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         if (*flags & MS_RDONLY) {
 153                 return 0;
 154         }
 155         mark_buffer_dirty(qs->sb_buf);
 156
 157         return 0;
 158 }
 159
 160 struct buffer_head *qnx4_getblk(struct inode *inode, int nr,
 161                                  int create)
 162 {
 163         struct buffer_head *result = NULL;
 164
 165         if ( nr >= 0 )
 166                 nr = qnx4_block_map( inode, nr );
 167         if (nr) {
 168                 result = sb_getblk(inode->i_sb, nr);
 169                 return result;
 170         }
 171         if (!create) {
 172                 return NULL;
 173         }
 174 #if 0
 175         tmp = qnx4_new_block(inode->i_sb);
 176         if (!tmp) {
 177                 return NULL;
 178         }
 179         result = sb_getblk(inode->i_sb, tmp);
 180         if (tst) {
 181                 qnx4_free_block(inode->i_sb, tmp);
 182                 brelse(result);
 183                 goto repeat;
 184         }
 185         tst = tmp;
 186 #endif
 187         inode->i_ctime = CURRENT_TIME;
 188         mark_inode_dirty(inode);
 189         return result;
 190 }
 191
 192 struct buffer_head *qnx4_bread(struct inode *inode, int block, int create)
 193 {
 194         struct buffer_head *bh;
 195
 196         bh = qnx4_getblk(inode, block, create);
 197         if (!bh || buffer_uptodate(bh)) {
 198                 return bh;
 199         }
 200         ll_rw_block(READ, 1, &bh);
 201         wait_on_buffer(bh);
 202         if (buffer_uptodate(bh)) {
 203                 return bh;
 204         }
 205         brelse(bh);
 206
 207         return NULL;
 208 }
 209
 210 int qnx4_get_block( struct inode *inode, sector_t iblock, struct buffer_head *bh, int create )
 211 {
 212         unsigned long phys;
 213
 214         QNX4DEBUG(("qnx4: qnx4_get_block inode=[%ld] iblock=[%ld]\n",inode->i_ino,iblock));
 215
 216         phys = qnx4_block_map( inode, iblock );
 217         if ( phys ) {
 218                 // logical block is before EOF
 219                 map_bh(bh, inode->i_sb, phys);
 220         } else if ( create ) {
 221                 // to be done.
 222         }
 223         return 0;
 224 }
 225
 226 unsigned long qnx4_block_map( struct inode *inode, long iblock )
 227 {
 228         int ix;
 229         long offset, i_xblk;
 230         unsigned long block = 0;
 231         struct buffer_head *bh = 0;
 232         struct qnx4_xblk *xblk = 0;
 233         struct qnx4_inode_entry *qnx4_inode = qnx4_raw_inode(inode);
 234         qnx4_nxtnt_t nxtnt = le16_to_cpu(qnx4_inode->di_num_xtnts);
 235
 236         if ( iblock < le32_to_cpu(qnx4_inode->di_first_xtnt.xtnt_size) ) {
 237                 // iblock is in the first extent. This is easy.
 238                 block = le32_to_cpu(qnx4_inode->di_first_xtnt.xtnt_blk) + iblock - 1;
 239         } else {
 240                 // iblock is beyond first extent. We have to follow the extent chain.
 241                 i_xblk = le32_to_cpu(qnx4_inode->di_xblk);
 242                 offset = iblock - le32_to_cpu(qnx4_inode->di_first_xtnt.xtnt_size);
 243                 ix = 0;
 244                 while ( --nxtnt > 0 ) {
 245                         if ( ix == 0 ) {
 246                                 // read next xtnt block.
 247                                 bh = sb_bread(inode->i_sb, i_xblk - 1);
 248                                 if ( !bh ) {
 249                                         QNX4DEBUG(("qnx4: I/O error reading xtnt block [%ld])\n", i_xblk - 1));
 250                                         return -EIO;
 251                                 }
 252                                 xblk = (struct qnx4_xblk*)bh->b_data;
 253                                 if ( memcmp( xblk->xblk_signature, "IamXblk", 7 ) ) {
 254                                         QNX4DEBUG(("qnx4: block at %ld is not a valid xtnt\n", qnx4_inode->i_xblk));
 255                                         return -EIO;
 256                                 }
 257                         }
 258                         if ( offset < le32_to_cpu(xblk->xblk_xtnts[ix].xtnt_size) ) {
 259                                 // got it!
