arch/common/boot/grub2/fs/jfs.c

   1 /* jfs.c - JFS.  */
   2 /*
   3  *  GRUB  --  GRand Unified Bootloader
   4  *  Copyright (C) 2004,2005,2006,2007  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 #include <grub/err.h>
  21 #include <grub/file.h>
  22 #include <grub/mm.h>
  23 #include <grub/misc.h>
  24 #include <grub/disk.h>
  25 #include <grub/dl.h>
  26 #include <grub/types.h>
  27
  28 #define GRUB_JFS_MAX_SYMLNK_CNT 8
  29 #define GRUB_JFS_FILETYPE_MASK  0170000
  30 #define GRUB_JFS_FILETYPE_REG   0100000
  31 #define GRUB_JFS_FILETYPE_LNK   0120000
  32 #define GRUB_JFS_FILETYPE_DIR   0040000
  33
  34 #define GRUB_JFS_SBLOCK         64
  35 #define GRUB_JFS_AGGR_INODE     2
  36 #define GRUB_JFS_FS1_INODE_BLK  104
  37
  38 #define GRUB_JFS_TREE_LEAF      2
  39
  40 struct grub_jfs_sblock
  41 {
  42   /* The magic for JFS.  It should contain the string "JFS1".  */
  43   grub_uint8_t magic[4];
  44   grub_uint32_t version;
  45   grub_uint64_t ag_size;
  46
  47   /* The size of a filesystem block in bytes.  XXX: currently only
  48      4096 was tested.  */
  49   grub_uint32_t blksz;
  50   grub_uint16_t log2_blksz;
  51
  52   grub_uint8_t unused[71];
  53   grub_uint8_t volname[11];
  54 };
  55
  56 struct grub_jfs_extent
  57 {
  58   /* The length of the extent in filesystem blocks.  */
  59   grub_uint16_t length;
  60   grub_uint8_t length2;
  61
  62   /* The physical offset of the first block on the disk.  */
  63   grub_uint8_t blk1;
  64   grub_uint32_t blk2;
  65 } __attribute__ ((packed));
  66
  67 struct grub_jfs_iag
  68 {
  69   grub_uint8_t unused[3072];
  70   struct grub_jfs_extent inodes[128];
  71 } __attribute__ ((packed));
  72
  73
  74 /* The head of the tree used to find extents.  */
  75 struct grub_jfs_treehead
  76 {
  77   grub_uint64_t next;
  78   grub_uint64_t prev;
  79
  80   grub_uint8_t flags;
  81   grub_uint8_t unused;
  82
  83   grub_uint16_t count;
  84   grub_uint16_t max;
  85   grub_uint8_t unused2[10];
  86 } __attribute__ ((packed));
  87
  88 /* A node in the extent tree.  */
  89 struct grub_jfs_tree_extent
  90 {
  91   grub_uint8_t flags;
  92   grub_uint16_t unused;
  93
  94   /* The offset is the key used to lookup an extent.  */
  95   grub_uint8_t offset1;
  96   grub_uint32_t offset2;
  97
  98   struct grub_jfs_extent extent;
  99 } __attribute__ ((packed));
 100
 101 /* The tree of directory entries.  */
 102 struct grub_jfs_tree_dir
 103 {
 104   /* Pointers to the previous and next tree headers of other nodes on
 105      this level.  */
 106   grub_uint64_t nextb;
 107   grub_uint64_t prevb;
 108
 109   grub_uint8_t flags;
 110
 111   /* The amount of dirents in this node.  */
 112   grub_uint8_t count;
 113   grub_uint8_t freecnt;
 114   grub_uint8_t freelist;
 115   grub_uint8_t maxslot;
 116
 117   /* The location of the sorted array of pointers to dirents.  */
 118   grub_uint8_t sindex;
 119   grub_uint8_t unused[10];
 120 } __attribute__ ((packed));
 121
 122 /* An internal node in the dirents tree.  */
 123 struct grub_jfs_internal_dirent
 124 {
 125   struct grub_jfs_extent ex;
 126   grub_uint8_t next;
 127   grub_uint8_t len;
 128   grub_uint16_t namepart[11];
 129 } __attribute__ ((packed));
