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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 "ctree.h"
10#include "delayed-ref.h"
11#include "transaction.h"
12#include "qgroup.h"
13#include "space-info.h"
14
15struct kmem_cache *btrfs_delayed_ref_head_cachep;
16struct kmem_cache *btrfs_delayed_tree_ref_cachep;
17struct kmem_cache *btrfs_delayed_data_ref_cachep;
18struct kmem_cache *btrfs_delayed_extent_op_cachep;
19/*
20 * delayed back reference update tracking. For subvolume trees
21 * we queue up extent allocations and backref maintenance for
22 * delayed processing. This avoids deep call chains where we
23 * add extents in the middle of btrfs_search_slot, and it allows
24 * us to buffer up frequently modified backrefs in an rb tree instead
25 * of hammering updates on the extent allocation tree.
26 */
27
28bool btrfs_check_space_for_delayed_refs(struct btrfs_fs_info *fs_info)
29{
30 struct btrfs_block_rsv *delayed_refs_rsv = &fs_info->delayed_refs_rsv;
31 struct btrfs_block_rsv *global_rsv = &fs_info->global_block_rsv;
32 bool ret = false;
33 u64 reserved;
34
35 spin_lock(&global_rsv->lock);
36 reserved = global_rsv->reserved;
37 spin_unlock(&global_rsv->lock);
38
39 /*
40 * Since the global reserve is just kind of magic we don't really want
41 * to rely on it to save our bacon, so if our size is more than the
42 * delayed_refs_rsv and the global rsv then it's time to think about
43 * bailing.
44 */
45 spin_lock(&delayed_refs_rsv->lock);
46 reserved += delayed_refs_rsv->reserved;
47 if (delayed_refs_rsv->size >= reserved)
48 ret = true;
49 spin_unlock(&delayed_refs_rsv->lock);
50 return ret;
51}
52
53int btrfs_should_throttle_delayed_refs(struct btrfs_trans_handle *trans)
54{
55 u64 num_entries =
56 atomic_read(&trans->transaction->delayed_refs.num_entries);
57 u64 avg_runtime;
58 u64 val;
59
60 smp_mb();
61 avg_runtime = trans->fs_info->avg_delayed_ref_runtime;
62 val = num_entries * avg_runtime;
63 if (val >= NSEC_PER_SEC)
64 return 1;
65 if (val >= NSEC_PER_SEC / 2)
66 return 2;
67
68 return btrfs_check_space_for_delayed_refs(trans->fs_info);
69}
70
71/**
72 * btrfs_delayed_refs_rsv_release - release a ref head's reservation.
73 * @fs_info - the fs_info for our fs.
74 * @nr - the number of items to drop.
75 *
76 * This drops the delayed ref head's count from the delayed refs rsv and frees
77 * any excess reservation we had.
78 */
79void btrfs_delayed_refs_rsv_release(struct btrfs_fs_info *fs_info, int nr)
80{
81 struct btrfs_block_rsv *block_rsv = &fs_info->delayed_refs_rsv;
82 u64 num_bytes = btrfs_calc_insert_metadata_size(fs_info, nr);
83 u64 released = 0;
84
85 released = __btrfs_block_rsv_release(fs_info, block_rsv, num_bytes,
86 NULL);
87 if (released)
88 trace_btrfs_space_reservation(fs_info, "delayed_refs_rsv",
89 0, released, 0);
90}
91
92/*
93 * btrfs_update_delayed_refs_rsv - adjust the size of the delayed refs rsv
94 * @trans - the trans that may have generated delayed refs
95 *
96 * This is to be called anytime we may have adjusted trans->delayed_ref_updates,
97 * it'll calculate the additional size and add it to the delayed_refs_rsv.
98 */
99void btrfs_update_delayed_refs_rsv(struct btrfs_trans_handle *trans)
100{
101 struct btrfs_fs_info *fs_info = trans->fs_info;
102 struct btrfs_block_rsv *delayed_rsv = &fs_info->delayed_refs_rsv;
103 u64 num_bytes;
104
105 if (!trans->delayed_ref_updates)
106 return;
107
108 num_bytes = btrfs_calc_insert_metadata_size(fs_info,
109 trans->delayed_ref_updates);
110 spin_lock(&delayed_rsv->lock);
111 delayed_rsv->size += num_bytes;
112 delayed_rsv->full = 0;
113 spin_unlock(&delayed_rsv->lock);
114 trans->delayed_ref_updates = 0;
115}
116
117/**
118 * btrfs_migrate_to_delayed_refs_rsv - transfer bytes to our delayed refs rsv.
119 * @fs_info - the fs info for our fs.
120 * @src - the source block rsv to transfer from.
121 * @num_bytes - the number of bytes to transfer.
122 *
123 * This transfers up to the num_bytes amount from the src rsv to the
124 * delayed_refs_rsv. Any extra bytes are returned to the space info.
