrfs_delayed_ref_root *delayed_refs,
585 struct btrfs_delayed_ref_head *head)
586{
587 lockdep_assert_held(&delayed_refs->lock);
588 lockdep_assert_held(&head->lock);
589
590 rb_erase_cached(&head->href_node, &delayed_refs->href_root);
591 RB_CLEAR_NODE(&head->href_node);
592 atomic_dec(&delayed_refs->num_entries);
593 delayed_refs->num_heads--;
594 if (head->processing == 0)
595 delayed_refs->num_heads_ready--;
596}
597
598/*
599 * Helper to insert the ref_node to the tail or merge with tail.
600 *
601 * Return 0 for insert.
602 * Return >0 for merge.
603 */
604static int insert_delayed_ref(struct btrfs_trans_handle *trans,
605 struct btrfs_delayed_ref_root *root,
606 struct btrfs_delayed_ref_head *href,
607 struct btrfs_delayed_ref_node *ref)
608{
609 struct btrfs_delayed_ref_node *exist;
610 int mod;
611 int ret = 0;
612
613 spin_lock(&href->lock);
614 exist = tree_insert(&href->ref_tree, ref);
615 if (!exist)
616 goto inserted;
617
618 /* Now we are sure we can merge */
619 ret = 1;
620 if (exist->action == ref->action) {
621 mod = ref->ref_mod;
622 } else {
623 /* Need to change action */
624 if (exist->ref_mod < ref->ref_mod) {
625 exist->action = ref->action;
626 mod = -exist->ref_mod;
627 exist->ref_mod = ref->ref_mod;
628 if (ref->action == BTRFS_ADD_DELAYED_REF)
629 list_add_tail(&exist->add_list,
630 &href->ref_add_list);
631 else if (ref->action == BTRFS_DROP_DELAYED_REF) {
632 ASSERT(!list_empty(&exist->add_list));
633 list_del(&exist->add_list);
634 } else {
635 ASSERT(0);
636 }
637 } else
638 mod = -ref->ref_mod;
639 }
640 exist->ref_mod += mod;
641
642 /* remove existing tail if its ref_mod is zero */
643 if (exist->ref_mod == 0)
644 drop_delayed_ref(trans, root, href, exist);
645 spin_unlock(&href->lock);
646 return ret;
647inserted:
648 if (ref->action == BTRFS_ADD_DELAYED_REF)
649 list_add_tail(&ref->add_list, &href->ref_add_list);
650 atomic_inc(&root->num_entries);
651 spin_unlock(&href->lock);
652 return ret;
653}
654
655/*
656 * helper function to update the accounting in the head ref
657 * existing and update must have the same bytenr
658 */
659static noinline void update_existing_head_ref(struct btrfs_trans_handle *trans,
660 struct btrfs_delayed_ref_head *existing,
661 struct btrfs_delayed_ref_head *update)
662{
663 struct btrfs_delayed_ref_root *delayed_refs =
664 &trans->transaction->delayed_refs;
665 struct btrfs_fs_info *fs_info = trans->fs_info;
666 int old_ref_mod;
667
668 BUG_ON(existing->is_data != update->is_data);
669
670 spin_lock(&existing->lock);
671 if (update->must_insert_reserved) {
672 /* if the extent was freed and then
673 * reallocated before the delayed ref
674 * entries were processed, we can end up
675 * with an existing head ref without
676 * the must_insert_reserved flag set.
677 * Set it again here
678 */
679 existing->must_insert_reserved = update->must_insert_reserved;
680
681 /*
682 * update the num_bytes so we make sure the accounting
683 * is done correctly
684 */
685 existing->num_bytes = update->num_bytes;
686
687 }
688
689 if (update->extent_op) {
690 if (!existing->extent_op) {
691 existing->extent_op = update->extent_op;
692 } else {
693 if (update->extent_op->update_key) {
694 memcpy(&existing->extent_op->key,
695 &update->extent_op->key,
696 sizeof(update->extent_op->key));
697 existing->extent_op->update_key = true;
698 }
699 if (update->extent_op->update_flags) {
700 existing->extent_op->flags_to_set |=
701 update->extent_op->flags_to_set;
702 existing->extent_op->update_flags = true;
703 }
704 btrfs_free_delayed_extent_op(update->extent_op);
705 }
706 }
707 /*
708 * update the reference mod on the head to reflect this new operation,
709 * only need the lock for this case cause we could be processing it
710 * currently, for refs we just added we know we're a-ok.
711 */
712 old_ref_mod = existing->total_ref_mod;
713 existing->ref_mod += update->ref_mod;
714 existing->total_ref_mod += update->ref_mod;
715
716 /*
717 * If we are going to from a positive ref mod to a negative or vice
718 * versa we need to make sure to adjust pending_csums accordingly.
719 */
720 if (existing->is_data) {
721 u64 csum_leaves =
722 btrfs_csum_bytes_to_leaves(fs_info,
723 existing->num_bytes);
724
725 if (existing->total_ref_mod >= 0 && old_ref_mod < 0) {
726 delayed_refs->pending_csums -= existing->num_bytes;
727 btrfs_delayed_refs_rsv_release(fs_info, csum_leaves);
728 }
729 if (existing->total_ref_mod < 0 && old_ref_mod >= 0) {
730 delayed_refs->pending_csums += existing->num_bytes;
731 trans->delayed_ref_updates += csum_leaves;
732 }
733 }
734
735 spin_unlock(&existing->lock);
736}
737
738static void init_delayed_ref_head(struct btrfs_delayed_ref_head *head_ref,
739 struct btrfs_qgroup_extent_record *qrecord,
740 u64 bytenr, u64 num_bytes, u64 ref_root,
741 u64 reserved, int action, bool is_data,
742 bool is_system)
743{
744 int count_mod = 1;
745 int must_insert_reserved = 0;
746
747 /* If reserved is provided, it must be a data extent. */
748 BUG_ON(!is_data && reserved);
749
750 /*
751 * The head node stores the sum of all the mods, so dropping a ref
752 * should drop the sum in the head node by one.
753 */
754 if (action == BTRFS_UPDATE_DELAYED_HEAD)
755 count_mod = 0;
756 else if (action == BTRFS_DROP_DELAYED_REF)
757 count_mod = -1;
758
759 /*
760 * BTRFS_ADD_DELAYED_EXTENT means that we need to update the reserved
761 * accounting when the extent is finally added, or if a later
762 * modification deletes the delayed ref without ever inserting the
763 * extent into the extent allocation tree. ref->must_insert_reserved
764 * is the flag used to record that accounting mods are required.
765 *
766 * Once we record must_insert_reserved, switch the action to
767 * BTRFS_ADD_DELAYED_REF because other special casing is not required.
768 */
769 if (action == BTRFS_ADD_DELAYED_EXTENT)
770 must_insert_reserved = 1;
771 else
772 must_insert_reserved = 0;
773
774 refcount_set(&head_ref->refs, 1);
775 head_ref->bytenr = bytenr;
776 head_ref->num_bytes = num_bytes;
777 head_ref->ref_mod = count_mod;
778 head_ref->must_insert_reserved = must_insert_reserved;
779 head_ref->is_data = is_data;
780 head_ref->is_system = is_system;
781 head_ref->ref_tree = RB_ROOT_CACHED;
782 INIT_LIST_HEAD(&head_ref->ref_add_list);
783 RB_CLEAR_NODE(&head_ref->href_node);
784 head_ref->processing = 0;
785 head_ref->total_ref_mod = count_mod;
786 spin_lock_init(&head_ref->lock);
787 mutex_init(&head_ref->mutex);
788
789 if (qrecord) {
790 if (ref_root && reserved) {
791 qrecord->data_rsv = reserved;
792 qrecord->data_rsv_refroot = ref_root;
793 }
794 qrecord->bytenr = bytenr;
795 qrecord->num_bytes = num_bytes;
796 qrecord->old_roots = NULL;
797 }
798}
799
800/*
801 * helper function to actually insert a head node into the rbtree.
802 * this does all the dirty work in terms of maintaining the correct
803 * overall modification count.
