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/backing-dev.h>
  18#include <linux/mount.h>
  19#include <linux/init.h>
  20#include <linux/nls.h>
  21#include <linux/parser.h>
  22#include <linux/seq_file.h>
  23#include <linux/slab.h>
  24#include <linux/vfs.h>
  25
  26#include "hfs_fs.h"
  27#include "btree.h"
  28
  29static struct kmem_cache *hfs_inode_cachep;
  30
  31MODULE_LICENSE("GPL");
  32
  33static int hfs_sync_fs(struct super_block *sb, int wait)
  34{
  35        hfs_mdb_commit(sb);
  36        return 0;
  37}
  38
  39/*
  40 * hfs_put_super()
  41 *
  42 * This is the put_super() entry in the super_operations structure for
  43 * HFS filesystems.  The purpose is to release the resources
  44 * associated with the superblock sb.
  45 */
  46static void hfs_put_super(struct super_block *sb)
  47{
  48        cancel_delayed_work_sync(&HFS_SB(sb)->mdb_work);
  49        hfs_mdb_close(sb);
  50        /* release the MDB's resources */
  51        hfs_mdb_put(sb);
  52}
  53
  54static void flush_mdb(struct work_struct *work)
  55{
  56        struct hfs_sb_info *sbi;
  57        struct super_block *sb;
  58
  59        sbi = container_of(work, struct hfs_sb_info, mdb_work.work);
  60        sb = sbi->sb;
  61
  62        spin_lock(&sbi->work_lock);
  63        sbi->work_queued = 0;
  64        spin_unlock(&sbi->work_lock);
  65
  66        hfs_mdb_commit(sb);
  67}
  68
  69void hfs_mark_mdb_dirty(struct super_block *sb)
  70{
  71        struct hfs_sb_info *sbi = HFS_SB(sb);
  72        unsigned long delay;
  73
  74        if (sb->s_flags & MS_RDONLY)
  75                return;
  76
  77        spin_lock(&sbi->work_lock);
  78        if (!sbi->work_queued) {
  79                delay = msecs_to_jiffies(dirty_writeback_interval * 10);
  80                queue_delayed_work(system_long_wq, &sbi->mdb_work, delay);
  81                sbi->work_queued = 1;
  82        }
  83        spin_unlock(&sbi->work_lock);
  84}
  85
  86/*
  87 * hfs_statfs()
  88 *
  89 * This is the statfs() entry in the super_operations structure for
  90 * HFS filesystems.  The purpose is to return various data about the
  91 * filesystem.
  92 *
  93 * changed f_files/f_ffree to reflect the fs_ablock/free_ablocks.
  94 */
  95static int hfs_statfs(struct dentry *dentry, struct kstatfs *buf)
  96{
  97        struct super_block *sb = dentry->d_sb;
  98        u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
  99
 100        buf->f_type = HFS_SUPER_MAGIC;
 101        buf->f_bsize = sb->s_blocksize;
 102        buf->f_blocks = (u32)HFS_SB(sb)->fs_ablocks * HFS_SB(sb)->fs_div;
 103        buf->f_bfree = (u32)HFS_SB(sb)->free_ablocks * HFS_SB(sb)->fs_div;
 104        buf->f_bavail = buf->f_bfree;
 105        buf->f_files = HFS_SB(sb)->fs_ablocks;
 106        buf->f_ffree = HFS_SB(sb)->free_ablocks;
 107        buf->f_fsid.val[0] = (u32)id;
 108        buf->f_fsid.val[1] = (u32)(id >> 32);
 109        buf->f_namelen = HFS_NAMELEN;
 110
 111        return 0;
 112}
 113
 114static int hfs_remount(struct super_block *sb, int *flags, char *data)
 115{
 116        sync_filesystem(sb);
 117        *flags |= MS_NODIRATIME;
 118        if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
 119                return 0;
 120        if (!(*flags & MS_RDONLY)) {
 121                if (!(HFS_SB(sb)->mdb->drAtrb & cpu_to_be16(HFS_SB_ATTRIB_UNMNT))) {
 122                        pr_warn("filesystem was not cleanly unmounted, running fsck.hfs is recommended.  leaving read-only.\n");
 123                        sb->s_flags |= MS_RDONLY;
 124                        *flags |= MS_RDONLY;
 125                } else if (HFS_SB(sb)->mdb->drAtrb & cpu_to_be16(HFS_SB_ATTRIB_SLOCK)) {
 126                        pr_warn("filesystem is marked locked, leaving read-only.\n");
