fs/qnx4/inode.c

   1 /*
   2  * QNX4 file system, Linux implementation.
   3  *
   4  * Version : 0.2.1
   5  *
   6  * Using parts of the xiafs filesystem.
   7  *
   8  * History :
   9  *
  10  * 01-06-1998 by Richard Frowijn : first release.
  11  * 20-06-1998 by Frank Denis : Linux 2.1.99+ support, boot signature, misc.
  12  * 30-06-1998 by Frank Denis : first step to write inodes.
  13  */
  14
  15 #include <linux/config.h>
  16 #include <linux/module.h>
  17 #include <linux/types.h>
  18 #include <linux/string.h>
  19 #include <linux/errno.h>
  20 #include <linux/slab.h>
  21 #include <linux/fs.h>
  22 #include <linux/qnx4_fs.h>
  23 #include <linux/init.h>
  24 #include <linux/highuid.h>
  25 #include <linux/smp_lock.h>
  26 #include <linux/pagemap.h>
  27 #include <linux/buffer_head.h>
  28 #include <linux/vfs.h>
  29 #include <asm/uaccess.h>
  30
  31 #define QNX4_VERSION  4
  32 #define QNX4_BMNAME   ".bitmap"
  33
  34 static struct super_operations qnx4_sops;
  35
  36 #ifdef CONFIG_QNX4FS_RW
  37
  38 int qnx4_sync_inode(struct inode *inode)
  39 {
  40         int err = 0;
  41 # if 0
  42         struct buffer_head *bh;
  43
  44         bh = qnx4_update_inode(inode);
  45         if (bh && buffer_dirty(bh))
  46         {
  47                 sync_dirty_buffer(bh);
  48                 if (buffer_req(bh) && !buffer_uptodate(bh))
  49                 {
  50                         printk ("IO error syncing qnx4 inode [%s:%08lx]\n",
  51                                 inode->i_sb->s_id, inode->i_ino);
  52                         err = -1;
  53                 }
  54                 brelse (bh);
  55         } else if (!bh) {
  56                 err = -1;
  57         }
  58 # endif
  59
  60         return err;
  61 }
  62
  63 static void qnx4_delete_inode(struct inode *inode)
  64 {
  65         QNX4DEBUG(("qnx4: deleting inode [%lu]\n", (unsigned long) inode->i_ino));
  66         inode->i_size = 0;
  67         qnx4_truncate(inode);
  68         lock_kernel();
  69         qnx4_free_inode(inode);
  70         unlock_kernel();
  71 }
  72
  73 static void qnx4_write_super(struct super_block *sb)
  74 {
  75         lock_kernel();
  76         QNX4DEBUG(("qnx4: write_super\n"));
  77         sb->s_dirt = 0;
  78         unlock_kernel();
  79 }
  80
  81 static void qnx4_write_inode(struct inode *inode, int unused)
  82 {
  83         struct qnx4_inode_entry *raw_inode;
  84         int block, ino;
  85         struct buffer_head *bh;
  86         ino = inode->i_ino;
  87
  88         QNX4DEBUG(("qnx4: write inode 1.\n"));
  89         if (inode->i_nlink == 0) {
  90                 return;
  91         }
  92         if (!ino) {
  93                 printk("qnx4: bad inode number on dev %s: %d is out of range\n",
  94                        inode->i_sb->s_id, ino);
  95                 return;
  96         }
  97         QNX4DEBUG(("qnx4: write inode 2.\n"));
  98         block = ino / QNX4_INODES_PER_BLOCK;
  99         lock_kernel();
 100         if (!(bh = sb_bread(inode->i_sb, block))) {
 101                 printk("qnx4: major problem: unable to read inode from dev "
 102                        "%s\n", inode->i_sb->s_id);
 103                 unlock_kernel();
 104                 return;
 105         }
 106         raw_inode = ((struct qnx4_inode_entry *) bh->b_data) +
 107             (ino % QNX4_INODES_PER_BLOCK);
 108         raw_inode->di_mode  = cpu_to_le16(inode->i_mode);
 109         raw_inode->di_uid   = cpu_to_le16(fs_high2lowuid(inode->i_uid));
 110         raw_inode->di_gid   = cpu_to_le16(fs_high2lowgid(inode->i_gid));
 111         raw_inode->di_nlink = cpu_to_le16(inode->i_nlink);
 112         raw_inode->di_size  = cpu_to_le32(inode->i_size);
