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 <linux/smp_lock.h>
  20 #include <linux/slab.h>
  21 #include "affs.h"
  22
  23 extern struct timezone sys_tz;
  24
  25 static int affs_statfs(struct dentry *dentry, struct kstatfs *buf);
  26 static int affs_remount (struct super_block *sb, int *flags, char *data);
  27
  28 static void
  29 affs_commit_super(struct super_block *sb, int clean)
  30 {
  31         struct affs_sb_info *sbi = AFFS_SB(sb);
  32         struct buffer_head *bh = sbi->s_root_bh;
  33         struct affs_root_tail *tail = AFFS_ROOT_TAIL(sb, bh);
  34
  35         tail->bm_flag = cpu_to_be32(clean);
  36         secs_to_datestamp(get_seconds(), &tail->disk_change);
  37         affs_fix_checksum(sb, bh);
  38         mark_buffer_dirty(bh);
  39 }
  40
  41 static void
  42 affs_put_super(struct super_block *sb)
  43 {
  44         struct affs_sb_info *sbi = AFFS_SB(sb);
  45         pr_debug("AFFS: put_super()\n");
  46
  47         lock_kernel();
  48
  49         if (!(sb->s_flags & MS_RDONLY))
  50                 affs_commit_super(sb, 1);
  51
  52         kfree(sbi->s_prefix);
  53         affs_free_bitmap(sb);
  54         affs_brelse(sbi->s_root_bh);
  55         kfree(sbi);
  56         sb->s_fs_info = NULL;
  57
  58         unlock_kernel();
  59 }
  60
  61 static void
  62 affs_write_super(struct super_block *sb)
  63 {
  64         int clean = 2;
  65
  66         lock_super(sb);
  67         if (!(sb->s_flags & MS_RDONLY)) {
  68                 //      if (sbi->s_bitmap[i].bm_bh) {
  69                 //              if (buffer_dirty(sbi->s_bitmap[i].bm_bh)) {
  70                 //                      clean = 0;
  71                 affs_commit_super(sb, clean);
  72                 sb->s_dirt = !clean;    /* redo until bitmap synced */
  73         } else
  74                 sb->s_dirt = 0;
  75         unlock_super(sb);
  76
  77         pr_debug("AFFS: write_super() at %lu, clean=%d\n", get_seconds(), clean);
  78 }
  79
  80 static int
  81 affs_sync_fs(struct super_block *sb, int wait)
  82 {
  83         lock_super(sb);
  84         affs_commit_super(sb, 2);
  85         sb->s_dirt = 0;
  86         unlock_super(sb);
  87         return 0;
  88 }
  89
  90 static struct kmem_cache * affs_inode_cachep;
  91
  92 static struct inode *affs_alloc_inode(struct super_block *sb)
  93 {
  94         struct affs_inode_info *i;
  95
  96         i = kmem_cache_alloc(affs_inode_cachep, GFP_KERNEL);
  97         if (!i)
  98                 return NULL;
  99
 100         i->vfs_inode.i_version = 1;
 101         i->i_lc = NULL;
 102         i->i_ext_bh = NULL;
 103         i->i_pa_cnt = 0;
 104
 105         return &i->vfs_inode;
 106 }
 107
 108 static void affs_destroy_inode(struct inode *inode)
 109 {
 110         kmem_cache_free(affs_inode_cachep, AFFS_I(inode));
 111 }
 112
 113 static void init_once(void *foo)
 114 {
 115         struct affs_inode_info *ei = (struct affs_inode_info *) foo;
 116
 117         init_MUTEX(&ei->i_link_lock);
 118         init_MUTEX(&ei->i_ext_lock);
 119         inode_init_once(&ei->vfs_inode);
 120 }
 121
 122 static int init_inodecache(void)
 123 {
 124         affs_inode_cachep = kmem_cache_create("affs_inode_cache",
 125                                              sizeof(struct affs_inode_info),
 126                                              0, (SLAB_RECLAIM_ACCOUNT|
 127                                                 SLAB_MEM_SPREAD),
 128                                              init_once);
 129         if (affs_inode_cachep == NULL)
 130                 return -ENOMEM;
 131         return 0;
 132 }
 133
 134 static void destroy_inodecache(void)
 135 {
 136         kmem_cache_destroy(affs_inode_cachep);
 137 }
 138
 139 static const struct super_operations affs_sops = {
 140         .alloc_inode    = affs_alloc_inode,
 141         .destroy_inode  = affs_destroy_inode,
 142         .write_inode    = affs_write_inode,
