git.oblomov.eu Git - linux-2.6/blob - fs/affs/super.c

   1 /*
   2  *  linux/fs/affs/inode.c
   3  *
   4  *  (c) 1996  Hans-Joachim Widmaier - Rewritten
   5  *
   6  *  (C) 1993  Ray Burr - Modified for Amiga FFS filesystem.
   7  *
   8  *  (C) 1992  Eric Youngdale Modified for ISO 9660 filesystem.
   9  *
  10  *  (C) 1991  Linus Torvalds - minix filesystem
  11  */
  12
  13 #include <linux/module.h>
  14 #include <linux/init.h>
  15 #include <linux/statfs.h>
  16 #include <linux/parser.h>
  17 #include <linux/magic.h>
  18 #include <linux/sched.h>
  19 #include <linux/smp_lock.h>
  20 #include "affs.h"
  21
  22 extern struct timezone sys_tz;
  23
  24 static int affs_statfs(struct dentry *dentry, struct kstatfs *buf);
  25 static int affs_remount (struct super_block *sb, int *flags, char *data);
  26
  27 static void
  28 affs_put_super(struct super_block *sb)
  29 {
  30         struct affs_sb_info *sbi = AFFS_SB(sb);
  31         pr_debug("AFFS: put_super()\n");
  32
  33         lock_kernel();
  34
  35         if (!(sb->s_flags & MS_RDONLY)) {
  36                 AFFS_ROOT_TAIL(sb, sbi->s_root_bh)->bm_flag = cpu_to_be32(1);
  37                 secs_to_datestamp(get_seconds(),
  38                                   &AFFS_ROOT_TAIL(sb, sbi->s_root_bh)->disk_change);
  39                 affs_fix_checksum(sb, sbi->s_root_bh);
  40                 mark_buffer_dirty(sbi->s_root_bh);
  41         }
  42
  43         kfree(sbi->s_prefix);
  44         affs_free_bitmap(sb);
  45         affs_brelse(sbi->s_root_bh);
  46         kfree(sbi);
  47         sb->s_fs_info = NULL;
  48
  49         unlock_kernel();
  50 }
  51
  52 static void
  53 affs_write_super(struct super_block *sb)
  54 {
  55         int clean = 2;
  56         struct affs_sb_info *sbi = AFFS_SB(sb);
  57
  58         lock_super(sb);
  59         if (!(sb->s_flags & MS_RDONLY)) {
  60                 //      if (sbi->s_bitmap[i].bm_bh) {
  61                 //              if (buffer_dirty(sbi->s_bitmap[i].bm_bh)) {
  62                 //                      clean = 0;
  63                 AFFS_ROOT_TAIL(sb, sbi->s_root_bh)->bm_flag = cpu_to_be32(clean);
  64                 secs_to_datestamp(get_seconds(),
  65                                   &AFFS_ROOT_TAIL(sb, sbi->s_root_bh)->disk_change);
  66                 affs_fix_checksum(sb, sbi->s_root_bh);
  67                 mark_buffer_dirty(sbi->s_root_bh);
  68                 sb->s_dirt = !clean;    /* redo until bitmap synced */
  69         } else
  70                 sb->s_dirt = 0;
  71         unlock_super(sb);
  72
  73         pr_debug("AFFS: write_super() at %lu, clean=%d\n", get_seconds(), clean);
  74 }
  75
  76 static struct kmem_cache * affs_inode_cachep;
  77
  78 static struct inode *affs_alloc_inode(struct super_block *sb)
  79 {
  80         struct affs_inode_info *i;
  81
  82         i = kmem_cache_alloc(affs_inode_cachep, GFP_KERNEL);
  83         if (!i)
  84                 return NULL;
  85
  86         i->vfs_inode.i_version = 1;
  87         i->i_lc = NULL;
  88         i->i_ext_bh = NULL;
  89         i->i_pa_cnt = 0;
  90
  91         return &i->vfs_inode;
  92 }
  93
  94 static void affs_destroy_inode(struct inode *inode)
  95 {
  96         kmem_cache_free(affs_inode_cachep, AFFS_I(inode));
  97 }
  98
  99 static void init_once(void *foo)
 100 {
 101         struct affs_inode_info *ei = (struct affs_inode_info *) foo;
 102
 103         init_MUTEX(&ei->i_link_lock);
 104         init_MUTEX(&ei->i_ext_lock);
 105         inode_init_once(&ei->vfs_inode);
 106 }
 107
 108 static int init_inodecache(void)
 109 {
 110         affs_inode_cachep = kmem_cache_create("affs_inode_cache",
 111                                              sizeof(struct affs_inode_info),
 112                                              0, (SLAB_RECLAIM_ACCOUNT|
 113                                                 SLAB_MEM_SPREAD),
 114                                              init_once);
 115         if (affs_inode_cachep == NULL)
