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/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/vfs.h>
  23
  24 #include "hfs_fs.h"
  25 #include "btree.h"
  26
  27 static struct kmem_cache *hfs_inode_cachep;
  28
  29 MODULE_LICENSE("GPL");
  30
  31 /*
  32  * hfs_write_super()
  33  *
  34  * Description:
  35  *   This function is called by the VFS only. When the filesystem
  36  *   is mounted r/w it updates the MDB on disk.
  37  * Input Variable(s):
  38  *   struct super_block *sb: Pointer to the hfs superblock
  39  * Output Variable(s):
  40  *   NONE
  41  * Returns:
  42  *   void
  43  * Preconditions:
  44  *   'sb' points to a "valid" (struct super_block).
  45  * Postconditions:
  46  *   The MDB is marked 'unsuccessfully unmounted' by clearing bit 8 of drAtrb
  47  *   (hfs_put_super() must set this flag!). Some MDB fields are updated
  48  *   and the MDB buffer is written to disk by calling hfs_mdb_commit().
  49  */
  50 static void hfs_write_super(struct super_block *sb)
  51 {
  52         lock_super(sb);
  53         sb->s_dirt = 0;
  54
  55         /* sync everything to the buffers */
  56         if (!(sb->s_flags & MS_RDONLY))
  57                 hfs_mdb_commit(sb);
  58         unlock_super(sb);
  59 }
  60
  61 static int hfs_sync_fs(struct super_block *sb, int wait)
  62 {
  63         lock_super(sb);
  64         hfs_mdb_commit(sb);
  65         sb->s_dirt = 0;
  66         unlock_super(sb);
  67
  68         return 0;
  69 }
  70
  71 /*
  72  * hfs_put_super()
  73  *
  74  * This is the put_super() entry in the super_operations structure for
  75  * HFS filesystems.  The purpose is to release the resources
  76  * associated with the superblock sb.
  77  */
  78 static void hfs_put_super(struct super_block *sb)
  79 {
  80         lock_kernel();
  81
  82         if (sb->s_dirt)
  83                 hfs_write_super(sb);
  84         hfs_mdb_close(sb);
  85         /* release the MDB's resources */
  86         hfs_mdb_put(sb);
  87
  88         unlock_kernel();
  89 }
  90
  91 /*
  92  * hfs_statfs()
  93  *
  94  * This is the statfs() entry in the super_operations structure for
  95  * HFS filesystems.  The purpose is to return various data about the
  96  * filesystem.
  97  *
  98  * changed f_files/f_ffree to reflect the fs_ablock/free_ablocks.
  99  */
 100 static int hfs_statfs(struct dentry *dentry, struct kstatfs *buf)
 101 {
 102         struct super_block *sb = dentry->d_sb;
 103         u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
 104
 105         buf->f_type = HFS_SUPER_MAGIC;
 106         buf->f_bsize = sb->s_blocksize;
 107         buf->f_blocks = (u32)HFS_SB(sb)->fs_ablocks * HFS_SB(sb)->fs_div;
 108         buf->f_bfree = (u32)HFS_SB(sb)->free_ablocks * HFS_SB(sb)->fs_div;
 109         buf->f_bavail = buf->f_bfree;
 110         buf->f_files = HFS_SB(sb)->fs_ablocks;
 111         buf->f_ffree = HFS_SB(sb)->free_ablocks;
 112         buf->f_fsid.val[0] = (u32)id;
 113         buf->f_fsid.val[1] = (u32)(id >> 32);
 114         buf->f_namelen = HFS_NAMELEN;
 115
 116         return 0;
 117 }
 118
 119 static int hfs_remount(struct super_block *sb, int *flags, char *data)
 120 {
 121         *flags |= MS_NODIRATIME;
 122         if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
 123                 return 0;
 124         if (!(*flags & MS_RDONLY)) {
 125                 if (!(HFS_SB(sb)->mdb->drAtrb & cpu_to_be16(HFS_SB_ATTRIB_UNMNT))) {
 126                         printk(KERN_WARNING "hfs: filesystem was not cleanly unmounted, "
 127                                "running fsck.hfs is recommended.  leaving read-only.\n");
 128                         sb->s_flags |= MS_RDONLY;
 129                         *flags |= MS_RDONLY;
 130                 } else if (HFS_SB(sb)->mdb->drAtrb & cpu_to_be16(HFS_SB_ATTRIB_SLOCK)) {
 131                         printk(KERN_WARNING "hfs: filesystem is marked locked, leaving read-only.\n");
 132                         sb->s_flags |= MS_RDONLY;
 133                         *flags |= MS_RDONLY;
 134                 }
 135         }
 136         return 0;
