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/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 static int hfs_sync_fs(struct super_block *sb, int wait)
  33 {
  34         hfs_mdb_commit(sb);
  35         return 0;
  36 }
  37
  38 /*
  39  * hfs_put_super()
  40  *
  41  * This is the put_super() entry in the super_operations structure for
  42  * HFS filesystems.  The purpose is to release the resources
  43  * associated with the superblock sb.
  44  */
  45 static void hfs_put_super(struct super_block *sb)
  46 {
  47         cancel_delayed_work_sync(&HFS_SB(sb)->mdb_work);
  48         hfs_mdb_close(sb);
  49         /* release the MDB's resources */
  50         hfs_mdb_put(sb);
  51 }
  52
  53 static void flush_mdb(struct work_struct *work)
  54 {
  55         struct hfs_sb_info *sbi;
  56         struct super_block *sb;
  57
  58         sbi = container_of(work, struct hfs_sb_info, mdb_work.work);
  59         sb = sbi->sb;
  60
  61         spin_lock(&sbi->work_lock);
  62         sbi->work_queued = 0;
  63         spin_unlock(&sbi->work_lock);
  64
  65         hfs_mdb_commit(sb);
  66 }
  67
  68 void hfs_mark_mdb_dirty(struct super_block *sb)
  69 {
  70         struct hfs_sb_info *sbi = HFS_SB(sb);
  71         unsigned long delay;
  72
  73         if (sb->s_flags & MS_RDONLY)
  74                 return;
  75
  76         spin_lock(&sbi->work_lock);
  77         if (!sbi->work_queued) {
  78                 delay = msecs_to_jiffies(dirty_writeback_interval * 10);
  79                 queue_delayed_work(system_long_wq, &sbi->mdb_work, delay);
  80                 sbi->work_queued = 1;
  81         }
  82         spin_unlock(&sbi->work_lock);
  83 }
  84
  85 /*
  86  * hfs_statfs()
  87  *
  88  * This is the statfs() entry in the super_operations structure for
  89  * HFS filesystems.  The purpose is to return various data about the
  90  * filesystem.
  91  *
  92  * changed f_files/f_ffree to reflect the fs_ablock/free_ablocks.
  93  */
  94 static int hfs_statfs(struct dentry *dentry, struct kstatfs *buf)
  95 {
  96         struct super_block *sb = dentry->d_sb;
  97         u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
  98
  99         buf->f_type = HFS_SUPER_MAGIC;
 100         buf->f_bsize = sb->s_blocksize;
 101         buf->f_blocks = (u32)HFS_SB(sb)->fs_ablocks * HFS_SB(sb)->fs_div;
 102         buf->f_bfree = (u32)HFS_SB(sb)->free_ablocks * HFS_SB(sb)->fs_div;
 103         buf->f_bavail = buf->f_bfree;
 104         buf->f_files = HFS_SB(sb)->fs_ablocks;
 105         buf->f_ffree = HFS_SB(sb)->free_ablocks;
 106         buf->f_fsid.val[0] = (u32)id;
 107         buf->f_fsid.val[1] = (u32)(id >> 32);
 108         buf->f_namelen = HFS_NAMELEN;
 109
 110         return 0;
 111 }
 112
 113 static int hfs_remount(struct super_block *sb, int *flags, char *data)
 114 {
 115         *flags |= MS_NODIRATIME;
 116         if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
 117                 return 0;
 118         if (!(*flags & MS_RDONLY)) {
 119                 if (!(HFS_SB(sb)->mdb->drAtrb & cpu_to_be16(HFS_SB_ATTRIB_UNMNT))) {
 120                         pr_warn("filesystem was not cleanly unmounted, running fsck.hfs is recommended.  leaving read-only.\n");
 121                         sb->s_flags |= MS_RDONLY;
 122                         *flags |= MS_RDONLY;
 123                 } else if (HFS_SB(sb)->mdb->drAtrb & cpu_to_be16(HFS_SB_ATTRIB_SLOCK)) {
 124                         pr_warn("filesystem is marked locked, leaving read-only.\n");
 125                         sb->s_flags |= MS_RDONLY;
 126                         *flags |= MS_RDONLY;
