SAFE public projects git trees. - safe/jmp/linux-2.6/blob - fs/affs/super.c

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