From patchwork Sun May 2 21:50:25 2010 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ryota OZAKI X-Patchwork-Id: 51469 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 B8215B7D69 for ; Mon, 3 May 2010 08:01:58 +1000 (EST) Received: from localhost ([127.0.0.1]:55410 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1O8h9X-0006Dx-Oy for incoming@patchwork.ozlabs.org; Sun, 02 May 2010 17:56:43 -0400 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1O8h6X-0005hF-Ka for qemu-devel@nongnu.org; Sun, 02 May 2010 17:53:37 -0400 Received: from [140.186.70.92] (port=55979 helo=eggs.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1O8h6W-0005gy-A8 for qemu-devel@nongnu.org; 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Sun, 02 May 2010 14:53:32 -0700 (PDT) Received: from localhost.localdomain (host105.nvlab.org [122.1.115.105]) by mx.google.com with ESMTPS id f11sm21194706wai.23.2010.05.02.14.53.30 (version=SSLv3 cipher=RC4-MD5); Sun, 02 May 2010 14:53:31 -0700 (PDT) From: Ryota Ozaki To: qemu-devel@nongnu.org Date: Mon, 3 May 2010 06:50:25 +0900 Message-Id: <1272837025-4975-1-git-send-email-ozaki.ryota@gmail.com> X-Mailer: git-send-email 1.6.5.2 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.6 (newer, 2) Subject: [Qemu-devel] [PATCH] 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 - 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 --- 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);