fs/affs/namei.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  *  linux/fs/affs/namei.c
   4  *
   5  *  (c) 1996  Hans-Joachim Widmaier - Rewritten
   6  *
   7  *  (C) 1993  Ray Burr - Modified for Amiga FFS filesystem.
   8  *
   9  *  (C) 1991  Linus Torvalds - minix filesystem
  10  */
  11
  12 #include "affs.h"
  13 #include <linux/exportfs.h>
  14
  15 typedef int (*toupper_t)(int);
  16
  17 /* Simple toupper() for DOS\1 */
  18
  19 static int
  20 affs_toupper(int ch)
  21 {
  22         return ch >= 'a' && ch <= 'z' ? ch -= ('a' - 'A') : ch;
  23 }
  24
  25 /* International toupper() for DOS\3 ("international") */
  26
  27 static int
  28 affs_intl_toupper(int ch)
  29 {
  30         return (ch >= 'a' && ch <= 'z') || (ch >= 0xE0
  31                 && ch <= 0xFE && ch != 0xF7) ?
  32                 ch - ('a' - 'A') : ch;
  33 }
  34
  35 static inline toupper_t
  36 affs_get_toupper(struct super_block *sb)
  37 {
  38         return affs_test_opt(AFFS_SB(sb)->s_flags, SF_INTL) ?
  39                affs_intl_toupper : affs_toupper;
  40 }
  41
  42 /*
  43  * Note: the dentry argument is the parent dentry.
  44  */
  45 static inline int
  46 __affs_hash_dentry(const struct dentry *dentry, struct qstr *qstr, toupper_t toupper, bool notruncate)
  47 {
  48         const u8 *name = qstr->name;
  49         unsigned long hash;
  50         int retval;
  51         u32 len;
  52
  53         retval = affs_check_name(qstr->name, qstr->len, notruncate);
  54         if (retval)
  55                 return retval;
  56
  57         hash = init_name_hash(dentry);
  58         len = min(qstr->len, AFFSNAMEMAX);
  59         for (; len > 0; name++, len--)
  60                 hash = partial_name_hash(toupper(*name), hash);
  61         qstr->hash = end_name_hash(hash);
  62
  63         return 0;
  64 }
  65
  66 static int
  67 affs_hash_dentry(const struct dentry *dentry, struct qstr *qstr)
  68 {
  69         return __affs_hash_dentry(dentry, qstr, affs_toupper,
  70                                   affs_nofilenametruncate(dentry));
  71
  72 }
  73
  74 static int
  75 affs_intl_hash_dentry(const struct dentry *dentry, struct qstr *qstr)
  76 {
  77         return __affs_hash_dentry(dentry, qstr, affs_intl_toupper,
  78                                   affs_nofilenametruncate(dentry));
  79
  80 }
  81
  82 static inline int __affs_compare_dentry(unsigned int len,
  83                 const char *str, const struct qstr *name, toupper_t toupper,
  84                 bool notruncate)
  85 {
  86         const u8 *aname = str;
  87         const u8 *bname = name->name;
  88
  89         /*
  90          * 'str' is the name of an already existing dentry, so the name
  91          * must be valid. 'name' must be validated first.
  92          */
  93
  94         if (affs_check_name(name->name, name->len, notruncate))
  95                 return 1;
  96
  97         /*
  98          * If the names are longer than the allowed 30 chars,
  99          * the excess is ignored, so their length may differ.
 100          */
 101         if (len >= AFFSNAMEMAX) {
 102                 if (name->len < AFFSNAMEMAX)
 103                         return 1;
 104                 len = AFFSNAMEMAX;
 105         } else if (len != name->len)
 106                 return 1;
 107
 108         for (; len > 0; len--)
 109                 if (toupper(*aname++) != toupper(*bname++))
 110                         return 1;
 111
 112         return 0;
 113 }
 114
 115 static int
 116 affs_compare_dentry(const struct dentry *dentry,
 117                 unsigned int len, const char *str, const struct qstr *name)
 118 {
 119
 120         return __affs_compare_dentry(len, str, name, affs_toupper,
 121                                      affs_nofilenametruncate(dentry));
 122 }
 123
 124 static int
 125 affs_intl_compare_dentry(const struct dentry *dentry,
 126                 unsigned int len, const char *str, const struct qstr *name)
 127 {
 128         return __affs_compare_dentry(len, str, name, affs_intl_toupper,
 129                                      affs_nofilenametruncate(dentry));
 130
 131 }
 132
 133 /*
 134  * NOTE! unlike strncmp, affs_match returns 1 for success, 0 for failure.
