fs/squashfs/inode.c

   1 /*
   2  * Squashfs - a compressed read only filesystem for Linux
   3  *
   4  * Copyright (c) 2002, 2003, 2004, 2005, 2006
   5  * Phillip Lougher <phillip@lougher.org.uk>
   6  *
   7  * This program is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU General Public License
   9  * as published by the Free Software Foundation; either version 2,
  10  * or (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program; if not, write to the Free Software
  19  * Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  20  *
  21  * inode.c
  22  */
  23
  24 #include <linux/types.h>
  25 #include <linux/squashfs_fs.h>
  26 #include <linux/module.h>
  27 #include <linux/errno.h>
  28 #include <linux/slab.h>
  29 #include <linux/zlib.h>
  30 #include <linux/fs.h>
  31 #include <linux/smp_lock.h>
  32 #include <linux/slab.h>
  33 #include <linux/squashfs_fs_sb.h>
  34 #include <linux/squashfs_fs_i.h>
  35 #include <linux/buffer_head.h>
  36 #include <linux/vfs.h>
  37 #include <linux/init.h>
  38 #include <linux/dcache.h>
  39 #include <linux/wait.h>
  40 #include <linux/blkdev.h>
  41 #include <linux/vmalloc.h>
  42 #include <asm/uaccess.h>
  43 #include <asm/semaphore.h>
  44
  45 #include "squashfs.h"
  46
  47 static void squashfs_put_super(struct super_block *);
  48 static int squashfs_statfs(struct dentry *, struct kstatfs *);
  49 static int squashfs_symlink_readpage(struct file *file, struct page *page);
  50 static int squashfs_readpage(struct file *file, struct page *page);
  51 static int squashfs_readpage4K(struct file *file, struct page *page);
  52 static int squashfs_readdir(struct file *, void *, filldir_t);
  53 static struct inode *squashfs_alloc_inode(struct super_block *sb);
  54 static void squashfs_destroy_inode(struct inode *inode);
  55 static int init_inodecache(void);
  56 static void destroy_inodecache(void);
  57 static struct dentry *squashfs_lookup(struct inode *, struct dentry *,
  58                                 struct nameidata *);
  59 static struct inode *squashfs_iget(struct super_block *s, squashfs_inode_t inode);
  60 static long long read_blocklist(struct inode *inode, int index,
  61                                 int readahead_blks, char *block_list,
  62                                 unsigned short **block_p, unsigned int *bsize);
  63 static int squashfs_get_sb(struct file_system_type *, int,
  64                                 const char *, void *, struct vfsmount *);
  65
  66 static struct file_system_type squashfs_fs_type = {
  67         .owner = THIS_MODULE,
  68         .name = "squashfs",
  69         .get_sb = squashfs_get_sb,
  70         .kill_sb = kill_block_super,
  71         .fs_flags = FS_REQUIRES_DEV
  72 };
  73
  74 static unsigned char squashfs_filetype_table[] = {
  75         DT_UNKNOWN, DT_DIR, DT_REG, DT_LNK, DT_BLK, DT_CHR, DT_FIFO, DT_SOCK
  76 };
  77
  78 static struct super_operations squashfs_ops = {
  79         .alloc_inode = squashfs_alloc_inode,
  80         .destroy_inode = squashfs_destroy_inode,
  81         .statfs = squashfs_statfs,
  82         .put_super = squashfs_put_super,
  83 };
  84
  85 SQSH_EXTERN struct address_space_operations squashfs_symlink_aops = {
  86         .readpage = squashfs_symlink_readpage
  87 };
  88
  89 SQSH_EXTERN struct address_space_operations squashfs_aops = {
  90         .readpage = squashfs_readpage
  91 };
  92
  93 SQSH_EXTERN struct address_space_operations squashfs_aops_4K = {
  94         .readpage = squashfs_readpage4K
  95 };
  96
  97 static struct file_operations squashfs_dir_ops = {
  98         .read = generic_read_dir,
  99         .readdir = squashfs_readdir
 100 };
 101
 102 SQSH_EXTERN struct inode_operations squashfs_dir_inode_ops = {
 103         .lookup = squashfs_lookup
 104 };
 105
 106
 107 static struct buffer_head *get_block_length(struct super_block *s,
 108                                 int *cur_index, int *offset, int *c_byte)
 109 {
 110         struct squashfs_sb_info *msblk = s->s_fs_info;
 111         unsigned short temp;
 112         struct buffer_head *bh;
 113
 114         if (!(bh = sb_bread(s, *cur_index)))
 115                 goto out;
 116
 117         if (msblk->devblksize - *offset == 1) {
 118                 if (msblk->swap)
 119                         ((unsigned char *) &temp)[1] = *((unsigned char *)
 120                                 (bh->b_data + *offset));
 121                 else
 122                         ((unsigned char *) &temp)[0] = *((unsigned char *)
 123                                 (bh->b_data + *offset));
 124                 brelse(bh);
 125                 if (!(bh = sb_bread(s, ++(*cur_index))))
 126                         goto out;
 127                 if (msblk->swap)
 128                         ((unsigned char *) &temp)[0] = *((unsigned char *)
 129                                 bh->b_data);
 130                 else
 131                         ((unsigned char *) &temp)[1] = *((unsigned char *)
 132                                 bh->b_data);
 133                 *c_byte = temp;
 134                 *offset = 1;
 135         } else {
 136                 if (msblk->swap) {
 137                         ((unsigned char *) &temp)[1] = *((unsigned char *)
 138                                 (bh->b_data + *offset));
 139                         ((unsigned char *) &temp)[0] = *((unsigned char *)
 140                                 (bh->b_data + *offset + 1));
 141                 } else {
 142                         ((unsigned char *) &temp)[0] = *((unsigned char *)
 143                                 (bh->b_data + *offset));
 144                         ((unsigned char *) &temp)[1] = *((unsigned char *)
 145                                 (bh->b_data + *offset + 1));
 146                 }
 147                 *c_byte = temp;
 148                 *offset += 2;
 149         }
 150
 151         if (SQUASHFS_CHECK_DATA(msblk->sblk.flags)) {
 152                 if (*offset == msblk->devblksize) {
 153                         brelse(bh);
 154                         if (!(bh = sb_bread(s, ++(*cur_index))))
 155                                 goto out;
 156                         *offset = 0;
 157                 }
 158                 if (*((unsigned char *) (bh->b_data + *offset)) !=
 159                                                 SQUASHFS_MARKER_BYTE) {
 160                         ERROR("Metadata block marker corrupt @ %x\n",
 161                                                 *cur_index);
 162                         brelse(bh);
 163                         goto out;
 164                 }
 165                 (*offset)++;
 166         }
 167         return bh;
 168
 169 out:
 170         return NULL;
 171 }
 172
 173
 174 SQSH_EXTERN unsigned int squashfs_read_data(struct super_block *s, char *buffer,
 175                         long long index, unsigned int length,
 176                         long long *next_index, int srclength)
 177 {
 178         struct squashfs_sb_info *msblk = s->s_fs_info;
 179         struct squashfs_super_block *sblk = &msblk->sblk;
 180         struct buffer_head *bh[((SQUASHFS_FILE_MAX_SIZE - 1) >>
 181                         msblk->devblksize_log2) + 2];
 182         unsigned int offset = index & ((1 << msblk->devblksize_log2) - 1);
 183         unsigned int cur_index = index >> msblk->devblksize_log2;
 184         int bytes, avail_bytes, b = 0, k = 0;
 185         char *c_buffer;
 186         unsigned int compressed;
 187         unsigned int c_byte = length;
 188
 189         if (c_byte) {
 190                 bytes = msblk->devblksize - offset;
 191                 compressed = SQUASHFS_COMPRESSED_BLOCK(c_byte);
 192                 c_buffer = compressed ? msblk->read_data : buffer;
 193                 c_byte = SQUASHFS_COMPRESSED_SIZE_BLOCK(c_byte);
 194
 195                 TRACE("Block @ 0x%llx, %scompressed size %d, src size %d\n", index, compressed
 196                                         ? "" : "un", (unsigned int) c_byte, srclength);
 197
 198                 if (c_byte > srclength || index < 0 || (index + c_byte) > sblk->bytes_used)
 199                         goto read_failure;
 200
 201                 if (!(bh[0] = sb_getblk(s, cur_index)))
 202                         goto block_release;
 203
 204                 for (b = 1; bytes < c_byte; b++) {
 205                         if (!(bh[b] = sb_getblk(s, ++cur_index)))
 206                                 goto block_release;
 207                         bytes += msblk->devblksize;
 208                 }
 209                 ll_rw_block(READ, b, bh);
 210         } else {
 211                 if (index < 0 || (index + 2) > sblk->bytes_used)
 212                         goto read_failure;
 213
 214                 if (!(bh[0] = get_block_length(s, &cur_index, &offset,
 215                                                                 &c_byte)))
 216                         goto read_failure;
 217
 218                 bytes = msblk->devblksize - offset;
 219                 compressed = SQUASHFS_COMPRESSED(c_byte);
 220                 c_buffer = compressed ? msblk->read_data : buffer;
 221                 c_byte = SQUASHFS_COMPRESSED_SIZE(c_byte);
 222
 223                 TRACE("Block @ 0x%llx, %scompressed size %d\n", index, compressed
 224                                         ? "" : "un", (unsigned int) c_byte);
 225
 226                 if (c_byte > srclength || (index + c_byte) > sblk->bytes_used)
 227                         goto read_failure;
 228
 229                 for (b = 1; bytes < c_byte; b++) {
 230                         if (!(bh[b] = sb_getblk(s, ++cur_index)))
 231                                 goto block_release;
 232                         bytes += msblk->devblksize;
 233                 }
 234                 ll_rw_block(READ, b - 1, bh + 1);
 235         }
 236
 237         if (compressed)
 238                 down(&msblk->read_data_mutex);
 239
 240         for (bytes = 0; k < b; k++) {
 241                 avail_bytes = (c_byte - bytes) > (msblk->devblksize - offset) ?
