fs/affs/super.c

   1 /*
   2  *  linux/fs/affs/inode.c
   3  *
   4  *  (c) 1996  Hans-Joachim Widmaier - Rewritten
   5  *
   6  *  (C) 1993  Ray Burr - Modified for Amiga FFS filesystem.
   7  *
   8  *  (C) 1992  Eric Youngdale Modified for ISO 9660 filesystem.
   9  *
  10  *  (C) 1991  Linus Torvalds - minix filesystem
  11  */
  12
  13 #include <linux/module.h>
  14 #include <linux/init.h>
  15 #include <linux/statfs.h>
  16 #include <linux/parser.h>
  17 #include <linux/magic.h>
  18 #include <linux/sched.h>
  19 #include "affs.h"
  20
  21 extern struct timezone sys_tz;
  22
  23 static int affs_statfs(struct dentry *dentry, struct kstatfs *buf);
  24 static int affs_remount (struct super_block *sb, int *flags, char *data);
  25
  26 static void
  27 affs_put_super(struct super_block *sb)
  28 {
  29         struct affs_sb_info *sbi = AFFS_SB(sb);
  30         pr_debug("AFFS: put_super()\n");
  31
  32         lock_kernel();
  33
  34         if (!(sb->s_flags & MS_RDONLY)) {
  35                 AFFS_ROOT_TAIL(sb, sbi->s_root_bh)->bm_flag = cpu_to_be32(1);
  36                 secs_to_datestamp(get_seconds(),
  37                                   &AFFS_ROOT_TAIL(sb, sbi->s_root_bh)->disk_change);
  38                 affs_fix_checksum(sb, sbi->s_root_bh);
  39                 mark_buffer_dirty(sbi->s_root_bh);
  40         }
  41
  42         kfree(sbi->s_prefix);
  43         affs_free_bitmap(sb);
  44         affs_brelse(sbi->s_root_bh);
  45         kfree(sbi);
  46         sb->s_fs_info = NULL;
  47
  48         unlock_kernel();
  49 }
  50
  51 static void
  52 affs_write_super(struct super_block *sb)
  53 {
  54         int clean = 2;
  55         struct affs_sb_info *sbi = AFFS_SB(sb);
  56
  57         if (!(sb->s_flags & MS_RDONLY)) {
  58                 //      if (sbi->s_bitmap[i].bm_bh) {
  59                 //              if (buffer_dirty(sbi->s_bitmap[i].bm_bh)) {
  60                 //                      clean = 0;
  61                 AFFS_ROOT_TAIL(sb, sbi->s_root_bh)->bm_flag = cpu_to_be32(clean);
  62                 secs_to_datestamp(get_seconds(),
  63                                   &AFFS_ROOT_TAIL(sb, sbi->s_root_bh)->disk_change);
  64                 affs_fix_checksum(sb, sbi->s_root_bh);
  65                 mark_buffer_dirty(sbi->s_root_bh);
  66                 sb->s_dirt = !clean;    /* redo until bitmap synced */
  67         } else
  68                 sb->s_dirt = 0;
  69
  70         pr_debug("AFFS: write_super() at %lu, clean=%d\n", get_seconds(), clean);
  71 }
  72
  73 static struct kmem_cache * affs_inode_cachep;
  74
  75 static struct inode *affs_alloc_inode(struct super_block *sb)
  76 {
  77         struct affs_inode_info *i;
  78
  79         i = kmem_cache_alloc(affs_inode_cachep, GFP_KERNEL);
  80         if (!i)
  81                 return NULL;
  82
  83         i->vfs_inode.i_version = 1;
  84         i->i_lc = NULL;
  85         i->i_ext_bh = NULL;
  86         i->i_pa_cnt = 0;
  87
  88         return &i->vfs_inode;
  89 }
  90
  91 static void affs_destroy_inode(struct inode *inode)
  92 {
  93         kmem_cache_free(affs_inode_cachep, AFFS_I(inode));
  94 }
  95
  96 static void init_once(void *foo)
  97 {
  98         struct affs_inode_info *ei = (struct affs_inode_info *) foo;
  99
 100         init_MUTEX(&ei->i_link_lock);
 101         init_MUTEX(&ei->i_ext_lock);
 102         inode_init_once(&ei->vfs_inode);
 103 }
 104
 105 static int init_inodecache(void)
 106 {
 107         affs_inode_cachep = kmem_cache_create("affs_inode_cache",
 108                                              sizeof(struct affs_inode_info),
 109                                              0, (SLAB_RECLAIM_ACCOUNT|
 110                                                 SLAB_MEM_SPREAD),
 111                                              init_once);
 112         if (affs_inode_cachep == NULL)
 113                 return -ENOMEM;
 114         return 0;
 115 }
 116
 117 static void destroy_inodecache(void)
