libblkid-tiny/btrfs.c

   1 /*
   2  * Copyright (C) 2009 Karel Zak <kzak@redhat.com>
   3  *
   4  * This file may be redistributed under the terms of the
   5  * GNU Lesser General Public License.
   6  */
   7 #include <stdio.h>
   8 #include <stdlib.h>
   9 #include <unistd.h>
  10 #include <string.h>
  11 #include <stdint.h>
  12
  13 #include "superblocks.h"
  14
  15 struct btrfs_super_block {
  16         uint8_t csum[32];
  17         uint8_t fsid[16];
  18         uint64_t bytenr;
  19         uint64_t flags;
  20         uint8_t magic[8];
  21         uint64_t generation;
  22         uint64_t root;
  23         uint64_t chunk_root;
  24         uint64_t log_root;
  25         uint64_t log_root_transid;
  26         uint64_t total_bytes;
  27         uint64_t bytes_used;
  28         uint64_t root_dir_objectid;
  29         uint64_t num_devices;
  30         uint32_t sectorsize;
  31         uint32_t nodesize;
  32         uint32_t leafsize;
  33         uint32_t stripesize;
  34         uint32_t sys_chunk_array_size;
  35         uint64_t chunk_root_generation;
  36         uint64_t compat_flags;
  37         uint64_t compat_ro_flags;
  38         uint64_t incompat_flags;
  39         uint16_t csum_type;
  40         uint8_t root_level;
  41         uint8_t chunk_root_level;
  42         uint8_t log_root_level;
  43         struct btrfs_dev_item {
  44                 uint64_t devid;
  45                 uint64_t total_bytes;
  46                 uint64_t bytes_used;
  47                 uint32_t io_align;
  48                 uint32_t io_width;
  49                 uint32_t sector_size;
  50                 uint64_t type;
  51                 uint64_t generation;
  52                 uint64_t start_offset;
  53                 uint32_t dev_group;
  54                 uint8_t seek_speed;
  55                 uint8_t bandwidth;
  56                 uint8_t uuid[16];
  57                 uint8_t fsid[16];
  58         } __attribute__ ((__packed__)) dev_item;
  59         uint8_t label[256];
  60 } __attribute__ ((__packed__));
  61
  62 static int probe_btrfs(blkid_probe pr, const struct blkid_idmag *mag)
  63 {
  64         struct btrfs_super_block *bfs;
  65
  66         bfs = blkid_probe_get_sb(pr, mag, struct btrfs_super_block);
  67         if (!bfs)
  68                 return errno ? -errno : 1;
  69
  70         if (*bfs->label)
  71                 blkid_probe_set_label(pr,
  72                                 (unsigned char *) bfs->label,
  73                                 sizeof(bfs->label));
  74
  75         blkid_probe_set_uuid(pr, bfs->fsid);
  76         blkid_probe_set_uuid_as(pr, bfs->dev_item.uuid, "UUID_SUB");
  77
  78         return 0;
  79 }
  80
  81 const struct blkid_idinfo btrfs_idinfo =
  82 {
  83         .name           = "btrfs",
  84         .usage          = BLKID_USAGE_FILESYSTEM,
  85         .probefunc      = probe_btrfs,
  86         .minsz          = 1024 * 1024,
  87         .magics         =
  88         {
  89           { .magic = "_BHRfS_M", .len = 8, .sboff = 0x40, .kboff = 64 },
  90           { NULL }
  91         }
  92 };
  93