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 } 512