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/smp_lock.h>
  23 #include <linux/vfs.h>
  24
  25 #include "hfs_fs.h"
  26 #include "btree.h"
  27
  28 static struct kmem_cache *hfs_inode_cachep;
  29
  30 MODULE_LICENSE("GPL");
  31
  32 /*
  33  * hfs_write_super()
  34  *
  35  * Description:
  36  *   This function is called by the VFS only. When the filesystem
  37  *   is mounted r/w it updates the MDB on disk.
  38  * Input Variable(s):
  39  *   struct super_block *sb: Pointer to the hfs superblock
  40  * Output Variable(s):
  41  *   NONE
  42  * Returns:
  43  *   void
  44  * Preconditions:
  45  *   'sb' points to a "valid" (struct super_block).
  46  * Postconditions:
  47  *   The MDB is marked 'unsuccessfully unmounted' by clearing bit 8 of drAtrb
  48  *   (hfs_put_super() must set this flag!). Some MDB fields are updated
  49  *   and the MDB buffer is written to disk by calling hfs_mdb_commit().
  50  */
  51 static void hfs_write_super(struct super_block *sb)
  52 {
  53         lock_super(sb);
  54         sb->s_dirt = 0;
  55
  56         /* sync everything to the buffers */
  57         if (!(sb->s_flags & MS_RDONLY))
  58                 hfs_mdb_commit(sb);
  59         unlock_super(sb);
  60 }
  61
  62 static int hfs_sync_fs(struct super_block *sb, int wait)
  63 {
  64         lock_super(sb);
  65         hfs_mdb_commit(sb);
  66         sb->s_dirt = 0;
  67         unlock_super(sb);
  68
  69         return 0;
  70 }
  71
  72 /*
  73  * hfs_put_super()
  74  *
  75  * This is the put_super() entry in the super_operations structure for
  76  * HFS filesystems.  The purpose is to release the resources
  77  * associated with the superblock sb.
  78  */
  79 static void hfs_put_super(struct super_block *sb)
  80 {
  81         lock_kernel();
  82
  83         if (sb->s_dirt)
  84                 hfs_write_super(sb);
  85         hfs_mdb_close(sb);
  86         /* release the MDB's resources */
  87         hfs_mdb_put(sb);
  88
  89         unlock_kernel();
  90 }
  91
  92 /*
  93  * hfs_statfs()
  94  *
  95  * This is the statfs() entry in the super_operations structure for
  96  * HFS filesystems.  The purpose is to return various data about the
  97  * filesystem.
  98  *
  99  * changed f_files/f_ffree to reflect the fs_ablock/free_ablocks.
 100  */
 101 static int hfs_statfs(struct dentry *dentry, struct kstatfs *buf)
 102 {
 103         struct super_block *sb = dentry->d_sb;
 104         u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
 105
 106         buf->f_type = HFS_SUPER_MAGIC;
 107         buf->f_bsize = sb->s_blocksize;
 108         buf->f_blocks = (u32)HFS_SB(sb)->fs_ablocks * HFS_SB(sb)->fs_div;
 109         buf->f_bfree = (u32)HFS_SB(sb)->free_ablocks * HFS_SB(sb)->fs_div;
 110         buf->f_bavail = buf->f_bfree;
 111         buf->f_files = HFS_SB(sb)->fs_ablocks;
 112         buf->f_ffree = HFS_SB(sb)->free_ablocks;
 113         buf->f_fsid.val[0] = (u32)id;
 114         buf->f_fsid.val[1] = (u32)(id >> 32);
 115         buf->f_namelen = HFS_NAMELEN;
 116
 117         return 0;
 118 }
 119
 120 static int hfs_remount(struct super_block *sb, int *flags, char *data)
 121 {
 122         *flags |= MS_NODIRATIME;
 123         if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
 124                 return 0;
 125         if (!(*flags & MS_RDONLY)) {
 126                 if (!(HFS_SB(sb)->mdb->drAtrb & cpu_to_be16(HFS_SB_ATTRIB_UNMNT))) {
 127                         printk(KERN_WARNING "hfs: filesystem was not cleanly unmounted, "
 128                                "running fsck.hfs is recommended.  leaving read-only.\n");
 129                         sb->s_flags |= MS_RDONLY;
 130                         *flags |= MS_RDONLY;
