diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index 81f8b4f..6e4bf02 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -1694,6 +1694,7 @@
 	}
 
 	if (bio) {
+		bio->bi_size = 0;
 		bio->bi_bdev = bdev;
 		bio->bi_sector = first_sector;
 	}