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 <linux/math64.h> 12 #include "affs.h" 13 14 /* 15 * Functions for accessing Amiga-FFS structures. 16 */ 17 18 19 /* Insert a header block bh into the directory dir 20 * caller must hold AFFS_DIR->i_hash_lock! 21 */ 22 23 int 24 affs_insert_hash(struct inode *dir, struct buffer_head *bh) 25 { 26 struct super_block *sb = dir->i_sb; 27 struct buffer_head *dir_bh; 28 u32 ino, hash_ino; 29 int offset; 30 31 ino = bh->b_blocknr; 32 offset = affs_hash_name(sb, AFFS_TAIL(sb, bh)->name + 1, AFFS_TAIL(sb, bh)->name[0]); 33 34 pr_debug("%s(dir=%lu, ino=%d)\n", __func__, dir->i_ino, ino); 35 36 dir_bh = affs_bread(sb, dir->i_ino); 37 if (!dir_bh) 38 return -EIO; 39 40 hash_ino = be32_to_cpu(AFFS_HEAD(dir_bh)->table[offset]); 41 while (hash_ino) { 42 affs_brelse(dir_bh); 43 dir_bh = affs_bread(sb, hash_ino); 44 if (!dir_bh) 45 return -EIO; 46 hash_ino = be32_to_cpu(AFFS_TAIL(sb, dir_bh)->hash_chain); 47 } 48 AFFS_TAIL(sb, bh)->parent = cpu_to_be32(dir->i_ino); 49 AFFS_TAIL(sb, bh)->hash_chain = 0; 50 affs_fix_checksum(sb, bh); 51 52 if (dir->i_ino == dir_bh->b_blocknr) 53 AFFS_HEAD(dir_bh)->table[offset] = cpu_to_be32(ino); 54 else 55 AFFS_TAIL(sb, dir_bh)->hash_chain = cpu_to_be32(ino); 56 57 affs_adjust_checksum(dir_bh, ino); 58 mark_buffer_dirty_inode(dir_bh, dir); 59 affs_brelse(dir_bh); 60 61 dir->i_mtime = dir->i_ctime = current_time(dir); 62 dir->i_version++; 63 mark_inode_dirty(dir); 64 65 return 0; 66 } 67 68 /* Remove a header block from its directory. 69 * caller must hold AFFS_DIR->i_hash_lock! 70 */ 71 72 int 73 affs_remove_hash(struct inode *dir, struct buffer_head *rem_bh) 74 { 75 struct super_block *sb; 76 struct buffer_head *bh; 77 u32 rem_ino, hash_ino; 78 __be32 ino; 79 int offset, retval; 80 81 sb = dir->i_sb; 82 rem_ino = rem_bh->b_blocknr; 83 offset = affs_hash_name(sb, AFFS_TAIL(sb, rem_bh)->name+1, AFFS_TAIL(sb, rem_bh)->name[0]); 84 pr_debug("%s(dir=%lu, ino=%d, hashval=%d)\n", __func__, dir->i_ino, 85 rem_ino, offset); 86 87 bh = affs_bread(sb, dir->i_ino); 88 if (!bh) 89 return -EIO; 90 91 retval = -ENOENT; 92 hash_ino = be32_to_cpu(AFFS_HEAD(bh)->table[offset]); 93 while (hash_ino) { 94 if (hash_ino == rem_ino) { 95 ino = AFFS_TAIL(sb, rem_bh)->hash_chain; 96 if (dir->i_ino == bh->b_blocknr) 97 AFFS_HEAD(bh)->table[offset] = ino; 98 else 99 AFFS_TAIL(sb, bh)->hash_chain = ino; 100 affs_adjust_checksum(bh, be32_to_cpu(ino) - hash_ino); 101 mark_buffer_dirty_inode(bh, dir); 102 AFFS_TAIL(sb, rem_bh)->parent = 0; 103 retval = 0; 104 break; 105 } 106 affs_brelse(bh); 107 bh = affs_bread(sb, hash_ino); 108 if (!bh) 109 return -EIO; 110 hash_ino = be32_to_cpu(AFFS_TAIL(sb, bh)->hash_chain); 111 } 112 113 affs_brelse(bh); 114 115 dir->i_mtime = dir->i_ctime = current_time(dir); 116 dir->i_version++; 117 mark_inode_dirty(dir); 118 119 return retval; 120 } 121 122 static void 123 affs_fix_dcache(struct inode *inode, u32 entry_ino) 124 { 125 struct dentry *dentry; 126 spin_lock(&inode->i_lock); 127 hlist_for_each_entry(dentry, &inode->i_dentry, d_u.d_alias) { 128 if (entry_ino == (u32)(long)dentry->d_fsdata) { 129 dentry->d_fsdata = (void *)inode->i_ino; 130 break; 131 } 132 } 133 spin_unlock(&inode->i_lock); 134 } 135 136 137 /* Remove header from link chain */ 138 139 static int 140 affs_remove_link(struct dentry *dentry) 141 { 142 struct inode *dir, *inode = d_inode(dentry); 143 struct super_block *sb = inode->i_sb; 144 struct buffer_head *bh, *link_bh = NULL; 145 u32 link_ino, ino; 146 int retval; 147 148 pr_debug("%s(key=%ld)\n", __func__, inode->i_ino); 149 retval = -EIO; 150 bh = affs_bread(sb, inode->i_ino); 151 if (!bh) 152 goto done; 153 154 link_ino = (u32)(long)dentry->d_fsdata; 155 if (inode->i_ino == link_ino) { 156 /* we can't remove the head of the link, as its blocknr is still used as ino, 157 * so we remove the block of the first link instead. 158 */ 159 link_ino = be32_to_cpu(AFFS_TAIL(sb, bh)->link_chain); 160 link_bh = affs_bread(sb, link_ino); 161 if (!link_bh) 162 goto done; 163 164 dir = affs_iget(sb, be32_to_cpu(AFFS_TAIL(sb, link_bh)->parent)); 165 if (IS_ERR(dir)) { 166 retval = PTR_ERR(dir); 167 goto done; 168 } 169 170 affs_lock_dir(dir); 171 /* 172 * if there's a dentry for that block, make it 173 * refer to inode itself. 174 */ 175 affs_fix_dcache(inode, link_ino); 176 retval = affs_remove_hash(dir, link_bh); 177 if (retval) { 178 affs_unlock_dir(dir); 179 goto done; 180 } 181 mark_buffer_dirty_inode(link_bh, inode); 182 183 memcpy(AFFS_TAIL(sb, bh)->name, AFFS_TAIL(sb, link_bh)->name, 32); 184 retval = affs_insert_hash(dir, bh); 185 if (retval) { 186 affs_unlock_dir(dir); 187 goto done; 188 } 189 mark_buffer_dirty_inode(bh, inode); 190 191 affs_unlock_dir(dir); 192 iput(dir); 193 } else { 194 link_bh = affs_bread(sb, link_ino); 195 if (!link_bh) 196 goto done; 197 } 198 199 while ((ino = be32_to_cpu(AFFS_TAIL(sb, bh)->link_chain)) != 0) { 200 if (ino == link_ino) { 201 __be32 ino2 = AFFS_TAIL(sb, link_bh)->link_chain; 202 AFFS_TAIL(sb, bh)->link_chain = ino2; 203 affs_adjust_checksum(bh, be32_to_cpu(ino2) - link_ino); 204 mark_buffer_dirty_inode(bh, inode); 205 retval = 0; 206 /* Fix the link count, if bh is a normal header block without links */ 207 switch (be32_to_cpu(AFFS_TAIL(sb, bh)->stype)) { 208 case ST_LINKDIR: 209 case ST_LINKFILE: 210 break; 211 default: 212 if (!AFFS_TAIL(sb, bh)->link_chain) 213 set_nlink(inode, 1); 214 } 215 affs_free_block(sb, link_ino); 216 goto done; 217 } 218 affs_brelse(bh); 219 bh = affs_bread(sb, ino); 220 if (!bh) 221 goto done; 222 } 223 retval = -ENOENT; 224 done: 225 affs_brelse(link_bh); 226 affs_brelse(bh); 227 return retval; 228 } 229 230 231 static int 232 affs_empty_dir(struct inode *inode) 233 { 234 struct super_block *sb = inode->i_sb; 235 struct buffer_head *bh; 236 int retval, size; 237 238 retval = -EIO; 239 bh = affs_bread(sb, inode->i_ino); 240 if (!bh) 241 goto done; 242 243 retval = -ENOTEMPTY; 244 for (size = AFFS_SB(sb)->s_hashsize - 1; size >= 0; size--) 245 if (AFFS_HEAD(bh)->table[size]) 246 goto not_empty; 247 retval = 0; 248 not_empty: 249 affs_brelse(bh); 250 done: 251 return retval; 252 } 253 254 255 /* Remove a filesystem object. If the object to be removed has 256 * links to it, one of the links must be changed to inherit 