findmnt: add new command

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

4 files changed, 436 insertions, 1 deletions

diff --git a/include/pathnames.h b/include/pathnames.h
index 7d57c528..c0572954 100644
--- a/include/pathnames.h
+++ b/include/pathnames.h
@@ -79,6 +79,7 @@
 #define _PATH_PROC_MOUNTS	"/proc/mounts"
 #define _PATH_PROC_PARTITIONS	"/proc/partitions"
 #define _PATH_PROC_DEVICES	"/proc/devices"
+#define _PATH_PROC_MOUNTINFO	"/proc/self/mountinfo"
 
 #define _PATH_SYS_BLOCK		"/sys/block"
 
diff --git a/misc-utils/.gitignore b/misc-utils/.gitignore
index 5d34a50d..a39caaf3 100644
--- a/misc-utils/.gitignore
+++ b/misc-utils/.gitignore
@@ -17,3 +17,4 @@ uuidd
 findfs
 blkid
 wipefs
+findmnt
diff --git a/misc-utils/Makefile.am b/misc-utils/Makefile.am
index c98107d6..218a2103 100644
--- a/misc-utils/Makefile.am
+++ b/misc-utils/Makefile.am
@@ -34,7 +34,7 @@ endif
 endif
 
 if BUILD_LIBBLKID
-sbin_PROGRAMS += blkid findfs wipefs
+sbin_PROGRAMS += blkid findfs wipefs findmnt
 dist_man_MANS += blkid.8 findfs.8 wipefs.8
 blkid_SOURCES = blkid.c $(top_srcdir)/lib/ismounted.c \
 		$(top_srcdir)/lib/strtosize.c
@@ -45,6 +45,8 @@ findfs_CFLAGS = $(AM_CFLAGS) -I$(ul_libblkid_incdir)
 wipefs_SOURCES = wipefs.c $(top_srcdir)/lib/strtosize.c
 wipefs_LDADD = $(ul_libblkid_la)
 wipefs_CFLAGS = $(AM_CFLAGS) -I$(ul_libblkid_incdir)
+findmnt_LDADD = $(ul_libmount_la)
+findmnt_CFLAGS = $(AM_CFLAGS) -I$(ul_libmount_incdir)
 if HAVE_STATIC_BLKID
 sbin_PROGRAMS += blkid.static
 blkid_static_SOURCES = $(blkid_SOURCES)
diff --git a/misc-utils/findmnt.c b/misc-utils/findmnt.c
new file mode 100644
index 00000000..04aadb77
--- /dev/null
+++ b/misc-utils/findmnt.c
@@ -0,0 +1,431 @@
+/*
+ * findmnt(8)
+ *
+ * Copyright (C) 2010 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 <err.h>
+#include <unistd.h>
+#include <getopt.h>
+#include <string.h>
+
+#include <mount.h>
+
+#include "pathnames.h"
+#include "nls.h"
+
+/*
+ * Column IDs
+ */
+enum {
+	COL_SOURCE,
+	COL_TARGET,
+	COL_FSTYPE,
+	COL_OPTIONS,
+	COL_ISMOUNTED,
+	COL_LABEL,
+	COL_UUID,
+
+	__NCOLUMNS
+};
+
+/*
+ * Column names
+ */
+const char *colnames[] = {
+	[COL_SOURCE] = "source",
+	[COL_TARGET] = "target",
+	[COL_FSTYPE] = "fstype",
+	[COL_OPTIONS] = "options",
+	[COL_ISMOUNTED] = "mounted",
+	[COL_LABEL] = "label",
+	[COL_UUID] = "uuid"
+};
+
+enum {
+	FL_EVALUATE	= (1 << 1),
+	FL_CANONICALIZE = (1 << 2),
+	FL_FIRSTONLY	= (1 << 3),
+	FL_INVERT	= (1 << 4)
+};
+
+struct match_data {
+	const char *source;
+	const char *target;
+	const char *fstypes;
+	const char *options;
+};
+
+int flags;
+int columns[ __NCOLUMNS ];
+int ncolumns;
+mnt_cache *cache;
+
+/*
+ * converts @name to column ID
+ */
+static int get_column_id(const char *name, size_t namesz)
