2 * Copyright (C) 2007 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.
20 #include <linux/sched.h>
21 #include <linux/writeback.h>
22 #include <linux/pagemap.h>
25 #include "transaction.h"
27 #include "ref-cache.h"
29 static int total_trans = 0;
30 extern struct kmem_cache *btrfs_trans_handle_cachep;
31 extern struct kmem_cache *btrfs_transaction_cachep;
33 #define BTRFS_ROOT_TRANS_TAG 0
35 static noinline void put_transaction(struct btrfs_transaction *transaction)
37 WARN_ON(transaction->use_count == 0);
38 transaction->use_count--;
39 if (transaction->use_count == 0) {
40 WARN_ON(total_trans == 0);
42 list_del_init(&transaction->list);
43 memset(transaction, 0, sizeof(*transaction));
44 kmem_cache_free(btrfs_transaction_cachep, transaction);
48 static noinline int join_transaction(struct btrfs_root *root)
50 struct btrfs_transaction *cur_trans;
51 cur_trans = root->fs_info->running_transaction;
53 cur_trans = kmem_cache_alloc(btrfs_transaction_cachep,
57 root->fs_info->generation++;
58 root->fs_info->last_alloc = 0;
59 root->fs_info->last_data_alloc = 0;
60 cur_trans->num_writers = 1;
61 cur_trans->num_joined = 0;
62 cur_trans->transid = root->fs_info->generation;
63 init_waitqueue_head(&cur_trans->writer_wait);
64 init_waitqueue_head(&cur_trans->commit_wait);
65 cur_trans->in_commit = 0;
66 cur_trans->blocked = 0;
67 cur_trans->use_count = 1;
68 cur_trans->commit_done = 0;
69 cur_trans->start_time = get_seconds();
70 INIT_LIST_HEAD(&cur_trans->pending_snapshots);
71 list_add_tail(&cur_trans->list, &root->fs_info->trans_list);
72 extent_io_tree_init(&cur_trans->dirty_pages,
73 root->fs_info->btree_inode->i_mapping,
75 spin_lock(&root->fs_info->new_trans_lock);
76 root->fs_info->running_transaction = cur_trans;
77 spin_unlock(&root->fs_info->new_trans_lock);
79 cur_trans->num_writers++;
80 cur_trans->num_joined++;
86 static noinline int record_root_in_trans(struct btrfs_root *root)
88 struct btrfs_dirty_root *dirty;
89 u64 running_trans_id = root->fs_info->running_transaction->transid;
90 if (root->ref_cows && root->last_trans < running_trans_id) {
91 WARN_ON(root == root->fs_info->extent_root);
92 if (root->root_item.refs != 0) {
93 radix_tree_tag_set(&root->fs_info->fs_roots_radix,
94 (unsigned long)root->root_key.objectid,
95 BTRFS_ROOT_TRANS_TAG);
97 dirty = kmalloc(sizeof(*dirty), GFP_NOFS);
99 dirty->root = kmalloc(sizeof(*dirty->root), GFP_NOFS);
100 BUG_ON(!dirty->root);
101 dirty->latest_root = root;
102 INIT_LIST_HEAD(&dirty->list);
104 root->commit_root = btrfs_root_node(root);
106 memcpy(dirty->root, root, sizeof(*root));
107 spin_lock_init(&dirty->root->node_lock);
108 spin_lock_init(&dirty->root->list_lock);
109 mutex_init(&dirty->root->objectid_mutex);
110 INIT_LIST_HEAD(&dirty->root->dead_list);
111 dirty->root->node = root->commit_root;
112 dirty->root->commit_root = NULL;
114 spin_lock(&root->list_lock);
115 list_add(&dirty->root->dead_list, &root->dead_list);
116 spin_unlock(&root->list_lock);
118 root->dirty_root = dirty;
122 root->last_trans = running_trans_id;
127 static void wait_current_trans(struct btrfs_root *root)
129 struct btrfs_transaction *cur_trans;
131 cur_trans = root->fs_info->running_transaction;
132 if (cur_trans && cur_trans->blocked) {
134 cur_trans->use_count++;
136 prepare_to_wait(&root->fs_info->transaction_wait, &wait,
137 TASK_UNINTERRUPTIBLE);
138 if (cur_trans->blocked) {
139 mutex_unlock(&root->fs_info->trans_mutex);
