fs/ext2.c

   1 /* ext2.c - Second Extended filesystem */
   2 /*
   3  *  GRUB  --  GRand Unified Bootloader
   4  *  Copyright (C) 2003,2004,2005,2007,2008  Free Software Foundation, Inc.
   5  *
   6  *  GRUB is free software: you can redistribute it and/or modify
   7  *  it under the terms of the GNU General Public License as published by
   8  *  the Free Software Foundation, either version 3 of the License, or
   9  *  (at your option) any later version.
  10  *
  11  *  GRUB 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
  14  *  GNU General Public License for more details.
  15  *
  16  *  You should have received a copy of the GNU General Public License
  17  *  along with GRUB.  If not, see <http://www.gnu.org/licenses/>.
  18  */
  19
  20 /* Magic value used to identify an ext2 filesystem.  */
  21 #define EXT2_MAGIC              0xEF53
  22 /* Amount of indirect blocks in an inode.  */
  23 #define INDIRECT_BLOCKS         12
  24 /* Maximum length of a pathname.  */
  25 #define EXT2_PATH_MAX           4096
  26 /* Maximum nesting of symlinks, used to prevent a loop.  */
  27 #define EXT2_MAX_SYMLINKCNT     8
  28
  29 /* The good old revision and the default inode size.  */
  30 #define EXT2_GOOD_OLD_REVISION          0
  31 #define EXT2_GOOD_OLD_INODE_SIZE        128
  32
  33 /* Filetype used in directory entry.  */
  34 #define FILETYPE_UNKNOWN        0
  35 #define FILETYPE_REG            1
  36 #define FILETYPE_DIRECTORY      2
  37 #define FILETYPE_SYMLINK        7
  38
  39 /* Filetype information as used in inodes.  */
  40 #define FILETYPE_INO_MASK       0170000
  41 #define FILETYPE_INO_REG        0100000
  42 #define FILETYPE_INO_DIRECTORY  0040000
  43 #define FILETYPE_INO_SYMLINK    0120000
  44
  45 #include <grub/err.h>
  46 #include <grub/file.h>
  47 #include <grub/mm.h>
  48 #include <grub/misc.h>
  49 #include <grub/disk.h>
  50 #include <grub/dl.h>
  51 #include <grub/types.h>
  52 #include <grub/fshelp.h>
  53
  54 /* Log2 size of ext2 block in 512 blocks.  */
  55 #define LOG2_EXT2_BLOCK_SIZE(data)                      \
  56         (grub_le_to_cpu32 (data->sblock.log2_block_size) + 1)
  57
  58 /* Log2 size of ext2 block in bytes.  */
  59 #define LOG2_BLOCK_SIZE(data)                                   \
  60         (grub_le_to_cpu32 (data->sblock.log2_block_size) + 10)
  61
  62 /* The size of an ext2 block in bytes.  */
  63 #define EXT2_BLOCK_SIZE(data)           (1 << LOG2_BLOCK_SIZE (data))
  64
  65 /* The revision level.  */
  66 #define EXT2_REVISION(data)     grub_le_to_cpu32 (data->sblock.revision_level)
  67
  68 /* The inode size.  */
  69 #define EXT2_INODE_SIZE(data)   \
  70         (EXT2_REVISION (data) == EXT2_GOOD_OLD_REVISION \
  71          ? EXT2_GOOD_OLD_INODE_SIZE \
  72          : grub_le_to_cpu16 (data->sblock.inode_size))
  73
  74 /* Superblock filesystem feature flags (RW compatible)
  75  * A filesystem with any of these enabled can be read and written by a driver
  76  * that does not understand them without causing metadata/data corruption.  */
  77 #define EXT2_FEATURE_COMPAT_DIR_PREALLOC        0x0001
  78 #define EXT2_FEATURE_COMPAT_IMAGIC_INODES       0x0002
  79 #define EXT3_FEATURE_COMPAT_HAS_JOURNAL         0x0004
  80 #define EXT2_FEATURE_COMPAT_EXT_ATTR            0x0008
  81 #define EXT2_FEATURE_COMPAT_RESIZE_INODE        0x0010
  82 #define EXT2_FEATURE_COMPAT_DIR_INDEX           0x0020
  83 /* Superblock filesystem feature flags (RO compatible)
  84  * A filesystem with any of these enabled can be safely read by a driver that
  85  * does not understand them, but should not be written to, usually because
  86  * additional metadata is required.  */
  87 #define EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER     0x0001
  88 #define EXT2_FEATURE_RO_COMPAT_LARGE_FILE       0x0002
  89 #define EXT2_FEATURE_RO_COMPAT_BTREE_DIR        0x0004
  90 #define EXT4_FEATURE_RO_COMPAT_GDT_CSUM         0x0010
