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 D1C97C678D5 for ; Wed, 8 Mar 2023 09:47:14 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1pZqNm-0000h0-WA; Wed, 08 Mar 2023 04:46:51 -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 1pZqNl-0000gq-To for qemu-devel@nongnu.org; Wed, 08 Mar 2023 04:46:49 -0500 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1pZqNk-0007Ez-G2 for qemu-devel@nongnu.org; Wed, 08 Mar 2023 04:46:49 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1678268807; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=lUxty9YKFQNpP7yeM8nWFQoZgmLljx2dCjM+E79Cki8=; b=PN4wyTCmS0ase/VsD/Bmv8cHbwbO/NpCmLm5M+jIOOcgwNQ1isJr5wBnd+Qt5KfeZc8TgG 4tRGFmv9GBHFeGDcbe+SLjB4Smrc62Hp6h0clOEVSlQBr2yq9NVOZEH/HnGf0gV2Z6IVua YjmZ3TbBoPsMzymiU8HkLSmYTdu3Y8w= 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-28-qquNYdVIPCulhFh8tgBxfQ-1; Wed, 08 Mar 2023 04:46:44 -0500 X-MC-Unique: qquNYdVIPCulhFh8tgBxfQ-1 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.rdu2.redhat.com [10.11.54.1]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 6D21A85A588; Wed, 8 Mar 2023 09:46:44 +0000 (UTC) Received: from redhat.com (unknown [10.39.192.240]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 7C11F40C83B6; Wed, 8 Mar 2023 09:46:42 +0000 (UTC) Date: Wed, 8 Mar 2023 10:46:41 +0100 From: Kevin Wolf To: Stefan Hajnoczi Cc: qemu-devel@nongnu.org, Hanna Reitz , qemu-block@nongnu.org, Emanuele Giuseppe Esposito , Paolo Bonzini Subject: Re: [PATCH v2 0/3] block: protect BlockBackend->queued_requests with a lock Message-ID: References: <20230307210427.269214-1-stefanha@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20230307210427.269214-1-stefanha@redhat.com> X-Scanned-By: MIMEDefang 3.1 on 10.11.54.1 Received-SPF: pass client-ip=170.10.133.124; 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_H2=-0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 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 Am 07.03.2023 um 22:04 hat Stefan Hajnoczi geschrieben: > v2: > - Use qatomic_fetch_inc/dec() for readability in Patch 1 [Hanna] > > QEMU block layer multi-queue support involves running I/O requests from > multiple threads. Shared state must be protected somehow to avoid thread-safety > issues. > > The BlockBackend->queued_requests CoQueue is accessed without a lock and will > likely be corrupted when multiple threads queue requests at the same time. > > This patch series make BlockBackend->queued_requests thread-safe. Thanks, applied to the block-next branch. Kevin