fs/affs/super.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  *  linux/fs/affs/inode.c
   4  *
   5  *  (c) 1996  Hans-Joachim Widmaier - Rewritten
   6  *
   7  *  (C) 1993  Ray Burr - Modified for Amiga FFS filesystem.
   8  *
   9  *  (C) 1992  Eric Youngdale Modified for ISO 9660 filesystem.
  10  *
  11  *  (C) 1991  Linus Torvalds - minix filesystem
  12  */
  13
  14 #include <linux/module.h>
  15 #include <linux/init.h>
  16 #include <linux/statfs.h>
  17 #include <linux/parser.h>
  18 #include <linux/magic.h>
  19 #include <linux/sched.h>
  20 #include <linux/cred.h>
  21 #include <linux/slab.h>
  22 #include <linux/writeback.h>
  23 #include <linux/blkdev.h>
  24 #include <linux/seq_file.h>
  25 #include <linux/iversion.h>
  26 #include "affs.h"
  27
  28 static int affs_statfs(struct dentry *dentry, struct kstatfs *buf);
  29 static int affs_show_options(struct seq_file *m, struct dentry *root);
  30 static int affs_remount (struct super_block *sb, int *flags, char *data);
  31
  32 static void
  33 affs_commit_super(struct super_block *sb, int wait)
  34 {
  35         struct affs_sb_info *sbi = AFFS_SB(sb);
  36         struct buffer_head *bh = sbi->s_root_bh;
  37         struct affs_root_tail *tail = AFFS_ROOT_TAIL(sb, bh);
  38
  39         lock_buffer(bh);
  40         affs_secs_to_datestamp(ktime_get_real_seconds(), &tail->disk_change);
  41         affs_fix_checksum(sb, bh);
  42         unlock_buffer(bh);
  43
  44         mark_buffer_dirty(bh);
  45         if (wait)
  46                 sync_dirty_buffer(bh);
  47 }
  48
  49 static void
  50 affs_put_super(struct super_block *sb)
  51 {
  52         struct affs_sb_info *sbi = AFFS_SB(sb);
  53         pr_debug("%s()\n", __func__);
  54
  55         cancel_delayed_work_sync(&sbi->sb_work);
  56 }
  57
  58 static int
  59 affs_sync_fs(struct super_block *sb, int wait)
  60 {
  61         affs_commit_super(sb, wait);
  62         return 0;
  63 }
  64
  65 static void flush_superblock(struct work_struct *work)
  66 {
  67         struct affs_sb_info *sbi;
  68         struct super_block *sb;
  69
  70         sbi = container_of(work, struct affs_sb_info, sb_work.work);
  71         sb = sbi->sb;
  72
  73         spin_lock(&sbi->work_lock);
  74         sbi->work_queued = 0;
  75         spin_unlock(&sbi->work_lock);
  76
  77         affs_commit_super(sb, 1);
  78 }
  79
  80 void affs_mark_sb_dirty(struct super_block *sb)
  81 {
  82         struct affs_sb_info *sbi = AFFS_SB(sb);
  83         unsigned long delay;
  84
  85         if (sb_rdonly(sb))
  86                return;
  87
  88         spin_lock(&sbi->work_lock);
  89         if (!sbi->work_queued) {
  90                delay = msecs_to_jiffies(dirty_writeback_interval * 10);
  91                queue_delayed_work(system_long_wq, &sbi->sb_work, delay);
  92                sbi->work_queued = 1;
  93         }
  94         spin_unlock(&sbi->work_lock);
  95 }
  96
  97 static struct kmem_cache * affs_inode_cachep;
  98
  99 static struct inode *affs_alloc_inode(struct super_block *sb)
 100 {
 101         struct affs_inode_info *i;
 102
 103         i = alloc_inode_sb(sb, affs_inode_cachep, GFP_KERNEL);
 104         if (!i)
 105                 return NULL;
 106
 107         inode_set_iversion(&i->vfs_inode, 1);
 108         i->i_lc = NULL;
 109         i->i_ext_bh = NULL;
 110         i->i_pa_cnt = 0;
 111
 112         return &i->vfs_inode;
 113 }
 114
 115 static void affs_free_inode(struct inode *inode)
 116 {
 117         kmem_cache_free(affs_inode_cachep, AFFS_I(inode));
 118 }
 119
 120 static void init_once(void *foo)
 121 {
 122         struct affs_inode_info *ei = (struct affs_inode_info *) foo;
 123
 124         mutex_init(&ei->i_link_lock);
