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/slab.h>
21 #include <linux/sched.h>
22 #include <linux/writeback.h>
23 #include <linux/pagemap.h>
24 #include <linux/blkdev.h>
25 #include <linux/uuid.h>
28 #include "transaction.h"
31 #include "inode-map.h"
33 #include "dev-replace.h"
35 #define BTRFS_ROOT_TRANS_TAG 0
37 void put_transaction(struct btrfs_transaction *transaction)
39 WARN_ON(atomic_read(&transaction->use_count) == 0);
40 if (atomic_dec_and_test(&transaction->use_count)) {
41 BUG_ON(!list_empty(&transaction->list));
42 WARN_ON(transaction->delayed_refs.root.rb_node);
43 kmem_cache_free(btrfs_transaction_cachep, transaction);
47 static noinline void switch_commit_root(struct btrfs_root *root)
49 free_extent_buffer(root->commit_root);
50 root->commit_root = btrfs_root_node(root);
53 static inline int can_join_transaction(struct btrfs_transaction *trans,
56 return !(trans->in_commit &&
58 type != TRANS_JOIN_NOLOCK);
62 * either allocate a new transaction or hop into the existing one
64 static noinline int join_transaction(struct btrfs_root *root, int type)
66 struct btrfs_transaction *cur_trans;
67 struct btrfs_fs_info *fs_info = root->fs_info;
69 spin_lock(&fs_info->trans_lock);
71 /* The file system has been taken offline. No new transactions. */
72 if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state)) {
73 spin_unlock(&fs_info->trans_lock);
77 if (fs_info->trans_no_join) {
79 * If we are JOIN_NOLOCK we're already committing a current
80 * transaction, we just need a handle to deal with something
81 * when committing the transaction, such as inode cache and
82 * space cache. It is a special case.
84 if (type != TRANS_JOIN_NOLOCK) {
85 spin_unlock(&fs_info->trans_lock);
90 cur_trans = fs_info->running_transaction;
92 if (cur_trans->aborted) {
93 spin_unlock(&fs_info->trans_lock);
94 return cur_trans->aborted;
96 if (!can_join_transaction(cur_trans, type)) {
97 spin_unlock(&fs_info->trans_lock);
100 atomic_inc(&cur_trans->use_count);
101 atomic_inc(&cur_trans->num_writers);
102 cur_trans->num_joined++;
103 spin_unlock(&fs_info->trans_lock);
106 spin_unlock(&fs_info->trans_lock);
109 * If we are ATTACH, we just want to catch the current transaction,
110 * and commit it. If there is no transaction, just return ENOENT.
112 if (type == TRANS_ATTACH)
115 cur_trans = kmem_cache_alloc(btrfs_transaction_cachep, GFP_NOFS);
119 spin_lock(&fs_info->trans_lock);
120 if (fs_info->running_transaction) {
122 * someone started a transaction after we unlocked. Make sure
123 * to redo the trans_no_join checks above
125 kmem_cache_free(btrfs_transaction_cachep, cur_trans);
127 } else if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state)) {
128 spin_unlock(&fs_info->trans_lock);
129 kmem_cache_free(btrfs_transaction_cachep, cur_trans);
133 atomic_set(&cur_trans->num_writers, 1);
134 cur_trans->num_joined = 0;
135 init_waitqueue_head(&cur_trans->writer_wait);
136 init_waitqueue_head(&cur_trans->commit_wait);
137 cur_trans->in_commit = 0;
138 cur_trans->blocked = 0;
140 * One for this trans handle, one so it will live on until we
141 * commit the transaction.
143 atomic_set(&cur_trans->use_count, 2);
144 cur_trans->commit_done = 0;
145 cur_trans->start_time = get_seconds();
147 cur_trans->delayed_refs.root = RB_ROOT;
148 cur_trans->delayed_refs.num_entries = 0;
149 cur_trans->delayed_refs.num_heads_ready = 0;
150 cur_trans->delayed_refs.num_heads = 0;
151 cur_trans->delayed_refs.flushing = 0;
152 cur_trans->delayed_refs.run_delayed_start = 0;
155 * although the tree mod log is per file system and not per transaction,
156 * the log must never go across transaction boundaries.
159 if (!list_empty(&fs_info->tree_mod_seq_list))
160 WARN(1, KERN_ERR "btrfs: tree_mod_seq_list not empty when "
161 "creating a fresh transaction\n");
162 if (!RB_EMPTY_ROOT(&fs_info->tree_mod_log))
163 WARN(1, KERN_ERR "btrfs: tree_mod_log rb tree not empty when "
164 "creating a fresh transaction\n");
165 atomic_set(&fs_info->tree_mod_seq, 0);
167 spin_lock_init(&cur_trans->commit_lock);
168 spin_lock_init(&cur_trans->delayed_refs.lock);
169 atomic_set(&cur_trans->delayed_refs.procs_running_refs, 0);
170 atomic_set(&cur_trans->delayed_refs.ref_seq, 0);
171 init_waitqueue_head(&cur_trans->delayed_refs.wait);
173 INIT_LIST_HEAD(&cur_trans->pending_snapshots);
174 INIT_LIST_HEAD(&cur_trans->ordered_operations);
175 list_add_tail(&cur_trans->list, &fs_info->trans_list);
176 extent_io_tree_init(&cur_trans->dirty_pages,
177 fs_info->btree_inode->i_mapping);
178 fs_info->generation++;
179 cur_trans->transid = fs_info->generation;
180 fs_info->running_transaction = cur_trans;
181 cur_trans->aborted = 0;
182 spin_unlock(&fs_info->trans_lock);
188 * this does all the record keeping required to make sure that a reference
189 * counted root is properly recorded in a given transaction. This is required
190 * to make sure the old root from before we joined the transaction is deleted
191 * when the transaction commits
193 static int record_root_in_trans(struct btrfs_trans_handle *trans,
194 struct btrfs_root *root)
196 if (root->ref_cows && root->last_trans < trans->transid) {
197 WARN_ON(root == root->fs_info->extent_root);
198 WARN_ON(root->commit_root != root->node);
201 * see below for in_trans_setup usage rules
202 * we have the reloc mutex held now, so there
203 * is only one writer in this function
205 root->in_trans_setup = 1;
207 /* make sure readers find in_trans_setup before
208 * they find our root->last_trans update
212 spin_lock(&root->fs_info->fs_roots_radix_lock);
213 if (root->last_trans == trans->transid) {
214 spin_unlock(&root->fs_info->fs_roots_radix_lock);
217 radix_tree_tag_set(&root->fs_info->fs_roots_radix,
218 (unsigned long)root->root_key.objectid,
219 BTRFS_ROOT_TRANS_TAG);
220 spin_unlock(&root->fs_info->fs_roots_radix_lock);
221 root->last_trans = trans->transid;
223 /* this is pretty tricky. We don't want to
224 * take the relocation lock in btrfs_record_root_in_trans
225 * unless we're really doing the first setup for this root in
228 * Normally we'd use root->last_trans as a flag to decide
229 * if we want to take the expensive mutex.
