linux/fs/hfs/super.c
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   1/*
   2 *  linux/fs/hfs/super.c
   3 *
   4 * Copyright (C) 1995-1997  Paul H. Hargrove
   5 * (C) 2003 Ardis Technologies <roman@ardistech.com>
   6 * This file may be distributed under the terms of the GNU General Public License.
   7 *
   8 * This file contains hfs_read_super(), some of the super_ops and
   9 * init_hfs_fs() and exit_hfs_fs().  The remaining super_ops are in
  10 * inode.c since they deal with inodes.
  11 *
  12 * Based on the minix file system code, (C) 1991, 1992 by Linus Torvalds
  13 */
  14
  15#include <linux/module.h>
  16#include <linux/blkdev.h>
  17#include <linux/mount.h>
  18#include <linux/init.h>
  19#include <linux/nls.h>
  20#include <linux/parser.h>
  21#include <linux/seq_file.h>
  22#include <linux/slab.h>
  23#include <linux/vfs.h>
  24
  25#include "hfs_fs.h"
  26#include "btree.h"
  27
  28static struct kmem_cache *hfs_inode_cachep;
  29
  30MODULE_LICENSE("GPL");
  31
  32static int hfs_sync_fs(struct super_block *sb, int wait)
  33{
  34        hfs_mdb_commit(sb);
  35        return 0;
  36}
  37
  38/*
  39 * hfs_put_super()
  40 *
  41 * This is the put_super() entry in the super_operations structure for
  42 * HFS filesystems.  The purpose is to release the resources
  43 * associated with the superblock sb.
  44 */
  45static void hfs_put_super(struct super_block *sb)
  46{
  47        cancel_delayed_work_sync(&HFS_SB(sb)->mdb_work);
  48        hfs_mdb_close(sb);
  49        /* release the MDB's resources */
  50        hfs_mdb_put(sb);
  51}
  52
  53static void flush_mdb(struct work_struct *work)
  54{
  55        struct hfs_sb_info *sbi;
  56        struct super_block *sb;
  57
  58        sbi = container_of(work, struct hfs_sb_info, mdb_work.work);
  59        sb = sbi->sb;
  60
  61        spin_lock(&sbi->work_lock);
  62        sbi->work_queued = 0;
  63        spin_unlock(&sbi->work_lock);
  64
  65        hfs_mdb_commit(sb);
  66}
  67
  68void hfs_mark_mdb_dirty(struct super_block *sb)
  69{
  70        struct hfs_sb_info *sbi = HFS_SB(sb);
  71        unsigned long delay;
  72
  73        if (sb->s_flags & MS_RDONLY)
  74                return;
  75
  76        spin_lock(&sbi->work_lock);
  77        if (!sbi->work_queued) {
  78                delay = msecs_to_jiffies(dirty_writeback_interval * 10);
  79                queue_delayed_work(system_long_wq, &sbi->mdb_work, delay);
  80                sbi->work_queued = 1;
  81        }
  82        spin_unlock(&sbi->work_lock);
  83}
  84
  85/*
  86 * hfs_statfs()
  87 *
  88 * This is the statfs() entry in the super_operations structure for
  89 * HFS filesystems.  The purpose is to return various data about the
  90 * filesystem.
  91 *
  92 * changed f_files/f_ffree to reflect the fs_ablock/free_ablocks.
