From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:41908) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1boqM8-0008NN-KK for qemu-devel@nongnu.org; Tue, 27 Sep 2016 07:15:25 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1boqM3-0004Ht-Lu for qemu-devel@nongnu.org; Tue, 27 Sep 2016 07:15:24 -0400 Date: Tue, 27 Sep 2016 13:15:14 +0200 From: Kevin Wolf Message-ID: <20160927111514.GH4090@noname.str.redhat.com> References: <1474968813-14181-1-git-send-email-famz@redhat.com> <20160927110405.GC13510@lemon> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20160927110405.GC13510@lemon> Subject: Re: [Qemu-devel] [PATCH v2] block: Turn on "unmap" in active commit List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Fam Zheng Cc: qemu-devel@nongnu.org, Jeff Cody , qemu-block@nongnu.org, Max Reitz Am 27.09.2016 um 13:04 hat Fam Zheng geschrieben: > On Tue, 09/27 17:33, Fam Zheng wrote: > > We already specified BDRV_O_UNMAP when opening images in 'qemu-img > > commit', but didn't turn on the "unmap" in the active commit job. This > > patch fixes that so that zeroed clusters in top image can be discarded > > which is desired in the virt-sparsify use case, where a temporary > > overlay is created and fstrim'ed before commiting back, to free space in > > the original image. > > > > This also enables it for block-commit. > > > > Signed-off-by: Fam Zheng > > --- > > v2: Add "unmap" to block-commit as well. [Kevin] > > --- > > block/mirror.c | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > diff --git a/block/mirror.c b/block/mirror.c > > index f9d1fec..8f6f506 100644 > > --- a/block/mirror.c > > +++ b/block/mirror.c > > @@ -1043,7 +1043,7 @@ void commit_active_start(const char *job_id, BlockDriverState *bs, > > mirror_start_job(job_id, bs, base, NULL, speed, 0, 0, > > MIRROR_LEAVE_BACKING_CHAIN, > > on_error, on_error, false, cb, opaque, &local_err, > > - &commit_active_job_driver, false, base, auto_complete); > > + &commit_active_job_driver, true, base, auto_complete); > > I'm an idiot! I changed the wrong parameter (is_none_mode). Actually, the idiotic part is having a function with eighteen parameters. Not too surprising that someone confuses them sooner or later... Perhaps we could enable QAPI boxing for blockdev-mirror and then just pass down a struct. Then we could have designated initialisers here in commit_active_start() and it would be obvious if the wrong one is changed. Not something to do in this series, of course, just a general idea for improvement. Kevin