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         truncate_inode_pages(&inode->i_data, 0);
  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 int 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 0;
  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 -EIO;
  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 -EIO;
 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         return 0;
 122 }
 123
 124 #endif
 125
 126 static void qnx4_put_super(struct super_block *sb);
 127 static struct inode *qnx4_alloc_inode(struct super_block *sb);
 128 static void qnx4_destroy_inode(struct inode *inode);
 129 static void qnx4_read_inode(struct inode *);
 130 static int qnx4_remount(struct super_block *sb, int *flags, char *data);
 131 static int qnx4_statfs(struct super_block *, struct kstatfs *);
 132
 133 static struct super_operations qnx4_sops =
 134 {
 135         .alloc_inode    = qnx4_alloc_inode,
 136         .destroy_inode  = qnx4_destroy_inode,
 137         .read_inode     = qnx4_read_inode,
 138         .put_super      = qnx4_put_super,
 139         .statfs         = qnx4_statfs,
 140         .remount_fs     = qnx4_remount,
 141 #ifdef CONFIG_QNX4FS_RW
 142         .write_inode    = qnx4_write_inode,
 143         .delete_inode   = qnx4_delete_inode,
 144         .write_super    = qnx4_write_super,
 145 #endif
 146 };
 147
 148 static int qnx4_remount(struct super_block *sb, int *flags, char *data)
 149 {
 150         struct qnx4_sb_info *qs;
 151
 152         qs = qnx4_sb(sb);
 153         qs->Version = QNX4_VERSION;
 154 #ifndef CONFIG_QNX4FS_RW
 155         *flags |= MS_RDONLY;
 156 #endif
 157         if (*flags & MS_RDONLY) {
 158                 return 0;
 159         }
 160
 161         mark_buffer_dirty(qs->sb_buf);
 162
 163         return 0;
 164 }
 165
 166 static struct buffer_head *qnx4_getblk(struct inode *inode, int nr,
 167                                        int create)
 168 {
 169         struct buffer_head *result = NULL;
 170
 171         if ( nr >= 0 )
 172                 nr = qnx4_block_map( inode, nr );
 173         if (nr) {
 174                 result = sb_getblk(inode->i_sb, nr);
 175                 return result;
 176         }
 177         if (!create) {
 178                 return NULL;
 179         }
 180 #if 0
 181         tmp = qnx4_new_block(inode->i_sb);
 182         if (!tmp) {
 183                 return NULL;
 184         }
 185         result = sb_getblk(inode->i_sb, tmp);
 186         if (tst) {
 187                 qnx4_free_block(inode->i_sb, tmp);
 188                 brelse(result);
 189                 goto repeat;
 190         }
 191         tst = tmp;
 192 #endif
 193         inode->i_ctime = CURRENT_TIME_SEC;
 194         mark_inode_dirty(inode);
 195         return result;
 196 }
 197
 198 struct buffer_head *qnx4_bread(struct inode *inode, int block, int create)
 199 {
 200         struct buffer_head *bh;
 201
 202         bh = qnx4_getblk(inode, block, create);
 203         if (!bh || buffer_uptodate(bh)) {
 204                 return bh;
 205         }
 206         ll_rw_block(READ, 1, &bh);
 207         wait_on_buffer(bh);
 208         if (buffer_uptodate(bh)) {
 209                 return bh;
 210         }
 211         brelse(bh);
 212
 213         return NULL;
 214 }
 215
 216 static int qnx4_get_block( struct inode *inode, sector_t iblock, struct buffer_head *bh, int create )
 217 {
 218         unsigned long phys;
 219
 220         QNX4DEBUG(("qnx4: qnx4_get_block inode=[%ld] iblock=[%ld]\n",inode->i_ino,iblock));
 221
 222         phys = qnx4_block_map( inode, iblock );
 223         if ( phys ) {
 224                 // logical block is before EOF
 225                 map_bh(bh, inode->i_sb, phys);
 226         } else if ( create ) {
 227                 // to be done.
 228         }
 229         return 0;
 230 }
 231
 232 unsigned long qnx4_block_map( struct inode *inode, long iblock )
 233 {
 234         int ix;
 235         long offset, i_xblk;
 236         unsigned long block = 0;
 237         struct buffer_head *bh = NULL;
 238         struct qnx4_xblk *xblk = NULL;
 239         struct qnx4_inode_entry *qnx4_inode = qnx4_raw_inode(inode);
 240         u16 nxtnt = le16_to_cpu(qnx4_inode->di_num_xtnts);
 241
 242         if ( iblock < le32_to_cpu(qnx4_inode->di_first_xtnt.xtnt_size) ) {
 243                 // iblock is in the first extent. This is easy.
 244                 block = le32_to_cpu(qnx4_inode->di_first_xtnt.xtnt_blk) + iblock - 1;
 245         } else {
 246                 // iblock is beyond first extent. We have to follow the extent chain.