 143         .delete_inode   = affs_delete_inode,
 144         .clear_inode    = affs_clear_inode,
 145         .put_super      = affs_put_super,
 146         .write_super    = affs_write_super,
 147         .sync_fs        = affs_sync_fs,
 148         .statfs         = affs_statfs,
 149         .remount_fs     = affs_remount,
 150         .show_options   = generic_show_options,
 151 };
 152
 153 enum {
 154         Opt_bs, Opt_mode, Opt_mufs, Opt_prefix, Opt_protect,
 155         Opt_reserved, Opt_root, Opt_setgid, Opt_setuid,
 156         Opt_verbose, Opt_volume, Opt_ignore, Opt_err,
 157 };
 158
 159 static const match_table_t tokens = {
 160         {Opt_bs, "bs=%u"},
 161         {Opt_mode, "mode=%o"},
 162         {Opt_mufs, "mufs"},
 163         {Opt_prefix, "prefix=%s"},
 164         {Opt_protect, "protect"},
 165         {Opt_reserved, "reserved=%u"},
 166         {Opt_root, "root=%u"},
 167         {Opt_setgid, "setgid=%u"},
 168         {Opt_setuid, "setuid=%u"},
 169         {Opt_verbose, "verbose"},
 170         {Opt_volume, "volume=%s"},
 171         {Opt_ignore, "grpquota"},
 172         {Opt_ignore, "noquota"},
 173         {Opt_ignore, "quota"},
 174         {Opt_ignore, "usrquota"},
 175         {Opt_err, NULL},
 176 };
 177
 178 static int
 179 parse_options(char *options, uid_t *uid, gid_t *gid, int *mode, int *reserved, s32 *root,
 180                 int *blocksize, char **prefix, char *volume, unsigned long *mount_opts)
 181 {
 182         char *p;
 183         substring_t args[MAX_OPT_ARGS];
 184
 185         /* Fill in defaults */
 186
 187         *uid        = current_uid();
 188         *gid        = current_gid();
 189         *reserved   = 2;
 190         *root       = -1;
 191         *blocksize  = -1;
 192         volume[0]   = ':';
 193         volume[1]   = 0;
 194         *mount_opts = 0;
 195         if (!options)
 196                 return 1;
 197
 198         while ((p = strsep(&options, ",")) != NULL) {
 199                 int token, n, option;
 200                 if (!*p)
 201                         continue;
 202
 203                 token = match_token(p, tokens, args);
 204                 switch (token) {
 205                 case Opt_bs:
 206                         if (match_int(&args[0], &n))
 207                                 return 0;
 208                         if (n != 512 && n != 1024 && n != 2048
 209                             && n != 4096) {
 210                                 printk ("AFFS: Invalid blocksize (512, 1024, 2048, 4096 allowed)\n");
 211                                 return 0;
 212                         }
 213                         *blocksize = n;
 214                         break;
 215                 case Opt_mode:
 216                         if (match_octal(&args[0], &option))
 217                                 return 0;
 218                         *mode = option & 0777;
 219                         *mount_opts |= SF_SETMODE;
 220                         break;
 221                 case Opt_mufs:
 222                         *mount_opts |= SF_MUFS;
 223                         break;
 224                 case Opt_prefix:
 225                         *prefix = match_strdup(&args[0]);
 226                         if (!*prefix)
 227                                 return 0;
 228                         *mount_opts |= SF_PREFIX;
 229                         break;
 230                 case Opt_protect:
 231                         *mount_opts |= SF_IMMUTABLE;
 232                         break;
 233                 case Opt_reserved:
 234                         if (match_int(&args[0], reserved))
 235                                 return 0;
 236                         break;
 237                 case Opt_root:
 238                         if (match_int(&args[0], root))
 239                                 return 0;
 240                         break;
 241                 case Opt_setgid:
 242                         if (match_int(&args[0], &option))
 243                                 return 0;
 244                         *gid = option;
 245                         *mount_opts |= SF_SETGID;
 246                         break;
 247                 case Opt_setuid:
 248                         if (match_int(&args[0], &option))
 249                                 return 0;
 250                         *uid = option;
 251                         *mount_opts |= SF_SETUID;
 252                         break;
 253                 case Opt_verbose:
 254                         *mount_opts |= SF_VERBOSE;
 255                         break;
 256                 case Opt_volume: {
 257                         char *vol = match_strdup(&args[0]);
 258                         if (!vol)
 259                                 return 0;
 260                         strlcpy(volume, vol, 32);
 261                         kfree(vol);
 262                         break;
 263                 }
 264                 case Opt_ignore:
 265                         /* Silently ignore the quota options */
 266                         break;
 267                 default:
 268                         printk("AFFS: Unrecognized mount option \"%s\" "
 269                                         "or missing value\n", p);
 270                         return 0;
 271                 }
 272         }
 273         return 1;
 274 }
 275
 276 /* This function definitely needs to be split up. Some fine day I'll
 277  * hopefully have the guts to do so. Until then: sorry for the mess.
 278  */
 279
 280 static int affs_fill_super(struct super_block *sb, void *data, int silent)
 281 {
 282         struct affs_sb_info     *sbi;
 283         struct buffer_head      *root_bh = NULL;
 284         struct buffer_head      *boot_bh;
 285         struct inode            *root_inode = NULL;
 286         s32                      root_block;
 287         int                      size, blocksize;
 288         u32                      chksum;
 289         int                      num_bm;
 290         int                      i, j;
 291         s32                      key;
 292         uid_t                    uid;
 293         gid_t                    gid;
 294         int                      reserved;
 295         unsigned long            mount_flags;
 296         int                      tmp_flags;     /* fix remount prototype... */
 297         u8                       sig[4];
 298         int                      ret = -EINVAL;
 299
 300         save_mount_options(sb, data);
 301
 302         pr_debug("AFFS: read_super(%s)\n",data ? (const char *)data : "no options");
 303
 304         sb->s_magic             = AFFS_SUPER_MAGIC;
 305         sb->s_op                = &affs_sops;
 306         sb->s_flags |= MS_NODIRATIME;
 307
 308         sbi = kzalloc(sizeof(struct affs_sb_info), GFP_KERNEL);
 309         if (!sbi)
 310                 return -ENOMEM;
 311         sb->s_fs_info = sbi;
 312         mutex_init(&sbi->s_bmlock);
 313         spin_lock_init(&sbi->symlink_lock);
 314
 315         if (!parse_options(data,&uid,&gid,&i,&reserved,&root_block,
 316                                 &blocksize,&sbi->s_prefix,
 317                                 sbi->s_volume, &mount_flags)) {
 318                 printk(KERN_ERR "AFFS: Error parsing options\n");
 319                 kfree(sbi->s_prefix);
 320                 kfree(sbi);
 321                 return -EINVAL;
 322         }
 323         /* N.B. after this point s_prefix must be released */
 324
 325         sbi->s_flags   = mount_flags;
 326         sbi->s_mode    = i;
 327         sbi->s_uid     = uid;
 328         sbi->s_gid     = gid;
 329         sbi->s_reserved= reserved;
 330
 331         /* Get the size of the device in 512-byte blocks.
 332          * If we later see that the partition uses bigger
 333          * blocks, we will have to change it.