 242                                         msblk->devblksize - offset :
 243                                         c_byte - bytes;
 244                 wait_on_buffer(bh[k]);
 245                 if (!buffer_uptodate(bh[k]))
 246                         goto block_release;
 247                 memcpy(c_buffer + bytes, bh[k]->b_data + offset, avail_bytes);
 248                 bytes += avail_bytes;
 249                 offset = 0;
 250                 brelse(bh[k]);
 251         }
 252
 253         /*
 254          * uncompress block
 255          */
 256         if (compressed) {
 257                 int zlib_err;
 258
 259                 msblk->stream.next_in = c_buffer;
 260                 msblk->stream.avail_in = c_byte;
 261                 msblk->stream.next_out = buffer;
 262                 msblk->stream.avail_out = srclength;
 263
 264                 if (((zlib_err = zlib_inflateInit(&msblk->stream)) != Z_OK) ||
 265                                 ((zlib_err = zlib_inflate(&msblk->stream, Z_FINISH))
 266                                  != Z_STREAM_END) || ((zlib_err =
 267                                 zlib_inflateEnd(&msblk->stream)) != Z_OK)) {
 268                         ERROR("zlib_fs returned unexpected result 0x%x\n",
 269                                 zlib_err);
 270                         bytes = 0;
 271                 } else
 272                         bytes = msblk->stream.total_out;
 273
 274                 up(&msblk->read_data_mutex);
 275         }
 276
 277         if (next_index)
 278                 *next_index = index + c_byte + (length ? 0 :
 279                                 (SQUASHFS_CHECK_DATA(msblk->sblk.flags)
 280                                  ? 3 : 2));
 281         return bytes;
 282
 283 block_release:
 284         for (; k < b; k++)
 285                 brelse(bh[k]);
 286
 287 read_failure:
 288         ERROR("sb_bread failed reading block 0x%x\n", cur_index);
 289         return 0;
 290 }
 291
 292
 293 SQSH_EXTERN int squashfs_get_cached_block(struct super_block *s, char *buffer,
 294                                 long long block, unsigned int offset,
 295                                 int length, long long *next_block,
 296                                 unsigned int *next_offset)
 297 {
 298         struct squashfs_sb_info *msblk = s->s_fs_info;
 299         int n, i, bytes, return_length = length;
 300         long long next_index;
 301
 302         TRACE("Entered squashfs_get_cached_block [%llx:%x]\n", block, offset);
 303
 304         while ( 1 ) {
 305                 for (i = 0; i < SQUASHFS_CACHED_BLKS; i++)
 306                         if (msblk->block_cache[i].block == block)
 307                                 break;
 308
 309                 down(&msblk->block_cache_mutex);
 310
 311                 if (i == SQUASHFS_CACHED_BLKS) {
 312                         /* read inode header block */
 313                         for (i = msblk->next_cache, n = SQUASHFS_CACHED_BLKS;
 314                                         n ; n --, i = (i + 1) %
 315                                         SQUASHFS_CACHED_BLKS)
 316                                 if (msblk->block_cache[i].block !=
 317                                                         SQUASHFS_USED_BLK)
 318                                         break;
 319
 320                         if (n == 0) {
 321                                 wait_queue_t wait;
 322
 323                                 init_waitqueue_entry(&wait, current);
 324                                 add_wait_queue(&msblk->waitq, &wait);
 325                                 set_current_state(TASK_UNINTERRUPTIBLE);
 326                                 up(&msblk->block_cache_mutex);
 327                                 schedule();
 328                                 set_current_state(TASK_RUNNING);
 329                                 remove_wait_queue(&msblk->waitq, &wait);
 330                                 continue;
 331                         }
 332                         msblk->next_cache = (i + 1) % SQUASHFS_CACHED_BLKS;
 333
 334                         if (msblk->block_cache[i].block ==
 335                                                         SQUASHFS_INVALID_BLK) {
 336                                 if (!(msblk->block_cache[i].data =
 337                                                 kmalloc(SQUASHFS_METADATA_SIZE,
 338                                                 GFP_KERNEL))) {
 339                                         ERROR("Failed to allocate cache"
 340                                                         "block\n");
 341                                         up(&msblk->block_cache_mutex);
 342                                         goto out;
 343                                 }
 344                         }
 345
 346                         msblk->block_cache[i].block = SQUASHFS_USED_BLK;
 347                         up(&msblk->block_cache_mutex);
 348
 349                         msblk->block_cache[i].length = squashfs_read_data(s,
 350                                 msblk->block_cache[i].data, block, 0, &next_index,
 351                                 SQUASHFS_METADATA_SIZE);
 352
 353                         if (msblk->block_cache[i].length == 0) {
 354                                 ERROR("Unable to read cache block [%llx:%x]\n",
 355                                                 block, offset);
 356                                 down(&msblk->block_cache_mutex);
 357                                 msblk->block_cache[i].block = SQUASHFS_INVALID_BLK;
 358                                 kfree(msblk->block_cache[i].data);
 359                                 wake_up(&msblk->waitq);
 360                                 up(&msblk->block_cache_mutex);
 361                                 goto out;
 362                         }
 363
 364                         down(&msblk->block_cache_mutex);
 365                         wake_up(&msblk->waitq);
 366                         msblk->block_cache[i].block = block;
 367                         msblk->block_cache[i].next_index = next_index;
 368                         TRACE("Read cache block [%llx:%x]\n", block, offset);
 369                 }
 370
 371                 if (msblk->block_cache[i].block != block) {
 372                         up(&msblk->block_cache_mutex);
 373                         continue;
 374                 }
 375
 376                 bytes = msblk->block_cache[i].length - offset;
 377
 378                 if (bytes < 1)
 379                         goto out;
 380                 else if (bytes >= length) {
 381                         if (buffer)
 382                                 memcpy(buffer, msblk->block_cache[i].data +
 383                                                 offset, length);
 384                         if (msblk->block_cache[i].length - offset == length) {
 385                                 *next_block = msblk->block_cache[i].next_index;
 386                                 *next_offset = 0;
 387                         } else {
 388                                 *next_block = block;
 389                                 *next_offset = offset + length;
 390                         }
 391                         up(&msblk->block_cache_mutex);
 392                         goto finish;
 393                 } else {
 394                         if (buffer) {
 395                                 memcpy(buffer, msblk->block_cache[i].data +
 396                                                 offset, bytes);
 397                                 buffer += bytes;
 398                         }
 399                         block = msblk->block_cache[i].next_index;
 400                         up(&msblk->block_cache_mutex);
 401                         length -= bytes;
 402                         offset = 0;
 403                 }
 404         }
 405
 406 finish:
 407         return return_length;
 408 out:
 409         return 0;
 410 }
 411
 412
 413 static int get_fragment_location(struct super_block *s, unsigned int fragment,
 414                                 long long *fragment_start_block,
 415                                 unsigned int *fragment_size)
 416 {
 417         struct squashfs_sb_info *msblk = s->s_fs_info;
 418         long long start_block =
 419                 msblk->fragment_index[SQUASHFS_FRAGMENT_INDEX(fragment)];
 420         int offset = SQUASHFS_FRAGMENT_INDEX_OFFSET(fragment);
 421         struct squashfs_fragment_entry fragment_entry;
 422
 423         if (msblk->swap) {
 424                 struct squashfs_fragment_entry sfragment_entry;
 425
 426                 if (!squashfs_get_cached_block(s, (char *) &sfragment_entry,
 427                                         start_block, offset,
 428                                         sizeof(sfragment_entry), &start_block,
 429                                         &offset))
 430                         goto out;
 431                 SQUASHFS_SWAP_FRAGMENT_ENTRY(&fragment_entry, &sfragment_entry);
 432         } else
 433                 if (!squashfs_get_cached_block(s, (char *) &fragment_entry,
 434                                         start_block, offset,
 435                                         sizeof(fragment_entry), &start_block,
 436                                         &offset))
 437                         goto out;
 438
 439         *fragment_start_block = fragment_entry.start_block;
 440         *fragment_size = fragment_entry.size;
 441
 442         return 1;
 443
 444 out:
 445         return 0;
 446 }
 447
 448
 449 SQSH_EXTERN void release_cached_fragment(struct squashfs_sb_info *msblk, struct
 450                                         squashfs_fragment_cache *fragment)
 451 {
 452         down(&msblk->fragment_mutex);
 453         fragment->locked --;
 454         wake_up(&msblk->fragment_wait_queue);
 455         up(&msblk->fragment_mutex);
 456 }
 457
 458
 459 SQSH_EXTERN struct squashfs_fragment_cache *get_cached_fragment(struct super_block
 460                                         *s, long long start_block,
 461                                         int length)
 462 {
 463         int i, n;
 464         struct squashfs_sb_info *msblk = s->s_fs_info;
 465         struct squashfs_super_block *sblk = &msblk->sblk;
 466
 467         while ( 1 ) {
 468                 down(&msblk->fragment_mutex);
 469
 470                 for (i = 0; i < SQUASHFS_CACHED_FRAGMENTS &&
 471                                 msblk->fragment[i].block != start_block; i++);
 472
 473                 if (i == SQUASHFS_CACHED_FRAGMENTS) {
 474                         for (i = msblk->next_fragment, n =
 475                                 SQUASHFS_CACHED_FRAGMENTS; n &&
 476                                 msblk->fragment[i].locked; n--, i = (i + 1) %
 477                                 SQUASHFS_CACHED_FRAGMENTS);
 478
 479                         if (n == 0) {
 480                                 wait_queue_t wait;
 481
 482                                 init_waitqueue_entry(&wait, current);
 483                                 add_wait_queue(&msblk->fragment_wait_queue,
 484                                                                         &wait);
 485                                 set_current_state(TASK_UNINTERRUPTIBLE);
 486                                 up(&msblk->fragment_mutex);
 487                                 schedule();
 488                                 set_current_state(TASK_RUNNING);
 489                                 remove_wait_queue(&msblk->fragment_wait_queue,
 490                                                                         &wait);
 491                                 continue;
 492                         }
 493                         msblk->next_fragment = (msblk->next_fragment + 1) %
 494                                 SQUASHFS_CACHED_FRAGMENTS;
 495
 496                         if (msblk->fragment[i].data == NULL)
 497                                 if (!(msblk->fragment[i].data = SQUASHFS_ALLOC
 498                                                 (SQUASHFS_FILE_MAX_SIZE))) {
 499                                         ERROR("Failed to allocate fragment "
 500                                                         "cache block\n");
 501                                         up(&msblk->fragment_mutex);
 502                                         goto out;
 503                                 }
 504
 505                         msblk->fragment[i].block = SQUASHFS_INVALID_BLK;
 506                         msblk->fragment[i].locked = 1;
 507                         up(&msblk->fragment_mutex);
 508
 509                         if (!(msblk->fragment[i].length = squashfs_read_data(s,
 510                                                 msblk->fragment[i].data,
 511                                                 start_block, length, NULL,
 512                                                 sblk->block_size))) {
 513                                 ERROR("Unable to read fragment cache block "
 514                                                         "[%llx]\n", start_block);
 515                                 msblk->fragment[i].locked = 0;
 516                                 goto out;
 517                         }
 518
 519                         msblk->fragment[i].block = start_block;
 520                         TRACE("New fragment %d, start block %lld, locked %d\n",
 521                                                 i, msblk->fragment[i].block,
 522                                                 msblk->fragment[i].locked);
 523                         break;
 524                 }
 525
 526                 msblk->fragment[i].locked++;
 527                 up(&msblk->fragment_mutex);
 528                 TRACE("Got fragment %d, start block %lld, locked %d\n", i,
 529                                                 msblk->fragment[i].block,
 530                                                 msblk->fragment[i].locked);
 531                 break;
 532         }
 533
 534         return &msblk->fragment[i];
 535
 536 out:
 537         return NULL;
 538 }
 539
 540
 541 static struct inode *squashfs_new_inode(struct super_block *s,
 542                 struct squashfs_base_inode_header *inodeb)
 543 {
 544         struct squashfs_sb_info *msblk = s->s_fs_info;
