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 68D19C54E71 for ; Tue, 19 Mar 2024 18:03:13 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1rmdnM-0003zp-RC; Tue, 19 Mar 2024 14:02:40 -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 1rmdnI-0003zS-QO for qemu-devel@nongnu.org; Tue, 19 Mar 2024 14:02:39 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1rmdnB-0007Ok-00 for qemu-devel@nongnu.org; Tue, 19 Mar 2024 14:02:36 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1710871347; h=from:from:reply-to: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=tmYCQ9k4fNsyxQYNhV2s9IWffrO3e8BfxyQmwKCj6v0=; b=jQ+E7XR3BNPHkN4hGYozwXBb3PomFOTwBZbHDWnZu01CD96bHSFTvA9Lf8ccZhU5GBjRu/ dsVlCEHimwwyZ2RXvp4jK3yk4TvJ1grnf2t5vbwzpZi2rDeP3BfylLcC3lvxDhDFqrUQlt U4ONFZfv6CgigOEvU/mJPeyPE43XcrQ= Received: from mimecast-mx02.redhat.com (mx-ext.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-12-yyOkum5HNkeNg2gv8XI_Vw-1; Tue, 19 Mar 2024 14:02:16 -0400 X-MC-Unique: yyOkum5HNkeNg2gv8XI_Vw-1 Received: from smtp.corp.redhat.com (int-mx09.intmail.prod.int.rdu2.redhat.com [10.11.54.9]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 241203C0D7C5; Tue, 19 Mar 2024 18:02:16 +0000 (UTC) Received: from redhat.com (unknown [10.42.28.88]) by smtp.corp.redhat.com (Postfix) with ESMTPS id EC103492BC8; Tue, 19 Mar 2024 18:02:14 +0000 (UTC) Date: Tue, 19 Mar 2024 18:02:09 +0000 From: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= To: Andrey Drobyshev Cc: qemu-devel@nongnu.org, michael.roth@amd.com, kkostiuk@redhat.com, marcandre.lureau@redhat.com, philmd@linaro.org, den@virtuozzo.com Subject: Re: [PATCH v3 6/7] qga/commands-posix: don't do fork()/exec() when suspending via sysfs Message-ID: References: <20240315122946.39168-1-andrey.drobyshev@virtuozzo.com> <20240315122946.39168-7-andrey.drobyshev@virtuozzo.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20240315122946.39168-7-andrey.drobyshev@virtuozzo.com> User-Agent: Mutt/2.2.12 (2023-09-09) X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.9 Received-SPF: pass client-ip=170.10.133.124; envelope-from=berrange@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -24 X-Spam_score: -2.5 X-Spam_bar: -- X-Spam_report: (-2.5 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.422, 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_H4=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: , Reply-To: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org On Fri, Mar 15, 2024 at 02:29:45PM +0200, Andrey Drobyshev wrote: > Since commit 246d76eba ("qga: guest_suspend: decoupling pm-utils and sys > logic") pm-utils logic is running in a separate child from the sysfs > logic. Now when suspending via sysfs we don't really need to do that in > a separate process as we only need to perform one write to /sys/power/state. > > Let's just use g_file_set_contents() to simplify things here. > > Suggested-by: Daniel P. Berrangé > Signed-off-by: Andrey Drobyshev > --- > qga/commands-posix.c | 41 +++++------------------------------------ > 1 file changed, 5 insertions(+), 36 deletions(-) Reviewed-by: Daniel P. Berrangé > > diff --git a/qga/commands-posix.c b/qga/commands-posix.c > index 610d225d30..e0ea377f65 100644 > --- a/qga/commands-posix.c > +++ b/qga/commands-posix.c > @@ -1928,52 +1928,21 @@ static bool linux_sys_state_supports_mode(SuspendMode mode, Error **errp) > > static void linux_sys_state_suspend(SuspendMode mode, Error **errp) > { > - Error *local_err = NULL; > + GError *local_gerr = NULL; > const char *sysfile_strs[3] = {"disk", "mem", NULL}; > const char *sysfile_str = sysfile_strs[mode]; > - pid_t pid; > - int status; > > if (!sysfile_str) { > error_setg(errp, "unknown guest suspend mode"); > return; > } > > - pid = fork(); > - if (!pid) { > - /* child */ > - int fd; > - > - setsid(); > - reopen_fd_to_null(0); > - reopen_fd_to_null(1); > - reopen_fd_to_null(2); > - > - fd = open(LINUX_SYS_STATE_FILE, O_WRONLY); > - if (fd < 0) { > - _exit(EXIT_FAILURE); > - } > - > - if (write(fd, sysfile_str, strlen(sysfile_str)) < 0) { > - _exit(EXIT_FAILURE); > - } > - > - _exit(EXIT_SUCCESS); > - } else if (pid < 0) { > - error_setg_errno(errp, errno, "failed to create child process"); > - return; > - } > - > - ga_wait_child(pid, &status, &local_err); > - if (local_err) { > - error_propagate(errp, local_err); > + if (!g_file_set_contents(LINUX_SYS_STATE_FILE, sysfile_str, > + -1, &local_gerr)) { > + error_setg(errp, "suspend: cannot write to '%s': %s", > + LINUX_SYS_STATE_FILE, local_gerr->message); You need to declare with "g_autoptr(GError) local_gerr = NULL" to avoid a leak here. > return; > } > - > - if (WEXITSTATUS(status)) { > - error_setg(errp, "child process has failed to suspend"); > - } > - > } > > static void guest_suspend(SuspendMode mode, Error **errp) > -- > 2.39.3 > With regards, Daniel -- |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| |: https://libvirt.org -o- https://fstop138.berrange.com :| |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|