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/slab.h>
  23 #include <linux/smp_lock.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 /*
  34  * hfs_write_super()
  35  *
  36  * Description:
  37  *   This function is called by the VFS only. When the filesystem
  38  *   is mounted r/w it updates the MDB on disk.
  39  * Input Variable(s):
  40  *   struct super_block *sb: Pointer to the hfs superblock
  41  * Output Variable(s):
  42  *   NONE
  43  * Returns:
  44  *   void
  45  * Preconditions:
  46  *   'sb' points to a "valid" (struct super_block).
  47  * Postconditions:
  48  *   The MDB is marked 'unsuccessfully unmounted' by clearing bit 8 of drAtrb
  49  *   (hfs_put_super() must set this flag!). Some MDB fields are updated
  50  *   and the MDB buffer is written to disk by calling hfs_mdb_commit().
  51  */
  52 static void hfs_write_super(struct super_block *sb)
  53 {
  54         lock_super(sb);
  55         sb->s_dirt = 0;
  56
  57         /* sync everything to the buffers */
  58         if (!(sb->s_flags & MS_RDONLY))
  59                 hfs_mdb_commit(sb);
  60         unlock_super(sb);
  61 }
  62
  63 static int hfs_sync_fs(struct super_block *sb, int wait)
  64 {
  65         lock_super(sb);
  66         hfs_mdb_commit(sb);
  67         sb->s_dirt = 0;
  68         unlock_super(sb);
  69
  70         return 0;
  71 }
  72
  73 /*
  74  * hfs_put_super()
  75  *
  76  * This is the put_super() entry in the super_operations structure for
  77  * HFS filesystems.  The purpose is to release the resources
  78  * associated with the superblock sb.
  79  */
  80 static void hfs_put_super(struct super_block *sb)
  81 {
  82         lock_kernel();
  83
  84         if (sb->s_dirt)
  85                 hfs_write_super(sb);
  86         hfs_mdb_close(sb);
  87         /* release the MDB's resources */
  88         hfs_mdb_put(sb);
  89
  90         unlock_kernel();
  91 }
  92
  93 /*
  94  * hfs_statfs()
  95  *
  96  * This is the statfs() entry in the super_operations structure for
  97  * HFS filesystems.  The purpose is to return various data about the
  98  * filesystem.
  99  *
 100  * changed f_files/f_ffree to reflect the fs_ablock/free_ablocks.
 101  */
 102 static int hfs_statfs(struct dentry *dentry, struct kstatfs *buf)
 103 {
 104         struct super_block *sb = dentry->d_sb;
 105         u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
 106
 107         buf->f_type = HFS_SUPER_MAGIC;
 108         buf->f_bsize = sb->s_blocksize;
 109         buf->f_blocks = (u32)HFS_SB(sb)->fs_ablocks * HFS_SB(sb)->fs_div;
 110         buf->f_bfree = (u32)HFS_SB(sb)->free_ablocks * HFS_SB(sb)->fs_div;
 111         buf->f_bavail = buf->f_bfree;
 112         buf->f_files = HFS_SB(sb)->fs_ablocks;
 113         buf->f_ffree = HFS_SB(sb)->free_ablocks;
 114         buf->f_fsid.val[0] = (u32)id;
 115         buf->f_fsid.val[1] = (u32)(id >> 32);
 116         buf->f_namelen = HFS_NAMELEN;
 117
 118         return 0;
 119 }
 120
 121 static int hfs_remount(struct super_block *sb, int *flags, char *data)
 122 {
 123         *flags |= MS_NODIRATIME;
 124         if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
 125                 return 0;
 126         if (!(*flags & MS_RDONLY)) {
 127                 if (!(HFS_SB(sb)->mdb->drAtrb & cpu_to_be16(HFS_SB_ATTRIB_UNMNT))) {
 128                         printk(KERN_WARNING "hfs: filesystem was not cleanly unmounted, "
 129                                "running fsck.hfs is recommended.  leaving read-only.\n");
 130                         sb->s_flags |= MS_RDONLY;
 131                         *flags |= MS_RDONLY;
 132                 } else if (HFS_SB(sb)->mdb->drAtrb & cpu_to_be16(HFS_SB_ATTRIB_SLOCK)) {