125 */
126void btrfs_migrate_to_delayed_refs_rsv(struct btrfs_fs_info *fs_info,
127 struct btrfs_block_rsv *src,
128 u64 num_bytes)
129{
130 struct btrfs_block_rsv *delayed_refs_rsv = &fs_info->delayed_refs_rsv;
131 u64 to_free = 0;
132
133 spin_lock(&src->lock);
134 src->reserved -= num_bytes;
135 src->size -= num_bytes;
136 spin_unlock(&src->lock);
137
138 spin_lock(&delayed_refs_rsv->lock);
139 if (delayed_refs_rsv->size > delayed_refs_rsv->reserved) {
140 u64 delta = delayed_refs_rsv->size -
141 delayed_refs_rsv->reserved;
142 if (num_bytes > delta) {
143 to_free = num_bytes - delta;
144 num_bytes = delta;
145 }
146 } else {
147 to_free = num_bytes;
148 num_bytes = 0;
149 }
150
151 if (num_bytes)
152 delayed_refs_rsv->reserved += num_bytes;
153 if (delayed_refs_rsv->reserved >= delayed_refs_rsv->size)
154 delayed_refs_rsv->full = 1;
155 spin_unlock(&delayed_refs_rsv->lock);
156
157 if (num_bytes)
158 trace_btrfs_space_reservation(fs_info, "delayed_refs_rsv",
159 0, num_bytes, 1);
160 if (to_free)
161 btrfs_space_info_free_bytes_may_use(fs_info,
162 delayed_refs_rsv->space_info, to_free);
163}
164
165/**
166 * btrfs_delayed_refs_rsv_refill - refill based on our delayed refs usage.
167 * @fs_info - the fs_info for our fs.
168 * @flush - control how we can flush for this reservation.
169 *
170 * This will refill the delayed block_rsv up to 1 items size worth of space and
171 * will return -ENOSPC if we can't make the reservation.
172 */
173int btrfs_delayed_refs_rsv_refill(struct btrfs_fs_info *fs_info,
174 enum btrfs_reserve_flush_enum flush)
175{
176 struct btrfs_block_rsv *block_rsv = &fs_info->delayed_refs_rsv;
177 u64 limit = btrfs_calc_insert_metadata_size(fs_info, 1);
178 u64 num_bytes = 0;
179 int ret = -ENOSPC;
180
181 spin_lock(&block_rsv->lock);
182 if (block_rsv->reserved < block_rsv->size) {
183 num_bytes = block_rsv->size - block_rsv->reserved;
184 num_bytes = min(num_bytes, limit);
185 }
186 spin_unlock(&block_rsv->lock);
187
188 if (!num_bytes)
189 return 0;
190
191 ret = btrfs_reserve_metadata_bytes(fs_info->extent_root, block_rsv,
192 num_bytes, flush);
193 if (ret)
194 return ret;
195 btrfs_block_rsv_add_bytes(block_rsv, num_bytes, 0);
196 trace_btrfs_space_reservation(fs_info, "delayed_refs_rsv",
197 0, num_bytes, 1);
198 return 0;
199}
200
201/*
202 * compare two delayed tree backrefs with same bytenr and type
203 */
204static int comp_tree_refs(struct btrfs_delayed_tree_ref *ref1,
205 struct btrfs_delayed_tree_ref *ref2)
206{
207 if (ref1->node.type == BTRFS_TREE_BLOCK_REF_KEY) {
208 if (ref1->root < ref2->root)
209 return -1;
210 if (ref1->root > ref2->root)
211 return 1;
212 } else {
213 if (ref1->parent < ref2->parent)
214 return -1;
215 if (ref1->parent > ref2->parent)
216 return 1;
217 }
218 return 0;
219}
220
221/*
222 * compare two delayed data backrefs with same bytenr and type
223 */
224static int comp_data_refs(struct btrfs_delayed_data_ref *ref1,
225 struct btrfs_delayed_data_ref *ref2)
226{
227 if (ref1->node.type == BTRFS_EXTENT_DATA_REF_KEY) {
228 if (ref1->root < ref2->root)
229 return -1;
230 if (ref1->root > ref2->root)
231 return 1;
232 if (ref1->objectid < ref2->objectid)
233 return -1;
234 if (ref1->objectid > ref2->objectid)
235 return 1;
236 if (ref1->offset < ref2->offset)
237 return -1;
238 if (ref1->offset > ref2->offset)
239 return 1;
240 } else {
241 if (ref1->parent < ref2->parent)
242 return -1;
243 if (ref1->parent > ref2->parent)
244 return 1;
245 }
246 return 0;
247}
248
249static int comp_refs(struct btrfs_delayed_ref_node *ref1,
250 struct btrfs_delayed_ref_node *ref2,
251 bool check_seq)
252{
253 int ret = 0;
254
255 if (ref1->type < ref2->type)
256 return -1;
257 if (ref1->type > ref2->type)
258 return 1;
259 if (ref1->type == BTRFS_TREE_BLOCK_REF_KEY ||
260 ref1->type == BTRFS_SHARED_BLOCK_REF_KEY)
261 ret = comp_tree_refs(btrfs_delayed_node_to_tree_ref(ref1),
262 btrfs_delayed_node_to_tree_ref(ref2));
263 else
264 ret = comp_data_refs(btrfs_delayed_node_to_data_ref(ref1),
265 btrfs_delayed_node_to_data_ref(ref2));
266 if (ret)
267 return ret;
268 if (check_seq) {
269 if (ref1->seq < ref2->seq)
270 return -1;
271 if (ref1->seq > ref2->seq)
272 return 1;
273 }
274 return 0;
275}
276
277/* insert a new ref to head ref rbtree */
278static struct btrfs_delayed_ref_head *htree_insert(struct rb_root_cached *root,
279 struct rb_node *node)
280{
281 struct rb_node **p = &root->rb_root.rb_node;
282 struct rb_node *parent_node = NULL;
283 struct btrfs_delayed_ref_head *entry;
284 struct btrfs_delayed_ref_head *ins;
285 u64 bytenr;
286 bool leftmost = true;
287
288 ins = rb_entry(node, struct btrfs_delayed_ref_head, href_node);
289 bytenr = ins->bytenr;
