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 int squashfs_read_inode(struct inode *i, 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, const char *, void *,
  64                                 struct vfsmount *);
  65 static void vfs_read_inode(struct inode *i);
  66 static struct dentry *squashfs_get_parent(struct dentry *child);
  67
  68 static struct file_system_type squashfs_fs_type = {
  69         .owner = THIS_MODULE,
  70         .name = "squashfs",
  71         .get_sb = squashfs_get_sb,
  72         .kill_sb = kill_block_super,
  73         .fs_flags = FS_REQUIRES_DEV
  74 };
  75
  76 static unsigned char squashfs_filetype_table[] = {
  77         DT_UNKNOWN, DT_DIR, DT_REG, DT_LNK, DT_BLK, DT_CHR, DT_FIFO, DT_SOCK
  78 };
  79
  80 static struct super_operations squashfs_super_ops = {
  81         .alloc_inode = squashfs_alloc_inode,
  82         .destroy_inode = squashfs_destroy_inode,
  83         .statfs = squashfs_statfs,
  84         .put_super = squashfs_put_super,
  85 };
  86
  87 static struct super_operations squashfs_export_super_ops = {
  88         .alloc_inode = squashfs_alloc_inode,
  89         .destroy_inode = squashfs_destroy_inode,
  90         .statfs = squashfs_statfs,
  91         .put_super = squashfs_put_super,
  92         .read_inode = vfs_read_inode
  93 };
  94
  95 struct export_operations squashfs_export_ops = {
  96         .get_parent = squashfs_get_parent
  97 };
  98
  99 SQSH_EXTERN struct address_space_operations squashfs_symlink_aops = {
 100         .readpage = squashfs_symlink_readpage
 101 };
 102
 103 SQSH_EXTERN struct address_space_operations squashfs_aops = {
 104         .readpage = squashfs_readpage
 105 };
 106
 107 SQSH_EXTERN struct address_space_operations squashfs_aops_4K = {
 108         .readpage = squashfs_readpage4K
 109 };
 110
 111 static struct file_operations squashfs_dir_ops = {
 112         .read = generic_read_dir,
 113         .readdir = squashfs_readdir
 114 };
 115
 116 SQSH_EXTERN struct inode_operations squashfs_dir_inode_ops = {
 117         .lookup = squashfs_lookup
 118 };
 119
 120
 121 static struct buffer_head *get_block_length(struct super_block *s,
 122                                 int *cur_index, int *offset, int *c_byte)
 123 {
 124         struct squashfs_sb_info *msblk = s->s_fs_info;
 125         unsigned short temp;
 126         struct buffer_head *bh;
 127
 128         if (!(bh = sb_bread(s, *cur_index)))
 129                 goto out;
 130
 131         if (msblk->devblksize - *offset == 1) {
 132                 if (msblk->swap)
 133                         ((unsigned char *) &temp)[1] = *((unsigned char *)
 134                                 (bh->b_data + *offset));
 135                 else
 136                         ((unsigned char *) &temp)[0] = *((unsigned char *)
 137                                 (bh->b_data + *offset));
 138                 brelse(bh);
 139                 if (!(bh = sb_bread(s, ++(*cur_index))))
 140                         goto out;
 141                 if (msblk->swap)
 142                         ((unsigned char *) &temp)[0] = *((unsigned char *)
 143                                 bh->b_data);
 144                 else
 145                         ((unsigned char *) &temp)[1] = *((unsigned char *)
 146                                 bh->b_data);
 147                 *c_byte = temp;
 148                 *offset = 1;
 149         } else {
 150                 if (msblk->swap) {
 151                         ((unsigned char *) &temp)[1] = *((unsigned char *)
 152                                 (bh->b_data + *offset));
 153                         ((unsigned char *) &temp)[0] = *((unsigned char *)
 154                                 (bh->b_data + *offset + 1));
 155                 } else {
 156                         ((unsigned char *) &temp)[0] = *((unsigned char *)
 157                                 (bh->b_data + *offset));
 158                         ((unsigned char *) &temp)[1] = *((unsigned char *)
 159                                 (bh->b_data + *offset + 1));
 160                 }
 161                 *c_byte = temp;
 162                 *offset += 2;
 163         }
 164
 165         if (SQUASHFS_CHECK_DATA(msblk->sblk.flags)) {
 166                 if (*offset == msblk->devblksize) {
 167                         brelse(bh);
 168                         if (!(bh = sb_bread(s, ++(*cur_index))))
 169                                 goto out;
 170                         *offset = 0;
 171                 }
 172                 if (*((unsigned char *) (bh->b_data + *offset)) !=
 173                                                 SQUASHFS_MARKER_BYTE) {
 174                         ERROR("Metadata block marker corrupt @ %x\n",
 175                                                 *cur_index);
 176                         brelse(bh);
 177                         goto out;
 178                 }
 179                 (*offset)++;
 180         }
 181         return bh;
 182
 183 out:
 184         return NULL;
 185 }
 186
 187
 188 SQSH_EXTERN unsigned int squashfs_read_data(struct super_block *s, char *buffer,
 189                         long long index, unsigned int length,
 190                         long long *next_index, int srclength)
 191 {
 192         struct squashfs_sb_info *msblk = s->s_fs_info;
 193         struct squashfs_super_block *sblk = &msblk->sblk;
 194         struct buffer_head *bh[((SQUASHFS_FILE_MAX_SIZE - 1) >>
 195                         msblk->devblksize_log2) + 2];
 196         unsigned int offset = index & ((1 << msblk->devblksize_log2) - 1);
 197         unsigned int cur_index = index >> msblk->devblksize_log2;
 198         int bytes, avail_bytes, b = 0, k = 0;
 199         char *c_buffer;
 200         unsigned int compressed;
 201         unsigned int c_byte = length;
 202
 203         if (c_byte) {
 204                 bytes = msblk->devblksize - offset;
 205                 compressed = SQUASHFS_COMPRESSED_BLOCK(c_byte);
 206                 c_buffer = compressed ? msblk->read_data : buffer;
 207                 c_byte = SQUASHFS_COMPRESSED_SIZE_BLOCK(c_byte);
 208
 209                 TRACE("Block @ 0x%llx, %scompressed size %d, src size %d\n", index, compressed
 210                                         ? "" : "un", (unsigned int) c_byte, srclength);
 211
 212                 if (c_byte > srclength || index < 0 || (index + c_byte) > sblk->bytes_used)
 213                         goto read_failure;
 214
 215                 if (!(bh[0] = sb_getblk(s, cur_index)))
 216                         goto block_release;
 217
 218                 for (b = 1; bytes < c_byte; b++) {
 219                         if (!(bh[b] = sb_getblk(s, ++cur_index)))
 220                                 goto block_release;
 221                         bytes += msblk->devblksize;
 222                 }
 223                 ll_rw_block(READ, b, bh);
 224         } else {
 225                 if (index < 0 || (index + 2) > sblk->bytes_used)
 226                         goto read_failure;
 227
 228                 if (!(bh[0] = get_block_length(s, &cur_index, &offset,
 229                                                                 &c_byte)))
 230                         goto read_failure;
 231
 232                 bytes = msblk->devblksize - offset;
 233                 compressed = SQUASHFS_COMPRESSED(c_byte);
 234                 c_buffer = compressed ? msblk->read_data : buffer;
 235                 c_byte = SQUASHFS_COMPRESSED_SIZE(c_byte);
 236
 237                 TRACE("Block @ 0x%llx, %scompressed size %d\n", index, compressed
 238                                         ? "" : "un", (unsigned int) c_byte);
 239
 240                 if (c_byte > srclength || (index + c_byte) > sblk->bytes_used)
 241                         goto read_failure;
 242
 243                 for (b = 1; bytes < c_byte; b++) {
 244                         if (!(bh[b] = sb_getblk(s, ++cur_index)))
 245                                 goto block_release;
 246                         bytes += msblk->devblksize;
 247                 }
 248                 ll_rw_block(READ, b - 1, bh + 1);
 249         }
 250
 251         if (compressed)
 252                 down(&msblk->read_data_mutex);
 253
 254         for (bytes = 0; k < b; k++) {
 255                 avail_bytes = (c_byte - bytes) > (msblk->devblksize - offset) ?
 256                                         msblk->devblksize - offset :
 257                                         c_byte - bytes;
 258                 wait_on_buffer(bh[k]);
 259                 if (!buffer_uptodate(bh[k]))
 260                         goto block_release;
 261                 memcpy(c_buffer + bytes, bh[k]->b_data + offset, avail_bytes);
 262                 bytes += avail_bytes;
 263                 offset = 0;
 264                 brelse(bh[k]);
 265         }
 266
 267         /*
 268          * uncompress block
 269          */
 270         if (compressed) {
 271                 int zlib_err;
 272
 273                 msblk->stream.next_in = c_buffer;
 274                 msblk->stream.avail_in = c_byte;
 275                 msblk->stream.next_out = buffer;
 276                 //msblk->stream.avail_out = msblk->read_size;//srclength;
 277                 msblk->stream.avail_out = srclength;
 278
 279                 if (((zlib_err = zlib_inflateInit(&msblk->stream)) != Z_OK) ||
 280                                 ((zlib_err = zlib_inflate(&msblk->stream, Z_FINISH))
 281                                  != Z_STREAM_END) || ((zlib_err =
 282                                 zlib_inflateEnd(&msblk->stream)) != Z_OK)) {
 283                         //ERROR("zlib_fs returned unexpected result 0x%x\n",
 284                         //      zlib_err);
 285                         ERROR("zlib_fs returned unexpected result 0x%x, srclength %d\n",
 286                                 zlib_err, srclength);
 287                         bytes = 0;
 288                 } else
 289                         bytes = msblk->stream.total_out;
 290
 291                 up(&msblk->read_data_mutex);
 292         }
 293
 294         if (next_index)
 295                 *next_index = index + c_byte + (length ? 0 :
 296                                 (SQUASHFS_CHECK_DATA(msblk->sblk.flags)
 297                                  ? 3 : 2));
 298         return bytes;
 299
 300 block_release:
 301         for (; k < b; k++)
 302                 brelse(bh[k]);
 303
 304 read_failure:
 305         ERROR("sb_bread failed reading block 0x%x\n", cur_index);
 306         return 0;
 307 }
 308
 309
 310 SQSH_EXTERN int squashfs_get_cached_block(struct super_block *s, char *buffer,
 311                                 long long block, unsigned int offset,
 312                                 int length, long long *next_block,
 313                                 unsigned int *next_offset)
 314 {
 315         struct squashfs_sb_info *msblk = s->s_fs_info;
 316         int n, i, bytes, return_length = length;
 317         long long next_index;
 318
 319         TRACE("Entered squashfs_get_cached_block [%llx:%x]\n", block, offset);
 320
 321         while ( 1 ) {
 322                 for (i = 0; i < SQUASHFS_CACHED_BLKS; i++)
 323                         if (msblk->block_cache[i].block == block)
 324                                 break;
 325
 326                 down(&msblk->block_cache_mutex);
 327
 328                 if (i == SQUASHFS_CACHED_BLKS) {
 329                         /* read inode header block */
 330                         for (i = msblk->next_cache, n = SQUASHFS_CACHED_BLKS;
 331                                         n ; n --, i = (i + 1) %
 332                                         SQUASHFS_CACHED_BLKS)
 333                                 if (msblk->block_cache[i].block !=
 334                                                         SQUASHFS_USED_BLK)
 335                                         break;
 336
 337                         if (n == 0) {
 338                                 wait_queue_t wait;
 339
 340                                 init_waitqueue_entry(&wait, current);
 341                                 add_wait_queue(&msblk->waitq, &wait);
 342                                 set_current_state(TASK_UNINTERRUPTIBLE);
 343                                 up(&msblk->block_cache_mutex);
 344                                 schedule();
 345                                 set_current_state(TASK_RUNNING);
 346                                 remove_wait_queue(&msblk->waitq, &wait);
 347                                 continue;
 348                         }
 349                         msblk->next_cache = (i + 1) % SQUASHFS_CACHED_BLKS;
 350
 351                         if (msblk->block_cache[i].block ==
 352                                                         SQUASHFS_INVALID_BLK) {
 353                                 if (!(msblk->block_cache[i].data =
 354                                                 kmalloc(SQUASHFS_METADATA_SIZE,
 355                                                 GFP_KERNEL))) {
