Loading...
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/*
2 * Copyright (C) 2009 Oracle. All rights reserved.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
17 */
18
19#include <linux/sched.h>
20#include <linux/slab.h>
21#include <linux/sort.h>
22#include "ctree.h"
23#include "delayed-ref.h"
24#include "transaction.h"
25#include "qgroup.h"
26
27struct kmem_cache *btrfs_delayed_ref_head_cachep;
28struct kmem_cache *btrfs_delayed_tree_ref_cachep;
29struct kmem_cache *btrfs_delayed_data_ref_cachep;
30struct kmem_cache *btrfs_delayed_extent_op_cachep;
31/*
32 * delayed back reference update tracking. For subvolume trees
33 * we queue up extent allocations and backref maintenance for
34 * delayed processing. This avoids deep call chains where we
35 * add extents in the middle of btrfs_search_slot, and it allows
36 * us to buffer up frequently modified backrefs in an rb tree instead
37 * of hammering updates on the extent allocation tree.
38 */
39
40/*
41 * compare two delayed tree backrefs with same bytenr and type
42 */
43static int comp_tree_refs(struct btrfs_delayed_tree_ref *ref2,
44 struct btrfs_delayed_tree_ref *ref1, int type)
45{
46 if (type == BTRFS_TREE_BLOCK_REF_KEY) {
47 if (ref1->root < ref2->root)
48 return -1;
49 if (ref1->root > ref2->root)
50 return 1;
51 } else {
52 if (ref1->parent < ref2->parent)
53 return -1;
54 if (ref1->parent > ref2->parent)
55 return 1;
56 }
57 return 0;
58}
59
60/*
61 * compare two delayed data backrefs with same bytenr and type
62 */
63static int comp_data_refs(struct btrfs_delayed_data_ref *ref2,
64 struct btrfs_delayed_data_ref *ref1)
65{
66 if (ref1->node.type == BTRFS_EXTENT_DATA_REF_KEY) {
67 if (ref1->root < ref2->root)
68 return -1;
69 if (ref1->root > ref2->root)
70 return 1;
71 if (ref1->objectid < ref2->objectid)
72 return -1;
73 if (ref1->objectid > ref2->objectid)
74 return 1;
75 if (ref1->offset < ref2->offset)
76 return -1;
77 if (ref1->offset > ref2->offset)
78 return 1;
79 } else {
80 if (ref1->parent < ref2->parent)
81 return -1;
82 if (ref1->parent > ref2->parent)
83 return 1;
84 }
85 return 0;
86}
87
88/* insert a new ref to head ref rbtree */
89static struct btrfs_delayed_ref_head *htree_insert(struct rb_root *root,
90 struct rb_node *node)
91{
92 struct rb_node **p = &root->rb_node;
93 struct rb_node *parent_node = NULL;
94 struct btrfs_delayed_ref_head *entry;
95 struct btrfs_delayed_ref_head *ins;
96 u64 bytenr;
97
98 ins = rb_entry(node, struct btrfs_delayed_ref_head, href_node);
99 bytenr = ins->node.bytenr;
100 while (*p) {
101 parent_node = *p;
102 entry = rb_entry(parent_node, struct btrfs_delayed_ref_head,
103 href_node);
104
105 if (bytenr < entry->node.bytenr)
106 p = &(*p)->rb_left;
107 else if (bytenr > entry->node.bytenr)
108 p = &(*p)->rb_right;
109 else
110 return entry;
111 }
112
113 rb_link_node(node, parent_node, p);
114 rb_insert_color(node, root);
115 return NULL;
116}
117
118/*
119 * find an head entry based on bytenr. This returns the delayed ref
120 * head if it was able to find one, or NULL if nothing was in that spot.
121 * If return_bigger is given, the next bigger entry is returned if no exact
122 * match is found.
