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_module() and cleanup_module().  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/config.h>
  16 #include <linux/module.h>
  17 #include <linux/blkdev.h>
  18 #include <linux/mount.h>
  19 #include <linux/init.h>
  20 #include <linux/nls.h>
  21 #include <linux/parser.h>
  22 #include <linux/seq_file.h>
  23 #include <linux/vfs.h>
  24
  25 #include "hfs_fs.h"
  26 #include "btree.h"
  27
  28 static kmem_cache_t *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         sb->s_dirt = 0;
  54         if (sb->s_flags & MS_RDONLY)
  55                 return;
  56         /* sync everything to the buffers */
  57         hfs_mdb_commit(sb);
  58 }
  59
  60 /*
  61  * hfs_put_super()
  62  *
  63  * This is the put_super() entry in the super_operations structure for
  64  * HFS filesystems.  The purpose is to release the resources
  65  * associated with the superblock sb.
  66  */
  67 static void hfs_put_super(struct super_block *sb)
  68 {
  69         hfs_mdb_close(sb);
  70         /* release the MDB's resources */
  71         hfs_mdb_put(sb);
  72 }
  73
  74 /*
  75  * hfs_statfs()
  76  *
  77  * This is the statfs() entry in the super_operations structure for
  78  * HFS filesystems.  The purpose is to return various data about the
  79  * filesystem.
  80  *
  81  * changed f_files/f_ffree to reflect the fs_ablock/free_ablocks.
  82  */
  83 static int hfs_statfs(struct dentry *dentry, struct kstatfs *buf)
  84 {
  85         struct super_block *sb = dentry->d_sb;
  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_namelen = HFS_NAMELEN;
  95
  96         return 0;
  97 }
  98
  99 static int hfs_remount(struct super_block *sb, int *flags, char *data)
 100 {
 101         *flags |= MS_NODIRATIME;
 102         if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
 103                 return 0;
 104         if (!(*flags & MS_RDONLY)) {
 105                 if (!(HFS_SB(sb)->mdb->drAtrb & cpu_to_be16(HFS_SB_ATTRIB_UNMNT))) {
 106                         printk(KERN_WARNING "hfs: filesystem was not cleanly unmounted, "
 107                                "running fsck.hfs is recommended.  leaving read-only.\n");
 108                         sb->s_flags |= MS_RDONLY;
 109                         *flags |= MS_RDONLY;
 110                 } else if (HFS_SB(sb)->mdb->drAtrb & cpu_to_be16(HFS_SB_ATTRIB_SLOCK)) {
 111                         printk(KERN_WARNING "hfs: filesystem is marked locked, leaving read-only.\n");
 112                         sb->s_flags |= MS_RDONLY;
 113                         *flags |= MS_RDONLY;
 114                 }
 115         }
 116         return 0;
 117 }
 118
 119 static int hfs_show_options(struct seq_file *seq, struct vfsmount *mnt)
 120 {
 121         struct hfs_sb_info *sbi = HFS_SB(mnt->mnt_sb);
 122
 123         if (sbi->s_creator != cpu_to_be32(0x3f3f3f3f))
 124                 seq_printf(seq, ",creator=%.4s", (char *)&sbi->s_creator);
 125         if (sbi->s_type != cpu_to_be32(0x3f3f3f3f))
 126                 seq_printf(seq, ",type=%.4s", (char *)&sbi->s_type);
 127         seq_printf(seq, ",uid=%u,gid=%u", sbi->s_uid, sbi->s_gid);
 128         if (sbi->s_file_umask != 0133)
 129                 seq_printf(seq, ",file_umask=%o", sbi->s_file_umask);
 130         if (sbi->s_dir_umask != 0022)
 131                 seq_printf(seq, ",dir_umask=%o", sbi->s_dir_umask);
 132         if (sbi->part >= 0)
 133                 seq_printf(seq, ",part=%u", sbi->part);
 134         if (sbi->session >= 0)
 135                 seq_printf(seq, ",session=%u", sbi->session);
 136         if (sbi->nls_disk)
 137                 seq_printf(seq, ",codepage=%s", sbi->nls_disk->charset);
 138         if (sbi->nls_io)
 139                 seq_printf(seq, ",iocharset=%s", sbi->nls_io->charset);
 140         if (sbi->s_quiet)
 141                 seq_printf(seq, ",quiet");
 142         return 0;
 143 }
 144
 145 static struct inode *hfs_alloc_inode(struct super_block *sb)
 146 {
 147         struct hfs_inode_info *i;
 148
 149         i = kmem_cache_alloc(hfs_inode_cachep, SLAB_KERNEL);
 150         return i ? &i->vfs_inode : NULL;
 151 }
 152
 153 static void hfs_destroy_inode(struct inode *inode)
 154 {
 155         kmem_cache_free(hfs_inode_cachep, HFS_I(inode));
 156 }
 157
 158 static struct super_operations hfs_super_operations = {
 159         .alloc_inode    = hfs_alloc_inode,
 160         .destroy_inode  = hfs_destroy_inode,
 161         .write_inode    = hfs_write_inode,
 162         .clear_inode    = hfs_clear_inode,
 163         .put_super      = hfs_put_super,
 164         .write_super    = hfs_write_super,
 165         .statfs         = hfs_statfs,
 166         .remount_fs     = hfs_remount,
 167         .show_options   = hfs_show_options,
 168 };
 169
 170 enum {
 171         opt_uid, opt_gid, opt_umask, opt_file_umask, opt_dir_umask,
 172         opt_part, opt_session, opt_type, opt_creator, opt_quiet,