 125         mutex_init(&ei->i_ext_lock);
 126         inode_init_once(&ei->vfs_inode);
 127 }
 128
 129 static int __init init_inodecache(void)
 130 {
 131         affs_inode_cachep = kmem_cache_create("affs_inode_cache",
 132                                              sizeof(struct affs_inode_info),
 133                                              0, (SLAB_RECLAIM_ACCOUNT | SLAB_ACCOUNT),
 134                                              init_once);
 135         if (affs_inode_cachep == NULL)
 136                 return -ENOMEM;
 137         return 0;
 138 }
 139
 140 static void destroy_inodecache(void)
 141 {
 142         /*
 143          * Make sure all delayed rcu free inodes are flushed before we
 144          * destroy cache.
 145          */
 146         rcu_barrier();
 147         kmem_cache_destroy(affs_inode_cachep);
 148 }
 149
 150 static const struct super_operations affs_sops = {
 151         .alloc_inode    = affs_alloc_inode,
 152         .free_inode     = affs_free_inode,
 153         .write_inode    = affs_write_inode,
 154         .evict_inode    = affs_evict_inode,
 155         .put_super      = affs_put_super,
 156         .sync_fs        = affs_sync_fs,
 157         .statfs         = affs_statfs,
 158         .remount_fs     = affs_remount,
 159         .show_options   = affs_show_options,
 160 };
 161
 162 enum {
 163         Opt_bs, Opt_mode, Opt_mufs, Opt_notruncate, Opt_prefix, Opt_protect,
 164         Opt_reserved, Opt_root, Opt_setgid, Opt_setuid,
 165         Opt_verbose, Opt_volume, Opt_ignore, Opt_err,
 166 };
 167
 168 static const match_table_t tokens = {
 169         {Opt_bs, "bs=%u"},
 170         {Opt_mode, "mode=%o"},
 171         {Opt_mufs, "mufs"},
 172         {Opt_notruncate, "nofilenametruncate"},
 173         {Opt_prefix, "prefix=%s"},
 174         {Opt_protect, "protect"},
 175         {Opt_reserved, "reserved=%u"},
 176         {Opt_root, "root=%u"},
 177         {Opt_setgid, "setgid=%u"},
 178         {Opt_setuid, "setuid=%u"},
 179         {Opt_verbose, "verbose"},
 180         {Opt_volume, "volume=%s"},
 181         {Opt_ignore, "grpquota"},
 182         {Opt_ignore, "noquota"},
 183         {Opt_ignore, "quota"},
 184         {Opt_ignore, "usrquota"},
 185         {Opt_err, NULL},
 186 };
 187
 188 static int
 189 parse_options(char *options, kuid_t *uid, kgid_t *gid, int *mode, int *reserved, s32 *root,
 190                 int *blocksize, char **prefix, char *volume, unsigned long *mount_opts)
 191 {
 192         char *p;
 193         substring_t args[MAX_OPT_ARGS];
 194
 195         /* Fill in defaults */
 196
 197         *uid        = current_uid();
 198         *gid        = current_gid();
 199         *reserved   = 2;
 200         *root       = -1;
 201         *blocksize  = -1;
 202         volume[0]   = ':';
 203         volume[1]   = 0;
 204         *mount_opts = 0;
 205         if (!options)
 206                 return 1;
 207
 208         while ((p = strsep(&options, ",")) != NULL) {
 209                 int token, n, option;
 210                 if (!*p)
 211                         continue;
 212
 213                 token = match_token(p, tokens, args);
 214                 switch (token) {
 215                 case Opt_bs:
 216                         if (match_int(&args[0], &n))
 217                                 return 0;
 218                         if (n != 512 && n != 1024 && n != 2048
 219                             && n != 4096) {
 220                                 pr_warn("Invalid blocksize (512, 1024, 2048, 4096 allowed)\n");
 221                                 return 0;
 222                         }
 223                         *blocksize = n;
 224                         break;
 225                 case Opt_mode:
 226                         if (match_octal(&args[0], &option))
 227                                 return 0;
 228                         *mode = option & 0777;
 229                         affs_set_opt(*mount_opts, SF_SETMODE);
 230                         break;
 231                 case Opt_mufs:
 232                         affs_set_opt(*mount_opts, SF_MUFS);
 233                         break;
 234                 case Opt_notruncate:
 235                         affs_set_opt(*mount_opts, SF_NO_TRUNCATE);
 236                         break;
 237                 case Opt_prefix:
 238                         kfree(*prefix);
 239                         *prefix = match_strdup(&args[0]);
 240                         if (!*prefix)
 241                                 return 0;
 242                         affs_set_opt(*mount_opts, SF_PREFIX);
 243                         break;
 244                 case Opt_protect:
 245                         affs_set_opt(*mount_opts, SF_IMMUTABLE);
 246                         break;
 247                 case Opt_reserved:
 248                         if (match_int(&args[0], reserved))
 249                                 return 0;
 250                         break;
 251                 case Opt_root:
 252                         if (match_int(&args[0], root))
 253                                 return 0;
 254                         break;
 255                 case Opt_setgid:
 256                         if (match_int(&args[0], &option))
 257                                 return 0;
 258                         *gid = make_kgid(current_user_ns(), option);
 259                         if (!gid_valid(*gid))
 260                                 return 0;
 261                         affs_set_opt(*mount_opts, SF_SETGID);
 262                         break;
 263                 case Opt_setuid:
 264                         if (match_int(&args[0], &option))
 265                                 return 0;
 266                         *uid = make_kuid(current_user_ns(), option);
 267                         if (!uid_valid(*uid))
 268                                 return 0;
 269                         affs_set_opt(*mount_opts, SF_SETUID);
 270                         break;
 271                 case Opt_verbose:
 272                         affs_set_opt(*mount_opts, SF_VERBOSE);
 273                         break;
 274                 case Opt_volume: {
 275                         char *vol = match_strdup(&args[0]);
 276                         if (!vol)
 277                                 return 0;
 278                         strscpy(volume, vol, 32);
 279                         kfree(vol);
 280                         break;
 281                 }
 282                 case Opt_ignore:
 283                         /* Silently ignore the quota options */
 284                         break;
 285                 default:
 286                         pr_warn("Unrecognized mount option \"%s\" or missing value\n",
 287                                 p);
 288                         return 0;
 289                 }
 290         }
 291         return 1;
 292 }
 293
 294 static int affs_show_options(struct seq_file *m, struct dentry *root)
 295 {
 296         struct super_block *sb = root->d_sb;
 297         struct affs_sb_info *sbi = AFFS_SB(sb);
 298
 299         if (sb->s_blocksize)
 300                 seq_printf(m, ",bs=%lu", sb->s_blocksize);
 301         if (affs_test_opt(sbi->s_flags, SF_SETMODE))
 302                 seq_printf(m, ",mode=%o", sbi->s_mode);
 303         if (affs_test_opt(sbi->s_flags, SF_MUFS))
 304                 seq_puts(m, ",mufs");
 305         if (affs_test_opt(sbi->s_flags, SF_NO_TRUNCATE))
 306                 seq_puts(m, ",nofilenametruncate");