290 while (*p) {
291 parent_node = *p;
292 entry = rb_entry(parent_node, struct btrfs_delayed_ref_head,
293 href_node);
294
295 if (bytenr < entry->bytenr) {
296 p = &(*p)->rb_left;
297 } else if (bytenr > entry->bytenr) {
298 p = &(*p)->rb_right;
299 leftmost = false;
300 } else {
301 return entry;
302 }
303 }
304
305 rb_link_node(node, parent_node, p);
306 rb_insert_color_cached(node, root, leftmost);
307 return NULL;
308}
309
310static struct btrfs_delayed_ref_node* tree_insert(struct rb_root_cached *root,
311 struct btrfs_delayed_ref_node *ins)
312{
313 struct rb_node **p = &root->rb_root.rb_node;
314 struct rb_node *node = &ins->ref_node;
315 struct rb_node *parent_node = NULL;
316 struct btrfs_delayed_ref_node *entry;
317 bool leftmost = true;
318
319 while (*p) {
320 int comp;
321
322 parent_node = *p;
323 entry = rb_entry(parent_node, struct btrfs_delayed_ref_node,
324 ref_node);
325 comp = comp_refs(ins, entry, true);
326 if (comp < 0) {
327 p = &(*p)->rb_left;
328 } else if (comp > 0) {
329 p = &(*p)->rb_right;
330 leftmost = false;
331 } else {
332 return entry;
333 }
334 }
335
336 rb_link_node(node, parent_node, p);
337 rb_insert_color_cached(node, root, leftmost);
338 return NULL;
339}
340
341static struct btrfs_delayed_ref_head *find_first_ref_head(
342 struct btrfs_delayed_ref_root *dr)
343{
344 struct rb_node *n;
345 struct btrfs_delayed_ref_head *entry;
346
347 n = rb_first_cached(&dr->href_root);
348 if (!n)
349 return NULL;
350
351 entry = rb_entry(n, struct btrfs_delayed_ref_head, href_node);
352
353 return entry;
354}
355
356/*
357 * Find a head entry based on bytenr. This returns the delayed ref head if it
358 * was able to find one, or NULL if nothing was in that spot. If return_bigger
359 * is given, the next bigger entry is returned if no exact match is found.
360 */
361static struct btrfs_delayed_ref_head *find_ref_head(
362 struct btrfs_delayed_ref_root *dr, u64 bytenr,
363 bool return_bigger)
364{
365 struct rb_root *root = &dr->href_root.rb_root;
366 struct rb_node *n;
367 struct btrfs_delayed_ref_head *entry;
368
369 n = root->rb_node;
370 entry = NULL;
371 while (n) {
372 entry = rb_entry(n, struct btrfs_delayed_ref_head, href_node);
373
374 if (bytenr < entry->bytenr)
375 n = n->rb_left;
376 else if (bytenr > entry->bytenr)
377 n = n->rb_right;
378 else
379 return entry;
380 }
381 if (entry && return_bigger) {
382 if (bytenr > entry->bytenr) {
383 n = rb_next(&entry->href_node);
384 if (!n)
385 return NULL;
386 entry = rb_entry(n, struct btrfs_delayed_ref_head,
387 href_node);
388 }
389 return entry;
390 }
391 return NULL;
392}
393
394int btrfs_delayed_ref_lock(struct btrfs_delayed_ref_root *delayed_refs,
395 struct btrfs_delayed_ref_head *head)
396{
397 lockdep_assert_held(&delayed_refs->lock);
398 if (mutex_trylock(&head->mutex))
399 return 0;
400
401 refcount_inc(&head->refs);
402 spin_unlock(&delayed_refs->lock);
403
404 mutex_lock(&head->mutex);
405 spin_lock(&delayed_refs->lock);
406 if (RB_EMPTY_NODE(&head->href_node)) {
407 mutex_unlock(&head->mutex);
408 btrfs_put_delayed_ref_head(head);
409 return -EAGAIN;
410 }
411 btrfs_put_delayed_ref_head(head);
412 return 0;
413}
414
415static inline void drop_delayed_ref(struct btrfs_trans_handle *trans,
416 struct btrfs_delayed_ref_root *delayed_refs,
417 struct btrfs_delayed_ref_head *head,
418 struct btrfs_delayed_ref_node *ref)
419{
420 lockdep_assert_held(&head->lock);
421 rb_erase_cached(&ref->ref_node, &head->ref_tree);
422 RB_CLEAR_NODE(&ref->ref_node);
423 if (!list_empty(&ref->add_list))
424 list_del(&ref->add_list);
425 ref->in_tree = 0;
426 btrfs_put_delayed_ref(ref);
427 atomic_dec(&delayed_refs->num_entries);
428}
429
430static bool merge_ref(struct btrfs_trans_handle *trans,
431 struct btrfs_delayed_ref_root *delayed_refs,
432 struct btrfs_delayed_ref_head *head,
433 struct btrfs_delayed_ref_node *ref,
434 u64 seq)
435{
436 struct btrfs_delayed_ref_node *next;
437 struct rb_node *node = rb_next(&ref->ref_node);
438 bool done = false;
439
440 while (!done && node) {
441 int mod;
442
443 next = rb_entry(node, struct btrfs_delayed_ref_node, ref_node);
444 node = rb_next(node);
445 if (seq && next->seq >= seq)
446 break;
447 if (comp_refs(ref, next, false))
448 break;
449
450 if (ref->action == next->action) {
451 mod = next->ref_mod;
452 } else {
453 if (ref->ref_mod < next->ref_mod) {
454 swap(ref, next);
455 done = true;
456 }
457 mod = -next->ref_mod;
458 }
459
460 drop_delayed_ref(trans, delayed_refs, head, next);
461 ref->ref_mod += mod;
462 if (ref->ref_mod == 0) {
463 drop_delayed_ref(trans, delayed_refs, head, ref);
464 done = true;
465 } else {
466 /*
467 * Can't have multiples of the same ref on a tree block.