  91 #define EXT4_FEATURE_RO_COMPAT_DIR_NLINK        0x0020
  92 #define EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE      0x0040
  93 /* Superblock filesystem feature flags (back-incompatible)
  94  * A filesystem with any of these enabled should not be attempted to be read
  95  * by a driver that does not understand them, since they usually indicate
  96  * metadata format changes that might confuse the reader.  */
  97 #define EXT2_FEATURE_INCOMPAT_COMPRESSION       0x0001
  98 #define EXT2_FEATURE_INCOMPAT_FILETYPE          0x0002
  99 #define EXT3_FEATURE_INCOMPAT_RECOVER           0x0004 /* Needs recovery */
 100 #define EXT3_FEATURE_INCOMPAT_JOURNAL_DEV       0x0008 /* Volume is journal device */
 101 #define EXT2_FEATURE_INCOMPAT_META_BG           0x0010
 102 #define EXT4_FEATURE_INCOMPAT_EXTENTS           0x0040 /* Extents used */
 103 #define EXT4_FEATURE_INCOMPAT_64BIT             0x0080
 104 #define EXT4_FEATURE_INCOMPAT_FLEX_BG           0x0200
 105
 106 /* The set of back-incompatible features this driver DOES support. Add (OR)
 107  * flags here as the related features are implemented into the driver.  */
 108 #define EXT2_DRIVER_SUPPORTED_INCOMPAT ( EXT2_FEATURE_INCOMPAT_FILETYPE \
 109                                        | EXT4_FEATURE_INCOMPAT_EXTENTS  \
 110                                        | EXT4_FEATURE_INCOMPAT_FLEX_BG )
 111 /* List of rationales for the ignored "incompatible" features:
 112  * needs_recovery: Not really back-incompatible - was added as such to forbid
 113  *                 ext2 drivers from mounting an ext3 volume with a dirty
 114  *                 journal because they will ignore the journal, but the next
 115  *                 ext3 driver to mount the volume will find the journal and
 116  *                 replay it, potentially corrupting the metadata written by
 117  *                 the ext2 drivers. Safe to ignore for this RO driver.  */
 118 #define EXT2_DRIVER_IGNORED_INCOMPAT ( EXT3_FEATURE_INCOMPAT_RECOVER )
 119
 120
 121 #define EXT3_JOURNAL_MAGIC_NUMBER       0xc03b3998U
 122
 123 #define EXT3_JOURNAL_DESCRIPTOR_BLOCK   1
 124 #define EXT3_JOURNAL_COMMIT_BLOCK       2
 125 #define EXT3_JOURNAL_SUPERBLOCK_V1      3
 126 #define EXT3_JOURNAL_SUPERBLOCK_V2      4
 127 #define EXT3_JOURNAL_REVOKE_BLOCK       5
 128
 129 #define EXT3_JOURNAL_FLAG_ESCAPE        1
 130 #define EXT3_JOURNAL_FLAG_SAME_UUID     2
 131 #define EXT3_JOURNAL_FLAG_DELETED       4
 132 #define EXT3_JOURNAL_FLAG_LAST_TAG      8
 133
 134 #define EXT4_EXTENTS_FLAG               0x80000
 135
 136 /* The ext2 superblock.  */
 137 struct grub_ext2_sblock
 138 {
 139   grub_uint32_t total_inodes;
 140   grub_uint32_t total_blocks;
 141   grub_uint32_t reserved_blocks;
 142   grub_uint32_t free_blocks;
 143   grub_uint32_t free_inodes;
 144   grub_uint32_t first_data_block;
 145   grub_uint32_t log2_block_size;
 146   grub_uint32_t log2_fragment_size;
 147   grub_uint32_t blocks_per_group;
 148   grub_uint32_t fragments_per_group;
 149   grub_uint32_t inodes_per_group;
 150   grub_uint32_t mtime;
 151   grub_uint32_t utime;
 152   grub_uint16_t mnt_count;
 153   grub_uint16_t max_mnt_count;
 154   grub_uint16_t magic;
 155   grub_uint16_t fs_state;
 156   grub_uint16_t error_handling;
 157   grub_uint16_t minor_revision_level;
 158   grub_uint32_t lastcheck;
 159   grub_uint32_t checkinterval;
 160   grub_uint32_t creator_os;
 161   grub_uint32_t revision_level;
 162   grub_uint16_t uid_reserved;
 163   grub_uint16_t gid_reserved;
 164   grub_uint32_t first_inode;
 165   grub_uint16_t inode_size;
 166   grub_uint16_t block_group_number;
 167   grub_uint32_t feature_compatibility;
 168   grub_uint32_t feature_incompat;
 169   grub_uint32_t feature_ro_compat;
 170   grub_uint16_t uuid[8];
 171   char volume_name[16];
 172   char last_mounted_on[64];
 173   grub_uint32_t compression_info;
 174   grub_uint8_t prealloc_blocks;
 175   grub_uint8_t prealloc_dir_blocks;