804 */
805static noinline struct btrfs_delayed_ref_head *
806add_delayed_ref_head(struct btrfs_trans_handle *trans,
807 struct btrfs_delayed_ref_head *head_ref,
808 struct btrfs_qgroup_extent_record *qrecord,
809 int action, int *qrecord_inserted_ret)
810{
811 struct btrfs_delayed_ref_head *existing;
812 struct btrfs_delayed_ref_root *delayed_refs;
813 int qrecord_inserted = 0;
814
815 delayed_refs = &trans->transaction->delayed_refs;
816
817 /* Record qgroup extent info if provided */
818 if (qrecord) {
819 if (btrfs_qgroup_trace_extent_nolock(trans->fs_info,
820 delayed_refs, qrecord))
821 kfree(qrecord);
822 else
823 qrecord_inserted = 1;
824 }
825
826 trace_add_delayed_ref_head(trans->fs_info, head_ref, action);
827
828 existing = htree_insert(&delayed_refs->href_root,
829 &head_ref->href_node);
830 if (existing) {
831 update_existing_head_ref(trans, existing, head_ref);
832 /*
833 * we've updated the existing ref, free the newly
834 * allocated ref
835 */
836 kmem_cache_free(btrfs_delayed_ref_head_cachep, head_ref);
837 head_ref = existing;
838 } else {
839 if (head_ref->is_data && head_ref->ref_mod < 0) {
840 delayed_refs->pending_csums += head_ref->num_bytes;
841 trans->delayed_ref_updates +=
842 btrfs_csum_bytes_to_leaves(trans->fs_info,
843 head_ref->num_bytes);
844 }
845 delayed_refs->num_heads++;
846 delayed_refs->num_heads_ready++;
847 atomic_inc(&delayed_refs->num_entries);
848 trans->delayed_ref_updates++;
849 }
850 if (qrecord_inserted_ret)
851 *qrecord_inserted_ret = qrecord_inserted;
852
853 return head_ref;
854}
855
856/*
857 * init_delayed_ref_common - Initialize the structure which represents a
858 * modification to a an extent.
859 *
860 * @fs_info: Internal to the mounted filesystem mount structure.
861 *
862 * @ref: The structure which is going to be initialized.
863 *
864 * @bytenr: The logical address of the extent for which a modification is
865 * going to be recorded.
866 *
867 * @num_bytes: Size of the extent whose modification is being recorded.
868 *
869 * @ref_root: The id of the root where this modification has originated, this
870 * can be either one of the well-known metadata trees or the
871 * subvolume id which references this extent.
872 *
873 * @action: Can be one of BTRFS_ADD_DELAYED_REF/BTRFS_DROP_DELAYED_REF or
874 * BTRFS_ADD_DELAYED_EXTENT
875 *
876 * @ref_type: Holds the type of the extent which is being recorded, can be
877 * one of BTRFS_SHARED_BLOCK_REF_KEY/BTRFS_TREE_BLOCK_REF_KEY
878 * when recording a metadata extent or BTRFS_SHARED_DATA_REF_KEY/
879 * BTRFS_EXTENT_DATA_REF_KEY when recording data extent
880 */
881static void init_delayed_ref_common(struct btrfs_fs_info *fs_info,
882 struct btrfs_delayed_ref_node *ref,
883 u64 bytenr, u64 num_bytes, u64 ref_root,
884 int action, u8 ref_type)
885{
886 u64 seq = 0;
887
888 if (action == BTRFS_ADD_DELAYED_EXTENT)
889 action = BTRFS_ADD_DELAYED_REF;
890
891 if (is_fstree(ref_root))
892 seq = atomic64_read(&fs_info->tree_mod_seq);
893
894 refcount_set(&ref->refs, 1);
895 ref->bytenr = bytenr;
896 ref->num_bytes = num_bytes;
897 ref->ref_mod = 1;
898 ref->action = action;
899 ref->is_head = 0;
900 ref->in_tree = 1;
901 ref->seq = seq;
902 ref->type = ref_type;
903 RB_CLEAR_NODE(&ref->ref_node);
904 INIT_LIST_HEAD(&ref->add_list);
905}
906
907/*
908 * add a delayed tree ref. This does all of the accounting required
909 * to make sure the delayed ref is eventually processed before this
910 * transaction commits.
911 */
912int btrfs_add_delayed_tree_ref(struct btrfs_trans_handle *trans,
913 struct btrfs_ref *generic_ref,
914 struct btrfs_delayed_extent_op *extent_op)
915{
916 struct btrfs_fs_info *fs_info = trans->fs_info;
917 struct btrfs_delayed_tree_ref *ref;
918 struct btrfs_delayed_ref_head *head_ref;
919 struct btrfs_delayed_ref_root *delayed_refs;
920 struct btrfs_qgroup_extent_record *record = NULL;
921 int qrecord_inserted;
922 bool is_system;
923 int action = generic_ref->action;
924 int level = generic_ref->tree_ref.level;
925 int ret;
926 u64 bytenr = generic_ref->bytenr;
927 u64 num_bytes = generic_ref->len;
928 u64 parent = generic_ref->parent;
929 u8 ref_type;
930
931 is_system = (generic_ref->tree_ref.owning_root == BTRFS_CHUNK_TREE_OBJECTID);
932
933 ASSERT(generic_ref->type == BTRFS_REF_METADATA && generic_ref->action);
934 ref = kmem_cache_alloc(btrfs_delayed_tree_ref_cachep, GFP_NOFS);
935 if (!ref)
936 return -ENOMEM;
937
938 head_ref = kmem_cache_alloc(btrfs_delayed_ref_head_cachep, GFP_NOFS);
939 if (!head_ref) {
940 kmem_cache_free(btrfs_delayed_tree_ref_cachep, ref);
941 return -ENOMEM;
942 }
943
944 if (test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags) &&
945 !generic_ref->skip_qgroup) {
946 record = kzalloc(sizeof(*record), GFP_NOFS);
947 if (!record) {
948 kmem_cache_free(btrfs_delayed_tree_ref_cachep, ref);
949 kmem_cache_free(btrfs_delayed_ref_head_cachep, head_ref);
950 return -ENOMEM;
951 }
952 }
953
954 if (parent)
955 ref_type = BTRFS_SHARED_BLOCK_REF_KEY;
956 else
957 ref_type = BTRFS_TREE_BLOCK_REF_KEY;
958
959 init_delayed_ref_common(fs_info, &ref->node, bytenr, num_bytes,
960 generic_ref->tree_ref.owning_root, action,
961 ref_type);
962 ref->root = generic_ref->tree_ref.owning_root;
963 ref->parent = parent;
964 ref->level = level;
965
966 init_delayed_ref_head(head_ref, record, bytenr, num_bytes,
967 generic_ref->tree_ref.owning_root, 0, action,
968 false, is_system);
969 head_ref->extent_op = extent_op;
970
971 delayed_refs = &trans->transaction->delayed_refs;
972 spin_lock(&delayed_refs->lock);
973
974 /*
975 * insert both the head node and the new ref without dropping
976 * the spin lock
977 */
978 head_ref = add_delayed_ref_head(trans, head_ref, record,
979 action, &qrecord_inserted);
980
981 ret = insert_delayed_ref(trans, delayed_refs, head_ref, &ref->node);
982 spin_unlock(&delayed_refs->lock);
983
984 /*
985 * Need to update the delayed_refs_rsv with any changes we may have
986 * made.
987 */
988 btrfs_update_delayed_refs_rsv(trans);
989
990 trace_add_delayed_tree_ref(fs_info, &ref->node, ref,
991 action == BTRFS_ADD_DELAYED_EXTENT ?
992 BTRFS_ADD_DELAYED_REF : action);
993 if (ret > 0)
994 kmem_cache_free(btrfs_delayed_tree_ref_cachep, ref);
995
996 if (qrecord_inserted)
997 btrfs_qgroup_trace_extent_post(trans, record);
998
999 return 0;
1000}
1001
1002/*
1003 * add a delayed data ref. it's similar to btrfs_add_delayed_tree_ref.