 130
 131 /* A leaf node in the dirents tree.  */
 132 struct grub_jfs_leaf_dirent
 133 {
 134   /* The inode for this dirent.  */
 135   grub_uint32_t inode;
 136   grub_uint8_t next;
 137
 138   /* The size of the name.  */
 139   grub_uint8_t len;
 140   grub_uint16_t namepart[11];
 141   grub_uint32_t index;
 142 } __attribute__ ((packed));
 143
 144 /* A leaf in the dirents tree.  This one is used if the previously
 145    dirent was not big enough to store the name.  */
 146 struct grub_jfs_leaf_next_dirent
 147 {
 148   grub_uint8_t next;
 149   grub_uint8_t len;
 150   grub_uint16_t namepart[15];
 151 } __attribute__ ((packed));
 152
 153 struct grub_jfs_inode
 154 {
 155   grub_uint32_t stamp;
 156   grub_uint32_t fileset;
 157   grub_uint32_t inode;
 158   grub_uint8_t unused[12];
 159   grub_uint64_t size;
 160   grub_uint8_t unused2[20];
 161   grub_uint32_t mode;
 162   grub_uint8_t unused3[72];
 163   grub_uint8_t unused4[96];
 164
 165   union
 166   {
 167     /* The tree describing the extents of the file.  */
 168     struct __attribute__ ((packed))
 169     {
 170       struct grub_jfs_treehead tree;
 171       struct grub_jfs_tree_extent extents[16];
 172     } file;
 173     union
 174     {
 175       /* The tree describing the dirents.  */
 176       struct
 177       {
 178         grub_uint8_t unused[16];
 179         grub_uint8_t flags;
 180
 181         /* Amount of dirents in this node.  */
 182         grub_uint8_t count;
 183         grub_uint8_t freecnt;
 184         grub_uint8_t freelist;
 185         grub_uint32_t idotdot;
 186         grub_uint8_t sorted[8];
 187       } header;
 188       struct grub_jfs_leaf_dirent dirents[8];
 189     } dir __attribute__ ((packed));
 190     /* Fast symlink.  */
 191     struct
 192     {
 193       grub_uint8_t unused[32];
 194       grub_uint8_t path[128];
 195     } symlink;
 196   } __attribute__ ((packed));
 197 } __attribute__ ((packed));
 198
 199 struct grub_jfs_data
 200 {
 201   struct grub_jfs_sblock sblock;
 202   grub_disk_t disk;
 203   struct grub_jfs_inode fileset;
 204   struct grub_jfs_inode currinode;
 205   int pos;
 206   int linknest;
 207 } __attribute__ ((packed));
 208
 209 struct grub_jfs_diropen
 210 {
 211   int index;
 212   union
 213   {
 214     struct grub_jfs_tree_dir header;
 215     struct grub_jfs_leaf_dirent dirent[0];
 216     struct grub_jfs_leaf_next_dirent next_dirent[0];
 217     char sorted[0];
 218   } *dirpage __attribute__ ((packed));
 219   struct grub_jfs_data *data;
 220   struct grub_jfs_inode *inode;
 221   int count;
 222   char *sorted;
 223   struct grub_jfs_leaf_dirent *leaf;
 224   struct grub_jfs_leaf_next_dirent *next_leaf;
 225
 226   /* The filename and inode of the last read dirent.  */
 227   char name[255];
 228   grub_uint32_t ino;
 229 } __attribute__ ((packed));
 230
 231
 232 #ifndef GRUB_UTIL
 233 static grub_dl_t my_mod;
 234 #endif
 235 \f
 236 static grub_err_t grub_jfs_lookup_symlink (struct grub_jfs_data *data, int ino);
 237
 238 /* Get the block number for the block BLK in the node INODE in the
 239    mounted filesystem DATA.  */
 240 static int
 241 grub_jfs_blkno (struct grub_jfs_data *data, struct grub_jfs_inode *inode,