 131                 } else if (HFS_SB(sb)->mdb->drAtrb & cpu_to_be16(HFS_SB_ATTRIB_SLOCK)) {
 132                         printk(KERN_WARNING "hfs: filesystem is marked locked, leaving read-only.\n");
 133                         sb->s_flags |= MS_RDONLY;
 134                         *flags |= MS_RDONLY;
 135                 }
 136         }
 137         return 0;
 138 }
 139
 140 static int hfs_show_options(struct seq_file *seq, struct vfsmount *mnt)
 141 {
 142         struct hfs_sb_info *sbi = HFS_SB(mnt->mnt_sb);
 143
 144         if (sbi->s_creator != cpu_to_be32(0x3f3f3f3f))
 145                 seq_printf(seq, ",creator=%.4s", (char *)&sbi->s_creator);
 146         if (sbi->s_type != cpu_to_be32(0x3f3f3f3f))
 147                 seq_printf(seq, ",type=%.4s", (char *)&sbi->s_type);
 148         seq_printf(seq, ",uid=%u,gid=%u", sbi->s_uid, sbi->s_gid);
 149         if (sbi->s_file_umask != 0133)
 150                 seq_printf(seq, ",file_umask=%o", sbi->s_file_umask);
 151         if (sbi->s_dir_umask != 0022)
 152                 seq_printf(seq, ",dir_umask=%o", sbi->s_dir_umask);
 153         if (sbi->part >= 0)
 154                 seq_printf(seq, ",part=%u", sbi->part);
 155         if (sbi->session >= 0)
 156                 seq_printf(seq, ",session=%u", sbi->session);
 157         if (sbi->nls_disk)
 158                 seq_printf(seq, ",codepage=%s", sbi->nls_disk->charset);
 159         if (sbi->nls_io)
 160                 seq_printf(seq, ",iocharset=%s", sbi->nls_io->charset);
 161         if (sbi->s_quiet)
 162                 seq_printf(seq, ",quiet");
 163         return 0;
 164 }
 165
 166 static struct inode *hfs_alloc_inode(struct super_block *sb)
 167 {
 168         struct hfs_inode_info *i;
 169
 170         i = kmem_cache_alloc(hfs_inode_cachep, GFP_KERNEL);
 171         return i ? &i->vfs_inode : NULL;
 172 }
 173
 174 static void hfs_destroy_inode(struct inode *inode)
 175 {
 176         kmem_cache_free(hfs_inode_cachep, HFS_I(inode));
 177 }
 178
 179 static const struct super_operations hfs_super_operations = {
 180         .alloc_inode    = hfs_alloc_inode,
 181         .destroy_inode  = hfs_destroy_inode,
 182         .write_inode    = hfs_write_inode,
 183         .clear_inode    = hfs_clear_inode,
 184         .put_super      = hfs_put_super,
 185         .write_super    = hfs_write_super,
 186         .sync_fs        = hfs_sync_fs,
 187         .statfs         = hfs_statfs,
 188         .remount_fs     = hfs_remount,
 189         .show_options   = hfs_show_options,
 190 };
 191
 192 enum {
 193         opt_uid, opt_gid, opt_umask, opt_file_umask, opt_dir_umask,
 194         opt_part, opt_session, opt_type, opt_creator, opt_quiet,
 195         opt_codepage, opt_iocharset,
 196         opt_err
 197 };
 198
 199 static const match_table_t tokens = {
 200         { opt_uid, "uid=%u" },
 201         { opt_gid, "gid=%u" },
 202         { opt_umask, "umask=%o" },
 203         { opt_file_umask, "file_umask=%o" },
 204         { opt_dir_umask, "dir_umask=%o" },
 205         { opt_part, "part=%u" },
 206         { opt_session, "session=%u" },
 207         { opt_type, "type=%s" },
 208         { opt_creator, "creator=%s" },
 209         { opt_quiet, "quiet" },
 210         { opt_codepage, "codepage=%s" },
 211         { opt_iocharset, "iocharset=%s" },
 212         { opt_err, NULL }
 213 };
 214
 215 static inline int match_fourchar(substring_t *arg, u32 *result)
 216 {
 217         if (arg->to - arg->from != 4)
 218                 return -EINVAL;
 219         memcpy(result, arg->from, 4);
 220         return 0;
 221 }
 222
 223 /*
 224  * parse_options()
 225  *
 226  * adapted from linux/fs/msdos/inode.c written 1992,93 by Werner Almesberger
 227  * This function is called by hfs_read_super() to parse the mount options.
