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/init.h>
  17 #include <linux/slab.h>
  18 #include <linux/highuid.h>
  19 #include <linux/smp_lock.h>
  20 #include <linux/pagemap.h>
  21 #include <linux/buffer_head.h>
  22 #include <linux/writeback.h>
  23 #include <linux/statfs.h>
  24 #include "qnx4.h"
  25
  26 #define QNX4_VERSION  4
  27 #define QNX4_BMNAME   ".bitmap"
  28
  29 static const struct super_operations qnx4_sops;
  30
  31 #ifdef CONFIG_QNX4FS_RW
  32
  33 static void qnx4_delete_inode(struct inode *inode)
  34 {
  35         QNX4DEBUG(("qnx4: deleting inode [%lu]\n", (unsigned long) inode->i_ino));
  36         truncate_inode_pages(&inode->i_data, 0);
  37         inode->i_size = 0;
  38         qnx4_truncate(inode);
  39         lock_kernel();
  40         qnx4_free_inode(inode);
  41         unlock_kernel();
  42 }
  43
  44 static int qnx4_write_inode(struct inode *inode, int do_sync)
  45 {
  46         struct qnx4_inode_entry *raw_inode;
  47         int block, ino;
  48         struct buffer_head *bh;
  49         ino = inode->i_ino;
  50
  51         QNX4DEBUG(("qnx4: write inode 1.\n"));
  52         if (inode->i_nlink == 0) {
  53                 return 0;
  54         }
  55         if (!ino) {
  56                 printk("qnx4: bad inode number on dev %s: %d is out of range\n",
  57                        inode->i_sb->s_id, ino);
  58                 return -EIO;
  59         }
  60         QNX4DEBUG(("qnx4: write inode 2.\n"));
  61         block = ino / QNX4_INODES_PER_BLOCK;
  62         lock_kernel();
  63         if (!(bh = sb_bread(inode->i_sb, block))) {
  64                 printk("qnx4: major problem: unable to read inode from dev "
  65                        "%s\n", inode->i_sb->s_id);
  66                 unlock_kernel();
  67                 return -EIO;
  68         }
  69         raw_inode = ((struct qnx4_inode_entry *) bh->b_data) +
  70             (ino % QNX4_INODES_PER_BLOCK);
  71         raw_inode->di_mode  = cpu_to_le16(inode->i_mode);
  72         raw_inode->di_uid   = cpu_to_le16(fs_high2lowuid(inode->i_uid));
  73         raw_inode->di_gid   = cpu_to_le16(fs_high2lowgid(inode->i_gid));
  74         raw_inode->di_nlink = cpu_to_le16(inode->i_nlink);
  75         raw_inode->di_size  = cpu_to_le32(inode->i_size);
  76         raw_inode->di_mtime = cpu_to_le32(inode->i_mtime.tv_sec);
  77         raw_inode->di_atime = cpu_to_le32(inode->i_atime.tv_sec);
  78         raw_inode->di_ctime = cpu_to_le32(inode->i_ctime.tv_sec);
  79         raw_inode->di_first_xtnt.xtnt_size = cpu_to_le32(inode->i_blocks);
  80         mark_buffer_dirty(bh);
  81         if (do_sync) {
  82                 sync_dirty_buffer(bh);
  83                 if (buffer_req(bh) && !buffer_uptodate(bh)) {
  84                         printk("qnx4: IO error syncing inode [%s:%08x]\n",
  85                                         inode->i_sb->s_id, ino);
  86                         brelse(bh);
  87                         unlock_kernel();
  88                         return -EIO;
  89                 }
  90         }
  91         brelse(bh);
  92         unlock_kernel();
  93         return 0;
  94 }
  95
  96 #endif
  97
  98 static void qnx4_put_super(struct super_block *sb);
  99 static struct inode *qnx4_alloc_inode(struct super_block *sb);
 100 static void qnx4_destroy_inode(struct inode *inode);
 101 static int qnx4_remount(struct super_block *sb, int *flags, char *data);
 102 static int qnx4_statfs(struct dentry *, struct kstatfs *);
 103
 104 static const struct super_operations qnx4_sops =
 105 {
 106         .alloc_inode    = qnx4_alloc_inode,
