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