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 *, struct qstr *);
  17static int       affs_compare_dentry(const struct dentry *parent, const struct dentry *dentry,
  18                unsigned int len, const char *str, const struct qstr *name);
  19static int       affs_intl_toupper(int ch);
  20static int       affs_intl_hash_dentry(const struct dentry *, struct qstr *);
  21static 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
  24const struct dentry_operations affs_dentry_operations = {
  25        .d_hash         = affs_hash_dentry,
  26        .d_compare      = affs_compare_dentry,
  27};
  28
  29const 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
  37static int
  38affs_toupper(int ch)
  39{
  40        return ch >= 'a' && ch <= 'z' ? ch -= ('a' - 'A') : ch;
  41}
  42
  43/* International toupper() for DOS\3 ("international") */
  44
  45static int
  46affs_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
  53static inline toupper_t
  54affs_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 */
  62static 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
  82static int
  83affs_hash_dentry(const struct dentry *dentry, struct qstr *qstr)
  84{
  85        return __affs_hash_dentry(qstr, affs_toupper);
  86}
  87static int
  88affs_intl_hash_dentry(const struct dentry *dentry, struct qstr *qstr)
  89{
  90        return __affs_hash_dentry(qstr, affs_intl_toupper);
  91}
  92
  93static 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
 125static int
 126affs_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}
 131static int
 132affs_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
 142static inline int
 143affs_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
 161int
 162affs_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
 174static struct buffer_head *
 175affs_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
 203struct dentry *
 204affs_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
 237int
 238affs_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
 247int
 248affs_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
 277int
 278affs_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
 306int
 307affs_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
 316int
 317affs_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
 384err:
 385        clear_nlink(inode);
 386        mark_inode_dirty(inode);
 387        iput(inode);
 388        return error;
 389}
 390
 391int
 392affs_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
 402int
 403affs_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
 444done:
 445        mark_buffer_dirty_inode(bh, retval ? old_dir : new_dir);
 446        affs_brelse(bh);
 447        return retval;
 448}
 449
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