 545         struct inode *i = new_inode(s);
 546
 547         if (i) {
 548                 i->i_ino = inodeb->inode_number;
 549                 i->i_mtime.tv_sec = inodeb->mtime;
 550                 i->i_atime.tv_sec = inodeb->mtime;
 551                 i->i_ctime.tv_sec = inodeb->mtime;
 552                 i->i_uid = msblk->uid[inodeb->uid];
 553                 i->i_mode = inodeb->mode;
 554                 i->i_size = 0;
 555                 if (inodeb->guid == SQUASHFS_GUIDS)
 556                         i->i_gid = i->i_uid;
 557                 else
 558                         i->i_gid = msblk->guid[inodeb->guid];
 559         }
 560
 561         return i;
 562 }
 563
 564
 565 static struct inode *squashfs_iget(struct super_block *s, squashfs_inode_t inode)
 566 {
 567         struct inode *i;
 568         struct squashfs_sb_info *msblk = s->s_fs_info;
 569         struct squashfs_super_block *sblk = &msblk->sblk;
 570         long long block = SQUASHFS_INODE_BLK(inode) +
 571                 sblk->inode_table_start;
 572         unsigned int offset = SQUASHFS_INODE_OFFSET(inode);
 573         long long next_block;
 574         unsigned int next_offset;
 575         union squashfs_inode_header id, sid;
 576         struct squashfs_base_inode_header *inodeb = &id.base,
 577                                           *sinodeb = &sid.base;
 578
 579         TRACE("Entered squashfs_iget\n");
 580
 581         if (msblk->swap) {
 582                 if (!squashfs_get_cached_block(s, (char *) sinodeb, block,
 583                                         offset, sizeof(*sinodeb), &next_block,
 584                                         &next_offset))
 585                         goto failed_read;
 586                 SQUASHFS_SWAP_BASE_INODE_HEADER(inodeb, sinodeb,
 587                                         sizeof(*sinodeb));
 588         } else
 589                 if (!squashfs_get_cached_block(s, (char *) inodeb, block,
 590                                         offset, sizeof(*inodeb), &next_block,
 591                                         &next_offset))
 592                         goto failed_read;
 593
 594         switch(inodeb->inode_type) {
 595                 case SQUASHFS_FILE_TYPE: {
 596                         unsigned int frag_size;
 597                         long long frag_blk;
 598                         struct squashfs_reg_inode_header *inodep = &id.reg;
 599                         struct squashfs_reg_inode_header *sinodep = &sid.reg;
 600
 601                         if (msblk->swap) {
 602                                 if (!squashfs_get_cached_block(s, (char *)
 603                                                 sinodep, block, offset,
 604                                                 sizeof(*sinodep), &next_block,
 605                                                 &next_offset))
 606                                         goto failed_read;
 607                                 SQUASHFS_SWAP_REG_INODE_HEADER(inodep, sinodep);
 608                         } else
 609                                 if (!squashfs_get_cached_block(s, (char *)
 610                                                 inodep, block, offset,
 611                                                 sizeof(*inodep), &next_block,
 612                                                 &next_offset))
 613                                         goto failed_read;
 614
 615                         frag_blk = SQUASHFS_INVALID_BLK;
 616                         if (inodep->fragment != SQUASHFS_INVALID_FRAG &&
 617                                         !get_fragment_location(s,
 618                                         inodep->fragment, &frag_blk, &frag_size))
 619                                 goto failed_read;
 620
 621                         if((i = squashfs_new_inode(s, inodeb)) == NULL)
 622                                 goto failed_read1;
 623
 624                         i->i_nlink = 1;
 625                         i->i_size = inodep->file_size;
 626                         i->i_fop = &generic_ro_fops;
 627                         i->i_mode |= S_IFREG;
 628                         i->i_blocks = ((i->i_size - 1) >> 9) + 1;
 629                         SQUASHFS_I(i)->u.s1.fragment_start_block = frag_blk;
 630                         SQUASHFS_I(i)->u.s1.fragment_size = frag_size;
 631                         SQUASHFS_I(i)->u.s1.fragment_offset = inodep->offset;
 632                         SQUASHFS_I(i)->start_block = inodep->start_block;
 633                         SQUASHFS_I(i)->u.s1.block_list_start = next_block;
 634                         SQUASHFS_I(i)->offset = next_offset;
 635                         if (sblk->block_size > 4096)
 636                                 i->i_data.a_ops = &squashfs_aops;
 637                         else
 638                                 i->i_data.a_ops = &squashfs_aops_4K;
 639
 640                         TRACE("File inode %x:%x, start_block %llx, "
 641                                         "block_list_start %llx, offset %x\n",
 642                                         SQUASHFS_INODE_BLK(inode), offset,
 643                                         inodep->start_block, next_block,
 644                                         next_offset);
 645                         break;
 646                 }
 647                 case SQUASHFS_LREG_TYPE: {
 648                         unsigned int frag_size;
 649                         long long frag_blk;
 650                         struct squashfs_lreg_inode_header *inodep = &id.lreg;
 651                         struct squashfs_lreg_inode_header *sinodep = &sid.lreg;
 652
 653                         if (msblk->swap) {
 654                                 if (!squashfs_get_cached_block(s, (char *)
 655                                                 sinodep, block, offset,
 656                                                 sizeof(*sinodep), &next_block,
 657                                                 &next_offset))
 658                                         goto failed_read;
 659                                 SQUASHFS_SWAP_LREG_INODE_HEADER(inodep, sinodep);
 660                         } else
 661                                 if (!squashfs_get_cached_block(s, (char *)
 662                                                 inodep, block, offset,
 663                                                 sizeof(*inodep), &next_block,
 664                                                 &next_offset))
 665                                         goto failed_read;
 666
 667                         frag_blk = SQUASHFS_INVALID_BLK;
 668                         if (inodep->fragment != SQUASHFS_INVALID_FRAG &&
 669                                         !get_fragment_location(s,
 670                                         inodep->fragment, &frag_blk, &frag_size))
 671                                 goto failed_read;
 672
 673                         if((i = squashfs_new_inode(s, inodeb)) == NULL)
 674                                 goto failed_read1;
 675
 676                         i->i_nlink = inodep->nlink;
 677                         i->i_size = inodep->file_size;
 678                         i->i_fop = &generic_ro_fops;
 679                         i->i_mode |= S_IFREG;
 680                         i->i_blocks = ((i->i_size - 1) >> 9) + 1;
 681                         SQUASHFS_I(i)->u.s1.fragment_start_block = frag_blk;
 682                         SQUASHFS_I(i)->u.s1.fragment_size = frag_size;
 683                         SQUASHFS_I(i)->u.s1.fragment_offset = inodep->offset;
 684                         SQUASHFS_I(i)->start_block = inodep->start_block;
 685                         SQUASHFS_I(i)->u.s1.block_list_start = next_block;
 686                         SQUASHFS_I(i)->offset = next_offset;
 687                         if (sblk->block_size > 4096)
 688                                 i->i_data.a_ops = &squashfs_aops;
 689                         else
 690                                 i->i_data.a_ops = &squashfs_aops_4K;
 691
 692                         TRACE("File inode %x:%x, start_block %llx, "
 693                                         "block_list_start %llx, offset %x\n",
 694                                         SQUASHFS_INODE_BLK(inode), offset,
 695                                         inodep->start_block, next_block,
 696                                         next_offset);
 697                         break;
 698                 }
 699                 case SQUASHFS_DIR_TYPE: {
 700                         struct squashfs_dir_inode_header *inodep = &id.dir;
 701                         struct squashfs_dir_inode_header *sinodep = &sid.dir;
 702
 703                         if (msblk->swap) {
 704                                 if (!squashfs_get_cached_block(s, (char *)
 705                                                 sinodep, block, offset,
 706                                                 sizeof(*sinodep), &next_block,
 707                                                 &next_offset))
 708                                         goto failed_read;
 709                                 SQUASHFS_SWAP_DIR_INODE_HEADER(inodep, sinodep);
 710                         } else
 711                                 if (!squashfs_get_cached_block(s, (char *)
 712                                                 inodep, block, offset,
 713                                                 sizeof(*inodep), &next_block,
 714                                                 &next_offset))
 715                                         goto failed_read;
 716
 717                         if((i = squashfs_new_inode(s, inodeb)) == NULL)
 718                                 goto failed_read1;
 719
 720                         i->i_nlink = inodep->nlink;
 721                         i->i_size = inodep->file_size;
 722                         i->i_op = &squashfs_dir_inode_ops;
 723                         i->i_fop = &squashfs_dir_ops;
 724                         i->i_mode |= S_IFDIR;
 725                         SQUASHFS_I(i)->start_block = inodep->start_block;
 726                         SQUASHFS_I(i)->offset = inodep->offset;
 727                         SQUASHFS_I(i)->u.s2.directory_index_count = 0;
 728                         SQUASHFS_I(i)->u.s2.parent_inode = inodep->parent_inode;
 729
 730                         TRACE("Directory inode %x:%x, start_block %x, offset "
 731                                         "%x\n", SQUASHFS_INODE_BLK(inode),
 732                                         offset, inodep->start_block,
 733                                         inodep->offset);
 734                         break;
 735                 }
 736                 case SQUASHFS_LDIR_TYPE: {
 737                         struct squashfs_ldir_inode_header *inodep = &id.ldir;
 738                         struct squashfs_ldir_inode_header *sinodep = &sid.ldir;
 739
 740                         if (msblk->swap) {
 741                                 if (!squashfs_get_cached_block(s, (char *)
 742                                                 sinodep, block, offset,
 743                                                 sizeof(*sinodep), &next_block,
 744                                                 &next_offset))
 745                                         goto failed_read;
 746                                 SQUASHFS_SWAP_LDIR_INODE_HEADER(inodep,
 747                                                 sinodep);
 748                         } else
 749                                 if (!squashfs_get_cached_block(s, (char *)
 750                                                 inodep, block, offset,
 751                                                 sizeof(*inodep), &next_block,
 752                                                 &next_offset))
 753                                         goto failed_read;
 754
 755                         if((i = squashfs_new_inode(s, inodeb)) == NULL)
 756                                 goto failed_read1;
 757
 758                         i->i_nlink = inodep->nlink;
 759                         i->i_size = inodep->file_size;
 760                         i->i_op = &squashfs_dir_inode_ops;
 761                         i->i_fop = &squashfs_dir_ops;
 762                         i->i_mode |= S_IFDIR;
 763                         SQUASHFS_I(i)->start_block = inodep->start_block;
 764                         SQUASHFS_I(i)->offset = inodep->offset;
 765                         SQUASHFS_I(i)->u.s2.directory_index_start = next_block;
 766                         SQUASHFS_I(i)->u.s2.directory_index_offset =
 767                                                                 next_offset;
 768                         SQUASHFS_I(i)->u.s2.directory_index_count =
 769                                                                 inodep->i_count;
 770                         SQUASHFS_I(i)->u.s2.parent_inode = inodep->parent_inode;
 771
 772                         TRACE("Long directory inode %x:%x, start_block %x, "
 773                                         "offset %x\n",
 774                                         SQUASHFS_INODE_BLK(inode), offset,
 775                                         inodep->start_block, inodep->offset);
 776                         break;
 777                 }
 778                 case SQUASHFS_SYMLINK_TYPE: {
 779                         struct squashfs_symlink_inode_header *inodep =
 780                                                                 &id.symlink;
 781                         struct squashfs_symlink_inode_header *sinodep =
 782                                                                 &sid.symlink;
 783
 784                         if (msblk->swap) {
 785                                 if (!squashfs_get_cached_block(s, (char *)
 786                                                 sinodep, block, offset,
 787                                                 sizeof(*sinodep), &next_block,
 788                                                 &next_offset))
 789                                         goto failed_read;
 790                                 SQUASHFS_SWAP_SYMLINK_INODE_HEADER(inodep,
 791                                                                 sinodep);
 792                         } else