 118 {
 119         kmem_cache_destroy(affs_inode_cachep);
 120 }
 121
 122 static const struct super_operations affs_sops = {
 123         .alloc_inode    = affs_alloc_inode,
 124         .destroy_inode  = affs_destroy_inode,
 125         .write_inode    = affs_write_inode,
 126         .delete_inode   = affs_delete_inode,
 127         .clear_inode    = affs_clear_inode,
 128         .put_super      = affs_put_super,
 129         .write_super    = affs_write_super,
 130         .statfs         = affs_statfs,
 131         .remount_fs     = affs_remount,
 132         .show_options   = generic_show_options,
 133 };
 134
 135 enum {
 136         Opt_bs, Opt_mode, Opt_mufs, Opt_prefix, Opt_protect,
 137         Opt_reserved, Opt_root, Opt_setgid, Opt_setuid,
 138         Opt_verbose, Opt_volume, Opt_ignore, Opt_err,
 139 };
 140
 141 static const match_table_t tokens = {
 142         {Opt_bs, "bs=%u"},
 143         {Opt_mode, "mode=%o"},
 144         {Opt_mufs, "mufs"},
 145         {Opt_prefix, "prefix=%s"},
 146         {Opt_protect, "protect"},
 147         {Opt_reserved, "reserved=%u"},
 148         {Opt_root, "root=%u"},
 149         {Opt_setgid, "setgid=%u"},
 150         {Opt_setuid, "setuid=%u"},
 151         {Opt_verbose, "verbose"},
 152         {Opt_volume, "volume=%s"},
 153         {Opt_ignore, "grpquota"},
 154         {Opt_ignore, "noquota"},
 155         {Opt_ignore, "quota"},
 156         {Opt_ignore, "usrquota"},
 157         {Opt_err, NULL},
 158 };
 159
 160 static int
 161 parse_options(char *options, uid_t *uid, gid_t *gid, int *mode, int *reserved, s32 *root,
 162                 int *blocksize, char **prefix, char *volume, unsigned long *mount_opts)
 163 {
 164         char *p;
 165         substring_t args[MAX_OPT_ARGS];
 166
 167         /* Fill in defaults */
 168
 169         *uid        = current_uid();
 170         *gid        = current_gid();
 171         *reserved   = 2;
 172         *root       = -1;
 173         *blocksize  = -1;
 174         volume[0]   = ':';
 175         volume[1]   = 0;
 176         *mount_opts = 0;
 177         if (!options)
 178                 return 1;
 179
 180         while ((p = strsep(&options, ",")) != NULL) {
 181                 int token, n, option;
 182                 if (!*p)
 183                         continue;
 184
 185                 token = match_token(p, tokens, args);
 186                 switch (token) {
 187                 case Opt_bs:
 188                         if (match_int(&args[0], &n))
 189                                 return -EINVAL;
 190                         if (n != 512 && n != 1024 && n != 2048
 191                             && n != 4096) {
 192                                 printk ("AFFS: Invalid blocksize (512, 1024, 2048, 4096 allowed)\n");
 193                                 return 0;
 194                         }
 195                         *blocksize = n;
 196                         break;
 197                 case Opt_mode:
 198                         if (match_octal(&args[0], &option))
 199                                 return 1;
 200                         *mode = option & 0777;
 201                         *mount_opts |= SF_SETMODE;
 202                         break;
 203                 case Opt_mufs:
 204                         *mount_opts |= SF_MUFS;
 205                         break;
 206                 case Opt_prefix:
 207                         /* Free any previous prefix */
 208                         kfree(*prefix);
 209                         *prefix = match_strdup(&args[0]);
 210                         if (!*prefix)
 211                                 return 0;
 212                         *mount_opts |= SF_PREFIX;
 213                         break;
 214                 case Opt_protect:
 215                         *mount_opts |= SF_IMMUTABLE;
 216                         break;
 217                 case Opt_reserved:
 218                         if (match_int(&args[0], reserved))
