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",
 142                        from_kuid_munged(&init_user_ns, sbi->s_uid),
 143                        from_kgid_munged(&init_user_ns, sbi->s_gid));
 144        if (sbi->s_file_umask != 0133)
 145                seq_printf(seq, ",file_umask=%o", sbi->s_file_umask);
 146        if (sbi->s_dir_umask != 0022)
 147                seq_printf(seq, ",dir_umask=%o", sbi->s_dir_umask);
 148        if (sbi->part >= 0)
 149                seq_printf(seq, ",part=%u", sbi->part);
 150        if (sbi->session >= 0)
 151                seq_printf(seq, ",session=%u", sbi->session);
 152        if (sbi->nls_disk)
 153                seq_printf(seq, ",codepage=%s", sbi->nls_disk->charset);
 154        if (sbi->nls_io)
 155                seq_printf(seq, ",iocharset=%s", sbi->nls_io->charset);
 156        if (sbi->s_quiet)
 157                seq_printf(seq, ",quiet");
 158        return 0;
 159}
 160
 161static struct inode *hfs_alloc_inode(struct super_block *sb)
 162{
 163        struct hfs_inode_info *i;
 164
 165        i = kmem_cache_alloc(hfs_inode_cachep, GFP_KERNEL);
 166        return i ? &i->vfs_inode : NULL;
 167}
 168
 169static void hfs_i_callback(struct rcu_head *head)
 170{
 171        struct inode *inode = container_of(head, struct inode, i_rcu);
 172        kmem_cache_free(hfs_inode_cachep, HFS_I(inode));
 173}
 174
 175static void hfs_destroy_inode(struct inode *inode)
 176{
 177        call_rcu(&inode->i_rcu, hfs_i_callback);
 178}
 179
 180static const struct super_operations hfs_super_operations = {
 181        .alloc_inode    = hfs_alloc_inode,
 182        .destroy_inode  = hfs_destroy_inode,
 183        .write_inode    = hfs_write_inode,
 184        .evict_inode    = hfs_evict_inode,
 185        .put_super      = hfs_put_super,
 186        .sync_fs        = hfs_sync_fs,
 187        .statfs         = hfs_statfs,
 188        .remount_fs     = hfs_remount,
 189        .show_options   = hfs_show_options,
 190};
 191
 192enum {
 193        opt_uid, opt_gid, opt_umask, opt_file_umask, opt_dir_umask,
 194        opt_part, opt_session, opt_type, opt_creator, opt_quiet,
 195        opt_codepage, opt_iocharset,
 196        opt_err
 197};
 198
 199static const match_table_t tokens = {
 200        { opt_uid, "uid=%u" },
 201        { opt_gid, "gid=%u" },
 202        { opt_umask, "umask=%o" },
 203        { opt_file_umask, "file_umask=%o" },
 204        { opt_dir_umask, "dir_umask=%o" },
 205        { opt_part, "part=%u" },
 206        { opt_session, "session=%u" },
 207        { opt_type, "type=%s" },
 208        { opt_creator, "creator=%s" },
 209        { opt_quiet, "quiet" },
 210        { opt_codepage, "codepage=%s" },
 211        { opt_iocharset, "iocharset=%s" },
 212        { opt_err, NULL }
 213};
 214
 215static inline int match_fourchar(substring_t *arg, u32 *result)
 216{
 217        if (arg->to - arg->from != 4)
 218                return -EINVAL;
 219        memcpy(result, arg->from, 4);
 220        return 0;
 221}
 222
 223/*
 224 * parse_options()
 225 *
 226 * adapted from linux/fs/msdos/inode.c written 1992,93 by Werner Almesberger
 227 * This function is called by hfs_read_super() to parse the mount options.