 135  */
 136
 137 static inline int
 138 affs_match(struct dentry *dentry, const u8 *name2, toupper_t toupper)
 139 {
 140         const u8 *name = dentry->d_name.name;
 141         int len = dentry->d_name.len;
 142
 143         if (len >= AFFSNAMEMAX) {
 144                 if (*name2 < AFFSNAMEMAX)
 145                         return 0;
 146                 len = AFFSNAMEMAX;
 147         } else if (len != *name2)
 148                 return 0;
 149
 150         for (name2++; len > 0; len--)
 151                 if (toupper(*name++) != toupper(*name2++))
 152                         return 0;
 153         return 1;
 154 }
 155
 156 int
 157 affs_hash_name(struct super_block *sb, const u8 *name, unsigned int len)
 158 {
 159         toupper_t toupper = affs_get_toupper(sb);
 160         u32 hash;
 161
 162         hash = len = min(len, AFFSNAMEMAX);
 163         for (; len > 0; len--)
 164                 hash = (hash * 13 + toupper(*name++)) & 0x7ff;
 165
 166         return hash % AFFS_SB(sb)->s_hashsize;
 167 }
 168
 169 static struct buffer_head *
 170 affs_find_entry(struct inode *dir, struct dentry *dentry)
 171 {
 172         struct super_block *sb = dir->i_sb;
 173         struct buffer_head *bh;
 174         toupper_t toupper = affs_get_toupper(sb);
 175         u32 key;
 176
 177         pr_debug("%s(\"%pd\")\n", __func__, dentry);
 178
 179         bh = affs_bread(sb, dir->i_ino);
 180         if (!bh)
 181                 return ERR_PTR(-EIO);
 182
 183         key = be32_to_cpu(AFFS_HEAD(bh)->table[affs_hash_name(sb, dentry->d_name.name, dentry->d_name.len)]);
 184
 185         for (;;) {
 186                 affs_brelse(bh);
 187                 if (key == 0)
 188                         return NULL;
 189                 bh = affs_bread(sb, key);
 190                 if (!bh)
 191                         return ERR_PTR(-EIO);
 192                 if (affs_match(dentry, AFFS_TAIL(sb, bh)->name, toupper))
 193                         return bh;
 194                 key = be32_to_cpu(AFFS_TAIL(sb, bh)->hash_chain);
 195         }
 196 }
 197
 198 struct dentry *
 199 affs_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
 200 {
 201         struct super_block *sb = dir->i_sb;
 202         struct buffer_head *bh;
 203         struct inode *inode = NULL;
 204
 205         pr_debug("%s(\"%pd\")\n", __func__, dentry);
 206
 207         affs_lock_dir(dir);
 208         bh = affs_find_entry(dir, dentry);
 209         affs_unlock_dir(dir);
 210         if (IS_ERR(bh))
 211                 return ERR_CAST(bh);
 212         if (bh) {
 213                 u32 ino = bh->b_blocknr;
 214
 215                 /* store the real header ino in d_fsdata for faster lookups */
 216                 dentry->d_fsdata = (void *)(long)ino;
 217                 switch (be32_to_cpu(AFFS_TAIL(sb, bh)->stype)) {
 218                 //link to dirs disabled
 219                 //case ST_LINKDIR:
 220                 case ST_LINKFILE:
 221                         ino = be32_to_cpu(AFFS_TAIL(sb, bh)->original);
 222                 }
 223                 affs_brelse(bh);
 224                 inode = affs_iget(sb, ino);
 225                 if (IS_ERR(inode))
 226                         return ERR_CAST(inode);
 227         }
 228         d_add(dentry, inode);
 229         return NULL;
 230 }
 231
 232 int
 233 affs_unlink(struct inode *dir, struct dentry *dentry)
 234 {
 235         pr_debug("%s(dir=%lu, %lu \"%pd\")\n", __func__, dir->i_ino,
 236                  d_inode(dentry)->i_ino, dentry);
 237
 238         return affs_remove_header(dentry);
 239 }
 240
 241 int
 242 affs_create(struct inode *dir, struct dentry *dentry, umode_t mode, bool excl)
 243 {
 244         struct super_block *sb = dir->i_sb;
 245         struct inode    *inode;
 246         int              error;
 247
 248         pr_debug("%s(%lu,\"%pd\",0%ho)\n",
 249                  __func__, dir->i_ino, dentry, mode);
 250
 251         inode = affs_new_inode(dir);
 252         if (!inode)
 253                 return -ENOSPC;
 254
 255         inode->i_mode = mode;
 256         affs_mode_to_prot(inode);
 257         mark_inode_dirty(inode);
 258
 259         inode->i_op = &affs_file_inode_operations;
 260         inode->i_fop = &affs_file_operations;
 261         inode->i_mapping->a_ops = affs_test_opt(AFFS_SB(sb)->s_flags, SF_OFS) ?