 793                                 if (!squashfs_get_cached_block(s, (char *)
 794                                                 inodep, block, offset,
 795                                                 sizeof(*inodep), &next_block,
 796                                                 &next_offset))
 797                                         goto failed_read;
 798
 799                         if((i = squashfs_new_inode(s, inodeb)) == NULL)
 800                                 goto failed_read1;
 801
 802                         i->i_nlink = inodep->nlink;
 803                         i->i_size = inodep->symlink_size;
 804                         i->i_op = &page_symlink_inode_operations;
 805                         i->i_data.a_ops = &squashfs_symlink_aops;
 806                         i->i_mode |= S_IFLNK;
 807                         SQUASHFS_I(i)->start_block = next_block;
 808                         SQUASHFS_I(i)->offset = next_offset;
 809
 810                         TRACE("Symbolic link inode %x:%x, start_block %llx, "
 811                                         "offset %x\n",
 812                                         SQUASHFS_INODE_BLK(inode), offset,
 813                                         next_block, next_offset);
 814                         break;
 815                  }
 816                  case SQUASHFS_BLKDEV_TYPE:
 817                  case SQUASHFS_CHRDEV_TYPE: {
 818                         struct squashfs_dev_inode_header *inodep = &id.dev;
 819                         struct squashfs_dev_inode_header *sinodep = &sid.dev;
 820
 821                         if (msblk->swap) {
 822                                 if (!squashfs_get_cached_block(s, (char *)
 823                                                 sinodep, block, offset,
 824                                                 sizeof(*sinodep), &next_block,
 825                                                 &next_offset))
 826                                         goto failed_read;
 827                                 SQUASHFS_SWAP_DEV_INODE_HEADER(inodep, sinodep);
 828                         } else
 829                                 if (!squashfs_get_cached_block(s, (char *)
 830                                                 inodep, block, offset,
 831                                                 sizeof(*inodep), &next_block,
 832                                                 &next_offset))
 833                                         goto failed_read;
 834
 835                         if ((i = squashfs_new_inode(s, inodeb)) == NULL)
 836                                 goto failed_read1;
 837
 838                         i->i_nlink = inodep->nlink;
 839                         i->i_mode |= (inodeb->inode_type ==
 840                                         SQUASHFS_CHRDEV_TYPE) ?  S_IFCHR :
 841                                         S_IFBLK;
 842                         init_special_inode(i, i->i_mode,
 843                                         old_decode_dev(inodep->rdev));
 844
 845                         TRACE("Device inode %x:%x, rdev %x\n",
 846                                         SQUASHFS_INODE_BLK(inode), offset,
 847                                         inodep->rdev);
 848                         break;
 849                  }
 850                  case SQUASHFS_FIFO_TYPE:
 851                  case SQUASHFS_SOCKET_TYPE: {
 852                         struct squashfs_ipc_inode_header *inodep = &id.ipc;
 853                         struct squashfs_ipc_inode_header *sinodep = &sid.ipc;
 854
 855                         if (msblk->swap) {
 856                                 if (!squashfs_get_cached_block(s, (char *)
 857                                                 sinodep, block, offset,
 858                                                 sizeof(*sinodep), &next_block,
 859                                                 &next_offset))
 860                                         goto failed_read;
 861                                 SQUASHFS_SWAP_IPC_INODE_HEADER(inodep, sinodep);
 862                         } else
 863                                 if (!squashfs_get_cached_block(s, (char *)
 864                                                 inodep, block, offset,
 865                                                 sizeof(*inodep), &next_block,
 866                                                 &next_offset))
 867                                         goto failed_read;
 868
 869                         if ((i = squashfs_new_inode(s, inodeb)) == NULL)
 870                                 goto failed_read1;
 871
 872                         i->i_nlink = inodep->nlink;
 873                         i->i_mode |= (inodeb->inode_type == SQUASHFS_FIFO_TYPE)
 874                                                         ? S_IFIFO : S_IFSOCK;
 875                         init_special_inode(i, i->i_mode, 0);
 876                         break;
 877                  }
 878                  default:
 879                         ERROR("Unknown inode type %d in squashfs_iget!\n",
 880                                         inodeb->inode_type);
 881                         goto failed_read1;
 882         }
 883
 884         insert_inode_hash(i);
 885         return i;
 886
 887 failed_read:
 888         ERROR("Unable to read inode [%llx:%x]\n", block, offset);
 889
 890 failed_read1:
 891         return NULL;
 892 }
 893
 894
 895 static int read_fragment_index_table(struct super_block *s)
 896 {
 897         struct squashfs_sb_info *msblk = s->s_fs_info;
 898         struct squashfs_super_block *sblk = &msblk->sblk;
 899         unsigned int length = SQUASHFS_FRAGMENT_INDEX_BYTES(sblk->fragments);
 900
 901         if (length == 0)
 902                 return 1;
 903
 904         /* Allocate fragment index table */
 905         if (!(msblk->fragment_index = kmalloc(SQUASHFS_FRAGMENT_INDEX_BYTES
 906                                         (sblk->fragments), GFP_KERNEL))) {
 907                 ERROR("Failed to allocate uid/gid table\n");
 908                 return 0;
 909         }
 910
 911         if (!squashfs_read_data(s, (char *) msblk->fragment_index,
 912                         sblk->fragment_table_start, length |
 913                         SQUASHFS_COMPRESSED_BIT_BLOCK, NULL, length)) {
 914                 ERROR("unable to read fragment index table\n");
 915                 return 0;
 916         }
 917
 918         if (msblk->swap) {
 919                 int i;
 920                 long long fragment;
 921
 922                 for (i = 0; i < SQUASHFS_FRAGMENT_INDEXES(sblk->fragments);
 923                                                                         i++) {
 924                         SQUASHFS_SWAP_FRAGMENT_INDEXES((&fragment),
 925                                                 &msblk->fragment_index[i], 1);
 926                         msblk->fragment_index[i] = fragment;
 927                 }
 928         }
 929
 930         return 1;
 931 }
 932
 933
 934 static int supported_squashfs_filesystem(struct squashfs_sb_info *msblk, int silent)
 935 {
 936         struct squashfs_super_block *sblk = &msblk->sblk;
 937
 938         msblk->iget = squashfs_iget;
 939         msblk->read_blocklist = read_blocklist;
 940         msblk->read_fragment_index_table = read_fragment_index_table;
 941
 942         if (sblk->s_major == 1) {
 943                 if (!squashfs_1_0_supported(msblk)) {
 944                         SERROR("Major/Minor mismatch, Squashfs 1.0 filesystems "
 945                                 "are unsupported\n");
 946                         SERROR("Please recompile with "
 947                                 "Squashfs 1.0 support enabled\n");
 948                         return 0;
 949                 }
 950         } else if (sblk->s_major == 2) {
 951                 if (!squashfs_2_0_supported(msblk)) {
 952                         SERROR("Major/Minor mismatch, Squashfs 2.0 filesystems "
 953                                 "are unsupported\n");
 954                         SERROR("Please recompile with "
 955                                 "Squashfs 2.0 support enabled\n");
 956                         return 0;
 957                 }
 958         } else if(sblk->s_major != SQUASHFS_MAJOR || sblk->s_minor >
 959                         SQUASHFS_MINOR) {
 960                 SERROR("Major/Minor mismatch, trying to mount newer %d.%d "
 961                                 "filesystem\n", sblk->s_major, sblk->s_minor);
 962                 SERROR("Please update your kernel\n");
 963                 return 0;
 964         }
 965
 966         return 1;
 967 }
 968
 969
 970 static int squashfs_fill_super(struct super_block *s, void *data, int silent)
 971 {
 972         struct squashfs_sb_info *msblk;
 973         struct squashfs_super_block *sblk;
 974         int i;
 975         char b[BDEVNAME_SIZE];
 976         struct inode *root;
 977
 978         TRACE("Entered squashfs_read_superblock\n");
 979
 980         if (!(s->s_fs_info = kmalloc(sizeof(struct squashfs_sb_info),
 981                                                 GFP_KERNEL))) {
 982                 ERROR("Failed to allocate superblock\n");
 983                 goto failure;
 984         }
 985         memset(s->s_fs_info, 0, sizeof(struct squashfs_sb_info));
 986         msblk = s->s_fs_info;
 987         if (!(msblk->stream.workspace = vmalloc(zlib_inflate_workspacesize()))) {
 988                 ERROR("Failed to allocate zlib workspace\n");
 989                 goto failure;
 990         }
 991         sblk = &msblk->sblk;
 992
 993         msblk->devblksize = sb_min_blocksize(s, BLOCK_SIZE);
 994         msblk->devblksize_log2 = ffz(~msblk->devblksize);
 995
 996         init_MUTEX(&msblk->read_data_mutex);
 997         init_MUTEX(&msblk->read_page_mutex);
 998         init_MUTEX(&msblk->block_cache_mutex);
 999         init_MUTEX(&msblk->fragment_mutex);
1000         init_MUTEX(&msblk->meta_index_mutex);
1001
1002         init_waitqueue_head(&msblk->waitq);
1003         init_waitqueue_head(&msblk->fragment_wait_queue);
1004
1005         sblk->bytes_used = sizeof(struct squashfs_super_block);
1006         if (!squashfs_read_data(s, (char *) sblk, SQUASHFS_START,
1007                                         sizeof(struct squashfs_super_block) |
1008                                         SQUASHFS_COMPRESSED_BIT_BLOCK, NULL,
1009                                         sizeof(struct squashfs_super_block))) {
1010                 SERROR("unable to read superblock\n");
1011                 goto failed_mount;
1012         }
1013
1014         /* Check it is a SQUASHFS superblock */
1015         msblk->swap = 0;
1016         if ((s->s_magic = sblk->s_magic) != SQUASHFS_MAGIC) {
1017                 if (sblk->s_magic == SQUASHFS_MAGIC_SWAP) {
1018                         struct squashfs_super_block ssblk;
1019
1020                         WARNING("Mounting a different endian SQUASHFS "
1021                                 "filesystem on %s\n", bdevname(s->s_bdev, b));
1022
1023                         SQUASHFS_SWAP_SUPER_BLOCK(&ssblk, sblk);
1024                         memcpy(sblk, &ssblk, sizeof(struct squashfs_super_block));
1025                         msblk->swap = 1;
1026                 } else  {
1027                         SERROR("Can't find a SQUASHFS superblock on %s\n",
1028                                                         bdevname(s->s_bdev, b));
1029                         goto failed_mount;
1030                 }
1031         }
1032
1033         /* Check the MAJOR & MINOR versions */
1034         if(!supported_squashfs_filesystem(msblk, silent))
1035                 goto failed_mount;
1036
1037         /* Check the filesystem does not extend beyond the end of the
1038            block device */
1039         if(sblk->bytes_used < 0 || sblk->bytes_used > i_size_read(s->s_bdev->bd_inode))
1040                 goto failed_mount;
1041
1042         /* Check the root inode for sanity */
1043         if (SQUASHFS_INODE_OFFSET(sblk->root_inode) > SQUASHFS_METADATA_SIZE)
1044                 goto failed_mount;
1045
1046         TRACE("Found valid superblock on %s\n", bdevname(s->s_bdev, b));
1047         TRACE("Inodes are %scompressed\n",
1048                                         SQUASHFS_UNCOMPRESSED_INODES
1049                                         (sblk->flags) ? "un" : "");
1050         TRACE("Data is %scompressed\n",
1051                                         SQUASHFS_UNCOMPRESSED_DATA(sblk->flags)
1052                                         ? "un" : "");
1053         TRACE("Check data is %s present in the filesystem\n",
1054                                         SQUASHFS_CHECK_DATA(sblk->flags) ?
1055                                         "" : "not");
1056         TRACE("Filesystem size %lld bytes\n", sblk->bytes_used);
1057         TRACE("Block size %d\n", sblk->block_size);
1058         TRACE("Number of inodes %d\n", sblk->inodes);
1059         if (sblk->s_major > 1)
1060                 TRACE("Number of fragments %d\n", sblk->fragments);
1061         TRACE("Number of uids %d\n", sblk->no_uids);
1062         TRACE("Number of gids %d\n", sblk->no_guids);
1063         TRACE("sblk->inode_table_start %llx\n", sblk->inode_table_start);
1064         TRACE("sblk->directory_table_start %llx\n", sblk->directory_table_start);
1065         if (sblk->s_major > 1)
1066                 TRACE("sblk->fragment_table_start %llx\n",
1067                                         sblk->fragment_table_start);
1068         TRACE("sblk->uid_start %llx\n", sblk->uid_start);
1069
1070         s->s_flags |= MS_RDONLY;
1071         s->s_op = &squashfs_ops;
1072
1073         /* Init inode_table block pointer array */
1074         if (!(msblk->block_cache = kmalloc(sizeof(struct squashfs_cache) *
1075                                         SQUASHFS_CACHED_BLKS, GFP_KERNEL))) {
1076                 ERROR("Failed to allocate block cache\n");
1077                 goto failed_mount;
1078         }
1079
1080         for (i = 0; i < SQUASHFS_CACHED_BLKS; i++)
1081                 msblk->block_cache[i].block = SQUASHFS_INVALID_BLK;
1082
1083         msblk->next_cache = 0;
1084
1085         /* Allocate read_data block */
1086         msblk->read_size = (sblk->block_size < SQUASHFS_METADATA_SIZE) ?