+{
+	int i;
+
+	for (i = 0; i < __NCOLUMNS; i++) {
+		const char *cn = colnames[i];
+
+		if (!strncmp(name, cn, namesz) && !*(cn + namesz))
+			return i;
+	}
+
+	errx(EXIT_FAILURE, _("unknown column: %*s"), (int) namesz, name);
+	return -1;
+}
+
+/*
+ * parses list of columns from @str and set column IDs to columns[]
+ */
+static int ctl_set_columns(const char *str)
+{
+	const char *begin = NULL, *end = NULL, *p;
+
+	ncolumns = 0;
+
+	if (!str || !*str)
+		return -1;
+
+	p = str;
+	for (; p && *p; p++) {
+		if (!begin)
+			begin = p;		/* begin of the column name */
+		if (*p == ',')
+			end = p;		/* terminate the name */
+		if (*(p + 1) == '\0')
+			end = p + 1;		/* end of string */
+		if (!begin || !end)
+			continue;
+		if (end <= begin)
+			return -1;
+
+		columns[ ncolumns++ ] =	get_column_id(begin, end - begin);
+	}
+	return 0;
+}
+
+static int print_column(mnt_fs *fs, int id)
+{
+	const char *str = NULL;
+
+	if (!fs)
+		return -1;
+
+	switch(id) {
+	case COL_SOURCE:
+		/* dir or dev */
+		str = mnt_fs_get_source(fs);
+
+		if (str && ((flags & FL_EVALUATE) || (flags & FL_CANONICALIZE)))
+			str = mnt_resolve_spec(str, cache);
+		break;
+	case COL_TARGET:
+		str = mnt_fs_get_target(fs);
+		break;
+	case COL_FSTYPE:
+		str = mnt_fs_get_fstype(fs);
+		break;
+	case COL_OPTIONS:
+		str = mnt_fs_get_optstr(fs);
+		break;
+	default:
+		return -1;
+	}
+
+	if (str)
+		printf("%s", str);
+	return 0;
+}
+
+static int print_fs(mnt_fs *fs)
+{
+	int i;
+
+	for (i = 0; i < ncolumns; i++) {
+		print_column(fs, i);
+		printf("\t");
+	}
+	printf("\n");
+	return 0;
+}
+
+static mnt_tab *parse_tabfile(const char *path)
+{
+	mnt_tab *tb = mnt_new_tab(path);
+	if (!tb)
+		return NULL;
+
+	if (mnt_tab_parse_file(tb) != 0)
+		goto err;
+
+	if (mnt_tab_get_nerrs(tb)) {
+		char buf[BUFSIZ];
+		mnt_tab_strerror(tb, buf, sizeof(buf));
+		warnx(_("%s: parse error: %s"), path, buf);
+	}
+	return tb;
+err:
+	mnt_free_tab(tb);
+	err(EXIT_FAILURE, _("can't read: %s"), path);
+
+	return NULL;
+}
+
+static int match_func(mnt_fs *fs, void *data)
+{
+	struct match_data *m = (struct match_data *) data;
+	int rc = flags & FL_INVERT ? 1 : 0;
+
+	/*fprintf(stderr, "source: %s : %s\n", m->source, mnt_fs_get_source(fs));*/
+
+	if (m->target && !mnt_fs_match_target(fs, m->target, cache))
+		return rc;
+	if (m->source && !mnt_fs_match_source(fs, m->source, cache))
+		return rc;
+	if (m->fstypes && !mnt_fs_match_fstype(fs, m->fstypes))
+		return rc;
+	if (m->options && !mnt_fs_match_options(fs, m->options))
+		return rc;
+
+	return !rc;
+}
+
+static inline int is_list_mode(struct match_data *m)
+{
+	return (!m->source && !m->target && !m->fstypes && !m->options);
+}
+
+static inline int is_mount_mode(struct match_data *m, int fl)
