fs/affs/amigaffs.c

   1 /*
   2  *  linux/fs/affs/amigaffs.c
   3  *
   4  *  (c) 1996  Hans-Joachim Widmaier - Rewritten
   5  *
   6  *  (C) 1993  Ray Burr - Amiga FFS filesystem.
   7  *
   8  *  Please send bug reports to: hjw@zvw.de
   9  */
  10
  11 #include <stdarg.h>
  12 #include <linux/stat.h>
  13 #include <linux/time.h>
  14 #include <linux/affs_fs.h>
  15 #include <linux/string.h>
  16 #include <linux/mm.h>
  17 #include <linux/amigaffs.h>
  18 #include <linux/buffer_head.h>
  19
  20 extern struct timezone sys_tz;
  21
  22 static char ErrorBuffer[256];
  23
  24 /*
  25  * Functions for accessing Amiga-FFS structures.
  26  */
  27
  28
  29 /* Insert a header block bh into the directory dir
  30  * caller must hold AFFS_DIR->i_hash_lock!
  31  */
  32
  33 int
  34 affs_insert_hash(struct inode *dir, struct buffer_head *bh)
  35 {
  36         struct super_block *sb = dir->i_sb;
  37         struct buffer_head *dir_bh;
  38         u32 ino, hash_ino;
  39         int offset;
  40
  41         ino = bh->b_blocknr;
  42         offset = affs_hash_name(sb, AFFS_TAIL(sb, bh)->name + 1, AFFS_TAIL(sb, bh)->name[0]);
  43
  44         pr_debug("AFFS: insert_hash(dir=%u, ino=%d)\n", (u32)dir->i_ino, ino);
  45
  46         dir_bh = affs_bread(sb, dir->i_ino);
  47         if (!dir_bh)
  48                 return -EIO;
  49
  50         hash_ino = be32_to_cpu(AFFS_HEAD(dir_bh)->table[offset]);
  51         while (hash_ino) {
  52                 affs_brelse(dir_bh);
  53                 dir_bh = affs_bread(sb, hash_ino);
  54                 if (!dir_bh)
  55                         return -EIO;
  56                 hash_ino = be32_to_cpu(AFFS_TAIL(sb, dir_bh)->hash_chain);
  57         }
  58         AFFS_TAIL(sb, bh)->parent = cpu_to_be32(dir->i_ino);
  59         AFFS_TAIL(sb, bh)->hash_chain = 0;
  60         affs_fix_checksum(sb, bh);
  61
  62         if (dir->i_ino == dir_bh->b_blocknr)
  63                 AFFS_HEAD(dir_bh)->table[offset] = cpu_to_be32(ino);
  64         else
  65                 AFFS_TAIL(sb, dir_bh)->hash_chain = cpu_to_be32(ino);
  66
  67         affs_adjust_checksum(dir_bh, ino);
  68         mark_buffer_dirty_inode(dir_bh, dir);
  69         affs_brelse(dir_bh);
  70
  71         dir->i_mtime = dir->i_ctime = CURRENT_TIME;
  72         dir->i_version++;
  73         mark_inode_dirty(dir);
  74
  75         return 0;
  76 }
  77
  78 /* Remove a header block from its directory.
  79  * caller must hold AFFS_DIR->i_hash_lock!
