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 X-Spam-Level: X-Spam-Status: No, score=-13.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id AA1E3C433FE for ; Mon, 7 Dec 2020 15:40:04 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id 0917D23731 for ; Mon, 7 Dec 2020 15:40:03 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0917D23731 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:36550 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1kmIcM-0002HW-Iw for qemu-devel@archiver.kernel.org; Mon, 07 Dec 2020 10:40:02 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:44392) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kmIaY-0001Bz-QL for qemu-devel@nongnu.org; Mon, 07 Dec 2020 10:38:12 -0500 Received: from us-smtp-delivery-124.mimecast.com ([63.128.21.124]:50868) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1kmIaU-0000Jm-Gx for qemu-devel@nongnu.org; Mon, 07 Dec 2020 10:38:10 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1607355485; 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=KkiLjMggtKD7XEXxYEV7wcY6OCwl9L2NMhF2xynTaIk=; b=SxRGAi0vhVNx5XrH5qTTkmbOJrvBny1kV18rPM/2gKXYs7mkyE4v5sUfQMmGcTi1fRP56p REq2xzulWTFfQm0s/ZhWu7zy7VxTSQ9Clq2pWn3tWzMGgaPoGkOnsotu8U4oFzxmUxVZej n9YoEMUI+GW08frU53CzveOlPy2olos= 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-24-2QSpXQHJMxWr6LYbeIvcTQ-1; Mon, 07 Dec 2020 10:38:03 -0500 X-MC-Unique: 2QSpXQHJMxWr6LYbeIvcTQ-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 69462858183; Mon, 7 Dec 2020 15:38:02 +0000 (UTC) Received: from merkur.fritz.box (ovpn-113-161.ams2.redhat.com [10.36.113.161]) by smtp.corp.redhat.com (Postfix) with ESMTPS id EEF6D5D9D0; Mon, 7 Dec 2020 15:37:54 +0000 (UTC) Date: Mon, 7 Dec 2020 16:37:53 +0100 From: Kevin Wolf To: Sergio Lopez Subject: Re: [PATCH 1/2] virtio-blk: Acquire context while switching them on dataplane start Message-ID: <20201207153753.GD5281@merkur.fritz.box> References: <20201204165347.73542-1-slp@redhat.com> <20201204165347.73542-2-slp@redhat.com> MIME-Version: 1.0 In-Reply-To: <20201204165347.73542-2-slp@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=kwolf@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Received-SPF: pass client-ip=63.128.21.124; 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 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: Stefan Hajnoczi , qemu-devel@nongnu.org, qemu-block@nongnu.org, Max Reitz Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Am 04.12.2020 um 17:53 hat Sergio Lopez geschrieben: > On dataplane start, acquire the new AIO context before calling > 'blk_set_aio_context', releasing it immediately afterwards. This > prevents reaching the AIO context attach/detach notifier functions > without having acquired it first. > > It was also the only place where 'blk_set_aio_context' was called with > an unprotected AIO context. > > Signed-off-by: Sergio Lopez > --- > hw/block/dataplane/virtio-blk.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/hw/block/dataplane/virtio-blk.c b/hw/block/dataplane/virtio-blk.c > index 37499c5564..034e43cb1f 100644 > --- a/hw/block/dataplane/virtio-blk.c > +++ b/hw/block/dataplane/virtio-blk.c > @@ -214,7 +214,9 @@ int virtio_blk_data_plane_start(VirtIODevice *vdev) > vblk->dataplane_started = true; > trace_virtio_blk_data_plane_start(s); > > + aio_context_acquire(s->ctx); > r = blk_set_aio_context(s->conf->conf.blk, s->ctx, &local_err); > + aio_context_release(s->ctx); bdrv_set_aio_context_ignore() is documented like this: * The caller must own the AioContext lock for the old AioContext of bs, but it * must not own the AioContext lock for new_context (unless new_context is the * same as the current context of bs). Doesn't this patch lock the new context instead of the old one? Kevin