linux/fs/hfs/super.c
<<
>>
Prefs
   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                        pr_warn("filesystem was not cleanly unmounted, running fsck.hfs is recommended.  leaving read-only.\n");
 121                        sb->s_flags |= MS_RDONLY;
 122                        *flags |= MS_RDONLY;
 123                } else if (HFS_SB(sb)->mdb->drAtrb & cpu_to_be16(HFS_SB_ATTRIB_SLOCK)) {
 124                        pr_warn("filesystem is marked locked, leaving read-only.\n");
 125                        sb->s_flags |= MS_RDONLY;
 126                        *flags |= MS_RDONLY;
 127                }
 128        }
 129        return 0;
 130}
 131
 132static int hfs_show_options(struct seq_file *seq, struct dentry *root)
 133{
 134        struct hfs_sb_info *sbi = HFS_SB(root->d_sb);
 135
 136        if (sbi->s_creator != cpu_to_be32(0x3f3f3f3f))
 137                seq_printf(seq, ",creator=%.4s", (char *)&sbi->s_creator);
 138        if (sbi->s_type != cpu_to_be32(0x3f3f3f3f))
 139                seq_printf(seq, ",type=%.4s", (char *)&sbi->s_type);
 140        seq_printf(seq, ",uid=%u,gid=%u",
 141                        from_kuid_munged(&init_user_ns, sbi->s_uid),
 142                        from_kgid_munged(&init_user_ns, sbi->s_gid));
 143        if (sbi->s_file_umask != 0133)
 144                seq_printf(seq, ",file_umask=%o", sbi->s_file_umask);
 145        if (sbi->s_dir_umask != 0022)
 146                seq_printf(seq, ",dir_umask=%o", sbi->s_dir_umask);
 147        if (sbi->part >= 0)
 148                seq_printf(seq, ",part=%u", sbi->part);
 149        if (sbi->session >= 0)
 150                seq_printf(seq, ",session=%u", sbi->session);
 151        if (sbi->nls_disk)
 152                seq_printf(seq, ",codepage=%s", sbi->nls_disk->charset);
 153        if (sbi->nls_io)
 154                seq_printf(seq, ",iocharset=%s", sbi->nls_io->charset);
 155        if (sbi->s_quiet)
 156                seq_printf(seq, ",quiet");
 157        return 0;
 158}
 159
 160static struct inode *hfs_alloc_inode(struct super_block *sb)
 161{
 162        struct hfs_inode_info *i;
 163
 164        i = kmem_cache_alloc(hfs_inode_cachep, GFP_KERNEL);
 165        return i ? &i->vfs_inode : NULL;
 166}
 167
 168static void hfs_i_callback(struct rcu_head *head)
 169{
 170        struct inode *inode = container_of(head, struct inode, i_rcu);
 171        kmem_cache_free(hfs_inode_cachep, HFS_I(inode));
 172}
 173
 174static void hfs_destroy_inode(struct inode *inode)
 175{
 176        call_rcu(&inode->i_rcu, hfs_i_callback);
 177}
 178
 179static const struct super_operations hfs_super_operations = {
 180        .alloc_inode    = hfs_alloc_inode,
 181        .destroy_inode  = hfs_destroy_inode,
 182        .write_inode    = hfs_write_inode,
 183        .evict_inode    = hfs_evict_inode,
 184        .put_super      = hfs_put_super,
 185        .sync_fs        = hfs_sync_fs,
 186        .statfs         = hfs_statfs,
 187        .remount_fs     = hfs_remount,
 188        .show_options   = hfs_show_options,
 189};
 190
 191enum {
 192        opt_uid, opt_gid, opt_umask, opt_file_umask, opt_dir_umask,
 193        opt_part, opt_session, opt_type, opt_creator, opt_quiet,
 194        opt_codepage, opt_iocharset,
 195        opt_err
 196};
 197
 198static const match_table_t tokens = {
 199        { opt_uid, "uid=%u" },
 200        { opt_gid, "gid=%u" },
 201        { opt_umask, "umask=%o" },
 202        { opt_file_umask, "file_umask=%o" },
 203        { opt_dir_umask, "dir_umask=%o" },
 204        { opt_part, "part=%u" },
 205        { opt_session, "session=%u" },
 206        { opt_type, "type=%s" },
 207        { opt_creator, "creator=%s" },
 208        { opt_quiet, "quiet" },
 209        { opt_codepage, "codepage=%s" },
 210        { opt_iocharset, "iocharset=%s" },
 211        { opt_err, NULL }
 212};
 213
 214static inline int match_fourchar(substring_t *arg, u32 *result)
 215{
 216        if (arg->to - arg->from != 4)
 217                return -EINVAL;
 218        memcpy(result, arg->from, 4);
 219        return 0;
 220}
 221
 222/*
 223 * parse_options()
 224 *
 225 * adapted from linux/fs/msdos/inode.c written 1992,93 by Werner Almesberger
 226 * This function is called by hfs_read_super() to parse the mount options.
