linux/fs/befs/linuxvfs.c
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   1/*
   2 * linux/fs/befs/linuxvfs.c
   3 *
   4 * Copyright (C) 2001 Will Dyson <will_dyson@pobox.com
   5 *
   6 */
   7
   8#include <linux/module.h>
   9#include <linux/slab.h>
  10#include <linux/fs.h>
  11#include <linux/errno.h>
  12#include <linux/stat.h>
  13#include <linux/nls.h>
  14#include <linux/buffer_head.h>
  15#include <linux/vfs.h>
  16#include <linux/parser.h>
  17#include <linux/namei.h>
  18#include <linux/sched.h>
  19
  20#include "befs.h"
  21#include "btree.h"
  22#include "inode.h"
  23#include "datastream.h"
  24#include "super.h"
  25#include "io.h"
  26
  27MODULE_DESCRIPTION("BeOS File System (BeFS) driver");
  28MODULE_AUTHOR("Will Dyson");
  29MODULE_LICENSE("GPL");
  30
  31/* The units the vfs expects inode->i_blocks to be in */
  32#define VFS_BLOCK_SIZE 512
  33
  34static int befs_readdir(struct file *, void *, filldir_t);
  35static int befs_get_block(struct inode *, sector_t, struct buffer_head *, int);
  36static int befs_readpage(struct file *file, struct page *page);
  37static sector_t befs_bmap(struct address_space *mapping, sector_t block);
  38static struct dentry *befs_lookup(struct inode *, struct dentry *, unsigned int);
  39static struct inode *befs_iget(struct super_block *, unsigned long);
  40static struct inode *befs_alloc_inode(struct super_block *sb);
  41static void befs_destroy_inode(struct inode *inode);
  42static int befs_init_inodecache(void);
  43static void befs_destroy_inodecache(void);
  44static void *befs_follow_link(struct dentry *, struct nameidata *);
  45static void befs_put_link(struct dentry *, struct nameidata *, void *);
  46static int befs_utf2nls(struct super_block *sb, const char *in, int in_len,
  47                        char **out, int *out_len);
  48static int befs_nls2utf(struct super_block *sb, const char *in, int in_len,
  49                        char **out, int *out_len);
  50static void befs_put_super(struct super_block *);
  51static int befs_remount(struct super_block *, int *, char *);
  52static int befs_statfs(struct dentry *, struct kstatfs *);
  53static int parse_options(char *, befs_mount_options *);
  54
  55static const struct super_operations befs_sops = {
  56        .alloc_inode    = befs_alloc_inode,     /* allocate a new inode */
  57        .destroy_inode  = befs_destroy_inode, /* deallocate an inode */
  58        .put_super      = befs_put_super,       /* uninit super */
  59        .statfs         = befs_statfs,  /* statfs */
  60        .remount_fs     = befs_remount,
  61        .show_options   = generic_show_options,
  62};
  63
  64/* slab cache for befs_inode_info objects */
  65static struct kmem_cache *befs_inode_cachep;
  66
  67static const struct file_operations befs_dir_operations = {
  68        .read           = generic_read_dir,
  69        .readdir        = befs_readdir,
  70        .llseek         = generic_file_llseek,
  71};
  72
  73static const struct inode_operations befs_dir_inode_operations = {
  74        .lookup         = befs_lookup,
  75};
  76
  77static const struct address_space_operations befs_aops = {
  78        .readpage       = befs_readpage,
  79        .bmap           = befs_bmap,
  80};
  81
  82static const struct inode_operations befs_symlink_inode_operations = {
  83        .readlink       = generic_readlink,
  84        .follow_link    = befs_follow_link,
  85        .put_link       = befs_put_link,
  86};
  87
  88/* 
  89 * Called by generic_file_read() to read a page of data
  90 * 
  91 * In turn, simply calls a generic block read function and
  92 * passes it the address of befs_get_block, for mapping file
  93 * positions to disk blocks.
  94 */
  95static int
  96befs_readpage(struct file *file, struct page *page)
  97{
  98        return block_read_full_page(page, befs_get_block);
  99}
 100
 101static sector_t
 102befs_bmap(struct address_space *mapping, sector_t block)
 103{
 104        return generic_block_bmap(mapping, block, befs_get_block);
 105}
 106
 107/* 
 108 * Generic function to map a file position (block) to a 
 109 * disk offset (passed back in bh_result).
 110 *
 111 * Used by many higher level functions.
 112 *
 113 * Calls befs_fblock2brun() in datastream.c to do the real work.
