Btrfs: check return value of kmalloc()

The check on the return value of kmalloc() is added to some places.
Signed-off-by: NTsutomu Itoh <t-itoh@jp.fujitsu.com>
Signed-off-by: NChris Mason <chris.mason@oracle.com>

fs/btrfs/extent-tree.c

@@ -8059,6 +8059,10 @@ static noinline int relocate_one_extent(struct btrfs_root *extent_root,
 				u64 group_start = group->key.objectid;
 				new_extents = kmalloc(sizeof(*new_extents),
 						      GFP_NOFS);
+				if (!new_extents) {
+					ret = -ENOMEM;
+					goto out;
+				}
 				nr_extents = 1;
 				ret = get_new_locations(reloc_inode,
 							extent_key,

fs/btrfs/inode.c

@@ -953,6 +953,7 @@ static int cow_file_range_async(struct inode *inode, struct page *locked_page,
 			 1, 0, NULL, GFP_NOFS);
 	while (start < end) {
 		async_cow = kmalloc(sizeof(*async_cow), GFP_NOFS);
+		BUG_ON(!async_cow);
 		async_cow->inode = inode;
 		async_cow->root = root;
 		async_cow->locked_page = locked_page;
@@ -5001,6 +5002,8 @@ static noinline int uncompress_inline(struct btrfs_path *path,
 	inline_size = btrfs_file_extent_inline_item_len(leaf,
 					btrfs_item_nr(leaf, path->slots[0]));
 	tmp = kmalloc(inline_size, GFP_NOFS);
+	if (!tmp)
+		return -ENOMEM;
 	ptr = btrfs_file_extent_inline_start(item);
 
 	read_extent_buffer(leaf, tmp, ptr, inline_size);