 173         opt_codepage, opt_iocharset,
 174         opt_err
 175 };
 176
 177 static match_table_t tokens = {
 178         { opt_uid, "uid=%u" },
 179         { opt_gid, "gid=%u" },
 180         { opt_umask, "umask=%o" },
 181         { opt_file_umask, "file_umask=%o" },
 182         { opt_dir_umask, "dir_umask=%o" },
 183         { opt_part, "part=%u" },
 184         { opt_session, "session=%u" },
 185         { opt_type, "type=%s" },
 186         { opt_creator, "creator=%s" },
 187         { opt_quiet, "quiet" },
 188         { opt_codepage, "codepage=%s" },
 189         { opt_iocharset, "iocharset=%s" },
 190         { opt_err, NULL }
 191 };
 192
 193 static inline int match_fourchar(substring_t *arg, u32 *result)
 194 {
 195         if (arg->to - arg->from != 4)
 196                 return -EINVAL;
 197         memcpy(result, arg->from, 4);
 198         return 0;
 199 }
 200
 201 /*
 202  * parse_options()
 203  *
 204  * adapted from linux/fs/msdos/inode.c written 1992,93 by Werner Almesberger
 205  * This function is called by hfs_read_super() to parse the mount options.
 206  */
 207 static int parse_options(char *options, struct hfs_sb_info *hsb)
 208 {
 209         char *p;
 210         substring_t args[MAX_OPT_ARGS];
 211         int tmp, token;
 212
 213         /* initialize the sb with defaults */
 214         hsb->s_uid = current->uid;
 215         hsb->s_gid = current->gid;
 216         hsb->s_file_umask = 0133;
 217         hsb->s_dir_umask = 0022;
 218         hsb->s_type = hsb->s_creator = cpu_to_be32(0x3f3f3f3f); /* == '????' */
 219         hsb->s_quiet = 0;
 220         hsb->part = -1;
 221         hsb->session = -1;
 222
 223         if (!options)
 224                 return 1;
 225
 226         while ((p = strsep(&options, ",")) != NULL) {
 227                 if (!*p)
 228                         continue;
 229
 230                 token = match_token(p, tokens, args);
 231                 switch (token) {
 232                 case opt_uid:
 233                         if (match_int(&args[0], &tmp)) {
 234                                 printk(KERN_ERR "hfs: uid requires an argument\n");
 235                                 return 0;
 236                         }
 237                         hsb->s_uid = (uid_t)tmp;
 238                         break;
 239                 case opt_gid:
 240                         if (match_int(&args[0], &tmp)) {
 241                                 printk(KERN_ERR "hfs: gid requires an argument\n");
 242                                 return 0;
 243                         }
 244                         hsb->s_gid = (gid_t)tmp;
 245                         break;
 246                 case opt_umask:
 247                         if (match_octal(&args[0], &tmp)) {
 248                                 printk(KERN_ERR "hfs: umask requires a value\n");
 249                                 return 0;
 250                         }
 251                         hsb->s_file_umask = (umode_t)tmp;
 252                         hsb->s_dir_umask = (umode_t)tmp;
 253                         break;
 254                 case opt_file_umask:
 255                         if (match_octal(&args[0], &tmp)) {
 256                                 printk(KERN_ERR "hfs: file_umask requires a value\n");
 257                                 return 0;
 258                         }
 259                         hsb->s_file_umask = (umode_t)tmp;
 260                         break;
 261                 case opt_dir_umask:
 262                         if (match_octal(&args[0], &tmp)) {
 263                                 printk(KERN_ERR "hfs: dir_umask requires a value\n");
 264                                 return 0;
 265                         }
 266                         hsb->s_dir_umask = (umode_t)tmp;
 267                         break;
 268                 case opt_part:
 269                         if (match_int(&args[0], &hsb->part)) {
 270                                 printk(KERN_ERR "hfs: part requires an argument\n");
 271                                 return 0;
 272                         }
 273                         break;
 274                 case opt_session:
 275                         if (match_int(&args[0], &hsb->session)) {
 276                                 printk(KERN_ERR "hfs: session requires an argument\n");
 277                                 return 0;
 278                         }
 279                         break;
 280                 case opt_type:
 281                         if (match_fourchar(&args[0], &hsb->s_type)) {
 282                                 printk(KERN_ERR "hfs: type requires a 4 character value\n");
 283                                 return 0;
 284                         }
 285                         break;
 286                 case opt_creator:
 287                         if (match_fourchar(&args[0], &hsb->s_creator)) {
 288                                 printk(KERN_ERR "hfs: creator requires a 4 character value\n");