1004 */
1005int btrfs_add_delayed_data_ref(struct btrfs_trans_handle *trans,
1006 struct btrfs_ref *generic_ref,
1007 u64 reserved)
1008{
1009 struct btrfs_fs_info *fs_info = trans->fs_info;
1010 struct btrfs_delayed_data_ref *ref;
1011 struct btrfs_delayed_ref_head *head_ref;
1012 struct btrfs_delayed_ref_root *delayed_refs;
1013 struct btrfs_qgroup_extent_record *record = NULL;
1014 int qrecord_inserted;
1015 int action = generic_ref->action;
1016 int ret;
1017 u64 bytenr = generic_ref->bytenr;
1018 u64 num_bytes = generic_ref->len;
1019 u64 parent = generic_ref->parent;
1020 u64 ref_root = generic_ref->data_ref.owning_root;
1021 u64 owner = generic_ref->data_ref.ino;
1022 u64 offset = generic_ref->data_ref.offset;
1023 u8 ref_type;
1024
1025 ASSERT(generic_ref->type == BTRFS_REF_DATA && action);
1026 ref = kmem_cache_alloc(btrfs_delayed_data_ref_cachep, GFP_NOFS);
1027 if (!ref)
1028 return -ENOMEM;
1029
1030 if (parent)
1031 ref_type = BTRFS_SHARED_DATA_REF_KEY;
1032 else
1033 ref_type = BTRFS_EXTENT_DATA_REF_KEY;
1034 init_delayed_ref_common(fs_info, &ref->node, bytenr, num_bytes,
1035 ref_root, action, ref_type);
1036 ref->root = ref_root;
1037 ref->parent = parent;
1038 ref->objectid = owner;
1039 ref->offset = offset;
1040
1041
1042 head_ref = kmem_cache_alloc(btrfs_delayed_ref_head_cachep, GFP_NOFS);
1043 if (!head_ref) {
1044 kmem_cache_free(btrfs_delayed_data_ref_cachep, ref);
1045 return -ENOMEM;
1046 }
1047
1048 if (test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags) &&
1049 !generic_ref->skip_qgroup) {
1050 record = kzalloc(sizeof(*record), GFP_NOFS);
1051 if (!record) {
1052 kmem_cache_free(btrfs_delayed_data_ref_cachep, ref);
1053 kmem_cache_free(btrfs_delayed_ref_head_cachep,
1054 head_ref);
1055 return -ENOMEM;
1056 }
1057 }
1058
1059 init_delayed_ref_head(head_ref, record, bytenr, num_bytes, ref_root,
1060 reserved, action, true, false);
1061 head_ref->extent_op = NULL;
1062
1063 delayed_refs = &trans->transaction->delayed_refs;
1064 spin_lock(&delayed_refs->lock);
1065
1066 /*
1067 * insert both the head node and the new ref without dropping
1068 * the spin lock
1069 */
1070 head_ref = add_delayed_ref_head(trans, head_ref, record,
1071 action, &qrecord_inserted);
1072
1073 ret = insert_delayed_ref(trans, delayed_refs, head_ref, &ref->node);
1074 spin_unlock(&delayed_refs->lock);
1075
1076 /*
1077 * Need to update the delayed_refs_rsv with any changes we may have
1078 * made.
1079 */
1080 btrfs_update_delayed_refs_rsv(trans);
1081
1082 trace_add_delayed_data_ref(trans->fs_info, &ref->node, ref,
1083 action == BTRFS_ADD_DELAYED_EXTENT ?
1084 BTRFS_ADD_DELAYED_REF : action);
1085 if (ret > 0)
1086 kmem_cache_free(btrfs_delayed_data_ref_cachep, ref);
1087
1088
1089 if (qrecord_inserted)
1090 return btrfs_qgroup_trace_extent_post(trans, record);
1091 return 0;
1092}
1093
1094int btrfs_add_delayed_extent_op(struct btrfs_trans_handle *trans,
1095 u64 bytenr, u64 num_bytes,
1096 struct btrfs_delayed_extent_op *extent_op)
1097{
1098 struct btrfs_delayed_ref_head *head_ref;
1099 struct btrfs_delayed_ref_root *delayed_refs;
1100
1101 head_ref = kmem_cache_alloc(btrfs_delayed_ref_head_cachep, GFP_NOFS);
1102 if (!head_ref)
1103 return -ENOMEM;
1104
1105 init_delayed_ref_head(head_ref, NULL, bytenr, num_bytes, 0, 0,
1106 BTRFS_UPDATE_DELAYED_HEAD, false, false);
1107 head_ref->extent_op = extent_op;
1108
1109 delayed_refs = &trans->transaction->delayed_refs;
1110 spin_lock(&delayed_refs->lock);
1111
1112 add_delayed_ref_head(trans, head_ref, NULL, BTRFS_UPDATE_DELAYED_HEAD,
1113 NULL);
1114
1115 spin_unlock(&delayed_refs->lock);
1116
1117 /*
1118 * Need to update the delayed_refs_rsv with any changes we may have
1119 * made.
1120 */
1121 btrfs_update_delayed_refs_rsv(trans);
1122 return 0;
1123}
1124
1125/*
1126 * This does a simple search for the head node for a given extent. Returns the
1127 * head node if found, or NULL if not.
1128 */
1129struct btrfs_delayed_ref_head *
1130btrfs_find_delayed_ref_head(struct btrfs_delayed_ref_root *delayed_refs, u64 bytenr)
1131{
1132 lockdep_assert_held(&delayed_refs->lock);
1133
1134 return find_ref_head(delayed_refs, bytenr, false);
1135}
1136
1137void __cold btrfs_delayed_ref_exit(void)
1138{
1139 kmem_cache_destroy(btrfs_delayed_ref_head_cachep);
1140 kmem_cache_destroy(btrfs_delayed_tree_ref_cachep);
1141 kmem_cache_destroy(btrfs_delayed_data_ref_cachep);
1142 kmem_cache_destroy(btrfs_delayed_extent_op_cachep);
1143}
1144
1145int __init btrfs_delayed_ref_init(void)
1146{
1147 btrfs_delayed_ref_head_cachep = kmem_cache_create(
1148 "btrfs_delayed_ref_head",
1149 sizeof(struct btrfs_delayed_ref_head), 0,
1150 SLAB_MEM_SPREAD, NULL);
1151 if (!btrfs_delayed_ref_head_cachep)
1152 goto fail;
1153
1154 btrfs_delayed_tree_ref_cachep = kmem_cache_create(
1155 "btrfs_delayed_tree_ref",
1156 sizeof(struct btrfs_delayed_tree_ref), 0,
1157 SLAB_MEM_SPREAD, NULL);
1158 if (!btrfs_delayed_tree_ref_cachep)
1159 goto fail;
1160
1161 btrfs_delayed_data_ref_cachep = kmem_cache_create(
1162 "btrfs_delayed_data_ref",
1163 sizeof(struct btrfs_delayed_data_ref), 0,
1164 SLAB_MEM_SPREAD, NULL);
1165 if (!btrfs_delayed_data_ref_cachep)
1166 goto fail;
1167
1168 btrfs_delayed_extent_op_cachep = kmem_cache_create(
1169 "btrfs_delayed_extent_op",
1170 sizeof(struct btrfs_delayed_extent_op), 0,
1171 SLAB_MEM_SPREAD, NULL);
1172 if (!btrfs_delayed_extent_op_cachep)
1173 goto fail;
1174
1175 return 0;
1176fail:
1177 btrfs_delayed_ref_exit();
1178 return -ENOMEM;
1179}
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (C) 2009 Oracle. All rights reserved.
4 */
5
6#include <linux/sched.h>
7#include <linux/slab.h>
8#include <linux/sort.h>
9#include "ctree.h"
10#include "delayed-ref.h"
11#include "transaction.h"
12#include "qgroup.h"
13#include "space-info.h"
14#include "tree-mod-log.h"
15
16struct kmem_cache *btrfs_delayed_ref_head_cachep;
17struct kmem_cache *btrfs_delayed_tree_ref_cachep;
18struct kmem_cache *btrfs_delayed_data_ref_cachep;
19struct kmem_cache *btrfs_delayed_extent_op_cachep;
20/*
21 * delayed back reference update tracking. For subvolume trees
22 * we queue up extent allocations and backref maintenance for
23 * delayed processing. This avoids deep call chains where we
24 * add extents in the middle of btrfs_search_slot, and it allows
25 * us to buffer up frequently modified backrefs in an rb tree instead
26 * of hammering updates on the extent allocation tree.
27 */
28
29bool btrfs_check_space_for_delayed_refs(struct btrfs_fs_info *fs_info)
30{
31 struct btrfs_block_rsv *delayed_refs_rsv = &fs_info->delayed_refs_rsv;
32 struct btrfs_block_rsv *global_rsv = &fs_info->global_block_rsv;
33 bool ret = false;
34 u64 reserved;
35
36 spin_lock(&global_rsv->lock);
37 reserved = global_rsv->reserved;
38 spin_unlock(&global_rsv->lock);
39
40 /*
41 * Since the global reserve is just kind of magic we don't really want
42 * to rely on it to save our bacon, so if our size is more than the
43 * delayed_refs_rsv and the global rsv then it's time to think about
44 * bailing.
