util-linux/volume_id/ext.c

   1 /*
   2  * volume_id - reads filesystem label and uuid
   3  *
   4  * Copyright (C) 2004 Kay Sievers <kay.sievers@vrfy.org>
   5  *
   6  *      This library is free software; you can redistribute it and/or
   7  *      modify it under the terms of the GNU Lesser General Public
   8  *      License as published by the Free Software Foundation; either
   9  *      version 2.1 of the License, or (at your option) any later version.
  10  *
  11  *      This library is distributed in the hope that it will be useful,
  12  *      but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  *      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  14  *      Lesser General Public License for more details.
  15  *
  16  *      You should have received a copy of the GNU Lesser General Public
  17  *      License along with this library; if not, write to the Free Software
  18  *      Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  19  */
  20
  21 #include "volume_id_internal.h"
  22
  23 struct ext2_super_block {
  24         uint32_t        inodes_count;
  25         uint32_t        blocks_count;
  26         uint32_t        r_blocks_count;
  27         uint32_t        free_blocks_count;
  28         uint32_t        free_inodes_count;
  29         uint32_t        first_data_block;
  30         uint32_t        log_block_size;
  31         uint32_t        dummy3[7];
  32         uint8_t magic[2];
  33         uint16_t        state;
  34         uint32_t        dummy5[8];
  35         uint32_t        feature_compat;
  36         uint32_t        feature_incompat;
  37         uint32_t        feature_ro_compat;
  38         uint8_t uuid[16];
  39         uint8_t volume_name[16];
  40 } PACKED;
  41
  42 #define EXT_SUPERBLOCK_OFFSET                   0x400
  43
  44 /* for s_flags */
  45 #define EXT2_FLAGS_TEST_FILESYS                 0x0004
  46
  47 /* for s_feature_compat */
  48 #define EXT3_FEATURE_COMPAT_HAS_JOURNAL         0x0004
  49
  50 /* for s_feature_ro_compat */
  51 #define EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER     0x0001
  52 #define EXT2_FEATURE_RO_COMPAT_LARGE_FILE       0x0002
  53 #define EXT2_FEATURE_RO_COMPAT_BTREE_DIR        0x0004
  54 #define EXT4_FEATURE_RO_COMPAT_HUGE_FILE        0x0008
  55 #define EXT4_FEATURE_RO_COMPAT_GDT_CSUM         0x0010
  56 #define EXT4_FEATURE_RO_COMPAT_DIR_NLINK        0x0020
  57 #define EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE      0x0040
  58
  59 /* for s_feature_incompat */
  60 #define EXT2_FEATURE_INCOMPAT_FILETYPE          0x0002
  61 #define EXT3_FEATURE_INCOMPAT_RECOVER           0x0004
  62 #define EXT3_FEATURE_INCOMPAT_JOURNAL_DEV       0x0008
  63 #define EXT2_FEATURE_INCOMPAT_META_BG           0x0010
  64 #define EXT4_FEATURE_INCOMPAT_EXTENTS           0x0040 /* extents support */
  65 #define EXT4_FEATURE_INCOMPAT_64BIT             0x0080
  66 #define EXT4_FEATURE_INCOMPAT_MMP               0x0100
  67 #define EXT4_FEATURE_INCOMPAT_FLEX_BG           0x0200
  68
  69 #define EXT2_FEATURE_RO_COMPAT_SUPP     (EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER| \
  70                                          EXT2_FEATURE_RO_COMPAT_LARGE_FILE| \
  71                                          EXT2_FEATURE_RO_COMPAT_BTREE_DIR)
  72 #define EXT2_FEATURE_INCOMPAT_SUPP      (EXT2_FEATURE_INCOMPAT_FILETYPE| \
  73                                          EXT2_FEATURE_INCOMPAT_META_BG)
  74 #define EXT2_FEATURE_INCOMPAT_UNSUPPORTED       ~EXT2_FEATURE_INCOMPAT_SUPP
  75 #define EXT2_FEATURE_RO_COMPAT_UNSUPPORTED      ~EXT2_FEATURE_RO_COMPAT_SUPP
  76
  77 #define EXT3_FEATURE_RO_COMPAT_SUPP     (EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER| \
  78                                          EXT2_FEATURE_RO_COMPAT_LARGE_FILE| \
  79                                          EXT2_FEATURE_RO_COMPAT_BTREE_DIR)
  80 #define EXT3_FEATURE_INCOMPAT_SUPP      (EXT2_FEATURE_INCOMPAT_FILETYPE| \
  81                                          EXT3_FEATURE_INCOMPAT_RECOVER| \
  82                                          EXT2_FEATURE_INCOMPAT_META_BG)
  83 #define EXT3_FEATURE_INCOMPAT_UNSUPPORTED       ~EXT3_FEATURE_INCOMPAT_SUPP
  84 #define EXT3_FEATURE_RO_COMPAT_UNSUPPORTED      ~EXT3_FEATURE_RO_COMPAT_SUPP
  85
  86 int FAST_FUNC volume_id_probe_ext(struct volume_id *id /*,uint64_t off*/)
  87 {
  88 #define off ((uint64_t)0)
  89         struct ext2_super_block *es;
  90
  91         dbg("ext: probing at offset 0x%llx", (unsigned long long) off);
  92
  93         es = volume_id_get_buffer(id, off + EXT_SUPERBLOCK_OFFSET, 0x200);
  94         if (es == NULL)
  95                 return -1;
  96
  97         if (es->magic[0] != 0123 || es->magic[1] != 0357) {
  98                 dbg("ext: no magic found");
  99                 return -1;
 100         }
 101
 102 //      volume_id_set_usage(id, VOLUME_ID_FILESYSTEM);
 103 //      volume_id_set_label_raw(id, es->volume_name, 16);
 104         volume_id_set_label_string(id, es->volume_name, 16);
 105         volume_id_set_uuid(id, es->uuid, UUID_DCE);
 106         dbg("ext: label '%s' uuid '%s'", id->label, id->uuid);
 107
 108 #if ENABLE_FEATURE_BLKID_TYPE
 109         if ((es->feature_ro_compat & cpu_to_le32(EXT4_FEATURE_RO_COMPAT_HUGE_FILE | EXT4_FEATURE_RO_COMPAT_DIR_NLINK))
 110          || (es->feature_incompat & cpu_to_le32(EXT4_FEATURE_INCOMPAT_EXTENTS | EXT4_FEATURE_INCOMPAT_64BIT))
 111         ) {
 112                 id->type = "ext4";
 113         }
 114         else if (es->feature_compat & cpu_to_le32(EXT3_FEATURE_COMPAT_HAS_JOURNAL))
 115                 id->type = "ext3";
 116         else
 117                 id->type = "ext2";
 118 #endif
 119         return 0;
 120 }