diff --git a/fs/fat/inode.c b/fs/fat/inode.c
index 761073544217..9bfe607c892e 100644
--- a/fs/fat/inode.c
+++ b/fs/fat/inode.c
@@ -173,10 +173,12 @@ static ssize_t fat_direct_IO(int rw, struct kiocb *iocb,
 		 *
 		 * But we must fill the remaining area or hole by nul for
 		 * updating ->mmu_private.
+		 *
+		 * Return 0, and fallback to normal buffered write.
 		 */
 		loff_t size = offset + iov_length(iov, nr_segs);
 		if (MSDOS_I(inode)->mmu_private < size)
-			return -EINVAL;
+			return 0;
 	}
 
 	/*