2 * Copyright (C) 2009 Oracle. All rights reserved.
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.
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.
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.
19 #include <linux/sched.h>
20 #include <linux/slab.h>
21 #include <linux/sort.h>
23 #include "delayed-ref.h"
24 #include "transaction.h"
26 struct kmem_cache *btrfs_delayed_ref_head_cachep;
27 struct kmem_cache *btrfs_delayed_tree_ref_cachep;
28 struct kmem_cache *btrfs_delayed_data_ref_cachep;
29 struct kmem_cache *btrfs_delayed_extent_op_cachep;
31 * delayed back reference update tracking. For subvolume trees
32 * we queue up extent allocations and backref maintenance for
33 * delayed processing. This avoids deep call chains where we
34 * add extents in the middle of btrfs_search_slot, and it allows
35 * us to buffer up frequently modified backrefs in an rb tree instead
36 * of hammering updates on the extent allocation tree.
40 * compare two delayed tree backrefs with same bytenr and type
42 static int comp_tree_refs(struct btrfs_delayed_tree_ref *ref2,
43 struct btrfs_delayed_tree_ref *ref1, int type)
45 if (type == BTRFS_TREE_BLOCK_REF_KEY) {
46 if (ref1->root < ref2->root)
48 if (ref1->root > ref2->root)
51 if (ref1->parent < ref2->parent)
53 if (ref1->parent > ref2->parent)
60 * compare two delayed data backrefs with same bytenr and type
62 static int comp_data_refs(struct btrfs_delayed_data_ref *ref2,
63 struct btrfs_delayed_data_ref *ref1)
65 if (ref1->node.type == BTRFS_EXTENT_DATA_REF_KEY) {
66 if (ref1->root < ref2->root)
68 if (ref1->root > ref2->root)
70 if (ref1->objectid < ref2->objectid)
72 if (ref1->objectid > ref2->objectid)
74 if (ref1->offset < ref2->offset)
76 if (ref1->offset > ref2->offset)
79 if (ref1->parent < ref2->parent)
81 if (ref1->parent > ref2->parent)
88 * entries in the rb tree are ordered by the byte number of the extent,
89 * type of the delayed backrefs and content of delayed backrefs.
91 static int comp_entry(struct btrfs_delayed_ref_node *ref2,
92 struct btrfs_delayed_ref_node *ref1,
95 if (ref1->bytenr < ref2->bytenr)
97 if (ref1->bytenr > ref2->bytenr)
99 if (ref1->is_head && ref2->is_head)
105 if (ref1->type < ref2->type)
107 if (ref1->type > ref2->type)
109 /* merging of sequenced refs is not allowed */
111 if (ref1->seq < ref2->seq)
113 if (ref1->seq > ref2->seq)
116 if (ref1->type == BTRFS_TREE_BLOCK_REF_KEY ||
117 ref1->type == BTRFS_SHARED_BLOCK_REF_KEY) {
118 return comp_tree_refs(btrfs_delayed_node_to_tree_ref(ref2),
119 btrfs_delayed_node_to_tree_ref(ref1),
121 } else if (ref1->type == BTRFS_EXTENT_DATA_REF_KEY ||
122 ref1->type == BTRFS_SHARED_DATA_REF_KEY) {
123 return comp_data_refs(btrfs_delayed_node_to_data_ref(ref2),
124 btrfs_delayed_node_to_data_ref(ref1));
131 * insert a new ref into the rbtree. This returns any existing refs
132 * for the same (bytenr,parent) tuple, or NULL if the new node was properly
135 static struct btrfs_delayed_ref_node *tree_insert(struct rb_root *root,
136 struct rb_node *node)
138 struct rb_node **p = &root->rb_node;
139 struct rb_node *parent_node = NULL;
140 struct btrfs_delayed_ref_node *entry;
141 struct btrfs_delayed_ref_node *ins;
144 ins = rb_entry(node, struct btrfs_delayed_ref_node, rb_node);
147 entry = rb_entry(parent_node, struct btrfs_delayed_ref_node,
150 cmp = comp_entry(entry, ins, 1);
159 rb_link_node(node, parent_node, p);
160 rb_insert_color(node, root);
164 /* insert a new ref to head ref rbtree */
165 static struct btrfs_delayed_ref_head *htree_insert(struct rb_root *root,
166 struct rb_node *node)
168 struct rb_node **p = &root->rb_node;
169 struct rb_node *parent_node = NULL;
170 struct btrfs_delayed_ref_head *entry;
171 struct btrfs_delayed_ref_head *ins;
174 ins = rb_entry(node, struct btrfs_delayed_ref_head, href_node);
175 bytenr = ins->node.bytenr;
178 entry = rb_entry(parent_node, struct btrfs_delayed_ref_head,
181 if (bytenr < entry->node.bytenr)
183 else if (bytenr > entry->node.bytenr)
189 rb_link_node(node, parent_node, p);
190 rb_insert_color(node, root);
195 * find an head entry based on bytenr. This returns the delayed ref
196 * head if it was able to find one, or NULL if nothing was in that spot.