1087                                         SQUASHFS_METADATA_SIZE :
1088                                         sblk->block_size;
1089
1090         if (!(msblk->read_data = kmalloc(msblk->read_size, GFP_KERNEL))) {
1091                 ERROR("Failed to allocate read_data block\n");
1092                 goto failed_mount;
1093         }
1094
1095         /* Allocate read_page block */
1096         if (!(msblk->read_page = kmalloc(sblk->block_size, GFP_KERNEL))) {
1097                 ERROR("Failed to allocate read_page block\n");
1098                 goto failed_mount;
1099         }
1100
1101         /* Allocate uid and gid tables */
1102         if (!(msblk->uid = kmalloc((sblk->no_uids + sblk->no_guids) *
1103                                         sizeof(unsigned int), GFP_KERNEL))) {
1104                 ERROR("Failed to allocate uid/gid table\n");
1105                 goto failed_mount;
1106         }
1107         msblk->guid = msblk->uid + sblk->no_uids;
1108
1109         if (msblk->swap) {
1110                 unsigned int suid[sblk->no_uids + sblk->no_guids];
1111
1112                 if (!squashfs_read_data(s, (char *) &suid, sblk->uid_start,
1113                                         ((sblk->no_uids + sblk->no_guids) *
1114                                          sizeof(unsigned int)) |
1115                                         SQUASHFS_COMPRESSED_BIT_BLOCK, NULL,
1116                                         (sblk->no_uids + sblk->no_guids) *
1117                                         sizeof(unsigned int))) {
1118                         ERROR("unable to read uid/gid table\n");
1119                         goto failed_mount;
1120                 }
1121
1122                 SQUASHFS_SWAP_DATA(msblk->uid, suid, (sblk->no_uids +
1123                         sblk->no_guids), (sizeof(unsigned int) * 8));
1124         } else
1125                 if (!squashfs_read_data(s, (char *) msblk->uid, sblk->uid_start,
1126                                         ((sblk->no_uids + sblk->no_guids) *
1127                                          sizeof(unsigned int)) |
1128                                         SQUASHFS_COMPRESSED_BIT_BLOCK, NULL,
1129                                         (sblk->no_uids + sblk->no_guids) *
1130                                         sizeof(unsigned int))) {
1131                         ERROR("unable to read uid/gid table\n");
1132                         goto failed_mount;
1133                 }
1134
1135
1136         if (sblk->s_major == 1 && squashfs_1_0_supported(msblk))
1137                 goto allocate_root;
1138
1139         if (!(msblk->fragment = kmalloc(sizeof(struct squashfs_fragment_cache) *
1140                                 SQUASHFS_CACHED_FRAGMENTS, GFP_KERNEL))) {
1141                 ERROR("Failed to allocate fragment block cache\n");
1142                 goto failed_mount;
1143         }
1144
1145         for (i = 0; i < SQUASHFS_CACHED_FRAGMENTS; i++) {
1146                 msblk->fragment[i].locked = 0;
1147                 msblk->fragment[i].block = SQUASHFS_INVALID_BLK;
1148                 msblk->fragment[i].data = NULL;
1149         }
1150
1151         msblk->next_fragment = 0;
1152
1153         /* Allocate fragment index table */
1154         if (msblk->read_fragment_index_table(s) == 0)
1155                 goto failed_mount;
1156
1157 allocate_root:
1158         if ((root = (msblk->iget)(s, sblk->root_inode)) == NULL)
1159                 goto failed_mount;
1160
1161         if ((s->s_root = d_alloc_root(root)) == NULL) {
1162                 ERROR("Root inode create failed\n");
1163                 iput(root);
1164                 goto failed_mount;
1165         }
1166
1167         TRACE("Leaving squashfs_read_super\n");
1168         return 0;
1169
1170 failed_mount:
1171         kfree(msblk->fragment_index);
1172         kfree(msblk->fragment);
1173         kfree(msblk->uid);
1174         kfree(msblk->read_page);
1175         kfree(msblk->read_data);
1176         kfree(msblk->block_cache);
1177         kfree(msblk->fragment_index_2);
1178         vfree(msblk->stream.workspace);
1179         kfree(s->s_fs_info);
1180         s->s_fs_info = NULL;
1181         return -EINVAL;
1182
1183 failure:
1184         return -ENOMEM;
1185 }
1186
1187
1188 static int squashfs_statfs(struct dentry *s, struct kstatfs *buf)
1189 {
1190         struct squashfs_sb_info *msblk = s->d_sb->s_fs_info;
1191         struct squashfs_super_block *sblk = &msblk->sblk;
1192
1193         TRACE("Entered squashfs_statfs\n");
1194
1195         buf->f_type = SQUASHFS_MAGIC;
1196         buf->f_bsize = sblk->block_size;
1197         buf->f_blocks = ((sblk->bytes_used - 1) >> sblk->block_log) + 1;
1198         buf->f_bfree = buf->f_bavail = 0;
1199         buf->f_files = sblk->inodes;
1200         buf->f_ffree = 0;
1201         buf->f_namelen = SQUASHFS_NAME_LEN;
1202
1203         return 0;
1204 }
1205
1206
1207 static int squashfs_symlink_readpage(struct file *file, struct page *page)
1208 {
1209         struct inode *inode = page->mapping->host;
1210         int index = page->index << PAGE_CACHE_SHIFT, length, bytes;
1211         long long block = SQUASHFS_I(inode)->start_block;
1212         int offset = SQUASHFS_I(inode)->offset;
1213         void *pageaddr = kmap(page);
1214
1215         TRACE("Entered squashfs_symlink_readpage, page index %ld, start block "
1216                                 "%llx, offset %x\n", page->index,
1217                                 SQUASHFS_I(inode)->start_block,
1218                                 SQUASHFS_I(inode)->offset);
1219
1220         for (length = 0; length < index; length += bytes) {
1221                 if (!(bytes = squashfs_get_cached_block(inode->i_sb, NULL,
1222                                 block, offset, PAGE_CACHE_SIZE, &block,
1223                                 &offset))) {
1224                         ERROR("Unable to read symbolic link [%llx:%x]\n", block,
1225                                         offset);
1226                         goto skip_read;
1227                 }
1228         }
1229
1230         if (length != index) {
1231                 ERROR("(squashfs_symlink_readpage) length != index\n");
1232                 bytes = 0;
1233                 goto skip_read;
1234         }
1235
1236         bytes = (i_size_read(inode) - length) > PAGE_CACHE_SIZE ? PAGE_CACHE_SIZE :
1237                                         i_size_read(inode) - length;
1238
1239         if (!(bytes = squashfs_get_cached_block(inode->i_sb, pageaddr, block,
1240                                         offset, bytes, &block, &offset)))
1241                 ERROR("Unable to read symbolic link [%llx:%x]\n", block, offset);
1242
1243 skip_read:
1244         memset(pageaddr + bytes, 0, PAGE_CACHE_SIZE - bytes);
1245         kunmap(page);
1246         SetPageUptodate(page);
1247         unlock_page(page);
1248
1249         return 0;
1250 }
1251
1252
1253 struct meta_index *locate_meta_index(struct inode *inode, int index, int offset)
1254 {
1255         struct meta_index *meta = NULL;
1256         struct squashfs_sb_info *msblk = inode->i_sb->s_fs_info;
1257         int i;
1258
1259         down(&msblk->meta_index_mutex);
1260
1261         TRACE("locate_meta_index: index %d, offset %d\n", index, offset);
1262
1263         if(msblk->meta_index == NULL)
1264                 goto not_allocated;
1265
1266         for (i = 0; i < SQUASHFS_META_NUMBER; i ++)
1267                 if (msblk->meta_index[i].inode_number == inode->i_ino &&
1268                                 msblk->meta_index[i].offset >= offset &&
1269                                 msblk->meta_index[i].offset <= index &&
1270                                 msblk->meta_index[i].locked == 0) {
1271                         TRACE("locate_meta_index: entry %d, offset %d\n", i,
1272                                         msblk->meta_index[i].offset);
1273                         meta = &msblk->meta_index[i];
1274                         offset = meta->offset;
1275                 }
1276
1277         if (meta)
1278                 meta->locked = 1;
1279
1280 not_allocated:
1281         up(&msblk->meta_index_mutex);
1282
1283         return meta;
1284 }
1285
1286
1287 struct meta_index *empty_meta_index(struct inode *inode, int offset, int skip)
1288 {
1289         struct squashfs_sb_info *msblk = inode->i_sb->s_fs_info;
1290         struct meta_index *meta = NULL;
1291         int i;
1292
1293         down(&msblk->meta_index_mutex);
1294
1295         TRACE("empty_meta_index: offset %d, skip %d\n", offset, skip);
1296
1297         if(msblk->meta_index == NULL) {
1298                 if (!(msblk->meta_index = kmalloc(sizeof(struct meta_index) *
1299                                         SQUASHFS_META_NUMBER, GFP_KERNEL))) {
1300                         ERROR("Failed to allocate meta_index\n");
1301                         goto failed;
1302                 }
1303                 for(i = 0; i < SQUASHFS_META_NUMBER; i++) {
1304                         msblk->meta_index[i].inode_number = 0;
1305                         msblk->meta_index[i].locked = 0;
1306                 }
1307                 msblk->next_meta_index = 0;
1308         }
1309
1310         for(i = SQUASHFS_META_NUMBER; i &&
1311                         msblk->meta_index[msblk->next_meta_index].locked; i --)
1312                 msblk->next_meta_index = (msblk->next_meta_index + 1) %
1313                         SQUASHFS_META_NUMBER;
1314
1315         if(i == 0) {
1316                 TRACE("empty_meta_index: failed!\n");
1317                 goto failed;
1318         }
1319
1320         TRACE("empty_meta_index: returned meta entry %d, %p\n",
1321                         msblk->next_meta_index,
1322                         &msblk->meta_index[msblk->next_meta_index]);
1323
1324         meta = &msblk->meta_index[msblk->next_meta_index];
1325         msblk->next_meta_index = (msblk->next_meta_index + 1) %
1326                         SQUASHFS_META_NUMBER;
1327
1328         meta->inode_number = inode->i_ino;
1329         meta->offset = offset;
1330         meta->skip = skip;
1331         meta->entries = 0;
1332         meta->locked = 1;
1333
1334 failed:
1335         up(&msblk->meta_index_mutex);
1336         return meta;
1337 }
1338
1339
1340 void release_meta_index(struct inode *inode, struct meta_index *meta)
1341 {
1342         meta->locked = 0;
1343 }
1344
1345
1346 static int read_block_index(struct super_block *s, int blocks, char *block_list,
1347                 long long *start_block, int *offset)
1348 {
1349         struct squashfs_sb_info *msblk = s->s_fs_info;
1350         unsigned int *block_listp;
1351         int block = 0;
1352
1353         if (msblk->swap) {