 113         raw_inode->di_mtime = cpu_to_le32(inode->i_mtime.tv_sec);
 114         raw_inode->di_atime = cpu_to_le32(inode->i_atime.tv_sec);
 115         raw_inode->di_ctime = cpu_to_le32(inode->i_ctime.tv_sec);
 116         raw_inode->di_first_xtnt.xtnt_size = cpu_to_le32(inode->i_blocks);
 117         mark_buffer_dirty(bh);
 118         brelse(bh);
 119         unlock_kernel();
 120 }
 121
 122 #endif
 123
 124 static void qnx4_put_super(struct super_block *sb);
 125 static struct inode *qnx4_alloc_inode(struct super_block *sb);
 126 static void qnx4_destroy_inode(struct inode *inode);
 127 static void qnx4_read_inode(struct inode *);
 128 static int qnx4_remount(struct super_block *sb, int *flags, char *data);
 129 static int qnx4_statfs(struct super_block *, struct kstatfs *);
 130
 131 static struct super_operations qnx4_sops =
 132 {
 133         .alloc_inode    = qnx4_alloc_inode,
 134         .destroy_inode  = qnx4_destroy_inode,
 135         .read_inode     = qnx4_read_inode,
 136         .put_super      = qnx4_put_super,
 137         .statfs         = qnx4_statfs,
 138         .remount_fs     = qnx4_remount,
 139 #ifdef CONFIG_QNX4FS_RW
 140         .write_inode    = qnx4_write_inode,
 141         .delete_inode   = qnx4_delete_inode,
 142         .write_super    = qnx4_write_super,
 143 #endif
 144 };
 145
 146 static int qnx4_remount(struct super_block *sb, int *flags, char *data)
 147 {
 148         struct qnx4_sb_info *qs;
 149
 150         qs = qnx4_sb(sb);
 151         qs->Version = QNX4_VERSION;
 152 #ifndef CONFIG_QNX4FS_RW
 153         *flags |= MS_RDONLY;
 154 #endif
 155         if (*flags & MS_RDONLY) {
 156                 return 0;
 157         }
 158
 159         mark_buffer_dirty(qs->sb_buf);
 160
 161         return 0;
 162 }
 163
 164 struct buffer_head *qnx4_getblk(struct inode *inode, int nr,
 165                                  int create)
 166 {
 167         struct buffer_head *result = NULL;
 168
 169         if ( nr >= 0 )
 170                 nr = qnx4_block_map( inode, nr );
 171         if (nr) {
 172                 result = sb_getblk(inode->i_sb, nr);
 173                 return result;
 174         }
 175         if (!create) {
 176                 return NULL;
 177         }
 178 #if 0
 179         tmp = qnx4_new_block(inode->i_sb);
 180         if (!tmp) {
 181                 return NULL;
 182         }
 183         result = sb_getblk(inode->i_sb, tmp);
 184         if (tst) {
 185                 qnx4_free_block(inode->i_sb, tmp);
 186                 brelse(result);
 187                 goto repeat;
 188         }
 189         tst = tmp;
 190 #endif
 191         inode->i_ctime = CURRENT_TIME;
 192         mark_inode_dirty(inode);
 193         return result;
 194 }
 195
 196 struct buffer_head *qnx4_bread(struct inode *inode, int block, int create)
 197 {
 198         struct buffer_head *bh;
 199
 200         bh = qnx4_getblk(inode, block, create);
 201         if (!bh || buffer_uptodate(bh)) {
 202                 return bh;
 203         }
 204         ll_rw_block(READ, 1, &bh);
 205         wait_on_buffer(bh);
 206         if (buffer_uptodate(bh)) {
 207                 return bh;
 208         }
 209         brelse(bh);
 210
 211         return NULL;
 212 }
 213
 214 int qnx4_get_block( struct inode *inode, sector_t iblock, struct buffer_head *bh, int create )
 215 {
 216         unsigned long phys;
 217
 218         QNX4DEBUG(("qnx4: qnx4_get_block inode=[%ld] iblock=[%ld]\n",inode->i_ino,iblock));
 219
 220         phys = qnx4_block_map( inode, iblock );
 221         if ( phys ) {
 222                 // logical block is before EOF
 223                 map_bh(bh, inode->i_sb, phys);
 224         } else if ( create ) {
 225                 // to be done.
