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