Btrfs: remove scrub_super_lock holding in btrfs_sync_log()

Originally, we introduced scrub_super_lock to synchronize
tree log code with scrubbing super.

However we can replace scrub_super_lock with device_list_mutex,
because writing super will hold this mutex, this will reduce an extra
lock holding when writing supers in sync log code.

Signed-off-by: Wang Shilong <wangsl.fnst@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>

1 files changed, 0 insertions, 2 deletions

diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c
index f98002ed32b1..257cbae8c948 100644
--- a/fs/btrfs/tree-log.c
+++ b/fs/btrfs/tree-log.c
@@ -2586,9 +2586,7 @@ int btrfs_sync_log(struct btrfs_trans_handle *trans,
          * the running transaction open, so a full commit can't hop
          * in and cause problems either.
          */
-        btrfs_scrub_pause_super(root);
         ret = write_ctree_super(trans, root->fs_info->tree_root, 1);
-        btrfs_scrub_continue_super(root);
         if (ret) {
                 btrfs_abort_transaction(trans, root, ret);
                 goto out_wake_log_root;