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