468 */
469 WARN_ON(ref->type == BTRFS_TREE_BLOCK_REF_KEY ||
470 ref->type == BTRFS_SHARED_BLOCK_REF_KEY);
471 }
472 }
473
474 return done;
475}
476
477void btrfs_merge_delayed_refs(struct btrfs_trans_handle *trans,
478 struct btrfs_delayed_ref_root *delayed_refs,
479 struct btrfs_delayed_ref_head *head)
480{
481 struct btrfs_fs_info *fs_info = trans->fs_info;
482 struct btrfs_delayed_ref_node *ref;
483 struct rb_node *node;
484 u64 seq = 0;
485
486 lockdep_assert_held(&head->lock);
487
488 if (RB_EMPTY_ROOT(&head->ref_tree.rb_root))
489 return;
490
491 /* We don't have too many refs to merge for data. */
492 if (head->is_data)
493 return;
494
495 spin_lock(&fs_info->tree_mod_seq_lock);
496 if (!list_empty(&fs_info->tree_mod_seq_list)) {
497 struct seq_list *elem;
498
499 elem = list_first_entry(&fs_info->tree_mod_seq_list,
500 struct seq_list, list);
501 seq = elem->seq;
502 }
503 spin_unlock(&fs_info->tree_mod_seq_lock);
504
505again:
506 for (node = rb_first_cached(&head->ref_tree); node;
507 node = rb_next(node)) {
508 ref = rb_entry(node, struct btrfs_delayed_ref_node, ref_node);
509 if (seq && ref->seq >= seq)
510 continue;
511 if (merge_ref(trans, delayed_refs, head, ref, seq))
512 goto again;
513 }
514}
515
516int btrfs_check_delayed_seq(struct btrfs_fs_info *fs_info, u64 seq)
517{
518 struct seq_list *elem;
519 int ret = 0;
520
521 spin_lock(&fs_info->tree_mod_seq_lock);
522 if (!list_empty(&fs_info->tree_mod_seq_list)) {
523 elem = list_first_entry(&fs_info->tree_mod_seq_list,
524 struct seq_list, list);
525 if (seq >= elem->seq) {
526 btrfs_debug(fs_info,
527 "holding back delayed_ref %#x.%x, lowest is %#x.%x",
528 (u32)(seq >> 32), (u32)seq,
529 (u32)(elem->seq >> 32), (u32)elem->seq);
530 ret = 1;
531 }
532 }
533
534 spin_unlock(&fs_info->tree_mod_seq_lock);
535 return ret;
536}
537
538struct btrfs_delayed_ref_head *btrfs_select_ref_head(
539 struct btrfs_delayed_ref_root *delayed_refs)
540{
541 struct btrfs_delayed_ref_head *head;
542
543again:
544 head = find_ref_head(delayed_refs, delayed_refs->run_delayed_start,
545 true);
546 if (!head && delayed_refs->run_delayed_start != 0) {
547 delayed_refs->run_delayed_start = 0;
548 head = find_first_ref_head(delayed_refs);
549 }
550 if (!head)
551 return NULL;
552
553 while (head->processing) {
554 struct rb_node *node;
555
556 node = rb_next(&head->href_node);
557 if (!node) {
558 if (delayed_refs->run_delayed_start == 0)
559 return NULL;
560 delayed_refs->run_delayed_start = 0;
561 goto again;
562 }
563 head = rb_entry(node, struct btrfs_delayed_ref_head,
564 href_node);
565 }
566
567 head->processing = 1;
568 WARN_ON(delayed_refs->num_heads_ready == 0);
569 delayed_refs->num_heads_ready--;
570 delayed_refs->run_delayed_start = head->bytenr +
571 head->num_bytes;
572 return head;
573}
574
575void btrfs_delete_ref_head(struct btrfs_delayed_ref_root *delayed_refs,
576 struct btrfs_delayed_ref_head *head)
577{
578 lockdep_assert_held(&delayed_refs->lock);
579 lockdep_assert_held(&head->lock);
580
581 rb_erase_cached(&head->href_node, &delayed_refs->href_root);
582 RB_CLEAR_NODE(&head->href_node);
583 atomic_dec(&delayed_refs->num_entries);
584 delayed_refs->num_heads--;
585 if (head->processing == 0)
586 delayed_refs->num_heads_ready--;
587}
588
589/*
590 * Helper to insert the ref_node to the tail or merge with tail.
591 *
592 * Return 0 for insert.
593 * Return >0 for merge.