45 */
46 spin_lock(&delayed_refs_rsv->lock);
47 reserved += delayed_refs_rsv->reserved;
48 if (delayed_refs_rsv->size >= reserved)
49 ret = true;
50 spin_unlock(&delayed_refs_rsv->lock);
51 return ret;
52}
53
54int btrfs_should_throttle_delayed_refs(struct btrfs_trans_handle *trans)
55{
56 u64 num_entries =
57 atomic_read(&trans->transaction->delayed_refs.num_entries);
58 u64 avg_runtime;
59 u64 val;
60
61 smp_mb();
62 avg_runtime = trans->fs_info->avg_delayed_ref_runtime;
63 val = num_entries * avg_runtime;
64 if (val >= NSEC_PER_SEC)
65 return 1;
66 if (val >= NSEC_PER_SEC / 2)
67 return 2;
68
69 return btrfs_check_space_for_delayed_refs(trans->fs_info);
70}
71
72/**
73 * Release a ref head's reservation
74 *
75 * @fs_info: the filesystem
76 * @nr: number of items to drop
77 *
78 * This drops the delayed ref head's count from the delayed refs rsv and frees
79 * any excess reservation we had.
80 */
81void btrfs_delayed_refs_rsv_release(struct btrfs_fs_info *fs_info, int nr)
82{
83 struct btrfs_block_rsv *block_rsv = &fs_info->delayed_refs_rsv;
84 u64 num_bytes = btrfs_calc_insert_metadata_size(fs_info, nr);
85 u64 released = 0;
86
87 released = btrfs_block_rsv_release(fs_info, block_rsv, num_bytes, NULL);
88 if (released)
89 trace_btrfs_space_reservation(fs_info, "delayed_refs_rsv",
90 0, released, 0);
91}
92
93/*
94 * btrfs_update_delayed_refs_rsv - adjust the size of the delayed refs rsv
95 * @trans - the trans that may have generated delayed refs
96 *
97 * This is to be called anytime we may have adjusted trans->delayed_ref_updates,
98 * it'll calculate the additional size and add it to the delayed_refs_rsv.
99 */
100void btrfs_update_delayed_refs_rsv(struct btrfs_trans_handle *trans)
101{
102 struct btrfs_fs_info *fs_info = trans->fs_info;
103 struct btrfs_block_rsv *delayed_rsv = &fs_info->delayed_refs_rsv;
104 u64 num_bytes;
105
106 if (!trans->delayed_ref_updates)
107 return;
108
109 num_bytes = btrfs_calc_insert_metadata_size(fs_info,
110 trans->delayed_ref_updates);
111 spin_lock(&delayed_rsv->lock);
112 delayed_rsv->size += num_bytes;
113 delayed_rsv->full = 0;
114 spin_unlock(&delayed_rsv->lock);
115 trans->delayed_ref_updates = 0;
116}
117
118/**
119 * Transfer bytes to our delayed refs rsv
120 *
121 * @fs_info: the filesystem
122 * @src: source block rsv to transfer from
123 * @num_bytes: number of bytes to transfer
124 *
125 * This transfers up to the num_bytes amount from the src rsv to the
126 * delayed_refs_rsv. Any extra bytes are returned to the space info.
127 */
128void btrfs_migrate_to_delayed_refs_rsv(struct btrfs_fs_info *fs_info,
129 struct btrfs_block_rsv *src,
130 u64 num_bytes)
131{
132 struct btrfs_block_rsv *delayed_refs_rsv = &fs_info->delayed_refs_rsv;
133 u64 to_free = 0;
134
135 spin_lock(&src->lock);
136 src->reserved -= num_bytes;
137 src->size -= num_bytes;
138 spin_unlock(&src->lock);
139
140 spin_lock(&delayed_refs_rsv->lock);
141 if (delayed_refs_rsv->size > delayed_refs_rsv->reserved) {
142 u64 delta = delayed_refs_rsv->size -
143 delayed_refs_rsv->reserved;
144 if (num_bytes > delta) {
145 to_free = num_bytes - delta;
146 num_bytes = delta;
147 }
148 } else {
149 to_free = num_bytes;
150 num_bytes = 0;
151 }
152
153 if (num_bytes)
154 delayed_refs_rsv->reserved += num_bytes;
155 if (delayed_refs_rsv->reserved >= delayed_refs_rsv->size)
156 delayed_refs_rsv->full = 1;
157 spin_unlock(&delayed_refs_rsv->lock);
158
159 if (num_bytes)
160 trace_btrfs_space_reservation(fs_info, "delayed_refs_rsv",
161 0, num_bytes, 1);
162 if (to_free)
163 btrfs_space_info_free_bytes_may_use(fs_info,
164 delayed_refs_rsv->space_info, to_free);
165}
166
167/**
168 * Refill based on our delayed refs usage
169 *
170 * @fs_info: the filesystem
171 * @flush: control how we can flush for this reservation.
172 *
173 * This will refill the delayed block_rsv up to 1 items size worth of space and
174 * will return -ENOSPC if we can't make the reservation.
175 */
176int btrfs_delayed_refs_rsv_refill(struct btrfs_fs_info *fs_info,
177 enum btrfs_reserve_flush_enum flush)
178{
179 struct btrfs_block_rsv *block_rsv = &fs_info->delayed_refs_rsv;
180 u64 limit = btrfs_calc_insert_metadata_size(fs_info, 1);
181 u64 num_bytes = 0;
182 int ret = -ENOSPC;
183
184 spin_lock(&block_rsv->lock);
185 if (block_rsv->reserved < block_rsv->size) {
186 num_bytes = block_rsv->size - block_rsv->reserved;
187 num_bytes = min(num_bytes, limit);
188 }
189 spin_unlock(&block_rsv->lock);
190
191 if (!num_bytes)
192 return 0;
193
194 ret = btrfs_reserve_metadata_bytes(fs_info->extent_root, block_rsv,
195 num_bytes, flush);
196 if (ret)
197 return ret;
198 btrfs_block_rsv_add_bytes(block_rsv, num_bytes, 0);
199 trace_btrfs_space_reservation(fs_info, "delayed_refs_rsv",
200 0, num_bytes, 1);
201 return 0;
202}
203
204/*
205 * compare two delayed tree backrefs with same bytenr and type
206 */
207static int comp_tree_refs(struct btrfs_delayed_tree_ref *ref1,
208 struct btrfs_delayed_tree_ref *ref2)
209{
210 if (ref1->node.type == BTRFS_TREE_BLOCK_REF_KEY) {
211 if (ref1->root < ref2->root)
212 return -1;
213 if (ref1->root > ref2->root)
214 return 1;
215 } else {
216 if (ref1->parent < ref2->parent)
217 return -1;
218 if (ref1->parent > ref2->parent)
219 return 1;
220 }
221 return 0;
222}
223
224/*
225 * compare two delayed data backrefs with same bytenr and type
226 */
227static int comp_data_refs(struct btrfs_delayed_data_ref *ref1,
228 struct btrfs_delayed_data_ref *ref2)
229{
230 if (ref1->node.type == BTRFS_EXTENT_DATA_REF_KEY) {
231 if (ref1->root < ref2->root)
232 return -1;
233 if (ref1->root > ref2->root)
234 return 1;
235 if (ref1->objectid < ref2->objectid)
236 return -1;
237 if (ref1->objectid > ref2->objectid)
238 return 1;
239 if (ref1->offset < ref2->offset)
240 return -1;
241 if (ref1->offset > ref2->offset)
242 return 1;
243 } else {
244 if (ref1->parent < ref2->parent)
245 return -1;
246 if (ref1->parent > ref2->parent)
