fs/qnx6/inode.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * QNX6 file system, Linux implementation.
   4  *
   5  * Version : 1.0.0
   6  *
   7  * History :
   8  *
   9  * 01-02-2012 by Kai Bankett (chaosman@ontika.net) : first release.
  10  * 16-02-2012 pagemap extension by Al Viro
  11  *
  12  */
  13
  14 #include <linux/module.h>
  15 #include <linux/init.h>
  16 #include <linux/slab.h>
  17 #include <linux/highuid.h>
  18 #include <linux/pagemap.h>
  19 #include <linux/buffer_head.h>
  20 #include <linux/writeback.h>
  21 #include <linux/statfs.h>
  22 #include <linux/parser.h>
  23 #include <linux/seq_file.h>
  24 #include <linux/mount.h>
  25 #include <linux/crc32.h>
  26 #include <linux/mpage.h>
  27 #include "qnx6.h"
  28
  29 static const struct super_operations qnx6_sops;
  30
  31 static void qnx6_put_super(struct super_block *sb);
  32 static struct inode *qnx6_alloc_inode(struct super_block *sb);
  33 static void qnx6_free_inode(struct inode *inode);
  34 static int qnx6_remount(struct super_block *sb, int *flags, char *data);
  35 static int qnx6_statfs(struct dentry *dentry, struct kstatfs *buf);
  36 static int qnx6_show_options(struct seq_file *seq, struct dentry *root);
  37
  38 static const struct super_operations qnx6_sops = {
  39         .alloc_inode    = qnx6_alloc_inode,
  40         .free_inode     = qnx6_free_inode,
  41         .put_super      = qnx6_put_super,
  42         .statfs         = qnx6_statfs,
  43         .remount_fs     = qnx6_remount,
  44         .show_options   = qnx6_show_options,
  45 };
  46
  47 static int qnx6_show_options(struct seq_file *seq, struct dentry *root)
  48 {
  49         struct super_block *sb = root->d_sb;
  50         struct qnx6_sb_info *sbi = QNX6_SB(sb);
  51
  52         if (sbi->s_mount_opt & QNX6_MOUNT_MMI_FS)
  53                 seq_puts(seq, ",mmi_fs");
  54         return 0;
  55 }
  56
  57 static int qnx6_remount(struct super_block *sb, int *flags, char *data)
  58 {
  59         sync_filesystem(sb);
  60         *flags |= SB_RDONLY;
  61         return 0;
  62 }
  63
  64 static unsigned qnx6_get_devblock(struct super_block *sb, __fs32 block)
  65 {
  66         struct qnx6_sb_info *sbi = QNX6_SB(sb);
  67         return fs32_to_cpu(sbi, block) + sbi->s_blks_off;
  68 }
  69
  70 static unsigned qnx6_block_map(struct inode *inode, unsigned iblock);
  71
  72 static int qnx6_get_block(struct inode *inode, sector_t iblock,
  73                         struct buffer_head *bh, int create)
  74 {
  75         unsigned phys;
  76
  77         pr_debug("qnx6_get_block inode=[%ld] iblock=[%ld]\n",
  78                  inode->i_ino, (unsigned long)iblock);
  79
  80         phys = qnx6_block_map(inode, iblock);
  81         if (phys) {
  82                 /* logical block is before EOF */
  83                 map_bh(bh, inode->i_sb, phys);
  84         }
  85         return 0;
  86 }
  87
  88 static int qnx6_check_blockptr(__fs32 ptr)
  89 {
  90         if (ptr == ~(__fs32)0) {
  91                 pr_err("hit unused blockpointer.\n");