 260                                 block = le32_to_cpu(xblk->xblk_xtnts[ix].xtnt_blk) + offset - 1;
 261                                 break;
 262                         }
 263                         offset -= le32_to_cpu(xblk->xblk_xtnts[ix].xtnt_size);
 264                         if ( ++ix >= xblk->xblk_num_xtnts ) {
 265                                 i_xblk = le32_to_cpu(xblk->xblk_next_xblk);
 266                                 ix = 0;
 267                                 brelse( bh );
 268                                 bh = 0;
 269                         }
 270                 }
 271                 if ( bh )
 272                         brelse( bh );
 273         }
 274
 275         QNX4DEBUG(("qnx4: mapping block %ld of inode %ld = %ld\n",iblock,inode->i_ino,block));
 276         return block;
 277 }
 278
 279 static int qnx4_statfs(struct super_block *sb, struct kstatfs *buf)
 280 {
 281         lock_kernel();
 282
 283         buf->f_type    = sb->s_magic;
 284         buf->f_bsize   = sb->s_blocksize;
 285         buf->f_blocks  = le32_to_cpu(qnx4_sb(sb)->BitMap->di_size) * 8;
 286         buf->f_bfree   = qnx4_count_free_blocks(sb);
 287         buf->f_bavail  = buf->f_bfree;
 288         buf->f_namelen = QNX4_NAME_MAX;
 289
 290         unlock_kernel();
 291
 292         return 0;
 293 }
 294
 295 /*
 296  * Check the root directory of the filesystem to make sure
 297  * it really _is_ a qnx4 filesystem, and to check the size
 298  * of the directory entry.
 299  */
 300 static const char *qnx4_checkroot(struct super_block *sb)
 301 {
 302         struct buffer_head *bh;
 303         struct qnx4_inode_entry *rootdir;
 304         int rd, rl;
 305         int i, j;
 306         int found = 0;
 307
 308         if (*(qnx4_sb(sb)->sb->RootDir.di_fname) != '/') {
 309                 return "no qnx4 filesystem (no root dir).";
 310         } else {
 311                 QNX4DEBUG(("QNX4 filesystem found on dev %s.\n", sb->s_id));
 312                 rd = le32_to_cpu(qnx4_sb(sb)->sb->RootDir.di_first_xtnt.xtnt_blk) - 1;
 313                 rl = le32_to_cpu(qnx4_sb(sb)->sb->RootDir.di_first_xtnt.xtnt_size);
 314                 for (j = 0; j < rl; j++) {
 315                         bh = sb_bread(sb, rd + j);      /* root dir, first block */
 316                         if (bh == NULL) {
 317                                 return "unable to read root entry.";
 318                         }
 319                         for (i = 0; i < QNX4_INODES_PER_BLOCK; i++) {
 320                                 rootdir = (struct qnx4_inode_entry *) (bh->b_data + i * QNX4_DIR_ENTRY_SIZE);
 321                                 if (rootdir->di_fname != NULL) {
 322                                         QNX4DEBUG(("Rootdir entry found : [%s]\n", rootdir->di_fname));
 323                                         if (!strncmp(rootdir->di_fname, QNX4_BMNAME, sizeof QNX4_BMNAME)) {
 324                                                 found = 1;
 325                                                 qnx4_sb(sb)->BitMap = kmalloc( sizeof( struct qnx4_inode_entry ), GFP_KERNEL );
 326                                                 if (!qnx4_sb(sb)->BitMap) {
 327                                                         brelse (bh);
 328                                                         return "not enough memory for bitmap inode";
 329                                                 }
 330                                                 memcpy( qnx4_sb(sb)->BitMap, rootdir, sizeof( struct qnx4_inode_entry ) );      /* keep bitmap inode known */
 331                                                 break;
 332                                         }
 333                                 }
 334                         }
 335                         brelse(bh);
 336                         if (found != 0) {
 337                                 break;
 338                         }
 339                 }
 340                 if (found == 0) {
 341                         return "bitmap file not found.";
 342                 }
 343         }
 344         return NULL;
 345 }
 346
 347 static int qnx4_fill_super(struct super_block *s, void *data, int silent)
 348 {
 349         struct buffer_head *bh;
 350         struct inode *root;
 351         const char *errmsg;
 352         struct qnx4_sb_info *qs;
 353
 354         qs = kmalloc(sizeof(struct qnx4_sb_info), GFP_KERNEL);
 355         if (!qs)