141 mutex_lock(&root->fs_info->trans_mutex);
142 finish_wait(&root->fs_info->transaction_wait,
145 finish_wait(&root->fs_info->transaction_wait,
150 put_transaction(cur_trans);
154 struct btrfs_trans_handle *start_transaction(struct btrfs_root *root,
155 int num_blocks, int wait)
157 struct btrfs_trans_handle *h =
158 kmem_cache_alloc(btrfs_trans_handle_cachep, GFP_NOFS);
161 mutex_lock(&root->fs_info->trans_mutex);
162 if ((wait == 1 && !root->fs_info->open_ioctl_trans) || wait == 2)
163 wait_current_trans(root);
164 ret = join_transaction(root);
167 record_root_in_trans(root);
168 h->transid = root->fs_info->running_transaction->transid;
169 h->transaction = root->fs_info->running_transaction;
170 h->blocks_reserved = num_blocks;
172 h->block_group = NULL;
173 h->alloc_exclude_nr = 0;
174 h->alloc_exclude_start = 0;
175 root->fs_info->running_transaction->use_count++;
176 mutex_unlock(&root->fs_info->trans_mutex);
180 struct btrfs_trans_handle *btrfs_start_transaction(struct btrfs_root *root,
183 return start_transaction(root, num_blocks, 1);
185 struct btrfs_trans_handle *btrfs_join_transaction(struct btrfs_root *root,
188 return start_transaction(root, num_blocks, 0);
191 struct btrfs_trans_handle *btrfs_start_ioctl_transaction(struct btrfs_root *r,
194 return start_transaction(r, num_blocks, 2);
198 static noinline int wait_for_commit(struct btrfs_root *root,
199 struct btrfs_transaction *commit)
202 mutex_lock(&root->fs_info->trans_mutex);
203 while(!commit->commit_done) {
204 prepare_to_wait(&commit->commit_wait, &wait,
205 TASK_UNINTERRUPTIBLE);
206 if (commit->commit_done)
208 mutex_unlock(&root->fs_info->trans_mutex);
210 mutex_lock(&root->fs_info->trans_mutex);
212 mutex_unlock(&root->fs_info->trans_mutex);
213 finish_wait(&commit->commit_wait, &wait);
217 static void throttle_on_drops(struct btrfs_root *root)
219 struct btrfs_fs_info *info = root->fs_info;
220 int harder_count = 0;
223 if (atomic_read(&info->throttles)) {
226 thr = atomic_read(&info->throttle_gen);
229 prepare_to_wait(&info->transaction_throttle,
230 &wait, TASK_UNINTERRUPTIBLE);
231 if (!atomic_read(&info->throttles)) {
232 finish_wait(&info->transaction_throttle, &wait);
236 finish_wait(&info->transaction_throttle, &wait);
237 } while (thr == atomic_read(&info->throttle_gen));
240 if (root->fs_info->total_ref_cache_size > 1 * 1024 * 1024 &&
244 if (root->fs_info->total_ref_cache_size > 5 * 1024 * 1024 &&
248 if (root->fs_info->total_ref_cache_size > 10 * 1024 * 1024 &&
254 void btrfs_throttle(struct btrfs_root *root)
256 mutex_lock(&root->fs_info->trans_mutex);
257 if (!root->fs_info->open_ioctl_trans)
258 wait_current_trans(root);
259 mutex_unlock(&root->fs_info->trans_mutex);
261 throttle_on_drops(root);
264 static int __btrfs_end_transaction(struct btrfs_trans_handle *trans,
265 struct btrfs_root *root, int throttle)
267 struct btrfs_transaction *cur_trans;
268 struct btrfs_fs_info *info = root->fs_info;
270 mutex_lock(&info->trans_mutex);
271 cur_trans = info->running_transaction;
272 WARN_ON(cur_trans != trans->transaction);
273 WARN_ON(cur_trans->num_writers < 1);
274 cur_trans->num_writers--;
276 if (waitqueue_active(&cur_trans->writer_wait))
277 wake_up(&cur_trans->writer_wait);
278 put_transaction(cur_trans);
279 mutex_unlock(&info->trans_mutex);
280 memset(trans, 0, sizeof(*trans));
281 kmem_cache_free(btrfs_trans_handle_cachep, trans);
284 throttle_on_drops(root);