1354                 char sblock_list[blocks << 2];
1355
1356                 if (!squashfs_get_cached_block(s, sblock_list, *start_block,
1357                                 *offset, blocks << 2, start_block, offset)) {
1358                         ERROR("Unable to read block list [%llx:%x]\n",
1359                                 *start_block, *offset);
1360                         goto failure;
1361                 }
1362                 SQUASHFS_SWAP_INTS(((unsigned int *)block_list),
1363                                 ((unsigned int *)sblock_list), blocks);
1364         } else
1365                 if (!squashfs_get_cached_block(s, block_list, *start_block,
1366                                 *offset, blocks << 2, start_block, offset)) {
1367                         ERROR("Unable to read block list [%llx:%x]\n",
1368                                 *start_block, *offset);
1369                         goto failure;
1370                 }
1371
1372         for (block_listp = (unsigned int *) block_list; blocks;
1373                                 block_listp++, blocks --)
1374                 block += SQUASHFS_COMPRESSED_SIZE_BLOCK(*block_listp);
1375
1376         return block;
1377
1378 failure:
1379         return -1;
1380 }
1381
1382
1383 #define SIZE 256
1384
1385 static inline int calculate_skip(int blocks) {
1386         int skip = (blocks - 1) / ((SQUASHFS_SLOTS * SQUASHFS_META_ENTRIES + 1) * SQUASHFS_META_INDEXES);
1387         return skip >= 7 ? 7 : skip + 1;
1388 }
1389
1390
1391 static int get_meta_index(struct inode *inode, int index,
1392                 long long *index_block, int *index_offset,
1393                 long long *data_block, char *block_list)
1394 {
1395         struct squashfs_sb_info *msblk = inode->i_sb->s_fs_info;
1396         struct squashfs_super_block *sblk = &msblk->sblk;
1397         int skip = calculate_skip(i_size_read(inode) >> sblk->block_log);
1398         int offset = 0;
1399         struct meta_index *meta;
1400         struct meta_entry *meta_entry;
1401         long long cur_index_block = SQUASHFS_I(inode)->u.s1.block_list_start;
1402         int cur_offset = SQUASHFS_I(inode)->offset;
1403         long long cur_data_block = SQUASHFS_I(inode)->start_block;
1404         int i;
1405
1406         index /= SQUASHFS_META_INDEXES * skip;
1407
1408         while ( offset < index ) {
1409                 meta = locate_meta_index(inode, index, offset + 1);
1410
1411                 if (meta == NULL) {
1412                         if ((meta = empty_meta_index(inode, offset + 1,
1413                                                         skip)) == NULL)
1414                                 goto all_done;
1415                 } else {
1416                         offset = index < meta->offset + meta->entries ? index :
1417                                 meta->offset + meta->entries - 1;
1418                         meta_entry = &meta->meta_entry[offset - meta->offset];
1419                         cur_index_block = meta_entry->index_block + sblk->inode_table_start;
1420                         cur_offset = meta_entry->offset;
1421                         cur_data_block = meta_entry->data_block;
1422                         TRACE("get_meta_index: offset %d, meta->offset %d, "
1423                                 "meta->entries %d\n", offset, meta->offset,
1424                                 meta->entries);
1425                         TRACE("get_meta_index: index_block 0x%llx, offset 0x%x"
1426                                 " data_block 0x%llx\n", cur_index_block,
1427                                 cur_offset, cur_data_block);
1428                 }
1429
1430                 for (i = meta->offset + meta->entries; i <= index &&
1431                                 i < meta->offset + SQUASHFS_META_ENTRIES; i++) {
1432                         int blocks = skip * SQUASHFS_META_INDEXES;
1433
1434                         while (blocks) {
1435                                 int block = blocks > (SIZE >> 2) ? (SIZE >> 2) :
1436                                         blocks;
1437                                 int res = read_block_index(inode->i_sb, block,
1438                                         block_list, &cur_index_block,
1439                                         &cur_offset);
1440
1441                                 if (res == -1)
1442                                         goto failed;
1443
1444                                 cur_data_block += res;
1445                                 blocks -= block;
1446                         }
1447
1448                         meta_entry = &meta->meta_entry[i - meta->offset];
1449                         meta_entry->index_block = cur_index_block - sblk->inode_table_start;
1450                         meta_entry->offset = cur_offset;
1451                         meta_entry->data_block = cur_data_block;
1452                         meta->entries ++;
1453                         offset ++;
1454                 }
1455
1456                 TRACE("get_meta_index: meta->offset %d, meta->entries %d\n",
1457                                 meta->offset, meta->entries);
1458
1459                 release_meta_index(inode, meta);
1460         }
1461
1462 all_done:
1463         *index_block = cur_index_block;
1464         *index_offset = cur_offset;
1465         *data_block = cur_data_block;
1466
1467         return offset * SQUASHFS_META_INDEXES * skip;
1468
1469 failed:
1470         release_meta_index(inode, meta);
1471         return -1;
1472 }
1473
1474
1475 static long long read_blocklist(struct inode *inode, int index,
1476                                 int readahead_blks, char *block_list,
1477                                 unsigned short **block_p, unsigned int *bsize)
1478 {
1479         long long block_ptr;
1480         int offset;
1481         long long block;
1482         int res = get_meta_index(inode, index, &block_ptr, &offset, &block,
1483                 block_list);
1484
1485         TRACE("read_blocklist: res %d, index %d, block_ptr 0x%llx, offset"
1486                        " 0x%x, block 0x%llx\n", res, index, block_ptr, offset,
1487                        block);
1488
1489         if(res == -1)
1490                 goto failure;
1491
1492         index -= res;
1493
1494         while ( index ) {
1495                 int blocks = index > (SIZE >> 2) ? (SIZE >> 2) : index;
1496                 int res = read_block_index(inode->i_sb, blocks, block_list,
1497                         &block_ptr, &offset);
1498                 if (res == -1)
1499                         goto failure;
1500                 block += res;
1501                 index -= blocks;
1502         }
1503
1504         if (read_block_index(inode->i_sb, 1, block_list,
1505                         &block_ptr, &offset) == -1)
1506                 goto failure;
1507         *bsize = *((unsigned int *) block_list);
1508
1509         return block;
1510
1511 failure:
1512         return 0;
1513 }
1514
1515
1516 static int squashfs_readpage(struct file *file, struct page *page)
1517 {
1518         struct inode *inode = page->mapping->host;
1519         struct squashfs_sb_info *msblk = inode->i_sb->s_fs_info;
1520         struct squashfs_super_block *sblk = &msblk->sblk;
1521         unsigned char *block_list;
1522         long long block;
1523         unsigned int bsize, i = 0, bytes = 0, byte_offset = 0;
1524         int index = page->index >> (sblk->block_log - PAGE_CACHE_SHIFT);
1525         void *pageaddr;
1526         struct squashfs_fragment_cache *fragment = NULL;
1527         char *data_ptr = msblk->read_page;
1528
1529         int mask = (1 << (sblk->block_log - PAGE_CACHE_SHIFT)) - 1;
1530         int start_index = page->index & ~mask;
1531         int end_index = start_index | mask;
1532
1533         TRACE("Entered squashfs_readpage, page index %lx, start block %llx\n",
1534                                         page->index,
1535                                         SQUASHFS_I(inode)->start_block);
1536
1537         if (!(block_list = kmalloc(SIZE, GFP_KERNEL))) {
1538                 ERROR("Failed to allocate block_list\n");
1539                 goto skip_read;
1540         }
1541
1542         if (page->index >= ((i_size_read(inode) + PAGE_CACHE_SIZE - 1) >>
1543                                         PAGE_CACHE_SHIFT))
1544                 goto skip_read;
1545
1546         if (SQUASHFS_I(inode)->u.s1.fragment_start_block == SQUASHFS_INVALID_BLK
1547                                         || index < (i_size_read(inode) >>
1548                                         sblk->block_log)) {
1549                 if ((block = (msblk->read_blocklist)(inode, index, 1,
1550                                         block_list, NULL, &bsize)) == 0)
1551                         goto skip_read;
1552
1553                 down(&msblk->read_page_mutex);
1554
1555                 if (!(bytes = squashfs_read_data(inode->i_sb, msblk->read_page,
1556                                         block, bsize, NULL,
1557                                         msblk->read_size))) {
1558                         ERROR("Unable to read page, block %llx, size %x\n", block,
1559                                         bsize);
1560                         up(&msblk->read_page_mutex);
1561                         goto skip_read;
1562                 }
1563         } else {
1564                 if ((fragment = get_cached_fragment(inode->i_sb,
1565                                         SQUASHFS_I(inode)->
1566                                         u.s1.fragment_start_block,
1567                                         SQUASHFS_I(inode)->u.s1.fragment_size))
1568                                         == NULL) {
1569                         ERROR("Unable to read page, block %llx, size %x\n",
1570                                         SQUASHFS_I(inode)->
1571                                         u.s1.fragment_start_block,
1572                                         (int) SQUASHFS_I(inode)->
1573                                         u.s1.fragment_size);
1574                         goto skip_read;
1575                 }
1576                 bytes = SQUASHFS_I(inode)->u.s1.fragment_offset +
1577                                         (i_size_read(inode) & (sblk->block_size
1578                                         - 1));
1579                 byte_offset = SQUASHFS_I(inode)->u.s1.fragment_offset;
1580                 data_ptr = fragment->data;
1581         }
1582
1583         for (i = start_index; i <= end_index && byte_offset < bytes;
1584                                         i++, byte_offset += PAGE_CACHE_SIZE) {
1585                 struct page *push_page;
1586                 int available_bytes = (bytes - byte_offset) > PAGE_CACHE_SIZE ?