123 */
124static struct btrfs_delayed_ref_head *
125find_ref_head(struct rb_root *root, u64 bytenr,
126 int return_bigger)
127{
128 struct rb_node *n;
129 struct btrfs_delayed_ref_head *entry;
130
131 n = root->rb_node;
132 entry = NULL;
133 while (n) {
134 entry = rb_entry(n, struct btrfs_delayed_ref_head, href_node);
135
136 if (bytenr < entry->node.bytenr)
137 n = n->rb_left;
138 else if (bytenr > entry->node.bytenr)
139 n = n->rb_right;
140 else
141 return entry;
142 }
143 if (entry && return_bigger) {
144 if (bytenr > entry->node.bytenr) {
145 n = rb_next(&entry->href_node);
146 if (!n)
147 n = rb_first(root);
148 entry = rb_entry(n, struct btrfs_delayed_ref_head,
149 href_node);
150 return entry;
151 }
152 return entry;
153 }
154 return NULL;
155}
156
157int btrfs_delayed_ref_lock(struct btrfs_trans_handle *trans,
158 struct btrfs_delayed_ref_head *head)
159{
160 struct btrfs_delayed_ref_root *delayed_refs;
161
162 delayed_refs = &trans->transaction->delayed_refs;
163 assert_spin_locked(&delayed_refs->lock);
164 if (mutex_trylock(&head->mutex))
165 return 0;
166
167 atomic_inc(&head->node.refs);
168 spin_unlock(&delayed_refs->lock);
169
170 mutex_lock(&head->mutex);
171 spin_lock(&delayed_refs->lock);
172 if (!head->node.in_tree) {
173 mutex_unlock(&head->mutex);
174 btrfs_put_delayed_ref(&head->node);
175 return -EAGAIN;
176 }
177 btrfs_put_delayed_ref(&head->node);
178 return 0;
179}
180
181static inline void drop_delayed_ref(struct btrfs_trans_handle *trans,
182 struct btrfs_delayed_ref_root *delayed_refs,
183 struct btrfs_delayed_ref_head *head,
184 struct btrfs_delayed_ref_node *ref)
185{
186 if (btrfs_delayed_ref_is_head(ref)) {
187 head = btrfs_delayed_node_to_head(ref);
188 rb_erase(&head->href_node, &delayed_refs->href_root);
189 } else {
190 assert_spin_locked(&head->lock);
191 list_del(&ref->list);
192 if (!list_empty(&ref->add_list))
193 list_del(&ref->add_list);
194 }
195 ref->in_tree = 0;
196 btrfs_put_delayed_ref(ref);
197 atomic_dec(&delayed_refs->num_entries);
198 if (trans->delayed_ref_updates)
199 trans->delayed_ref_updates--;
200}
201
202static bool merge_ref(struct btrfs_trans_handle *trans,
203 struct btrfs_delayed_ref_root *delayed_refs,
204 struct btrfs_delayed_ref_head *head,
205 struct btrfs_delayed_ref_node *ref,
206 u64 seq)
207{
208 struct btrfs_delayed_ref_node *next;
209 bool done = false;
210
211 next = list_first_entry(&head->ref_list, struct btrfs_delayed_ref_node,
212 list);
213 while (!done && &next->list != &head->ref_list) {
214 int mod;
215 struct btrfs_delayed_ref_node *next2;
216
217 next2 = list_next_entry(next, list);
218
219 if (next == ref)
220 goto next;
221
222 if (seq && next->seq >= seq)
223 goto next;
224
225 if (next->type != ref->type)
226 goto next;
227
228 if ((ref->type == BTRFS_TREE_BLOCK_REF_KEY ||
229 ref->type == BTRFS_SHARED_BLOCK_REF_KEY) &&
230 comp_tree_refs(btrfs_delayed_node_to_tree_ref(ref),
231 btrfs_delayed_node_to_tree_ref(next),
232 ref->type))
233 goto next;
234 if ((ref->type == BTRFS_EXTENT_DATA_REF_KEY ||
235 ref->type == BTRFS_SHARED_DATA_REF_KEY) &&
236 comp_data_refs(btrfs_delayed_node_to_data_ref(ref),
237 btrfs_delayed_node_to_data_ref(next)))
238 goto next;
239
240 if (ref->action == next->action) {
241 mod = next->ref_mod;
242 } else {
243 if (ref->ref_mod < next->ref_mod) {
244 swap(ref, next);
245 done = true;
246 }
247 mod = -next->ref_mod;
248 }
249
250 drop_delayed_ref(trans, delayed_refs, head, next);
251 ref->ref_mod += mod;
252 if (ref->ref_mod == 0) {
253 drop_delayed_ref(trans, delayed_refs, head, ref);
254 done = true;
255 } else {
256 /*
257 * Can't have multiples of the same ref on a tree block.