  93 */
  94static int hfs_statfs(struct dentry *dentry, struct kstatfs *buf)
  95{
  96        struct super_block *sb = dentry->d_sb;
  97        u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
  98
  99        buf->f_type = HFS_SUPER_MAGIC;
 100        buf->f_bsize = sb->s_blocksize;
 101        buf->f_blocks = (u32)HFS_SB(sb)->fs_ablocks * HFS_SB(sb)->fs_div;
 102        buf->f_bfree = (u32)HFS_SB(sb)->free_ablocks * HFS_SB(sb)->fs_div;
 103        buf->f_bavail = buf->f_bfree;
 104        buf->f_files = HFS_SB(sb)->fs_ablocks;
 105        buf->f_ffree = HFS_SB(sb)->free_ablocks;
 106        buf->f_fsid.val[0] = (u32)id;
 107        buf->f_fsid.val[1] = (u32)(id >> 32);
 108        buf->f_namelen = HFS_NAMELEN;
 109
 110        return 0;
 111}
 112
 113static int hfs_remount(struct super_block *sb, int *flags, char *data)
 114{
 115        *flags |= MS_NODIRATIME;
 116        if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
 117                return 0;
 118        if (!(*flags & MS_RDONLY)) {
 119                if (!(HFS_SB(sb)->mdb->drAtrb & cpu_to_be16(HFS_SB_ATTRIB_UNMNT))) {
 120                        printk(KERN_WARNING "hfs: filesystem was not cleanly unmounted, "
 121                               "running fsck.hfs is recommended.  leaving read-only.\n");
 122                        sb->s_flags |= MS_RDONLY;
 123                        *flags |= MS_RDONLY;
 124                } else if (HFS_SB(sb)->mdb->drAtrb & cpu_to_be16(HFS_SB_ATTRIB_SLOCK)) {
 125                        printk(KERN_WARNING "hfs: filesystem is marked locked, leaving read-only.\n");
 126                        sb->s_flags |= MS_RDONLY;
 127                        *flags |= MS_RDONLY;
 128                }
 129        }
 130        return 0;
 131}
 132
 133static int hfs_show_options(struct seq_file *seq, struct dentry *root)
 134{
 135        struct hfs_sb_info *sbi = HFS_SB(root->d_sb);
 136
 137        if (sbi->s_creator != cpu_to_be32(0x3f3f3f3f))
 138                seq_printf(seq, ",creator=%.4s", (char *)&sbi->s_creator);
 139        if (sbi->s_type != cpu_to_be32(0x3f3f3f3f))
 140                seq_printf(seq, ",type=%.4s", (char *)&sbi->s_type);
 141        seq_printf(seq, ",uid=%u,gid=%u", sbi->s_uid, sbi->s_gid);
 142        if (sbi->s_file_umask != 0133)
 143                seq_printf(seq, ",file_umask=%o", sbi->s_file_umask);
 144        if (sbi->s_dir_umask != 0022)
 145                seq_printf(seq, ",dir_umask=%o", sbi->s_dir_umask);
 146        if (sbi->part >= 0)
 147                seq_printf(seq, ",part=%u", sbi->part);
 148        if (sbi->session >= 0)
 149                seq_printf(seq, ",session=%u", sbi->session);
 150        if (sbi->nls_disk)
 151                seq_printf(seq, ",codepage=%s", sbi->nls_disk->charset);
 152        if (sbi->nls_io)
 153                seq_printf(seq, ",iocharset=%s", sbi->nls_io->charset);
 154        if (sbi->s_quiet)
 155                seq_printf(seq, ",quiet");
 156        return 0;
 157}
 158
 159static struct inode *hfs_alloc_inode(struct super_block *sb)
 160{
 161        struct hfs_inode_info *i;
 162
 163        i = kmem_cache_alloc(hfs_inode_cachep, GFP_KERNEL);
 164        return i ? &i->vfs_inode : NULL;
 165}
 166
 167static void hfs_i_callback(struct rcu_head *head)
 168{
 169        struct inode *inode = container_of(head, struct inode, i_rcu);
 170        kmem_cache_free(hfs_inode_cachep, HFS_I(inode));
 171}
 172
 173static void hfs_destroy_inode(struct inode *inode)
 174{
 175        call_rcu(&inode->i_rcu, hfs_i_callback);
 176}
 177
 178static const struct super_operations hfs_super_operations = {
 179        .alloc_inode    = hfs_alloc_inode,
 180        .destroy_inode  = hfs_destroy_inode,
 181        .write_inode    = hfs_write_inode,
 182        .evict_inode    = hfs_evict_inode,
 183        .put_super      = hfs_put_super,
 184        .sync_fs        = hfs_sync_fs,
 185        .statfs         = hfs_statfs,
