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/module.h>
  16 #include <linux/types.h>
  17 #include <linux/string.h>
  18 #include <linux/errno.h>
  19 #include <linux/slab.h>
  20 #include <linux/fs.h>
  21 #include <linux/qnx4_fs.h>
  22 #include <linux/init.h>
  23 #include <linux/highuid.h>
  24 #include <linux/smp_lock.h>
  25 #include <linux/pagemap.h>
  26 #include <linux/buffer_head.h>
  27 #include <linux/vfs.h>
  28 #include <asm/uaccess.h>
  29
  30 #define QNX4_VERSION  4
  31 #define QNX4_BMNAME   ".bitmap"
  32
  33 static const struct super_operations qnx4_sops;
  34
  35 #ifdef CONFIG_QNX4FS_RW
  36
  37 int qnx4_sync_inode(struct inode *inode)
  38 {
  39         int err = 0;
  40 # if 0
  41         struct buffer_head *bh;
  42
  43         bh = qnx4_update_inode(inode);
  44         if (bh && buffer_dirty(bh))
  45         {
  46                 sync_dirty_buffer(bh);
  47                 if (buffer_req(bh) && !buffer_uptodate(bh))
  48                 {
  49                         printk ("IO error syncing qnx4 inode [%s:%08lx]\n",
  50                                 inode->i_sb->s_id, inode->i_ino);
  51                         err = -1;
  52                 }
  53                 brelse (bh);
  54         } else if (!bh) {
  55                 err = -1;
  56         }
  57 # endif
  58
  59         return err;
  60 }
  61
  62 static void qnx4_delete_inode(struct inode *inode)
  63 {
  64         QNX4DEBUG(("qnx4: deleting inode [%lu]\n", (unsigned long) inode->i_ino));
  65         truncate_inode_pages(&inode->i_data, 0);
  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 int 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 0;
  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 -EIO;
  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 -EIO;
 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         return 0;
 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 dentry *, struct kstatfs *);
 131
 132 static const 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 #ifndef CONFIG_QNX4FS_RW
 154         *flags |= MS_RDONLY;
 155 #endif
 156         if (*flags & MS_RDONLY) {
 157                 return 0;
 158         }
 159
 160         mark_buffer_dirty(qs->sb_buf);
 161
 162         return 0;
 163 }
 164
 165 static struct buffer_head *qnx4_getblk(struct inode *inode, int nr,
 166                                        int create)
 167 {
 168         struct buffer_head *result = NULL;
 169
 170         if ( nr >= 0 )
 171                 nr = qnx4_block_map( inode, nr );
 172         if (nr) {
 173                 result = sb_getblk(inode->i_sb, nr);
 174                 return result;
 175         }
 176         if (!create) {
 177                 return NULL;
 178         }
 179 #if 0
 180         tmp = qnx4_new_block(inode->i_sb);
 181         if (!tmp) {
 182                 return NULL;
 183         }
 184         result = sb_getblk(inode->i_sb, tmp);
 185         if (tst) {
 186                 qnx4_free_block(inode->i_sb, tmp);
 187                 brelse(result);
 188                 goto repeat;
 189         }
 190         tst = tmp;
 191 #endif
 192         inode->i_ctime = CURRENT_TIME_SEC;
 193         mark_inode_dirty(inode);
 194         return result;
 195 }
 196
 197 struct buffer_head *qnx4_bread(struct inode *inode, int block, int create)
 198 {
 199         struct buffer_head *bh;
 200
 201         bh = qnx4_getblk(inode, block, create);
 202         if (!bh || buffer_uptodate(bh)) {
 203                 return bh;
 204         }
 205         ll_rw_block(READ, 1, &bh);
 206         wait_on_buffer(bh);
 207         if (buffer_uptodate(bh)) {
 208                 return bh;
 209         }
 210         brelse(bh);
 211
 212         return NULL;
 213 }
 214
 215 static int qnx4_get_block( struct inode *inode, sector_t iblock, struct buffer_head *bh, int create )
 216 {
 217         unsigned long phys;
 218
 219         QNX4DEBUG(("qnx4: qnx4_get_block inode=[%ld] iblock=[%ld]\n",inode->i_ino,iblock));
 220
 221         phys = qnx4_block_map( inode, iblock );
 222         if ( phys ) {
 223                 // logical block is before EOF
 224                 map_bh(bh, inode->i_sb, phys);
 225         } else if ( create ) {
 226                 // to be done.