594 */
595static int insert_delayed_ref(struct btrfs_trans_handle *trans,
596 struct btrfs_delayed_ref_root *root,
597 struct btrfs_delayed_ref_head *href,
598 struct btrfs_delayed_ref_node *ref)
599{
600 struct btrfs_delayed_ref_node *exist;
601 int mod;
602 int ret = 0;
603
604 spin_lock(&href->lock);
605 exist = tree_insert(&href->ref_tree, ref);
606 if (!exist)
607 goto inserted;
608
609 /* Now we are sure we can merge */
610 ret = 1;
611 if (exist->action == ref->action) {
612 mod = ref->ref_mod;
613 } else {
614 /* Need to change action */
615 if (exist->ref_mod < ref->ref_mod) {
616 exist->action = ref->action;
617 mod = -exist->ref_mod;
618 exist->ref_mod = ref->ref_mod;
619 if (ref->action == BTRFS_ADD_DELAYED_REF)
620 list_add_tail(&exist->add_list,
621 &href->ref_add_list);
622 else if (ref->action == BTRFS_DROP_DELAYED_REF) {
623 ASSERT(!list_empty(&exist->add_list));
624 list_del(&exist->add_list);
625 } else {
626 ASSERT(0);
627 }
628 } else
629 mod = -ref->ref_mod;
630 }
631 exist->ref_mod += mod;
632
633 /* remove existing tail if its ref_mod is zero */
634 if (exist->ref_mod == 0)
635 drop_delayed_ref(trans, root, href, exist);
636 spin_unlock(&href->lock);
637 return ret;
638inserted:
639 if (ref->action == BTRFS_ADD_DELAYED_REF)
640 list_add_tail(&ref->add_list, &href->ref_add_list);
641 atomic_inc(&root->num_entries);
642 spin_unlock(&href->lock);
643 return ret;
644}
645
646/*
647 * helper function to update the accounting in the head ref
648 * existing and update must have the same bytenr
649 */
650static noinline void update_existing_head_ref(struct btrfs_trans_handle *trans,
651 struct btrfs_delayed_ref_head *existing,
652 struct btrfs_delayed_ref_head *update,
653 int *old_ref_mod_ret)
654{
655 struct btrfs_delayed_ref_root *delayed_refs =
656 &trans->transaction->delayed_refs;
657 struct btrfs_fs_info *fs_info = trans->fs_info;
658 int old_ref_mod;
659
660 BUG_ON(existing->is_data != update->is_data);
661
662 spin_lock(&existing->lock);
663 if (update->must_insert_reserved) {
664 /* if the extent was freed and then
665 * reallocated before the delayed ref
666 * entries were processed, we can end up
667 * with an existing head ref without
668 * the must_insert_reserved flag set.
669 * Set it again here
670 */
671 existing->must_insert_reserved = update->must_insert_reserved;
672
673 /*
674 * update the num_bytes so we make sure the accounting
675 * is done correctly
676 */
677 existing->num_bytes = update->num_bytes;
678
679 }
680
681 if (update->extent_op) {
682 if (!existing->extent_op) {
683 existing->extent_op = update->extent_op;
684 } else {
685 if (update->extent_op->update_key) {
686 memcpy(&existing->extent_op->key,
687 &update->extent_op->key,
688 sizeof(update->extent_op->key));
689 existing->extent_op->update_key = true;
690 }
691 if (update->extent_op->update_flags) {
692 existing->extent_op->flags_to_set |=
693 update->extent_op->flags_to_set;
694 existing->extent_op->update_flags = true;
695 }
696 btrfs_free_delayed_extent_op(update->extent_op);
697 }
698 }
699 /*
700 * update the reference mod on the head to reflect this new operation,
701 * only need the lock for this case cause we could be processing it
702 * currently, for refs we just added we know we're a-ok.
703 */
704 old_ref_mod = existing->total_ref_mod;
705 if (old_ref_mod_ret)
706 *old_ref_mod_ret = old_ref_mod;
707 existing->ref_mod += update->ref_mod;
708 existing->total_ref_mod += update->ref_mod;
709
710 /*
711 * If we are going to from a positive ref mod to a negative or vice
712 * versa we need to make sure to adjust pending_csums accordingly.
713 */
714 if (existing->is_data) {
715 u64 csum_leaves =
716 btrfs_csum_bytes_to_leaves(fs_info,
717 existing->num_bytes);
718
719 if (existing->total_ref_mod >= 0 && old_ref_mod < 0) {
720 delayed_refs->pending_csums -= existing->num_bytes;
721 btrfs_delayed_refs_rsv_release(fs_info, csum_leaves);
722 }
723 if (existing->total_ref_mod < 0 && old_ref_mod >= 0) {
724 delayed_refs->pending_csums += existing->num_bytes;
725 trans->delayed_ref_updates += csum_leaves;
726 }
727 }
728 spin_unlock(&existing->lock);
729}
730
731static void init_delayed_ref_head(struct btrfs_delayed_ref_head *head_ref,
732 struct btrfs_qgroup_extent_record *qrecord,
733 u64 bytenr, u64 num_bytes, u64 ref_root,
734 u64 reserved, int action, bool is_data,
735 bool is_system)
736{
737 int count_mod = 1;
738 int must_insert_reserved = 0;
739
740 /* If reserved is provided, it must be a data extent. */
741 BUG_ON(!is_data && reserved);
742
743 /*
744 * The head node stores the sum of all the mods, so dropping a ref
745 * should drop the sum in the head node by one.
746 */
747 if (action == BTRFS_UPDATE_DELAYED_HEAD)
748 count_mod = 0;
749 else if (action == BTRFS_DROP_DELAYED_REF)
750 count_mod = -1;
751
752 /*
753 * BTRFS_ADD_DELAYED_EXTENT means that we need to update the reserved
754 * accounting when the extent is finally added, or if a later
755 * modification deletes the delayed ref without ever inserting the
756 * extent into the extent allocation tree. ref->must_insert_reserved
757 * is the flag used to record that accounting mods are required.
758 *
759 * Once we record must_insert_reserved, switch the action to
760 * BTRFS_ADD_DELAYED_REF because other special casing is not required.
