src/hibernate-resume/hibernate-resume.c

   1 /* SPDX-License-Identifier: LGPL-2.1+ */
   2 /***
   3   This file is part of systemd.
   4
   5   Copyright 2014 Ivan Shapovalov
   6 ***/
   7
   8 #include <errno.h>
   9 #include <stdio.h>
  10 #include <sys/stat.h>
  11
  12 #include "alloc-util.h"
  13 #include "fileio.h"
  14 #include "log.h"
  15 #include "util.h"
  16
  17 int main(int argc, char *argv[]) {
  18         struct stat st;
  19         const char *device;
  20         _cleanup_free_ char *major_minor = NULL;
  21         int r;
  22
  23         if (argc != 2) {
  24                 log_error("This program expects one argument.");
  25                 return EXIT_FAILURE;
  26         }
  27
  28         log_set_target(LOG_TARGET_AUTO);
  29         log_parse_environment();
  30         log_open();
  31
  32         umask(0022);
  33
  34         /* Refuse to run unless we are in an initrd() */
  35         if (!in_initrd())
  36                 return EXIT_SUCCESS;
  37
  38         device = argv[1];
  39
  40         if (stat(device, &st) < 0) {
  41                 log_error_errno(errno, "Failed to stat '%s': %m", device);
  42                 return EXIT_FAILURE;
  43         }
  44
  45         if (!S_ISBLK(st.st_mode)) {
  46                 log_error("Resume device '%s' is not a block device.", device);
  47                 return EXIT_FAILURE;
  48         }
  49
  50         if (asprintf(&major_minor, "%d:%d", major(st.st_rdev), minor(st.st_rdev)) < 0) {
  51                 log_oom();
  52                 return EXIT_FAILURE;
  53         }
  54
  55         r = write_string_file("/sys/power/resume", major_minor, WRITE_STRING_FILE_CREATE);
  56         if (r < 0) {
  57                 log_error_errno(r, "Failed to write '%s' to /sys/power/resume: %m", major_minor);
  58                 return EXIT_FAILURE;
  59         }
  60
  61         /*
  62          * The write above shall not return.
  63          *
  64          * However, failed resume is a normal condition (may mean that there is
  65          * no hibernation image).
  66          */
  67
  68         log_info("Could not resume from '%s' (%s).", device, major_minor);
  69         return EXIT_SUCCESS;
  70 }