From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:33204) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fxZts-0003Xs-AJ for qemu-devel@nongnu.org; Wed, 05 Sep 2018 11:39:25 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fxZtr-0002pn-EH for qemu-devel@nongnu.org; Wed, 05 Sep 2018 11:39:24 -0400 References: <20180904170930.28619-1-jsnow@redhat.com> <20180904170930.28619-6-jsnow@redhat.com> From: John Snow Message-ID: <9cda4756-3bcf-01a9-5fbc-755a4e722581@redhat.com> Date: Wed, 5 Sep 2018 11:39:14 -0400 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH v4 05/15] block/mirror: don't install backing chain on abort List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Max Reitz , qemu-block@nongnu.org, qemu-devel@nongnu.org Cc: "Dr. David Alan Gilbert" , Jeff Cody , Markus Armbruster , Kevin Wolf , jtc@redhat.com, Eric Blake On 09/05/2018 06:40 AM, Max Reitz wrote: > On 2018-09-04 19:09, John Snow wrote: >> In cases where we abort the block/mirror job, there's no point in >> installing the new backing chain before we finish aborting. >> >> Move this to the "success" portion of mirror_exit. > > Sounds a bit weird now that you don't do any moving. > I ought to proofread my commit messages when I make changes... >> Signed-off-by: John Snow >> --- >> block/mirror.c | 7 ++----- >> 1 file changed, 2 insertions(+), 5 deletions(-) >> >> diff --git a/block/mirror.c b/block/mirror.c >> index cba555b4ef..3365bcfdfb 100644 >> --- a/block/mirror.c >> +++ b/block/mirror.c >> @@ -642,7 +642,7 @@ static void mirror_exit(Job *job) >> * required before it could become a backing file of target_bs. */ >> bdrv_child_try_set_perm(mirror_top_bs->backing, 0, BLK_PERM_ALL, >> &error_abort); >> - if (s->backing_mode == MIRROR_SOURCE_BACKING_CHAIN) { >> + if (ret == 0 && s->backing_mode == MIRROR_SOURCE_BACKING_CHAIN) { >> BlockDriverState *backing = s->is_none_mode ? src : s->base; >> if (backing_bs(target_bs) != backing) { >> bdrv_set_backing_hd(target_bs, backing, &local_err); >> @@ -659,10 +659,7 @@ static void mirror_exit(Job *job) >> } >> >> if (s->should_complete && ret == 0) { >> - BlockDriverState *to_replace = src; >> - if (s->to_replace) { >> - to_replace = s->to_replace; >> - } >> + BlockDriverState *to_replace = s->to_replace ? s->to_replace : src; >> >> if (bdrv_get_flags(target_bs) != bdrv_get_flags(to_replace)) { >> bdrv_reopen(target_bs, bdrv_get_flags(to_replace), NULL); > > And this hunk now looks out of place. Sure, it makes sense, but why is > it in this patch now? :-) > > (Moving it into the next patch would make more sense, I think.) > > I'd like to give an R-b anyway, but I know that I shouldn't, so I won't. > > Max > I have to admit that my appetite for patch purity is just... low. I know it's something we care a lot in the QEMU project, but after a number of years I'm just not overwhelmed to care about it in any significant capacity. I suppose the main argument for this practice is ease of backporting, yes? --js