From patchwork Wed May 13 11:05:14 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Max Reitz X-Patchwork-Id: 282876 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.5 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5546CC2D0FC for ; Wed, 13 May 2020 11:09:36 +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 2584520740 for ; Wed, 13 May 2020 11:09:36 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="H3vc6J21" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2584520740 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+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:55198 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jYpGZ-00070p-8J for qemu-devel@archiver.kernel.org; Wed, 13 May 2020 07:09:35 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:54620) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1jYpDH-0001BO-Uw for qemu-devel@nongnu.org; Wed, 13 May 2020 07:06:12 -0400 Received: from us-smtp-2.mimecast.com ([205.139.110.61]:51180 helo=us-smtp-delivery-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 1jYpD9-0003MD-1M for qemu-devel@nongnu.org; Wed, 13 May 2020 07:06:11 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1589367962; 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=fK6KQ4pwLSoW86nxua2xGTjV9b9+bhfx2+zi+8sREm0=; b=H3vc6J21l5zzmP7Wb7YgYKfc8ixaOEquD8lOhnQrVB2sIGaid/xAYXCCqCUtdu/cmMU9ao 1weB2bnxQ5vYYvf5VpvjFZa3Gqz9QntbL5bKOyFTSZgT9V4t2D6fjkH3V670WDH21Ay38q 18pj8EXnDEfvW4Vk2W/6Y0UJvUgu7FA= 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-262-miFrCp96O5Sw2JMgwg5hNA-1; Wed, 13 May 2020 07:06:00 -0400 X-MC-Unique: miFrCp96O5Sw2JMgwg5hNA-1 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 7B14719200C3; Wed, 13 May 2020 11:05:59 +0000 (UTC) Received: from localhost (unknown [10.40.193.218]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 0E94F1002382; Wed, 13 May 2020 11:05:58 +0000 (UTC) From: Max Reitz To: qemu-block@nongnu.org Subject: [PATCH v4 04/34] block: Add BdrvChildRole and BdrvChildRoleBits Date: Wed, 13 May 2020 13:05:14 +0200 Message-Id: <20200513110544.176672-5-mreitz@redhat.com> In-Reply-To: <20200513110544.176672-1-mreitz@redhat.com> References: <20200513110544.176672-1-mreitz@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Received-SPF: pass client-ip=205.139.110.61; envelope-from=mreitz@redhat.com; helo=us-smtp-delivery-1.mimecast.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/05/13 01:56:38 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: Kevin Wolf , qemu-devel@nongnu.org, Max Reitz Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" This mask will supplement BdrvChildClass when it comes to what role (or combination of roles) a child takes for its parent. It consists of BdrvChildRoleBits values (which is an enum). Because empty enums are not allowed, let us just start with it filled. Signed-off-by: Max Reitz --- include/block/block.h | 56 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 56 insertions(+) diff --git a/include/block/block.h b/include/block/block.h index bc42e507bb..86cffa9ffd 100644 --- a/include/block/block.h +++ b/include/block/block.h @@ -268,6 +268,62 @@ enum { DEFAULT_PERM_UNCHANGED = BLK_PERM_ALL & ~DEFAULT_PERM_PASSTHROUGH, }; +/* + * Flags parent nodes give for the child nodes to specify what kind of + * role(s) they take. + * + * At least one of DATA, METADATA, FILTERED, or COW must be set for + * every child. + */ +enum BdrvChildRoleBits { + /* + * This child stores data. + * Any node may have an arbitrary number of such children. + */ + BDRV_CHILD_DATA = (1 << 0), + + /* + * This child stores metadata. + * Any node may have an arbitrary number of metadata-storing + * children. + */ + BDRV_CHILD_METADATA = (1 << 1), + + /* + * A child that always presents exactly the same visible data as + * the parent, e.g. by virtue of the parent forwarding all reads + * and writes. + * This flag is mutually exclusive with DATA, METADATA, and COW. + * Any node may have at most one filtered child at a time. + */ + BDRV_CHILD_FILTERED = (1 << 2), + + /* + * Child from which to read all data that isn’t allocated in the + * parent (i.e., the backing child); such data is copied to the + * parent through COW (and optionally COR). + * This field is mutually exclusive with DATA, METADATA, and + * FILTERED. + * Any node may have at most one such backing child at a time. + */ + BDRV_CHILD_COW = (1 << 3), + + /* + * The primary child. For most drivers, this is the child whose + * filename applies best to the parent node. + * Any node may have at most one primary child at a time. + */ + BDRV_CHILD_PRIMARY = (1 << 4), + + /* Useful combination of flags */ + BDRV_CHILD_IMAGE = BDRV_CHILD_DATA + | BDRV_CHILD_METADATA + | BDRV_CHILD_PRIMARY, +}; + +/* Mask of BdrvChildRoleBits values */ +typedef unsigned int BdrvChildRole; + char *bdrv_perm_names(uint64_t perm); uint64_t bdrv_qapi_perm_to_blk_perm(BlockPermission qapi_perm);