From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alex Elder Subject: [PATCH] rbd: ignore zero-overlap parent Date: Sat, 11 May 2013 12:38:11 -0500 Message-ID: <518E8203.6050308@inktank.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: Received: from mail-ia0-f176.google.com ([209.85.210.176]:45846 "EHLO mail-ia0-f176.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753777Ab3EKRiM (ORCPT ); Sat, 11 May 2013 13:38:12 -0400 Received: by mail-ia0-f176.google.com with SMTP id j38so5571928iad.7 for ; Sat, 11 May 2013 10:38:12 -0700 (PDT) Received: from [172.22.22.4] (c-71-195-31-37.hsd1.mn.comcast.net. [71.195.31.37]) by mx.google.com with ESMTPSA id d9sm5614097igr.4.2013.05.11.10.38.10 for (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Sat, 11 May 2013 10:38:11 -0700 (PDT) Sender: ceph-devel-owner@vger.kernel.org List-ID: To: ceph-devel@vger.kernel.org An rbd clone image that has an overlap with its parent of 0 is effectively not a layered image at all. Detect this case and treat such an image as non-layered. Issue a warning to be sure the user knows what's going on. This resolves: http://tracker.ceph.com/issues/5028 Signed-off-by: Alex Elder --- drivers/block/rbd.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c index b9221a0..3a8135f 100644 --- a/drivers/block/rbd.c +++ b/drivers/block/rbd.c @@ -3655,9 +3655,13 @@ static int rbd_dev_v2_parent_info(struct rbd_device *rbd_dev) ceph_decode_64_safe(&p, end, parent_spec->snap_id, out_err); ceph_decode_64_safe(&p, end, overlap, out_err); - rbd_dev->parent_overlap = overlap; - rbd_dev->parent_spec = parent_spec; - parent_spec = NULL; /* rbd_dev now owns this */ + if (overlap) { + rbd_dev->parent_spec = parent_spec; + parent_spec = NULL; /* rbd_dev now owns this */ + rbd_dev->parent_overlap = overlap; + } else { + rbd_warn(rbd_dev, "ignoring parent of clone with overlap 0\n"); + } out: ret = 0; out_err: -- 1.7.9.5