libblkid-tiny/ext.c

   1 /*
   2  * Copyright (C) 1999, 2001 by Andries Brouwer
   3  * Copyright (C) 1999, 2000, 2003 by Theodore Ts'o
   4  * Copyright (C) 2008 Karel Zak <kzak@redhat.com>
   5  *
   6  * This file may be redistributed under the terms of the
   7  * GNU Lesser General Public License.
   8  */
   9 #include <stdio.h>
  10 #include <stdlib.h>
  11 #include <unistd.h>
  12 #include <string.h>
  13 #include <errno.h>
  14 #include <ctype.h>
  15 #include <stdint.h>
  16 #ifdef __linux__
  17 #include <sys/utsname.h>
  18 #endif
  19 #include <time.h>
  20
  21 #include "superblocks.h"
  22
  23 struct ext2_super_block {
  24         uint32_t                s_inodes_count;
  25         uint32_t                s_blocks_count;
  26         uint32_t                s_r_blocks_count;
  27         uint32_t                s_free_blocks_count;
  28         uint32_t                s_free_inodes_count;
  29         uint32_t                s_first_data_block;
  30         uint32_t                s_log_block_size;
  31         uint32_t                s_dummy3[7];
  32         unsigned char           s_magic[2];
  33         uint16_t                s_state;
  34         uint16_t                s_errors;
  35         uint16_t                s_minor_rev_level;
  36         uint32_t                s_lastcheck;
  37         uint32_t                s_checkinterval;
  38         uint32_t                s_creator_os;
  39         uint32_t                s_rev_level;
  40         uint16_t                s_def_resuid;
  41         uint16_t                s_def_resgid;
  42         uint32_t                s_first_ino;
  43         uint16_t                s_inode_size;
  44         uint16_t                s_block_group_nr;
  45         uint32_t                s_feature_compat;
  46         uint32_t                s_feature_incompat;
  47         uint32_t                s_feature_ro_compat;
  48         unsigned char           s_uuid[16];
  49         char                    s_volume_name[16];
  50         char                    s_last_mounted[64];
  51         uint32_t                s_algorithm_usage_bitmap;
  52         uint8_t                 s_prealloc_blocks;
  53         uint8_t                 s_prealloc_dir_blocks;
  54         uint16_t                s_reserved_gdt_blocks;
  55         uint8_t                 s_journal_uuid[16];
  56         uint32_t                s_journal_inum;
  57         uint32_t                s_journal_dev;
  58         uint32_t                s_last_orphan;
  59         uint32_t                s_hash_seed[4];
  60         uint8_t                 s_def_hash_version;
  61         uint8_t                 s_jnl_backup_type;
  62         uint16_t                s_reserved_word_pad;
  63         uint32_t                s_default_mount_opts;
  64         uint32_t                s_first_meta_bg;
  65         uint32_t                s_mkfs_time;
  66         uint32_t                s_jnl_blocks[17];
  67         uint32_t                s_blocks_count_hi;
  68         uint32_t                s_r_blocks_count_hi;
  69         uint32_t                s_free_blocks_hi;
  70         uint16_t                s_min_extra_isize;
  71         uint16_t                s_want_extra_isize;
  72         uint32_t                s_flags;
