1 /* 2 * linux/fs/affs/namei.c 3 * 4 * (c) 1996 Hans-Joachim Widmaier - Rewritten 5 * 6 * (C) 1993 Ray Burr - Modified for Amiga FFS filesystem. 7 * 8 * (C) 1991 Linus Torvalds - minix filesystem 9 */ 10 11 #include "affs.h" 12 #include <linux/exportfs.h> 13 14 typedef int (*toupper_t)(int); 15 16 /* Simple toupper() for DOS\1 */ 17 18 static int 19 affs_toupper(int ch) 20 { 21 return ch >= 'a' && ch <= 'z' ? ch -= ('a' - 'A') : ch; 22 } 23 24 /* International toupper() for DOS\3 ("international") */ 25 26 static int 27 affs_intl_toupper(int ch) 28 { 29 return (ch >= 'a' && ch <= 'z') || (ch >= 0xE0 30 && ch <= 0xFE && ch != 0xF7) ? 31 ch - ('a' - 'A') : ch; 32 } 33 34 static inline toupper_t 35 affs_get_toupper(struct super_block *sb) 36 { 37 return affs_test_opt(AFFS_SB(sb)->s_flags, SF_INTL) ? 38 affs_intl_toupper : affs_toupper; 39 } 40 41 /* 42 * Note: the dentry argument is the parent dentry. 43 */ 44 static inline int 45 __affs_hash_dentry(const struct dentry *dentry, struct qstr *qstr, toupper_t toupper, bool notruncate) 46 { 47 const u8 *name = qstr->name; 48 unsigned long hash; 49 int retval; 50 u32 len; 51 52 retval = affs_check_name(qstr->name, qstr->len, notruncate); 53 if (retval) 54 return retval; 55 56 hash = init_name_hash(dentry); 57 len = min(qstr->len, AFFSNAMEMAX); 58 for (; len > 0; name++, len--) 59 hash = partial_name_hash(toupper(*name), hash); 60 qstr->hash = end_name_hash(hash); 61 62 return 0; 63 } 64 65 static int 66 affs_hash_dentry(const struct dentry *dentry, struct qstr *qstr) 67 { 68 return __affs_hash_dentry(dentry, qstr, affs_toupper, 69 affs_nofilenametruncate(dentry)); 70 71 } 72 73 static int 74 affs_intl_hash_dentry(const struct dentry *dentry, struct qstr *qstr) 75 { 76 return __affs_hash_dentry(dentry, qstr, affs_intl_toupper, 77 affs_nofilenametruncate(dentry)); 78 79 } 80 81 static inline int __affs_compare_dentry(unsigned int len, 82 const char *str, const struct qstr *name, toupper_t toupper, 83 bool notruncate) 84 { 85 const u8 *aname = str; 86 const u8 *bname = name->name; 87 88 /* 89 * 'str' is the name of an already existing dentry, so the name 90 * must be valid. 'name' must be validated first. 91 */ 92 93 if (affs_check_name(name->name, name->len, notruncate)) 94 return 1; 95 96 /* 97 * If the names are longer than the allowed 30 chars, 98 * the excess is ignored, so their length may differ. 99 */ 100 if (len >= AFFSNAMEMAX) { 101 if (name->len < AFFSNAMEMAX) 102 return 1; 103 len = AFFSNAMEMAX; 104 } else if (len != name->len) 105 return 1; 106 107 for (; len > 0; len--) 108 if (toupper(*aname++) != toupper(*bname++)) 109 return 1; 110 111 return 0; 112 } 113 114 static int 115 affs_compare_dentry(const struct dentry *dentry, 116 unsigned int len, const char *str, const struct qstr *name) 117 { 118 119 return __affs_compare_dentry(len, str, name, affs_toupper, 120 affs_nofilenametruncate(dentry)); 121 } 122 123 static int 124 affs_intl_compare_dentry(const struct dentry *dentry, 125 unsigned int len, const char *str, const struct qstr *name) 126 { 127 return __affs_compare_dentry(len, str, name, affs_intl_toupper, 128 affs_nofilenametruncate(dentry)); 129 130 } 131 132 /* 133 * NOTE! unlike strncmp, affs_match returns 1 for success, 0 for failure. 