 247                 i_xblk = le32_to_cpu(qnx4_inode->di_xblk);
 248                 offset = iblock - le32_to_cpu(qnx4_inode->di_first_xtnt.xtnt_size);
 249                 ix = 0;
 250                 while ( --nxtnt > 0 ) {
 251                         if ( ix == 0 ) {
 252                                 // read next xtnt block.
 253                                 bh = sb_bread(inode->i_sb, i_xblk - 1);
 254                                 if ( !bh ) {
 255                                         QNX4DEBUG(("qnx4: I/O error reading xtnt block [%ld])\n", i_xblk - 1));
 256                                         return -EIO;
 257                                 }
 258                                 xblk = (struct qnx4_xblk*)bh->b_data;
 259                                 if ( memcmp( xblk->xblk_signature, "IamXblk", 7 ) ) {
 260                                         QNX4DEBUG(("qnx4: block at %ld is not a valid xtnt\n", qnx4_inode->i_xblk));
 261                                         return -EIO;
 262                                 }
 263                         }
 264                         if ( offset < le32_to_cpu(xblk->xblk_xtnts[ix].xtnt_size) ) {
 265                                 // got it!
 266                                 block = le32_to_cpu(xblk->xblk_xtnts[ix].xtnt_blk) + offset - 1;
 267                                 break;
 268                         }
 269                         offset -= le32_to_cpu(xblk->xblk_xtnts[ix].xtnt_size);
 270                         if ( ++ix >= xblk->xblk_num_xtnts ) {
 271                                 i_xblk = le32_to_cpu(xblk->xblk_next_xblk);
 272                                 ix = 0;
 273                                 brelse( bh );
 274                                 bh = NULL;
 275                         }
 276                 }
 277                 if ( bh )
 278                         brelse( bh );
 279         }
 280
 281         QNX4DEBUG(("qnx4: mapping block %ld of inode %ld = %ld\n",iblock,inode->i_ino,block));
 282         return block;
 283 }
 284
 285 static int qnx4_statfs(struct super_block *sb, struct kstatfs *buf)
 286 {
 287         lock_kernel();
 288
 289         buf->f_type    = sb->s_magic;
 290         buf->f_bsize   = sb->s_blocksize;
 291         buf->f_blocks  = le32_to_cpu(qnx4_sb(sb)->BitMap->di_size) * 8;
 292         buf->f_bfree   = qnx4_count_free_blocks(sb);
 293         buf->f_bavail  = buf->f_bfree;
 294         buf->f_namelen = QNX4_NAME_MAX;
 295
 296         unlock_kernel();
 297
 298         return 0;
 299 }
 300
 301 /*
 302  * Check the root directory of the filesystem to make sure
 303  * it really _is_ a qnx4 filesystem, and to check the size
 304  * of the directory entry.
 305  */
 306 static const char *qnx4_checkroot(struct super_block *sb)
 307 {
 308         struct buffer_head *bh;
 309         struct qnx4_inode_entry *rootdir;
 310         int rd, rl;
 311         int i, j;
 312         int found = 0;
 313
 314         if (*(qnx4_sb(sb)->sb->RootDir.di_fname) != '/') {
 315                 return "no qnx4 filesystem (no root dir).";
 316         } else {
 317                 QNX4DEBUG(("QNX4 filesystem found on dev %s.\n", sb->s_id));
 318                 rd = le32_to_cpu(qnx4_sb(sb)->sb->RootDir.di_first_xtnt.xtnt_blk) - 1;
 319                 rl = le32_to_cpu(qnx4_sb(sb)->sb->RootDir.di_first_xtnt.xtnt_size);
 320                 for (j = 0; j < rl; j++) {
 321                         bh = sb_bread(sb, rd + j);      /* root dir, first block */
 322                         if (bh == NULL) {
 323                                 return "unable to read root entry.";
 324                         }
 325                         for (i = 0; i < QNX4_INODES_PER_BLOCK; i++) {
 326                                 rootdir = (struct qnx4_inode_entry *) (bh->b_data + i * QNX4_DIR_ENTRY_SIZE);
 327                                 if (rootdir->di_fname != NULL) {
 328                                         QNX4DEBUG(("Rootdir entry found : [%s]\n", rootdir->di_fname));
 329                                         if (!strncmp(rootdir->di_fname, QNX4_BMNAME, sizeof QNX4_BMNAME)) {
 330                                                 found = 1;
 331                                                 qnx4_sb(sb)->BitMap = kmalloc( sizeof( struct qnx4_inode_entry ), GFP_KERNEL );
 332                                                 if (!qnx4_sb(sb)->BitMap) {
 333                                                         brelse (bh);
 334                                                         return "not enough memory for bitmap inode";
 335                                                 }
 336                                                 memcpy( qnx4_sb(sb)->BitMap, rootdir, sizeof( struct qnx4_inode_entry ) );      /* keep bitmap inode known */
