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 A079CC001B1 for ; Mon, 19 Jun 2023 09:24:38 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1qBB7J-00071e-Hu; Mon, 19 Jun 2023 05:24:09 -0400 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 1qBB7H-00071M-L1 for qemu-devel@nongnu.org; Mon, 19 Jun 2023 05:24:07 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1qBB7F-0003Fl-26 for qemu-devel@nongnu.org; Mon, 19 Jun 2023 05:24:06 -0400 Received: from pps.filterd (m0360072.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.17.1.19/8.17.1.19) with ESMTP id 35J9MYSk027138; Mon, 19 Jun 2023 09:24:02 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ibm.com; h=date : from : to : cc : subject : message-id : in-reply-to : references : mime-version : content-type : content-transfer-encoding; s=pp1; bh=wFplvQ+st/Ax9xaSYSbveoi7bz/jQ/ap7BgMr/HRQYI=; b=Ypnz7O39SMZfdrpLjC+o+j0m9wBVS6SzKxHEDteL6gX3Fy5jMSECJBlg1c/P6Bj4mcuv alztmQblAR0aUceE9h46g306XEXoBCkEG3Y4K+k7IDj+MxB5h7XFu6m22+9H3T8cD85W fHuhPElteuhTBLcqSv3eIdUoKbvu2dLJEMcb/rbxE6CWFfU9rx8QvtiV6d540JWetUMt qinczsYAXlalu7EZnJ+9J9kAAaSsLeCfZKIqWMLl/z2CfEA4nUKfRgS/PiXm48XpSmGa 4c/sGvlgZYn1VJcHa0Q9qKBheHOxslnp+RKiBHA4zv5NPBDIGi/02EHwWOsctOKFmhm4 bg== Received: from pps.reinject (localhost [127.0.0.1]) by mx0a-001b2d01.pphosted.com (PPS) with ESMTPS id 3ramb60122-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Mon, 19 Jun 2023 09:24:01 +0000 Received: from m0360072.ppops.net (m0360072.ppops.net [127.0.0.1]) by pps.reinject (8.17.1.5/8.17.1.5) with ESMTP id 35J9N0iC028370; Mon, 19 Jun 2023 09:24:01 GMT Received: from ppma05fra.de.ibm.com (6c.4a.5195.ip4.static.sl-reverse.com [149.81.74.108]) by mx0a-001b2d01.pphosted.com (PPS) with ESMTPS id 3ramb6011m-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Mon, 19 Jun 2023 09:24:01 +0000 Received: from pps.filterd (ppma05fra.de.ibm.com [127.0.0.1]) by ppma05fra.de.ibm.com (8.17.1.19/8.17.1.19) with ESMTP id 35J9LuqX009469; Mon, 19 Jun 2023 09:23:59 GMT Received: from smtprelay05.fra02v.mail.ibm.com ([9.218.2.225]) by ppma05fra.de.ibm.com (PPS) with ESMTPS id 3r94f50xsr-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Mon, 19 Jun 2023 09:23:59 +0000 Received: from smtpav03.fra02v.mail.ibm.com (smtpav03.fra02v.mail.ibm.com [10.20.54.102]) by smtprelay05.fra02v.mail.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 35J9NvlA22217454 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Mon, 19 Jun 2023 09:23:57 GMT Received: from smtpav03.fra02v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 110F820043; Mon, 19 Jun 2023 09:23:57 +0000 (GMT) Received: from smtpav03.fra02v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id CD94020040; Mon, 19 Jun 2023 09:23:56 +0000 (GMT) Received: from p-imbrenda (unknown [9.152.224.66]) by smtpav03.fra02v.mail.ibm.com (Postfix) with ESMTP; Mon, 19 Jun 2023 09:23:56 +0000 (GMT) Date: Mon, 19 Jun 2023 11:19:52 +0200 From: Claudio Imbrenda To: Bin Meng Cc: qemu-devel@nongnu.org, Zhangjin Wu , Juan Quintela , "Michael S. Tsirkin" , Paolo Bonzini Subject: Re: [PATCH v3 5/6] util/async-teardown: Use qemu_close_range() to close fds Message-ID: <20230619111952.0b7d86f2@p-imbrenda> In-Reply-To: <20230617053621.50359-6-bmeng@tinylab.org> References: <20230617053621.50359-1-bmeng@tinylab.org> <20230617053621.50359-6-bmeng@tinylab.org> Organization: IBM X-Mailer: Claws Mail 4.1.1 (GTK 3.24.38; x86_64-redhat-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-TM-AS-GCONF: 00 X-Proofpoint-ORIG-GUID: