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