source: MondoRescue/branches/3.3/mindi-busybox/util-linux/fstrim.c@ 3621

/* vi: set sw=4 ts=4: */
/*
 * fstrim.c - discard the part (or whole) of mounted filesystem.
 *
 * 03 March 2012 - Malek Degachi <malek-degachi@laposte.net>
 * Adapted for busybox from util-linux-2.12a.
 *
 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
 */

//config:config FSTRIM
//config:   bool "fstrim"
//config:   default y
//config:   select PLATFORM_LINUX
//config:   help
//config:     Discard unused blocks on a mounted filesystem.

//applet:IF_FSTRIM(APPLET(fstrim, BB_DIR_SBIN, BB_SUID_DROP))

//kbuild:lib-$(CONFIG_FSTRIM) += fstrim.o

//usage:#define fstrim_trivial_usage
//usage:       "[OPTIONS] MOUNTPOINT"
//usage:#define fstrim_full_usage "\n\n"
//usage:    IF_LONG_OPTS(
//usage:       "    -o,--offset=OFFSET  Offset in bytes to discard from"
//usage:     "\n    -l,--length=LEN     Bytes to discard"
//usage:     "\n    -m,--minimum=MIN    Minimum extent length"
//usage:     "\n    -v,--verbose        Print number of discarded bytes"
//usage:    )
//usage:    IF_NOT_LONG_OPTS(
//usage:       "    -o OFFSET   Offset in bytes to discard from"
//usage:     "\n    -l LEN      Bytes to discard"
//usage:     "\n    -m MIN      Minimum extent length"
//usage:     "\n    -v      Print number of discarded bytes"
//usage:    )

#include "libbb.h"
#include <linux/fs.h>

#ifndef FITRIM
struct fstrim_range {
    uint64_t start;
    uint64_t len;
    uint64_t minlen;
};
#define FITRIM      _IOWR('X', 121, struct fstrim_range)
#endif

static const struct suffix_mult fstrim_sfx[] = {
    { "KiB", 1024 },
    { "kiB", 1024 },
    { "K", 1024 },
    { "k", 1024 },
    { "MiB", 1048576 },
    { "miB", 1048576 },
    { "M", 1048576 },
    { "m", 1048576 },
    { "GiB", 1073741824 },
    { "giB", 1073741824 },
    { "G", 1073741824 },
    { "g", 1073741824 },
    { "KB", 1000 },
    { "MB", 1000000 },
    { "GB", 1000000000 },
    { "", 0 }
};

int fstrim_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int fstrim_main(int argc UNUSED_PARAM, char **argv)
{
    struct fstrim_range range;
    char *arg_o, *arg_l, *arg_m, *mp;
    unsigned opts;
    int fd;

    enum {
        OPT_o = (1 << 0),
        OPT_l = (1 << 1),
        OPT_m = (1 << 2),
        OPT_v = (1 << 3),
    };

#if ENABLE_LONG_OPTS
    static const char getopt_longopts[] ALIGN1 =
        "offset\0"    Required_argument    "o"
        "length\0"    Required_argument    "l"
        "minimum\0"   Required_argument    "m"
        "verbose\0"   No_argument          "v"
        ;
    applet_long_options = getopt_longopts;
#endif

    opt_complementary = "=1"; /* exactly one non-option arg: the mountpoint */
    opts = getopt32(argv, "o:l:m:v", &arg_o, &arg_l, &arg_m);

    memset(&range, 0, sizeof(range));
    range.len = ULLONG_MAX;

    if (opts & OPT_o)
        range.start = xatoull_sfx(arg_o, fstrim_sfx);
    if (opts & OPT_l)
        range.len = xatoull_sfx(arg_l, fstrim_sfx);
    if (opts & OPT_m)
        range.minlen = xatoull_sfx(arg_m, fstrim_sfx);

    mp = argv[optind];
    if (find_block_device(mp)) {
        fd = xopen_nonblocking(mp);
        xioctl(fd, FITRIM, &range);
        if (ENABLE_FEATURE_CLEAN_UP)
            close(fd);

        if (opts & OPT_v)
            printf("%s: %llu bytes trimmed\n", mp, (unsigned long long)range.len);
        return EXIT_SUCCESS;
    }
    return EXIT_FAILURE;
}