257 * the file or directory. As above, any inode will do. 258 * The buffer will not be freed. If the header is a link, the 259 * block will be marked as free. 260 * This function returns a negative error number in case of 261 * an error, else 0 if the inode is to be deleted or 1 if not. 262 */ 263 264 int 265 affs_remove_header(struct dentry *dentry) 266 { 267 struct super_block *sb; 268 struct inode *inode, *dir; 269 struct buffer_head *bh = NULL; 270 int retval; 271 272 dir = d_inode(dentry->d_parent); 273 sb = dir->i_sb; 274 275 retval = -ENOENT; 276 inode = d_inode(dentry); 277 if (!inode) 278 goto done; 279 280 pr_debug("%s(key=%ld)\n", __func__, inode->i_ino); 281 retval = -EIO; 282 bh = affs_bread(sb, (u32)(long)dentry->d_fsdata); 283 if (!bh) 284 goto done; 285 286 affs_lock_link(inode); 287 affs_lock_dir(dir); 288 switch (be32_to_cpu(AFFS_TAIL(sb, bh)->stype)) { 289 case ST_USERDIR: 290 /* if we ever want to support links to dirs 291 * i_hash_lock of the inode must only be 292 * taken after some checks 293 */ 294 affs_lock_dir(inode); 295 retval = affs_empty_dir(inode); 296 affs_unlock_dir(inode); 297 if (retval) 298 goto done_unlock; 299 break; 300 default: 301 break; 302 } 303 304 retval = affs_remove_hash(dir, bh); 305 if (retval) 306 goto done_unlock; 307 mark_buffer_dirty_inode(bh, inode); 308 309 affs_unlock_dir(dir); 310 311 if (inode->i_nlink > 1) 312 retval = affs_remove_link(dentry); 313 else 314 clear_nlink(inode); 315 affs_unlock_link(inode); 316 inode->i_ctime = current_time(inode); 317 mark_inode_dirty(inode); 318 319 done: 320 affs_brelse(bh); 321 return retval; 322 323 done_unlock: 324 affs_unlock_dir(dir); 325 affs_unlock_link(inode); 326 goto done; 327 } 328 329 /* Checksum a block, do various consistency checks and optionally return 330 the blocks type number. DATA points to the block. If their pointers 331 are non-null, *PTYPE and *STYPE are set to the primary and secondary 332 block types respectively, *HASHSIZE is set to the size of the hashtable 333 (which lets us calculate the block size). 334 Returns non-zero if the block is not consistent. */ 335 336 u32 337 affs_checksum_block(struct super_block *sb, struct buffer_head *bh) 338 { 339 __be32 *ptr = (__be32 *)bh->b_data; 340 u32 sum; 341 int bsize; 342 343 sum = 0; 344 for (bsize = sb->s_blocksize / sizeof(__be32); bsize > 0; bsize--) 345 sum += be32_to_cpu(*ptr++); 346 return sum; 347 } 348 349 /* 350 * Calculate the checksum of a disk block and store it 351 * at the indicated position. 352 */ 353 354 void 355 affs_fix_checksum(struct super_block *sb, struct buffer_head *bh) 356 { 357 int cnt = sb->s_blocksize / sizeof(__be32); 358 __be32 *ptr = (__be32 *)bh->b_data; 359 u32 checksum; 360 __be32 *checksumptr; 361 362 checksumptr = ptr + 5; 363 *checksumptr = 0; 364 for (checksum = 0; cnt > 0; ptr++, cnt--) 365 checksum += be32_to_cpu(*ptr); 366 *checksumptr = cpu_to_be32(-checksum); 367 } 368 369 void 370 secs_to_datestamp(time64_t secs, struct affs_date *ds) 371 { 372 u32 days; 373 u32 minute; 374 s32 rem; 375 376 secs -= sys_tz.tz_minuteswest * 60 + ((8 * 365 + 2) * 24 * 60 * 60); 377 if (secs < 0) 378 secs = 0; 379 days = div_s64_rem(secs, 86400, &rem); 380 minute = rem / 60; 381 rem -= minute * 60; 382 383 ds->days = cpu_to_be32(days); 384 ds->mins = cpu_to_be32(minute); 385 ds->ticks = cpu_to_be32(rem * 50); 386 } 387 388 umode_t 389 prot_to_mode(u32 prot) 390 { 391 umode_t mode = 0; 392 393 if (!