 219                                 return 1;
 220                         break;
 221                 case Opt_root:
 222                         if (match_int(&args[0], root))
 223                                 return 1;
 224                         break;
 225                 case Opt_setgid:
 226                         if (match_int(&args[0], &option))
 227                                 return 1;
 228                         *gid = option;
 229                         *mount_opts |= SF_SETGID;
 230                         break;
 231                 case Opt_setuid:
 232                         if (match_int(&args[0], &option))
 233                                 return -EINVAL;
 234                         *uid = option;
 235                         *mount_opts |= SF_SETUID;
 236                         break;
 237                 case Opt_verbose:
 238                         *mount_opts |= SF_VERBOSE;
 239                         break;
 240                 case Opt_volume: {
 241                         char *vol = match_strdup(&args[0]);
 242                         if (!vol)
 243                                 return 0;
 244                         strlcpy(volume, vol, 32);
 245                         kfree(vol);
 246                         break;
 247                 }
 248                 case Opt_ignore:
 249                         /* Silently ignore the quota options */
 250                         break;
 251                 default:
 252                         printk("AFFS: Unrecognized mount option \"%s\" "
 253                                         "or missing value\n", p);
 254                         return 0;
 255                 }
 256         }
 257         return 1;
 258 }
 259
 260 /* This function definitely needs to be split up. Some fine day I'll
 261  * hopefully have the guts to do so. Until then: sorry for the mess.
 262  */
 263
 264 static int affs_fill_super(struct super_block *sb, void *data, int silent)
 265 {
 266         struct affs_sb_info     *sbi;
 267         struct buffer_head      *root_bh = NULL;
 268         struct buffer_head      *boot_bh;
 269         struct inode            *root_inode = NULL;
 270         s32                      root_block;
 271         int                      size, blocksize;
 272         u32                      chksum;
 273         int                      num_bm;
 274         int                      i, j;
 275         s32                      key;
 276         uid_t                    uid;
 277         gid_t                    gid;
 278         int                      reserved;
 279         unsigned long            mount_flags;
 280         int                      tmp_flags;     /* fix remount prototype... */
 281         u8                       sig[4];
 282         int                      ret = -EINVAL;
 283
 284         save_mount_options(sb, data);
 285
 286         pr_debug("AFFS: read_super(%s)\n",data ? (const char *)data : "no options");
 287
 288         sb->s_magic             = AFFS_SUPER_MAGIC;
 289         sb->s_op                = &affs_sops;
 290         sb->s_flags |= MS_NODIRATIME;
 291
 292         sbi = kzalloc(sizeof(struct affs_sb_info), GFP_KERNEL);
 293         if (!sbi)
 294                 return -ENOMEM;
 295         sb->s_fs_info = sbi;
 296         mutex_init(&sbi->s_bmlock);
 297
 298         if (!parse_options(data,&uid,&gid,&i,&reserved,&root_block,
 299                                 &blocksize,&sbi->s_prefix,
 300                                 sbi->s_volume, &mount_flags)) {
 301                 printk(KERN_ERR "AFFS: Error parsing options\n");
 302                 return -EINVAL;
 303         }
 304         /* N.B. after this point s_prefix must be released */
 305
 306         sbi->s_flags   = mount_flags;
 307         sbi->s_mode    = i;
 308         sbi->s_uid     = uid;
 309         sbi->s_gid     = gid;
 310         sbi->s_reserved= reserved;
 311
 312         /* Get the size of the device in 512-byte blocks.
