[PATCH v3] Btrfs: remove unused check of skip_locking

[Liu Bo <bo.liu@linux.alibaba.com>]

The check is superfluous since all of callers who set search_for_commit
also have skip_locking set.

ASSERT() is put in place to ensure skip_locking is set by callers.

Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Liu Bo <bo.liu@linux.alibaba.com>
---
v3: Add assertion and comments to ensure skip_locking is not forgot by callers.
v2: Rebase.

 fs/btrfs/ctree.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
index a2bcfdf85726..9c4f6b919d51 100644
--- a/fs/btrfs/ctree.c
+++ b/fs/btrfs/ctree.c
@@ -2623,8 +2623,11 @@ static struct extent_buffer *btrfs_search_slot_get_root(struct btrfs_root *root,
 		level = btrfs_header_level(b);
 		if (p->need_commit_sem)
 			up_read(&fs_info->commit_root_sem);
-		if (!p->skip_locking)
-			btrfs_tree_read_lock(b);
+		/*
+		 * Ensure that all callers have set skip_locking when
+		 * p->search_commit_root = 1.
+		 */
+		ASSERT(p->skip_locking == 1);
 
 		goto out;
 	}
-- 
1.8.3.1