root/fs/hfs/super.c

DEFINITIONS

1. hfs_sync_fs
2. hfs_put_super
3. flush_mdb
4. hfs_mark_mdb_dirty
5. hfs_statfs
6. hfs_remount
7. hfs_show_options
8. hfs_alloc_inode
9. hfs_free_inode
10. match_fourchar
11. parse_options
12. hfs_fill_super
13. hfs_mount
14. hfs_init_once
15. init_hfs_fs
16. exit_hfs_fs

   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/backing-dev.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/slab.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 static int hfs_sync_fs(struct super_block *sb, int wait)
  34 {
  35         hfs_mdb_commit(sb);
  36         return 0;
  37 }
  38 
  39 /*
  40  * hfs_put_super()
  41  *
  42  * This is the put_super() entry in the super_operations structure for
  43  * HFS filesystems.  The purpose is to release the resources
  44  * associated with the superblock sb.
  45  */
  46 static void hfs_put_super(struct super_block *sb)
  47 {
  48         cancel_delayed_work_sync(&HFS_SB(sb)->mdb_work);
  49         hfs_mdb_close(sb);
  50         /* release the MDB's resources */
  51         hfs_mdb_put(sb);
  52 }
  53 
  54 static void flush_mdb(struct work_struct *work)
  55 {
  56         struct hfs_sb_info *sbi;
  57         struct super_block *sb;
  58 
  59         sbi = container_of(work, struct hfs_sb_info, mdb_work.work);
  60         sb = sbi->sb;
  61 
  62         spin_lock(&sbi->work_lock);
  63         sbi->work_queued = 0;
  64         spin_unlock(&sbi->work_lock);
  65 
  66         hfs_mdb_commit(sb);
  67 }
  68 
  69 void hfs_mark_mdb_dirty(struct super_block *sb)
  70 {
  71         struct hfs_sb_info *sbi = HFS_SB(sb);
  72         unsigned long delay;
  73 
  74         if (sb_rdonly(sb))
  75                 return;
  76 
  77         spin_lock(&sbi->work_lock);
  78         if (!sbi->work_queued) {
  79                 delay = msecs_to_jiffies(dirty_writeback_interval * 10);
  80                 queue_delayed_work(system_long_wq, &sbi->mdb_work, delay);
  81                 sbi->work_queued = 1;
  82         }
  83         spin_unlock(&sbi->work_lock);
  84 }
  85 
  86 /*
  87  * hfs_statfs()
  88  *
  89  * This is the statfs() entry in the super_operations structure for
  90  * HFS filesystems.  The purpose is to return various data about the
  91  * filesystem.
  92  *
  93  * changed f_files/f_ffree to reflect the fs_ablock/free_ablocks.
  94  */
  95 static int hfs_statfs(struct dentry *dentry, struct kstatfs *buf)
  96 {
  97         struct super_block *sb = dentry->d_sb;
  98         u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
  99 
 100         buf->f_type = HFS_SUPER_MAGIC;
 101         buf->f_bsize = sb->s_blocksize;
 102         buf->f_blocks = (u32)HFS_SB(sb)->fs_ablocks * HFS_SB(sb)->fs_div;
 103         buf->f_bfree = (u32)HFS_SB(sb)->free_ablocks * HFS_SB(sb)->fs_div;
 104         buf->f_bavail = buf->f_bfree;
 105         buf->f_files = HFS_SB(sb)->fs_ablocks;
 106         buf->f_ffree = HFS_SB(sb)->free_ablocks;
 107         buf->f_fsid.val[0] = (u32)id;
 108         buf->f_fsid.val[1] = (u32)(id >> 32);
 109         buf->f_namelen = HFS_NAMELEN;
 110 
 111         return 0;
 112 }
 113 
 114 static int hfs_remount(struct super_block *sb, int *flags, char *data)
 115 {
 116         sync_filesystem(sb);
 117         *flags |= SB_NODIRATIME;
 118         if ((bool)(*flags & SB_RDONLY) == sb_rdonly(sb))
 119                 return 0;
 120         if (!(*flags & SB_RDONLY)) {
 121                 if (!(HFS_SB(sb)->mdb->drAtrb & cpu_to_be16(HFS_SB_ATTRIB_UNMNT))) {
 122                         pr_warn("filesystem was not cleanly unmounted, running fsck.hfs is recommended.  leaving read-only.\n");
