From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org 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 smtp.lore.kernel.org (Postfix) with ESMTPS id 0CB91ECAAA1 for ; Thu, 27 Oct 2022 18:33:45 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1oo7g5-0001He-V8; Thu, 27 Oct 2022 14:32:29 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1oo7g3-0001B5-OT for qemu-devel@nongnu.org; Thu, 27 Oct 2022 14:32:27 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1oo7g0-0002PC-7y for qemu-devel@nongnu.org; Thu, 27 Oct 2022 14:32:27 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1666895543; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=7Cf/X7gQtfuOmGLbxm4ouPN4MTl69jYTN+3EneXyksQ=; b=C7SehuAqfQM/jtipHOHyjQk9pJDLcstxD6Qs3+ATHWCet8UcBCycb12RCPMV+nJHOvKszY Jfnvdt4r2ChgyN33J2iLNT8DuQAWSliY/yVXzGYH0EWOz3UBtLmoqSVlhXnXNtAxFlrfeq 6fQV6NuGPRL/mhuSA8ANUAVHhX0Oidw= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-458-xPj04jeOPLGmlkLWaWvDCg-1; Thu, 27 Oct 2022 14:32:22 -0400 X-MC-Unique: xPj04jeOPLGmlkLWaWvDCg-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.rdu2.redhat.com [10.11.54.3]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 4EF65101AA79; Thu, 27 Oct 2022 18:32:21 +0000 (UTC) Received: from merkur.fritz.box (unknown [10.39.194.12]) by smtp.corp.redhat.com (Postfix) with ESMTP id 0477E1121320; Thu, 27 Oct 2022 18:32:10 +0000 (UTC) From: Kevin Wolf To: qemu-block@nongnu.org Cc: kwolf@redhat.com, stefanha@redhat.com, qemu-devel@nongnu.org Subject: [PULL 08/58] block: BlockDriver: add .filtered_child_is_backing field Date: Thu, 27 Oct 2022 20:30:56 +0200 Message-Id: <20221027183146.463129-9-kwolf@redhat.com> In-Reply-To: <20221027183146.463129-1-kwolf@redhat.com> References: <20221027183146.463129-1-kwolf@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 3.1 on 10.11.54.3 Received-SPF: pass client-ip=170.10.133.124; envelope-from=kwolf@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -25 X-Spam_score: -2.6 X-Spam_bar: -- X-Spam_report: (-2.6 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.515, 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_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "Qemu-devel" Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org From: Vladimir Sementsov-Ogievskiy Unfortunately not all filters use .file child as filtered child. Two exclusions are mirror_top and commit_top. Happily they both are private filters. Bad thing is that this inconsistency is observable through qmp commands query-block / query-named-block-nodes. So, could we just change mirror_top and commit_top to use file child as all other filter driver is an open question. Probably, we could do that with some kind of deprecation period, but how to warn users during it? For now, let's just add a field so we can distinguish them in generic code, it will be used in further commits. Signed-off-by: Vladimir Sementsov-Ogievskiy Reviewed-by: Hanna Reitz Message-Id: <20220726201134.924743-2-vsementsov@yandex-team.ru> Reviewed-by: Kevin Wolf Signed-off-by: Kevin Wolf --- include/block/block_int-common.h | 13 +++++++++++++ block/commit.c | 1 + block/mirror.c | 1 + 3 files changed, 15 insertions(+) diff --git a/include/block/block_int-common.h b/include/block/block_int-common.h index d7c0a7e96f..95392052c9 100644 --- a/include/block/block_int-common.h +++ b/include/block/block_int-common.h @@ -119,6 +119,19 @@ struct BlockDriver { * (And this filtered child must then be bs->file or bs->backing.) */ bool is_filter; + /* + * Only make sense for filter drivers, for others must be false. + * If true, filtered child is bs->backing. Otherwise it's bs->file. + * Only two internal filters use bs->backing as filtered child and has this + * field set to true: mirror_top and commit_top. + * + * Never create any more such filters! + * + * TODO: imagine how to deprecate this behavior and make all filters work + * similarly using bs->file as filtered child. + */ + bool filtered_child_is_backing; + /* * Set to true if the BlockDriver is a format driver. Format nodes * generally do not expect their children to be other format nodes diff --git a/block/commit.c b/block/commit.c index 38571510cb..e210e86bac 100644 --- a/block/commit.c +++ b/block/commit.c @@ -238,6 +238,7 @@ static BlockDriver bdrv_commit_top = { .bdrv_child_perm = bdrv_commit_top_child_perm, .is_filter = true, + .filtered_child_is_backing = true, }; void commit_start(const char *job_id, BlockDriverState *bs, diff --git a/block/mirror.c b/block/mirror.c index 80c0109d39..f9432af3df 100644 --- a/block/mirror.c +++ b/block/mirror.c @@ -1587,6 +1587,7 @@ static BlockDriver bdrv_mirror_top = { .bdrv_child_perm = bdrv_mirror_top_child_perm, .is_filter = true, + .filtered_child_is_backing = true, }; static BlockJob *mirror_start_job( -- 2.37.3