231 * But, we have to set root->last_trans before we
232 * init the relocation root, otherwise, we trip over warnings
233 * in ctree.c. The solution used here is to flag ourselves
234 * with root->in_trans_setup. When this is 1, we're still
235 * fixing up the reloc trees and everyone must wait.
237 * When this is zero, they can trust root->last_trans and fly
238 * through btrfs_record_root_in_trans without having to take the
239 * lock. smp_wmb() makes sure that all the writes above are
240 * done before we pop in the zero below
242 btrfs_init_reloc_root(trans, root);
244 root->in_trans_setup = 0;
250 int btrfs_record_root_in_trans(struct btrfs_trans_handle *trans,
251 struct btrfs_root *root)
257 * see record_root_in_trans for comments about in_trans_setup usage
261 if (root->last_trans == trans->transid &&
262 !root->in_trans_setup)
265 mutex_lock(&root->fs_info->reloc_mutex);
266 record_root_in_trans(trans, root);
267 mutex_unlock(&root->fs_info->reloc_mutex);
272 /* wait for commit against the current transaction to become unblocked
273 * when this is done, it is safe to start a new transaction, but the current
274 * transaction might not be fully on disk.
276 static void wait_current_trans(struct btrfs_root *root)
278 struct btrfs_transaction *cur_trans;
280 spin_lock(&root->fs_info->trans_lock);
281 cur_trans = root->fs_info->running_transaction;
282 if (cur_trans && cur_trans->blocked) {
283 atomic_inc(&cur_trans->use_count);
284 spin_unlock(&root->fs_info->trans_lock);
286 wait_event(root->fs_info->transaction_wait,
287 !cur_trans->blocked);
288 put_transaction(cur_trans);
290 spin_unlock(&root->fs_info->trans_lock);
294 static int may_wait_transaction(struct btrfs_root *root, int type)
296 if (root->fs_info->log_root_recovering)
299 if (type == TRANS_USERSPACE)
302 if (type == TRANS_START &&
303 !atomic_read(&root->fs_info->open_ioctl_trans))
309 static struct btrfs_trans_handle *
310 start_transaction(struct btrfs_root *root, u64 num_items, int type,
311 enum btrfs_reserve_flush_enum flush)
313 struct btrfs_trans_handle *h;
314 struct btrfs_transaction *cur_trans;
317 u64 qgroup_reserved = 0;
319 if (test_bit(BTRFS_FS_STATE_ERROR, &root->fs_info->fs_state))
320 return ERR_PTR(-EROFS);
322 if (current->journal_info) {
323 WARN_ON(type != TRANS_JOIN && type != TRANS_JOIN_NOLOCK);
324 h = current->journal_info;
326 WARN_ON(h->use_count > 2);
327 h->orig_rsv = h->block_rsv;
333 * Do the reservation before we join the transaction so we can do all
334 * the appropriate flushing if need be.
336 if (num_items > 0 && root != root->fs_info->chunk_root) {
337 if (root->fs_info->quota_enabled &&
338 is_fstree(root->root_key.objectid)) {
339 qgroup_reserved = num_items * root->leafsize;
340 ret = btrfs_qgroup_reserve(root, qgroup_reserved);
345 num_bytes = btrfs_calc_trans_metadata_size(root, num_items);
346 ret = btrfs_block_rsv_add(root,
347 &root->fs_info->trans_block_rsv,
353 h = kmem_cache_alloc(btrfs_trans_handle_cachep, GFP_NOFS);
360 * If we are JOIN_NOLOCK we're already committing a transaction and
361 * waiting on this guy, so we don't need to do the sb_start_intwrite
362 * because we're already holding a ref. We need this because we could
363 * have raced in and did an fsync() on a file which can kick a commit
364 * and then we deadlock with somebody doing a freeze.
366 * If we are ATTACH, it means we just want to catch the current
367 * transaction and commit it, so we needn't do sb_start_intwrite().
369 if (type < TRANS_JOIN_NOLOCK)
370 sb_start_intwrite(root->fs_info->sb);
372 if (may_wait_transaction(root, type))
373 wait_current_trans(root);
376 ret = join_transaction(root, type);
378 wait_current_trans(root);
379 if (unlikely(type == TRANS_ATTACH))
382 } while (ret == -EBUSY);
385 /* We must get the transaction if we are JOIN_NOLOCK. */
386 BUG_ON(type == TRANS_JOIN_NOLOCK);
390 cur_trans = root->fs_info->running_transaction;
392 h->transid = cur_trans->transid;
393 h->transaction = cur_trans;
395 h->bytes_reserved = 0;
397 h->delayed_ref_updates = 0;
403 h->qgroup_reserved = 0;
404 h->delayed_ref_elem.seq = 0;
406 h->allocating_chunk = false;
407 INIT_LIST_HEAD(&h->qgroup_ref_list);
408 INIT_LIST_HEAD(&h->new_bgs);
411 if (cur_trans->blocked && may_wait_transaction(root, type)) {
412 btrfs_commit_transaction(h, root);
417 trace_btrfs_space_reservation(root->fs_info, "transaction",
418 h->transid, num_bytes, 1);
419 h->block_rsv = &root->fs_info->trans_block_rsv;
420 h->bytes_reserved = num_bytes;
422 h->qgroup_reserved = qgroup_reserved;
425 btrfs_record_root_in_trans(h, root);
427 if (!current->journal_info && type != TRANS_USERSPACE)
428 current->journal_info = h;
432 if (type < TRANS_JOIN_NOLOCK)
433 sb_end_intwrite(root->fs_info->sb);
434 kmem_cache_free(btrfs_trans_handle_cachep, h);
437 btrfs_block_rsv_release(root, &root->fs_info->trans_block_rsv,
441 btrfs_qgroup_free(root, qgroup_reserved);
445 struct btrfs_trans_handle *btrfs_start_transaction(struct btrfs_root *root,
448 return start_transaction(root, num_items, TRANS_START,
449 BTRFS_RESERVE_FLUSH_ALL);
452 struct btrfs_trans_handle *btrfs_start_transaction_lflush(
453 struct btrfs_root *root, int num_items)
455 return start_transaction(root, num_items, TRANS_START,
456 BTRFS_RESERVE_FLUSH_LIMIT);
459 struct btrfs_trans_handle *btrfs_join_transaction(struct btrfs_root *root)
461 return start_transaction(root, 0, TRANS_JOIN, 0);
464 struct btrfs_trans_handle *btrfs_join_transaction_nolock(struct btrfs_root *root)
466 return start_transaction(root, 0, TRANS_JOIN_NOLOCK, 0);
469 struct btrfs_trans_handle *btrfs_start_ioctl_transaction(struct btrfs_root *root)
471 return start_transaction(root, 0, TRANS_USERSPACE, 0);
475 * btrfs_attach_transaction() - catch the running transaction
477 * It is used when we want to commit the current the transaction, but
478 * don't want to start a new one.