 356                 return -ENOMEM;
 357         s->s_fs_info = qs;
 358         memset(qs, 0, sizeof(struct qnx4_sb_info));
 359
 360         sb_set_blocksize(s, QNX4_BLOCK_SIZE);
 361
 362         /* Check the superblock signature. Since the qnx4 code is
 363            dangerous, we should leave as quickly as possible
 364            if we don't belong here... */
 365         bh = sb_bread(s, 1);
 366         if (!bh) {
 367                 printk("qnx4: unable to read the superblock\n");
 368                 goto outnobh;
 369         }
 370         if ( le32_to_cpu( *(__u32*)bh->b_data ) != QNX4_SUPER_MAGIC ) {
 371                 if (!silent)
 372                         printk("qnx4: wrong fsid in superblock.\n");
 373                 goto out;
 374         }
 375         s->s_op = &qnx4_sops;
 376         s->s_magic = QNX4_SUPER_MAGIC;
 377 #ifndef CONFIG_QNX4FS_RW
 378         s->s_flags |= MS_RDONLY;        /* Yup, read-only yet */
 379 #endif
 380         qnx4_sb(s)->sb_buf = bh;
 381         qnx4_sb(s)->sb = (struct qnx4_super_block *) bh->b_data;
 382
 383
 384         /* check before allocating dentries, inodes, .. */
 385         errmsg = qnx4_checkroot(s);
 386         if (errmsg != NULL) {
 387                 if (!silent)
 388                         printk("qnx4: %s\n", errmsg);
 389                 goto out;
 390         }
 391
 392         /* does root not have inode number QNX4_ROOT_INO ?? */
 393         root = iget(s, QNX4_ROOT_INO * QNX4_INODES_PER_BLOCK);
 394         if (!root) {
 395                 printk("qnx4: get inode failed\n");
 396                 goto out;
 397         }
 398
 399         s->s_root = d_alloc_root(root);
 400         if (s->s_root == NULL)
 401                 goto outi;
 402
 403         brelse(bh);
 404
 405         return 0;
 406
 407       outi:
 408         iput(root);
 409       out:
 410         brelse(bh);
 411       outnobh:
 412         kfree(qs);
 413         s->s_fs_info = NULL;
 414         return -EINVAL;
 415 }
 416
 417 static void qnx4_put_super(struct super_block *sb)
 418 {
 419         struct qnx4_sb_info *qs = qnx4_sb(sb);
 420         kfree( qs->BitMap );
 421         kfree( qs );
 422         sb->s_fs_info = NULL;
 423         return;
 424 }
 425
 426 static int qnx4_writepage(struct page *page, struct writeback_control *wbc)
 427 {
 428         return block_write_full_page(page,qnx4_get_block, wbc);
 429 }
 430 static int qnx4_readpage(struct file *file, struct page *page)
 431 {
 432         return block_read_full_page(page,qnx4_get_block);
 433 }
 434 static int qnx4_prepare_write(struct file *file, struct page *page,
 435                               unsigned from, unsigned to)
 436 {
 437         struct qnx4_inode_info *qnx4_inode = qnx4_i(page->mapping->host);
 438         return cont_prepare_write(page, from, to, qnx4_get_block,
 439                                   &qnx4_inode->mmu_private);
 440 }
 441 static sector_t qnx4_bmap(struct address_space *mapping, sector_t block)
 442 {
 443         return generic_block_bmap(mapping,block,qnx4_get_block);
 444 }
 445 struct address_space_operations qnx4_aops = {
 446         .readpage       = qnx4_readpage,
 447         .writepage      = qnx4_writepage,
 448         .sync_page      = block_sync_page,
 449         .prepare_write  = qnx4_prepare_write,
 450         .commit_write   = generic_commit_write,
 451         .bmap           = qnx4_bmap
 452 };
 453
 454 static void qnx4_read_inode(struct inode *inode)
 455 {
 456         struct buffer_head *bh;
 457         struct qnx4_inode_entry *raw_inode;
 458         int block, ino;
 459         struct super_block *sb = inode->i_sb;
 460         struct qnx4_inode_entry *qnx4_inode = qnx4_raw_inode(inode);
 461
 462         ino = inode->i_ino;
 463         inode->i_mode = 0;
 464
 465         QNX4DEBUG(("Reading inode : [%d]\n", ino));
 466         if (!ino) {
 467                 printk("qnx4: bad inode number on dev %s: %d is out of range\n",
 468                        sb->s_id, ino);
 469                 return;
 470         }
 471         block = ino / QNX4_INODES_PER_BLOCK;
 472
 473         if (!(bh = sb_bread(sb, block))) {
 474                 printk("qnx4: major problem: unable to read inode from dev "
 475                        "%s\n", sb->s_id);
 476                 return;
 477         }
 478         raw_inode = ((struct qnx4_inode_entry *) bh->b_data) +
 479             (ino % QNX4_INODES_PER_BLOCK);
 480
