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