 228 */
 229static int parse_options(char *options, struct hfs_sb_info *hsb)
 230{
 231        char *p;
 232        substring_t args[MAX_OPT_ARGS];
 233        int tmp, token;
 234
 235        /* initialize the sb with defaults */
 236        hsb->s_uid = current_uid();
 237        hsb->s_gid = current_gid();
 238        hsb->s_file_umask = 0133;
 239        hsb->s_dir_umask = 0022;
 240        hsb->s_type = hsb->s_creator = cpu_to_be32(0x3f3f3f3f); /* == '????' */
 241        hsb->s_quiet = 0;
 242        hsb->part = -1;
 243        hsb->session = -1;
 244
 245        if (!options)
 246                return 1;
 247
 248        while ((p = strsep(&options, ",")) != NULL) {
 249                if (!*p)
 250                        continue;
 251
 252                token = match_token(p, tokens, args);
 253                switch (token) {
 254                case opt_uid:
 255                        if (match_int(&args[0], &tmp)) {
 256                                printk(KERN_ERR "hfs: uid requires an argument\n");
 257                                return 0;
 258                        }
 259                        hsb->s_uid = make_kuid(current_user_ns(), (uid_t)tmp);
 260                        if (!uid_valid(hsb->s_uid)) {
 261                                printk(KERN_ERR "hfs: invalid uid %d\n", tmp);
 262                                return 0;
 263                        }
 264                        break;
 265                case opt_gid:
 266                        if (match_int(&args[0], &tmp)) {
 267                                printk(KERN_ERR "hfs: gid requires an argument\n");
 268                                return 0;
 269                        }
 270                        hsb->s_gid = make_kgid(current_user_ns(), (gid_t)tmp);
 271                        if (!gid_valid(hsb->s_gid)) {
 272                                printk(KERN_ERR "hfs: invalid gid %d\n", tmp);
 273                                return 0;
 274                        }
 275                        break;
 276                case opt_umask:
 277                        if (match_octal(&args[0], &tmp)) {
 278                                printk(KERN_ERR "hfs: umask requires a value\n");
 279                                return 0;
 280                        }
 281                        hsb->s_file_umask = (umode_t)tmp;
 282                        hsb->s_dir_umask = (umode_t)tmp;
 283                        break;
 284                case opt_file_umask:
 285                        if (match_octal(&args[0], &tmp)) {
 286                                printk(KERN_ERR "hfs: file_umask requires a value\n");
 287                                return 0;
 288                        }
 289                        hsb->s_file_umask = (umode_t)tmp;
 290                        break;
 291                case opt_dir_umask:
 292                        if (match_octal(&args[0], &tmp)) {
 293                                printk(KERN_ERR "hfs: dir_umask requires a value\n");
 294                                return 0;
 295                        }
 296                        hsb->s_dir_umask = (umode_t)tmp;
 297                        break;
 298                case opt_part:
 299                        if (match_int(&args[0], &hsb->part)) {
 300                                printk(KERN_ERR "hfs: part requires an argument\n");
 301                                return 0;
 302                        }
 303                        break;
 304                case opt_session:
 305                        if (match_int(&args[0], &hsb->session)) {
 306                                printk(KERN_ERR "hfs: session requires an argument\n");
 307                                return 0;
 308                        }
 309                        break;
 310                case opt_type:
 311                        if (match_fourchar(&args[0], &hsb->s_type)) {
 312                                printk(KERN_ERR "hfs: type requires a 4 character value\n");
 313                                return 0;
 314                        }
 315                        break;
 316                case opt_creator:
 317                        if (match_fourchar(&args[0], &hsb->s_creator)) {
 318                                printk(KERN_ERR "hfs: creator requires a 4 character value\n");
 319                                return 0;
 320                        }
 321                        break;
 322                case opt_quiet:
 323                        hsb->s_quiet = 1;
 324                        break;
 325                case opt_codepage:
 326                        if (hsb->nls_disk) {
 327                                printk(KERN_ERR "hfs: unable to change codepage\n");
 328                                return 0;
 329                        }
 330                        p = match_strdup(&args[0]);
 331                        if (p)
 332                                hsb->nls_disk = load_nls(p);
 333                        if (!hsb->nls_disk) {
 334                                printk(KERN_ERR "hfs: unable to load codepage \"%s\"\n", p);
 335                                kfree(p);
 336                                return 0;
 337                        }
 338                        kfree(p);
 339                        break;
 340                case opt_iocharset:
 341                        if (hsb->nls_io) {
 342                                printk(KERN_ERR "hfs: unable to change iocharset\n");
 343                                return 0;
 344                        }
 345                        p = match_strdup(&args[0]);
 346                        if (p)
 347                                hsb->nls_io = load_nls(p);
 348                        if (!hsb->nls_io) {
 349                                printk(KERN_ERR "hfs: unable to load iocharset \"%s\"\n", p);
 350                                kfree(p);
 351                                return 0;
 352                        }
 353                        kfree(p);
 354                        break;
 355                default:
 356                        return 0;
 357                }
 358        }
 359
 360        if (hsb->nls_disk && !hsb->nls_io) {
 361                hsb->nls_io = load_nls_default();
 362                if (!hsb->nls_io) {
 363                        printk(KERN_ERR "hfs: unable to load default iocharset\n");
 364                        return 0;
 365                }
 366        }
 367        hsb->s_dir_umask &= 0777;
 368        hsb->s_file_umask &= 0577;
 369
 370        return 1;
 371}
 372
 373/*
 374 * hfs_read_super()
 375 *
 376 * This is the function that is responsible for mounting an HFS
 377 * filesystem.  It performs all the tasks necessary to get enough data
 378 * from the disk to read the root inode.  This includes parsing the
 379 * mount options, dealing with Macintosh partitions, reading the
 380 * superblock and the allocation bitmap blocks, calling
 381 * hfs_btree_init() to get the necessary data about the extents and
 382 * catalog B-trees and, finally, reading the root inode into memory.