 481         inode->i_mode    = le16_to_cpu(raw_inode->di_mode);
 482         inode->i_uid     = (uid_t)le16_to_cpu(raw_inode->di_uid);
 483         inode->i_gid     = (gid_t)le16_to_cpu(raw_inode->di_gid);
 484         inode->i_nlink   = le16_to_cpu(raw_inode->di_nlink);
 485         inode->i_size    = le32_to_cpu(raw_inode->di_size);
 486         inode->i_mtime.tv_sec   = le32_to_cpu(raw_inode->di_mtime);
 487         inode->i_mtime.tv_nsec = 0;
 488         inode->i_atime.tv_sec   = le32_to_cpu(raw_inode->di_atime);
 489         inode->i_atime.tv_nsec = 0;
 490         inode->i_ctime.tv_sec   = le32_to_cpu(raw_inode->di_ctime);
 491         inode->i_ctime.tv_nsec = 0;
 492         inode->i_blocks  = le32_to_cpu(raw_inode->di_first_xtnt.xtnt_size);
 493         inode->i_blksize = QNX4_DIR_ENTRY_SIZE;
 494
 495         memcpy(qnx4_inode, raw_inode, QNX4_DIR_ENTRY_SIZE);
 496         if (S_ISREG(inode->i_mode)) {
 497                 inode->i_op = &qnx4_file_inode_operations;
 498                 inode->i_fop = &qnx4_file_operations;
 499                 inode->i_mapping->a_ops = &qnx4_aops;
 500                 qnx4_i(inode)->mmu_private = inode->i_size;
 501         } else if (S_ISDIR(inode->i_mode)) {
 502                 inode->i_op = &qnx4_dir_inode_operations;
 503                 inode->i_fop = &qnx4_dir_operations;
 504         } else if (S_ISLNK(inode->i_mode)) {
 505                 inode->i_op = &page_symlink_inode_operations;
 506                 inode->i_mapping->a_ops = &qnx4_aops;
 507                 qnx4_i(inode)->mmu_private = inode->i_size;
 508         } else
 509                 printk("qnx4: bad inode %d on dev %s\n",ino,sb->s_id);
 510         brelse(bh);
 511 }
 512
 513 static kmem_cache_t *qnx4_inode_cachep;
 514
 515 static struct inode *qnx4_alloc_inode(struct super_block *sb)
 516 {
 517         struct qnx4_inode_info *ei;
 518         ei = kmem_cache_alloc(qnx4_inode_cachep, SLAB_KERNEL);
 519         if (!ei)
 520                 return NULL;
 521         return &ei->vfs_inode;
 522 }
 523
 524 static void qnx4_destroy_inode(struct inode *inode)
 525 {
 526         kmem_cache_free(qnx4_inode_cachep, qnx4_i(inode));
 527 }
 528
 529 static void init_once(void *foo, kmem_cache_t * cachep,
 530                       unsigned long flags)
 531 {
 532         struct qnx4_inode_info *ei = (struct qnx4_inode_info *) foo;
 533
 534         if ((flags & (SLAB_CTOR_VERIFY | SLAB_CTOR_CONSTRUCTOR)) ==
 535             SLAB_CTOR_CONSTRUCTOR)
 536                 inode_init_once(&ei->vfs_inode);
 537 }
 538
 539 static int init_inodecache(void)
 540 {
 541         qnx4_inode_cachep = kmem_cache_create("qnx4_inode_cache",
 542                                              sizeof(struct qnx4_inode_info),
 543                                              0, SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT,
 544                                              init_once, NULL);
 545         if (qnx4_inode_cachep == NULL)
 546                 return -ENOMEM;
 547         return 0;
 548 }
 549
 550 static void destroy_inodecache(void)
 551 {
 552         if (kmem_cache_destroy(qnx4_inode_cachep))
 553                 printk(KERN_INFO
 554                        "qnx4_inode_cache: not all structures were freed\n");
 555 }
 556
 557 static struct super_block *qnx4_get_sb(struct file_system_type *fs_type,
 558         int flags, const char *dev_name, void *data)
 559 {
 560         return get_sb_bdev(fs_type, flags, dev_name, data, qnx4_fill_super);
 561 }
 562
 563 static struct file_system_type qnx4_fs_type = {
 564         .owner          = THIS_MODULE,
 565         .name           = "qnx4",
 566         .get_sb         = qnx4_get_sb,
 567         .kill_sb        = kill_block_super,
 568         .fs_flags       = FS_REQUIRES_DEV,
 569 };
 570
 571 static int __init init_qnx4_fs(void)
 572 {
 573         int err;
 574
 575         err = init_inodecache();
 576         if (err)
 577                 return err;
 578
 579         err = register_filesystem(&qnx4_fs_type);
 580         if (err) {
 581                 destroy_inodecache();
 582                 return err;
 583         }
 584
 585         printk("QNX4 filesystem 0.2.3 registered.\n");
 586         return 0;
 587 }
 588
 589 static void __exit exit_qnx4_fs(void)
 590 {
 591         unregister_filesystem(&qnx4_fs_type);
 592         destroy_inodecache();
 593 }
 594
 595 module_init(init_qnx4_fs)
 596 module_exit(exit_qnx4_fs)
 597 MODULE_LICENSE("GPL");
 598