289 int btrfs_end_transaction(struct btrfs_trans_handle *trans,
290 struct btrfs_root *root)
292 return __btrfs_end_transaction(trans, root, 0);
295 int btrfs_end_transaction_throttle(struct btrfs_trans_handle *trans,
296 struct btrfs_root *root)
298 return __btrfs_end_transaction(trans, root, 1);
302 int btrfs_write_and_wait_transaction(struct btrfs_trans_handle *trans,
303 struct btrfs_root *root)
308 struct extent_io_tree *dirty_pages;
310 struct inode *btree_inode = root->fs_info->btree_inode;
315 if (!trans || !trans->transaction) {
316 return filemap_write_and_wait(btree_inode->i_mapping);
318 dirty_pages = &trans->transaction->dirty_pages;
320 ret = find_first_extent_bit(dirty_pages, start, &start, &end,
324 while(start <= end) {
325 if (btrfs_congested_async(root->fs_info, 0))
326 congestion_wait(WRITE, HZ/10);
329 index = start >> PAGE_CACHE_SHIFT;
330 start = (u64)(index + 1) << PAGE_CACHE_SHIFT;
331 page = find_lock_page(btree_inode->i_mapping, index);
334 if (PageWriteback(page)) {
336 wait_on_page_writeback(page);
339 page_cache_release(page);
343 err = write_one_page(page, 0);
346 page_cache_release(page);
350 ret = find_first_extent_bit(dirty_pages, 0, &start, &end,
355 clear_extent_dirty(dirty_pages, start, end, GFP_NOFS);
356 while(start <= end) {
357 index = start >> PAGE_CACHE_SHIFT;
358 start = (u64)(index + 1) << PAGE_CACHE_SHIFT;
359 page = find_get_page(btree_inode->i_mapping, index);
362 if (PageDirty(page)) {
364 err = write_one_page(page, 0);
368 wait_on_page_writeback(page);
369 page_cache_release(page);
378 static int update_cowonly_root(struct btrfs_trans_handle *trans,
379 struct btrfs_root *root)
383 struct btrfs_root *tree_root = root->fs_info->tree_root;
385 btrfs_write_dirty_block_groups(trans, root);
387 old_root_bytenr = btrfs_root_bytenr(&root->root_item);
388 if (old_root_bytenr == root->node->start)
390 btrfs_set_root_bytenr(&root->root_item,
392 btrfs_set_root_level(&root->root_item,
393 btrfs_header_level(root->node));
394 ret = btrfs_update_root(trans, tree_root,
398 btrfs_write_dirty_block_groups(trans, root);
403 int btrfs_commit_tree_roots(struct btrfs_trans_handle *trans,
404 struct btrfs_root *root)
406 struct btrfs_fs_info *fs_info = root->fs_info;
407 struct list_head *next;
409 while(!list_empty(&fs_info->dirty_cowonly_roots)) {
410 next = fs_info->dirty_cowonly_roots.next;
412 root = list_entry(next, struct btrfs_root, dirty_list);
413 update_cowonly_root(trans, root);
418 int btrfs_add_dead_root(struct btrfs_root *root, struct btrfs_root *latest)
420 struct btrfs_dirty_root *dirty;
422 dirty = kmalloc(sizeof(*dirty), GFP_NOFS);
426 dirty->latest_root = latest;
428 mutex_lock(&root->fs_info->trans_mutex);
429 list_add(&dirty->list, &latest->fs_info->dead_roots);
430 mutex_unlock(&root->fs_info->trans_mutex);
434 static noinline int add_dirty_roots(struct btrfs_trans_handle *trans,
435 struct radix_tree_root *radix,
436 struct list_head *list)
438 struct btrfs_dirty_root *dirty;
439 struct btrfs_root *gang[8];
440 struct btrfs_root *root;
447 ret = radix_tree_gang_lookup_tag(radix, (void **)gang, 0,
449 BTRFS_ROOT_TRANS_TAG);
452 for (i = 0; i < ret; i++) {
454 radix_tree_tag_clear(radix,
455 (unsigned long)root->root_key.objectid,
456 BTRFS_ROOT_TRANS_TAG);
458 BUG_ON(!root->ref_tree);
459 dirty = root->dirty_root;
461 if (root->commit_root == root->node) {
462 WARN_ON(root->node->start !=
463 btrfs_root_bytenr(&root->root_item));
465 free_extent_buffer(root->commit_root);
