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