 116                 return -ENOMEM;
 117         return 0;
 118 }
 119
 120 static void destroy_inodecache(void)
 121 {
 122         kmem_cache_destroy(affs_inode_cachep);
 123 }
 124
 125 static const struct super_operations affs_sops = {
 126         .alloc_inode    = affs_alloc_inode,
 127         .destroy_inode  = affs_destroy_inode,
 128         .write_inode    = affs_write_inode,
 129         .delete_inode   = affs_delete_inode,
 130         .clear_inode    = affs_clear_inode,
 131         .put_super      = affs_put_super,
 132         .write_super    = affs_write_super,
 133         .statfs         = affs_statfs,
 134         .remount_fs     = affs_remount,
 135         .show_options   = generic_show_options,
 136 };
 137
 138 enum {
 139         Opt_bs, Opt_mode, Opt_mufs, Opt_prefix, Opt_protect,
 140         Opt_reserved, Opt_root, Opt_setgid, Opt_setuid,
 141         Opt_verbose, Opt_volume, Opt_ignore, Opt_err,
 142 };
 143
 144 static const match_table_t tokens = {
 145         {Opt_bs, "bs=%u"},
 146         {Opt_mode, "mode=%o"},
 147         {Opt_mufs, "mufs"},
 148         {Opt_prefix, "prefix=%s"},
 149         {Opt_protect, "protect"},
 150         {Opt_reserved, "reserved=%u"},
 151         {Opt_root, "root=%u"},
 152         {Opt_setgid, "setgid=%u"},
 153         {Opt_setuid, "setuid=%u"},
 154         {Opt_verbose, "verbose"},
 155         {Opt_volume, "volume=%s"},
 156         {Opt_ignore, "grpquota"},
 157         {Opt_ignore, "noquota"},
 158         {Opt_ignore, "quota"},
 159         {Opt_ignore, "usrquota"},
 160         {Opt_err, NULL},
 161 };
 162
 163 static int
 164 parse_options(char *options, uid_t *uid, gid_t *gid, int *mode, int *reserved, s32 *root,
 165                 int *blocksize, char **prefix, char *volume, unsigned long *mount_opts)
 166 {
 167         char *p;
 168         substring_t args[MAX_OPT_ARGS];
 169
 170         /* Fill in defaults */
 171
 172         *uid        = current_uid();
 173         *gid        = current_gid();
 174         *reserved   = 2;
 175         *root       = -1;
 176         *blocksize  = -1;
 177         volume[0]   = ':';
 178         volume[1]   = 0;
 179         *mount_opts = 0;
 180         if (!options)
 181                 return 1;
 182
 183         while ((p = strsep(&options, ",")) != NULL) {
 184                 int token, n, option;
 185                 if (!*p)
 186                         continue;
 187
 188                 token = match_token(p, tokens, args);
 189                 switch (token) {
 190                 case Opt_bs:
 191                         if (match_int(&args[0], &n))
 192                                 return -EINVAL;
 193                         if (n != 512 && n != 1024 && n != 2048
 194                             && n != 4096) {
 195                                 printk ("AFFS: Invalid blocksize (512, 1024, 2048, 4096 allowed)\n");
 196                                 return 0;
 197                         }
 198                         *blocksize = n;
 199                         break;
 200                 case Opt_mode:
 201                         if (match_octal(&args[0], &option))
 202                                 return 1;
 203                         *mode = option & 0777;
 204                         *mount_opts |= SF_SETMODE;
 205                         break;
 206                 case Opt_mufs:
 207                         *mount_opts |= SF_MUFS;
 208                         break;
 209                 case Opt_prefix:
 210                         /* Free any previous prefix */
 211                         kfree(*prefix);
 212                         *prefix = match_strdup(&args[0]);
 213                         if (!*prefix)
 214                                 return 0;
 215                         *mount_opts |= SF_PREFIX;
 216                         break;
 217                 case Opt_protect:
 218                         *mount_opts |= SF_IMMUTABLE;
 219                         break;
 220                 case Opt_reserved:
