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>
23 #include <linux/blkdev.h>
26 #include "transaction.h"
30 #define BTRFS_ROOT_TRANS_TAG 0
32 static noinline void put_transaction(struct btrfs_transaction *transaction)
34 WARN_ON(transaction->use_count == 0);
35 transaction->use_count--;
36 if (transaction->use_count == 0) {
37 list_del_init(&transaction->list);
38 memset(transaction, 0, sizeof(*transaction));
39 kmem_cache_free(btrfs_transaction_cachep, transaction);
43 static noinline void switch_commit_root(struct btrfs_root *root)
45 free_extent_buffer(root->commit_root);
46 root->commit_root = btrfs_root_node(root);
50 * either allocate a new transaction or hop into the existing one
52 static noinline int join_transaction(struct btrfs_root *root)
54 struct btrfs_transaction *cur_trans;
55 cur_trans = root->fs_info->running_transaction;
57 cur_trans = kmem_cache_alloc(btrfs_transaction_cachep,
60 root->fs_info->generation++;
61 cur_trans->num_writers = 1;
62 cur_trans->num_joined = 0;
63 cur_trans->transid = root->fs_info->generation;
64 init_waitqueue_head(&cur_trans->writer_wait);
65 init_waitqueue_head(&cur_trans->commit_wait);
66 cur_trans->in_commit = 0;
67 cur_trans->blocked = 0;
68 cur_trans->use_count = 1;
69 cur_trans->commit_done = 0;
70 cur_trans->start_time = get_seconds();
72 cur_trans->delayed_refs.root = RB_ROOT;
73 cur_trans->delayed_refs.num_entries = 0;
74 cur_trans->delayed_refs.num_heads_ready = 0;
75 cur_trans->delayed_refs.num_heads = 0;
76 cur_trans->delayed_refs.flushing = 0;
77 cur_trans->delayed_refs.run_delayed_start = 0;
78 spin_lock_init(&cur_trans->delayed_refs.lock);
80 INIT_LIST_HEAD(&cur_trans->pending_snapshots);
81 list_add_tail(&cur_trans->list, &root->fs_info->trans_list);
82 extent_io_tree_init(&cur_trans->dirty_pages,
83 root->fs_info->btree_inode->i_mapping,
85 spin_lock(&root->fs_info->new_trans_lock);
86 root->fs_info->running_transaction = cur_trans;
87 spin_unlock(&root->fs_info->new_trans_lock);
89 cur_trans->num_writers++;
90 cur_trans->num_joined++;
97 * this does all the record keeping required to make sure that a reference
98 * counted root is properly recorded in a given transaction. This is required
99 * to make sure the old root from before we joined the transaction is deleted
100 * when the transaction commits
102 static noinline int record_root_in_trans(struct btrfs_trans_handle *trans,
103 struct btrfs_root *root)
105 if (root->ref_cows && root->last_trans < trans->transid) {
106 WARN_ON(root == root->fs_info->extent_root);
107 WARN_ON(root->commit_root != root->node);
109 radix_tree_tag_set(&root->fs_info->fs_roots_radix,
110 (unsigned long)root->root_key.objectid,
111 BTRFS_ROOT_TRANS_TAG);
112 root->last_trans = trans->transid;
113 btrfs_init_reloc_root(trans, root);
118 int btrfs_record_root_in_trans(struct btrfs_trans_handle *trans,
119 struct btrfs_root *root)
124 mutex_lock(&root->fs_info->trans_mutex);
125 if (root->last_trans == trans->transid) {
126 mutex_unlock(&root->fs_info->trans_mutex);
130 record_root_in_trans(trans, root);
131 mutex_unlock(&root->fs_info->trans_mutex);
135 /* wait for commit against the current transaction to become unblocked
136 * when this is done, it is safe to start a new transaction, but the current
137 * transaction might not be fully on disk.