 289                                 return 0;
 290                         }
 291                         break;
 292                 case opt_quiet:
 293                         hsb->s_quiet = 1;
 294                         break;
 295                 case opt_codepage:
 296                         if (hsb->nls_disk) {
 297                                 printk(KERN_ERR "hfs: unable to change codepage\n");
 298                                 return 0;
 299                         }
 300                         p = match_strdup(&args[0]);
 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                         hsb->nls_io = load_nls(p);
 316                         if (!hsb->nls_io) {
 317                                 printk(KERN_ERR "hfs: unable to load iocharset \"%s\"\n", p);
 318                                 kfree(p);
 319                                 return 0;
 320                         }
 321                         kfree(p);
 322                         break;
 323                 default:
 324                         return 0;
 325                 }
 326         }
 327
 328         if (hsb->nls_disk && !hsb->nls_io) {
 329                 hsb->nls_io = load_nls_default();
 330                 if (!hsb->nls_io) {
 331                         printk(KERN_ERR "hfs: unable to load default iocharset\n");
 332                         return 0;
 333                 }
 334         }
 335         hsb->s_dir_umask &= 0777;
 336         hsb->s_file_umask &= 0577;
 337
 338         return 1;
 339 }
 340
 341 /*
 342  * hfs_read_super()
 343  *
 344  * This is the function that is responsible for mounting an HFS
 345  * filesystem.  It performs all the tasks necessary to get enough data
 346  * from the disk to read the root inode.  This includes parsing the
 347  * mount options, dealing with Macintosh partitions, reading the
 348  * superblock and the allocation bitmap blocks, calling
 349  * hfs_btree_init() to get the necessary data about the extents and
 350  * catalog B-trees and, finally, reading the root inode into memory.
 351  */
 352 static int hfs_fill_super(struct super_block *sb, void *data, int silent)
 353 {
 354         struct hfs_sb_info *sbi;
 355         struct hfs_find_data fd;
 356         hfs_cat_rec rec;
 357         struct inode *root_inode;
 358         int res;
 359
 360         sbi = kmalloc(sizeof(struct hfs_sb_info), GFP_KERNEL);
 361         if (!sbi)
 362                 return -ENOMEM;
 363         sb->s_fs_info = sbi;
 364         memset(sbi, 0, sizeof(struct hfs_sb_info));
 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         init_MUTEX(&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         root_inode = hfs_iget(sb, &fd.search_key->cat, &rec);
 396         hfs_find_exit(&fd);
 397         if (!root_inode)
 398                 goto bail_no_root;
 399
 400         sb->s_root = d_alloc_root(root_inode);
 401         if (!sb->s_root)
 402                 goto bail_iput;
 403
 404         sb->s_root->d_op = &hfs_dentry_operations;
 405
 406         /* everything's okay */
 407         return 0;
 408
 409 bail_iput:
 410         iput(root_inode);
 411 bail_no_root:
 412         printk(KERN_ERR "hfs: get root inode failed.\n");
 413 bail:
 414         hfs_mdb_put(sb);
 415         return res;
 416 }
 417
 418 static int hfs_get_sb(struct file_system_type *fs_type,
 419                       int flags, const char *dev_name, void *data,
 420                       struct vfsmount *mnt)
 421 {
 422         return get_sb_bdev(fs_type, flags, dev_name, data, hfs_fill_super, mnt);
 423 }
 424
 425 static struct file_system_type hfs_fs_type = {
 426         .owner          = THIS_MODULE,
 427         .name           = "hfs",
 428         .get_sb         = hfs_get_sb,
 429         .kill_sb        = kill_block_super,
 430         .fs_flags       = FS_REQUIRES_DEV,
 431 };
 432
 433 static void hfs_init_once(void *p, kmem_cache_t *cachep, unsigned long flags)
 434 {
 435         struct hfs_inode_info *i = p;
 436
 437         if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) == SLAB_CTOR_CONSTRUCTOR)
 438                 inode_init_once(&i->vfs_inode);
 439 }
 440
 441 static int __init init_hfs_fs(void)
 442 {
 443         int err;
 444
 445         hfs_inode_cachep = kmem_cache_create("hfs_inode_cache",
 446                 sizeof(struct hfs_inode_info), 0, SLAB_HWCACHE_ALIGN,
 447                 hfs_init_once, NULL);
 448         if (!hfs_inode_cachep)
 449                 return -ENOMEM;
 450         err = register_filesystem(&hfs_fs_type);
 451         if (err)
 452                 kmem_cache_destroy(hfs_inode_cachep);
 453         return err;
 454 }
 455
 456 static void __exit exit_hfs_fs(void)
 457 {
 458         unregister_filesystem(&hfs_fs_type);
 459         if (kmem_cache_destroy(hfs_inode_cachep))
 460                 printk(KERN_ERR "hfs_inode_cache: not all structures were freed\n");
 461 }
 462
 463 module_init(init_hfs_fs)
 464 module_exit(exit_hfs_fs)