480 * Note: If this function return -ENOENT, it just means there is no
481 * running transaction. But it is possible that the inactive transaction
482 * is still in the memory, not fully on disk. If you hope there is no
483 * inactive transaction in the fs when -ENOENT is returned, you should
485 * btrfs_attach_transaction_barrier()
487 struct btrfs_trans_handle *btrfs_attach_transaction(struct btrfs_root *root)
489 return start_transaction(root, 0, TRANS_ATTACH, 0);
493 * btrfs_attach_transaction() - catch the running transaction
495 * It is similar to the above function, the differentia is this one
496 * will wait for all the inactive transactions until they fully
499 struct btrfs_trans_handle *
500 btrfs_attach_transaction_barrier(struct btrfs_root *root)
502 struct btrfs_trans_handle *trans;
504 trans = start_transaction(root, 0, TRANS_ATTACH, 0);
505 if (IS_ERR(trans) && PTR_ERR(trans) == -ENOENT)
506 btrfs_wait_for_commit(root, 0);
511 /* wait for a transaction commit to be fully complete */
512 static noinline void wait_for_commit(struct btrfs_root *root,
513 struct btrfs_transaction *commit)
515 wait_event(commit->commit_wait, commit->commit_done);
518 int btrfs_wait_for_commit(struct btrfs_root *root, u64 transid)
520 struct btrfs_transaction *cur_trans = NULL, *t;
524 if (transid <= root->fs_info->last_trans_committed)
528 /* find specified transaction */
529 spin_lock(&root->fs_info->trans_lock);
530 list_for_each_entry(t, &root->fs_info->trans_list, list) {
531 if (t->transid == transid) {
533 atomic_inc(&cur_trans->use_count);
537 if (t->transid > transid) {
542 spin_unlock(&root->fs_info->trans_lock);
543 /* The specified transaction doesn't exist */
547 /* find newest transaction that is committing | committed */
548 spin_lock(&root->fs_info->trans_lock);
549 list_for_each_entry_reverse(t, &root->fs_info->trans_list,
555 atomic_inc(&cur_trans->use_count);
559 spin_unlock(&root->fs_info->trans_lock);
561 goto out; /* nothing committing|committed */
564 wait_for_commit(root, cur_trans);
565 put_transaction(cur_trans);
570 void btrfs_throttle(struct btrfs_root *root)
572 if (!atomic_read(&root->fs_info->open_ioctl_trans))
573 wait_current_trans(root);
576 static int should_end_transaction(struct btrfs_trans_handle *trans,
577 struct btrfs_root *root)
581 ret = btrfs_block_rsv_check(root, &root->fs_info->global_block_rsv, 5);
585 int btrfs_should_end_transaction(struct btrfs_trans_handle *trans,
586 struct btrfs_root *root)
588 struct btrfs_transaction *cur_trans = trans->transaction;
593 if (cur_trans->blocked || cur_trans->delayed_refs.flushing)
596 updates = trans->delayed_ref_updates;
597 trans->delayed_ref_updates = 0;
599 err = btrfs_run_delayed_refs(trans, root, updates);
600 if (err) /* Error code will also eval true */
604 return should_end_transaction(trans, root);
607 static int __btrfs_end_transaction(struct btrfs_trans_handle *trans,
608 struct btrfs_root *root, int throttle)
610 struct btrfs_transaction *cur_trans = trans->transaction;
611 struct btrfs_fs_info *info = root->fs_info;
613 int lock = (trans->type != TRANS_JOIN_NOLOCK);
616 if (--trans->use_count) {
617 trans->block_rsv = trans->orig_rsv;
622 * do the qgroup accounting as early as possible
624 err = btrfs_delayed_refs_qgroup_accounting(trans, info);
626 btrfs_trans_release_metadata(trans, root);
627 trans->block_rsv = NULL;
629 * the same root has to be passed to start_transaction and
630 * end_transaction. Subvolume quota depends on this.
632 WARN_ON(trans->root != root);
634 if (trans->qgroup_reserved) {
635 btrfs_qgroup_free(root, trans->qgroup_reserved);
636 trans->qgroup_reserved = 0;
639 if (!list_empty(&trans->new_bgs))
640 btrfs_create_pending_block_groups(trans, root);
643 unsigned long cur = trans->delayed_ref_updates;
644 trans->delayed_ref_updates = 0;
646 trans->transaction->delayed_refs.num_heads_ready > 64) {
647 trans->delayed_ref_updates = 0;
648 btrfs_run_delayed_refs(trans, root, cur);
655 btrfs_trans_release_metadata(trans, root);
656 trans->block_rsv = NULL;
658 if (!list_empty(&trans->new_bgs))
659 btrfs_create_pending_block_groups(trans, root);
661 if (lock && !atomic_read(&root->fs_info->open_ioctl_trans) &&
662 should_end_transaction(trans, root)) {
663 trans->transaction->blocked = 1;
667 if (lock && cur_trans->blocked && !cur_trans->in_commit) {
670 * We may race with somebody else here so end up having
671 * to call end_transaction on ourselves again, so inc
675 return btrfs_commit_transaction(trans, root);
677 wake_up_process(info->transaction_kthread);
681 if (trans->type < TRANS_JOIN_NOLOCK)
682 sb_end_intwrite(root->fs_info->sb);
684 WARN_ON(cur_trans != info->running_transaction);
685 WARN_ON(atomic_read(&cur_trans->num_writers) < 1);
686 atomic_dec(&cur_trans->num_writers);
689 if (waitqueue_active(&cur_trans->writer_wait))
690 wake_up(&cur_trans->writer_wait);
691 put_transaction(cur_trans);
693 if (current->journal_info == trans)
694 current->journal_info = NULL;
697 btrfs_run_delayed_iputs(root);
699 if (trans->aborted ||
700 test_bit(BTRFS_FS_STATE_ERROR, &root->fs_info->fs_state))
702 assert_qgroups_uptodate(trans);
704 kmem_cache_free(btrfs_trans_handle_cachep, trans);
708 int btrfs_end_transaction(struct btrfs_trans_handle *trans,
709 struct btrfs_root *root)
713 ret = __btrfs_end_transaction(trans, root, 0);
719 int btrfs_end_transaction_throttle(struct btrfs_trans_handle *trans,
720 struct btrfs_root *root)
724 ret = __btrfs_end_transaction(trans, root, 1);
730 int btrfs_end_transaction_dmeta(struct btrfs_trans_handle *trans,
731 struct btrfs_root *root)
733 return __btrfs_end_transaction(trans, root, 1);
737 * when btree blocks are allocated, they have some corresponding bits set for
738 * them in one of two extent_io trees. This is used to make sure all of
739 * those extents are sent to disk but does not wait on them
741 int btrfs_write_marked_extents(struct btrfs_root *root,
742 struct extent_io_tree *dirty_pages, int mark)
746 struct address_space *mapping = root->fs_info->btree_inode->i_mapping;