139 static void wait_current_trans(struct btrfs_root *root)
141 struct btrfs_transaction *cur_trans;
143 cur_trans = root->fs_info->running_transaction;
144 if (cur_trans && cur_trans->blocked) {
146 cur_trans->use_count++;
148 prepare_to_wait(&root->fs_info->transaction_wait, &wait,
149 TASK_UNINTERRUPTIBLE);
150 if (!cur_trans->blocked)
152 mutex_unlock(&root->fs_info->trans_mutex);
154 mutex_lock(&root->fs_info->trans_mutex);
156 finish_wait(&root->fs_info->transaction_wait, &wait);
157 put_transaction(cur_trans);
161 enum btrfs_trans_type {
167 static struct btrfs_trans_handle *start_transaction(struct btrfs_root *root,
168 int num_blocks, int type)
170 struct btrfs_trans_handle *h =
171 kmem_cache_alloc(btrfs_trans_handle_cachep, GFP_NOFS);
174 mutex_lock(&root->fs_info->trans_mutex);
175 if (!root->fs_info->log_root_recovering &&
176 ((type == TRANS_START && !root->fs_info->open_ioctl_trans) ||
177 type == TRANS_USERSPACE))
178 wait_current_trans(root);
179 ret = join_transaction(root);
182 h->transid = root->fs_info->running_transaction->transid;
183 h->transaction = root->fs_info->running_transaction;
184 h->blocks_reserved = num_blocks;
187 h->alloc_exclude_nr = 0;
188 h->alloc_exclude_start = 0;
189 h->delayed_ref_updates = 0;
191 if (!current->journal_info && type != TRANS_USERSPACE)
192 current->journal_info = h;
194 root->fs_info->running_transaction->use_count++;
195 record_root_in_trans(h, root);
196 mutex_unlock(&root->fs_info->trans_mutex);
200 struct btrfs_trans_handle *btrfs_start_transaction(struct btrfs_root *root,
203 return start_transaction(root, num_blocks, TRANS_START);
205 struct btrfs_trans_handle *btrfs_join_transaction(struct btrfs_root *root,
208 return start_transaction(root, num_blocks, TRANS_JOIN);
211 struct btrfs_trans_handle *btrfs_start_ioctl_transaction(struct btrfs_root *r,
214 return start_transaction(r, num_blocks, TRANS_USERSPACE);
217 /* wait for a transaction commit to be fully complete */
218 static noinline int wait_for_commit(struct btrfs_root *root,
219 struct btrfs_transaction *commit)
222 mutex_lock(&root->fs_info->trans_mutex);
223 while (!commit->commit_done) {
224 prepare_to_wait(&commit->commit_wait, &wait,
225 TASK_UNINTERRUPTIBLE);
226 if (commit->commit_done)
228 mutex_unlock(&root->fs_info->trans_mutex);
230 mutex_lock(&root->fs_info->trans_mutex);
232 mutex_unlock(&root->fs_info->trans_mutex);
233 finish_wait(&commit->commit_wait, &wait);
239 * rate limit against the drop_snapshot code. This helps to slow down new
240 * operations if the drop_snapshot code isn't able to keep up.