197 * If return_bigger is given, the next bigger entry is returned if no exact
200 static struct btrfs_delayed_ref_head *
201 find_ref_head(struct rb_root *root, u64 bytenr,
205 struct btrfs_delayed_ref_head *entry;
210 entry = rb_entry(n, struct btrfs_delayed_ref_head, href_node);
212 if (bytenr < entry->node.bytenr)
214 else if (bytenr > entry->node.bytenr)
219 if (entry && return_bigger) {
220 if (bytenr > entry->node.bytenr) {
221 n = rb_next(&entry->href_node);
224 entry = rb_entry(n, struct btrfs_delayed_ref_head,
233 int btrfs_delayed_ref_lock(struct btrfs_trans_handle *trans,
234 struct btrfs_delayed_ref_head *head)
236 struct btrfs_delayed_ref_root *delayed_refs;
238 delayed_refs = &trans->transaction->delayed_refs;
239 assert_spin_locked(&delayed_refs->lock);
240 if (mutex_trylock(&head->mutex))
243 atomic_inc(&head->node.refs);
244 spin_unlock(&delayed_refs->lock);
246 mutex_lock(&head->mutex);
247 spin_lock(&delayed_refs->lock);
248 if (!head->node.in_tree) {
249 mutex_unlock(&head->mutex);
250 btrfs_put_delayed_ref(&head->node);
253 btrfs_put_delayed_ref(&head->node);
257 static inline void drop_delayed_ref(struct btrfs_trans_handle *trans,
258 struct btrfs_delayed_ref_root *delayed_refs,
259 struct btrfs_delayed_ref_head *head,
260 struct btrfs_delayed_ref_node *ref)
262 if (btrfs_delayed_ref_is_head(ref)) {
263 head = btrfs_delayed_node_to_head(ref);
264 rb_erase(&head->href_node, &delayed_refs->href_root);
266 assert_spin_locked(&head->lock);
267 rb_erase(&ref->rb_node, &head->ref_root);
270 btrfs_put_delayed_ref(ref);
271 atomic_dec(&delayed_refs->num_entries);
272 if (trans->delayed_ref_updates)
273 trans->delayed_ref_updates--;
276 static int merge_ref(struct btrfs_trans_handle *trans,
277 struct btrfs_delayed_ref_root *delayed_refs,
278 struct btrfs_delayed_ref_head *head,
279 struct btrfs_delayed_ref_node *ref, u64 seq)
281 struct rb_node *node;
285 node = rb_next(&ref->rb_node);
286 while (!done && node) {
287 struct btrfs_delayed_ref_node *next;
289 next = rb_entry(node, struct btrfs_delayed_ref_node, rb_node);
290 node = rb_next(node);
291 if (seq && next->seq >= seq)
293 if (comp_entry(ref, next, 0))
296 if (ref->action == next->action) {
299 if (ref->ref_mod < next->ref_mod) {
300 struct btrfs_delayed_ref_node *tmp;
307 mod = -next->ref_mod;
310 drop_delayed_ref(trans, delayed_refs, head, next);
312 if (ref->ref_mod == 0) {
313 drop_delayed_ref(trans, delayed_refs, head, ref);
317 * You can't have multiples of the same ref on a tree
320 WARN_ON(ref->type == BTRFS_TREE_BLOCK_REF_KEY ||
321 ref->type == BTRFS_SHARED_BLOCK_REF_KEY);
327 void btrfs_merge_delayed_refs(struct btrfs_trans_handle *trans,
328 struct btrfs_fs_info *fs_info,
329 struct btrfs_delayed_ref_root *delayed_refs,
330 struct btrfs_delayed_ref_head *head)
332 struct rb_node *node;
335 assert_spin_locked(&head->lock);
