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
  13 typedef int (*toupper_t)(int);
  14
  15 static int       affs_toupper(int ch);
  16 static int       affs_hash_dentry(const struct dentry *, struct qstr *);
  17 static int       affs_compare_dentry(const struct dentry *parent, const struct dentry *dentry,
  18                 unsigned int len, const char *str, const struct qstr *name);
  19 static int       affs_intl_toupper(int ch);
  20 static int       affs_intl_hash_dentry(const struct dentry *, struct qstr *);
  21 static int       affs_intl_compare_dentry(const struct dentry *parent, const struct dentry *dentry,
  22                 unsigned int len, const char *str, const struct qstr *name);
  23
  24 const struct dentry_operations affs_dentry_operations = {
  25         .d_hash         = affs_hash_dentry,
  26         .d_compare      = affs_compare_dentry,
  27 };
  28
  29 const struct dentry_operations affs_intl_dentry_operations = {
  30         .d_hash         = affs_intl_hash_dentry,
  31         .d_compare      = affs_intl_compare_dentry,
  32 };
  33
  34
  35 /* Simple toupper() for DOS\1 */
  36
  37 static int
  38 affs_toupper(int ch)
  39 {
  40         return ch >= 'a' && ch <= 'z' ? ch -= ('a' - 'A') : ch;
  41 }
  42
  43 /* International toupper() for DOS\3 ("international") */
  44
  45 static int
  46 affs_intl_toupper(int ch)
  47 {
  48         return (ch >= 'a' && ch <= 'z') || (ch >= 0xE0
  49                 && ch <= 0xFE && ch != 0xF7) ?
  50                 ch - ('a' - 'A') : ch;
  51 }
  52
  53 static inline toupper_t
  54 affs_get_toupper(struct super_block *sb)
  55 {
  56         return AFFS_SB(sb)->s_flags & SF_INTL ? affs_intl_toupper : affs_toupper;
  57 }
  58
  59 /*
  60  * Note: the dentry argument is the parent dentry.
  61  */
  62 static inline int
  63 __affs_hash_dentry(struct qstr *qstr, toupper_t toupper, bool notruncate)
  64 {
  65         const u8 *name = qstr->name;
  66         unsigned long hash;
  67         int i;
  68
  69         i = affs_check_name(qstr->name, qstr->len, notruncate);
  70         if (i)
  71                 return i;
  72
  73         hash = init_name_hash();
  74         i = min(qstr->len, 30u);
  75         for (; i > 0; name++, i--)
  76                 hash = partial_name_hash(toupper(*name), hash);
  77         qstr->hash = end_name_hash(hash);
  78
  79         return 0;
  80 }
  81
  82 static int
  83 affs_hash_dentry(const struct dentry *dentry, struct qstr *qstr)
  84 {
  85         return __affs_hash_dentry(qstr, affs_toupper,
  86                                   affs_nofilenametruncate(dentry));
  87
  88 }
  89
  90 static int
  91 affs_intl_hash_dentry(const struct dentry *dentry, struct qstr *qstr)
  92 {
  93         return __affs_hash_dentry(qstr, affs_intl_toupper,
  94                                   affs_nofilenametruncate(dentry));
  95
  96 }
  97
  98 static inline int __affs_compare_dentry(unsigned int len,
  99                 const char *str, const struct qstr *name, toupper_t toupper,
 100                 bool notruncate)
 101 {
 102         const u8 *aname = str;
 103         const u8 *bname = name->name;
 104
 105         /*
 106          * 'str' is the name of an already existing dentry, so the name
 107          * must be valid. 'name' must be validated first.
 108          */
 109
 110         if (affs_check_name(name->name, name->len, notruncate))
 111                 return 1;
 112
 113         /*
 114          * If the names are longer than the allowed 30 chars,
 115          * the excess is ignored, so their length may differ.
