libmount: add new exprimental umount(8)

Signed-off-by: Karel Zak <kzak@redhat.com>

1 files changed, 253 insertions, 0 deletions

diff --git a/libmount/samples/umount.c b/libmount/samples/umount.c
new file mode 100644
index 000000000..c9b1da308
--- /dev/null
+++ b/libmount/samples/umount.c
@@ -0,0 +1,253 @@
+/*
+ * umount(8) -- mount a filesystem
+ *
+ * Copyright (C) 2011 Red Hat, Inc. All rights reserved.
+ * Written by Karel Zak <kzak@redhat.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it would be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <errno.h>
+#include <string.h>
+#include <getopt.h>
+#include <unistd.h>
+#include <sys/types.h>
+
+#include <libmount.h>
+
+#include "nls.h"
+#include "c.h"
+#include "env.h"
+#include "optutils.h"
+
+static int table_parser_errcb(struct libmnt_table *tb __attribute__((__unused__)),
+			const char *filename, int line)
+{
+	if (filename)
+		warnx(_("%s: parse error: ignore entry at line %d."),
+							filename, line);
+	return 0;
+}
+
+static void __attribute__((__noreturn__)) print_version(void)
+{
+	const char *ver = NULL;
+
+	mnt_get_library_version(&ver);
+
+	printf(_("%s from %s (libmount %s)\n"),
+			program_invocation_short_name, PACKAGE_STRING, ver);
+	exit(EXIT_SUCCESS);
+}
+
+static void __attribute__((__noreturn__)) usage(FILE *out)
+{
+	fputs(USAGE_HEADER, out);
+	fprintf(out, _(
+		" %1$s [-hV]\n"
+		" %1$s -a [options]\n"
+		" %1$s [options] <source> | <directory>\n"),
+		program_invocation_short_name);
+
+	fputs(USAGE_OPTIONS, out);
+	fprintf(out, _(
+	" -a, --all               mount all filesystems mentioned in fstab\n"
+	" -c, --no-canonicalize   don't canonicalize paths\n"
+	" -d, --detach-loop       if mounted loop device, also free this loop device\n"
+	"     --fake              dry run; skip the umount(2) syscall\n"
+	" -f, --force             force unmount (in case of an unreachable NFS system)\n"));
+	fprintf(out, _(
+	" -i, --internal-only     don't call the umount.<type> helpers\n"
+	" -n, --no-mtab           don't write to /etc/mtab\n"
+	" -l, --lazy              detach the filesystem now, and cleanup all later\n"));
+	fprintf(out, _(
+	" -O, --test-opts <list>  limit the set of filesystems (use with -a)\n"
+	" -r, --read-only         In case unmounting fails, try to remount read-only\n"
+	" -t, --types <list>      limit the set of filesystem types\n"
+	" -v, --verbose           say what is being done\n"));
+
+	fputs(USAGE_SEPARATOR, out);
+	fputs(USAGE_HELP, out);
+	fputs(USAGE_VERSION, out);
+	fprintf(out, USAGE_MAN_TAIL("umount(8)"));
+
+	exit(out == stderr ? EXIT_FAILURE : EXIT_SUCCESS);
+}
+
+static void __attribute__((__noreturn__)) exit_non_root(const char *option)
+{
+	const uid_t ruid = getuid();
+	const uid_t euid = geteuid();
+
+	if (ruid == 0 && euid != 0) {
+		/* user is root, but setuid to non-root */
+		if (option)
+			errx(EXIT_FAILURE,
+				_("only root can use \"--%s\" option "
+				 "(effective UID is %u)"),
+					option, euid);
+		errx(EXIT_FAILURE, _("only root can do that "
+				 "(effective UID is %u)"), euid);
+	}
+	if (option)
+		errx(EXIT_FAILURE, _("only root can use \"--%s\" option"), option);