 107         .destroy_inode  = qnx4_destroy_inode,
 108         .put_super      = qnx4_put_super,
 109         .statfs         = qnx4_statfs,
 110         .remount_fs     = qnx4_remount,
 111 #ifdef CONFIG_QNX4FS_RW
 112         .write_inode    = qnx4_write_inode,
 113         .delete_inode   = qnx4_delete_inode,
 114 #endif
 115 };
 116
 117 static int qnx4_remount(struct super_block *sb, int *flags, char *data)
 118 {
 119         struct qnx4_sb_info *qs;
 120
 121         qs = qnx4_sb(sb);
 122         qs->Version = QNX4_VERSION;
 123 #ifndef CONFIG_QNX4FS_RW
 124         *flags |= MS_RDONLY;
 125 #endif
 126         if (*flags & MS_RDONLY) {
 127                 return 0;
 128         }
 129
 130         mark_buffer_dirty(qs->sb_buf);
 131
 132         return 0;
 133 }
 134
 135 static struct buffer_head *qnx4_getblk(struct inode *inode, int nr,
 136                                        int create)
 137 {
 138         struct buffer_head *result = NULL;
 139
 140         if ( nr >= 0 )
 141                 nr = qnx4_block_map( inode, nr );
 142         if (nr) {
 143                 result = sb_getblk(inode->i_sb, nr);
 144                 return result;
 145         }
 146         if (!create) {
 147                 return NULL;
 148         }
 149 #if 0
 150         tmp = qnx4_new_block(inode->i_sb);
 151         if (!tmp) {
 152                 return NULL;
 153         }
 154         result = sb_getblk(inode->i_sb, tmp);
 155         if (tst) {
 156                 qnx4_free_block(inode->i_sb, tmp);
 157                 brelse(result);
 158                 goto repeat;
 159         }
 160         tst = tmp;
 161 #endif
 162         inode->i_ctime = CURRENT_TIME_SEC;
 163         mark_inode_dirty(inode);
 164         return result;
 165 }
 166
 167 struct buffer_head *qnx4_bread(struct inode *inode, int block, int create)
 168 {
 169         struct buffer_head *bh;
 170
 171         bh = qnx4_getblk(inode, block, create);
 172         if (!bh || buffer_uptodate(bh)) {
 173                 return bh;
 174         }
 175         ll_rw_block(READ, 1, &bh);
 176         wait_on_buffer(bh);
 177         if (buffer_uptodate(bh)) {
 178                 return bh;
 179         }
 180         brelse(bh);
 181
 182         return NULL;
 183 }
 184
 185 static int qnx4_get_block( struct inode *inode, sector_t iblock, struct buffer_head *bh, int create )
 186 {
 187         unsigned long phys;
 188
 189         QNX4DEBUG(("qnx4: qnx4_get_block inode=[%ld] iblock=[%ld]\n",inode->i_ino,iblock));
 190
 191         phys = qnx4_block_map( inode, iblock );
 192         if ( phys ) {
 193                 // logical block is before EOF
 194                 map_bh(bh, inode->i_sb, phys);
 195         } else if ( create ) {
 196                 // to be done.
 197         }
 198         return 0;
 199 }
 200
 201 unsigned long qnx4_block_map( struct inode *inode, long iblock )
 202 {
 203         int ix;
 204         long offset, i_xblk;
 205         unsigned long block = 0;
 206         struct buffer_head *bh = NULL;
 207         struct qnx4_xblk *xblk = NULL;
 208         struct qnx4_inode_entry *qnx4_inode = qnx4_raw_inode(inode);
 209         u16 nxtnt = le16_to_cpu(qnx4_inode->di_num_xtnts);
 210
 211         if ( iblock < le32_to_cpu(qnx4_inode->di_first_xtnt.xtnt_size) ) {
 212                 // iblock is in the first extent. This is easy.
 213                 block = le32_to_cpu(qnx4_inode->di_first_xtnt.xtnt_blk) + iblock - 1;
 214         } else {
 215                 // iblock is beyond first extent. We have to follow the extent chain.