 227         }
 228         return 0;
 229 }
 230
 231 unsigned long qnx4_block_map( struct inode *inode, long iblock )
 232 {
 233         int ix;
 234         long offset, i_xblk;
 235         unsigned long block = 0;
 236         struct buffer_head *bh = NULL;
 237         struct qnx4_xblk *xblk = NULL;
 238         struct qnx4_inode_entry *qnx4_inode = qnx4_raw_inode(inode);
 239         u16 nxtnt = le16_to_cpu(qnx4_inode->di_num_xtnts);
 240
 241         if ( iblock < le32_to_cpu(qnx4_inode->di_first_xtnt.xtnt_size) ) {
 242                 // iblock is in the first extent. This is easy.
 243                 block = le32_to_cpu(qnx4_inode->di_first_xtnt.xtnt_blk) + iblock - 1;
 244         } else {
 245                 // iblock is beyond first extent. We have to follow the extent chain.
 246                 i_xblk = le32_to_cpu(qnx4_inode->di_xblk);
 247                 offset = iblock - le32_to_cpu(qnx4_inode->di_first_xtnt.xtnt_size);
 248                 ix = 0;
 249                 while ( --nxtnt > 0 ) {
 250                         if ( ix == 0 ) {
 251                                 // read next xtnt block.
 252                                 bh = sb_bread(inode->i_sb, i_xblk - 1);
 253                                 if ( !bh ) {
 254                                         QNX4DEBUG(("qnx4: I/O error reading xtnt block [%ld])\n", i_xblk - 1));
 255                                         return -EIO;
 256                                 }
 257                                 xblk = (struct qnx4_xblk*)bh->b_data;
 258                                 if ( memcmp( xblk->xblk_signature, "IamXblk", 7 ) ) {
 259                                         QNX4DEBUG(("qnx4: block at %ld is not a valid xtnt\n", qnx4_inode->i_xblk));
 260                                         return -EIO;
 261                                 }
 262                         }
 263                         if ( offset < le32_to_cpu(xblk->xblk_xtnts[ix].xtnt_size) ) {
 264                                 // got it!
 265                                 block = le32_to_cpu(xblk->xblk_xtnts[ix].xtnt_blk) + offset - 1;
 266                                 break;
 267                         }
 268                         offset -= le32_to_cpu(xblk->xblk_xtnts[ix].xtnt_size);
 269                         if ( ++ix >= xblk->xblk_num_xtnts ) {
 270                                 i_xblk = le32_to_cpu(xblk->xblk_next_xblk);
 271                                 ix = 0;
 272                                 brelse( bh );
 273                                 bh = NULL;
 274                         }
 275                 }
 276                 if ( bh )
 277                         brelse( bh );
 278         }
 279
 280         QNX4DEBUG(("qnx4: mapping block %ld of inode %ld = %ld\n",iblock,inode->i_ino,block));
 281         return block;
 282 }
 283
 284 static int qnx4_statfs(struct dentry *dentry, struct kstatfs *buf)
 285 {
 286         struct super_block *sb = dentry->d_sb;
 287
 288         lock_kernel();
 289
 290         buf->f_type    = sb->s_magic;
 291         buf->f_bsize   = sb->s_blocksize;
 292         buf->f_blocks  = le32_to_cpu(qnx4_sb(sb)->BitMap->di_size) * 8;
 293         buf->f_bfree   = qnx4_count_free_blocks(sb);
 294         buf->f_bavail  = buf->f_bfree;
 295         buf->f_namelen = QNX4_NAME_MAX;
 296
 297         unlock_kernel();
 298
 299         return 0;
 300 }
 301
 302 /*
 303  * Check the root directory of the filesystem to make sure
 304  * it really _is_ a qnx4 filesystem, and to check the size
 305  * of the directory entry.
