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=-7.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED 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 8A779C072B5 for ; Fri, 24 May 2019 15:11:28 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 55A7D20862 for ; Fri, 24 May 2019 15:11:28 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 55A7D20862 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 ([127.0.0.1]:56036 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hUBqx-0007jO-H8 for qemu-devel@archiver.kernel.org; Fri, 24 May 2019 11:11:27 -0400 Received: from eggs.gnu.org ([209.51.188.92]:54536) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hUBoz-0006RH-Oh for qemu-devel@nongnu.org; Fri, 24 May 2019 11:09:26 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hUBoh-0000ge-Kx for qemu-devel@nongnu.org; Fri, 24 May 2019 11:09:13 -0400 Received: from mx1.redhat.com ([209.132.183.28]:50616) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1hUBnN-00089f-VG; Fri, 24 May 2019 11:07:49 -0400 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 2DC063088A63; Fri, 24 May 2019 15:07:31 +0000 (UTC) Received: from [10.3.116.169] (ovpn-116-169.phx2.redhat.com [10.3.116.169]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 738C11001E77; Fri, 24 May 2019 15:07:28 +0000 (UTC) To: Max Reitz , qemu-block@nongnu.org References: <20190508211820.17851-1-mreitz@redhat.com> <20190508211820.17851-2-mreitz@redhat.com> From: Eric Blake Openpgp: preference=signencrypt Autocrypt: addr=eblake@redhat.com; keydata= xsBNBEvHyWwBCACw7DwsQIh0kAbUXyqhfiKAKOTVu6OiMGffw2w90Ggrp4bdVKmCaEXlrVLU xphBM8mb+wsFkU+pq9YR621WXo9REYVIl0FxKeQo9dyQBZ/XvmUMka4NOmHtFg74nvkpJFCD TUNzmqfcjdKhfFV0d7P/ixKQeZr2WP1xMcjmAQY5YvQ2lUoHP43m8TtpB1LkjyYBCodd+LkV GmCx2Bop1LSblbvbrOm2bKpZdBPjncRNob73eTpIXEutvEaHH72LzpzksfcKM+M18cyRH+nP sAd98xIbVjm3Jm4k4d5oQyE2HwOur+trk2EcxTgdp17QapuWPwMfhaNq3runaX7x34zhABEB AAHNHkVyaWMgQmxha2UgPGVibGFrZUByZWRoYXQuY29tPsLAegQTAQgAJAIbAwULCQgHAwUV CgkICwUWAgMBAAIeAQIXgAUCS8fL9QIZAQAKCRCnoWtKJSdDahBHCACbl/5FGkUqJ89GAjeX RjpAeJtdKhujir0iS4CMSIng7fCiGZ0fNJCpL5RpViSo03Q7l37ss+No+dJI8KtAp6ID+PMz wTJe5Egtv/KGUKSDvOLYJ9WIIbftEObekP+GBpWP2+KbpADsc7EsNd70sYxExD3liwVJYqLc Rw7so1PEIFp+Ni9A1DrBR5NaJBnno2PHzHPTS9nmZVYm/4I32qkLXOcdX0XElO8VPDoVobG6 gELf4v/vIImdmxLh/w5WctUpBhWWIfQDvSOW2VZDOihm7pzhQodr3QP/GDLfpK6wI7exeu3P pfPtqwa06s1pae3ad13mZGzkBdNKs1HEm8x6zsBNBEvHyWwBCADGkMFzFjmmyqAEn5D+Mt4P zPdO8NatsDw8Qit3Rmzu+kUygxyYbz52ZO40WUu7EgQ5kDTOeRPnTOd7awWDQcl1gGBXgrkR pAlQ0l0ReO57Q0eglFydLMi5bkwYhfY+TwDPMh3aOP5qBXkm4qIYSsxb8A+i00P72AqFb9Q7 3weG/flxSPApLYQE5qWGSXjOkXJv42NGS6o6gd4RmD6Ap5e8ACo1lSMPfTpGzXlt4aRkBfvb NCfNsQikLZzFYDLbQgKBA33BDeV6vNJ9Cj0SgEGOkYyed4I6AbU0kIy1hHAm1r6+sAnEdIKj cHi3xWH/UPrZW5flM8Kqo14OTDkI9EtlABEBAAHCwF8EGAEIAAkFAkvHyWwCGwwACgkQp6Fr SiUnQ2q03wgAmRFGDeXzc58NX0NrDijUu0zx3Lns/qZ9VrkSWbNZBFjpWKaeL1fdVeE4TDGm I5mRRIsStjQzc2R9b+2VBUhlAqY1nAiBDv0Qnt+9cLiuEICeUwlyl42YdwpmY0ELcy5+u6wz mK/jxrYOpzXKDwLq5k4X+hmGuSNWWAN3gHiJqmJZPkhFPUIozZUCeEc76pS/IUN72NfprZmF Dp6/QDjDFtfS39bHSWXKVZUbqaMPqlj/z6Ugk027/3GUjHHr8WkeL1ezWepYDY7WSoXwfoAL 2UXYsMAr/uUncSKlfjvArhsej0S4zbqim2ZY6S8aRWw94J3bSvJR+Nwbs34GPTD4Pg== Organization: Red Hat, Inc. Message-ID: <1ed0b731-cbbd-0cdd-32f6-913d2b57edfa@redhat.com> Date: Fri, 24 May 2019 10:07:27 -0500 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.6.1 MIME-Version: 1.0 In-Reply-To: <20190508211820.17851-2-mreitz@redhat.com> Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="Ilx6g9IlvnOjb9pFZDXHUYmqhiYVHep6w" X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.47]); Fri, 24 May 2019 15:07:36 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 209.132.183.28 X-Content-Filtered-By: Mailman/MimeDel 2.1.21 Subject: Re: [Qemu-devel] [PATCH v3 1/5] qemu-nbd: Add --pid-file option X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Kevin Wolf , =?UTF-8?Q?Daniel_P_=2e_Berrang=c3=a9?