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 7ED30C6FA99 for ; Tue, 7 Mar 2023 21:05:23 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1pZeUB-00087X-H1; Tue, 07 Mar 2023 16:04:39 -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 1pZeU9-000876-CO for qemu-devel@nongnu.org; Tue, 07 Mar 2023 16:04:37 -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 1pZeU7-0002h7-FI for qemu-devel@nongnu.org; Tue, 07 Mar 2023 16:04:37 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1678223074; 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: content-transfer-encoding:content-transfer-encoding; bh=DGFlRYFse81y+NjAZOVSKqcFfBmW7GTHM6RiEeSm23M=; b=JCy179LBUw7mwqxE0c/JElJMWvc+4G2UQIRABUHyNCZt7yAPwseUJ3aJ0RLP1E2SIFXnzB W2XnZtUS8afxyNjOZ7M41EUeiQ+uSlfccLYZUlzc26jTXoAJDt0JECuwzbwPSbc1z0nQ1C yCsS5Ne53OV1S5J5XnXPZQHfiBFvDJk= 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-623-f7TkeZKvNvK80PwMB9Z7vQ-1; Tue, 07 Mar 2023 16:04:30 -0500 X-MC-Unique: f7TkeZKvNvK80PwMB9Z7vQ-1 Received: from smtp.corp.redhat.com (int-mx10.intmail.prod.int.rdu2.redhat.com [10.11.54.10]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 5D45880D181; Tue, 7 Mar 2023 21:04:30 +0000 (UTC) Received: from localhost (unknown [10.39.192.86]) by smtp.corp.redhat.com (Postfix) with ESMTP id D756A492C3E; Tue, 7 Mar 2023 21:04:29 +0000 (UTC) From: Stefan Hajnoczi To: qemu-devel@nongnu.org Cc: Hanna Reitz , Kevin Wolf , qemu-block@nongnu.org, Emanuele Giuseppe Esposito , Paolo Bonzini , Stefan Hajnoczi Subject: [PATCH v2 0/3] block: protect BlockBackend->queued_requests with a lock Date: Tue, 7 Mar 2023 16:04:24 -0500 Message-Id: <20230307210427.269214-1-stefanha@redhat.com> Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 3.1 on 10.11.54.10 Received-SPF: pass client-ip=170.10.129.124; envelope-from=stefanha@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 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. Stefan Hajnoczi (3): block: make BlockBackend->quiesce_counter atomic block: make BlockBackend->disable_request_queuing atomic block: protect BlockBackend->queued_requests with a lock block/block-backend.c | 37 ++++++++++++++++++++++++++----------- 1 file changed, 26 insertions(+), 11 deletions(-) -- 2.39.2