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 180B3C4332F for ; Thu, 10 Nov 2022 12:10:40 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1ot6Nr-0005Yp-UP; Thu, 10 Nov 2022 07:10:15 -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 1ot6No-0005Xn-VC for qemu-devel@nongnu.org; Thu, 10 Nov 2022 07:10:13 -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 1ot6Nl-00019e-Ck for qemu-devel@nongnu.org; Thu, 10 Nov 2022 07:10:10 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1668082208; 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=kAsrBlElC3PLCz9wCaADJO+zkp1Y3XBFOH5WIFmrr9k=; b=JPnqoqBrO0iF/LsW22o5LGJLd/MOTiSLie+0kSNYATloHOq2rrAAM9Iui9f+Lz6vG/3UwK YNeizTxXgDbWR+ZEy18bhj8z/5jSm3vdZYnLwAEJvN+3phvW+mbTuQxNOh9qvchDwSrGPJ PzPvVIwyNFmutXoVehLH4LdKErL8r9I= Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-159-z61XLka8Pk6q45KDw0upLw-1; Thu, 10 Nov 2022 07:10:02 -0500 X-MC-Unique: z61XLka8Pk6q45KDw0upLw-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.rdu2.redhat.com [10.11.54.4]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 6DC3E3C1068D; Thu, 10 Nov 2022 12:10:02 +0000 (UTC) Received: from redhat.com (unknown [10.39.195.15]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 8F18120290AF; Thu, 10 Nov 2022 12:10:01 +0000 (UTC) Date: Thu, 10 Nov 2022 13:10:00 +0100 From: Kevin Wolf To: Hanna Reitz Cc: qemu-block@nongnu.org, qemu-devel@nongnu.org, John Snow , Vladimir Sementsov-Ogievskiy Subject: Re: [PATCH for-7.2 3/5] block/mirror: Fix NULL s->job in active writes Message-ID: References: <20221109165452.67927-1-hreitz@redhat.com> <20221109165452.67927-4-hreitz@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20221109165452.67927-4-hreitz@redhat.com> X-Scanned-By: MIMEDefang 3.1 on 10.11.54.4 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_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 09.11.2022 um 17:54 hat Hanna Reitz geschrieben: > There is a small gap in mirror_start_job() before putting the mirror > filter node into the block graph (bdrv_append() call) and the actual job > being created. Before the job is created, MirrorBDSOpaque.job is NULL. > > It is possible that requests come in when bdrv_drained_end() is called, > and those requests would see MirrorBDSOpaque.job == NULL. Have our > filter node handle that case gracefully. > > Signed-off-by: Hanna Reitz This can only happen because bdrv_drained_end() polls, right? So after changing that it won't be necessary any more, but this series is for 7.2 and the drain one isn't, so this is the right thing to do for now. Reviewed-by: Kevin Wolf