337 * We don't have too much refs to merge in the case of delayed data
343 spin_lock(&fs_info->tree_mod_seq_lock);
344 if (!list_empty(&fs_info->tree_mod_seq_list)) {
345 struct seq_list *elem;
347 elem = list_first_entry(&fs_info->tree_mod_seq_list,
348 struct seq_list, list);
351 spin_unlock(&fs_info->tree_mod_seq_lock);
353 node = rb_first(&head->ref_root);
355 struct btrfs_delayed_ref_node *ref;
357 ref = rb_entry(node, struct btrfs_delayed_ref_node,
359 /* We can't merge refs that are outside of our seq count */
360 if (seq && ref->seq >= seq)
362 if (merge_ref(trans, delayed_refs, head, ref, seq))
363 node = rb_first(&head->ref_root);
365 node = rb_next(&ref->rb_node);
369 int btrfs_check_delayed_seq(struct btrfs_fs_info *fs_info,
370 struct btrfs_delayed_ref_root *delayed_refs,
373 struct seq_list *elem;
376 spin_lock(&fs_info->tree_mod_seq_lock);
377 if (!list_empty(&fs_info->tree_mod_seq_list)) {
378 elem = list_first_entry(&fs_info->tree_mod_seq_list,
379 struct seq_list, list);
380 if (seq >= elem->seq) {
381 pr_debug("holding back delayed_ref %#x.%x, lowest is %#x.%x (%p)\n",
382 (u32)(seq >> 32), (u32)seq,
383 (u32)(elem->seq >> 32), (u32)elem->seq,
389 spin_unlock(&fs_info->tree_mod_seq_lock);
393 struct btrfs_delayed_ref_head *
394 btrfs_select_ref_head(struct btrfs_trans_handle *trans)
396 struct btrfs_delayed_ref_root *delayed_refs;
397 struct btrfs_delayed_ref_head *head;
401 delayed_refs = &trans->transaction->delayed_refs;
404 start = delayed_refs->run_delayed_start;
405 head = find_ref_head(&delayed_refs->href_root, start, 1);
406 if (!head && !loop) {
407 delayed_refs->run_delayed_start = 0;
410 head = find_ref_head(&delayed_refs->href_root, start, 1);
413 } else if (!head && loop) {
417 while (head->processing) {
418 struct rb_node *node;
420 node = rb_next(&head->href_node);
424 delayed_refs->run_delayed_start = 0;
429 head = rb_entry(node, struct btrfs_delayed_ref_head,
433 head->processing = 1;
434 WARN_ON(delayed_refs->num_heads_ready == 0);
435 delayed_refs->num_heads_ready--;
436 delayed_refs->run_delayed_start = head->node.bytenr +
437 head->node.num_bytes;
442 * helper function to update an extent delayed ref in the
443 * rbtree. existing and update must both have the same
446 * This may free existing if the update cancels out whatever
447 * operation it was doing.
450 update_existing_ref(struct btrfs_trans_handle *trans,
451 struct btrfs_delayed_ref_root *delayed_refs,
452 struct btrfs_delayed_ref_head *head,
453 struct btrfs_delayed_ref_node *existing,
454 struct btrfs_delayed_ref_node *update)
456 if (update->action != existing->action) {
458 * this is effectively undoing either an add or a
459 * drop. We decrement the ref_mod, and if it goes
460 * down to zero we just delete the entry without
461 * every changing the extent allocation tree.
