From patchwork Fri Dec 8 12:43:52 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kevin Wolf X-Patchwork-Id: 13485376 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 A4069C4167B for ; Fri, 8 Dec 2023 12:45:06 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1rBaD9-0006di-RZ; Fri, 08 Dec 2023 07:44:07 -0500 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 1rBaD8-0006dY-NS for qemu-devel@nongnu.org; Fri, 08 Dec 2023 07:44:06 -0500 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 1rBaD7-00037t-4w for qemu-devel@nongnu.org; Fri, 08 Dec 2023 07:44:06 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1702039444; 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; bh=8pXml5/Y9kknCNvq95S1/zECYp6R8f+59oINf2was3c=; b=LJ56fBP7VEk2gnkpjghnjPXXpZckRUTGrf8XUKdGvlR52T3DTWDNNb8CGnD8RIUDKuYTNO 4ti9NFMsypIBCzY7XmAe0NzI37RRAU9fohD7KPrVxD1foVcRm2EWSo3+gb1A3P4SCARX/i 8hJ8syiDtBIU+lRSJkGfP3i3jVvrUaU= Received: from mimecast-mx02.redhat.com (mx-ext.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-197-P0O8VB_GP0O3_LKBZi-vcQ-1; Fri, 08 Dec 2023 07:43:59 -0500 X-MC-Unique: P0O8VB_GP0O3_LKBZi-vcQ-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.rdu2.redhat.com [10.11.54.2]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 505921C0F476; Fri, 8 Dec 2023 12:43:59 +0000 (UTC) Received: from merkur.redhat.com (unknown [10.39.193.74]) by smtp.corp.redhat.com (Postfix) with ESMTP id 62A9F40C6EB9; Fri, 8 Dec 2023 12:43:58 +0000 (UTC) From: Kevin Wolf To: qemu-block@nongnu.org Cc: kwolf@redhat.com, stefanha@redhat.com, qemu-devel@nongnu.org, qemu-stable@nongnu.org Subject: [PATCH for-8.2] block: Fix AioContext locking in qmp_block_resize() Date: Fri, 8 Dec 2023 13:43:52 +0100 Message-ID: <20231208124352.30295-1-kwolf@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.2 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, RCVD_IN_MSPIKE_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, 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 The AioContext must be unlocked before calling blk_co_unref(), because it takes the AioContext lock internally in blk_unref_bh(), which is scheduled in the main thread. If we don't unlock, the AioContext is locked twice and nested event loops such as in bdrv_graph_wrlock() will deadlock. Cc: qemu-stable@nongnu.org Fixes: https://issues.redhat.com/browse/RHEL-15965 Fixes: 0c7d204f50c382c6baac8c94bd57af4a022b3888 Signed-off-by: Kevin Wolf --- blockdev.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/blockdev.c b/blockdev.c index 4c1177e8db..c91f49e7b6 100644 --- a/blockdev.c +++ b/blockdev.c @@ -2400,8 +2400,9 @@ void coroutine_fn qmp_block_resize(const char *device, const char *node_name, bdrv_co_lock(bs); bdrv_drained_end(bs); - blk_co_unref(blk); bdrv_co_unlock(bs); + + blk_co_unref(blk); } void qmp_block_stream(const char *job_id, const char *device,