  92                 return 0;
  93         }
  94         return 1;
  95 }
  96
  97 static int qnx6_read_folio(struct file *file, struct folio *folio)
  98 {
  99         return mpage_read_folio(folio, qnx6_get_block);
 100 }
 101
 102 static void qnx6_readahead(struct readahead_control *rac)
 103 {
 104         mpage_readahead(rac, qnx6_get_block);
 105 }
 106
 107 /*
 108  * returns the block number for the no-th element in the tree
 109  * inodebits requred as there are multiple inodes in one inode block
 110  */
 111 static unsigned qnx6_block_map(struct inode *inode, unsigned no)
 112 {
 113         struct super_block *s = inode->i_sb;
 114         struct qnx6_sb_info *sbi = QNX6_SB(s);
 115         struct qnx6_inode_info *ei = QNX6_I(inode);
 116         unsigned block = 0;
 117         struct buffer_head *bh;
 118         __fs32 ptr;
 119         int levelptr;
 120         int ptrbits = sbi->s_ptrbits;
 121         int bitdelta;
 122         u32 mask = (1 << ptrbits) - 1;
 123         int depth = ei->di_filelevels;
 124         int i;
 125
 126         bitdelta = ptrbits * depth;
 127         levelptr = no >> bitdelta;
 128
 129         if (levelptr > QNX6_NO_DIRECT_POINTERS - 1) {
 130                 pr_err("Requested file block number (%u) too big.", no);
 131                 return 0;
 132         }
 133
 134         block = qnx6_get_devblock(s, ei->di_block_ptr[levelptr]);
 135
 136         for (i = 0; i < depth; i++) {
 137                 bh = sb_bread(s, block);
 138                 if (!bh) {
 139                         pr_err("Error reading block (%u)\n", block);
 140                         return 0;
 141                 }
 142                 bitdelta -= ptrbits;
 143                 levelptr = (no >> bitdelta) & mask;
 144                 ptr = ((__fs32 *)bh->b_data)[levelptr];
 145
 146                 if (!qnx6_check_blockptr(ptr))
 147                         return 0;
 148
 149                 block = qnx6_get_devblock(s, ptr);
 150                 brelse(bh);
 151         }
 152         return block;
 153 }
 154
 155 static int qnx6_statfs(struct dentry *dentry, struct kstatfs *buf)
 156 {
 157         struct super_block *sb = dentry->d_sb;
 158         struct qnx6_sb_info *sbi = QNX6_SB(sb);
 159         u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
 160
 161         buf->f_type    = sb->s_magic;
 162         buf->f_bsize   = sb->s_blocksize;
 163         buf->f_blocks  = fs32_to_cpu(sbi, sbi->sb->sb_num_blocks);
 164         buf->f_bfree   = fs32_to_cpu(sbi, sbi->sb->sb_free_blocks);
 165         buf->f_files   = fs32_to_cpu(sbi, sbi->sb->sb_num_inodes);
 166         buf->f_ffree   = fs32_to_cpu(sbi, sbi->sb->sb_free_inodes);
 167         buf->f_bavail  = buf->f_bfree;
 168         buf->f_namelen = QNX6_LONG_NAME_MAX;
 169         buf->f_fsid    = u64_to_fsid(id);
 170
 171         return 0;
 172 }
 173
 174 /*
 175  * Check the root directory of the filesystem to make sure
 176  * it really _is_ a qnx6 filesystem, and to check the size
 177  * of the directory entry.
