release/src/router/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
  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 MOUNT_CNT] "
  32 //usage:       "[-i DAYS] "
  33 //usage:       "[-L LABEL] "
  34 //usage:       "BLOCKDEV"
  35 //usage:
  36 //usage:#define tune2fs_full_usage "\n\n"
  37 //usage:       "Adjust filesystem options on ext[23] filesystems"
  38 //applet:IF_E2LABEL(APPLET_ODDNAME(e2label, tune2fs, BB_DIR_SBIN, BB_SUID_DROP, tune2fs))
  39
  40 enum {
  41         OPT_L = 1 << 0, // label
  42         OPT_c = 1 << 1, // max mount count
  43         OPT_i = 1 << 2, // check interval
  44 };
  45
  46 int tune2fs_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
  47 int tune2fs_main(int argc UNUSED_PARAM, char **argv)
  48 {
  49         unsigned opts;
  50         const char *label, *str_c, *str_i;
  51         struct ext2_super_block *sb;
  52         int fd;
  53
  54         opt_complementary = "=1";
  55         opts = getopt32(argv, "L:c:i:", &label, &str_c, &str_i);
  56         if (!opts)
  57                 bb_show_usage();
  58         argv += optind; // argv[0] -- device
  59
  60         // read superblock
  61         fd = xopen(argv[0], O_RDWR);
  62         xlseek(fd, 1024, SEEK_SET);
  63         sb = xzalloc(1024);
  64         xread(fd, sb, 1024);
  65
  66         // mangle superblock
  67         //STORE_LE(sb->s_wtime, time(NULL)); - why bother?
  68
  69         // set the label
  70         if (opts & OPT_L)
  71                 safe_strncpy((char *)sb->s_volume_name, label, sizeof(sb->s_volume_name));
  72
  73         if (opts & OPT_c) {
  74                 int n = xatoi_range(str_c, -1, 0xfffe);
  75                 if (n == 0)
  76                         n = -1;
  77                 STORE_LE(sb->s_max_mnt_count, (unsigned)n);
  78         }
  79
  80         if (opts & OPT_i) {
  81                 unsigned n = xatou_range(str_i, 0, (unsigned)0xffffffff / (24*60*60)) * 24*60*60;
  82                 STORE_LE(sb->s_checkinterval, n);
  83         }
  84
  85         // write superblock
  86         xlseek(fd, 1024, SEEK_SET);
  87         xwrite(fd, sb, 1024);
  88
  89         if (ENABLE_FEATURE_CLEAN_UP) {
  90                 free(sb);
  91         }
  92
  93         xclose(fd);
  94         return EXIT_SUCCESS;
  95 }