From patchwork Mon May 14 14:56:32 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Michael Roth X-Patchwork-Id: 159032 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id 625B2B702E for ; Tue, 15 May 2012 00:57:16 +1000 (EST) Received: from localhost ([::1]:43448 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1STwi2-0003h7-8r for incoming@patchwork.ozlabs.org; Mon, 14 May 2012 10:57:14 -0400 Received: from eggs.gnu.org ([208.118.235.92]:55052) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1STwhu-0003h0-Ik for qemu-devel@nongnu.org; Mon, 14 May 2012 10:57:07 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1STwho-00077F-Qd for qemu-devel@nongnu.org; Mon, 14 May 2012 10:57:06 -0400 Received: from mail-ob0-f173.google.com ([209.85.214.173]:51644) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1STwho-00076I-JJ for qemu-devel@nongnu.org; Mon, 14 May 2012 10:57:00 -0400 Received: by mail-ob0-f173.google.com with SMTP id wd20so9283583obb.4 for ; Mon, 14 May 2012 07:56:59 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=sender:from:to:cc:subject:date:message-id:x-mailer:in-reply-to :references; bh=cLtdBdegkhjn6BLbw42EPWQhfceocI4UJhyS7iKKVQ4=; b=EeXoYfwrm30jd5E+tn+V2+3GcAsa656TrGZ/OcnbYpaHLRM5hwF/XIqYx+/kDbXE9y fyb92DRF1Uf8RRQ3hylOQbro9BneExauK2UL86DfPm80T/ki5fusXFQZkjg2VyCr6krD a1ZU6+Z/vfgMV/YYYbW2IhPlddlR5vlnXdyLXtFlJXknHlGFA0XhsLkAJwWOgvyylEG3 7CBCqJ8B9ufYWIUi+LsNaIvjqFyEJnJZe7n1bDaC3MfTOwGdn+hJrA6G4fs8yr++QXUr mJG3XpRC6zazRf3OLznr877QyeStkGktPWYA9Esr1Ktpvi7jVrxOJy157JcRQ5ky+Ejp P5Xw== Received: by 10.182.159.41 with SMTP id wz9mr11749778obb.69.1337007419749; Mon, 14 May 2012 07:56:59 -0700 (PDT) Received: from localhost.localdomain ([32.97.110.59]) by mx.google.com with ESMTPS id i11sm19360344obp.17.2012.05.14.07.56.57 (version=TLSv1/SSLv3 cipher=OTHER); Mon, 14 May 2012 07:56:58 -0700 (PDT) From: Michael Roth To: qemu-devel@nongnu.org Date: Mon, 14 May 2012 09:56:32 -0500 Message-Id: <1337007392-30304-3-git-send-email-mdroth@linux.vnet.ibm.com> X-Mailer: git-send-email 1.7.4.1 In-Reply-To: <1337007392-30304-1-git-send-email-mdroth@linux.vnet.ibm.com> References: <1336763987-10920-1-git-send-email-lcapitulino@redhat.com> <1337007392-30304-1-git-send-email-mdroth@linux.vnet.ibm.com> X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 209.85.214.173 Cc: eblake@redhat.com, lcapitulino@redhat.com Subject: [Qemu-devel] [PATCH 2/2] qemu-ga: guest-shutdown: become synchronous X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org From: Luiz Capitulino Last commit dropped qemu-ga's SIGCHLD handler, used to automatically reap terminated children processes. This introduced a bug to qmp_guest_shutdown(): it will generate zombies. This problem probably doesn't matter in the success case, as the VM will shutdown anyway, but let's do the right thing and reap the created process. This ultimately means that guest-shutdown is now a synchronous command. An interesting side effect is that guest-shutdown is now able to report an error to the client if shutting down fails. Signed-off-by: Luiz Capitulino Signed-off-by: Michael Roth Reviewed-by: Eric Blake --- qga/commands-posix.c | 21 ++++++++++++++++----- 1 files changed, 16 insertions(+), 5 deletions(-) diff --git a/qga/commands-posix.c b/qga/commands-posix.c index cb97646..9a59276 100644 --- a/qga/commands-posix.c +++ b/qga/commands-posix.c @@ -36,8 +36,9 @@ void qmp_guest_shutdown(bool has_mode, const char *mode, Error **err) { - int ret; const char *shutdown_flag; + int ret, status; + pid_t rpid, pid; slog("guest-shutdown called, mode: %s", mode); if (!has_mode || strcmp(mode, "powerdown") == 0) { @@ -52,8 +53,8 @@ void qmp_guest_shutdown(bool has_mode, const char *mode, Error **err) return; } - ret = fork(); - if (ret == 0) { + pid = fork(); + if (pid == 0) { /* child, start the shutdown */ setsid(); fclose(stdin); @@ -66,9 +67,19 @@ void qmp_guest_shutdown(bool has_mode, const char *mode, Error **err) slog("guest-shutdown failed: %s", strerror(errno)); } exit(!!ret); - } else if (ret < 0) { - error_set(err, QERR_UNDEFINED_ERROR); + } else if (pid < 0) { + goto exit_err; } + + do { + rpid = waitpid(pid, &status, 0); + } while (rpid == -1 && errno == EINTR); + if (rpid == pid && WIFEXITED(status) && !WEXITSTATUS(status)) { + return; + } + +exit_err: + error_set(err, QERR_UNDEFINED_ERROR); } typedef struct GuestFileHandle {