 176   grub_uint16_t reserved_gdt_blocks;
 177   grub_uint8_t journal_uuid[16];
 178   grub_uint32_t journal_inum;
 179   grub_uint32_t journal_dev;
 180   grub_uint32_t last_orphan;
 181   grub_uint32_t hash_seed[4];
 182   grub_uint8_t def_hash_version;
 183   grub_uint8_t jnl_backup_type;
 184   grub_uint16_t reserved_word_pad;
 185   grub_uint32_t default_mount_opts;
 186   grub_uint32_t first_meta_bg;
 187   grub_uint32_t mkfs_time;
 188   grub_uint32_t jnl_blocks[17];
 189 };
 190
 191 /* The ext2 blockgroup.  */
 192 struct grub_ext2_block_group
 193 {
 194   grub_uint32_t block_id;
 195   grub_uint32_t inode_id;
 196   grub_uint32_t inode_table_id;
 197   grub_uint16_t free_blocks;
 198   grub_uint16_t free_inodes;
 199   grub_uint16_t used_dirs;
 200   grub_uint16_t pad;
 201   grub_uint32_t reserved[3];
 202 };
 203
 204 /* The ext2 inode.  */
 205 struct grub_ext2_inode
 206 {
 207   grub_uint16_t mode;
 208   grub_uint16_t uid;
 209   grub_uint32_t size;
 210   grub_uint32_t atime;
 211   grub_uint32_t ctime;
 212   grub_uint32_t mtime;
 213   grub_uint32_t dtime;
 214   grub_uint16_t gid;
 215   grub_uint16_t nlinks;
 216   grub_uint32_t blockcnt;  /* Blocks of 512 bytes!! */
 217   grub_uint32_t flags;
 218   grub_uint32_t osd1;
 219   union
 220   {
 221     struct datablocks
 222     {
 223       grub_uint32_t dir_blocks[INDIRECT_BLOCKS];
 224       grub_uint32_t indir_block;
 225       grub_uint32_t double_indir_block;
 226       grub_uint32_t triple_indir_block;
 227     } blocks;
 228     char symlink[60];
 229   };
 230   grub_uint32_t version;
 231   grub_uint32_t acl;
 232   grub_uint32_t dir_acl;
 233   grub_uint32_t fragment_addr;
 234   grub_uint32_t osd2[3];
 235 };
 236
 237 /* The header of an ext2 directory entry.  */
 238 struct ext2_dirent
 239 {
 240   grub_uint32_t inode;
 241   grub_uint16_t direntlen;
 242   grub_uint8_t namelen;
 243   grub_uint8_t filetype;
 244 };
 245
 246 struct grub_ext3_journal_header
 247 {
 248   grub_uint32_t magic;
 249   grub_uint32_t block_type;
 250   grub_uint32_t sequence;
 251 };
 252
 253 struct grub_ext3_journal_revoke_header
 254 {
 255   struct grub_ext3_journal_header header;
 256   grub_uint32_t count;
 257   grub_uint32_t data[0];
 258 };
 259
 260 struct grub_ext3_journal_block_tag
 261 {
 262   grub_uint32_t block;
 263   grub_uint32_t flags;
 264 };
 265
 266 struct grub_ext3_journal_sblock
 267 {
 268   struct grub_ext3_journal_header header;
 269   grub_uint32_t block_size;
 270   grub_uint32_t maxlen;
 271   grub_uint32_t first;
 272   grub_uint32_t sequence;
 273   grub_uint32_t start;
 274 };
 275
 276 #define EXT4_EXT_MAGIC          0xf30a
 277
 278 struct grub_ext4_extent_header
 279 {
 280   grub_uint16_t magic;
 281   grub_uint16_t entries;
 282   grub_uint16_t max;
 283   grub_uint16_t depth;
 284   grub_uint32_t generation;
 285 };
 286
 287 struct grub_ext4_extent
 288 {
 289   grub_uint32_t block;
 290   grub_uint16_t len;
 291   grub_uint16_t start_hi;
 292   grub_uint32_t start;
 293 };
 294
 295 struct grub_ext4_extent_idx
 296 {
 297   grub_uint32_t block;
 298   grub_uint32_t leaf;
 299   grub_uint16_t leaf_hi;
 300   grub_uint16_t unused;
 301 };
 302
 303 struct grub_fshelp_node
 304 {
 305   struct grub_ext2_data *data;
 306   struct grub_ext2_inode inode;
 307   int ino;
 308   int inode_read;
 309 };
 310
 311 /* Information about a "mounted" ext2 filesystem.  */
 312 struct grub_ext2_data
 313 {
 314   struct grub_ext2_sblock sblock;
 315   grub_disk_t disk;
 316   struct grub_ext2_inode *inode;
 317   struct grub_fshelp_node diropen;
 318 };
 319
 320 static grub_dl_t my_mod;
 321
 322 \f
 323
 324 /* Read into BLKGRP the blockgroup descriptor of blockgroup GROUP of
 325    the mounted filesystem DATA.  */
 326 inline static grub_err_t
 327 grub_ext2_blockgroup (struct grub_ext2_data *data, int group,
 328                       struct grub_ext2_block_group *blkgrp)
 329 {
