Btrfs: deal with NULL srv_rsv in the delalloc inode reservation code

btrfs_update_inode is sometimes called with a null reservation.

Signed-off-by: Chris Mason <chris.mason@oracle.com>

diff --git a/fs/btrfs/delayed-inode.c b/fs/btrfs/delayed-inode.c
index 6a1a6800776c93cdfc41228ccf1b94e85a693e17..c7ddf8a01c54347b9f364862040436ac8768b757 100644 (file)
--- a/fs/btrfs/delayed-inode.c
+++ b/fs/btrfs/delayed-inode.c
@@ -640,8 +640,8 @@ static int btrfs_delayed_inode_reserve_metadata(
         * Now if src_rsv == delalloc_block_rsv we'll let it just steal since
         * we're accounted for.
         */
-       if (!trans->bytes_reserved &&
-           src_rsv != &root->fs_info->delalloc_block_rsv) {
+       if (!src_rsv || (!trans->bytes_reserved &&
+           src_rsv != &root->fs_info->delalloc_block_rsv)) {
                ret = btrfs_block_rsv_add_noflush(root, dst_rsv, num_bytes);
                /*
                 * Since we're under a transaction reserve_metadata_bytes could