 356                                         ERROR("Failed to allocate cache"
 357                                                         "block\n");
 358                                         up(&msblk->block_cache_mutex);
 359                                         goto out;
 360                                 }
 361                         }
 362
 363                         msblk->block_cache[i].block = SQUASHFS_USED_BLK;
 364                         up(&msblk->block_cache_mutex);
 365
 366                         msblk->block_cache[i].length = squashfs_read_data(s,
 367                                 msblk->block_cache[i].data, block, 0, &next_index, SQUASHFS_METADATA_SIZE);
 368                         if (msblk->block_cache[i].length == 0) {
 369                                 ERROR("Unable to read cache block [%llx:%x]\n",
 370                                                 block, offset);
 371                                 down(&msblk->block_cache_mutex);
 372                                 msblk->block_cache[i].block = SQUASHFS_INVALID_BLK;
 373                                 kfree(msblk->block_cache[i].data);
 374                                 wake_up(&msblk->waitq);
 375                                 up(&msblk->block_cache_mutex);
 376                                 goto out;
 377                         }
 378
 379                         down(&msblk->block_cache_mutex);
 380                         wake_up(&msblk->waitq);
 381                         msblk->block_cache[i].block = block;
 382                         msblk->block_cache[i].next_index = next_index;
 383                         TRACE("Read cache block [%llx:%x]\n", block, offset);
 384                 }
 385
 386                 if (msblk->block_cache[i].block != block) {
 387                         up(&msblk->block_cache_mutex);
 388                         continue;
 389                 }
 390
 391                 bytes = msblk->block_cache[i].length - offset;
 392
 393                 if (bytes < 1) {
 394                         up(&msblk->block_cache_mutex);
 395                         goto out;
 396                 } else if (bytes >= length) {
 397                         if (buffer)
 398                                 memcpy(buffer, msblk->block_cache[i].data +
 399                                                 offset, length);
 400                         if (msblk->block_cache[i].length - offset == length) {
 401                                 *next_block = msblk->block_cache[i].next_index;
 402                                 *next_offset = 0;
 403                         } else {
 404                                 *next_block = block;
 405                                 *next_offset = offset + length;
 406                         }
 407                         up(&msblk->block_cache_mutex);
 408                         goto finish;
 409                 } else {
 410                         if (buffer) {
 411                                 memcpy(buffer, msblk->block_cache[i].data +
 412                                                 offset, bytes);
 413                                 buffer += bytes;
 414                         }
 415                         block = msblk->block_cache[i].next_index;
 416                         up(&msblk->block_cache_mutex);
 417                         length -= bytes;
 418                         offset = 0;
 419                 }
 420         }
 421
 422 finish:
 423         return return_length;
 424 out:
 425         return 0;
 426 }
 427
 428
 429 static int get_fragment_location(struct super_block *s, unsigned int fragment,
 430                                 long long *fragment_start_block,
 431                                 unsigned int *fragment_size)
 432 {
 433         struct squashfs_sb_info *msblk = s->s_fs_info;
 434         long long start_block =
 435                 msblk->fragment_index[SQUASHFS_FRAGMENT_INDEX(fragment)];
 436         int offset = SQUASHFS_FRAGMENT_INDEX_OFFSET(fragment);
 437         struct squashfs_fragment_entry fragment_entry;
 438
 439         if (msblk->swap) {
 440                 struct squashfs_fragment_entry sfragment_entry;
 441
 442                 if (!squashfs_get_cached_block(s, (char *) &sfragment_entry,
 443                                         start_block, offset,
 444                                         sizeof(sfragment_entry), &start_block,
 445                                         &offset))
 446                         goto out;
 447                 SQUASHFS_SWAP_FRAGMENT_ENTRY(&fragment_entry, &sfragment_entry);
 448         } else
 449                 if (!squashfs_get_cached_block(s, (char *) &fragment_entry,
 450                                         start_block, offset,
 451                                         sizeof(fragment_entry), &start_block,
 452                                         &offset))
 453                         goto out;
 454
 455         *fragment_start_block = fragment_entry.start_block;
 456         *fragment_size = fragment_entry.size;
 457
 458         return 1;
 459
 460 out:
 461         return 0;
 462 }
 463
 464
 465 SQSH_EXTERN void release_cached_fragment(struct squashfs_sb_info *msblk, struct
 466                                         squashfs_fragment_cache *fragment)
 467 {
 468         down(&msblk->fragment_mutex);
 469         fragment->locked --;
 470         wake_up(&msblk->fragment_wait_queue);
 471         up(&msblk->fragment_mutex);
 472 }
 473
 474
 475 SQSH_EXTERN struct squashfs_fragment_cache *get_cached_fragment(struct super_block
 476                                         *s, long long start_block,
 477                                         int length)
 478 {
 479         int i, n;
 480         struct squashfs_sb_info *msblk = s->s_fs_info;
 481         struct squashfs_super_block *sblk = &msblk->sblk;
 482
 483         while ( 1 ) {
 484                 down(&msblk->fragment_mutex);
 485
 486                 for (i = 0; i < SQUASHFS_CACHED_FRAGMENTS &&
 487                                 msblk->fragment[i].block != start_block; i++);
 488
 489                 if (i == SQUASHFS_CACHED_FRAGMENTS) {
 490                         for (i = msblk->next_fragment, n =
 491                                 SQUASHFS_CACHED_FRAGMENTS; n &&
 492                                 msblk->fragment[i].locked; n--, i = (i + 1) %
 493                                 SQUASHFS_CACHED_FRAGMENTS);
 494
 495                         if (n == 0) {
 496                                 wait_queue_t wait;
 497
 498                                 init_waitqueue_entry(&wait, current);
 499                                 add_wait_queue(&msblk->fragment_wait_queue,
 500                                                                         &wait);
 501                                 set_current_state(TASK_UNINTERRUPTIBLE);
 502                                 up(&msblk->fragment_mutex);
 503                                 schedule();
 504                                 set_current_state(TASK_RUNNING);
 505                                 remove_wait_queue(&msblk->fragment_wait_queue,
 506                                                                         &wait);
 507                                 continue;
 508                         }
 509                         msblk->next_fragment = (msblk->next_fragment + 1) %
 510                                 SQUASHFS_CACHED_FRAGMENTS;
 511
 512                         if (msblk->fragment[i].data == NULL)
 513                                 if (!(msblk->fragment[i].data = SQUASHFS_ALLOC
 514                                                 (SQUASHFS_FILE_MAX_SIZE))) {
 515                                         ERROR("Failed to allocate fragment "
 516                                                         "cache block\n");
 517                                         up(&msblk->fragment_mutex);
 518                                         goto out;
 519                                 }
 520
 521                         msblk->fragment[i].block = SQUASHFS_INVALID_BLK;
 522                         msblk->fragment[i].locked = 1;
 523                         up(&msblk->fragment_mutex);
 524
 525                         if (!(msblk->fragment[i].length = squashfs_read_data(s,
 526                                                 msblk->fragment[i].data,
 527                                                 start_block, length, NULL, sblk->block_size))) {
 528                                 ERROR("Unable to read fragment cache block "
 529                                                         "[%llx]\n", start_block);
 530                                 msblk->fragment[i].locked = 0;
 531                                 goto out;
 532                         }
 533
 534                         msblk->fragment[i].block = start_block;
 535                         TRACE("New fragment %d, start block %lld, locked %d\n",
 536                                                 i, msblk->fragment[i].block,
 537                                                 msblk->fragment[i].locked);
 538                         break;
 539                 }
 540
 541                 msblk->fragment[i].locked++;
 542                 up(&msblk->fragment_mutex);
 543                 TRACE("Got fragment %d, start block %lld, locked %d\n", i,
 544                                                 msblk->fragment[i].block,
 545                                                 msblk->fragment[i].locked);
 546                 break;
 547         }
 548
 549         return &msblk->fragment[i];
 550
 551 out:
 552         return NULL;
 553 }
 554
 555
 556 static void squashfs_new_inode(struct squashfs_sb_info *msblk, struct inode *i,
 557                 struct squashfs_base_inode_header *inodeb)
 558 {
 559         i->i_ino = inodeb->inode_number;
 560         i->i_mtime.tv_sec = inodeb->mtime;
 561         i->i_atime.tv_sec = inodeb->mtime;
 562         i->i_ctime.tv_sec = inodeb->mtime;
 563         i->i_uid = msblk->uid[inodeb->uid];
 564         i->i_mode = inodeb->mode;
 565         i->i_size = 0;
 566         if (inodeb->guid == SQUASHFS_GUIDS)
 567                 i->i_gid = i->i_uid;
 568         else
 569                 i->i_gid = msblk->guid[inodeb->guid];
 570 }
 571
 572
 573 static squashfs_inode_t squashfs_inode_lookup(struct super_block *s, int ino)
 574 {
 575         struct squashfs_sb_info *msblk = s->s_fs_info;
 576         long long start = msblk->inode_lookup_table[SQUASHFS_LOOKUP_BLOCK(ino - 1)];
 577         int offset = SQUASHFS_LOOKUP_BLOCK_OFFSET(ino - 1);
 578         squashfs_inode_t inode;
 579
 580         TRACE("Entered squashfs_inode_lookup, inode_number = %d\n", ino);
 581
 582         if (msblk->swap) {
 583                 squashfs_inode_t sinode;
 584
 585                 if (!squashfs_get_cached_block(s, (char *) &sinode, start, offset,
 586                                         sizeof(sinode), &start, &offset))
 587                         goto out;
 588                 SQUASHFS_SWAP_INODE_T((&inode), &sinode);
 589         } else if (!squashfs_get_cached_block(s, (char *) &inode, start, offset,
 590                                         sizeof(inode), &start, &offset))
 591                         goto out;
 592
 593         TRACE("squashfs_inode_lookup, inode = 0x%llx\n", inode);
 594
 595         return inode;
 596
 597 out:
 598         return SQUASHFS_INVALID_BLK;
 599 }
 600
 601
 602 static void vfs_read_inode(struct inode *i)
 603 {
 604         struct squashfs_sb_info *msblk = i->i_sb->s_fs_info;
 605         squashfs_inode_t inode = squashfs_inode_lookup(i->i_sb, i->i_ino);
 606
 607         TRACE("Entered vfs_read_inode\n");
 608
 609         if(inode != SQUASHFS_INVALID_BLK)
 610                 (msblk->read_inode)(i, inode);
 611 }
 612
 613
 614 static struct dentry *squashfs_get_parent(struct dentry *child)
 615 {
 616         struct inode *i = child->d_inode;
 617         struct inode *parent = iget(i->i_sb, SQUASHFS_I(i)->u.s2.parent_inode);
 618         struct dentry *rv;
 619
 620         TRACE("Entered squashfs_get_parent\n");
 621
 622         if(parent == NULL) {
 623                 rv = ERR_PTR(-EACCES);
 624                 goto out;
 625         }
 626
 627         rv = d_alloc_anon(parent);
 628         if(rv == NULL)
 629                 rv = ERR_PTR(-ENOMEM);
 630
 631 out:
 632         return rv;
 633 }
 634
 635
 636 SQSH_EXTERN struct inode *squashfs_iget(struct super_block *s, squashfs_inode_t inode, unsigned int inode_number)
 637 {
 638         struct squashfs_sb_info *msblk = s->s_fs_info;
 639         struct inode *i = iget_locked(s, inode_number);
 640
 641         TRACE("Entered squashfs_iget\n");
 642
 643         if(i && (i->i_state & I_NEW)) {
 644                 (msblk->read_inode)(i, inode);
 645                 unlock_new_inode(i);
 646         }
 647
 648         return i;
 649 }
 650
 651
 652 static int squashfs_read_inode(struct inode *i, squashfs_inode_t inode)