 306  */
 307 static const char *qnx4_checkroot(struct super_block *sb)
 308 {
 309         struct buffer_head *bh;
 310         struct qnx4_inode_entry *rootdir;
 311         int rd, rl;
 312         int i, j;
 313         int found = 0;
 314
 315         if (*(qnx4_sb(sb)->sb->RootDir.di_fname) != '/') {
 316                 return "no qnx4 filesystem (no root dir).";
 317         } else {
 318                 QNX4DEBUG(("QNX4 filesystem found on dev %s.\n", sb->s_id));
 319                 rd = le32_to_cpu(qnx4_sb(sb)->sb->RootDir.di_first_xtnt.xtnt_blk) - 1;
 320                 rl = le32_to_cpu(qnx4_sb(sb)->sb->RootDir.di_first_xtnt.xtnt_size);
 321                 for (j = 0; j < rl; j++) {
 322                         bh = sb_bread(sb, rd + j);      /* root dir, first block */
 323                         if (bh == NULL) {
 324                                 return "unable to read root entry.";
 325                         }
 326                         for (i = 0; i < QNX4_INODES_PER_BLOCK; i++) {
 327                                 rootdir = (struct qnx4_inode_entry *) (bh->b_data + i * QNX4_DIR_ENTRY_SIZE);
 328                                 if (rootdir->di_fname != NULL) {
 329                                         QNX4DEBUG(("Rootdir entry found : [%s]\n", rootdir->di_fname));
 330                                         if (!strncmp(rootdir->di_fname, QNX4_BMNAME, sizeof QNX4_BMNAME)) {
 331                                                 found = 1;
 332                                                 qnx4_sb(sb)->BitMap = kmalloc( sizeof( struct qnx4_inode_entry ), GFP_KERNEL );
 333                                                 if (!qnx4_sb(sb)->BitMap) {
 334                                                         brelse (bh);
 335                                                         return "not enough memory for bitmap inode";
 336                                                 }
 337                                                 memcpy( qnx4_sb(sb)->BitMap, rootdir, sizeof( struct qnx4_inode_entry ) );      /* keep bitmap inode known */
 338                                                 break;
 339                                         }
 340                                 }
 341                         }
 342                         brelse(bh);
 343                         if (found != 0) {
 344                                 break;
 345                         }
 346                 }
 347                 if (found == 0) {
 348                         return "bitmap file not found.";
 349                 }
 350         }
 351         return NULL;
 352 }
 353
 354 static int qnx4_fill_super(struct super_block *s, void *data, int silent)
 355 {
 356         struct buffer_head *bh;
 357         struct inode *root;
 358         const char *errmsg;
 359         struct qnx4_sb_info *qs;
 360
 361         qs = kzalloc(sizeof(struct qnx4_sb_info), GFP_KERNEL);
 362         if (!qs)
 363                 return -ENOMEM;
 364         s->s_fs_info = qs;
 365
 366         sb_set_blocksize(s, QNX4_BLOCK_SIZE);
 367
 368         /* Check the superblock signature. Since the qnx4 code is
 369            dangerous, we should leave as quickly as possible
 370            if we don't belong here... */
 371         bh = sb_bread(s, 1);
 372         if (!bh) {
 373                 printk("qnx4: unable to read the superblock\n");
 374                 goto outnobh;
 375         }
 376         if ( le32_to_cpup((__le32*) bh->b_data) != QNX4_SUPER_MAGIC ) {