 242                 unsigned int blk)
 243 {
 244   auto int getblk (struct grub_jfs_treehead *treehead,
 245                    struct grub_jfs_tree_extent *extents);
 246
 247   int getblk (struct grub_jfs_treehead *treehead,
 248               struct grub_jfs_tree_extent *extents)
 249     {
 250       int found = -1;
 251       int i;
 252
 253       for (i = 0; i < grub_le_to_cpu16 (treehead->count) - 2; i++)
 254         {
 255           if (treehead->flags & GRUB_JFS_TREE_LEAF)
 256             {
 257               /* Read the leafnode.  */
 258               if (grub_le_to_cpu32 (extents[i].offset2) <= blk
 259                   && ((grub_le_to_cpu16 (extents[i].extent.length))
 260                       + (extents[i].extent.length2 << 8)
 261                       + grub_le_to_cpu32 (extents[i].offset2)) > blk)
 262                 return (blk - grub_le_to_cpu32 (extents[i].offset2)
 263                         + grub_le_to_cpu32 (extents[i].extent.blk2));
 264             }
 265           else
 266             if (blk >= grub_le_to_cpu32 (extents[i].offset2))
 267               found = i;
 268         }
 269
 270       if (found != -1)
 271         {
 272           struct
 273           {
 274             struct grub_jfs_treehead treehead;
 275             struct grub_jfs_tree_extent extents[254];
 276           } tree;
 277
 278           if (grub_disk_read (data->disk,
 279                               grub_le_to_cpu32 (extents[found].extent.blk2)
 280                               << (grub_le_to_cpu16 (data->sblock.log2_blksz)
 281                                   - GRUB_DISK_SECTOR_BITS), 0,
 282                               sizeof (tree), (char *) &tree))
 283             return -1;
 284
 285           return getblk (&tree.treehead, &tree.extents[0]);
 286         }
 287
 288       return -1;
 289     }
 290
 291   return getblk (&inode->file.tree, &inode->file.extents[0]);
 292 }
 293
 294
 295 static grub_err_t
 296 grub_jfs_read_inode (struct grub_jfs_data *data, int ino,
 297                      struct grub_jfs_inode *inode)
 298 {
 299   struct grub_jfs_iag iag;
 300   int iagnum = ino / 4096;
 301   int inoext = (ino % 4096) / 32;
 302   int inonum = (ino % 4096) % 32;
 303   grub_uint32_t iagblk;
 304   grub_uint32_t inoblk;
 305
 306   iagblk = grub_jfs_blkno (data, &data->fileset, iagnum + 1);
 307   if (grub_errno)
 308     return grub_errno;
 309
 310   /* Read in the IAG.  */
 311   if (grub_disk_read (data->disk,
 312                       iagblk << (grub_le_to_cpu16 (data->sblock.log2_blksz)
 313                                  - GRUB_DISK_SECTOR_BITS), 0,
 314                       sizeof (struct grub_jfs_iag), (char *) &iag))
 315     return grub_errno;
 316
 317   inoblk = grub_le_to_cpu32 (iag.inodes[inoext].blk2);
 318   inoblk <<= (grub_le_to_cpu16 (data->sblock.log2_blksz)
 319               - GRUB_DISK_SECTOR_BITS);
 320   inoblk += inonum;
 321
 322   if (grub_disk_read (data->disk, inoblk, 0,
 323                       sizeof (struct grub_jfs_inode), (char *) inode))
 324     return grub_errno;
 325
 326   return 0;
 327 }
 328
 329
 330 static struct grub_jfs_data *
 331 grub_jfs_mount (grub_disk_t disk)
 332 {
 333   struct grub_jfs_data *data = 0;