 228  */
 229 static int parse_options(char *options, struct hfs_sb_info *hsb)
 230 {
 231         char *p;
 232         substring_t args[MAX_OPT_ARGS];
 233         int tmp, token;
 234
 235         /* initialize the sb with defaults */
 236         hsb->s_uid = current_uid();
 237         hsb->s_gid = current_gid();
 238         hsb->s_file_umask = 0133;
 239         hsb->s_dir_umask = 0022;
 240         hsb->s_type = hsb->s_creator = cpu_to_be32(0x3f3f3f3f); /* == '????' */
 241         hsb->s_quiet = 0;
 242         hsb->part = -1;
 243         hsb->session = -1;
 244
 245         if (!options)
 246                 return 1;
 247
 248         while ((p = strsep(&options, ",")) != NULL) {
 249                 if (!*p)
 250                         continue;
 251
 252                 token = match_token(p, tokens, args);
 253                 switch (token) {
 254                 case opt_uid:
 255                         if (match_int(&args[0], &tmp)) {
 256                                 printk(KERN_ERR "hfs: uid requires an argument\n");
 257                                 return 0;
 258                         }
 259                         hsb->s_uid = (uid_t)tmp;
 260                         break;
 261                 case opt_gid:
 262                         if (match_int(&args[0], &tmp)) {
 263                                 printk(KERN_ERR "hfs: gid requires an argument\n");
 264                                 return 0;
 265                         }
 266                         hsb->s_gid = (gid_t)tmp;
 267                         break;
 268                 case opt_umask:
 269                         if (match_octal(&args[0], &tmp)) {
 270                                 printk(KERN_ERR "hfs: umask requires a value\n");
 271                                 return 0;
 272                         }
 273                         hsb->s_file_umask = (umode_t)tmp;
 274                         hsb->s_dir_umask = (umode_t)tmp;
 275                         break;
 276                 case opt_file_umask:
 277                         if (match_octal(&args[0], &tmp)) {
 278                                 printk(KERN_ERR "hfs: file_umask requires a value\n");
 279                                 return 0;
 280                         }
 281                         hsb->s_file_umask = (umode_t)tmp;
 282                         break;
 283                 case opt_dir_umask:
 284                         if (match_octal(&args[0], &tmp)) {
 285                                 printk(KERN_ERR "hfs: dir_umask requires a value\n");
 286                                 return 0;
 287                         }
 288                         hsb->s_dir_umask = (umode_t)tmp;
 289                         break;
 290                 case opt_part:
 291                         if (match_int(&args[0], &hsb->part)) {
 292                                 printk(KERN_ERR "hfs: part requires an argument\n");
 293                                 return 0;
 294                         }
 295                         break;
 296                 case opt_session:
 297                         if (match_int(&args[0], &hsb->session)) {
 298                                 printk(KERN_ERR "hfs: session requires an argument\n");
 299                                 return 0;
 300                         }
 301                         break;
 302                 case opt_type:
 303                         if (match_fourchar(&args[0], &hsb->s_type)) {
 304                                 printk(KERN_ERR "hfs: type requires a 4 character value\n");
 305                                 return 0;
 306                         }
 307                         break;
 308                 case opt_creator:
 309                         if (match_fourchar(&args[0], &hsb->s_creator)) {
 310                                 printk(KERN_ERR "hfs: creator requires a 4 character value\n");
 311                                 return 0;
 312                         }
 313                         break;
 314                 case opt_quiet:
 315                         hsb->s_quiet = 1;
 316                         break;
 317                 case opt_codepage:
 318                         if (hsb->nls_disk) {
 319                                 printk(KERN_ERR "hfs: unable to change codepage\n");
 320                                 return 0;
 321                         }
 322                         p = match_strdup(&args[0]);
 323                         if (p)
 324                                 hsb->nls_disk = load_nls(p);
 325                         if (!hsb->nls_disk) {
 326                                 printk(KERN_ERR "hfs: unable to load codepage \"%s\"\n", p);
 327                                 kfree(p);
 328                                 return 0;
 329                         }
 330                         kfree(p);
 331                         break;
 332                 case opt_iocharset:
 333                         if (hsb->nls_io) {
 334                                 printk(KERN_ERR "hfs: unable to change iocharset\n");
 335                                 return 0;
 336                         }
 337                         p = match_strdup(&args[0]);
 338                         if (p)
 339                                 hsb->nls_io = load_nls(p);
 340                         if (!hsb->nls_io) {
 341                                 printk(KERN_ERR "hfs: unable to load iocharset \"%s\"\n", p);
 342                                 kfree(p);
 343                                 return 0;
 344                         }
 345                         kfree(p);
 346                         break;
 347                 default:
 348                         return 0;
 349                 }
 350         }
 351
 352         if (hsb->nls_disk && !hsb->nls_io) {
 353                 hsb->nls_io = load_nls_default();
 354                 if (!hsb->nls_io) {
 355                         printk(KERN_ERR "hfs: unable to load default iocharset\n");
 356                         return 0;
 357                 }
 358         }
 359         hsb->s_dir_umask &= 0777;
 360         hsb->s_file_umask &= 0577;
 361
 362         return 1;
 363 }
 364
 365 /*
 366  * hfs_read_super()
 367  *
 368  * This is the function that is responsible for mounting an HFS
 369  * filesystem.  It performs all the tasks necessary to get enough data
 370  * from the disk to read the root inode.  This includes parsing the
 371  * mount options, dealing with Macintosh partitions, reading the
 372  * superblock and the allocation bitmap blocks, calling
 373  * hfs_btree_init() to get the necessary data about the extents and
 374  * catalog B-trees and, finally, reading the root inode into memory.