 330   return grub_disk_read (data->disk,
 331                          ((grub_le_to_cpu32 (data->sblock.first_data_block) + 1)
 332                           << LOG2_EXT2_BLOCK_SIZE (data)),
 333                          group * sizeof (struct grub_ext2_block_group),
 334                          sizeof (struct grub_ext2_block_group), blkgrp);
 335 }
 336
 337 static struct grub_ext4_extent_header *
 338 grub_ext4_find_leaf (struct grub_ext2_data *data, char *buf,
 339                      struct grub_ext4_extent_header *ext_block,
 340                      grub_uint32_t fileblock)
 341 {
 342   struct grub_ext4_extent_idx *index;
 343
 344   while (1)
 345     {
 346       int i;
 347       grub_disk_addr_t block;
 348
 349       index = (struct grub_ext4_extent_idx *) (ext_block + 1);
 350
 351       if (grub_le_to_cpu16(ext_block->magic) != EXT4_EXT_MAGIC)
 352         return 0;
 353
 354       if (ext_block->depth == 0)
 355         return ext_block;
 356
 357       for (i = 0; i < grub_le_to_cpu16 (ext_block->entries); i++)
 358         {
 359           if (fileblock < grub_le_to_cpu32(index[i].block))
 360             break;
 361         }
 362
 363       if (--i < 0)
 364         return 0;
 365
 366       block = grub_le_to_cpu16 (index[i].leaf_hi);
 367       block = (block << 32) + grub_le_to_cpu32 (index[i].leaf);
 368       if (grub_disk_read (data->disk,
 369                           block << LOG2_EXT2_BLOCK_SIZE (data),
 370                           0, EXT2_BLOCK_SIZE(data), buf))
 371         return 0;
 372
 373       ext_block = (struct grub_ext4_extent_header *) buf;
 374     }
 375 }
 376
 377 static grub_disk_addr_t
 378 grub_ext2_read_block (grub_fshelp_node_t node, grub_disk_addr_t fileblock)
 379 {
 380   struct grub_ext2_data *data = node->data;
 381   struct grub_ext2_inode *inode = &node->inode;
 382   int blknr = -1;
 383   unsigned int blksz = EXT2_BLOCK_SIZE (data);
 384   int log2_blksz = LOG2_EXT2_BLOCK_SIZE (data);
 385
 386   if (grub_le_to_cpu32(inode->flags) & EXT4_EXTENTS_FLAG)
 387     {
 388       char buf[EXT2_BLOCK_SIZE(data)];
 389       struct grub_ext4_extent_header *leaf;
 390       struct grub_ext4_extent *ext;
 391       int i;
 392
 393       leaf = grub_ext4_find_leaf (data, buf,
 394                                   (struct grub_ext4_extent_header *) inode->blocks.dir_blocks,
 395                                   fileblock);
 396       if (! leaf)
 397         {
 398           grub_error (GRUB_ERR_BAD_FS, "invalid extent");
 399           return -1;
 400         }
 401
 402       ext = (struct grub_ext4_extent *) (leaf + 1);
 403       for (i = 0; i < grub_le_to_cpu16 (leaf->entries); i++)
 404         {
 405           if (fileblock < grub_le_to_cpu32 (ext[i].block))
 406             break;
 407         }
 408
 409       if (--i >= 0)
 410         {
 411           fileblock -= grub_le_to_cpu32 (ext[i].block);
 412           if (fileblock >= grub_le_to_cpu16 (ext[i].len))
 413             return 0;
 414           else
 415             {
 416               grub_disk_addr_t start;
 417
 418               start = grub_le_to_cpu16 (ext[i].start_hi);
 419               start = (start << 32) + grub_le_to_cpu32 (ext[i].start);
 420
 421               return fileblock + start;
 422             }
 423         }
 424       else
 425         {
 426           grub_error (GRUB_ERR_BAD_FS, "something wrong with extent");
 427           return -1;
 428         }
 429     }
 430   /* Direct blocks.  */
 431   if (fileblock < INDIRECT_BLOCKS)
 432     blknr = grub_le_to_cpu32 (inode->blocks.dir_blocks[fileblock]);
 433   /* Indirect.  */
 434   else if (fileblock < INDIRECT_BLOCKS + blksz / 4)
 435     {
 436       grub_uint32_t indir[blksz / 4];
 437
 438       if (grub_disk_read (data->disk,
 439                           grub_le_to_cpu32 (inode->blocks.indir_block)
 440                           << log2_blksz,
 441                           0, blksz, indir))