242 static void throttle_on_drops(struct btrfs_root *root)
244 struct btrfs_fs_info *info = root->fs_info;
245 int harder_count = 0;
248 if (atomic_read(&info->throttles)) {
251 thr = atomic_read(&info->throttle_gen);
254 prepare_to_wait(&info->transaction_throttle,
255 &wait, TASK_UNINTERRUPTIBLE);
256 if (!atomic_read(&info->throttles)) {
257 finish_wait(&info->transaction_throttle, &wait);
261 finish_wait(&info->transaction_throttle, &wait);
262 } while (thr == atomic_read(&info->throttle_gen));
265 if (root->fs_info->total_ref_cache_size > 1 * 1024 * 1024 &&
269 if (root->fs_info->total_ref_cache_size > 5 * 1024 * 1024 &&
273 if (root->fs_info->total_ref_cache_size > 10 * 1024 * 1024 &&
280 void btrfs_throttle(struct btrfs_root *root)
282 mutex_lock(&root->fs_info->trans_mutex);
283 if (!root->fs_info->open_ioctl_trans)
284 wait_current_trans(root);
285 mutex_unlock(&root->fs_info->trans_mutex);
288 static int __btrfs_end_transaction(struct btrfs_trans_handle *trans,
289 struct btrfs_root *root, int throttle)
291 struct btrfs_transaction *cur_trans;
292 struct btrfs_fs_info *info = root->fs_info;
296 unsigned long cur = trans->delayed_ref_updates;
297 trans->delayed_ref_updates = 0;
299 trans->transaction->delayed_refs.num_heads_ready > 64) {
300 trans->delayed_ref_updates = 0;
303 * do a full flush if the transaction is trying
306 if (trans->transaction->delayed_refs.flushing)
308 btrfs_run_delayed_refs(trans, root, cur);
315 mutex_lock(&info->trans_mutex);
316 cur_trans = info->running_transaction;
317 WARN_ON(cur_trans != trans->transaction);
318 WARN_ON(cur_trans->num_writers < 1);
319 cur_trans->num_writers--;
321 if (waitqueue_active(&cur_trans->writer_wait))
322 wake_up(&cur_trans->writer_wait);
323 put_transaction(cur_trans);
324 mutex_unlock(&info->trans_mutex);
326 if (current->journal_info == trans)
327 current->journal_info = NULL;
328 memset(trans, 0, sizeof(*trans));
329 kmem_cache_free(btrfs_trans_handle_cachep, trans);
332 btrfs_run_delayed_iputs(root);
337 int btrfs_end_transaction(struct btrfs_trans_handle *trans,
338 struct btrfs_root *root)
340 return __btrfs_end_transaction(trans, root, 0);
343 int btrfs_end_transaction_throttle(struct btrfs_trans_handle *trans,
344 struct btrfs_root *root)
346 return __btrfs_end_transaction(trans, root, 1);
350 * when btree blocks are allocated, they have some corresponding bits set for
351 * them in one of two extent_io trees. This is used to make sure all of
352 * those extents are sent to disk but does not wait on them
354 int btrfs_write_marked_extents(struct btrfs_root *root,
355 struct extent_io_tree *dirty_pages, int mark)
361 struct inode *btree_inode = root->fs_info->btree_inode;
367 ret = find_first_extent_bit(dirty_pages, start, &start, &end,
371 while (start <= end) {
374 index = start >> PAGE_CACHE_SHIFT;
375 start = (u64)(index + 1) << PAGE_CACHE_SHIFT;
376 page = find_get_page(btree_inode->i_mapping, index);
380 btree_lock_page_hook(page);
381 if (!page->mapping) {
383 page_cache_release(page);
387 if (PageWriteback(page)) {
389 wait_on_page_writeback(page);
392 page_cache_release(page);
396 err = write_one_page(page, 0);
399 page_cache_release(page);
408 * when btree blocks are allocated, they have some corresponding bits set for
409 * them in one of two extent_io trees. This is used to make sure all of
410 * those extents are on disk for transaction or log commit. We wait
411 * on all the pages and clear them from the dirty pages state tree
413 int btrfs_wait_marked_extents(struct btrfs_root *root,
414 struct extent_io_tree *dirty_pages, int mark)
420 struct inode *btree_inode = root->fs_info->btree_inode;
426 ret = find_first_extent_bit(dirty_pages, start, &start, &end,
431 clear_extent_bits(dirty_pages, start, end, mark, GFP_NOFS);
432 while (start <= end) {
433 index = start >> PAGE_CACHE_SHIFT;
434 start = (u64)(index + 1) << PAGE_CACHE_SHIFT;
435 page = find_get_page(btree_inode->i_mapping, index);
438 if (PageDirty(page)) {
439 btree_lock_page_hook(page);
440 wait_on_page_writeback(page);
441 err = write_one_page(page, 0);
445 wait_on_page_writeback(page);
446 page_cache_release(page);
456 * when btree blocks are allocated, they have some corresponding bits set for
457 * them in one of two extent_io trees. This is used to make sure all of
458 * those extents are on disk for transaction or log commit
460 int btrfs_write_and_wait_marked_extents(struct btrfs_root *root,
461 struct extent_io_tree *dirty_pages, int mark)
466 ret = btrfs_write_marked_extents(root, dirty_pages, mark);
467 ret2 = btrfs_wait_marked_extents(root, dirty_pages, mark);
471 int btrfs_write_and_wait_transaction(struct btrfs_trans_handle *trans,
472 struct btrfs_root *root)
474 if (!trans || !trans->transaction) {
475 struct inode *btree_inode;
476 btree_inode = root->fs_info->btree_inode;
477 return filemap_write_and_wait(btree_inode->i_mapping);
479 return btrfs_write_and_wait_marked_extents(root,
480 &trans->transaction->dirty_pages,
485 * this is used to update the root pointer in the tree of tree roots.