 375  */
 376 static int hfs_fill_super(struct super_block *sb, void *data, int silent)
 377 {
 378         struct hfs_sb_info *sbi;
 379         struct hfs_find_data fd;
 380         hfs_cat_rec rec;
 381         struct inode *root_inode;
 382         int res;
 383
 384         sbi = kzalloc(sizeof(struct hfs_sb_info), GFP_KERNEL);
 385         if (!sbi)
 386                 return -ENOMEM;
 387         sb->s_fs_info = sbi;
 388         INIT_HLIST_HEAD(&sbi->rsrc_inodes);
 389
 390         res = -EINVAL;
 391         if (!parse_options((char *)data, sbi)) {
 392                 printk(KERN_ERR "hfs: unable to parse mount options.\n");
 393                 goto bail;
 394         }
 395
 396         sb->s_op = &hfs_super_operations;
 397         sb->s_flags |= MS_NODIRATIME;
 398         mutex_init(&sbi->bitmap_lock);
 399
 400         res = hfs_mdb_get(sb);
 401         if (res) {
 402                 if (!silent)
 403                         printk(KERN_WARNING "hfs: can't find a HFS filesystem on dev %s.\n",
 404                                 hfs_mdb_name(sb));
 405                 res = -EINVAL;
 406                 goto bail;
 407         }
 408
 409         /* try to get the root inode */
 410         hfs_find_init(HFS_SB(sb)->cat_tree, &fd);
 411         res = hfs_cat_find_brec(sb, HFS_ROOT_CNID, &fd);
 412         if (!res) {
 413                 if (fd.entrylength > sizeof(rec) || fd.entrylength < 0) {
 414                         res =  -EIO;
 415                         goto bail;
 416                 }
 417                 hfs_bnode_read(fd.bnode, &rec, fd.entryoffset, fd.entrylength);
 418         }
 419         if (res) {
 420                 hfs_find_exit(&fd);
 421                 goto bail_no_root;
 422         }
 423         res = -EINVAL;
 424         root_inode = hfs_iget(sb, &fd.search_key->cat, &rec);
 425         hfs_find_exit(&fd);
 426         if (!root_inode)
 427                 goto bail_no_root;
 428
 429         res = -ENOMEM;
 430         sb->s_root = d_alloc_root(root_inode);
 431         if (!sb->s_root)
 432                 goto bail_iput;
 433
 434         sb->s_root->d_op = &hfs_dentry_operations;
 435
 436         /* everything's okay */
 437         return 0;
 438
 439 bail_iput:
 440         iput(root_inode);
 441 bail_no_root:
 442         printk(KERN_ERR "hfs: get root inode failed.\n");
 443 bail:
 444         hfs_mdb_put(sb);
 445         return res;
 446 }
 447
 448 static int hfs_get_sb(struct file_system_type *fs_type,
 449                       int flags, const char *dev_name, void *data,
 450                       struct vfsmount *mnt)
 451 {
 452         return get_sb_bdev(fs_type, flags, dev_name, data, hfs_fill_super, mnt);
 453 }
 454
 455 static struct file_system_type hfs_fs_type = {
 456         .owner          = THIS_MODULE,
 457         .name           = "hfs",
 458         .get_sb         = hfs_get_sb,
 459         .kill_sb        = kill_block_super,
 460         .fs_flags       = FS_REQUIRES_DEV,
 461 };
 462
 463 static void hfs_init_once(void *p)
 464 {
 465         struct hfs_inode_info *i = p;
 466
 467         inode_init_once(&i->vfs_inode);
 468 }
 469
 470 static int __init init_hfs_fs(void)
 471 {
 472         int err;
 473
 474         hfs_inode_cachep = kmem_cache_create("hfs_inode_cache",
 475                 sizeof(struct hfs_inode_info), 0, SLAB_HWCACHE_ALIGN,
 476                 hfs_init_once);
 477         if (!hfs_inode_cachep)
 478                 return -ENOMEM;
 479         err = register_filesystem(&hfs_fs_type);
 480         if (err)
 481                 kmem_cache_destroy(hfs_inode_cachep);
 482         return err;
 483 }
 484
 485 static void __exit exit_hfs_fs(void)
 486 {
 487         unregister_filesystem(&hfs_fs_type);
 488         kmem_cache_destroy(hfs_inode_cachep);
 489 }
 490
 491 module_init(init_hfs_fs)
 492 module_exit(exit_hfs_fs)