466 root->commit_root = NULL;
467 root->dirty_root = NULL;
469 spin_lock(&root->list_lock);
470 list_del_init(&dirty->root->dead_list);
471 spin_unlock(&root->list_lock);
476 /* make sure to update the root on disk
477 * so we get any updates to the block used
480 err = btrfs_update_root(trans,
481 root->fs_info->tree_root,
487 memset(&root->root_item.drop_progress, 0,
488 sizeof(struct btrfs_disk_key));
489 root->root_item.drop_level = 0;
490 root->commit_root = NULL;
491 root->dirty_root = NULL;
492 root->root_key.offset = root->fs_info->generation;
493 btrfs_set_root_bytenr(&root->root_item,
495 btrfs_set_root_level(&root->root_item,
496 btrfs_header_level(root->node));
497 err = btrfs_insert_root(trans, root->fs_info->tree_root,
503 refs = btrfs_root_refs(&dirty->root->root_item);
504 btrfs_set_root_refs(&dirty->root->root_item, refs - 1);
505 err = btrfs_update_root(trans, root->fs_info->tree_root,
506 &dirty->root->root_key,
507 &dirty->root->root_item);
511 list_add(&dirty->list, list);
514 free_extent_buffer(dirty->root->node);
523 int btrfs_defrag_root(struct btrfs_root *root, int cacheonly)
525 struct btrfs_fs_info *info = root->fs_info;
527 struct btrfs_trans_handle *trans;
531 if (root->defrag_running)
533 trans = btrfs_start_transaction(root, 1);
535 root->defrag_running = 1;
536 ret = btrfs_defrag_leaves(trans, root, cacheonly);
537 nr = trans->blocks_used;
538 btrfs_end_transaction(trans, root);
539 btrfs_btree_balance_dirty(info->tree_root, nr);
542 trans = btrfs_start_transaction(root, 1);
543 if (root->fs_info->closing || ret != -EAGAIN)
546 root->defrag_running = 0;
548 btrfs_end_transaction(trans, root);
552 static noinline int drop_dirty_roots(struct btrfs_root *tree_root,
553 struct list_head *list)
555 struct btrfs_dirty_root *dirty;
556 struct btrfs_trans_handle *trans;
564 while(!list_empty(list)) {
565 struct btrfs_root *root;
567 dirty = list_entry(list->prev, struct btrfs_dirty_root, list);
568 list_del_init(&dirty->list);
570 num_bytes = btrfs_root_used(&dirty->root->root_item);
571 root = dirty->latest_root;
572 atomic_inc(&root->fs_info->throttles);
574 mutex_lock(&root->fs_info->drop_mutex);
576 trans = btrfs_start_transaction(tree_root, 1);
577 ret = btrfs_drop_snapshot(trans, dirty->root);
578 if (ret != -EAGAIN) {
582 err = btrfs_update_root(trans,
584 &dirty->root->root_key,
585 &dirty->root->root_item);
588 nr = trans->blocks_used;
589 ret = btrfs_end_transaction(trans, tree_root);
592 mutex_unlock(&root->fs_info->drop_mutex);
593 btrfs_btree_balance_dirty(tree_root, nr);
595 mutex_lock(&root->fs_info->drop_mutex);
598 atomic_dec(&root->fs_info->throttles);
599 wake_up(&root->fs_info->transaction_throttle);
601 mutex_lock(&root->fs_info->alloc_mutex);
602 num_bytes -= btrfs_root_used(&dirty->root->root_item);
603 bytes_used = btrfs_root_used(&root->root_item);
605 record_root_in_trans(root);
606 btrfs_set_root_used(&root->root_item,
607 bytes_used - num_bytes);
609 mutex_unlock(&root->fs_info->alloc_mutex);
611 ret = btrfs_del_root(trans, tree_root, &dirty->root->root_key);
616 mutex_unlock(&root->fs_info->drop_mutex);
618 spin_lock(&root->list_lock);
619 list_del_init(&dirty->root->dead_list);
620 if (!list_empty(&root->dead_list)) {
621 struct btrfs_root *oldest;
622 oldest = list_entry(root->dead_list.prev,
623 struct btrfs_root, dead_list);
624 max_useless = oldest->root_key.offset - 1;
626 max_useless = root->root_key.offset - 1;
