[{"id":1769366,"web_url":"http://patchwork.ozlabs.org/comment/1769366/","msgid":"","list_archive_url":null,"date":"2017-09-15T18:58:34","subject":"Re: [Qemu-devel] [PATCH 4/6] block: Base permissions on rw state\n\tafter reopen","submitter":{"id":6591,"url":"http://patchwork.ozlabs.org/api/people/6591/","name":"Eric Blake","email":"eblake@redhat.com"},"content":"On 09/15/2017 05:10 AM, Kevin Wolf wrote:\n> When new permissions are calculated during bdrv_reopen(), they need to\n> be based on the state of the graph as it will be after the reopen has\n> completed, not on the current state of the involved nodes.\n> \n> This patch makes bdrv_is_writable() optionally accept a BlockReopenQueue\n> from which the new flags are taken. This is then used for determining\n> the new bs->file permissions of format drivers as soon as we add the\n> code to actually pass a non-NULL reopen queue to the .bdrv_child_perm\n> callbacks.\n> \n> While moving bdrv_is_writable(), make it static. It isn't used outside\n> block.c.\n> \n> Signed-off-by: Kevin Wolf \n> ---\n> include/block/block.h | 1 -\n> block.c | 52 ++++++++++++++++++++++++++++++++++++---------------\n> 2 files changed, 37 insertions(+), 16 deletions(-)\n> \n\n> + * Return the flags that @bs will have after the reopens in @q have\n> + * successfully completed. If @q is NULL (or @bs is not contained in @q),\n> + * return the current flags.\n> + */\n> +static int bdrv_reopen_get_flags(BlockReopenQueue *q, BlockDriverState *bs)\n\n> +/* Returns whether the image file can be written to after the reopen queue @q\n> + * has been successfully applied, or right now if @q is NULL. */\n> +static bool bdrv_is_writable(BlockDriverState *bs, BlockReopenQueue *q)\n\nIs it worth having both functions with arguments in the same order?\n\n> +{\n> + int flags = bdrv_reopen_get_flags(q, bs);\n> +\n\nNo real semantic impact to leave it as is, but it would avoid the odd\nswap of arguments here. So either way,\n\nReviewed-by: Eric Blake ","headers":{"Return-Path":"","X-Original-To":"incoming@patchwork.ozlabs.org","Delivered-To":"patchwork-incoming@bilbo.ozlabs.org","Authentication-Results":["ozlabs.org;\n\tspf=pass (mailfrom) smtp.mailfrom=nongnu.org\n\t(client-ip=2001:4830:134:3::11; helo=lists.gnu.org;\n\tenvelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org;\n\treceiver=)","ext-mx02.extmail.prod.ext.phx2.redhat.com;\n\tdmarc=none (p=none dis=none) header.from=redhat.com","ext-mx02.extmail.prod.ext.phx2.redhat.com;\n\tspf=fail smtp.mailfrom=eblake@redhat.com"],"Received":["from lists.gnu.org (lists.gnu.org [IPv6:2001:4830:134:3::11])\n\t(using TLSv1 with cipher AES256-SHA (256/256 bits))\n\t(No client certificate requested)\n\tby ozlabs.org (Postfix) with ESMTPS id 3xv4Sh35tGz9s7g\n\tfor ;\n\tSat, 16 Sep 2017 04:59:15 +1000 (AEST)","from localhost ([::1]:54656 helo=lists.gnu.org)\n\tby lists.gnu.org with esmtp (Exim 4.71) (envelope-from\n\t)\n\tid 1dsvpY-0004os-To\n\tfor incoming@patchwork.ozlabs.org; Fri, 15 Sep 2017 14:59:12 -0400","from eggs.gnu.org ([2001:4830:134:3::10]:51356)\n\tby lists.gnu.org with esmtp (Exim 4.71)\n\t(envelope-from ) id 1dsvp8-0004nD-Ci\n\tfor qemu-devel@nongnu.org; Fri, 15 Sep 2017 14:58:47 -0400","from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71)\n\t(envelope-from ) id 1dsvp7-0004nO-Dy\n\tfor qemu-devel@nongnu.org; Fri, 15 Sep 2017 14:58:46 -0400","from mx1.redhat.com ([209.132.183.28]:47972)\n\tby eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32)\n\t(Exim 4.71) (envelope-from )\n\tid 1dsvp1-0004lW-Vw; Fri, 15 Sep 2017 14:58:40 -0400","from smtp.corp.redhat.com\n\t(int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15])\n\t(using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits))\n\t(No client certificate requested)\n\tby mx1.redhat.com (Postfix) with ESMTPS id D0D63883CF;\n\tFri, 15 Sep 2017 18:58:38 +0000 (UTC)","from [10.10.124.97] (ovpn-124-97.rdu2.redhat.com [10.10.124.97])\n\tby smtp.corp.redhat.com (Postfix) with ESMTP id 3826F62462;\n\tFri, 15 Sep 2017 18:58:35 +0000 (UTC)"],"DMARC-Filter":"OpenDMARC Filter v1.3.2 mx1.redhat.com D0D63883CF","To":"Kevin Wolf , qemu-block@nongnu.org","References":"<20170915101008.16646-1-kwolf@redhat.com>\n\t<20170915101008.16646-5-kwolf@redhat.com>","From":"Eric Blake ","Openpgp":"url=http://people.redhat.com/eblake/eblake.gpg","Organization":"Red Hat, Inc.","Message-ID":"","Date":"Fri, 15 Sep 2017 13:58:34 -0500","User-Agent":"Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101\n\tThunderbird/52.3.0","MIME-Version":"1.0","In-Reply-To":"<20170915101008.16646-5-kwolf@redhat.com>","Content-Type":"multipart/signed; micalg=pgp-sha256;\n\tprotocol=\"application/pgp-signature\";\n\tboundary=\"n532sskllLXMQIJJnXNW8HUE8OLDnnaGk\"","X-Scanned-By":"MIMEDefang 2.79 on 10.5.11.15","X-Greylist":"Sender IP whitelisted, not delayed by milter-greylist-4.5.16\n\t(mx1.redhat.com [10.5.110.26]);\n\tFri, 15 Sep 2017 18:58:38 +0000 (UTC)","X-detected-operating-system":"by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic]\n\t[fuzzy]","X-Received-From":"209.132.183.28","X-Content-Filtered-By":"Mailman/MimeDel 2.1.21","Subject":"Re: [Qemu-devel] [PATCH 4/6] block: Base permissions on rw state\n\tafter reopen","X-BeenThere":"qemu-devel@nongnu.org","X-Mailman-Version":"2.1.21","Precedence":"list","List-Id":"","List-Unsubscribe":",\n\t","List-Archive":"","List-Post":"","List-Help":"","List-Subscribe":",\n\t","Cc":"famz@redhat.com, qemu-devel@nongnu.org, mreitz@redhat.com","Errors-To":"qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org","Sender":"\"Qemu-devel\"\n\t"}}]