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 <linux/slab.h>
  20#include <linux/writeback.h>
  21#include "affs.h"
  22
  23extern struct timezone sys_tz;
  24
  25static int affs_statfs(struct dentry *dentry, struct kstatfs *buf);
  26static int affs_remount (struct super_block *sb, int *flags, char *data);
  27
  28static void
  29affs_commit_super(struct super_block *sb, int wait)
  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        lock_buffer(bh);
  36        secs_to_datestamp(get_seconds(), &tail->disk_change);
  37        affs_fix_checksum(sb, bh);
  38        unlock_buffer(bh);
  39
  40        mark_buffer_dirty(bh);
  41        if (wait)
  42                sync_dirty_buffer(bh);
  43}
  44
  45static void
  46affs_put_super(struct super_block *sb)
  47{
  48        struct affs_sb_info *sbi = AFFS_SB(sb);
  49        pr_debug("AFFS: put_super()\n");
  50
  51        cancel_delayed_work_sync(&sbi->sb_work);
  52        kfree(sbi->s_prefix);
  53        affs_free_bitmap(sb);
  54        affs_brelse(sbi->s_root_bh);
  55        kfree(sbi);
  56        sb->s_fs_info = NULL;
  57}
  58
  59static int
  60affs_sync_fs(struct super_block *sb, int wait)
  61{
  62        affs_commit_super(sb, wait);
  63        return 0;
  64}
  65
  66static void flush_superblock(struct work_struct *work)
  67{
  68        struct affs_sb_info *sbi;
  69        struct super_block *sb;
  70
  71        sbi = container_of(work, struct affs_sb_info, sb_work.work);
  72        sb = sbi->sb;
  73
  74        spin_lock(&sbi->work_lock);
  75        sbi->work_queued = 0;
  76        spin_unlock(&sbi->work_lock);
  77
  78        affs_commit_super(sb, 1);
  79}
  80
  81void affs_mark_sb_dirty(struct super_block *sb)
  82{
  83        struct affs_sb_info *sbi = AFFS_SB(sb);
  84        unsigned long delay;
  85
  86        if (sb->s_flags & MS_RDONLY)
  87               return;
  88
  89        spin_lock(&sbi->work_lock);
  90        if (!sbi->work_queued) {
  91               delay = msecs_to_jiffies(dirty_writeback_interval * 10);
  92               queue_delayed_work(system_long_wq, &sbi->sb_work, delay);
  93               sbi->work_queued = 1;
  94        }
  95        spin_unlock(&sbi->work_lock);
  96}
  97
  98static struct kmem_cache * affs_inode_cachep;
  99
 100static struct inode *affs_alloc_inode(struct super_block *sb)
 101{
 102        struct affs_inode_info *i;
 103
 104        i = kmem_cache_alloc(affs_inode_cachep, GFP_KERNEL);
 105        if (!i)
 106                return NULL;
 107
 108        i->vfs_inode.i_version = 1;
 109        i->i_lc = NULL;
 110        i->i_ext_bh = NULL;
 111        i->i_pa_cnt = 0;
 112
 113        return &i->vfs_inode;
 114}
 115
 116static void affs_i_callback(struct rcu_head *head)
 117{
 118        struct inode *inode = container_of(head, struct inode, i_rcu);
 119        kmem_cache_free(affs_inode_cachep, AFFS_I(inode));
 120}
 121
 122static void affs_destroy_inode(struct inode *inode)
 123{
 124        call_rcu(&inode->i_rcu, affs_i_callback);
 125}
 126
 127static void init_once(void *foo)
 128{
 129        struct affs_inode_info *ei = (struct affs_inode_info *) foo;
 130
 131        sema_init(&ei->i_link_lock, 1);
 132        sema_init(&ei->i_ext_lock, 1);
 133        inode_init_once(&ei->vfs_inode);
 134}
 135
 136static int init_inodecache(void)
 137{
 138        affs_inode_cachep = kmem_cache_create("affs_inode_cache",
 139                                             sizeof(struct affs_inode_info),
 140                                             0, (SLAB_RECLAIM_ACCOUNT|
 141                                                SLAB_MEM_SPREAD),
 142                                             init_once);
 143        if (affs_inode_cachep == NULL)
 144                return -ENOMEM;
 145        return 0;
 146}
 147
 148static void destroy_inodecache(void)
 149{
 150        kmem_cache_destroy(affs_inode_cachep);
 151}
 152