 334
 335   data = grub_malloc (sizeof (struct grub_jfs_data));
 336   if (!data)
 337     return 0;
 338
 339   /* Read the superblock.  */
 340   if (grub_disk_read (disk, GRUB_JFS_SBLOCK, 0,
 341                       sizeof (struct grub_jfs_sblock), (char *) &data->sblock))
 342     goto fail;
 343
 344   if (grub_strncmp ((char *) (data->sblock.magic), "JFS1", 4))
 345     {
 346       grub_error (GRUB_ERR_BAD_FS, "not a jfs filesystem");
 347       goto fail;
 348     }
 349
 350   data->disk = disk;
 351   data->pos = 0;
 352   data->linknest = 0;
 353
 354   /* Read the inode of the first fileset.  */
 355   if (grub_disk_read (data->disk, GRUB_JFS_FS1_INODE_BLK, 0,
 356                       sizeof (struct grub_jfs_inode), (char *) &data->fileset))
 357     goto fail;
 358
 359   return data;
 360
 361  fail:
 362   grub_free (data);
 363
 364   if (grub_errno == GRUB_ERR_OUT_OF_RANGE)
 365     grub_error (GRUB_ERR_BAD_FS, "not a jfs filesystem");
 366
 367   return 0;
 368 }
 369
 370
 371 static struct grub_jfs_diropen *
 372 grub_jfs_opendir (struct grub_jfs_data *data, struct grub_jfs_inode *inode)
 373 {
 374   struct grub_jfs_internal_dirent *de;
 375   struct grub_jfs_diropen *diro;
 376   int blk;
 377
 378   de = (struct grub_jfs_internal_dirent *) inode->dir.dirents;
 379
 380   if (!((grub_le_to_cpu32 (inode->mode)
 381          & GRUB_JFS_FILETYPE_MASK) == GRUB_JFS_FILETYPE_DIR))
 382     {
 383       grub_error (GRUB_ERR_BAD_FILE_TYPE, "not a directory");
 384       return 0;
 385     }
 386
 387   diro = grub_malloc (sizeof (struct grub_jfs_diropen));
 388   if (!diro)
 389     return 0;
 390
 391   diro->index = 0;
 392   diro->data = data;
 393   diro->inode = inode;
 394
 395   /* Check if the entire tree is contained within the inode.  */
 396   if (inode->file.tree.flags & GRUB_JFS_TREE_LEAF)
 397     {
 398       diro->leaf = inode->dir.dirents;
 399       diro->next_leaf = (struct grub_jfs_leaf_next_dirent *) de;
 400       diro->sorted = (char *) (inode->dir.header.sorted);
 401       diro->count = inode->dir.header.count;
 402       diro->dirpage = 0;
 403
 404       return diro;
 405     }
 406
 407   diro->dirpage = grub_malloc (grub_le_to_cpu32 (data->sblock.blksz));
 408   if (!diro->dirpage)
 409     {
 410       grub_free (diro);
 411       return 0;
 412     }
 413
 414   blk = grub_le_to_cpu32 (de[inode->dir.header.sorted[0]].ex.blk2);
 415   blk <<= (grub_le_to_cpu16 (data->sblock.log2_blksz) - GRUB_DISK_SECTOR_BITS);
 416
 417   /* Read in the nodes until we are on the leaf node level.  */
 418   do
 419     {
 420       int index;
 421       if (grub_disk_read (data->disk, blk, 0,
 422                           grub_le_to_cpu32 (data->sblock.blksz),
 423                           diro->dirpage->sorted))
 424         {
 425           grub_free (diro->dirpage);
 426           grub_free (diro);
 427           return 0;
 428         }
 429
 430       de = (struct grub_jfs_internal_dirent *) diro->dirpage->dirent;
 431       index = diro->dirpage->sorted[diro->dirpage->header.sindex * 32];
 432       blk = (grub_le_to_cpu32 (de[index].ex.blk2)
 433              << (grub_le_to_cpu16 (data->sblock.log2_blksz)
 434                  - GRUB_DISK_SECTOR_BITS));