 653 {
 654         struct super_block *s = i->i_sb;
 655         struct squashfs_sb_info *msblk = s->s_fs_info;
 656         struct squashfs_super_block *sblk = &msblk->sblk;
 657         long long block = SQUASHFS_INODE_BLK(inode) +
 658                 sblk->inode_table_start;
 659         unsigned int offset = SQUASHFS_INODE_OFFSET(inode);
 660         long long next_block;
 661         unsigned int next_offset;
 662         union squashfs_inode_header id, sid;
 663         struct squashfs_base_inode_header *inodeb = &id.base,
 664                                           *sinodeb = &sid.base;
 665
 666         TRACE("Entered squashfs_read_inode\n");
 667
 668         if (msblk->swap) {
 669                 if (!squashfs_get_cached_block(s, (char *) sinodeb, block,
 670                                         offset, sizeof(*sinodeb), &next_block,
 671                                         &next_offset))
 672                         goto failed_read;
 673                 SQUASHFS_SWAP_BASE_INODE_HEADER(inodeb, sinodeb,
 674                                         sizeof(*sinodeb));
 675         } else
 676                 if (!squashfs_get_cached_block(s, (char *) inodeb, block,
 677                                         offset, sizeof(*inodeb), &next_block,
 678                                         &next_offset))
 679                         goto failed_read;
 680
 681         squashfs_new_inode(msblk, i, inodeb);
 682
 683         switch(inodeb->inode_type) {
 684                 case SQUASHFS_FILE_TYPE: {
 685                         unsigned int frag_size;
 686                         long long frag_blk;
 687                         struct squashfs_reg_inode_header *inodep = &id.reg;
 688                         struct squashfs_reg_inode_header *sinodep = &sid.reg;
 689
 690                         if (msblk->swap) {
 691                                 if (!squashfs_get_cached_block(s, (char *)
 692                                                 sinodep, block, offset,
 693                                                 sizeof(*sinodep), &next_block,
 694                                                 &next_offset))
 695                                         goto failed_read;
 696                                 SQUASHFS_SWAP_REG_INODE_HEADER(inodep, sinodep);
 697                         } else
 698                                 if (!squashfs_get_cached_block(s, (char *)
 699                                                 inodep, block, offset,
 700                                                 sizeof(*inodep), &next_block,
 701                                                 &next_offset))
 702                                         goto failed_read;
 703
 704                         frag_blk = SQUASHFS_INVALID_BLK;
 705                         if (inodep->fragment != SQUASHFS_INVALID_FRAG &&
 706                                         !get_fragment_location(s,
 707                                         inodep->fragment, &frag_blk, &frag_size))
 708                                 goto failed_read;
 709
 710                         i->i_nlink = 1;
 711                         i->i_size = inodep->file_size;
 712                         i->i_fop = &generic_ro_fops;
 713                         i->i_mode |= S_IFREG;
 714                         i->i_blocks = ((i->i_size - 1) >> 9) + 1;
 715                         SQUASHFS_I(i)->u.s1.fragment_start_block = frag_blk;
 716                         SQUASHFS_I(i)->u.s1.fragment_size = frag_size;
 717                         SQUASHFS_I(i)->u.s1.fragment_offset = inodep->offset;
 718                         SQUASHFS_I(i)->start_block = inodep->start_block;
 719                         SQUASHFS_I(i)->u.s1.block_list_start = next_block;
 720                         SQUASHFS_I(i)->offset = next_offset;
 721                         if (sblk->block_size > 4096)
 722                                 i->i_data.a_ops = &squashfs_aops;
 723                         else
 724                                 i->i_data.a_ops = &squashfs_aops_4K;
 725
 726                         TRACE("File inode %x:%x, start_block %llx, "
 727                                         "block_list_start %llx, offset %x\n",
 728                                         SQUASHFS_INODE_BLK(inode), offset,
 729                                         inodep->start_block, next_block,
 730                                         next_offset);
 731                         break;
 732                 }
 733                 case SQUASHFS_LREG_TYPE: {
 734                         unsigned int frag_size;
 735                         long long frag_blk;
 736                         struct squashfs_lreg_inode_header *inodep = &id.lreg;
 737                         struct squashfs_lreg_inode_header *sinodep = &sid.lreg;
 738
 739                         if (msblk->swap) {
 740                                 if (!squashfs_get_cached_block(s, (char *)
 741                                                 sinodep, block, offset,
 742                                                 sizeof(*sinodep), &next_block,
 743                                                 &next_offset))
 744                                         goto failed_read;
 745                                 SQUASHFS_SWAP_LREG_INODE_HEADER(inodep, sinodep);
 746                         } else
 747                                 if (!squashfs_get_cached_block(s, (char *)
 748                                                 inodep, block, offset,
 749                                                 sizeof(*inodep), &next_block,
 750                                                 &next_offset))
 751                                         goto failed_read;
 752
 753                         frag_blk = SQUASHFS_INVALID_BLK;
 754                         if (inodep->fragment != SQUASHFS_INVALID_FRAG &&
 755                                         !get_fragment_location(s,
 756                                         inodep->fragment, &frag_blk, &frag_size))
 757                                 goto failed_read;
 758
 759                         i->i_nlink = inodep->nlink;
 760                         i->i_size = inodep->file_size;
 761                         i->i_fop = &generic_ro_fops;
 762                         i->i_mode |= S_IFREG;
 763                         i->i_blocks = ((i->i_size - 1) >> 9) + 1;
 764                         SQUASHFS_I(i)->u.s1.fragment_start_block = frag_blk;
 765                         SQUASHFS_I(i)->u.s1.fragment_size = frag_size;
 766                         SQUASHFS_I(i)->u.s1.fragment_offset = inodep->offset;
 767                         SQUASHFS_I(i)->start_block = inodep->start_block;
 768                         SQUASHFS_I(i)->u.s1.block_list_start = next_block;
 769                         SQUASHFS_I(i)->offset = next_offset;
 770                         if (sblk->block_size > 4096)
 771                                 i->i_data.a_ops = &squashfs_aops;
 772                         else
 773                                 i->i_data.a_ops = &squashfs_aops_4K;
 774
 775                         TRACE("File inode %x:%x, start_block %llx, "
 776                                         "block_list_start %llx, offset %x\n",
 777                                         SQUASHFS_INODE_BLK(inode), offset,
 778                                         inodep->start_block, next_block,
 779                                         next_offset);
 780                         break;
 781                 }
 782                 case SQUASHFS_DIR_TYPE: {
 783                         struct squashfs_dir_inode_header *inodep = &id.dir;
 784                         struct squashfs_dir_inode_header *sinodep = &sid.dir;
 785
 786                         if (msblk->swap) {
 787                                 if (!squashfs_get_cached_block(s, (char *)
 788                                                 sinodep, block, offset,
 789                                                 sizeof(*sinodep), &next_block,
 790                                                 &next_offset))
 791                                         goto failed_read;
 792                                 SQUASHFS_SWAP_DIR_INODE_HEADER(inodep, sinodep);
 793                         } else
 794                                 if (!squashfs_get_cached_block(s, (char *)
 795                                                 inodep, block, offset,
 796                                                 sizeof(*inodep), &next_block,
 797                                                 &next_offset))
 798                                         goto failed_read;
 799
 800                         i->i_nlink = inodep->nlink;
 801                         i->i_size = inodep->file_size;
 802                         i->i_op = &squashfs_dir_inode_ops;
 803                         i->i_fop = &squashfs_dir_ops;
 804                         i->i_mode |= S_IFDIR;
 805                         SQUASHFS_I(i)->start_block = inodep->start_block;
 806                         SQUASHFS_I(i)->offset = inodep->offset;
 807                         SQUASHFS_I(i)->u.s2.directory_index_count = 0;
 808                         SQUASHFS_I(i)->u.s2.parent_inode = inodep->parent_inode;
 809
 810                         TRACE("Directory inode %x:%x, start_block %x, offset "
 811                                         "%x\n", SQUASHFS_INODE_BLK(inode),
 812                                         offset, inodep->start_block,
 813                                         inodep->offset);
 814                         break;
 815                 }
 816                 case SQUASHFS_LDIR_TYPE: {
 817                         struct squashfs_ldir_inode_header *inodep = &id.ldir;
 818                         struct squashfs_ldir_inode_header *sinodep = &sid.ldir;
 819
 820                         if (msblk->swap) {
 821                                 if (!squashfs_get_cached_block(s, (char *)
 822                                                 sinodep, block, offset,
 823                                                 sizeof(*sinodep), &next_block,
 824                                                 &next_offset))
 825                                         goto failed_read;
 826                                 SQUASHFS_SWAP_LDIR_INODE_HEADER(inodep,
 827                                                 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                         i->i_nlink = inodep->nlink;
 836                         i->i_size = inodep->file_size;
 837                         i->i_op = &squashfs_dir_inode_ops;
 838                         i->i_fop = &squashfs_dir_ops;
 839                         i->i_mode |= S_IFDIR;
 840                         SQUASHFS_I(i)->start_block = inodep->start_block;
 841                         SQUASHFS_I(i)->offset = inodep->offset;
 842                         SQUASHFS_I(i)->u.s2.directory_index_start = next_block;
 843                         SQUASHFS_I(i)->u.s2.directory_index_offset =
 844                                                                 next_offset;
 845                         SQUASHFS_I(i)->u.s2.directory_index_count =
 846                                                                 inodep->i_count;
 847                         SQUASHFS_I(i)->u.s2.parent_inode = inodep->parent_inode;
 848
 849                         TRACE("Long directory inode %x:%x, start_block %x, "
 850                                         "offset %x\n",
 851                                         SQUASHFS_INODE_BLK(inode), offset,
 852                                         inodep->start_block, inodep->offset);
 853                         break;
 854                 }
 855                 case SQUASHFS_SYMLINK_TYPE: {
 856                         struct squashfs_symlink_inode_header *inodep =
 857                                                                 &id.symlink;
 858                         struct squashfs_symlink_inode_header *sinodep =
 859                                                                 &sid.symlink;
 860
 861                         if (msblk->swap) {
 862                                 if (!squashfs_get_cached_block(s, (char *)
 863                                                 sinodep, block, offset,
 864                                                 sizeof(*sinodep), &next_block,
 865                                                 &next_offset))
 866                                         goto failed_read;
 867                                 SQUASHFS_SWAP_SYMLINK_INODE_HEADER(inodep,
 868                                                                 sinodep);
 869                         } else
 870                                 if (!squashfs_get_cached_block(s, (char *)
 871                                                 inodep, block, offset,
 872                                                 sizeof(*inodep), &next_block,
 873                                                 &next_offset))
 874                                         goto failed_read;