 221                         if (match_int(&args[0], reserved))
 222                                 return 1;
 223                         break;
 224                 case Opt_root:
 225                         if (match_int(&args[0], root))
 226                                 return 1;
 227                         break;
 228                 case Opt_setgid:
 229                         if (match_int(&args[0], &option))
 230                                 return 1;
 231                         *gid = option;
 232                         *mount_opts |= SF_SETGID;
 233                         break;
 234                 case Opt_setuid:
 235                         if (match_int(&args[0], &option))
 236                                 return -EINVAL;
 237                         *uid = option;
 238                         *mount_opts |= SF_SETUID;
 239                         break;
 240                 case Opt_verbose:
 241                         *mount_opts |= SF_VERBOSE;
 242                         break;
 243                 case Opt_volume: {
 244                         char *vol = match_strdup(&args[0]);
 245                         if (!vol)
 246                                 return 0;
 247                         strlcpy(volume, vol, 32);
 248                         kfree(vol);
 249                         break;
 250                 }
 251                 case Opt_ignore:
 252                         /* Silently ignore the quota options */
 253                         break;
 254                 default:
 255                         printk("AFFS: Unrecognized mount option \"%s\" "
 256                                         "or missing value\n", p);
 257                         return 0;
 258                 }
 259         }
 260         return 1;
 261 }
 262
 263 /* This function definitely needs to be split up. Some fine day I'll
 264  * hopefully have the guts to do so. Until then: sorry for the mess.
 265  */
 266
 267 static int affs_fill_super(struct super_block *sb, void *data, int silent)
 268 {
 269         struct affs_sb_info     *sbi;
 270         struct buffer_head      *root_bh = NULL;
 271         struct buffer_head      *boot_bh;
 272         struct inode            *root_inode = NULL;
 273         s32                      root_block;
 274         int                      size, blocksize;
 275         u32                      chksum;
 276         int                      num_bm;
 277         int                      i, j;
 278         s32                      key;
 279         uid_t                    uid;
 280         gid_t                    gid;
 281         int                      reserved;
 282         unsigned long            mount_flags;
 283         int                      tmp_flags;     /* fix remount prototype... */
 284         u8                       sig[4];
 285         int                      ret = -EINVAL;
 286
 287         save_mount_options(sb, data);
 288
 289         pr_debug("AFFS: read_super(%s)\n",data ? (const char *)data : "no options");
 290
 291         sb->s_magic             = AFFS_SUPER_MAGIC;
 292         sb->s_op                = &affs_sops;
 293         sb->s_flags |= MS_NODIRATIME;
 294
 295         sbi = kzalloc(sizeof(struct affs_sb_info), GFP_KERNEL);
 296         if (!sbi)
 297                 return -ENOMEM;
 298         sb->s_fs_info = sbi;
 299         mutex_init(&sbi->s_bmlock);
 300
 301         if (!parse_options(data,&uid,&gid,&i,&reserved,&root_block,
 302                                 &blocksize,&sbi->s_prefix,
 303                                 sbi->s_volume, &mount_flags)) {
 304                 printk(KERN_ERR "AFFS: Error parsing options\n");
 305                 return -EINVAL;
 306         }
 307         /* N.B. after this point s_prefix must be released */
 308
 309         sbi->s_flags   = mount_flags;
 310         sbi->s_mode    = i;
 311         sbi->s_uid     = uid;
 312         sbi->s_gid     = gid;
 313         sbi->s_reserved= reserved;
 314
 315         /* Get the size of the device in 512-byte blocks.
