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 2724BC77B73 for ; Tue, 30 May 2023 16:39:36 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1q42II-0000EV-Pb; Tue, 30 May 2023 12:33:58 -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 1q42HY-0006nP-V1 for qemu-devel@nongnu.org; Tue, 30 May 2023 12:33:14 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1q42HU-0008M1-JG for qemu-devel@nongnu.org; Tue, 30 May 2023 12:33:12 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1685464387; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=vNX5d1MVjTiz6h8ElDqn9RxFOn0J+KmMVLk3KNi4vbk=; b=CWzbnKbP1IzwBqM+9dyMOwP0MAGCOp7czXJj2KFR1UBgHTyGCMBU6hv1slMReY8+yUbtFB ZueDx2jv9OiR06f2sGrcF3y7r9zcODZxckaYLzQSxNszdoYkkcyZOEEyPewLucrvjKqvDi hEY7moOPaTzif1Zlw1oO/ozjJgf48Fw= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-479-GvmR2AiBPf-518At2W9WkA-1; Tue, 30 May 2023 12:32:57 -0400 X-MC-Unique: GvmR2AiBPf-518At2W9WkA-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.rdu2.redhat.com [10.11.54.8]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id A6600800969; Tue, 30 May 2023 16:32:56 +0000 (UTC) Received: from merkur.redhat.com (unknown [10.39.194.4]) by smtp.corp.redhat.com (Postfix) with ESMTP id E9738C154D3; Tue, 30 May 2023 16:32:55 +0000 (UTC) From: Kevin Wolf To: qemu-block@nongnu.org Cc: kwolf@redhat.com, richard.henderson@linaro.org, qemu-devel@nongnu.org Subject: [PULL 10/32] block: Fix AioContext locking in bdrv_insert_node() Date: Tue, 30 May 2023 18:32:17 +0200 Message-Id: <20230530163239.576632-11-kwolf@redhat.com> In-Reply-To: <20230530163239.576632-1-kwolf@redhat.com> References: <20230530163239.576632-1-kwolf@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 3.1 on 10.11.54.8 Received-SPF: pass client-ip=170.10.129.124; envelope-from=kwolf@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -22 X-Spam_score: -2.3 X-Spam_bar: -- X-Spam_report: (-2.3 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.167, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=unavailable 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 While calling bdrv_new_open_driver_opts(), the main AioContext lock must be held, not the lock of the AioContext of the block subtree it will be added to afterwards. Signed-off-by: Kevin Wolf Message-Id: <20230525124713.401149-11-kwolf@redhat.com> Reviewed-by: Stefan Hajnoczi Signed-off-by: Kevin Wolf --- block.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/block.c b/block.c index 29dea3a6a1..ec65fcf732 100644 --- a/block.c +++ b/block.c @@ -5399,12 +5399,17 @@ static void bdrv_delete(BlockDriverState *bs) * empty set of options. The reference to the QDict belongs to the block layer * after the call (even on failure), so if the caller intends to reuse the * dictionary, it needs to use qobject_ref() before calling bdrv_open. + * + * The caller holds the AioContext lock for @bs. It must make sure that @bs + * stays in the same AioContext, i.e. @options must not refer to nodes in a + * different AioContext. */ BlockDriverState *bdrv_insert_node(BlockDriverState *bs, QDict *options, int flags, Error **errp) { ERRP_GUARD(); int ret; + AioContext *ctx = bdrv_get_aio_context(bs); BlockDriverState *new_node_bs = NULL; const char *drvname, *node_name; BlockDriver *drv; @@ -5425,8 +5430,14 @@ BlockDriverState *bdrv_insert_node(BlockDriverState *bs, QDict *options, GLOBAL_STATE_CODE(); + aio_context_release(ctx); + aio_context_acquire(qemu_get_aio_context()); new_node_bs = bdrv_new_open_driver_opts(drv, node_name, options, flags, errp); + aio_context_release(qemu_get_aio_context()); + aio_context_acquire(ctx); + assert(bdrv_get_aio_context(bs) == ctx); + options = NULL; /* bdrv_new_open_driver() eats options */ if (!new_node_bs) { error_prepend(errp, "Could not create node: "); -- 2.40.1