 442         return grub_errno;
 443
 444       blknr = grub_le_to_cpu32 (indir[fileblock - INDIRECT_BLOCKS]);
 445     }
 446   /* Double indirect.  */
 447   else if (fileblock < INDIRECT_BLOCKS + blksz / 4 * (blksz / 4 + 1))
 448     {
 449       unsigned int perblock = blksz / 4;
 450       unsigned int rblock = fileblock - (INDIRECT_BLOCKS
 451                                          + blksz / 4);
 452       grub_uint32_t indir[blksz / 4];
 453
 454       if (grub_disk_read (data->disk,
 455                           grub_le_to_cpu32 (inode->blocks.double_indir_block)
 456                           << log2_blksz,
 457                           0, blksz, indir))
 458         return grub_errno;
 459
 460       if (grub_disk_read (data->disk,
 461                           grub_le_to_cpu32 (indir[rblock / perblock])
 462                           << log2_blksz,
 463                           0, blksz, indir))
 464         return grub_errno;
 465
 466
 467       blknr = grub_le_to_cpu32 (indir[rblock % perblock]);
 468     }
 469   /* triple indirect.  */
 470   else
 471     {
 472       grub_error (GRUB_ERR_NOT_IMPLEMENTED_YET,
 473                   "ext2fs doesn't support triple indirect blocks");
 474     }
 475
 476   return blknr;
 477 }
 478
 479 /* Read LEN bytes from the file described by DATA starting with byte
 480    POS.  Return the amount of read bytes in READ.  */
 481 static grub_ssize_t
 482 grub_ext2_read_file (grub_fshelp_node_t node,
 483                      void NESTED_FUNC_ATTR (*read_hook) (grub_disk_addr_t sector,
 484                                         unsigned offset, unsigned length),
 485                      int pos, grub_size_t len, char *buf)
 486 {
 487   return grub_fshelp_read_file (node->data->disk, node, read_hook,
 488                                 pos, len, buf, grub_ext2_read_block,
 489                                 node->inode.size,
 490                                 LOG2_EXT2_BLOCK_SIZE (node->data));
 491
 492 }
 493
 494
 495 /* Read the inode INO for the file described by DATA into INODE.  */
 496 static grub_err_t
 497 grub_ext2_read_inode (struct grub_ext2_data *data,
 498                       int ino, struct grub_ext2_inode *inode)
 499 {
 500   struct grub_ext2_block_group blkgrp;
 501   struct grub_ext2_sblock *sblock = &data->sblock;
 502   int inodes_per_block;
 503   unsigned int blkno;
 504   unsigned int blkoff;
 505
 506   /* It is easier to calculate if the first inode is 0.  */
 507   ino--;
 508
 509   grub_ext2_blockgroup (data,
 510                         ino / grub_le_to_cpu32 (sblock->inodes_per_group),
 511                         &blkgrp);
 512   if (grub_errno)
 513     return grub_errno;
 514
 515   inodes_per_block = EXT2_BLOCK_SIZE (data) / EXT2_INODE_SIZE (data);
 516   blkno = (ino % grub_le_to_cpu32 (sblock->inodes_per_group))
 517     / inodes_per_block;
 518   blkoff = (ino % grub_le_to_cpu32 (sblock->inodes_per_group))
 519     % inodes_per_block;
 520
 521   /* Read the inode.  */
 522   if (grub_disk_read (data->disk,
 523                       ((grub_le_to_cpu32 (blkgrp.inode_table_id) + blkno)
 524                         << LOG2_EXT2_BLOCK_SIZE (data)),
 525                       EXT2_INODE_SIZE (data) * blkoff,
 526                       sizeof (struct grub_ext2_inode), inode))
 527     return grub_errno;
 528
 529   return 0;
 530 }
 531
 532 static struct grub_ext2_data *
 533 grub_ext2_mount (grub_disk_t disk)
 534 {
 535   struct grub_ext2_data *data;
 536
 537   data = grub_malloc (sizeof (struct grub_ext2_data));
 538   if (!data)
 539     return 0;
 540
 541   /* Read the superblock.  */
 542   grub_disk_read (disk, 1 * 2, 0, sizeof (struct grub_ext2_sblock),
 543                   &data->sblock);
 544   if (grub_errno)
 545     goto fail;
 546
 547   /* Make sure this is an ext2 filesystem.  */
 548   if (grub_le_to_cpu16 (data->sblock.magic) != EXT2_MAGIC)
 549     {
