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