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(&inode->i_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(&inode->i_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 affs_unlock_dir(dir); 184 goto done; 185 } 186 mark_buffer_dirty_inode(link_bh, inode); 187 188 memcpy(AFFS_TAIL(sb, bh)->name, AFFS_TAIL(sb, link_bh)->name, 32); 189 retval = affs_insert_hash(dir, bh); 190 if (retval) { 191 affs_unlock_dir(dir); 192 goto done; 193 } 194 mark_buffer_dirty_inode(bh, inode); 195 196 affs_unlock_dir(dir); 197 iput(dir); 198 } else { 199 link_bh = affs_bread(sb, link_ino); 200 if (!link_bh) 201 goto done; 202 } 203 204 while ((ino = be32_to_cpu(AFFS_TAIL(sb, bh)->link_chain)) != 0) { 205 if (ino == link_ino) { 206 __be32 ino2 = AFFS_TAIL(sb, link_bh)->link_chain; 207 AFFS_TAIL(sb, bh)->link_chain = ino2; 208 affs_adjust_checksum(bh, be32_to_cpu(ino2) - link_ino); 209 mark_buffer_dirty_inode(bh, inode); 210 retval = 0; 211 /* Fix the link count, if bh is a normal header block without links */ 212 switch (be32_to_cpu(AFFS_TAIL(sb, bh)->stype)) { 213 case ST_LINKDIR: 214 case ST_LINKFILE: 215 break; 216 default: 217 if (!AFFS_TAIL(sb, bh)->link_chain) 218 inode->i_nlink = 1; 219 } 220 affs_free_block(sb, link_ino); 221 goto done; 222 } 223 affs_brelse(bh); 224 bh = affs_bread(sb, ino); 225 if (!bh) 226 goto done; 227 } 228 retval = -ENOENT; 229 done: 230 affs_brelse(link_bh); 231 affs_brelse(bh); 232 return retval; 233 } 234 235 236 static int 237 affs_empty_dir(struct inode *inode) 238 { 239 struct super_block *sb = inode->i_sb; 240 struct buffer_head *bh; 241 int retval, size; 242 243 retval = -EIO; 244 bh = affs_bread(sb, inode->i_ino); 245 if (!bh) 246 goto done; 247 248 retval = -ENOTEMPTY; 249 for (size = AFFS_SB(sb)->s_hashsize - 1; size >= 0; size--) 250 if (AFFS_HEAD(bh)->table[size]) 251 goto not_empty; 252 retval = 0; 253 not_empty: 254 affs_brelse(bh); 255 done: 256 return retval; 257 } 258 259 260 /* Remove a filesystem object. If the object to be removed has 261 * links to it, one of the links must be changed to inherit 262 * the file or directory. As above, any inode will do. 263 * The buffer will not be freed. If the header is a link, the 264 * block will be marked as free. 265 * This function returns a negative error number in case of 266 * an error, else 0 if the inode is to be deleted or 1 if not. 267 */ 268 269 int 270 affs_remove_header(struct dentry *dentry) 271 { 272 struct super_block *sb; 273 struct inode *inode, *dir; 274 struct buffer_head *bh = NULL; 275 int retval; 276 277 dir = dentry->d_parent->d_inode; 278 sb = dir->i_sb; 279 280 retval = -ENOENT; 281 inode = dentry->d_inode; 282 if (!inode) 283 goto done; 284 285 pr_debug("AFFS: remove_header(key=%ld)\n", inode->i_ino); 286 retval = -EIO; 287 bh = affs_bread(sb, (u32)(long)dentry->d_fsdata); 288 if (!bh) 289 goto done; 290 291 affs_lock_link(inode); 292 affs_lock_dir(dir); 293 switch (be32_to_cpu(AFFS_TAIL(sb, bh)->stype)) { 294 case ST_USERDIR: 295 /* if we ever want to support links to dirs 296 * i_hash_lock of the inode must only be 297 * taken after some checks 298 */ 299 affs_lock_dir(inode); 300 retval = affs_empty_dir(inode); 301 affs_unlock_dir(inode); 302 if (retval) 303 goto done_unlock; 304 break; 305 default: 306 break; 307 } 308 309 retval = affs_remove_hash(dir, bh); 310 if (retval) 311 goto done_unlock; 312 mark_buffer_dirty_inode(bh, inode); 313 314 affs_unlock_dir(dir); 315 316 if (inode->i_nlink > 1) 317 retval = affs_remove_link(dentry); 318 else 319 inode->i_nlink = 0; 320 affs_unlock_link(inode); 321 inode->i_ctime = CURRENT_TIME_SEC; 322 mark_inode_dirty(inode); 323 324 done: 325 affs_brelse(bh); 326 return retval; 327 328 done_unlock: 329 affs_unlock_dir(dir); 330 affs_unlock_link(inode); 331 goto done; 332 } 333 334 /* Checksum a block, do various consistency checks and optionally return 335 the blocks type number. DATA points to the block. If their pointers 336 are non-null, *PTYPE and *STYPE are set to the primary and secondary 337 block types respectively, *HASHSIZE is set to the size of the hashtable 338 (which lets us calculate the block size). 