247 return 1;
248 }
249 return 0;
250}
251
252static int comp_refs(struct btrfs_delayed_ref_node *ref1,
253 struct btrfs_delayed_ref_node *ref2,
254 bool check_seq)
255{
256 int ret = 0;
257
258 if (ref1->type < ref2->type)
259 return -1;
260 if (ref1->type > ref2->type)
261 return 1;
262 if (ref1->type == BTRFS_TREE_BLOCK_REF_KEY ||
263 ref1->type == BTRFS_SHARED_BLOCK_REF_KEY)
264 ret = comp_tree_refs(btrfs_delayed_node_to_tree_ref(ref1),
265 btrfs_delayed_node_to_tree_ref(ref2));
266 else
267 ret = comp_data_refs(btrfs_delayed_node_to_data_ref(ref1),
268 btrfs_delayed_node_to_data_ref(ref2));
269 if (ret)
270 return ret;
271 if (check_seq) {
272 if (ref1->seq < ref2->seq)
273 return -1;
274 if (ref1->seq > ref2->seq)
275 return 1;
276 }
277 return 0;
278}
279
280/* insert a new ref to head ref rbtree */
281static struct btrfs_delayed_ref_head *htree_insert(struct rb_root_cached *root,
282 struct rb_node *node)
283{
284 struct rb_node **p = &root->rb_root.rb_node;
285 struct rb_node *parent_node = NULL;
286 struct btrfs_delayed_ref_head *entry;
287 struct btrfs_delayed_ref_head *ins;
288 u64 bytenr;
289 bool leftmost = true;
290
291 ins = rb_entry(node, struct btrfs_delayed_ref_head, href_node);
292 bytenr = ins->bytenr;
293 while (*p) {
294 parent_node = *p;
295 entry = rb_entry(parent_node, struct btrfs_delayed_ref_head,
296 href_node);
297
298 if (bytenr < entry->bytenr) {
299 p = &(*p)->rb_left;
300 } else if (bytenr > entry->bytenr) {
301 p = &(*p)->rb_right;
302 leftmost = false;
303 } else {
304 return entry;
305 }
306 }
307
308 rb_link_node(node, parent_node, p);
309 rb_insert_color_cached(node, root, leftmost);
310 return NULL;
311}
312
313static struct btrfs_delayed_ref_node* tree_insert(struct rb_root_cached *root,
314 struct btrfs_delayed_ref_node *ins)
315{
316 struct rb_node **p = &root->rb_root.rb_node;
317 struct rb_node *node = &ins->ref_node;
318 struct rb_node *parent_node = NULL;
319 struct btrfs_delayed_ref_node *entry;
320 bool leftmost = true;
321
322 while (*p) {
323 int comp;
324
325 parent_node = *p;
326 entry = rb_entry(parent_node, struct btrfs_delayed_ref_node,
327 ref_node);
328 comp = comp_refs(ins, entry, true);
329 if (comp < 0) {
330 p = &(*p)->rb_left;
331 } else if (comp > 0) {
332 p = &(*p)->rb_right;
333 leftmost = false;
334 } else {
335 return entry;
336 }
337 }
338
339 rb_link_node(node, parent_node, p);
340 rb_insert_color_cached(node, root, leftmost);
341 return NULL;
342}
343
344static struct btrfs_delayed_ref_head *find_first_ref_head(
345 struct btrfs_delayed_ref_root *dr)
346{
347 struct rb_node *n;
348 struct btrfs_delayed_ref_head *entry;
349
350 n = rb_first_cached(&dr->href_root);
351 if (!n)
352 return NULL;
353
354 entry = rb_entry(n, struct btrfs_delayed_ref_head, href_node);
355
356 return entry;
357}
358
359/*
360 * Find a head entry based on bytenr. This returns the delayed ref head if it
361 * was able to find one, or NULL if nothing was in that spot. If return_bigger
362 * is given, the next bigger entry is returned if no exact match is found.
363 */
364static struct btrfs_delayed_ref_head *find_ref_head(
365 struct btrfs_delayed_ref_root *dr, u64 bytenr,
366 bool return_bigger)
367{
368 struct rb_root *root = &dr->href_root.rb_root;
369 struct rb_node *n;
370 struct btrfs_delayed_ref_head *entry;
371
372 n = root->rb_node;
373 entry = NULL;
374 while (n) {
375 entry = rb_entry(n, struct btrfs_delayed_ref_head, href_node);
376
377 if (bytenr < entry->bytenr)
378 n = n->rb_left;
379 else if (bytenr > entry->bytenr)
380 n = n->rb_right;
381 else
382 return entry;
383 }
384 if (entry && return_bigger) {
385 if (bytenr > entry->bytenr) {
386 n = rb_next(&entry->href_node);
387 if (!n)
388 return NULL;
389 entry = rb_entry(n, struct btrfs_delayed_ref_head,
390 href_node);
391 }
392 return entry;
393 }
394 return NULL;
395}
396
397int btrfs_delayed_ref_lock(struct btrfs_delayed_ref_root *delayed_refs,
398 struct btrfs_delayed_ref_head *head)
399{
400 lockdep_assert_held(&delayed_refs->lock);
401 if (mutex_trylock(&head->mutex))
402 return 0;
403
404 refcount_inc(&head->refs);
405 spin_unlock(&delayed_refs->lock);
406
407 mutex_lock(&head->mutex);
408 spin_lock(&delayed_refs->lock);
409 if (RB_EMPTY_NODE(&head->href_node)) {
410 mutex_unlock(&head->mutex);
411 btrfs_put_delayed_ref_head(head);
412 return -EAGAIN;
413 }
414 btrfs_put_delayed_ref_head(head);
415 return 0;
416}
417
418static inline void drop_delayed_ref(struct btrfs_trans_handle *trans,
419 struct btrfs_delayed_ref_root *delayed_refs,
420 struct btrfs_delayed_ref_head *head,
421 struct btrfs_delayed_ref_node *ref)
422{
423 lockdep_assert_held(&head->lock);
424 rb_erase_cached(&ref->ref_node, &head->ref_tree);
425 RB_CLEAR_NODE(&ref->ref_node);
426 if (!list_empty(&ref->add_list))
427 list_del(&ref->add_list);
428 ref->in_tree = 0;
429 btrfs_put_delayed_ref(ref);
430 atomic_dec(&delayed_refs->num_entries);
431}
432
433static bool merge_ref(struct btrfs_trans_handle *trans,
434 struct btrfs_delayed_ref_root *delayed_refs,
435 struct btrfs_delayed_ref_head *head,
436 struct btrfs_delayed_ref_node *ref,
437 u64 seq)
438{
439 struct btrfs_delayed_ref_node *next;
440 struct rb_node *node = rb_next(&ref->ref_node);
441 bool done = false;
442
443 while (!done && node) {
444 int mod;
445
446 next = rb_entry(node, struct btrfs_delayed_ref_node, ref_node);
447 node = rb_next(node);
448 if (seq && next->seq >= seq)
449 break;
450 if (comp_refs(ref, next, false))
451 break;
452
453 if (ref->action == next->action) {
454 mod = next->ref_mod;
455 } else {
456 if (ref->ref_mod < next->ref_mod) {
457 swap(ref, next);
458 done = true;
459 }
460 mod = -next->ref_mod;
461 }
462
463 drop_delayed_ref(trans, delayed_refs, head, next);
464 ref->ref_mod += mod;
465 if (ref->ref_mod == 0) {
466 drop_delayed_ref(trans, delayed_refs, head, ref);
467 done = true;
468 } else {
469 /*
470 * Can't have multiples of the same ref on a tree block.