487 * But, in the case of the extent allocation tree, updating the root
488 * pointer may allocate blocks which may change the root of the extent
491 * So, this loops and repeats and makes sure the cowonly root didn't
492 * change while the root pointer was being updated in the metadata.
494 static int update_cowonly_root(struct btrfs_trans_handle *trans,
495 struct btrfs_root *root)
500 struct btrfs_root *tree_root = root->fs_info->tree_root;
502 old_root_used = btrfs_root_used(&root->root_item);
503 btrfs_write_dirty_block_groups(trans, root);
506 old_root_bytenr = btrfs_root_bytenr(&root->root_item);
507 if (old_root_bytenr == root->node->start &&
508 old_root_used == btrfs_root_used(&root->root_item))
511 btrfs_set_root_node(&root->root_item, root->node);
512 ret = btrfs_update_root(trans, tree_root,
517 old_root_used = btrfs_root_used(&root->root_item);
518 ret = btrfs_write_dirty_block_groups(trans, root);
522 if (root != root->fs_info->extent_root)
523 switch_commit_root(root);
529 * update all the cowonly tree roots on disk
531 static noinline int commit_cowonly_roots(struct btrfs_trans_handle *trans,
532 struct btrfs_root *root)
534 struct btrfs_fs_info *fs_info = root->fs_info;
535 struct list_head *next;
536 struct extent_buffer *eb;
539 ret = btrfs_run_delayed_refs(trans, root, (unsigned long)-1);
542 eb = btrfs_lock_root_node(fs_info->tree_root);
543 btrfs_cow_block(trans, fs_info->tree_root, eb, NULL, 0, &eb);
544 btrfs_tree_unlock(eb);
545 free_extent_buffer(eb);
547 ret = btrfs_run_delayed_refs(trans, root, (unsigned long)-1);
550 while (!list_empty(&fs_info->dirty_cowonly_roots)) {
551 next = fs_info->dirty_cowonly_roots.next;
553 root = list_entry(next, struct btrfs_root, dirty_list);
555 update_cowonly_root(trans, root);
558 down_write(&fs_info->extent_commit_sem);
559 switch_commit_root(fs_info->extent_root);
560 up_write(&fs_info->extent_commit_sem);
566 * dead roots are old snapshots that need to be deleted. This allocates
567 * a dirty root struct and adds it into the list of dead roots that need to
570 int btrfs_add_dead_root(struct btrfs_root *root)
572 mutex_lock(&root->fs_info->trans_mutex);
573 list_add(&root->root_list, &root->fs_info->dead_roots);
574 mutex_unlock(&root->fs_info->trans_mutex);
579 * update all the cowonly tree roots on disk
581 static noinline int commit_fs_roots(struct btrfs_trans_handle *trans,
582 struct btrfs_root *root)
584 struct btrfs_root *gang[8];
585 struct btrfs_fs_info *fs_info = root->fs_info;
591 ret = radix_tree_gang_lookup_tag(&fs_info->fs_roots_radix,
594 BTRFS_ROOT_TRANS_TAG);
597 for (i = 0; i < ret; i++) {
599 radix_tree_tag_clear(&fs_info->fs_roots_radix,
600 (unsigned long)root->root_key.objectid,
601 BTRFS_ROOT_TRANS_TAG);
603 btrfs_free_log(trans, root);
604 btrfs_update_reloc_root(trans, root);
606 if (root->commit_root != root->node) {
607 switch_commit_root(root);
608 btrfs_set_root_node(&root->root_item,
612 err = btrfs_update_root(trans, fs_info->tree_root,
623 * defrag a given btree. If cacheonly == 1, this won't read from the disk,
624 * otherwise every leaf in the btree is read and defragged.
