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 static 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         dentry->d_op = AFFS_SB(sb)->s_flags & SF_INTL ? &affs_intl_dentry_operations : &affs_dentry_operations;
 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("AFFS: unlink(dir=%d, %lu \"%.*s\")\n", (u32)dir->i_ino,
 252                  dentry->d_inode->i_ino,
 253                  (int)dentry->d_name.len, dentry->d_name.name);
 254
 255         return affs_remove_header(dentry);
 256 }
 257
 258 int
 259 affs_create(struct inode *dir, struct dentry *dentry, int mode, struct nameidata *nd)
 260 {
 261         struct super_block *sb = dir->i_sb;
 262         struct inode    *inode;
 263         int              error;
 264
 265         pr_debug("AFFS: create(%lu,\"%.*s\",0%o)\n",dir->i_ino,(int)dentry->d_name.len,
 266                  dentry->d_name.name,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                 inode->i_nlink = 0;
 282                 iput(inode);
 283                 return error;
 284         }
 285         return 0;
 286 }
 287
 288 int
 289 affs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
 290 {
 291         struct inode            *inode;
 292         int                      error;
 293
 294         pr_debug("AFFS: mkdir(%lu,\"%.*s\",0%o)\n",dir->i_ino,
 295                  (int)dentry->d_name.len,dentry->d_name.name,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                 inode->i_nlink = 0;
 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("AFFS: rmdir(dir=%u, %lu \"%.*s\")\n", (u32)dir->i_ino,
 321                  dentry->d_inode->i_ino,
 322                  (int)dentry->d_name.len, dentry->d_name.name);
 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("AFFS: symlink(%lu,\"%.*s\" -> \"%s\")\n",dir->i_ino,
 338                  (int)dentry->d_name.len,dentry->d_name.name,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         inode->i_nlink = 0;
 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("AFFS: link(%u, %u, \"%.*s\")\n", (u32)inode->i_ino, (u32)dir->i_ino,
 408                  (int)dentry->d_name.len,dentry->d_name.name);
 409
 410         return affs_add_entry(dir, inode, dentry, ST_LINKFILE);
 411 }
 412
 413 int
 414 affs_rename(struct inode *old_dir, struct dentry *old_dentry,
 415             struct inode *new_dir, struct dentry *new_dentry)
 416 {
 417         struct super_block *sb = old_dir->i_sb;
 418         struct buffer_head *bh = NULL;
 419         int retval;
 420
 421         pr_debug("AFFS: rename(old=%u,\"%*s\" to new=%u,\"%*s\")\n",
 422                  (u32)old_dir->i_ino, (int)old_dentry->d_name.len, old_dentry->d_name.name,
 423                  (u32)new_dir->i_ino, (int)new_dentry->d_name.len, new_dentry->d_name.name);
 424
 425         retval = affs_check_name(new_dentry->d_name.name,new_dentry->d_name.len);
 426         if (retval)
 427                 return retval;
 428
 429         /* Unlink destination if it already exists */
 430         if (new_dentry->d_inode) {
 431                 retval = affs_remove_header(new_dentry);
 432                 if (retval)
 433                         return retval;
 434         }
 435
 436         bh = affs_bread(sb, old_dentry->d_inode->i_ino);
 437         if (!bh)
 438                 return -EIO;
 439
 440         /* Remove header from its parent directory. */
 441         affs_lock_dir(old_dir);
 442         retval = affs_remove_hash(old_dir, bh);
 443         affs_unlock_dir(old_dir);
 444         if (retval)
 445                 goto done;
 446
 447         /* And insert it into the new directory with the new name. */
 448         affs_copy_name(AFFS_TAIL(sb, bh)->name, new_dentry);
 449         affs_fix_checksum(sb, bh);
 450         affs_lock_dir(new_dir);
 451         retval = affs_insert_hash(new_dir, bh);
 452         affs_unlock_dir(new_dir);
 453         /* TODO: move it back to old_dir, if error? */
 454
 455 done:
 456         mark_buffer_dirty_inode(bh, retval ? old_dir : new_dir);
 457         affs_brelse(bh);
 458         return retval;
 459 }