From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mike Snitzer Subject: Re: [PATCH v2 02/17] dm snapshot: add suspended flag to dm_snapshot Date: Mon, 16 Nov 2009 13:17:17 -0500 Message-ID: <20091116181716.GA17448@redhat.com> References: <1256078825-11331-1-git-send-email-snitzer@redhat.com> <1256078825-11331-3-git-send-email-snitzer@redhat.com> <20091105005635.GN13375@agk-dp.fab.redhat.com> Reply-To: device-mapper development Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20091105005635.GN13375@agk-dp.fab.redhat.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: dm-devel-bounces@redhat.com Errors-To: dm-devel-bounces@redhat.com To: Alasdair G Kergon Cc: device-mapper development List-Id: dm-devel.ids On Wed, Nov 04 2009 at 7:56pm -0500, Alasdair G Kergon wrote: > On Tue, Oct 20, 2009 at 06:46:50PM -0400, Mike Snitzer wrote: > > Allow the snapshot target to be able to verify its state relative to a > > requested operation. Allows for invalid operations to be prevented, > > e.g. an attempt handover an "old" snapshot's exceptions without it > > having been suspended first. > > OK - same as we do in dm-raid1. > > But just be aware that: > /* This does not get reverted if there's an error later. */ > dm_table_presuspend_targets(map); > > and so it's not identical to querying the dm_suspended() property directly. Right, it is now clear that I should be using postsuspend. The handover patch has a need to know that another snapshot target has been suspended; setting dm-snapshot's 'suspended' in .presuspend doesn't give us that information. So the dm-snapshot-track-suspended-state-in-target.patch that you have queued should be changed with: s/presuspend/postsuspend/ (the same search and replace is needed in the v7 handover patch) Mike