 313          * If we later see that the partition uses bigger
 314          * blocks, we will have to change it.
 315          */
 316
 317         size = sb->s_bdev->bd_inode->i_size >> 9;
 318         pr_debug("AFFS: initial blocksize=%d, #blocks=%d\n", 512, size);
 319
 320         affs_set_blocksize(sb, PAGE_SIZE);
 321         /* Try to find root block. Its location depends on the block size. */
 322
 323         i = 512;
 324         j = 4096;
 325         if (blocksize > 0) {
 326                 i = j = blocksize;
 327                 size = size / (blocksize / 512);
 328         }
 329         for (blocksize = i, key = 0; blocksize <= j; blocksize <<= 1, size >>= 1) {
 330                 sbi->s_root_block = root_block;
 331                 if (root_block < 0)
 332                         sbi->s_root_block = (reserved + size - 1) / 2;
 333                 pr_debug("AFFS: setting blocksize to %d\n", blocksize);
 334                 affs_set_blocksize(sb, blocksize);
 335                 sbi->s_partition_size = size;
 336
 337                 /* The root block location that was calculated above is not
 338                  * correct if the partition size is an odd number of 512-
 339                  * byte blocks, which will be rounded down to a number of
 340                  * 1024-byte blocks, and if there were an even number of
 341                  * reserved blocks. Ideally, all partition checkers should
 342                  * report the real number of blocks of the real blocksize,
 343                  * but since this just cannot be done, we have to try to
 344                  * find the root block anyways. In the above case, it is one
 345                  * block behind the calculated one. So we check this one, too.
 346                  */
 347                 for (num_bm = 0; num_bm < 2; num_bm++) {
 348                         pr_debug("AFFS: Dev %s, trying root=%u, bs=%d, "
 349                                 "size=%d, reserved=%d\n",
 350                                 sb->s_id,
 351                                 sbi->s_root_block + num_bm,
 352                                 blocksize, size, reserved);
 353                         root_bh = affs_bread(sb, sbi->s_root_block + num_bm);
 354                         if (!root_bh)
 355                                 continue;
 356                         if (!affs_checksum_block(sb, root_bh) &&
 357                             be32_to_cpu(AFFS_ROOT_HEAD(root_bh)->ptype) == T_SHORT &&
 358                             be32_to_cpu(AFFS_ROOT_TAIL(sb, root_bh)->stype) == ST_ROOT) {
 359                                 sbi->s_hashsize    = blocksize / 4 - 56;
 360                                 sbi->s_root_block += num_bm;
 361                                 key                        = 1;
 362                                 goto got_root;
 363                         }
 364                         affs_brelse(root_bh);
 365                         root_bh = NULL;
 366                 }
 367         }
 368         if (!silent)
 369                 printk(KERN_ERR "AFFS: No valid root block on device %s\n",
 370                         sb->s_id);
 371         goto out_error;
 372
 373         /* N.B. after this point bh must be released */
 374 got_root:
 375         root_block = sbi->s_root_block;
 376
 377         /* Find out which kind of FS we have */
 378         boot_bh = sb_bread(sb, 0);
 379         if (!boot_bh) {
 380                 printk(KERN_ERR "AFFS: Cannot read boot block\n");
 381                 goto out_error;
 382         }
 383         memcpy(sig, boot_bh->b_data, 4);
 384         brelse(boot_bh);
 385         chksum = be32_to_cpu(*(__be32 *)sig);
 386
 387         /* Dircache filesystems are compatible with non-dircache ones
 388          * when reading. As long as they aren't supported, writing is
 389          * not recommended.