628 spin_unlock(&root->list_lock);
630 nr = trans->blocks_used;
631 ret = btrfs_end_transaction(trans, tree_root);
634 ret = btrfs_remove_leaf_refs(root, max_useless);
637 free_extent_buffer(dirty->root->node);
641 btrfs_btree_balance_dirty(tree_root, nr);
647 static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans,
648 struct btrfs_fs_info *fs_info,
649 struct btrfs_pending_snapshot *pending)
651 struct btrfs_key key;
652 struct btrfs_root_item *new_root_item;
653 struct btrfs_root *tree_root = fs_info->tree_root;
654 struct btrfs_root *root = pending->root;
655 struct extent_buffer *tmp;
656 struct extent_buffer *old;
661 new_root_item = kmalloc(sizeof(*new_root_item), GFP_NOFS);
662 if (!new_root_item) {
666 ret = btrfs_find_free_objectid(trans, tree_root, 0, &objectid);
670 memcpy(new_root_item, &root->root_item, sizeof(*new_root_item));
672 key.objectid = objectid;
674 btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
676 old = btrfs_lock_root_node(root);
677 btrfs_cow_block(trans, root, old, NULL, 0, &old, 0);
679 btrfs_copy_root(trans, root, old, &tmp, objectid);
680 btrfs_tree_unlock(old);
681 free_extent_buffer(old);
683 btrfs_set_root_bytenr(new_root_item, tmp->start);
684 btrfs_set_root_level(new_root_item, btrfs_header_level(tmp));
685 ret = btrfs_insert_root(trans, root->fs_info->tree_root, &key,
687 btrfs_tree_unlock(tmp);
688 free_extent_buffer(tmp);
693 * insert the directory item
695 key.offset = (u64)-1;
696 namelen = strlen(pending->name);
697 ret = btrfs_insert_dir_item(trans, root->fs_info->tree_root,
698 pending->name, namelen,
699 root->fs_info->sb->s_root->d_inode->i_ino,
700 &key, BTRFS_FT_DIR, 0);
705 ret = btrfs_insert_inode_ref(trans, root->fs_info->tree_root,
706 pending->name, strlen(pending->name), objectid,
707 root->fs_info->sb->s_root->d_inode->i_ino, 0);
709 /* Invalidate existing dcache entry for new snapshot. */
710 btrfs_invalidate_dcache_root(root, pending->name, namelen);
713 kfree(new_root_item);
717 static noinline int create_pending_snapshots(struct btrfs_trans_handle *trans,
718 struct btrfs_fs_info *fs_info)
720 struct btrfs_pending_snapshot *pending;
721 struct list_head *head = &trans->transaction->pending_snapshots;
724 while(!list_empty(head)) {
725 pending = list_entry(head->next,
726 struct btrfs_pending_snapshot, list);
727 ret = create_pending_snapshot(trans, fs_info, pending);
729 list_del(&pending->list);
730 kfree(pending->name);
736 int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
737 struct btrfs_root *root)
739 unsigned long joined = 0;
740 unsigned long timeout = 1;
741 struct btrfs_transaction *cur_trans;
742 struct btrfs_transaction *prev_trans = NULL;
743 struct btrfs_root *chunk_root = root->fs_info->chunk_root;
744 struct list_head dirty_fs_roots;
745 struct extent_io_tree *pinned_copy;
749 INIT_LIST_HEAD(&dirty_fs_roots);
751 mutex_lock(&root->fs_info->trans_mutex);
752 if (trans->transaction->in_commit) {
753 cur_trans = trans->transaction;
754 trans->transaction->use_count++;
755 mutex_unlock(&root->fs_info->trans_mutex);
756 btrfs_end_transaction(trans, root);
758 ret = wait_for_commit(root, cur_trans);
761 mutex_lock(&root->fs_info->trans_mutex);
762 put_transaction(cur_trans);
763 mutex_unlock(&root->fs_info->trans_mutex);
768 pinned_copy = kmalloc(sizeof(*pinned_copy), GFP_NOFS);
772 extent_io_tree_init(pinned_copy,
773 root->fs_info->btree_inode->i_mapping, GFP_NOFS);