 216                 i_xblk = le32_to_cpu(qnx4_inode->di_xblk);
 217                 offset = iblock - le32_to_cpu(qnx4_inode->di_first_xtnt.xtnt_size);
 218                 ix = 0;
 219                 while ( --nxtnt > 0 ) {
 220                         if ( ix == 0 ) {
 221                                 // read next xtnt block.
 222                                 bh = sb_bread(inode->i_sb, i_xblk - 1);
 223                                 if ( !bh ) {
 224                                         QNX4DEBUG(("qnx4: I/O error reading xtnt block [%ld])\n", i_xblk - 1));
 225                                         return -EIO;
 226                                 }
 227                                 xblk = (struct qnx4_xblk*)bh->b_data;
 228                                 if ( memcmp( xblk->xblk_signature, "IamXblk", 7 ) ) {
 229                                         QNX4DEBUG(("qnx4: block at %ld is not a valid xtnt\n", qnx4_inode->i_xblk));
 230                                         return -EIO;
 231                                 }
 232                         }
 233                         if ( offset < le32_to_cpu(xblk->xblk_xtnts[ix].xtnt_size) ) {
 234                                 // got it!
 235                                 block = le32_to_cpu(xblk->xblk_xtnts[ix].xtnt_blk) + offset - 1;
 236                                 break;
 237                         }
 238                         offset -= le32_to_cpu(xblk->xblk_xtnts[ix].xtnt_size);
 239                         if ( ++ix >= xblk->xblk_num_xtnts ) {
 240                                 i_xblk = le32_to_cpu(xblk->xblk_next_xblk);
 241                                 ix = 0;
 242                                 brelse( bh );
 243                                 bh = NULL;
 244                         }
 245                 }
 246                 if ( bh )
 247                         brelse( bh );
 248         }
 249
 250         QNX4DEBUG(("qnx4: mapping block %ld of inode %ld = %ld\n",iblock,inode->i_ino,block));
 251         return block;
 252 }
 253
 254 static int qnx4_statfs(struct dentry *dentry, struct kstatfs *buf)
 255 {
 256         struct super_block *sb = dentry->d_sb;
 257         u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
 258
 259         lock_kernel();
 260
 261         buf->f_type    = sb->s_magic;
 262         buf->f_bsize   = sb->s_blocksize;
 263         buf->f_blocks  = le32_to_cpu(qnx4_sb(sb)->BitMap->di_size) * 8;
 264         buf->f_bfree   = qnx4_count_free_blocks(sb);
 265         buf->f_bavail  = buf->f_bfree;
 266         buf->f_namelen = QNX4_NAME_MAX;
 267         buf->f_fsid.val[0] = (u32)id;
 268         buf->f_fsid.val[1] = (u32)(id >> 32);
 269
 270         unlock_kernel();
 271
 272         return 0;
 273 }
 274
 275 /*
 276  * Check the root directory of the filesystem to make sure
 277  * it really _is_ a qnx4 filesystem, and to check the size
 278  * of the directory entry.