 390          */
 391         if ((chksum == FS_DCFFS || chksum == MUFS_DCFFS || chksum == FS_DCOFS
 392              || chksum == MUFS_DCOFS) && !(sb->s_flags & MS_RDONLY)) {
 393                 printk(KERN_NOTICE "AFFS: Dircache FS - mounting %s read only\n",
 394                         sb->s_id);
 395                 sb->s_flags |= MS_RDONLY;
 396         }
 397         switch (chksum) {
 398                 case MUFS_FS:
 399                 case MUFS_INTLFFS:
 400                 case MUFS_DCFFS:
 401                         sbi->s_flags |= SF_MUFS;
 402                         /* fall thru */
 403                 case FS_INTLFFS:
 404                 case FS_DCFFS:
 405                         sbi->s_flags |= SF_INTL;
 406                         break;
 407                 case MUFS_FFS:
 408                         sbi->s_flags |= SF_MUFS;
 409                         break;
 410                 case FS_FFS:
 411                         break;
 412                 case MUFS_OFS:
 413                         sbi->s_flags |= SF_MUFS;
 414                         /* fall thru */
 415                 case FS_OFS:
 416                         sbi->s_flags |= SF_OFS;
 417                         sb->s_flags |= MS_NOEXEC;
 418                         break;
 419                 case MUFS_DCOFS:
 420                 case MUFS_INTLOFS:
 421                         sbi->s_flags |= SF_MUFS;
 422                 case FS_DCOFS:
 423                 case FS_INTLOFS:
 424                         sbi->s_flags |= SF_INTL | SF_OFS;
 425                         sb->s_flags |= MS_NOEXEC;
 426                         break;
 427                 default:
 428                         printk(KERN_ERR "AFFS: Unknown filesystem on device %s: %08X\n",
 429                                 sb->s_id, chksum);
 430                         goto out_error;
 431         }
 432
 433         if (mount_flags & SF_VERBOSE) {
 434                 u8 len = AFFS_ROOT_TAIL(sb, root_bh)->disk_name[0];
 435                 printk(KERN_NOTICE "AFFS: Mounting volume \"%.*s\": Type=%.3s\\%c, Blocksize=%d\n",
 436                         len > 31 ? 31 : len,
 437                         AFFS_ROOT_TAIL(sb, root_bh)->disk_name + 1,
 438                         sig, sig[3] + '0', blocksize);
 439         }
 440
 441         sb->s_flags |= MS_NODEV | MS_NOSUID;
 442
 443         sbi->s_data_blksize = sb->s_blocksize;
 444         if (sbi->s_flags & SF_OFS)
 445                 sbi->s_data_blksize -= 24;
 446
 447         /* Keep super block in cache */
 448         sbi->s_root_bh = root_bh;
 449         /* N.B. after this point s_root_bh must be released */
 450
 451         tmp_flags = sb->s_flags;
 452         if (affs_init_bitmap(sb, &tmp_flags))
 453                 goto out_error;
 454         sb->s_flags = tmp_flags;
 455
 456         /* set up enough so that it can read an inode */
 457
 458         root_inode = affs_iget(sb, root_block);
 459         if (IS_ERR(root_inode)) {
 460                 ret = PTR_ERR(root_inode);
 461                 goto out_error_noinode;
 462         }
 463
 464         sb->s_root = d_alloc_root(root_inode);
 465         if (!sb->s_root) {
 466                 printk(KERN_ERR "AFFS: Get root inode failed\n");
 467                 goto out_error;
 468         }
 469         sb->s_root->d_op = &affs_dentry_operations;
 470
 471         pr_debug("AFFS: s_flags=%lX\n",sb->s_flags);
 472         return 0;
 473
 474         /*
 475          * Begin the cascaded cleanup ...
