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)
  64 {
  65         const u8 *name = qstr->name;
  66         unsigned long hash;
  67         int i;
  68
  69         i = affs_check_name(qstr->name, qstr->len);
  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 }
  87 static int
  88 affs_intl_hash_dentry(const struct dentry *dentry, struct qstr *qstr)
  89 {
  90         return __affs_hash_dentry(qstr, affs_intl_toupper);
  91 }
  92
  93 static inline int __affs_compare_dentry(unsigned int len,
  94                 const char *str, const struct qstr *name, toupper_t toupper)
  95 {
  96         const u8 *aname = str;
  97         const u8 *bname = name->name;
  98
  99         /*
 100          * 'str' is the name of an already existing dentry, so the name
 101          * must be valid. 'name' must be validated first.
 102          */
 103
 104         if (affs_check_name(name->name, name->len))
 105                 return 1;
 106
 107         /*
 108          * If the names are longer than the allowed 30 chars,
 109          * the excess is ignored, so their length may differ.
 110          */
 111         if (len >= 30) {
 112                 if (name->len < 30)
 113                         return 1;
 114                 len = 30;
 115         } else if (len != name->len)
 116                 return 1;
 117
 118         for (; len > 0; len--)
 119                 if (toupper(*aname++) != toupper(*bname++))
 120                         return 1;
 121
 122         return 0;
 123 }
 124
 125 static int
 126 affs_compare_dentry(const struct dentry *parent, const struct dentry *dentry,
 127                 unsigned int len, const char *str, const struct qstr *name)
 128 {
 129         return __affs_compare_dentry(len, str, name, affs_toupper);
 130 }
 131 static int
 132 affs_intl_compare_dentry(const struct dentry *parent, const struct dentry *dentry,
 133                 unsigned int len, const char *str, const struct qstr *name)
 134 {
 135         return __affs_compare_dentry(len, str, name, affs_intl_toupper);
 136 }
 137
 138 /*
 139  * NOTE! unlike strncmp, affs_match returns 1 for success, 0 for failure.
 140  */
 141
 142 static inline int
 143 affs_match(struct dentry *dentry, const u8 *name2, toupper_t toupper)
 144 {
 145         const u8 *name = dentry->d_name.name;
 146         int len = dentry->d_name.len;
 147
 148         if (len >= 30) {
 149                 if (*name2 < 30)
 150                         return 0;
 151                 len = 30;
 152         } else if (len != *name2)
 153                 return 0;
 154
 155         for (name2++; len > 0; len--)
 156                 if (toupper(*name++) != toupper(*name2++))
 157                         return 0;
 158         return 1;
 159 }
 160
 161 int
 162 affs_hash_name(struct super_block *sb, const u8 *name, unsigned int len)
 163 {
 164         toupper_t toupper = affs_get_toupper(sb);
 165         int hash;
 166
 167         hash = len = min(len, 30u);
 168         for (; len > 0; len--)
 169                 hash = (hash * 13 + toupper(*name++)) & 0x7ff;
 170
 171         return hash % AFFS_SB(sb)->s_hashsize;
 172 }
 173
 174 static struct buffer_head *
 175 affs_find_entry(struct inode *dir, struct dentry *dentry)
 176 {
 177         struct super_block *sb = dir->i_sb;
 178         struct buffer_head *bh;
 179         toupper_t toupper = affs_get_toupper(sb);
 180         u32 key;
 181
 182         pr_debug("AFFS: find_entry(\"%.*s\")\n", (int)dentry->d_name.len, dentry->d_name.name);
 183
 184         bh = affs_bread(sb, dir->i_ino);
 185         if (!bh)
 186                 return ERR_PTR(-EIO);
 187
 188         key = be32_to_cpu(AFFS_HEAD(bh)->table[affs_hash_name(sb, dentry->d_name.name, dentry->d_name.len)]);
 189
 190         for (;;) {
 191                 affs_brelse(bh);
 192                 if (key == 0)
 193                         return NULL;
 194                 bh = affs_bread(sb, key);
 195                 if (!bh)
 196                         return ERR_PTR(-EIO);
 197                 if (affs_match(dentry, AFFS_TAIL(sb, bh)->name, toupper))
 198                         return bh;