 550       grub_error (GRUB_ERR_BAD_FS, "not an ext2 filesystem");
 551       goto fail;
 552     }
 553
 554   /* Check the FS doesn't have feature bits enabled that we don't support. */
 555   if (grub_le_to_cpu32 (data->sblock.feature_incompat)
 556         & ~(EXT2_DRIVER_SUPPORTED_INCOMPAT | EXT2_DRIVER_IGNORED_INCOMPAT))
 557     {
 558       grub_error (GRUB_ERR_BAD_FS, "filesystem has unsupported incompatible features");
 559       goto fail;
 560     }
 561
 562
 563   data->disk = disk;
 564
 565   data->diropen.data = data;
 566   data->diropen.ino = 2;
 567   data->diropen.inode_read = 1;
 568
 569   data->inode = &data->diropen.inode;
 570
 571   grub_ext2_read_inode (data, 2, data->inode);
 572   if (grub_errno)
 573     goto fail;
 574
 575   return data;
 576
 577  fail:
 578   if (grub_errno == GRUB_ERR_OUT_OF_RANGE)
 579     grub_error (GRUB_ERR_BAD_FS, "not an ext2 filesystem");
 580
 581   grub_free (data);
 582   return 0;
 583 }
 584
 585 static char *
 586 grub_ext2_read_symlink (grub_fshelp_node_t node)
 587 {
 588   char *symlink;
 589   struct grub_fshelp_node *diro = node;
 590
 591   if (! diro->inode_read)
 592     {
 593       grub_ext2_read_inode (diro->data, diro->ino, &diro->inode);
 594       if (grub_errno)
 595         return 0;
 596     }
 597
 598   symlink = grub_malloc (grub_le_to_cpu32 (diro->inode.size) + 1);
 599   if (! symlink)
 600     return 0;
 601
 602   /* If the filesize of the symlink is bigger than
 603      60 the symlink is stored in a separate block,
 604      otherwise it is stored in the inode.  */
 605   if (grub_le_to_cpu32 (diro->inode.size) <= 60)
 606     grub_strncpy (symlink,
 607                   diro->inode.symlink,
 608                   grub_le_to_cpu32 (diro->inode.size));
 609   else
 610     {
 611       grub_ext2_read_file (diro, 0, 0,
 612                            grub_le_to_cpu32 (diro->inode.size),
 613                            symlink);
 614       if (grub_errno)
 615         {
 616           grub_free (symlink);
 617           return 0;
 618         }
 619     }
 620
 621   symlink[grub_le_to_cpu32 (diro->inode.size)] = '\0';
 622   return symlink;
 623 }
 624
 625 static int
 626 grub_ext2_iterate_dir (grub_fshelp_node_t dir,
 627                        int NESTED_FUNC_ATTR
 628                        (*hook) (const char *filename,
 629                                 enum grub_fshelp_filetype filetype,
 630                                 grub_fshelp_node_t node))
 631 {
 632   unsigned int fpos = 0;
 633   struct grub_fshelp_node *diro = (struct grub_fshelp_node *) dir;
 634
 635   if (! diro->inode_read)
 636     {
 637       grub_ext2_read_inode (diro->data, diro->ino, &diro->inode);
 638       if (grub_errno)
 639         return 0;
 640     }
 641
 642   /* Search the file.  */
 643   while (fpos < grub_le_to_cpu32 (diro->inode.size))
 644     {
 645       struct ext2_dirent dirent;
 646
 647       grub_ext2_read_file (diro, 0, fpos, sizeof (struct ext2_dirent),
 648                            (char *) &dirent);
 649       if (grub_errno)
 650         return 0;
 651
 652       if (dirent.direntlen == 0)
 653         return 0;
 654
 655       if (dirent.namelen != 0)
 656         {
 657           char filename[dirent.namelen + 1];
 658           struct grub_fshelp_node *fdiro;
 659           enum grub_fshelp_filetype type = GRUB_FSHELP_UNKNOWN;
 660
 661           grub_ext2_read_file (diro, 0, fpos + sizeof (struct ext2_dirent),
 662                                dirent.namelen, filename);
 663           if (grub_errno)
 664             return 0;
 665
 666           fdiro = grub_malloc (sizeof (struct grub_fshelp_node));
 667           if (! fdiro)
 668             return 0;
 669
 670           fdiro->data = diro->data;
 671           fdiro->ino = grub_le_to_cpu32 (dirent.inode);
 672
 673           filename[dirent.namelen] = '\0';
 674
 675           if (dirent.filetype != FILETYPE_UNKNOWN)
 676             {
 677               fdiro->inode_read = 0;