 383 */
 384static int hfs_fill_super(struct super_block *sb, void *data, int silent)
 385{
 386        struct hfs_sb_info *sbi;
 387        struct hfs_find_data fd;
 388        hfs_cat_rec rec;
 389        struct inode *root_inode;
 390        int res;
 391
 392        sbi = kzalloc(sizeof(struct hfs_sb_info), GFP_KERNEL);
 393        if (!sbi)
 394                return -ENOMEM;
 395
 396        sbi->sb = sb;
 397        sb->s_fs_info = sbi;
 398        spin_lock_init(&sbi->work_lock);
 399        INIT_DELAYED_WORK(&sbi->mdb_work, flush_mdb);
 400
 401        res = -EINVAL;
 402        if (!parse_options((char *)data, sbi)) {
 403                printk(KERN_ERR "hfs: unable to parse mount options.\n");
 404                goto bail;
 405        }
 406
 407        sb->s_op = &hfs_super_operations;
 408        sb->s_flags |= MS_NODIRATIME;
 409        mutex_init(&sbi->bitmap_lock);
 410
 411        res = hfs_mdb_get(sb);
 412        if (res) {
 413                if (!silent)
 414                        printk(KERN_WARNING "hfs: can't find a HFS filesystem on dev %s.\n",
 415                                hfs_mdb_name(sb));
 416                res = -EINVAL;
 417                goto bail;
 418        }
 419
 420        /* try to get the root inode */
 421        hfs_find_init(HFS_SB(sb)->cat_tree, &fd);
 422        res = hfs_cat_find_brec(sb, HFS_ROOT_CNID, &fd);
 423        if (!res) {
 424                if (fd.entrylength > sizeof(rec) || fd.entrylength < 0) {
 425                        res =  -EIO;
 426                        goto bail;
 427                }
 428                hfs_bnode_read(fd.bnode, &rec, fd.entryoffset, fd.entrylength);
 429        }
 430        if (res) {
 431                hfs_find_exit(&fd);
 432                goto bail_no_root;
 433        }
 434        res = -EINVAL;
 435        root_inode = hfs_iget(sb, &fd.search_key->cat, &rec);
 436        hfs_find_exit(&fd);
 437        if (!root_inode)
 438                goto bail_no_root;
 439
 440        sb->s_d_op = &hfs_dentry_operations;
 441        res = -ENOMEM;
 442        sb->s_root = d_make_root(root_inode);
 443        if (!sb->s_root)
 444                goto bail_no_root;
 445
 446        /* everything's okay */
 447        return 0;
 448
 449bail_no_root:
 450        printk(KERN_ERR "hfs: get root inode failed.\n");
 451bail:
 452        hfs_mdb_put(sb);
 453        return res;
 454}
 455
 456static struct dentry *hfs_mount(struct file_system_type *fs_type,
 457                      int flags, const char *dev_name, void *data)
 458{
 459        return mount_bdev(fs_type, flags, dev_name, data, hfs_fill_super);
 460}
 461
 462static struct file_system_type hfs_fs_type = {
 463        .owner          = THIS_MODULE,
 464        .name           = "hfs",
 465        .mount          = hfs_mount,
 466        .kill_sb        = kill_block_super,
 467        .fs_flags       = FS_REQUIRES_DEV,
 468};
 469
 470static void hfs_init_once(void *p)
 471{
 472        struct hfs_inode_info *i = p;
 473
 474        inode_init_once(&i->vfs_inode);
 475}
 476
 477static int __init init_hfs_fs(void)
 478{
 479        int err;
 480
 481        hfs_inode_cachep = kmem_cache_create("hfs_inode_cache",
 482                sizeof(struct hfs_inode_info), 0, SLAB_HWCACHE_ALIGN,
 483                hfs_init_once);
 484        if (!hfs_inode_cachep)
 485                return -ENOMEM;
 486        err = register_filesystem(&hfs_fs_type);
 487        if (err)
 488                kmem_cache_destroy(hfs_inode_cachep);
 489        return err;
 490}
 491
 492static void __exit exit_hfs_fs(void)
 493{
 494        unregister_filesystem(&hfs_fs_type);
 495
 496        /*
 497         * Make sure all delayed rcu free inodes are flushed before we
 498         * destroy cache.
 499         */
 500        rcu_barrier();
 501        kmem_cache_destroy(hfs_inode_cachep);
 502}
 503
 504module_init(init_hfs_fs)
 505module_exit(exit_hfs_fs)
 506
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