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