 127                        sb->s_flags |= MS_RDONLY;
 128                        *flags |= MS_RDONLY;
 129                }
 130        }
 131        return 0;
 132}
 133
 134static int hfs_show_options(struct seq_file *seq, struct dentry *root)
 135{
 136        struct hfs_sb_info *sbi = HFS_SB(root->d_sb);
 137
 138        if (sbi->s_creator != cpu_to_be32(0x3f3f3f3f))
 139                seq_show_option_n(seq, "creator", (char *)&sbi->s_creator, 4);
 140        if (sbi->s_type != cpu_to_be32(0x3f3f3f3f))
 141                seq_show_option_n(seq, "type", (char *)&sbi->s_type, 4);
 142        seq_printf(seq, ",uid=%u,gid=%u",
 143                        from_kuid_munged(&init_user_ns, sbi->s_uid),
 144                        from_kgid_munged(&init_user_ns, sbi->s_gid));
 145        if (sbi->s_file_umask != 0133)
 146                seq_printf(seq, ",file_umask=%o", sbi->s_file_umask);
 147        if (sbi->s_dir_umask != 0022)
 148                seq_printf(seq, ",dir_umask=%o", sbi->s_dir_umask);
 149        if (sbi->part >= 0)
 150                seq_printf(seq, ",part=%u", sbi->part);
 151        if (sbi->session >= 0)
 152                seq_printf(seq, ",session=%u", sbi->session);
 153        if (sbi->nls_disk)
 154                seq_printf(seq, ",codepage=%s", sbi->nls_disk->charset);
 155        if (sbi->nls_io)
 156                seq_printf(seq, ",iocharset=%s", sbi->nls_io->charset);
 157        if (sbi->s_quiet)
 158                seq_printf(seq, ",quiet");
 159        return 0;
 160}
 161
 162static struct inode *hfs_alloc_inode(struct super_block *sb)
 163{
 164        struct hfs_inode_info *i;
 165
 166        i = kmem_cache_alloc(hfs_inode_cachep, GFP_KERNEL);
 167        return i ? &i->vfs_inode : NULL;
 168}
 169
 170static void hfs_i_callback(struct rcu_head *head)
 171{
 172        struct inode *inode = container_of(head, struct inode, i_rcu);
 173        kmem_cache_free(hfs_inode_cachep, HFS_I(inode));
 174}
 175
 176static void hfs_destroy_inode(struct inode *inode)
 177{
 178        call_rcu(&inode->i_rcu, hfs_i_callback);
 179}
 180
 181static const struct super_operations hfs_super_operations = {
 182        .alloc_inode    = hfs_alloc_inode,
 183        .destroy_inode  = hfs_destroy_inode,
 184        .write_inode    = hfs_write_inode,
 185        .evict_inode    = hfs_evict_inode,
 186        .put_super      = hfs_put_super,
 187        .sync_fs        = hfs_sync_fs,
 188        .statfs         = hfs_statfs,
 189        .remount_fs     = hfs_remount,
 190        .show_options   = hfs_show_options,
 191};
 192
 193enum {
 194        opt_uid, opt_gid, opt_umask, opt_file_umask, opt_dir_umask,
 195        opt_part, opt_session, opt_type, opt_creator, opt_quiet,
 196        opt_codepage, opt_iocharset,
 197        opt_err
 198};
 199
 200static const match_table_t tokens = {
 201        { opt_uid, "uid=%u" },
 202        { opt_gid, "gid=%u" },
 203        { opt_umask, "umask=%o" },
 204        { opt_file_umask, "file_umask=%o" },
 205        { opt_dir_umask, "dir_umask=%o" },
 206        { opt_part, "part=%u" },
 207        { opt_session, "session=%u" },
 208        { opt_type, "type=%s" },
 209        { opt_creator, "creator=%s" },
 210        { opt_quiet, "quiet" },
 211        { opt_codepage, "codepage=%s" },
 212        { opt_iocharset, "iocharset=%s" },
 213        { opt_err, NULL }
 214};
 215
 216static inline int match_fourchar(substring_t *arg, u32 *result)
 217{
 218        if (arg->to - arg->from != 4)
 219                return -EINVAL;
 220        memcpy(result, arg->from, 4);
 221        return 0;
 222}
 223
 224/*
 225 * parse_options()
 226 *
 227 * adapted from linux/fs/msdos/inode.c written 1992,93 by Werner Almesberger
 228 * This function is called by hfs_read_super() to parse the mount options.