 178  */
 179 static const char *qnx6_checkroot(struct super_block *s)
 180 {
 181         static char match_root[2][3] = {".\0\0", "..\0"};
 182         int i, error = 0;
 183         struct qnx6_dir_entry *dir_entry;
 184         struct inode *root = d_inode(s->s_root);
 185         struct address_space *mapping = root->i_mapping;
 186         struct page *page = read_mapping_page(mapping, 0, NULL);
 187         if (IS_ERR(page))
 188                 return "error reading root directory";
 189         kmap(page);
 190         dir_entry = page_address(page);
 191         for (i = 0; i < 2; i++) {
 192                 /* maximum 3 bytes - due to match_root limitation */
 193                 if (strncmp(dir_entry[i].de_fname, match_root[i], 3))
 194                         error = 1;
 195         }
 196         qnx6_put_page(page);
 197         if (error)
 198                 return "error reading root directory.";
 199         return NULL;
 200 }
 201
 202 #ifdef CONFIG_QNX6FS_DEBUG
 203 void qnx6_superblock_debug(struct qnx6_super_block *sb, struct super_block *s)
 204 {
 205         struct qnx6_sb_info *sbi = QNX6_SB(s);
 206
 207         pr_debug("magic: %08x\n", fs32_to_cpu(sbi, sb->sb_magic));
 208         pr_debug("checksum: %08x\n", fs32_to_cpu(sbi, sb->sb_checksum));
 209         pr_debug("serial: %llx\n", fs64_to_cpu(sbi, sb->sb_serial));
 210         pr_debug("flags: %08x\n", fs32_to_cpu(sbi, sb->sb_flags));
 211         pr_debug("blocksize: %08x\n", fs32_to_cpu(sbi, sb->sb_blocksize));
 212         pr_debug("num_inodes: %08x\n", fs32_to_cpu(sbi, sb->sb_num_inodes));
 213         pr_debug("free_inodes: %08x\n", fs32_to_cpu(sbi, sb->sb_free_inodes));
 214         pr_debug("num_blocks: %08x\n", fs32_to_cpu(sbi, sb->sb_num_blocks));
 215         pr_debug("free_blocks: %08x\n", fs32_to_cpu(sbi, sb->sb_free_blocks));
 216         pr_debug("inode_levels: %02x\n", sb->Inode.levels);
 217 }
 218 #endif
 219
 220 enum {
 221         Opt_mmifs,
 222         Opt_err
 223 };
 224
 225 static const match_table_t tokens = {
 226         {Opt_mmifs, "mmi_fs"},
 227         {Opt_err, NULL}
 228 };
 229
 230 static int qnx6_parse_options(char *options, struct super_block *sb)
 231 {
 232         char *p;
 233         struct qnx6_sb_info *sbi = QNX6_SB(sb);
 234         substring_t args[MAX_OPT_ARGS];
 235
 236         if (!options)
 237                 return 1;
 238
 239         while ((p = strsep(&options, ",")) != NULL) {
 240                 int token;
 241                 if (!*p)
 242                         continue;
 243
 244                 token = match_token(p, tokens, args);
 245                 switch (token) {
 246                 case Opt_mmifs:
 247                         set_opt(sbi->s_mount_opt, MMI_FS);
 248                         break;
 249                 default:
 250                         return 0;
 251                 }
 252         }
 253         return 1;
 254 }
 255
 256 static struct buffer_head *qnx6_check_first_superblock(struct super_block *s,
 257                                 int offset, int silent)
 258 {
 259         struct qnx6_sb_info *sbi = QNX6_SB(s);
 260         struct buffer_head *bh;
 261         struct qnx6_super_block *sb;
 262
 263         /* Check the superblock signatures
 264            start with the first superblock */
 265         bh = sb_bread(s, offset);
 266         if (!bh) {
 267                 pr_err("unable to read the first superblock\n");
 268                 return NULL;
 269         }
 270         sb = (struct qnx6_super_block *)bh->b_data;
 271         if (fs32_to_cpu(sbi, sb->sb_magic) != QNX6_SUPER_MAGIC) {
 272                 sbi->s_bytesex = BYTESEX_BE;
 273                 if (fs32_to_cpu(sbi, sb->sb_magic) == QNX6_SUPER_MAGIC) {
 274                         /* we got a big endian fs */
 275                         pr_debug("fs got different endianness.\n");
