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