 334          */
 335
 336         size = sb->s_bdev->bd_inode->i_size >> 9;
 337         pr_debug("AFFS: initial blocksize=%d, #blocks=%d\n", 512, size);
 338
 339         affs_set_blocksize(sb, PAGE_SIZE);
 340         /* Try to find root block. Its location depends on the block size. */
 341
 342         i = 512;
 343         j = 4096;
 344         if (blocksize > 0) {
 345                 i = j = blocksize;
 346                 size = size / (blocksize / 512);
 347         }
 348         for (blocksize = i, key = 0; blocksize <= j; blocksize <<= 1, size >>= 1) {
 349                 sbi->s_root_block = root_block;
 350                 if (root_block < 0)
 351                         sbi->s_root_block = (reserved + size - 1) / 2;
 352                 pr_debug("AFFS: setting blocksize to %d\n", blocksize);
 353                 affs_set_blocksize(sb, blocksize);
 354                 sbi->s_partition_size = size;
 355
 356                 /* The root block location that was calculated above is not
 357                  * correct if the partition size is an odd number of 512-
 358                  * byte blocks, which will be rounded down to a number of
 359                  * 1024-byte blocks, and if there were an even number of
 360                  * reserved blocks. Ideally, all partition checkers should
 361                  * report the real number of blocks of the real blocksize,
 362                  * but since this just cannot be done, we have to try to
 363                  * find the root block anyways. In the above case, it is one
 364                  * block behind the calculated one. So we check this one, too.
 365                  */
 366                 for (num_bm = 0; num_bm < 2; num_bm++) {
 367                         pr_debug("AFFS: Dev %s, trying root=%u, bs=%d, "
 368                                 "size=%d, reserved=%d\n",
 369                                 sb->s_id,
 370                                 sbi->s_root_block + num_bm,
 371                                 blocksize, size, reserved);
 372                         root_bh = affs_bread(sb, sbi->s_root_block + num_bm);
 373                         if (!root_bh)
 374                                 continue;
 375                         if (!affs_checksum_block(sb, root_bh) &&
 376                             be32_to_cpu(AFFS_ROOT_HEAD(root_bh)->ptype) == T_SHORT &&
 377                             be32_to_cpu(AFFS_ROOT_TAIL(sb, root_bh)->stype) == ST_ROOT) {
 378                                 sbi->s_hashsize    = blocksize / 4 - 56;
 379                                 sbi->s_root_block += num_bm;
 380                                 key                        = 1;
 381                                 goto got_root;
 382                         }
 383                         affs_brelse(root_bh);
 384                         root_bh = NULL;
 385                 }
 386         }
 387         if (!silent)
 388                 printk(KERN_ERR "AFFS: No valid root block on device %s\n",
 389                         sb->s_id);
 390         goto out_error;
 391
 392         /* N.B. after this point bh must be released */
 393 got_root:
 394         root_block = sbi->s_root_block;
 395
 396         /* Find out which kind of FS we have */
 397         boot_bh = sb_bread(sb, 0);
 398         if (!boot_bh) {
 399                 printk(KERN_ERR "AFFS: Cannot read boot block\n");
 400                 goto out_error;
 401         }
 402         memcpy(sig, boot_bh->b_data, 4);
 403         brelse(boot_bh);
 404         chksum = be32_to_cpu(*(__be32 *)sig);
 405
 406         /* Dircache filesystems are compatible with non-dircache ones
 407          * when reading. As long as they aren't supported, writing is
 408          * not recommended.