258 */
259 WARN_ON(ref->type == BTRFS_TREE_BLOCK_REF_KEY ||
260 ref->type == BTRFS_SHARED_BLOCK_REF_KEY);
261 }
262next:
263 next = next2;
264 }
265
266 return done;
267}
268
269void btrfs_merge_delayed_refs(struct btrfs_trans_handle *trans,
270 struct btrfs_fs_info *fs_info,
271 struct btrfs_delayed_ref_root *delayed_refs,
272 struct btrfs_delayed_ref_head *head)
273{
274 struct btrfs_delayed_ref_node *ref;
275 u64 seq = 0;
276
277 assert_spin_locked(&head->lock);
278
279 if (list_empty(&head->ref_list))
280 return;
281
282 /* We don't have too many refs to merge for data. */
283 if (head->is_data)
284 return;
285
286 spin_lock(&fs_info->tree_mod_seq_lock);
287 if (!list_empty(&fs_info->tree_mod_seq_list)) {
288 struct seq_list *elem;
289
290 elem = list_first_entry(&fs_info->tree_mod_seq_list,
291 struct seq_list, list);
292 seq = elem->seq;
293 }
294 spin_unlock(&fs_info->tree_mod_seq_lock);
295
296 ref = list_first_entry(&head->ref_list, struct btrfs_delayed_ref_node,
297 list);
298 while (&ref->list != &head->ref_list) {
299 if (seq && ref->seq >= seq)
300 goto next;
301
302 if (merge_ref(trans, delayed_refs, head, ref, seq)) {
303 if (list_empty(&head->ref_list))
304 break;
305 ref = list_first_entry(&head->ref_list,
306 struct btrfs_delayed_ref_node,
307 list);
308 continue;
309 }
310next:
311 ref = list_next_entry(ref, list);
312 }
313}
314
315int btrfs_check_delayed_seq(struct btrfs_fs_info *fs_info,
316 struct btrfs_delayed_ref_root *delayed_refs,
317 u64 seq)
318{
319 struct seq_list *elem;
320 int ret = 0;
321
322 spin_lock(&fs_info->tree_mod_seq_lock);
323 if (!list_empty(&fs_info->tree_mod_seq_list)) {
324 elem = list_first_entry(&fs_info->tree_mod_seq_list,
325 struct seq_list, list);
326 if (seq >= elem->seq) {
327 btrfs_debug(fs_info,
328 "holding back delayed_ref %#x.%x, lowest is %#x.%x (%p)",
329 (u32)(seq >> 32), (u32)seq,
330 (u32)(elem->seq >> 32), (u32)elem->seq,
331 delayed_refs);
332 ret = 1;
333 }
334 }
335
336 spin_unlock(&fs_info->tree_mod_seq_lock);
337 return ret;
338}
339
340struct btrfs_delayed_ref_head *
341btrfs_select_ref_head(struct btrfs_trans_handle *trans)
342{
343 struct btrfs_delayed_ref_root *delayed_refs;
344 struct btrfs_delayed_ref_head *head;
345 u64 start;
346 bool loop = false;
347
348 delayed_refs = &trans->transaction->delayed_refs;
349
350again:
351 start = delayed_refs->run_delayed_start;
352 head = find_ref_head(&delayed_refs->href_root, start, 1);
353 if (!head && !loop) {
354 delayed_refs->run_delayed_start = 0;
355 start = 0;
356 loop = true;
357 head = find_ref_head(&delayed_refs->href_root, start, 1);
358 if (!head)
359 return NULL;
360 } else if (!head && loop) {
361 return NULL;
362 }
363
364 while (head->processing) {
365 struct rb_node *node;
366
367 node = rb_next(&head->href_node);
368 if (!node) {
369 if (loop)
370 return NULL;
371 delayed_refs->run_delayed_start = 0;
372 start = 0;
373 loop = true;
374 goto again;
375 }
376 head = rb_entry(node, struct btrfs_delayed_ref_head,
377 href_node);
378 }
379
380 head->processing = 1;
381 WARN_ON(delayed_refs->num_heads_ready == 0);
382 delayed_refs->num_heads_ready--;
383 delayed_refs->run_delayed_start = head->node.bytenr +
384 head->node.num_bytes;
385 return head;
386}
387
388/*
389 * Helper to insert the ref_node to the tail or merge with tail.
390 *
391 * Return 0 for insert.
392 * Return >0 for merge.
