mirror of
https://github.com/libguestfs/libguestfs.git
synced 2026-03-21 22:53:37 +00:00
346 lines
8.8 KiB
C
346 lines
8.8 KiB
C
/* guestunmount
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* Copyright (C) 2013 Red Hat Inc.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
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*/
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#include <config.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <stdint.h>
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#include <stdbool.h>
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#include <inttypes.h>
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#include <string.h>
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#include <unistd.h>
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#include <getopt.h>
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#include <errno.h>
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#include <error.h>
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#include <locale.h>
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#include <libintl.h>
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#include <poll.h>
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#include <limits.h>
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#include <signal.h>
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#include <sys/types.h>
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#include <sys/wait.h>
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#include "guestfs.h"
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#include "guestfs-utils.h"
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#include "ignore-value.h"
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#include "getprogname.h"
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#include "display-options.h"
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static int do_fusermount (const char *mountpoint, char **error_rtn);
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static void do_fuser (const char *mountpoint);
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static bool quiet = false;
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static size_t retries = 5;
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static bool verbose = false;
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static void __attribute__((noreturn))
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usage (int status)
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{
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if (status != EXIT_SUCCESS)
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fprintf (stderr, _("Try ‘%s --help’ for more information.\n"),
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getprogname ());
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else {
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printf (_("%s: clean up a mounted filesystem\n"
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"Copyright (C) 2013 Red Hat Inc.\n"
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"Usage:\n"
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" %s [--fd=FD] mountpoint\n"
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"Options:\n"
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" --fd=FD Pipe file descriptor to monitor\n"
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" --help Display help message and exit\n"
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" -q|--quiet Don't print fusermount errors\n"
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" --no-retry Don't retry fusermount\n"
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" --retry=N Retry fusermount N times (default: 5)\n"
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" -v|--verbose Verbose messages\n"
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" -V|--version Display version and exit\n"
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),
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getprogname (), getprogname ());
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}
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exit (status);
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}
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int
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main (int argc, char *argv[])
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{
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enum { HELP_OPTION = CHAR_MAX + 1 };
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static const char options[] = "qvV";
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static const struct option long_options[] = {
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{ "fd", 1, 0, 0 },
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{ "help", 0, 0, HELP_OPTION },
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{ "quiet", 0, 0, 'q' },
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{ "long-options", 0, 0, 0 },
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{ "no-retry", 0, 0, 0 },
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{ "retry", 1, 0, 0 },
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{ "short-options", 0, 0, 0 },
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{ "verbose", 0, 0, 'v' },
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{ "version", 0, 0, 'V' },
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{ 0, 0, 0, 0 }
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};
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int c, fd = -1;
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int option_index;
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const char *mountpoint;
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struct pollfd pollfd;
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char *error_str = NULL;
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size_t i;
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setlocale (LC_ALL, "");
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bindtextdomain (PACKAGE, LOCALEBASEDIR);
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textdomain (PACKAGE);
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for (;;) {
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c = getopt_long (argc, argv, options, long_options, &option_index);
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if (c == -1) break;
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switch (c) {
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case 0: /* options which are long only */
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if (STREQ (long_options[option_index].name, "long-options"))
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display_long_options (long_options);
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else if (STREQ (long_options[option_index].name, "short-options"))
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display_short_options (options);
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else if (STREQ (long_options[option_index].name, "fd")) {
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if (sscanf (optarg, "%d", &fd) != 1 || fd < 0)
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error (EXIT_FAILURE, 0, _("cannot parse fd option ‘%s’"), optarg);
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} else if (STREQ (long_options[option_index].name, "no-retry")) {
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retries = 0;
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} else if (STREQ (long_options[option_index].name, "retry")) {
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if (sscanf (optarg, "%zu", &retries) != 1 || retries >= 64)
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error (EXIT_FAILURE, 0,
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_("cannot parse retries option or value is too large ‘%s’"),
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optarg);
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} else
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error (EXIT_FAILURE, 0,
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_("unknown long option: %s (%d)"),
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long_options[option_index].name, option_index);
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break;
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case 'q':
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quiet = true;
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break;
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case 'v':
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verbose = true;
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break;
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case 'V':
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printf ("guestunmount %s %s\n", PACKAGE_NAME, PACKAGE_VERSION);
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exit (EXIT_SUCCESS);
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case HELP_OPTION:
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usage (EXIT_SUCCESS);
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default:
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usage (EXIT_FAILURE);
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}
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}
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/* We'd better have a mountpoint. */
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if (optind+1 != argc)
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error (EXIT_FAILURE, 0,
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_("you must specify a mountpoint in the host filesystem\n"));
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mountpoint = argv[optind];
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/* Monitor the pipe until we get POLLHUP. */
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if (fd >= 0) {
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ignore_value (chdir ("/"));
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/* Ignore keyboard signals. */
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sigaction(SIGINT, &(struct sigaction){ .sa_handler = SIG_IGN, .sa_flags = SA_RESTART }, NULL);
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sigaction(SIGQUIT, &(struct sigaction){ .sa_handler = SIG_IGN, .sa_flags = SA_RESTART }, NULL);
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while (1) {
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pollfd.fd = fd;
