From patchwork Wed Sep 6 09:32:03 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Denis V. Lunev" X-Patchwork-Id: 13375429 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 3D9D8EB8FAD for ; Wed, 6 Sep 2023 09:33:02 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1qdotb-0008Mu-FS; Wed, 06 Sep 2023 05:32:24 -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 1qdotV-0008Lj-K8; Wed, 06 Sep 2023 05:32:19 -0400 Received: from relay.virtuozzo.com ([130.117.225.111]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1qdotS-0000f2-Vu; Wed, 06 Sep 2023 05:32:17 -0400 Received: from ch-vpn.virtuozzo.com ([130.117.225.6] helo=iris.sw.ru) by relay.virtuozzo.com with esmtp (Exim 4.96) (envelope-from ) id 1qdoqK-005qCB-2x; Wed, 06 Sep 2023 11:31:59 +0200 From: "Denis V. Lunev" To: qemu-devel@nongnu.org, qemu-block@nongnu.org Cc: den@openvz.org, Eric Blake , Vladimir Sementsov-Ogievskiy Subject: [PATCH 1/8] qemu-nbd: improve error message for dup2 error Date: Wed, 6 Sep 2023 11:32:03 +0200 Message-Id: <20230906093210.339585-2-den@openvz.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230906093210.339585-1-den@openvz.org> References: <20230906093210.339585-1-den@openvz.org> MIME-Version: 1.0 Received-SPF: pass client-ip=130.117.225.111; envelope-from=den@openvz.org; helo=relay.virtuozzo.com X-Spam_score_int: -18 X-Spam_score: -1.9 X-Spam_bar: - X-Spam_report: (-1.9 / 5.0 requ) BAYES_00=-1.9, 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 This error is happened when 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 Reviewed-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 aaccaa3318..4575e4291e 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); }