From patchwork Tue May 12 14:53:05 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrey Shinkevich X-Patchwork-Id: 1288504 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=nongnu.org (client-ip=209.51.188.17; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=) Authentication-Results: ozlabs.org; dmarc=fail (p=none dis=none) header.from=virtuozzo.com 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 ozlabs.org (Postfix) with ESMTPS id 49M19D2K1Jz9sTV for ; Wed, 13 May 2020 00:56:48 +1000 (AEST) Received: from localhost ([::1]:33008 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jYWKr-0002Sj-VM for incoming@patchwork.ozlabs.org; Tue, 12 May 2020 10:56:45 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:60278) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1jYWHl-0004vj-Av; Tue, 12 May 2020 10:53:33 -0400 Received: from relay.sw.ru ([185.231.240.75]:45888) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1jYWHi-0005p2-A9; Tue, 12 May 2020 10:53:32 -0400 Received: from dhcp-172-16-25-136.sw.ru ([172.16.25.136] helo=localhost.sw.ru) by relay.sw.ru with esmtp (Exim 4.92.3) (envelope-from ) id 1jYWHZ-0003c8-1h; Tue, 12 May 2020 17:53:21 +0300 From: Andrey Shinkevich To: qemu-block@nongnu.org Subject: [PATCH v3 04/15] block: Add chain helper functions Date: Tue, 12 May 2020 17:53:05 +0300 Message-Id: <1589295196-773454-5-git-send-email-andrey.shinkevich@virtuozzo.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1589295196-773454-1-git-send-email-andrey.shinkevich@virtuozzo.com> References: <1589295196-773454-1-git-send-email-andrey.shinkevich@virtuozzo.com> Received-SPF: pass client-ip=185.231.240.75; envelope-from=andrey.shinkevich@virtuozzo.com; helo=relay.sw.ru X-detected-operating-system: by eggs.gnu.org: First seen = 2020/05/12 10:53:25 X-ACL-Warn: Detected OS = Linux 3.1-3.10 X-Spam_score_int: -18 X-Spam_score: -1.9 X-Spam_bar: - X-Spam_report: (-1.9 / 5.0 requ) BAYES_00=-1.9, SPF_PASS=-0.001, URIBL_BLOCKED=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, fam@euphon.net, vsementsov@virtuozzo.com, armbru@redhat.com, qemu-devel@nongnu.org, stefanha@redhat.com, andrey.shinkevich@virtuozzo.com, den@openvz.org, mreitz@redhat.com, jsnow@redhat.com Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.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 Reviewed-by: Vladimir Sementsov-Ogievskiy --- block.c | 55 +++++++++++++++++++++++++++++++++++++++++++++++ include/block/block_int.h | 3 +++ 2 files changed, 58 insertions(+) diff --git a/block.c b/block.c index b2aae2e..5b4ebfe 100644 --- a/block.c +++ b/block.c @@ -6863,3 +6863,58 @@ BdrvChild *bdrv_primary_child(BlockDriverState *bs) { return bdrv_filtered_rw_child(bs) ?: bs->file; } + +static BlockDriverState *bdrv_skip_filters(BlockDriverState *bs, + bool stop_on_explicit_filter) +{ + BdrvChild *filtered; + + if (!bs) { + return NULL; + } + + while (!(stop_on_explicit_filter && !bs->implicit)) { + filtered = bdrv_filtered_rw_child(bs); + if (!filtered) { + break; + } + bs = filtered->bs; + } + /* + * Note that this treats nodes with bs->drv == NULL as not being + * R/W 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 an RW-filtered child down the chain starting from @bs + * (including @bs itself). + */ +BlockDriverState *bdrv_skip_implicit_filters(BlockDriverState *bs) +{ + return bdrv_skip_filters(bs, true); +} + +/* + * Return the first BDS that does not have an RW-filtered child down + * the chain starting from @bs (including @bs itself). + */ +BlockDriverState *bdrv_skip_rw_filters(BlockDriverState *bs) +{ + return bdrv_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_rw_filters(bdrv_filtered_cow_bs(bdrv_skip_rw_filters(bs))); +} diff --git a/include/block/block_int.h b/include/block/block_int.h index dca59e9..86f7666 100644 --- a/include/block/block_int.h +++ b/include/block/block_int.h @@ -1347,6 +1347,9 @@ BdrvChild *bdrv_filtered_child(BlockDriverState *bs); BdrvChild *bdrv_metadata_child(BlockDriverState *bs); BdrvChild *bdrv_storage_child(BlockDriverState *bs); BdrvChild *bdrv_primary_child(BlockDriverState *bs); +BlockDriverState *bdrv_skip_implicit_filters(BlockDriverState *bs); +BlockDriverState *bdrv_skip_rw_filters(BlockDriverState *bs); +BlockDriverState *bdrv_backing_chain_next(BlockDriverState *bs); static inline BlockDriverState *child_bs(BdrvChild *child) {