diff options
Diffstat (limited to 'sys-utils/mountpoint.c')
| -rw-r--r-- | sys-utils/mountpoint.c | 212 |
1 files changed, 212 insertions, 0 deletions
diff --git a/sys-utils/mountpoint.c b/sys-utils/mountpoint.c new file mode 100644 index 0000000..6ab813d --- /dev/null +++ b/sys-utils/mountpoint.c @@ -0,0 +1,212 @@ +/* + * mountpoint(1) - see if a directory is a mountpoint + * + * This is libmount based reimplementation of the mountpoit(1) + * from sysvinit project. + * + * + * 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., + * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. + */ + +#include <stdio.h> +#include <stdlib.h> +#include <errno.h> +#include <string.h> +#include <getopt.h> +#include <unistd.h> +#include <sys/types.h> +#include <sys/stat.h> + +#include <libmount.h> + +#include "nls.h" +#include "xalloc.h" +#include "c.h" +#include "closestream.h" + +static int quiet; + +static int dir_to_device(const char *spec, dev_t *dev) +{ + struct libmnt_table *tb = mnt_new_table_from_file("/proc/self/mountinfo"); + struct libmnt_fs *fs; + struct libmnt_cache *cache; + int rc = -1; + + if (!tb) { + /* + * Fallback. Traditional way to detect mountpoints. This way + * is independent on /proc, but not able to detect bind mounts. + */ + struct stat pst, st; + char buf[PATH_MAX], *cn; + int len; + + if (stat(spec, &st) != 0) + return -1; + + cn = mnt_resolve_path(spec, NULL); /* canonicalize */ + + len = snprintf(buf, sizeof(buf), "%s/..", cn ? cn : spec); + free(cn); + + if (len < 0 || (size_t) len + 1 > sizeof(buf)) + return -1; + if (stat(buf, &pst) !=0) + return -1; + + if ((st.st_dev != pst.st_dev) || + (st.st_dev == pst.st_dev && st.st_ino == pst.st_ino)) { + *dev = st.st_dev; + return 0; + } + + return -1; + } + + /* to canonicalize all necessary paths */ + cache = mnt_new_cache(); + mnt_table_set_cache(tb, cache); + + fs = mnt_table_find_target(tb, spec, MNT_ITER_BACKWARD); + if (fs && mnt_fs_get_target(fs)) { + *dev = mnt_fs_get_devno(fs); + rc = 0; + } + + mnt_free_table(tb); + mnt_free_cache(cache); + return rc; +} + +static int print_devno(const char *devname, struct stat *st) +{ + struct stat stbuf; + + if (!st && stat(devname, &stbuf) == 0) + st = &stbuf; + if (!st) + return -1; + if (!S_ISBLK(st->st_mode)) { + if (!quiet) + warnx(_("%s: not a block device"), devname); + return -1; + } + printf("%u:%u\n", major(st->st_rdev), minor(st->st_rdev)); + return 0; +} + +static void __attribute__((__noreturn__)) usage(FILE *out) +{ + fputs(USAGE_HEADER, out); + fprintf(out, + _(" %1$s [-qd] /path/to/directory\n" + " %1$s -x /dev/device\n"), program_invocation_short_name); + + fputs(USAGE_OPTIONS, out); + fputs(_(" -q, --quiet quiet mode - don't print anything\n" + " -d, --fs-devno print maj:min device number of the filesystem\n" + " -x, --devno print maj:min device number of the block device\n"), out); + fputs(USAGE_SEPARATOR, out); + fputs(USAGE_HELP, out); + fputs(USAGE_VERSION, out); + fprintf(out, USAGE_MAN_TAIL("mountpoint(1)")); + + exit(out == stderr ? EXIT_FAILURE : EXIT_SUCCESS); +} + +int main(int argc, char **argv) +{ + int c, fs_devno = 0, dev_devno = 0, rc = 0; + char *spec; + struct stat st; + + static const struct option longopts[] = { + { "quiet", 0, 0, 'q' }, + { "fs-devno", 0, 0, 'd' }, + { "devno", 0, 0, 'x' }, + { "help", 0, 0, 'h' }, + { "version", 0, 0, 'V' }, + { NULL, 0, 0, 0 } + }; + + setlocale(LC_ALL, ""); + bindtextdomain(PACKAGE, LOCALEDIR); + textdomain(PACKAGE); + atexit(close_stdout); + + mnt_init_debug(0); + + while ((c = getopt_long(argc, argv, "qdxhV", longopts, NULL)) != -1) { + + switch(c) { + case 'q': + quiet = 1; + break; + case 'd': + fs_devno = 1; + break; + case 'x': + dev_devno = 1; + break; + case 'h': + usage(stdout); + break; + case 'V': + printf(UTIL_LINUX_VERSION); + return EXIT_SUCCESS; + default: + usage(stderr); + break; + } + } + + if (optind + 1 != argc) + usage(stderr); + + spec = argv[optind++]; + + if (stat(spec, &st)) { + if (!quiet) + err(EXIT_FAILURE, "%s", spec); + return EXIT_FAILURE; + } + if (dev_devno) + rc = print_devno(spec, &st); + else { + dev_t src; + + if (!S_ISDIR(st.st_mode)) { + if (!quiet) + errx(EXIT_FAILURE, _("%s: not a directory"), spec); + return EXIT_FAILURE; + } + + if ( dir_to_device(spec, &src)) { + if (!quiet) + printf(_("%s is not a mountpoint\n"), spec); + return EXIT_FAILURE; + } + if (fs_devno) + printf("%u:%u\n", major(src), minor(src)); + else if (!quiet) + printf(_("%s is a mountpoint\n"), spec); + } + + return rc ? EXIT_FAILURE : EXIT_SUCCESS; +} |