 137 }
 138
 139 static int hfs_show_options(struct seq_file *seq, struct vfsmount *mnt)
 140 {
 141         struct hfs_sb_info *sbi = HFS_SB(mnt->mnt_sb);
 142
 143         if (sbi->s_creator != cpu_to_be32(0x3f3f3f3f))
 144                 seq_printf(seq, ",creator=%.4s", (char *)&sbi->s_creator);
 145         if (sbi->s_type != cpu_to_be32(0x3f3f3f3f))
 146                 seq_printf(seq, ",type=%.4s", (char *)&sbi->s_type);
 147         seq_printf(seq, ",uid=%u,gid=%u", sbi->s_uid, sbi->s_gid);
 148         if (sbi->s_file_umask != 0133)
 149                 seq_printf(seq, ",file_umask=%o", sbi->s_file_umask);
 150         if (sbi->s_dir_umask != 0022)
 151                 seq_printf(seq, ",dir_umask=%o", sbi->s_dir_umask);
 152         if (sbi->part >= 0)
 153                 seq_printf(seq, ",part=%u", sbi->part);
 154         if (sbi->session >= 0)
 155                 seq_printf(seq, ",session=%u", sbi->session);
 156         if (sbi->nls_disk)
 157                 seq_printf(seq, ",codepage=%s", sbi->nls_disk->charset);
 158         if (sbi->nls_io)
 159                 seq_printf(seq, ",iocharset=%s", sbi->nls_io->charset);
 160         if (sbi->s_quiet)
 161                 seq_printf(seq, ",quiet");
 162         return 0;
 163 }
 164
 165 static struct inode *hfs_alloc_inode(struct super_block *sb)
 166 {
 167         struct hfs_inode_info *i;
 168
 169         i = kmem_cache_alloc(hfs_inode_cachep, GFP_KERNEL);
 170         return i ? &i->vfs_inode : NULL;
 171 }
 172
 173 static void hfs_destroy_inode(struct inode *inode)
 174 {
 175         kmem_cache_free(hfs_inode_cachep, HFS_I(inode));
 176 }
 177
 178 static const struct super_operations hfs_super_operations = {
 179         .alloc_inode    = hfs_alloc_inode,
 180         .destroy_inode  = hfs_destroy_inode,
 181         .write_inode    = hfs_write_inode,
 182         .clear_inode    = hfs_clear_inode,
 183         .put_super      = hfs_put_super,
 184         .write_super    = hfs_write_super,
 185         .sync_fs        = hfs_sync_fs,
 186         .statfs         = hfs_statfs,
 187         .remount_fs     = hfs_remount,
 188         .show_options   = hfs_show_options,
 189 };
 190
 191 enum {
 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
 198 static 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
 214 static 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  */
 228 static 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                                 printk(KERN_ERR "hfs: uid requires an argument\n");
 256                                 return 0;
 257                         }
 258                         hsb->s_uid = (uid_t)tmp;
 259                         break;
 260                 case opt_gid:
 261                         if (match_int(&args[0], &tmp)) {
 262                                 printk(KERN_ERR "hfs: gid requires an argument\n");
 263                                 return 0;
 264                         }
 265                         hsb->s_gid = (gid_t)tmp;
 266                         break;
 267                 case opt_umask:
 268                         if (match_octal(&args[0], &tmp)) {
 269                                 printk(KERN_ERR "hfs: umask requires a value\n");
 270                                 return 0;
 271                         }
 272                         hsb->s_file_umask = (umode_t)tmp;
 273                         hsb->s_dir_umask = (umode_t)tmp;
 274                         break;
 275                 case opt_file_umask:
 276                         if (match_octal(&args[0], &tmp)) {
 277                                 printk(KERN_ERR "hfs: file_umask requires a value\n");
 278                                 return 0;
 279                         }
 280                         hsb->s_file_umask = (umode_t)tmp;
 281                         break;
 282                 case opt_dir_umask:
 283                         if (match_octal(&args[0], &tmp)) {
 284                                 printk(KERN_ERR "hfs: dir_umask requires a value\n");
 285                                 return 0;