747 struct extent_state *cached_state = NULL;
750 struct blk_plug plug;
752 blk_start_plug(&plug);
753 while (!find_first_extent_bit(dirty_pages, start, &start, &end,
754 mark, &cached_state)) {
755 convert_extent_bit(dirty_pages, start, end, EXTENT_NEED_WAIT,
756 mark, &cached_state, GFP_NOFS);
758 err = filemap_fdatawrite_range(mapping, start, end);
766 blk_finish_plug(&plug);
771 * when btree blocks are allocated, they have some corresponding bits set for
772 * them in one of two extent_io trees. This is used to make sure all of
773 * those extents are on disk for transaction or log commit. We wait
774 * on all the pages and clear them from the dirty pages state tree
776 int btrfs_wait_marked_extents(struct btrfs_root *root,
777 struct extent_io_tree *dirty_pages, int mark)
781 struct address_space *mapping = root->fs_info->btree_inode->i_mapping;
782 struct extent_state *cached_state = NULL;
786 while (!find_first_extent_bit(dirty_pages, start, &start, &end,
787 EXTENT_NEED_WAIT, &cached_state)) {
788 clear_extent_bit(dirty_pages, start, end, EXTENT_NEED_WAIT,
789 0, 0, &cached_state, GFP_NOFS);
790 err = filemap_fdatawait_range(mapping, start, end);
802 * when btree blocks are allocated, they have some corresponding bits set for
803 * them in one of two extent_io trees. This is used to make sure all of
804 * those extents are on disk for transaction or log commit
806 int btrfs_write_and_wait_marked_extents(struct btrfs_root *root,
807 struct extent_io_tree *dirty_pages, int mark)
812 ret = btrfs_write_marked_extents(root, dirty_pages, mark);
813 ret2 = btrfs_wait_marked_extents(root, dirty_pages, mark);
822 int btrfs_write_and_wait_transaction(struct btrfs_trans_handle *trans,
823 struct btrfs_root *root)
825 if (!trans || !trans->transaction) {
826 struct inode *btree_inode;
827 btree_inode = root->fs_info->btree_inode;
828 return filemap_write_and_wait(btree_inode->i_mapping);
830 return btrfs_write_and_wait_marked_extents(root,
831 &trans->transaction->dirty_pages,
836 * this is used to update the root pointer in the tree of tree roots.
838 * But, in the case of the extent allocation tree, updating the root
839 * pointer may allocate blocks which may change the root of the extent
842 * So, this loops and repeats and makes sure the cowonly root didn't
843 * change while the root pointer was being updated in the metadata.
845 static int update_cowonly_root(struct btrfs_trans_handle *trans,
846 struct btrfs_root *root)
851 struct btrfs_root *tree_root = root->fs_info->tree_root;
853 old_root_used = btrfs_root_used(&root->root_item);
854 btrfs_write_dirty_block_groups(trans, root);
857 old_root_bytenr = btrfs_root_bytenr(&root->root_item);
858 if (old_root_bytenr == root->node->start &&
859 old_root_used == btrfs_root_used(&root->root_item))
862 btrfs_set_root_node(&root->root_item, root->node);
863 ret = btrfs_update_root(trans, tree_root,
869 old_root_used = btrfs_root_used(&root->root_item);
870 ret = btrfs_write_dirty_block_groups(trans, root);
875 if (root != root->fs_info->extent_root)
876 switch_commit_root(root);
882 * update all the cowonly tree roots on disk
884 * The error handling in this function may not be obvious. Any of the
885 * failures will cause the file system to go offline. We still need
886 * to clean up the delayed refs.
888 static noinline int commit_cowonly_roots(struct btrfs_trans_handle *trans,
889 struct btrfs_root *root)
891 struct btrfs_fs_info *fs_info = root->fs_info;
892 struct list_head *next;
893 struct extent_buffer *eb;
896 ret = btrfs_run_delayed_refs(trans, root, (unsigned long)-1);
900 eb = btrfs_lock_root_node(fs_info->tree_root);
901 ret = btrfs_cow_block(trans, fs_info->tree_root, eb, NULL,
903 btrfs_tree_unlock(eb);
904 free_extent_buffer(eb);
909 ret = btrfs_run_delayed_refs(trans, root, (unsigned long)-1);
913 ret = btrfs_run_dev_stats(trans, root->fs_info);
915 ret = btrfs_run_dev_replace(trans, root->fs_info);
918 ret = btrfs_run_qgroups(trans, root->fs_info);
921 /* run_qgroups might have added some more refs */
922 ret = btrfs_run_delayed_refs(trans, root, (unsigned long)-1);
925 while (!list_empty(&fs_info->dirty_cowonly_roots)) {
926 next = fs_info->dirty_cowonly_roots.next;
928 root = list_entry(next, struct btrfs_root, dirty_list);
930 ret = update_cowonly_root(trans, root);
935 down_write(&fs_info->extent_commit_sem);
936 switch_commit_root(fs_info->extent_root);
937 up_write(&fs_info->extent_commit_sem);
939 btrfs_after_dev_replace_commit(fs_info);
945 * dead roots are old snapshots that need to be deleted. This allocates
946 * a dirty root struct and adds it into the list of dead roots that need to
949 int btrfs_add_dead_root(struct btrfs_root *root)
951 spin_lock(&root->fs_info->trans_lock);
952 list_add(&root->root_list, &root->fs_info->dead_roots);
953 spin_unlock(&root->fs_info->trans_lock);
958 * update all the cowonly tree roots on disk
960 static noinline int commit_fs_roots(struct btrfs_trans_handle *trans,
961 struct btrfs_root *root)
963 struct btrfs_root *gang[8];
964 struct btrfs_fs_info *fs_info = root->fs_info;
969 spin_lock(&fs_info->fs_roots_radix_lock);
971 ret = radix_tree_gang_lookup_tag(&fs_info->fs_roots_radix,
974 BTRFS_ROOT_TRANS_TAG);
977 for (i = 0; i < ret; i++) {
979 radix_tree_tag_clear(&fs_info->fs_roots_radix,
980 (unsigned long)root->root_key.objectid,
981 BTRFS_ROOT_TRANS_TAG);
982 spin_unlock(&fs_info->fs_roots_radix_lock);
984 btrfs_free_log(trans, root);
985 btrfs_update_reloc_root(trans, root);
986 btrfs_orphan_commit_root(trans, root);
988 btrfs_save_ino_cache(root, trans);
990 /* see comments in should_cow_block() */
994 if (root->commit_root != root->node) {
995 mutex_lock(&root->fs_commit_mutex);
996 switch_commit_root(root);
997 btrfs_unpin_free_ino(root);
998 mutex_unlock(&root->fs_commit_mutex);
1000 btrfs_set_root_node(&root->root_item,
1004 err = btrfs_update_root(trans, fs_info->tree_root,
1007 spin_lock(&fs_info->fs_roots_radix_lock);
1012 spin_unlock(&fs_info->fs_roots_radix_lock);
1017 * defrag a given btree.
1018 * Every leaf in the btree is read and defragged.