 123                         sb->s_flags |= SB_RDONLY;
 124                         *flags |= SB_RDONLY;
 125                 } else if (HFS_SB(sb)->mdb->drAtrb & cpu_to_be16(HFS_SB_ATTRIB_SLOCK)) {
 126                         pr_warn("filesystem is marked locked, leaving read-only.\n");
 127                         sb->s_flags |= SB_RDONLY;
 128                         *flags |= SB_RDONLY;
 129                 }
 130         }
 131         return 0;
 132 }
 133 
 134 static int hfs_show_options(struct seq_file *seq, struct dentry *root)
 135 {
 136         struct hfs_sb_info *sbi = HFS_SB(root->d_sb);
 137 
 138         if (sbi->s_creator != cpu_to_be32(0x3f3f3f3f))
 139                 seq_show_option_n(seq, "creator", (char *)&sbi->s_creator, 4);
 140         if (sbi->s_type != cpu_to_be32(0x3f3f3f3f))
 141                 seq_show_option_n(seq, "type", (char *)&sbi->s_type, 4);
 142         seq_printf(seq, ",uid=%u,gid=%u",
 143                         from_kuid_munged(&init_user_ns, sbi->s_uid),
 144                         from_kgid_munged(&init_user_ns, sbi->s_gid));
 145         if (sbi->s_file_umask != 0133)
 146                 seq_printf(seq, ",file_umask=%o", sbi->s_file_umask);
 147         if (sbi->s_dir_umask != 0022)
 148                 seq_printf(seq, ",dir_umask=%o", sbi->s_dir_umask);
 149         if (sbi->part >= 0)
 150                 seq_printf(seq, ",part=%u", sbi->part);
 151         if (sbi->session >= 0)
 152                 seq_printf(seq, ",session=%u", sbi->session);
 153         if (sbi->nls_disk)
 154                 seq_printf(seq, ",codepage=%s", sbi->nls_disk->charset);
 155         if (sbi->nls_io)
 156                 seq_printf(seq, ",iocharset=%s", sbi->nls_io->charset);
 157         if (sbi->s_quiet)
 158                 seq_printf(seq, ",quiet");
 159         return 0;
 160 }
 161 
 162 static struct inode *hfs_alloc_inode(struct super_block *sb)
 163 {
 164         struct hfs_inode_info *i;
 165 
 166         i = kmem_cache_alloc(hfs_inode_cachep, GFP_KERNEL);
 167         return i ? &i->vfs_inode : NULL;
 168 }
 169 
 170 static void hfs_free_inode(struct inode *inode)
 171 {
 172         kmem_cache_free(hfs_inode_cachep, HFS_I(inode));
 173 }
 174 
 175 static const struct super_operations hfs_super_operations = {
 176         .alloc_inode    = hfs_alloc_inode,
 177         .free_inode     = hfs_free_inode,
 178         .write_inode    = hfs_write_inode,
 179         .evict_inode    = hfs_evict_inode,
 180         .put_super      = hfs_put_super,
 181         .sync_fs        = hfs_sync_fs,
 182         .statfs         = hfs_statfs,
 183         .remount_fs     = hfs_remount,
 184         .show_options   = hfs_show_options,
 185 };
 186 
 187 enum {
 188         opt_uid, opt_gid, opt_umask, opt_file_umask, opt_dir_umask,
 189         opt_part, opt_session, opt_type, opt_creator, opt_quiet,
 190         opt_codepage, opt_iocharset,
 191         opt_err
 192 };
 193 
 194 static const match_table_t tokens = {
 195         { opt_uid, "uid=%u" },
 196         { opt_gid, "gid=%u" },
 197         { opt_umask, "umask=%o" },
 198         { opt_file_umask, "file_umask=%o" },
 199         { opt_dir_umask, "dir_umask=%o" },
 200         { opt_part, "part=%u" },
 201         { opt_session, "session=%u" },
 202         { opt_type, "type=%s" },
 203         { opt_creator, "creator=%s" },
 204         { opt_quiet, "quiet" },
 205         { opt_codepage, "codepage=%s" },
 206         { opt_iocharset, "iocharset=%s" },
 207         { opt_err, NULL }
 208 };
 209 
 210 static inline int match_fourchar(substring_t *arg, u32 *result)
 211 {
 212         if (arg->to - arg->from != 4)
