src/hibernate-resume/hibernate-resume.c

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