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