 213                 return -EINVAL;
 214         memcpy(result, arg->from, 4);
 215         return 0;
 216 }
 217 
 218 /*
 219  * parse_options()
 220  *
 221  * adapted from linux/fs/msdos/inode.c written 1992,93 by Werner Almesberger
 222  * This function is called by hfs_read_super() to parse the mount options.
 223  */
 224 static int parse_options(char *options, struct hfs_sb_info *hsb)
 225 {
 226         char *p;
 227         substring_t args[MAX_OPT_ARGS];
 228         int tmp, token;
 229 
 230         /* initialize the sb with defaults */
 231         hsb->s_uid = current_uid();
 232         hsb->s_gid = current_gid();
 233         hsb->s_file_umask = 0133;
 234         hsb->s_dir_umask = 0022;
 235         hsb->s_type = hsb->s_creator = cpu_to_be32(0x3f3f3f3f); /* == '????' */
 236         hsb->s_quiet = 0;
 237         hsb->part = -1;
 238         hsb->session = -1;
 239 
 240         if (!options)
 241                 return 1;
 242 
 243         while ((p = strsep(&options, ",")) != NULL) {
 244                 if (!*p)
 245                         continue;
 246 
 247                 token = match_token(p, tokens, args);
 248                 switch (token) {
 249                 case opt_uid:
 250                         if (match_int(&args[0], &tmp)) {
 251                                 pr_err("uid requires an argument\n");
 252                                 return 0;
 253                         }
 254                         hsb->s_uid = make_kuid(current_user_ns(), (uid_t)tmp);
 255                         if (!uid_valid(hsb->s_uid)) {
 256                                 pr_err("invalid uid %d\n", tmp);
 257                                 return 0;
 258                         }
 259                         break;
 260                 case opt_gid:
 261                         if (match_int(&args[0], &tmp)) {
 262                                 pr_err("gid requires an argument\n");
 263                                 return 0;
 264                         }
 265                         hsb->s_gid = make_kgid(current_user_ns(), (gid_t)tmp);
 266                         if (!gid_valid(hsb->s_gid)) {
 267                                 pr_err("invalid gid %d\n", tmp);
 268                                 return 0;
 269                         }
 270                         break;
 271                 case opt_umask:
 272                         if (match_octal(&args[0], &tmp)) {
 273                                 pr_err("umask requires a value\n");
 274                                 return 0;
 275                         }
 276                         hsb->s_file_umask = (umode_t)tmp;
 277                         hsb->s_dir_umask = (umode_t)tmp;
 278                         break;
 279                 case opt_file_umask:
 280                         if (match_octal(&args[0], &tmp)) {
 281                                 pr_err("file_umask requires a value\n");
 282                                 return 0;
 283                         }
 284                         hsb->s_file_umask = (umode_t)tmp;
 285                         break;
 286                 case opt_dir_umask:
 287                         if (match_octal(&args[0], &tmp)) {
 288                                 pr_err("dir_umask requires a value\n");
 289                                 return 0;
 290                         }
 291                         hsb->s_dir_umask = (umode_t)tmp;
 292                         break;
 293                 case opt_part:
 294                         if (match_int(&args[0], &hsb->part)) {
 295                                 pr_err("part requires an argument\n");
 296                                 return 0;
