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 inode *inode, u32 entry_ino) 126 { 127 struct dentry *dentry; 128 spin_lock(&inode->i_lock); 129 hlist_for_each_entry(dentry, &inode->i_dentry, d_alias) { 130 if (entry_ino == (u32)(long)dentry->d_fsdata) { 131 dentry->d_fsdata = (void *)inode->i_ino; 132 break; 133 } 134 } 135 spin_unlock(&inode->i_lock); 136 } 137 138 139 /* Remove header from link chain */ 140 141 static int 142 affs_remove_link(struct dentry *dentry) 143 { 144 struct inode *dir, *inode = dentry->d_inode; 145 struct super_block *sb = inode->i_sb; 146 struct buffer_head *bh = NULL, *link_bh = NULL; 147 u32 link_ino, ino; 148 int retval; 149 150 pr_debug("AFFS: remove_link(key=%ld)\n", inode->i_ino); 151 retval = -EIO; 152 bh = affs_bread(sb, inode->i_ino); 153 if (!bh) 154 goto done; 155 156 link_ino = (u32)(long)dentry->d_fsdata; 157 if (inode->i_ino == link_ino) { 158 /* we can't remove the head of the link, as its blocknr is still used as ino, 159 * so we remove the block of the first link instead. 160 */ 161 link_ino = be32_to_cpu(AFFS_TAIL(sb, bh)->link_chain); 162 link_bh = affs_bread(sb, link_ino); 163 if (!link_bh) 164 goto done; 165 166 dir = affs_iget(sb, be32_to_cpu(AFFS_TAIL(sb, link_bh)->parent)); 167 if (IS_ERR(dir)) { 168 retval = PTR_ERR(dir); 169 goto done; 170 } 171 172 affs_lock_dir(dir); 173 /* 174 * if there's a dentry for that block, make it 175 * refer to inode itself. 176 */ 177 affs_fix_dcache(inode, link_ino); 178 retval = affs_remove_hash(dir, link_bh); 179 if (retval) { 180 affs_unlock_dir(dir); 181 goto done; 182 } 183 mark_buffer_dirty_inode(link_bh, inode); 184 185 memcpy(AFFS_TAIL(sb, bh)->name, AFFS_TAIL(sb, link_bh)->name, 32); 186 retval = affs_insert_hash(dir, bh); 187 if (retval) { 188 affs_unlock_dir(dir); 189 goto done; 190 } 191 mark_buffer_dirty_inode(bh, inode); 192 193 affs_unlock_dir(dir); 194 iput(dir); 195 } else { 196 link_bh = affs_bread(sb, link_ino); 197 if (!link_bh) 198 goto done; 199 } 200 201 while ((ino = be32_to_cpu(AFFS_TAIL(sb, bh)->link_chain)) != 0) { 202 if (ino == link_ino) { 203 __be32 ino2 = AFFS_TAIL(sb, link_bh)->link_chain; 204 AFFS_TAIL(sb, bh)->link_chain = ino2; 205 affs_adjust_checksum(bh, be32_to_cpu(ino2) - link_ino); 206 mark_buffer_dirty_inode(bh, inode); 207 retval = 0; 208 /* Fix the link count, if bh is a normal header block without links */ 209 switch (be32_to_cpu(AFFS_TAIL(sb, bh)->stype)) { 210 case ST_LINKDIR: 211 case ST_LINKFILE: 212 break; 213 default: 214 if (!AFFS_TAIL(sb, bh)->link_chain) 215 set_nlink(inode, 1); 216 } 217 affs_free_block(sb, link_ino); 218 goto done; 219 } 220 affs_brelse(bh); 221 bh = affs_bread(sb, ino); 222 if (!bh) 223 goto done; 224 } 225 retval = -ENOENT; 226 done: 227 affs_brelse(link_bh); 228 affs_brelse(bh); 229 return retval; 230 } 231 232 233 static int 234 affs_empty_dir(struct inode *inode) 235 { 236 struct super_block *sb = inode->i_sb; 237 struct buffer_head *bh; 238 int retval, size; 239 240 retval = -EIO; 241 bh = affs_bread(sb, inode->i_ino); 242 if (!bh) 243 goto done; 244 245 retval = -ENOTEMPTY; 246 for (size = AFFS_SB(sb)->s_hashsize - 1; size >= 0; size--) 247 if (AFFS_HEAD(bh)->table[size]) 248 goto not_empty; 249 retval = 0; 