From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:44676) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Z3OQK-0005Ii-O2 for qemu-devel@nongnu.org; Fri, 12 Jun 2015 08:51:05 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Z3OQA-0003Hr-CX for qemu-devel@nongnu.org; Fri, 12 Jun 2015 08:51:04 -0400 Received: from e06smtp13.uk.ibm.com ([195.75.94.109]:34954) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Z3OQ9-0003GQ-S7 for qemu-devel@nongnu.org; Fri, 12 Jun 2015 08:50:54 -0400 Received: from /spool/local by e06smtp13.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Fri, 12 Jun 2015 13:50:51 +0100 Message-ID: <557AD5A6.60705@de.ibm.com> Date: Fri, 12 Jun 2015 14:50:46 +0200 From: Christian Borntraeger MIME-Version: 1.0 References: <1433936297-7098-1-git-send-email-yarygin@linux.vnet.ibm.com> <1433936297-7098-3-git-send-email-yarygin@linux.vnet.ibm.com> <20150611025154.GA17234@ad.nay.redhat.com> In-Reply-To: <20150611025154.GA17234@ad.nay.redhat.com> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH 2/3] virtio-blk: Use blk_drain() to drain IO requests List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Fam Zheng , Alexander Yarygin Cc: Kevin Wolf , qemu-block@nongnu.org, Ekaterina Tumanova , qemu-devel@nongnu.org, qemu-stable@nongnu.org, Stefan Hajnoczi , Cornelia Huck , Paolo Bonzini Am 11.06.2015 um 04:51 schrieb Fam Zheng: > On Wed, 06/10 14:38, Alexander Yarygin wrote: >> Each call of the virtio_blk_reset() function calls blk_drain_all(), >> which works for all existing BlockDriverStates, while draining only >> one is needed. >> >> This patch replaces blk_drain_all() by blk_drain() in virtio_blk_reset(). > > Please add a note "virtio_blk_data_plane_stop should be called after draining > because it restores vblk->complete_request" as well. >> >> Cc: Christian Borntraeger >> Cc: Cornelia Huck >> Cc: Kevin Wolf >> Cc: Paolo Bonzini >> Cc: Stefan Hajnoczi > > Cc: qemu-stable@nongnu.org Only for the move of virtio_blk_data_plane_stop? Are we sure that we can call blk_drain safely on old version? What about the following: respin without RFC patch 1: move virtio_blk_data_plane_stop, remove comment. cc stable patch 2: introduce blk_drain patch 3: blk_drain_all -> blk_drain patch 4: As RFC "Let bdrv_drain_all() to call aio_poll() for each AioContext" So that Stefan/Kevin can apply 1-3. and we can then review 4. Makes sense? Christian > >> Signed-off-by: Alexander Yarygin >> --- >> hw/block/virtio-blk.c | 11 ++++++----- >> 1 file changed, 6 insertions(+), 5 deletions(-) >> >> diff --git a/hw/block/virtio-blk.c b/hw/block/virtio-blk.c >> index e6afe97..2009092 100644 >> --- a/hw/block/virtio-blk.c >> +++ b/hw/block/virtio-blk.c >> @@ -652,15 +652,16 @@ static void virtio_blk_reset(VirtIODevice *vdev) >> { >> VirtIOBlock *s = VIRTIO_BLK(vdev); >> >> - if (s->dataplane) { >> - virtio_blk_data_plane_stop(s->dataplane); >> - } >> - >> /* >> * This should cancel pending requests, but can't do nicely until there >> * are per-device request lists. >> */ > > This comment can be dropped now. > >> - blk_drain_all(); >> + blk_drain(s->blk); >> + >> + if (s->dataplane) { >> + virtio_blk_data_plane_stop(s->dataplane); >> + } >> + >> blk_set_enable_write_cache(s->blk, s->original_wce); >> } >> >> -- >> 1.9.1 >> >> >