 297                         }
 298                         break;
 299                 case opt_session:
 300                         if (match_int(&args[0], &hsb->session)) {
 301                                 pr_err("session requires an argument\n");
 302                                 return 0;
 303                         }
 304                         break;
 305                 case opt_type:
 306                         if (match_fourchar(&args[0], &hsb->s_type)) {
 307                                 pr_err("type requires a 4 character value\n");
 308                                 return 0;
 309                         }
 310                         break;
 311                 case opt_creator:
 312                         if (match_fourchar(&args[0], &hsb->s_creator)) {
 313                                 pr_err("creator requires a 4 character value\n");
 314                                 return 0;
 315                         }
 316                         break;
 317                 case opt_quiet:
 318                         hsb->s_quiet = 1;
 319                         break;
 320                 case opt_codepage:
 321                         if (hsb->nls_disk) {
 322                                 pr_err("unable to change codepage\n");
 323                                 return 0;
 324                         }
 325                         p = match_strdup(&args[0]);
 326                         if (p)
 327                                 hsb->nls_disk = load_nls(p);
 328                         if (!hsb->nls_disk) {
 329                                 pr_err("unable to load codepage \"%s\"\n", p);
 330                                 kfree(p);
 331                                 return 0;
 332                         }
 333                         kfree(p);
 334                         break;
 335                 case opt_iocharset:
 336                         if (hsb->nls_io) {
 337                                 pr_err("unable to change iocharset\n");
 338                                 return 0;
 339                         }
 340                         p = match_strdup(&args[0]);
 341                         if (p)
 342                                 hsb->nls_io = load_nls(p);
 343                         if (!hsb->nls_io) {
 344                                 pr_err("unable to load iocharset \"%s\"\n", p);
 345                                 kfree(p);
 346                                 return 0;
 347                         }
 348                         kfree(p);
 349                         break;
 350                 default:
 351                         return 0;
 352                 }
 353         }
 354 
 355         if (hsb->nls_disk && !hsb->nls_io) {
 356                 hsb->nls_io = load_nls_default();
 357                 if (!hsb->nls_io) {
 358                         pr_err("unable to load default iocharset\n");
 359                         return 0;
 360                 }
 361         }
 362         hsb->s_dir_umask &= 0777;
 363         hsb->s_file_umask &= 0577;
 364 
 365         return 1;
 366 }
 367 
 368 /*
 369  * hfs_read_super()
 370  *
 371  * This is the function that is responsible for mounting an HFS
 372  * filesystem.  It performs all the tasks necessary to get enough data
 373  * from the disk to read the root inode.  This includes parsing the
 374  * mount options, dealing with Macintosh partitions, reading the
 375  * superblock and the allocation bitmap blocks, calling
 376  * hfs_btree_init() to get the necessary data about the extents and
 377  * catalog B-trees and, finally, reading the root inode into memory.