 186        .remount_fs     = hfs_remount,
 187        .show_options   = hfs_show_options,
 188};
 189
 190enum {
 191        opt_uid, opt_gid, opt_umask, opt_file_umask, opt_dir_umask,
 192        opt_part, opt_session, opt_type, opt_creator, opt_quiet,
 193        opt_codepage, opt_iocharset,
 194        opt_err
 195};
 196
 197static const match_table_t tokens = {
 198        { opt_uid, "uid=%u" },
 199        { opt_gid, "gid=%u" },
 200        { opt_umask, "umask=%o" },
 201        { opt_file_umask, "file_umask=%o" },
 202        { opt_dir_umask, "dir_umask=%o" },
 203        { opt_part, "part=%u" },
 204        { opt_session, "session=%u" },
 205        { opt_type, "type=%s" },
 206        { opt_creator, "creator=%s" },
 207        { opt_quiet, "quiet" },
 208        { opt_codepage, "codepage=%s" },
 209        { opt_iocharset, "iocharset=%s" },
 210        { opt_err, NULL }
 211};
 212
 213static inline int match_fourchar(substring_t *arg, u32 *result)
 214{
 215        if (arg->to - arg->from != 4)
 216                return -EINVAL;
 217        memcpy(result, arg->from, 4);
 218        return 0;
 219}
 220
 221/*
 222 * parse_options()
 223 *
 224 * adapted from linux/fs/msdos/inode.c written 1992,93 by Werner Almesberger
 225 * This function is called by hfs_read_super() to parse the mount options.
 226 */
 227static int parse_options(char *options, struct hfs_sb_info *hsb)
 228{
 229        char *p;
 230        substring_t args[MAX_OPT_ARGS];
 231        int tmp, token;
 232
 233        /* initialize the sb with defaults */
 234        hsb->s_uid = current_uid();
 235        hsb->s_gid = current_gid();
 236        hsb->s_file_umask = 0133;
 237        hsb->s_dir_umask = 0022;
 238        hsb->s_type = hsb->s_creator = cpu_to_be32(0x3f3f3f3f); /* == '????' */
 239        hsb->s_quiet = 0;
 240        hsb->part = -1;
 241        hsb->session = -1;
 242
 243        if (!options)
 244                return 1;
 245
 246        while ((p = strsep(&options, ",")) != NULL) {
 247                if (!*p)
 248                        continue;
 249
 250                token = match_token(p, tokens, args);
 251                switch (token) {
 252                case opt_uid:
 253                        if (match_int(&args[0], &tmp)) {
 254                                printk(KERN_ERR "hfs: uid requires an argument\n");
 255                                return 0;
 256                        }
 257                        hsb->s_uid = (uid_t)tmp;
 258                        break;
 259                case opt_gid:
 260                        if (match_int(&args[0], &tmp)) {
 261                                printk(KERN_ERR "hfs: gid requires an argument\n");
 262                                return 0;
 263                        }
 264                        hsb->s_gid = (gid_t)tmp;
 265                        break;
 266                case opt_umask:
 267                        if (match_octal(&args[0], &tmp)) {
 268                                printk(KERN_ERR "hfs: umask requires a value\n");
 269                                return 0;
 270                        }
 271                        hsb->s_file_umask = (umode_t)tmp;
 272                        hsb->s_dir_umask = (umode_t)tmp;
 273                        break;
 274                case opt_file_umask:
 275                        if (match_octal(&args[0], &tmp)) {
 276                                printk(KERN_ERR "hfs: file_umask requires a value\n");
 277                                return 0;
 278                        }
 279                        hsb->s_file_umask = (umode_t)tmp;
 280                        break;
 281                case opt_dir_umask:
 282                        if (match_octal(&args[0], &tmp)) {
 283                                printk(KERN_ERR "hfs: dir_umask requires a value\n");
 284                                return 0;
 285                        }
 286                        hsb->s_dir_umask = (umode_t)tmp;
