diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 9333e4cda68d..4cdfc6f8e6a9 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -3178,6 +3178,8 @@ static int btrfs_extent_same(struct inode *src, u64 loff, u64 olen,
 			const u64 sz = BTRFS_I(src)->root->fs_info->sectorsize;
 
 			len = round_down(i_size_read(src), sz) - loff;
+			if (len == 0)
+				return 0;
 			olen = len;
 		}
 	}