775 trans->transaction->in_commit = 1;
776 trans->transaction->blocked = 1;
777 cur_trans = trans->transaction;
778 if (cur_trans->list.prev != &root->fs_info->trans_list) {
779 prev_trans = list_entry(cur_trans->list.prev,
780 struct btrfs_transaction, list);
781 if (!prev_trans->commit_done) {
782 prev_trans->use_count++;
783 mutex_unlock(&root->fs_info->trans_mutex);
785 wait_for_commit(root, prev_trans);
787 mutex_lock(&root->fs_info->trans_mutex);
788 put_transaction(prev_trans);
793 int snap_pending = 0;
794 joined = cur_trans->num_joined;
795 if (!list_empty(&trans->transaction->pending_snapshots))
798 WARN_ON(cur_trans != trans->transaction);
799 prepare_to_wait(&cur_trans->writer_wait, &wait,
800 TASK_UNINTERRUPTIBLE);
802 if (cur_trans->num_writers > 1)
803 timeout = MAX_SCHEDULE_TIMEOUT;
807 mutex_unlock(&root->fs_info->trans_mutex);
810 ret = btrfs_wait_ordered_extents(root, 1);
814 schedule_timeout(timeout);
816 mutex_lock(&root->fs_info->trans_mutex);
817 finish_wait(&cur_trans->writer_wait, &wait);
818 } while (cur_trans->num_writers > 1 ||
819 (cur_trans->num_joined != joined));
821 ret = create_pending_snapshots(trans, root->fs_info);
824 WARN_ON(cur_trans != trans->transaction);
826 ret = add_dirty_roots(trans, &root->fs_info->fs_roots_radix,
830 ret = btrfs_commit_tree_roots(trans, root);
833 cur_trans = root->fs_info->running_transaction;
834 spin_lock(&root->fs_info->new_trans_lock);
835 root->fs_info->running_transaction = NULL;
836 spin_unlock(&root->fs_info->new_trans_lock);
837 btrfs_set_super_generation(&root->fs_info->super_copy,
839 btrfs_set_super_root(&root->fs_info->super_copy,
840 root->fs_info->tree_root->node->start);
841 btrfs_set_super_root_level(&root->fs_info->super_copy,
842 btrfs_header_level(root->fs_info->tree_root->node));
844 btrfs_set_super_chunk_root(&root->fs_info->super_copy,
845 chunk_root->node->start);
846 btrfs_set_super_chunk_root_level(&root->fs_info->super_copy,
847 btrfs_header_level(chunk_root->node));
848 memcpy(&root->fs_info->super_for_commit, &root->fs_info->super_copy,
849 sizeof(root->fs_info->super_copy));
851 btrfs_copy_pinned(root, pinned_copy);
853 trans->transaction->blocked = 0;
854 wake_up(&root->fs_info->transaction_throttle);
855 wake_up(&root->fs_info->transaction_wait);
857 mutex_unlock(&root->fs_info->trans_mutex);
858 ret = btrfs_write_and_wait_transaction(trans, root);
860 write_ctree_super(trans, root);
862 btrfs_finish_extent_commit(trans, root, pinned_copy);
863 mutex_lock(&root->fs_info->trans_mutex);
867 cur_trans->commit_done = 1;
868 root->fs_info->last_trans_committed = cur_trans->transid;
869 wake_up(&cur_trans->commit_wait);
870 put_transaction(cur_trans);
871 put_transaction(cur_trans);
873 list_splice_init(&dirty_fs_roots, &root->fs_info->dead_roots);
874 if (root->fs_info->closing)
875 list_splice_init(&root->fs_info->dead_roots, &dirty_fs_roots);
877 mutex_unlock(&root->fs_info->trans_mutex);
878 kmem_cache_free(btrfs_trans_handle_cachep, trans);
880 if (root->fs_info->closing) {
881 drop_dirty_roots(root->fs_info->tree_root, &dirty_fs_roots);
886 int btrfs_clean_old_snapshots(struct btrfs_root *root)
888 struct list_head dirty_roots;
889 INIT_LIST_HEAD(&dirty_roots);
891 mutex_lock(&root->fs_info->trans_mutex);
892 list_splice_init(&root->fs_info->dead_roots, &dirty_roots);
893 mutex_unlock(&root->fs_info->trans_mutex);
895 if (!list_empty(&dirty_roots)) {
896 drop_dirty_roots(root, &dirty_roots);