 307         if (affs_test_opt(sbi->s_flags, SF_PREFIX))
 308                 seq_printf(m, ",prefix=%s", sbi->s_prefix);
 309         if (affs_test_opt(sbi->s_flags, SF_IMMUTABLE))
 310                 seq_puts(m, ",protect");
 311         if (sbi->s_reserved != 2)
 312                 seq_printf(m, ",reserved=%u", sbi->s_reserved);
 313         if (sbi->s_root_block != (sbi->s_reserved + sbi->s_partition_size - 1) / 2)
 314                 seq_printf(m, ",root=%u", sbi->s_root_block);
 315         if (affs_test_opt(sbi->s_flags, SF_SETGID))
 316                 seq_printf(m, ",setgid=%u",
 317                            from_kgid_munged(&init_user_ns, sbi->s_gid));
 318         if (affs_test_opt(sbi->s_flags, SF_SETUID))
 319                 seq_printf(m, ",setuid=%u",
 320                            from_kuid_munged(&init_user_ns, sbi->s_uid));
 321         if (affs_test_opt(sbi->s_flags, SF_VERBOSE))
 322                 seq_puts(m, ",verbose");
 323         if (sbi->s_volume[0])
 324                 seq_printf(m, ",volume=%s", sbi->s_volume);
 325         return 0;
 326 }
 327
 328 /* This function definitely needs to be split up. Some fine day I'll
 329  * hopefully have the guts to do so. Until then: sorry for the mess.
 330  */
 331
 332 static int affs_fill_super(struct super_block *sb, void *data, int silent)
 333 {
 334         struct affs_sb_info     *sbi;
 335         struct buffer_head      *root_bh = NULL;
 336         struct buffer_head      *boot_bh;
 337         struct inode            *root_inode = NULL;
 338         s32                      root_block;
 339         int                      size, blocksize;
 340         u32                      chksum;
 341         int                      num_bm;
 342         int                      i, j;
 343         kuid_t                   uid;
 344         kgid_t                   gid;
 345         int                      reserved;
 346         unsigned long            mount_flags;
 347         int                      tmp_flags;     /* fix remount prototype... */
 348         u8                       sig[4];
 349         int                      ret;
 350
 351         pr_debug("read_super(%s)\n", data ? (const char *)data : "no options");
 352
 353         sb->s_magic             = AFFS_SUPER_MAGIC;
 354         sb->s_op                = &affs_sops;
 355         sb->s_flags |= SB_NODIRATIME;
 356
 357         sb->s_time_gran = NSEC_PER_SEC;
 358         sb->s_time_min = sys_tz.tz_minuteswest * 60 + AFFS_EPOCH_DELTA;
 359         sb->s_time_max = 86400LL * U32_MAX + 86400 + sb->s_time_min;
 360
 361         sbi = kzalloc(sizeof(struct affs_sb_info), GFP_KERNEL);
 362         if (!sbi)
 363                 return -ENOMEM;
 364
 365         sb->s_fs_info = sbi;
 366         sbi->sb = sb;
 367         mutex_init(&sbi->s_bmlock);
 368         spin_lock_init(&sbi->symlink_lock);
 369         spin_lock_init(&sbi->work_lock);
 370         INIT_DELAYED_WORK(&sbi->sb_work, flush_superblock);
 371
 372         if (!parse_options(data,&uid,&gid,&i,&reserved,&root_block,
 373                                 &blocksize,&sbi->s_prefix,
 374                                 sbi->s_volume, &mount_flags)) {
 375                 pr_err("Error parsing options\n");
 376                 return -EINVAL;
 377         }
 378         /* N.B. after this point s_prefix must be released */
 379
 380         sbi->s_flags   = mount_flags;
 381         sbi->s_mode    = i;
 382         sbi->s_uid     = uid;
 383         sbi->s_gid     = gid;
 384         sbi->s_reserved= reserved;
 385
 386         /* Get the size of the device in 512-byte blocks.
 387          * If we later see that the partition uses bigger
 388          * blocks, we will have to change it.
