From patchwork Wed Jul 19 20:27:40 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eric Blake X-Patchwork-Id: 13319502 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 EA277C001B0 for ; Wed, 19 Jul 2023 20:40:03 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1qMDv7-0005wt-SP; Wed, 19 Jul 2023 16:37:13 -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 1qMDv5-0005uI-0w for qemu-devel@nongnu.org; Wed, 19 Jul 2023 16:37:11 -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 1qMDv2-0001my-Hm for qemu-devel@nongnu.org; Wed, 19 Jul 2023 16:37:10 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1689799028; 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=zIj6ia/VfHjmhRT5f4gk4X0quoSAGEgCZpYC++Rn3Ro=; b=HkAhE9d86LTyxP5YWpLbFYrz4NuF8b9ZnNhGf4hDg3Ehl+SIugEHm8VR6/AqAEAyiOqLeD gbjFMUr2hmT3JGJ5Iez+tcvzprSrLf5ZlE0uRyKeQfCDxUVp3hYKa9BpJcIz217NdZuXFh R1ccbed8EO+3govBJiWfGlFr5s0CFm4= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-304-QkErrctJPY-iXwTVGojEmg-1; Wed, 19 Jul 2023 16:37:04 -0400 X-MC-Unique: QkErrctJPY-iXwTVGojEmg-1 Received: from smtp.corp.redhat.com (int-mx10.intmail.prod.int.rdu2.redhat.com [10.11.54.10]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 54B80100813E; Wed, 19 Jul 2023 20:37:04 +0000 (UTC) Received: from green.redhat.com (unknown [10.2.16.192]) by smtp.corp.redhat.com (Postfix) with ESMTP id E4CC24CD0F5; Wed, 19 Jul 2023 20:37:03 +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 03/14] qemu-nbd: properly report error if qemu_daemon() is failed Date: Wed, 19 Jul 2023 15:27:40 -0500 Message-ID: <20230719202736.2675295-19-eblake@redhat.com> In-Reply-To: <20230719202736.2675295-16-eblake@redhat.com> References: <20230719202736.2675295-16-eblake@redhat.com> MIME-Version: 1.0 Content-type: text/plain X-Scanned-By: MIMEDefang 3.1 on 10.11.54.10 Received-SPF: pass client-ip=170.10.133.124; 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, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=unavailable 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" errno has been overwritten by dup2() just below qemu_daemon() and thus improperly returned to the caller. Fix accordingly. Signed-off-by: Denis V. Lunev CC: Eric Blake CC: Vladimir Sementsov-Ogievskiy Message-ID: <20230717145544.194786-5-den@openvz.org> Reviewed-by: Eric Blake [eblake: reorder patch series] Signed-off-by: Eric Blake --- qemu-nbd.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/qemu-nbd.c b/qemu-nbd.c index 186ce9474c3..5a8ae1f7472 100644 --- a/qemu-nbd.c +++ b/qemu-nbd.c @@ -932,14 +932,17 @@ int main(int argc, char **argv) error_report("Failed to fork: %s", strerror(errno)); exit(EXIT_FAILURE); } else if (pid == 0) { + int saved_errno; + close(stderr_fd[0]); ret = qemu_daemon(1, 0); + saved_errno = errno; /* dup2 will overwrite error below */ /* Temporarily redirect stderr to the parent's pipe... */ dup2(stderr_fd[1], STDERR_FILENO); if (ret < 0) { - error_report("Failed to daemonize: %s", strerror(errno)); + error_report("Failed to daemonize: %s", strerror(saved_errno)); exit(EXIT_FAILURE); }