diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index 714adc4ac4c2..1bbd26b4fc5c 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -3690,6 +3690,7 @@ int map_private_extent_buffer(struct extent_buffer *eb, unsigned long start,
 		       "wanted %lu %lu\n", (unsigned long long)eb->start,
 		       eb->len, start, min_len);
 		WARN_ON(1);
+		return -EINVAL;
 	}
 
 	p = extent_buffer_page(eb, i);