 678
 679               if (dirent.filetype == FILETYPE_DIRECTORY)
 680                 type = GRUB_FSHELP_DIR;
 681               else if (dirent.filetype == FILETYPE_SYMLINK)
 682                 type = GRUB_FSHELP_SYMLINK;
 683               else if (dirent.filetype == FILETYPE_REG)
 684                 type = GRUB_FSHELP_REG;
 685             }
 686           else
 687             {
 688               /* The filetype can not be read from the dirent, read
 689                  the inode to get more information.  */
 690               grub_ext2_read_inode (diro->data,
 691                                     grub_le_to_cpu32 (dirent.inode),
 692                                     &fdiro->inode);
 693               if (grub_errno)
 694                 {
 695                   grub_free (fdiro);
 696                   return 0;
 697                 }
 698
 699               fdiro->inode_read = 1;
 700
 701               if ((grub_le_to_cpu16 (fdiro->inode.mode)
 702                    & FILETYPE_INO_MASK) == FILETYPE_INO_DIRECTORY)
 703                 type = GRUB_FSHELP_DIR;
 704               else if ((grub_le_to_cpu16 (fdiro->inode.mode)
 705                         & FILETYPE_INO_MASK) == FILETYPE_INO_SYMLINK)
 706                 type = GRUB_FSHELP_SYMLINK;
 707               else if ((grub_le_to_cpu16 (fdiro->inode.mode)
 708                         & FILETYPE_INO_MASK) == FILETYPE_INO_REG)
 709                 type = GRUB_FSHELP_REG;
 710             }
 711
 712           if (hook (filename, type, fdiro))
 713             return 1;
 714         }
 715
 716       fpos += grub_le_to_cpu16 (dirent.direntlen);
 717     }
 718
 719   return 0;
 720 }
 721
 722 /* Open a file named NAME and initialize FILE.  */
 723 static grub_err_t
 724 grub_ext2_open (struct grub_file *file, const char *name)
 725 {
 726   struct grub_ext2_data *data;
 727   struct grub_fshelp_node *fdiro = 0;
 728
 729   grub_dl_ref (my_mod);
 730
 731   data = grub_ext2_mount (file->device->disk);
 732   if (! data)
 733     goto fail;
 734
 735   grub_fshelp_find_file (name, &data->diropen, &fdiro, grub_ext2_iterate_dir,
 736                          grub_ext2_read_symlink, GRUB_FSHELP_REG);
 737   if (grub_errno)
 738     goto fail;
 739
 740   if (! fdiro->inode_read)
 741     {
 742       grub_ext2_read_inode (data, fdiro->ino, &fdiro->inode);
 743       if (grub_errno)
 744         goto fail;
 745     }
 746
 747   grub_memcpy (data->inode, &fdiro->inode, sizeof (struct grub_ext2_inode));
 748   grub_free (fdiro);
 749
 750   file->size = grub_le_to_cpu32 (data->inode->size);
 751   file->data = data;
 752   file->offset = 0;
 753
 754   return 0;
 755
 756  fail:
 757   if (fdiro != &data->diropen)
 758     grub_free (fdiro);
 759   grub_free (data);
 760
 761   grub_dl_unref (my_mod);
 762
 763   return grub_errno;
 764 }
 765
 766 static grub_err_t
 767 grub_ext2_close (grub_file_t file)
 768 {
 769   grub_free (file->data);
 770
 771   grub_dl_unref (my_mod);
 772
 773   return GRUB_ERR_NONE;
 774 }
 775
 776 /* Read LEN bytes data from FILE into BUF.  */
 777 static grub_ssize_t
 778 grub_ext2_read (grub_file_t file, char *buf, grub_size_t len)
 779 {
 780   struct grub_ext2_data *data = (struct grub_ext2_data *) file->data;
 781
 782   return grub_ext2_read_file (&data->diropen, file->read_hook,
 783                               file->offset, len, buf);
 784 }
 785
 786
 787 static grub_err_t
 788 grub_ext2_dir (grub_device_t device, const char *path,
 789                int (*hook) (const char *filename,
 790                             const struct grub_dirhook_info *info))
 791 {
 792   struct grub_ext2_data *data = 0;
 793   struct grub_fshelp_node *fdiro = 0;
 794
 795   auto int NESTED_FUNC_ATTR iterate (const char *filename,
 796                                      enum grub_fshelp_filetype filetype,
 797                                      grub_fshelp_node_t node);
 798