 875
 876                         i->i_nlink = inodep->nlink;
 877                         i->i_size = inodep->symlink_size;
 878                         i->i_op = &page_symlink_inode_operations;
 879                         i->i_data.a_ops = &squashfs_symlink_aops;
 880                         i->i_mode |= S_IFLNK;
 881                         SQUASHFS_I(i)->start_block = next_block;
 882                         SQUASHFS_I(i)->offset = next_offset;
 883
 884                         TRACE("Symbolic link inode %x:%x, start_block %llx, "
 885                                         "offset %x\n",
 886                                         SQUASHFS_INODE_BLK(inode), offset,
 887                                         next_block, next_offset);
 888                         break;
 889                  }
 890                  case SQUASHFS_BLKDEV_TYPE:
 891                  case SQUASHFS_CHRDEV_TYPE: {
 892                         struct squashfs_dev_inode_header *inodep = &id.dev;
 893                         struct squashfs_dev_inode_header *sinodep = &sid.dev;
 894
 895                         if (msblk->swap) {
 896                                 if (!squashfs_get_cached_block(s, (char *)
 897                                                 sinodep, block, offset,
 898                                                 sizeof(*sinodep), &next_block,
 899                                                 &next_offset))
 900                                         goto failed_read;
 901                                 SQUASHFS_SWAP_DEV_INODE_HEADER(inodep, sinodep);
 902                         } else
 903                                 if (!squashfs_get_cached_block(s, (char *)
 904                                                 inodep, block, offset,
 905                                                 sizeof(*inodep), &next_block,
 906                                                 &next_offset))
 907                                         goto failed_read;
 908
 909                         i->i_nlink = inodep->nlink;
 910                         i->i_mode |= (inodeb->inode_type ==
 911                                         SQUASHFS_CHRDEV_TYPE) ?  S_IFCHR :
 912                                         S_IFBLK;
 913                         init_special_inode(i, i->i_mode,
 914                                         old_decode_dev(inodep->rdev));
 915
 916                         TRACE("Device inode %x:%x, rdev %x\n",
 917                                         SQUASHFS_INODE_BLK(inode), offset,
 918                                         inodep->rdev);
 919                         break;
 920                  }
 921                  case SQUASHFS_FIFO_TYPE:
 922                  case SQUASHFS_SOCKET_TYPE: {
 923                         struct squashfs_ipc_inode_header *inodep = &id.ipc;
 924                         struct squashfs_ipc_inode_header *sinodep = &sid.ipc;
 925
 926                         if (msblk->swap) {
 927                                 if (!squashfs_get_cached_block(s, (char *)
 928                                                 sinodep, block, offset,
 929                                                 sizeof(*sinodep), &next_block,
 930                                                 &next_offset))
 931                                         goto failed_read;
 932                                 SQUASHFS_SWAP_IPC_INODE_HEADER(inodep, sinodep);
 933                         } else
 934                                 if (!squashfs_get_cached_block(s, (char *)
 935                                                 inodep, block, offset,
 936                                                 sizeof(*inodep), &next_block,
 937                                                 &next_offset))
 938                                         goto failed_read;
 939
 940                         i->i_nlink = inodep->nlink;
 941                         i->i_mode |= (inodeb->inode_type == SQUASHFS_FIFO_TYPE)
 942                                                         ? S_IFIFO : S_IFSOCK;
 943                         init_special_inode(i, i->i_mode, 0);
 944                         break;
 945                  }
 946                  default:
 947                         ERROR("Unknown inode type %d in squashfs_iget!\n",
 948                                         inodeb->inode_type);
 949                         goto failed_read1;
 950         }
 951
 952         return 1;
 953
 954 failed_read:
 955         ERROR("Unable to read inode [%llx:%x]\n", block, offset);
 956
 957 failed_read1:
 958         make_bad_inode(i);
 959         return 0;
 960 }
 961
 962
 963 static int read_inode_lookup_table(struct super_block *s)
 964 {
 965         struct squashfs_sb_info *msblk = s->s_fs_info;
 966         struct squashfs_super_block *sblk = &msblk->sblk;
 967         unsigned int length = SQUASHFS_LOOKUP_BLOCK_BYTES(sblk->inodes);
 968
 969         TRACE("In read_inode_lookup_table, length %d\n", length);
 970
 971         /* Allocate inode lookup table */
 972         if (!(msblk->inode_lookup_table = kmalloc(length, GFP_KERNEL))) {
 973                 ERROR("Failed to allocate inode lookup table\n");
 974                 return 0;
 975         }
 976
 977         if (!squashfs_read_data(s, (char *) msblk->inode_lookup_table,
 978                         sblk->lookup_table_start, length |
 979                         SQUASHFS_COMPRESSED_BIT_BLOCK, NULL, length)) {
 980                 ERROR("unable to read inode lookup table\n");
 981                 return 0;
 982         }
 983
 984         if (msblk->swap) {
 985                 int i;
 986                 long long block;
 987
 988                 for (i = 0; i < SQUASHFS_LOOKUP_BLOCKS(sblk->inodes); i++) {
 989                         SQUASHFS_SWAP_LOOKUP_BLOCKS((&block),
 990                                                 &msblk->inode_lookup_table[i], 1);
 991                         msblk->inode_lookup_table[i] = block;
 992                 }
 993         }
 994
 995         return 1;
 996 }
 997
 998
 999 static int read_fragment_index_table(struct super_block *s)
1000 {
1001         struct squashfs_sb_info *msblk = s->s_fs_info;
1002         struct squashfs_super_block *sblk = &msblk->sblk;
1003         unsigned int length = SQUASHFS_FRAGMENT_INDEX_BYTES(sblk->fragments);
1004
1005         if(length == 0)
1006                 return 1;
1007
1008         /* Allocate fragment index table */
1009         if (!(msblk->fragment_index = kmalloc(length, GFP_KERNEL))) {
1010                 ERROR("Failed to allocate fragment index table\n");
1011                 return 0;
1012         }
1013
1014         if (!squashfs_read_data(s, (char *) msblk->fragment_index,
1015                         sblk->fragment_table_start, length |
1016                         SQUASHFS_COMPRESSED_BIT_BLOCK, NULL, length)) {
1017                 ERROR("unable to read fragment index table\n");
1018                 return 0;
1019         }
1020
1021         if (msblk->swap) {
1022                 int i;
1023                 long long fragment;
1024
1025                 for (i = 0; i < SQUASHFS_FRAGMENT_INDEXES(sblk->fragments); i++) {
1026                         SQUASHFS_SWAP_FRAGMENT_INDEXES((&fragment),
1027                                                 &msblk->fragment_index[i], 1);
1028                         msblk->fragment_index[i] = fragment;
1029                 }
1030         }
1031
1032         return 1;
1033 }
1034
1035
1036 static int supported_squashfs_filesystem(struct squashfs_sb_info *msblk, int silent)
1037 {
1038         struct squashfs_super_block *sblk = &msblk->sblk;
1039
1040         msblk->read_inode = squashfs_read_inode;
1041         msblk->read_blocklist = read_blocklist;
1042         msblk->read_fragment_index_table = read_fragment_index_table;
1043
1044         if (sblk->s_major == 1) {
1045                 if (!squashfs_1_0_supported(msblk)) {
1046                         SERROR("Major/Minor mismatch, Squashfs 1.0 filesystems "
1047                                 "are unsupported\n");
1048                         SERROR("Please recompile with "
1049                                 "Squashfs 1.0 support enabled\n");
1050                         return 0;
1051                 }
1052         } else if (sblk->s_major == 2) {
1053                 if (!squashfs_2_0_supported(msblk)) {
1054                         SERROR("Major/Minor mismatch, Squashfs 2.0 filesystems "
1055                                 "are unsupported\n");
1056                         SERROR("Please recompile with "
1057                                 "Squashfs 2.0 support enabled\n");
1058                         return 0;
1059                 }
1060         } else if(sblk->s_major != SQUASHFS_MAJOR || sblk->s_minor >
1061                         SQUASHFS_MINOR) {
1062                 SERROR("Major/Minor mismatch, trying to mount newer %d.%d "
1063                                 "filesystem\n", sblk->s_major, sblk->s_minor);
1064                 SERROR("Please update your kernel\n");
1065                 return 0;
1066         }
1067
1068         return 1;
1069 }
1070
1071
1072 static int squashfs_fill_super(struct super_block *s, void *data, int silent)
1073 {
1074         struct squashfs_sb_info *msblk;
1075         struct squashfs_super_block *sblk;
1076         int i;
1077         char b[BDEVNAME_SIZE];
1078         struct inode *root;
1079
1080         TRACE("Entered squashfs_read_superblock\n");
1081
1082         if (!(s->s_fs_info = kmalloc(sizeof(struct squashfs_sb_info),
1083                                                 GFP_KERNEL))) {
1084                 ERROR("Failed to allocate superblock\n");
1085                 goto failure;
1086         }
1087         memset(s->s_fs_info, 0, sizeof(struct squashfs_sb_info));
1088         msblk = s->s_fs_info;
1089         if (!(msblk->stream.workspace = vmalloc(zlib_inflate_workspacesize()))) {
1090                 ERROR("Failed to allocate zlib workspace\n");
1091                 goto failure;
1092         }
1093         sblk = &msblk->sblk;
1094
1095         msblk->devblksize = sb_min_blocksize(s, BLOCK_SIZE);
1096         msblk->devblksize_log2 = ffz(~msblk->devblksize);
1097
1098         init_MUTEX(&msblk->read_data_mutex);
1099         init_MUTEX(&msblk->read_page_mutex);
1100         init_MUTEX(&msblk->block_cache_mutex);
1101         init_MUTEX(&msblk->fragment_mutex);
1102         init_MUTEX(&msblk->meta_index_mutex);
1103
1104         init_waitqueue_head(&msblk->waitq);
1105         init_waitqueue_head(&msblk->fragment_wait_queue);
1106
1107         sblk->bytes_used = sizeof(struct squashfs_super_block);
1108         if (!squashfs_read_data(s, (char *) sblk, SQUASHFS_START,
1109                                         sizeof(struct squashfs_super_block) |
1110                                         SQUASHFS_COMPRESSED_BIT_BLOCK, NULL, sizeof(struct squashfs_super_block))) {
1111                 SERROR("unable to read superblock\n");
1112                 goto failed_mount;
1113         }
1114
1115         /* Check it is a SQUASHFS superblock */
1116         msblk->swap = 0;
1117         if ((s->s_magic = sblk->s_magic) != SQUASHFS_MAGIC) {
1118                 if (sblk->s_magic == SQUASHFS_MAGIC_SWAP) {
1119                         struct squashfs_super_block ssblk;
1120
1121                         WARNING("Mounting a different endian SQUASHFS "
1122                                 "filesystem on %s\n", bdevname(s->s_bdev, b));
1123
1124                         SQUASHFS_SWAP_SUPER_BLOCK(&ssblk, sblk);
1125                         memcpy(sblk, &ssblk, sizeof(struct squashfs_super_block));
1126                         msblk->swap = 1;
1127                 } else  {
1128                         SERROR("Can't find a SQUASHFS superblock on %s\n",
1129                                                         bdevname(s->s_bdev, b));
1130                         goto failed_mount;
1131                 }
1132         }
1133
1134         /* Check the MAJOR & MINOR versions */
1135         if(!supported_squashfs_filesystem(msblk, silent))
1136                 goto failed_mount;
1137
1138         /* Check the filesystem does not extend beyond the end of the
1139            block device */
1140         if(sblk->bytes_used < 0 || sblk->bytes_used > i_size_read(s->s_bdev->bd_inode))
1141                 goto failed_mount;
1142
1143         /* Check the root inode for sanity */
1144         if (SQUASHFS_INODE_OFFSET(sblk->root_inode) > SQUASHFS_METADATA_SIZE)
1145                 goto failed_mount;
1146
1147         TRACE("Found valid superblock on %s\n", bdevname(s->s_bdev, b));
1148         TRACE("Inodes are %scompressed\n",
1149                                         SQUASHFS_UNCOMPRESSED_INODES
1150                                         (sblk->flags) ? "un" : "");
1151         TRACE("Data is %scompressed\n",
1152                                         SQUASHFS_UNCOMPRESSED_DATA(sblk->flags)
1153                                         ? "un" : "");