1587                                         PAGE_CACHE_SIZE : bytes - byte_offset;
1588
1589                 TRACE("bytes %d, i %d, byte_offset %d, available_bytes %d\n",
1590                                         bytes, i, byte_offset, available_bytes);
1591
1592                 if (i == page->index)  {
1593                         pageaddr = kmap_atomic(page, KM_USER0);
1594                         memcpy(pageaddr, data_ptr + byte_offset,
1595                                         available_bytes);
1596                         memset(pageaddr + available_bytes, 0,
1597                                         PAGE_CACHE_SIZE - available_bytes);
1598                         kunmap_atomic(pageaddr, KM_USER0);
1599                         flush_dcache_page(page);
1600                         SetPageUptodate(page);
1601                         unlock_page(page);
1602                 } else if ((push_page =
1603                                 grab_cache_page_nowait(page->mapping, i))) {
1604                         pageaddr = kmap_atomic(push_page, KM_USER0);
1605
1606                         memcpy(pageaddr, data_ptr + byte_offset,
1607                                         available_bytes);
1608                         memset(pageaddr + available_bytes, 0,
1609                                         PAGE_CACHE_SIZE - available_bytes);
1610                         kunmap_atomic(pageaddr, KM_USER0);
1611                         flush_dcache_page(push_page);
1612                         SetPageUptodate(push_page);
1613                         unlock_page(push_page);
1614                         page_cache_release(push_page);
1615                 }
1616         }
1617
1618         if (SQUASHFS_I(inode)->u.s1.fragment_start_block == SQUASHFS_INVALID_BLK
1619                                         || index < (i_size_read(inode) >>
1620                                         sblk->block_log))
1621                 up(&msblk->read_page_mutex);
1622         else
1623                 release_cached_fragment(msblk, fragment);
1624
1625         kfree(block_list);
1626         return 0;
1627
1628 skip_read:
1629         pageaddr = kmap_atomic(page, KM_USER0);
1630         memset(pageaddr + bytes, 0, PAGE_CACHE_SIZE - bytes);
1631         kunmap_atomic(pageaddr, KM_USER0);
1632         flush_dcache_page(page);
1633         SetPageUptodate(page);
1634         unlock_page(page);
1635
1636         kfree(block_list);
1637         return 0;
1638 }
1639
1640
1641 static int squashfs_readpage4K(struct file *file, struct page *page)
1642 {
1643         struct inode *inode = page->mapping->host;
1644         struct squashfs_sb_info *msblk = inode->i_sb->s_fs_info;
1645         struct squashfs_super_block *sblk = &msblk->sblk;
1646         unsigned char *block_list;
1647         long long block;
1648         unsigned int bsize, bytes = 0;
1649         void *pageaddr;
1650
1651         TRACE("Entered squashfs_readpage4K, page index %lx, start block %llx\n",
1652                                         page->index,
1653                                         SQUASHFS_I(inode)->start_block);
1654
1655         if (page->index >= ((i_size_read(inode) + PAGE_CACHE_SIZE - 1) >>
1656                                         PAGE_CACHE_SHIFT)) {
1657                 block_list = NULL;
1658                 goto skip_read;
1659         }
1660
1661         if (!(block_list = kmalloc(SIZE, GFP_KERNEL))) {
1662                 ERROR("Failed to allocate block_list\n");
1663                 goto skip_read;
1664         }
1665
1666         if (SQUASHFS_I(inode)->u.s1.fragment_start_block == SQUASHFS_INVALID_BLK
1667                                         || page->index < (i_size_read(inode) >>
1668                                         sblk->block_log)) {
1669                 block = (msblk->read_blocklist)(inode, page->index, 1,
1670                                         block_list, NULL, &bsize);
1671
1672                 down(&msblk->read_page_mutex);
1673                 bytes = squashfs_read_data(inode->i_sb, msblk->read_page, block,
1674                                         bsize, NULL, msblk->read_size);
1675                 if (bytes) {
1676                         pageaddr = kmap_atomic(page, KM_USER0);
1677                         memcpy(pageaddr, msblk->read_page, bytes);
1678                         kunmap_atomic(pageaddr, KM_USER0);
1679                 } else
1680                         ERROR("Unable to read page, block %llx, size %x\n",
1681                                         block, bsize);
1682                 up(&msblk->read_page_mutex);
1683         } else {
1684                 struct squashfs_fragment_cache *fragment =
1685                         get_cached_fragment(inode->i_sb,
1686                                         SQUASHFS_I(inode)->
1687                                         u.s1.fragment_start_block,
1688                                         SQUASHFS_I(inode)-> u.s1.fragment_size);
1689                 if (fragment) {
1690                         bytes = i_size_read(inode) & (sblk->block_size - 1);
1691                         pageaddr = kmap_atomic(page, KM_USER0);
1692                         memcpy(pageaddr, fragment->data + SQUASHFS_I(inode)->
1693                                         u.s1.fragment_offset, bytes);
1694                         kunmap_atomic(pageaddr, KM_USER0);
1695                         release_cached_fragment(msblk, fragment);
1696                 } else
1697                         ERROR("Unable to read page, block %llx, size %x\n",
1698                                         SQUASHFS_I(inode)->
1699                                         u.s1.fragment_start_block, (int)
1700                                         SQUASHFS_I(inode)-> u.s1.fragment_size);
1701         }
1702
1703 skip_read:
1704         pageaddr = kmap_atomic(page, KM_USER0);
1705         memset(pageaddr + bytes, 0, PAGE_CACHE_SIZE - bytes);
1706         kunmap_atomic(pageaddr, KM_USER0);
1707         flush_dcache_page(page);
1708         SetPageUptodate(page);
1709         unlock_page(page);
1710
1711         kfree(block_list);
1712         return 0;
1713 }
1714
1715
1716 static int get_dir_index_using_offset(struct super_block *s, long long
1717                                 *next_block, unsigned int *next_offset,
1718                                 long long index_start,
1719                                 unsigned int index_offset, int i_count,
1720                                 long long f_pos)
1721 {
1722         struct squashfs_sb_info *msblk = s->s_fs_info;
1723         struct squashfs_super_block *sblk = &msblk->sblk;
1724         int i, length = 0;
1725         struct squashfs_dir_index index;
1726
1727         TRACE("Entered get_dir_index_using_offset, i_count %d, f_pos %d\n",
1728                                         i_count, (unsigned int) f_pos);
1729
1730         f_pos =- 3;
1731         if (f_pos == 0)
1732                 goto finish;
1733
1734         for (i = 0; i < i_count; i++) {
1735                 if (msblk->swap) {
1736                         struct squashfs_dir_index sindex;
1737                         squashfs_get_cached_block(s, (char *) &sindex,
1738                                         index_start, index_offset,
1739                                         sizeof(sindex), &index_start,
1740                                         &index_offset);
1741                         SQUASHFS_SWAP_DIR_INDEX(&index, &sindex);
1742                 } else
1743                         squashfs_get_cached_block(s, (char *) &index,
1744                                         index_start, index_offset,
1745                                         sizeof(index), &index_start,
1746                                         &index_offset);
1747
1748                 if (index.index > f_pos)
1749                         break;
1750
1751                 squashfs_get_cached_block(s, NULL, index_start, index_offset,
1752                                         index.size + 1, &index_start,
1753                                         &index_offset);
1754
1755                 length = index.index;
1756                 *next_block = index.start_block + sblk->directory_table_start;
1757         }
1758
1759         *next_offset = (length + *next_offset) % SQUASHFS_METADATA_SIZE;
1760
1761 finish:
1762         return length + 3;
1763 }
1764
1765
1766 static int get_dir_index_using_name(struct super_block *s, long long
1767                                 *next_block, unsigned int *next_offset,
1768                                 long long index_start,
1769                                 unsigned int index_offset, int i_count,
1770                                 const char *name, int size)
1771 {
1772         struct squashfs_sb_info *msblk = s->s_fs_info;
1773         struct squashfs_super_block *sblk = &msblk->sblk;
1774         int i, length = 0;
1775         struct squashfs_dir_index *index;
1776         char *str;
1777
1778         TRACE("Entered get_dir_index_using_name, i_count %d\n", i_count);
1779
1780         if (!(str = kmalloc(sizeof(struct squashfs_dir_index) +
1781                 (SQUASHFS_NAME_LEN + 1) * 2, GFP_KERNEL))) {
1782                 ERROR("Failed to allocate squashfs_dir_index\n");
1783                 goto failure;
1784         }
1785
1786         index = (struct squashfs_dir_index *) (str + SQUASHFS_NAME_LEN + 1);
1787         strncpy(str, name, size);
1788         str[size] = '\0';
1789
1790         for (i = 0; i < i_count; i++) {
1791                 if (msblk->swap) {
1792                         struct squashfs_dir_index sindex;
1793                         squashfs_get_cached_block(s, (char *) &sindex,
1794                                         index_start, index_offset,
1795                                         sizeof(sindex), &index_start,
1796                                         &index_offset);
1797                         SQUASHFS_SWAP_DIR_INDEX(index, &sindex);
1798                 } else
1799                         squashfs_get_cached_block(s, (char *) index,
1800                                         index_start, index_offset,
1801                                         sizeof(struct squashfs_dir_index),
1802                                         &index_start, &index_offset);
1803
1804                 squashfs_get_cached_block(s, index->name, index_start,
1805                                         index_offset, index->size + 1,
1806                                         &index_start, &index_offset);
1807
1808                 index->name[index->size + 1] = '\0';
1809
1810                 if (strcmp(index->name, str) > 0)
1811                         break;
1812
1813                 length = index->index;
1814                 *next_block = index->start_block + sblk->directory_table_start;
1815         }
1816
1817         *next_offset = (length + *next_offset) % SQUASHFS_METADATA_SIZE;
1818         kfree(str);
1819 failure:
1820         return length + 3;
1821 }
1822
1823
1824 static int squashfs_readdir(struct file *file, void *dirent, filldir_t filldir)
1825 {
1826         struct inode *i = file->f_dentry->d_inode;
1827         struct squashfs_sb_info *msblk = i->i_sb->s_fs_info;
1828         struct squashfs_super_block *sblk = &msblk->sblk;
1829         long long next_block = SQUASHFS_I(i)->start_block +
1830                 sblk->directory_table_start;
1831         int next_offset = SQUASHFS_I(i)->offset, length = 0,
1832                 dir_count;
1833         struct squashfs_dir_header dirh;
1834         struct squashfs_dir_entry *dire;
1835
1836         TRACE("Entered squashfs_readdir [%llx:%x]\n", next_block, next_offset);
1837
1838         if (!(dire = kmalloc(sizeof(struct squashfs_dir_entry) +
1839                 SQUASHFS_NAME_LEN + 1, GFP_KERNEL))) {
1840                 ERROR("Failed to allocate squashfs_dir_entry\n");
1841                 goto finish;
1842         }
1843
1844         while(file->f_pos < 3) {
1845                 char *name;
1846                 int size, i_ino;
1847
1848                 if(file->f_pos == 0) {
1849                         name = ".";
1850                         size = 1;
1851                         i_ino = i->i_ino;
1852                 } else {
1853                         name = "..";
1854                         size = 2;
1855                         i_ino = SQUASHFS_I(i)->u.s2.parent_inode;
1856                 }
1857                 TRACE("Calling filldir(%x, %s, %d, %d, %d, %d)\n",
1858                                 (unsigned int) dirent, name, size, (int)
1859                                 file->f_pos, i_ino,
1860                                 squashfs_filetype_table[1]);
1861
1862                 if (filldir(dirent, name, size,
1863                                 file->f_pos, i_ino,
1864                                 squashfs_filetype_table[1]) < 0) {
1865                                 TRACE("Filldir returned less than 0\n");
1866                                 goto finish;
1867                 }
1868                 file->f_pos += size;
1869         }
1870
1871         length = get_dir_index_using_offset(i->i_sb, &next_block, &next_offset,
1872                                 SQUASHFS_I(i)->u.s2.directory_index_start,
1873                                 SQUASHFS_I(i)->u.s2.directory_index_offset,
1874                                 SQUASHFS_I(i)->u.s2.directory_index_count,
1875                                 file->f_pos);
1876
1877         while (length < i_size_read(i)) {
1878                 /* read directory header */
