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_rdonly(sb))
  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 = u64_to_fsid(id);
 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        sync_filesystem(sb);
 116        *flags |= SB_NODIRATIME;
 117        if ((bool)(*flags & SB_RDONLY) == sb_rdonly(sb))
 118                return 0;
 119        if (!(*flags & SB_RDONLY)) {
 120                if (!(HFS_SB(sb)->mdb->drAtrb & cpu_to_be16(HFS_SB_ATTRIB_UNMNT))) {
 121                        pr_warn("filesystem was not cleanly unmounted, running fsck.hfs is recommended.  leaving read-only.\n");
 122                        sb->s_flags |= SB_RDONLY;
 123                        *flags |= SB_RDONLY;
 124                } else if (HFS_SB(sb)->mdb->drAtrb & cpu_to_be16(HFS_SB_ATTRIB_SLOCK)) {
 125                        pr_warn("filesystem is marked locked, leaving read-only.\n");
 126                        sb->s_flags |= SB_RDONLY;
 127                        *flags |= SB_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_show_option_n(seq, "creator", (char *)&sbi->s_creator, 4);
 139        if (sbi->s_type != cpu_to_be32(0x3f3f3f3f))
 140                seq_show_option_n(seq, "type", (char *)&sbi->s_type, 4);
 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_free_inode(struct inode *inode)
 170{
 171        kmem_cache_free(hfs_inode_cachep, HFS_I(inode));
 172}
 173
 174static const struct super_operations hfs_super_operations = {
 175        .alloc_inode    = hfs_alloc_inode,
 176        .free_inode     = hfs_free_inode,
 177        .write_inode    = hfs_write_inode,
 178        .evict_inode    = hfs_evict_inode,
 179        .put_super      = hfs_put_super,
 180        .sync_fs        = hfs_sync_fs,
 181        .statfs         = hfs_statfs,
 182        .remount_fs     = hfs_remount,
 183        .show_options   = hfs_show_options,
 184};
 185
 186enum {
 187        opt_uid, opt_gid, opt_umask, opt_file_umask, opt_dir_umask,
 188        opt_part, opt_session, opt_type, opt_creator, opt_quiet,
 189        opt_codepage, opt_iocharset,
 190        opt_err
 191};
 192
 193static const match_table_t tokens = {
 194        { opt_uid, "uid=%u" },
 195        { opt_gid, "gid=%u" },
 196        { opt_umask, "umask=%o" },
 197        { opt_file_umask, "file_umask=%o" },
 198        { opt_dir_umask, "dir_umask=%o" },
 199        { opt_part, "part=%u" },
 200        { opt_session, "session=%u" },
 201        { opt_type, "type=%s" },
 202        { opt_creator, "creator=%s" },
 203        { opt_quiet, "quiet" },
 204        { opt_codepage, "codepage=%s" },
 205        { opt_iocharset, "iocharset=%s" },
 206        { opt_err, NULL }
 207};
 208
 209static inline int match_fourchar(substring_t *arg, u32 *result)
 210{
 211        if (arg->to - arg->from != 4)
 212                return -EINVAL;
 213        memcpy(result, arg->from, 4);
 214        return 0;
 215}
 216
 217/*
 218 * parse_options()
 219 *
 220 * adapted from linux/fs/msdos/inode.c written 1992,93 by Werner Almesberger
 221 * This function is called by hfs_read_super() to parse the mount options.