250 not_empty: 251 affs_brelse(bh); 252 done: 253 return retval; 254 } 255 256 257 /* Remove a filesystem object. If the object to be removed has 258 * links to it, one of the links must be changed to inherit 259 * the file or directory. As above, any inode will do. 260 * The buffer will not be freed. If the header is a link, the 261 * block will be marked as free. 262 * This function returns a negative error number in case of 263 * an error, else 0 if the inode is to be deleted or 1 if not. 264 */ 265 266 int 267 affs_remove_header(struct dentry *dentry) 268 { 269 struct super_block *sb; 270 struct inode *inode, *dir; 271 struct buffer_head *bh = NULL; 272 int retval; 273 274 dir = dentry->d_parent->d_inode; 275 sb = dir->i_sb; 276 277 retval = -ENOENT; 278 inode = dentry->d_inode; 279 if (!inode) 280 goto done; 281 282 pr_debug("AFFS: remove_header(key=%ld)\n", inode->i_ino); 283 retval = -EIO; 284 bh = affs_bread(sb, (u32)(long)dentry->d_fsdata); 285 if (!bh) 286 goto done; 287 288 affs_lock_link(inode); 289 affs_lock_dir(dir); 290 switch (be32_to_cpu(AFFS_TAIL(sb, bh)->stype)) { 291 case ST_USERDIR: 292 /* if we ever want to support links to dirs 293 * i_hash_lock of the inode must only be 294 * taken after some checks 295 */ 296 affs_lock_dir(inode); 297 retval = affs_empty_dir(inode); 298 affs_unlock_dir(inode); 299 if (retval) 300 goto done_unlock; 301 break; 302 default: 303 break; 304 } 305 306 retval = affs_remove_hash(dir, bh); 307 if (retval) 308 goto done_unlock; 309 mark_buffer_dirty_inode(bh, inode); 310 311 affs_unlock_dir(dir); 312 313 if (inode->i_nlink > 1) 314 retval = affs_remove_link(dentry); 315 else 316 clear_nlink(inode); 317 affs_unlock_link(inode); 318 inode->i_ctime = CURRENT_TIME_SEC; 319 mark_inode_dirty(inode); 320 321 done: 322 affs_brelse(bh); 323 return retval; 324 325 done_unlock: 326 affs_unlock_dir(dir); 327 affs_unlock_link(inode); 328 goto done; 329 } 330 331 /* Checksum a block, do various consistency checks and optionally return 332 the blocks type number. DATA points to the block. If their pointers 333 are non-null, *PTYPE and *STYPE are set to the primary and secondary 334 block types respectively, *HASHSIZE is set to the size of the hashtable 335 (which lets us calculate the block size). 336 Returns non-zero if the block is not consistent. */ 337 338 u32 339 affs_checksum_block(struct super_block *sb, struct buffer_head *bh) 340 { 341 __be32 *ptr = (__be32 *)bh->b_data; 342 u32 sum; 343 int bsize; 344 345 sum = 0; 346 for (bsize = sb->s_blocksize / sizeof(__be32); bsize > 0; bsize--) 347 sum += be32_to_cpu(*ptr++); 348 return sum; 349 } 350 351 /* 352 * Calculate the checksum of a disk block and store it 353 * at the indicated position. 354 */ 355 356 void 357 affs_fix_checksum(struct super_block *sb, struct buffer_head *bh) 358 { 359 int cnt = sb->s_blocksize / sizeof(__be32); 360 __be32 *ptr = (__be32 *)bh->b_data; 361 u32 checksum; 362 __be32 *checksumptr; 363 364 checksumptr = ptr + 5; 365 *checksumptr = 0; 366 for (checksum = 0; cnt > 0; ptr++, cnt--) 367 checksum += be32_to_cpu(*ptr); 368 *checksumptr = cpu_to_be32(-checksum); 369 } 370 371 void 372 secs_to_datestamp(time_t secs, struct affs_date *ds) 373 { 374 u32 days; 375 u32 minute; 376 377 secs -= sys_tz.tz_minuteswest * 60 + ((8 * 365 + 2) * 24 * 60 * 60); 378 if (secs < 0) 379 secs = 0; 380 days = secs / 86400; 381 secs -= days * 86400; 382 minute = secs / 60; 383 secs -= minute * 60; 384 385 ds->days = cpu_to_be32(days); 386 ds->mins = cpu_to_be32(minute); 387 ds->ticks = cpu_to_be32(secs * 50); 388 } 389 390 umode_t 391 prot_to_mode(u32 prot) 392 { 393 umode_t mode = 0; 394 395 if (!