git.sesse.net Git - bcachefs-tools-debian/blob - probe-bcache.c

   1 /*
   2  * Author: Kent Overstreet <kmo@daterainc.com>
   3  *
   4  * GPLv2
   5  */
   6
   7 #define _FILE_OFFSET_BITS       64
   8 #define __USE_FILE_OFFSET64
   9 #define _XOPEN_SOURCE 500
  10
  11 #include <blkid/blkid.h>
  12 #include <fcntl.h>
  13 #include <linux/fs.h>
  14 #include <stdbool.h>
  15 #include <stdint.h>
  16 #include <stdio.h>
  17 #include <stdlib.h>
  18 #include <string.h>
  19 #include <sys/ioctl.h>
  20 #include <sys/types.h>
  21 #include <sys/stat.h>
  22 #include <unistd.h>
  23 #include <uuid/uuid.h>
  24
  25 #include "bcache.h"
  26
  27 int main(int argc, char **argv)
  28 {
  29         bool udev = false;
  30         int i, o;
  31         extern char *optarg;
  32         struct cache_sb sb;
  33         char uuid[40];
  34         blkid_probe pr;
  35
  36         while ((o = getopt(argc, argv, "o:")) != EOF)
  37                 switch (o) {
  38                 case 'o':
  39                         if (strcmp("udev", optarg)) {
  40                                 printf("Invalid output format %s\n", optarg);
  41                                 exit(EXIT_FAILURE);
  42                         }
  43                         udev = true;
  44                         break;
  45                 }
  46
  47
  48         argv += optind;
  49         argc -= optind;
  50
  51         for (i = 0; i < argc; i++) {
  52                 int fd = open(argv[i], O_RDONLY);
  53                 if (fd == -1)
  54                         continue;
  55
  56                 if (!(pr = blkid_new_probe()))
  57                         continue;
  58                 if (blkid_probe_set_device(pr, fd, 0, 0))
  59                         continue;
  60                 /* probe partitions too */
  61                 if (blkid_probe_enable_partitions(pr, true))
  62                         continue;
  63                 /* bail if anything was found
  64                  * probe-bcache isn't needed once blkid recognizes bcache */
  65                 if (!blkid_do_probe(pr)) {
  66                         continue;
  67                 }
  68
  69                 if (pread(fd, &sb, sizeof(sb), SB_START) != sizeof(sb))
  70                         continue;
  71
  72                 if (memcmp(&sb.magic, &BCACHE_MAGIC, sizeof(sb.magic)))
  73                         continue;
  74
  75                 uuid_unparse(sb.disk_uuid.b, uuid);
  76
  77                 if (udev)
  78                         printf("ID_FS_UUID=%s\n"
  79                                "ID_FS_UUID_ENC=%s\n"
  80                                "ID_FS_TYPE=bcache\n",
  81                                uuid, uuid);
  82                 else
  83                         printf("%s: UUID=\"\" TYPE=\"bcache\"\n", uuid);
  84         }
  85
  86         return 0;
  87 }