From patchwork Fri Sep 8 01:35:43 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eric Blake X-Patchwork-Id: 13376951 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 653D2EC8756 for ; Fri, 8 Sep 2023 01:37:27 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1qeQQ1-0008Rl-R3; Thu, 07 Sep 2023 21:36:21 -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 1qeQPz-0008RA-UO for qemu-devel@nongnu.org; Thu, 07 Sep 2023 21:36:19 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1qeQPx-0007tJ-So for qemu-devel@nongnu.org; Thu, 07 Sep 2023 21:36:19 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1694136977; 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=qCymb+XKC5BGfrNg5MkNioHTkONLw1SJSajLqrf9dlU=; b=V26sdMCRNK8/45WZnp6ajZP0TZI8LX4Mum0+TE+qGmefNYcvGB4HiaDABgl+Sql7nUSzZ5 9ycXfuaiSThbibL9wyRLDNe4PEBH+eFOzUjB63XYS8TXU97fmfc6GCPtR++JwCsLY5xEvU 1+vm5WxOp21gUfiU+07O0g1kcu7LpP8= Received: from mimecast-mx02.redhat.com (mx-ext.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-413-BIHw3ZV4OeCS4cAZISQwDg-1; Thu, 07 Sep 2023 21:36:15 -0400 X-MC-Unique: BIHw3ZV4OeCS4cAZISQwDg-1 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.rdu2.redhat.com [10.11.54.1]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 4A5F31C07839; Fri, 8 Sep 2023 01:36:15 +0000 (UTC) Received: from green.redhat.com (unknown [10.2.16.21]) by smtp.corp.redhat.com (Postfix) with ESMTP id CE9314024322; Fri, 8 Sep 2023 01:36:14 +0000 (UTC) From: Eric Blake To: qemu-devel@nongnu.org Cc: "Denis V. Lunev" , Vladimir Sementsov-Ogievskiy , qemu-block@nongnu.org (open list:Network Block Dev...) Subject: [PULL 07/13] qemu-nbd: improve error message for dup2 error Date: Thu, 7 Sep 2023 20:35:43 -0500 Message-ID: <20230908013535.990731-22-eblake@redhat.com> In-Reply-To: <20230908013535.990731-15-eblake@redhat.com> References: <20230908013535.990731-15-eblake@redhat.com> MIME-Version: 1.0 Content-type: text/plain X-Scanned-By: MIMEDefang 3.1 on 10.11.54.1 Received-SPF: pass client-ip=170.10.129.124; envelope-from=eblake@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, 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 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 From: "Denis V. Lunev" This error happens if we are not able to close the pipe to the parent (to trace errors in the child process) and assign stderr to /dev/null as required by the daemonizing convention. Signed-off-by: Denis V. Lunev Suggested-by: Eric Blake CC: Eric Blake CC: Vladimir Sementsov-Ogievskiy Message-ID: <20230906093210.339585-2-den@openvz.org> Reviewed-by: Eric Blake [eblake: commit message grammar] Signed-off-by: Eric Blake --- qemu-nbd.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/qemu-nbd.c b/qemu-nbd.c index b47459f781d..e2480061a16 100644 --- a/qemu-nbd.c +++ b/qemu-nbd.c @@ -324,7 +324,7 @@ static void *nbd_client_thread(void *arg) } else { /* Close stderr so that the qemu-nbd process exits. */ if (dup2(STDOUT_FILENO, STDERR_FILENO) < 0) { - error_report("Could not set stderr to /dev/null: %s", + error_report("Could not release pipe to parent: %s", strerror(errno)); exit(EXIT_FAILURE); } @@ -1181,7 +1181,7 @@ int main(int argc, char **argv) if (fork_process) { if (dup2(STDOUT_FILENO, STDERR_FILENO) < 0) { - error_report("Could not set stderr to /dev/null: %s", + error_report("Could not release pipe to parent: %s", strerror(errno)); exit(EXIT_FAILURE); }