626 int btrfs_defrag_root(struct btrfs_root *root, int cacheonly)
628 struct btrfs_fs_info *info = root->fs_info;
630 struct btrfs_trans_handle *trans;
634 if (root->defrag_running)
636 trans = btrfs_start_transaction(root, 1);
638 root->defrag_running = 1;
639 ret = btrfs_defrag_leaves(trans, root, cacheonly);
640 nr = trans->blocks_used;
641 btrfs_end_transaction(trans, root);
642 btrfs_btree_balance_dirty(info->tree_root, nr);
645 trans = btrfs_start_transaction(root, 1);
646 if (root->fs_info->closing || ret != -EAGAIN)
649 root->defrag_running = 0;
651 btrfs_end_transaction(trans, root);
657 * when dropping snapshots, we generate a ton of delayed refs, and it makes
658 * sense not to join the transaction while it is trying to flush the current
659 * queue of delayed refs out.
661 * This is used by the drop snapshot code only
663 static noinline int wait_transaction_pre_flush(struct btrfs_fs_info *info)
667 mutex_lock(&info->trans_mutex);
668 while (info->running_transaction &&
669 info->running_transaction->delayed_refs.flushing) {
670 prepare_to_wait(&info->transaction_wait, &wait,
671 TASK_UNINTERRUPTIBLE);
672 mutex_unlock(&info->trans_mutex);
676 mutex_lock(&info->trans_mutex);
677 finish_wait(&info->transaction_wait, &wait);
679 mutex_unlock(&info->trans_mutex);
684 * Given a list of roots that need to be deleted, call btrfs_drop_snapshot on
687 int btrfs_drop_dead_root(struct btrfs_root *root)
689 struct btrfs_trans_handle *trans;
690 struct btrfs_root *tree_root = root->fs_info->tree_root;
696 * we don't want to jump in and create a bunch of
697 * delayed refs if the transaction is starting to close
699 wait_transaction_pre_flush(tree_root->fs_info);
700 trans = btrfs_start_transaction(tree_root, 1);
703 * we've joined a transaction, make sure it isn't
706 if (trans->transaction->delayed_refs.flushing) {
707 btrfs_end_transaction(trans, tree_root);
711 ret = btrfs_drop_snapshot(trans, root);
715 ret = btrfs_update_root(trans, tree_root,
721 nr = trans->blocks_used;
722 ret = btrfs_end_transaction(trans, tree_root);
725 btrfs_btree_balance_dirty(tree_root, nr);
730 ret = btrfs_del_root(trans, tree_root, &root->root_key);
733 nr = trans->blocks_used;
734 ret = btrfs_end_transaction(trans, tree_root);
737 free_extent_buffer(root->node);
738 free_extent_buffer(root->commit_root);
741 btrfs_btree_balance_dirty(tree_root, nr);
747 * new snapshots need to be created at a very specific time in the
748 * transaction commit. This does the actual creation
750 static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans,
751 struct btrfs_fs_info *fs_info,
752 struct btrfs_pending_snapshot *pending)
754 struct btrfs_key key;
755 struct btrfs_root_item *new_root_item;
756 struct btrfs_root *tree_root = fs_info->tree_root;
757 struct btrfs_root *root = pending->root;
758 struct extent_buffer *tmp;
759 struct extent_buffer *old;
763 new_root_item = kmalloc(sizeof(*new_root_item), GFP_NOFS);
764 if (!new_root_item) {
768 ret = btrfs_find_free_objectid(trans, tree_root, 0, &objectid);
772 record_root_in_trans(trans, root);
773 btrfs_set_root_last_snapshot(&root->root_item, trans->transid);
774 memcpy(new_root_item, &root->root_item, sizeof(*new_root_item));
776 key.objectid = objectid;
777 /* record when the snapshot was created in key.offset */
778 key.offset = trans->transid;
779 btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
781 old = btrfs_lock_root_node(root);
782 btrfs_cow_block(trans, root, old, NULL, 0, &old);
783 btrfs_set_lock_blocking(old);
785 btrfs_copy_root(trans, root, old, &tmp, objectid);
786 btrfs_tree_unlock(old);
787 free_extent_buffer(old);