134 */ 135 136 static inline int 137 affs_match(struct dentry *dentry, const u8 *name2, toupper_t toupper) 138 { 139 const u8 *name = dentry->d_name.name; 140 int len = dentry->d_name.len; 141 142 if (len >= AFFSNAMEMAX) { 143 if (*name2 < AFFSNAMEMAX) 144 return 0; 145 len = AFFSNAMEMAX; 146 } else if (len != *name2) 147 return 0; 148 149 for (name2++; len > 0; len--) 150 if (toupper(*name++) != toupper(*name2++)) 151 return 0; 152 return 1; 153 } 154 155 int 156 affs_hash_name(struct super_block *sb, const u8 *name, unsigned int len) 157 { 158 toupper_t toupper = affs_get_toupper(sb); 159 u32 hash; 160 161 hash = len = min(len, AFFSNAMEMAX); 162 for (; len > 0; len--) 163 hash = (hash * 13 + toupper(*name++)) & 0x7ff; 164 165 return hash % AFFS_SB(sb)->s_hashsize; 166 } 167 168 static struct buffer_head * 169 affs_find_entry(struct inode *dir, struct dentry *dentry) 170 { 171 struct super_block *sb = dir->i_sb; 172 struct buffer_head *bh; 173 toupper_t toupper = affs_get_toupper(sb); 174 u32 key; 175 176 pr_debug("%s(\"%pd\")\n", __func__, dentry); 177 178 bh = affs_bread(sb, dir->i_ino); 179 if (!bh) 180 return ERR_PTR(-EIO); 181 182 key = be32_to_cpu(AFFS_HEAD(bh)->table[affs_hash_name(sb, dentry->d_name.name, dentry->d_name.len)]); 183 184 for (;;) { 185 affs_brelse(bh); 186 if (key == 0) 187 return NULL; 188 bh = affs_bread(sb, key); 189 if (!bh) 190 return ERR_PTR(-EIO); 191 if (affs_match(dentry, AFFS_TAIL(sb, bh)->name, toupper)) 192 return bh; 193 key = be32_to_cpu(AFFS_TAIL(sb, bh)->hash_chain); 194 } 195 } 196 197 struct dentry * 198 affs_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags) 199 { 200 struct super_block *sb = dir->i_sb; 201 struct buffer_head *bh; 202 struct inode *inode = NULL; 203 204 pr_debug("%s(\"%pd\")\n", __func__, dentry); 205 206 affs_lock_dir(dir); 207 bh = affs_find_entry(dir, dentry); 208 affs_unlock_dir(dir); 209 if (IS_ERR(bh)) 210 return ERR_CAST(bh); 211 if (bh) { 212 u32 ino = bh->b_blocknr; 213 214 /* store the real header ino in d_fsdata for faster lookups */ 215 dentry->d_fsdata = (void *)(long)ino; 216 switch (be32_to_cpu(AFFS_TAIL(sb, bh)->stype)) { 217 //link to dirs disabled 218 //case ST_LINKDIR: 219 case ST_LINKFILE: 220 ino = be32_to_cpu(AFFS_TAIL(sb, bh)->original); 221 } 222 affs_brelse(bh); 223 inode = affs_iget(sb, ino); 224 if (IS_ERR(inode)) 225 return ERR_CAST(inode); 226 } 227 d_add(dentry, inode); 228 return NULL; 229 } 230 231 int 232 affs_unlink(struct inode *dir, struct dentry *dentry) 233 { 234 pr_debug("%s(dir=%lu, %lu \"%pd\")\n", __func__, dir->i_ino, 235 d_inode(dentry)->i_ino, dentry); 236 237 return affs_remove_header(dentry); 238 } 239 