 287                        break;
 288                case opt_part:
 289                        if (match_int(&args[0], &hsb->part)) {
 290                                printk(KERN_ERR "hfs: part requires an argument\n");
 291                                return 0;
 292                        }
 293                        break;
 294                case opt_session:
 295                        if (match_int(&args[0], &hsb->session)) {
 296                                printk(KERN_ERR "hfs: session requires an argument\n");
 297                                return 0;
 298                        }
 299                        break;
 300                case opt_type:
 301                        if (match_fourchar(&args[0], &hsb->s_type)) {
 302                                printk(KERN_ERR "hfs: type requires a 4 character value\n");
 303                                return 0;
 304                        }
 305                        break;
 306                case opt_creator:
 307                        if (match_fourchar(&args[0], &hsb->s_creator)) {
 308                                printk(KERN_ERR "hfs: creator requires a 4 character value\n");
 309                                return 0;
 310                        }
 311                        break;
 312                case opt_quiet:
 313                        hsb->s_quiet = 1;
 314                        break;
 315                case opt_codepage:
 316                        if (hsb->nls_disk) {
 317                                printk(KERN_ERR "hfs: unable to change codepage\n");
 318                                return 0;
 319                        }
 320                        p = match_strdup(&args[0]);
 321                        if (p)
 322                                hsb->nls_disk = load_nls(p);
 323                        if (!hsb->nls_disk) {
 324                                printk(KERN_ERR "hfs: unable to load codepage \"%s\"\n", p);
 325                                kfree(p);
 326                                return 0;
 327                        }
 328                        kfree(p);
 329                        break;
 330                case opt_iocharset:
 331                        if (hsb->nls_io) {
 332                                printk(KERN_ERR "hfs: unable to change iocharset\n");
 333                                return 0;
 334                        }
 335                        p = match_strdup(&args[0]);
 336                        if (p)
 337                                hsb->nls_io = load_nls(p);
 338                        if (!hsb->nls_io) {
 339                                printk(KERN_ERR "hfs: unable to load iocharset \"%s\"\n", p);
 340                                kfree(p);
 341                                return 0;
 342                        }
 343                        kfree(p);
 344                        break;
 345                default:
 346                        return 0;
 347                }
 348        }
 349
 350        if (hsb->nls_disk && !hsb->nls_io) {
 351                hsb->nls_io = load_nls_default();
 352                if (!hsb->nls_io) {
 353                        printk(KERN_ERR "hfs: unable to load default iocharset\n");
 354                        return 0;
 355                }
 356        }
 357        hsb->s_dir_umask &= 0777;
 358        hsb->s_file_umask &= 0577;
 359
 360        return 1;
 361}
 362
 363/*
 364 * hfs_read_super()
 365 *
 366 * This is the function that is responsible for mounting an HFS
 367 * filesystem.  It performs all the tasks necessary to get enough data
 368 * from the disk to read the root inode.  This includes parsing the
 369 * mount options, dealing with Macintosh partitions, reading the
 370 * superblock and the allocation bitmap blocks, calling
 371 * hfs_btree_init() to get the necessary data about the extents and
 372 * catalog B-trees and, finally, reading the root inode into memory.
