Btrfs: check return value of kmalloc()

The check on the return value of kmalloc() is added to some places.

Signed-off-by: Tsutomu Itoh <[e-mail]>
Signed-off-by: Chris Mason <[e-mail]>

fs/btrfs/extent-tree.c

···
 				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

···
 			 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;
···
 	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);