240 int 241 affs_create(struct inode *dir, struct dentry *dentry, umode_t mode, bool excl) 242 { 243 struct super_block *sb = dir->i_sb; 244 struct inode *inode; 245 int error; 246 247 pr_debug("%s(%lu,\"%pd\",0%ho)\n", 248 __func__, dir->i_ino, dentry, mode); 249 250 inode = affs_new_inode(dir); 251 if (!inode) 252 return -ENOSPC; 253 254 inode->i_mode = mode; 255 affs_mode_to_prot(inode); 256 mark_inode_dirty(inode); 257 258 inode->i_op = &affs_file_inode_operations; 259 inode->i_fop = &affs_file_operations; 260 inode->i_mapping->a_ops = affs_test_opt(AFFS_SB(sb)->s_flags, SF_OFS) ? 261 &affs_aops_ofs : &affs_aops; 262 error = affs_add_entry(dir, inode, dentry, ST_FILE); 263 if (error) { 264 clear_nlink(inode); 265 iput(inode); 266 return error; 267 } 268 return 0; 269 } 270 271 int 272 affs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode) 273 { 274 struct inode *inode; 275 int error; 276 277 pr_debug("%s(%lu,\"%pd\",0%ho)\n", 278 __func__, dir->i_ino, dentry, mode); 279 280 inode = affs_new_inode(dir); 281 if (!inode) 282 return -ENOSPC; 283 284 inode->i_mode = S_IFDIR | mode; 285 affs_mode_to_prot(inode); 286 287 inode->i_op = &affs_dir_inode_operations; 288 inode->i_fop = &affs_dir_operations; 289 290 error = affs_add_entry(dir, inode, dentry, ST_USERDIR); 291 if (error) { 292 clear_nlink(inode); 293 mark_inode_dirty(inode); 294 iput(inode); 295 return error; 296 } 297 return 0; 298 } 299 300 int 301 affs_rmdir(struct inode *dir, struct dentry *dentry) 302 { 303 pr_debug("%s(dir=%lu, %lu \"%pd\")\n", __func__, dir->i_ino, 304 d_inode(dentry)->i_ino, dentry); 305 306 return affs_remove_header(dentry); 307 } 308 309 int 310 affs_symlink(struct inode *dir, struct dentry *dentry, const char *symname) 311 { 312 struct super_block *sb = dir->i_sb; 313 struct buffer_head *bh; 314 struct inode *inode; 315 char *p; 316 int i, maxlen, error; 317 char c, lc; 318 319 pr_debug("%s(%lu,\"%pd\" -> \"%s\")\n", 320 __func__, dir->i_ino, dentry, symname); 321 322 maxlen = AFFS_SB(sb)->s_hashsize * sizeof(u32) - 1; 323 inode = affs_new_inode(dir); 324 if (!inode) 325 return -ENOSPC; 326 327 inode->i_op = &affs_symlink_inode_operations; 328 inode_nohighmem(inode); 329 inode->i_data.a_ops = &affs_symlink_aops; 330 inode->i_mode = S_IFLNK | 0777; 331 affs_mode_to_prot(inode); 332 333 error = -EIO; 334 bh = affs_bread(sb, inode->i_ino); 335 if (!bh) 336 goto err; 337 i = 0; 338 p = (char *)AFFS_HEAD(bh)->table; 339 lc = '/'; 340 if (*symname == '/') { 341 struct affs_sb_info *sbi = AFFS_SB(sb); 342 while (*symname == '/') 343 symname++; 344 spin_lock(&sbi->symlink_lock); 345 while (sbi->s_volume[i]) /* Cannot overflow */ 346 *p++ = sbi->s_volume[i++]; 347 spin_unlock(&sbi->symlink_lock); 348 } 349 while (i < maxlen && (c = *symname++)) { 350 if (c == '.' && lc == '/' && *symname == '.' && symname[1] == '/') { 351 *p++ = '/'; 352 i++; 353 symname += 2; 354 lc = '/'; 355 } else if (c == '.' && lc == '/' && *symname == '/') { 356 symname++; 357 lc = '/'; 358 } else { 359 *p++ = c; 360 lc = c; 361 i++; 362 } 363 if (lc == '/') 364 while (*symname == '/') 365 symname++; 366 } 367 *p = 0; 368 inode->i_size = i + 1; 369 mark_buffer_dirty_inode(bh, inode); 370 affs_brelse(bh); 371 mark_inode_dirty(inode); 372 373 error = affs_add_entry(dir, inode, dentry, ST_SOFTLINK); 374 if (error) 375 goto err; 376 377 return 0; 378 379 err: 380 clear_nlink(inode); 381 mark_inode_dirty(inode); 382 iput(inode); 383 return error; 384 } 385 386 int 387 affs_link(struct dentry *old_dentry, struct inode *dir, struct dentry *dentry) 388 { 389 struct inode *inode = d_inode(old_dentry); 390 391 pr_debug("%s(%lu, %lu, \"%pd\")\n", __func__, inode->i_ino, dir->i_ino, 392 dentry); 393 394 return affs_add_entry(dir, inode, dentry, ST_LINKFILE); 395 } 396 397 static int 398 affs_rename(struct inode *old_dir, struct dentry *old_dentry, 399 struct inode *new_dir, struct dentry *new_dentry) 400 { 401 struct super_block *sb = old_dir->i_sb; 402 struct buffer_head *bh = NULL; 403 int retval; 404 405 retval = affs_check_name(new_dentry->d_name.name, 406 new_dentry->d_name.len, 407 affs_nofilenametruncate(old_dentry)); 408 409 if (retval) 410 return retval; 411 412 /* Unlink destination if it already exists */ 413 if (d_really_is_positive(new_dentry)) { 414 retval = affs_remove_header(new_dentry); 415 if (retval) 416 return retval; 417 } 418 419 bh = affs_bread(sb, d_inode(old_dentry)->i_ino); 420 if (!bh) 421 return -EIO; 422 423 /* Remove header from its parent directory. */ 424 affs_lock_dir(old_dir); 425 retval = affs_remove_hash(old_dir, bh); 426 affs_unlock_dir(old_dir); 427 if (retval) 428 goto done; 429 430 /* And insert it into the new directory with the new name. */ 431 affs_copy_name(AFFS_TAIL(sb, bh)->name, new_dentry); 432 affs_fix_checksum(sb, bh); 433 affs_lock_dir(new_dir); 434 retval = affs_insert_hash(new_dir, bh); 435 affs_unlock_dir(new_dir); 436 /* TODO: move it back to old_dir, if error? */ 437 438 done: 439 mark_buffer_dirty_inode(bh, retval ? old_dir : new_dir); 440 affs_brelse(bh); 441 return retval; 442 } 443 444 static int 445 affs_xrename(struct inode *old_dir, struct dentry *old_dentry, 446 struct inode *new_dir, struct dentry *new_dentry) 447 { 448 449 struct super_block *sb = old_dir->i_sb; 450 struct buffer_head *bh_old = NULL; 451 struct buffer_head *bh_new = NULL; 452 int retval; 453 454 bh_old = affs_bread(sb, d_inode(old_dentry)->i_ino); 455 if (!bh_old) 456 return -EIO; 457 458 bh_new = affs_bread(sb, d_inode(new_dentry)->i_ino); 459 if (!bh_new) 460 return -EIO; 461 462 /* Remove old header from its parent directory. */ 463 affs_lock_dir(old_dir); 464 retval = affs_remove_hash(old_dir, bh_old); 465 affs_unlock_dir(old_dir); 466 if (retval) 467 goto done; 468 469 /* Remove new header from its parent directory. */ 470 affs_lock_dir(new_dir); 471 retval = affs_remove_hash(new_dir, bh_new); 472 affs_unlock_dir(new_dir); 473 