 226         }
 227         return 0;
 228 }
 229
 230 unsigned long qnx4_block_map( struct inode *inode, long iblock )
 231 {
 232         int ix;
 233         long offset, i_xblk;
 234         unsigned long block = 0;
 235         struct buffer_head *bh = 0;
 236         struct qnx4_xblk *xblk = 0;
 237         struct qnx4_inode_entry *qnx4_inode = qnx4_raw_inode(inode);
 238         qnx4_nxtnt_t nxtnt = le16_to_cpu(qnx4_inode->di_num_xtnts);
 239
 240         if ( iblock < le32_to_cpu(qnx4_inode->di_first_xtnt.xtnt_size) ) {
 241                 // iblock is in the first extent. This is easy.
 242                 block = le32_to_cpu(qnx4_inode->di_first_xtnt.xtnt_blk) + iblock - 1;
 243         } else {
 244                 // iblock is beyond first extent. We have to follow the extent chain.
 245                 i_xblk = le32_to_cpu(qnx4_inode->di_xblk);
 246                 offset = iblock - le32_to_cpu(qnx4_inode->di_first_xtnt.xtnt_size);
 247                 ix = 0;
 248                 while ( --nxtnt > 0 ) {
 249                         if ( ix == 0 ) {
 250                                 // read next xtnt block.
 251                                 bh = sb_bread(inode->i_sb, i_xblk - 1);
 252                                 if ( !bh ) {
 253                                         QNX4DEBUG(("qnx4: I/O error reading xtnt block [%ld])\n", i_xblk - 1));
 254                                         return -EIO;
 255                                 }
 256                                 xblk = (struct qnx4_xblk*)bh->b_data;
 257                                 if ( memcmp( xblk->xblk_signature, "IamXblk", 7 ) ) {
 258                                         QNX4DEBUG(("qnx4: block at %ld is not a valid xtnt\n", qnx4_inode->i_xblk));
 259                                         return -EIO;
 260                                 }
 261                         }
 262                         if ( offset < le32_to_cpu(xblk->xblk_xtnts[ix].xtnt_size) ) {
 263                                 // got it!
 264                                 block = le32_to_cpu(xblk->xblk_xtnts[ix].xtnt_blk) + offset - 1;
 265                                 break;
 266                         }
 267                         offset -= le32_to_cpu(xblk->xblk_xtnts[ix].xtnt_size);
 268                         if ( ++ix >= xblk->xblk_num_xtnts ) {
 269                                 i_xblk = le32_to_cpu(xblk->xblk_next_xblk);
 270                                 ix = 0;
 271                                 brelse( bh );
 272                                 bh = 0;
 273                         }
 274                 }
 275                 if ( bh )
 276                         brelse( bh );
 277         }
 278
 279         QNX4DEBUG(("qnx4: mapping block %ld of inode %ld = %ld\n",iblock,inode->i_ino,block));
 280         return block;
 281 }
 282
 283 static int qnx4_statfs(struct super_block *sb, struct kstatfs *buf)
 284 {
 285         lock_kernel();
 286
 287         buf->f_type    = sb->s_magic;
 288         buf->f_bsize   = sb->s_blocksize;
 289         buf->f_blocks  = le32_to_cpu(qnx4_sb(sb)->BitMap->di_size) * 8;
 290         buf->f_bfree   = qnx4_count_free_blocks(sb);
 291         buf->f_bavail  = buf->f_bfree;
 292         buf->f_namelen = QNX4_NAME_MAX;
 293
 294         unlock_kernel();
 295
 296         return 0;
 297 }
 298
 299 /*
 300  * Check the root directory of the filesystem to make sure
 301  * it really _is_ a qnx4 filesystem, and to check the size
 302  * of the directory entry.
