SAFE public projects git trees. - safe/jmp/linux-2.6/blob - 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 /*
  62  * hfs_put_super()
  63  *
  64  * This is the put_super() entry in the super_operations structure for
  65  * HFS filesystems.  The purpose is to release the resources
  66  * associated with the superblock sb.
  67  */
  68 static void hfs_put_super(struct super_block *sb)
  69 {
  70         lock_kernel();
  71
  72         if (sb->s_dirt)
  73                 hfs_write_super(sb);
  74         hfs_mdb_close(sb);
  75         /* release the MDB's resources */
  76         hfs_mdb_put(sb);
  77
  78         unlock_kernel();
  79 }
  80
  81 /*
  82  * hfs_statfs()
  83  *
  84  * This is the statfs() entry in the super_operations structure for
  85  * HFS filesystems.  The purpose is to return various data about the
  86  * filesystem.
  87  *
  88  * changed f_files/f_ffree to reflect the fs_ablock/free_ablocks.
  89  */
  90 static int hfs_statfs(struct dentry *dentry, struct kstatfs *buf)
  91 {
  92         struct super_block *sb = dentry->d_sb;
  93         u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
  94
  95         buf->f_type = HFS_SUPER_MAGIC;
  96         buf->f_bsize = sb->s_blocksize;
  97         buf->f_blocks = (u32)HFS_SB(sb)->fs_ablocks * HFS_SB(sb)->fs_div;
  98         buf->f_bfree = (u32)HFS_SB(sb)->free_ablocks * HFS_SB(sb)->fs_div;
  99         buf->f_bavail = buf->f_bfree;
 100         buf->f_files = HFS_SB(sb)->fs_ablocks;
 101         buf->f_ffree = HFS_SB(sb)->free_ablocks;
 102         buf->f_fsid.val[0] = (u32)id;
 103         buf->f_fsid.val[1] = (u32)(id >> 32);
 104         buf->f_namelen = HFS_NAMELEN;
 105
 106         return 0;
 107 }
 108
 109 static int hfs_remount(struct super_block *sb, int *flags, char *data)
 110 {
 111         *flags |= MS_NODIRATIME;
 112         if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
 113                 return 0;
 114         if (!(*flags & MS_RDONLY)) {
 115                 if (!(HFS_SB(sb)->mdb->drAtrb & cpu_to_be16(HFS_SB_ATTRIB_UNMNT))) {
 116                         printk(KERN_WARNING "hfs: filesystem was not cleanly unmounted, "
 117                                "running fsck.hfs is recommended.  leaving read-only.\n");
 118                         sb->s_flags |= MS_RDONLY;
 119                         *flags |= MS_RDONLY;
 120                 } else if (HFS_SB(sb)->mdb->drAtrb & cpu_to_be16(HFS_SB_ATTRIB_SLOCK)) {
 121                         printk(KERN_WARNING "hfs: filesystem is marked locked, leaving read-only.\n");
 122                         sb->s_flags |= MS_RDONLY;
 123                         *flags |= MS_RDONLY;
 124                 }
 125         }
 126         return 0;
 127 }
 128
 129 static int hfs_show_options(struct seq_file *seq, struct vfsmount *mnt)
 130 {
 131         struct hfs_sb_info *sbi = HFS_SB(mnt->mnt_sb);
 132
 133         if (sbi->s_creator != cpu_to_be32(0x3f3f3f3f))
 134                 seq_printf(seq, ",creator=%.4s", (char *)&sbi->s_creator);
 135         if (sbi->s_type != cpu_to_be32(0x3f3f3f3f))
 136                 seq_printf(seq, ",type=%.4s", (char *)&sbi->s_type);
 137         seq_printf(seq, ",uid=%u,gid=%u", sbi->s_uid, sbi->s_gid);
 138         if (sbi->s_file_umask != 0133)
 139                 seq_printf(seq, ",file_umask=%o", sbi->s_file_umask);
 140         if (sbi->s_dir_umask != 0022)
 141                 seq_printf(seq, ",dir_umask=%o", sbi->s_dir_umask);
 142         if (sbi->part >= 0)
 143                 seq_printf(seq, ",part=%u", sbi->part);
 144         if (sbi->session >= 0)
 145                 seq_printf(seq, ",session=%u", sbi->session);
 146         if (sbi->nls_disk)
 147                 seq_printf(seq, ",codepage=%s", sbi->nls_disk->charset);
 148         if (sbi->nls_io)
 149                 seq_printf(seq, ",iocharset=%s", sbi->nls_io->charset);
 150         if (sbi->s_quiet)
 151                 seq_printf(seq, ",quiet");
 152         return 0;
 153 }
 154
 155 static struct inode *hfs_alloc_inode(struct super_block *sb)
 156 {
 157         struct hfs_inode_info *i;
 158
 159         i = kmem_cache_alloc(hfs_inode_cachep, GFP_KERNEL);
 160         return i ? &i->vfs_inode : NULL;
 161 }
 162
 163 static void hfs_destroy_inode(struct inode *inode)