 262                                   &affs_aops_ofs : &affs_aops;
 263         error = affs_add_entry(dir, inode, dentry, ST_FILE);
 264         if (error) {
 265                 clear_nlink(inode);
 266                 iput(inode);
 267                 return error;
 268         }
 269         return 0;
 270 }
 271
 272 int
 273 affs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
 274 {
 275         struct inode            *inode;
 276         int                      error;
 277
 278         pr_debug("%s(%lu,\"%pd\",0%ho)\n",
 279                  __func__, dir->i_ino, dentry, mode);
 280
 281         inode = affs_new_inode(dir);
 282         if (!inode)
 283                 return -ENOSPC;
 284
 285         inode->i_mode = S_IFDIR | mode;
 286         affs_mode_to_prot(inode);
 287
 288         inode->i_op = &affs_dir_inode_operations;
 289         inode->i_fop = &affs_dir_operations;
 290
 291         error = affs_add_entry(dir, inode, dentry, ST_USERDIR);
 292         if (error) {
 293                 clear_nlink(inode);
 294                 mark_inode_dirty(inode);
 295                 iput(inode);
 296                 return error;
 297         }
 298         return 0;
 299 }
 300
 301 int
 302 affs_rmdir(struct inode *dir, struct dentry *dentry)
 303 {
 304         pr_debug("%s(dir=%lu, %lu \"%pd\")\n", __func__, dir->i_ino,
 305                  d_inode(dentry)->i_ino, dentry);
 306
 307         return affs_remove_header(dentry);
 308 }
 309
 310 int
 311 affs_symlink(struct inode *dir, struct dentry *dentry, const char *symname)
 312 {
 313         struct super_block      *sb = dir->i_sb;
 314         struct buffer_head      *bh;
 315         struct inode            *inode;
 316         char                    *p;
 317         int                      i, maxlen, error;
 318         char                     c, lc;
 319
 320         pr_debug("%s(%lu,\"%pd\" -> \"%s\")\n",
 321                  __func__, dir->i_ino, dentry, symname);
 322
 323         maxlen = AFFS_SB(sb)->s_hashsize * sizeof(u32) - 1;
 324         inode  = affs_new_inode(dir);
 325         if (!inode)
 326                 return -ENOSPC;
 327
 328         inode->i_op = &affs_symlink_inode_operations;
 329         inode_nohighmem(inode);
 330         inode->i_data.a_ops = &affs_symlink_aops;
 331         inode->i_mode = S_IFLNK | 0777;
 332         affs_mode_to_prot(inode);
 333
 334         error = -EIO;
 335         bh = affs_bread(sb, inode->i_ino);
 336         if (!bh)
 337                 goto err;
 338         i  = 0;
 339         p  = (char *)AFFS_HEAD(bh)->table;
 340         lc = '/';
 341         if (*symname == '/') {
 342                 struct affs_sb_info *sbi = AFFS_SB(sb);
 343                 while (*symname == '/')
 344                         symname++;
 345                 spin_lock(&sbi->symlink_lock);
 346                 while (sbi->s_volume[i])        /* Cannot overflow */
 347                         *p++ = sbi->s_volume[i++];
 348                 spin_unlock(&sbi->symlink_lock);
 349         }
 350         while (i < maxlen && (c = *symname++)) {
 351                 if (c == '.' && lc == '/' && *symname == '.' && symname[1] == '/') {
 352                         *p++ = '/';
 353                         i++;
 354                         symname += 2;
 355                         lc = '/';
 356                 } else if (c == '.' && lc == '/' && *symname == '/') {
 357                         symname++;
 358                         lc = '/';
 359                 } else {
 360                         *p++ = c;
 361                         lc   = c;
 362                         i++;
 363                 }
 364                 if (lc == '/')
 365                         while (*symname == '/')