393 */
394static int
395add_delayed_ref_tail_merge(struct btrfs_trans_handle *trans,
396 struct btrfs_delayed_ref_root *root,
397 struct btrfs_delayed_ref_head *href,
398 struct btrfs_delayed_ref_node *ref)
399{
400 struct btrfs_delayed_ref_node *exist;
401 int mod;
402 int ret = 0;
403
404 spin_lock(&href->lock);
405 /* Check whether we can merge the tail node with ref */
406 if (list_empty(&href->ref_list))
407 goto add_tail;
408 exist = list_entry(href->ref_list.prev, struct btrfs_delayed_ref_node,
409 list);
410 /* No need to compare bytenr nor is_head */
411 if (exist->type != ref->type || exist->seq != ref->seq)
412 goto add_tail;
413
414 if ((exist->type == BTRFS_TREE_BLOCK_REF_KEY ||
415 exist->type == BTRFS_SHARED_BLOCK_REF_KEY) &&
416 comp_tree_refs(btrfs_delayed_node_to_tree_ref(exist),
417 btrfs_delayed_node_to_tree_ref(ref),
418 ref->type))
419 goto add_tail;
420 if ((exist->type == BTRFS_EXTENT_DATA_REF_KEY ||
421 exist->type == BTRFS_SHARED_DATA_REF_KEY) &&
422 comp_data_refs(btrfs_delayed_node_to_data_ref(exist),
423 btrfs_delayed_node_to_data_ref(ref)))
424 goto add_tail;
425
426 /* Now we are sure we can merge */
427 ret = 1;
428 if (exist->action == ref->action) {
429 mod = ref->ref_mod;
430 } else {
431 /* Need to change action */
432 if (exist->ref_mod < ref->ref_mod) {
433 exist->action = ref->action;
434 mod = -exist->ref_mod;
435 exist->ref_mod = ref->ref_mod;
436 if (ref->action == BTRFS_ADD_DELAYED_REF)
437 list_add_tail(&exist->add_list,
438 &href->ref_add_list);
439 else if (ref->action == BTRFS_DROP_DELAYED_REF) {
440 ASSERT(!list_empty(&exist->add_list));
441 list_del(&exist->add_list);
442 } else {
443 ASSERT(0);
444 }
445 } else
446 mod = -ref->ref_mod;
447 }
448 exist->ref_mod += mod;
449
450 /* remove existing tail if its ref_mod is zero */
451 if (exist->ref_mod == 0)
452 drop_delayed_ref(trans, root, href, exist);
453 spin_unlock(&href->lock);
454 return ret;
455
456add_tail:
457 list_add_tail(&ref->list, &href->ref_list);
458 if (ref->action == BTRFS_ADD_DELAYED_REF)
459 list_add_tail(&ref->add_list, &href->ref_add_list);
460 atomic_inc(&root->num_entries);
461 trans->delayed_ref_updates++;
462 spin_unlock(&href->lock);
463 return ret;
464}
465
466/*
467 * helper function to update the accounting in the head ref
468 * existing and update must have the same bytenr
469 */
470static noinline void
471update_existing_head_ref(struct btrfs_delayed_ref_root *delayed_refs,
472 struct btrfs_delayed_ref_node *existing,
473 struct btrfs_delayed_ref_node *update)
474{
475 struct btrfs_delayed_ref_head *existing_ref;
476 struct btrfs_delayed_ref_head *ref;
477 int old_ref_mod;
478
479 existing_ref = btrfs_delayed_node_to_head(existing);
480 ref = btrfs_delayed_node_to_head(update);
481 BUG_ON(existing_ref->is_data != ref->is_data);
482
483 spin_lock(&existing_ref->lock);
484 if (ref->must_insert_reserved) {
485 /* if the extent was freed and then
486 * reallocated before the delayed ref
487 * entries were processed, we can end up
488 * with an existing head ref without
489 * the must_insert_reserved flag set.
490 * Set it again here
491 */
492 existing_ref->must_insert_reserved = ref->must_insert_reserved;
493
494 /*
495 * update the num_bytes so we make sure the accounting
496 * is done correctly
497 */
498 existing->num_bytes = update->num_bytes;
499
500 }
501
502 if (ref->extent_op) {
503 if (!existing_ref->extent_op) {
504 existing_ref->extent_op = ref->extent_op;
505 } else {
506 if (ref->extent_op->update_key) {
507 memcpy(&existing_ref->extent_op->key,
508 &ref->extent_op->key,
509 sizeof(ref->extent_op->key));
510 existing_ref->extent_op->update_key = true;
511 }
512 if (ref->extent_op->update_flags) {
513 existing_ref->extent_op->flags_to_set |=
514 ref->extent_op->flags_to_set;
515 existing_ref->extent_op->update_flags = true;
516 }
517 btrfs_free_delayed_extent_op(ref->extent_op);
518 }
519 }
520 /*
521 * update the reference mod on the head to reflect this new operation,
522 * only need the lock for this case cause we could be processing it
523 * currently, for refs we just added we know we're a-ok.
