busybox/e2fsprogs/tune2fs.c

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/* vi: set sw=4 ts=4: */
/*
* tune2fs: utility to modify EXT2 filesystem
*
* Busybox'ed (2009) by Vladimir Dronnikov <dronnikov@gmail.com>
*
* Licensed under GPLv2, see file LICENSE in this tarball for details.
*/
#include "libbb.h"
#include <linux/fs.h>
#include <linux/ext2_fs.h>
// storage helpers
char BUG_wrong_field_size(void);
#define STORE_LE(field, value) \
do { \
if (sizeof(field) == 4) \
field = SWAP_LE32(value); \
else if (sizeof(field) == 2) \
field = SWAP_LE16(value); \
else if (sizeof(field) == 1) \
field = (value); \
else \
BUG_wrong_field_size(); \
} while (0)
#define FETCH_LE32(field) \
(sizeof(field) == 4 ? SWAP_LE32(field) : BUG_wrong_field_size())
enum {
OPT_L = 1 << 0, // label
};
int tune2fs_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int tune2fs_main(int argc UNUSED_PARAM, char **argv)
{
unsigned opts;
const char *label;
struct ext2_super_block *sb;
int fd;
opt_complementary = "=1";
opts = getopt32(argv, "L:", &label);
argv += optind; // argv[0] -- device
if (!opts)
bb_show_usage();
// read superblock
fd = xopen(argv[0], O_RDWR);
xlseek(fd, 1024, SEEK_SET);
sb = xzalloc(1024);
xread(fd, sb, 1024);
// mangle superblock
//STORE_LE(sb->s_wtime, time(NULL)); - why bother?
// set the label
if (1 /*opts & OPT_L*/)
safe_strncpy((char *)sb->s_volume_name, label, sizeof(sb->s_volume_name));
// write superblock
xlseek(fd, 1024, SEEK_SET);
xwrite(fd, sb, 1024);
if (ENABLE_FEATURE_CLEAN_UP) {
free(sb);
}
xclose(fd);
return EXIT_SUCCESS;
}