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