btrfs: check NULL or not

Should check if functions returns NULL or not.

Signed-off-by: Tsutomu Itoh <t-itoh@jp.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>

1 files changed, 6 insertions, 0 deletions

diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
index 99599f1c1554..b5baff0dccfe 100644
--- a/fs/btrfs/ctree.c
+++ b/fs/btrfs/ctree.c
@@ -2516,6 +2516,9 @@ static int push_leaf_right(struct btrfs_trans_handle *trans, struct btrfs_root
         btrfs_assert_tree_locked(path->nodes[1]);
 
         right = read_node_slot(root, upper, slot + 1);
+        if (right == NULL)
+                return 1;
+
         btrfs_tree_lock(right);
         btrfs_set_lock_blocking(right);
 
@@ -2766,6 +2769,9 @@ static int push_leaf_left(struct btrfs_trans_handle *trans, struct btrfs_root
         btrfs_assert_tree_locked(path->nodes[1]);
 
         left = read_node_slot(root, path->nodes[1], slot - 1);
+        if (left == NULL)
+                return 1;
+
         btrfs_tree_lock(left);
         btrfs_set_lock_blocking(left);