789 btrfs_set_root_node(new_root_item, tmp);
790 ret = btrfs_insert_root(trans, root->fs_info->tree_root, &key,
792 btrfs_tree_unlock(tmp);
793 free_extent_buffer(tmp);
797 key.offset = (u64)-1;
798 memcpy(&pending->root_key, &key, sizeof(key));
800 kfree(new_root_item);
804 static noinline int finish_pending_snapshot(struct btrfs_fs_info *fs_info,
805 struct btrfs_pending_snapshot *pending)
810 struct btrfs_trans_handle *trans;
811 struct inode *parent_inode;
812 struct btrfs_root *parent_root;
814 parent_inode = pending->dentry->d_parent->d_inode;
815 parent_root = BTRFS_I(parent_inode)->root;
816 trans = btrfs_join_transaction(parent_root, 1);
819 * insert the directory item
821 namelen = strlen(pending->name);
822 ret = btrfs_set_inode_index(parent_inode, &index);
823 ret = btrfs_insert_dir_item(trans, parent_root,
824 pending->name, namelen,
826 &pending->root_key, BTRFS_FT_DIR, index);
831 btrfs_i_size_write(parent_inode, parent_inode->i_size + namelen * 2);
832 ret = btrfs_update_inode(trans, parent_root, parent_inode);
835 ret = btrfs_add_root_ref(trans, parent_root->fs_info->tree_root,
836 pending->root_key.objectid,
837 parent_root->root_key.objectid,
838 parent_inode->i_ino, index, pending->name,
844 btrfs_end_transaction(trans, fs_info->fs_root);
849 * create all the snapshots we've scheduled for creation
851 static noinline int create_pending_snapshots(struct btrfs_trans_handle *trans,
852 struct btrfs_fs_info *fs_info)
854 struct btrfs_pending_snapshot *pending;
855 struct list_head *head = &trans->transaction->pending_snapshots;
858 list_for_each_entry(pending, head, list) {
859 ret = create_pending_snapshot(trans, fs_info, pending);
865 static noinline int finish_pending_snapshots(struct btrfs_trans_handle *trans,
866 struct btrfs_fs_info *fs_info)
868 struct btrfs_pending_snapshot *pending;
869 struct list_head *head = &trans->transaction->pending_snapshots;
872 while (!list_empty(head)) {
873 pending = list_entry(head->next,
874 struct btrfs_pending_snapshot, list);
875 ret = finish_pending_snapshot(fs_info, pending);
877 list_del(&pending->list);
878 kfree(pending->name);
884 static void update_super_roots(struct btrfs_root *root)
886 struct btrfs_root_item *root_item;
887 struct btrfs_super_block *super;
889 super = &root->fs_info->super_copy;
891 root_item = &root->fs_info->chunk_root->root_item;
892 super->chunk_root = root_item->bytenr;
893 super->chunk_root_generation = root_item->generation;
894 super->chunk_root_level = root_item->level;
896 root_item = &root->fs_info->tree_root->root_item;
897 super->root = root_item->bytenr;
898 super->generation = root_item->generation;
899 super->root_level = root_item->level;
902 int btrfs_transaction_in_commit(struct btrfs_fs_info *info)
905 spin_lock(&info->new_trans_lock);
906 if (info->running_transaction)
907 ret = info->running_transaction->in_commit;
908 spin_unlock(&info->new_trans_lock);
912 int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
913 struct btrfs_root *root)
915 unsigned long joined = 0;
916 unsigned long timeout = 1;
917 struct btrfs_transaction *cur_trans;
918 struct btrfs_transaction *prev_trans = NULL;
922 unsigned long now = get_seconds();
923 int flush_on_commit = btrfs_test_opt(root, FLUSHONCOMMIT);
925 btrfs_run_ordered_operations(root, 0);
927 /* make a pass through all the delayed refs we have so far
928 * any runnings procs may add more while we are here
930 ret = btrfs_run_delayed_refs(trans, root, 0);
933 cur_trans = trans->transaction;
935 * set the flushing flag so procs in this transaction have to
936 * start sending their work down.