 116          */
 117         if (len >= 30) {
 118                 if (name->len < 30)
 119                         return 1;
 120                 len = 30;
 121         } else if (len != name->len)
 122                 return 1;
 123
 124         for (; len > 0; len--)
 125                 if (toupper(*aname++) != toupper(*bname++))
 126                         return 1;
 127
 128         return 0;
 129 }
 130
 131 static int
 132 affs_compare_dentry(const struct dentry *parent, const struct dentry *dentry,
 133                 unsigned int len, const char *str, const struct qstr *name)
 134 {
 135
 136         return __affs_compare_dentry(len, str, name, affs_toupper,
 137                                      affs_nofilenametruncate(parent));
 138 }
 139
 140 static int
 141 affs_intl_compare_dentry(const struct dentry *parent, const struct dentry *dentry,
 142                 unsigned int len, const char *str, const struct qstr *name)
 143 {
 144         return __affs_compare_dentry(len, str, name, affs_intl_toupper,
 145                                      affs_nofilenametruncate(parent));
 146
 147 }
 148
 149 /*
 150  * NOTE! unlike strncmp, affs_match returns 1 for success, 0 for failure.
 151  */
 152
 153 static inline int
 154 affs_match(struct dentry *dentry, const u8 *name2, toupper_t toupper)
 155 {
 156         const u8 *name = dentry->d_name.name;
 157         int len = dentry->d_name.len;
 158
 159         if (len >= 30) {
 160                 if (*name2 < 30)
 161                         return 0;
 162                 len = 30;
 163         } else if (len != *name2)
 164                 return 0;
 165
 166         for (name2++; len > 0; len--)
 167                 if (toupper(*name++) != toupper(*name2++))
 168                         return 0;
 169         return 1;
 170 }
 171
 172 int
 173 affs_hash_name(struct super_block *sb, const u8 *name, unsigned int len)
 174 {
 175         toupper_t toupper = affs_get_toupper(sb);
 176         int hash;
 177
 178         hash = len = min(len, 30u);
 179         for (; len > 0; len--)
 180                 hash = (hash * 13 + toupper(*name++)) & 0x7ff;
 181
 182         return hash % AFFS_SB(sb)->s_hashsize;
 183 }
 184
 185 static struct buffer_head *
 186 affs_find_entry(struct inode *dir, struct dentry *dentry)
 187 {
 188         struct super_block *sb = dir->i_sb;
 189         struct buffer_head *bh;
 190         toupper_t toupper = affs_get_toupper(sb);
 191         u32 key;
 192
 193         pr_debug("%s(\"%pd\")\n", __func__, dentry);
 194
 195         bh = affs_bread(sb, dir->i_ino);
 196         if (!bh)
 197                 return ERR_PTR(-EIO);
 198
 199         key = be32_to_cpu(AFFS_HEAD(bh)->table[affs_hash_name(sb, dentry->d_name.name, dentry->d_name.len)]);
 200
 201         for (;;) {
 202                 affs_brelse(bh);
 203                 if (key == 0)
 204                         return NULL;
 205                 bh = affs_bread(sb, key);
 206                 if (!bh)
 207                         return ERR_PTR(-EIO);
 208                 if (affs_match(dentry, AFFS_TAIL(sb, bh)->name, toupper))
 209                         return bh;
 210                 key = be32_to_cpu(AFFS_TAIL(sb, bh)->hash_chain);
 211         }
 212 }
 213
 214 struct dentry *
 215 affs_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
 216 {
 217         struct super_block *sb = dir->i_sb;
 218         struct buffer_head *bh;
 219         struct inode *inode = NULL;
 220
 221         pr_debug("%s(\"%pd\")\n", __func__, dentry);
 222
 223         affs_lock_dir(dir);
 224         bh = affs_find_entry(dir, dentry);
 225         affs_unlock_dir(dir);
 226         if (IS_ERR(bh))
 227                 return ERR_CAST(bh);
 228         if (bh) {
 229                 u32 ino = bh->b_blocknr;
 230
 231                 /* store the real header ino in d_fsdata for faster lookups */
 232                 dentry->d_fsdata = (void *)(long)ino;
 233                 switch (be32_to_cpu(AFFS_TAIL(sb, bh)->stype)) {