 199                 key = be32_to_cpu(AFFS_TAIL(sb, bh)->hash_chain);
 200         }
 201 }
 202
 203 struct dentry *
 204 affs_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
 205 {
 206         struct super_block *sb = dir->i_sb;
 207         struct buffer_head *bh;
 208         struct inode *inode = NULL;
 209
 210         pr_debug("AFFS: lookup(\"%.*s\")\n",(int)dentry->d_name.len,dentry->d_name.name);
 211
 212         affs_lock_dir(dir);
 213         bh = affs_find_entry(dir, dentry);
 214         affs_unlock_dir(dir);
 215         if (IS_ERR(bh))
 216                 return ERR_CAST(bh);
 217         if (bh) {
 218                 u32 ino = bh->b_blocknr;
 219
 220                 /* store the real header ino in d_fsdata for faster lookups */
 221                 dentry->d_fsdata = (void *)(long)ino;
 222                 switch (be32_to_cpu(AFFS_TAIL(sb, bh)->stype)) {
 223                 //link to dirs disabled
 224                 //case ST_LINKDIR:
 225                 case ST_LINKFILE:
 226                         ino = be32_to_cpu(AFFS_TAIL(sb, bh)->original);
 227                 }
 228                 affs_brelse(bh);
 229                 inode = affs_iget(sb, ino);
 230                 if (IS_ERR(inode))
 231                         return ERR_CAST(inode);
 232         }
 233         d_add(dentry, inode);
 234         return NULL;
 235 }
 236
 237 int
 238 affs_unlink(struct inode *dir, struct dentry *dentry)
 239 {
 240         pr_debug("AFFS: unlink(dir=%d, %lu \"%.*s\")\n", (u32)dir->i_ino,
 241                  dentry->d_inode->i_ino,
 242                  (int)dentry->d_name.len, dentry->d_name.name);
 243
 244         return affs_remove_header(dentry);
 245 }
 246
 247 int
 248 affs_create(struct inode *dir, struct dentry *dentry, umode_t mode, bool excl)
 249 {
 250         struct super_block *sb = dir->i_sb;
 251         struct inode    *inode;
 252         int              error;
 253
 254         pr_debug("AFFS: create(%lu,\"%.*s\",0%ho)\n",dir->i_ino,(int)dentry->d_name.len,
 255                  dentry->d_name.name,mode);
 256
 257         inode = affs_new_inode(dir);
 258         if (!inode)
 259                 return -ENOSPC;
 260
 261         inode->i_mode = mode;
 262         mode_to_prot(inode);
 263         mark_inode_dirty(inode);
 264
 265         inode->i_op = &affs_file_inode_operations;
 266         inode->i_fop = &affs_file_operations;
 267         inode->i_mapping->a_ops = (AFFS_SB(sb)->s_flags & SF_OFS) ? &affs_aops_ofs : &affs_aops;
 268         error = affs_add_entry(dir, inode, dentry, ST_FILE);
 269         if (error) {
 270                 clear_nlink(inode);
 271                 iput(inode);
 272                 return error;
 273         }
 274         return 0;
 275 }
 276
 277 int
 278 affs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
 279 {
 280         struct inode            *inode;
 281         int                      error;
 282
 283         pr_debug("AFFS: mkdir(%lu,\"%.*s\",0%ho)\n",dir->i_ino,
 284                  (int)dentry->d_name.len,dentry->d_name.name,mode);
 285
 286         inode = affs_new_inode(dir);
 287         if (!inode)
 288                 return -ENOSPC;
 289
 290         inode->i_mode = S_IFDIR | mode;
 291         mode_to_prot(inode);
 292
 293         inode->i_op = &affs_dir_inode_operations;
 294         inode->i_fop = &affs_dir_operations;
 295
 296         error = affs_add_entry(dir, inode, dentry, ST_USERDIR);
 297         if (error) {
 298                 clear_nlink(inode);
 299                 mark_inode_dirty(inode);
 300                 iput(inode);
 301                 return error;
 302         }
 303         return 0;
 304 }
 305
 306 int
 307 affs_rmdir(struct inode *dir, struct dentry *dentry)
 308 {
 309         pr_debug("AFFS: rmdir(dir=%u, %lu \"%.*s\")\n", (u32)dir->i_ino,
 310                  dentry->d_inode->i_ino,
 311                  (int)dentry->d_name.len, dentry->d_name.name);
 312
 313         return affs_remove_header(dentry);
 314 }
 315
 316 int
 317 affs_symlink(struct inode *dir, struct dentry *dentry, const char *symname)
 318 {