 164 {
 165         kmem_cache_free(hfs_inode_cachep, HFS_I(inode));
 166 }
 167
 168 static const struct super_operations hfs_super_operations = {
 169         .alloc_inode    = hfs_alloc_inode,
 170         .destroy_inode  = hfs_destroy_inode,
 171         .write_inode    = hfs_write_inode,
 172         .clear_inode    = hfs_clear_inode,
 173         .put_super      = hfs_put_super,
 174         .write_super    = hfs_write_super,
 175         .statfs         = hfs_statfs,
 176         .remount_fs     = hfs_remount,
 177         .show_options   = hfs_show_options,
 178 };
 179
 180 enum {
 181         opt_uid, opt_gid, opt_umask, opt_file_umask, opt_dir_umask,
 182         opt_part, opt_session, opt_type, opt_creator, opt_quiet,
 183         opt_codepage, opt_iocharset,
 184         opt_err
 185 };
 186
 187 static const match_table_t tokens = {
 188         { opt_uid, "uid=%u" },
 189         { opt_gid, "gid=%u" },
 190         { opt_umask, "umask=%o" },
 191         { opt_file_umask, "file_umask=%o" },
 192         { opt_dir_umask, "dir_umask=%o" },
 193         { opt_part, "part=%u" },
 194         { opt_session, "session=%u" },
 195         { opt_type, "type=%s" },
 196         { opt_creator, "creator=%s" },
 197         { opt_quiet, "quiet" },
 198         { opt_codepage, "codepage=%s" },
 199         { opt_iocharset, "iocharset=%s" },
 200         { opt_err, NULL }
 201 };
 202
 203 static inline int match_fourchar(substring_t *arg, u32 *result)
 204 {
 205         if (arg->to - arg->from != 4)
 206                 return -EINVAL;
 207         memcpy(result, arg->from, 4);
 208         return 0;
 209 }
 210
 211 /*
 212  * parse_options()
 213  *
 214  * adapted from linux/fs/msdos/inode.c written 1992,93 by Werner Almesberger
 215  * This function is called by hfs_read_super() to parse the mount options.
 216  */
 217 static int parse_options(char *options, struct hfs_sb_info *hsb)
 218 {
 219         char *p;
 220         substring_t args[MAX_OPT_ARGS];
 221         int tmp, token;
 222
 223         /* initialize the sb with defaults */
 224         hsb->s_uid = current_uid();
 225         hsb->s_gid = current_gid();
 226         hsb->s_file_umask = 0133;
 227         hsb->s_dir_umask = 0022;
 228         hsb->s_type = hsb->s_creator = cpu_to_be32(0x3f3f3f3f); /* == '????' */
 229         hsb->s_quiet = 0;
 230         hsb->part = -1;
 231         hsb->session = -1;
 232
 233         if (!options)
 234                 return 1;
 235
 236         while ((p = strsep(&options, ",")) != NULL) {
 237                 if (!*p)
 238                         continue;
 239
 240                 token = match_token(p, tokens, args);
 241                 switch (token) {
 242                 case opt_uid:
 243                         if (match_int(&args[0], &tmp)) {
 244                                 printk(KERN_ERR "hfs: uid requires an argument\n");
 245                                 return 0;
 246                         }
 247                         hsb->s_uid = (uid_t)tmp;
 248                         break;
 249                 case opt_gid:
 250                         if (match_int(&args[0], &tmp)) {
 251                                 printk(KERN_ERR "hfs: gid requires an argument\n");
 252                                 return 0;
 253                         }
 254                         hsb->s_gid = (gid_t)tmp;
 255                         break;
 256                 case opt_umask:
 257                         if (match_octal(&args[0], &tmp)) {
 258                                 printk(KERN_ERR "hfs: umask requires a value\n");
 259                                 return 0;
 260                         }
 261                         hsb->s_file_umask = (umode_t)tmp;
 262                         hsb->s_dir_umask = (umode_t)tmp;
 263                         break;
 264                 case opt_file_umask:
 265                         if (match_octal(&args[0], &tmp)) {
 266                                 printk(KERN_ERR "hfs: file_umask requires a value\n");
 267                                 return 0;
 268                         }
 269                         hsb->s_file_umask = (umode_t)tmp;
 270                         break;
 271                 case opt_dir_umask:
 272                         if (match_octal(&args[0], &tmp)) {