 373 */
 374static int hfs_fill_super(struct super_block *sb, void *data, int silent)
 375{
 376        struct hfs_sb_info *sbi;
 377        struct hfs_find_data fd;
 378        hfs_cat_rec rec;
 379        struct inode *root_inode;
 380        int res;
 381
 382        sbi = kzalloc(sizeof(struct hfs_sb_info), GFP_KERNEL);
 383        if (!sbi)
 384                return -ENOMEM;
 385
 386        sbi->sb = sb;
 387        sb->s_fs_info = sbi;
 388        spin_lock_init(&sbi->work_lock);
 389        INIT_DELAYED_WORK(&sbi->mdb_work, flush_mdb);
 390
 391        res = -EINVAL;
 392        if (!parse_options((char *)data, sbi)) {
 393                printk(KERN_ERR "hfs: unable to parse mount options.\n");
 394                goto bail;
 395        }
 396
 397        sb->s_op = &hfs_super_operations;
 398        sb->s_flags |= MS_NODIRATIME;
 399        mutex_init(&sbi->bitmap_lock);
 400
 401        res = hfs_mdb_get(sb);
 402        if (res) {
 403                if (!silent)
 404                        printk(KERN_WARNING "hfs: can't find a HFS filesystem on dev %s.\n",
 405                                hfs_mdb_name(sb));
 406                res = -EINVAL;
 407                goto bail;
 408        }
 409
 410        /* try to get the root inode */
 411        hfs_find_init(HFS_SB(sb)->cat_tree, &fd);
 412        res = hfs_cat_find_brec(sb, HFS_ROOT_CNID, &fd);
 413        if (!res) {
 414                if (fd.entrylength > sizeof(rec) || fd.entrylength < 0) {
 415                        res =  -EIO;
 416                        goto bail;
 417                }
 418                hfs_bnode_read(fd.bnode, &rec, fd.entryoffset, fd.entrylength);
 419        }
 420        if (res) {
 421                hfs_find_exit(&fd);
 422                goto bail_no_root;
 423        }
 424        res = -EINVAL;
 425        root_inode = hfs_iget(sb, &fd.search_key->cat, &rec);
 426        hfs_find_exit(&fd);
 427        if (!root_inode)
 428                goto bail_no_root;
 429
 430        sb->s_d_op = &hfs_dentry_operations;
 431        res = -ENOMEM;
 432        sb->s_root = d_make_root(root_inode);
 433        if (!sb->s_root)
 434                goto bail_no_root;
 435
 436        /* everything's okay */
 437        return 0;
 438
 439bail_no_root:
 440        printk(KERN_ERR "hfs: get root inode failed.\n");
 441bail:
 442        hfs_mdb_put(sb);
 443        return res;
 444}
 445
 446static struct dentry *hfs_mount(struct file_system_type *fs_type,
 447                      int flags, const char *dev_name, void *data)
 448{
 449        return mount_bdev(fs_type, flags, dev_name, data, hfs_fill_super);
 450}
 451
 452static struct file_system_type hfs_fs_type = {
 453        .owner          = THIS_MODULE,
 454        .name           = "hfs",
 455        .mount          = hfs_mount,
 456        .kill_sb        = kill_block_super,
 457        .fs_flags       = FS_REQUIRES_DEV,
 458};
 459
 460static void hfs_init_once(void *p)
 461{
 462        struct hfs_inode_info *i = p;
 463
 464        inode_init_once(&i->vfs_inode);
 465}
 466
 467static int __init init_hfs_fs(void)
 468{
 469        int err;
 470
 471        hfs_inode_cachep = kmem_cache_create("hfs_inode_cache",
 472                sizeof(struct hfs_inode_info), 0, SLAB_HWCACHE_ALIGN,
 473                hfs_init_once);
 474        if (!hfs_inode_cachep)
 475                return -ENOMEM;
 476        err = register_filesystem(&hfs_fs_type);
 477        if (err)
 478                kmem_cache_destroy(hfs_inode_cachep);
 479        return err;
 480}
 481
 482static void __exit exit_hfs_fs(void)
 483{
 484        unregister_filesystem(&hfs_fs_type);
 485        kmem_cache_destroy(hfs_inode_cachep);
 486}
 487
 488module_init(init_hfs_fs)
 489module_exit(exit_hfs_fs)
 490
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