  73         uint16_t                s_raid_stride;
  74         uint16_t                s_mmp_interval;
  75         uint64_t                s_mmp_block;
  76         uint32_t                s_raid_stripe_width;
  77         uint32_t                s_reserved[163];
  78 } __attribute__((packed));
  79
  80 /* magic string */
  81 #define EXT_SB_MAGIC                            "\123\357"
  82 /* supper block offset */
  83 #define EXT_SB_OFF                              0x400
  84 /* supper block offset in kB */
  85 #define EXT_SB_KBOFF                            (EXT_SB_OFF >> 10)
  86 /* magic string offset within super block */
  87 #define EXT_MAG_OFF                             0x38
  88
  89
  90
  91 /* for s_flags */
  92 #define EXT2_FLAGS_TEST_FILESYS         0x0004
  93
  94 /* for s_feature_compat */
  95 #define EXT3_FEATURE_COMPAT_HAS_JOURNAL         0x0004
  96
  97 /* for s_feature_ro_compat */
  98 #define EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER     0x0001
  99 #define EXT2_FEATURE_RO_COMPAT_LARGE_FILE       0x0002
 100 #define EXT2_FEATURE_RO_COMPAT_BTREE_DIR        0x0004
 101 #define EXT4_FEATURE_RO_COMPAT_HUGE_FILE        0x0008
 102 #define EXT4_FEATURE_RO_COMPAT_GDT_CSUM         0x0010
 103 #define EXT4_FEATURE_RO_COMPAT_DIR_NLINK        0x0020
 104 #define EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE      0x0040
 105
 106 /* for s_feature_incompat */
 107 #define EXT2_FEATURE_INCOMPAT_FILETYPE          0x0002
 108 #define EXT3_FEATURE_INCOMPAT_RECOVER           0x0004
 109 #define EXT3_FEATURE_INCOMPAT_JOURNAL_DEV       0x0008
 110 #define EXT2_FEATURE_INCOMPAT_META_BG           0x0010
 111 #define EXT4_FEATURE_INCOMPAT_EXTENTS           0x0040 /* extents support */
 112 #define EXT4_FEATURE_INCOMPAT_64BIT             0x0080
 113 #define EXT4_FEATURE_INCOMPAT_MMP               0x0100
 114 #define EXT4_FEATURE_INCOMPAT_FLEX_BG           0x0200
 115
 116 #define EXT2_FEATURE_RO_COMPAT_SUPP     (EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER| \
 117                                          EXT2_FEATURE_RO_COMPAT_LARGE_FILE| \
 118                                          EXT2_FEATURE_RO_COMPAT_BTREE_DIR)
 119 #define EXT2_FEATURE_INCOMPAT_SUPP      (EXT2_FEATURE_INCOMPAT_FILETYPE| \
 120                                          EXT2_FEATURE_INCOMPAT_META_BG)
 121 #define EXT2_FEATURE_INCOMPAT_UNSUPPORTED       ~EXT2_FEATURE_INCOMPAT_SUPP
 122 #define EXT2_FEATURE_RO_COMPAT_UNSUPPORTED      ~EXT2_FEATURE_RO_COMPAT_SUPP
 123
 124 #define EXT3_FEATURE_RO_COMPAT_SUPP     (EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER| \
 125                                          EXT2_FEATURE_RO_COMPAT_LARGE_FILE| \
 126                                          EXT2_FEATURE_RO_COMPAT_BTREE_DIR)
 127 #define EXT3_FEATURE_INCOMPAT_SUPP      (EXT2_FEATURE_INCOMPAT_FILETYPE| \
 128                                          EXT3_FEATURE_INCOMPAT_RECOVER| \
 129                                          EXT2_FEATURE_INCOMPAT_META_BG)
 130 #define EXT3_FEATURE_INCOMPAT_UNSUPPORTED       ~EXT3_FEATURE_INCOMPAT_SUPP
 131 #define EXT3_FEATURE_RO_COMPAT_UNSUPPORTED      ~EXT3_FEATURE_RO_COMPAT_SUPP
 132
 133 /*
 134  * Starting in 2.6.29, ext4 can be used to support filesystems
 135  * without a journal.
