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