1154         TRACE("Check data is %s present in the filesystem\n",
1155                                         SQUASHFS_CHECK_DATA(sblk->flags) ?
1156                                         "" : "not");
1157         TRACE("Filesystem size %lld bytes\n", sblk->bytes_used);
1158         TRACE("Block size %d\n", sblk->block_size);
1159         TRACE("Number of inodes %d\n", sblk->inodes);
1160         if (sblk->s_major > 1)
1161                 TRACE("Number of fragments %d\n", sblk->fragments);
1162         TRACE("Number of uids %d\n", sblk->no_uids);
1163         TRACE("Number of gids %d\n", sblk->no_guids);
1164         TRACE("sblk->inode_table_start %llx\n", sblk->inode_table_start);
1165         TRACE("sblk->directory_table_start %llx\n", sblk->directory_table_start);
1166         if (sblk->s_major > 1)
1167                 TRACE("sblk->fragment_table_start %llx\n",
1168                                         sblk->fragment_table_start);
1169         TRACE("sblk->uid_start %llx\n", sblk->uid_start);
1170
1171         s->s_flags |= MS_RDONLY;
1172         s->s_op = &squashfs_super_ops;
1173
1174         /* Init inode_table block pointer array */
1175         if (!(msblk->block_cache = kmalloc(sizeof(struct squashfs_cache) *
1176                                         SQUASHFS_CACHED_BLKS, GFP_KERNEL))) {
1177                 ERROR("Failed to allocate block cache\n");
1178                 goto failed_mount;
1179         }
1180
1181         for (i = 0; i < SQUASHFS_CACHED_BLKS; i++)
1182                 msblk->block_cache[i].block = SQUASHFS_INVALID_BLK;
1183
1184         msblk->next_cache = 0;
1185
1186         /* Allocate read_data block */
1187         msblk->read_size = (sblk->block_size < SQUASHFS_METADATA_SIZE) ?
1188                                         SQUASHFS_METADATA_SIZE :
1189                                         sblk->block_size;
1190
1191         if (!(msblk->read_data = kmalloc(msblk->read_size, GFP_KERNEL))) {
1192                 ERROR("Failed to allocate read_data block\n");
1193                 goto failed_mount;
1194         }
1195
1196         /* Allocate read_page block */
1197         if (!(msblk->read_page = kmalloc(sblk->block_size, GFP_KERNEL))) {
1198                 ERROR("Failed to allocate read_page block\n");
1199                 goto failed_mount;
1200         }
1201
1202         /* Allocate uid and gid tables */
1203         if (!(msblk->uid = kmalloc((sblk->no_uids + sblk->no_guids) *
1204                                         sizeof(unsigned int), GFP_KERNEL))) {
1205                 ERROR("Failed to allocate uid/gid table\n");
1206                 goto failed_mount;
1207         }
1208         msblk->guid = msblk->uid + sblk->no_uids;
1209
1210         if (msblk->swap) {
1211                 unsigned int suid[sblk->no_uids + sblk->no_guids];
1212
1213                 if (!squashfs_read_data(s, (char *) &suid, sblk->uid_start,
1214                                         ((sblk->no_uids + sblk->no_guids) *
1215                                          sizeof(unsigned int)) |
1216                                         SQUASHFS_COMPRESSED_BIT_BLOCK, NULL, (sblk->no_uids + sblk->no_guids) * sizeof(unsigned int))) {
1217                         ERROR("unable to read uid/gid table\n");
1218                         goto failed_mount;
1219                 }
1220
1221                 SQUASHFS_SWAP_DATA(msblk->uid, suid, (sblk->no_uids +
1222                         sblk->no_guids), (sizeof(unsigned int) * 8));
1223         } else
1224                 if (!squashfs_read_data(s, (char *) msblk->uid, sblk->uid_start,
1225                                         ((sblk->no_uids + sblk->no_guids) *
1226                                          sizeof(unsigned int)) |
1227                                         SQUASHFS_COMPRESSED_BIT_BLOCK, NULL, (sblk->no_uids + sblk->no_guids) * sizeof(unsigned int))) {
1228                         ERROR("unable to read uid/gid table\n");
1229                         goto failed_mount;
1230                 }
1231
1232
1233         if (sblk->s_major == 1 && squashfs_1_0_supported(msblk))
1234                 goto allocate_root;
1235
1236         if (!(msblk->fragment = kmalloc(sizeof(struct squashfs_fragment_cache) *
1237                                 SQUASHFS_CACHED_FRAGMENTS, GFP_KERNEL))) {
1238                 ERROR("Failed to allocate fragment block cache\n");
1239                 goto failed_mount;
1240         }
1241
1242         for (i = 0; i < SQUASHFS_CACHED_FRAGMENTS; i++) {
1243                 msblk->fragment[i].locked = 0;
1244                 msblk->fragment[i].block = SQUASHFS_INVALID_BLK;
1245                 msblk->fragment[i].data = NULL;
1246         }
1247
1248         msblk->next_fragment = 0;
1249
1250         /* Allocate and read fragment index table */
1251         if (msblk->read_fragment_index_table(s) == 0)
1252                 goto failed_mount;
1253
1254         if(sblk->lookup_table_start == SQUASHFS_INVALID_BLK)
1255                 goto allocate_root;
1256
1257         /* Allocate and read inode lookup table */
1258         if (read_inode_lookup_table(s) == 0)
1259                 goto failed_mount;
1260
1261         s->s_op = &squashfs_export_super_ops;
1262         s->s_export_op = &squashfs_export_ops;
1263
1264 allocate_root:
1265         root = new_inode(s);
1266         if ((msblk->read_inode)(root, sblk->root_inode) == 0)
1267                 goto failed_mount;
1268         insert_inode_hash(root);
1269
1270         if ((s->s_root = d_alloc_root(root)) == NULL) {
1271                 ERROR("Root inode create failed\n");
1272                 iput(root);
1273                 goto failed_mount;
1274         }
1275
1276         TRACE("Leaving squashfs_read_super\n");
1277         return 0;
1278
1279 failed_mount:
1280         kfree(msblk->inode_lookup_table);
1281         kfree(msblk->fragment_index);
1282         kfree(msblk->fragment);
1283         kfree(msblk->uid);
1284         kfree(msblk->read_page);
1285         kfree(msblk->read_data);
1286         kfree(msblk->block_cache);
1287         kfree(msblk->fragment_index_2);
1288         vfree(msblk->stream.workspace);
1289         kfree(s->s_fs_info);
1290         s->s_fs_info = NULL;
1291         return -EINVAL;
1292
1293 failure:
1294         return -ENOMEM;
1295 }
1296
1297
1298 static int squashfs_statfs(struct dentry *dentry, struct kstatfs *buf)
1299 {
1300         struct squashfs_sb_info *msblk = dentry->d_sb->s_fs_info;
1301         struct squashfs_super_block *sblk = &msblk->sblk;
1302
1303         TRACE("Entered squashfs_statfs\n");
1304
1305         buf->f_type = SQUASHFS_MAGIC;
1306         buf->f_bsize = sblk->block_size;
1307         buf->f_blocks = ((sblk->bytes_used - 1) >> sblk->block_log) + 1;
1308         buf->f_bfree = buf->f_bavail = 0;
1309         buf->f_files = sblk->inodes;
1310         buf->f_ffree = 0;
1311         buf->f_namelen = SQUASHFS_NAME_LEN;
1312
1313         return 0;
1314 }
1315
1316
1317 static int squashfs_symlink_readpage(struct file *file, struct page *page)
1318 {
1319         struct inode *inode = page->mapping->host;
1320         int index = page->index << PAGE_CACHE_SHIFT, length, bytes;
1321         long long block = SQUASHFS_I(inode)->start_block;
1322         int offset = SQUASHFS_I(inode)->offset;
1323         void *pageaddr = kmap(page);
1324
1325         TRACE("Entered squashfs_symlink_readpage, page index %ld, start block "
1326                                 "%llx, offset %x\n", page->index,
1327                                 SQUASHFS_I(inode)->start_block,
1328                                 SQUASHFS_I(inode)->offset);
1329
1330         for (length = 0; length < index; length += bytes) {
1331                 if (!(bytes = squashfs_get_cached_block(inode->i_sb, NULL,
1332                                 block, offset, PAGE_CACHE_SIZE, &block,
1333                                 &offset))) {
1334                         ERROR("Unable to read symbolic link [%llx:%x]\n", block,
1335                                         offset);
1336                         goto skip_read;
1337                 }
1338         }
1339
1340         if (length != index) {
1341                 ERROR("(squashfs_symlink_readpage) length != index\n");
1342                 bytes = 0;
1343                 goto skip_read;
1344         }
1345
1346         bytes = (i_size_read(inode) - length) > PAGE_CACHE_SIZE ? PAGE_CACHE_SIZE :
1347                                         i_size_read(inode) - length;
1348
1349         if (!(bytes = squashfs_get_cached_block(inode->i_sb, pageaddr, block,
1350                                         offset, bytes, &block, &offset)))
1351                 ERROR("Unable to read symbolic link [%llx:%x]\n", block, offset);
1352
1353 skip_read:
1354         memset(pageaddr + bytes, 0, PAGE_CACHE_SIZE - bytes);
1355         kunmap(page);
1356         SetPageUptodate(page);
1357         unlock_page(page);
1358
1359         return 0;
1360 }
1361
1362
1363 struct meta_index *locate_meta_index(struct inode *inode, int index, int offset)
1364 {
1365         struct meta_index *meta = NULL;
1366         struct squashfs_sb_info *msblk = inode->i_sb->s_fs_info;
1367         int i;
1368
1369         down(&msblk->meta_index_mutex);
1370
1371         TRACE("locate_meta_index: index %d, offset %d\n", index, offset);
1372
1373         if(msblk->meta_index == NULL)
1374                 goto not_allocated;
1375
1376         for (i = 0; i < SQUASHFS_META_NUMBER; i ++)
1377                 if (msblk->meta_index[i].inode_number == inode->i_ino &&
1378                                 msblk->meta_index[i].offset >= offset &&
1379                                 msblk->meta_index[i].offset <= index &&
1380                                 msblk->meta_index[i].locked == 0) {
1381                         TRACE("locate_meta_index: entry %d, offset %d\n", i,
1382                                         msblk->meta_index[i].offset);
1383                         meta = &msblk->meta_index[i];
1384                         offset = meta->offset;
1385                 }
1386
1387         if (meta)
1388                 meta->locked = 1;
1389
1390 not_allocated:
1391         up(&msblk->meta_index_mutex);
1392
1393         return meta;
1394 }
1395
1396
1397 struct meta_index *empty_meta_index(struct inode *inode, int offset, int skip)
1398 {
1399         struct squashfs_sb_info *msblk = inode->i_sb->s_fs_info;
1400         struct meta_index *meta = NULL;
1401         int i;
1402
1403         down(&msblk->meta_index_mutex);
1404
1405         TRACE("empty_meta_index: offset %d, skip %d\n", offset, skip);
1406
1407         if(msblk->meta_index == NULL) {
1408                 if (!(msblk->meta_index = kmalloc(sizeof(struct meta_index) *
1409                                         SQUASHFS_META_NUMBER, GFP_KERNEL))) {
1410                         ERROR("Failed to allocate meta_index\n");
1411                         goto failed;
1412                 }
1413                 for(i = 0; i < SQUASHFS_META_NUMBER; i++) {
1414                         msblk->meta_index[i].inode_number = 0;
1415                         msblk->meta_index[i].locked = 0;
1416                 }
1417                 msblk->next_meta_index = 0;
1418         }
1419
1420         for(i = SQUASHFS_META_NUMBER; i &&
1421                         msblk->meta_index[msblk->next_meta_index].locked; i --)
1422                 msblk->next_meta_index = (msblk->next_meta_index + 1) %
1423                         SQUASHFS_META_NUMBER;
1424
1425         if(i == 0) {
1426                 TRACE("empty_meta_index: failed!\n");
1427                 goto failed;
1428         }
1429
1430         TRACE("empty_meta_index: returned meta entry %d, %p\n",
1431                         msblk->next_meta_index,