 153static const struct super_operations affs_sops = {
 154        .alloc_inode    = affs_alloc_inode,
 155        .destroy_inode  = affs_destroy_inode,
 156        .write_inode    = affs_write_inode,
 157        .evict_inode    = affs_evict_inode,
 158        .put_super      = affs_put_super,
 159        .sync_fs        = affs_sync_fs,
 160        .statfs         = affs_statfs,
 161        .remount_fs     = affs_remount,
 162        .show_options   = generic_show_options,
 163};
 164
 165enum {
 166        Opt_bs, Opt_mode, Opt_mufs, Opt_prefix, Opt_protect,
 167        Opt_reserved, Opt_root, Opt_setgid, Opt_setuid,
 168        Opt_verbose, Opt_volume, Opt_ignore, Opt_err,
 169};
 170
 171static const match_table_t tokens = {
 172        {Opt_bs, "bs=%u"},
 173        {Opt_mode, "mode=%o"},
 174        {Opt_mufs, "mufs"},
 175        {Opt_prefix, "prefix=%s"},
 176        {Opt_protect, "protect"},
 177        {Opt_reserved, "reserved=%u"},
 178        {Opt_root, "root=%u"},
 179        {Opt_setgid, "setgid=%u"},
 180        {Opt_setuid, "setuid=%u"},
 181        {Opt_verbose, "verbose"},
 182        {Opt_volume, "volume=%s"},
 183        {Opt_ignore, "grpquota"},
 184        {Opt_ignore, "noquota"},
 185        {Opt_ignore, "quota"},
 186        {Opt_ignore, "usrquota"},
 187        {Opt_err, NULL},
 188};
 189
 190static int
 191parse_options(char *options, uid_t *uid, gid_t *gid, int *mode, int *reserved, s32 *root,
 192                int *blocksize, char **prefix, char *volume, unsigned long *mount_opts)
 193{
 194        char *p;
 195        substring_t args[MAX_OPT_ARGS];
 196
 197        /* Fill in defaults */
 198
 199        *uid        = current_uid();
 200        *gid        = current_gid();
 201        *reserved   = 2;
 202        *root       = -1;
 203        *blocksize  = -1;
 204        volume[0]   = ':';
 205        volume[1]   = 0;
 206        *mount_opts = 0;
 207        if (!options)
 208                return 1;
 209
 210        while ((p = strsep(&options, ",")) != NULL) {
 211                int token, n, option;
 212                if (!*p)
 213                        continue;
 214
 215                token = match_token(p, tokens, args);
 216                switch (token) {
 217                case Opt_bs:
 218                        if (match_int(&args[0], &n))
 219                                return 0;
 220                        if (n != 512 && n != 1024 && n != 2048
 221                            && n != 4096) {
 222                                printk ("AFFS: Invalid blocksize (512, 1024, 2048, 4096 allowed)\n");
 223                                return 0;
 224                        }
 225                        *blocksize = n;
 226                        break;
 227                case Opt_mode:
 228                        if (match_octal(&args[0], &option))
 229                                return 0;
 230                        *mode = option & 0777;
 231                        *mount_opts |= SF_SETMODE;
 232                        break;
 233                case Opt_mufs:
 234                        *mount_opts |= SF_MUFS;
 235                        break;
 236                case Opt_prefix:
 237                        *prefix = match_strdup(&args[0]);
 238                        if (!*prefix)
 239                                return 0;
 240                        *mount_opts |= SF_PREFIX;
 241                        break;
 242                case Opt_protect:
 243                        *mount_opts |= SF_IMMUTABLE;
 244                        break;
 245                case Opt_reserved:
 246                        if (match_int(&args[0], reserved))
 247                                return 0;
 248                        break;
 249                case Opt_root:
 250                        if (match_int(&args[0], root))
 251                                return 0;
 252                        break;
 253                case Opt_setgid:
 254                        if (match_int(&args[0], &option))
