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>

3 files changed, 10 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;
diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index 6411ed6ca449..8862dda46ff6 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -1920,6 +1920,8 @@ static int submit_extent_page(int rw, struct extent_io_tree *tree,
                 nr = bio_get_nr_vecs(bdev);
 
         bio = btrfs_bio_alloc(bdev, sector, nr, GFP_NOFS | __GFP_HIGH);
+        if (!bio)
+                return -ENOMEM;
 
         bio_add_page(bio, page, page_size, offset);
         bio->bi_end_io = end_io_func;
diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c
index 42dfc3077040..6d66e5caff97 100644
--- a/fs/btrfs/tree-log.c
+++ b/fs/btrfs/tree-log.c
@@ -2751,7 +2751,13 @@ static int btrfs_log_inode(struct btrfs_trans_handle *trans,
         log = root->log_root;
 
         path = btrfs_alloc_path();
+        if (!path)
+                return -ENOMEM;
         dst_path = btrfs_alloc_path();
+        if (!dst_path) {
+                btrfs_free_path(path);
+                return -ENOMEM;
+        }
 
         min_key.objectid = inode->i_ino;
         min_key.type = BTRFS_INODE_ITEM_KEY;