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 56DA6CCA47B for ; Tue, 5 Jul 2022 08:21:38 +0000 (UTC) Received: from localhost ([::1]:50972 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1o8doP-0001ZB-5j for qemu-devel@archiver.kernel.org; Tue, 05 Jul 2022 04:21:37 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:60714) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1o8db1-0001rx-SI for qemu-devel@nongnu.org; Tue, 05 Jul 2022 04:07:47 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]:44037) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1o8db0-00008F-94 for qemu-devel@nongnu.org; Tue, 05 Jul 2022 04:07:47 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1657008465; 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=AVVOJu77iTKaQsjh1si8MGhHVaB10APAIJXcXHcK8Yw=; b=UMRt+2ap8qqnle64A0IPcUSkG6d1pRrXjrjBonhAigQg93k4DkPJPBnZZdKyaIRRhR+yuF 46VvJPQow+USUKitX/ZTEOzr+Gj94iLNtKmsq4LgwJfSOfzq+Ue89TjlyUU7eIsFM15v8v RJGi7c1Qg1iVRiukmsTX546nArqKYrY= Received: from mail-wr1-f71.google.com (mail-wr1-f71.google.com [209.85.221.71]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-663-03HEuz2MMXiIX38vVwa-Kw-1; Tue, 05 Jul 2022 04:07:43 -0400 X-MC-Unique: 03HEuz2MMXiIX38vVwa-Kw-1 Received: by mail-wr1-f71.google.com with SMTP id s1-20020a5d69c1000000b0021b9f3abfebso1700470wrw.2 for ; Tue, 05 Jul 2022 01:07:43 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:message-id:date:mime-version:user-agent:subject :content-language:to:cc:references:from:in-reply-to :content-transfer-encoding; bh=AVVOJu77iTKaQsjh1si8MGhHVaB10APAIJXcXHcK8Yw=; b=Ml5/ZS1GrgTrT+6ZCPeMU87X7fJdHdcpWWjiihHlC1pAXNlori050ocKyaUvCVUSNG 7iOlJM89NNZQIu98JTSlj1OhEIGWVm8n9bZbwFXPWze5QrZKALEOgKKcZX6KY6I8RmKN zL9Ru1sHwydFRaYDQ+xTIqvz5ILDIU9T5SDNw3dgxVuXUMXlF33sbxhnay064fbyU41G L4nWBqcBYd34+A7k1xTIVVjMgB650kZVJ4HLczr9zKawH2vzKnN0QV6CoL8xgL5uOm9M BOkZZE2Xv16rrVUZUjyi9FSGM1D6CIT3HQognMYJ4DkXLxTp3ZzKRINugeMSMeg1JHiN Avqw== X-Gm-Message-State: AJIora8GU0TvohavAGPTQksaW49ef1y2vK1EQ6M3Akk83LQ437RaICP+ CTQM6i/hqmCfXnVCh9cfA//7YpmzkDqrmc+jwteNnZPMPdCJ/D2vWT5WoX5ttblXYzDf1Y/efRT iAAao1TOyz7ICgzo= X-Received: by 2002:a05:6000:904:b0:21a:3dca:4297 with SMTP id bz4-20020a056000090400b0021a3dca4297mr30716009wrb.487.1657008462422; Tue, 05 Jul 2022 01:07:42 -0700 (PDT) X-Google-Smtp-Source: AGRyM1tSHBOWgz3K+VXI44eVFWLOFBT10UCOjAorCVoBrr8xeWpCx3jqR+mlVDZqM3bfQkNAPe2Usw== X-Received: by 2002:a05:6000:904:b0:21a:3dca:4297 with SMTP id bz4-20020a056000090400b0021a3dca4297mr30715989wrb.487.1657008462224; Tue, 05 Jul 2022 01:07:42 -0700 (PDT) Received: from [192.168.149.123] (58.254.164.109.static.wline.lns.sme.cust.swisscom.ch. [109.164.254.58]) by smtp.gmail.com with ESMTPSA id d10-20020adff2ca000000b0021a38089e99sm32156827wrp.57.2022.07.05.01.07.41 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 05 Jul 2022 01:07:41 -0700 (PDT) Message-ID: <0c4ff18c-f12f-6955-09b8-8acd3126492e@redhat.com> Date: Tue, 5 Jul 2022 10:07:40 +0200 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.2.0 Subject: Re: [PATCH v8 05/20] job.c: add job_lock/unlock while keeping job.h intact Content-Language: en-US To: Stefan Hajnoczi Cc: qemu-block@nongnu.org, Kevin Wolf , Hanna Reitz , Paolo Bonzini , John Snow , Vladimir Sementsov-Ogievskiy , Wen Congyang , Xie Changlong , Markus Armbruster , Fam Zheng , qemu-devel@nongnu.org References: <20220629141538.3400679-1-eesposit@redhat.com> <20220629141538.3400679-6-eesposit@redhat.com> From: Emanuele Giuseppe Esposito In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Received-SPF: pass client-ip=170.10.129.124; envelope-from=eesposit@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -28 X-Spam_score: -2.9 X-Spam_bar: -- X-Spam_report: (-2.9 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.082, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, NICE_REPLY_A=-0.001, RCVD_IN_DNSWL_LOW=-0.7, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=ham 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" Am 05/07/2022 um 09:39 schrieb Stefan Hajnoczi: > On Wed, Jun 29, 2022 at 10:15:23AM -0400, Emanuele Giuseppe Esposito wrote: >> +void job_ref(Job *job) >> +{ >> + JOB_LOCK_GUARD(); >> + job_ref_locked(job); >> +} > > You don't need to fix this, but just a note: > > This API seems dangerous. If we don't hold the lock, how can we be sure > job won't be unreferenced before we call job_ref()? We would need to be > sure there exists another reference that won't be released until > job_ref() returns... > I guess that's a drawback of using this new serie organization :) This function is just a temporary placeholder to avoid having _locked functions being called without the lock held (see previous serie suggestions from Vladimir and Kevin). Emanuele