 337                                                 break;
 338                                         }
 339                                 }
 340                         }
 341                         brelse(bh);
 342                         if (found != 0) {
 343                                 break;
 344                         }
 345                 }
 346                 if (found == 0) {
 347                         return "bitmap file not found.";
 348                 }
 349         }
 350         return NULL;
 351 }
 352
 353 static int qnx4_fill_super(struct super_block *s, void *data, int silent)
 354 {
 355         struct buffer_head *bh;
 356         struct inode *root;
 357         const char *errmsg;
 358         struct qnx4_sb_info *qs;
 359
 360         qs = kmalloc(sizeof(struct qnx4_sb_info), GFP_KERNEL);
 361         if (!qs)
 362                 return -ENOMEM;
 363         s->s_fs_info = qs;
 364         memset(qs, 0, sizeof(struct qnx4_sb_info));
 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 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         inode->i_blksize = QNX4_DIR_ENTRY_SIZE;
 500
 501         memcpy(qnx4_inode, raw_inode, QNX4_DIR_ENTRY_SIZE);
 502         if (S_ISREG(inode->i_mode)) {
 503                 inode->i_op = &qnx4_file_inode_operations;
 504                 inode->i_fop = &qnx4_file_operations;
 505                 inode->i_mapping->a_ops = &qnx4_aops;
 506                 qnx4_i(inode)->mmu_private = inode->i_size;
 507         } else if (S_ISDIR(inode->i_mode)) {
 508                 inode->i_op = &qnx4_dir_inode_operations;
 509                 inode->i_fop = &qnx4_dir_operations;
 510         } else if (S_ISLNK(inode->i_mode)) {
 511                 inode->i_op = &page_symlink_inode_operations;
 512                 inode->i_mapping->a_ops = &qnx4_aops;
 513                 qnx4_i(inode)->mmu_private = inode->i_size;
 514         } else
 515                 printk("qnx4: bad inode %d on dev %s\n",ino,sb->s_id);
 516         brelse(bh);
 517 }
 518
 519 static kmem_cache_t *qnx4_inode_cachep;
 520
 521 static struct inode *qnx4_alloc_inode(struct super_block *sb)
 522 {
 523         struct qnx4_inode_info *ei;
 524         ei = kmem_cache_alloc(qnx4_inode_cachep, SLAB_KERNEL);
 525         if (!ei)
 526                 return NULL;
 527         return &ei->vfs_inode;
 528 }
 529
 530 static void qnx4_destroy_inode(struct inode *inode)
 531 {
 532         kmem_cache_free(qnx4_inode_cachep, qnx4_i(inode));
 533 }
 534
 535 static void init_once(void *foo, kmem_cache_t * cachep,
 536                       unsigned long flags)
 537 {
 538         struct qnx4_inode_info *ei = (struct qnx4_inode_info *) foo;
 539
 540         if ((flags & (SLAB_CTOR_VERIFY | SLAB_CTOR_CONSTRUCTOR)) ==
 541             SLAB_CTOR_CONSTRUCTOR)
 542                 inode_init_once(&ei->vfs_inode);
 543 }
 544
 545 static int init_inodecache(void)
 546 {
 547         qnx4_inode_cachep = kmem_cache_create("qnx4_inode_cache",
 548                                              sizeof(struct qnx4_inode_info),
 549                                              0, SLAB_RECLAIM_ACCOUNT,
 550                                              init_once, NULL);
 551         if (qnx4_inode_cachep == NULL)
 552                 return -ENOMEM;
 553         return 0;
 554 }
 555
 556 static void destroy_inodecache(void)
 557 {
 558         if (kmem_cache_destroy(qnx4_inode_cachep))
 559                 printk(KERN_INFO
 560                        "qnx4_inode_cache: not all structures were freed\n");
 561 }
 562
 563 static struct super_block *qnx4_get_sb(struct file_system_type *fs_type,
 564         int flags, const char *dev_name, void *data)
 565 {
 566         return get_sb_bdev(fs_type, flags, dev_name, data, qnx4_fill_super);
 567 }
 568
 569 static struct file_system_type qnx4_fs_type = {
 570         .owner          = THIS_MODULE,
 571         .name           = "qnx4",
 572         .get_sb         = qnx4_get_sb,
 573         .kill_sb        = kill_block_super,
 574         .fs_flags       = FS_REQUIRES_DEV,
 575 };
 576
 577 static int __init init_qnx4_fs(void)
 578 {
 579         int err;
 580
 581         err = init_inodecache();
 582         if (err)
 583                 return err;
 584
 585         err = register_filesystem(&qnx4_fs_type);
 586         if (err) {
 587                 destroy_inodecache();
 588                 return err;
 589         }
 590
 591         printk("QNX4 filesystem 0.2.3 registered.\n");
 592         return 0;
 593 }
 594
 595 static void __exit exit_qnx4_fs(void)
 596 {
 597         unregister_filesystem(&qnx4_fs_type);
 598         destroy_inodecache();
 599 }
 600
 601 module_init(init_qnx4_fs)
 602 module_exit(exit_qnx4_fs)
 603 MODULE_LICENSE("GPL");
 604