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 75BD6C433EF for ; Fri, 4 Mar 2022 10:23:56 +0000 (UTC) Received: from localhost ([::1]:34450 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1nQ56J-0006dz-3Y for qemu-devel@archiver.kernel.org; Fri, 04 Mar 2022 05:23:55 -0500 Received: from eggs.gnu.org ([209.51.188.92]:40514) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1nQ53M-0004Km-42 for qemu-devel@nongnu.org; Fri, 04 Mar 2022 05:20:53 -0500 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:53329) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1nQ53K-000231-Pi for qemu-devel@nongnu.org; Fri, 04 Mar 2022 05:20:51 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1646389250; 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=AV6aeINCyhEid84tyuZpLcbbAEVehAtxRgfa8zDL4aM=; b=NPuvmd4ct2D08bD3O/xFzn45QnyU8apXYkx4tEY+1KCsTIMtl1aLa2yLdRvGSp8ZUERuNM DQ/uIsVbjA59MLn4Q1JsyQk66VerttuoAqiMa9TV5R5VgLUMviAk51xN4xX7sKr2juAIAa RNDZwCQb+G5x1PH9Q/+jd4F7irCvUKQ= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-616-himtsi-gNrKkmjUoLlNaMw-1; Fri, 04 Mar 2022 05:20:48 -0500 X-MC-Unique: himtsi-gNrKkmjUoLlNaMw-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id D8766800423; Fri, 4 Mar 2022 10:20:47 +0000 (UTC) Received: from redhat.com (unknown [10.39.194.38]) by smtp.corp.redhat.com (Postfix) with ESMTPS id C78177C0CB; Fri, 4 Mar 2022 10:20:41 +0000 (UTC) Date: Fri, 4 Mar 2022 11:20:39 +0100 From: Kevin Wolf To: Daniel =?iso-8859-1?Q?P=2E_Berrang=E9?= Subject: Re: [PATCH v2 1/4] os-posix: Add os_set_daemonize() Message-ID: References: <20220303164814.284974-1-hreitz@redhat.com> <20220303164814.284974-2-hreitz@redhat.com> MIME-Version: 1.0 In-Reply-To: X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 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=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit Received-SPF: pass client-ip=170.10.133.124; envelope-from=kwolf@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, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H5=0.001, RCVD_IN_MSPIKE_WL=0.001, 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: , Cc: Paolo Bonzini , Hanna Reitz , qemu-devel@nongnu.org, qemu-block@nongnu.org Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Am 04.03.2022 um 10:19 hat Daniel P. Berrangé geschrieben: > On Thu, Mar 03, 2022 at 05:48:11PM +0100, Hanna Reitz wrote: > > The daemonizing functions in os-posix (os_daemonize() and > > os_setup_post()) only daemonize the process if the static `daemonize` > > variable is set. Right now, it can only be set by os_parse_cmd_args(). > > > > In order to use os_daemonize() and os_setup_post() from the storage > > daemon to have it be daemonized, we need some other way to set this > > `daemonize` variable, because I would rather not tap into the system > > emulator's arg-parsing code. Therefore, this patch adds an > > os_set_daemonize() function, which will return an error on os-win32 > > (because daemonizing is not supported there). > > IMHO the real flaw here is the design of 'os_daemonize' in that it > relies on static state. If I see a call to a function 'os_daemonize()' > I expect to be daemonized on return, but with this design that is not > guaranteed which is a big surprise. > > I'd suggest we push the condition into the caller instead of adding > this extra function, so we have the more sane pattern: > > if (daemonmize()) { > os_daemonize() > } It's not as simple, the static daemonize variable is used in more places than just os_daemonize(). I'm not sure if it's worth changing how all of this works, but if we did, it would be a refactoring mostly focussed on the system emulator and an issue separate from adding the option to the storage daemon. Kevin