 229 */
 230static int parse_options(char *options, struct hfs_sb_info *hsb)
 231{
 232        char *p;
 233        substring_t args[MAX_OPT_ARGS];
 234        int tmp, token;
 235
 236        /* initialize the sb with defaults */
 237        hsb->s_uid = current_uid();
 238        hsb->s_gid = current_gid();
 239        hsb->s_file_umask = 0133;
 240        hsb->s_dir_umask = 0022;
 241        hsb->s_type = hsb->s_creator = cpu_to_be32(0x3f3f3f3f); /* == '????' */
 242        hsb->s_quiet = 0;
 243        hsb->part = -1;
 244        hsb->session = -1;
 245
 246        if (!options)
 247                return 1;
 248
 249        while ((p = strsep(&options, ",")) != NULL) {
 250                if (!*p)
 251                        continue;
 252
 253                token = match_token(p, tokens, args);
 254                switch (token) {
 255                case opt_uid:
 256                        if (match_int(&args[0], &tmp)) {
 257                                pr_err("uid requires an argument\n");
 258                                return 0;
 259                        }
 260                        hsb->s_uid = make_kuid(current_user_ns(), (uid_t)tmp);
 261                        if (!uid_valid(hsb->s_uid)) {
 262                                pr_err("invalid uid %d\n", tmp);
 263                                return 0;
 264                        }
 265                        break;
 266                case opt_gid:
 267                        if (match_int(&args[0], &tmp)) {
 268                                pr_err("gid requires an argument\n");
 269                                return 0;
 270                        }
 271                        hsb->s_gid = make_kgid(current_user_ns(), (gid_t)tmp);
 272                        if (!gid_valid(hsb->s_gid)) {
 273                                pr_err("invalid gid %d\n", tmp);
 274                                return 0;
 275                        }
 276                        break;
 277                case opt_umask:
 278                        if (match_octal(&args[0], &tmp)) {
 279                                pr_err("umask requires a value\n");
 280                                return 0;
 281                        }
 282                        hsb->s_file_umask = (umode_t)tmp;
 283                        hsb->s_dir_umask = (umode_t)tmp;
 284                        break;
 285                case opt_file_umask:
 286                        if (match_octal(&args[0], &tmp)) {
 287                                pr_err("file_umask requires a value\n");
 288                                return 0;
 289                        }
 290                        hsb->s_file_umask = (umode_t)tmp;
 291                        break;
 292                case opt_dir_umask:
 293                        if (match_octal(&args[0], &tmp)) {
 294                                pr_err("dir_umask requires a value\n");
 295                                return 0;
 296                        }
 297                        hsb->s_dir_umask = (umode_t)tmp;
 298                        break;
 299                case opt_part:
 300                        if (match_int(&args[0], &hsb->part)) {
 301                                pr_err("part requires an argument\n");
 302                                return 0;
 303                        }
 304                        break;
 305                case opt_session:
 306                        if (match_int(&args[0], &hsb->session)) {
 307                                pr_err("session requires an argument\n");
 308                                return 0;
 309                        }
 310                        break;
 311                case opt_type:
 312                        if (match_fourchar(&args[0], &hsb->s_type)) {
 313                                pr_err("type requires a 4 character value\n");
 314                                return 0;
 315                        }
 316                        break;
 317                case opt_creator:
 318                        if (match_fourchar(&args[0], &hsb->s_creator)) {
 319                                pr_err("creator requires a 4 character value\n");
 320                                return 0;
 321                        }
 322                        break;
 323                case opt_quiet:
 324                        hsb->s_quiet = 1;
 325                        break;
 326                case opt_codepage:
 327                        if (hsb->nls_disk) {
 328                                pr_err("unable to change codepage\n");
 329                                return 0;
 330                        }
 331                        p = match_strdup(&args[0]);
 332                        if (p)
 333                                hsb->nls_disk = load_nls(p);
 334                        if (!hsb->nls_disk) {
 335                                pr_err("unable to load codepage \"%s\"\n", p);
 336                                kfree(p);
 337                                return 0;
 338                        }
 339                        kfree(p);
 340                        break;
 341                case opt_iocharset:
 342                        if (hsb->nls_io) {
 343                                pr_err("unable to change iocharset\n");
 344                                return 0;
 345                        }
 346                        p = match_strdup(&args[0]);
 347                        if (p)
 348                                hsb->nls_io = load_nls(p);
 349                        if (!hsb->nls_io) {
 350                                pr_err("unable to load iocharset \"%s\"\n", p);
 351                                kfree(p);
 352                                return 0;
 353                        }
 354                        kfree(p);
 355                        break;
 356                default:
 357                        return 0;
 358                }
 359        }
 360
 361        if (hsb->nls_disk && !hsb->nls_io) {
 362                hsb->nls_io = load_nls_default();
 363                if (!hsb->nls_io) {
 364                        pr_err("unable to load default iocharset\n");
 365                        return 0;
 366                }
 367        }
 368        hsb->s_dir_umask &= 0777;
 369        hsb->s_file_umask &= 0577;
 370
 371        return 1;
 372}
 373
 374/*
 375 * hfs_read_super()
 376 *
 377 * This is the function that is responsible for mounting an HFS
 378 * filesystem.  It performs all the tasks necessary to get enough data
 379 * from the disk to read the root inode.  This includes parsing the
 380 * mount options, dealing with Macintosh partitions, reading the
 381 * superblock and the allocation bitmap blocks, calling
 382 * hfs_btree_init() to get the necessary data about the extents and
 383 * catalog B-trees and, finally, reading the root inode into memory.