(prot & FIBF_NOWRITE)) 394 mode |= S_IWUSR; 395 if (!(prot & FIBF_NOREAD)) 396 mode |= S_IRUSR; 397 if (!(prot & FIBF_NOEXECUTE)) 398 mode |= S_IXUSR; 399 if (prot & FIBF_GRP_WRITE) 400 mode |= S_IWGRP; 401 if (prot & FIBF_GRP_READ) 402 mode |= S_IRGRP; 403 if (prot & FIBF_GRP_EXECUTE) 404 mode |= S_IXGRP; 405 if (prot & FIBF_OTR_WRITE) 406 mode |= S_IWOTH; 407 if (prot & FIBF_OTR_READ) 408 mode |= S_IROTH; 409 if (prot & FIBF_OTR_EXECUTE) 410 mode |= S_IXOTH; 411 412 return mode; 413 } 414 415 void 416 mode_to_prot(struct inode *inode) 417 { 418 u32 prot = AFFS_I(inode)->i_protect; 419 umode_t mode = inode->i_mode; 420 421 if (!(mode & S_IXUSR)) 422 prot |= FIBF_NOEXECUTE; 423 if (!(mode & S_IRUSR)) 424 prot |= FIBF_NOREAD; 425 if (!(mode & S_IWUSR)) 426 prot |= FIBF_NOWRITE; 427 if (mode & S_IXGRP) 428 prot |= FIBF_GRP_EXECUTE; 429 if (mode & S_IRGRP) 430 prot |= FIBF_GRP_READ; 431 if (mode & S_IWGRP) 432 prot |= FIBF_GRP_WRITE; 433 if (mode & S_IXOTH) 434 prot |= FIBF_OTR_EXECUTE; 435 if (mode & S_IROTH) 436 prot |= FIBF_OTR_READ; 437 if (mode & S_IWOTH) 438 prot |= FIBF_OTR_WRITE; 439 440 AFFS_I(inode)->i_protect = prot; 441 } 442 443 void 444 affs_error(struct super_block *sb, const char *function, const char *fmt, ...) 445 { 446 struct va_format vaf; 447 va_list args; 448 449 va_start(args, fmt); 450 vaf.fmt = fmt; 451 vaf.va = &args; 452 pr_crit("error (device %s): %s(): %pV\n", sb->s_id, function, &vaf); 453 if (!(sb->s_flags & MS_RDONLY)) 454 pr_warn("Remounting filesystem read-only\n"); 455 sb->s_flags |= MS_RDONLY; 456 va_end(args); 457 } 458 459 void 460 affs_warning(struct super_block *sb, const char *function, const char *fmt, ...) 461 { 462 struct va_format vaf; 463 va_list args; 464 465 va_start(args, fmt); 466 vaf.fmt = fmt; 467 vaf.va = &args; 468 pr_warn("(device %s): %s(): %pV\n", sb->s_id, function, &vaf); 469 va_end(args); 470 } 471 472 bool 473 affs_nofilenametruncate(const struct dentry *dentry) 474 { 475 return affs_test_opt(AFFS_SB(dentry->d_sb)->s_flags, SF_NO_TRUNCATE); 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, bool notruncate) 482 { 483 int i; 484 485 if (len > AFFSNAMEMAX) { 486 if (notruncate) 487 return -ENAMETOOLONG; 488 len = AFFSNAMEMAX; 489 } 490 for (i = 0; i < len; i++) { 491 if (name[i] < ' ' || name[i] == ':' 492 || (name[i] > 0x7e && name[i] < 0xa0)) 493 return -EINVAL; 494 } 495 496 return 0; 497 } 498 499 /* This function copies name to bstr, with at most 30 500 * characters length. The bstr will be prepended by 501 * a length byte. 502 * NOTE: The name will must be already checked by 503 * affs_check_name()! 504 */ 505 506 int 507 affs_copy_name(unsigned char *bstr, struct dentry *dentry) 508 { 509 u32 len = min(dentry->d_name.len, AFFSNAMEMAX); 510 511 *bstr++ = len; 512 memcpy(bstr, dentry->d_name.name, len); 513 return len; 514 } 515