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, 8 insertions, 0 deletions

diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index f9efb68fc2e3..a0c37b2ee9ed 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -353,6 +353,10 @@ static int csum_dirty_buffer(struct btrfs_root *root, struct page *page)
         WARN_ON(len == 0);
 
         eb = alloc_extent_buffer(tree, start, len, page, GFP_NOFS);
+        if (eb == NULL) {
+                WARN_ON(1);
+                goto out;
+        }
         ret = btree_read_extent_buffer_pages(root, eb, start + PAGE_CACHE_SIZE,
                                              btrfs_header_generation(eb));
         BUG_ON(ret);
@@ -427,6 +431,10 @@ static int btree_readpage_end_io_hook(struct page *page, u64 start, u64 end,
         WARN_ON(len == 0);
 
         eb = alloc_extent_buffer(tree, start, len, page, GFP_NOFS);
+        if (eb == NULL) {
+                ret = -EIO;
+                goto out;
+        }
 
         found_start = btrfs_header_bytenr(eb);
         if (found_start != start) {