  80  */
  81
  82 int
  83 affs_remove_hash(struct inode *dir, struct buffer_head *rem_bh)
  84 {
  85         struct super_block *sb;
  86         struct buffer_head *bh;
  87         u32 rem_ino, hash_ino;
  88         __be32 ino;
  89         int offset, retval;
  90
  91         sb = dir->i_sb;
  92         rem_ino = rem_bh->b_blocknr;
  93         offset = affs_hash_name(sb, AFFS_TAIL(sb, rem_bh)->name+1, AFFS_TAIL(sb, rem_bh)->name[0]);
  94         pr_debug("AFFS: remove_hash(dir=%d, ino=%d, hashval=%d)\n", (u32)dir->i_ino, rem_ino, offset);
  95
  96         bh = affs_bread(sb, dir->i_ino);
  97         if (!bh)
  98                 return -EIO;
  99
 100         retval = -ENOENT;
 101         hash_ino = be32_to_cpu(AFFS_HEAD(bh)->table[offset]);
 102         while (hash_ino) {
 103                 if (hash_ino == rem_ino) {
 104                         ino = AFFS_TAIL(sb, rem_bh)->hash_chain;
 105                         if (dir->i_ino == bh->b_blocknr)
 106                                 AFFS_HEAD(bh)->table[offset] = ino;
 107                         else
 108                                 AFFS_TAIL(sb, bh)->hash_chain = ino;
 109                         affs_adjust_checksum(bh, be32_to_cpu(ino) - hash_ino);
 110                         mark_buffer_dirty_inode(bh, dir);
 111                         AFFS_TAIL(sb, rem_bh)->parent = 0;
 112                         retval = 0;
 113                         break;
 114                 }
 115                 affs_brelse(bh);
 116                 bh = affs_bread(sb, hash_ino);
 117                 if (!bh)
 118                         return -EIO;
 119                 hash_ino = be32_to_cpu(AFFS_TAIL(sb, bh)->hash_chain);
 120         }
 121
 122         affs_brelse(bh);
 123
 124         dir->i_mtime = dir->i_ctime = CURRENT_TIME;
 125         dir->i_version++;
 126         mark_inode_dirty(dir);
 127
 128         return retval;
 129 }
 130
 131 static void
 132 affs_fix_dcache(struct dentry *dentry, u32 entry_ino)
 133 {
 134         struct inode *inode = dentry->d_inode;
 135         void *data = dentry->d_fsdata;
 136         struct list_head *head, *next;
 137
 138         spin_lock(&dcache_lock);
 139         head = &inode->i_dentry;
 140         next = head->next;
 141         while (next != head) {
 142                 dentry = list_entry(next, struct dentry, d_alias);
 143                 if (entry_ino == (u32)(long)dentry->d_fsdata) {
 144                         dentry->d_fsdata = data;
 145                         break;
 146                 }
 147                 next = next->next;
 148         }
 149         spin_unlock(&dcache_lock);
 150 }
 151
 152
 153 /* Remove header from link chain */
 154
 155 static int
 156 affs_remove_link(struct dentry *dentry)
 157 {
 158         struct inode *dir, *inode = dentry->d_inode;
 159         struct super_block *sb = inode->i_sb;
 160         struct buffer_head *bh = NULL, *link_bh = NULL;
 161         u32 link_ino, ino;
 162         int retval;
 163
 164         pr_debug("AFFS: remove_link(key=%ld)\n", inode->i_ino);
 165         retval = -EIO;
 166         bh = affs_bread(sb, inode->i_ino);
 167         if (!bh)
 168                 goto done;
 169
 170         link_ino = (u32)(long)dentry->d_fsdata;
 171         if (inode->i_ino == link_ino) {
 172                 /* we can't remove the head of the link, as its blocknr is still used as ino,
 173                  * so we remove the block of the first link instead.