1020 int btrfs_defrag_root(struct btrfs_root *root)
1022 struct btrfs_fs_info *info = root->fs_info;
1023 struct btrfs_trans_handle *trans;
1026 if (xchg(&root->defrag_running, 1))
1030 trans = btrfs_start_transaction(root, 0);
1032 return PTR_ERR(trans);
1034 ret = btrfs_defrag_leaves(trans, root);
1036 btrfs_end_transaction(trans, root);
1037 btrfs_btree_balance_dirty(info->tree_root);
1040 if (btrfs_fs_closing(root->fs_info) || ret != -EAGAIN)
1043 if (btrfs_defrag_cancelled(root->fs_info)) {
1044 printk(KERN_DEBUG "btrfs: defrag_root cancelled\n");
1049 root->defrag_running = 0;
1054 * new snapshots need to be created at a very specific time in the
1055 * transaction commit. This does the actual creation.
1058 * If the error which may affect the commitment of the current transaction
1059 * happens, we should return the error number. If the error which just affect
1060 * the creation of the pending snapshots, just return 0.
1062 static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans,
1063 struct btrfs_fs_info *fs_info,
1064 struct btrfs_pending_snapshot *pending)
1066 struct btrfs_key key;
1067 struct btrfs_root_item *new_root_item;
1068 struct btrfs_root *tree_root = fs_info->tree_root;
1069 struct btrfs_root *root = pending->root;
1070 struct btrfs_root *parent_root;
1071 struct btrfs_block_rsv *rsv;
1072 struct inode *parent_inode;
1073 struct btrfs_path *path;
1074 struct btrfs_dir_item *dir_item;
1075 struct dentry *dentry;
1076 struct extent_buffer *tmp;
1077 struct extent_buffer *old;
1078 struct timespec cur_time = CURRENT_TIME;
1086 path = btrfs_alloc_path();
1088 pending->error = -ENOMEM;
1092 new_root_item = kmalloc(sizeof(*new_root_item), GFP_NOFS);
1093 if (!new_root_item) {
1094 pending->error = -ENOMEM;
1095 goto root_item_alloc_fail;
1098 pending->error = btrfs_find_free_objectid(tree_root, &objectid);
1100 goto no_free_objectid;
1102 btrfs_reloc_pre_snapshot(trans, pending, &to_reserve);
1104 if (to_reserve > 0) {
1105 pending->error = btrfs_block_rsv_add(root,
1106 &pending->block_rsv,
1108 BTRFS_RESERVE_NO_FLUSH);
1110 goto no_free_objectid;
1113 pending->error = btrfs_qgroup_inherit(trans, fs_info,
1114 root->root_key.objectid,
1115 objectid, pending->inherit);
1117 goto no_free_objectid;
1119 key.objectid = objectid;
1120 key.offset = (u64)-1;
1121 key.type = BTRFS_ROOT_ITEM_KEY;
1123 rsv = trans->block_rsv;
1124 trans->block_rsv = &pending->block_rsv;
1125 trans->bytes_reserved = trans->block_rsv->reserved;
1127 dentry = pending->dentry;
1128 parent_inode = pending->dir;
1129 parent_root = BTRFS_I(parent_inode)->root;
1130 record_root_in_trans(trans, parent_root);
1133 * insert the directory item
1135 ret = btrfs_set_inode_index(parent_inode, &index);
1136 BUG_ON(ret); /* -ENOMEM */
1138 /* check if there is a file/dir which has the same name. */
1139 dir_item = btrfs_lookup_dir_item(NULL, parent_root, path,
1140 btrfs_ino(parent_inode),
1141 dentry->d_name.name,
1142 dentry->d_name.len, 0);
1143 if (dir_item != NULL && !IS_ERR(dir_item)) {
1144 pending->error = -EEXIST;
1145 goto dir_item_existed;
1146 } else if (IS_ERR(dir_item)) {
1147 ret = PTR_ERR(dir_item);
1148 btrfs_abort_transaction(trans, root, ret);
1151 btrfs_release_path(path);
1154 * pull in the delayed directory update
1155 * and the delayed inode item
1156 * otherwise we corrupt the FS during
1159 ret = btrfs_run_delayed_items(trans, root);
1160 if (ret) { /* Transaction aborted */
1161 btrfs_abort_transaction(trans, root, ret);
1165 record_root_in_trans(trans, root);
1166 btrfs_set_root_last_snapshot(&root->root_item, trans->transid);
1167 memcpy(new_root_item, &root->root_item, sizeof(*new_root_item));
1168 btrfs_check_and_init_root_item(new_root_item);
1170 root_flags = btrfs_root_flags(new_root_item);
1171 if (pending->readonly)
1172 root_flags |= BTRFS_ROOT_SUBVOL_RDONLY;
1174 root_flags &= ~BTRFS_ROOT_SUBVOL_RDONLY;
1175 btrfs_set_root_flags(new_root_item, root_flags);
1177 btrfs_set_root_generation_v2(new_root_item,
1179 uuid_le_gen(&new_uuid);
1180 memcpy(new_root_item->uuid, new_uuid.b, BTRFS_UUID_SIZE);
1181 memcpy(new_root_item->parent_uuid, root->root_item.uuid,
1183 new_root_item->otime.sec = cpu_to_le64(cur_time.tv_sec);
1184 new_root_item->otime.nsec = cpu_to_le32(cur_time.tv_nsec);
1185 btrfs_set_root_otransid(new_root_item, trans->transid);
1186 memset(&new_root_item->stime, 0, sizeof(new_root_item->stime));
1187 memset(&new_root_item->rtime, 0, sizeof(new_root_item->rtime));
1188 btrfs_set_root_stransid(new_root_item, 0);
1189 btrfs_set_root_rtransid(new_root_item, 0);
1191 old = btrfs_lock_root_node(root);
1192 ret = btrfs_cow_block(trans, root, old, NULL, 0, &old);
1194 btrfs_tree_unlock(old);
1195 free_extent_buffer(old);
1196 btrfs_abort_transaction(trans, root, ret);
1200 btrfs_set_lock_blocking(old);
1202 ret = btrfs_copy_root(trans, root, old, &tmp, objectid);
1203 /* clean up in any case */
1204 btrfs_tree_unlock(old);
1205 free_extent_buffer(old);
1207 btrfs_abort_transaction(trans, root, ret);
1211 /* see comments in should_cow_block() */
1212 root->force_cow = 1;
1215 btrfs_set_root_node(new_root_item, tmp);
1216 /* record when the snapshot was created in key.offset */
1217 key.offset = trans->transid;