 435     } while (!(diro->dirpage->header.flags & GRUB_JFS_TREE_LEAF));
 436
 437   diro->leaf = diro->dirpage->dirent;
 438   diro->next_leaf = diro->dirpage->next_dirent;
 439   diro->sorted = &diro->dirpage->sorted[diro->dirpage->header.sindex * 32];
 440   diro->count = diro->dirpage->header.count;
 441
 442   return diro;
 443 }
 444
 445
 446 static void
 447 grub_jfs_closedir (struct grub_jfs_diropen *diro)
 448 {
 449   if (!diro)
 450     return;
 451   grub_free (diro->dirpage);
 452   grub_free (diro);
 453 }
 454
 455
 456 /* Read in the next dirent from the directory described by DIRO.  */
 457 static grub_err_t
 458 grub_jfs_getent (struct grub_jfs_diropen *diro)
 459 {
 460   int strpos = 0;
 461   struct grub_jfs_leaf_dirent *leaf;
 462   struct grub_jfs_leaf_next_dirent *next_leaf;
 463   int len;
 464   int nextent;
 465   grub_uint16_t filename[255];
 466
 467   auto void addstr (grub_uint16_t *uname, int ulen);
 468
 469   /* Add the unicode string to the utf16 filename buffer.  */
 470   void addstr (grub_uint16_t *name, int ulen)
 471     {
 472       while (ulen--)
 473         filename[strpos++] = *(name++);
 474     }
 475
 476   /* The last node, read in more.  */
 477   if (diro->index == diro->count)
 478     {
 479       unsigned int next;
 480
 481       /* If the inode contains the entry tree or if this was the last
 482          node, there is nothing to read.  */
 483       if ((diro->inode->file.tree.flags & GRUB_JFS_TREE_LEAF)
 484           || !grub_le_to_cpu64 (diro->dirpage->header.nextb))
 485         return GRUB_ERR_OUT_OF_RANGE;
 486
 487       next = grub_le_to_cpu64 (diro->dirpage->header.nextb);
 488       next <<= (grub_le_to_cpu16 (diro->data->sblock.log2_blksz)
 489                 - GRUB_DISK_SECTOR_BITS);
 490
 491       if (grub_disk_read (diro->data->disk, next, 0,
 492                           grub_le_to_cpu32 (diro->data->sblock.blksz),
 493                           diro->dirpage->sorted))
 494         return grub_errno;
 495
 496       diro->leaf = diro->dirpage->dirent;
 497       diro->next_leaf = diro->dirpage->next_dirent;
 498       diro->sorted = &diro->dirpage->sorted[diro->dirpage->header.sindex * 32];
 499       diro->count = diro->dirpage->header.count;
 500       diro->index = 0;
 501     }
 502
 503   leaf = &diro->leaf[(int) diro->sorted[diro->index]];
 504   next_leaf = &diro->next_leaf[diro->index];
 505
 506   len = leaf->len;
 507   if (!len)
 508     {
 509       diro->index++;
 510       return grub_jfs_getent (diro);
 511     }
 512
 513   addstr (leaf->namepart, len < 11 ? len : 11);
 514   diro->ino = grub_le_to_cpu32 (leaf->inode);
 515   len -= 11;
 516
 517   /* Move down to the leaf level.  */
 518   nextent = leaf->next;
 519   if (leaf->next != 255)
 520     do
 521       {
 522         next_leaf = &diro->next_leaf[nextent];
 523         addstr (next_leaf->namepart, len < 15 ? len : 15 );
 524
 525         len -= 15;
 526         nextent = next_leaf->next;
 527       } while (next_leaf->next != 255 && len > 0);
 528
 529   diro->index++;
 530
 531   /* Convert the temporary UTF16 filename to UTF8.  */
 532   *grub_utf16_to_utf8 ((grub_uint8_t *) (diro->name), filename, strpos) = '\0';
 533