 255                                return 0;
 256                        *gid = option;
 257                        *mount_opts |= SF_SETGID;
 258                        break;
 259                case Opt_setuid:
 260                        if (match_int(&args[0], &option))
 261                                return 0;
 262                        *uid = option;
 263                        *mount_opts |= SF_SETUID;
 264                        break;
 265                case Opt_verbose:
 266                        *mount_opts |= SF_VERBOSE;
 267                        break;
 268                case Opt_volume: {
 269                        char *vol = match_strdup(&args[0]);
 270                        if (!vol)
 271                                return 0;
 272                        strlcpy(volume, vol, 32);
 273                        kfree(vol);
 274                        break;
 275                }
 276                case Opt_ignore:
 277                        /* Silently ignore the quota options */
 278                        break;
 279                default:
 280                        printk("AFFS: Unrecognized mount option \"%s\" "
 281                                        "or missing value\n", p);
 282                        return 0;
 283                }
 284        }
 285        return 1;
 286}
 287
 288/* This function definitely needs to be split up. Some fine day I'll
 289 * hopefully have the guts to do so. Until then: sorry for the mess.
 290 */
 291
 292static int affs_fill_super(struct super_block *sb, void *data, int silent)
 293{
 294        struct affs_sb_info     *sbi;
 295        struct buffer_head      *root_bh = NULL;
 296        struct buffer_head      *boot_bh;
 297        struct inode            *root_inode = NULL;
 298        s32                      root_block;
 299        int                      size, blocksize;
 300        u32                      chksum;
 301        int                      num_bm;
 302        int                      i, j;
 303        s32                      key;
 304        uid_t                    uid;
 305        gid_t                    gid;
 306        int                      reserved;
 307        unsigned long            mount_flags;
 308        int                      tmp_flags;     /* fix remount prototype... */
 309        u8                       sig[4];
 310        int                      ret = -EINVAL;
 311
 312        save_mount_options(sb, data);
 313
 314        pr_debug("AFFS: read_super(%s)\n",data ? (const char *)data : "no options");
 315
 316        sb->s_magic             = AFFS_SUPER_MAGIC;
 317        sb->s_op                = &affs_sops;
 318        sb->s_flags |= MS_NODIRATIME;
 319
 320        sbi = kzalloc(sizeof(struct affs_sb_info), GFP_KERNEL);
 321        if (!sbi)
 322                return -ENOMEM;
 323
 324        sb->s_fs_info = sbi;
 325        sbi->sb = sb;
 326        mutex_init(&sbi->s_bmlock);
 327        spin_lock_init(&sbi->symlink_lock);
 328        spin_lock_init(&sbi->work_lock);
 329        INIT_DELAYED_WORK(&sbi->sb_work, flush_superblock);
 330
 331        if (!parse_options(data,&uid,&gid,&i,&reserved,&root_block,
 332                                &blocksize,&sbi->s_prefix,
 333                                sbi->s_volume, &mount_flags)) {
 334                printk(KERN_ERR "AFFS: Error parsing options\n");
 335                kfree(sbi->s_prefix);
 336                kfree(sbi);
 337                return -EINVAL;
 338        }
 339        /* N.B. after this point s_prefix must be released */
 340
 341        sbi->s_flags   = mount_flags;
 342        sbi->s_mode    = i;
 343        sbi->s_uid     = uid;
 344        sbi->s_gid     = gid;
 345        sbi->s_reserved= reserved;
 346
 347        /* Get the size of the device in 512-byte blocks.
 348         * If we later see that the partition uses bigger
 349         * blocks, we will have to change it.