 114 *
 115 * -WD 10-26-01
 116 */
 117
 118static int
 119befs_get_block(struct inode *inode, sector_t block,
 120               struct buffer_head *bh_result, int create)
 121{
 122        struct super_block *sb = inode->i_sb;
 123        befs_data_stream *ds = &BEFS_I(inode)->i_data.ds;
 124        befs_block_run run = BAD_IADDR;
 125        int res = 0;
 126        ulong disk_off;
 127
 128        befs_debug(sb, "---> befs_get_block() for inode %lu, block %ld",
 129                   inode->i_ino, block);
 130
 131        if (block < 0) {
 132                befs_error(sb, "befs_get_block() was asked for a block "
 133                           "number less than zero: block %ld in inode %lu",
 134                           block, inode->i_ino);
 135                return -EIO;
 136        }
 137
 138        if (create) {
 139                befs_error(sb, "befs_get_block() was asked to write to "
 140                           "block %ld in inode %lu", block, inode->i_ino);
 141                return -EPERM;
 142        }
 143
 144        res = befs_fblock2brun(sb, ds, block, &run);
 145        if (res != BEFS_OK) {
 146                befs_error(sb,
 147                           "<--- befs_get_block() for inode %lu, block "
 148                           "%ld ERROR", inode->i_ino, block);
 149                return -EFBIG;
 150        }
 151
 152        disk_off = (ulong) iaddr2blockno(sb, &run);
 153
 154        map_bh(bh_result, inode->i_sb, disk_off);
 155
 156        befs_debug(sb, "<--- befs_get_block() for inode %lu, block %ld, "
 157                   "disk address %lu", inode->i_ino, block, disk_off);
 158
 159        return 0;
 160}
 161
 162static struct dentry *
 163befs_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
 164{
 165        struct inode *inode = NULL;
 166        struct super_block *sb = dir->i_sb;
 167        befs_data_stream *ds = &BEFS_I(dir)->i_data.ds;
 168        befs_off_t offset;
 169        int ret;
 170        int utfnamelen;
 171        char *utfname;
 172        const char *name = dentry->d_name.name;
 173
 174        befs_debug(sb, "---> befs_lookup() "
 175                   "name %s inode %ld", dentry->d_name.name, dir->i_ino);
 176
 177        /* Convert to UTF-8 */
 178        if (BEFS_SB(sb)->nls) {
 179                ret =
 180                    befs_nls2utf(sb, name, strlen(name), &utfname, &utfnamelen);
 181                if (ret < 0) {
 182                        befs_debug(sb, "<--- befs_lookup() ERROR");
 183                        return ERR_PTR(ret);
 184                }
 185                ret = befs_btree_find(sb, ds, utfname, &offset);
 186                kfree(utfname);
 187
 188        } else {
 189                ret = befs_btree_find(sb, ds, dentry->d_name.name, &offset);
 190        }
 191
 192        if (ret == BEFS_BT_NOT_FOUND) {
 193                befs_debug(sb, "<--- befs_lookup() %s not found",
 194                           dentry->d_name.name);
 195                return ERR_PTR(-ENOENT);
 196
 197        } else if (ret != BEFS_OK || offset == 0) {
 198                befs_warning(sb, "<--- befs_lookup() Error");
 199                return ERR_PTR(-ENODATA);
 200        }
 201
 202        inode = befs_iget(dir->i_sb, (ino_t) offset);
 203        if (IS_ERR(inode))
 204                return ERR_CAST(inode);
 205
 206        d_add(dentry, inode);
 207
 208        befs_debug(sb, "<--- befs_lookup()");
 209
 210        return NULL;
 211}
 212
 213static int
 214befs_readdir(struct file *filp, void *dirent, filldir_t filldir)
 215{
 216        struct inode *inode = filp->f_path.dentry->d_inode;
 217        struct super_block *sb = inode->i_sb;
 218        befs_data_stream *ds = &BEFS_I(inode)->i_data.ds;
 219        befs_off_t value;
 220        int result;
 221        size_t keysize;
 222        unsigned char d_type;
 223        char keybuf[BEFS_NAME_LEN + 1];
 224        char *nlsname;
 225        int nlsnamelen;
 226        const char *dirname = filp->f_path.dentry->d_name.name;
 227
 228        befs_debug(sb, "---> befs_readdir() "
 229                   "name %s, inode %ld, filp->f_pos %Ld",
 230                   dirname, inode->i_ino, filp->f_pos);
 231
 232        result = befs_btree_read(sb, ds, filp->f_pos, BEFS_NAME_LEN + 1,
 233                                 keybuf, &keysize, &value);
 234
 235        if (result == BEFS_ERR) {
