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