1432                         &msblk->meta_index[msblk->next_meta_index]);
1433
1434         meta = &msblk->meta_index[msblk->next_meta_index];
1435         msblk->next_meta_index = (msblk->next_meta_index + 1) %
1436                         SQUASHFS_META_NUMBER;
1437
1438         meta->inode_number = inode->i_ino;
1439         meta->offset = offset;
1440         meta->skip = skip;
1441         meta->entries = 0;
1442         meta->locked = 1;
1443
1444 failed:
1445         up(&msblk->meta_index_mutex);
1446         return meta;
1447 }
1448
1449
1450 void release_meta_index(struct inode *inode, struct meta_index *meta)
1451 {
1452         meta->locked = 0;
1453 }
1454
1455
1456 static int read_block_index(struct super_block *s, int blocks, char *block_list,
1457                 long long *start_block, int *offset)
1458 {
1459         struct squashfs_sb_info *msblk = s->s_fs_info;
1460         unsigned int *block_listp;
1461         int block = 0;
1462
1463         if (msblk->swap) {
1464                 char sblock_list[blocks << 2];
1465
1466                 if (!squashfs_get_cached_block(s, sblock_list, *start_block,
1467                                 *offset, blocks << 2, start_block, offset)) {
1468                         ERROR("Unable to read block list [%llx:%x]\n",
1469                                 *start_block, *offset);
1470                         goto failure;
1471                 }
1472                 SQUASHFS_SWAP_INTS(((unsigned int *)block_list),
1473                                 ((unsigned int *)sblock_list), blocks);
1474         } else
1475                 if (!squashfs_get_cached_block(s, block_list, *start_block,
1476                                 *offset, blocks << 2, start_block, offset)) {
1477                         ERROR("Unable to read block list [%llx:%x]\n",
1478                                 *start_block, *offset);
1479                         goto failure;
1480                 }
1481
1482         for (block_listp = (unsigned int *) block_list; blocks;
1483                                 block_listp++, blocks --)
1484                 block += SQUASHFS_COMPRESSED_SIZE_BLOCK(*block_listp);
1485
1486         return block;
1487
1488 failure:
1489         return -1;
1490 }
1491
1492
1493 #define SIZE 256
1494
1495 static inline int calculate_skip(int blocks) {
1496         int skip = (blocks - 1) / ((SQUASHFS_SLOTS * SQUASHFS_META_ENTRIES + 1) * SQUASHFS_META_INDEXES);
1497         return skip >= 7 ? 7 : skip + 1;
1498 }
1499
1500
1501 static int get_meta_index(struct inode *inode, int index,
1502                 long long *index_block, int *index_offset,
1503                 long long *data_block, char *block_list)
1504 {
1505         struct squashfs_sb_info *msblk = inode->i_sb->s_fs_info;
1506         struct squashfs_super_block *sblk = &msblk->sblk;
1507         int skip = calculate_skip(i_size_read(inode) >> sblk->block_log);
1508         int offset = 0;
1509         struct meta_index *meta;
1510         struct meta_entry *meta_entry;
1511         long long cur_index_block = SQUASHFS_I(inode)->u.s1.block_list_start;
1512         int cur_offset = SQUASHFS_I(inode)->offset;
1513         long long cur_data_block = SQUASHFS_I(inode)->start_block;
1514         int i;
1515
1516         index /= SQUASHFS_META_INDEXES * skip;
1517
1518         while ( offset < index ) {
1519                 meta = locate_meta_index(inode, index, offset + 1);
1520
1521                 if (meta == NULL) {
1522                         if ((meta = empty_meta_index(inode, offset + 1,
1523                                                         skip)) == NULL)
1524                                 goto all_done;
1525                 } else {
1526                         if(meta->entries == 0)
1527                                 goto failed;
1528                         offset = index < meta->offset + meta->entries ? index :
1529                                 meta->offset + meta->entries - 1;
1530                         meta_entry = &meta->meta_entry[offset - meta->offset];
1531                         cur_index_block = meta_entry->index_block + sblk->inode_table_start;
1532                         cur_offset = meta_entry->offset;
1533                         cur_data_block = meta_entry->data_block;
1534                         TRACE("get_meta_index: offset %d, meta->offset %d, "
1535                                 "meta->entries %d\n", offset, meta->offset,
1536                                 meta->entries);
1537                         TRACE("get_meta_index: index_block 0x%llx, offset 0x%x"
1538                                 " data_block 0x%llx\n", cur_index_block,
1539                                 cur_offset, cur_data_block);
1540                 }
1541
1542                 for (i = meta->offset + meta->entries; i <= index &&
1543                                 i < meta->offset + SQUASHFS_META_ENTRIES; i++) {
1544                         int blocks = skip * SQUASHFS_META_INDEXES;
1545
1546                         while (blocks) {
1547                                 int block = blocks > (SIZE >> 2) ? (SIZE >> 2) :
1548                                         blocks;
1549                                 int res = read_block_index(inode->i_sb, block,
1550                                         block_list, &cur_index_block,
1551                                         &cur_offset);
1552
1553                                 if (res == -1)
1554                                         goto failed;
1555
1556                                 cur_data_block += res;
1557                                 blocks -= block;
1558                         }
1559
1560                         meta_entry = &meta->meta_entry[i - meta->offset];
1561                         meta_entry->index_block = cur_index_block - sblk->inode_table_start;
1562                         meta_entry->offset = cur_offset;
1563                         meta_entry->data_block = cur_data_block;
1564                         meta->entries ++;
1565                         offset ++;
1566                 }
1567
1568                 TRACE("get_meta_index: meta->offset %d, meta->entries %d\n",
1569                                 meta->offset, meta->entries);
1570
1571                 release_meta_index(inode, meta);
1572         }
1573
1574 all_done:
1575         *index_block = cur_index_block;
1576         *index_offset = cur_offset;
1577         *data_block = cur_data_block;
1578
1579         return offset * SQUASHFS_META_INDEXES * skip;
1580
1581 failed:
1582         release_meta_index(inode, meta);
1583         return -1;
1584 }
1585
1586
1587 static long long read_blocklist(struct inode *inode, int index,
1588                                 int readahead_blks, char *block_list,
1589                                 unsigned short **block_p, unsigned int *bsize)
1590 {
1591         long long block_ptr;
1592         int offset;
1593         long long block;
1594         int res = get_meta_index(inode, index, &block_ptr, &offset, &block,
1595                 block_list);
1596
1597         TRACE("read_blocklist: res %d, index %d, block_ptr 0x%llx, offset"
1598                        " 0x%x, block 0x%llx\n", res, index, block_ptr, offset,
1599                        block);
1600
1601         if(res == -1)
1602                 goto failure;
1603
1604         index -= res;
1605
1606         while ( index ) {
1607                 int blocks = index > (SIZE >> 2) ? (SIZE >> 2) : index;
1608                 int res = read_block_index(inode->i_sb, blocks, block_list,
1609                         &block_ptr, &offset);
1610                 if (res == -1)
1611                         goto failure;
1612                 block += res;
1613                 index -= blocks;
1614         }
1615
1616         if (read_block_index(inode->i_sb, 1, block_list,
1617                         &block_ptr, &offset) == -1)
1618                 goto failure;
1619         *bsize = *((unsigned int *) block_list);
1620
1621         return block;
1622
1623 failure:
1624         return 0;
1625 }
1626
1627
1628 static int squashfs_readpage(struct file *file, struct page *page)
1629 {
1630         struct inode *inode = page->mapping->host;
1631         struct squashfs_sb_info *msblk = inode->i_sb->s_fs_info;
1632         struct squashfs_super_block *sblk = &msblk->sblk;
1633         unsigned char *block_list;
1634         long long block;
1635         unsigned int bsize, i = 0, bytes = 0, byte_offset = 0;
1636         int index = page->index >> (sblk->block_log - PAGE_CACHE_SHIFT);
1637         void *pageaddr;
1638         struct squashfs_fragment_cache *fragment = NULL;
1639         char *data_ptr = msblk->read_page;
1640
1641         int mask = (1 << (sblk->block_log - PAGE_CACHE_SHIFT)) - 1;
1642         int start_index = page->index & ~mask;
1643         int end_index = start_index | mask;
1644
1645         TRACE("Entered squashfs_readpage, page index %lx, start block %llx\n",
1646                                         page->index,
1647                                         SQUASHFS_I(inode)->start_block);
1648
1649         if (!(block_list = kmalloc(SIZE, GFP_KERNEL))) {
1650                 ERROR("Failed to allocate block_list\n");
1651                 goto skip_read;
1652         }
1653
1654         if (page->index >= ((i_size_read(inode) + PAGE_CACHE_SIZE - 1) >>
1655                                         PAGE_CACHE_SHIFT))
1656                 goto skip_read;
1657
1658         if (SQUASHFS_I(inode)->u.s1.fragment_start_block == SQUASHFS_INVALID_BLK
1659                                         || index < (i_size_read(inode) >>
1660                                         sblk->block_log)) {
1661                 if ((block = (msblk->read_blocklist)(inode, index, 1,
1662                                         block_list, NULL, &bsize)) == 0)
1663                         goto skip_read;
1664
1665                 down(&msblk->read_page_mutex);
1666
1667                 if (!(bytes = squashfs_read_data(inode->i_sb, msblk->read_page,
1668                                         block, bsize, NULL, sblk->block_size))) {
1669                         ERROR("Unable to read page, block %llx, size %x\n", block,
1670                                         bsize);
1671                         up(&msblk->read_page_mutex);
1672                         goto skip_read;
1673                 }
1674         } else {
1675                 if ((fragment = get_cached_fragment(inode->i_sb,
1676                                         SQUASHFS_I(inode)->
1677                                         u.s1.fragment_start_block,
1678                                         SQUASHFS_I(inode)->u.s1.fragment_size))
1679                                         == NULL) {
1680                         ERROR("Unable to read page, block %llx, size %x\n",
1681                                         SQUASHFS_I(inode)->
1682                                         u.s1.fragment_start_block,
1683                                         (int) SQUASHFS_I(inode)->
1684                                         u.s1.fragment_size);
1685                         goto skip_read;
1686                 }
1687                 bytes = SQUASHFS_I(inode)->u.s1.fragment_offset +
1688                                         (i_size_read(inode) & (sblk->block_size
1689                                         - 1));
1690                 byte_offset = SQUASHFS_I(inode)->u.s1.fragment_offset;
1691                 data_ptr = fragment->data;
1692         }
1693
1694         for (i = start_index; i <= end_index && byte_offset < bytes;
1695                                         i++, byte_offset += PAGE_CACHE_SIZE) {
1696                 struct page *push_page;
1697                 int avail = (bytes - byte_offset) > PAGE_CACHE_SIZE ?
