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 #ifndef GRUB_UTIL
 321 static grub_dl_t my_mod;
 322 #endif
 323
 324 \f
 325
 326 /* Read into BLKGRP the blockgroup descriptor of blockgroup GROUP of
 327    the mounted filesystem DATA.  */
 328 inline static grub_err_t
 329 grub_ext2_blockgroup (struct grub_ext2_data *data, int group,
 330                       struct grub_ext2_block_group *blkgrp)
 331 {
 332   return grub_disk_read (data->disk,
 333                          ((grub_le_to_cpu32 (data->sblock.first_data_block) + 1)
 334                           << LOG2_EXT2_BLOCK_SIZE (data)),
 335                          group * sizeof (struct grub_ext2_block_group),
 336                          sizeof (struct grub_ext2_block_group), (char *) blkgrp);
 337 }
 338
 339 static struct grub_ext4_extent_header *
 340 grub_ext4_find_leaf (struct grub_ext2_data *data, char *buf,
 341                      struct grub_ext4_extent_header *ext_block,
 342                      grub_uint32_t fileblock)
 343 {
 344   struct grub_ext4_extent_idx *index;
 345
 346   while (1)
 347     {
 348       int i;
 349       grub_disk_addr_t block;
 350
 351       index = (struct grub_ext4_extent_idx *) (ext_block + 1);
 352
 353       if (grub_le_to_cpu16(ext_block->magic) != EXT4_EXT_MAGIC)
 354         return 0;
 355
 356       if (ext_block->depth == 0)
 357         return ext_block;
 358
 359       for (i = 0; i < grub_le_to_cpu16 (ext_block->entries); i++)
 360         {
 361           if (fileblock < grub_le_to_cpu32(index[i].block))
 362             break;
 363         }
 364
 365       if (--i < 0)
 366         return 0;
 367
 368       block = grub_le_to_cpu16 (index[i].leaf_hi);
 369       block = (block << 32) + grub_le_to_cpu32 (index[i].leaf);
 370       if (grub_disk_read (data->disk,
 371                           block << LOG2_EXT2_BLOCK_SIZE (data),
 372                           0, EXT2_BLOCK_SIZE(data), buf))
 373         return 0;
 374
 375       ext_block = (struct grub_ext4_extent_header *) buf;
 376     }
 377 }
 378
 379 static grub_disk_addr_t
 380 grub_ext2_read_block (grub_fshelp_node_t node, grub_disk_addr_t fileblock)
 381 {
 382   struct grub_ext2_data *data = node->data;
 383   struct grub_ext2_inode *inode = &node->inode;
 384   int blknr = -1;
 385   unsigned int blksz = EXT2_BLOCK_SIZE (data);
 386   int log2_blksz = LOG2_EXT2_BLOCK_SIZE (data);
 387
 388   if (grub_le_to_cpu32(inode->flags) & EXT4_EXTENTS_FLAG)
 389     {
 390       char buf[EXT2_BLOCK_SIZE(data)];
 391       struct grub_ext4_extent_header *leaf;
 392       struct grub_ext4_extent *ext;
 393       int i;
 394
 395       leaf = grub_ext4_find_leaf (data, buf,
 396                                   (struct grub_ext4_extent_header *) inode->blocks.dir_blocks,
 397                                   fileblock);
 398       if (! leaf)
 399         {
 400           grub_error (GRUB_ERR_BAD_FS, "invalid extent");
 401           return -1;
 402         }
 403
 404       ext = (struct grub_ext4_extent *) (leaf + 1);
 405       for (i = 0; i < grub_le_to_cpu16 (leaf->entries); i++)
 406         {
 407           if (fileblock < grub_le_to_cpu32 (ext[i].block))
 408             break;
 409         }
 410
 411       if (--i >= 0)
 412         {
 413           fileblock -= grub_le_to_cpu32 (ext[i].block);
 414           if (fileblock >= grub_le_to_cpu16 (ext[i].len))
 415             return 0;