 389          */
 390
 391         size = bdev_nr_sectors(sb->s_bdev);
 392         pr_debug("initial blocksize=%d, #blocks=%d\n", 512, size);
 393
 394         affs_set_blocksize(sb, PAGE_SIZE);
 395         /* Try to find root block. Its location depends on the block size. */
 396
 397         i = bdev_logical_block_size(sb->s_bdev);
 398         j = PAGE_SIZE;
 399         if (blocksize > 0) {
 400                 i = j = blocksize;
 401                 size = size / (blocksize / 512);
 402         }
 403
 404         for (blocksize = i; blocksize <= j; blocksize <<= 1, size >>= 1) {
 405                 sbi->s_root_block = root_block;
 406                 if (root_block < 0)
 407                         sbi->s_root_block = (reserved + size - 1) / 2;
 408                 pr_debug("setting blocksize to %d\n", blocksize);
 409                 affs_set_blocksize(sb, blocksize);
 410                 sbi->s_partition_size = size;
 411
 412                 /* The root block location that was calculated above is not
 413                  * correct if the partition size is an odd number of 512-
 414                  * byte blocks, which will be rounded down to a number of
 415                  * 1024-byte blocks, and if there were an even number of
 416                  * reserved blocks. Ideally, all partition checkers should
 417                  * report the real number of blocks of the real blocksize,
 418                  * but since this just cannot be done, we have to try to
 419                  * find the root block anyways. In the above case, it is one
 420                  * block behind the calculated one. So we check this one, too.
 421                  */
 422                 for (num_bm = 0; num_bm < 2; num_bm++) {
 423                         pr_debug("Dev %s, trying root=%u, bs=%d, "
 424                                 "size=%d, reserved=%d\n",
 425                                 sb->s_id,
 426                                 sbi->s_root_block + num_bm,
 427                                 blocksize, size, reserved);
 428                         root_bh = affs_bread(sb, sbi->s_root_block + num_bm);
 429                         if (!root_bh)
 430                                 continue;
 431                         if (!affs_checksum_block(sb, root_bh) &&
 432                             be32_to_cpu(AFFS_ROOT_HEAD(root_bh)->ptype) == T_SHORT &&
 433                             be32_to_cpu(AFFS_ROOT_TAIL(sb, root_bh)->stype) == ST_ROOT) {
 434                                 sbi->s_hashsize    = blocksize / 4 - 56;
 435                                 sbi->s_root_block += num_bm;
 436                                 goto got_root;
 437                         }
 438                         affs_brelse(root_bh);
 439                         root_bh = NULL;
 440                 }
 441         }
 442         if (!silent)
 443                 pr_err("No valid root block on device %s\n", sb->s_id);
 444         return -EINVAL;
 445
 446         /* N.B. after this point bh must be released */
 447 got_root:
 448         /* Keep super block in cache */
 449         sbi->s_root_bh = root_bh;
 450         root_block = sbi->s_root_block;
 451
 452         /* Find out which kind of FS we have */
 453         boot_bh = sb_bread(sb, 0);
 454         if (!boot_bh) {
 455                 pr_err("Cannot read boot block\n");
 456                 return -EINVAL;
 457         }
 458         memcpy(sig, boot_bh->b_data, 4);
 459         brelse(boot_bh);
 460         chksum = be32_to_cpu(*(__be32 *)sig);
 461
 462         /* Dircache filesystems are compatible with non-dircache ones
 463          * when reading. As long as they aren't supported, writing is
 464          * not recommended.