 133                         printk(KERN_WARNING "hfs: filesystem is marked locked, leaving read-only.\n");
 134                         sb->s_flags |= MS_RDONLY;
 135                         *flags |= MS_RDONLY;
 136                 }
 137         }
 138         return 0;
 139 }
 140
 141 static int hfs_show_options(struct seq_file *seq, struct vfsmount *mnt)
 142 {
 143         struct hfs_sb_info *sbi = HFS_SB(mnt->mnt_sb);
 144
 145         if (sbi->s_creator != cpu_to_be32(0x3f3f3f3f))
 146                 seq_printf(seq, ",creator=%.4s", (char *)&sbi->s_creator);
 147         if (sbi->s_type != cpu_to_be32(0x3f3f3f3f))
 148                 seq_printf(seq, ",type=%.4s", (char *)&sbi->s_type);
 149         seq_printf(seq, ",uid=%u,gid=%u", sbi->s_uid, sbi->s_gid);
 150         if (sbi->s_file_umask != 0133)
 151                 seq_printf(seq, ",file_umask=%o", sbi->s_file_umask);
 152         if (sbi->s_dir_umask != 0022)
 153                 seq_printf(seq, ",dir_umask=%o", sbi->s_dir_umask);
 154         if (sbi->part >= 0)
 155                 seq_printf(seq, ",part=%u", sbi->part);
 156         if (sbi->session >= 0)
 157                 seq_printf(seq, ",session=%u", sbi->session);
 158         if (sbi->nls_disk)
 159                 seq_printf(seq, ",codepage=%s", sbi->nls_disk->charset);
 160         if (sbi->nls_io)
 161                 seq_printf(seq, ",iocharset=%s", sbi->nls_io->charset);
 162         if (sbi->s_quiet)
 163                 seq_printf(seq, ",quiet");
 164         return 0;
 165 }
 166
 167 static struct inode *hfs_alloc_inode(struct super_block *sb)
 168 {
 169         struct hfs_inode_info *i;
 170
 171         i = kmem_cache_alloc(hfs_inode_cachep, GFP_KERNEL);
 172         return i ? &i->vfs_inode : NULL;
 173 }
 174
 175 static void hfs_destroy_inode(struct inode *inode)
 176 {
 177         kmem_cache_free(hfs_inode_cachep, HFS_I(inode));
 178 }
 179
 180 static const struct super_operations hfs_super_operations = {
 181         .alloc_inode    = hfs_alloc_inode,
 182         .destroy_inode  = hfs_destroy_inode,
 183         .write_inode    = hfs_write_inode,
 184         .evict_inode    = hfs_evict_inode,
 185         .put_super      = hfs_put_super,
 186         .write_super    = hfs_write_super,
 187         .sync_fs        = hfs_sync_fs,
 188         .statfs         = hfs_statfs,
 189         .remount_fs     = hfs_remount,
 190         .show_options   = hfs_show_options,
 191 };
 192
 193 enum {
 194         opt_uid, opt_gid, opt_umask, opt_file_umask, opt_dir_umask,
 195         opt_part, opt_session, opt_type, opt_creator, opt_quiet,
 196         opt_codepage, opt_iocharset,
 197         opt_err
 198 };
 199
 200 static const match_table_t tokens = {
 201         { opt_uid, "uid=%u" },
 202         { opt_gid, "gid=%u" },
 203         { opt_umask, "umask=%o" },
 204         { opt_file_umask, "file_umask=%o" },
 205         { opt_dir_umask, "dir_umask=%o" },
 206         { opt_part, "part=%u" },
 207         { opt_session, "session=%u" },
 208         { opt_type, "type=%s" },
 209         { opt_creator, "creator=%s" },
 210         { opt_quiet, "quiet" },
 211         { opt_codepage, "codepage=%s" },
 212         { opt_iocharset, "iocharset=%s" },
 213         { opt_err, NULL }
 214 };
 215
 216 static inline int match_fourchar(substring_t *arg, u32 *result)
 217 {
 218         if (arg->to - arg->from != 4)
 219                 return -EINVAL;
 220         memcpy(result, arg->from, 4);
 221         return 0;
 222 }
 223
 224 /*
 225  * parse_options()
 226  *
 227  * adapted from linux/fs/msdos/inode.c written 1992,93 by Werner Almesberger
 228  * This function is called by hfs_read_super() to parse the mount options.