 416           else
 417             {
 418               grub_disk_addr_t start;
 419
 420               start = grub_le_to_cpu16 (ext[i].start_hi);
 421               start = (start << 32) + grub_le_to_cpu32 (ext[i].start);
 422
 423               return fileblock + start;
 424             }
 425         }
 426       else
 427         {
 428           grub_error (GRUB_ERR_BAD_FS, "something wrong with extent");
 429           return -1;
 430         }
 431     }
 432   /* Direct blocks.  */
 433   if (fileblock < INDIRECT_BLOCKS)
 434     blknr = grub_le_to_cpu32 (inode->blocks.dir_blocks[fileblock]);
 435   /* Indirect.  */
 436   else if (fileblock < INDIRECT_BLOCKS + blksz / 4)
 437     {
 438       grub_uint32_t indir[blksz / 4];
 439
 440       if (grub_disk_read (data->disk,
 441                           grub_le_to_cpu32 (inode->blocks.indir_block)
 442                           << log2_blksz,
 443                           0, blksz, (char *) indir))
 444         return grub_errno;
 445
 446       blknr = grub_le_to_cpu32 (indir[fileblock - INDIRECT_BLOCKS]);
 447     }
 448   /* Double indirect.  */
 449   else if (fileblock < INDIRECT_BLOCKS + blksz / 4 * (blksz / 4 + 1))
 450     {
 451       unsigned int perblock = blksz / 4;
 452       unsigned int rblock = fileblock - (INDIRECT_BLOCKS
 453                                          + blksz / 4);
 454       grub_uint32_t indir[blksz / 4];
 455
 456       if (grub_disk_read (data->disk,
 457                           grub_le_to_cpu32 (inode->blocks.double_indir_block)
 458                           << log2_blksz,
 459                           0, blksz, (char *) indir))
 460         return grub_errno;
 461
 462       if (grub_disk_read (data->disk,
 463                           grub_le_to_cpu32 (indir[rblock / perblock])
 464                           << log2_blksz,
 465                           0, blksz, (char *) indir))
 466         return grub_errno;
 467
 468
 469       blknr = grub_le_to_cpu32 (indir[rblock % perblock]);
 470     }
 471   /* triple indirect.  */
 472   else
 473     {
 474       grub_error (GRUB_ERR_NOT_IMPLEMENTED_YET,
 475                   "ext2fs doesn't support triple indirect blocks");
 476     }
 477
 478   return blknr;
 479 }
 480
 481 /* Read LEN bytes from the file described by DATA starting with byte
 482    POS.  Return the amount of read bytes in READ.  */
 483 static grub_ssize_t
 484 grub_ext2_read_file (grub_fshelp_node_t node,
 485                      void NESTED_FUNC_ATTR (*read_hook) (grub_disk_addr_t sector,
 486                                         unsigned offset, unsigned length),
 487                      int pos, grub_size_t len, char *buf)
 488 {
 489   return grub_fshelp_read_file (node->data->disk, node, read_hook,
 490                                 pos, len, buf, grub_ext2_read_block,
 491                                 node->inode.size,
 492                                 LOG2_EXT2_BLOCK_SIZE (node->data));
 493
 494 }
 495
 496
 497 /* Read the inode INO for the file described by DATA into INODE.  */
 498 static grub_err_t
 499 grub_ext2_read_inode (struct grub_ext2_data *data,
 500                       int ino, struct grub_ext2_inode *inode)
 501 {
 502   struct grub_ext2_block_group blkgrp;
 503   struct grub_ext2_sblock *sblock = &data->sblock;
 504   int inodes_per_block;
 505   unsigned int blkno;
 506   unsigned int blkoff;
 507