471 */
472 WARN_ON(ref->type == BTRFS_TREE_BLOCK_REF_KEY ||
473 ref->type == BTRFS_SHARED_BLOCK_REF_KEY);
474 }
475 }
476
477 return done;
478}
479
480void btrfs_merge_delayed_refs(struct btrfs_trans_handle *trans,
481 struct btrfs_delayed_ref_root *delayed_refs,
482 struct btrfs_delayed_ref_head *head)
483{
484 struct btrfs_fs_info *fs_info = trans->fs_info;
485 struct btrfs_delayed_ref_node *ref;
486 struct rb_node *node;
487 u64 seq = 0;
488
489 lockdep_assert_held(&head->lock);
490
491 if (RB_EMPTY_ROOT(&head->ref_tree.rb_root))
492 return;
493
494 /* We don't have too many refs to merge for data. */
495 if (head->is_data)
496 return;
497
498 seq = btrfs_tree_mod_log_lowest_seq(fs_info);
499again:
500 for (node = rb_first_cached(&head->ref_tree); node;
501 node = rb_next(node)) {
502 ref = rb_entry(node, struct btrfs_delayed_ref_node, ref_node);
503 if (seq && ref->seq >= seq)
504 continue;
505 if (merge_ref(trans, delayed_refs, head, ref, seq))
506 goto again;
507 }
508}
509
510int btrfs_check_delayed_seq(struct btrfs_fs_info *fs_info, u64 seq)
511{
512 int ret = 0;
513 u64 min_seq = btrfs_tree_mod_log_lowest_seq(fs_info);
514
515 if (min_seq != 0 && seq >= min_seq) {
516 btrfs_debug(fs_info,
517 "holding back delayed_ref %llu, lowest is %llu",
518 seq, min_seq);
519 ret = 1;
520 }
521
522 return ret;
523}
524
525struct btrfs_delayed_ref_head *btrfs_select_ref_head(
526 struct btrfs_delayed_ref_root *delayed_refs)
527{
528 struct btrfs_delayed_ref_head *head;
529
530again:
531 head = find_ref_head(delayed_refs, delayed_refs->run_delayed_start,
532 true);
533 if (!head && delayed_refs->run_delayed_start != 0) {
534 delayed_refs->run_delayed_start = 0;
535 head = find_first_ref_head(delayed_refs);
536 }
537 if (!head)
538 return NULL;
539
540 while (head->processing) {
541 struct rb_node *node;
542
543 node = rb_next(&head->href_node);
544 if (!node) {
545 if (delayed_refs->run_delayed_start == 0)
546 return NULL;
547 delayed_refs->run_delayed_start = 0;
548 goto again;
549 }
550 head = rb_entry(node, struct btrfs_delayed_ref_head,
551 href_node);
552 }
553
554 head->processing = 1;
555 WARN_ON(delayed_refs->num_heads_ready == 0);
556 delayed_refs->num_heads_ready--;
557 delayed_refs->run_delayed_start = head->bytenr +
558 head->num_bytes;
559 return head;
560}
561
562void btrfs_delete_ref_head(struct btrfs_delayed_ref_root *delayed_refs,
563 struct btrfs_delayed_ref_head *head)
564{
565 lockdep_assert_held(&delayed_refs->lock);
566 lockdep_assert_held(&head->lock);
567
568 rb_erase_cached(&head->href_node, &delayed_refs->href_root);
569 RB_CLEAR_NODE(&head->href_node);
570 atomic_dec(&delayed_refs->num_entries);
571 delayed_refs->num_heads--;
572 if (head->processing == 0)
573 delayed_refs->num_heads_ready--;
574}
575
576/*
577 * Helper to insert the ref_node to the tail or merge with tail.
578 *
579 * Return 0 for insert.
580 * Return >0 for merge.
581 */
582static int insert_delayed_ref(struct btrfs_trans_handle *trans,
583 struct btrfs_delayed_ref_root *root,
584 struct btrfs_delayed_ref_head *href,
585 struct btrfs_delayed_ref_node *ref)
586{
587 struct btrfs_delayed_ref_node *exist;
588 int mod;
589 int ret = 0;
590
591 spin_lock(&href->lock);
592 exist = tree_insert(&href->ref_tree, ref);
593 if (!exist)
594 goto inserted;
595
596 /* Now we are sure we can merge */
597 ret = 1;
598 if (exist->action == ref->action) {
599 mod = ref->ref_mod;
600 } else {
601 /* Need to change action */
602 if (exist->ref_mod < ref->ref_mod) {
603 exist->action = ref->action;
604 mod = -exist->ref_mod;
605 exist->ref_mod = ref->ref_mod;
606 if (ref->action == BTRFS_ADD_DELAYED_REF)
607 list_add_tail(&exist->add_list,
608 &href->ref_add_list);
609 else if (ref->action == BTRFS_DROP_DELAYED_REF) {
610 ASSERT(!list_empty(&exist->add_list));
611 list_del(&exist->add_list);
612 } else {
613 ASSERT(0);
614 }
615 } else
616 mod = -ref->ref_mod;
617 }
618 exist->ref_mod += mod;
619
620 /* remove existing tail if its ref_mod is zero */
621 if (exist->ref_mod == 0)
622 drop_delayed_ref(trans, root, href, exist);
623 spin_unlock(&href->lock);
624 return ret;
625inserted:
626 if (ref->action == BTRFS_ADD_DELAYED_REF)
627 list_add_tail(&ref->add_list, &href->ref_add_list);
628 atomic_inc(&root->num_entries);
629 spin_unlock(&href->lock);
630 return ret;
631}
632
633/*
634 * helper function to update the accounting in the head ref
635 * existing and update must have the same bytenr
636 */
637static noinline void update_existing_head_ref(struct btrfs_trans_handle *trans,
638 struct btrfs_delayed_ref_head *existing,
639 struct btrfs_delayed_ref_head *update)
640{
641 struct btrfs_delayed_ref_root *delayed_refs =
642 &trans->transaction->delayed_refs;
643 struct btrfs_fs_info *fs_info = trans->fs_info;
644 int old_ref_mod;
645
646 BUG_ON(existing->is_data != update->is_data);
647
648 spin_lock(&existing->lock);
649 if (update->must_insert_reserved) {
650 /* if the extent was freed and then
651 * reallocated before the delayed ref
652 * entries were processed, we can end up
653 * with an existing head ref without
654 * the must_insert_reserved flag set.
655 * Set it again here
656 */
657 existing->must_insert_reserved = update->must_insert_reserved;
658
659 /*
660 * update the num_bytes so we make sure the accounting
661 * is done correctly
662 */
663 existing->num_bytes = update->num_bytes;
664
665 }
666
667 if (update->extent_op) {
668 if (!existing->extent_op) {
669 existing->extent_op = update->extent_op;
670 } else {
671 if (update->extent_op->update_key) {
672 memcpy(&existing->extent_op->key,
673 &update->extent_op->key,
674 sizeof(update->extent_op->key));
675 existing->extent_op->update_key = true;
676 }
677 if (update->extent_op->update_flags) {
678 existing->extent_op->flags_to_set |=
679 update->extent_op->flags_to_set;
680 existing->extent_op->update_flags = true;
681 }
682 btrfs_free_delayed_extent_op(update->extent_op);
683 }
684 }
685 /*
686 * update the reference mod on the head to reflect this new operation,
687 * only need the lock for this case cause we could be processing it
688 * currently, for refs we just added we know we're a-ok.
689 */
690 old_ref_mod = existing->total_ref_mod;
691 existing->ref_mod += update->ref_mod;
692 existing->total_ref_mod += update->ref_mod;
693
694 /*
695 * If we are going to from a positive ref mod to a negative or vice
696 * versa we need to make sure to adjust pending_csums accordingly.
697 */
698 if (existing->is_data) {
699 u64 csum_leaves =
700 btrfs_csum_bytes_to_leaves(fs_info,
701 existing->num_bytes);
702
703 if (existing->total_ref_mod >= 0 && old_ref_mod < 0) {
704 delayed_refs->pending_csums -= existing->num_bytes;
705 btrfs_delayed_refs_rsv_release(fs_info, csum_leaves);
706 }
707 if (existing->total_ref_mod < 0 && old_ref_mod >= 0) {
708 delayed_refs->pending_csums += existing->num_bytes;
709 trans->delayed_ref_updates += csum_leaves;
710 }
711 }
712
713 spin_unlock(&existing->lock);
714}
715
716static void init_delayed_ref_head(struct btrfs_delayed_ref_head *head_ref,
717 struct btrfs_qgroup_extent_record *qrecord,
718 u64 bytenr, u64 num_bytes, u64 ref_root,
719 u64 reserved, int action, bool is_data,
720 bool is_system)
721{
722 int count_mod = 1;
723 int must_insert_reserved = 0;
724
725 /* If reserved is provided, it must be a data extent. */
726 BUG_ON(!is_data && reserved);
727
728 /*
729 * The head node stores the sum of all the mods, so dropping a ref
730 * should drop the sum in the head node by one.
731 */
732 if (action == BTRFS_UPDATE_DELAYED_HEAD)
733 count_mod = 0;
734 else if (action == BTRFS_DROP_DELAYED_REF)
735 count_mod = -1;
736
737 /*
738 * BTRFS_ADD_DELAYED_EXTENT means that we need to update the reserved
739 * accounting when the extent is finally added, or if a later
740 * modification deletes the delayed ref without ever inserting the
741 * extent into the extent allocation tree. ref->must_insert_reserved
742 * is the flag used to record that accounting mods are required.
743 *
744 * Once we record must_insert_reserved, switch the action to
745 * BTRFS_ADD_DELAYED_REF because other special casing is not required.