 229  */
 230 static int parse_options(char *options, struct hfs_sb_info *hsb)
 231 {
 232         char *p;
 233         substring_t args[MAX_OPT_ARGS];
 234         int tmp, token;
 235
 236         /* initialize the sb with defaults */
 237         hsb->s_uid = current_uid();
 238         hsb->s_gid = current_gid();
 239         hsb->s_file_umask = 0133;
 240         hsb->s_dir_umask = 0022;
 241         hsb->s_type = hsb->s_creator = cpu_to_be32(0x3f3f3f3f); /* == '????' */
 242         hsb->s_quiet = 0;
 243         hsb->part = -1;
 244         hsb->session = -1;
 245
 246         if (!options)
 247                 return 1;
 248
 249         while ((p = strsep(&options, ",")) != NULL) {
 250                 if (!*p)
 251                         continue;
 252
 253                 token = match_token(p, tokens, args);
 254                 switch (token) {
 255                 case opt_uid:
 256                         if (match_int(&args[0], &tmp)) {
 257                                 printk(KERN_ERR "hfs: uid requires an argument\n");
 258                                 return 0;
 259                         }
 260                         hsb->s_uid = (uid_t)tmp;
 261                         break;
 262                 case opt_gid:
 263                         if (match_int(&args[0], &tmp)) {
 264                                 printk(KERN_ERR "hfs: gid requires an argument\n");
 265                                 return 0;
 266                         }
 267                         hsb->s_gid = (gid_t)tmp;
 268                         break;
 269                 case opt_umask:
 270                         if (match_octal(&args[0], &tmp)) {
 271                                 printk(KERN_ERR "hfs: umask requires a value\n");
 272                                 return 0;
 273                         }
 274                         hsb->s_file_umask = (umode_t)tmp;
 275                         hsb->s_dir_umask = (umode_t)tmp;
 276                         break;
 277                 case opt_file_umask:
 278                         if (match_octal(&args[0], &tmp)) {
 279                                 printk(KERN_ERR "hfs: file_umask requires a value\n");
 280                                 return 0;
 281                         }
 282                         hsb->s_file_umask = (umode_t)tmp;
 283                         break;
 284                 case opt_dir_umask:
 285                         if (match_octal(&args[0], &tmp)) {
 286                                 printk(KERN_ERR "hfs: dir_umask requires a value\n");
 287                                 return 0;
 288                         }
 289                         hsb->s_dir_umask = (umode_t)tmp;
 290                         break;
 291                 case opt_part:
 292                         if (match_int(&args[0], &hsb->part)) {
 293                                 printk(KERN_ERR "hfs: part requires an argument\n");
 294                                 return 0;
 295                         }
 296                         break;
 297                 case opt_session:
 298                         if (match_int(&args[0], &hsb->session)) {
 299                                 printk(KERN_ERR "hfs: session requires an argument\n");
 300                                 return 0;
 301                         }
 302                         break;
 303                 case opt_type:
 304                         if (match_fourchar(&args[0], &hsb->s_type)) {
 305                                 printk(KERN_ERR "hfs: type requires a 4 character value\n");
 306                                 return 0;
 307                         }
 308                         break;
 309                 case opt_creator:
 310                         if (match_fourchar(&args[0], &hsb->s_creator)) {
 311                                 printk(KERN_ERR "hfs: creator requires a 4 character value\n");
 312                                 return 0;
 313                         }
 314                         break;
 315                 case opt_quiet:
 316                         hsb->s_quiet = 1;
 317                         break;
 318                 case opt_codepage:
 319                         if (hsb->nls_disk) {
 320                                 printk(KERN_ERR "hfs: unable to change codepage\n");
 321                                 return 0;
 322                         }
 323                         p = match_strdup(&args[0]);
 324                         if (p)
 325                                 hsb->nls_disk = load_nls(p);
 326                         if (!hsb->nls_disk) {
 327                                 printk(KERN_ERR "hfs: unable to load codepage \"%s\"\n", p);
 328                                 kfree(p);
 329                                 return 0;
 330                         }
 331                         kfree(p);
 332                         break;
 333                 case opt_iocharset:
 334                         if (hsb->nls_io) {
 335                                 printk(KERN_ERR "hfs: unable to change iocharset\n");
 336                                 return 0;
 337                         }
 338                         p = match_strdup(&args[0]);
 339                         if (p)
 340                                 hsb->nls_io = load_nls(p);
 341                         if (!hsb->nls_io) {
 342                                 printk(KERN_ERR "hfs: unable to load iocharset \"%s\"\n", p);
 343                                 kfree(p);
 344                                 return 0;
 345                         }
 346                         kfree(p);
 347                         break;
 348                 default:
 349                         return 0;
 350                 }
 351         }
 352
 353         if (hsb->nls_disk && !hsb->nls_io) {
 354                 hsb->nls_io = load_nls_default();
 355                 if (!hsb->nls_io) {
 356                         printk(KERN_ERR "hfs: unable to load default iocharset\n");
 357                         return 0;
 358                 }
 359         }
 360         hsb->s_dir_umask &= 0777;
 361         hsb->s_file_umask &= 0577;
 362
 363         return 1;
 364 }
 365
 366 /*
 367  * hfs_read_super()
 368  *
 369  * This is the function that is responsible for mounting an HFS
 370  * filesystem.  It performs all the tasks necessary to get enough data
 371  * from the disk to read the root inode.  This includes parsing the
 372  * mount options, dealing with Macintosh partitions, reading the
 373  * superblock and the allocation bitmap blocks, calling
 374  * hfs_btree_init() to get the necessary data about the extents and
 375  * catalog B-trees and, finally, reading the root inode into memory.