464 if (existing->ref_mod == 0)
465 drop_delayed_ref(trans, delayed_refs, head, existing);
467 WARN_ON(existing->type == BTRFS_TREE_BLOCK_REF_KEY ||
468 existing->type == BTRFS_SHARED_BLOCK_REF_KEY);
470 WARN_ON(existing->type == BTRFS_TREE_BLOCK_REF_KEY ||
471 existing->type == BTRFS_SHARED_BLOCK_REF_KEY);
473 * the action on the existing ref matches
474 * the action on the ref we're trying to add.
475 * Bump the ref_mod by one so the backref that
476 * is eventually added/removed has the correct
479 existing->ref_mod += update->ref_mod;
484 * helper function to update the accounting in the head ref
485 * existing and update must have the same bytenr
488 update_existing_head_ref(struct btrfs_delayed_ref_node *existing,
489 struct btrfs_delayed_ref_node *update)
491 struct btrfs_delayed_ref_head *existing_ref;
492 struct btrfs_delayed_ref_head *ref;
494 existing_ref = btrfs_delayed_node_to_head(existing);
495 ref = btrfs_delayed_node_to_head(update);
496 BUG_ON(existing_ref->is_data != ref->is_data);
498 spin_lock(&existing_ref->lock);
499 if (ref->must_insert_reserved) {
500 /* if the extent was freed and then
501 * reallocated before the delayed ref
502 * entries were processed, we can end up
503 * with an existing head ref without
504 * the must_insert_reserved flag set.
507 existing_ref->must_insert_reserved = ref->must_insert_reserved;
510 * update the num_bytes so we make sure the accounting
513 existing->num_bytes = update->num_bytes;
517 if (ref->extent_op) {
518 if (!existing_ref->extent_op) {
519 existing_ref->extent_op = ref->extent_op;
521 if (ref->extent_op->update_key) {
522 memcpy(&existing_ref->extent_op->key,
523 &ref->extent_op->key,
524 sizeof(ref->extent_op->key));
525 existing_ref->extent_op->update_key = 1;
527 if (ref->extent_op->update_flags) {
528 existing_ref->extent_op->flags_to_set |=
529 ref->extent_op->flags_to_set;
530 existing_ref->extent_op->update_flags = 1;
532 btrfs_free_delayed_extent_op(ref->extent_op);
536 * update the reference mod on the head to reflect this new operation,
537 * only need the lock for this case cause we could be processing it
538 * currently, for refs we just added we know we're a-ok.
540 existing->ref_mod += update->ref_mod;
541 spin_unlock(&existing_ref->lock);
545 * helper function to actually insert a head node into the rbtree.
546 * this does all the dirty work in terms of maintaining the correct
547 * overall modification count.
549 static noinline struct btrfs_delayed_ref_head *
550 add_delayed_ref_head(struct btrfs_fs_info *fs_info,
551 struct btrfs_trans_handle *trans,
552 struct btrfs_delayed_ref_node *ref, u64 bytenr,
553 u64 num_bytes, int action, int is_data)
555 struct btrfs_delayed_ref_head *existing;
556 struct btrfs_delayed_ref_head *head_ref = NULL;
557 struct btrfs_delayed_ref_root *delayed_refs;
559 int must_insert_reserved = 0;
562 * the head node stores the sum of all the mods, so dropping a ref
563 * should drop the sum in the head node by one.
565 if (action == BTRFS_UPDATE_DELAYED_HEAD)
567 else if (action == BTRFS_DROP_DELAYED_REF)
571 * BTRFS_ADD_DELAYED_EXTENT means that we need to update
572 * the reserved accounting when the extent is finally added, or
573 * if a later modification deletes the delayed ref without ever
574 * inserting the extent into the extent allocation tree.
575 * ref->must_insert_reserved is the flag used to record
576 * that accounting mods are required.
