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 path_cxt *disk = NULL, *part = NULL;
  36         dev_t devno = 0;
  37         int rc = -1;
  38
  39         /*
  40          * wholedisk
  41          */
  42         if (fstat(fd, &st) || !S_ISBLK(st.st_mode))
  43                 goto done;
  44         devno = st.st_rdev;
  45         disk = ul_new_sysfs_path(devno, NULL, NULL);
  46         if (!disk)
  47                 goto done;
  48         /*
  49          * partition
  50          */
  51         devno = sysfs_blkdev_partno_to_devno(disk, partno);
  52         if (!devno)
  53                 goto done;
  54
  55         part = ul_new_sysfs_path(devno, disk, NULL);
  56         if (!part)
  57                 goto done;
  58         if (ul_path_read_u64(part, start, "start"))
  59                 goto done;
  60
  61         rc = 0;
  62 done:
  63         ul_unref_path(part);
  64         ul_unref_path(disk);
  65         return rc;
  66 }
  67
  68 int main(int argc, char **argv)
  69 {
  70         int c, fd, partno;
  71         const char *wholedisk;
  72         uint64_t start;
  73
  74         static const struct option longopts[] = {
  75                 {"help", no_argument, NULL, 'h'},
  76                 {"version", no_argument, NULL, 'V'},
  77                 {NULL, 0, NULL, '0'},
  78         };
  79
  80         setlocale(LC_ALL, "");
  81         bindtextdomain(PACKAGE, LOCALEDIR);
  82         textdomain(PACKAGE);
  83         close_stdout_atexit();
  84
  85         while ((c = getopt_long(argc, argv, "Vh", longopts, NULL)) != -1)
  86                 switch (c) {
  87                 case 'V':
  88                         print_version(EXIT_SUCCESS);
  89                 case 'h':
  90                         usage();
  91                 default:
  92                         errtryhelp(EXIT_FAILURE);
  93                 }
  94
  95         if (argc != 4) {
  96                 warnx(_("not enough arguments"));
  97                 errtryhelp(EXIT_FAILURE);
  98         }
  99
 100         wholedisk = argv[1];
 101         partno = strtou32_or_err(argv[2], _("invalid partition number argument"));
 102
 103         if ((fd = open(wholedisk, O_RDONLY)) < 0)
 104                 err(EXIT_FAILURE, _("cannot open %s"), wholedisk);
 105
 106         if (get_partition_start(fd, partno, &start))
 107                 err(EXIT_FAILURE, _("%s: failed to get start of the partition number %s"),
 108                                 wholedisk, argv[2]);
 109
 110         if (partx_resize_partition(fd, partno, start,
 111                         strtou64_or_err(argv[3], _("invalid length argument"))))
 112                 err(EXIT_FAILURE, _("failed to resize partition"));
 113
 114         if (close_fd(fd) != 0)
 115                 err(EXIT_FAILURE, _("write failed"));
 116
 117         return 0;
 118 }