btrfs: checking NULL or not in some functions

Because NULL is returned when the memory allocation fails,
it is checked whether it is NULL.

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

1 files changed, 2 insertions, 0 deletions

diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index f96641a93fc9..9de4ff03882a 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -6496,6 +6496,8 @@ static noinline int relocate_inode_pages(struct inode *inode, u64 start,
         int ret = 0;
 
         ra = kzalloc(sizeof(*ra), GFP_NOFS);
+        if (!ra)
+                return -ENOMEM;
 
         mutex_lock(&inode->i_mutex);
         first_index = start >> PAGE_CACHE_SHIFT;