 234                 //link to dirs disabled
 235                 //case ST_LINKDIR:
 236                 case ST_LINKFILE:
 237                         ino = be32_to_cpu(AFFS_TAIL(sb, bh)->original);
 238                 }
 239                 affs_brelse(bh);
 240                 inode = affs_iget(sb, ino);
 241                 if (IS_ERR(inode))
 242                         return ERR_CAST(inode);
 243         }
 244         d_add(dentry, inode);
 245         return NULL;
 246 }
 247
 248 int
 249 affs_unlink(struct inode *dir, struct dentry *dentry)
 250 {
 251         pr_debug("%s(dir=%d, %lu \"%pd\")\n",
 252                  __func__, (u32)dir->i_ino, dentry->d_inode->i_ino,
 253                 dentry);
 254
 255         return affs_remove_header(dentry);
 256 }
 257
 258 int
 259 affs_create(struct inode *dir, struct dentry *dentry, umode_t mode, bool excl)
 260 {
 261         struct super_block *sb = dir->i_sb;
 262         struct inode    *inode;
 263         int              error;
 264
 265         pr_debug("%s(%lu,\"%pd\",0%ho)\n",
 266                  __func__, dir->i_ino, dentry, mode);
 267
 268         inode = affs_new_inode(dir);
 269         if (!inode)
 270                 return -ENOSPC;
 271
 272         inode->i_mode = mode;
 273         mode_to_prot(inode);
 274         mark_inode_dirty(inode);
 275
 276         inode->i_op = &affs_file_inode_operations;
 277         inode->i_fop = &affs_file_operations;
 278         inode->i_mapping->a_ops = (AFFS_SB(sb)->s_flags & SF_OFS) ? &affs_aops_ofs : &affs_aops;
 279         error = affs_add_entry(dir, inode, dentry, ST_FILE);
 280         if (error) {
 281                 clear_nlink(inode);
 282                 iput(inode);
 283                 return error;
 284         }
 285         return 0;
 286 }
 287
 288 int
 289 affs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
 290 {
 291         struct inode            *inode;
 292         int                      error;
 293
 294         pr_debug("%s(%lu,\"%pd\",0%ho)\n",
 295                  __func__, dir->i_ino, dentry, mode);
 296
 297         inode = affs_new_inode(dir);
 298         if (!inode)
 299                 return -ENOSPC;
 300
 301         inode->i_mode = S_IFDIR | mode;
 302         mode_to_prot(inode);
 303
 304         inode->i_op = &affs_dir_inode_operations;
 305         inode->i_fop = &affs_dir_operations;
 306
 307         error = affs_add_entry(dir, inode, dentry, ST_USERDIR);
 308         if (error) {
 309                 clear_nlink(inode);
 310                 mark_inode_dirty(inode);
 311                 iput(inode);
 312                 return error;
 313         }
 314         return 0;
 315 }
 316
 317 int
 318 affs_rmdir(struct inode *dir, struct dentry *dentry)
 319 {
 320         pr_debug("%s(dir=%u, %lu \"%pd\")\n",
 321                 __func__, (u32)dir->i_ino, dentry->d_inode->i_ino,
 322                  dentry);
 323
 324         return affs_remove_header(dentry);
 325 }
 326
 327 int
 328 affs_symlink(struct inode *dir, struct dentry *dentry, const char *symname)
 329 {
 330         struct super_block      *sb = dir->i_sb;
 331         struct buffer_head      *bh;
 332         struct inode            *inode;
 333         char                    *p;
 334         int                      i, maxlen, error;
 335         char                     c, lc;
 336
 337         pr_debug("%s(%lu,\"%pd\" -> \"%s\")\n",
 338                  __func__, dir->i_ino, dentry, symname);
 339
 340         maxlen = AFFS_SB(sb)->s_hashsize * sizeof(u32) - 1;
 341         inode  = affs_new_inode(dir);
 342         if (!inode)
 343                 return -ENOSPC;
 344
 345         inode->i_op = &affs_symlink_inode_operations;
 346         inode->i_data.a_ops = &affs_symlink_aops;
 347         inode->i_mode = S_IFLNK | 0777;
 348         mode_to_prot(inode);
 349
 350         error = -EIO;
 351         bh = affs_bread(sb, inode->i_ino);
 352         if (!bh)
 353                 goto err;