 127                 }
 128         }
 129         return 0;
 130 }
 131
 132 static int hfs_show_options(struct seq_file *seq, struct dentry *root)
 133 {
 134         struct hfs_sb_info *sbi = HFS_SB(root->d_sb);
 135
 136         if (sbi->s_creator != cpu_to_be32(0x3f3f3f3f))
 137                 seq_printf(seq, ",creator=%.4s", (char *)&sbi->s_creator);
 138         if (sbi->s_type != cpu_to_be32(0x3f3f3f3f))
 139                 seq_printf(seq, ",type=%.4s", (char *)&sbi->s_type);
 140         seq_printf(seq, ",uid=%u,gid=%u",
 141                         from_kuid_munged(&init_user_ns, sbi->s_uid),
 142                         from_kgid_munged(&init_user_ns, sbi->s_gid));
 143         if (sbi->s_file_umask != 0133)
 144                 seq_printf(seq, ",file_umask=%o", sbi->s_file_umask);
 145         if (sbi->s_dir_umask != 0022)
 146                 seq_printf(seq, ",dir_umask=%o", sbi->s_dir_umask);
 147         if (sbi->part >= 0)
 148                 seq_printf(seq, ",part=%u", sbi->part);
 149         if (sbi->session >= 0)
 150                 seq_printf(seq, ",session=%u", sbi->session);
 151         if (sbi->nls_disk)
 152                 seq_printf(seq, ",codepage=%s", sbi->nls_disk->charset);
 153         if (sbi->nls_io)
 154                 seq_printf(seq, ",iocharset=%s", sbi->nls_io->charset);
 155         if (sbi->s_quiet)
 156                 seq_printf(seq, ",quiet");
 157         return 0;
 158 }
 159
 160 static struct inode *hfs_alloc_inode(struct super_block *sb)
 161 {
 162         struct hfs_inode_info *i;
 163
 164         i = kmem_cache_alloc(hfs_inode_cachep, GFP_KERNEL);
 165         return i ? &i->vfs_inode : NULL;
 166 }
 167
 168 static void hfs_i_callback(struct rcu_head *head)
 169 {
 170         struct inode *inode = container_of(head, struct inode, i_rcu);
 171         kmem_cache_free(hfs_inode_cachep, HFS_I(inode));
 172 }
 173
 174 static void hfs_destroy_inode(struct inode *inode)
 175 {
 176         call_rcu(&inode->i_rcu, hfs_i_callback);
 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         .evict_inode    = hfs_evict_inode,
 184         .put_super      = hfs_put_super,
 185         .sync_fs        = hfs_sync_fs,
 186         .statfs         = hfs_statfs,
 187         .remount_fs     = hfs_remount,
 188         .show_options   = hfs_show_options,
 189 };
 190
 191 enum {
 192         opt_uid, opt_gid, opt_umask, opt_file_umask, opt_dir_umask,
 193         opt_part, opt_session, opt_type, opt_creator, opt_quiet,
 194         opt_codepage, opt_iocharset,
 195         opt_err
 196 };
 197
 198 static const match_table_t tokens = {
 199         { opt_uid, "uid=%u" },
 200         { opt_gid, "gid=%u" },
 201         { opt_umask, "umask=%o" },
 202         { opt_file_umask, "file_umask=%o" },
 203         { opt_dir_umask, "dir_umask=%o" },
 204         { opt_part, "part=%u" },
 205         { opt_session, "session=%u" },
 206         { opt_type, "type=%s" },
 207         { opt_creator, "creator=%s" },
 208         { opt_quiet, "quiet" },
 209         { opt_codepage, "codepage=%s" },
 210         { opt_iocharset, "iocharset=%s" },
 211         { opt_err, NULL }
 212 };
 213
 214 static inline int match_fourchar(substring_t *arg, u32 *result)
 215 {
 216         if (arg->to - arg->from != 4)
 217                 return -EINVAL;
 218         memcpy(result, arg->from, 4);
 219         return 0;
 220 }
 221
 222 /*
 223  * parse_options()
 224  *
 225  * adapted from linux/fs/msdos/inode.c written 1992,93 by Werner Almesberger
 226  * This function is called by hfs_read_super() to parse the mount options.
