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