761 */
762 if (action == BTRFS_ADD_DELAYED_EXTENT)
763 must_insert_reserved = 1;
764 else
765 must_insert_reserved = 0;
766
767 refcount_set(&head_ref->refs, 1);
768 head_ref->bytenr = bytenr;
769 head_ref->num_bytes = num_bytes;
770 head_ref->ref_mod = count_mod;
771 head_ref->must_insert_reserved = must_insert_reserved;
772 head_ref->is_data = is_data;
773 head_ref->is_system = is_system;
774 head_ref->ref_tree = RB_ROOT_CACHED;
775 INIT_LIST_HEAD(&head_ref->ref_add_list);
776 RB_CLEAR_NODE(&head_ref->href_node);
777 head_ref->processing = 0;
778 head_ref->total_ref_mod = count_mod;
779 spin_lock_init(&head_ref->lock);
780 mutex_init(&head_ref->mutex);
781
782 if (qrecord) {
783 if (ref_root && reserved) {
784 qrecord->data_rsv = reserved;
785 qrecord->data_rsv_refroot = ref_root;
786 }
787 qrecord->bytenr = bytenr;
788 qrecord->num_bytes = num_bytes;
789 qrecord->old_roots = NULL;
790 }
791}
792
793/*
794 * helper function to actually insert a head node into the rbtree.
795 * this does all the dirty work in terms of maintaining the correct
796 * overall modification count.
797 */
798static noinline struct btrfs_delayed_ref_head *
799add_delayed_ref_head(struct btrfs_trans_handle *trans,
800 struct btrfs_delayed_ref_head *head_ref,
801 struct btrfs_qgroup_extent_record *qrecord,
802 int action, int *qrecord_inserted_ret,
803 int *old_ref_mod, int *new_ref_mod)
804{
805 struct btrfs_delayed_ref_head *existing;
806 struct btrfs_delayed_ref_root *delayed_refs;
807 int qrecord_inserted = 0;
808
809 delayed_refs = &trans->transaction->delayed_refs;
810
811 /* Record qgroup extent info if provided */
812 if (qrecord) {
813 if (btrfs_qgroup_trace_extent_nolock(trans->fs_info,
814 delayed_refs, qrecord))
815 kfree(qrecord);
816 else
817 qrecord_inserted = 1;
818 }
819
820 trace_add_delayed_ref_head(trans->fs_info, head_ref, action);
821
822 existing = htree_insert(&delayed_refs->href_root,
823 &head_ref->href_node);
824 if (existing) {
825 update_existing_head_ref(trans, existing, head_ref,
826 old_ref_mod);
827 /*
828 * we've updated the existing ref, free the newly
829 * allocated ref
830 */
831 kmem_cache_free(btrfs_delayed_ref_head_cachep, head_ref);
832 head_ref = existing;
833 } else {
834 if (old_ref_mod)
835 *old_ref_mod = 0;
836 if (head_ref->is_data && head_ref->ref_mod < 0) {
837 delayed_refs->pending_csums += head_ref->num_bytes;
838 trans->delayed_ref_updates +=
839 btrfs_csum_bytes_to_leaves(trans->fs_info,
840 head_ref->num_bytes);
841 }
842 delayed_refs->num_heads++;
843 delayed_refs->num_heads_ready++;
844 atomic_inc(&delayed_refs->num_entries);
845 trans->delayed_ref_updates++;
846 }
847 if (qrecord_inserted_ret)
848 *qrecord_inserted_ret = qrecord_inserted;
849 if (new_ref_mod)
850 *new_ref_mod = head_ref->total_ref_mod;
851
852 return head_ref;
853}
854
855/*
856 * init_delayed_ref_common - Initialize the structure which represents a
857 * modification to a an extent.
858 *
859 * @fs_info: Internal to the mounted filesystem mount structure.
860 *
861 * @ref: The structure which is going to be initialized.
862 *
863 * @bytenr: The logical address of the extent for which a modification is
864 * going to be recorded.
865 *
866 * @num_bytes: Size of the extent whose modification is being recorded.
867 *
868 * @ref_root: The id of the root where this modification has originated, this
869 * can be either one of the well-known metadata trees or the
870 * subvolume id which references this extent.
871 *
872 * @action: Can be one of BTRFS_ADD_DELAYED_REF/BTRFS_DROP_DELAYED_REF or
873 * BTRFS_ADD_DELAYED_EXTENT
874 *
875 * @ref_type: Holds the type of the extent which is being recorded, can be
876 * one of BTRFS_SHARED_BLOCK_REF_KEY/BTRFS_TREE_BLOCK_REF_KEY
877 * when recording a metadata extent or BTRFS_SHARED_DATA_REF_KEY/
878 * BTRFS_EXTENT_DATA_REF_KEY when recording data extent
879 */
880static void init_delayed_ref_common(struct btrfs_fs_info *fs_info,
881 struct btrfs_delayed_ref_node *ref,
882 u64 bytenr, u64 num_bytes, u64 ref_root,
883 int action, u8 ref_type)
884{
885 u64 seq = 0;
886
887 if (action == BTRFS_ADD_DELAYED_EXTENT)
888 action = BTRFS_ADD_DELAYED_REF;
889
890 if (is_fstree(ref_root))
891 seq = atomic64_read(&fs_info->tree_mod_seq);
892
893 refcount_set(&ref->refs, 1);
894 ref->bytenr = bytenr;
895 ref->num_bytes = num_bytes;
896 ref->ref_mod = 1;
897 ref->action = action;
898 ref->is_head = 0;
899 ref->in_tree = 1;
900 ref->seq = seq;
901 ref->type = ref_type;
902 RB_CLEAR_NODE(&ref->ref_node);
903 INIT_LIST_HEAD(&ref->add_list);
904}
905
906/*
907 * add a delayed tree ref. This does all of the accounting required
908 * to make sure the delayed ref is eventually processed before this
909 * transaction commits.
