106 lines
2.8 KiB
C
106 lines
2.8 KiB
C
/* vi: set sw=4 ts=4: */
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/*
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* mountpoint implementation for busybox
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*
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* Copyright (C) 2005 Bernhard Reutner-Fischer
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*
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* Licensed under GPLv2 or later, see file LICENSE in this source tree.
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*
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* Based on sysvinit's mountpoint
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*/
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//config:config MOUNTPOINT
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//config: bool "mountpoint (4.5 kb)"
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//config: default y
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//config: help
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//config: mountpoint checks if the directory is a mountpoint.
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//applet:IF_MOUNTPOINT(APPLET(mountpoint, BB_DIR_BIN, BB_SUID_DROP))
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//kbuild:lib-$(CONFIG_MOUNTPOINT) += mountpoint.o
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//usage:#define mountpoint_trivial_usage
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//usage: "[-q] <[-dn] DIR | -x DEVICE>"
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//usage:#define mountpoint_full_usage "\n\n"
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//usage: "Check if the directory is a mountpoint\n"
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//usage: "\n -q Quiet"
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//usage: "\n -d Print major/minor device number of the filesystem"
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//usage: "\n -n Print device name of the filesystem"
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//usage: "\n -x Print major/minor device number of the blockdevice"
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//usage:
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//usage:#define mountpoint_example_usage
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//usage: "$ mountpoint /proc\n"
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//usage: "/proc is not a mountpoint\n"
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//usage: "$ mountpoint /sys\n"
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//usage: "/sys is a mountpoint\n"
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#include "libbb.h"
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int mountpoint_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
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int mountpoint_main(int argc UNUSED_PARAM, char **argv)
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{
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struct stat st;
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const char *msg;
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char *arg;
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int rc, opt;
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opt_complementary = "=1"; /* must have one argument */
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opt = getopt32(argv, "qdxn");
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#define OPT_q (1)
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#define OPT_d (2)
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#define OPT_x (4)
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#define OPT_n (8)
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arg = argv[optind];
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msg = "%s";
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rc = (opt & OPT_x) ? stat(arg, &st) : lstat(arg, &st);
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if (rc != 0)
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goto err;
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if (opt & OPT_x) {
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if (S_ISBLK(st.st_mode)) {
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printf("%u:%u\n", major(st.st_rdev),
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minor(st.st_rdev));
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return EXIT_SUCCESS;
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}
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errno = 0; /* make perror_msg work as error_msg */
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msg = "%s: not a block device";
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goto err;
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}
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errno = ENOTDIR;
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if (S_ISDIR(st.st_mode)) {
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dev_t st_dev = st.st_dev;
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ino_t st_ino = st.st_ino;
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char *p = xasprintf("%s/..", arg);
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if (stat(p, &st) == 0) {
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//int is_mnt = (st_dev != st.st_dev) || (st_dev == st.st_dev && st_ino == st.st_ino);
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int is_not_mnt = (st_dev == st.st_dev) && (st_ino != st.st_ino);
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if (opt & OPT_d)
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printf("%u:%u\n", major(st_dev), minor(st_dev));
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if (opt & OPT_n) {
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const char *d = find_block_device(arg);
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/* name is undefined, but device is mounted -> anonymous superblock! */
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/* happens with btrfs */
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if (!d) {
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d = "UNKNOWN";
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/* TODO: iterate /proc/mounts, or /proc/self/mountinfo
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* to find out the device name */
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}
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printf("%s %s\n", d, arg);
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}
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if (!(opt & (OPT_q | OPT_d | OPT_n)))
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printf("%s is %sa mountpoint\n", arg, is_not_mnt ? "not " : "");
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return is_not_mnt;
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}
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arg = p;
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/* else: stat had set errno, just fall through */
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}
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err:
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if (!(opt & OPT_q))
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bb_perror_msg(msg, arg);
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return EXIT_FAILURE;
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}
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