 534   return 0;
 535 }
 536
 537
 538 /* Read LEN bytes from the file described by DATA starting with byte
 539    POS.  Return the amount of read bytes in READ.  */
 540 static grub_ssize_t
 541 grub_jfs_read_file (struct grub_jfs_data *data,
 542                     void NESTED_FUNC_ATTR (*read_hook) (grub_disk_addr_t sector,
 543                                        unsigned offset, unsigned length),
 544                     int pos, grub_size_t len, char *buf)
 545 {
 546   int i;
 547   int blockcnt;
 548
 549   /* Adjust len so it we can't read past the end of the file.  */
 550   if (len > data->currinode.size)
 551     len = data->currinode.size;
 552
 553   blockcnt = ((len + pos + grub_le_to_cpu32 (data->sblock.blksz) - 1)
 554               / grub_le_to_cpu32 (data->sblock.blksz));
 555
 556   for (i = pos / grub_le_to_cpu32 (data->sblock.blksz); i < blockcnt; i++)
 557     {
 558       int blknr;
 559       int blockoff = pos % grub_le_to_cpu32 (data->sblock.blksz);
 560       int blockend = grub_le_to_cpu32 (data->sblock.blksz);
 561
 562       int skipfirst = 0;
 563
 564       blknr = grub_jfs_blkno (data, &data->currinode, i);
 565       if (grub_errno)
 566         return -1;
 567
 568       /* Last block.  */
 569       if (i == blockcnt - 1)
 570         {
 571           blockend = (len + pos) % grub_le_to_cpu32 (data->sblock.blksz);
 572
 573           if (!blockend)
 574             blockend = grub_le_to_cpu32 (data->sblock.blksz);
 575         }
 576
 577       /* First block.  */
 578       if (i == (pos / (int) grub_le_to_cpu32 (data->sblock.blksz)))
 579         {
 580           skipfirst = blockoff;
 581           blockend -= skipfirst;
 582         }
 583
 584       data->disk->read_hook = read_hook;
 585       grub_disk_read (data->disk,
 586                       blknr << (grub_le_to_cpu16 (data->sblock.log2_blksz)
 587                                 - GRUB_DISK_SECTOR_BITS),
 588                       skipfirst, blockend, buf);
 589
 590       data->disk->read_hook = 0;
 591       if (grub_errno)
 592         return -1;
 593
 594       buf += grub_le_to_cpu32 (data->sblock.blksz) - skipfirst;
 595     }
 596
 597   return len;
 598 }
 599
 600
 601 /* Find the file with the pathname PATH on the filesystem described by
 602    DATA.  */
 603 static grub_err_t
 604 grub_jfs_find_file (struct grub_jfs_data *data, const char *path)
 605 {
 606   char fpath[grub_strlen (path)];
 607   char *name = fpath;
 608   char *next;
 609   unsigned int pos = 0;
 610   struct grub_jfs_diropen *diro;
 611
 612   grub_strncpy (fpath, path, grub_strlen (path) + 1);
 613
 614   if (grub_jfs_read_inode (data, GRUB_JFS_AGGR_INODE, &data->currinode))
 615     return grub_errno;
 616
 617   /* Skip the first slashes.  */
 618   while (*name == '/')
 619     {
 620       name++;
 621       if (!*name)
 622         return 0;
 623     }
 624
 625   /* Extract the actual part from the pathname.  */
 626   next = grub_strchr (name, '/');
 627   if (next)
 628     {
 629       while (*next == '/')
 630         {
 631           next[0] = '\0';
 632           next++;
 633         }
 634     }
 635   diro = grub_jfs_opendir (data, &data->currinode);
 636   if (!diro)
 637     return grub_errno;