 508   /* It is easier to calculate if the first inode is 0.  */
 509   ino--;
 510
 511   grub_ext2_blockgroup (data,
 512                         ino / grub_le_to_cpu32 (sblock->inodes_per_group),
 513                         &blkgrp);
 514   if (grub_errno)
 515     return grub_errno;
 516
 517   inodes_per_block = EXT2_BLOCK_SIZE (data) / EXT2_INODE_SIZE (data);
 518   blkno = (ino % grub_le_to_cpu32 (sblock->inodes_per_group))
 519     / inodes_per_block;
 520   blkoff = (ino % grub_le_to_cpu32 (sblock->inodes_per_group))
 521     % inodes_per_block;
 522
 523   /* Read the inode.  */
 524   if (grub_disk_read (data->disk,
 525                       ((grub_le_to_cpu32 (blkgrp.inode_table_id) + blkno)
 526                         << LOG2_EXT2_BLOCK_SIZE (data)),
 527                       EXT2_INODE_SIZE (data) * blkoff,
 528                       sizeof (struct grub_ext2_inode), (char *) inode))
 529     return grub_errno;
 530
 531   return 0;
 532 }
 533
 534 static struct grub_ext2_data *
 535 grub_ext2_mount (grub_disk_t disk)
 536 {
 537   struct grub_ext2_data *data;
 538
 539   data = grub_malloc (sizeof (struct grub_ext2_data));
 540   if (!data)
 541     return 0;
 542
 543   /* Read the superblock.  */
 544   grub_disk_read (disk, 1 * 2, 0, sizeof (struct grub_ext2_sblock),
 545                   (char *) &data->sblock);
 546   if (grub_errno)
 547     goto fail;
 548
 549   /* Make sure this is an ext2 filesystem.  */
 550   if (grub_le_to_cpu16 (data->sblock.magic) != EXT2_MAGIC)
 551     {
 552       grub_error (GRUB_ERR_BAD_FS, "not an ext2 filesystem");
 553       goto fail;
 554     }
 555
 556   /* Check the FS doesn't have feature bits enabled that we don't support. */
 557   if (grub_le_to_cpu32 (data->sblock.feature_incompat)
 558         & ~(EXT2_DRIVER_SUPPORTED_INCOMPAT | EXT2_DRIVER_IGNORED_INCOMPAT))
 559     {
 560       grub_error (GRUB_ERR_BAD_FS, "filesystem has unsupported incompatible features");
 561       goto fail;
 562     }
 563
 564
 565   data->disk = disk;
 566
 567   data->diropen.data = data;
 568   data->diropen.ino = 2;
 569   data->diropen.inode_read = 1;
 570
 571   data->inode = &data->diropen.inode;
 572
 573   grub_ext2_read_inode (data, 2, data->inode);
 574   if (grub_errno)
 575     goto fail;
 576
 577   return data;
 578
 579  fail:
 580   if (grub_errno == GRUB_ERR_OUT_OF_RANGE)
 581     grub_error (GRUB_ERR_BAD_FS, "not an ext2 filesystem");
 582
 583   grub_free (data);
 584   return 0;
 585 }
 586
 587 static char *
 588 grub_ext2_read_symlink (grub_fshelp_node_t node)
 589 {
 590   char *symlink;
 591   struct grub_fshelp_node *diro = node;
 592
 593   if (! diro->inode_read)
 594     {
 595       grub_ext2_read_inode (diro->data, diro->ino, &diro->inode);
 596       if (grub_errno)
 597         return 0;
 598     }
 599
 600   symlink = grub_malloc (grub_le_to_cpu32 (diro->inode.size) + 1);
 601   if (! symlink)
 602     return 0;
 603
 604   /* If the filesize of the symlink is bigger than
 605      60 the symlink is stored in a separate block,
 606      otherwise it is stored in the inode.  */
 607   if (grub_le_to_cpu32 (diro->inode.size) <= 60)
 608     grub_strncpy (symlink,
 609                   diro->inode.symlink,
 610                   grub_le_to_cpu32 (diro->inode.size));
 611   else
 612     {
 613       grub_ext2_read_file (diro, 0, 0,
 614                            grub_le_to_cpu32 (diro->inode.size),