 236                befs_debug(sb, "<--- befs_readdir() ERROR");
 237                befs_error(sb, "IO error reading %s (inode %lu)",
 238                           dirname, inode->i_ino);
 239                return -EIO;
 240
 241        } else if (result == BEFS_BT_END) {
 242                befs_debug(sb, "<--- befs_readdir() END");
 243                return 0;
 244
 245        } else if (result == BEFS_BT_EMPTY) {
 246                befs_debug(sb, "<--- befs_readdir() Empty directory");
 247                return 0;
 248        }
 249
 250        d_type = DT_UNKNOWN;
 251
 252        /* Convert to NLS */
 253        if (BEFS_SB(sb)->nls) {
 254                result =
 255                    befs_utf2nls(sb, keybuf, keysize, &nlsname, &nlsnamelen);
 256                if (result < 0) {
 257                        befs_debug(sb, "<--- befs_readdir() ERROR");
 258                        return result;
 259                }
 260                result = filldir(dirent, nlsname, nlsnamelen, filp->f_pos,
 261                                 (ino_t) value, d_type);
 262                kfree(nlsname);
 263
 264        } else {
 265                result = filldir(dirent, keybuf, keysize, filp->f_pos,
 266                                 (ino_t) value, d_type);
 267        }
 268
 269        filp->f_pos++;
 270
 271        befs_debug(sb, "<--- befs_readdir() filp->f_pos %Ld", filp->f_pos);
 272
 273        return 0;
 274}
 275
 276static struct inode *
 277befs_alloc_inode(struct super_block *sb)
 278{
 279        struct befs_inode_info *bi;
 280        bi = (struct befs_inode_info *)kmem_cache_alloc(befs_inode_cachep,
 281                                                        GFP_KERNEL);
 282        if (!bi)
 283                return NULL;
 284        return &bi->vfs_inode;
 285}
 286
 287static void befs_i_callback(struct rcu_head *head)
 288{
 289        struct inode *inode = container_of(head, struct inode, i_rcu);
 290        kmem_cache_free(befs_inode_cachep, BEFS_I(inode));
 291}
 292
 293static void befs_destroy_inode(struct inode *inode)
 294{
 295        call_rcu(&inode->i_rcu, befs_i_callback);
 296}
 297
 298static void init_once(void *foo)
 299{
 300        struct befs_inode_info *bi = (struct befs_inode_info *) foo;
 301
 302        inode_init_once(&bi->vfs_inode);
 303}
 304
 305static struct inode *befs_iget(struct super_block *sb, unsigned long ino)
 306{
 307        struct buffer_head *bh = NULL;
 308        befs_inode *raw_inode = NULL;
 309
 310        befs_sb_info *befs_sb = BEFS_SB(sb);
 311        befs_inode_info *befs_ino = NULL;
 312        struct inode *inode;
 313        long ret = -EIO;
 314
 315        befs_debug(sb, "---> befs_read_inode() " "inode = %lu", ino);
 316
 317        inode = iget_locked(sb, ino);
 318        if (IS_ERR(inode))
 319                return inode;
 320        if (!(inode->i_state & I_NEW))
 321                return inode;
 322
 323        befs_ino = BEFS_I(inode);
 324
 325        /* convert from vfs's inode number to befs's inode number */
 326        befs_ino->i_inode_num = blockno2iaddr(sb, inode->i_ino);
 327
 328        befs_debug(sb, "  real inode number [%u, %hu, %hu]",
 329                   befs_ino->i_inode_num.allocation_group,
 330                   befs_ino->i_inode_num.start, befs_ino->i_inode_num.len);
 331
 332        bh = befs_bread(sb, inode->i_ino);
 333        if (!bh) {
 334                befs_error(sb, "unable to read inode block - "
 335                           "inode = %lu", inode->i_ino);
 336                goto unacquire_none;
 337        }
 338
 339        raw_inode = (befs_inode *) bh->b_data;
 340
 341        befs_dump_inode(sb, raw_inode);
 342
 343        if (befs_check_inode(sb, raw_inode, inode->i_ino) != BEFS_OK) {
 344                befs_error(sb, "Bad inode: %lu", inode->i_ino);
 345                goto unacquire_bh;
 346        }
 347
 348        inode->i_mode = (umode_t) fs32_to_cpu(sb, raw_inode->mode);
 349
 350        /*
 351         * set uid and gid.  But since current BeOS is single user OS, so
 352         * you can change by "uid" or "gid" options.
 353         */   
 354
 355        inode->i_uid = befs_sb->mount_opts.use_uid ?
 356                befs_sb->mount_opts.uid :
 357                make_kuid(&init_user_ns, fs32_to_cpu(sb, raw_inode->uid));
 358        inode->i_gid = befs_sb->mount_opts.use_gid ?