 377                 if (!silent)
 378                         printk("qnx4: wrong fsid in superblock.\n");
 379                 goto out;
 380         }
 381         s->s_op = &qnx4_sops;
 382         s->s_magic = QNX4_SUPER_MAGIC;
 383 #ifndef CONFIG_QNX4FS_RW
 384         s->s_flags |= MS_RDONLY;        /* Yup, read-only yet */
 385 #endif
 386         qnx4_sb(s)->sb_buf = bh;
 387         qnx4_sb(s)->sb = (struct qnx4_super_block *) bh->b_data;
 388
 389
 390         /* check before allocating dentries, inodes, .. */
 391         errmsg = qnx4_checkroot(s);
 392         if (errmsg != NULL) {
 393                 if (!silent)
 394                         printk("qnx4: %s\n", errmsg);
 395                 goto out;
 396         }
 397
 398         /* does root not have inode number QNX4_ROOT_INO ?? */
 399         root = iget(s, QNX4_ROOT_INO * QNX4_INODES_PER_BLOCK);
 400         if (!root) {
 401                 printk("qnx4: get inode failed\n");
 402                 goto out;
 403         }
 404
 405         s->s_root = d_alloc_root(root);
 406         if (s->s_root == NULL)
 407                 goto outi;
 408
 409         brelse(bh);
 410
 411         return 0;
 412
 413       outi:
 414         iput(root);
 415       out:
 416         brelse(bh);
 417       outnobh:
 418         kfree(qs);
 419         s->s_fs_info = NULL;
 420         return -EINVAL;
 421 }
 422
 423 static void qnx4_put_super(struct super_block *sb)
 424 {
 425         struct qnx4_sb_info *qs = qnx4_sb(sb);
 426         kfree( qs->BitMap );
 427         kfree( qs );
 428         sb->s_fs_info = NULL;
 429         return;
 430 }
 431
 432 static int qnx4_writepage(struct page *page, struct writeback_control *wbc)
 433 {
 434         return block_write_full_page(page,qnx4_get_block, wbc);
 435 }
 436 static int qnx4_readpage(struct file *file, struct page *page)
 437 {
 438         return block_read_full_page(page,qnx4_get_block);
 439 }
 440 static int qnx4_prepare_write(struct file *file, struct page *page,
 441                               unsigned from, unsigned to)
 442 {
 443         struct qnx4_inode_info *qnx4_inode = qnx4_i(page->mapping->host);
 444         return cont_prepare_write(page, from, to, qnx4_get_block,
 445                                   &qnx4_inode->mmu_private);
 446 }
 447 static sector_t qnx4_bmap(struct address_space *mapping, sector_t block)
 448 {
 449         return generic_block_bmap(mapping,block,qnx4_get_block);
 450 }
 451 static const struct address_space_operations qnx4_aops = {
 452         .readpage       = qnx4_readpage,
 453         .writepage      = qnx4_writepage,
 454         .sync_page      = block_sync_page,
 455         .prepare_write  = qnx4_prepare_write,
 456         .commit_write   = generic_commit_write,
 457         .bmap           = qnx4_bmap
 458 };
 459
 460 static void qnx4_read_inode(struct inode *inode)
 461 {
 462         struct buffer_head *bh;
 463         struct qnx4_inode_entry *raw_inode;
 464         int block, ino;
 465         struct super_block *sb = inode->i_sb;
 466         struct qnx4_inode_entry *qnx4_inode = qnx4_raw_inode(inode);
 467
 468         ino = inode->i_ino;
 469         inode->i_mode = 0;
 470
 471         QNX4DEBUG(("Reading inode : [%d]\n", ino));
 472         if (!ino) {
 473                 printk("qnx4: bad inode number on dev %s: %d is out of range\n",
 474                        sb->s_id, ino);
 475                 return;
 476         }