 354         i  = 0;
 355         p  = (char *)AFFS_HEAD(bh)->table;
 356         lc = '/';
 357         if (*symname == '/') {
 358                 struct affs_sb_info *sbi = AFFS_SB(sb);
 359                 while (*symname == '/')
 360                         symname++;
 361                 spin_lock(&sbi->symlink_lock);
 362                 while (sbi->s_volume[i])        /* Cannot overflow */
 363                         *p++ = sbi->s_volume[i++];
 364                 spin_unlock(&sbi->symlink_lock);
 365         }
 366         while (i < maxlen && (c = *symname++)) {
 367                 if (c == '.' && lc == '/' && *symname == '.' && symname[1] == '/') {
 368                         *p++ = '/';
 369                         i++;
 370                         symname += 2;
 371                         lc = '/';
 372                 } else if (c == '.' && lc == '/' && *symname == '/') {
 373                         symname++;
 374                         lc = '/';
 375                 } else {
 376                         *p++ = c;
 377                         lc   = c;
 378                         i++;
 379                 }
 380                 if (lc == '/')
 381                         while (*symname == '/')
 382                                 symname++;
 383         }
 384         *p = 0;
 385         mark_buffer_dirty_inode(bh, inode);
 386         affs_brelse(bh);
 387         mark_inode_dirty(inode);
 388
 389         error = affs_add_entry(dir, inode, dentry, ST_SOFTLINK);
 390         if (error)
 391                 goto err;
 392
 393         return 0;
 394
 395 err:
 396         clear_nlink(inode);
 397         mark_inode_dirty(inode);
 398         iput(inode);
 399         return error;
 400 }
 401
 402 int
 403 affs_link(struct dentry *old_dentry, struct inode *dir, struct dentry *dentry)
 404 {
 405         struct inode *inode = old_dentry->d_inode;
 406
 407         pr_debug("%s(%u, %u, \"%pd\")\n",
 408                  __func__, (u32)inode->i_ino, (u32)dir->i_ino,
 409                  dentry);
 410
 411         return affs_add_entry(dir, inode, dentry, ST_LINKFILE);
 412 }
 413
 414 int
 415 affs_rename(struct inode *old_dir, struct dentry *old_dentry,
 416             struct inode *new_dir, struct dentry *new_dentry)
 417 {
 418         struct super_block *sb = old_dir->i_sb;
 419         struct buffer_head *bh = NULL;
 420         int retval;
 421
 422         pr_debug("%s(old=%u,\"%pd\" to new=%u,\"%pd\")\n",
 423                  __func__, (u32)old_dir->i_ino, old_dentry,
 424                  (u32)new_dir->i_ino, new_dentry);
 425
 426         retval = affs_check_name(new_dentry->d_name.name,
 427                                  new_dentry->d_name.len,
 428                                  affs_nofilenametruncate(old_dentry));
 429
 430         if (retval)
 431                 return retval;
 432
 433         /* Unlink destination if it already exists */
 434         if (new_dentry->d_inode) {
 435                 retval = affs_remove_header(new_dentry);
 436                 if (retval)
 437                         return retval;
 438         }
 439
 440         bh = affs_bread(sb, old_dentry->d_inode->i_ino);
 441         if (!bh)
 442                 return -EIO;
 443
 444         /* Remove header from its parent directory. */
 445         affs_lock_dir(old_dir);
 446         retval = affs_remove_hash(old_dir, bh);
 447         affs_unlock_dir(old_dir);
 448         if (retval)
 449                 goto done;
 450
 451         /* And insert it into the new directory with the new name. */
 452         affs_copy_name(AFFS_TAIL(sb, bh)->name, new_dentry);
 453         affs_fix_checksum(sb, bh);
 454         affs_lock_dir(new_dir);
 455         retval = affs_insert_hash(new_dir, bh);
 456         affs_unlock_dir(new_dir);
 457         /* TODO: move it back to old_dir, if error? */
 458
 459 done:
 460         mark_buffer_dirty_inode(bh, retval ? old_dir : new_dir);
 461         affs_brelse(bh);
 462         return retval;
 463 }