 316          * If we later see that the partition uses bigger
 317          * blocks, we will have to change it.
 318          */
 319
 320         size = sb->s_bdev->bd_inode->i_size >> 9;
 321         pr_debug("AFFS: initial blocksize=%d, #blocks=%d\n", 512, size);
 322
 323         affs_set_blocksize(sb, PAGE_SIZE);
 324         /* Try to find root block. Its location depends on the block size. */
 325
 326         i = 512;
 327         j = 4096;
 328         if (blocksize > 0) {
 329                 i = j = blocksize;
 330                 size = size / (blocksize / 512);
 331         }
 332         for (blocksize = i, key = 0; blocksize <= j; blocksize <<= 1, size >>= 1) {
 333                 sbi->s_root_block = root_block;
 334                 if (root_block < 0)
 335                         sbi->s_root_block = (reserved + size - 1) / 2;
 336                 pr_debug("AFFS: setting blocksize to %d\n", blocksize);
 337                 affs_set_blocksize(sb, blocksize);
 338                 sbi->s_partition_size = size;
 339
 340                 /* The root block location that was calculated above is not
 341                  * correct if the partition size is an odd number of 512-
 342                  * byte blocks, which will be rounded down to a number of
 343                  * 1024-byte blocks, and if there were an even number of
 344                  * reserved blocks. Ideally, all partition checkers should
 345                  * report the real number of blocks of the real blocksize,
 346                  * but since this just cannot be done, we have to try to
 347                  * find the root block anyways. In the above case, it is one
 348                  * block behind the calculated one. So we check this one, too.
 349                  */
 350                 for (num_bm = 0; num_bm < 2; num_bm++) {
 351                         pr_debug("AFFS: Dev %s, trying root=%u, bs=%d, "
 352                                 "size=%d, reserved=%d\n",
 353                                 sb->s_id,
 354                                 sbi->s_root_block + num_bm,
 355                                 blocksize, size, reserved);
 356                         root_bh = affs_bread(sb, sbi->s_root_block + num_bm);
 357                         if (!root_bh)
 358                                 continue;
 359                         if (!affs_checksum_block(sb, root_bh) &&
 360                             be32_to_cpu(AFFS_ROOT_HEAD(root_bh)->ptype) == T_SHORT &&
 361                             be32_to_cpu(AFFS_ROOT_TAIL(sb, root_bh)->stype) == ST_ROOT) {
 362                                 sbi->s_hashsize    = blocksize / 4 - 56;
 363                                 sbi->s_root_block += num_bm;
 364                                 key                        = 1;
 365                                 goto got_root;
 366                         }
 367                         affs_brelse(root_bh);
 368                         root_bh = NULL;
 369                 }
 370         }
 371         if (!silent)
 372                 printk(KERN_ERR "AFFS: No valid root block on device %s\n",
 373                         sb->s_id);
 374         goto out_error;
 375
 376         /* N.B. after this point bh must be released */
 377 got_root:
 378         root_block = sbi->s_root_block;
 379
 380         /* Find out which kind of FS we have */
 381         boot_bh = sb_bread(sb, 0);
 382         if (!boot_bh) {
 383                 printk(KERN_ERR "AFFS: Cannot read boot block\n");
 384                 goto out_error;
 385         }
 386         memcpy(sig, boot_bh->b_data, 4);
 387         brelse(boot_bh);
 388         chksum = be32_to_cpu(*(__be32 *)sig);
 389
 390         /* Dircache filesystems are compatible with non-dircache ones
 391          * when reading. As long as they aren't supported, writing is
 392          * not recommended.