 136  */
 137 #define EXT4_SUPPORTS_EXT2 KERNEL_VERSION(2, 6, 29)
 138
 139 /*
 140  * reads superblock and returns:
 141  *      fc = feature_compat
 142  *      fi = feature_incompat
 143  *      frc = feature_ro_compat
 144  */
 145 static struct ext2_super_block *ext_get_super(
 146                 blkid_probe pr, uint32_t *fc, uint32_t *fi, uint32_t *frc)
 147 {
 148         struct ext2_super_block *es;
 149
 150         es = (struct ext2_super_block *)
 151                         blkid_probe_get_buffer(pr, EXT_SB_OFF, 0x200);
 152         if (!es)
 153                 return NULL;
 154         if (fc)
 155                 *fc = le32_to_cpu(es->s_feature_compat);
 156         if (fi)
 157                 *fi = le32_to_cpu(es->s_feature_incompat);
 158         if (frc)
 159                 *frc = le32_to_cpu(es->s_feature_ro_compat);
 160
 161         return es;
 162 }
 163
 164 static void ext_get_info(blkid_probe pr, int ver, struct ext2_super_block *es)
 165 {
 166 #if 0
 167         struct blkid_chain *chn = blkid_probe_get_chain(pr);
 168 #endif
 169
 170         DBG(PROBE, ul_debug("ext2_sb.compat = %08X:%08X:%08X",
 171                    le32_to_cpu(es->s_feature_compat),
 172                    le32_to_cpu(es->s_feature_incompat),
 173                    le32_to_cpu(es->s_feature_ro_compat)));
 174
 175         if (strlen(es->s_volume_name))
 176                 blkid_probe_set_label(pr, (unsigned char *) es->s_volume_name,
 177                                         sizeof(es->s_volume_name));
 178         blkid_probe_set_uuid(pr, es->s_uuid);
 179
 180         if (le32_to_cpu(es->s_feature_compat) & EXT3_FEATURE_COMPAT_HAS_JOURNAL)
 181                 blkid_probe_set_uuid_as(pr, es->s_journal_uuid, "EXT_JOURNAL");
 182
 183 #if 0
 184         if (ver != 2 && (chn->flags & BLKID_SUBLKS_SECTYPE) &&
 185             ((le32_to_cpu(es->s_feature_incompat) & EXT2_FEATURE_INCOMPAT_UNSUPPORTED) == 0))
 186                 blkid_probe_set_value(pr, "SEC_TYPE",
 187                                 (unsigned char *) "ext2",
 188                                 sizeof("ext2"));
 189 #endif
 190
 191         blkid_probe_sprintf_version(pr, "%u.%u",
 192                 le32_to_cpu(es->s_rev_level),
 193                 le16_to_cpu(es->s_minor_rev_level));
 194 }
 195
 196
 197 static int probe_jbd(blkid_probe pr,
 198                 const struct blkid_idmag *mag __attribute__((__unused__)))
 199 {
 200         struct ext2_super_block *es;
 201         uint32_t fi;
 202
 203         es = ext_get_super(pr, NULL, &fi, NULL);
 204         if (!es)
 205                 return errno ? -errno : 1;
 206         if (!(fi & EXT3_FEATURE_INCOMPAT_JOURNAL_DEV))
 207                 return 1;
 208
 209         ext_get_info(pr, 2, es);
 210         blkid_probe_set_uuid_as(pr, es->s_uuid, "LOGUUID");
 211
 212         return 0;
 213 }
 214
 215 static int probe_ext2(blkid_probe pr,
 216                 const struct blkid_idmag *mag __attribute__((__unused__)))
 217 {
 218         struct ext2_super_block *es;
 219         uint32_t fc, frc, fi;
 220
 221         es = ext_get_super(pr, &fc, &fi, &frc);
 222         if (!es)
 223                 return errno ? -errno : 1;
 224
 225         /* Distinguish between ext3 and ext2 */
 226         if (fc & EXT3_FEATURE_COMPAT_HAS_JOURNAL)
 227                 return 1;
 228
 229         /* Any features which ext2 doesn't understand */
 230         if ((frc & EXT2_FEATURE_RO_COMPAT_UNSUPPORTED) ||
 231             (fi  & EXT2_FEATURE_INCOMPAT_UNSUPPORTED))
 232                 return 1;
 233
 234         ext_get_info(pr, 2, es);
 235         return 0;
 236 }
 237
 238 static int probe_ext3(blkid_probe pr,
 239                 const struct blkid_idmag *mag __attribute__((__unused__)))
 240 {
 241         struct ext2_super_block *es;
 242         uint32_t fc, frc, fi;
 243
 244         es = ext_get_super(pr, &fc, &fi, &frc);
 245         if (!es)
 246                 return errno ? -errno : 1;
 247
 248         /* ext3 requires journal */