910 */
911int btrfs_add_delayed_tree_ref(struct btrfs_trans_handle *trans,
912 struct btrfs_ref *generic_ref,
913 struct btrfs_delayed_extent_op *extent_op,
914 int *old_ref_mod, int *new_ref_mod)
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->real_root == BTRFS_CHUNK_TREE_OBJECTID);
932
933 ASSERT(generic_ref->type == BTRFS_REF_METADATA && generic_ref->action);
934 BUG_ON(extent_op && extent_op->is_data);
935 ref = kmem_cache_alloc(btrfs_delayed_tree_ref_cachep, GFP_NOFS);
936 if (!ref)
937 return -ENOMEM;
938
939 head_ref = kmem_cache_alloc(btrfs_delayed_ref_head_cachep, GFP_NOFS);
940 if (!head_ref) {
941 kmem_cache_free(btrfs_delayed_tree_ref_cachep, ref);
942 return -ENOMEM;
943 }
944
945 if (test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags) &&
946 is_fstree(generic_ref->real_root) &&
947 is_fstree(generic_ref->tree_ref.root) &&
948 !generic_ref->skip_qgroup) {
949 record = kzalloc(sizeof(*record), GFP_NOFS);
950 if (!record) {
951 kmem_cache_free(btrfs_delayed_tree_ref_cachep, ref);
952 kmem_cache_free(btrfs_delayed_ref_head_cachep, head_ref);
953 return -ENOMEM;
954 }
955 }
956
957 if (parent)
958 ref_type = BTRFS_SHARED_BLOCK_REF_KEY;
959 else
960 ref_type = BTRFS_TREE_BLOCK_REF_KEY;
961
962 init_delayed_ref_common(fs_info, &ref->node, bytenr, num_bytes,
963 generic_ref->tree_ref.root, action, ref_type);
964 ref->root = generic_ref->tree_ref.root;
965 ref->parent = parent;
966 ref->level = level;
967
968 init_delayed_ref_head(head_ref, record, bytenr, num_bytes,
969 generic_ref->tree_ref.root, 0, action, false,
970 is_system);
971 head_ref->extent_op = extent_op;
972
973 delayed_refs = &trans->transaction->delayed_refs;
974 spin_lock(&delayed_refs->lock);
975
976 /*
977 * insert both the head node and the new ref without dropping
978 * the spin lock
979 */
980 head_ref = add_delayed_ref_head(trans, head_ref, record,
981 action, &qrecord_inserted,
982 old_ref_mod, new_ref_mod);
983
984 ret = insert_delayed_ref(trans, delayed_refs, head_ref, &ref->node);
985 spin_unlock(&delayed_refs->lock);
986
987 /*
988 * Need to update the delayed_refs_rsv with any changes we may have
989 * made.
990 */
991 btrfs_update_delayed_refs_rsv(trans);
992
993 trace_add_delayed_tree_ref(fs_info, &ref->node, ref,
994 action == BTRFS_ADD_DELAYED_EXTENT ?
995 BTRFS_ADD_DELAYED_REF : action);
996 if (ret > 0)
997 kmem_cache_free(btrfs_delayed_tree_ref_cachep, ref);
998
999 if (qrecord_inserted)
1000 btrfs_qgroup_trace_extent_post(fs_info, record);
1001
1002 return 0;
1003}
1004
1005/*
1006 * add a delayed data ref. it's similar to btrfs_add_delayed_tree_ref.
1007 */
1008int btrfs_add_delayed_data_ref(struct btrfs_trans_handle *trans,
1009 struct btrfs_ref *generic_ref,
1010 u64 reserved, int *old_ref_mod,
1011 int *new_ref_mod)
1012{
1013 struct btrfs_fs_info *fs_info = trans->fs_info;
1014 struct btrfs_delayed_data_ref *ref;
1015 struct btrfs_delayed_ref_head *head_ref;
1016 struct btrfs_delayed_ref_root *delayed_refs;
1017 struct btrfs_qgroup_extent_record *record = NULL;
1018 int qrecord_inserted;
1019 int action = generic_ref->action;
1020 int ret;
1021 u64 bytenr = generic_ref->bytenr;
1022 u64 num_bytes = generic_ref->len;
1023 u64 parent = generic_ref->parent;
1024 u64 ref_root = generic_ref->data_ref.ref_root;
1025 u64 owner = generic_ref->data_ref.ino;
1026 u64 offset = generic_ref->data_ref.offset;
1027 u8 ref_type;
1028
1029 ASSERT(generic_ref->type == BTRFS_REF_DATA && action);
1030 ref = kmem_cache_alloc(btrfs_delayed_data_ref_cachep, GFP_NOFS);
1031 if (!ref)
1032 return -ENOMEM;
1033
1034 if (parent)
1035 ref_type = BTRFS_SHARED_DATA_REF_KEY;
1036 else
1037 ref_type = BTRFS_EXTENT_DATA_REF_KEY;
1038 init_delayed_ref_common(fs_info, &ref->node, bytenr, num_bytes,
1039 ref_root, action, ref_type);
1040 ref->root = ref_root;
1041 ref->parent = parent;
1042 ref->objectid = owner;
1043 ref->offset = offset;
1044
1045
1046 head_ref = kmem_cache_alloc(btrfs_delayed_ref_head_cachep, GFP_NOFS);
1047 if (!head_ref) {
1048 kmem_cache_free(btrfs_delayed_data_ref_cachep, ref);
1049 return -ENOMEM;
1050 }
1051
1052 if (test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags) &&
1053 is_fstree(ref_root) &&
1054 is_fstree(generic_ref->real_root) &&
1055 !generic_ref->skip_qgroup) {
1056 record = kzalloc(sizeof(*record), GFP_NOFS);
1057 if (!record) {
1058 kmem_cache_free(btrfs_delayed_data_ref_cachep, ref);
1059 kmem_cache_free(btrfs_delayed_ref_head_cachep,
1060 head_ref);
1061 return -ENOMEM;
1062 }
1063 }
1064
1065 init_delayed_ref_head(head_ref, record, bytenr, num_bytes, ref_root,
1066 reserved, action, true, false);
1067 head_ref->extent_op = NULL;
1068
1069 delayed_refs = &trans->transaction->delayed_refs;
1070 spin_lock(&delayed_refs->lock);
1071
1072 /*
1073 * insert both the head node and the new ref without dropping
1074 * the spin lock
1075 */
1076 head_ref = add_delayed_ref_head(trans, head_ref, record,
1077 action, &qrecord_inserted,
1078 old_ref_mod, new_ref_mod);
1079
1080 ret = insert_delayed_ref(trans, delayed_refs, head_ref, &ref->node);
1081 spin_unlock(&delayed_refs->lock);
1082
1083 /*
1084 * Need to update the delayed_refs_rsv with any changes we may have
1085 * made.
