From patchwork Tue Jul 26 20:11:33 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Vladimir Sementsov-Ogievskiy X-Patchwork-Id: 1661002 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: bilbo.ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=yandex-team.ru header.i=@yandex-team.ru header.a=rsa-sha256 header.s=default header.b=Ix4syYO3; dkim-atps=neutral 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=) 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 bilbo.ozlabs.org (Postfix) with ESMTPS id 4LspMR6WKFz9sFs for ; Wed, 27 Jul 2022 06:25:55 +1000 (AEST) Received: from localhost ([::1]:50396 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1oGR7p-0005s2-No for incoming@patchwork.ozlabs.org; Tue, 26 Jul 2022 16:25:53 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:58552) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1oGQuk-0001Jt-4f; Tue, 26 Jul 2022 16:12:23 -0400 Received: from forwardcorp1j.mail.yandex.net ([5.45.199.163]:47792) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1oGQui-0001Hh-1Z; Tue, 26 Jul 2022 16:12:21 -0400 Received: from sas1-7470331623bb.qloud-c.yandex.net (sas1-7470331623bb.qloud-c.yandex.net [IPv6:2a02:6b8:c08:bd1e:0:640:7470:3316]) by forwardcorp1j.mail.yandex.net (Yandex) with ESMTP id 3CE1B2E1C6A; Tue, 26 Jul 2022 23:12:11 +0300 (MSK) Received: from localhost.localdomain (172.31.44.48-vpn.dhcp.yndx.net [172.31.44.48]) by sas1-7470331623bb.qloud-c.yandex.net (smtpcorp/Yandex) with ESMTPSA id ZssKVYgWJm-CAO0JcVS; Tue, 26 Jul 2022 23:12:10 +0300 (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)) (Client certificate not present) X-Yandex-Fwd: 1 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=yandex-team.ru; s=default; t=1658866330; bh=sPtLArjWYB88od/2JdIUzS/SuNMzIlHO8CijWViWhOE=; h=Message-Id:Date:In-Reply-To:Cc:Subject:References:To:From; b=Ix4syYO3KK+qnVJ9u6lvoZJ1ZxNNoa8xjRINZCkEnJYL60VZjLZn/JjvRk7GcJN3l 0UeGNhVhO8MZXCNU8OP2aDMpowZwO6ldyEcTBsgQUcThNvNixNKIVIYcgxOO2sf0ZX 0MACpX1+r0dfeaoKOmHNiZD1voUH2Pd8M9BU77tk= Authentication-Results: sas1-7470331623bb.qloud-c.yandex.net; dkim=pass header.i=@yandex-team.ru From: Vladimir Sementsov-Ogievskiy To: qemu-block@nongnu.org Cc: qemu-devel@nongnu.org, kwolf@redhat.com, hreitz@redhat.com, vsementsov@yandex-team.ru Subject: [PATCH v7 14/15] block/snapshot: drop indirection around bdrv_snapshot_fallback_ptr Date: Tue, 26 Jul 2022 23:11:33 +0300 Message-Id: <20220726201134.924743-15-vsementsov@yandex-team.ru> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20220726201134.924743-1-vsementsov@yandex-team.ru> References: <20220726201134.924743-1-vsementsov@yandex-team.ru> MIME-Version: 1.0 Received-SPF: pass client-ip=5.45.199.163; envelope-from=vsementsov@yandex-team.ru; helo=forwardcorp1j.mail.yandex.net X-Spam_score_int: -27 X-Spam_score: -2.8 X-Spam_bar: -- X-Spam_report: (-2.8 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_LOW=-0.7, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 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: , Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" Now the indirection is not actually used, we can safely reduce it to simple pointer. For consistency do a bit of refactoring to get rid of _ptr suffixes that become meaningless. Signed-off-by: Vladimir Sementsov-Ogievskiy Reviewed-by: Hanna Reitz --- block/snapshot.c | 38 ++++++++++++++++---------------------- 1 file changed, 16 insertions(+), 22 deletions(-) diff --git a/block/snapshot.c b/block/snapshot.c index f3971ac2bd..e22ac3eac6 100644 --- a/block/snapshot.c +++ b/block/snapshot.c @@ -151,34 +151,29 @@ bool bdrv_snapshot_find_by_id_and_name(BlockDriverState *bs, } /** - * Return a pointer to the child BDS pointer to which we can fall + * Return a pointer to child of given BDS to which we can fall * back if the given BDS does not support snapshots. * Return NULL if there is no BDS to (safely) fall back to. - * - * We need to return an indirect pointer because bdrv_snapshot_goto() - * has to modify the BdrvChild pointer. */ -static BdrvChild **bdrv_snapshot_fallback_ptr(BlockDriverState *bs) +static BdrvChild *bdrv_snapshot_fallback_child(BlockDriverState *bs) { - BdrvChild **fallback; - BdrvChild *child = bdrv_primary_child(bs); + BdrvChild *fallback = bdrv_primary_child(bs); + BdrvChild *child; /* We allow fallback only to primary child */ - if (!child) { + if (!fallback) { return NULL; } - fallback = (child == bs->file ? &bs->file : &bs->backing); - assert(*fallback == child); /* * Check that there are no other children that would need to be * snapshotted. If there are, it is not safe to fall back to - * *fallback. + * fallback. */ QLIST_FOREACH(child, &bs->children, next) { if (child->role & (BDRV_CHILD_DATA | BDRV_CHILD_METADATA | BDRV_CHILD_FILTERED) && - child != *fallback) + child != fallback) { return NULL; } @@ -189,8 +184,7 @@ static BdrvChild **bdrv_snapshot_fallback_ptr(BlockDriverState *bs) static BlockDriverState *bdrv_snapshot_fallback(BlockDriverState *bs) { - BdrvChild **child_ptr = bdrv_snapshot_fallback_ptr(bs); - return child_ptr ? (*child_ptr)->bs : NULL; + return child_bs(bdrv_snapshot_fallback_child(bs)); } int bdrv_can_snapshot(BlockDriverState *bs) @@ -237,7 +231,7 @@ int bdrv_snapshot_goto(BlockDriverState *bs, Error **errp) { BlockDriver *drv = bs->drv; - BdrvChild **fallback_ptr; + BdrvChild *fallback; int ret, open_ret; GLOBAL_STATE_CODE(); @@ -260,13 +254,13 @@ int bdrv_snapshot_goto(BlockDriverState *bs, return ret; } - fallback_ptr = bdrv_snapshot_fallback_ptr(bs); - if (fallback_ptr) { + fallback = bdrv_snapshot_fallback_child(bs); + if (fallback) { QDict *options; QDict *file_options; Error *local_err = NULL; - BlockDriverState *fallback_bs = (*fallback_ptr)->bs; - char *subqdict_prefix = g_strdup_printf("%s.", (*fallback_ptr)->name); + BlockDriverState *fallback_bs = fallback->bs; + char *subqdict_prefix = g_strdup_printf("%s.", fallback->name); options = qdict_clone_shallow(bs->options); @@ -277,8 +271,8 @@ int bdrv_snapshot_goto(BlockDriverState *bs, qobject_unref(file_options); g_free(subqdict_prefix); - /* Force .bdrv_open() below to re-attach fallback_bs on *fallback_ptr */ - qdict_put_str(options, (*fallback_ptr)->name, + /* Force .bdrv_open() below to re-attach fallback_bs on fallback */ + qdict_put_str(options, fallback->name, bdrv_get_node_name(fallback_bs)); /* Now close bs, apply the snapshot on fallback_bs, and re-open bs */ @@ -287,7 +281,7 @@ int bdrv_snapshot_goto(BlockDriverState *bs, } /* .bdrv_open() will re-attach it */ - bdrv_unref_child(bs, *fallback_ptr); + bdrv_unref_child(bs, fallback); ret = bdrv_snapshot_goto(fallback_bs, snapshot_id, errp); open_ret = drv->bdrv_open(bs, options, bs->open_flags, &local_err);