524 */
525 old_ref_mod = existing_ref->total_ref_mod;
526 existing->ref_mod += update->ref_mod;
527 existing_ref->total_ref_mod += update->ref_mod;
528
529 /*
530 * If we are going to from a positive ref mod to a negative or vice
531 * versa we need to make sure to adjust pending_csums accordingly.
532 */
533 if (existing_ref->is_data) {
534 if (existing_ref->total_ref_mod >= 0 && old_ref_mod < 0)
535 delayed_refs->pending_csums -= existing->num_bytes;
536 if (existing_ref->total_ref_mod < 0 && old_ref_mod >= 0)
537 delayed_refs->pending_csums += existing->num_bytes;
538 }
539 spin_unlock(&existing_ref->lock);
540}
541
542/*
543 * helper function to actually insert a head node into the rbtree.
544 * this does all the dirty work in terms of maintaining the correct
545 * overall modification count.
546 */
547static noinline struct btrfs_delayed_ref_head *
548add_delayed_ref_head(struct btrfs_fs_info *fs_info,
549 struct btrfs_trans_handle *trans,
550 struct btrfs_delayed_ref_node *ref,
551 struct btrfs_qgroup_extent_record *qrecord,
552 u64 bytenr, u64 num_bytes, u64 ref_root, u64 reserved,
553 int action, int is_data)
554{
555 struct btrfs_delayed_ref_head *existing;
556 struct btrfs_delayed_ref_head *head_ref = NULL;
557 struct btrfs_delayed_ref_root *delayed_refs;
558 int count_mod = 1;
559 int must_insert_reserved = 0;
560
561 /* If reserved is provided, it must be a data extent. */
562 BUG_ON(!is_data && reserved);
563
564 /*
565 * the head node stores the sum of all the mods, so dropping a ref
566 * should drop the sum in the head node by one.
567 */
568 if (action == BTRFS_UPDATE_DELAYED_HEAD)
569 count_mod = 0;
570 else if (action == BTRFS_DROP_DELAYED_REF)
571 count_mod = -1;
572
573 /*
574 * BTRFS_ADD_DELAYED_EXTENT means that we need to update
575 * the reserved accounting when the extent is finally added, or
576 * if a later modification deletes the delayed ref without ever
577 * inserting the extent into the extent allocation tree.
578 * ref->must_insert_reserved is the flag used to record
579 * that accounting mods are required.
580 *
581 * Once we record must_insert_reserved, switch the action to
582 * BTRFS_ADD_DELAYED_REF because other special casing is not required.
583 */
584 if (action == BTRFS_ADD_DELAYED_EXTENT)
585 must_insert_reserved = 1;
586 else
587 must_insert_reserved = 0;
588
589 delayed_refs = &trans->transaction->delayed_refs;
590
591 /* first set the basic ref node struct up */
592 atomic_set(&ref->refs, 1);
593 ref->bytenr = bytenr;
594 ref->num_bytes = num_bytes;
595 ref->ref_mod = count_mod;
596 ref->type = 0;
597 ref->action = 0;
598 ref->is_head = 1;
599 ref->in_tree = 1;
600 ref->seq = 0;
601
602 head_ref = btrfs_delayed_node_to_head(ref);
603 head_ref->must_insert_reserved = must_insert_reserved;
604 head_ref->is_data = is_data;
605 INIT_LIST_HEAD(&head_ref->ref_list);
606 INIT_LIST_HEAD(&head_ref->ref_add_list);
607 head_ref->processing = 0;
608 head_ref->total_ref_mod = count_mod;
609 head_ref->qgroup_reserved = 0;
610 head_ref->qgroup_ref_root = 0;
611
612 /* Record qgroup extent info if provided */
613 if (qrecord) {
614 if (ref_root && reserved) {
615 head_ref->qgroup_ref_root = ref_root;
616 head_ref->qgroup_reserved = reserved;
617 }
618
619 qrecord->bytenr = bytenr;
620 qrecord->num_bytes = num_bytes;
621 qrecord->old_roots = NULL;
622
623 if(btrfs_qgroup_trace_extent_nolock(fs_info,
624 delayed_refs, qrecord))
625 kfree(qrecord);
626 }
627
628 spin_lock_init(&head_ref->lock);
629 mutex_init(&head_ref->mutex);
630
631 trace_add_delayed_ref_head(fs_info, ref, head_ref, action);
632
633 existing = htree_insert(&delayed_refs->href_root,
634 &head_ref->href_node);
635 if (existing) {
636 WARN_ON(ref_root && reserved && existing->qgroup_ref_root
637 && existing->qgroup_reserved);
638 update_existing_head_ref(delayed_refs, &existing->node, ref);
639 /*
640 * we've updated the existing ref, free the newly
641 * allocated ref
642 */
643 kmem_cache_free(btrfs_delayed_ref_head_cachep, head_ref);
644 head_ref = existing;
645 } else {
646 if (is_data && count_mod < 0)
647 delayed_refs->pending_csums += num_bytes;
648 delayed_refs->num_heads++;
649 delayed_refs->num_heads_ready++;
650 atomic_inc(&delayed_refs->num_entries);
651 trans->delayed_ref_updates++;
652 }
653 return head_ref;
654}
655
656/*
657 * helper to insert a delayed tree ref into the rbtree.
