fs/affs/namei.c

   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         mark_buffer_dirty_inode(bh, inode);
 369         affs_brelse(bh);
 370         mark_inode_dirty(inode);
 371
 372         error = affs_add_entry(dir, inode, dentry, ST_SOFTLINK);
 373         if (error)
 374                 goto err;
 375
 376         return 0;
 377
 378 err:
 379         clear_nlink(inode);
 380         mark_inode_dirty(inode);
 381         iput(inode);
 382         return error;
 383 }
 384
 385 int
 386 affs_link(struct dentry *old_dentry, struct inode *dir, struct dentry *dentry)
 387 {
 388         struct inode *inode = d_inode(old_dentry);
 389
 390         pr_debug("%s(%lu, %lu, \"%pd\")\n", __func__, inode->i_ino, dir->i_ino,
 391                  dentry);
 392
 393         return affs_add_entry(dir, inode, dentry, ST_LINKFILE);
 394 }
 395
 396 int
 397 affs_rename(struct inode *old_dir, struct dentry *old_dentry,
 398             struct inode *new_dir, struct dentry *new_dentry,
 399             unsigned int flags)
 400 {
 401         struct super_block *sb = old_dir->i_sb;
 402         struct buffer_head *bh = NULL;
 403         int retval;
 404
 405         if (flags & ~RENAME_NOREPLACE)
 406                 return -EINVAL;
 407
 408         pr_debug("%s(old=%lu,\"%pd\" to new=%lu,\"%pd\")\n", __func__,
 409                  old_dir->i_ino, old_dentry, new_dir->i_ino, new_dentry);
 410
 411         retval = affs_check_name(new_dentry->d_name.name,
 412                                  new_dentry->d_name.len,
 413                                  affs_nofilenametruncate(old_dentry));
 414
 415         if (retval)
 416                 return retval;
 417
 418         /* Unlink destination if it already exists */
 419         if (d_really_is_positive(new_dentry)) {
 420                 retval = affs_remove_header(new_dentry);
 421                 if (retval)
 422                         return retval;
 423         }
 424
 425         bh = affs_bread(sb, d_inode(old_dentry)->i_ino);
 426         if (!bh)
 427                 return -EIO;
 428
 429         /* Remove header from its parent directory. */
 430         affs_lock_dir(old_dir);
 431         retval = affs_remove_hash(old_dir, bh);
 432         affs_unlock_dir(old_dir);
 433         if (retval)
 434                 goto done;
 435
 436         /* And insert it into the new directory with the new name. */
 437         affs_copy_name(AFFS_TAIL(sb, bh)->name, new_dentry);
 438         affs_fix_checksum(sb, bh);
 439         affs_lock_dir(new_dir);
 440         retval = affs_insert_hash(new_dir, bh);
 441         affs_unlock_dir(new_dir);
 442         /* TODO: move it back to old_dir, if error? */
 443
 444 done:
 445         mark_buffer_dirty_inode(bh, retval ? old_dir : new_dir);
 446         affs_brelse(bh);
 447         return retval;
 448 }
 449
 450 static struct dentry *affs_get_parent(struct dentry *child)
 451 {
 452         struct inode *parent;
 453         struct buffer_head *bh;
 454
 455         bh = affs_bread(child->d_sb, d_inode(child)->i_ino);
 456         if (!bh)
 457                 return ERR_PTR(-EIO);
 458
 459         parent = affs_iget(child->d_sb,
 460                            be32_to_cpu(AFFS_TAIL(child->d_sb, bh)->parent));
 461         brelse(bh);
 462         if (IS_ERR(parent))
 463                 return ERR_CAST(parent);
 464
 465         return d_obtain_alias(parent);
 466 }
 467
 468 static struct inode *affs_nfs_get_inode(struct super_block *sb, u64 ino,
 469                                         u32 generation)
 470 {
 471         struct inode *inode;
 472
 473         if (!affs_validblock(sb, ino))
 474                 return ERR_PTR(-ESTALE);
 475
 476         inode = affs_iget(sb, ino);
 477         if (IS_ERR(inode))
 478                 return ERR_CAST(inode);
 479
 480         if (generation && inode->i_generation != generation) {
 481                 iput(inode);
 482                 return ERR_PTR(-ESTALE);
 483         }
 484
 485         return inode;
 486 }
 487
 488 static struct dentry *affs_fh_to_dentry(struct super_block *sb, struct fid *fid,
 489                                         int fh_len, int fh_type)
 490 {
 491         return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
 492                                     affs_nfs_get_inode);
 493 }
 494
 495 static struct dentry *affs_fh_to_parent(struct super_block *sb, struct fid *fid,
 496                                         int fh_len, int fh_type)
 497 {
 498         return generic_fh_to_parent(sb, fid, fh_len, fh_type,
 499                                     affs_nfs_get_inode);
 500 }
 501
 502 const struct export_operations affs_export_ops = {
 503         .fh_to_dentry = affs_fh_to_dentry,
 504         .fh_to_parent = affs_fh_to_parent,
 505         .get_parent = affs_get_parent,
 506 };
 507
 508 const struct dentry_operations affs_dentry_operations = {
 509         .d_hash         = affs_hash_dentry,
 510         .d_compare      = affs_compare_dentry,
 511 };
 512
 513 const struct dentry_operations affs_intl_dentry_operations = {
 514         .d_hash         = affs_intl_hash_dentry,
 515         .d_compare      = affs_intl_compare_dentry,
 516 };