disk-utils/resizepart.c

   1 #include <getopt.h>
   2 #include <stdio.h>
   3 #include <stdlib.h>
   4 #include <fcntl.h>
   5 #include <sys/types.h>
   6 #include <sys/stat.h>
   7 #include <unistd.h>
   8
   9 #include "c.h"
  10 #include "nls.h"
  11 #include "partx.h"
  12 #include "sysfs.h"
  13 #include "strutils.h"
  14 #include "closestream.h"
  15
  16 static void __attribute__((__noreturn__)) usage(void)
  17 {
  18         FILE *out = stdout;
  19         fputs(USAGE_HEADER, out);
  20         fprintf(out, _(" %s <disk device> <partition number> <length>\n"),
  21                 program_invocation_short_name);
  22
  23         fputs(USAGE_SEPARATOR, out);
  24         fputs(_("Tell the kernel about the new size of a partition.\n"), out);
  25
  26         fputs(USAGE_OPTIONS, out);
  27         printf(USAGE_HELP_OPTIONS(16));
  28         printf(USAGE_MAN_TAIL("resizepart(8)"));
  29         exit(EXIT_SUCCESS);
  30 }
  31
  32 static int get_partition_start(int fd, int partno, uint64_t *start)
  33 {
  34         struct stat st;
  35         struct sysfs_cxt disk = UL_SYSFSCXT_EMPTY,
  36                          part = UL_SYSFSCXT_EMPTY;
  37         dev_t devno = 0;
  38         int rc = -1;
  39
  40         /*
  41          * wholedisk
  42          */
  43         if (fstat(fd, &st) || !S_ISBLK(st.st_mode))
  44                 goto done;
  45         devno = st.st_rdev;
  46         if (sysfs_init(&disk, devno, NULL))
  47                 goto done;
  48         /*
  49          * partition
  50          */
  51         devno = sysfs_partno_to_devno(&disk, partno);
  52         if (!devno)
  53                 goto done;
  54         if (sysfs_init(&part, devno, &disk))
  55                 goto done;
  56         if (sysfs_read_u64(&part, "start", start))
  57                 goto done;
  58
  59         rc = 0;
  60 done:
  61         sysfs_deinit(&part);
  62         sysfs_deinit(&disk);
  63         return rc;
  64 }
  65
  66 int main(int argc, char **argv)
  67 {
  68         int c, fd, partno;
  69         const char *wholedisk;
  70         uint64_t start;
  71
  72         static const struct option longopts[] = {
  73                 {"help", no_argument, NULL, 'h'},
  74                 {"version", no_argument, NULL, 'V'},
  75                 {NULL, 0, NULL, '0'},
  76         };
  77
  78         setlocale(LC_ALL, "");
  79         bindtextdomain(PACKAGE, LOCALEDIR);
  80         textdomain(PACKAGE);
  81         atexit(close_stdout);
  82
  83         while ((c = getopt_long(argc, argv, "Vh", longopts, NULL)) != -1)
  84                 switch (c) {
  85                 case 'V':
  86                         printf(UTIL_LINUX_VERSION);
  87                         return EXIT_SUCCESS;
  88                 case 'h':
  89                         usage();
  90                 default:
  91                         errtryhelp(EXIT_FAILURE);
  92                 }
  93
  94         if (argc != 4) {
  95                 warnx(_("not enough arguments"));
  96                 errtryhelp(EXIT_FAILURE);
  97         }
  98
  99         wholedisk = argv[1];
 100         partno = strtou32_or_err(argv[2], _("invalid partition number argument"));
 101
 102         if ((fd = open(wholedisk, O_RDONLY)) < 0)
 103                 err(EXIT_FAILURE, _("cannot open %s"), wholedisk);
 104
 105         if (get_partition_start(fd, partno, &start))
 106                 err(EXIT_FAILURE, _("%s: failed to get start of the partition number %s"),
 107                                 wholedisk, argv[2]);
 108
 109         if (partx_resize_partition(fd, partno, start,
 110                         strtou64_or_err(argv[3], _("invalid length argument"))))
 111                 err(EXIT_FAILURE, _("failed to resize partition"));
 112
 113         if (close_fd(fd) != 0)
 114                 err(EXIT_FAILURE, _("write failed"));
 115
 116         return 0;
 117 }