 227 */
 228static int parse_options(char *options, struct hfs_sb_info *hsb)
 229{
 230        char *p;
 231        substring_t args[MAX_OPT_ARGS];
 232        int tmp, token;
 233
 234        /* initialize the sb with defaults */
 235        hsb->s_uid = current_uid();
 236        hsb->s_gid = current_gid();
 237        hsb->s_file_umask = 0133;
 238        hsb->s_dir_umask = 0022;
 239        hsb->s_type = hsb->s_creator = cpu_to_be32(0x3f3f3f3f); /* == '????' */
 240        hsb->s_quiet = 0;
 241        hsb->part = -1;
 242        hsb->session = -1;
 243
 244        if (!options)
 245                return 1;
 246
 247        while ((p = strsep(&options, ",")) != NULL) {
 248                if (!*p)
 249                        continue;
 250
 251                token = match_token(p, tokens, args);
 252                switch (token) {
 253                case opt_uid:
 254                        if (match_int(&args[0], &tmp)) {
 255                                pr_err("uid requires an argument\n");
 256                                return 0;
 257                        }
 258                        hsb->s_uid = make_kuid(current_user_ns(), (uid_t)tmp);
 259                        if (!uid_valid(hsb->s_uid)) {
 260                                pr_err("invalid uid %d\n", tmp);
 261                                return 0;
 262                        }
 263                        break;
 264                case opt_gid:
 265                        if (match_int(&args[0], &tmp)) {
 266                                pr_err("gid requires an argument\n");
 267                                return 0;
 268                        }
 269                        hsb->s_gid = make_kgid(current_user_ns(), (gid_t)tmp);
 270                        if (!gid_valid(hsb->s_gid)) {
 271                                pr_err("invalid gid %d\n", tmp);
 272                                return 0;
 273                        }
 274                        break;
 275                case opt_umask:
 276                        if (match_octal(&args[0], &tmp)) {
 277                                pr_err("umask requires a value\n");
 278                                return 0;
 279                        }
 280                        hsb->s_file_umask = (umode_t)tmp;
 281                        hsb->s_dir_umask = (umode_t)tmp;
 282                        break;
 283                case opt_file_umask:
 284                        if (match_octal(&args[0], &tmp)) {
 285                                pr_err("file_umask requires a value\n");
 286                                return 0;
 287                        }
 288                        hsb->s_file_umask = (umode_t)tmp;
 289                        break;
 290                case opt_dir_umask:
 291                        if (match_octal(&args[0], &tmp)) {
 292                                pr_err("dir_umask requires a value\n");
 293                                return 0;
 294                        }
 295                        hsb->s_dir_umask = (umode_t)tmp;
 296                        break;
 297                case opt_part:
 298                        if (match_int(&args[0], &hsb->part)) {
 299                                pr_err("part requires an argument\n");
 300                                return 0;
 301                        }
 302                        break;
 303                case opt_session:
 304                        if (match_int(&args[0], &hsb->session)) {
 305                                pr_err("session requires an argument\n");
 306                                return 0;
 307                        }
 308                        break;
 309                case opt_type:
 310                        if (match_fourchar(&args[0], &hsb->s_type)) {
 311                                pr_err("type requires a 4 character value\n");
 312                                return 0;
 313                        }
 314                        break;
 315                case opt_creator:
 316                        if (match_fourchar(&args[0], &hsb->s_creator)) {
 317                                pr_err("creator requires a 4 character value\n");
 318                                return 0;
 319                        }
 320                        break;
 321                case opt_quiet:
 322                        hsb->s_quiet = 1;
 323                        break;
 324                case opt_codepage:
 325                        if (hsb->nls_disk) {
 326                                pr_err("unable to change codepage\n");
 327                                return 0;
 328                        }
 329                        p = match_strdup(&args[0]);
 330                        if (p)
 331                                hsb->nls_disk = load_nls(p);
 332                        if (!hsb->nls_disk) {
 333                                pr_err("unable to load codepage \"%s\"\n", p);
 334                                kfree(p);
 335                                return 0;
 336                        }
 337                        kfree(p);
 338                        break;
 339                case opt_iocharset:
 340                        if (hsb->nls_io) {
 341                                pr_err("unable to change iocharset\n");
 342                                return 0;
 343                        }
 344                        p = match_strdup(&args[0]);
 345                        if (p)
 346                                hsb->nls_io = load_nls(p);
 347                        if (!hsb->nls_io) {
 348                                pr_err("unable to load iocharset \"%s\"\n", p);
 349                                kfree(p);
 350                                return 0;
 351                        }
 352                        kfree(p);
 353                        break;
 354                default:
 355                        return 0;
 356                }
 357        }
 358
 359        if (hsb->nls_disk && !hsb->nls_io) {
 360                hsb->nls_io = load_nls_default();
 361                if (!hsb->nls_io) {
 362                        pr_err("unable to load default iocharset\n");
 363                        return 0;
 364                }
 365        }
 366        hsb->s_dir_umask &= 0777;
 367        hsb->s_file_umask &= 0577;
 368
 369        return 1;
 370}
 371
 372/*
 373 * hfs_read_super()
 374 *
 375 * This is the function that is responsible for mounting an HFS
 376 * filesystem.  It performs all the tasks necessary to get enough data
 377 * from the disk to read the root inode.  This includes parsing the
 378 * mount options, dealing with Macintosh partitions, reading the
 379 * superblock and the allocation bitmap blocks, calling
 380 * hfs_btree_init() to get the necessary data about the extents and
 381 * catalog B-trees and, finally, reading the root inode into memory.