 276                         return bh;
 277                 } else
 278                         sbi->s_bytesex = BYTESEX_LE;
 279                 if (!silent) {
 280                         if (offset == 0) {
 281                                 pr_err("wrong signature (magic) in superblock #1.\n");
 282                         } else {
 283                                 pr_info("wrong signature (magic) at position (0x%lx) - will try alternative position (0x0000).\n",
 284                                         offset * s->s_blocksize);
 285                         }
 286                 }
 287                 brelse(bh);
 288                 return NULL;
 289         }
 290         return bh;
 291 }
 292
 293 static struct inode *qnx6_private_inode(struct super_block *s,
 294                                         struct qnx6_root_node *p);
 295
 296 static int qnx6_fill_super(struct super_block *s, void *data, int silent)
 297 {
 298         struct buffer_head *bh1 = NULL, *bh2 = NULL;
 299         struct qnx6_super_block *sb1 = NULL, *sb2 = NULL;
 300         struct qnx6_sb_info *sbi;
 301         struct inode *root;
 302         const char *errmsg;
 303         struct qnx6_sb_info *qs;
 304         int ret = -EINVAL;
 305         u64 offset;
 306         int bootblock_offset = QNX6_BOOTBLOCK_SIZE;
 307
 308         qs = kzalloc(sizeof(struct qnx6_sb_info), GFP_KERNEL);
 309         if (!qs)
 310                 return -ENOMEM;
 311         s->s_fs_info = qs;
 312
 313         /* Superblock always is 512 Byte long */
 314         if (!sb_set_blocksize(s, QNX6_SUPERBLOCK_SIZE)) {
 315                 pr_err("unable to set blocksize\n");
 316                 goto outnobh;
 317         }
 318
 319         /* parse the mount-options */
 320         if (!qnx6_parse_options((char *) data, s)) {
 321                 pr_err("invalid mount options.\n");
 322                 goto outnobh;
 323         }
 324         if (test_opt(s, MMI_FS)) {
 325                 sb1 = qnx6_mmi_fill_super(s, silent);
 326                 if (sb1)
 327                         goto mmi_success;
 328                 else
 329                         goto outnobh;
 330         }
 331         sbi = QNX6_SB(s);
 332         sbi->s_bytesex = BYTESEX_LE;
 333         /* Check the superblock signatures
 334            start with the first superblock */
 335         bh1 = qnx6_check_first_superblock(s,
 336                 bootblock_offset / QNX6_SUPERBLOCK_SIZE, silent);
 337         if (!bh1) {
 338                 /* try again without bootblock offset */
 339                 bh1 = qnx6_check_first_superblock(s, 0, silent);
 340                 if (!bh1) {
 341                         pr_err("unable to read the first superblock\n");
 342                         goto outnobh;
 343                 }
 344                 /* seems that no bootblock at partition start */
 345                 bootblock_offset = 0;
 346         }
 347         sb1 = (struct qnx6_super_block *)bh1->b_data;
 348
 349 #ifdef CONFIG_QNX6FS_DEBUG
 350         qnx6_superblock_debug(sb1, s);
 351 #endif
 352
 353         /* checksum check - start at byte 8 and end at byte 512 */
 354         if (fs32_to_cpu(sbi, sb1->sb_checksum) !=
 355                         crc32_be(0, (char *)(bh1->b_data + 8), 504)) {
 356                 pr_err("superblock #1 checksum error\n");
 357                 goto out;
 358         }
 359
 360         /* set new blocksize */
 361         if (!sb_set_blocksize(s, fs32_to_cpu(sbi, sb1->sb_blocksize))) {
 362                 pr_err("unable to set blocksize\n");
 363                 goto out;
 364         }
 365         /* blocksize invalidates bh - pull it back in */
 366         brelse(bh1);
 367         bh1 = sb_bread(s, bootblock_offset >> s->s_blocksize_bits);
 368         if (!bh1)
 369                 goto outnobh;