 273                                 printk(KERN_ERR "hfs: dir_umask requires a value\n");
 274                                 return 0;
 275                         }
 276                         hsb->s_dir_umask = (umode_t)tmp;
 277                         break;
 278                 case opt_part:
 279                         if (match_int(&args[0], &hsb->part)) {
 280                                 printk(KERN_ERR "hfs: part requires an argument\n");
 281                                 return 0;
 282                         }
 283                         break;
 284                 case opt_session:
 285                         if (match_int(&args[0], &hsb->session)) {
 286                                 printk(KERN_ERR "hfs: session requires an argument\n");
 287                                 return 0;
 288                         }
 289                         break;
 290                 case opt_type:
 291                         if (match_fourchar(&args[0], &hsb->s_type)) {
 292                                 printk(KERN_ERR "hfs: type requires a 4 character value\n");
 293                                 return 0;
 294                         }
 295                         break;
 296                 case opt_creator:
 297                         if (match_fourchar(&args[0], &hsb->s_creator)) {
 298                                 printk(KERN_ERR "hfs: creator requires a 4 character value\n");
 299                                 return 0;
 300                         }
 301                         break;
 302                 case opt_quiet:
 303                         hsb->s_quiet = 1;
 304                         break;
 305                 case opt_codepage:
 306                         if (hsb->nls_disk) {
 307                                 printk(KERN_ERR "hfs: unable to change codepage\n");
 308                                 return 0;
 309                         }
 310                         p = match_strdup(&args[0]);
 311                         if (p)
 312                                 hsb->nls_disk = load_nls(p);
 313                         if (!hsb->nls_disk) {
 314                                 printk(KERN_ERR "hfs: unable to load codepage \"%s\"\n", p);
 315                                 kfree(p);
 316                                 return 0;
 317                         }
 318                         kfree(p);
 319                         break;
 320                 case opt_iocharset:
 321                         if (hsb->nls_io) {
 322                                 printk(KERN_ERR "hfs: unable to change iocharset\n");
 323                                 return 0;
 324                         }
 325                         p = match_strdup(&args[0]);
 326                         if (p)
 327                                 hsb->nls_io = load_nls(p);
 328                         if (!hsb->nls_io) {
 329                                 printk(KERN_ERR "hfs: unable to load iocharset \"%s\"\n", p);
 330                                 kfree(p);
 331                                 return 0;
 332                         }
 333                         kfree(p);
 334                         break;
 335                 default:
 336                         return 0;
 337                 }
 338         }
 339
 340         if (hsb->nls_disk && !hsb->nls_io) {
 341                 hsb->nls_io = load_nls_default();
 342                 if (!hsb->nls_io) {
 343                         printk(KERN_ERR "hfs: unable to load default iocharset\n");
 344                         return 0;
 345                 }
 346         }
 347         hsb->s_dir_umask &= 0777;
 348         hsb->s_file_umask &= 0577;
 349
 350         return 1;
 351 }
 352
 353 /*
 354  * hfs_read_super()
 355  *
 356  * This is the function that is responsible for mounting an HFS
 357  * filesystem.  It performs all the tasks necessary to get enough data
 358  * from the disk to read the root inode.  This includes parsing the
 359  * mount options, dealing with Macintosh partitions, reading the
 360  * superblock and the allocation bitmap blocks, calling
 361  * hfs_btree_init() to get the necessary data about the extents and
 362  * catalog B-trees and, finally, reading the root inode into memory.
