Btrfs: don't start a new transaction when starting sync
If there is no running transaction in the fs, we needn't start a new one when
we want to start sync.
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
index bcc6b65..8db401f 100644
--- a/fs/btrfs/transaction.c
+++ b/fs/btrfs/transaction.c
@@ -1307,9 +1307,10 @@
* We've got freeze protection passed with the transaction.
* Tell lockdep about it.
*/
- rwsem_acquire_read(
- &ac->root->fs_info->sb->s_writers.lock_map[SB_FREEZE_FS-1],
- 0, 1, _THIS_IP_);
+ if (ac->newtrans->type < TRANS_JOIN_NOLOCK)
+ rwsem_acquire_read(
+ &ac->root->fs_info->sb->s_writers.lock_map[SB_FREEZE_FS-1],
+ 0, 1, _THIS_IP_);
current->journal_info = ac->newtrans;
@@ -1347,8 +1348,10 @@
* Tell lockdep we've released the freeze rwsem, since the
* async commit thread will be the one to unlock it.
*/
- rwsem_release(&root->fs_info->sb->s_writers.lock_map[SB_FREEZE_FS-1],
- 1, _THIS_IP_);
+ if (trans->type < TRANS_JOIN_NOLOCK)
+ rwsem_release(
+ &root->fs_info->sb->s_writers.lock_map[SB_FREEZE_FS-1],
+ 1, _THIS_IP_);
schedule_delayed_work(&ac->work, 0);