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pollfd.events = POLLIN;
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pollfd.revents = 0;
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if (poll (&pollfd, 1, -1) == -1) {
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if (errno != EAGAIN && errno != EINTR)
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error (EXIT_FAILURE, errno, "poll");
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}
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else {
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if ((pollfd.revents & POLLHUP) != 0)
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break;
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}
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}
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}
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/* Unmount the filesystem. We may have to try a few times. */
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for (i = 0; i <= retries; ++i) {
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if (i > 0)
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sleep (1 << (i-1));
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free (error_str);
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error_str = NULL;
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if (do_fusermount (mountpoint, &error_str) == 0)
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goto done;
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/* Did fusermount fail because the mountpoint is not mounted? */
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if (error_str &&
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strstr (error_str, "fusermount: entry for") != NULL) {
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goto not_mounted;
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}
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}
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/* fusermount failed after N retries */
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if (!quiet) {
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fprintf (stderr, _("%s: failed to unmount %s: %s\n"),
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getprogname (), mountpoint, error_str);
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do_fuser (mountpoint);
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}
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free (error_str);
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exit (2);
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/* not mounted */
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not_mounted:
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if (!quiet)
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fprintf (stderr, _("%s: %s is not mounted: %s\n"),
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getprogname (), mountpoint, error_str);
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free (error_str);
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exit (3);
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/* success */
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done:
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exit (EXIT_SUCCESS);
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}
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static int
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do_fusermount (const char *mountpoint, char **error_rtn)
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{
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int fd[2];
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pid_t pid;
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int r;
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char *buf = NULL;
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size_t allocsize = 0, len = 0;
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if (pipe (fd) == -1)
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error (EXIT_FAILURE, errno, "pipe");
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if (verbose)
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fprintf (stderr, "%s: running: fusermount -u %s\n",
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getprogname (), mountpoint);
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pid = fork ();
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if (pid == -1)
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error (EXIT_FAILURE, errno, "fork");
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if (pid == 0) { /* Child - run fusermount. */
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close (fd[0]);
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dup2 (fd[1], 1);
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dup2 (fd[1], 2);
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close (fd[1]);
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/* We have to parse error messages from fusermount, so ... */
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setenv ("LC_ALL", "C", 1);
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#ifdef __linux__
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execlp ("fusermount", "fusermount", "-u", mountpoint, NULL);
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#else
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/* use umount where fusermount is not available */
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execlp ("umount", "umount", mountpoint, NULL);
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#endif
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perror ("exec");
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_exit (EXIT_FAILURE);
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}
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/* Parent - read from the pipe any errors etc. */
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close (fd[1]);
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while (1) {
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if (len >= allocsize) {
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allocsize += 256;
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buf = realloc (buf, allocsize);
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if (buf == NULL)
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error (EXIT_FAILURE, errno, "realloc");
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}
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/* Leave space in the buffer for a terminating \0 character. */
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r = read (fd[0], &buf[len], allocsize - len - 1);
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if (r == -1)
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error (EXIT_FAILURE, errno, "read");
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if (r == 0)
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break;
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len += r;
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}
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if (close (fd[0]) == -1)
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error (EXIT_FAILURE, errno, "close");
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if (buf) {
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/* Remove any trailing \n from the error message. */
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while (len > 0 && buf[len-1] == '\n') {
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buf[len-1] = '\0';
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len--;
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}
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/* Make sure the error message is \0 terminated. */
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if (len < allocsize)
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buf[len] = '\0';
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}
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if (waitpid (pid, &r, 0) == -1)
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error (EXIT_FAILURE, errno, "waitpid");
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if (!WIFEXITED (r) || WEXITSTATUS (r) != 0) {
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if (verbose)
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fprintf (stderr, "%s\n", buf);
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*error_rtn = buf;
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return 1; /* fusermount or exec failed */
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}
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if (verbose)
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fprintf (stderr, "%s: fusermount successful\n",
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getprogname ());
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free (buf);
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return 0; /* fusermount successful */
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}
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/* Try running 'fuser' on the mountpoint. This is for information
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* only so don't fail if we can't run it.
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*/
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static void
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do_fuser (const char *mountpoint)
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{
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pid_t pid;
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pid = fork ();
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if (pid == -1)
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error (EXIT_FAILURE, errno, "fork");
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if (pid == 0) { /* Child - run fuser. */
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#ifdef __linux__
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execlp (FUSER, "fuser", "-v", "-m", mountpoint, NULL);
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#else
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execlp (FUSER, "fuser", "-c", mountpoint, NULL);
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#endif
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_exit (EXIT_FAILURE);
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}
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waitpid (pid, NULL, 0);
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}
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