 363  */
 364 static int hfs_fill_super(struct super_block *sb, void *data, int silent)
 365 {
 366         struct hfs_sb_info *sbi;
 367         struct hfs_find_data fd;
 368         hfs_cat_rec rec;
 369         struct inode *root_inode;
 370         int res;
 371
 372         sbi = kzalloc(sizeof(struct hfs_sb_info), GFP_KERNEL);
 373         if (!sbi)
 374                 return -ENOMEM;
 375         sb->s_fs_info = sbi;
 376         INIT_HLIST_HEAD(&sbi->rsrc_inodes);
 377
 378         res = -EINVAL;
 379         if (!parse_options((char *)data, sbi)) {
 380                 printk(KERN_ERR "hfs: unable to parse mount options.\n");
 381                 goto bail;
 382         }
 383
 384         sb->s_op = &hfs_super_operations;
 385         sb->s_flags |= MS_NODIRATIME;
 386         mutex_init(&sbi->bitmap_lock);
 387
 388         res = hfs_mdb_get(sb);
 389         if (res) {
 390                 if (!silent)
 391                         printk(KERN_WARNING "hfs: can't find a HFS filesystem on dev %s.\n",
 392                                 hfs_mdb_name(sb));
 393                 res = -EINVAL;
 394                 goto bail;
 395         }
 396
 397         /* try to get the root inode */
 398         hfs_find_init(HFS_SB(sb)->cat_tree, &fd);
 399         res = hfs_cat_find_brec(sb, HFS_ROOT_CNID, &fd);
 400         if (!res)
 401                 hfs_bnode_read(fd.bnode, &rec, fd.entryoffset, fd.entrylength);
 402         if (res) {
 403                 hfs_find_exit(&fd);
 404                 goto bail_no_root;
 405         }
 406         res = -EINVAL;
 407         root_inode = hfs_iget(sb, &fd.search_key->cat, &rec);
 408         hfs_find_exit(&fd);
 409         if (!root_inode)
 410                 goto bail_no_root;
 411
 412         res = -ENOMEM;
 413         sb->s_root = d_alloc_root(root_inode);
 414         if (!sb->s_root)
 415                 goto bail_iput;
 416
 417         sb->s_root->d_op = &hfs_dentry_operations;
 418
 419         /* everything's okay */
 420         return 0;
 421
 422 bail_iput:
 423         iput(root_inode);
 424 bail_no_root:
 425         printk(KERN_ERR "hfs: get root inode failed.\n");
 426 bail:
 427         hfs_mdb_put(sb);
 428         return res;
 429 }
 430
 431 static int hfs_get_sb(struct file_system_type *fs_type,
 432                       int flags, const char *dev_name, void *data,
 433                       struct vfsmount *mnt)
 434 {
 435         return get_sb_bdev(fs_type, flags, dev_name, data, hfs_fill_super, mnt);
 436 }
 437
 438 static struct file_system_type hfs_fs_type = {
 439         .owner          = THIS_MODULE,
 440         .name           = "hfs",
 441         .get_sb         = hfs_get_sb,
 442         .kill_sb        = kill_block_super,
 443         .fs_flags       = FS_REQUIRES_DEV,
 444 };
 445
 446 static void hfs_init_once(void *p)
 447 {
 448         struct hfs_inode_info *i = p;
 449
 450         inode_init_once(&i->vfs_inode);
 451 }
 452
 453 static int __init init_hfs_fs(void)
 454 {
 455         int err;
 456
 457         hfs_inode_cachep = kmem_cache_create("hfs_inode_cache",
 458                 sizeof(struct hfs_inode_info), 0, SLAB_HWCACHE_ALIGN,
 459                 hfs_init_once);
 460         if (!hfs_inode_cachep)
 461                 return -ENOMEM;
 462         err = register_filesystem(&hfs_fs_type);
 463         if (err)
 464                 kmem_cache_destroy(hfs_inode_cachep);
 465         return err;
 466 }
 467
 468 static void __exit exit_hfs_fs(void)
 469 {
 470         unregister_filesystem(&hfs_fs_type);
 471         kmem_cache_destroy(hfs_inode_cachep);
 472 }
 473
 474 module_init(init_hfs_fs)
 475 module_exit(exit_hfs_fs)