 366                                 symname++;
 367         }
 368         *p = 0;
 369         inode->i_size = i + 1;
 370         mark_buffer_dirty_inode(bh, inode);
 371         affs_brelse(bh);
 372         mark_inode_dirty(inode);
 373
 374         error = affs_add_entry(dir, inode, dentry, ST_SOFTLINK);
 375         if (error)
 376                 goto err;
 377
 378         return 0;
 379
 380 err:
 381         clear_nlink(inode);
 382         mark_inode_dirty(inode);
 383         iput(inode);
 384         return error;
 385 }
 386
 387 int
 388 affs_link(struct dentry *old_dentry, struct inode *dir, struct dentry *dentry)
 389 {
 390         struct inode *inode = d_inode(old_dentry);
 391
 392         pr_debug("%s(%lu, %lu, \"%pd\")\n", __func__, inode->i_ino, dir->i_ino,
 393                  dentry);
 394
 395         return affs_add_entry(dir, inode, dentry, ST_LINKFILE);
 396 }
 397
 398 static int
 399 affs_rename(struct inode *old_dir, struct dentry *old_dentry,
 400             struct inode *new_dir, struct dentry *new_dentry)
 401 {
 402         struct super_block *sb = old_dir->i_sb;
 403         struct buffer_head *bh = NULL;
 404         int retval;
 405
 406         retval = affs_check_name(new_dentry->d_name.name,
 407                                  new_dentry->d_name.len,
 408                                  affs_nofilenametruncate(old_dentry));
 409
 410         if (retval)
 411                 return retval;
 412
 413         /* Unlink destination if it already exists */
 414         if (d_really_is_positive(new_dentry)) {
 415                 retval = affs_remove_header(new_dentry);
 416                 if (retval)
 417                         return retval;
 418         }
 419
 420         bh = affs_bread(sb, d_inode(old_dentry)->i_ino);
 421         if (!bh)
 422                 return -EIO;
 423
 424         /* Remove header from its parent directory. */
 425         affs_lock_dir(old_dir);
 426         retval = affs_remove_hash(old_dir, bh);
 427         affs_unlock_dir(old_dir);
 428         if (retval)
 429                 goto done;
 430
 431         /* And insert it into the new directory with the new name. */
 432         affs_copy_name(AFFS_TAIL(sb, bh)->name, new_dentry);
 433         affs_fix_checksum(sb, bh);
 434         affs_lock_dir(new_dir);
 435         retval = affs_insert_hash(new_dir, bh);
 436         affs_unlock_dir(new_dir);
 437         /* TODO: move it back to old_dir, if error? */
 438
 439 done:
 440         mark_buffer_dirty_inode(bh, retval ? old_dir : new_dir);
 441         affs_brelse(bh);
 442         return retval;
 443 }
 444
 445 static int
 446 affs_xrename(struct inode *old_dir, struct dentry *old_dentry,
 447              struct inode *new_dir, struct dentry *new_dentry)
 448 {
 449
 450         struct super_block *sb = old_dir->i_sb;
 451         struct buffer_head *bh_old = NULL;
 452         struct buffer_head *bh_new = NULL;
 453         int retval;
 454
 455         bh_old = affs_bread(sb, d_inode(old_dentry)->i_ino);
 456         if (!bh_old)
 457                 return -EIO;
 458
 459         bh_new = affs_bread(sb, d_inode(new_dentry)->i_ino);
 460         if (!bh_new)
 461                 return -EIO;
 462
 463         /* Remove old header from its parent directory. */
 464         affs_lock_dir(old_dir);
 465         retval = affs_remove_hash(old_dir, bh_old);
 466         affs_unlock_dir(old_dir);
 467         if (retval)
 468                 goto done;
 469
 470         /* Remove new header from its parent directory. */
 471         affs_lock_dir(new_dir);
 472         retval = affs_remove_hash(new_dir, bh_new);
 473         affs_unlock_dir(new_dir);
 474         if (retval)
 475                 goto done;
 476
