diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index a3798a3a..64daf2a 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -7116,7 +7116,7 @@
 	alloc_end =  (offset + len + mask) & ~mask;
 
 	/* We only support the FALLOC_FL_KEEP_SIZE mode */
-	if (mode && (mode != FALLOC_FL_KEEP_SIZE))
+	if (mode & ~FALLOC_FL_KEEP_SIZE)
 		return -EOPNOTSUPP;
 
 	/*