 799   int NESTED_FUNC_ATTR iterate (const char *filename,
 800                                 enum grub_fshelp_filetype filetype,
 801                                 grub_fshelp_node_t node)
 802     {
 803       struct grub_dirhook_info info;
 804       grub_memset (&info, 0, sizeof (info));
 805       if (! node->inode_read)
 806         {
 807           grub_ext2_read_inode (data, node->ino, &node->inode);
 808           if (!grub_errno)
 809             node->inode_read = 1;
 810           grub_errno = GRUB_ERR_NONE;
 811         }
 812       if (node->inode_read)
 813         {
 814           info.mtimeset = 1;
 815           info.mtime = grub_le_to_cpu32 (node->inode.mtime);
 816         }
 817
 818       info.dir = ((filetype & GRUB_FSHELP_TYPE_MASK) == GRUB_FSHELP_DIR);
 819       grub_free (node);
 820       return hook (filename, &info);
 821     }
 822
 823   grub_dl_ref (my_mod);
 824
 825   data = grub_ext2_mount (device->disk);
 826   if (! data)
 827     goto fail;
 828
 829   grub_fshelp_find_file (path, &data->diropen, &fdiro, grub_ext2_iterate_dir,
 830                          grub_ext2_read_symlink, GRUB_FSHELP_DIR);
 831   if (grub_errno)
 832     goto fail;
 833
 834   grub_ext2_iterate_dir (fdiro, iterate);
 835
 836  fail:
 837   if (fdiro != &data->diropen)
 838     grub_free (fdiro);
 839   grub_free (data);
 840
 841   grub_dl_unref (my_mod);
 842
 843   return grub_errno;
 844 }
 845
 846 static grub_err_t
 847 grub_ext2_label (grub_device_t device, char **label)
 848 {
 849   struct grub_ext2_data *data;
 850   grub_disk_t disk = device->disk;
 851
 852   grub_dl_ref (my_mod);
 853
 854   data = grub_ext2_mount (disk);
 855   if (data)
 856     *label = grub_strndup (data->sblock.volume_name, 14);
 857   else
 858     *label = NULL;
 859
 860   grub_dl_unref (my_mod);
 861
 862   grub_free (data);
 863
 864   return grub_errno;
 865 }
 866
 867 static grub_err_t
 868 grub_ext2_uuid (grub_device_t device, char **uuid)
 869 {
 870   struct grub_ext2_data *data;
 871   grub_disk_t disk = device->disk;
 872
 873   grub_dl_ref (my_mod);
 874
 875   data = grub_ext2_mount (disk);
 876   if (data)
 877     {
 878       *uuid = grub_malloc (40 + sizeof ('\0'));
 879       grub_sprintf (*uuid, "%04x%04x-%04x-%04x-%04x-%04x%04x%04x",
 880                     grub_be_to_cpu16 (data->sblock.uuid[0]), grub_be_to_cpu16 (data->sblock.uuid[1]),
 881                     grub_be_to_cpu16 (data->sblock.uuid[2]), grub_be_to_cpu16 (data->sblock.uuid[3]),
 882                     grub_be_to_cpu16 (data->sblock.uuid[4]), grub_be_to_cpu16 (data->sblock.uuid[5]),
 883                     grub_be_to_cpu16 (data->sblock.uuid[6]), grub_be_to_cpu16 (data->sblock.uuid[7]));
 884     }
 885   else
 886     *uuid = NULL;
 887
 888   grub_dl_unref (my_mod);
 889
 890   grub_free (data);
 891
 892   return grub_errno;
 893 }
 894
 895 /* Get mtime.  */
 896 static grub_err_t
 897 grub_ext2_mtime (grub_device_t device, grub_int32_t *tm)
 898 {
 899   struct grub_ext2_data *data;
 900   grub_disk_t disk = device->disk;
 901
 902   grub_dl_ref (my_mod);
 903
 904   data = grub_ext2_mount (disk);
 905   if (!data)
 906     *tm = 0;
 907   else
 908     *tm = grub_le_to_cpu32 (data->sblock.utime);
 909
 910   grub_dl_unref (my_mod);
 911
 912   grub_free (data);
 913
 914   return grub_errno;
 915
 916 }
 917
 918
 919 \f
 920 static struct grub_fs grub_ext2_fs =
 921   {
 922     .name = "ext2",
 923     .dir = grub_ext2_dir,
 924     .open = grub_ext2_open,
 925     .read = grub_ext2_read,
 926     .close = grub_ext2_close,
 927     .label = grub_ext2_label,
 928     .uuid = grub_ext2_uuid,
 929     .mtime = grub_ext2_mtime,
 930 #ifdef GRUB_UTIL
 931     .reserved_first_sector = 1,
 932 #endif
 933     .next = 0
 934   };
 935
 936 GRUB_MOD_INIT(ext2)
 937 {
 938   grub_fs_register (&grub_ext2_fs);
 939   my_mod = mod;
 940 }
 941
 942 GRUB_MOD_FINI(ext2)
 943 {
 944   grub_fs_unregister (&grub_ext2_fs);
 945 }