 477         /* Insert old into the new directory with the new name. */
 478         affs_copy_name(AFFS_TAIL(sb, bh_old)->name, new_dentry);
 479         affs_fix_checksum(sb, bh_old);
 480         affs_lock_dir(new_dir);
 481         retval = affs_insert_hash(new_dir, bh_old);
 482         affs_unlock_dir(new_dir);
 483
 484         /* Insert new into the old directory with the old name. */
 485         affs_copy_name(AFFS_TAIL(sb, bh_new)->name, old_dentry);
 486         affs_fix_checksum(sb, bh_new);
 487         affs_lock_dir(old_dir);
 488         retval = affs_insert_hash(old_dir, bh_new);
 489         affs_unlock_dir(old_dir);
 490 done:
 491         mark_buffer_dirty_inode(bh_old, new_dir);
 492         mark_buffer_dirty_inode(bh_new, old_dir);
 493         affs_brelse(bh_old);
 494         affs_brelse(bh_new);
 495         return retval;
 496 }
 497
 498 int affs_rename2(struct inode *old_dir, struct dentry *old_dentry,
 499                         struct inode *new_dir, struct dentry *new_dentry,
 500                         unsigned int flags)
 501 {
 502
 503         if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE))
 504                 return -EINVAL;
 505
 506         pr_debug("%s(old=%lu,\"%pd\" to new=%lu,\"%pd\")\n", __func__,
 507                  old_dir->i_ino, old_dentry, new_dir->i_ino, new_dentry);
 508
 509         if (flags & RENAME_EXCHANGE)
 510                 return affs_xrename(old_dir, old_dentry, new_dir, new_dentry);
 511
 512         return affs_rename(old_dir, old_dentry, new_dir, new_dentry);
 513 }
 514
 515 static struct dentry *affs_get_parent(struct dentry *child)
 516 {
 517         struct inode *parent;
 518         struct buffer_head *bh;
 519
 520         bh = affs_bread(child->d_sb, d_inode(child)->i_ino);
 521         if (!bh)
 522                 return ERR_PTR(-EIO);
 523
 524         parent = affs_iget(child->d_sb,
 525                            be32_to_cpu(AFFS_TAIL(child->d_sb, bh)->parent));
 526         brelse(bh);
 527         if (IS_ERR(parent))
 528                 return ERR_CAST(parent);
 529
 530         return d_obtain_alias(parent);
 531 }
 532
 533 static struct inode *affs_nfs_get_inode(struct super_block *sb, u64 ino,
 534                                         u32 generation)
 535 {
 536         struct inode *inode;
 537
 538         if (!affs_validblock(sb, ino))
 539                 return ERR_PTR(-ESTALE);
 540
 541         inode = affs_iget(sb, ino);
 542         if (IS_ERR(inode))
 543                 return ERR_CAST(inode);
 544
 545         return inode;
 546 }
 547
 548 static struct dentry *affs_fh_to_dentry(struct super_block *sb, struct fid *fid,
 549                                         int fh_len, int fh_type)
 550 {
 551         return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
 552                                     affs_nfs_get_inode);
 553 }
 554
 555 static struct dentry *affs_fh_to_parent(struct super_block *sb, struct fid *fid,
 556                                         int fh_len, int fh_type)
 557 {
 558         return generic_fh_to_parent(sb, fid, fh_len, fh_type,
 559                                     affs_nfs_get_inode);
 560 }
 561
 562 const struct export_operations affs_export_ops = {
 563         .fh_to_dentry = affs_fh_to_dentry,
 564         .fh_to_parent = affs_fh_to_parent,
 565         .get_parent = affs_get_parent,
 566 };
 567
 568 const struct dentry_operations affs_dentry_operations = {
 569         .d_hash         = affs_hash_dentry,
 570         .d_compare      = affs_compare_dentry,
 571 };
 572
 573 const struct dentry_operations affs_intl_dentry_operations = {
 574         .d_hash         = affs_intl_hash_dentry,
 575         .d_compare      = affs_intl_compare_dentry,
 576 };