 376  */
 377 static int hfs_fill_super(struct super_block *sb, void *data, int silent)
 378 {
 379         struct hfs_sb_info *sbi;
 380         struct hfs_find_data fd;
 381         hfs_cat_rec rec;
 382         struct inode *root_inode;
 383         int res;
 384
 385         lock_kernel();
 386
 387         sbi = kzalloc(sizeof(struct hfs_sb_info), GFP_KERNEL);
 388         if (!sbi) {
 389                 unlock_kernel();
 390                 return -ENOMEM;
 391         }
 392         sb->s_fs_info = sbi;
 393         INIT_HLIST_HEAD(&sbi->rsrc_inodes);
 394
 395         res = -EINVAL;
 396         if (!parse_options((char *)data, sbi)) {
 397                 printk(KERN_ERR "hfs: unable to parse mount options.\n");
 398                 goto bail;
 399         }
 400
 401         sb->s_op = &hfs_super_operations;
 402         sb->s_flags |= MS_NODIRATIME;
 403         mutex_init(&sbi->bitmap_lock);
 404
 405         res = hfs_mdb_get(sb);
 406         if (res) {
 407                 if (!silent)
 408                         printk(KERN_WARNING "hfs: can't find a HFS filesystem on dev %s.\n",
 409                                 hfs_mdb_name(sb));
 410                 res = -EINVAL;
 411                 goto bail;
 412         }
 413
 414         /* try to get the root inode */
 415         hfs_find_init(HFS_SB(sb)->cat_tree, &fd);
 416         res = hfs_cat_find_brec(sb, HFS_ROOT_CNID, &fd);
 417         if (!res) {
 418                 if (fd.entrylength > sizeof(rec) || fd.entrylength < 0) {
 419                         res =  -EIO;
 420                         goto bail;
 421                 }
 422                 hfs_bnode_read(fd.bnode, &rec, fd.entryoffset, fd.entrylength);
 423         }
 424         if (res) {
 425                 hfs_find_exit(&fd);
 426                 goto bail_no_root;
 427         }
 428         res = -EINVAL;
 429         root_inode = hfs_iget(sb, &fd.search_key->cat, &rec);
 430         hfs_find_exit(&fd);
 431         if (!root_inode)
 432                 goto bail_no_root;
 433
 434         res = -ENOMEM;
 435         sb->s_root = d_alloc_root(root_inode);
 436         if (!sb->s_root)
 437                 goto bail_iput;
 438
 439         sb->s_root->d_op = &hfs_dentry_operations;
 440
 441         /* everything's okay */
 442         unlock_kernel();
 443         return 0;
 444
 445 bail_iput:
 446         iput(root_inode);
 447 bail_no_root:
 448         printk(KERN_ERR "hfs: get root inode failed.\n");
 449 bail:
 450         hfs_mdb_put(sb);
 451         unlock_kernel();
 452         return res;
 453 }
 454
 455 static int hfs_get_sb(struct file_system_type *fs_type,
 456                       int flags, const char *dev_name, void *data,
 457                       struct vfsmount *mnt)
 458 {
 459         return get_sb_bdev(fs_type, flags, dev_name, data, hfs_fill_super, mnt);
 460 }
 461
 462 static struct file_system_type hfs_fs_type = {
 463         .owner          = THIS_MODULE,
 464         .name           = "hfs",
 465         .get_sb         = hfs_get_sb,
 466         .kill_sb        = kill_block_super,
 467         .fs_flags       = FS_REQUIRES_DEV,
 468 };
 469
 470 static void hfs_init_once(void *p)
 471 {
 472         struct hfs_inode_info *i = p;
 473
 474         inode_init_once(&i->vfs_inode);
 475 }
 476
 477 static int __init init_hfs_fs(void)
 478 {
 479         int err;
 480
 481         hfs_inode_cachep = kmem_cache_create("hfs_inode_cache",
 482                 sizeof(struct hfs_inode_info), 0, SLAB_HWCACHE_ALIGN,
 483                 hfs_init_once);
 484         if (!hfs_inode_cachep)
 485                 return -ENOMEM;
 486         err = register_filesystem(&hfs_fs_type);
 487         if (err)
 488                 kmem_cache_destroy(hfs_inode_cachep);
 489         return err;
 490 }
 491
 492 static void __exit exit_hfs_fs(void)
 493 {
 494         unregister_filesystem(&hfs_fs_type);
 495         kmem_cache_destroy(hfs_inode_cachep);
 496 }
 497
 498 module_init(init_hfs_fs)
 499 module_exit(exit_hfs_fs)