 359                befs_sb->mount_opts.gid :
 360                make_kgid(&init_user_ns, fs32_to_cpu(sb, raw_inode->gid));
 361
 362        set_nlink(inode, 1);
 363
 364        /*
 365         * BEFS's time is 64 bits, but current VFS is 32 bits...
 366         * BEFS don't have access time. Nor inode change time. VFS
 367         * doesn't have creation time.
 368         * Also, the lower 16 bits of the last_modified_time and 
 369         * create_time are just a counter to help ensure uniqueness
 370         * for indexing purposes. (PFD, page 54)
 371         */
 372
 373        inode->i_mtime.tv_sec =
 374            fs64_to_cpu(sb, raw_inode->last_modified_time) >> 16;
 375        inode->i_mtime.tv_nsec = 0;   /* lower 16 bits are not a time */        
 376        inode->i_ctime = inode->i_mtime;
 377        inode->i_atime = inode->i_mtime;
 378
 379        befs_ino->i_inode_num = fsrun_to_cpu(sb, raw_inode->inode_num);
 380        befs_ino->i_parent = fsrun_to_cpu(sb, raw_inode->parent);
 381        befs_ino->i_attribute = fsrun_to_cpu(sb, raw_inode->attributes);
 382        befs_ino->i_flags = fs32_to_cpu(sb, raw_inode->flags);
 383
 384        if (S_ISLNK(inode->i_mode) && !(befs_ino->i_flags & BEFS_LONG_SYMLINK)){
 385                inode->i_size = 0;
 386                inode->i_blocks = befs_sb->block_size / VFS_BLOCK_SIZE;
 387                strncpy(befs_ino->i_data.symlink, raw_inode->data.symlink,
 388                        BEFS_SYMLINK_LEN - 1);
 389                befs_ino->i_data.symlink[BEFS_SYMLINK_LEN - 1] = '\0';
 390        } else {
 391                int num_blks;
 392
 393                befs_ino->i_data.ds =
 394                    fsds_to_cpu(sb, &raw_inode->data.datastream);
 395
 396                num_blks = befs_count_blocks(sb, &befs_ino->i_data.ds);
 397                inode->i_blocks =
 398                    num_blks * (befs_sb->block_size / VFS_BLOCK_SIZE);
 399                inode->i_size = befs_ino->i_data.ds.size;
 400        }
 401
 402        inode->i_mapping->a_ops = &befs_aops;
 403
 404        if (S_ISREG(inode->i_mode)) {
 405                inode->i_fop = &generic_ro_fops;
 406        } else if (S_ISDIR(inode->i_mode)) {
 407                inode->i_op = &befs_dir_inode_operations;
 408                inode->i_fop = &befs_dir_operations;
 409        } else if (S_ISLNK(inode->i_mode)) {
 410                inode->i_op = &befs_symlink_inode_operations;
 411        } else {
 412                befs_error(sb, "Inode %lu is not a regular file, "
 413                           "directory or symlink. THAT IS WRONG! BeFS has no "
 414                           "on disk special files", inode->i_ino);
 415                goto unacquire_bh;
 416        }
 417
 418        brelse(bh);
 419        befs_debug(sb, "<--- befs_read_inode()");
 420        unlock_new_inode(inode);
 421        return inode;
 422
 423      unacquire_bh:
 424        brelse(bh);
 425
 426      unacquire_none:
 427        iget_failed(inode);
 428        befs_debug(sb, "<--- befs_read_inode() - Bad inode");
 429        return ERR_PTR(ret);
 430}
 431
 432/* Initialize the inode cache. Called at fs setup.
 433 *
 434 * Taken from NFS implementation by Al Viro.
 435 */
 436static int
 437befs_init_inodecache(void)
 438{
 439        befs_inode_cachep = kmem_cache_create("befs_inode_cache",
 440                                              sizeof (struct befs_inode_info),
 441                                              0, (SLAB_RECLAIM_ACCOUNT|
 442                                                SLAB_MEM_SPREAD),
 443                                              init_once);
 444        if (befs_inode_cachep == NULL) {
 445                printk(KERN_ERR "befs_init_inodecache: "
 446                       "Couldn't initialize inode slabcache\n");
 447                return -ENOMEM;
 448        }
 449
 450        return 0;
 451}
 452
 453/* Called at fs teardown.
 454 * 
 455 * Taken from NFS implementation by Al Viro.
 456 */
 457static void
 458befs_destroy_inodecache(void)
 459{
 460        /*
 461         * Make sure all delayed rcu free inodes are flushed before we
 462         * destroy cache.
 463         */
 464        rcu_barrier();
 465        kmem_cache_destroy(befs_inode_cachep);
 466}
 467
 468/*
 469 * The inode of symbolic link is different to data stream.
 470 * The data stream become link name. Unless the LONG_SYMLINK
 471 * flag is set.