 409          */
 410         if ((chksum == FS_DCFFS || chksum == MUFS_DCFFS || chksum == FS_DCOFS
 411              || chksum == MUFS_DCOFS) && !(sb->s_flags & MS_RDONLY)) {
 412                 printk(KERN_NOTICE "AFFS: Dircache FS - mounting %s read only\n",
 413                         sb->s_id);
 414                 sb->s_flags |= MS_RDONLY;
 415         }
 416         switch (chksum) {
 417                 case MUFS_FS:
 418                 case MUFS_INTLFFS:
 419                 case MUFS_DCFFS:
 420                         sbi->s_flags |= SF_MUFS;
 421                         /* fall thru */
 422                 case FS_INTLFFS:
 423                 case FS_DCFFS:
 424                         sbi->s_flags |= SF_INTL;
 425                         break;
 426                 case MUFS_FFS:
 427                         sbi->s_flags |= SF_MUFS;
 428                         break;
 429                 case FS_FFS:
 430                         break;
 431                 case MUFS_OFS:
 432                         sbi->s_flags |= SF_MUFS;
 433                         /* fall thru */
 434                 case FS_OFS:
 435                         sbi->s_flags |= SF_OFS;
 436                         sb->s_flags |= MS_NOEXEC;
 437                         break;
 438                 case MUFS_DCOFS:
 439                 case MUFS_INTLOFS:
 440                         sbi->s_flags |= SF_MUFS;
 441                 case FS_DCOFS:
 442                 case FS_INTLOFS:
 443                         sbi->s_flags |= SF_INTL | SF_OFS;
 444                         sb->s_flags |= MS_NOEXEC;
 445                         break;
 446                 default:
 447                         printk(KERN_ERR "AFFS: Unknown filesystem on device %s: %08X\n",
 448                                 sb->s_id, chksum);
 449                         goto out_error;
 450         }
 451
 452         if (mount_flags & SF_VERBOSE) {
 453                 u8 len = AFFS_ROOT_TAIL(sb, root_bh)->disk_name[0];
 454                 printk(KERN_NOTICE "AFFS: Mounting volume \"%.*s\": Type=%.3s\\%c, Blocksize=%d\n",
 455                         len > 31 ? 31 : len,
 456                         AFFS_ROOT_TAIL(sb, root_bh)->disk_name + 1,
 457                         sig, sig[3] + '0', blocksize);
 458         }
 459
 460         sb->s_flags |= MS_NODEV | MS_NOSUID;
 461
 462         sbi->s_data_blksize = sb->s_blocksize;
 463         if (sbi->s_flags & SF_OFS)
 464                 sbi->s_data_blksize -= 24;
 465
 466         /* Keep super block in cache */
 467         sbi->s_root_bh = root_bh;
 468         /* N.B. after this point s_root_bh must be released */
 469
 470         tmp_flags = sb->s_flags;
 471         if (affs_init_bitmap(sb, &tmp_flags))
 472                 goto out_error;
 473         sb->s_flags = tmp_flags;
 474
 475         /* set up enough so that it can read an inode */
 476
 477         root_inode = affs_iget(sb, root_block);
 478         if (IS_ERR(root_inode)) {
 479                 ret = PTR_ERR(root_inode);
 480                 goto out_error_noinode;
 481         }
 482
 483         sb->s_root = d_alloc_root(root_inode);
 484         if (!sb->s_root) {
 485                 printk(KERN_ERR "AFFS: Get root inode failed\n");
 486                 goto out_error;
 487         }
 488         sb->s_root->d_op = &affs_dentry_operations;
 489
 490         pr_debug("AFFS: s_flags=%lX\n",sb->s_flags);
 491         return 0;
 492
 493         /*
 494          * Begin the cascaded cleanup ...