 350         */
 351
 352        size = sb->s_bdev->bd_inode->i_size >> 9;
 353        pr_debug("AFFS: initial blocksize=%d, #blocks=%d\n", 512, size);
 354
 355        affs_set_blocksize(sb, PAGE_SIZE);
 356        /* Try to find root block. Its location depends on the block size. */
 357
 358        i = 512;
 359        j = 4096;
 360        if (blocksize > 0) {
 361                i = j = blocksize;
 362                size = size / (blocksize / 512);
 363        }
 364        for (blocksize = i, key = 0; blocksize <= j; blocksize <<= 1, size >>= 1) {
 365                sbi->s_root_block = root_block;
 366                if (root_block < 0)
 367                        sbi->s_root_block = (reserved + size - 1) / 2;
 368                pr_debug("AFFS: setting blocksize to %d\n", blocksize);
 369                affs_set_blocksize(sb, blocksize);
 370                sbi->s_partition_size = size;
 371
 372                /* The root block location that was calculated above is not
 373                 * correct if the partition size is an odd number of 512-
 374                 * byte blocks, which will be rounded down to a number of
 375                 * 1024-byte blocks, and if there were an even number of
 376                 * reserved blocks. Ideally, all partition checkers should
 377                 * report the real number of blocks of the real blocksize,
 378                 * but since this just cannot be done, we have to try to
 379                 * find the root block anyways. In the above case, it is one
 380                 * block behind the calculated one. So we check this one, too.
 381                 */
 382                for (num_bm = 0; num_bm < 2; num_bm++) {
 383                        pr_debug("AFFS: Dev %s, trying root=%u, bs=%d, "
 384                                "size=%d, reserved=%d\n",
 385                                sb->s_id,
 386                                sbi->s_root_block + num_bm,
 387                                blocksize, size, reserved);
 388                        root_bh = affs_bread(sb, sbi->s_root_block + num_bm);
 389                        if (!root_bh)
 390                                continue;
 391                        if (!affs_checksum_block(sb, root_bh) &&
 392                            be32_to_cpu(AFFS_ROOT_HEAD(root_bh)->ptype) == T_SHORT &&
 393                            be32_to_cpu(AFFS_ROOT_TAIL(sb, root_bh)->stype) == ST_ROOT) {
 394                                sbi->s_hashsize    = blocksize / 4 - 56;
 395                                sbi->s_root_block += num_bm;
 396                                key                        = 1;
 397                                goto got_root;
 398                        }
 399                        affs_brelse(root_bh);
 400                        root_bh = NULL;
 401                }
 402        }
 403        if (!silent)
 404                printk(KERN_ERR "AFFS: No valid root block on device %s\n",
 405                        sb->s_id);
 406        goto out_error;
 407
 408        /* N.B. after this point bh must be released */
 409got_root:
 410        root_block = sbi->s_root_block;
 411
 412        /* Find out which kind of FS we have */
 413        boot_bh = sb_bread(sb, 0);
 414        if (!boot_bh) {
 415                printk(KERN_ERR "AFFS: Cannot read boot block\n");
 416                goto out_error;
 417        }
 418        memcpy(sig, boot_bh->b_data, 4);
 419        brelse(boot_bh);
 420        chksum = be32_to_cpu(*(__be32 *)sig);
 421
 422        /* Dircache filesystems are compatible with non-dircache ones
 423         * when reading. As long as they aren't supported, writing is
 424         * not recommended.