 472 */
 473static void *
 474befs_follow_link(struct dentry *dentry, struct nameidata *nd)
 475{
 476        befs_inode_info *befs_ino = BEFS_I(dentry->d_inode);
 477        char *link;
 478
 479        if (befs_ino->i_flags & BEFS_LONG_SYMLINK) {
 480                struct super_block *sb = dentry->d_sb;
 481                befs_data_stream *data = &befs_ino->i_data.ds;
 482                befs_off_t len = data->size;
 483
 484                if (len == 0) {
 485                        befs_error(sb, "Long symlink with illegal length");
 486                        link = ERR_PTR(-EIO);
 487                } else {
 488                        befs_debug(sb, "Follow long symlink");
 489
 490                        link = kmalloc(len, GFP_NOFS);
 491                        if (!link) {
 492                                link = ERR_PTR(-ENOMEM);
 493                        } else if (befs_read_lsymlink(sb, data, link, len) != len) {
 494                                kfree(link);
 495                                befs_error(sb, "Failed to read entire long symlink");
 496                                link = ERR_PTR(-EIO);
 497                        } else {
 498                                link[len - 1] = '\0';
 499                        }
 500                }
 501        } else {
 502                link = befs_ino->i_data.symlink;
 503        }
 504
 505        nd_set_link(nd, link);
 506        return NULL;
 507}
 508
 509static void befs_put_link(struct dentry *dentry, struct nameidata *nd, void *p)
 510{
 511        befs_inode_info *befs_ino = BEFS_I(dentry->d_inode);
 512        if (befs_ino->i_flags & BEFS_LONG_SYMLINK) {
 513                char *link = nd_get_link(nd);
 514                if (!IS_ERR(link))
 515                        kfree(link);
 516        }
 517}
 518
 519/*
 520 * UTF-8 to NLS charset  convert routine
 521 * 
 522 *
 523 * Changed 8/10/01 by Will Dyson. Now use uni2char() / char2uni() rather than
 524 * the nls tables directly
 525 */
 526
 527static int
 528befs_utf2nls(struct super_block *sb, const char *in,
 529             int in_len, char **out, int *out_len)
 530{
 531        struct nls_table *nls = BEFS_SB(sb)->nls;
 532        int i, o;
 533        unicode_t uni;
 534        int unilen, utflen;
 535        char *result;
 536        /* The utf8->nls conversion won't make the final nls string bigger
 537         * than the utf one, but if the string is pure ascii they'll have the
 538         * same width and an extra char is needed to save the additional \0
 539         */
 540        int maxlen = in_len + 1;
 541
 542        befs_debug(sb, "---> utf2nls()");
 543
 544        if (!nls) {
 545                befs_error(sb, "befs_utf2nls called with no NLS table loaded");
 546                return -EINVAL;
 547        }
 548
 549        *out = result = kmalloc(maxlen, GFP_NOFS);
 550        if (!*out) {
 551                befs_error(sb, "befs_utf2nls() cannot allocate memory");
 552                *out_len = 0;
 553                return -ENOMEM;
 554        }
 555
 556        for (i = o = 0; i < in_len; i += utflen, o += unilen) {
 557
 558                /* convert from UTF-8 to Unicode */
 559                utflen = utf8_to_utf32(&in[i], in_len - i, &uni);
 560                if (utflen < 0)
 561                        goto conv_err;
 562
 563                /* convert from Unicode to nls */
 564                if (uni > MAX_WCHAR_T)
 565                        goto conv_err;
 566                unilen = nls->uni2char(uni, &result[o], in_len - o);
 567                if (unilen < 0)
 568                        goto conv_err;
 569        }
 570        result[o] = '\0';
 571        *out_len = o;
 572
 573        befs_debug(sb, "<--- utf2nls()");
 574
 575        return o;
 576
 577      conv_err:
 578        befs_error(sb, "Name using character set %s contains a character that "
 579                   "cannot be converted to unicode.", nls->charset);
 580        befs_debug(sb, "<--- utf2nls()");
 581        kfree(result);
 582        return -EILSEQ;
 583}
 584
 585/**
 586 * befs_nls2utf - Convert NLS string to utf8 encodeing
 587 * @sb: Superblock
 588 * @src: Input string buffer in NLS format
 589 * @srclen: Length of input string in bytes
 590 * @dest: The output string in UTF-8 format
 591 * @destlen: Length of the output buffer
 592 * 
 593 * Converts input string @src, which is in the format of the loaded NLS map,
 594 * into a utf8 string.
 595 * 
 596 * The destination string @dest is allocated by this function and the caller is
 597 * responsible for freeing it with kfree()
 598 * 
 599 * On return, *@destlen is the length of @dest in bytes.