 477         block = ino / QNX4_INODES_PER_BLOCK;
 478
 479         if (!(bh = sb_bread(sb, block))) {
 480                 printk("qnx4: major problem: unable to read inode from dev "
 481                        "%s\n", sb->s_id);
 482                 return;
 483         }
 484         raw_inode = ((struct qnx4_inode_entry *) bh->b_data) +
 485             (ino % QNX4_INODES_PER_BLOCK);
 486
 487         inode->i_mode    = le16_to_cpu(raw_inode->di_mode);
 488         inode->i_uid     = (uid_t)le16_to_cpu(raw_inode->di_uid);
 489         inode->i_gid     = (gid_t)le16_to_cpu(raw_inode->di_gid);
 490         inode->i_nlink   = le16_to_cpu(raw_inode->di_nlink);
 491         inode->i_size    = le32_to_cpu(raw_inode->di_size);
 492         inode->i_mtime.tv_sec   = le32_to_cpu(raw_inode->di_mtime);
 493         inode->i_mtime.tv_nsec = 0;
 494         inode->i_atime.tv_sec   = le32_to_cpu(raw_inode->di_atime);
 495         inode->i_atime.tv_nsec = 0;
 496         inode->i_ctime.tv_sec   = le32_to_cpu(raw_inode->di_ctime);
 497         inode->i_ctime.tv_nsec = 0;
 498         inode->i_blocks  = le32_to_cpu(raw_inode->di_first_xtnt.xtnt_size);
 499
 500         memcpy(qnx4_inode, raw_inode, QNX4_DIR_ENTRY_SIZE);
 501         if (S_ISREG(inode->i_mode)) {
 502                 inode->i_op = &qnx4_file_inode_operations;
 503                 inode->i_fop = &qnx4_file_operations;
 504                 inode->i_mapping->a_ops = &qnx4_aops;
 505                 qnx4_i(inode)->mmu_private = inode->i_size;
 506         } else if (S_ISDIR(inode->i_mode)) {
 507                 inode->i_op = &qnx4_dir_inode_operations;
 508                 inode->i_fop = &qnx4_dir_operations;
 509         } else if (S_ISLNK(inode->i_mode)) {
 510                 inode->i_op = &page_symlink_inode_operations;
 511                 inode->i_mapping->a_ops = &qnx4_aops;
 512                 qnx4_i(inode)->mmu_private = inode->i_size;
 513         } else
 514                 printk("qnx4: bad inode %d on dev %s\n",ino,sb->s_id);
 515         brelse(bh);
 516 }
 517
 518 static struct kmem_cache *qnx4_inode_cachep;
 519
 520 static struct inode *qnx4_alloc_inode(struct super_block *sb)
 521 {
 522         struct qnx4_inode_info *ei;
 523         ei = kmem_cache_alloc(qnx4_inode_cachep, GFP_KERNEL);
 524         if (!ei)
 525                 return NULL;
 526         return &ei->vfs_inode;
 527 }
 528
 529 static void qnx4_destroy_inode(struct inode *inode)
 530 {
 531         kmem_cache_free(qnx4_inode_cachep, qnx4_i(inode));
 532 }
 533
 534 static void init_once(void *foo, struct kmem_cache * cachep,
 535                       unsigned long flags)
 536 {
 537         struct qnx4_inode_info *ei = (struct qnx4_inode_info *) foo;
 538
 539         if (flags & 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_RECLAIM_ACCOUNT|
 548                                                 SLAB_MEM_SPREAD),
 549                                              init_once, NULL);
 550         if (qnx4_inode_cachep == NULL)
 551                 return -ENOMEM;
 552         return 0;
 553 }
 554
 555 static void destroy_inodecache(void)
 556 {
 557         kmem_cache_destroy(qnx4_inode_cachep);
 558 }
 559
 560 static int qnx4_get_sb(struct file_system_type *fs_type,
 561         int flags, const char *dev_name, void *data, struct vfsmount *mnt)
 562 {
 563         return get_sb_bdev(fs_type, flags, dev_name, data, qnx4_fill_super,
 564                            mnt);
 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