 303  */
 304 static const char *qnx4_checkroot(struct super_block *sb)
 305 {
 306         struct buffer_head *bh;
 307         struct qnx4_inode_entry *rootdir;
 308         int rd, rl;
 309         int i, j;
 310         int found = 0;
 311
 312         if (*(qnx4_sb(sb)->sb->RootDir.di_fname) != '/') {
 313                 return "no qnx4 filesystem (no root dir).";
 314         } else {
 315                 QNX4DEBUG(("QNX4 filesystem found on dev %s.\n", sb->s_id));
 316                 rd = le32_to_cpu(qnx4_sb(sb)->sb->RootDir.di_first_xtnt.xtnt_blk) - 1;
 317                 rl = le32_to_cpu(qnx4_sb(sb)->sb->RootDir.di_first_xtnt.xtnt_size);
 318                 for (j = 0; j < rl; j++) {
 319                         bh = sb_bread(sb, rd + j);      /* root dir, first block */
 320                         if (bh == NULL) {
 321                                 return "unable to read root entry.";
 322                         }
 323                         for (i = 0; i < QNX4_INODES_PER_BLOCK; i++) {
 324                                 rootdir = (struct qnx4_inode_entry *) (bh->b_data + i * QNX4_DIR_ENTRY_SIZE);
 325                                 if (rootdir->di_fname != NULL) {
 326                                         QNX4DEBUG(("Rootdir entry found : [%s]\n", rootdir->di_fname));
 327                                         if (!strncmp(rootdir->di_fname, QNX4_BMNAME, sizeof QNX4_BMNAME)) {
 328                                                 found = 1;
 329                                                 qnx4_sb(sb)->BitMap = kmalloc( sizeof( struct qnx4_inode_entry ), GFP_KERNEL );
 330                                                 if (!qnx4_sb(sb)->BitMap) {
 331                                                         brelse (bh);
 332                                                         return "not enough memory for bitmap inode";
 333                                                 }
 334                                                 memcpy( qnx4_sb(sb)->BitMap, rootdir, sizeof( struct qnx4_inode_entry ) );      /* keep bitmap inode known */
 335                                                 break;
 336                                         }
 337                                 }
 338                         }
 339                         brelse(bh);
 340                         if (found != 0) {
 341                                 break;
 342                         }
 343                 }
 344                 if (found == 0) {
 345                         return "bitmap file not found.";
 346                 }
 347         }
 348         return NULL;
 349 }
 350
 351 static int qnx4_fill_super(struct super_block *s, void *data, int silent)
 352 {
 353         struct buffer_head *bh;
 354         struct inode *root;
 355         const char *errmsg;
 356         struct qnx4_sb_info *qs;
 357
 358         qs = kmalloc(sizeof(struct qnx4_sb_info), GFP_KERNEL);
 359         if (!qs)
 360                 return -ENOMEM;
 361         s->s_fs_info = qs;
 362         memset(qs, 0, sizeof(struct qnx4_sb_info));
 363
 364         sb_set_blocksize(s, QNX4_BLOCK_SIZE);
 365
 366         /* Check the superblock signature. Since the qnx4 code is
 367            dangerous, we should leave as quickly as possible
 368            if we don't belong here... */
 369         bh = sb_bread(s, 1);
 370         if (!bh) {
 371                 printk("qnx4: unable to read the superblock\n");
 372                 goto outnobh;
 373         }
 374         if ( le32_to_cpu( *(__u32*)bh->b_data ) != QNX4_SUPER_MAGIC ) {
 375                 if (!silent)
 376                         printk("qnx4: wrong fsid in superblock.\n");
 377                 goto out;
 378         }
 379         s->s_op = &qnx4_sops;
 380         s->s_magic = QNX4_SUPER_MAGIC;
 381 #ifndef CONFIG_QNX4FS_RW
 382         s->s_flags |= MS_RDONLY;        /* Yup, read-only yet */
 383 #endif
 384         qnx4_sb(s)->sb_buf = bh;