 384 */
 385static int hfs_fill_super(struct super_block *sb, void *data, int silent)
 386{
 387        struct hfs_sb_info *sbi;
 388        struct hfs_find_data fd;
 389        hfs_cat_rec rec;
 390        struct inode *root_inode;
 391        int res;
 392
 393        sbi = kzalloc(sizeof(struct hfs_sb_info), GFP_KERNEL);
 394        if (!sbi)
 395                return -ENOMEM;
 396
 397        sbi->sb = sb;
 398        sb->s_fs_info = sbi;
 399        spin_lock_init(&sbi->work_lock);
 400        INIT_DELAYED_WORK(&sbi->mdb_work, flush_mdb);
 401
 402        res = -EINVAL;
 403        if (!parse_options((char *)data, sbi)) {
 404                pr_err("unable to parse mount options\n");
 405                goto bail;
 406        }
 407
 408        sb->s_op = &hfs_super_operations;
 409        sb->s_flags |= MS_NODIRATIME;
 410        mutex_init(&sbi->bitmap_lock);
 411
 412        res = hfs_mdb_get(sb);
 413        if (res) {
 414                if (!silent)
 415                        pr_warn("can't find a HFS filesystem on dev %s\n",
 416                                hfs_mdb_name(sb));
 417                res = -EINVAL;
 418                goto bail;
 419        }
 420
 421        /* try to get the root inode */
 422        res = hfs_find_init(HFS_SB(sb)->cat_tree, &fd);
 423        if (res)
 424                goto bail_no_root;
 425        res = hfs_cat_find_brec(sb, HFS_ROOT_CNID, &fd);
 426        if (!res) {
 427                if (fd.entrylength > sizeof(rec) || fd.entrylength < 0) {
 428                        res =  -EIO;
 429                        goto bail;
 430                }
 431                hfs_bnode_read(fd.bnode, &rec, fd.entryoffset, fd.entrylength);
 432        }
 433        if (res) {
 434                hfs_find_exit(&fd);
 435                goto bail_no_root;
 436        }
 437        res = -EINVAL;
 438        root_inode = hfs_iget(sb, &fd.search_key->cat, &rec);
 439        hfs_find_exit(&fd);
 440        if (!root_inode)
 441                goto bail_no_root;
 442
 443        sb->s_d_op = &hfs_dentry_operations;
 444        res = -ENOMEM;
 445        sb->s_root = d_make_root(root_inode);
 446        if (!sb->s_root)
 447                goto bail_no_root;
 448
 449        /* everything's okay */
 450        return 0;
 451
 452bail_no_root:
 453        pr_err("get root inode failed\n");
 454bail:
 455        hfs_mdb_put(sb);
 456        return res;
 457}
 458
 459static struct dentry *hfs_mount(struct file_system_type *fs_type,
 460                      int flags, const char *dev_name, void *data)
 461{
 462        return mount_bdev(fs_type, flags, dev_name, data, hfs_fill_super);
 463}
 464
 465static struct file_system_type hfs_fs_type = {
 466        .owner          = THIS_MODULE,
 467        .name           = "hfs",
 468        .mount          = hfs_mount,
 469        .kill_sb        = kill_block_super,
 470        .fs_flags       = FS_REQUIRES_DEV,
 471};
 472MODULE_ALIAS_FS("hfs");
 473
 474static void hfs_init_once(void *p)
 475{
 476        struct hfs_inode_info *i = p;
 477
 478        inode_init_once(&i->vfs_inode);
 479}
 480
 481static int __init init_hfs_fs(void)
 482{
 483        int err;
 484
 485        hfs_inode_cachep = kmem_cache_create("hfs_inode_cache",
 486                sizeof(struct hfs_inode_info), 0,
 487                SLAB_HWCACHE_ALIGN|SLAB_ACCOUNT, hfs_init_once);
 488        if (!hfs_inode_cachep)
 489                return -ENOMEM;
 490        err = register_filesystem(&hfs_fs_type);
 491        if (err)
 492                kmem_cache_destroy(hfs_inode_cachep);
 493        return err;
 494}
 495
 496static void __exit exit_hfs_fs(void)
 497{
 498        unregister_filesystem(&hfs_fs_type);
 499
 500        /*
 501         * Make sure all delayed rcu free inodes are flushed before we
 502         * destroy cache.
 503         */
 504        rcu_barrier();
 505        kmem_cache_destroy(hfs_inode_cachep);
 506}
 507
 508module_init(init_hfs_fs)
 509module_exit(exit_hfs_fs)
 510