1698                                         PAGE_CACHE_SIZE : bytes - byte_offset;
1699
1700                 TRACE("bytes %d, i %d, byte_offset %d, available_bytes %d\n",
1701                                         bytes, i, byte_offset, avail);
1702
1703                 push_page = (i == page->index) ? page :
1704                         grab_cache_page_nowait(page->mapping, i);
1705
1706                 if (!push_page)
1707                         continue;
1708
1709                 if (PageUptodate(push_page))
1710                         goto skip_page;
1711
1712                 pageaddr = kmap_atomic(push_page, KM_USER0);
1713                 memcpy(pageaddr, data_ptr + byte_offset, avail);
1714                 memset(pageaddr + avail, 0, PAGE_CACHE_SIZE - avail);
1715                 kunmap_atomic(pageaddr, KM_USER0);
1716                 flush_dcache_page(push_page);
1717                 SetPageUptodate(push_page);
1718 skip_page:
1719                 unlock_page(push_page);
1720                 if(i != page->index)
1721                         page_cache_release(push_page);
1722         }
1723
1724         if (SQUASHFS_I(inode)->u.s1.fragment_start_block == SQUASHFS_INVALID_BLK
1725                                         || index < (i_size_read(inode) >>
1726                                         sblk->block_log))
1727                 up(&msblk->read_page_mutex);
1728         else
1729                 release_cached_fragment(msblk, fragment);
1730
1731         kfree(block_list);
1732         return 0;
1733
1734 skip_read:
1735         pageaddr = kmap_atomic(page, KM_USER0);
1736         memset(pageaddr + bytes, 0, PAGE_CACHE_SIZE - bytes);
1737         kunmap_atomic(pageaddr, KM_USER0);
1738         flush_dcache_page(page);
1739         SetPageUptodate(page);
1740         unlock_page(page);
1741
1742         kfree(block_list);
1743         return 0;
1744 }
1745
1746
1747 static int squashfs_readpage4K(struct file *file, struct page *page)
1748 {
1749         struct inode *inode = page->mapping->host;
1750         struct squashfs_sb_info *msblk = inode->i_sb->s_fs_info;
1751         struct squashfs_super_block *sblk = &msblk->sblk;
1752         unsigned char *block_list;
1753         long long block;
1754         unsigned int bsize, bytes = 0;
1755         void *pageaddr;
1756
1757         TRACE("Entered squashfs_readpage4K, page index %lx, start block %llx\n",
1758                                         page->index,
1759                                         SQUASHFS_I(inode)->start_block);
1760
1761         if (page->index >= ((i_size_read(inode) + PAGE_CACHE_SIZE - 1) >>
1762                                         PAGE_CACHE_SHIFT)) {
1763                 block_list = NULL;
1764                 goto skip_read;
1765         }
1766
1767         if (!(block_list = kmalloc(SIZE, GFP_KERNEL))) {
1768                 ERROR("Failed to allocate block_list\n");
1769                 goto skip_read;
1770         }
1771
1772         if (SQUASHFS_I(inode)->u.s1.fragment_start_block == SQUASHFS_INVALID_BLK
1773                                         || page->index < (i_size_read(inode) >>
1774                                         sblk->block_log)) {
1775                 block = (msblk->read_blocklist)(inode, page->index, 1,
1776                                         block_list, NULL, &bsize);
1777                 if(block == 0)
1778                         goto skip_read;
1779
1780                 down(&msblk->read_page_mutex);
1781                 bytes = squashfs_read_data(inode->i_sb, msblk->read_page, block,
1782                                         bsize, NULL, sblk->block_size);
1783                 if (bytes) {
1784                         pageaddr = kmap_atomic(page, KM_USER0);
1785                         memcpy(pageaddr, msblk->read_page, bytes);
1786                         kunmap_atomic(pageaddr, KM_USER0);
1787                 } else
1788                         ERROR("Unable to read page, block %llx, size %x\n",
1789                                         block, bsize);
1790                 up(&msblk->read_page_mutex);
1791         } else {
1792                 struct squashfs_fragment_cache *fragment =
1793                         get_cached_fragment(inode->i_sb,
1794                                         SQUASHFS_I(inode)->
1795                                         u.s1.fragment_start_block,
1796                                         SQUASHFS_I(inode)-> u.s1.fragment_size);
1797                 if (fragment) {
1798                         bytes = i_size_read(inode) & (sblk->block_size - 1);
1799                         pageaddr = kmap_atomic(page, KM_USER0);
1800                         memcpy(pageaddr, fragment->data + SQUASHFS_I(inode)->
1801                                         u.s1.fragment_offset, bytes);
1802                         kunmap_atomic(pageaddr, KM_USER0);
1803                         release_cached_fragment(msblk, fragment);
1804                 } else
1805                         ERROR("Unable to read page, block %llx, size %x\n",
1806                                         SQUASHFS_I(inode)->
1807                                         u.s1.fragment_start_block, (int)
1808                                         SQUASHFS_I(inode)-> u.s1.fragment_size);
1809         }
1810
1811 skip_read:
1812         pageaddr = kmap_atomic(page, KM_USER0);
1813         memset(pageaddr + bytes, 0, PAGE_CACHE_SIZE - bytes);
1814         kunmap_atomic(pageaddr, KM_USER0);
1815         flush_dcache_page(page);
1816         SetPageUptodate(page);
1817         unlock_page(page);
1818
1819         kfree(block_list);
1820         return 0;
1821 }
1822
1823
1824 static int get_dir_index_using_offset(struct super_block *s, long long
1825                                 *next_block, unsigned int *next_offset,
1826                                 long long index_start,
1827                                 unsigned int index_offset, int i_count,
1828                                 long long f_pos)
1829 {
1830         struct squashfs_sb_info *msblk = s->s_fs_info;
1831         struct squashfs_super_block *sblk = &msblk->sblk;
1832         int i, length = 0;
1833         struct squashfs_dir_index index;
1834
1835         TRACE("Entered get_dir_index_using_offset, i_count %d, f_pos %d\n",
1836                                         i_count, (unsigned int) f_pos);
1837
1838         f_pos =- 3;
1839         if (f_pos == 0)
1840                 goto finish;
1841
1842         for (i = 0; i < i_count; i++) {
1843                 if (msblk->swap) {
1844                         struct squashfs_dir_index sindex;
1845                         squashfs_get_cached_block(s, (char *) &sindex,
1846                                         index_start, index_offset,
1847                                         sizeof(sindex), &index_start,
1848                                         &index_offset);
1849                         SQUASHFS_SWAP_DIR_INDEX(&index, &sindex);
1850                 } else
1851                         squashfs_get_cached_block(s, (char *) &index,
1852                                         index_start, index_offset,
1853                                         sizeof(index), &index_start,
1854                                         &index_offset);
1855
1856                 if (index.index > f_pos)
1857                         break;
1858
1859                 squashfs_get_cached_block(s, NULL, index_start, index_offset,
1860                                         index.size + 1, &index_start,
1861                                         &index_offset);
1862
1863                 length = index.index;
1864                 *next_block = index.start_block + sblk->directory_table_start;
1865         }
1866
1867         *next_offset = (length + *next_offset) % SQUASHFS_METADATA_SIZE;
1868
1869 finish:
1870         return length + 3;
1871 }
1872
1873
1874 static int get_dir_index_using_name(struct super_block *s, long long
1875                                 *next_block, unsigned int *next_offset,
1876                                 long long index_start,
1877                                 unsigned int index_offset, int i_count,
1878                                 const char *name, int size)
1879 {
1880         struct squashfs_sb_info *msblk = s->s_fs_info;
1881         struct squashfs_super_block *sblk = &msblk->sblk;
1882         int i, length = 0;
1883         struct squashfs_dir_index *index;
1884         char *str;
1885
1886         TRACE("Entered get_dir_index_using_name, i_count %d\n", i_count);
1887
1888         if (!(str = kmalloc(sizeof(struct squashfs_dir_index) +
1889                 (SQUASHFS_NAME_LEN + 1) * 2, GFP_KERNEL))) {
1890                 ERROR("Failed to allocate squashfs_dir_index\n");
1891                 goto failure;
1892         }
1893
1894         index = (struct squashfs_dir_index *) (str + SQUASHFS_NAME_LEN + 1);
1895         strncpy(str, name, size);
1896         str[size] = '\0';
1897
1898         for (i = 0; i < i_count; i++) {
1899                 if (msblk->swap) {
1900                         struct squashfs_dir_index sindex;
1901                         squashfs_get_cached_block(s, (char *) &sindex,
1902                                         index_start, index_offset,
1903                                         sizeof(sindex), &index_start,
1904                                         &index_offset);
1905                         SQUASHFS_SWAP_DIR_INDEX(index, &sindex);
1906                 } else
1907                         squashfs_get_cached_block(s, (char *) index,
1908                                         index_start, index_offset,
1909                                         sizeof(struct squashfs_dir_index),
1910                                         &index_start, &index_offset);
1911
1912                 squashfs_get_cached_block(s, index->name, index_start,
1913                                         index_offset, index->size + 1,
1914                                         &index_start, &index_offset);
1915
1916                 index->name[index->size + 1] = '\0';
1917
1918                 if (strcmp(index->name, str) > 0)
1919                         break;
1920
1921                 length = index->index;
1922                 *next_block = index->start_block + sblk->directory_table_start;
1923         }
1924
1925         *next_offset = (length + *next_offset) % SQUASHFS_METADATA_SIZE;
1926         kfree(str);
1927 failure:
1928         return length + 3;
1929 }
1930
1931
1932 static int squashfs_readdir(struct file *file, void *dirent, filldir_t filldir)
1933 {
1934         struct inode *i = file->f_dentry->d_inode;
1935         struct squashfs_sb_info *msblk = i->i_sb->s_fs_info;
1936         struct squashfs_super_block *sblk = &msblk->sblk;
1937         long long next_block = SQUASHFS_I(i)->start_block +
1938                 sblk->directory_table_start;
1939         int next_offset = SQUASHFS_I(i)->offset, length = 0,
1940                 dir_count;
1941         struct squashfs_dir_header dirh;
1942         struct squashfs_dir_entry *dire;
1943
1944         TRACE("Entered squashfs_readdir [%llx:%x]\n", next_block, next_offset);
1945
1946         if (!(dire = kmalloc(sizeof(struct squashfs_dir_entry) +
1947                 SQUASHFS_NAME_LEN + 1, GFP_KERNEL))) {
1948                 ERROR("Failed to allocate squashfs_dir_entry\n");
1949                 goto finish;
1950         }
1951
1952         while(file->f_pos < 3) {
1953                 char *name;
1954                 int size, i_ino;
1955
1956                 if(file->f_pos == 0) {
1957                         name = ".";
1958                         size = 1;
1959                         i_ino = i->i_ino;
1960                 } else {
1961                         name = "..";
1962                         size = 2;
1963                         i_ino = SQUASHFS_I(i)->u.s2.parent_inode;
1964                 }
1965                 TRACE("Calling filldir(%x, %s, %d, %d, %d, %d)\n",
1966                                 (unsigned int) dirent, name, size, (int)
1967                                 file->f_pos, i_ino,
1968                                 squashfs_filetype_table[1]);
1969
1970                 if (filldir(dirent, name, size,
1971                                 file->f_pos, i_ino,
1972                                 squashfs_filetype_table[1]) < 0) {
1973                                 TRACE("Filldir returned less than 0\n");
1974                                 goto finish;
1975                 }
1976                 file->f_pos += size;
1977         }
1978
1979         length = get_dir_index_using_offset(i->i_sb, &next_block, &next_offset,
1980                                 SQUASHFS_I(i)->u.s2.directory_index_start,
1981                                 SQUASHFS_I(i)->u.s2.directory_index_offset,
1982                                 SQUASHFS_I(i)->u.s2.directory_index_count,
1983                                 file->f_pos);
1984
1985         while (length < i_size_read(i)) {
1986                 /* read directory header */
1987                 if (msblk->swap) {
1988                         struct squashfs_dir_header sdirh;
1989
1990                         if (!squashfs_get_cached_block(i->i_sb, (char *) &sdirh,
1991                                         next_block, next_offset, sizeof(sdirh),