 393          */
 394         if ((chksum == FS_DCFFS || chksum == MUFS_DCFFS || chksum == FS_DCOFS
 395              || chksum == MUFS_DCOFS) && !(sb->s_flags & MS_RDONLY)) {
 396                 printk(KERN_NOTICE "AFFS: Dircache FS - mounting %s read only\n",
 397                         sb->s_id);
 398                 sb->s_flags |= MS_RDONLY;
 399         }
 400         switch (chksum) {
 401                 case MUFS_FS:
 402                 case MUFS_INTLFFS:
 403                 case MUFS_DCFFS:
 404                         sbi->s_flags |= SF_MUFS;
 405                         /* fall thru */
 406                 case FS_INTLFFS:
 407                 case FS_DCFFS:
 408                         sbi->s_flags |= SF_INTL;
 409                         break;
 410                 case MUFS_FFS:
 411                         sbi->s_flags |= SF_MUFS;
 412                         break;
 413                 case FS_FFS:
 414                         break;
 415                 case MUFS_OFS:
 416                         sbi->s_flags |= SF_MUFS;
 417                         /* fall thru */
 418                 case FS_OFS:
 419                         sbi->s_flags |= SF_OFS;
 420                         sb->s_flags |= MS_NOEXEC;
 421                         break;
 422                 case MUFS_DCOFS:
 423                 case MUFS_INTLOFS:
 424                         sbi->s_flags |= SF_MUFS;
 425                 case FS_DCOFS:
 426                 case FS_INTLOFS:
 427                         sbi->s_flags |= SF_INTL | SF_OFS;
 428                         sb->s_flags |= MS_NOEXEC;
 429                         break;
 430                 default:
 431                         printk(KERN_ERR "AFFS: Unknown filesystem on device %s: %08X\n",
 432                                 sb->s_id, chksum);
 433                         goto out_error;
 434         }
 435
 436         if (mount_flags & SF_VERBOSE) {
 437                 u8 len = AFFS_ROOT_TAIL(sb, root_bh)->disk_name[0];
 438                 printk(KERN_NOTICE "AFFS: Mounting volume \"%.*s\": Type=%.3s\\%c, Blocksize=%d\n",
 439                         len > 31 ? 31 : len,
 440                         AFFS_ROOT_TAIL(sb, root_bh)->disk_name + 1,
 441                         sig, sig[3] + '0', blocksize);
 442         }
 443
 444         sb->s_flags |= MS_NODEV | MS_NOSUID;
 445
 446         sbi->s_data_blksize = sb->s_blocksize;
 447         if (sbi->s_flags & SF_OFS)
 448                 sbi->s_data_blksize -= 24;
 449
 450         /* Keep super block in cache */
 451         sbi->s_root_bh = root_bh;
 452         /* N.B. after this point s_root_bh must be released */
 453
 454         tmp_flags = sb->s_flags;
 455         if (affs_init_bitmap(sb, &tmp_flags))
 456                 goto out_error;
 457         sb->s_flags = tmp_flags;
 458
 459         /* set up enough so that it can read an inode */
 460
 461         root_inode = affs_iget(sb, root_block);
 462         if (IS_ERR(root_inode)) {
 463                 ret = PTR_ERR(root_inode);
 464                 goto out_error_noinode;
 465         }
 466
 467         sb->s_root = d_alloc_root(root_inode);
 468         if (!sb->s_root) {
 469                 printk(KERN_ERR "AFFS: Get root inode failed\n");
 470                 goto out_error;
 471         }
 472         sb->s_root->d_op = &affs_dentry_operations;
 473
 474         pr_debug("AFFS: s_flags=%lX\n",sb->s_flags);
 475         return 0;
 476
 477         /*
 478          * Begin the cascaded cleanup ...