 370         sb1 = (struct qnx6_super_block *)bh1->b_data;
 371
 372         /* calculate second superblock blocknumber */
 373         offset = fs32_to_cpu(sbi, sb1->sb_num_blocks) +
 374                 (bootblock_offset >> s->s_blocksize_bits) +
 375                 (QNX6_SUPERBLOCK_AREA >> s->s_blocksize_bits);
 376
 377         /* set bootblock offset */
 378         sbi->s_blks_off = (bootblock_offset >> s->s_blocksize_bits) +
 379                           (QNX6_SUPERBLOCK_AREA >> s->s_blocksize_bits);
 380
 381         /* next the second superblock */
 382         bh2 = sb_bread(s, offset);
 383         if (!bh2) {
 384                 pr_err("unable to read the second superblock\n");
 385                 goto out;
 386         }
 387         sb2 = (struct qnx6_super_block *)bh2->b_data;
 388         if (fs32_to_cpu(sbi, sb2->sb_magic) != QNX6_SUPER_MAGIC) {
 389                 if (!silent)
 390                         pr_err("wrong signature (magic) in superblock #2.\n");
 391                 goto out;
 392         }
 393
 394         /* checksum check - start at byte 8 and end at byte 512 */
 395         if (fs32_to_cpu(sbi, sb2->sb_checksum) !=
 396                                 crc32_be(0, (char *)(bh2->b_data + 8), 504)) {
 397                 pr_err("superblock #2 checksum error\n");
 398                 goto out;
 399         }
 400
 401         if (fs64_to_cpu(sbi, sb1->sb_serial) >=
 402                                         fs64_to_cpu(sbi, sb2->sb_serial)) {
 403                 /* superblock #1 active */
 404                 sbi->sb_buf = bh1;
 405                 sbi->sb = (struct qnx6_super_block *)bh1->b_data;
 406                 brelse(bh2);
 407                 pr_info("superblock #1 active\n");
 408         } else {
 409                 /* superblock #2 active */
 410                 sbi->sb_buf = bh2;
 411                 sbi->sb = (struct qnx6_super_block *)bh2->b_data;
 412                 brelse(bh1);
 413                 pr_info("superblock #2 active\n");
 414         }
 415 mmi_success:
 416         /* sanity check - limit maximum indirect pointer levels */
 417         if (sb1->Inode.levels > QNX6_PTR_MAX_LEVELS) {
 418                 pr_err("too many inode levels (max %i, sb %i)\n",
 419                        QNX6_PTR_MAX_LEVELS, sb1->Inode.levels);
 420                 goto out;
 421         }
 422         if (sb1->Longfile.levels > QNX6_PTR_MAX_LEVELS) {
 423                 pr_err("too many longfilename levels (max %i, sb %i)\n",
 424                        QNX6_PTR_MAX_LEVELS, sb1->Longfile.levels);
 425                 goto out;
 426         }
 427         s->s_op = &qnx6_sops;
 428         s->s_magic = QNX6_SUPER_MAGIC;
 429         s->s_flags |= SB_RDONLY;        /* Yup, read-only yet */
 430         s->s_time_min = 0;
 431         s->s_time_max = U32_MAX;
 432
 433         /* ease the later tree level calculations */
 434         sbi = QNX6_SB(s);
 435         sbi->s_ptrbits = ilog2(s->s_blocksize / 4);
 436         sbi->inodes = qnx6_private_inode(s, &sb1->Inode);
 437         if (!sbi->inodes)
 438                 goto out;
 439         sbi->longfile = qnx6_private_inode(s, &sb1->Longfile);
 440         if (!sbi->longfile)
 441                 goto out1;
 442
 443         /* prefetch root inode */
 444         root = qnx6_iget(s, QNX6_ROOT_INO);
 445         if (IS_ERR(root)) {
 446                 pr_err("get inode failed\n");
 447                 ret = PTR_ERR(root);
 448                 goto out2;
 449         }
 450
 451         ret = -ENOMEM;
 452         s->s_root = d_make_root(root);
 453         if (!s->s_root)
 454                 goto out2;
 455
 456         ret = -EINVAL;
 457         errmsg = qnx6_checkroot(s);
 458         if (errmsg != NULL) {
 459                 if (!silent)
 460                         pr_err("%s\n", errmsg);
 461                 goto out3;
 462         }
