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