 249         if (!(fc & EXT3_FEATURE_COMPAT_HAS_JOURNAL))
 250                 return 1;
 251
 252         /* Any features which ext3 doesn't understand */
 253         if ((frc & EXT3_FEATURE_RO_COMPAT_UNSUPPORTED) ||
 254             (fi  & EXT3_FEATURE_INCOMPAT_UNSUPPORTED))
 255                 return 1;
 256
 257         ext_get_info(pr, 3, es);
 258         return 0;
 259 }
 260
 261
 262 static int probe_ext4dev(blkid_probe pr,
 263                 const struct blkid_idmag *mag __attribute__((__unused__)))
 264 {
 265         struct ext2_super_block *es;
 266         uint32_t fc, frc, fi;
 267
 268         es = ext_get_super(pr, &fc, &fi, &frc);
 269         if (!es)
 270                 return errno ? -errno : 1;
 271
 272         /* Distinguish from jbd */
 273         if (fi & EXT3_FEATURE_INCOMPAT_JOURNAL_DEV)
 274                 return 1;
 275
 276         if (!(le32_to_cpu(es->s_flags) & EXT2_FLAGS_TEST_FILESYS))
 277                 return 1;
 278
 279         ext_get_info(pr, 4, es);
 280         return 0;
 281 }
 282
 283 static int probe_ext4(blkid_probe pr,
 284                 const struct blkid_idmag *mag __attribute__((__unused__)))
 285 {
 286         struct ext2_super_block *es;
 287         uint32_t fc, frc, fi;
 288
 289         es = ext_get_super(pr, &fc, &fi, &frc);
 290         if (!es)
 291                 return errno ? -errno : 1;
 292
 293         /* Distinguish from jbd */
 294         if (fi & EXT3_FEATURE_INCOMPAT_JOURNAL_DEV)
 295                 return 1;
 296
 297         /* Ext4 has at least one feature which ext3 doesn't understand */
 298         if (!(frc & EXT3_FEATURE_RO_COMPAT_UNSUPPORTED) &&
 299             !(fi  & EXT3_FEATURE_INCOMPAT_UNSUPPORTED))
 300                 return 1;
 301
 302         /*
 303          * If the filesystem is a OK for use by in-development
 304          * filesystem code, and ext4dev is supported or ext4 is not
 305          * supported, then don't call ourselves ext4, so we can redo
 306          * the detection and mark the filesystem as ext4dev.
 307          *
 308          * If the filesystem is marked as in use by production
 309          * filesystem, then it can only be used by ext4 and NOT by
 310          * ext4dev.
 311          */
 312         if (le32_to_cpu(es->s_flags) & EXT2_FLAGS_TEST_FILESYS)
 313                 return 1;
 314
 315         ext_get_info(pr, 4, es);
 316         return 0;
 317 }
 318
 319 #define BLKID_EXT_MAGICS \
 320         { \
 321                 {        \
 322                         .magic = EXT_SB_MAGIC, \
 323                         .len = sizeof(EXT_SB_MAGIC) - 1, \
 324                         .kboff = EXT_SB_KBOFF, \
 325                         .sboff = EXT_MAG_OFF \
 326                 }, \
 327                 { NULL } \
 328         }
 329
 330 const struct blkid_idinfo jbd_idinfo =
 331 {
 332         .name           = "jbd",
 333         .usage          = BLKID_USAGE_OTHER,
 334         .probefunc      = probe_jbd,
 335         .magics         = BLKID_EXT_MAGICS
 336 };
 337
 338 const struct blkid_idinfo ext2_idinfo =
 339 {
 340         .name           = "ext2",
 341         .usage          = BLKID_USAGE_FILESYSTEM,
 342         .probefunc      = probe_ext2,
 343         .magics         = BLKID_EXT_MAGICS
 344 };
 345
 346 const struct blkid_idinfo ext3_idinfo =
 347 {
 348         .name           = "ext3",
 349         .usage          = BLKID_USAGE_FILESYSTEM,
 350         .probefunc      = probe_ext3,
 351         .magics         = BLKID_EXT_MAGICS
 352 };
 353
 354 const struct blkid_idinfo ext4_idinfo =
 355 {
 356         .name           = "ext4",
 357         .usage          = BLKID_USAGE_FILESYSTEM,
 358         .probefunc      = probe_ext4,
 359         .magics         = BLKID_EXT_MAGICS
 360 };
 361
 362 const struct blkid_idinfo ext4dev_idinfo =
 363 {
 364         .name           = "ext4dev",
 365         .usage          = BLKID_USAGE_FILESYSTEM,
 366         .probefunc      = probe_ext4dev,
 367         .magics         = BLKID_EXT_MAGICS
 368 };
 369