 495          */
 496 out_error:
 497         if (root_inode)
 498                 iput(root_inode);
 499 out_error_noinode:
 500         kfree(sbi->s_bitmap);
 501         affs_brelse(root_bh);
 502         kfree(sbi->s_prefix);
 503         kfree(sbi);
 504         sb->s_fs_info = NULL;
 505         return ret;
 506 }
 507
 508 static int
 509 affs_remount(struct super_block *sb, int *flags, char *data)
 510 {
 511         struct affs_sb_info     *sbi = AFFS_SB(sb);
 512         int                      blocksize;
 513         uid_t                    uid;
 514         gid_t                    gid;
 515         int                      mode;
 516         int                      reserved;
 517         int                      root_block;
 518         unsigned long            mount_flags;
 519         int                      res = 0;
 520         char                    *new_opts = kstrdup(data, GFP_KERNEL);
 521         char                     volume[32];
 522         char                    *prefix = NULL;
 523
 524         pr_debug("AFFS: remount(flags=0x%x,opts=\"%s\")\n",*flags,data);
 525
 526         *flags |= MS_NODIRATIME;
 527
 528         memcpy(volume, sbi->s_volume, 32);
 529         if (!parse_options(data, &uid, &gid, &mode, &reserved, &root_block,
 530                            &blocksize, &prefix, volume,
 531                            &mount_flags)) {
 532                 kfree(prefix);
 533                 kfree(new_opts);
 534                 return -EINVAL;
 535         }
 536         lock_kernel();
 537         replace_mount_options(sb, new_opts);
 538
 539         sbi->s_flags = mount_flags;
 540         sbi->s_mode  = mode;
 541         sbi->s_uid   = uid;
 542         sbi->s_gid   = gid;
 543         /* protect against readers */
 544         spin_lock(&sbi->symlink_lock);
 545         if (prefix) {
 546                 kfree(sbi->s_prefix);
 547                 sbi->s_prefix = prefix;
 548         }
 549         memcpy(sbi->s_volume, volume, 32);
 550         spin_unlock(&sbi->symlink_lock);
 551
 552         if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY)) {
 553                 unlock_kernel();
 554                 return 0;
 555         }
 556         if (*flags & MS_RDONLY) {
 557                 sb->s_dirt = 1;
 558                 while (sb->s_dirt)
 559                         affs_write_super(sb);
 560                 affs_free_bitmap(sb);
 561         } else
 562                 res = affs_init_bitmap(sb, flags);
 563
 564         unlock_kernel();
 565         return res;
 566 }
 567
 568 static int
 569 affs_statfs(struct dentry *dentry, struct kstatfs *buf)
 570 {
 571         struct super_block *sb = dentry->d_sb;
 572         int              free;
 573         u64              id = huge_encode_dev(sb->s_bdev->bd_dev);
 574
 575         pr_debug("AFFS: statfs() partsize=%d, reserved=%d\n",AFFS_SB(sb)->s_partition_size,
 576              AFFS_SB(sb)->s_reserved);
 577
 578         free          = affs_count_free_blocks(sb);
 579         buf->f_type    = AFFS_SUPER_MAGIC;
 580         buf->f_bsize   = sb->s_blocksize;
 581         buf->f_blocks  = AFFS_SB(sb)->s_partition_size - AFFS_SB(sb)->s_reserved;
 582         buf->f_bfree   = free;
 583         buf->f_bavail  = free;
 584         buf->f_fsid.val[0] = (u32)id;
 585         buf->f_fsid.val[1] = (u32)(id >> 32);
 586         buf->f_namelen = 30;
 587         return 0;
 588 }
 589
 590 static int affs_get_sb(struct file_system_type *fs_type,
 591         int flags, const char *dev_name, void *data, struct vfsmount *mnt)
 592 {
 593         return get_sb_bdev(fs_type, flags, dev_name, data, affs_fill_super,
 594                            mnt);
 595 }
 596
 597 static struct file_system_type affs_fs_type = {
 598         .owner          = THIS_MODULE,
 599         .name           = "affs",
 600         .get_sb         = affs_get_sb,
 601         .kill_sb        = kill_block_super,
 602         .fs_flags       = FS_REQUIRES_DEV,
 603 };
 604
 605 static int __init init_affs_fs(void)
 606 {
 607         int err = init_inodecache();
 608         if (err)
 609                 goto out1;
 610         err = register_filesystem(&affs_fs_type);
 611         if (err)
 612                 goto out;
 613         return 0;
 614 out:
 615         destroy_inodecache();
 616 out1:
 617         return err;
 618 }
 619
 620 static void __exit exit_affs_fs(void)
 621 {
 622         unregister_filesystem(&affs_fs_type);
 623         destroy_inodecache();
 624 }
 625
 626 MODULE_DESCRIPTION("Amiga filesystem support for Linux");
 627 MODULE_LICENSE("GPL");
 628
 629 module_init(init_affs_fs)
 630 module_exit(exit_affs_fs)