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 4B80CC77B7A for ; Thu, 25 May 2023 12:48:53 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1q2AOA-0000HY-2Y; Thu, 25 May 2023 08:48:18 -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 1q2ANv-0008Gh-Vj for qemu-devel@nongnu.org; Thu, 25 May 2023 08:48:04 -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 1q2ANs-00021C-SK for qemu-devel@nongnu.org; Thu, 25 May 2023 08:48:03 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1685018857; 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=dFC09pXA9tuh88zbKA5lHFRjabbl46zk18uGxqCNxas=; b=JVJOgY+EUPRQwc+KiBmuWJQLnn9RQZlBHKcgGYRITHiFl8kgk2rS9+7RWq5XTMbnGfESaW P9GNrmO25cAWdpubDhJT+UV7b8VDM+1qsKnTwhqxROfCpQ+G64xLqmQGpIT2buwEAw+AHO I4VS3JU4XjROkQKVh6hOIPcKtvhtpak= Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-103-O7GXs3ihOX2PTvee5DScmw-1; Thu, 25 May 2023 08:47:35 -0400 X-MC-Unique: O7GXs3ihOX2PTvee5DScmw-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.rdu2.redhat.com [10.11.54.5]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 8FC212A59541; Thu, 25 May 2023 12:47:35 +0000 (UTC) Received: from merkur.fritz.box (unknown [10.39.194.166]) by smtp.corp.redhat.com (Postfix) with ESMTP id 8C7F47AF5; Thu, 25 May 2023 12:47:34 +0000 (UTC) From: Kevin Wolf To: qemu-block@nongnu.org Cc: kwolf@redhat.com, stefanha@redhat.com, hreitz@redhat.com, eblake@redhat.com, qemu-devel@nongnu.org Subject: [PATCH 10/12] block: Fix AioContext locking in bdrv_insert_node() Date: Thu, 25 May 2023 14:47:11 +0200 Message-Id: <20230525124713.401149-11-kwolf@redhat.com> In-Reply-To: <20230525124713.401149-1-kwolf@redhat.com> References: <20230525124713.401149-1-kwolf@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 3.1 on 10.11.54.5 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: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, 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=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 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 --- block.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/block.c b/block.c index e368a43761..d8cc145b77 100644 --- a/block.c +++ b/block.c @@ -5393,12 +5393,17 @@ 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; @@ -5419,8 +5424,14 @@ 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