 615                            symlink);
 616       if (grub_errno)
 617         {
 618           grub_free (symlink);
 619           return 0;
 620         }
 621     }
 622
 623   symlink[grub_le_to_cpu32 (diro->inode.size)] = '\0';
 624   return symlink;
 625 }
 626
 627 static int
 628 grub_ext2_iterate_dir (grub_fshelp_node_t dir,
 629                        int NESTED_FUNC_ATTR
 630                        (*hook) (const char *filename,
 631                                 enum grub_fshelp_filetype filetype,
 632                                 grub_fshelp_node_t node))
 633 {
 634   unsigned int fpos = 0;
 635   struct grub_fshelp_node *diro = (struct grub_fshelp_node *) dir;
 636
 637   if (! diro->inode_read)
 638     {
 639       grub_ext2_read_inode (diro->data, diro->ino, &diro->inode);
 640       if (grub_errno)
 641         return 0;
 642     }
 643
 644   /* Search the file.  */
 645   while (fpos < grub_le_to_cpu32 (diro->inode.size))
 646     {
 647       struct ext2_dirent dirent;
 648
 649       grub_ext2_read_file (diro, 0, fpos, sizeof (struct ext2_dirent),
 650                            (char *) &dirent);
 651       if (grub_errno)
 652         return 0;
 653
 654       if (dirent.namelen != 0)
 655         {
 656           char filename[dirent.namelen + 1];
 657           struct grub_fshelp_node *fdiro;
 658           enum grub_fshelp_filetype type = GRUB_FSHELP_UNKNOWN;
 659
 660           grub_ext2_read_file (diro, 0, fpos + sizeof (struct ext2_dirent),
 661                                dirent.namelen, filename);
 662           if (grub_errno)
 663             return 0;
 664
 665           fdiro = grub_malloc (sizeof (struct grub_fshelp_node));
 666           if (! fdiro)
 667             return 0;
 668
 669           fdiro->data = diro->data;
 670           fdiro->ino = grub_le_to_cpu32 (dirent.inode);
 671
 672           filename[dirent.namelen] = '\0';
 673
 674           if (dirent.filetype != FILETYPE_UNKNOWN)
 675             {
 676               fdiro->inode_read = 0;
 677
 678               if (dirent.filetype == FILETYPE_DIRECTORY)
 679                 type = GRUB_FSHELP_DIR;
 680               else if (dirent.filetype == FILETYPE_SYMLINK)
 681                 type = GRUB_FSHELP_SYMLINK;
 682               else if (dirent.filetype == FILETYPE_REG)
 683                 type = GRUB_FSHELP_REG;
 684             }
 685           else
 686             {
 687               /* The filetype can not be read from the dirent, read
 688                  the inode to get more information.  */
 689               grub_ext2_read_inode (diro->data,
 690                                     grub_le_to_cpu32 (dirent.inode),
 691                                     &fdiro->inode);
 692               if (grub_errno)
 693                 {
 694                   grub_free (fdiro);
 695                   return 0;
 696                 }
 697
 698               fdiro->inode_read = 1;
 699
 700               if ((grub_le_to_cpu16 (fdiro->inode.mode)
 701                    & FILETYPE_INO_MASK) == FILETYPE_INO_DIRECTORY)
 702                 type = GRUB_FSHELP_DIR;
 703               else if ((grub_le_to_cpu16 (fdiro->inode.mode)
 704                         & FILETYPE_INO_MASK) == FILETYPE_INO_SYMLINK)
 705                 type = GRUB_FSHELP_SYMLINK;
 706               else if ((grub_le_to_cpu16 (fdiro->inode.mode)
 707                         & FILETYPE_INO_MASK) == FILETYPE_INO_REG)