 279  */
 280 static const char *qnx4_checkroot(struct super_block *sb)
 281 {
 282         struct buffer_head *bh;
 283         struct qnx4_inode_entry *rootdir;
 284         int rd, rl;
 285         int i, j;
 286         int found = 0;
 287
 288         if (*(qnx4_sb(sb)->sb->RootDir.di_fname) != '/') {
 289                 return "no qnx4 filesystem (no root dir).";
 290         } else {
 291                 QNX4DEBUG(("QNX4 filesystem found on dev %s.\n", sb->s_id));
 292                 rd = le32_to_cpu(qnx4_sb(sb)->sb->RootDir.di_first_xtnt.xtnt_blk) - 1;
 293                 rl = le32_to_cpu(qnx4_sb(sb)->sb->RootDir.di_first_xtnt.xtnt_size);
 294                 for (j = 0; j < rl; j++) {
 295                         bh = sb_bread(sb, rd + j);      /* root dir, first block */
 296                         if (bh == NULL) {
 297                                 return "unable to read root entry.";
 298                         }
 299                         for (i = 0; i < QNX4_INODES_PER_BLOCK; i++) {
 300                                 rootdir = (struct qnx4_inode_entry *) (bh->b_data + i * QNX4_DIR_ENTRY_SIZE);
 301                                 if (rootdir->di_fname != NULL) {
 302                                         QNX4DEBUG(("Rootdir entry found : [%s]\n", rootdir->di_fname));
 303                                         if (!strncmp(rootdir->di_fname, QNX4_BMNAME, sizeof QNX4_BMNAME)) {
 304                                                 found = 1;
 305                                                 qnx4_sb(sb)->BitMap = kmalloc( sizeof( struct qnx4_inode_entry ), GFP_KERNEL );
 306                                                 if (!qnx4_sb(sb)->BitMap) {
 307                                                         brelse (bh);
 308                                                         return "not enough memory for bitmap inode";
 309                                                 }
 310                                                 memcpy( qnx4_sb(sb)->BitMap, rootdir, sizeof( struct qnx4_inode_entry ) );      /* keep bitmap inode known */
 311                                                 break;
 312                                         }
 313                                 }
 314                         }
 315                         brelse(bh);
 316                         if (found != 0) {
 317                                 break;
 318                         }
 319                 }
 320                 if (found == 0) {
 321                         return "bitmap file not found.";
 322                 }
 323         }
 324         return NULL;
 325 }
 326
 327 static int qnx4_fill_super(struct super_block *s, void *data, int silent)
 328 {
 329         struct buffer_head *bh;
 330         struct inode *root;
 331         const char *errmsg;
 332         struct qnx4_sb_info *qs;
 333         int ret = -EINVAL;
 334
 335         qs = kzalloc(sizeof(struct qnx4_sb_info), GFP_KERNEL);
 336         if (!qs)
 337                 return -ENOMEM;
 338         s->s_fs_info = qs;
 339
 340         sb_set_blocksize(s, QNX4_BLOCK_SIZE);
 341
 342         /* Check the superblock signature. Since the qnx4 code is
 343            dangerous, we should leave as quickly as possible
 344            if we don't belong here... */
 345         bh = sb_bread(s, 1);
 346         if (!bh) {
 347                 printk("qnx4: unable to read the superblock\n");
 348                 goto outnobh;
 349         }
 350         if ( le32_to_cpup((__le32*) bh->b_data) != QNX4_SUPER_MAGIC ) {
 351                 if (!silent)
 352                         printk("qnx4: wrong fsid in superblock.\n");
 353                 goto out;
 354         }
 355         s->s_op = &qnx4_sops;
 356         s->s_magic = QNX4_SUPER_MAGIC;
 357 #ifndef CONFIG_QNX4FS_RW
 358         s->s_flags |= MS_RDONLY;        /* Yup, read-only yet */
 359 #endif
 360         qnx4_sb(s)->sb_buf = bh;
 361         qnx4_sb(s)->sb = (struct qnx4_super_block *) bh->b_data;
 362
 363
 364         /* check before allocating dentries, inodes, .. */
 365         errmsg = qnx4_checkroot(s);
 366         if (errmsg != NULL) {
