From patchwork Mon Sep 7 11:08:50 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kevin Wolf X-Patchwork-Id: 306078 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=-10.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,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 76138C43461 for ; Mon, 7 Sep 2020 11:14:54 +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 01CB3218AC for ; Mon, 7 Sep 2020 11:14:53 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="MkHdalPa" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 01CB3218AC 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]:49928 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1kFF6r-0002e0-3z for qemu-devel@archiver.kernel.org; Mon, 07 Sep 2020 07:14:53 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:58984) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kFF2N-0002Yp-QI for qemu-devel@nongnu.org; Mon, 07 Sep 2020 07:10:15 -0400 Received: from us-smtp-2.mimecast.com ([207.211.31.81]:34080 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 1kFF2K-0007w8-JT for qemu-devel@nongnu.org; Mon, 07 Sep 2020 07:10:15 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1599477011; 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=uYKL4EUIg+tiDvl0ohfIl6kYYHmyzDlUQkHeFO5keDU=; b=MkHdalPaGWXpBn/eWrYc1xTE+I+NIr7ZfOQNodncrqQZsUFMuMMeSpwEMDN5TPgO3Dhk+0 NQ53tLqS2k4tobHBgVVNAttb0tMSBwlS02a6p/u4VM1GgUJY9IHArmZg7qkdSXdFDMi52E vrC03cbx+ltJejmAbEBzP0KzBsCsmAQ= 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-513-jydXnBrrMziKdtX0nY-Ztg-1; Mon, 07 Sep 2020 07:10:09 -0400 X-MC-Unique: jydXnBrrMziKdtX0nY-Ztg-1 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 04A481084C8A; Mon, 7 Sep 2020 11:10:08 +0000 (UTC) Received: from linux.fritz.box.com (ovpn-114-154.ams2.redhat.com [10.36.114.154]) by smtp.corp.redhat.com (Postfix) with ESMTP id 10AA77E435; Mon, 7 Sep 2020 11:10:06 +0000 (UTC) From: Kevin Wolf To: qemu-block@nongnu.org Subject: [PULL 18/64] block: Add chain helper functions Date: Mon, 7 Sep 2020 13:08:50 +0200 Message-Id: <20200907110936.261684-19-kwolf@redhat.com> In-Reply-To: <20200907110936.261684-1-kwolf@redhat.com> References: <20200907110936.261684-1-kwolf@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=kwolf@redhat.com X-Mimecast-Spam-Score: 0.001 X-Mimecast-Originator: redhat.com Received-SPF: pass client-ip=207.211.31.81; envelope-from=kwolf@redhat.com; helo=us-smtp-delivery-1.mimecast.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/09/06 22:29:02 X-ACL-Warn: Detected OS = Linux 2.2.x-3.x [generic] [fuzzy] X-Spam_score_int: -21 X-Spam_score: -2.2 X-Spam_bar: -- X-Spam_report: (-2.2 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.1, 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: 2.1.23 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+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" From: Max Reitz Add some helper functions for skipping filters in a chain of block nodes. Signed-off-by: Max Reitz --- include/block/block_int.h | 3 ++ block.c | 62 +++++++++++++++++++++++++++++++++++++++ 2 files changed, 65 insertions(+) diff --git a/include/block/block_int.h b/include/block/block_int.h index f280a95b26..8205ccaa62 100644 --- a/include/block/block_int.h +++ b/include/block/block_int.h @@ -1394,6 +1394,9 @@ BdrvChild *bdrv_cow_child(BlockDriverState *bs); BdrvChild *bdrv_filter_child(BlockDriverState *bs); BdrvChild *bdrv_filter_or_cow_child(BlockDriverState *bs); BdrvChild *bdrv_primary_child(BlockDriverState *bs); +BlockDriverState *bdrv_skip_implicit_filters(BlockDriverState *bs); +BlockDriverState *bdrv_skip_filters(BlockDriverState *bs); +BlockDriverState *bdrv_backing_chain_next(BlockDriverState *bs); static inline BlockDriverState *child_bs(BdrvChild *child) { diff --git a/block.c b/block.c index 9f866e8676..b162142609 100644 --- a/block.c +++ b/block.c @@ -7034,3 +7034,65 @@ BdrvChild *bdrv_primary_child(BlockDriverState *bs) return found; } + +static BlockDriverState *bdrv_do_skip_filters(BlockDriverState *bs, + bool stop_on_explicit_filter) +{ + BdrvChild *c; + + if (!bs) { + return NULL; + } + + while (!(stop_on_explicit_filter && !bs->implicit)) { + c = bdrv_filter_child(bs); + if (!c) { + /* + * A filter that is embedded in a working block graph must + * have a child. Assert this here so this function does + * not return a filter node that is not expected by the + * caller. + */ + assert(!bs->drv || !bs->drv->is_filter); + break; + } + bs = c->bs; + } + /* + * Note that this treats nodes with bs->drv == NULL as not being + * filters (bs->drv == NULL should be replaced by something else + * anyway). + * The advantage of this behavior is that this function will thus + * always return a non-NULL value (given a non-NULL @bs). + */ + + return bs; +} + +/* + * Return the first BDS that has not been added implicitly or that + * does not have a filtered child down the chain starting from @bs + * (including @bs itself). + */ +BlockDriverState *bdrv_skip_implicit_filters(BlockDriverState *bs) +{ + return bdrv_do_skip_filters(bs, true); +} + +/* + * Return the first BDS that does not have a filtered child down the + * chain starting from @bs (including @bs itself). + */ +BlockDriverState *bdrv_skip_filters(BlockDriverState *bs) +{ + return bdrv_do_skip_filters(bs, false); +} + +/* + * For a backing chain, return the first non-filter backing image of + * the first non-filter image. + */ +BlockDriverState *bdrv_backing_chain_next(BlockDriverState *bs) +{ + return bdrv_skip_filters(bdrv_cow_bs(bdrv_skip_filters(bs))); +}