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