578 * Once we record must_insert_reserved, switch the action to
579 * BTRFS_ADD_DELAYED_REF because other special casing is not required.
581 if (action == BTRFS_ADD_DELAYED_EXTENT)
582 must_insert_reserved = 1;
584 must_insert_reserved = 0;
586 delayed_refs = &trans->transaction->delayed_refs;
588 /* first set the basic ref node struct up */
589 atomic_set(&ref->refs, 1);
590 ref->bytenr = bytenr;
591 ref->num_bytes = num_bytes;
592 ref->ref_mod = count_mod;
599 head_ref = btrfs_delayed_node_to_head(ref);
600 head_ref->must_insert_reserved = must_insert_reserved;
601 head_ref->is_data = is_data;
602 head_ref->ref_root = RB_ROOT;
603 head_ref->processing = 0;
605 spin_lock_init(&head_ref->lock);
606 mutex_init(&head_ref->mutex);
608 trace_add_delayed_ref_head(ref, head_ref, action);
610 existing = htree_insert(&delayed_refs->href_root,
611 &head_ref->href_node);
613 update_existing_head_ref(&existing->node, ref);
615 * we've updated the existing ref, free the newly
618 kmem_cache_free(btrfs_delayed_ref_head_cachep, head_ref);
621 delayed_refs->num_heads++;
622 delayed_refs->num_heads_ready++;
623 atomic_inc(&delayed_refs->num_entries);
624 trans->delayed_ref_updates++;
630 * helper to insert a delayed tree ref into the rbtree.
633 add_delayed_tree_ref(struct btrfs_fs_info *fs_info,
634 struct btrfs_trans_handle *trans,
635 struct btrfs_delayed_ref_head *head_ref,
636 struct btrfs_delayed_ref_node *ref, u64 bytenr,
637 u64 num_bytes, u64 parent, u64 ref_root, int level,
638 int action, int for_cow)
640 struct btrfs_delayed_ref_node *existing;
641 struct btrfs_delayed_tree_ref *full_ref;
642 struct btrfs_delayed_ref_root *delayed_refs;
645 if (action == BTRFS_ADD_DELAYED_EXTENT)
646 action = BTRFS_ADD_DELAYED_REF;
648 delayed_refs = &trans->transaction->delayed_refs;
650 /* first set the basic ref node struct up */
651 atomic_set(&ref->refs, 1);
652 ref->bytenr = bytenr;
653 ref->num_bytes = num_bytes;
655 ref->action = action;
659 if (need_ref_seq(for_cow, ref_root))
660 seq = btrfs_get_tree_mod_seq(fs_info, &trans->delayed_ref_elem);
663 full_ref = btrfs_delayed_node_to_tree_ref(ref);
664 full_ref->parent = parent;
665 full_ref->root = ref_root;
667 ref->type = BTRFS_SHARED_BLOCK_REF_KEY;
669 ref->type = BTRFS_TREE_BLOCK_REF_KEY;
670 full_ref->level = level;
672 trace_add_delayed_tree_ref(ref, full_ref, action);
674 spin_lock(&head_ref->lock);
675 existing = tree_insert(&head_ref->ref_root, &ref->rb_node);
677 update_existing_ref(trans, delayed_refs, head_ref, existing,
680 * we've updated the existing ref, free the newly
683 kmem_cache_free(btrfs_delayed_tree_ref_cachep, full_ref);
685 atomic_inc(&delayed_refs->num_entries);
686 trans->delayed_ref_updates++;
688 spin_unlock(&head_ref->lock);
692 * helper to insert a delayed data ref into the rbtree.
