From patchwork Mon Apr 19 08:55:35 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Emanuele Giuseppe Esposito X-Patchwork-Id: 1467833 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=nongnu.org (client-ip=209.51.188.17; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=) Authentication-Results: ozlabs.org; dkim=fail reason="signature verification failed" (1024-bit key; unprotected) header.d=redhat.com header.i=@redhat.com header.a=rsa-sha256 header.s=mimecast20190719 header.b=i7fDYh0d; dkim-atps=neutral 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 ozlabs.org (Postfix) with ESMTPS id 4FP0zv6v0Qz9tlQ for ; Mon, 19 Apr 2021 18:56:43 +1000 (AEST) Received: from localhost ([::1]:57234 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lYPhx-0000d3-VM for incoming@patchwork.ozlabs.org; Mon, 19 Apr 2021 04:56:42 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:41644) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lYPhK-0000Zt-5Q for qemu-devel@nongnu.org; Mon, 19 Apr 2021 04:56:02 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:31059) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lYPhI-0000vw-K5 for qemu-devel@nongnu.org; Mon, 19 Apr 2021 04:56:01 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1618822560; 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: in-reply-to:in-reply-to:references:references; bh=F7NwFsCFY1ZCxrd9bRPmNUOXiKGCgh0XcDto2jSEUCQ=; b=i7fDYh0d95vWOWQfukIOZNs7wAqgRWFDVBMLe8WVhq3gRlGRcpk7k9K17VmDELrcK1xm/7 oQPqErrlQlvwmkd9malBUk3huj7h4ZlMQAtXXHq9l61+3brl1W9RpXkUja308yzh8G72yd 4f7Y/LSC38fB5YTl/jHBWrpuo7E999I= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-378-cxtm6m-yN_uXk7RBST2ShA-1; Mon, 19 Apr 2021 04:55:58 -0400 X-MC-Unique: cxtm6m-yN_uXk7RBST2ShA-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 5F579107ACF6; Mon, 19 Apr 2021 08:55:57 +0000 (UTC) Received: from localhost.localdomain.com (ovpn-114-195.ams2.redhat.com [10.36.114.195]) by smtp.corp.redhat.com (Postfix) with ESMTP id 93B5C5D742; Mon, 19 Apr 2021 08:55:54 +0000 (UTC) From: Emanuele Giuseppe Esposito To: qemu-block@nongnu.org Subject: [PATCH v2 2/8] block: protect write threshold QMP commands from concurrent requests Date: Mon, 19 Apr 2021 10:55:35 +0200 Message-Id: <20210419085541.22310-3-eesposit@redhat.com> In-Reply-To: <20210419085541.22310-1-eesposit@redhat.com> References: <20210419085541.22310-1-eesposit@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=eesposit@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Received-SPF: pass client-ip=170.10.133.124; envelope-from=eesposit@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -27 X-Spam_score: -2.8 X-Spam_bar: -- X-Spam_report: (-2.8 / 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_LOW=-0.7, RCVD_IN_MSPIKE_H4=-0.01, RCVD_IN_MSPIKE_WL=-0.01, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Kevin Wolf , Fam Zheng , qemu-devel@nongnu.org, Emanuele Giuseppe Esposito , Markus Armbruster , Max Reitz , Stefan Hajnoczi , Paolo Bonzini , John Snow Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" For simplicity, use bdrv_drained_begin/end to avoid concurrent writes to the write threshold, or reading it while it is being set. qmp_block_set_write_threshold is protected by the BQL. Reviewed-by: Stefan Hajnoczi Co-developed-by: Paolo Bonzini Signed-off-by: Emanuele Giuseppe Esposito --- block/write-threshold.c | 9 +++------ 1 file changed, 3 insertions(+), 6 deletions(-) diff --git a/block/write-threshold.c b/block/write-threshold.c index 63040fa4f2..77c74bdaa7 100644 --- a/block/write-threshold.c +++ b/block/write-threshold.c @@ -111,7 +111,6 @@ void qmp_block_set_write_threshold(const char *node_name, Error **errp) { BlockDriverState *bs; - AioContext *aio_context; bs = bdrv_find_node(node_name); if (!bs) { @@ -119,10 +118,8 @@ void qmp_block_set_write_threshold(const char *node_name, return; } - aio_context = bdrv_get_aio_context(bs); - aio_context_acquire(aio_context); - + /* Avoid a concurrent write_threshold_disable. */ + bdrv_drained_begin(bs); bdrv_write_threshold_set(bs, threshold_bytes); - - aio_context_release(aio_context); + bdrv_drained_end(bs); }