From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mike Snitzer Subject: Re: [PATCH 1/4] dm-snapshot-rework-origin-write Date: Tue, 6 Oct 2009 10:17:10 -0400 Message-ID: <20091006141710.GA19024@redhat.com> References: <1254769231-12053-1-git-send-email-snitzer@redhat.com> <1254769231-12053-2-git-send-email-snitzer@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: <1254769231-12053-2-git-send-email-snitzer@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: dm-devel@redhat.com Cc: Mikulas Patocka List-Id: dm-devel.ids On Mon, Oct 05 2009 at 3:00pm -0400, Mike Snitzer wrote: > From: Mikulas Patocka > > Rework writing to snapshot origin. > > The previous code selected one exception as "primary_pe", linked all other > exceptions on it and used reference counting to wait until all exceptions are > reallocated. This didn't work with exceptions with different chunk sizes: > https://bugzilla.redhat.com/show_bug.cgi?id=182659 > > I removed all the complexity with exceptions linking and reference counting. > Currently, bio is linked on one exception and when that exception is > reallocated, the bio is retried to possibly wait for other exceptions. > > Signed-off-by: Mikulas Patocka > Signed-off-by: Mike Snitzer FYI, I added my "Signed-off-by" because I had to update this patch to account for changes from these upstream linux-2.6 commits: 2913808e (dm snapshot: refactor __find_pending_exception) c6621392 (dm snapshot: avoid dropping lock in __find_pending_exception) 0cea9c78 (dm exception store: move dm_target pointer)