+	errx(EXIT_FAILURE, _("only root can do that"));
+}
+
+static int umount_all(struct libmnt_context *cxt __attribute__((__unused__)))
+{
+	return -1;	/* TODO */
+}
+
+static int umount_one(struct libmnt_context *cxt, const char *spec)
+{
+	int rc;
+
+	if (!spec)
+		return -EINVAL;
+
+	if (mnt_context_set_target(cxt, spec))
+		err(EXIT_FAILURE, _("failed to set umount target"));
+
+	rc = mnt_context_umount(cxt);
+	if (rc)
+		/* TODO mnt_context_strerror() */
+		warnx(_("%s: umount failed"), spec);
+
+	mnt_reset_context(cxt);
+	return rc;
+}
+
+int main(int argc, char **argv)
+{
+	int c, rc, all = 0;
+	struct libmnt_context *cxt;
+	char *types = NULL;
+
+	enum {
+		UMOUNT_OPT_FAKE = CHAR_MAX + 1,
+	};
+
+	static const struct option longopts[] = {
+		{ "all", 0, 0, 'a' },
+		{ "detach-loop", 0, 0, 'd' },
+		{ "fake", 0, 0, UMOUNT_OPT_FAKE },
+		{ "force", 0, 0, 'f' },
+		{ "help", 0, 0, 'h' },
+		{ "internal-only", 0, 0, 'i' },
+		{ "lazy", 0, 0, 'l' },
+		{ "no-canonicalize", 0, 0, 'c' },
+		{ "no-mtab", 0, 0, 'n' },
+		{ "read-only", 0, 0, 'r' },
+		{ "test-opts", 1, 0, 'O' },
+		{ "types", 1, 0, 't' },
+		{ "verbose", 0, 0, 'v' },
+		{ "version", 0, 0, 'V' },
+		{ NULL, 0, 0, 0 }
+	};
+
+	sanitize_env();
+	setlocale(LC_ALL, "");
+	bindtextdomain(PACKAGE, LOCALEDIR);
+	textdomain(PACKAGE);
+
+	mnt_init_debug(0);
+	cxt = mnt_new_context();
+	if (!cxt)
+		err(EXIT_FAILURE, _("libmount context allocation failed"));
+
+	mnt_context_set_tables_errcb(cxt, table_parser_errcb);
+
+	while ((c = getopt_long(argc, argv, "acdfhilnrO:t:vV",
+					longopts, NULL)) != -1) {
+
+
+		/* only few options are allowed for non-root users */
+		if (mnt_context_is_restricted(cxt) && !strchr("hdilVv", c))
+			exit_non_root(option_to_longopt(c, longopts));
+
+		switch(c) {
+		case 'a':
+			all = 1;
+			break;
+		case 'c':
+			mnt_context_disable_canonicalize(cxt, TRUE);
+			break;
+		case 'd':
+			mnt_context_enable_loopdel(cxt, TRUE);
+			break;
+		case UMOUNT_OPT_FAKE:
+			mnt_context_enable_fake(cxt, TRUE);
+			break;
+		case 'f':
+			mnt_context_enable_force(cxt, TRUE);
+			break;
+		case 'h':
+			usage(stdout);
+			break;
+		case 'i':
+			mnt_context_disable_helpers(cxt, TRUE);
+			break;
+		case 'l':
+			mnt_context_enable_lazy(cxt, TRUE);
+			break;
+		case 'n':
+			mnt_context_disable_mtab(cxt, TRUE);
+			break;
+		case 'r':
+			mnt_context_enable_rdonly_umount(cxt, TRUE);
+			break;
+		case 'O':
+			if (mnt_context_set_options_pattern(cxt, optarg))
+				err(EXIT_FAILURE, _("failed to set options pattern"));
+			break;
+		case 't':
+			types = optarg;
+			break;
+		case 'v':
+			mnt_context_enable_verbose(cxt, TRUE);
+			break;
+		case 'V':
+			print_version();
+			break;
+		default:
+			usage(stderr);
+			break;
+		}
+	}
+
+	argc -= optind;
+	argv += optind;
+
+	if (all) {
+		if (!types)
+			types = "noproc,nodevfs,nodevpts,nosysfs,norpc_pipefs,nonfsd";
+
+		mnt_context_set_fstype_pattern(cxt, types);
+		rc = umount_all(cxt);
+
+	} else if (argc < 1) {
+		usage(stderr);
+
+	} else while (argc--) {
+		rc += umount_one(cxt, *argv++);
+	}
+
+	mnt_free_context(cxt);
+	return rc ? EXIT_FAILURE : EXIT_SUCCESS;
+}
+