 174                  */
 175                 link_ino = be32_to_cpu(AFFS_TAIL(sb, bh)->link_chain);
 176                 link_bh = affs_bread(sb, link_ino);
 177                 if (!link_bh)
 178                         goto done;
 179
 180                 dir = iget(sb, be32_to_cpu(AFFS_TAIL(sb, link_bh)->parent));
 181                 if (!dir)
 182                         goto done;
 183
 184                 affs_lock_dir(dir);
 185                 affs_fix_dcache(dentry, link_ino);
 186                 retval = affs_remove_hash(dir, link_bh);
 187                 if (retval)
 188                         goto done;
 189                 mark_buffer_dirty_inode(link_bh, inode);
 190
 191                 memcpy(AFFS_TAIL(sb, bh)->name, AFFS_TAIL(sb, link_bh)->name, 32);
 192                 retval = affs_insert_hash(dir, bh);
 193                 if (retval)
 194                         goto done;
 195                 mark_buffer_dirty_inode(bh, inode);
 196
 197                 affs_unlock_dir(dir);
 198                 iput(dir);
 199         } else {
 200                 link_bh = affs_bread(sb, link_ino);
 201                 if (!link_bh)
 202                         goto done;
 203         }
 204
 205         while ((ino = be32_to_cpu(AFFS_TAIL(sb, bh)->link_chain)) != 0) {
 206                 if (ino == link_ino) {
 207                         __be32 ino2 = AFFS_TAIL(sb, link_bh)->link_chain;
 208                         AFFS_TAIL(sb, bh)->link_chain = ino2;
 209                         affs_adjust_checksum(bh, be32_to_cpu(ino2) - link_ino);
 210                         mark_buffer_dirty_inode(bh, inode);
 211                         retval = 0;
 212                         /* Fix the link count, if bh is a normal header block without links */
 213                         switch (be32_to_cpu(AFFS_TAIL(sb, bh)->stype)) {
 214                         case ST_LINKDIR:
 215                         case ST_LINKFILE:
 216                                 break;
 217                         default:
 218                                 if (!AFFS_TAIL(sb, bh)->link_chain)
 219                                         inode->i_nlink = 1;
 220                         }
 221                         affs_free_block(sb, link_ino);
 222                         goto done;
 223                 }
 224                 affs_brelse(bh);
 225                 bh = affs_bread(sb, ino);
 226                 if (!bh)
 227                         goto done;
 228         }
 229         retval = -ENOENT;
 230 done:
 231         affs_brelse(link_bh);
 232         affs_brelse(bh);
 233         return retval;
 234 }
 235
 236
 237 static int
 238 affs_empty_dir(struct inode *inode)
 239 {
 240         struct super_block *sb = inode->i_sb;
 241         struct buffer_head *bh;
 242         int retval, size;
 243
 244         retval = -EIO;
 245         bh = affs_bread(sb, inode->i_ino);
 246         if (!bh)
 247                 goto done;
 248
 249         retval = -ENOTEMPTY;
 250         for (size = AFFS_SB(sb)->s_hashsize - 1; size >= 0; size--)
 251                 if (AFFS_HEAD(bh)->table[size])
 252                         goto not_empty;
 253         retval = 0;
 254 not_empty:
 255         affs_brelse(bh);
 256 done:
 257         return retval;
 258 }
 259
 260
 261 /* Remove a filesystem object. If the object to be removed has
 262  * links to it, one of the links must be changed to inherit
 263  * the file or directory. As above, any inode will do.
 264  * The buffer will not be freed. If the header is a link, the
 265  * block will be marked as free.
 266  * This function returns a negative error number in case of
 267  * an error, else 0 if the inode is to be deleted or 1 if not.