 465          */
 466         if ((chksum == FS_DCFFS || chksum == MUFS_DCFFS || chksum == FS_DCOFS
 467              || chksum == MUFS_DCOFS) && !sb_rdonly(sb)) {
 468                 pr_notice("Dircache FS - mounting %s read only\n", sb->s_id);
 469                 sb->s_flags |= SB_RDONLY;
 470         }
 471         switch (chksum) {
 472         case MUFS_FS:
 473         case MUFS_INTLFFS:
 474         case MUFS_DCFFS:
 475                 affs_set_opt(sbi->s_flags, SF_MUFS);
 476                 fallthrough;
 477         case FS_INTLFFS:
 478         case FS_DCFFS:
 479                 affs_set_opt(sbi->s_flags, SF_INTL);
 480                 break;
 481         case MUFS_FFS:
 482                 affs_set_opt(sbi->s_flags, SF_MUFS);
 483                 break;
 484         case FS_FFS:
 485                 break;
 486         case MUFS_OFS:
 487                 affs_set_opt(sbi->s_flags, SF_MUFS);
 488                 fallthrough;
 489         case FS_OFS:
 490                 affs_set_opt(sbi->s_flags, SF_OFS);
 491                 sb->s_flags |= SB_NOEXEC;
 492                 break;
 493         case MUFS_DCOFS:
 494         case MUFS_INTLOFS:
 495                 affs_set_opt(sbi->s_flags, SF_MUFS);
 496                 fallthrough;
 497         case FS_DCOFS:
 498         case FS_INTLOFS:
 499                 affs_set_opt(sbi->s_flags, SF_INTL);
 500                 affs_set_opt(sbi->s_flags, SF_OFS);
 501                 sb->s_flags |= SB_NOEXEC;
 502                 break;
 503         default:
 504                 pr_err("Unknown filesystem on device %s: %08X\n",
 505                        sb->s_id, chksum);
 506                 return -EINVAL;
 507         }
 508
 509         if (affs_test_opt(mount_flags, SF_VERBOSE)) {
 510                 u8 len = AFFS_ROOT_TAIL(sb, root_bh)->disk_name[0];
 511                 pr_notice("Mounting volume \"%.*s\": Type=%.3s\\%c, Blocksize=%d\n",
 512                         len > 31 ? 31 : len,
 513                         AFFS_ROOT_TAIL(sb, root_bh)->disk_name + 1,
 514                         sig, sig[3] + '0', blocksize);
 515         }
 516
 517         sb->s_flags |= SB_NODEV | SB_NOSUID;
 518
 519         sbi->s_data_blksize = sb->s_blocksize;
 520         if (affs_test_opt(sbi->s_flags, SF_OFS))
 521                 sbi->s_data_blksize -= 24;
 522
 523         tmp_flags = sb->s_flags;
 524         ret = affs_init_bitmap(sb, &tmp_flags);
 525         if (ret)
 526                 return ret;
 527         sb->s_flags = tmp_flags;
 528
 529         /* set up enough so that it can read an inode */
 530
 531         root_inode = affs_iget(sb, root_block);
 532         if (IS_ERR(root_inode))
 533                 return PTR_ERR(root_inode);
 534
 535         if (affs_test_opt(AFFS_SB(sb)->s_flags, SF_INTL))
 536                 sb->s_d_op = &affs_intl_dentry_operations;
 537         else
 538                 sb->s_d_op = &affs_dentry_operations;
 539
 540         sb->s_root = d_make_root(root_inode);
 541         if (!sb->s_root) {
 542                 pr_err("AFFS: Get root inode failed\n");
 543                 return -ENOMEM;
 544         }
 545
 546         sb->s_export_op = &affs_export_ops;
 547         pr_debug("s_flags=%lX\n", sb->s_flags);
 548         return 0;
 549 }
 550
 551 static int
 552 affs_remount(struct super_block *sb, int *flags, char *data)
 553 {
 554         struct affs_sb_info     *sbi = AFFS_SB(sb);
 555         int                      blocksize;
 556         kuid_t                   uid;
 557         kgid_t                   gid;
 558         int                      mode;
 559         int                      reserved;
 560         int                      root_block;
 561         unsigned long            mount_flags;
 562         int                      res = 0;
 563         char                     volume[32];