695 add_delayed_data_ref(struct btrfs_fs_info *fs_info,
696 struct btrfs_trans_handle *trans,
697 struct btrfs_delayed_ref_head *head_ref,
698 struct btrfs_delayed_ref_node *ref, u64 bytenr,
699 u64 num_bytes, u64 parent, u64 ref_root, u64 owner,
700 u64 offset, int action, int for_cow)
702 struct btrfs_delayed_ref_node *existing;
703 struct btrfs_delayed_data_ref *full_ref;
704 struct btrfs_delayed_ref_root *delayed_refs;
707 if (action == BTRFS_ADD_DELAYED_EXTENT)
708 action = BTRFS_ADD_DELAYED_REF;
710 delayed_refs = &trans->transaction->delayed_refs;
712 /* first set the basic ref node struct up */
713 atomic_set(&ref->refs, 1);
714 ref->bytenr = bytenr;
715 ref->num_bytes = num_bytes;
717 ref->action = action;
721 if (need_ref_seq(for_cow, ref_root))
722 seq = btrfs_get_tree_mod_seq(fs_info, &trans->delayed_ref_elem);
725 full_ref = btrfs_delayed_node_to_data_ref(ref);
726 full_ref->parent = parent;
727 full_ref->root = ref_root;
729 ref->type = BTRFS_SHARED_DATA_REF_KEY;
731 ref->type = BTRFS_EXTENT_DATA_REF_KEY;
733 full_ref->objectid = owner;
734 full_ref->offset = offset;
736 trace_add_delayed_data_ref(ref, full_ref, action);
738 spin_lock(&head_ref->lock);
739 existing = tree_insert(&head_ref->ref_root, &ref->rb_node);
741 update_existing_ref(trans, delayed_refs, head_ref, existing,
744 * we've updated the existing ref, free the newly
747 kmem_cache_free(btrfs_delayed_data_ref_cachep, full_ref);
749 atomic_inc(&delayed_refs->num_entries);
750 trans->delayed_ref_updates++;
752 spin_unlock(&head_ref->lock);
756 * add a delayed tree ref. This does all of the accounting required
757 * to make sure the delayed ref is eventually processed before this
758 * transaction commits.
760 int btrfs_add_delayed_tree_ref(struct btrfs_fs_info *fs_info,
761 struct btrfs_trans_handle *trans,
762 u64 bytenr, u64 num_bytes, u64 parent,
763 u64 ref_root, int level, int action,
764 struct btrfs_delayed_extent_op *extent_op,
767 struct btrfs_delayed_tree_ref *ref;
768 struct btrfs_delayed_ref_head *head_ref;
769 struct btrfs_delayed_ref_root *delayed_refs;
771 BUG_ON(extent_op && extent_op->is_data);
772 ref = kmem_cache_alloc(btrfs_delayed_tree_ref_cachep, GFP_NOFS);
776 head_ref = kmem_cache_alloc(btrfs_delayed_ref_head_cachep, GFP_NOFS);
778 kmem_cache_free(btrfs_delayed_tree_ref_cachep, ref);
782 head_ref->extent_op = extent_op;
784 delayed_refs = &trans->transaction->delayed_refs;
785 spin_lock(&delayed_refs->lock);
788 * insert both the head node and the new ref without dropping
791 head_ref = add_delayed_ref_head(fs_info, trans, &head_ref->node,
792 bytenr, num_bytes, action, 0);
794 add_delayed_tree_ref(fs_info, trans, head_ref, &ref->node, bytenr,
795 num_bytes, parent, ref_root, level, action,
797 spin_unlock(&delayed_refs->lock);
798 if (need_ref_seq(for_cow, ref_root))
799 btrfs_qgroup_record_ref(trans, &ref->node, extent_op);
805 * add a delayed data ref. it's similar to btrfs_add_delayed_tree_ref.
