LXR busybox/e2fsprogs/tune2fs.c

   1/* vi: set sw=4 ts=4: */
   2/*
   3 * tune2fs: utility to modify EXT2 filesystem
   4 *
   5 * Busybox'ed (2009) by Vladimir Dronnikov <dronnikov@gmail.com>
   6 *
   7 * Licensed under GPLv2, see file LICENSE in this source tree.
   8 */
   9//config:config TUNE2FS
  10//config:       bool "tune2fs (4.4 kb)"
  11//config:       default n  # off: it is too limited compared to upstream version
  12//config:       help
  13//config:       tune2fs allows the system administrator to adjust various tunable
  14//config:       filesystem parameters on Linux ext2/ext3 filesystems.
  15
  16//applet:IF_TUNE2FS(APPLET_NOEXEC(tune2fs, tune2fs, BB_DIR_SBIN, BB_SUID_DROP, tune2fs))
  17
  18//TODO alias to "tune2fs -L LABEL": //applet:IF_E2LABEL(APPLET_ODDNAME(e2label, tune2fs, BB_DIR_SBIN, BB_SUID_DROP, e2label))
  19
  20//kbuild:lib-$(CONFIG_TUNE2FS) += tune2fs.o
  21
  22//usage:#define tune2fs_trivial_usage
  23//usage:       "[-c MAX_MOUNT_COUNT] "
  24////usage:     "[-e errors-behavior] [-g group] "
  25//usage:       "[-i DAYS] "
  26////usage:     "[-j] [-J journal-options] [-l] [-s sparse-flag] "
  27////usage:     "[-m reserved-blocks-percent] [-o [^]mount-options[,...]] "
  28////usage:     "[-r reserved-blocks-count] [-u user] "
  29//usage:       "[-C MOUNT_COUNT] "
  30//usage:       "[-L LABEL] "
  31////usage:     "[-M last-mounted-dir] [-O [^]feature[,...]] "
  32////usage:     "[-T last-check-time] [-U UUID] "
  33//usage:       "BLOCKDEV"
  34//usage:
  35//usage:#define tune2fs_full_usage "\n\n"
  36//usage:       "Adjust filesystem options on ext[23] filesystems"
  37
  38#include "libbb.h"
  39#include <linux/fs.h>
  40#include "bb_e2fs_defs.h"
  41
  42// storage helpers
  43char BUG_wrong_field_size(void);
  44#define STORE_LE(field, value) \
  45do { \
  46        if (sizeof(field) == 4) \
  47                field = SWAP_LE32(value); \
  48        else if (sizeof(field) == 2) \
  49                field = SWAP_LE16(value); \
  50        else if (sizeof(field) == 1) \
  51                field = (value); \
  52        else \
  53                BUG_wrong_field_size(); \
  54} while (0)
  55
  56#define FETCH_LE32(field) \
  57        (sizeof(field) == 4 ? SWAP_LE32(field) : BUG_wrong_field_size())
  58
  59enum {
  60        OPT_L = 1 << 0, // label
  61        OPT_c = 1 << 1, // max mount count
  62        OPT_i = 1 << 2, // check interval
  63        OPT_C = 1 << 3, // current mount count
  64};
  65
  66int tune2fs_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
  67int tune2fs_main(int argc UNUSED_PARAM, char **argv)
  68{
  69        unsigned opts;
  70        const char *label, *str_c, *str_i, *str_C;
  71        struct ext2_super_block *sb;
  72        int fd;
  73
  74        opts = getopt32(argv, "^" "L:c:i:C:" "\0" "=1", &label, &str_c, &str_i, &str_C);
  75        if (!opts)
  76                bb_show_usage();
  77        argv += optind; // argv[0] -- device
  78
  79        // read superblock
  80        fd = xopen(argv[0], O_RDWR);
  81        xlseek(fd, 1024, SEEK_SET);
  82        sb = xzalloc(1024);
  83        xread(fd, sb, 1024);
  84
  85        // mangle superblock
  86        //STORE_LE(sb->s_wtime, time(NULL)); - why bother?
  87
  88        if (opts & OPT_C) {
  89                int n = xatoi_range(str_C, 1, 0xfffe);
  90                STORE_LE(sb->s_mnt_count, (unsigned)n);
  91        }
  92
  93        // set the label
  94        if (opts & OPT_L)
  95                safe_strncpy((char *)sb->s_volume_name, label, sizeof(sb->s_volume_name));
  96
  97        if (opts & OPT_c) {
  98                int n = xatoi_range(str_c, -1, 0xfffe);
  99                if (n == 0)
 100                        n = -1;
 101                STORE_LE(sb->s_max_mnt_count, (unsigned)n);
 102        }
 103
 104        if (opts & OPT_i) {
 105                unsigned n = xatou_range(str_i, 0, (unsigned)0xffffffff / (24*60*60)) * 24*60*60;
 106                STORE_LE(sb->s_checkinterval, n);
 107        }
 108
 109        // write superblock
 110        xlseek(fd, 1024, SEEK_SET);
 111        xwrite(fd, sb, 1024);
 112
 113        if (ENABLE_FEATURE_CLEAN_UP) {
 114                free(sb);
 115        }
 116
 117        xclose(fd);
 118        return EXIT_SUCCESS;
 119}
 120