From patchwork Fri May 15 12:44:58 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kevin Wolf X-Patchwork-Id: 11551445 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 8277F912 for ; Fri, 15 May 2020 13:03:14 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 5AB8420759 for ; Fri, 15 May 2020 13:03:14 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="AsaiUB69" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5AB8420759 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Received: from localhost ([::1]:55294 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jZZzd-00020f-Ga for patchwork-qemu-devel@patchwork.kernel.org; Fri, 15 May 2020 09:03:13 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:45766) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1jZZjE-0002yV-VT for qemu-devel@nongnu.org; Fri, 15 May 2020 08:46:17 -0400 Received: from us-smtp-delivery-1.mimecast.com ([205.139.110.120]:51863 helo=us-smtp-1.mimecast.com) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1jZZjD-0002Mc-D6 for qemu-devel@nongnu.org; Fri, 15 May 2020 08:46:16 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1589546774; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=nXmlJBI08iCrvv2Fjzsccnd+uFEZ5bU04UQLWc261dg=; b=AsaiUB69ZKXF8SkM2ppq2An1RMYY2M57JHHW4t8LQsypxv4TzrbJRCVOS2lL+0klaE+1VI N9WImV7QeLLMqT0Pk/4Ob0yi3OR67k9VC5Dg+nQYpJgTh/W8vZPdr/g++oNZFqBkmc3Ct3 mK3cXc4q7rsi6XPHoFMFFm2itMG7ny4= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-334-ox-k4WhmObq2haeSPA2LCg-1; Fri, 15 May 2020 08:46:12 -0400 X-MC-Unique: ox-k4WhmObq2haeSPA2LCg-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 9EC95835B42; Fri, 15 May 2020 12:46:11 +0000 (UTC) Received: from linux.fritz.box.com (ovpn-113-110.ams2.redhat.com [10.36.113.110]) by smtp.corp.redhat.com (Postfix) with ESMTP id A266F2E16D; Fri, 15 May 2020 12:46:10 +0000 (UTC) From: Kevin Wolf To: qemu-block@nongnu.org Subject: [PULL 28/51] block: Pull out bdrv_default_perms_for_cow() Date: Fri, 15 May 2020 14:44:58 +0200 Message-Id: <20200515124521.335403-29-kwolf@redhat.com> In-Reply-To: <20200515124521.335403-1-kwolf@redhat.com> References: <20200515124521.335403-1-kwolf@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Received-SPF: pass client-ip=205.139.110.120; envelope-from=kwolf@redhat.com; helo=us-smtp-1.mimecast.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/05/14 23:27:07 X-ACL-Warn: Detected OS = Linux 2.2.x-3.x [generic] X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H2=-0.001, SPF_PASS=-0.001 autolearn=_AUTOLEARN X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: kwolf@redhat.com, peter.maydell@linaro.org, qemu-devel@nongnu.org Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" From: Max Reitz Right now, bdrv_format_default_perms() is used by format parents (generally). We want to switch to a model where most parents use a single BdrvChildClass, which then decides the permissions based on the child role. To do so, we have to split bdrv_format_default_perms() into separate functions for each such role. Signed-off-by: Max Reitz Message-Id: <20200513110544.176672-17-mreitz@redhat.com> Reviewed-by: Eric Blake Signed-off-by: Kevin Wolf --- block.c | 62 +++++++++++++++++++++++++++++++++++++-------------------- 1 file changed, 40 insertions(+), 22 deletions(-) diff --git a/block.c b/block.c index b3e7ae70c7..b12222a471 100644 --- a/block.c +++ b/block.c @@ -2468,6 +2468,44 @@ void bdrv_filter_default_perms(BlockDriverState *bs, BdrvChild *c, *nshared = (shared & DEFAULT_PERM_PASSTHROUGH) | DEFAULT_PERM_UNCHANGED; } +static void bdrv_default_perms_for_cow(BlockDriverState *bs, BdrvChild *c, + const BdrvChildClass *child_class, + BdrvChildRole role, + BlockReopenQueue *reopen_queue, + uint64_t perm, uint64_t shared, + uint64_t *nperm, uint64_t *nshared) +{ + assert(child_class == &child_backing || + (child_class == &child_of_bds && (role & BDRV_CHILD_COW))); + + /* + * We want consistent read from backing files if the parent needs it. + * No other operations are performed on backing files. + */ + perm &= BLK_PERM_CONSISTENT_READ; + + /* + * If the parent can deal with changing data, we're okay with a + * writable and resizable backing file. + * TODO Require !(perm & BLK_PERM_CONSISTENT_READ), too? + */ + if (shared & BLK_PERM_WRITE) { + shared = BLK_PERM_WRITE | BLK_PERM_RESIZE; + } else { + shared = 0; + } + + shared |= BLK_PERM_CONSISTENT_READ | BLK_PERM_GRAPH_MOD | + BLK_PERM_WRITE_UNCHANGED; + + if (bs->open_flags & BDRV_O_INACTIVE) { + shared |= BLK_PERM_WRITE | BLK_PERM_RESIZE; + } + + *nperm = perm; + *nshared = shared; +} + void bdrv_format_default_perms(BlockDriverState *bs, BdrvChild *c, const BdrvChildClass *child_class, BdrvChildRole role, @@ -2505,28 +2543,8 @@ void bdrv_format_default_perms(BlockDriverState *bs, BdrvChild *c, *nperm = perm; *nshared = shared; } else { - /* We want consistent read from backing files if the parent needs it. - * No other operations are performed on backing files. */ - perm &= BLK_PERM_CONSISTENT_READ; - - /* If the parent can deal with changing data, we're okay with a - * writable and resizable backing file. */ - /* TODO Require !(perm & BLK_PERM_CONSISTENT_READ), too? */ - if (shared & BLK_PERM_WRITE) { - shared = BLK_PERM_WRITE | BLK_PERM_RESIZE; - } else { - shared = 0; - } - - shared |= BLK_PERM_CONSISTENT_READ | BLK_PERM_GRAPH_MOD | - BLK_PERM_WRITE_UNCHANGED; - - if (bs->open_flags & BDRV_O_INACTIVE) { - shared |= BLK_PERM_WRITE | BLK_PERM_RESIZE; - } - - *nperm = perm; - *nshared = shared; + bdrv_default_perms_for_cow(bs, c, child_class, role, reopen_queue, + perm, shared, nperm, nshared); } }