 600 *
 601 * On success, the return value is the number of utf8 characters written to
 602 * the output buffer @dest.
 603 *  
 604 * On Failure, a negative number coresponding to the error code is returned.
 605 */
 606
 607static int
 608befs_nls2utf(struct super_block *sb, const char *in,
 609             int in_len, char **out, int *out_len)
 610{
 611        struct nls_table *nls = BEFS_SB(sb)->nls;
 612        int i, o;
 613        wchar_t uni;
 614        int unilen, utflen;
 615        char *result;
 616        /* There're nls characters that will translate to 3-chars-wide UTF-8
 617         * characters, a additional byte is needed to save the final \0
 618         * in special cases */
 619        int maxlen = (3 * in_len) + 1;
 620
 621        befs_debug(sb, "---> nls2utf()\n");
 622
 623        if (!nls) {
 624                befs_error(sb, "befs_nls2utf called with no NLS table loaded.");
 625                return -EINVAL;
 626        }
 627
 628        *out = result = kmalloc(maxlen, GFP_NOFS);
 629        if (!*out) {
 630                befs_error(sb, "befs_nls2utf() cannot allocate memory");
 631                *out_len = 0;
 632                return -ENOMEM;
 633        }
 634
 635        for (i = o = 0; i < in_len; i += unilen, o += utflen) {
 636
 637                /* convert from nls to unicode */
 638                unilen = nls->char2uni(&in[i], in_len - i, &uni);
 639                if (unilen < 0)
 640                        goto conv_err;
 641
 642                /* convert from unicode to UTF-8 */
 643                utflen = utf32_to_utf8(uni, &result[o], 3);
 644                if (utflen <= 0)
 645                        goto conv_err;
 646        }
 647
 648        result[o] = '\0';
 649        *out_len = o;
 650
 651        befs_debug(sb, "<--- nls2utf()");
 652
 653        return i;
 654
 655      conv_err:
 656        befs_error(sb, "Name using charecter set %s contains a charecter that "
 657                   "cannot be converted to unicode.", nls->charset);
 658        befs_debug(sb, "<--- nls2utf()");
 659        kfree(result);
 660        return -EILSEQ;
 661}
 662
 663/**
 664 * Use the
 665 *
 666 */
 667enum {
 668        Opt_uid, Opt_gid, Opt_charset, Opt_debug, Opt_err,
 669};
 670
 671static const match_table_t befs_tokens = {
 672        {Opt_uid, "uid=%d"},
 673        {Opt_gid, "gid=%d"},
 674        {Opt_charset, "iocharset=%s"},
 675        {Opt_debug, "debug"},
 676        {Opt_err, NULL}
 677};
 678
 679static int
 680parse_options(char *options, befs_mount_options * opts)
 681{
 682        char *p;
 683        substring_t args[MAX_OPT_ARGS];
 684        int option;
 685        kuid_t uid;
 686        kgid_t gid;
 687
 688        /* Initialize options */
 689        opts->uid = GLOBAL_ROOT_UID;
 690        opts->gid = GLOBAL_ROOT_GID;
 691        opts->use_uid = 0;
 692        opts->use_gid = 0;
 693        opts->iocharset = NULL;
 694        opts->debug = 0;
 695
 696        if (!options)
 697                return 1;
 698
 699        while ((p = strsep(&options, ",")) != NULL) {
 700                int token;
 701                if (!*p)
 702                        continue;
 703
 704                token = match_token(p, befs_tokens, args);
 705                switch (token) {
 706                case Opt_uid:
 707                        if (match_int(&args[0], &option))
 708                                return 0;
 709                        uid = INVALID_UID;
 710                        if (option >= 0)
 711                                uid = make_kuid(current_user_ns(), option);
 712                        if (!uid_valid(uid)) {
 713                                printk(KERN_ERR "BeFS: Invalid uid %d, "
 714                                                "using default\n", option);
 715                                break;
 716                        }
 717                        opts->uid = uid;
 718                        opts->use_uid = 1;
 719                        break;
 720                case Opt_gid:
 721                        if (match_int(&args[0], &option))
 722                                return 0;
 723                        gid = INVALID_GID;
 724                        if (option >= 0)
 725                                gid = make_kgid(current_user_ns(), option);
 726                        if (!gid_valid(gid)) {
 727                                printk(KERN_ERR "BeFS: Invalid gid %d, "
 728                                                "using default\n", option);
 729                                break;
 730                        }
 731                        opts->gid = gid;
 732                        opts->use_gid = 1;
 733                        break;
 734                case Opt_charset:
 735                        kfree(opts->iocharset);
 736                        opts->iocharset = match_strdup(&args[0]);
 737                        if (!opts->iocharset) {
 738                                printk(KERN_ERR "BeFS: allocation failure for "
 739                                                "iocharset string\n");
 740                                return 0;
 741                        }
 742                        break;
 743                case Opt_debug:
 744                        opts->debug = 1;
 745                        break;
 746                default:
 747                        printk(KERN_ERR "BeFS: Unrecognized mount option \"%s\" "
 748                                        "or missing value\n", p);
 749                        return 0;
 750                }
 751        }
 752        return 1;
 753}
 754
 755/* This function has the responsibiltiy of getting the
 756 * filesystem ready for unmounting. 