746 */
747 if (action == BTRFS_ADD_DELAYED_EXTENT)
748 must_insert_reserved = 1;
749 else
750 must_insert_reserved = 0;
751
752 refcount_set(&head_ref->refs, 1);
753 head_ref->bytenr = bytenr;
754 head_ref->num_bytes = num_bytes;
755 head_ref->ref_mod = count_mod;
756 head_ref->must_insert_reserved = must_insert_reserved;
757 head_ref->is_data = is_data;
758 head_ref->is_system = is_system;
759 head_ref->ref_tree = RB_ROOT_CACHED;
760 INIT_LIST_HEAD(&head_ref->ref_add_list);
761 RB_CLEAR_NODE(&head_ref->href_node);
762 head_ref->processing = 0;
763 head_ref->total_ref_mod = count_mod;
764 spin_lock_init(&head_ref->lock);
765 mutex_init(&head_ref->mutex);
766
767 if (qrecord) {
768 if (ref_root && reserved) {
769 qrecord->data_rsv = reserved;
770 qrecord->data_rsv_refroot = ref_root;
771 }
772 qrecord->bytenr = bytenr;
773 qrecord->num_bytes = num_bytes;
774 qrecord->old_roots = NULL;
775 }
776}
777
778/*
779 * helper function to actually insert a head node into the rbtree.
780 * this does all the dirty work in terms of maintaining the correct
781 * overall modification count.
782 */
783static noinline struct btrfs_delayed_ref_head *
784add_delayed_ref_head(struct btrfs_trans_handle *trans,
785 struct btrfs_delayed_ref_head *head_ref,
786 struct btrfs_qgroup_extent_record *qrecord,
787 int action, int *qrecord_inserted_ret)
788{
789 struct btrfs_delayed_ref_head *existing;
790 struct btrfs_delayed_ref_root *delayed_refs;
791 int qrecord_inserted = 0;
792
793 delayed_refs = &trans->transaction->delayed_refs;
794
795 /* Record qgroup extent info if provided */
796 if (qrecord) {
797 if (btrfs_qgroup_trace_extent_nolock(trans->fs_info,
798 delayed_refs, qrecord))
799 kfree(qrecord);
800 else
801 qrecord_inserted = 1;
802 }
803
804 trace_add_delayed_ref_head(trans->fs_info, head_ref, action);
805
806 existing = htree_insert(&delayed_refs->href_root,
807 &head_ref->href_node);
808 if (existing) {
809 update_existing_head_ref(trans, existing, head_ref);
810 /*
811 * we've updated the existing ref, free the newly
812 * allocated ref
813 */
814 kmem_cache_free(btrfs_delayed_ref_head_cachep, head_ref);
815 head_ref = existing;
816 } else {
817 if (head_ref->is_data && head_ref->ref_mod < 0) {
818 delayed_refs->pending_csums += head_ref->num_bytes;
819 trans->delayed_ref_updates +=
820 btrfs_csum_bytes_to_leaves(trans->fs_info,
821 head_ref->num_bytes);
822 }
823 delayed_refs->num_heads++;
824 delayed_refs->num_heads_ready++;
825 atomic_inc(&delayed_refs->num_entries);
826 trans->delayed_ref_updates++;
827 }
828 if (qrecord_inserted_ret)
829 *qrecord_inserted_ret = qrecord_inserted;
830
831 return head_ref;
832}
833
834/*
835 * init_delayed_ref_common - Initialize the structure which represents a
836 * modification to a an extent.
837 *
838 * @fs_info: Internal to the mounted filesystem mount structure.
839 *
840 * @ref: The structure which is going to be initialized.
841 *
842 * @bytenr: The logical address of the extent for which a modification is
843 * going to be recorded.
844 *
845 * @num_bytes: Size of the extent whose modification is being recorded.
846 *
847 * @ref_root: The id of the root where this modification has originated, this
848 * can be either one of the well-known metadata trees or the
849 * subvolume id which references this extent.
850 *
851 * @action: Can be one of BTRFS_ADD_DELAYED_REF/BTRFS_DROP_DELAYED_REF or
852 * BTRFS_ADD_DELAYED_EXTENT
853 *
854 * @ref_type: Holds the type of the extent which is being recorded, can be
855 * one of BTRFS_SHARED_BLOCK_REF_KEY/BTRFS_TREE_BLOCK_REF_KEY
856 * when recording a metadata extent or BTRFS_SHARED_DATA_REF_KEY/
857 * BTRFS_EXTENT_DATA_REF_KEY when recording data extent
858 */
859static void init_delayed_ref_common(struct btrfs_fs_info *fs_info,
860 struct btrfs_delayed_ref_node *ref,
861 u64 bytenr, u64 num_bytes, u64 ref_root,
862 int action, u8 ref_type)
863{
864 u64 seq = 0;
865
866 if (action == BTRFS_ADD_DELAYED_EXTENT)
867 action = BTRFS_ADD_DELAYED_REF;
868
869 if (is_fstree(ref_root))
870 seq = atomic64_read(&fs_info->tree_mod_seq);
871
872 refcount_set(&ref->refs, 1);
873 ref->bytenr = bytenr;
874 ref->num_bytes = num_bytes;
875 ref->ref_mod = 1;
876 ref->action = action;
877 ref->is_head = 0;
878 ref->in_tree = 1;
879 ref->seq = seq;
880 ref->type = ref_type;
881 RB_CLEAR_NODE(&ref->ref_node);
882 INIT_LIST_HEAD(&ref->add_list);
883}
884
885/*
886 * add a delayed tree ref. This does all of the accounting required
887 * to make sure the delayed ref is eventually processed before this
888 * transaction commits.
889 */
890int btrfs_add_delayed_tree_ref(struct btrfs_trans_handle *trans,
891 struct btrfs_ref *generic_ref,
892 struct btrfs_delayed_extent_op *extent_op)
893{
894 struct btrfs_fs_info *fs_info = trans->fs_info;
895 struct btrfs_delayed_tree_ref *ref;
896 struct btrfs_delayed_ref_head *head_ref;
897 struct btrfs_delayed_ref_root *delayed_refs;
898 struct btrfs_qgroup_extent_record *record = NULL;
899 int qrecord_inserted;
900 bool is_system;
901 int action = generic_ref->action;
902 int level = generic_ref->tree_ref.level;
903 int ret;
904 u64 bytenr = generic_ref->bytenr;
905 u64 num_bytes = generic_ref->len;
906 u64 parent = generic_ref->parent;
907 u8 ref_type;
908
909 is_system = (generic_ref->real_root == BTRFS_CHUNK_TREE_OBJECTID);
910
911 ASSERT(generic_ref->type == BTRFS_REF_METADATA && generic_ref->action);
912 BUG_ON(extent_op && extent_op->is_data);
913 ref = kmem_cache_alloc(btrfs_delayed_tree_ref_cachep, GFP_NOFS);
914 if (!ref)
915 return -ENOMEM;
916
917 head_ref = kmem_cache_alloc(btrfs_delayed_ref_head_cachep, GFP_NOFS);
918 if (!head_ref) {
919 kmem_cache_free(btrfs_delayed_tree_ref_cachep, ref);
920 return -ENOMEM;
921 }
922
923 if (test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags) &&
924 is_fstree(generic_ref->real_root) &&
925 is_fstree(generic_ref->tree_ref.root) &&
926 !generic_ref->skip_qgroup) {
927 record = kzalloc(sizeof(*record), GFP_NOFS);
928 if (!record) {
929 kmem_cache_free(btrfs_delayed_tree_ref_cachep, ref);
930 kmem_cache_free(btrfs_delayed_ref_head_cachep, head_ref);
931 return -ENOMEM;
932 }
933 }
934
935 if (parent)
936 ref_type = BTRFS_SHARED_BLOCK_REF_KEY;
937 else
938 ref_type = BTRFS_TREE_BLOCK_REF_KEY;
939
940 init_delayed_ref_common(fs_info, &ref->node, bytenr, num_bytes,
941 generic_ref->tree_ref.root, action, ref_type);
942 ref->root = generic_ref->tree_ref.root;
943 ref->parent = parent;
944 ref->level = level;
945
946 init_delayed_ref_head(head_ref, record, bytenr, num_bytes,
947 generic_ref->tree_ref.root, 0, action, false,
948 is_system);
949 head_ref->extent_op = extent_op;
950
951 delayed_refs = &trans->transaction->delayed_refs;
952 spin_lock(&delayed_refs->lock);
953
954 /*
955 * insert both the head node and the new ref without dropping
956 * the spin lock
957 */
958 head_ref = add_delayed_ref_head(trans, head_ref, record,
959 action, &qrecord_inserted);
960
961 ret = insert_delayed_ref(trans, delayed_refs, head_ref, &ref->node);
962 spin_unlock(&delayed_refs->lock);
963
964 /*
965 * Need to update the delayed_refs_rsv with any changes we may have
966 * made.
