From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:58835) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ary7A-0005pZ-4c for qemu-devel@nongnu.org; Sun, 17 Apr 2016 21:36:37 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ary79-0003fT-62 for qemu-devel@nongnu.org; Sun, 17 Apr 2016 21:36:36 -0400 Date: Mon, 18 Apr 2016 09:36:28 +0800 From: Fam Zheng Message-ID: <20160418013628.GD18893@ad-mail.usersys.redhat.com> References: <1460689866-31020-1-git-send-email-famz@redhat.com> <20160415151154.GG4341@noname.redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20160415151154.GG4341@noname.redhat.com> Subject: Re: [Qemu-devel] [PATCH] block: Inactivate all nodes at migration source List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Kevin Wolf Cc: qemu-devel@nongnu.org, Max Reitz , qemu-block@nongnu.org On Fri, 04/15 17:11, Kevin Wolf wrote: > Am 15.04.2016 um 05:11 hat Fam Zheng geschrieben: > > qcow2 is not necessarily the top layer node. Since bdrv_inactivate() > > doesn't recurse, we should ensure all block nodes are inactivated. > > > > Signed-off-by: Fam Zheng > > Hm, I don't think that's quite right. bdrv_inactivate_all() should be > the opposite of bdrv_invalidate_cache_all(), i.e. both operations should > affect the same nodes. > > Currently, both use bdrv_next(), but bdrv_invalidate_cache() is > partially recursive: It is called for bs->file (by block.c if there is > no implementation for bs, by the driver implementation otherwise), or > for all children in the quorum case, but not for other children like > bs->backing or the extents for VMDK. > > If you think that that sounds wrong, I'm with you. :-) The question is > how to fix it. I think I'd make bdrv_invalidate() recurse to all > children and then do the same for bdrv_inactivate(). That makes sense, I'll try again. Fam > > Kevin > > > block.c | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > diff --git a/block.c b/block.c > > index d4939b4..1c575e4 100644 > > --- a/block.c > > +++ b/block.c > > @@ -3270,7 +3270,7 @@ int bdrv_inactivate_all(void) > > BlockDriverState *bs = NULL; > > int ret; > > > > - while ((bs = bdrv_next(bs)) != NULL) { > > + while ((bs = bdrv_next_node(bs)) != NULL) { > > AioContext *aio_context = bdrv_get_aio_context(bs); > > > > aio_context_acquire(aio_context); > > -- > > 2.8.0 > >