658 */
659static noinline void
660add_delayed_tree_ref(struct btrfs_fs_info *fs_info,
661 struct btrfs_trans_handle *trans,
662 struct btrfs_delayed_ref_head *head_ref,
663 struct btrfs_delayed_ref_node *ref, u64 bytenr,
664 u64 num_bytes, u64 parent, u64 ref_root, int level,
665 int action)
666{
667 struct btrfs_delayed_tree_ref *full_ref;
668 struct btrfs_delayed_ref_root *delayed_refs;
669 u64 seq = 0;
670 int ret;
671
672 if (action == BTRFS_ADD_DELAYED_EXTENT)
673 action = BTRFS_ADD_DELAYED_REF;
674
675 if (is_fstree(ref_root))
676 seq = atomic64_read(&fs_info->tree_mod_seq);
677 delayed_refs = &trans->transaction->delayed_refs;
678
679 /* first set the basic ref node struct up */
680 atomic_set(&ref->refs, 1);
681 ref->bytenr = bytenr;
682 ref->num_bytes = num_bytes;
683 ref->ref_mod = 1;
684 ref->action = action;
685 ref->is_head = 0;
686 ref->in_tree = 1;
687 ref->seq = seq;
688 INIT_LIST_HEAD(&ref->list);
689 INIT_LIST_HEAD(&ref->add_list);
690
691 full_ref = btrfs_delayed_node_to_tree_ref(ref);
692 full_ref->parent = parent;
693 full_ref->root = ref_root;
694 if (parent)
695 ref->type = BTRFS_SHARED_BLOCK_REF_KEY;
696 else
697 ref->type = BTRFS_TREE_BLOCK_REF_KEY;
698 full_ref->level = level;
699
700 trace_add_delayed_tree_ref(fs_info, ref, full_ref, action);
701
702 ret = add_delayed_ref_tail_merge(trans, delayed_refs, head_ref, ref);
703
704 /*
705 * XXX: memory should be freed at the same level allocated.
706 * But bad practice is anywhere... Follow it now. Need cleanup.
707 */
708 if (ret > 0)
709 kmem_cache_free(btrfs_delayed_tree_ref_cachep, full_ref);
710}
711
712/*
713 * helper to insert a delayed data ref into the rbtree.
714 */
715static noinline void
716add_delayed_data_ref(struct btrfs_fs_info *fs_info,
717 struct btrfs_trans_handle *trans,
718 struct btrfs_delayed_ref_head *head_ref,
719 struct btrfs_delayed_ref_node *ref, u64 bytenr,
720 u64 num_bytes, u64 parent, u64 ref_root, u64 owner,
721 u64 offset, int action)
722{
723 struct btrfs_delayed_data_ref *full_ref;
724 struct btrfs_delayed_ref_root *delayed_refs;
725 u64 seq = 0;
726 int ret;
727
728 if (action == BTRFS_ADD_DELAYED_EXTENT)
729 action = BTRFS_ADD_DELAYED_REF;
730
731 delayed_refs = &trans->transaction->delayed_refs;
732
733 if (is_fstree(ref_root))
734 seq = atomic64_read(&fs_info->tree_mod_seq);
735
736 /* first set the basic ref node struct up */
737 atomic_set(&ref->refs, 1);
738 ref->bytenr = bytenr;
739 ref->num_bytes = num_bytes;
740 ref->ref_mod = 1;
741 ref->action = action;
742 ref->is_head = 0;
743 ref->in_tree = 1;
744 ref->seq = seq;
745 INIT_LIST_HEAD(&ref->list);
746 INIT_LIST_HEAD(&ref->add_list);
747
748 full_ref = btrfs_delayed_node_to_data_ref(ref);
749 full_ref->parent = parent;
750 full_ref->root = ref_root;
751 if (parent)
752 ref->type = BTRFS_SHARED_DATA_REF_KEY;
753 else
754 ref->type = BTRFS_EXTENT_DATA_REF_KEY;
755
756 full_ref->objectid = owner;
757 full_ref->offset = offset;
758
759 trace_add_delayed_data_ref(fs_info, ref, full_ref, action);
760
761 ret = add_delayed_ref_tail_merge(trans, delayed_refs, head_ref, ref);
762
763 if (ret > 0)
764 kmem_cache_free(btrfs_delayed_data_ref_cachep, full_ref);
765}
766
767/*
768 * add a delayed tree ref. This does all of the accounting required
769 * to make sure the delayed ref is eventually processed before this
770 * transaction commits.