1992                                         &next_block, &next_offset))
1993                                 goto failed_read;
1994
1995                         length += sizeof(sdirh);
1996                         SQUASHFS_SWAP_DIR_HEADER(&dirh, &sdirh);
1997                 } else {
1998                         if (!squashfs_get_cached_block(i->i_sb, (char *) &dirh,
1999                                         next_block, next_offset, sizeof(dirh),
2000                                         &next_block, &next_offset))
2001                                 goto failed_read;
2002
2003                         length += sizeof(dirh);
2004                 }
2005
2006                 dir_count = dirh.count + 1;
2007                 while (dir_count--) {
2008                         if (msblk->swap) {
2009                                 struct squashfs_dir_entry sdire;
2010                                 if (!squashfs_get_cached_block(i->i_sb, (char *)
2011                                                 &sdire, next_block, next_offset,
2012                                                 sizeof(sdire), &next_block,
2013                                                 &next_offset))
2014                                         goto failed_read;
2015
2016                                 length += sizeof(sdire);
2017                                 SQUASHFS_SWAP_DIR_ENTRY(dire, &sdire);
2018                         } else {
2019                                 if (!squashfs_get_cached_block(i->i_sb, (char *)
2020                                                 dire, next_block, next_offset,
2021                                                 sizeof(*dire), &next_block,
2022                                                 &next_offset))
2023                                         goto failed_read;
2024
2025                                 length += sizeof(*dire);
2026                         }
2027
2028                         if (!squashfs_get_cached_block(i->i_sb, dire->name,
2029                                                 next_block, next_offset,
2030                                                 dire->size + 1, &next_block,
2031                                                 &next_offset))
2032                                 goto failed_read;
2033
2034                         length += dire->size + 1;
2035
2036                         if (file->f_pos >= length)
2037                                 continue;
2038
2039                         dire->name[dire->size + 1] = '\0';
2040
2041                         TRACE("Calling filldir(%x, %s, %d, %d, %x:%x, %d, %d)\n",
2042                                         (unsigned int) dirent, dire->name,
2043                                         dire->size + 1, (int) file->f_pos,
2044                                         dirh.start_block, dire->offset,
2045                                         dirh.inode_number + dire->inode_number,
2046                                         squashfs_filetype_table[dire->type]);
2047
2048                         if (filldir(dirent, dire->name, dire->size + 1,
2049                                         file->f_pos,
2050                                         dirh.inode_number + dire->inode_number,
2051                                         squashfs_filetype_table[dire->type])
2052                                         < 0) {
2053                                 TRACE("Filldir returned less than 0\n");
2054                                 goto finish;
2055                         }
2056                         file->f_pos = length;
2057                 }
2058         }
2059
2060 finish:
2061         kfree(dire);
2062         return 0;
2063
2064 failed_read:
2065         ERROR("Unable to read directory block [%llx:%x]\n", next_block,
2066                 next_offset);
2067         kfree(dire);
2068         return 0;
2069 }
2070
2071
2072 static struct dentry *squashfs_lookup(struct inode *i, struct dentry *dentry,
2073                                 struct nameidata *nd)
2074 {
2075         const unsigned char *name = dentry->d_name.name;
2076         int len = dentry->d_name.len;
2077         struct inode *inode = NULL;
2078         struct squashfs_sb_info *msblk = i->i_sb->s_fs_info;
2079         struct squashfs_super_block *sblk = &msblk->sblk;
2080         long long next_block = SQUASHFS_I(i)->start_block +
2081                                 sblk->directory_table_start;
2082         int next_offset = SQUASHFS_I(i)->offset, length = 0,
2083                                 dir_count;
2084         struct squashfs_dir_header dirh;
2085         struct squashfs_dir_entry *dire;
2086
2087         TRACE("Entered squashfs_lookup [%llx:%x]\n", next_block, next_offset);
2088
2089         if (!(dire = kmalloc(sizeof(struct squashfs_dir_entry) +
2090                 SQUASHFS_NAME_LEN + 1, GFP_KERNEL))) {
2091                 ERROR("Failed to allocate squashfs_dir_entry\n");
2092                 goto exit_lookup;
2093         }
2094
2095         if (len > SQUASHFS_NAME_LEN)
2096                 goto exit_lookup;
2097
2098         length = get_dir_index_using_name(i->i_sb, &next_block, &next_offset,
2099                                 SQUASHFS_I(i)->u.s2.directory_index_start,
2100                                 SQUASHFS_I(i)->u.s2.directory_index_offset,
2101                                 SQUASHFS_I(i)->u.s2.directory_index_count, name,
2102                                 len);
2103
2104         while (length < i_size_read(i)) {
2105                 /* read directory header */
2106                 if (msblk->swap) {
2107                         struct squashfs_dir_header sdirh;
2108                         if (!squashfs_get_cached_block(i->i_sb, (char *) &sdirh,
2109                                         next_block, next_offset, sizeof(sdirh),
2110                                         &next_block, &next_offset))
2111                                 goto failed_read;
2112
2113                         length += sizeof(sdirh);
2114                         SQUASHFS_SWAP_DIR_HEADER(&dirh, &sdirh);
2115                 } else {
2116                         if (!squashfs_get_cached_block(i->i_sb, (char *) &dirh,
2117                                         next_block, next_offset, sizeof(dirh),
2118                                         &next_block, &next_offset))
2119                                 goto failed_read;
2120
2121                         length += sizeof(dirh);
2122                 }
2123
2124                 dir_count = dirh.count + 1;
2125                 while (dir_count--) {
2126                         if (msblk->swap) {
2127                                 struct squashfs_dir_entry sdire;
2128                                 if (!squashfs_get_cached_block(i->i_sb, (char *)
2129                                                 &sdire, next_block,next_offset,
2130                                                 sizeof(sdire), &next_block,
2131                                                 &next_offset))
2132                                         goto failed_read;
2133
2134                                 length += sizeof(sdire);
2135                                 SQUASHFS_SWAP_DIR_ENTRY(dire, &sdire);
2136                         } else {
2137                                 if (!squashfs_get_cached_block(i->i_sb, (char *)
2138                                                 dire, next_block,next_offset,
2139                                                 sizeof(*dire), &next_block,
2140                                                 &next_offset))
2141                                         goto failed_read;
2142
2143                                 length += sizeof(*dire);
2144                         }
2145
2146                         if (!squashfs_get_cached_block(i->i_sb, dire->name,
2147                                         next_block, next_offset, dire->size + 1,
2148                                         &next_block, &next_offset))
2149                                 goto failed_read;
2150
2151                         length += dire->size + 1;
2152
2153                         if (name[0] < dire->name[0])
2154                                 goto exit_lookup;
2155
2156                         if ((len == dire->size + 1) && !strncmp(name, dire->name, len)) {
2157                                 squashfs_inode_t ino = SQUASHFS_MKINODE(dirh.start_block,
2158                                                                 dire->offset);
2159
2160                                 TRACE("calling squashfs_iget for directory "
2161                                         "entry %s, inode %x:%x, %d\n", name,
2162                                         dirh.start_block, dire->offset,
2163                                         dirh.inode_number + dire->inode_number);
2164
2165                                 inode = squashfs_iget(i->i_sb, ino, dirh.inode_number + dire->inode_number);
2166
2167                                 goto exit_lookup;
2168                         }
2169                 }
2170         }
2171
2172 exit_lookup:
2173         kfree(dire);
2174         if (inode)
2175                 return d_splice_alias(inode, dentry);
2176         d_add(dentry, inode);
2177         return ERR_PTR(0);
2178
2179 failed_read:
2180         ERROR("Unable to read directory block [%llx:%x]\n", next_block,
2181                 next_offset);
2182         goto exit_lookup;
2183 }
2184
2185
2186 static void squashfs_put_super(struct super_block *s)
2187 {
2188         int i;
2189
2190         if (s->s_fs_info) {
2191                 struct squashfs_sb_info *sbi = s->s_fs_info;
2192                 if (sbi->block_cache)
2193                         for (i = 0; i < SQUASHFS_CACHED_BLKS; i++)
2194                                 if (sbi->block_cache[i].block !=
2195                                                         SQUASHFS_INVALID_BLK)
2196                                         kfree(sbi->block_cache[i].data);
2197                 if (sbi->fragment)
2198                         for (i = 0; i < SQUASHFS_CACHED_FRAGMENTS; i++)
2199                                 SQUASHFS_FREE(sbi->fragment[i].data);
2200                 kfree(sbi->fragment);
2201                 kfree(sbi->block_cache);
2202                 kfree(sbi->read_data);
2203                 kfree(sbi->read_page);
2204                 kfree(sbi->uid);
2205                 kfree(sbi->fragment_index);
2206                 kfree(sbi->fragment_index_2);
2207                 kfree(sbi->meta_index);
2208                 vfree(sbi->stream.workspace);
2209                 kfree(s->s_fs_info);
2210                 s->s_fs_info = NULL;
2211         }
2212 }
2213
2214
2215 static int squashfs_get_sb(struct file_system_type *fs_type, int flags,
2216                                 const char *dev_name, void *data,
2217                                 struct vfsmount *mnt)
2218 {
2219         return get_sb_bdev(fs_type, flags, dev_name, data, squashfs_fill_super,
2220                                 mnt);
2221 }
2222
2223
2224 static int __init init_squashfs_fs(void)
2225 {
2226         int err = init_inodecache();
2227         if (err)
2228                 goto out;
2229
2230         printk(KERN_INFO "squashfs: version 3.2-alpha (2006/12/12) "
2231                 "Phillip Lougher\n");
2232
2233         if ((err = register_filesystem(&squashfs_fs_type)))
2234                 destroy_inodecache();
2235
2236 out:
2237         return err;
2238 }
2239
2240
2241 static void __exit exit_squashfs_fs(void)
2242 {
2243         unregister_filesystem(&squashfs_fs_type);
2244         destroy_inodecache();
2245 }
2246
2247
2248 static kmem_cache_t * squashfs_inode_cachep;
2249
2250
2251 static struct inode *squashfs_alloc_inode(struct super_block *sb)
2252 {
2253         struct squashfs_inode_info *ei;
2254         ei = kmem_cache_alloc(squashfs_inode_cachep, SLAB_KERNEL);
2255         if (!ei)
2256                 return NULL;
2257         return &ei->vfs_inode;
2258 }
2259
2260
2261 static void squashfs_destroy_inode(struct inode *inode)
2262 {
2263         kmem_cache_free(squashfs_inode_cachep, SQUASHFS_I(inode));
2264 }
2265
2266
2267 static void init_once(void * foo, kmem_cache_t * cachep, unsigned long flags)
2268 {
2269         struct squashfs_inode_info *ei = foo;
2270
2271         if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) ==
2272                                                         SLAB_CTOR_CONSTRUCTOR)
2273                 inode_init_once(&ei->vfs_inode);
2274 }
2275
2276
2277 static int __init init_inodecache(void)
2278 {
2279         squashfs_inode_cachep = kmem_cache_create("squashfs_inode_cache",
2280              sizeof(struct squashfs_inode_info),
2281              0, SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT,
2282              init_once, NULL);
2283         if (squashfs_inode_cachep == NULL)
2284                 return -ENOMEM;
2285         return 0;
2286 }
2287
2288
2289 static void destroy_inodecache(void)
2290 {
2291         kmem_cache_destroy(squashfs_inode_cachep);
2292 }
2293
2294
2295 module_init(init_squashfs_fs);
2296 module_exit(exit_squashfs_fs);
2297 MODULE_DESCRIPTION("squashfs 3.2, a compressed read-only filesystem");
2298 MODULE_AUTHOR("Phillip Lougher <phillip@lougher.org.uk>");
2299 MODULE_LICENSE("GPL");