 463         return 0;
 464
 465 out3:
 466         dput(s->s_root);
 467         s->s_root = NULL;
 468 out2:
 469         iput(sbi->longfile);
 470 out1:
 471         iput(sbi->inodes);
 472 out:
 473         if (bh1)
 474                 brelse(bh1);
 475         if (bh2)
 476                 brelse(bh2);
 477 outnobh:
 478         kfree(qs);
 479         s->s_fs_info = NULL;
 480         return ret;
 481 }
 482
 483 static void qnx6_put_super(struct super_block *sb)
 484 {
 485         struct qnx6_sb_info *qs = QNX6_SB(sb);
 486         brelse(qs->sb_buf);
 487         iput(qs->longfile);
 488         iput(qs->inodes);
 489         kfree(qs);
 490         sb->s_fs_info = NULL;
 491         return;
 492 }
 493
 494 static sector_t qnx6_bmap(struct address_space *mapping, sector_t block)
 495 {
 496         return generic_block_bmap(mapping, block, qnx6_get_block);
 497 }
 498 static const struct address_space_operations qnx6_aops = {
 499         .read_folio     = qnx6_read_folio,
 500         .readahead      = qnx6_readahead,
 501         .bmap           = qnx6_bmap
 502 };
 503
 504 static struct inode *qnx6_private_inode(struct super_block *s,
 505                                         struct qnx6_root_node *p)
 506 {
 507         struct inode *inode = new_inode(s);
 508         if (inode) {
 509                 struct qnx6_inode_info *ei = QNX6_I(inode);
 510                 struct qnx6_sb_info *sbi = QNX6_SB(s);
 511                 inode->i_size = fs64_to_cpu(sbi, p->size);
 512                 memcpy(ei->di_block_ptr, p->ptr, sizeof(p->ptr));
 513                 ei->di_filelevels = p->levels;
 514                 inode->i_mode = S_IFREG | S_IRUSR; /* probably wrong */
 515                 inode->i_mapping->a_ops = &qnx6_aops;
 516         }
 517         return inode;
 518 }
 519
 520 struct inode *qnx6_iget(struct super_block *sb, unsigned ino)
 521 {
 522         struct qnx6_sb_info *sbi = QNX6_SB(sb);
 523         struct qnx6_inode_entry *raw_inode;
 524         struct inode *inode;
 525         struct qnx6_inode_info  *ei;
 526         struct address_space *mapping;
 527         struct page *page;
 528         u32 n, offs;
 529
 530         inode = iget_locked(sb, ino);
 531         if (!inode)
 532                 return ERR_PTR(-ENOMEM);
 533         if (!(inode->i_state & I_NEW))
 534                 return inode;
 535
 536         ei = QNX6_I(inode);
 537
 538         inode->i_mode = 0;
 539
 540         if (ino == 0) {
 541                 pr_err("bad inode number on dev %s: %u is out of range\n",
 542                        sb->s_id, ino);
 543                 iget_failed(inode);
 544                 return ERR_PTR(-EIO);
 545         }
 546         n = (ino - 1) >> (PAGE_SHIFT - QNX6_INODE_SIZE_BITS);
 547         offs = (ino - 1) & (~PAGE_MASK >> QNX6_INODE_SIZE_BITS);
 548         mapping = sbi->inodes->i_mapping;
 549         page = read_mapping_page(mapping, n, NULL);
 550         if (IS_ERR(page)) {
 551                 pr_err("major problem: unable to read inode from dev %s\n",
 552                        sb->s_id);
 553                 iget_failed(inode);
 554                 return ERR_CAST(page);
 555         }
 556         kmap(page);
 557         raw_inode = ((struct qnx6_inode_entry *)page_address(page)) + offs;
 558
 559         inode->i_mode    = fs16_to_cpu(sbi, raw_inode->di_mode);
 560         i_uid_write(inode, (uid_t)fs32_to_cpu(sbi, raw_inode->di_uid));
 561         i_gid_write(inode, (gid_t)fs32_to_cpu(sbi, raw_inode->di_gid));
 562         inode->i_size    = fs64_to_cpu(sbi, raw_inode->di_size);
 563         inode->i_mtime.tv_sec   = fs32_to_cpu(sbi, raw_inode->di_mtime);
 564         inode->i_mtime.tv_nsec = 0;
 565         inode->i_atime.tv_sec   = fs32_to_cpu(sbi, raw_inode->di_atime);
 566         inode->i_atime.tv_nsec = 0;
 567         inode->i_ctime.tv_sec   = fs32_to_cpu(sbi, raw_inode->di_ctime);