= , qemu-devel@nongnu.org Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" This is an OpenPGP/MIME signed message (RFC 4880 and 3156) --Ilx6g9IlvnOjb9pFZDXHUYmqhiYVHep6w From: Eric Blake To: Max Reitz , qemu-block@nongnu.org Cc: qemu-devel@nongnu.org, =?UTF-8?Q?Daniel_P_=2e_Berrang=c3=a9?= , Kevin Wolf Message-ID: <1ed0b731-cbbd-0cdd-32f6-913d2b57edfa@redhat.com> Subject: Re: [PATCH v3 1/5] qemu-nbd: Add --pid-file option References: <20190508211820.17851-1-mreitz@redhat.com> <20190508211820.17851-2-mreitz@redhat.com> In-Reply-To: <20190508211820.17851-2-mreitz@redhat.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable On 5/8/19 4:18 PM, Max Reitz wrote: > --fork is a bit boring if there is no way to get the child's PID. This= > option helps. >=20 > Signed-off-by: Max Reitz > --- > qemu-nbd.c | 11 +++++++++++ > qemu-nbd.texi | 2 ++ > 2 files changed, 13 insertions(+) >=20 > diff --git a/qemu-nbd.c b/qemu-nbd.c > index dca9e72cee..edb5195208 100644 > --- a/qemu-nbd.c > +++ b/qemu-nbd.c > @@ -59,6 +59,7 @@ > #define QEMU_NBD_OPT_IMAGE_OPTS 262 > #define QEMU_NBD_OPT_FORK 263 > #define QEMU_NBD_OPT_TLSAUTHZ 264 > +#define QEMU_NBD_OPT_PID_FILE 265 > =20 > #define MBR_SIZE 512 > =20 > @@ -111,6 +112,7 @@ static void usage(const char *name) > " specify tracing options\n" > " --fork fork off the server process and exit the = parent\n" > " once the server is running\n" > +" --pid-file=3DPATH store the server's process ID in the gi= ven file\n" Are we guaranteed that the pid file does not appear until after the socket has been created? /me rereads full file... > @@ -876,6 +880,9 @@ int main(int argc, char **argv) > case 'L': > list =3D true; > break; > + case QEMU_NBD_OPT_PID_FILE: > + pid_file_name =3D optarg; > + break; > } > } > =20 =2E.. socket_activation =3D check_socket_activation(); if (socket_activation =3D=3D 0) { setup_address_and_port(&bindto, &port); } else { /* Using socket activation - check user didn't use -p etc. */ =2E.. > @@ -1196,6 +1203,10 @@ int main(int argc, char **argv) > =20 > nbd_update_server_watch(); > =20 > + if (pid_file_name) { > + qemu_write_pidfile(pid_file_name, &error_fatal); > + } Yes, we are. So, > + > /* now when the initialization is (almost) complete, chdir("/") > * to free any busy filesystems */ > if (chdir("/") < 0) { > diff --git a/qemu-nbd.texi b/qemu-nbd.texi > index de342c76b8..7f55657722 100644 > --- a/qemu-nbd.texi > +++ b/qemu-nbd.texi > @@ -117,6 +117,8 @@ option; or provide the credentials needed for conne= cting as a client > in list mode. > @item --fork > Fork off the server process and exit the parent once the server is run= ning. > +@item --pid-file=3DPATH > +Store the server's process ID in the given file. since that is a useful trick to know (the pid file intentionally does NOT appear until after the socket is ready to go), we should mention it in the documentation. I can make that tweak while queueing, if you'd like. Reviewed-by: Eric Blake --=20 Eric Blake, Principal Software Engineer Red Hat, Inc. +1-919-301-3226 Virtualization: qemu.org | libvirt.org --Ilx6g9IlvnOjb9pFZDXHUYmqhiYVHep6w Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAEBCAAdFiEEccLMIrHEYCkn0vOqp6FrSiUnQ2oFAlzoCK8ACgkQp6FrSiUn Q2rhQwgArK0cG3M1LWcIxJ4n9F00xZY3rZpRetoCxa26Cbn7lgmXqhn64mV/bm0j CkjAUbytyt8H02xboh6ogOlWpGsEhqgdnItRZ9CFOEoowxBPf1dUS0uN3lxh1GCu 67HyXMk2S46S1xbfsiqZehbnSwvLDRjfywoWvk7cpV539fX/G0ET350JLEqgkf0/ UZGuQFJikqLEr7X5LmPe06P+vg0GC/tRTRAS+1FcYZvyFmop1BKLghtKXOvmSbwr ZlhbLT1M4WLtuwggLmicxoMPwCxAtIEZFSm3Vi/jDePwUIw4A/GD43O93uaZzIuv RKkbTqHeEJNbS85IiofMcolxovOVTw== =2BxJ -----END PGP SIGNATURE----- --Ilx6g9IlvnOjb9pFZDXHUYmqhiYVHep6w--