 385         qnx4_sb(s)->sb = (struct qnx4_super_block *) bh->b_data;
 386
 387
 388         /* check before allocating dentries, inodes, .. */
 389         errmsg = qnx4_checkroot(s);
 390         if (errmsg != NULL) {
 391                 if (!silent)
 392                         printk("qnx4: %s\n", errmsg);
 393                 goto out;
 394         }
 395
 396         /* does root not have inode number QNX4_ROOT_INO ?? */
 397         root = iget(s, QNX4_ROOT_INO * QNX4_INODES_PER_BLOCK);
 398         if (!root) {
 399                 printk("qnx4: get inode failed\n");
 400                 goto out;
 401         }
 402
 403         s->s_root = d_alloc_root(root);
 404         if (s->s_root == NULL)
 405                 goto outi;
 406
 407         brelse(bh);
 408
 409         return 0;
 410
 411       outi:
 412         iput(root);
 413       out:
 414         brelse(bh);
 415       outnobh:
 416         kfree(qs);
 417         s->s_fs_info = NULL;
 418         return -EINVAL;
 419 }
 420
 421 static void qnx4_put_super(struct super_block *sb)
 422 {
 423         struct qnx4_sb_info *qs = qnx4_sb(sb);
 424         kfree( qs->BitMap );
 425         kfree( qs );
 426         sb->s_fs_info = NULL;
 427         return;
 428 }
 429
 430 static int qnx4_writepage(struct page *page, struct writeback_control *wbc)
 431 {
 432         return block_write_full_page(page,qnx4_get_block, wbc);
 433 }
 434 static int qnx4_readpage(struct file *file, struct page *page)
 435 {
 436         return block_read_full_page(page,qnx4_get_block);
 437 }
 438 static int qnx4_prepare_write(struct file *file, struct page *page,
 439                               unsigned from, unsigned to)
 440 {
 441         struct qnx4_inode_info *qnx4_inode = qnx4_i(page->mapping->host);
 442         return cont_prepare_write(page, from, to, qnx4_get_block,
 443                                   &qnx4_inode->mmu_private);
 444 }
 445 static sector_t qnx4_bmap(struct address_space *mapping, sector_t block)
 446 {
 447         return generic_block_bmap(mapping,block,qnx4_get_block);
 448 }
 449 struct address_space_operations qnx4_aops = {
 450         .readpage       = qnx4_readpage,
 451         .writepage      = qnx4_writepage,
 452         .sync_page      = block_sync_page,
 453         .prepare_write  = qnx4_prepare_write,
 454         .commit_write   = generic_commit_write,
 455         .bmap           = qnx4_bmap
 456 };
 457
 458 static void qnx4_read_inode(struct inode *inode)
 459 {
 460         struct buffer_head *bh;
 461         struct qnx4_inode_entry *raw_inode;
 462         int block, ino;
 463         struct super_block *sb = inode->i_sb;
 464         struct qnx4_inode_entry *qnx4_inode = qnx4_raw_inode(inode);
 465
 466         ino = inode->i_ino;
 467         inode->i_mode = 0;
 468
 469         QNX4DEBUG(("Reading inode : [%d]\n", ino));
 470         if (!ino) {
 471                 printk("qnx4: bad inode number on dev %s: %d is out of range\n",
 472                        sb->s_id, ino);
 473                 return;
 474         }
 475         block = ino / QNX4_INODES_PER_BLOCK;
 476
 477         if (!(bh = sb_bread(sb, block))) {
 478                 printk("qnx4: major problem: unable to read inode from dev "
 479                        "%s\n", sb->s_id);
 480                 return;
 481         }
 482         raw_inode = ((struct qnx4_inode_entry *) bh->b_data) +
 483             (ino % QNX4_INODES_PER_BLOCK);
 484
 485         inode->i_mode    = le16_to_cpu(raw_inode->di_mode);
 486         inode->i_uid     = (uid_t)le16_to_cpu(raw_inode->di_uid);
 487         inode->i_gid     = (gid_t)le16_to_cpu(raw_inode->di_gid);
 488         inode->i_nlink   = le16_to_cpu(raw_inode->di_nlink);
 489         inode->i_size    = le32_to_cpu(raw_inode->di_size);
 490         inode->i_mtime.tv_sec   = le32_to_cpu(raw_inode->di_mtime);
 491         inode->i_mtime.tv_nsec = 0;
 492         inode->i_atime.tv_sec   = le32_to_cpu(raw_inode->di_atime);