Mr3p-3Apxh71kNkyu0mZsUz8Y0_COEES X-Proofpoint-GUID: vTTYgSYTXqCAzXsktA4OXQvcrAyALIHu X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.254,Aquarius:18.0.957,Hydra:6.0.591,FMLib:17.11.176.26 definitions=2023-06-19_06,2023-06-16_01,2023-05-22_02 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 spamscore=0 impostorscore=0 mlxscore=0 priorityscore=1501 clxscore=1011 phishscore=0 bulkscore=0 adultscore=0 lowpriorityscore=0 suspectscore=0 malwarescore=0 mlxlogscore=740 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2305260000 definitions=main-2306190081 Received-SPF: pass client-ip=148.163.158.5; envelope-from=imbrenda@linux.ibm.com; helo=mx0b-001b2d01.pphosted.com X-Spam_score_int: -29 X-Spam_score: -3.0 X-Spam_bar: --- X-Spam_report: (-3.0 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_MSPIKE_H5=-1, RCVD_IN_MSPIKE_WL=-0.01, 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-bounces+qemu-devel=archiver.kernel.org@nongnu.org On Sat, 17 Jun 2023 13:36:20 +0800 Bin Meng wrote: > From: Zhangjin Wu > > Based on the old close_all_open_fd() of util/async-teardown.c, a new > generic qemu_close_range() has been added in osdep.c. > > Now, let's switch over to use the generic qemu_close_range(). > > Signed-off-by: Zhangjin Wu > Signed-off-by: Bin Meng > > --- > > Changes in v3: > - limit the last_fd of qemu_close_range() to sysconf(_SC_OPEN_MAX) > > Changes in v2: > - new patch: "util/async-teardown: Use qemu_close_range() to close fds" > > util/async-teardown.c | 42 ++---------------------------------------- > 1 file changed, 2 insertions(+), 40 deletions(-) > > diff --git a/util/async-teardown.c b/util/async-teardown.c > index 7e0177a8da..e102912f3f 100644 > --- a/util/async-teardown.c > +++ b/util/async-teardown.c > @@ -29,44 +29,6 @@ > > static pid_t the_ppid; > > -/* > - * Close all open file descriptors. > - */ > -static void close_all_open_fd(void) > -{ > - struct dirent *de; > - int fd, dfd; > - DIR *dir; > - > -#ifdef CONFIG_CLOSE_RANGE > - int r = close_range(0, ~0U, 0); > - if (!r) { > - /* Success, no need to try other ways. */ > - return; > - } > -#endif > - > - dir = opendir("/proc/self/fd"); > - if (!dir) { > - /* If /proc is not mounted, close fds one by one. */ > - int open_max = sysconf(_SC_OPEN_MAX), i; > - for (i = 0; i < open_max; i++) { > - close(i); > - } > - return; > - } > - /* Avoid closing the directory. */ > - dfd = dirfd(dir); > - > - for (de = readdir(dir); de; de = readdir(dir)) { > - fd = atoi(de->d_name); > - if (fd != dfd) { > - close(fd); > - } > - } > - closedir(dir); > -} > - > static void hup_handler(int signal) > { > /* Check every second if this process has been reparented. */ > @@ -84,6 +46,7 @@ static int async_teardown_fn(void *arg) > struct sigaction sa = { .sa_handler = hup_handler }; > sigset_t hup_signal; > char name[16]; > + int open_max = sysconf(_SC_OPEN_MAX); > > /* Set a meaningful name for this process. */ > snprintf(name, 16, "cleanup/%d", the_ppid); > @@ -92,9 +55,8 @@ static int async_teardown_fn(void *arg) > /* > * Close all file descriptors that might have been inherited from the > * main qemu process when doing clone, needed to make libvirt happy. > - * Not using close_range for increased compatibility with older kernels. > */ > - close_all_open_fd(); > + qemu_close_range(0, open_max - 1); I think it would look easier to read if you just put the sysconf() call here and avoid an extra variable > > /* Set up a handler for SIGHUP and unblock SIGHUP. */ > sigaction(SIGHUP, &sa, NULL);