if (retval) 474 goto done; 475 476 /* Insert old into the new directory with the new name. */ 477 affs_copy_name(AFFS_TAIL(sb, bh_old)->name, new_dentry); 478 affs_fix_checksum(sb, bh_old); 479 affs_lock_dir(new_dir); 480 retval = affs_insert_hash(new_dir, bh_old); 481 affs_unlock_dir(new_dir); 482 483 /* Insert new into the old directory with the old name. */ 484 affs_copy_name(AFFS_TAIL(sb, bh_new)->name, old_dentry); 485 affs_fix_checksum(sb, bh_new); 486 affs_lock_dir(old_dir); 487 retval = affs_insert_hash(old_dir, bh_new); 488 affs_unlock_dir(old_dir); 489 done: 490 mark_buffer_dirty_inode(bh_old, new_dir); 491 mark_buffer_dirty_inode(bh_new, old_dir); 492 affs_brelse(bh_old); 493 affs_brelse(bh_new); 494 return retval; 495 } 496 497 int affs_rename2(struct inode *old_dir, struct dentry *old_dentry, 498 struct inode *new_dir, struct dentry *new_dentry, 499 unsigned int flags) 500 { 501 502 if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE)) 503 return -EINVAL; 504 505 pr_debug("%s(old=%lu,\"%pd\" to new=%lu,\"%pd\")\n", __func__, 506 old_dir->i_ino, old_dentry, new_dir->i_ino, new_dentry); 507 508 if (flags & RENAME_EXCHANGE) 509 return affs_xrename(old_dir, old_dentry, new_dir, new_dentry); 510 511 return affs_rename(old_dir, old_dentry, new_dir, new_dentry); 512 } 513 514 static struct dentry *affs_get_parent(struct dentry *child) 515 { 516 struct inode *parent; 517 struct buffer_head *bh; 518 519 bh = affs_bread(child->d_sb, d_inode(child)->i_ino); 520 if (!bh) 521 return ERR_PTR(-EIO); 522 523 parent = affs_iget(child->d_sb, 524 be32_to_cpu(AFFS_TAIL(child->d_sb, bh)->parent)); 525 brelse(bh); 526 if (IS_ERR(parent)) 527 return ERR_CAST(parent); 528 529 return d_obtain_alias(parent); 530 } 531 532 static struct inode *affs_nfs_get_inode(struct super_block *sb, u64 ino, 533 u32 generation) 534 { 535 struct inode *inode; 536 537 if (!affs_validblock(sb, ino)) 538 return ERR_PTR(-ESTALE); 539 540 inode = affs_iget(sb, ino); 541 if (IS_ERR(inode)) 542 return ERR_CAST(inode); 543 544 return inode; 545 } 546 547 static struct dentry *affs_fh_to_dentry(struct super_block *sb, struct fid *fid, 548 int fh_len, int fh_type) 549 { 550 return generic_fh_to_dentry(sb, fid, fh_len, fh_type, 551 affs_nfs_get_inode); 552 } 553 554 static struct dentry *affs_fh_to_parent(struct super_block *sb, struct fid *fid, 555 int fh_len, int fh_type) 556 { 557 return generic_fh_to_parent(sb, fid, fh_len, fh_type, 558 affs_nfs_get_inode); 559 } 560 561 const struct export_operations affs_export_ops = { 562 .fh_to_dentry = affs_fh_to_dentry, 563 .fh_to_parent = affs_fh_to_parent, 564 .get_parent = affs_get_parent, 565 }; 566 567 const struct dentry_operations affs_dentry_operations = { 568 .d_hash = affs_hash_dentry, 569 .d_compare = affs_compare_dentry, 570 }; 571 572 const struct dentry_operations affs_intl_dentry_operations = { 573 .d_hash = affs_intl_hash_dentry, 574 .d_compare = affs_intl_compare_dentry, 575 }; 576