 568         inode->i_ctime.tv_nsec = 0;
 569
 570         /* calc blocks based on 512 byte blocksize */
 571         inode->i_blocks = (inode->i_size + 511) >> 9;
 572
 573         memcpy(&ei->di_block_ptr, &raw_inode->di_block_ptr,
 574                                 sizeof(raw_inode->di_block_ptr));
 575         ei->di_filelevels = raw_inode->di_filelevels;
 576
 577         if (S_ISREG(inode->i_mode)) {
 578                 inode->i_fop = &generic_ro_fops;
 579                 inode->i_mapping->a_ops = &qnx6_aops;
 580         } else if (S_ISDIR(inode->i_mode)) {
 581                 inode->i_op = &qnx6_dir_inode_operations;
 582                 inode->i_fop = &qnx6_dir_operations;
 583                 inode->i_mapping->a_ops = &qnx6_aops;
 584         } else if (S_ISLNK(inode->i_mode)) {
 585                 inode->i_op = &page_symlink_inode_operations;
 586                 inode_nohighmem(inode);
 587                 inode->i_mapping->a_ops = &qnx6_aops;
 588         } else
 589                 init_special_inode(inode, inode->i_mode, 0);
 590         qnx6_put_page(page);
 591         unlock_new_inode(inode);
 592         return inode;
 593 }
 594
 595 static struct kmem_cache *qnx6_inode_cachep;
 596
 597 static struct inode *qnx6_alloc_inode(struct super_block *sb)
 598 {
 599         struct qnx6_inode_info *ei;
 600         ei = alloc_inode_sb(sb, qnx6_inode_cachep, GFP_KERNEL);
 601         if (!ei)
 602                 return NULL;
 603         return &ei->vfs_inode;
 604 }
 605
 606 static void qnx6_free_inode(struct inode *inode)
 607 {
 608         kmem_cache_free(qnx6_inode_cachep, QNX6_I(inode));
 609 }
 610
 611 static void init_once(void *foo)
 612 {
 613         struct qnx6_inode_info *ei = (struct qnx6_inode_info *) foo;
 614
 615         inode_init_once(&ei->vfs_inode);
 616 }
 617
 618 static int init_inodecache(void)
 619 {
 620         qnx6_inode_cachep = kmem_cache_create("qnx6_inode_cache",
 621                                              sizeof(struct qnx6_inode_info),
 622                                              0, (SLAB_RECLAIM_ACCOUNT|
 623                                                 SLAB_MEM_SPREAD|SLAB_ACCOUNT),
 624                                              init_once);
 625         if (!qnx6_inode_cachep)
 626                 return -ENOMEM;
 627         return 0;
 628 }
 629
 630 static void destroy_inodecache(void)
 631 {
 632         /*
 633          * Make sure all delayed rcu free inodes are flushed before we
 634          * destroy cache.
 635          */
 636         rcu_barrier();
 637         kmem_cache_destroy(qnx6_inode_cachep);
 638 }
 639
 640 static struct dentry *qnx6_mount(struct file_system_type *fs_type,
 641         int flags, const char *dev_name, void *data)
 642 {
 643         return mount_bdev(fs_type, flags, dev_name, data, qnx6_fill_super);
 644 }
 645
 646 static struct file_system_type qnx6_fs_type = {
 647         .owner          = THIS_MODULE,
 648         .name           = "qnx6",
 649         .mount          = qnx6_mount,
 650         .kill_sb        = kill_block_super,
 651         .fs_flags       = FS_REQUIRES_DEV,
 652 };
 653 MODULE_ALIAS_FS("qnx6");
 654
 655 static int __init init_qnx6_fs(void)
 656 {
 657         int err;
 658
 659         err = init_inodecache();
 660         if (err)
 661                 return err;
 662
 663         err = register_filesystem(&qnx6_fs_type);
 664         if (err) {
 665                 destroy_inodecache();
 666                 return err;
 667         }
 668
 669         pr_info("QNX6 filesystem 1.0.0 registered.\n");
 670         return 0;
 671 }
 672
 673 static void __exit exit_qnx6_fs(void)
 674 {
 675         unregister_filesystem(&qnx6_fs_type);
 676         destroy_inodecache();
 677 }
 678
 679 module_init(init_qnx6_fs)
 680 module_exit(exit_qnx6_fs)
 681 MODULE_LICENSE("GPL");