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