From patchwork Fri May 14 17:10:36 2010 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kevin Wolf X-Patchwork-Id: 52647 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [199.232.76.165]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id 0BBA8B7E60 for ; Sat, 15 May 2010 03:39:00 +1000 (EST) Received: from localhost ([127.0.0.1]:60293 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1OCyqe-0001o9-EP for incoming@patchwork.ozlabs.org; Fri, 14 May 2010 13:38:56 -0400 Received: from [140.186.70.92] (port=41373 helo=eggs.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1OCyQV-0000dx-Fr for qemu-devel@nongnu.org; Fri, 14 May 2010 13:11:57 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.69) (envelope-from ) id 1OCyQO-0001vb-3U for qemu-devel@nongnu.org; Fri, 14 May 2010 13:11:54 -0400 Received: from mx1.redhat.com ([209.132.183.28]:11988) by eggs.gnu.org with esmtp (Exim 4.69) (envelope-from ) id 1OCyQN-0001vB-SN for qemu-devel@nongnu.org; Fri, 14 May 2010 13:11:48 -0400 Received: from int-mx01.intmail.prod.int.phx2.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) by mx1.redhat.com (8.13.8/8.13.8) with ESMTP id o4EHBLcj032078 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); Fri, 14 May 2010 13:11:21 -0400 Received: from localhost.localdomain (vpn1-7-82.ams2.redhat.com [10.36.7.82]) by int-mx01.intmail.prod.int.phx2.redhat.com (8.13.8/8.13.8) with ESMTP id o4EHBFWW004751; Fri, 14 May 2010 13:11:19 -0400 From: Kevin Wolf To: anthony@codemonkey.ws Date: Fri, 14 May 2010 19:10:36 +0200 Message-Id: <1273857055-26715-3-git-send-email-kwolf@redhat.com> In-Reply-To: <1273857055-26715-1-git-send-email-kwolf@redhat.com> References: <1273857055-26715-1-git-send-email-kwolf@redhat.com> X-Scanned-By: MIMEDefang 2.67 on 10.5.11.11 X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. Cc: kwolf@redhat.com, qemu-devel@nongnu.org Subject: [Qemu-devel] [PATCH 02/21] qemu-nbd: Improve error reporting X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org From: Ryota Ozaki - use err(3) instead of errx(3) if errno is available to report why failed - let fail prior to daemon(3) if opening a nbd file is likely to fail after daemonizing to avoid silent failure exit - add missing 'ret = 1' when unix_socket_outgoing failed Signed-off-by: Ryota Ozaki Signed-off-by: Kevin Wolf --- qemu-nbd.c | 34 ++++++++++++++++++++++++---------- 1 files changed, 24 insertions(+), 10 deletions(-) diff --git a/qemu-nbd.c b/qemu-nbd.c index 25aa913..4e607cf 100644 --- a/qemu-nbd.c +++ b/qemu-nbd.c @@ -112,9 +112,12 @@ static int find_partition(BlockDriverState *bs, int partition, uint8_t data[512]; int i; int ext_partnum = 4; + int ret; - if (bdrv_read(bs, 0, data, 1)) - errx(EXIT_FAILURE, "error while reading"); + if ((ret = bdrv_read(bs, 0, data, 1)) < 0) { + errno = -ret; + err(EXIT_FAILURE, "error while reading"); + } if (data[510] != 0x55 || data[511] != 0xaa) { errno = -EINVAL; @@ -132,8 +135,10 @@ static int find_partition(BlockDriverState *bs, int partition, uint8_t data1[512]; int j; - if (bdrv_read(bs, mbr[i].start_sector_abs, data1, 1)) - errx(EXIT_FAILURE, "error while reading"); + if ((ret = bdrv_read(bs, mbr[i].start_sector_abs, data1, 1)) < 0) { + errno = -ret; + err(EXIT_FAILURE, "error while reading"); + } for (j = 0; j < 4; j++) { read_partition(&data1[446 + 16 * j], &ext[j]); @@ -316,7 +321,7 @@ int main(int argc, char **argv) if (disconnect) { fd = open(argv[optind], O_RDWR); if (fd == -1) - errx(EXIT_FAILURE, "Cannot open %s", argv[optind]); + err(EXIT_FAILURE, "Cannot open %s", argv[optind]); nbd_disconnect(fd); @@ -333,23 +338,30 @@ int main(int argc, char **argv) if (bs == NULL) return 1; - if (bdrv_open(bs, argv[optind], flags, NULL) < 0) - return 1; + if ((ret = bdrv_open(bs, argv[optind], flags, NULL)) < 0) { + errno = -ret; + err(EXIT_FAILURE, "Failed to bdrv_open '%s'", argv[optind]); + } fd_size = bs->total_sectors * 512; if (partition != -1 && find_partition(bs, partition, &dev_offset, &fd_size)) - errx(EXIT_FAILURE, "Could not find partition %d", partition); + err(EXIT_FAILURE, "Could not find partition %d", partition); if (device) { pid_t pid; int sock; + /* want to fail before daemonizing */ + if (access(device, R_OK|W_OK) == -1) { + err(EXIT_FAILURE, "Could not access '%s'", device); + } + if (!verbose) { /* detach client and server */ if (daemon(0, 0) == -1) { - errx(EXIT_FAILURE, "Failed to daemonize"); + err(EXIT_FAILURE, "Failed to daemonize"); } } @@ -372,8 +384,10 @@ int main(int argc, char **argv) do { sock = unix_socket_outgoing(socket); if (sock == -1) { - if (errno != ENOENT && errno != ECONNREFUSED) + if (errno != ENOENT && errno != ECONNREFUSED) { + ret = 1; goto out; + } sleep(1); /* wait children */ } } while (sock == -1);