 708                 type = GRUB_FSHELP_REG;
 709             }
 710
 711           if (hook (filename, type, fdiro))
 712             return 1;
 713         }
 714
 715       fpos += grub_le_to_cpu16 (dirent.direntlen);
 716     }
 717
 718   return 0;
 719 }
 720
 721 /* Open a file named NAME and initialize FILE.  */
 722 static grub_err_t
 723 grub_ext2_open (struct grub_file *file, const char *name)
 724 {
 725   struct grub_ext2_data *data;
 726   struct grub_fshelp_node *fdiro = 0;
 727
 728 #ifndef GRUB_UTIL
 729   grub_dl_ref (my_mod);
 730 #endif
 731
 732   data = grub_ext2_mount (file->device->disk);
 733   if (! data)
 734     goto fail;
 735
 736   grub_fshelp_find_file (name, &data->diropen, &fdiro, grub_ext2_iterate_dir,
 737                          grub_ext2_read_symlink, GRUB_FSHELP_REG);
 738   if (grub_errno)
 739     goto fail;
 740
 741   if (! fdiro->inode_read)
 742     {
 743       grub_ext2_read_inode (data, fdiro->ino, &fdiro->inode);
 744       if (grub_errno)
 745         goto fail;
 746     }
 747
 748   grub_memcpy (data->inode, &fdiro->inode, sizeof (struct grub_ext2_inode));
 749   grub_free (fdiro);
 750
 751   file->size = grub_le_to_cpu32 (data->inode->size);
 752   file->data = data;
 753   file->offset = 0;
 754
 755   return 0;
 756
 757  fail:
 758   if (fdiro != &data->diropen)
 759     grub_free (fdiro);
 760   grub_free (data);
 761
 762 #ifndef GRUB_UTIL
 763   grub_dl_unref (my_mod);
 764 #endif
 765
 766   return grub_errno;
 767 }
 768
 769 static grub_err_t
 770 grub_ext2_close (grub_file_t file)
 771 {
 772   grub_free (file->data);
 773
 774 #ifndef GRUB_UTIL
 775   grub_dl_unref (my_mod);
 776 #endif
 777
 778   return GRUB_ERR_NONE;
 779 }
 780
 781 /* Read LEN bytes data from FILE into BUF.  */
 782 static grub_ssize_t
 783 grub_ext2_read (grub_file_t file, char *buf, grub_size_t len)
 784 {
 785   struct grub_ext2_data *data = (struct grub_ext2_data *) file->data;
 786
 787   return grub_ext2_read_file (&data->diropen, file->read_hook,
 788                               file->offset, len, buf);
 789 }
 790
 791
 792 static grub_err_t
 793 grub_ext2_dir (grub_device_t device, const char *path,
 794                int (*hook) (const char *filename,
 795                             const struct grub_dirhook_info *info))
 796 {
 797   struct grub_ext2_data *data = 0;;
 798   struct grub_fshelp_node *fdiro = 0;
 799
 800   auto int NESTED_FUNC_ATTR iterate (const char *filename,
 801                                      enum grub_fshelp_filetype filetype,
 802                                      grub_fshelp_node_t node);
 803
 804   int NESTED_FUNC_ATTR iterate (const char *filename,
 805                                 enum grub_fshelp_filetype filetype,
 806                                 grub_fshelp_node_t node)
 807     {
 808       struct grub_dirhook_info info;
 809       grub_memset (&info, 0, sizeof (info));
 810       if (! node->inode_read)
 811         {
 812           grub_ext2_read_inode (data, node->ino, &node->inode);
 813           if (!grub_errno)
 814             node->inode_read = 1;
 815           grub_errno = GRUB_ERR_NONE;
 816         }
 817       if (node->inode_read)
 818         {
 819           info.mtimeset = 1;
 820           info.mtime = grub_le_to_cpu32 (node->inode.mtime);
 821         }
 822
 823       info.dir = ((filetype & GRUB_FSHELP_TYPE_MASK) == GRUB_FSHELP_DIR);
