From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org 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 smtp.lore.kernel.org (Postfix) with ESMTPS id 2FD5FC5B549 for ; Fri, 30 May 2025 15:13:36 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1uL1PE-0003US-Ov; Fri, 30 May 2025 11:12:25 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1uL1P9-0003Dr-Rv; Fri, 30 May 2025 11:12:19 -0400 Received: from proxmox-new.maurer-it.com ([94.136.29.106]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1uL1P7-0002HA-KP; Fri, 30 May 2025 11:12:19 -0400 Received: from proxmox-new.maurer-it.com (localhost.localdomain [127.0.0.1]) by proxmox-new.maurer-it.com (Proxmox) with ESMTP id 0B82B44766; Fri, 30 May 2025 17:11:44 +0200 (CEST) From: Fiona Ebner To: qemu-block@nongnu.org Cc: qemu-devel@nongnu.org, kwolf@redhat.com, den@virtuozzo.com, andrey.drobyshev@virtuozzo.com, hreitz@redhat.com, stefanha@redhat.com, eblake@redhat.com, jsnow@redhat.com, vsementsov@yandex-team.ru, xiechanglong.d@gmail.com, wencongyang2@huawei.com, berto@igalia.com, fam@euphon.net, ari@tuxera.com Subject: [PATCH v4 16/48] block: move drain outside of quorum_del_child() Date: Fri, 30 May 2025 17:10:53 +0200 Message-Id: <20250530151125.955508-17-f.ebner@proxmox.com> X-Mailer: git-send-email 2.39.5 In-Reply-To: <20250530151125.955508-1-f.ebner@proxmox.com> References: <20250530151125.955508-1-f.ebner@proxmox.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Received-SPF: pass client-ip=94.136.29.106; envelope-from=f.ebner@proxmox.com; helo=proxmox-new.maurer-it.com 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, RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001, RCVD_IN_VALIDITY_SAFE_BLOCKED=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: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org The quorum_del_child() callback runs under the graph lock, so it is not allowed to drain. It is only called as the .bdrv_del_child() callback, which is only called in the bdrv_del_child() function, which also runs under the graph lock. The bdrv_del_child() function is called by qmp_x_blockdev_change(). A drained section was already introduced there by commit "block: move drain out of quorum_add_child()". This finally finishes moving out the drain to places that are not under the graph lock started in "block: move draining out of bdrv_change_aio_context() and mark GRAPH_RDLOCK". Signed-off-by: Fiona Ebner --- Changes in v4: * Document requirement that all nodes need to be drained for bdrv_del_child() wrapper and callback. * Add function comment for bdrv_del_child() callback. block.c | 2 ++ block/quorum.c | 2 -- include/block/block_int-common.h | 7 +++++++ 3 files changed, 9 insertions(+), 2 deletions(-) diff --git a/block.c b/block.c index 15a8ccb822..bfd4340b24 100644 --- a/block.c +++ b/block.c @@ -8276,6 +8276,8 @@ void bdrv_add_child(BlockDriverState *parent_bs, BlockDriverState *child_bs, /* * Hot remove a BDS's child. Used in combination with bdrv_add_child, so the * user can take a child offline when it is broken and take a new child online. + * + * All block nodes must be drained. */ void bdrv_del_child(BlockDriverState *parent_bs, BdrvChild *child, Error **errp) { diff --git a/block/quorum.c b/block/quorum.c index 81407a38ee..cc3bc5f4e7 100644 --- a/block/quorum.c +++ b/block/quorum.c @@ -1147,9 +1147,7 @@ quorum_del_child(BlockDriverState *bs, BdrvChild *child, Error **errp) (s->num_children - i - 1) * sizeof(BdrvChild *)); s->children = g_renew(BdrvChild *, s->children, --s->num_children); - bdrv_drain_all_begin(); bdrv_unref_child(bs, child); - bdrv_drain_all_end(); quorum_refresh_flags(bs); } diff --git a/include/block/block_int-common.h b/include/block/block_int-common.h index f9e742f812..925a3e7353 100644 --- a/include/block/block_int-common.h +++ b/include/block/block_int-common.h @@ -406,6 +406,13 @@ struct BlockDriver { void GRAPH_WRLOCK_PTR (*bdrv_add_child)( BlockDriverState *parent, BlockDriverState *child, Error **errp); + /** + * Hot remove a BDS's child. Used in combination with bdrv_add_child, so the + * user can take a child offline when it is broken and take a new child + * online. + * + * All block nodes must be drained. + */ void GRAPH_WRLOCK_PTR (*bdrv_del_child)( BlockDriverState *parent, BdrvChild *child, Error **errp); -- 2.39.5