 757 * Basically, we free everything that we allocated in
 758 * befs_read_inode
 759 */
 760static void
 761befs_put_super(struct super_block *sb)
 762{
 763        kfree(BEFS_SB(sb)->mount_opts.iocharset);
 764        BEFS_SB(sb)->mount_opts.iocharset = NULL;
 765        unload_nls(BEFS_SB(sb)->nls);
 766        kfree(sb->s_fs_info);
 767        sb->s_fs_info = NULL;
 768}
 769
 770/* Allocate private field of the superblock, fill it.
 771 *
 772 * Finish filling the public superblock fields
 773 * Make the root directory
 774 * Load a set of NLS translations if needed.
 775 */
 776static int
 777befs_fill_super(struct super_block *sb, void *data, int silent)
 778{
 779        struct buffer_head *bh;
 780        befs_sb_info *befs_sb;
 781        befs_super_block *disk_sb;
 782        struct inode *root;
 783        long ret = -EINVAL;
 784        const unsigned long sb_block = 0;
 785        const off_t x86_sb_off = 512;
 786
 787        save_mount_options(sb, data);
 788
 789        sb->s_fs_info = kmalloc(sizeof (*befs_sb), GFP_KERNEL);
 790        if (sb->s_fs_info == NULL) {
 791                printk(KERN_ERR
 792                       "BeFS(%s): Unable to allocate memory for private "
 793                       "portion of superblock. Bailing.\n", sb->s_id);
 794                goto unacquire_none;
 795        }
 796        befs_sb = BEFS_SB(sb);
 797        memset(befs_sb, 0, sizeof(befs_sb_info));
 798
 799        if (!parse_options((char *) data, &befs_sb->mount_opts)) {
 800                befs_error(sb, "cannot parse mount options");
 801                goto unacquire_priv_sbp;
 802        }
 803
 804        befs_debug(sb, "---> befs_fill_super()");
 805
 806#ifndef CONFIG_BEFS_RW
 807        if (!(sb->s_flags & MS_RDONLY)) {
 808                befs_warning(sb,
 809                             "No write support. Marking filesystem read-only");
 810                sb->s_flags |= MS_RDONLY;
 811        }
 812#endif                          /* CONFIG_BEFS_RW */
 813
 814        /*
 815         * Set dummy blocksize to read super block.
 816         * Will be set to real fs blocksize later.
 817         *
 818         * Linux 2.4.10 and later refuse to read blocks smaller than
 819         * the hardsect size for the device. But we also need to read at 
 820         * least 1k to get the second 512 bytes of the volume.
 821         * -WD 10-26-01
 822         */ 
 823        sb_min_blocksize(sb, 1024);
 824
 825        if (!(bh = sb_bread(sb, sb_block))) {
 826                befs_error(sb, "unable to read superblock");
 827                goto unacquire_priv_sbp;
 828        }
 829
 830        /* account for offset of super block on x86 */
 831        disk_sb = (befs_super_block *) bh->b_data;
 832        if ((disk_sb->magic1 == BEFS_SUPER_MAGIC1_LE) ||
 833            (disk_sb->magic1 == BEFS_SUPER_MAGIC1_BE)) {
 834                befs_debug(sb, "Using PPC superblock location");
 835        } else {
 836                befs_debug(sb, "Using x86 superblock location");
 837                disk_sb =
 838                    (befs_super_block *) ((void *) bh->b_data + x86_sb_off);
 839        }
 840
 841        if (befs_load_sb(sb, disk_sb) != BEFS_OK)
 842                goto unacquire_bh;
 843
 844        befs_dump_super_block(sb, disk_sb);
 845
 846        brelse(bh);
 847
 848        if (befs_check_sb(sb) != BEFS_OK)
 849                goto unacquire_priv_sbp;
 850
 851        if( befs_sb->num_blocks > ~((sector_t)0) ) {
 852                befs_error(sb, "blocks count: %Lu "
 853                        "is larger than the host can use",
 854                        befs_sb->num_blocks);
 855                goto unacquire_priv_sbp;
 856        }
 857
 858        /*
 859         * set up enough so that it can read an inode
 860         * Fill in kernel superblock fields from private sb
 861         */
 862        sb->s_magic = BEFS_SUPER_MAGIC;
 863        /* Set real blocksize of fs */
 864        sb_set_blocksize(sb, (ulong) befs_sb->block_size);
 865        sb->s_op = &befs_sops;
