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#include "libbb.h"
  10#include <linux/fs.h>
  11#include <linux/ext2_fs.h>
  12
  13// storage helpers
  14char BUG_wrong_field_size(void);
  15#define STORE_LE(field, value) \
  16do { \
  17        if (sizeof(field) == 4) \
  18                field = SWAP_LE32(value); \
  19        else if (sizeof(field) == 2) \
  20                field = SWAP_LE16(value); \
  21        else if (sizeof(field) == 1) \
  22                field = (value); \
  23        else \
  24                BUG_wrong_field_size(); \
  25} while (0)
  26
  27#define FETCH_LE32(field) \
  28        (sizeof(field) == 4 ? SWAP_LE32(field) : BUG_wrong_field_size())
  29
  30//usage:#define tune2fs_trivial_usage
  31//usage:       "[-c MOUNT_CNT] "
  32////usage:     "[-e errors-behavior] [-g group] "
  33//usage:       "[-i DAYS] "
  34////usage:     "[-j] [-J journal-options] [-l] [-s sparse-flag] "
  35////usage:     "[-m reserved-blocks-percent] [-o [^]mount-options[,...]] "
  36////usage:     "[-r reserved-blocks-count] [-u user] [-C mount-count] "
  37//usage:       "[-L LABEL] "
  38////usage:     "[-M last-mounted-dir] [-O [^]feature[,...]] "
  39////usage:     "[-T last-check-time] [-U UUID] "
  40//usage:       "BLOCKDEV"
  41//usage:
  42//usage:#define tune2fs_full_usage "\n\n"
  43//usage:       "Adjust filesystem options on ext[23] filesystems"
  44
  45enum {
  46        OPT_L = 1 << 0, // label
  47        OPT_c = 1 << 1, // max mount count
  48        OPT_i = 1 << 2, // check interval
  49};
  50
  51int tune2fs_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
  52int tune2fs_main(int argc UNUSED_PARAM, char **argv)
  53{
  54        unsigned opts;
  55        const char *label, *str_c, *str_i;
  56        struct ext2_super_block *sb;
  57        int fd;
  58
  59        opt_complementary = "=1";
  60        opts = getopt32(argv, "L:c:i:", &label, &str_c, &str_i);
  61        if (!opts)
  62                bb_show_usage();
  63        argv += optind; // argv[0] -- device
  64
  65        // read superblock
  66        fd = xopen(argv[0], O_RDWR);
  67        xlseek(fd, 1024, SEEK_SET);
  68        sb = xzalloc(1024);
  69        xread(fd, sb, 1024);
  70
  71        // mangle superblock
  72        //STORE_LE(sb->s_wtime, time(NULL)); - why bother?
  73
  74        // set the label
  75        if (opts & OPT_L)
  76                safe_strncpy((char *)sb->s_volume_name, label, sizeof(sb->s_volume_name));
  77
  78        if (opts & OPT_c) {
  79                int n = xatoi_range(str_c, -1, 0xfffe);
  80                if (n == 0)
  81                        n = -1;
  82                STORE_LE(sb->s_max_mnt_count, (unsigned)n);
  83        }
  84
  85        if (opts & OPT_i) {
  86                unsigned n = xatou_range(str_i, 0, (unsigned)0xffffffff / (24*60*60)) * 24*60*60;
  87                STORE_LE(sb->s_checkinterval, n);
  88        }
  89
  90        // write superblock
  91        xlseek(fd, 1024, SEEK_SET);
  92        xwrite(fd, sb, 1024);
  93
  94        if (ENABLE_FEATURE_CLEAN_UP) {
  95                free(sb);
  96        }
  97
  98        xclose(fd);
  99        return EXIT_SUCCESS;
 100}
 101