1086 */
1087 btrfs_update_delayed_refs_rsv(trans);
1088
1089 trace_add_delayed_data_ref(trans->fs_info, &ref->node, ref,
1090 action == BTRFS_ADD_DELAYED_EXTENT ?
1091 BTRFS_ADD_DELAYED_REF : action);
1092 if (ret > 0)
1093 kmem_cache_free(btrfs_delayed_data_ref_cachep, ref);
1094
1095
1096 if (qrecord_inserted)
1097 return btrfs_qgroup_trace_extent_post(fs_info, record);
1098 return 0;
1099}
1100
1101int btrfs_add_delayed_extent_op(struct btrfs_trans_handle *trans,
1102 u64 bytenr, u64 num_bytes,
1103 struct btrfs_delayed_extent_op *extent_op)
1104{
1105 struct btrfs_delayed_ref_head *head_ref;
1106 struct btrfs_delayed_ref_root *delayed_refs;
1107
1108 head_ref = kmem_cache_alloc(btrfs_delayed_ref_head_cachep, GFP_NOFS);
1109 if (!head_ref)
1110 return -ENOMEM;
1111
1112 init_delayed_ref_head(head_ref, NULL, bytenr, num_bytes, 0, 0,
1113 BTRFS_UPDATE_DELAYED_HEAD, extent_op->is_data,
1114 false);
1115 head_ref->extent_op = extent_op;
1116
1117 delayed_refs = &trans->transaction->delayed_refs;
1118 spin_lock(&delayed_refs->lock);
1119
1120 add_delayed_ref_head(trans, head_ref, NULL, BTRFS_UPDATE_DELAYED_HEAD,
1121 NULL, NULL, NULL);
1122
1123 spin_unlock(&delayed_refs->lock);
1124
1125 /*
1126 * Need to update the delayed_refs_rsv with any changes we may have
1127 * made.
1128 */
1129 btrfs_update_delayed_refs_rsv(trans);
1130 return 0;
1131}
1132
1133/*
1134 * This does a simple search for the head node for a given extent. Returns the
1135 * head node if found, or NULL if not.
1136 */
1137struct btrfs_delayed_ref_head *
1138btrfs_find_delayed_ref_head(struct btrfs_delayed_ref_root *delayed_refs, u64 bytenr)
1139{
1140 lockdep_assert_held(&delayed_refs->lock);
1141
1142 return find_ref_head(delayed_refs, bytenr, false);
1143}
1144
1145void __cold btrfs_delayed_ref_exit(void)
1146{
1147 kmem_cache_destroy(btrfs_delayed_ref_head_cachep);
1148 kmem_cache_destroy(btrfs_delayed_tree_ref_cachep);
1149 kmem_cache_destroy(btrfs_delayed_data_ref_cachep);
1150 kmem_cache_destroy(btrfs_delayed_extent_op_cachep);
1151}
1152
1153int __init btrfs_delayed_ref_init(void)
1154{
1155 btrfs_delayed_ref_head_cachep = kmem_cache_create(
1156 "btrfs_delayed_ref_head",
1157 sizeof(struct btrfs_delayed_ref_head), 0,
1158 SLAB_MEM_SPREAD, NULL);
1159 if (!btrfs_delayed_ref_head_cachep)
1160 goto fail;
1161
1162 btrfs_delayed_tree_ref_cachep = kmem_cache_create(
1163 "btrfs_delayed_tree_ref",
1164 sizeof(struct btrfs_delayed_tree_ref), 0,
1165 SLAB_MEM_SPREAD, NULL);
1166 if (!btrfs_delayed_tree_ref_cachep)
1167 goto fail;
1168
1169 btrfs_delayed_data_ref_cachep = kmem_cache_create(
1170 "btrfs_delayed_data_ref",
1171 sizeof(struct btrfs_delayed_data_ref), 0,
1172 SLAB_MEM_SPREAD, NULL);
1173 if (!btrfs_delayed_data_ref_cachep)
1174 goto fail;
1175
1176 btrfs_delayed_extent_op_cachep = kmem_cache_create(
1177 "btrfs_delayed_extent_op",
1178 sizeof(struct btrfs_delayed_extent_op), 0,
1179 SLAB_MEM_SPREAD, NULL);
1180 if (!btrfs_delayed_extent_op_cachep)
1181 goto fail;
1182
1183 return 0;
1184fail:
1185 btrfs_delayed_ref_exit();
1186 return -ENOMEM;
1187}
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}