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 "bb_e2fs_defs.h"
  12
  13 // storage helpers
  14 char BUG_wrong_field_size(void);
  15 #define STORE_LE(field, value) \
  16 do { \
  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 MAX_MOUNT_COUNT] "
  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] "
  37 //usage:       "[-C MOUNT_COUNT] "
  38 //usage:       "[-L LABEL] "
  39 ////usage:     "[-M last-mounted-dir] [-O [^]feature[,...]] "
  40 ////usage:     "[-T last-check-time] [-U UUID] "
  41 //usage:       "BLOCKDEV"
  42 //usage:
  43 //usage:#define tune2fs_full_usage "\n\n"
  44 //usage:       "Adjust filesystem options on ext[23] filesystems"
  45
  46 enum {
  47         OPT_L = 1 << 0, // label
  48         OPT_c = 1 << 1, // max mount count
  49         OPT_i = 1 << 2, // check interval
  50         OPT_C = 1 << 3, // current mount count
  51 };
  52
  53 int tune2fs_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
  54 int tune2fs_main(int argc UNUSED_PARAM, char **argv)
  55 {
  56         unsigned opts;
  57         const char *label, *str_c, *str_i, *str_C;
  58         struct ext2_super_block *sb;
  59         int fd;
  60
  61         opt_complementary = "=1";
  62         opts = getopt32(argv, "L:c:i:C:", &label, &str_c, &str_i, &str_C);
  63         if (!opts)
  64                 bb_show_usage();
  65         argv += optind; // argv[0] -- device
  66
  67         // read superblock
  68         fd = xopen(argv[0], O_RDWR);
  69         xlseek(fd, 1024, SEEK_SET);
  70         sb = xzalloc(1024);
  71         xread(fd, sb, 1024);
  72
  73         // mangle superblock
  74         //STORE_LE(sb->s_wtime, time(NULL)); - why bother?
  75
  76         if (opts & OPT_C) {
  77                 int n = xatoi_range(str_C, 1, 0xfffe);
  78                 STORE_LE(sb->s_mnt_count, (unsigned)n);
  79         }
  80
  81         // set the label
  82         if (opts & OPT_L)
  83                 safe_strncpy((char *)sb->s_volume_name, label, sizeof(sb->s_volume_name));
  84
  85         if (opts & OPT_c) {
  86                 int n = xatoi_range(str_c, -1, 0xfffe);
  87                 if (n == 0)
  88                         n = -1;
  89                 STORE_LE(sb->s_max_mnt_count, (unsigned)n);
  90         }
  91
  92         if (opts & OPT_i) {
  93                 unsigned n = xatou_range(str_i, 0, (unsigned)0xffffffff / (24*60*60)) * 24*60*60;
  94                 STORE_LE(sb->s_checkinterval, n);
  95         }
  96
  97         // write superblock
  98         xlseek(fd, 1024, SEEK_SET);
  99         xwrite(fd, sb, 1024);
 100
 101         if (ENABLE_FEATURE_CLEAN_UP) {
 102                 free(sb);
 103         }
 104
 105         xclose(fd);
 106         return EXIT_SUCCESS;
 107 }