807 int btrfs_add_delayed_data_ref(struct btrfs_fs_info *fs_info,
808 struct btrfs_trans_handle *trans,
809 u64 bytenr, u64 num_bytes,
810 u64 parent, u64 ref_root,
811 u64 owner, u64 offset, int action,
812 struct btrfs_delayed_extent_op *extent_op,
815 struct btrfs_delayed_data_ref *ref;
816 struct btrfs_delayed_ref_head *head_ref;
817 struct btrfs_delayed_ref_root *delayed_refs;
819 BUG_ON(extent_op && !extent_op->is_data);
820 ref = kmem_cache_alloc(btrfs_delayed_data_ref_cachep, GFP_NOFS);
824 head_ref = kmem_cache_alloc(btrfs_delayed_ref_head_cachep, GFP_NOFS);
826 kmem_cache_free(btrfs_delayed_data_ref_cachep, ref);
830 head_ref->extent_op = extent_op;
832 delayed_refs = &trans->transaction->delayed_refs;
833 spin_lock(&delayed_refs->lock);
836 * insert both the head node and the new ref without dropping
839 head_ref = add_delayed_ref_head(fs_info, trans, &head_ref->node,
840 bytenr, num_bytes, action, 1);
842 add_delayed_data_ref(fs_info, trans, head_ref, &ref->node, bytenr,
843 num_bytes, parent, ref_root, owner, offset,
845 spin_unlock(&delayed_refs->lock);
846 if (need_ref_seq(for_cow, ref_root))
847 btrfs_qgroup_record_ref(trans, &ref->node, extent_op);
852 int btrfs_add_delayed_extent_op(struct btrfs_fs_info *fs_info,
853 struct btrfs_trans_handle *trans,
854 u64 bytenr, u64 num_bytes,
855 struct btrfs_delayed_extent_op *extent_op)
857 struct btrfs_delayed_ref_head *head_ref;
858 struct btrfs_delayed_ref_root *delayed_refs;
860 head_ref = kmem_cache_alloc(btrfs_delayed_ref_head_cachep, GFP_NOFS);
864 head_ref->extent_op = extent_op;
866 delayed_refs = &trans->transaction->delayed_refs;
867 spin_lock(&delayed_refs->lock);
869 add_delayed_ref_head(fs_info, trans, &head_ref->node, bytenr,
870 num_bytes, BTRFS_UPDATE_DELAYED_HEAD,
873 spin_unlock(&delayed_refs->lock);
878 * this does a simple search for the head node for a given extent.
879 * It must be called with the delayed ref spinlock held, and it returns
880 * the head node if any where found, or NULL if not.
882 struct btrfs_delayed_ref_head *
883 btrfs_find_delayed_ref_head(struct btrfs_trans_handle *trans, u64 bytenr)
885 struct btrfs_delayed_ref_root *delayed_refs;
887 delayed_refs = &trans->transaction->delayed_refs;
888 return find_ref_head(&delayed_refs->href_root, bytenr, 0);
891 void btrfs_delayed_ref_exit(void)
893 if (btrfs_delayed_ref_head_cachep)
894 kmem_cache_destroy(btrfs_delayed_ref_head_cachep);
895 if (btrfs_delayed_tree_ref_cachep)
896 kmem_cache_destroy(btrfs_delayed_tree_ref_cachep);
897 if (btrfs_delayed_data_ref_cachep)
898 kmem_cache_destroy(btrfs_delayed_data_ref_cachep);
899 if (btrfs_delayed_extent_op_cachep)
900 kmem_cache_destroy(btrfs_delayed_extent_op_cachep);
903 int btrfs_delayed_ref_init(void)
905 btrfs_delayed_ref_head_cachep = kmem_cache_create(
906 "btrfs_delayed_ref_head",
907 sizeof(struct btrfs_delayed_ref_head), 0,
908 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
909 if (!btrfs_delayed_ref_head_cachep)
912 btrfs_delayed_tree_ref_cachep = kmem_cache_create(
913 "btrfs_delayed_tree_ref",
914 sizeof(struct btrfs_delayed_tree_ref), 0,
915 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
916 if (!btrfs_delayed_tree_ref_cachep)
919 btrfs_delayed_data_ref_cachep = kmem_cache_create(
920 "btrfs_delayed_data_ref",
921 sizeof(struct btrfs_delayed_data_ref), 0,
922 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
923 if (!btrfs_delayed_data_ref_cachep)
926 btrfs_delayed_extent_op_cachep = kmem_cache_create(
927 "btrfs_delayed_extent_op",
928 sizeof(struct btrfs_delayed_extent_op), 0,
929 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
930 if (!btrfs_delayed_extent_op_cachep)
935 btrfs_delayed_ref_exit();