 378  */
 379 static int hfs_fill_super(struct super_block *sb, void *data, int silent)
 380 {
 381         struct hfs_sb_info *sbi;
 382         struct hfs_find_data fd;
 383         hfs_cat_rec rec;
 384         struct inode *root_inode;
 385         int res;
 386 
 387         sbi = kzalloc(sizeof(struct hfs_sb_info), GFP_KERNEL);
 388         if (!sbi)
 389                 return -ENOMEM;
 390 
 391         sbi->sb = sb;
 392         sb->s_fs_info = sbi;
 393         spin_lock_init(&sbi->work_lock);
 394         INIT_DELAYED_WORK(&sbi->mdb_work, flush_mdb);
 395 
 396         res = -EINVAL;
 397         if (!parse_options((char *)data, sbi)) {
 398                 pr_err("unable to parse mount options\n");
 399                 goto bail;
 400         }
 401 
 402         sb->s_op = &hfs_super_operations;
 403         sb->s_xattr = hfs_xattr_handlers;
 404         sb->s_flags |= SB_NODIRATIME;
 405         mutex_init(&sbi->bitmap_lock);
 406 
 407         res = hfs_mdb_get(sb);
 408         if (res) {
 409                 if (!silent)
 410                         pr_warn("can't find a HFS filesystem on dev %s\n",
 411                                 hfs_mdb_name(sb));
 412                 res = -EINVAL;
 413                 goto bail;
 414         }
 415 
 416         /* try to get the root inode */
 417         res = hfs_find_init(HFS_SB(sb)->cat_tree, &fd);
 418         if (res)
 419                 goto bail_no_root;
 420         res = hfs_cat_find_brec(sb, HFS_ROOT_CNID, &fd);
 421         if (!res) {
 422                 if (fd.entrylength > sizeof(rec) || fd.entrylength < 0) {
 423                         res =  -EIO;
 424                         goto bail;
 425                 }
 426                 hfs_bnode_read(fd.bnode, &rec, fd.entryoffset, fd.entrylength);
 427         }
 428         if (res) {
 429                 hfs_find_exit(&fd);
 430                 goto bail_no_root;
 431         }
 432         res = -EINVAL;
 433         root_inode = hfs_iget(sb, &fd.search_key->cat, &rec);
 434         hfs_find_exit(&fd);
 435         if (!root_inode)
 436                 goto bail_no_root;
 437 
 438         sb->s_d_op = &hfs_dentry_operations;
 439         res = -ENOMEM;
 440         sb->s_root = d_make_root(root_inode);
 441         if (!sb->s_root)
 442                 goto bail_no_root;
 443 
 444         /* everything's okay */
 445         return 0;
 446 
 447 bail_no_root:
 448         pr_err("get root inode failed\n");
 449 bail:
 450         hfs_mdb_put(sb);
 451         return res;
 452 }
 453 
 454 static struct dentry *hfs_mount(struct file_system_type *fs_type,
 455                       int flags, const char *dev_name, void *data)
 456 {
 457         return mount_bdev(fs_type, flags, dev_name, data, hfs_fill_super);
 458 }
 459 
 460 static struct file_system_type hfs_fs_type = {
 461         .owner          = THIS_MODULE,
 462         .name           = "hfs",
 463         .mount          = hfs_mount,
 464         .kill_sb        = kill_block_super,
 465         .fs_flags       = FS_REQUIRES_DEV,
 466 };
 467 MODULE_ALIAS_FS("hfs");
 468 
 469 static void hfs_init_once(void *p)
 470 {
 471         struct hfs_inode_info *i = p;
 472 
 473         inode_init_once(&i->vfs_inode);
 474 }
 475 
 476 static int __init init_hfs_fs(void)
 477 {
 478         int err;
 479 
 480         hfs_inode_cachep = kmem_cache_create("hfs_inode_cache",
 481                 sizeof(struct hfs_inode_info), 0,
 482                 SLAB_HWCACHE_ALIGN|SLAB_ACCOUNT, hfs_init_once);
 483         if (!hfs_inode_cachep)
 484                 return -ENOMEM;
 485         err = register_filesystem(&hfs_fs_type);
 486         if (err)
 487                 kmem_cache_destroy(hfs_inode_cachep);
 488         return err;
 489 }
 490 
 491 static void __exit exit_hfs_fs(void)
 492 {
 493         unregister_filesystem(&hfs_fs_type);
 494 
 495         /*
 496          * Make sure all delayed rcu free inodes are flushed before we
 497          * destroy cache.
 498          */
 499         rcu_barrier();
 500         kmem_cache_destroy(hfs_inode_cachep);
 501 }
 502 
 503 module_init(init_hfs_fs)
 504 module_exit(exit_hfs_fs)