From nobody Mon Feb 9 21:39:03 2026 Delivered-To: importer@patchew.org Authentication-Results: mx.zohomail.com; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=fail(p=none dis=none) header.from=virtuozzo.com ARC-Seal: i=1; a=rsa-sha256; t=1589303070; cv=none; d=zohomail.com; s=zohoarc; b=ghvzn9kDVP571wWxyZWcnAC7dqNtxe2GkOG3Alt7769dW1FrL/ttIdKLTY7vkRH8r0CjZ1Hyd3evogKyvvt6sBH0jxD7EHQtGx9qS6GbMGc2zpHJ4eLeU0fJnFaTkH5sTxO9BGLo/A3H5wCoTRBw1ci98nzk9CTr+RQpaC9vMko= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1589303070; h=Cc:Date:From:In-Reply-To:List-Subscribe:List-Post:List-Id:List-Archive:List-Help:List-Unsubscribe:Message-ID:References:Sender:Subject:To; bh=QVVluTPj59WiaPfDlFXaLCGa49/OObMX6lPcLkmJdI0=; b=lnRV+uWkKreqjvG21aLrauA3ExaLvhkSgtVaAg310o0rk1jJ452N9yWB25uTidolcxhdZwbzuGywI4ncH3QoJkFQ98t5S2Gptn8V6w2cqz7dtvOJoVrNoa0D8miXyO4BEb5wwr642kpfcVVy4q6Kh0aDDHlRZK/fVK1TEmfA/0M= ARC-Authentication-Results: i=1; mx.zohomail.com; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=fail header.from= (p=none dis=none) header.from= Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 1589303070740855.9156525669921; Tue, 12 May 2020 10:04:30 -0700 (PDT) Received: from localhost ([::1]:32786 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jYYKT-0002Z0-88 for importer@patchew.org; Tue, 12 May 2020 13:04:29 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:52452) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1jYY7l-0005QQ-Jt; Tue, 12 May 2020 12:51:21 -0400 Received: from relay.sw.ru ([185.231.240.75]:50560) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1jYY7j-0001RF-4S; Tue, 12 May 2020 12:51:21 -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 1jYY7D-0004nT-1o; Tue, 12 May 2020 19:50:47 +0300 From: Andrey Shinkevich To: qemu-block@nongnu.org Subject: [PATCH v4 08/15] block: Use CAFs when working with backing chains Date: Tue, 12 May 2020 19:50:38 +0300 Message-Id: <1589302245-893269-9-git-send-email-andrey.shinkevich@virtuozzo.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1589302245-893269-1-git-send-email-andrey.shinkevich@virtuozzo.com> References: <1589302245-893269-1-git-send-email-andrey.shinkevich@virtuozzo.com> Received-SPF: pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; 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 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+importer=patchew.org@nongnu.org Sender: "Qemu-devel" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" From: Max Reitz Use child access functions when iterating through backing chains so filters do not break the chain. Signed-off-by: Max Reitz --- block.c | 40 ++++++++++++++++++++++++++++------------ 1 file changed, 28 insertions(+), 12 deletions(-) diff --git a/block.c b/block.c index 459412e..69e9152 100644 --- a/block.c +++ b/block.c @@ -4593,7 +4593,8 @@ int bdrv_change_backing_file(BlockDriverState *bs, } =20 /* - * Finds the image layer in the chain that has 'bs' as its backing file. + * Finds the image layer in the chain that has 'bs' (or a filter on + * top of it) as its backing file. * * active is the current topmost image. * @@ -4605,11 +4606,18 @@ int bdrv_change_backing_file(BlockDriverState *bs, BlockDriverState *bdrv_find_overlay(BlockDriverState *active, BlockDriverState *bs) { - while (active && bs !=3D backing_bs(active)) { - active =3D backing_bs(active); + bs =3D bdrv_skip_rw_filters(bs); + active =3D bdrv_skip_rw_filters(active); + + while (active) { + BlockDriverState *next =3D bdrv_backing_chain_next(active); + if (bs =3D=3D next) { + return active; + } + active =3D next; } =20 - return active; + return NULL; } =20 /* Given a BDS, searches for the base layer. */ @@ -4761,9 +4769,7 @@ int bdrv_drop_intermediate(BlockDriverState *top, Blo= ckDriverState *base, * other intermediate nodes have been dropped. * If 'top' is an implicit node (e.g. "commit_top") we should skip * it because no one inherits from it. We use explicit_top for that. */ - while (explicit_top && explicit_top->implicit) { - explicit_top =3D backing_bs(explicit_top); - } + explicit_top =3D bdrv_skip_implicit_filters(explicit_top); update_inherits_from =3D bdrv_inherits_from_recursive(base, explicit_t= op); =20 /* success - we can delete the intermediate states, and link top->base= */ @@ -5205,7 +5211,7 @@ BlockDriverState *bdrv_lookup_bs(const char *device, bool bdrv_chain_contains(BlockDriverState *top, BlockDriverState *base) { while (top && top !=3D base) { - top =3D backing_bs(top); + top =3D bdrv_filtered_bs(top); } =20 return top !=3D NULL; @@ -5466,7 +5472,17 @@ BlockDriverState *bdrv_find_backing_image(BlockDrive= rState *bs, =20 is_protocol =3D path_has_protocol(backing_file); =20 - for (curr_bs =3D bs; curr_bs->backing; curr_bs =3D curr_bs->backing->b= s) { + /* + * Being largely a legacy function, skip any filters here + * (because filters do not have normal filenames, so they cannot + * match anyway; and allowing json:{} filenames is a bit out of + * scope). + */ + for (curr_bs =3D bdrv_skip_rw_filters(bs); + bdrv_filtered_cow_child(curr_bs) !=3D NULL; + curr_bs =3D bdrv_backing_chain_next(curr_bs)) + { + BlockDriverState *bs_below =3D bdrv_backing_chain_next(curr_bs); =20 /* If either of the filename paths is actually a protocol, then * compare unmodified paths; otherwise make paths relative */ @@ -5474,7 +5490,7 @@ BlockDriverState *bdrv_find_backing_image(BlockDriver= State *bs, char *backing_file_full_ret; =20 if (strcmp(backing_file, curr_bs->backing_file) =3D=3D 0) { - retval =3D curr_bs->backing->bs; + retval =3D bs_below; break; } /* Also check against the full backing filename for the image = */ @@ -5484,7 +5500,7 @@ BlockDriverState *bdrv_find_backing_image(BlockDriver= State *bs, bool equal =3D strcmp(backing_file, backing_file_full_ret)= =3D=3D 0; g_free(backing_file_full_ret); if (equal) { - retval =3D curr_bs->backing->bs; + retval =3D bs_below; break; } } @@ -5510,7 +5526,7 @@ BlockDriverState *bdrv_find_backing_image(BlockDriver= State *bs, g_free(filename_tmp); =20 if (strcmp(backing_file_full, filename_full) =3D=3D 0) { - retval =3D curr_bs->backing->bs; + retval =3D bs_below; break; } } --=20 1.8.3.1