1879                 if (msblk->swap) {
1880                         struct squashfs_dir_header sdirh;
1881
1882                         if (!squashfs_get_cached_block(i->i_sb, (char *) &sdirh,
1883                                         next_block, next_offset, sizeof(sdirh),
1884                                         &next_block, &next_offset))
1885                                 goto failed_read;
1886
1887                         length += sizeof(sdirh);
1888                         SQUASHFS_SWAP_DIR_HEADER(&dirh, &sdirh);
1889                 } else {
1890                         if (!squashfs_get_cached_block(i->i_sb, (char *) &dirh,
1891                                         next_block, next_offset, sizeof(dirh),
1892                                         &next_block, &next_offset))
1893                                 goto failed_read;
1894
1895                         length += sizeof(dirh);
1896                 }
1897
1898                 dir_count = dirh.count + 1;
1899                 while (dir_count--) {
1900                         if (msblk->swap) {
1901                                 struct squashfs_dir_entry sdire;
1902                                 if (!squashfs_get_cached_block(i->i_sb, (char *)
1903                                                 &sdire, next_block, next_offset,
1904                                                 sizeof(sdire), &next_block,
1905                                                 &next_offset))
1906                                         goto failed_read;
1907
1908                                 length += sizeof(sdire);
1909                                 SQUASHFS_SWAP_DIR_ENTRY(dire, &sdire);
1910                         } else {
1911                                 if (!squashfs_get_cached_block(i->i_sb, (char *)
1912                                                 dire, next_block, next_offset,
1913                                                 sizeof(*dire), &next_block,
1914                                                 &next_offset))
1915                                         goto failed_read;
1916
1917                                 length += sizeof(*dire);
1918                         }
1919
1920                         if (!squashfs_get_cached_block(i->i_sb, dire->name,
1921                                                 next_block, next_offset,
1922                                                 dire->size + 1, &next_block,
1923                                                 &next_offset))
1924                                 goto failed_read;
1925
1926                         length += dire->size + 1;
1927
1928                         if (file->f_pos >= length)
1929                                 continue;
1930
1931                         dire->name[dire->size + 1] = '\0';
1932
1933                         TRACE("Calling filldir(%x, %s, %d, %d, %x:%x, %d, %d)\n",
1934                                         (unsigned int) dirent, dire->name,
1935                                         dire->size + 1, (int) file->f_pos,
1936                                         dirh.start_block, dire->offset,
1937                                         dirh.inode_number + dire->inode_number,
1938                                         squashfs_filetype_table[dire->type]);
1939
1940                         if (filldir(dirent, dire->name, dire->size + 1,
1941                                         file->f_pos,
1942                                         dirh.inode_number + dire->inode_number,
1943                                         squashfs_filetype_table[dire->type])
1944                                         < 0) {
1945                                 TRACE("Filldir returned less than 0\n");
1946                                 goto finish;
1947                         }
1948                         file->f_pos = length;
1949                 }
1950         }
1951
1952 finish:
1953         kfree(dire);
1954         return 0;
1955
1956 failed_read:
1957         ERROR("Unable to read directory block [%llx:%x]\n", next_block,
1958                 next_offset);
1959         return 0;
1960 }
1961
1962
1963 static struct dentry *squashfs_lookup(struct inode *i, struct dentry *dentry,
1964                                 struct nameidata *nd)
1965 {
1966         const unsigned char *name = dentry->d_name.name;
1967         int len = dentry->d_name.len;
1968         struct inode *inode = NULL;
1969         struct squashfs_sb_info *msblk = i->i_sb->s_fs_info;
1970         struct squashfs_super_block *sblk = &msblk->sblk;
1971         long long next_block = SQUASHFS_I(i)->start_block +
1972                                 sblk->directory_table_start;
1973         int next_offset = SQUASHFS_I(i)->offset, length = 0,
1974                                 dir_count;
1975         struct squashfs_dir_header dirh;
1976         struct squashfs_dir_entry *dire;
1977
1978         TRACE("Entered squashfs_lookup [%llx:%x]\n", next_block, next_offset);
1979
1980         if (!(dire = kmalloc(sizeof(struct squashfs_dir_entry) +
1981                 SQUASHFS_NAME_LEN + 1, GFP_KERNEL))) {
1982                 ERROR("Failed to allocate squashfs_dir_entry\n");
1983                 goto exit_loop;
1984         }
1985
1986         if (len > SQUASHFS_NAME_LEN)
1987                 goto exit_loop;
1988
1989         length = get_dir_index_using_name(i->i_sb, &next_block, &next_offset,
1990                                 SQUASHFS_I(i)->u.s2.directory_index_start,
1991                                 SQUASHFS_I(i)->u.s2.directory_index_offset,
1992                                 SQUASHFS_I(i)->u.s2.directory_index_count, name,
1993                                 len);
1994
1995         while (length < i_size_read(i)) {
1996                 /* read directory header */
1997                 if (msblk->swap) {
1998                         struct squashfs_dir_header sdirh;
1999                         if (!squashfs_get_cached_block(i->i_sb, (char *) &sdirh,
2000                                         next_block, next_offset, sizeof(sdirh),
2001                                         &next_block, &next_offset))
2002                                 goto failed_read;
2003
2004                         length += sizeof(sdirh);
2005                         SQUASHFS_SWAP_DIR_HEADER(&dirh, &sdirh);
2006                 } else {
2007                         if (!squashfs_get_cached_block(i->i_sb, (char *) &dirh,
2008                                         next_block, next_offset, sizeof(dirh),
2009                                         &next_block, &next_offset))
2010                                 goto failed_read;
2011
2012                         length += sizeof(dirh);
2013                 }
2014
2015                 dir_count = dirh.count + 1;
2016                 while (dir_count--) {
2017                         if (msblk->swap) {
2018                                 struct squashfs_dir_entry sdire;
2019                                 if (!squashfs_get_cached_block(i->i_sb, (char *)
2020                                                 &sdire, next_block,next_offset,
2021                                                 sizeof(sdire), &next_block,
2022                                                 &next_offset))
2023                                         goto failed_read;
2024
2025                                 length += sizeof(sdire);
2026                                 SQUASHFS_SWAP_DIR_ENTRY(dire, &sdire);
2027                         } else {
2028                                 if (!squashfs_get_cached_block(i->i_sb, (char *)
2029                                                 dire, next_block,next_offset,
2030                                                 sizeof(*dire), &next_block,
2031                                                 &next_offset))
2032                                         goto failed_read;
2033
2034                                 length += sizeof(*dire);
2035                         }
2036
2037                         if (!squashfs_get_cached_block(i->i_sb, dire->name,
2038                                         next_block, next_offset, dire->size + 1,
2039                                         &next_block, &next_offset))
2040                                 goto failed_read;
2041
2042                         length += dire->size + 1;
2043
2044                         if (name[0] < dire->name[0])
2045                                 goto exit_loop;
2046
2047                         if ((len == dire->size + 1) && !strncmp(name,
2048                                                 dire->name, len)) {
2049                                 squashfs_inode_t ino =
2050                                         SQUASHFS_MKINODE(dirh.start_block,
2051                                         dire->offset);
2052
2053                                 TRACE("calling squashfs_iget for directory "
2054                                         "entry %s, inode %x:%x, %d\n", name,
2055                                         dirh.start_block, dire->offset,
2056                                         dirh.inode_number + dire->inode_number);
2057
2058                                 inode = (msblk->iget)(i->i_sb, ino);
2059
2060                                 goto exit_loop;
2061                         }
2062                 }
2063         }
2064
2065 exit_loop:
2066         kfree(dire);
2067         d_add(dentry, inode);
2068         return ERR_PTR(0);
2069
2070 failed_read:
2071         ERROR("Unable to read directory block [%llx:%x]\n", next_block,
2072                 next_offset);
2073         goto exit_loop;
2074 }
2075
2076
2077 static void squashfs_put_super(struct super_block *s)
2078 {
2079         int i;
2080
2081         if (s->s_fs_info) {
2082                 struct squashfs_sb_info *sbi = s->s_fs_info;
2083                 if (sbi->block_cache)
2084                         for (i = 0; i < SQUASHFS_CACHED_BLKS; i++)
2085                                 if (sbi->block_cache[i].block !=
2086                                                         SQUASHFS_INVALID_BLK)
2087                                         kfree(sbi->block_cache[i].data);
2088                 if (sbi->fragment)
2089                         for (i = 0; i < SQUASHFS_CACHED_FRAGMENTS; i++)
2090                                 SQUASHFS_FREE(sbi->fragment[i].data);
2091                 kfree(sbi->fragment);
2092                 kfree(sbi->block_cache);
2093                 kfree(sbi->read_data);
2094                 kfree(sbi->read_page);
2095                 kfree(sbi->uid);
2096                 kfree(sbi->fragment_index);
2097                 kfree(sbi->fragment_index_2);
2098                 kfree(sbi->meta_index);
2099                 vfree(sbi->stream.workspace);
2100                 kfree(s->s_fs_info);
2101                 s->s_fs_info = NULL;
2102         }
2103 }
2104
2105
2106 static int squashfs_get_sb(struct file_system_type *fs_type,
2107                                 int flags, const char *dev_name, void *data, struct vfsmount *mnt)
2108 {
2109         return get_sb_bdev(fs_type, flags, dev_name, data, squashfs_fill_super, mnt);
2110 }
2111
2112
2113 static int __init init_squashfs_fs(void)
2114 {
2115         int err = init_inodecache();
2116         if (err)
2117                 goto out;
2118
2119         printk(KERN_INFO "squashfs: version 3.1 (2006/08/09) "
2120                 "Phillip Lougher\n");
2121
2122         if ((err = register_filesystem(&squashfs_fs_type)))
2123                 destroy_inodecache();
2124
2125 out:
2126         return err;
2127 }
2128
2129
2130 static void __exit exit_squashfs_fs(void)
2131 {
2132         unregister_filesystem(&squashfs_fs_type);
2133         destroy_inodecache();
2134 }
2135
2136
2137 static kmem_cache_t * squashfs_inode_cachep;
2138
2139
2140 static struct inode *squashfs_alloc_inode(struct super_block *sb)
2141 {
2142         struct squashfs_inode_info *ei;
2143         ei = kmem_cache_alloc(squashfs_inode_cachep, SLAB_KERNEL);
2144         if (!ei)
2145                 return NULL;
2146         return &ei->vfs_inode;
2147 }
2148
2149
2150 static void squashfs_destroy_inode(struct inode *inode)
2151 {
2152         kmem_cache_free(squashfs_inode_cachep, SQUASHFS_I(inode));
2153 }
2154
2155
2156 static void init_once(void * foo, kmem_cache_t * cachep, unsigned long flags)
2157 {
2158         struct squashfs_inode_info *ei = foo;
2159
2160         if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) ==
2161                                                         SLAB_CTOR_CONSTRUCTOR)
2162                 inode_init_once(&ei->vfs_inode);
2163 }
2164
2165
2166 static int __init init_inodecache(void)
2167 {
2168         squashfs_inode_cachep = kmem_cache_create("squashfs_inode_cache",
2169              sizeof(struct squashfs_inode_info),
2170              0, SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT,
2171              init_once, NULL);
2172         if (squashfs_inode_cachep == NULL)
2173                 return -ENOMEM;
2174         return 0;
2175 }
2176
2177
2178 static void destroy_inodecache(void)
2179 {
2180         if (kmem_cache_destroy(squashfs_inode_cachep))
2181                 printk(KERN_INFO "squashfs_inode_cache: not all structures "
2182                         "were freed\n");
2183 }
2184
2185
2186 module_init(init_squashfs_fs);
2187 module_exit(exit_squashfs_fs);
2188 MODULE_DESCRIPTION("squashfs, a compressed read-only filesystem");
2189 MODULE_AUTHOR("Phillip Lougher <phillip@lougher.org.uk>");
2190 MODULE_LICENSE("GPL");