 638
 639   for (;;)
 640     {
 641       if (grub_strlen (name) == 0)
 642         return GRUB_ERR_NONE;
 643
 644       if (grub_jfs_getent (diro) == GRUB_ERR_OUT_OF_RANGE)
 645         break;
 646
 647       /* Check if the current direntry matches the current part of the
 648          pathname.  */
 649       if (!grub_strcmp (name, diro->name))
 650         {
 651           int ino = diro->ino;
 652           int dirino = grub_le_to_cpu32 (data->currinode.inode);
 653
 654           grub_jfs_closedir (diro);
 655           diro = 0;
 656
 657           if (grub_jfs_read_inode (data, ino, &data->currinode))
 658             break;
 659
 660           /* Check if this is a symlink.  */
 661           if ((grub_le_to_cpu32 (data->currinode.mode)
 662                & GRUB_JFS_FILETYPE_MASK) == GRUB_JFS_FILETYPE_LNK)
 663             {
 664               grub_jfs_lookup_symlink (data, dirino);
 665               if (grub_errno)
 666                 return grub_errno;
 667             }
 668
 669           if (!next)
 670             return 0;
 671
 672           pos = 0;
 673
 674           name = next;
 675           next = grub_strchr (name, '/');
 676           if (next)
 677             {
 678               next[0] = '\0';
 679               next++;
 680             }
 681
 682           /* Open this directory for reading dirents.  */
 683           diro = grub_jfs_opendir (data, &data->currinode);
 684           if (!diro)
 685             return grub_errno;
 686
 687           continue;
 688         }
 689     }
 690
 691   grub_jfs_closedir (diro);
 692   grub_error (GRUB_ERR_FILE_NOT_FOUND, "file not found");
 693   return grub_errno;
 694 }
 695
 696
 697 static grub_err_t
 698 grub_jfs_lookup_symlink (struct grub_jfs_data *data, int ino)
 699 {
 700   int size = grub_le_to_cpu64 (data->currinode.size);
 701   char symlink[size + 1];
 702
 703   if (++data->linknest > GRUB_JFS_MAX_SYMLNK_CNT)
 704     return grub_error (GRUB_ERR_SYMLINK_LOOP, "too deep nesting of symlinks");
 705
 706   if (size <= 128)
 707     grub_strncpy (symlink, (char *) (data->currinode.symlink.path), 128);
 708   else if (grub_jfs_read_file (data, 0, 0, size, symlink) < 0)
 709     return grub_errno;
 710
 711   symlink[size] = '\0';
 712
 713   /* The symlink is an absolute path, go back to the root inode.  */
 714   if (symlink[0] == '/')
 715     ino = 2;
 716
 717   /* Now load in the old inode.  */
 718   if (grub_jfs_read_inode (data, ino, &data->currinode))
 719     return grub_errno;
 720
 721   grub_jfs_find_file (data, symlink);
 722   if (grub_errno)
 723     grub_error (grub_errno, "Can not follow symlink `%s'.", symlink);
 724
 725   return grub_errno;
 726 }
 727 \f
 728
 729 static grub_err_t
 730 grub_jfs_dir (grub_device_t device, const char *path,
 731               int (*hook) (const char *filename, int dir))
 732 {
 733   struct grub_jfs_data *data = 0;
 734   struct grub_jfs_diropen *diro = 0;
 735
 736 #ifndef GRUB_UTIL
 737   grub_dl_ref (my_mod);
 738 #endif
 739
 740   data = grub_jfs_mount (device->disk);
 741   if (!data)
 742     goto fail;
 743
 744   if (grub_jfs_find_file (data, path))
 745     goto fail;
 746
 747   diro = grub_jfs_opendir (data, &data->currinode);