 222 */
 223static int parse_options(char *options, struct hfs_sb_info *hsb)
 224{
 225        char *p;
 226        substring_t args[MAX_OPT_ARGS];
 227        int tmp, token;
 228
 229        /* initialize the sb with defaults */
 230        hsb->s_uid = current_uid();
 231        hsb->s_gid = current_gid();
 232        hsb->s_file_umask = 0133;
 233        hsb->s_dir_umask = 0022;
 234        hsb->s_type = hsb->s_creator = cpu_to_be32(0x3f3f3f3f); /* == '????' */
 235        hsb->s_quiet = 0;
 236        hsb->part = -1;
 237        hsb->session = -1;
 238
 239        if (!options)
 240                return 1;
 241
 242        while ((p = strsep(&options, ",")) != NULL) {
 243                if (!*p)
 244                        continue;
 245
 246                token = match_token(p, tokens, args);
 247                switch (token) {
 248                case opt_uid:
 249                        if (match_int(&args[0], &tmp)) {
 250                                pr_err("uid requires an argument\n");
 251                                return 0;
 252                        }
 253                        hsb->s_uid = make_kuid(current_user_ns(), (uid_t)tmp);
 254                        if (!uid_valid(hsb->s_uid)) {
 255                                pr_err("invalid uid %d\n", tmp);
 256                                return 0;
 257                        }
 258                        break;
 259                case opt_gid:
 260                        if (match_int(&args[0], &tmp)) {
 261                                pr_err("gid requires an argument\n");
 262                                return 0;
 263                        }
 264                        hsb->s_gid = make_kgid(current_user_ns(), (gid_t)tmp);
 265                        if (!gid_valid(hsb->s_gid)) {
 266                                pr_err("invalid gid %d\n", tmp);
 267                                return 0;
 268                        }
 269                        break;
 270                case opt_umask:
 271                        if (match_octal(&args[0], &tmp)) {
 272                                pr_err("umask requires a value\n");
 273                                return 0;
 274                        }
 275                        hsb->s_file_umask = (umode_t)tmp;
 276                        hsb->s_dir_umask = (umode_t)tmp;
 277                        break;
 278                case opt_file_umask:
 279                        if (match_octal(&args[0], &tmp)) {
 280                                pr_err("file_umask requires a value\n");
 281                                return 0;
 282                        }
 283                        hsb->s_file_umask = (umode_t)tmp;
 284                        break;
 285                case opt_dir_umask:
 286                        if (match_octal(&args[0], &tmp)) {
 287                                pr_err("dir_umask requires a value\n");
 288                                return 0;
 289                        }
 290                        hsb->s_dir_umask = (umode_t)tmp;
 291                        break;
 292                case opt_part:
 293                        if (match_int(&args[0], &hsb->part)) {
 294                                pr_err("part requires an argument\n");
 295                                return 0;
 296                        }
 297                        break;
 298                case opt_session:
 299                        if (match_int(&args[0], &hsb->session)) {
 300                                pr_err("session requires an argument\n");
 301                                return 0;
 302                        }
 303                        break;
 304                case opt_type:
 305                        if (match_fourchar(&args[0], &hsb->s_type)) {
 306                                pr_err("type requires a 4 character value\n");
 307                                return 0;
 308                        }
 309                        break;
 310                case opt_creator:
 311                        if (match_fourchar(&args[0], &hsb->s_creator)) {
 312                                pr_err("creator requires a 4 character value\n");
 313                                return 0;
 314                        }
 315                        break;
 316                case opt_quiet:
 317                        hsb->s_quiet = 1;
 318                        break;
 319                case opt_codepage:
 320                        if (hsb->nls_disk) {
 321                                pr_err("unable to change codepage\n");
 322                                return 0;
 323                        }
 324                        p = match_strdup(&args[0]);
 325                        if (p)
 326                                hsb->nls_disk = load_nls(p);
 327                        if (!hsb->nls_disk) {
 328                                pr_err("unable to load codepage \"%s\"\n", p);
 329                                kfree(p);
 330                                return 0;
 331                        }
 332                        kfree(p);
 333                        break;
 334                case opt_iocharset:
 335                        if (hsb->nls_io) {
 336                                pr_err("unable to change iocharset\n");
 337                                return 0;
 338                        }
 339                        p = match_strdup(&args[0]);
 340                        if (p)
 341                                hsb->nls_io = load_nls(p);
 342                        if (!hsb->nls_io) {
 343                                pr_err("unable to load iocharset \"%s\"\n", p);
 344                                kfree(p);
 345                                return 0;
 346                        }
 347                        kfree(p);
 348                        break;
 349                default:
 350                        return 0;
 351                }
 352        }
 353
 354        if (hsb->nls_disk && !hsb->nls_io) {
 355                hsb->nls_io = load_nls_default();
 356                if (!hsb->nls_io) {
 357                        pr_err("unable to load default iocharset\n");
 358                        return 0;
 359                }
 360        }
 361        hsb->s_dir_umask &= 0777;
 362        hsb->s_file_umask &= 0577;
 363
 364        return 1;
 365}
 366
 367/*
 368 * hfs_read_super()
 369 *
 370 * This is the function that is responsible for mounting an HFS
 371 * filesystem.  It performs all the tasks necessary to get enough data
 372 * from the disk to read the root inode.  This includes parsing the
 373 * mount options, dealing with Macintosh partitions, reading the
 374 * superblock and the allocation bitmap blocks, calling
 375 * hfs_btree_init() to get the necessary data about the extents and
 376 * catalog B-trees and, finally, reading the root inode into memory.