967 */
968 btrfs_update_delayed_refs_rsv(trans);
969
970 trace_add_delayed_tree_ref(fs_info, &ref->node, ref,
971 action == BTRFS_ADD_DELAYED_EXTENT ?
972 BTRFS_ADD_DELAYED_REF : action);
973 if (ret > 0)
974 kmem_cache_free(btrfs_delayed_tree_ref_cachep, ref);
975
976 if (qrecord_inserted)
977 btrfs_qgroup_trace_extent_post(trans, record);
978
979 return 0;
980}
981
982/*
983 * add a delayed data ref. it's similar to btrfs_add_delayed_tree_ref.
984 */
985int btrfs_add_delayed_data_ref(struct btrfs_trans_handle *trans,
986 struct btrfs_ref *generic_ref,
987 u64 reserved)
988{
989 struct btrfs_fs_info *fs_info = trans->fs_info;
990 struct btrfs_delayed_data_ref *ref;
991 struct btrfs_delayed_ref_head *head_ref;
992 struct btrfs_delayed_ref_root *delayed_refs;
993 struct btrfs_qgroup_extent_record *record = NULL;
994 int qrecord_inserted;
995 int action = generic_ref->action;
996 int ret;
997 u64 bytenr = generic_ref->bytenr;
998 u64 num_bytes = generic_ref->len;
999 u64 parent = generic_ref->parent;
1000 u64 ref_root = generic_ref->data_ref.ref_root;
1001 u64 owner = generic_ref->data_ref.ino;
1002 u64 offset = generic_ref->data_ref.offset;
1003 u8 ref_type;
1004
1005 ASSERT(generic_ref->type == BTRFS_REF_DATA && action);
1006 ref = kmem_cache_alloc(btrfs_delayed_data_ref_cachep, GFP_NOFS);
1007 if (!ref)
1008 return -ENOMEM;
1009
1010 if (parent)
1011 ref_type = BTRFS_SHARED_DATA_REF_KEY;
1012 else
1013 ref_type = BTRFS_EXTENT_DATA_REF_KEY;
1014 init_delayed_ref_common(fs_info, &ref->node, bytenr, num_bytes,
1015 ref_root, action, ref_type);
1016 ref->root = ref_root;
1017 ref->parent = parent;
1018 ref->objectid = owner;
1019 ref->offset = offset;
1020
1021
1022 head_ref = kmem_cache_alloc(btrfs_delayed_ref_head_cachep, GFP_NOFS);
1023 if (!head_ref) {
1024 kmem_cache_free(btrfs_delayed_data_ref_cachep, ref);
1025 return -ENOMEM;
1026 }
1027
1028 if (test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags) &&
1029 is_fstree(ref_root) &&
1030 is_fstree(generic_ref->real_root) &&
1031 !generic_ref->skip_qgroup) {
1032 record = kzalloc(sizeof(*record), GFP_NOFS);
1033 if (!record) {
1034 kmem_cache_free(btrfs_delayed_data_ref_cachep, ref);
1035 kmem_cache_free(btrfs_delayed_ref_head_cachep,
1036 head_ref);
1037 return -ENOMEM;
1038 }
1039 }
1040
1041 init_delayed_ref_head(head_ref, record, bytenr, num_bytes, ref_root,
1042 reserved, action, true, false);
1043 head_ref->extent_op = NULL;
1044
1045 delayed_refs = &trans->transaction->delayed_refs;
1046 spin_lock(&delayed_refs->lock);
1047
1048 /*
1049 * insert both the head node and the new ref without dropping
1050 * the spin lock
1051 */
1052 head_ref = add_delayed_ref_head(trans, head_ref, record,
1053 action, &qrecord_inserted);
1054
1055 ret = insert_delayed_ref(trans, delayed_refs, head_ref, &ref->node);
1056 spin_unlock(&delayed_refs->lock);
1057
1058 /*
1059 * Need to update the delayed_refs_rsv with any changes we may have
1060 * made.
1061 */
1062 btrfs_update_delayed_refs_rsv(trans);
1063
1064 trace_add_delayed_data_ref(trans->fs_info, &ref->node, ref,
1065 action == BTRFS_ADD_DELAYED_EXTENT ?
1066 BTRFS_ADD_DELAYED_REF : action);
1067 if (ret > 0)
1068 kmem_cache_free(btrfs_delayed_data_ref_cachep, ref);
1069
1070
1071 if (qrecord_inserted)
1072 return btrfs_qgroup_trace_extent_post(trans, record);
1073 return 0;
1074}
1075
1076int btrfs_add_delayed_extent_op(struct btrfs_trans_handle *trans,
1077 u64 bytenr, u64 num_bytes,
1078 struct btrfs_delayed_extent_op *extent_op)
1079{
1080 struct btrfs_delayed_ref_head *head_ref;
1081 struct btrfs_delayed_ref_root *delayed_refs;
1082
1083 head_ref = kmem_cache_alloc(btrfs_delayed_ref_head_cachep, GFP_NOFS);
1084 if (!head_ref)
1085 return -ENOMEM;
1086
1087 init_delayed_ref_head(head_ref, NULL, bytenr, num_bytes, 0, 0,
1088 BTRFS_UPDATE_DELAYED_HEAD, extent_op->is_data,
1089 false);
1090 head_ref->extent_op = extent_op;
1091
1092 delayed_refs = &trans->transaction->delayed_refs;
1093 spin_lock(&delayed_refs->lock);
1094
1095 add_delayed_ref_head(trans, head_ref, NULL, BTRFS_UPDATE_DELAYED_HEAD,
1096 NULL);
1097
1098 spin_unlock(&delayed_refs->lock);
1099
1100 /*
1101 * Need to update the delayed_refs_rsv with any changes we may have
1102 * made.
1103 */
1104 btrfs_update_delayed_refs_rsv(trans);
1105 return 0;
1106}
1107
1108/*
1109 * This does a simple search for the head node for a given extent. Returns the
1110 * head node if found, or NULL if not.
1111 */
1112struct btrfs_delayed_ref_head *
1113btrfs_find_delayed_ref_head(struct btrfs_delayed_ref_root *delayed_refs, u64 bytenr)
1114{
1115 lockdep_assert_held(&delayed_refs->lock);
1116
1117 return find_ref_head(delayed_refs, bytenr, false);
1118}
1119
1120void __cold btrfs_delayed_ref_exit(void)
1121{
1122 kmem_cache_destroy(btrfs_delayed_ref_head_cachep);
1123 kmem_cache_destroy(btrfs_delayed_tree_ref_cachep);
1124 kmem_cache_destroy(btrfs_delayed_data_ref_cachep);
1125 kmem_cache_destroy(btrfs_delayed_extent_op_cachep);
1126}
1127
1128int __init btrfs_delayed_ref_init(void)
1129{
1130 btrfs_delayed_ref_head_cachep = kmem_cache_create(
1131 "btrfs_delayed_ref_head",
1132 sizeof(struct btrfs_delayed_ref_head), 0,
1133 SLAB_MEM_SPREAD, NULL);
1134 if (!btrfs_delayed_ref_head_cachep)
1135 goto fail;
1136
1137 btrfs_delayed_tree_ref_cachep = kmem_cache_create(
1138 "btrfs_delayed_tree_ref",
1139 sizeof(struct btrfs_delayed_tree_ref), 0,
1140 SLAB_MEM_SPREAD, NULL);
1141 if (!btrfs_delayed_tree_ref_cachep)
1142 goto fail;
1143
1144 btrfs_delayed_data_ref_cachep = kmem_cache_create(
1145 "btrfs_delayed_data_ref",
1146 sizeof(struct btrfs_delayed_data_ref), 0,
1147 SLAB_MEM_SPREAD, NULL);
1148 if (!btrfs_delayed_data_ref_cachep)
1149 goto fail;
1150
1151 btrfs_delayed_extent_op_cachep = kmem_cache_create(
1152 "btrfs_delayed_extent_op",
1153 sizeof(struct btrfs_delayed_extent_op), 0,
1154 SLAB_MEM_SPREAD, NULL);
1155 if (!btrfs_delayed_extent_op_cachep)
1156 goto fail;
1157
1158 return 0;
1159fail:
1160 btrfs_delayed_ref_exit();
1161 return -ENOMEM;
1162}