 476          */
 477 out_error:
 478         if (root_inode)
 479                 iput(root_inode);
 480 out_error_noinode:
 481         kfree(sbi->s_bitmap);
 482         affs_brelse(root_bh);
 483         kfree(sbi->s_prefix);
 484         kfree(sbi);
 485         sb->s_fs_info = NULL;
 486         return ret;
 487 }
 488
 489 static int
 490 affs_remount(struct super_block *sb, int *flags, char *data)
 491 {
 492         struct affs_sb_info     *sbi = AFFS_SB(sb);
 493         int                      blocksize;
 494         uid_t                    uid;
 495         gid_t                    gid;
 496         int                      mode;
 497         int                      reserved;
 498         int                      root_block;
 499         unsigned long            mount_flags;
 500         int                      res = 0;
 501         char                    *new_opts = kstrdup(data, GFP_KERNEL);
 502
 503         pr_debug("AFFS: remount(flags=0x%x,opts=\"%s\")\n",*flags,data);
 504
 505         *flags |= MS_NODIRATIME;
 506
 507         if (!parse_options(data, &uid, &gid, &mode, &reserved, &root_block,
 508                            &blocksize, &sbi->s_prefix, sbi->s_volume,
 509                            &mount_flags)) {
 510                 kfree(new_opts);
 511                 return -EINVAL;
 512         }
 513         replace_mount_options(sb, new_opts);
 514
 515         sbi->s_flags = mount_flags;
 516         sbi->s_mode  = mode;
 517         sbi->s_uid   = uid;
 518         sbi->s_gid   = gid;
 519
 520         if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
 521                 return 0;
 522         if (*flags & MS_RDONLY) {
 523                 sb->s_dirt = 1;
 524                 while (sb->s_dirt)
 525                         affs_write_super(sb);
 526                 affs_free_bitmap(sb);
 527         } else
 528                 res = affs_init_bitmap(sb, flags);
 529
 530         return res;
 531 }
 532
 533 static int
 534 affs_statfs(struct dentry *dentry, struct kstatfs *buf)
 535 {
 536         struct super_block *sb = dentry->d_sb;
 537         int              free;
 538         u64              id = huge_encode_dev(sb->s_bdev->bd_dev);
 539
 540         pr_debug("AFFS: statfs() partsize=%d, reserved=%d\n",AFFS_SB(sb)->s_partition_size,
 541              AFFS_SB(sb)->s_reserved);
 542
 543         free          = affs_count_free_blocks(sb);
 544         buf->f_type    = AFFS_SUPER_MAGIC;
 545         buf->f_bsize   = sb->s_blocksize;
 546         buf->f_blocks  = AFFS_SB(sb)->s_partition_size - AFFS_SB(sb)->s_reserved;
 547         buf->f_bfree   = free;
 548         buf->f_bavail  = free;
 549         buf->f_fsid.val[0] = (u32)id;
 550         buf->f_fsid.val[1] = (u32)(id >> 32);
 551         buf->f_namelen = 30;
 552         return 0;
 553 }
 554
 555 static int affs_get_sb(struct file_system_type *fs_type,
 556         int flags, const char *dev_name, void *data, struct vfsmount *mnt)
 557 {
 558         return get_sb_bdev(fs_type, flags, dev_name, data, affs_fill_super,
 559                            mnt);
 560 }
 561
 562 static struct file_system_type affs_fs_type = {
 563         .owner          = THIS_MODULE,
 564         .name           = "affs",
 565         .get_sb         = affs_get_sb,
 566         .kill_sb        = kill_block_super,
 567         .fs_flags       = FS_REQUIRES_DEV,
 568 };
 569
 570 static int __init init_affs_fs(void)
 571 {
 572         int err = init_inodecache();
 573         if (err)
 574                 goto out1;
 575         err = register_filesystem(&affs_fs_type);
 576         if (err)
 577                 goto out;
 578         return 0;
 579 out:
 580         destroy_inodecache();
 581 out1:
 582         return err;
 583 }
 584
 585 static void __exit exit_affs_fs(void)
 586 {
 587         unregister_filesystem(&affs_fs_type);
 588         destroy_inodecache();
 589 }
 590
 591 MODULE_DESCRIPTION("Amiga filesystem support for Linux");
 592 MODULE_LICENSE("GPL");
 593
 594 module_init(init_affs_fs)
 595 module_exit(exit_affs_fs)