 367                 if (!silent)
 368                         printk("qnx4: %s\n", errmsg);
 369                 goto out;
 370         }
 371
 372         /* does root not have inode number QNX4_ROOT_INO ?? */
 373         root = qnx4_iget(s, QNX4_ROOT_INO * QNX4_INODES_PER_BLOCK);
 374         if (IS_ERR(root)) {
 375                 printk("qnx4: get inode failed\n");
 376                 ret = PTR_ERR(root);
 377                 goto out;
 378         }
 379
 380         ret = -ENOMEM;
 381         s->s_root = d_alloc_root(root);
 382         if (s->s_root == NULL)
 383                 goto outi;
 384
 385         brelse(bh);
 386
 387         return 0;
 388
 389       outi:
 390         iput(root);
 391       out:
 392         brelse(bh);
 393       outnobh:
 394         kfree(qs);
 395         s->s_fs_info = NULL;
 396         return ret;
 397 }
 398
 399 static void qnx4_put_super(struct super_block *sb)
 400 {
 401         struct qnx4_sb_info *qs = qnx4_sb(sb);
 402         kfree( qs->BitMap );
 403         kfree( qs );
 404         sb->s_fs_info = NULL;
 405         return;
 406 }
 407
 408 static int qnx4_writepage(struct page *page, struct writeback_control *wbc)
 409 {
 410         return block_write_full_page(page,qnx4_get_block, wbc);
 411 }
 412
 413 static int qnx4_readpage(struct file *file, struct page *page)
 414 {
 415         return block_read_full_page(page,qnx4_get_block);
 416 }
 417
 418 static int qnx4_write_begin(struct file *file, struct address_space *mapping,
 419                         loff_t pos, unsigned len, unsigned flags,
 420                         struct page **pagep, void **fsdata)
 421 {
 422         struct qnx4_inode_info *qnx4_inode = qnx4_i(mapping->host);
 423         *pagep = NULL;
 424         return cont_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
 425                                 qnx4_get_block,
 426                                 &qnx4_inode->mmu_private);
 427 }
 428 static sector_t qnx4_bmap(struct address_space *mapping, sector_t block)
 429 {
 430         return generic_block_bmap(mapping,block,qnx4_get_block);
 431 }
 432 static const struct address_space_operations qnx4_aops = {
 433         .readpage       = qnx4_readpage,
 434         .writepage      = qnx4_writepage,
 435         .sync_page      = block_sync_page,
 436         .write_begin    = qnx4_write_begin,
 437         .write_end      = generic_write_end,
 438         .bmap           = qnx4_bmap
 439 };
 440
 441 struct inode *qnx4_iget(struct super_block *sb, unsigned long ino)
 442 {
 443         struct buffer_head *bh;
 444         struct qnx4_inode_entry *raw_inode;
 445         int block;
 446         struct qnx4_inode_entry *qnx4_inode;
 447         struct inode *inode;
 448
 449         inode = iget_locked(sb, ino);
 450         if (!inode)
 451                 return ERR_PTR(-ENOMEM);
 452         if (!(inode->i_state & I_NEW))
 453                 return inode;
 454
 455         qnx4_inode = qnx4_raw_inode(inode);
 456         inode->i_mode = 0;
 457
 458         QNX4DEBUG(("Reading inode : [%d]\n", ino));
 459         if (!ino) {
 460                 printk(KERN_ERR "qnx4: bad inode number on dev %s: %lu is "
 461                                 "out of range\n",
 462                        sb->s_id, ino);
 463                 iget_failed(inode);
 464                 return ERR_PTR(-EIO);
 465         }
 466         block = ino / QNX4_INODES_PER_BLOCK;
 467
 468         if (!(bh = sb_bread(sb, block))) {
 469                 printk("qnx4: major problem: unable to read inode from dev "
 470                        "%s\n", sb->s_id);
 471                 iget_failed(inode);
 472                 return ERR_PTR(-EIO);
 473         }
 474         raw_inode = ((struct qnx4_inode_entry *) bh->b_data) +
 475             (ino % QNX4_INODES_PER_BLOCK);
 476
 477         inode->i_mode    = le16_to_cpu(raw_inode->di_mode);
 478         inode->i_uid     = (uid_t)le16_to_cpu(raw_inode->di_uid);
 479         inode->i_gid     = (gid_t)le16_to_cpu(raw_inode->di_gid);
 480         inode->i_nlink   = le16_to_cpu(raw_inode->di_nlink);