771 */
772int btrfs_add_delayed_tree_ref(struct btrfs_fs_info *fs_info,
773 struct btrfs_trans_handle *trans,
774 u64 bytenr, u64 num_bytes, u64 parent,
775 u64 ref_root, int level, int action,
776 struct btrfs_delayed_extent_op *extent_op)
777{
778 struct btrfs_delayed_tree_ref *ref;
779 struct btrfs_delayed_ref_head *head_ref;
780 struct btrfs_delayed_ref_root *delayed_refs;
781 struct btrfs_qgroup_extent_record *record = NULL;
782
783 BUG_ON(extent_op && extent_op->is_data);
784 ref = kmem_cache_alloc(btrfs_delayed_tree_ref_cachep, GFP_NOFS);
785 if (!ref)
786 return -ENOMEM;
787
788 head_ref = kmem_cache_alloc(btrfs_delayed_ref_head_cachep, GFP_NOFS);
789 if (!head_ref)
790 goto free_ref;
791
792 if (test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags) &&
793 is_fstree(ref_root)) {
794 record = kmalloc(sizeof(*record), GFP_NOFS);
795 if (!record)
796 goto free_head_ref;
797 }
798
799 head_ref->extent_op = extent_op;
800
801 delayed_refs = &trans->transaction->delayed_refs;
802 spin_lock(&delayed_refs->lock);
803
804 /*
805 * insert both the head node and the new ref without dropping
806 * the spin lock
807 */
808 head_ref = add_delayed_ref_head(fs_info, trans, &head_ref->node, record,
809 bytenr, num_bytes, 0, 0, action, 0);
810
811 add_delayed_tree_ref(fs_info, trans, head_ref, &ref->node, bytenr,
812 num_bytes, parent, ref_root, level, action);
813 spin_unlock(&delayed_refs->lock);
814
815 return 0;
816
817free_head_ref:
818 kmem_cache_free(btrfs_delayed_ref_head_cachep, head_ref);
819free_ref:
820 kmem_cache_free(btrfs_delayed_tree_ref_cachep, ref);
821
822 return -ENOMEM;
823}
824
825/*
826 * add a delayed data ref. it's similar to btrfs_add_delayed_tree_ref.
