util-linux/fstrim.c

   1 /* vi: set sw=4 ts=4: */
   2 /*
   3  * fstrim.c - discard the part (or whole) of mounted filesystem.
   4  *
   5  * 03 March 2012 - Malek Degachi <malek-degachi@laposte.net>
   6  * Adapted for busybox from util-linux-2.12a.
   7  *
   8  * Licensed under GPLv2 or later, see file LICENSE in this source tree.
   9  */
  10 //config:config FSTRIM
  11 //config:       bool "fstrim (4.4 kb)"
  12 //config:       default y
  13 //config:       select PLATFORM_LINUX
  14 //config:       help
  15 //config:       Discard unused blocks on a mounted filesystem.
  16
  17 //applet:IF_FSTRIM(APPLET_NOEXEC(fstrim, fstrim, BB_DIR_SBIN, BB_SUID_DROP, fstrim))
  18
  19 //kbuild:lib-$(CONFIG_FSTRIM) += fstrim.o
  20
  21 //usage:#define fstrim_trivial_usage
  22 //usage:       "[OPTIONS] MOUNTPOINT"
  23 //usage:#define fstrim_full_usage "\n\n"
  24 //usage:        IF_LONG_OPTS(
  25 //usage:       "        -o,--offset OFFSET      Offset in bytes to discard from"
  26 //usage:     "\n        -l,--length LEN         Bytes to discard"
  27 //usage:     "\n        -m,--minimum MIN        Minimum extent length"
  28 //usage:     "\n        -v,--verbose            Print number of discarded bytes"
  29 //usage:        )
  30 //usage:        IF_NOT_LONG_OPTS(
  31 //usage:       "        -o OFFSET       Offset in bytes to discard from"
  32 //usage:     "\n        -l LEN          Bytes to discard"
  33 //usage:     "\n        -m MIN          Minimum extent length"
  34 //usage:     "\n        -v              Print number of discarded bytes"
  35 //usage:        )
  36
  37 #include "libbb.h"
  38 #include <linux/fs.h>
  39
  40 #ifndef FITRIM
  41 struct fstrim_range {
  42         uint64_t start;
  43         uint64_t len;
  44         uint64_t minlen;
  45 };
  46 #define FITRIM          _IOWR('X', 121, struct fstrim_range)
  47 #endif
  48
  49 int fstrim_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
  50 int fstrim_main(int argc UNUSED_PARAM, char **argv)
  51 {
  52         struct fstrim_range range;
  53         char *arg_o, *arg_l, *arg_m, *mp;
  54         unsigned opts;
  55         int fd;
  56
  57         enum {
  58                 OPT_o = (1 << 0),
  59                 OPT_l = (1 << 1),
  60                 OPT_m = (1 << 2),
  61                 OPT_v = (1 << 3),
  62         };
  63
  64 #if ENABLE_LONG_OPTS
  65         static const char fstrim_longopts[] ALIGN1 =
  66                 "offset\0"    Required_argument    "o"
  67                 "length\0"    Required_argument    "l"
  68                 "minimum\0"   Required_argument    "m"
  69                 "verbose\0"   No_argument          "v"
  70                 ;
  71 #endif
  72
  73         opts = getopt32long(argv, "^"
  74                         "o:l:m:v"
  75                         "\0" "=1", fstrim_longopts,
  76                         &arg_o, &arg_l, &arg_m
  77         );
  78
  79         memset(&range, 0, sizeof(range));
  80         range.len = ULLONG_MAX;
  81
  82         if (opts & OPT_o)
  83                 range.start = xatoull_sfx(arg_o, kmg_i_suffixes);
  84         if (opts & OPT_l)
  85                 range.len = xatoull_sfx(arg_l, kmg_i_suffixes);
  86         if (opts & OPT_m)
  87                 range.minlen = xatoull_sfx(arg_m, kmg_i_suffixes);
  88
  89         mp = argv[optind];
  90 //Wwhy bother checking that it's a blockdev?
  91 //      if (find_block_device(mp)) {
  92                 fd = xopen_nonblocking(mp);
  93
  94                 /* On ENOTTY error, util-linux 2.31 says:
  95                  * "fstrim: FILE: the discard operation is not supported"
  96                  */
  97                 xioctl(fd, FITRIM, &range);
  98
  99                 if (ENABLE_FEATURE_CLEAN_UP)
 100                         close(fd);
 101
 102                 if (opts & OPT_v)
 103                         printf("%s: %llu bytes trimmed\n", mp, (unsigned long long)range.len);
 104                 return EXIT_SUCCESS;
 105 //      }
 106         return EXIT_FAILURE;
 107 }