linux/fs/affs/namei.c
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   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
  13typedef int (*toupper_t)(int);
  14
  15static int       affs_toupper(int ch);
  16static int       affs_hash_dentry(const struct dentry *,
  17                const struct inode *, struct qstr *);
  18static 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);
  22static int       affs_intl_toupper(int ch);
  23static int       affs_intl_hash_dentry(const struct dentry *,
  24                const struct inode *, struct qstr *);
  25static 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
  30const struct dentry_operations affs_dentry_operations = {
  31        .d_hash         = affs_hash_dentry,
  32        .d_compare      = affs_compare_dentry,
  33};
  34
  35const 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
  43static int
  44affs_toupper(int ch)
  45{
  46        return ch >= 'a' && ch <= 'z' ? ch -= ('a' - 'A') : ch;
  47}
  48
  49/* International toupper() for DOS\3 ("international") */
  50
  51static int
  52affs_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
  59static inline toupper_t
  60affs_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 */
  68static 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
  88static int
  89affs_hash_dentry(const struct dentry *dentry, const struct inode *inode,
  90                struct qstr *qstr)
  91{
  92        return __affs_hash_dentry(qstr, affs_toupper);
  93}
  94static int
  95affs_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
 101static 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
 133static int
 134affs_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}
 140static int
 141affs_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
 152static inline int
 153affs_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
 171int
 172affs_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
 184static struct buffer_head *
 185affs_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
 213struct dentry *
 214affs_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
 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
 247int
 248affs_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
 257int
 258affs_create(struct inode *dir, struct dentry *dentry, umode_t mode, bool excl)
 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%ho)\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
 287int
 288affs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
 289{
 290        struct inode            *inode;
 291        int                      error;
 292
 293        pr_debug("AFFS: mkdir(%lu,\"%.*s\",0%ho)\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
 316int
 317affs_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
 326int
 327affs_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
 394err:
 395        clear_nlink(inode);
 396        mark_inode_dirty(inode);
 397        iput(inode);
 398        return error;
 399}
 400
 401int
 402affs_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
 412int
 413affs_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
 454done:
 455        mark_buffer_dirty_inode(bh, retval ? old_dir : new_dir);
 456        affs_brelse(bh);
 457        return retval;
 458}
 459
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