+{
+	if (!m->source)
+	       return 0;		/* <devname|TAG=|mountpoint> is required */
+	if (m->fstypes || m->options)
+		return 0;		/* cannot be restricted by -t or -O */
+	if (!(fl & FL_FIRSTONLY))
+		return 0;		/* we have to return the first entry only */
+
+	return 1;			/* ok */
+}
+
+static void __attribute__((__noreturn__)) usage(FILE *out)
+{
+	fprintf(out, _("Usage: %s [options] <spec> [<target>]\n\nOptions:\n"),
+			program_invocation_short_name);
+
+	fprintf(out, _(
+	" -s, --fstab            search in static table of filesystems\n"
+	" -m, --mtab             search in table of mounted filesystems (default)\n"
+	" -k, --kernel           search in kernel (mountinfo) file\n\n"
+
+	" -c, --canonicalize     canonicalize printed paths\n"
+	" -d, --direction <word> search direction - 'forward' or 'backward'\n"
+	" -e, --evaluate         print all TAGs (LABEL/UUID) evaluated\n"
+	" -h, --help             print this help\n"
+	" -i, --invert           invert sense of matching\n"
+        " -l, --first-only       print the first found filesystem only\n"
+	" -o, --output <list>    output columns\n"
+	" -O, --options <list>   limit the set of filesystems by mount options\n"
+	" -t, --types <list>     limit the set of filesystem by FS types\n"));
+
+	fprintf(out, _("\nFor more information see findmnt(1).\n"));
+
+	exit(out == stderr ? EXIT_FAILURE : EXIT_SUCCESS);
+}
+
+int main(int argc, char *argv[])
+{
+	char *tabfile = NULL;
+	int direction = MNT_ITER_FORWARD, ct = 0;
+	mnt_tab *tb;
+	mnt_iter *itr;
+	mnt_fs *fs = NULL;
+	int c;
+	struct match_data mdata_buf, *mdata = &mdata_buf;
+
+	struct option longopts[] = {
+	    { "fstab",        0, 0, 's' },
+	    { "mtab",         0, 0, 'm' },
+	    { "kernel",       0, 0, 'k' },
+	    { "canonicalize", 0, 0, 'c' },
+	    { "direction",    1, 0, 'd' },
+	    { "evaluate",     0, 0, 'e' },
+	    { "help",         0, 0, 'h' },
+	    { "invert",       0, 0, 'i' },
+	    { "first-only",   0, 0, 'l' },
+	    { "output",       0, 0, 'o' },
+	    { "options",      1, 0, 'O' },
+	    { "types",        1, 0, 't' },
+	    { NULL,           0, 0, 0 }
+	};
+
+	setlocale(LC_ALL, "");
+	bindtextdomain(PACKAGE, LOCALEDIR);
+	textdomain(PACKAGE);
+
+	/* default */
+	columns[ncolumns++] = COL_SOURCE;
+	columns[ncolumns++] = COL_TARGET;
+	columns[ncolumns++] = COL_FSTYPE;
+	columns[ncolumns++] = COL_OPTIONS;
+
+	memset(mdata, 0, sizeof(*mdata));
+
+	while ((c = getopt_long(argc, argv, "cd:ehiloO:kmst:", longopts, NULL)) != -1) {
+		switch(c) {
+		case 'c':
+			flags |= FL_CANONICALIZE;
+			break;
+		case 'd':
+			if (!strcmp(optarg, _("forward")))
+				direction = MNT_ITER_FORWARD;
+			else if (!strcmp(optarg, _("backward")))