339 Returns non-zero if the block is not consistent. */ 340 341 u32 342 affs_checksum_block(struct super_block *sb, struct buffer_head *bh) 343 { 344 __be32 *ptr = (__be32 *)bh->b_data; 345 u32 sum; 346 int bsize; 347 348 sum = 0; 349 for (bsize = sb->s_blocksize / sizeof(__be32); bsize > 0; bsize--) 350 sum += be32_to_cpu(*ptr++); 351 return sum; 352 } 353 354 /* 355 * Calculate the checksum of a disk block and store it 356 * at the indicated position. 357 */ 358 359 void 360 affs_fix_checksum(struct super_block *sb, struct buffer_head *bh) 361 { 362 int cnt = sb->s_blocksize / sizeof(__be32); 363 __be32 *ptr = (__be32 *)bh->b_data; 364 u32 checksum; 365 __be32 *checksumptr; 366 367 checksumptr = ptr + 5; 368 *checksumptr = 0; 369 for (checksum = 0; cnt > 0; ptr++, cnt--) 370 checksum += be32_to_cpu(*ptr); 371 *checksumptr = cpu_to_be32(-checksum); 372 } 373 374 void 375 secs_to_datestamp(time_t secs, struct affs_date *ds) 376 { 377 u32 days; 378 u32 minute; 379 380 secs -= sys_tz.tz_minuteswest * 60 + ((8 * 365 + 2) * 24 * 60 * 60); 381 if (secs < 0) 382 secs = 0; 383 days = secs / 86400; 384 secs -= days * 86400; 385 minute = secs / 60; 386 secs -= minute * 60; 387 388 ds->days = cpu_to_be32(days); 389 ds->mins = cpu_to_be32(minute); 390 ds->ticks = cpu_to_be32(secs * 50); 391 } 392 393 mode_t 394 prot_to_mode(u32 prot) 395 { 396 int mode = 0; 397 398 if (!(prot & FIBF_NOWRITE)) 399 mode |= S_IWUSR; 400 if (!(prot & FIBF_NOREAD)) 401 mode |= S_IRUSR; 402 if (!(prot & FIBF_NOEXECUTE)) 403 mode |= S_IXUSR; 404 if (prot & FIBF_GRP_WRITE) 405 mode |= S_IWGRP; 406 if (prot & FIBF_GRP_READ) 407 mode |= S_IRGRP; 408 if (prot & FIBF_GRP_EXECUTE) 409 mode |= S_IXGRP; 410 if (prot & FIBF_OTR_WRITE) 411 mode |= S_IWOTH; 412 if (prot & FIBF_OTR_READ) 413 mode |= S_IROTH; 414 if (prot & FIBF_OTR_EXECUTE) 415 mode |= S_IXOTH; 416 417 return mode; 418 } 419 420 void 421 mode_to_prot(struct inode *inode) 422 { 423 u32 prot = AFFS_I(inode)->i_protect; 424 mode_t mode = inode->i_mode; 425 426 if (!(mode & S_IXUSR)) 427 prot |= FIBF_NOEXECUTE; 428 if (!(mode & S_IRUSR)) 429 prot |= FIBF_NOREAD; 430 if (!(mode & S_IWUSR)) 431 prot |= FIBF_NOWRITE; 432 if (mode & S_IXGRP) 433 prot |= FIBF_GRP_EXECUTE; 434 if (mode & S_IRGRP) 435 prot |= FIBF_GRP_READ; 436 if (mode & S_IWGRP) 437 prot |= FIBF_GRP_WRITE; 438 if (mode & S_IXOTH) 439 prot |= FIBF_OTR_EXECUTE; 440 if (mode & S_IROTH) 441 prot |= FIBF_OTR_READ; 442 if (mode & S_IWOTH) 443 prot |= FIBF_OTR_WRITE; 444 445 AFFS_I(inode)->i_protect = prot; 446 } 447 448 void 449 affs_error(struct super_block *sb, const char *function, const char *fmt, ...) 450 { 451 va_list args; 452 453 va_start(args,fmt); 454 vsnprintf(ErrorBuffer,sizeof(ErrorBuffer),fmt,args); 455 va_end(args); 456 457 printk(KERN_CRIT "AFFS error (device %s): %s(): %s\n", sb->s_id, 458 function,ErrorBuffer); 459 if (!(sb->s_flags & MS_RDONLY)) 460 printk(KERN_WARNING "AFFS: Remounting filesystem read-only\n"); 461 sb->s_flags |= MS_RDONLY; 462 } 463 464 void 465 affs_warning(struct super_block *sb, const char *function, const char *fmt, ...) 466 { 467 va_list args; 468 469 va_start(args,fmt); 470 vsnprintf(ErrorBuffer,sizeof(ErrorBuffer),fmt,args); 471 va_end(args); 472 473 printk(KERN_WARNING "AFFS warning (device %s): %s(): %s\n", sb->s_id, 474 function,ErrorBuffer); 475 } 476 477 /* Check if the name is valid for a affs object. */ 478 479 int 480 affs_check_name(const unsigned char *name, int len) 481 { 482 int i; 483 484 if (len > 30) 485 #ifdef AFFS_NO_TRUNCATE 486 return -ENAMETOOLONG; 487 #else 488 len = 30; 489 #endif 490 491 for (i = 0; i < len; i++) { 492 if (name[i] < ' ' || name[i] == ':' 493 || (name[i] > 0x7e && name[i] < 0xa0)) 494 return -EINVAL; 495 } 496 497 return 0; 498 } 499 500 /* This function copies name to bstr, with at most 30 501 * characters length. The bstr will be prepended by 502 * a length byte. 503 * NOTE: The name will must be already checked by 504 * affs_check_name()! 505 */ 506 507 int 508 affs_copy_name(unsigned char *bstr, struct dentry *dentry) 509 { 510 int len = min(dentry->d_name.len, 30u); 511 512 *bstr++ = len; 513 memcpy(bstr, dentry->d_name.name, len); 514 return len; 515 } 516