938 cur_trans->delayed_refs.flushing = 1;
940 ret = btrfs_run_delayed_refs(trans, root, 0);
943 mutex_lock(&root->fs_info->trans_mutex);
944 if (cur_trans->in_commit) {
945 cur_trans->use_count++;
946 mutex_unlock(&root->fs_info->trans_mutex);
947 btrfs_end_transaction(trans, root);
949 ret = wait_for_commit(root, cur_trans);
952 mutex_lock(&root->fs_info->trans_mutex);
953 put_transaction(cur_trans);
954 mutex_unlock(&root->fs_info->trans_mutex);
959 trans->transaction->in_commit = 1;
960 trans->transaction->blocked = 1;
961 if (cur_trans->list.prev != &root->fs_info->trans_list) {
962 prev_trans = list_entry(cur_trans->list.prev,
963 struct btrfs_transaction, list);
964 if (!prev_trans->commit_done) {
965 prev_trans->use_count++;
966 mutex_unlock(&root->fs_info->trans_mutex);
968 wait_for_commit(root, prev_trans);
970 mutex_lock(&root->fs_info->trans_mutex);
971 put_transaction(prev_trans);
975 if (now < cur_trans->start_time || now - cur_trans->start_time < 1)
979 int snap_pending = 0;
980 joined = cur_trans->num_joined;
981 if (!list_empty(&trans->transaction->pending_snapshots))
984 WARN_ON(cur_trans != trans->transaction);
985 prepare_to_wait(&cur_trans->writer_wait, &wait,
986 TASK_UNINTERRUPTIBLE);
988 if (cur_trans->num_writers > 1)
989 timeout = MAX_SCHEDULE_TIMEOUT;
990 else if (should_grow)
993 mutex_unlock(&root->fs_info->trans_mutex);
995 if (flush_on_commit || snap_pending) {
996 btrfs_start_delalloc_inodes(root, 1);
997 ret = btrfs_wait_ordered_extents(root, 0, 1);
1002 * rename don't use btrfs_join_transaction, so, once we
1003 * set the transaction to blocked above, we aren't going
1004 * to get any new ordered operations. We can safely run
1005 * it here and no for sure that nothing new will be added
1008 btrfs_run_ordered_operations(root, 1);
1011 if (cur_trans->num_writers > 1 || should_grow)
1012 schedule_timeout(timeout);
1014 mutex_lock(&root->fs_info->trans_mutex);
1015 finish_wait(&cur_trans->writer_wait, &wait);
1016 } while (cur_trans->num_writers > 1 ||
1017 (should_grow && cur_trans->num_joined != joined));
1019 ret = create_pending_snapshots(trans, root->fs_info);
1022 ret = btrfs_run_delayed_refs(trans, root, (unsigned long)-1);
1025 WARN_ON(cur_trans != trans->transaction);
1027 /* btrfs_commit_tree_roots is responsible for getting the
1028 * various roots consistent with each other. Every pointer
1029 * in the tree of tree roots has to point to the most up to date
1030 * root for every subvolume and other tree. So, we have to keep
1031 * the tree logging code from jumping in and changing any
1034 * At this point in the commit, there can't be any tree-log
1035 * writers, but a little lower down we drop the trans mutex
1036 * and let new people in. By holding the tree_log_mutex
1037 * from now until after the super is written, we avoid races
1038 * with the tree-log code.