 866        root = befs_iget(sb, iaddr2blockno(sb, &(befs_sb->root_dir)));
 867        if (IS_ERR(root)) {
 868                ret = PTR_ERR(root);
 869                goto unacquire_priv_sbp;
 870        }
 871        sb->s_root = d_make_root(root);
 872        if (!sb->s_root) {
 873                befs_error(sb, "get root inode failed");
 874                goto unacquire_priv_sbp;
 875        }
 876
 877        /* load nls library */
 878        if (befs_sb->mount_opts.iocharset) {
 879                befs_debug(sb, "Loading nls: %s",
 880                           befs_sb->mount_opts.iocharset);
 881                befs_sb->nls = load_nls(befs_sb->mount_opts.iocharset);
 882                if (!befs_sb->nls) {
 883                        befs_warning(sb, "Cannot load nls %s"
 884                                        " loading default nls",
 885                                        befs_sb->mount_opts.iocharset);
 886                        befs_sb->nls = load_nls_default();
 887                }
 888        /* load default nls if none is specified  in mount options */
 889        } else {
 890                befs_debug(sb, "Loading default nls");
 891                befs_sb->nls = load_nls_default();
 892        }
 893
 894        return 0;
 895/*****************/
 896      unacquire_bh:
 897        brelse(bh);
 898
 899      unacquire_priv_sbp:
 900        kfree(befs_sb->mount_opts.iocharset);
 901        kfree(sb->s_fs_info);
 902
 903      unacquire_none:
 904        sb->s_fs_info = NULL;
 905        return ret;
 906}
 907
 908static int
 909befs_remount(struct super_block *sb, int *flags, char *data)
 910{
 911        if (!(*flags & MS_RDONLY))
 912                return -EINVAL;
 913        return 0;
 914}
 915
 916static int
 917befs_statfs(struct dentry *dentry, struct kstatfs *buf)
 918{
 919        struct super_block *sb = dentry->d_sb;
 920        u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
 921
 922        befs_debug(sb, "---> befs_statfs()");
 923
 924        buf->f_type = BEFS_SUPER_MAGIC;
 925        buf->f_bsize = sb->s_blocksize;
 926        buf->f_blocks = BEFS_SB(sb)->num_blocks;
 927        buf->f_bfree = BEFS_SB(sb)->num_blocks - BEFS_SB(sb)->used_blocks;
 928        buf->f_bavail = buf->f_bfree;
 929        buf->f_files = 0;       /* UNKNOWN */
 930        buf->f_ffree = 0;       /* UNKNOWN */
 931        buf->f_fsid.val[0] = (u32)id;
 932        buf->f_fsid.val[1] = (u32)(id >> 32);
 933        buf->f_namelen = BEFS_NAME_LEN;
 934
 935        befs_debug(sb, "<--- befs_statfs()");
 936
 937        return 0;
 938}
 939
 940static struct dentry *
 941befs_mount(struct file_system_type *fs_type, int flags, const char *dev_name,
 942            void *data)
 943{
 944        return mount_bdev(fs_type, flags, dev_name, data, befs_fill_super);
 945}
 946
 947static struct file_system_type befs_fs_type = {
 948        .owner          = THIS_MODULE,
 949        .name           = "befs",
 950        .mount          = befs_mount,
 951        .kill_sb        = kill_block_super,
 952        .fs_flags       = FS_REQUIRES_DEV,      
 953};
 954
 955static int __init
 956init_befs_fs(void)
 957{
 958        int err;
 959
 960        printk(KERN_INFO "BeFS version: %s\n", BEFS_VERSION);
 961
 962        err = befs_init_inodecache();
 963        if (err)
 964                goto unacquire_none;
 965
 966        err = register_filesystem(&befs_fs_type);
 967        if (err)
 968                goto unacquire_inodecache;
 969
 970        return 0;
 971
 972unacquire_inodecache:
 973        befs_destroy_inodecache();
 974
 975unacquire_none:
 976        return err;
 977}
 978
 979static void __exit
 980exit_befs_fs(void)
 981{
 982        befs_destroy_inodecache();
 983
 984        unregister_filesystem(&befs_fs_type);
 985}
 986
 987/*
 988Macros that typecheck the init and exit functions,
 989ensures that they are called at init and cleanup,
 990and eliminates warnings about unused functions.
 991*/
 992module_init(init_befs_fs)
 993module_exit(exit_befs_fs)
 994
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