1218 ret = btrfs_insert_root(trans, tree_root, &key, new_root_item);
1219 btrfs_tree_unlock(tmp);
1220 free_extent_buffer(tmp);
1222 btrfs_abort_transaction(trans, root, ret);
1227 * insert root back/forward references
1229 ret = btrfs_add_root_ref(trans, tree_root, objectid,
1230 parent_root->root_key.objectid,
1231 btrfs_ino(parent_inode), index,
1232 dentry->d_name.name, dentry->d_name.len);
1234 btrfs_abort_transaction(trans, root, ret);
1238 key.offset = (u64)-1;
1239 pending->snap = btrfs_read_fs_root_no_name(root->fs_info, &key);
1240 if (IS_ERR(pending->snap)) {
1241 ret = PTR_ERR(pending->snap);
1242 btrfs_abort_transaction(trans, root, ret);
1246 ret = btrfs_reloc_post_snapshot(trans, pending);
1248 btrfs_abort_transaction(trans, root, ret);
1252 ret = btrfs_run_delayed_refs(trans, root, (unsigned long)-1);
1254 btrfs_abort_transaction(trans, root, ret);
1258 ret = btrfs_insert_dir_item(trans, parent_root,
1259 dentry->d_name.name, dentry->d_name.len,
1261 BTRFS_FT_DIR, index);
1262 /* We have check then name at the beginning, so it is impossible. */
1263 BUG_ON(ret == -EEXIST || ret == -EOVERFLOW);
1265 btrfs_abort_transaction(trans, root, ret);
1269 btrfs_i_size_write(parent_inode, parent_inode->i_size +
1270 dentry->d_name.len * 2);
1271 parent_inode->i_mtime = parent_inode->i_ctime = CURRENT_TIME;
1272 ret = btrfs_update_inode_fallback(trans, parent_root, parent_inode);
1274 btrfs_abort_transaction(trans, root, ret);
1276 pending->error = ret;
1278 trans->block_rsv = rsv;
1279 trans->bytes_reserved = 0;
1281 kfree(new_root_item);
1282 root_item_alloc_fail:
1283 btrfs_free_path(path);
1288 * create all the snapshots we've scheduled for creation
1290 static noinline int create_pending_snapshots(struct btrfs_trans_handle *trans,
1291 struct btrfs_fs_info *fs_info)
1293 struct btrfs_pending_snapshot *pending, *next;
1294 struct list_head *head = &trans->transaction->pending_snapshots;
1297 list_for_each_entry_safe(pending, next, head, list) {
1298 list_del(&pending->list);
1299 ret = create_pending_snapshot(trans, fs_info, pending);
1306 static void update_super_roots(struct btrfs_root *root)
1308 struct btrfs_root_item *root_item;
1309 struct btrfs_super_block *super;
1311 super = root->fs_info->super_copy;
1313 root_item = &root->fs_info->chunk_root->root_item;
1314 super->chunk_root = root_item->bytenr;
1315 super->chunk_root_generation = root_item->generation;
1316 super->chunk_root_level = root_item->level;
1318 root_item = &root->fs_info->tree_root->root_item;
1319 super->root = root_item->bytenr;
1320 super->generation = root_item->generation;
1321 super->root_level = root_item->level;
1322 if (btrfs_test_opt(root, SPACE_CACHE))
1323 super->cache_generation = root_item->generation;
1326 int btrfs_transaction_in_commit(struct btrfs_fs_info *info)
1329 spin_lock(&info->trans_lock);
1330 if (info->running_transaction)
1331 ret = info->running_transaction->in_commit;
1332 spin_unlock(&info->trans_lock);
1336 int btrfs_transaction_blocked(struct btrfs_fs_info *info)
1339 spin_lock(&info->trans_lock);
1340 if (info->running_transaction)
1341 ret = info->running_transaction->blocked;
1342 spin_unlock(&info->trans_lock);
1347 * wait for the current transaction commit to start and block subsequent
1350 static void wait_current_trans_commit_start(struct btrfs_root *root,
1351 struct btrfs_transaction *trans)
1353 wait_event(root->fs_info->transaction_blocked_wait, trans->in_commit);
1357 * wait for the current transaction to start and then become unblocked.
1360 static void wait_current_trans_commit_start_and_unblock(struct btrfs_root *root,
1361 struct btrfs_transaction *trans)
1363 wait_event(root->fs_info->transaction_wait,
1364 trans->commit_done || (trans->in_commit && !trans->blocked));
1368 * commit transactions asynchronously. once btrfs_commit_transaction_async
1369 * returns, any subsequent transaction will not be allowed to join.
1371 struct btrfs_async_commit {
1372 struct btrfs_trans_handle *newtrans;
1373 struct btrfs_root *root;
1374 struct work_struct work;
1377 static void do_async_commit(struct work_struct *work)
1379 struct btrfs_async_commit *ac =
1380 container_of(work, struct btrfs_async_commit, work);
1383 * We've got freeze protection passed with the transaction.
1384 * Tell lockdep about it.
1386 if (ac->newtrans->type < TRANS_JOIN_NOLOCK)
1388 &ac->root->fs_info->sb->s_writers.lock_map[SB_FREEZE_FS-1],
1391 current->journal_info = ac->newtrans;
1393 btrfs_commit_transaction(ac->newtrans, ac->root);
1397 int btrfs_commit_transaction_async(struct btrfs_trans_handle *trans,
1398 struct btrfs_root *root,
1399 int wait_for_unblock)
1401 struct btrfs_async_commit *ac;
1402 struct btrfs_transaction *cur_trans;
1404 ac = kmalloc(sizeof(*ac), GFP_NOFS);
1408 INIT_WORK(&ac->work, do_async_commit);
1410 ac->newtrans = btrfs_join_transaction(root);
1411 if (IS_ERR(ac->newtrans)) {
1412 int err = PTR_ERR(ac->newtrans);
1417 /* take transaction reference */
1418 cur_trans = trans->transaction;
1419 atomic_inc(&cur_trans->use_count);
1421 btrfs_end_transaction(trans, root);
1424 * Tell lockdep we've released the freeze rwsem, since the
1425 * async commit thread will be the one to unlock it.