(prot & FIBF_NOWRITE)) 396 mode |= S_IWUSR; 397 if (!(prot & FIBF_NOREAD)) 398 mode |= S_IRUSR; 399 if (!(prot & FIBF_NOEXECUTE)) 400 mode |= S_IXUSR; 401 if (prot & FIBF_GRP_WRITE) 402 mode |= S_IWGRP; 403 if (prot & FIBF_GRP_READ) 404 mode |= S_IRGRP; 405 if (prot & FIBF_GRP_EXECUTE) 406 mode |= S_IXGRP; 407 if (prot & FIBF_OTR_WRITE) 408 mode |= S_IWOTH; 409 if (prot & FIBF_OTR_READ) 410 mode |= S_IROTH; 411 if (prot & FIBF_OTR_EXECUTE) 412 mode |= S_IXOTH; 413 414 return mode; 415 } 416 417 void 418 mode_to_prot(struct inode *inode) 419 { 420 u32 prot = AFFS_I(inode)->i_protect; 421 umode_t mode = inode->i_mode; 422 423 if (!(mode & S_IXUSR)) 424 prot |= FIBF_NOEXECUTE; 425 if (!(mode & S_IRUSR)) 426 prot |= FIBF_NOREAD; 427 if (!(mode & S_IWUSR)) 428 prot |= FIBF_NOWRITE; 429 if (mode & S_IXGRP) 430 prot |= FIBF_GRP_EXECUTE; 431 if (mode & S_IRGRP) 432 prot |= FIBF_GRP_READ; 433 if (mode & S_IWGRP) 434 prot |= FIBF_GRP_WRITE; 435 if (mode & S_IXOTH) 436 prot |= FIBF_OTR_EXECUTE; 437 if (mode & S_IROTH) 438 prot |= FIBF_OTR_READ; 439 if (mode & S_IWOTH) 440 prot |= FIBF_OTR_WRITE; 441 442 AFFS_I(inode)->i_protect = prot; 443 } 444 445 void 446 affs_error(struct super_block *sb, const char *function, const char *fmt, ...) 447 { 448 va_list args; 449 450 va_start(args,fmt); 451 vsnprintf(ErrorBuffer,sizeof(ErrorBuffer),fmt,args); 452 va_end(args); 453 454 printk(KERN_CRIT "AFFS error (device %s): %s(): %s\n", sb->s_id, 455 function,ErrorBuffer); 456 if (!(sb->s_flags & MS_RDONLY)) 457 printk(KERN_WARNING "AFFS: Remounting filesystem read-only\n"); 458 sb->s_flags |= MS_RDONLY; 459 } 460 461 void 462 affs_warning(struct super_block *sb, const char *function, const char *fmt, ...) 463 { 464 va_list args; 465 466 va_start(args,fmt); 467 vsnprintf(ErrorBuffer,sizeof(ErrorBuffer),fmt,args); 468 va_end(args); 469 470 printk(KERN_WARNING "AFFS warning (device %s): %s(): %s\n", sb->s_id, 471 function,ErrorBuffer); 472 } 473 474 /* Check if the name is valid for a affs object. */ 475 476 int 477 affs_check_name(const unsigned char *name, int len) 478 { 479 int i; 480 481 if (len > 30) 482 #ifdef AFFS_NO_TRUNCATE 483 return -ENAMETOOLONG; 484 #else 485 len = 30; 486 #endif 487 488 for (i = 0; i < len; i++) { 489 if (name[i] < ' ' || name[i] == ':' 490 || (name[i] > 0x7e && name[i] < 0xa0)) 491 return -EINVAL; 492 } 493 494 return 0; 495 } 496 497 /* This function copies name to bstr, with at most 30 498 * characters length. The bstr will be prepended by 499 * a length byte. 500 * NOTE: The name will must be already checked by 501 * affs_check_name()! 502 */ 503 504 int 505 affs_copy_name(unsigned char *bstr, struct dentry *dentry) 506 { 507 int len = min(dentry->d_name.len, 30u); 508 509 *bstr++ = len; 510 memcpy(bstr, dentry->d_name.name, len); 511 return len; 512 } 513