[PATCH 10/20] ovl: narrow locking in ovl_cleanup_index()

[NeilBrown <neil@brown.name>]

ovl_cleanup_index() takes a lock on the directory and then does a lookup
and possibly one of two different cleanups.
This patch narrows the locking to use the _unlocked() versions of the
lookup and one cleanup, and just takes the lock for the other cleanup.

A subsequent patch will take the lock into the cleanup.

Signed-off-by: NeilBrown <neil@brown.name>
---
 fs/overlayfs/util.c | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/fs/overlayfs/util.c b/fs/overlayfs/util.c
index 9ce9fe62ef28..7369193b11ec 100644
--- a/fs/overlayfs/util.c
+++ b/fs/overlayfs/util.c
@@ -1107,21 +1107,20 @@ static void ovl_cleanup_index(struct dentry *dentry)
 		goto out;
 	}
 
-	inode_lock_nested(dir, I_MUTEX_PARENT);
-	index = ovl_lookup_upper(ofs, name.name, indexdir, name.len);
+	index = ovl_lookup_upper_unlocked(ofs, name.name, indexdir, name.len);
 	err = PTR_ERR(index);
 	if (IS_ERR(index)) {
 		index = NULL;
 	} else if (ovl_index_all(dentry->d_sb)) {
 		/* Whiteout orphan index to block future open by handle */
+		inode_lock_nested(dir, I_MUTEX_PARENT);
 		err = ovl_cleanup_and_whiteout(OVL_FS(dentry->d_sb),
 					       indexdir, index);
+		inode_unlock(dir);
 	} else {
 		/* Cleanup orphan index entries */
-		err = ovl_cleanup(ofs, dir, index);
+		err = ovl_cleanup_unlocked(ofs, indexdir, index);
 	}
-
-	inode_unlock(dir);
 	if (err)
 		goto fail;
 
-- 
2.49.0