1427 if (trans->type < TRANS_JOIN_NOLOCK)
1429 &root->fs_info->sb->s_writers.lock_map[SB_FREEZE_FS-1],
1432 schedule_work(&ac->work);
1434 /* wait for transaction to start and unblock */
1435 if (wait_for_unblock)
1436 wait_current_trans_commit_start_and_unblock(root, cur_trans);
1438 wait_current_trans_commit_start(root, cur_trans);
1440 if (current->journal_info == trans)
1441 current->journal_info = NULL;
1443 put_transaction(cur_trans);
1448 static void cleanup_transaction(struct btrfs_trans_handle *trans,
1449 struct btrfs_root *root, int err)
1451 struct btrfs_transaction *cur_trans = trans->transaction;
1454 WARN_ON(trans->use_count > 1);
1456 btrfs_abort_transaction(trans, root, err);
1458 spin_lock(&root->fs_info->trans_lock);
1460 if (list_empty(&cur_trans->list)) {
1461 spin_unlock(&root->fs_info->trans_lock);
1462 btrfs_end_transaction(trans, root);
1466 list_del_init(&cur_trans->list);
1467 if (cur_trans == root->fs_info->running_transaction) {
1468 root->fs_info->trans_no_join = 1;
1469 spin_unlock(&root->fs_info->trans_lock);
1470 wait_event(cur_trans->writer_wait,
1471 atomic_read(&cur_trans->num_writers) == 1);
1473 spin_lock(&root->fs_info->trans_lock);
1474 root->fs_info->running_transaction = NULL;
1476 spin_unlock(&root->fs_info->trans_lock);
1478 btrfs_cleanup_one_transaction(trans->transaction, root);
1480 put_transaction(cur_trans);
1481 put_transaction(cur_trans);
1483 trace_btrfs_transaction_commit(root);
1485 btrfs_scrub_continue(root);
1487 if (current->journal_info == trans)
1488 current->journal_info = NULL;
1490 kmem_cache_free(btrfs_trans_handle_cachep, trans);
1493 static int btrfs_flush_all_pending_stuffs(struct btrfs_trans_handle *trans,
1494 struct btrfs_root *root)
1496 int flush_on_commit = btrfs_test_opt(root, FLUSHONCOMMIT);
1497 int snap_pending = 0;
1500 if (!flush_on_commit) {
1501 spin_lock(&root->fs_info->trans_lock);
1502 if (!list_empty(&trans->transaction->pending_snapshots))
1504 spin_unlock(&root->fs_info->trans_lock);
1507 if (flush_on_commit || snap_pending) {
1508 ret = btrfs_start_delalloc_inodes(root, 1);
1511 btrfs_wait_ordered_extents(root, 1);
1514 ret = btrfs_run_delayed_items(trans, root);
1519 * running the delayed items may have added new refs. account
1520 * them now so that they hinder processing of more delayed refs
1521 * as little as possible.
1523 btrfs_delayed_refs_qgroup_accounting(trans, root->fs_info);
1526 * rename don't use btrfs_join_transaction, so, once we
1527 * set the transaction to blocked above, we aren't going
1528 * to get any new ordered operations. We can safely run
1529 * it here and no for sure that nothing new will be added
1532 ret = btrfs_run_ordered_operations(trans, root, 1);
1538 * btrfs_transaction state sequence:
1539 * in_commit = 0, blocked = 0 (initial)
1540 * in_commit = 1, blocked = 1
1544 int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
1545 struct btrfs_root *root)
1547 unsigned long joined = 0;
1548 struct btrfs_transaction *cur_trans = trans->transaction;
1549 struct btrfs_transaction *prev_trans = NULL;
1552 int should_grow = 0;
1553 unsigned long now = get_seconds();
1555 ret = btrfs_run_ordered_operations(trans, root, 0);
1557 btrfs_abort_transaction(trans, root, ret);
1558 btrfs_end_transaction(trans, root);
1562 /* Stop the commit early if ->aborted is set */
1563 if (unlikely(ACCESS_ONCE(cur_trans->aborted))) {
1564 ret = cur_trans->aborted;
1565 btrfs_end_transaction(trans, root);
1569 /* make a pass through all the delayed refs we have so far
1570 * any runnings procs may add more while we are here
1572 ret = btrfs_run_delayed_refs(trans, root, 0);
1574 btrfs_end_transaction(trans, root);
1578 btrfs_trans_release_metadata(trans, root);
1579 trans->block_rsv = NULL;
1580 if (trans->qgroup_reserved) {
1581 btrfs_qgroup_free(root, trans->qgroup_reserved);
1582 trans->qgroup_reserved = 0;
1585 cur_trans = trans->transaction;
1588 * set the flushing flag so procs in this transaction have to
1589 * start sending their work down.
1591 cur_trans->delayed_refs.flushing = 1;
1593 if (!list_empty(&trans->new_bgs))
1594 btrfs_create_pending_block_groups(trans, root);
1596 ret = btrfs_run_delayed_refs(trans, root, 0);
1598 btrfs_end_transaction(trans, root);
1602 spin_lock(&cur_trans->commit_lock);
1603 if (cur_trans->in_commit) {
1604 spin_unlock(&cur_trans->commit_lock);
1605 atomic_inc(&cur_trans->use_count);
1606 ret = btrfs_end_transaction(trans, root);
1608 wait_for_commit(root, cur_trans);
1610 put_transaction(cur_trans);
1615 trans->transaction->in_commit = 1;
1616 trans->transaction->blocked = 1;
1617 spin_unlock(&cur_trans->commit_lock);
1618 wake_up(&root->fs_info->transaction_blocked_wait);
1620 spin_lock(&root->fs_info->trans_lock);
1621 if (cur_trans->list.prev != &root->fs_info->trans_list) {
1622 prev_trans = list_entry(cur_trans->list.prev,
1623 struct btrfs_transaction, list);
1624 if (!prev_trans->commit_done) {
1625 atomic_inc(&prev_trans->use_count);
1626 spin_unlock(&root->fs_info->trans_lock);
1628 wait_for_commit(root, prev_trans);
1630 put_transaction(prev_trans);
1632 spin_unlock(&root->fs_info->trans_lock);
1635 spin_unlock(&root->fs_info->trans_lock);
1638 if (!btrfs_test_opt(root, SSD) &&
1639 (now < cur_trans->start_time || now - cur_trans->start_time < 1))
1643 joined = cur_trans->num_joined;
1645 WARN_ON(cur_trans != trans->transaction);
1647 ret = btrfs_flush_all_pending_stuffs(trans, root);
1649 goto cleanup_transaction;
1651 prepare_to_wait(&cur_trans->writer_wait, &wait,
1652 TASK_UNINTERRUPTIBLE);
1654 if (atomic_read(&cur_trans->num_writers) > 1)
1655 schedule_timeout(MAX_SCHEDULE_TIMEOUT);
1656 else if (should_grow)
1657 schedule_timeout(1);
1659 finish_wait(&cur_trans->writer_wait, &wait);
1660 } while (atomic_read(&cur_trans->num_writers) > 1 ||
1661 (should_grow && cur_trans->num_joined != joined));
1663 ret = btrfs_flush_all_pending_stuffs(trans, root);
1665 goto cleanup_transaction;
1668 * Ok now we need to make sure to block out any other joins while we
1669 * commit the transaction. We could have started a join before setting
1670 * no_join so make sure to wait for num_writers to == 1 again.
1672 spin_lock(&root->fs_info->trans_lock);
1673 root->fs_info->trans_no_join = 1;
1674 spin_unlock(&root->fs_info->trans_lock);
1675 wait_event(cur_trans->writer_wait,
1676 atomic_read(&cur_trans->num_writers) == 1);
1678 /* ->aborted might be set after the previous check, so check it */
1679 if (unlikely(ACCESS_ONCE(cur_trans->aborted))) {
1680 ret = cur_trans->aborted;
1681 goto cleanup_transaction;
1684 * the reloc mutex makes sure that we stop
1685 * the balancing code from coming in and moving
1686 * extents around in the middle of the commit
1688 mutex_lock(&root->fs_info->reloc_mutex);
1691 * We needn't worry about the delayed items because we will
1692 * deal with them in create_pending_snapshot(), which is the
1693 * core function of the snapshot creation.