 268  */
 269
 270 int
 271 affs_remove_header(struct dentry *dentry)
 272 {
 273         struct super_block *sb;
 274         struct inode *inode, *dir;
 275         struct buffer_head *bh = NULL;
 276         int retval;
 277
 278         dir = dentry->d_parent->d_inode;
 279         sb = dir->i_sb;
 280
 281         retval = -ENOENT;
 282         inode = dentry->d_inode;
 283         if (!inode)
 284                 goto done;
 285
 286         pr_debug("AFFS: remove_header(key=%ld)\n", inode->i_ino);
 287         retval = -EIO;
 288         bh = affs_bread(sb, (u32)(long)dentry->d_fsdata);
 289         if (!bh)
 290                 goto done;
 291
 292         affs_lock_link(inode);
 293         affs_lock_dir(dir);
 294         switch (be32_to_cpu(AFFS_TAIL(sb, bh)->stype)) {
 295         case ST_USERDIR:
 296                 /* if we ever want to support links to dirs
 297                  * i_hash_lock of the inode must only be
 298                  * taken after some checks
 299                  */
 300                 affs_lock_dir(inode);
 301                 retval = affs_empty_dir(inode);
 302                 affs_unlock_dir(inode);
 303                 if (retval)
 304                         goto done_unlock;
 305                 break;
 306         default:
 307                 break;
 308         }
 309
 310         retval = affs_remove_hash(dir, bh);
 311         if (retval)
 312                 goto done_unlock;
 313         mark_buffer_dirty_inode(bh, inode);
 314
 315         affs_unlock_dir(dir);
 316
 317         if (inode->i_nlink > 1)
 318                 retval = affs_remove_link(dentry);
 319         else
 320                 inode->i_nlink = 0;
 321         affs_unlock_link(inode);
 322         inode->i_ctime = CURRENT_TIME;
 323         mark_inode_dirty(inode);
 324
 325 done:
 326         affs_brelse(bh);
 327         return retval;
 328
 329 done_unlock:
 330         affs_unlock_dir(dir);
 331         affs_unlock_link(inode);
 332         goto done;
 333 }
 334
 335 /* Checksum a block, do various consistency checks and optionally return
 336    the blocks type number.  DATA points to the block.  If their pointers
 337    are non-null, *PTYPE and *STYPE are set to the primary and secondary
 338    block types respectively, *HASHSIZE is set to the size of the hashtable
 339    (which lets us calculate the block size).
 340    Returns non-zero if the block is not consistent. */
 341
 342 u32
 343 affs_checksum_block(struct super_block *sb, struct buffer_head *bh)
 344 {
 345         __be32 *ptr = (__be32 *)bh->b_data;
 346         u32 sum;
 347         int bsize;
 348
 349         sum = 0;
 350         for (bsize = sb->s_blocksize / sizeof(__be32); bsize > 0; bsize--)
 351                 sum += be32_to_cpu(*ptr++);
 352         return sum;
 353 }
 354
 355 /*
 356  * Calculate the checksum of a disk block and store it
 357  * at the indicated position.
 358  */
 359
 360 void
 361 affs_fix_checksum(struct super_block *sb, struct buffer_head *bh)
 362 {
 363         int cnt = sb->s_blocksize / sizeof(__be32);
 364         __be32 *ptr = (__be32 *)bh->b_data;
 365         u32 checksum;
 366         __be32 *checksumptr;
 367
 368         checksumptr = ptr + 5;
 369         *checksumptr = 0;
 370         for (checksum = 0; cnt > 0; ptr++, cnt--)
 371                 checksum += be32_to_cpu(*ptr);
 372         *checksumptr = cpu_to_be32(-checksum);
 373 }
 374
 375 void
 376 secs_to_datestamp(time_t secs, struct affs_date *ds)
 377 {
 378         u32      days;
 379         u32      minute;
 380
 381         secs -= sys_tz.tz_minuteswest * 60 + ((8 * 365 + 2) * 24 * 60 * 60);
 382         if (secs < 0)
 383                 secs = 0;
 384         days    = secs / 86400;
 385         secs   -= days * 86400;
 386         minute  = secs / 60;
 387         secs   -= minute * 60;
 388