827 */
828int btrfs_add_delayed_data_ref(struct btrfs_fs_info *fs_info,
829 struct btrfs_trans_handle *trans,
830 u64 bytenr, u64 num_bytes,
831 u64 parent, u64 ref_root,
832 u64 owner, u64 offset, u64 reserved, int action,
833 struct btrfs_delayed_extent_op *extent_op)
834{
835 struct btrfs_delayed_data_ref *ref;
836 struct btrfs_delayed_ref_head *head_ref;
837 struct btrfs_delayed_ref_root *delayed_refs;
838 struct btrfs_qgroup_extent_record *record = NULL;
839
840 BUG_ON(extent_op && !extent_op->is_data);
841 ref = kmem_cache_alloc(btrfs_delayed_data_ref_cachep, GFP_NOFS);
842 if (!ref)
843 return -ENOMEM;
844
845 head_ref = kmem_cache_alloc(btrfs_delayed_ref_head_cachep, GFP_NOFS);
846 if (!head_ref) {
847 kmem_cache_free(btrfs_delayed_data_ref_cachep, ref);
848 return -ENOMEM;
849 }
850
851 if (test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags) &&
852 is_fstree(ref_root)) {
853 record = kmalloc(sizeof(*record), GFP_NOFS);
854 if (!record) {
855 kmem_cache_free(btrfs_delayed_data_ref_cachep, ref);
856 kmem_cache_free(btrfs_delayed_ref_head_cachep,
857 head_ref);
858 return -ENOMEM;
859 }
860 }
861
862 head_ref->extent_op = extent_op;
863
864 delayed_refs = &trans->transaction->delayed_refs;
865 spin_lock(&delayed_refs->lock);
866
867 /*
868 * insert both the head node and the new ref without dropping
869 * the spin lock
870 */
871 head_ref = add_delayed_ref_head(fs_info, trans, &head_ref->node, record,
872 bytenr, num_bytes, ref_root, reserved,
873 action, 1);
874
875 add_delayed_data_ref(fs_info, trans, head_ref, &ref->node, bytenr,
876 num_bytes, parent, ref_root, owner, offset,
877 action);
878 spin_unlock(&delayed_refs->lock);
879
880 return 0;
881}
882
883int btrfs_add_delayed_extent_op(struct btrfs_fs_info *fs_info,
884 struct btrfs_trans_handle *trans,
885 u64 bytenr, u64 num_bytes,
886 struct btrfs_delayed_extent_op *extent_op)
887{
888 struct btrfs_delayed_ref_head *head_ref;
889 struct btrfs_delayed_ref_root *delayed_refs;
890
891 head_ref = kmem_cache_alloc(btrfs_delayed_ref_head_cachep, GFP_NOFS);
892 if (!head_ref)
893 return -ENOMEM;
894
895 head_ref->extent_op = extent_op;
896
897 delayed_refs = &trans->transaction->delayed_refs;
898 spin_lock(&delayed_refs->lock);
899
900 add_delayed_ref_head(fs_info, trans, &head_ref->node, NULL, bytenr,
901 num_bytes, 0, 0, BTRFS_UPDATE_DELAYED_HEAD,
902 extent_op->is_data);
903
904 spin_unlock(&delayed_refs->lock);
905 return 0;
906}
907
908/*
909 * this does a simple search for the head node for a given extent.
910 * It must be called with the delayed ref spinlock held, and it returns
911 * the head node if any where found, or NULL if not.
912 */
913struct btrfs_delayed_ref_head *
914btrfs_find_delayed_ref_head(struct btrfs_trans_handle *trans, u64 bytenr)
915{
916 struct btrfs_delayed_ref_root *delayed_refs;
917
918 delayed_refs = &trans->transaction->delayed_refs;
919 return find_ref_head(&delayed_refs->href_root, bytenr, 0);
920}
921
922void btrfs_delayed_ref_exit(void)
923{
924 kmem_cache_destroy(btrfs_delayed_ref_head_cachep);
925 kmem_cache_destroy(btrfs_delayed_tree_ref_cachep);
926 kmem_cache_destroy(btrfs_delayed_data_ref_cachep);
927 kmem_cache_destroy(btrfs_delayed_extent_op_cachep);
928}
929
930int btrfs_delayed_ref_init(void)
931{
932 btrfs_delayed_ref_head_cachep = kmem_cache_create(
933 "btrfs_delayed_ref_head",
934 sizeof(struct btrfs_delayed_ref_head), 0,
935 SLAB_MEM_SPREAD, NULL);
936 if (!btrfs_delayed_ref_head_cachep)
937 goto fail;
938
939 btrfs_delayed_tree_ref_cachep = kmem_cache_create(
940 "btrfs_delayed_tree_ref",
941 sizeof(struct btrfs_delayed_tree_ref), 0,
942 SLAB_MEM_SPREAD, NULL);
943 if (!btrfs_delayed_tree_ref_cachep)
944 goto fail;
945
946 btrfs_delayed_data_ref_cachep = kmem_cache_create(
947 "btrfs_delayed_data_ref",
948 sizeof(struct btrfs_delayed_data_ref), 0,
949 SLAB_MEM_SPREAD, NULL);
950 if (!btrfs_delayed_data_ref_cachep)
951 goto fail;
952
953 btrfs_delayed_extent_op_cachep = kmem_cache_create(
954 "btrfs_delayed_extent_op",
955 sizeof(struct btrfs_delayed_extent_op), 0,
956 SLAB_MEM_SPREAD, NULL);
957 if (!btrfs_delayed_extent_op_cachep)
958 goto fail;
959
960 return 0;
961fail:
962 btrfs_delayed_ref_exit();
963 return -ENOMEM;
964}