 382 */
 383static int hfs_fill_super(struct super_block *sb, void *data, int silent)
 384{
 385        struct hfs_sb_info *sbi;
 386        struct hfs_find_data fd;
 387        hfs_cat_rec rec;
 388        struct inode *root_inode;
 389        int res;
 390
 391        sbi = kzalloc(sizeof(struct hfs_sb_info), GFP_KERNEL);
 392        if (!sbi)
 393                return -ENOMEM;
 394
 395        sbi->sb = sb;
 396        sb->s_fs_info = sbi;
 397        spin_lock_init(&sbi->work_lock);
 398        INIT_DELAYED_WORK(&sbi->mdb_work, flush_mdb);
 399
 400        res = -EINVAL;
 401        if (!parse_options((char *)data, sbi)) {
 402                pr_err("unable to parse mount options\n");
 403                goto bail;
 404        }
 405
 406        sb->s_op = &hfs_super_operations;
 407        sb->s_flags |= MS_NODIRATIME;
 408        mutex_init(&sbi->bitmap_lock);
 409
 410        res = hfs_mdb_get(sb);
 411        if (res) {
 412                if (!silent)
 413                        pr_warn("can't find a HFS filesystem on dev %s\n",
 414                                hfs_mdb_name(sb));
 415                res = -EINVAL;
 416                goto bail;
 417        }
 418
 419        /* try to get the root inode */
 420        res = hfs_find_init(HFS_SB(sb)->cat_tree, &fd);
 421        if (res)
 422                goto bail_no_root;
 423        res = hfs_cat_find_brec(sb, HFS_ROOT_CNID, &fd);
 424        if (!res) {
 425                if (fd.entrylength > sizeof(rec) || fd.entrylength < 0) {
 426                        res =  -EIO;
 427                        goto bail;
 428                }
 429                hfs_bnode_read(fd.bnode, &rec, fd.entryoffset, fd.entrylength);
 430        }
 431        if (res) {
 432                hfs_find_exit(&fd);
 433                goto bail_no_root;
 434        }
 435        res = -EINVAL;
 436        root_inode = hfs_iget(sb, &fd.search_key->cat, &rec);
 437        hfs_find_exit(&fd);
 438        if (!root_inode)
 439                goto bail_no_root;
 440
 441        sb->s_d_op = &hfs_dentry_operations;
 442        res = -ENOMEM;
 443        sb->s_root = d_make_root(root_inode);
 444        if (!sb->s_root)
 445                goto bail_no_root;
 446
 447        /* everything's okay */
 448        return 0;
 449
 450bail_no_root:
 451        pr_err("get root inode failed\n");
 452bail:
 453        hfs_mdb_put(sb);
 454        return res;
 455}
 456
 457static struct dentry *hfs_mount(struct file_system_type *fs_type,
 458                      int flags, const char *dev_name, void *data)
 459{
 460        return mount_bdev(fs_type, flags, dev_name, data, hfs_fill_super);
 461}
 462
 463static struct file_system_type hfs_fs_type = {
 464        .owner          = THIS_MODULE,
 465        .name           = "hfs",
 466        .mount          = hfs_mount,
 467        .kill_sb        = kill_block_super,
 468        .fs_flags       = FS_REQUIRES_DEV,
 469};
 470MODULE_ALIAS_FS("hfs");
 471
 472static void hfs_init_once(void *p)
 473{
 474        struct hfs_inode_info *i = p;
 475
 476        inode_init_once(&i->vfs_inode);
 477}
 478
 479static int __init init_hfs_fs(void)
 480{
 481        int err;
 482
 483        hfs_inode_cachep = kmem_cache_create("hfs_inode_cache",
 484                sizeof(struct hfs_inode_info), 0, SLAB_HWCACHE_ALIGN,
 485                hfs_init_once);
 486        if (!hfs_inode_cachep)
 487                return -ENOMEM;
 488        err = register_filesystem(&hfs_fs_type);
 489        if (err)
 490                kmem_cache_destroy(hfs_inode_cachep);
 491        return err;
 492}
 493
 494static void __exit exit_hfs_fs(void)
 495{
 496        unregister_filesystem(&hfs_fs_type);
 497
 498        /*
 499         * Make sure all delayed rcu free inodes are flushed before we
 500         * destroy cache.
 501         */
 502        rcu_barrier();
 503        kmem_cache_destroy(hfs_inode_cachep);
 504}
 505
 506module_init(init_hfs_fs)
 507module_exit(exit_hfs_fs)
 508
lxr.linux.no kindly hosted by Redpill Linpro AS, provider of Linux consulting and operations services since 1995.