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