 425         */
 426        if ((chksum == FS_DCFFS || chksum == MUFS_DCFFS || chksum == FS_DCOFS
 427             || chksum == MUFS_DCOFS) && !(sb->s_flags & MS_RDONLY)) {
 428                printk(KERN_NOTICE "AFFS: Dircache FS - mounting %s read only\n",
 429                        sb->s_id);
 430                sb->s_flags |= MS_RDONLY;
 431        }
 432        switch (chksum) {
 433                case MUFS_FS:
 434                case MUFS_INTLFFS:
 435                case MUFS_DCFFS:
 436                        sbi->s_flags |= SF_MUFS;
 437                        /* fall thru */
 438                case FS_INTLFFS:
 439                case FS_DCFFS:
 440                        sbi->s_flags |= SF_INTL;
 441                        break;
 442                case MUFS_FFS:
 443                        sbi->s_flags |= SF_MUFS;
 444                        break;
 445                case FS_FFS:
 446                        break;
 447                case MUFS_OFS:
 448                        sbi->s_flags |= SF_MUFS;
 449                        /* fall thru */
 450                case FS_OFS:
 451                        sbi->s_flags |= SF_OFS;
 452                        sb->s_flags |= MS_NOEXEC;
 453                        break;
 454                case MUFS_DCOFS:
 455                case MUFS_INTLOFS:
 456                        sbi->s_flags |= SF_MUFS;
 457                case FS_DCOFS:
 458                case FS_INTLOFS:
 459                        sbi->s_flags |= SF_INTL | SF_OFS;
 460                        sb->s_flags |= MS_NOEXEC;
 461                        break;
 462                default:
 463                        printk(KERN_ERR "AFFS: Unknown filesystem on device %s: %08X\n",
 464                                sb->s_id, chksum);
 465                        goto out_error;
 466        }
 467
 468        if (mount_flags & SF_VERBOSE) {
 469                u8 len = AFFS_ROOT_TAIL(sb, root_bh)->disk_name[0];
 470                printk(KERN_NOTICE "AFFS: Mounting volume \"%.*s\": Type=%.3s\\%c, Blocksize=%d\n",
 471                        len > 31 ? 31 : len,
 472                        AFFS_ROOT_TAIL(sb, root_bh)->disk_name + 1,
 473                        sig, sig[3] + '0', blocksize);
 474        }
 475
 476        sb->s_flags |= MS_NODEV | MS_NOSUID;
 477
 478        sbi->s_data_blksize = sb->s_blocksize;
 479        if (sbi->s_flags & SF_OFS)
 480                sbi->s_data_blksize -= 24;
 481
 482        /* Keep super block in cache */
 483        sbi->s_root_bh = root_bh;
 484        /* N.B. after this point s_root_bh must be released */
 485
 486        tmp_flags = sb->s_flags;
 487        if (affs_init_bitmap(sb, &tmp_flags))
 488                goto out_error;
 489        sb->s_flags = tmp_flags;
 490
 491        /* set up enough so that it can read an inode */
 492
 493        root_inode = affs_iget(sb, root_block);
 494        if (IS_ERR(root_inode)) {
 495                ret = PTR_ERR(root_inode);
 496                goto out_error;
 497        }
 498
 499        if (AFFS_SB(sb)->s_flags & SF_INTL)
 500                sb->s_d_op = &affs_intl_dentry_operations;
 501        else
 502                sb->s_d_op = &affs_dentry_operations;
 503
 504        sb->s_root = d_make_root(root_inode);
 505        if (!sb->s_root) {
 506                printk(KERN_ERR "AFFS: Get root inode failed\n");
 507                goto out_error;
 508        }
 509
 510        pr_debug("AFFS: s_flags=%lX\n",sb->s_flags);
 511        return 0;
 512
 513        /*
 514         * Begin the cascaded cleanup ...