+				direction = MNT_ITER_BACKWARD;
+			else
+				errx(EXIT_FAILURE,
+					_("uknown direction '%s')"), optarg);
+			break;
+		case 'e':
+			flags |= FL_EVALUATE;
+			break;
+		case 'h':
+			usage(stdout);
+			break;
+		case 'i':
+			flags |= FL_INVERT;
+			break;
+		case 'l':
+			flags |= FL_FIRSTONLY;
+			break;
+		case 'o':
+			ctl_set_columns(optarg);
+			break;
+		case 'O':
+			mdata->options = optarg;
+			break;
+		case 'm':
+			if (tabfile)
+				errx(EXIT_FAILURE, _("--{fstab,mtab,kernel} "
+					"options are mutually exclusive"));
+			tabfile = _PATH_MOUNTED;
+			break;
+		case 's':
+			if (tabfile)
+				errx(EXIT_FAILURE, _("--{fstab,mtab,kernel} "
+					"options are mutually exclusive"));
+			tabfile = _PATH_MNTTAB;
+			break;
+		case 'k':
+			if (tabfile)
+				errx(EXIT_FAILURE, _("--{fstab,mtab,kernel} "
+					"options are mutually exclusive"));
+			tabfile = _PATH_PROC_MOUNTINFO;
+			break;
+		case 't':
+			mdata->fstypes = optarg;
+			break;
+		default:
+			usage(stderr);
+			break;
+		}
+	}
+
+	if (!tabfile)
+		tabfile = _PATH_MOUNTED;
+	if (optind < argc)
+		/* dev, tag or mountpoint */
+		mdata->source = argv[optind++];
+	if (optind < argc)
+		/* mountpoint */
+		mdata->target = argv[optind++];
+
+	tb = parse_tabfile(tabfile);
+	if (!tb)
+		return EXIT_FAILURE;
+
+	itr = mnt_new_iter(direction);
+	if (!itr)
+		err(EXIT_FAILURE, _("failed to initialize libmount iterator"));
+
+	cache = mnt_new_cache();
+	if (!cache)
+		err(EXIT_FAILURE, _("failed to initialize libmount cache"));
+
+	mnt_tab_set_cache(tb, cache);
+
+	if (is_list_mode(mdata)) {
+		/*
+		 * Print whole file
+		 */
+		while(mnt_tab_next_fs(tb, itr, &fs) == 0) {
+			print_fs(fs);
+			ct++;
+			if (flags & FL_FIRSTONLY)
+				break;
+		}
+	} else if (is_mount_mode(mdata, flags)) {
+
+		/*
+		 * Look up for FS in the same way how mount(8) searchs in fstab
+		 *
+		 *   findmnt -l <spec>
+		 */
+		fs = mnt_tab_find_source(tb, mdata->source, direction);
+		if (!fs)
+			fs = mnt_tab_find_target(tb, mdata->source, direction);
+		if (fs) {
+			print_fs(fs);
+			ct++;
+		}
+	} else {
+		/*
+		 * Look up for all matching entries
+		 *
+		 *    findmnt [-l] <source> <target> [-O <options>] [-t <types>]
+		 *    findmnt [-l] <spec> [-O <options>] [-t <types>]
+		 */
+again:
+		while (!mnt_tab_find_next_fs(tb, itr,
+					match_func, (void *) mdata, &fs)) {
+			print_fs(fs);
+			ct++;
+			if (flags & FL_FIRSTONLY)
+				break;
+		}
+		if (!ct && !mdata->target && mdata->source) {
+			/* swap 'spec' and target. */
+			mdata->target = mdata->source;
+			mdata->source = NULL;
+			mnt_reset_iter(itr, direction);
+			goto again;
+		}
+	}
+
+	mnt_free_tab(tb);
+	mnt_free_cache(cache);
+	mnt_free_iter(itr);
+
+	return ct ? EXIT_SUCCESS : 2;
+}