1040 mutex_lock(&root->fs_info->tree_log_mutex);
1042 ret = commit_fs_roots(trans, root);
1045 /* commit_fs_roots gets rid of all the tree log roots, it is now
1046 * safe to free the root of tree log roots
1048 btrfs_free_log_root_tree(trans, root->fs_info);
1050 ret = commit_cowonly_roots(trans, root);
1053 btrfs_prepare_extent_commit(trans, root);
1055 cur_trans = root->fs_info->running_transaction;
1056 spin_lock(&root->fs_info->new_trans_lock);
1057 root->fs_info->running_transaction = NULL;
1058 spin_unlock(&root->fs_info->new_trans_lock);
1060 btrfs_set_root_node(&root->fs_info->tree_root->root_item,
1061 root->fs_info->tree_root->node);
1062 switch_commit_root(root->fs_info->tree_root);
1064 btrfs_set_root_node(&root->fs_info->chunk_root->root_item,
1065 root->fs_info->chunk_root->node);
1066 switch_commit_root(root->fs_info->chunk_root);
1068 update_super_roots(root);
1070 if (!root->fs_info->log_root_recovering) {
1071 btrfs_set_super_log_root(&root->fs_info->super_copy, 0);
1072 btrfs_set_super_log_root_level(&root->fs_info->super_copy, 0);
1075 memcpy(&root->fs_info->super_for_commit, &root->fs_info->super_copy,
1076 sizeof(root->fs_info->super_copy));
1078 trans->transaction->blocked = 0;
1080 wake_up(&root->fs_info->transaction_wait);
1082 mutex_unlock(&root->fs_info->trans_mutex);
1083 ret = btrfs_write_and_wait_transaction(trans, root);
1085 write_ctree_super(trans, root, 0);
1088 * the super is written, we can safely allow the tree-loggers
1089 * to go about their business
1091 mutex_unlock(&root->fs_info->tree_log_mutex);
1093 btrfs_finish_extent_commit(trans, root);
1095 /* do the directory inserts of any pending snapshot creations */
1096 finish_pending_snapshots(trans, root->fs_info);
1098 mutex_lock(&root->fs_info->trans_mutex);
1100 cur_trans->commit_done = 1;
1102 root->fs_info->last_trans_committed = cur_trans->transid;
1104 wake_up(&cur_trans->commit_wait);
1106 put_transaction(cur_trans);
1107 put_transaction(cur_trans);
1109 mutex_unlock(&root->fs_info->trans_mutex);
1111 if (current->journal_info == trans)
1112 current->journal_info = NULL;
1114 kmem_cache_free(btrfs_trans_handle_cachep, trans);
1116 if (current != root->fs_info->transaction_kthread)
1117 btrfs_run_delayed_iputs(root);
1123 * interface function to delete all the snapshots we have scheduled for deletion
1125 int btrfs_clean_old_snapshots(struct btrfs_root *root)
1128 struct btrfs_fs_info *fs_info = root->fs_info;
1130 mutex_lock(&fs_info->trans_mutex);
1131 list_splice_init(&fs_info->dead_roots, &list);
1132 mutex_unlock(&fs_info->trans_mutex);
1134 while (!list_empty(&list)) {
1135 root = list_entry(list.next, struct btrfs_root, root_list);
1136 list_del(&root->root_list);
1138 if (btrfs_header_backref_rev(root->node) <
1139 BTRFS_MIXED_BACKREF_REV)
1140 btrfs_drop_snapshot(root, 0);
1142 btrfs_drop_snapshot(root, 1);