 515         */
 516out_error:
 517        kfree(sbi->s_bitmap);
 518        affs_brelse(root_bh);
 519        kfree(sbi->s_prefix);
 520        kfree(sbi);
 521        sb->s_fs_info = NULL;
 522        return ret;
 523}
 524
 525static int
 526affs_remount(struct super_block *sb, int *flags, char *data)
 527{
 528        struct affs_sb_info     *sbi = AFFS_SB(sb);
 529        int                      blocksize;
 530        uid_t                    uid;
 531        gid_t                    gid;
 532        int                      mode;
 533        int                      reserved;
 534        int                      root_block;
 535        unsigned long            mount_flags;
 536        int                      res = 0;
 537        char                    *new_opts = kstrdup(data, GFP_KERNEL);
 538        char                     volume[32];
 539        char                    *prefix = NULL;
 540
 541        pr_debug("AFFS: remount(flags=0x%x,opts=\"%s\")\n",*flags,data);
 542
 543        *flags |= MS_NODIRATIME;
 544
 545        memcpy(volume, sbi->s_volume, 32);
 546        if (!parse_options(data, &uid, &gid, &mode, &reserved, &root_block,
 547                           &blocksize, &prefix, volume,
 548                           &mount_flags)) {
 549                kfree(prefix);
 550                kfree(new_opts);
 551                return -EINVAL;
 552        }
 553
 554        flush_delayed_work_sync(&sbi->sb_work);
 555        replace_mount_options(sb, new_opts);
 556
 557        sbi->s_flags = mount_flags;
 558        sbi->s_mode  = mode;
 559        sbi->s_uid   = uid;
 560        sbi->s_gid   = gid;
 561        /* protect against readers */
 562        spin_lock(&sbi->symlink_lock);
 563        if (prefix) {
 564                kfree(sbi->s_prefix);
 565                sbi->s_prefix = prefix;
 566        }
 567        memcpy(sbi->s_volume, volume, 32);
 568        spin_unlock(&sbi->symlink_lock);
 569
 570        if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
 571                return 0;
 572
 573        if (*flags & MS_RDONLY)
 574                affs_free_bitmap(sb);
 575        else
 576                res = affs_init_bitmap(sb, flags);
 577
 578        return res;
 579}
 580
 581static int
 582affs_statfs(struct dentry *dentry, struct kstatfs *buf)
 583{
 584        struct super_block *sb = dentry->d_sb;
 585        int              free;
 586        u64              id = huge_encode_dev(sb->s_bdev->bd_dev);
 587
 588        pr_debug("AFFS: statfs() partsize=%d, reserved=%d\n",AFFS_SB(sb)->s_partition_size,
 589             AFFS_SB(sb)->s_reserved);
 590
 591        free          = affs_count_free_blocks(sb);
 592        buf->f_type    = AFFS_SUPER_MAGIC;
 593        buf->f_bsize   = sb->s_blocksize;
 594        buf->f_blocks  = AFFS_SB(sb)->s_partition_size - AFFS_SB(sb)->s_reserved;
 595        buf->f_bfree   = free;
 596        buf->f_bavail  = free;
 597        buf->f_fsid.val[0] = (u32)id;
 598        buf->f_fsid.val[1] = (u32)(id >> 32);
 599        buf->f_namelen = 30;
 600        return 0;
 601}
 602
 603static struct dentry *affs_mount(struct file_system_type *fs_type,
 604        int flags, const char *dev_name, void *data)
 605{
 606        return mount_bdev(fs_type, flags, dev_name, data, affs_fill_super);
 607}
 608
 609static struct file_system_type affs_fs_type = {
 610        .owner          = THIS_MODULE,
 611        .name           = "affs",
 612        .mount          = affs_mount,
 613        .kill_sb        = kill_block_super,
 614        .fs_flags       = FS_REQUIRES_DEV,
 615};
 616
 617static int __init init_affs_fs(void)
 618{
 619        int err = init_inodecache();
 620        if (err)
 621                goto out1;
 622        err = register_filesystem(&affs_fs_type);
 623        if (err)
 624                goto out;
 625        return 0;
 626out:
 627        destroy_inodecache();
 628out1:
 629        return err;
 630}
 631
 632static void __exit exit_affs_fs(void)
 633{
 634        unregister_filesystem(&affs_fs_type);
 635        destroy_inodecache();
 636}
 637
 638MODULE_DESCRIPTION("Amiga filesystem support for Linux");
 639MODULE_LICENSE("GPL");
 640
 641module_init(init_affs_fs)
 642module_exit(exit_affs_fs)
 643
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