 389         ds->days = cpu_to_be32(days);
 390         ds->mins = cpu_to_be32(minute);
 391         ds->ticks = cpu_to_be32(secs * 50);
 392 }
 393
 394 mode_t
 395 prot_to_mode(u32 prot)
 396 {
 397         int mode = 0;
 398
 399         if (!(prot & FIBF_NOWRITE))
 400                 mode |= S_IWUSR;
 401         if (!(prot & FIBF_NOREAD))
 402                 mode |= S_IRUSR;
 403         if (!(prot & FIBF_NOEXECUTE))
 404                 mode |= S_IXUSR;
 405         if (prot & FIBF_GRP_WRITE)
 406                 mode |= S_IWGRP;
 407         if (prot & FIBF_GRP_READ)
 408                 mode |= S_IRGRP;
 409         if (prot & FIBF_GRP_EXECUTE)
 410                 mode |= S_IXGRP;
 411         if (prot & FIBF_OTR_WRITE)
 412                 mode |= S_IWOTH;
 413         if (prot & FIBF_OTR_READ)
 414                 mode |= S_IROTH;
 415         if (prot & FIBF_OTR_EXECUTE)
 416                 mode |= S_IXOTH;
 417
 418         return mode;
 419 }
 420
 421 void
 422 mode_to_prot(struct inode *inode)
 423 {
 424         u32 prot = AFFS_I(inode)->i_protect;
 425         mode_t mode = inode->i_mode;
 426
 427         if (!(mode & S_IXUSR))
 428                 prot |= FIBF_NOEXECUTE;
 429         if (!(mode & S_IRUSR))
 430                 prot |= FIBF_NOREAD;
 431         if (!(mode & S_IWUSR))
 432                 prot |= FIBF_NOWRITE;
 433         if (mode & S_IXGRP)
 434                 prot |= FIBF_GRP_EXECUTE;
 435         if (mode & S_IRGRP)
 436                 prot |= FIBF_GRP_READ;
 437         if (mode & S_IWGRP)
 438                 prot |= FIBF_GRP_WRITE;
 439         if (mode & S_IXOTH)
 440                 prot |= FIBF_OTR_EXECUTE;
 441         if (mode & S_IROTH)
 442                 prot |= FIBF_OTR_READ;
 443         if (mode & S_IWOTH)
 444                 prot |= FIBF_OTR_WRITE;
 445
 446         AFFS_I(inode)->i_protect = prot;
 447 }
 448
 449 void
 450 affs_error(struct super_block *sb, const char *function, const char *fmt, ...)
 451 {
 452         va_list  args;
 453
 454         va_start(args,fmt);
 455         vsprintf(ErrorBuffer,fmt,args);
 456         va_end(args);
 457
 458         printk(KERN_CRIT "AFFS error (device %s): %s(): %s\n", sb->s_id,
 459                 function,ErrorBuffer);
 460         if (!(sb->s_flags & MS_RDONLY))
 461                 printk(KERN_WARNING "AFFS: Remounting filesystem read-only\n");
 462         sb->s_flags |= MS_RDONLY;
 463 }
 464
 465 void
 466 affs_warning(struct super_block *sb, const char *function, const char *fmt, ...)
 467 {
 468         va_list  args;
 469
 470         va_start(args,fmt);
 471         vsprintf(ErrorBuffer,fmt,args);
 472         va_end(args);
 473
 474         printk(KERN_WARNING "AFFS warning (device %s): %s(): %s\n", sb->s_id,
 475                 function,ErrorBuffer);
 476 }
 477
 478 /* Check if the name is valid for a affs object. */
 479
 480 int
 481 affs_check_name(const unsigned char *name, int len)
 482 {
 483         int      i;
 484
 485         if (len > 30)
 486 #ifdef AFFS_NO_TRUNCATE
 487                 return -ENAMETOOLONG;
 488 #else
 489                 len = 30;
 490 #endif
 491
 492         for (i = 0; i < len; i++) {
 493                 if (name[i] < ' ' || name[i] == ':'
 494                     || (name[i] > 0x7e && name[i] < 0xa0))
 495                         return -EINVAL;
 496         }
 497
 498         return 0;
 499 }
 500
 501 /* This function copies name to bstr, with at most 30
 502  * characters length. The bstr will be prepended by
 503  * a length byte.
 504  * NOTE: The name will must be already checked by
 505  *       affs_check_name()!
 506  */
 507
 508 int
 509 affs_copy_name(unsigned char *bstr, struct dentry *dentry)
 510 {
 511         int len = min(dentry->d_name.len, 30u);
 512
 513         *bstr++ = len;
 514         memcpy(bstr, dentry->d_name.name, len);
 515         return len;
 516 }