 377 */
 378static int hfs_fill_super(struct super_block *sb, void *data, int silent)
 379{
 380        struct hfs_sb_info *sbi;
 381        struct hfs_find_data fd;
 382        hfs_cat_rec rec;
 383        struct inode *root_inode;
 384        int res;
 385
 386        sbi = kzalloc(sizeof(struct hfs_sb_info), GFP_KERNEL);
 387        if (!sbi)
 388                return -ENOMEM;
 389
 390        sbi->sb = sb;
 391        sb->s_fs_info = sbi;
 392        spin_lock_init(&sbi->work_lock);
 393        INIT_DELAYED_WORK(&sbi->mdb_work, flush_mdb);
 394
 395        res = -EINVAL;
 396        if (!parse_options((char *)data, sbi)) {
 397                pr_err("unable to parse mount options\n");
 398                goto bail;
 399        }
 400
 401        sb->s_op = &hfs_super_operations;
 402        sb->s_xattr = hfs_xattr_handlers;
 403        sb->s_flags |= SB_NODIRATIME;
 404        mutex_init(&sbi->bitmap_lock);
 405
 406        res = hfs_mdb_get(sb);
 407        if (res) {
 408                if (!silent)
 409                        pr_warn("can't find a HFS filesystem on dev %s\n",
 410                                hfs_mdb_name(sb));
 411                res = -EINVAL;
 412                goto bail;
 413        }
 414
 415        /* try to get the root inode */
 416        res = hfs_find_init(HFS_SB(sb)->cat_tree, &fd);
 417        if (res)
 418                goto bail_no_root;
 419        res = hfs_cat_find_brec(sb, HFS_ROOT_CNID, &fd);
 420        if (!res) {
 421                if (fd.entrylength > sizeof(rec) || fd.entrylength < 0) {
 422                        res =  -EIO;
 423                        goto bail_hfs_find;
 424                }
 425                hfs_bnode_read(fd.bnode, &rec, fd.entryoffset, fd.entrylength);
 426        }
 427        if (res)
 428                goto bail_hfs_find;
 429        res = -EINVAL;
 430        root_inode = hfs_iget(sb, &fd.search_key->cat, &rec);
 431        hfs_find_exit(&fd);
 432        if (!root_inode)
 433                goto bail_no_root;
 434
 435        sb->s_d_op = &hfs_dentry_operations;
 436        res = -ENOMEM;
 437        sb->s_root = d_make_root(root_inode);
 438        if (!sb->s_root)
 439                goto bail_no_root;
 440
 441        /* everything's okay */
 442        return 0;
 443
 444bail_hfs_find:
 445        hfs_find_exit(&fd);
 446bail_no_root:
 447        pr_err("get root inode failed\n");
 448bail:
 449        hfs_mdb_put(sb);
 450        return res;
 451}
 452
 453static struct dentry *hfs_mount(struct file_system_type *fs_type,
 454                      int flags, const char *dev_name, void *data)
 455{
 456        return mount_bdev(fs_type, flags, dev_name, data, hfs_fill_super);
 457}
 458
 459static struct file_system_type hfs_fs_type = {
 460        .owner          = THIS_MODULE,
 461        .name           = "hfs",
 462        .mount          = hfs_mount,
 463        .kill_sb        = kill_block_super,
 464        .fs_flags       = FS_REQUIRES_DEV,
 465};
 466MODULE_ALIAS_FS("hfs");
 467
 468static void hfs_init_once(void *p)
 469{
 470        struct hfs_inode_info *i = p;
 471
 472        inode_init_once(&i->vfs_inode);
 473}
 474
 475static int __init init_hfs_fs(void)
 476{
 477        int err;
 478
 479        hfs_inode_cachep = kmem_cache_create("hfs_inode_cache",
 480                sizeof(struct hfs_inode_info), 0,
 481                SLAB_HWCACHE_ALIGN|SLAB_ACCOUNT, hfs_init_once);
 482        if (!hfs_inode_cachep)
 483                return -ENOMEM;
 484        err = register_filesystem(&hfs_fs_type);
 485        if (err)
 486                kmem_cache_destroy(hfs_inode_cachep);
 487        return err;
 488}
 489
 490static void __exit exit_hfs_fs(void)
 491{
 492        unregister_filesystem(&hfs_fs_type);
 493
 494        /*
 495         * Make sure all delayed rcu free inodes are flushed before we
 496         * destroy cache.
 497         */
 498        rcu_barrier();
 499        kmem_cache_destroy(hfs_inode_cachep);
 500}
 501
 502module_init(init_hfs_fs)
 503module_exit(exit_hfs_fs)
 504