 319         struct super_block      *sb = dir->i_sb;
 320         struct buffer_head      *bh;
 321         struct inode            *inode;
 322         char                    *p;
 323         int                      i, maxlen, error;
 324         char                     c, lc;
 325
 326         pr_debug("AFFS: symlink(%lu,\"%.*s\" -> \"%s\")\n",dir->i_ino,
 327                  (int)dentry->d_name.len,dentry->d_name.name,symname);
 328
 329         maxlen = AFFS_SB(sb)->s_hashsize * sizeof(u32) - 1;
 330         inode  = affs_new_inode(dir);
 331         if (!inode)
 332                 return -ENOSPC;
 333
 334         inode->i_op = &affs_symlink_inode_operations;
 335         inode->i_data.a_ops = &affs_symlink_aops;
 336         inode->i_mode = S_IFLNK | 0777;
 337         mode_to_prot(inode);
 338
 339         error = -EIO;
 340         bh = affs_bread(sb, inode->i_ino);
 341         if (!bh)
 342                 goto err;
 343         i  = 0;
 344         p  = (char *)AFFS_HEAD(bh)->table;
 345         lc = '/';
 346         if (*symname == '/') {
 347                 struct affs_sb_info *sbi = AFFS_SB(sb);
 348                 while (*symname == '/')
 349                         symname++;
 350                 spin_lock(&sbi->symlink_lock);
 351                 while (sbi->s_volume[i])        /* Cannot overflow */
 352                         *p++ = sbi->s_volume[i++];
 353                 spin_unlock(&sbi->symlink_lock);
 354         }
 355         while (i < maxlen && (c = *symname++)) {
 356                 if (c == '.' && lc == '/' && *symname == '.' && symname[1] == '/') {
 357                         *p++ = '/';
 358                         i++;
 359                         symname += 2;
 360                         lc = '/';
 361                 } else if (c == '.' && lc == '/' && *symname == '/') {
 362                         symname++;
 363                         lc = '/';
 364                 } else {
 365                         *p++ = c;
 366                         lc   = c;
 367                         i++;
 368                 }
 369                 if (lc == '/')
 370                         while (*symname == '/')
 371                                 symname++;
 372         }
 373         *p = 0;
 374         mark_buffer_dirty_inode(bh, inode);
 375         affs_brelse(bh);
 376         mark_inode_dirty(inode);
 377
 378         error = affs_add_entry(dir, inode, dentry, ST_SOFTLINK);
 379         if (error)
 380                 goto err;
 381
 382         return 0;
 383
 384 err:
 385         clear_nlink(inode);
 386         mark_inode_dirty(inode);
 387         iput(inode);
 388         return error;
 389 }
 390
 391 int
 392 affs_link(struct dentry *old_dentry, struct inode *dir, struct dentry *dentry)
 393 {
 394         struct inode *inode = old_dentry->d_inode;
 395
 396         pr_debug("AFFS: link(%u, %u, \"%.*s\")\n", (u32)inode->i_ino, (u32)dir->i_ino,
 397                  (int)dentry->d_name.len,dentry->d_name.name);
 398
 399         return affs_add_entry(dir, inode, dentry, ST_LINKFILE);
 400 }
 401
 402 int
 403 affs_rename(struct inode *old_dir, struct dentry *old_dentry,
 404             struct inode *new_dir, struct dentry *new_dentry)
 405 {
 406         struct super_block *sb = old_dir->i_sb;
 407         struct buffer_head *bh = NULL;
 408         int retval;
 409
 410         pr_debug("AFFS: rename(old=%u,\"%*s\" to new=%u,\"%*s\")\n",
 411                  (u32)old_dir->i_ino, (int)old_dentry->d_name.len, old_dentry->d_name.name,
 412                  (u32)new_dir->i_ino, (int)new_dentry->d_name.len, new_dentry->d_name.name);
 413
 414         retval = affs_check_name(new_dentry->d_name.name,new_dentry->d_name.len);
 415         if (retval)
 416                 return retval;
 417
 418         /* Unlink destination if it already exists */
 419         if (new_dentry->d_inode) {
 420                 retval = affs_remove_header(new_dentry);
 421                 if (retval)
 422                         return retval;
 423         }
 424
 425         bh = affs_bread(sb, old_dentry->d_inode->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 }