 493         inode->i_atime.tv_nsec = 0;
 494         inode->i_ctime.tv_sec   = le32_to_cpu(raw_inode->di_ctime);
 495         inode->i_ctime.tv_nsec = 0;
 496         inode->i_blocks  = le32_to_cpu(raw_inode->di_first_xtnt.xtnt_size);
 497         inode->i_blksize = QNX4_DIR_ENTRY_SIZE;
 498
 499         memcpy(qnx4_inode, raw_inode, QNX4_DIR_ENTRY_SIZE);
 500         if (S_ISREG(inode->i_mode)) {
 501                 inode->i_op = &qnx4_file_inode_operations;
 502                 inode->i_fop = &qnx4_file_operations;
 503                 inode->i_mapping->a_ops = &qnx4_aops;
 504                 qnx4_i(inode)->mmu_private = inode->i_size;
 505         } else if (S_ISDIR(inode->i_mode)) {
 506                 inode->i_op = &qnx4_dir_inode_operations;
 507                 inode->i_fop = &qnx4_dir_operations;
 508         } else if (S_ISLNK(inode->i_mode)) {
 509                 inode->i_op = &page_symlink_inode_operations;
 510                 inode->i_mapping->a_ops = &qnx4_aops;
 511                 qnx4_i(inode)->mmu_private = inode->i_size;
 512         } else
 513                 printk("qnx4: bad inode %d on dev %s\n",ino,sb->s_id);
 514         brelse(bh);
 515 }
 516
 517 static kmem_cache_t *qnx4_inode_cachep;
 518
 519 static struct inode *qnx4_alloc_inode(struct super_block *sb)
 520 {
 521         struct qnx4_inode_info *ei;
 522         ei = kmem_cache_alloc(qnx4_inode_cachep, SLAB_KERNEL);
 523         if (!ei)
 524                 return NULL;
 525         return &ei->vfs_inode;
 526 }
 527
 528 static void qnx4_destroy_inode(struct inode *inode)
 529 {
 530         kmem_cache_free(qnx4_inode_cachep, qnx4_i(inode));
 531 }
 532
 533 static void init_once(void *foo, kmem_cache_t * cachep,
 534                       unsigned long flags)
 535 {
 536         struct qnx4_inode_info *ei = (struct qnx4_inode_info *) foo;
 537
 538         if ((flags & (SLAB_CTOR_VERIFY | SLAB_CTOR_CONSTRUCTOR)) ==
 539             SLAB_CTOR_CONSTRUCTOR)
 540                 inode_init_once(&ei->vfs_inode);
 541 }
 542
 543 static int init_inodecache(void)
 544 {
 545         qnx4_inode_cachep = kmem_cache_create("qnx4_inode_cache",
 546                                              sizeof(struct qnx4_inode_info),
 547                                              0, SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT,
 548                                              init_once, NULL);
 549         if (qnx4_inode_cachep == NULL)
 550                 return -ENOMEM;
 551         return 0;
 552 }
 553
 554 static void destroy_inodecache(void)
 555 {
 556         if (kmem_cache_destroy(qnx4_inode_cachep))
 557                 printk(KERN_INFO
 558                        "qnx4_inode_cache: not all structures were freed\n");
 559 }
 560
 561 static struct super_block *qnx4_get_sb(struct file_system_type *fs_type,
 562         int flags, const char *dev_name, void *data)
 563 {
 564         return get_sb_bdev(fs_type, flags, dev_name, data, qnx4_fill_super);
 565 }
 566
 567 static struct file_system_type qnx4_fs_type = {
 568         .owner          = THIS_MODULE,
 569         .name           = "qnx4",
 570         .get_sb         = qnx4_get_sb,
 571         .kill_sb        = kill_block_super,
 572         .fs_flags       = FS_REQUIRES_DEV,
 573 };
 574
 575 static int __init init_qnx4_fs(void)
 576 {
 577         int err;
 578
 579         err = init_inodecache();
 580         if (err)
 581                 return err;
 582
 583         err = register_filesystem(&qnx4_fs_type);
 584         if (err) {
 585                 destroy_inodecache();
 586                 return err;
 587         }
 588
 589         printk("QNX4 filesystem 0.2.3 registered.\n");
 590         return 0;
 591 }
 592
 593 static void __exit exit_qnx4_fs(void)
 594 {
 595         unregister_filesystem(&qnx4_fs_type);
 596         destroy_inodecache();
 597 }
 598
 599 module_init(init_qnx4_fs)
 600 module_exit(exit_qnx4_fs)
 601 MODULE_LICENSE("GPL");
 602