fs/hfs/super.c

   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
  29 static struct kmem_cache *hfs_inode_cachep;
  30
  31 MODULE_LICENSE("GPL");
  32
  33 static 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  */
  46 static 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
  54 static 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
  69 void 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  */
  95 static 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
 113 static 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
 133 static 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
 161 static 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
 169 static void hfs_free_inode(struct inode *inode)
 170 {
 171         kmem_cache_free(hfs_inode_cachep, HFS_I(inode));
 172 }
 173
 174 static 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
 186 enum {
 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
 193 static 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
 209 static 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  */
 223 static 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  */
 378 static 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;
 424                 }
 425                 hfs_bnode_read(fd.bnode, &rec, fd.entryoffset, fd.entrylength);
 426         }
 427         if (res) {
 428                 hfs_find_exit(&fd);
 429                 goto bail_no_root;
 430         }
 431         res = -EINVAL;
 432         root_inode = hfs_iget(sb, &fd.search_key->cat, &rec);
 433         hfs_find_exit(&fd);
 434         if (!root_inode)
 435                 goto bail_no_root;
 436
 437         sb->s_d_op = &hfs_dentry_operations;
 438         res = -ENOMEM;
 439         sb->s_root = d_make_root(root_inode);
 440         if (!sb->s_root)
 441                 goto bail_no_root;
 442
 443         /* everything's okay */
 444         return 0;
 445
 446 bail_no_root:
 447         pr_err("get root inode failed\n");
 448 bail:
 449         hfs_mdb_put(sb);
 450         return res;
 451 }
 452
 453 static 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
 459 static 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 };
 466 MODULE_ALIAS_FS("hfs");
 467
 468 static void hfs_init_once(void *p)
 469 {
 470         struct hfs_inode_info *i = p;
 471
 472         inode_init_once(&i->vfs_inode);
 473 }
 474
 475 static 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
 490 static 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
 502 module_init(init_hfs_fs)
 503 module_exit(exit_hfs_fs)