1695 ret = create_pending_snapshots(trans, root->fs_info);
1697 mutex_unlock(&root->fs_info->reloc_mutex);
1698 goto cleanup_transaction;
1702 * We insert the dir indexes of the snapshots and update the inode
1703 * of the snapshots' parents after the snapshot creation, so there
1704 * are some delayed items which are not dealt with. Now deal with
1707 * We needn't worry that this operation will corrupt the snapshots,
1708 * because all the tree which are snapshoted will be forced to COW
1709 * the nodes and leaves.
1711 ret = btrfs_run_delayed_items(trans, root);
1713 mutex_unlock(&root->fs_info->reloc_mutex);
1714 goto cleanup_transaction;
1717 ret = btrfs_run_delayed_refs(trans, root, (unsigned long)-1);
1719 mutex_unlock(&root->fs_info->reloc_mutex);
1720 goto cleanup_transaction;
1724 * make sure none of the code above managed to slip in a
1727 btrfs_assert_delayed_root_empty(root);
1729 WARN_ON(cur_trans != trans->transaction);
1731 btrfs_scrub_pause(root);
1732 /* btrfs_commit_tree_roots is responsible for getting the
1733 * various roots consistent with each other. Every pointer
1734 * in the tree of tree roots has to point to the most up to date
1735 * root for every subvolume and other tree. So, we have to keep
1736 * the tree logging code from jumping in and changing any
1739 * At this point in the commit, there can't be any tree-log
1740 * writers, but a little lower down we drop the trans mutex
1741 * and let new people in. By holding the tree_log_mutex
1742 * from now until after the super is written, we avoid races
1743 * with the tree-log code.
1745 mutex_lock(&root->fs_info->tree_log_mutex);
1747 ret = commit_fs_roots(trans, root);
1749 mutex_unlock(&root->fs_info->tree_log_mutex);
1750 mutex_unlock(&root->fs_info->reloc_mutex);
1751 goto cleanup_transaction;
1754 /* commit_fs_roots gets rid of all the tree log roots, it is now
1755 * safe to free the root of tree log roots
1757 btrfs_free_log_root_tree(trans, root->fs_info);
1759 ret = commit_cowonly_roots(trans, root);
1761 mutex_unlock(&root->fs_info->tree_log_mutex);
1762 mutex_unlock(&root->fs_info->reloc_mutex);
1763 goto cleanup_transaction;
1767 * The tasks which save the space cache and inode cache may also
1768 * update ->aborted, check it.
1770 if (unlikely(ACCESS_ONCE(cur_trans->aborted))) {
1771 ret = cur_trans->aborted;
1772 mutex_unlock(&root->fs_info->tree_log_mutex);
1773 mutex_unlock(&root->fs_info->reloc_mutex);
1774 goto cleanup_transaction;
1777 btrfs_prepare_extent_commit(trans, root);
1779 cur_trans = root->fs_info->running_transaction;
1781 btrfs_set_root_node(&root->fs_info->tree_root->root_item,
1782 root->fs_info->tree_root->node);
1783 switch_commit_root(root->fs_info->tree_root);
1785 btrfs_set_root_node(&root->fs_info->chunk_root->root_item,
1786 root->fs_info->chunk_root->node);
1787 switch_commit_root(root->fs_info->chunk_root);
1789 assert_qgroups_uptodate(trans);
1790 update_super_roots(root);
1792 if (!root->fs_info->log_root_recovering) {
1793 btrfs_set_super_log_root(root->fs_info->super_copy, 0);
1794 btrfs_set_super_log_root_level(root->fs_info->super_copy, 0);
1797 memcpy(root->fs_info->super_for_commit, root->fs_info->super_copy,
1798 sizeof(*root->fs_info->super_copy));
1800 trans->transaction->blocked = 0;
1801 spin_lock(&root->fs_info->trans_lock);
1802 root->fs_info->running_transaction = NULL;
1803 root->fs_info->trans_no_join = 0;
1804 spin_unlock(&root->fs_info->trans_lock);
1805 mutex_unlock(&root->fs_info->reloc_mutex);
1807 wake_up(&root->fs_info->transaction_wait);
1809 ret = btrfs_write_and_wait_transaction(trans, root);
1811 btrfs_error(root->fs_info, ret,
1812 "Error while writing out transaction.");
1813 mutex_unlock(&root->fs_info->tree_log_mutex);
1814 goto cleanup_transaction;
1817 ret = write_ctree_super(trans, root, 0);
1819 mutex_unlock(&root->fs_info->tree_log_mutex);
1820 goto cleanup_transaction;
1824 * the super is written, we can safely allow the tree-loggers
1825 * to go about their business
1827 mutex_unlock(&root->fs_info->tree_log_mutex);
1829 btrfs_finish_extent_commit(trans, root);
1831 cur_trans->commit_done = 1;
1833 root->fs_info->last_trans_committed = cur_trans->transid;
1835 wake_up(&cur_trans->commit_wait);
1837 spin_lock(&root->fs_info->trans_lock);
1838 list_del_init(&cur_trans->list);
1839 spin_unlock(&root->fs_info->trans_lock);
1841 put_transaction(cur_trans);
1842 put_transaction(cur_trans);
1844 if (trans->type < TRANS_JOIN_NOLOCK)
1845 sb_end_intwrite(root->fs_info->sb);
1847 trace_btrfs_transaction_commit(root);
1849 btrfs_scrub_continue(root);
1851 if (current->journal_info == trans)
1852 current->journal_info = NULL;
1854 kmem_cache_free(btrfs_trans_handle_cachep, trans);
1856 if (current != root->fs_info->transaction_kthread)
1857 btrfs_run_delayed_iputs(root);
1861 cleanup_transaction:
1862 btrfs_trans_release_metadata(trans, root);
1863 trans->block_rsv = NULL;
1864 if (trans->qgroup_reserved) {
1865 btrfs_qgroup_free(root, trans->qgroup_reserved);
1866 trans->qgroup_reserved = 0;
1868 btrfs_printk(root->fs_info, "Skipping commit of aborted transaction.\n");
1870 if (current->journal_info == trans)
1871 current->journal_info = NULL;
1872 cleanup_transaction(trans, root, ret);
1878 * interface function to delete all the snapshots we have scheduled for deletion
1880 int btrfs_clean_old_snapshots(struct btrfs_root *root)
1883 struct btrfs_fs_info *fs_info = root->fs_info;
1885 spin_lock(&fs_info->trans_lock);
1886 list_splice_init(&fs_info->dead_roots, &list);
1887 spin_unlock(&fs_info->trans_lock);
1889 while (!list_empty(&list)) {
1892 root = list_entry(list.next, struct btrfs_root, root_list);
1893 list_del(&root->root_list);
1895 btrfs_kill_all_delayed_nodes(root);
1897 if (btrfs_header_backref_rev(root->node) <
1898 BTRFS_MIXED_BACKREF_REV)
1899 ret = btrfs_drop_snapshot(root, NULL, 0, 0);
1901 ret =btrfs_drop_snapshot(root, NULL, 1, 0);