disk-utils/resizepart.c

   1 /*
   2  * SPDX-License-Identifier: GPL-2.0-or-later
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation; either version 2 of the License, or
   7  * (at your option) any later version.
   8  *
   9  * Copyright (C) 2012 Karel Zak <kzak@redhat.com>
  10  */
  11 #include <getopt.h>
  12 #include <stdio.h>
  13 #include <stdlib.h>
  14 #include <fcntl.h>
  15 #include <sys/types.h>
  16 #include <sys/stat.h>
  17 #include <unistd.h>
  18
  19 #include "c.h"
  20 #include "nls.h"
  21 #include "partx.h"
  22 #include "sysfs.h"
  23 #include "strutils.h"
  24 #include "closestream.h"
  25
  26 static void __attribute__((__noreturn__)) usage(void)
  27 {
  28         FILE *out = stdout;
  29         fputs(USAGE_HEADER, out);
  30         fprintf(out, _(" %s <disk device> <partition number> <length>\n"),
  31                 program_invocation_short_name);
  32
  33         fputs(USAGE_SEPARATOR, out);
  34         fputs(_("Tell the kernel about the new size of a partition.\n"), out);
  35
  36         fputs(USAGE_OPTIONS, out);
  37         fprintf(out, USAGE_HELP_OPTIONS(16));
  38         fprintf(out, USAGE_MAN_TAIL("resizepart(8)"));
  39         exit(EXIT_SUCCESS);
  40 }
  41
  42 static int get_partition_start(int fd, int partno, uint64_t *start)
  43 {
  44         struct stat st;
  45         struct path_cxt *disk = NULL, *part = NULL;
  46         dev_t devno = 0;
  47         int rc = -1;
  48
  49         /*
  50          * wholedisk
  51          */
  52         if (fstat(fd, &st) || !S_ISBLK(st.st_mode))
  53                 goto done;
  54         devno = st.st_rdev;
  55         disk = ul_new_sysfs_path(devno, NULL, NULL);
  56         if (!disk)
  57                 goto done;
  58         /*
  59          * partition
  60          */
  61         devno = sysfs_blkdev_partno_to_devno(disk, partno);
  62         if (!devno)
  63                 goto done;
  64
  65         part = ul_new_sysfs_path(devno, disk, NULL);
  66         if (!part)
  67                 goto done;
  68         if (ul_path_read_u64(part, start, "start"))
  69                 goto done;
  70
  71         rc = 0;
  72 done:
  73         ul_unref_path(part);
  74         ul_unref_path(disk);
  75         return rc;
  76 }
  77
  78 int main(int argc, char **argv)
  79 {
  80         int c, fd, partno;
  81         const char *wholedisk;
  82         uint64_t start;
  83
  84         static const struct option longopts[] = {
  85                 {"help", no_argument, NULL, 'h'},
  86                 {"version", no_argument, NULL, 'V'},
  87                 {NULL, 0, NULL, '0'},
  88         };
  89
  90         setlocale(LC_ALL, "");
  91         bindtextdomain(PACKAGE, LOCALEDIR);
  92         textdomain(PACKAGE);
  93         close_stdout_atexit();
  94
  95         while ((c = getopt_long(argc, argv, "Vh", longopts, NULL)) != -1)
  96                 switch (c) {
  97                 case 'V':
  98                         print_version(EXIT_SUCCESS);
  99                 case 'h':
 100                         usage();
 101                 default:
 102                         errtryhelp(EXIT_FAILURE);
 103                 }
 104
 105         if (argc != 4) {
 106                 warnx(_("not enough arguments"));
 107                 errtryhelp(EXIT_FAILURE);
 108         }
 109
 110         wholedisk = argv[1];
 111         partno = strtou32_or_err(argv[2], _("invalid partition number argument"));
 112
 113         if ((fd = open(wholedisk, O_RDONLY)) < 0)
 114                 err(EXIT_FAILURE, _("cannot open %s"), wholedisk);
 115
 116         if (get_partition_start(fd, partno, &start))
 117                 err(EXIT_FAILURE, _("%s: failed to get start of the partition number %s"),
 118                                 wholedisk, argv[2]);
 119
 120         if (partx_resize_partition(fd, partno, start,
 121                         strtou64_or_err(argv[3], _("invalid length argument"))))
 122                 err(EXIT_FAILURE, _("failed to resize partition"));
 123
 124         if (close_fd(fd) != 0)
 125                 err(EXIT_FAILURE, _("write failed"));
 126
 127         return 0;
 128 }