 824       grub_free (node);
 825       return hook (filename, &info);
 826     }
 827
 828 #ifndef GRUB_UTIL
 829   grub_dl_ref (my_mod);
 830 #endif
 831
 832   data = grub_ext2_mount (device->disk);
 833   if (! data)
 834     goto fail;
 835
 836   grub_fshelp_find_file (path, &data->diropen, &fdiro, grub_ext2_iterate_dir,
 837                          grub_ext2_read_symlink, GRUB_FSHELP_DIR);
 838   if (grub_errno)
 839     goto fail;
 840
 841   grub_ext2_iterate_dir (fdiro, iterate);
 842
 843  fail:
 844   if (fdiro != &data->diropen)
 845     grub_free (fdiro);
 846   grub_free (data);
 847
 848 #ifndef GRUB_UTIL
 849   grub_dl_unref (my_mod);
 850 #endif
 851
 852   return grub_errno;
 853 }
 854
 855 static grub_err_t
 856 grub_ext2_label (grub_device_t device, char **label)
 857 {
 858   struct grub_ext2_data *data;
 859   grub_disk_t disk = device->disk;
 860
 861 #ifndef GRUB_UTIL
 862   grub_dl_ref (my_mod);
 863 #endif
 864
 865   data = grub_ext2_mount (disk);
 866   if (data)
 867     *label = grub_strndup (data->sblock.volume_name, 14);
 868   else
 869     *label = NULL;
 870
 871 #ifndef GRUB_UTIL
 872   grub_dl_unref (my_mod);
 873 #endif
 874
 875   grub_free (data);
 876
 877   return grub_errno;
 878 }
 879
 880 static grub_err_t
 881 grub_ext2_uuid (grub_device_t device, char **uuid)
 882 {
 883   struct grub_ext2_data *data;
 884   grub_disk_t disk = device->disk;
 885
 886 #ifndef GRUB_UTIL
 887   grub_dl_ref (my_mod);
 888 #endif
 889
 890   data = grub_ext2_mount (disk);
 891   if (data)
 892     {
 893       *uuid = grub_malloc (40 + sizeof ('\0'));
 894       grub_sprintf (*uuid, "%04x%04x-%04x-%04x-%04x-%04x%04x%04x",
 895                     grub_be_to_cpu16 (data->sblock.uuid[0]), grub_be_to_cpu16 (data->sblock.uuid[1]),
 896                     grub_be_to_cpu16 (data->sblock.uuid[2]), grub_be_to_cpu16 (data->sblock.uuid[3]),
 897                     grub_be_to_cpu16 (data->sblock.uuid[4]), grub_be_to_cpu16 (data->sblock.uuid[5]),
 898                     grub_be_to_cpu16 (data->sblock.uuid[6]), grub_be_to_cpu16 (data->sblock.uuid[7]));
 899     }
 900   else
 901     *uuid = NULL;
 902
 903 #ifndef GRUB_UTIL
 904   grub_dl_unref (my_mod);
 905 #endif
 906
 907   grub_free (data);
 908
 909   return grub_errno;
 910 }
 911
 912 /* Get mtime.  */
 913 static grub_err_t
 914 grub_ext2_mtime (grub_device_t device, grub_int32_t *tm)
 915 {
 916   struct grub_ext2_data *data;
 917   grub_disk_t disk = device->disk;
 918
 919 #ifndef GRUB_UTIL
 920   grub_dl_ref (my_mod);
 921 #endif
 922
 923   data = grub_ext2_mount (disk);
 924   if (!data)
 925     *tm = 0;
 926   else
 927     *tm = grub_le_to_cpu32 (data->sblock.utime);
 928
 929 #ifndef GRUB_UTIL
 930   grub_dl_unref (my_mod);
 931 #endif
 932
 933   grub_free (data);
 934
 935   return grub_errno;
 936
 937 }
 938
 939
 940 \f
 941 static struct grub_fs grub_ext2_fs =
 942   {
 943     .name = "ext2",
 944     .dir = grub_ext2_dir,
 945     .open = grub_ext2_open,
 946     .read = grub_ext2_read,
 947     .close = grub_ext2_close,
 948     .label = grub_ext2_label,
 949     .uuid = grub_ext2_uuid,
 950     .mtime = grub_ext2_mtime,
 951     .next = 0
 952   };
 953
 954 GRUB_MOD_INIT(ext2)
 955 {
 956   grub_fs_register (&grub_ext2_fs);
 957 #ifndef GRUB_UTIL
 958   my_mod = mod;
 959 #endif
 960 }
 961
 962 GRUB_MOD_FINI(ext2)
 963 {
 964   grub_fs_unregister (&grub_ext2_fs);
 965 }