 564         char                    *prefix = NULL;
 565
 566         pr_debug("%s(flags=0x%x,opts=\"%s\")\n", __func__, *flags, data);
 567
 568         sync_filesystem(sb);
 569         *flags |= SB_NODIRATIME;
 570
 571         memcpy(volume, sbi->s_volume, 32);
 572         if (!parse_options(data, &uid, &gid, &mode, &reserved, &root_block,
 573                            &blocksize, &prefix, volume,
 574                            &mount_flags)) {
 575                 kfree(prefix);
 576                 return -EINVAL;
 577         }
 578
 579         flush_delayed_work(&sbi->sb_work);
 580
 581         sbi->s_flags = mount_flags;
 582         sbi->s_mode  = mode;
 583         sbi->s_uid   = uid;
 584         sbi->s_gid   = gid;
 585         /* protect against readers */
 586         spin_lock(&sbi->symlink_lock);
 587         if (prefix) {
 588                 kfree(sbi->s_prefix);
 589                 sbi->s_prefix = prefix;
 590         }
 591         memcpy(sbi->s_volume, volume, 32);
 592         spin_unlock(&sbi->symlink_lock);
 593
 594         if ((bool)(*flags & SB_RDONLY) == sb_rdonly(sb))
 595                 return 0;
 596
 597         if (*flags & SB_RDONLY)
 598                 affs_free_bitmap(sb);
 599         else
 600                 res = affs_init_bitmap(sb, flags);
 601
 602         return res;
 603 }
 604
 605 static int
 606 affs_statfs(struct dentry *dentry, struct kstatfs *buf)
 607 {
 608         struct super_block *sb = dentry->d_sb;
 609         int              free;
 610         u64              id = huge_encode_dev(sb->s_bdev->bd_dev);
 611
 612         pr_debug("%s() partsize=%d, reserved=%d\n",
 613                  __func__, AFFS_SB(sb)->s_partition_size,
 614                  AFFS_SB(sb)->s_reserved);
 615
 616         free          = affs_count_free_blocks(sb);
 617         buf->f_type    = AFFS_SUPER_MAGIC;
 618         buf->f_bsize   = sb->s_blocksize;
 619         buf->f_blocks  = AFFS_SB(sb)->s_partition_size - AFFS_SB(sb)->s_reserved;
 620         buf->f_bfree   = free;
 621         buf->f_bavail  = free;
 622         buf->f_fsid    = u64_to_fsid(id);
 623         buf->f_namelen = AFFSNAMEMAX;
 624         return 0;
 625 }
 626
 627 static struct dentry *affs_mount(struct file_system_type *fs_type,
 628         int flags, const char *dev_name, void *data)
 629 {
 630         return mount_bdev(fs_type, flags, dev_name, data, affs_fill_super);
 631 }
 632
 633 static void affs_kill_sb(struct super_block *sb)
 634 {
 635         struct affs_sb_info *sbi = AFFS_SB(sb);
 636         kill_block_super(sb);
 637         if (sbi) {
 638                 affs_free_bitmap(sb);
 639                 affs_brelse(sbi->s_root_bh);
 640                 kfree(sbi->s_prefix);
 641                 mutex_destroy(&sbi->s_bmlock);
 642                 kfree_rcu(sbi, rcu);
 643         }
 644 }
 645
 646 static struct file_system_type affs_fs_type = {
 647         .owner          = THIS_MODULE,
 648         .name           = "affs",
 649         .mount          = affs_mount,
 650         .kill_sb        = affs_kill_sb,
 651         .fs_flags       = FS_REQUIRES_DEV,
 652 };
 653 MODULE_ALIAS_FS("affs");
 654
 655 static int __init init_affs_fs(void)
 656 {
 657         int err = init_inodecache();
 658         if (err)
 659                 goto out1;
 660         err = register_filesystem(&affs_fs_type);
 661         if (err)
 662                 goto out;
 663         return 0;
 664 out:
 665         destroy_inodecache();
 666 out1:
 667         return err;
 668 }
 669
 670 static void __exit exit_affs_fs(void)
 671 {
 672         unregister_filesystem(&affs_fs_type);
 673         destroy_inodecache();
 674 }
 675
 676 MODULE_DESCRIPTION("Amiga filesystem support for Linux");
 677 MODULE_LICENSE("GPL");
 678
 679 module_init(init_affs_fs)
 680 module_exit(exit_affs_fs)