 286                         }
 287                         hsb->s_dir_umask = (umode_t)tmp;
 288                         break;
 289                 case opt_part:
 290                         if (match_int(&args[0], &hsb->part)) {
 291                                 printk(KERN_ERR "hfs: part requires an argument\n");
 292                                 return 0;
 293                         }
 294                         break;
 295                 case opt_session:
 296                         if (match_int(&args[0], &hsb->session)) {
 297                                 printk(KERN_ERR "hfs: session requires an argument\n");
 298                                 return 0;
 299                         }
 300                         break;
 301                 case opt_type:
 302                         if (match_fourchar(&args[0], &hsb->s_type)) {
 303                                 printk(KERN_ERR "hfs: type requires a 4 character value\n");
 304                                 return 0;
 305                         }
 306                         break;
 307                 case opt_creator:
 308                         if (match_fourchar(&args[0], &hsb->s_creator)) {
 309                                 printk(KERN_ERR "hfs: creator requires a 4 character value\n");
 310                                 return 0;
 311                         }
 312                         break;
 313                 case opt_quiet:
 314                         hsb->s_quiet = 1;
 315                         break;
 316                 case opt_codepage:
 317                         if (hsb->nls_disk) {
 318                                 printk(KERN_ERR "hfs: unable to change codepage\n");
 319                                 return 0;
 320                         }
 321                         p = match_strdup(&args[0]);
 322                         if (p)
 323                                 hsb->nls_disk = load_nls(p);
 324                         if (!hsb->nls_disk) {
 325                                 printk(KERN_ERR "hfs: unable to load codepage \"%s\"\n", p);
 326                                 kfree(p);
 327                                 return 0;
 328                         }
 329                         kfree(p);
 330                         break;
 331                 case opt_iocharset:
 332                         if (hsb->nls_io) {
 333                                 printk(KERN_ERR "hfs: unable to change iocharset\n");
 334                                 return 0;
 335                         }
 336                         p = match_strdup(&args[0]);
 337                         if (p)
 338                                 hsb->nls_io = load_nls(p);
 339                         if (!hsb->nls_io) {
 340                                 printk(KERN_ERR "hfs: unable to load iocharset \"%s\"\n", p);
 341                                 kfree(p);
 342                                 return 0;
 343                         }
 344                         kfree(p);
 345                         break;
 346                 default:
 347                         return 0;
 348                 }
 349         }
 350
 351         if (hsb->nls_disk && !hsb->nls_io) {
 352                 hsb->nls_io = load_nls_default();
 353                 if (!hsb->nls_io) {
 354                         printk(KERN_ERR "hfs: unable to load default iocharset\n");
 355                         return 0;
 356                 }
 357         }
 358         hsb->s_dir_umask &= 0777;
 359         hsb->s_file_umask &= 0577;
 360
 361         return 1;
 362 }
 363
 364 /*
 365  * hfs_read_super()
 366  *
 367  * This is the function that is responsible for mounting an HFS
 368  * filesystem.  It performs all the tasks necessary to get enough data
 369  * from the disk to read the root inode.  This includes parsing the
 370  * mount options, dealing with Macintosh partitions, reading the
 371  * superblock and the allocation bitmap blocks, calling
 372  * hfs_btree_init() to get the necessary data about the extents and
 373  * catalog B-trees and, finally, reading the root inode into memory.