 748   if (!diro)
 749     goto fail;
 750
 751   /* Iterate over the dirents in the directory that was found.  */
 752   while (grub_jfs_getent (diro) != GRUB_ERR_OUT_OF_RANGE)
 753     {
 754       struct grub_jfs_inode inode;
 755       int isdir;
 756
 757       if (grub_jfs_read_inode (data, diro->ino, &inode))
 758         goto fail;
 759
 760       isdir = (grub_le_to_cpu32 (inode.mode)
 761                & GRUB_JFS_FILETYPE_MASK) == GRUB_JFS_FILETYPE_DIR;
 762       if (hook (diro->name, isdir))
 763         goto fail;
 764     }
 765
 766   /* XXX: GRUB_ERR_OUT_OF_RANGE is used for the last dirent.  */
 767   if (grub_errno == GRUB_ERR_OUT_OF_RANGE)
 768     grub_errno = 0;
 769
 770  fail:
 771   grub_jfs_closedir (diro);
 772   grub_free (data);
 773
 774 #ifndef GRUB_UTIL
 775   grub_dl_unref (my_mod);
 776 #endif
 777
 778   return grub_errno;
 779 }
 780
 781
 782 /* Open a file named NAME and initialize FILE.  */
 783 static grub_err_t
 784 grub_jfs_open (struct grub_file *file, const char *name)
 785 {
 786   struct grub_jfs_data *data;
 787
 788 #ifndef GRUB_UTIL
 789   grub_dl_ref (my_mod);
 790 #endif
 791
 792   data = grub_jfs_mount (file->device->disk);
 793   if (!data)
 794     goto fail;
 795
 796   grub_jfs_find_file (data, name);
 797   if (grub_errno)
 798     goto fail;
 799
 800   /* It is only possible for open regular files.  */
 801   if (! ((grub_le_to_cpu32 (data->currinode.mode)
 802           & GRUB_JFS_FILETYPE_MASK) == GRUB_JFS_FILETYPE_REG))
 803     {
 804       grub_error (GRUB_ERR_BAD_FILE_TYPE, "not a regular file");
 805       goto fail;
 806     }
 807
 808   file->data = data;
 809   file->size = grub_le_to_cpu64 (data->currinode.size);
 810
 811   return 0;
 812
 813  fail:
 814
 815 #ifndef GRUB_UTIL
 816   grub_dl_unref (my_mod);
 817 #endif
 818
 819   grub_free (data);
 820
 821   return grub_errno;;
 822 }
 823
 824
 825 static grub_ssize_t
 826 grub_jfs_read (grub_file_t file, char *buf, grub_size_t len)
 827 {
 828   struct grub_jfs_data *data =
 829     (struct grub_jfs_data *) file->data;
 830
 831   return grub_jfs_read_file (data, file->read_hook, file->offset, len, buf);
 832 }
 833
 834
 835 static grub_err_t
 836 grub_jfs_close (grub_file_t file)
 837 {
 838   grub_free (file->data);
 839
 840 #ifndef GRUB_UTIL
 841   grub_dl_unref (my_mod);
 842 #endif
 843
 844   return GRUB_ERR_NONE;
 845 }
 846
 847
 848 static grub_err_t
 849 grub_jfs_label (grub_device_t device, char **label)
 850 {
 851   struct grub_jfs_data *data;
 852   data = grub_jfs_mount (device->disk);
 853
 854   if (data)
 855     *label = grub_strndup ((char *) (data->sblock.volname), 11);
 856   else
 857     *label = 0;
 858
 859   return grub_errno;
 860 }
 861 \f
 862
 863 static struct grub_fs grub_jfs_fs =
 864   {
 865     .name = "jfs",
 866     .dir = grub_jfs_dir,
 867     .open = grub_jfs_open,
 868     .read = grub_jfs_read,
 869     .close = grub_jfs_close,
 870     .label = grub_jfs_label,
 871     .next = 0
 872   };
 873
 874 GRUB_MOD_INIT(jfs)
 875 {
 876   grub_fs_register (&grub_jfs_fs);
 877 #ifndef GRUB_UTIL
 878   my_mod = mod;
 879 #endif
 880 }
 881
 882 GRUB_MOD_FINI(jfs)
 883 {
 884   grub_fs_unregister (&grub_jfs_fs);
 885 }