 481         inode->i_size    = le32_to_cpu(raw_inode->di_size);
 482         inode->i_mtime.tv_sec   = le32_to_cpu(raw_inode->di_mtime);
 483         inode->i_mtime.tv_nsec = 0;
 484         inode->i_atime.tv_sec   = le32_to_cpu(raw_inode->di_atime);
 485         inode->i_atime.tv_nsec = 0;
 486         inode->i_ctime.tv_sec   = le32_to_cpu(raw_inode->di_ctime);
 487         inode->i_ctime.tv_nsec = 0;
 488         inode->i_blocks  = le32_to_cpu(raw_inode->di_first_xtnt.xtnt_size);
 489
 490         memcpy(qnx4_inode, raw_inode, QNX4_DIR_ENTRY_SIZE);
 491         if (S_ISREG(inode->i_mode)) {
 492                 inode->i_op = &qnx4_file_inode_operations;
 493                 inode->i_fop = &qnx4_file_operations;
 494                 inode->i_mapping->a_ops = &qnx4_aops;
 495                 qnx4_i(inode)->mmu_private = inode->i_size;
 496         } else if (S_ISDIR(inode->i_mode)) {
 497                 inode->i_op = &qnx4_dir_inode_operations;
 498                 inode->i_fop = &qnx4_dir_operations;
 499         } else if (S_ISLNK(inode->i_mode)) {
 500                 inode->i_op = &page_symlink_inode_operations;
 501                 inode->i_mapping->a_ops = &qnx4_aops;
 502                 qnx4_i(inode)->mmu_private = inode->i_size;
 503         } else {
 504                 printk(KERN_ERR "qnx4: bad inode %lu on dev %s\n",
 505                         ino, sb->s_id);
 506                 iget_failed(inode);
 507                 brelse(bh);
 508                 return ERR_PTR(-EIO);
 509         }
 510         brelse(bh);
 511         unlock_new_inode(inode);
 512         return inode;
 513 }
 514
 515 static struct kmem_cache *qnx4_inode_cachep;
 516
 517 static struct inode *qnx4_alloc_inode(struct super_block *sb)
 518 {
 519         struct qnx4_inode_info *ei;
 520         ei = kmem_cache_alloc(qnx4_inode_cachep, GFP_KERNEL);
 521         if (!ei)
 522                 return NULL;
 523         return &ei->vfs_inode;
 524 }
 525
 526 static void qnx4_destroy_inode(struct inode *inode)
 527 {
 528         kmem_cache_free(qnx4_inode_cachep, qnx4_i(inode));
 529 }
 530
 531 static void init_once(void *foo)
 532 {
 533         struct qnx4_inode_info *ei = (struct qnx4_inode_info *) foo;
 534
 535         inode_init_once(&ei->vfs_inode);
 536 }
 537
 538 static int init_inodecache(void)
 539 {
 540         qnx4_inode_cachep = kmem_cache_create("qnx4_inode_cache",
 541                                              sizeof(struct qnx4_inode_info),
 542                                              0, (SLAB_RECLAIM_ACCOUNT|
 543                                                 SLAB_MEM_SPREAD),
 544                                              init_once);
 545         if (qnx4_inode_cachep == NULL)
 546                 return -ENOMEM;
 547         return 0;
 548 }
 549
 550 static void destroy_inodecache(void)
 551 {
 552         kmem_cache_destroy(qnx4_inode_cachep);
 553 }
 554
 555 static int qnx4_get_sb(struct file_system_type *fs_type,
 556         int flags, const char *dev_name, void *data, struct vfsmount *mnt)
 557 {
 558         return get_sb_bdev(fs_type, flags, dev_name, data, qnx4_fill_super,
 559                            mnt);
 560 }
 561
 562 static struct file_system_type qnx4_fs_type = {
 563         .owner          = THIS_MODULE,
 564         .name           = "qnx4",
 565         .get_sb         = qnx4_get_sb,
 566         .kill_sb        = kill_block_super,
 567         .fs_flags       = FS_REQUIRES_DEV,
 568 };
 569
 570 static int __init init_qnx4_fs(void)
 571 {
 572         int err;
 573
 574         err = init_inodecache();
 575         if (err)
 576                 return err;
 577
 578         err = register_filesystem(&qnx4_fs_type);
 579         if (err) {
 580                 destroy_inodecache();
 581                 return err;
 582         }
 583
 584         printk("QNX4 filesystem 0.2.3 registered.\n");
 585         return 0;
 586 }
 587
 588 static void __exit exit_qnx4_fs(void)
 589 {
 590         unregister_filesystem(&qnx4_fs_type);
 591         destroy_inodecache();
 592 }
 593
 594 module_init(init_qnx4_fs)
 595 module_exit(exit_qnx4_fs)
 596 MODULE_LICENSE("GPL");
 597