 374  */
 375 static int hfs_fill_super(struct super_block *sb, void *data, int silent)
 376 {
 377         struct hfs_sb_info *sbi;
 378         struct hfs_find_data fd;
 379         hfs_cat_rec rec;
 380         struct inode *root_inode;
 381         int res;
 382
 383         sbi = kzalloc(sizeof(struct hfs_sb_info), GFP_KERNEL);
 384         if (!sbi)
 385                 return -ENOMEM;
 386         sb->s_fs_info = sbi;
 387         INIT_HLIST_HEAD(&sbi->rsrc_inodes);
 388
 389         res = -EINVAL;
 390         if (!parse_options((char *)data, sbi)) {
 391                 printk(KERN_ERR "hfs: unable to parse mount options.\n");
 392                 goto bail;
 393         }
 394
 395         sb->s_op = &hfs_super_operations;
 396         sb->s_flags |= MS_NODIRATIME;
 397         mutex_init(&sbi->bitmap_lock);
 398
 399         res = hfs_mdb_get(sb);
 400         if (res) {
 401                 if (!silent)
 402                         printk(KERN_WARNING "hfs: can't find a HFS filesystem on dev %s.\n",
 403                                 hfs_mdb_name(sb));
 404                 res = -EINVAL;
 405                 goto bail;
 406         }
 407
 408         /* try to get the root inode */
 409         hfs_find_init(HFS_SB(sb)->cat_tree, &fd);
 410         res = hfs_cat_find_brec(sb, HFS_ROOT_CNID, &fd);
 411         if (!res)
 412                 hfs_bnode_read(fd.bnode, &rec, fd.entryoffset, fd.entrylength);
 413         if (res) {
 414                 hfs_find_exit(&fd);
 415                 goto bail_no_root;
 416         }
 417         res = -EINVAL;
 418         root_inode = hfs_iget(sb, &fd.search_key->cat, &rec);
 419         hfs_find_exit(&fd);
 420         if (!root_inode)
 421                 goto bail_no_root;
 422
 423         res = -ENOMEM;
 424         sb->s_root = d_alloc_root(root_inode);
 425         if (!sb->s_root)
 426                 goto bail_iput;
 427
 428         sb->s_root->d_op = &hfs_dentry_operations;
 429
 430         /* everything's okay */
 431         return 0;
 432
 433 bail_iput:
 434         iput(root_inode);
 435 bail_no_root:
 436         printk(KERN_ERR "hfs: get root inode failed.\n");
 437 bail:
 438         hfs_mdb_put(sb);
 439         return res;
 440 }
 441
 442 static int hfs_get_sb(struct file_system_type *fs_type,
 443                       int flags, const char *dev_name, void *data,
 444                       struct vfsmount *mnt)
 445 {
 446         return get_sb_bdev(fs_type, flags, dev_name, data, hfs_fill_super, mnt);
 447 }
 448
 449 static struct file_system_type hfs_fs_type = {
 450         .owner          = THIS_MODULE,
 451         .name           = "hfs",
 452         .get_sb         = hfs_get_sb,
 453         .kill_sb        = kill_block_super,
 454         .fs_flags       = FS_REQUIRES_DEV,
 455 };
 456
 457 static void hfs_init_once(void *p)
 458 {
 459         struct hfs_inode_info *i = p;
 460
 461         inode_init_once(&i->vfs_inode);
 462 }
 463
 464 static int __init init_hfs_fs(void)
 465 {
 466         int err;
 467
 468         hfs_inode_cachep = kmem_cache_create("hfs_inode_cache",
 469                 sizeof(struct hfs_inode_info), 0, SLAB_HWCACHE_ALIGN,
 470                 hfs_init_once);
 471         if (!hfs_inode_cachep)
 472                 return -ENOMEM;
 473         err = register_filesystem(&hfs_fs_type);
 474         if (err)
 475                 kmem_cache_destroy(hfs_inode_cachep);
 476         return err;
 477 }
 478
 479 static void __exit exit_hfs_fs(void)
 480 {
 481         unregister_filesystem(&hfs_fs_type);
 482         kmem_cache_destroy(hfs_inode_cachep);
 483 }
 484
 485 module_init(init_hfs_fs)
 486 module_exit(exit_hfs_fs)