 479          */
 480 out_error:
 481         if (root_inode)
 482                 iput(root_inode);
 483 out_error_noinode:
 484         kfree(sbi->s_bitmap);
 485         affs_brelse(root_bh);
 486         kfree(sbi->s_prefix);
 487         kfree(sbi);
 488         sb->s_fs_info = NULL;
 489         return ret;
 490 }
 491
 492 static int
 493 affs_remount(struct super_block *sb, int *flags, char *data)
 494 {
 495         struct affs_sb_info     *sbi = AFFS_SB(sb);
 496         int                      blocksize;
 497         uid_t                    uid;
 498         gid_t                    gid;
 499         int                      mode;
 500         int                      reserved;
 501         int                      root_block;
 502         unsigned long            mount_flags;
 503         int                      res = 0;
 504         char                    *new_opts = kstrdup(data, GFP_KERNEL);
 505
 506         pr_debug("AFFS: remount(flags=0x%x,opts=\"%s\")\n",*flags,data);
 507
 508         *flags |= MS_NODIRATIME;
 509
 510         if (!parse_options(data, &uid, &gid, &mode, &reserved, &root_block,
 511                            &blocksize, &sbi->s_prefix, sbi->s_volume,
 512                            &mount_flags)) {
 513                 kfree(new_opts);
 514                 return -EINVAL;
 515         }
 516         lock_kernel();
 517         replace_mount_options(sb, new_opts);
 518
 519         sbi->s_flags = mount_flags;
 520         sbi->s_mode  = mode;
 521         sbi->s_uid   = uid;
 522         sbi->s_gid   = gid;
 523
 524         if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY)) {
 525                 unlock_kernel();
 526                 return 0;
 527         }
 528         if (*flags & MS_RDONLY) {
 529                 sb->s_dirt = 1;
 530                 while (sb->s_dirt)
 531                         affs_write_super(sb);
 532                 affs_free_bitmap(sb);
 533         } else
 534                 res = affs_init_bitmap(sb, flags);
 535
 536         unlock_kernel();
 537         return res;
 538 }
 539
 540 static int
 541 affs_statfs(struct dentry *dentry, struct kstatfs *buf)
 542 {
 543         struct super_block *sb = dentry->d_sb;
 544         int              free;
 545         u64              id = huge_encode_dev(sb->s_bdev->bd_dev);
 546
 547         pr_debug("AFFS: statfs() partsize=%d, reserved=%d\n",AFFS_SB(sb)->s_partition_size,
 548              AFFS_SB(sb)->s_reserved);
 549
 550         free          = affs_count_free_blocks(sb);
 551         buf->f_type    = AFFS_SUPER_MAGIC;
 552         buf->f_bsize   = sb->s_blocksize;
 553         buf->f_blocks  = AFFS_SB(sb)->s_partition_size - AFFS_SB(sb)->s_reserved;
 554         buf->f_bfree   = free;
 555         buf->f_bavail  = free;
 556         buf->f_fsid.val[0] = (u32)id;
 557         buf->f_fsid.val[1] = (u32)(id >> 32);
 558         buf->f_namelen = 30;
 559         return 0;
 560 }
 561
 562 static int affs_get_sb(struct file_system_type *fs_type,
 563         int flags, const char *dev_name, void *data, struct vfsmount *mnt)
 564 {
 565         return get_sb_bdev(fs_type, flags, dev_name, data, affs_fill_super,
 566                            mnt);
 567 }
 568
 569 static struct file_system_type affs_fs_type = {
 570         .owner          = THIS_MODULE,
 571         .name           = "affs",
 572         .get_sb         = affs_get_sb,
 573         .kill_sb        = kill_block_super,
 574         .fs_flags       = FS_REQUIRES_DEV,
 575 };
 576
 577 static int __init init_affs_fs(void)
 578 {
 579         int err = init_inodecache();
 580         if (err)
 581                 goto out1;
 582         err = register_filesystem(&affs_fs_type);
 583         if (err)
 584                 goto out;
 585         return 0;
 586 out:
 587         destroy_inodecache();
 588 out1:
 589         return err;
 590 }
 591
 592 static void __exit exit_affs_fs(void)
 593 {
 594         unregister_filesystem(&affs_fs_type);
 595         destroy_inodecache();
 596 }
 597
 598 MODULE_DESCRIPTION("Amiga filesystem support for Linux");
 599 MODULE_LICENSE("GPL");
 600
 601 module_init(init_affs_fs)
 602 module_exit(exit_affs_fs)