 227  */
 228 static int parse_options(char *options, struct hfs_sb_info *hsb)
 229 {
 230         char *p;
 231         substring_t args[MAX_OPT_ARGS];
 232         int tmp, token;
 233
 234         /* initialize the sb with defaults */
 235         hsb->s_uid = current_uid();
 236         hsb->s_gid = current_gid();
 237         hsb->s_file_umask = 0133;
 238         hsb->s_dir_umask = 0022;
 239         hsb->s_type = hsb->s_creator = cpu_to_be32(0x3f3f3f3f); /* == '????' */
 240         hsb->s_quiet = 0;
 241         hsb->part = -1;
 242         hsb->session = -1;
 243
 244         if (!options)
 245                 return 1;
 246
 247         while ((p = strsep(&options, ",")) != NULL) {
 248                 if (!*p)
 249                         continue;
 250
 251                 token = match_token(p, tokens, args);
 252                 switch (token) {
 253                 case opt_uid:
 254                         if (match_int(&args[0], &tmp)) {
 255                                 pr_err("uid requires an argument\n");
 256                                 return 0;
 257                         }
 258                         hsb->s_uid = make_kuid(current_user_ns(), (uid_t)tmp);
 259                         if (!uid_valid(hsb->s_uid)) {
 260                                 pr_err("invalid uid %d\n", tmp);
 261                                 return 0;
 262                         }
 263                         break;
 264                 case opt_gid:
 265                         if (match_int(&args[0], &tmp)) {
 266                                 pr_err("gid requires an argument\n");
 267                                 return 0;
 268                         }
 269                         hsb->s_gid = make_kgid(current_user_ns(), (gid_t)tmp);
 270                         if (!gid_valid(hsb->s_gid)) {
 271                                 pr_err("invalid gid %d\n", tmp);
 272                                 return 0;
 273                         }
 274                         break;
 275                 case opt_umask:
 276                         if (match_octal(&args[0], &tmp)) {
 277                                 pr_err("umask requires a value\n");
 278                                 return 0;
 279                         }
 280                         hsb->s_file_umask = (umode_t)tmp;
 281                         hsb->s_dir_umask = (umode_t)tmp;
 282                         break;
 283                 case opt_file_umask:
 284                         if (match_octal(&args[0], &tmp)) {
 285                                 pr_err("file_umask requires a value\n");
 286                                 return 0;
 287                         }
 288                         hsb->s_file_umask = (umode_t)tmp;
 289                         break;
 290                 case opt_dir_umask:
 291                         if (match_octal(&args[0], &tmp)) {
 292                                 pr_err("dir_umask requires a value\n");
 293                                 return 0;
 294                         }
 295                         hsb->s_dir_umask = (umode_t)tmp;
 296                         break;
 297                 case opt_part:
 298                         if (match_int(&args[0], &hsb->part)) {
 299                                 pr_err("part requires an argument\n");
 300                                 return 0;
 301                         }
 302                         break;
 303                 case opt_session:
 304                         if (match_int(&args[0], &hsb->session)) {
 305                                 pr_err("session requires an argument\n");
 306                                 return 0;
 307                         }
 308                         break;
 309                 case opt_type:
 310                         if (match_fourchar(&args[0], &hsb->s_type)) {
 311                                 pr_err("type requires a 4 character value\n");
 312                                 return 0;
 313                         }
 314                         break;
 315                 case opt_creator:
 316                         if (match_fourchar(&args[0], &hsb->s_creator)) {
 317                                 pr_err("creator requires a 4 character value\n");
 318                                 return 0;
 319                         }
 320                         break;
 321                 case opt_quiet:
 322                         hsb->s_quiet = 1;
 323                         break;
 324                 case opt_codepage:
 325                         if (hsb->nls_disk) {
 326                                 pr_err("unable to change codepage\n");
 327                                 return 0;
 328                         }
 329                         p = match_strdup(&args[0]);
 330                         if (p)
 331                                 hsb->nls_disk = load_nls(p);
 332                         if (!hsb->nls_disk) {
 333                                 pr_err("unable to load codepage \"%s\"\n", p);
 334                                 kfree(p);
 335                                 return 0;
 336                         }
 337                         kfree(p);
 338                         break;
 339                 case opt_iocharset:
 340                         if (hsb->nls_io) {
 341                                 pr_err("unable to change iocharset\n");
 342                                 return 0;
 343                         }
 344                         p = match_strdup(&args[0]);
 345                         if (p)
 346                                 hsb->nls_io = load_nls(p);
 347                         if (!hsb->nls_io) {
 348                                 pr_err("unable to load iocharset \"%s\"\n", p);
 349                                 kfree(p);
 350                                 return 0;
 351                         }
 352                         kfree(p);
 353                         break;
 354                 default:
 355                         return 0;
 356                 }
 357         }
 358
 359         if (hsb->nls_disk && !hsb->nls_io) {
 360                 hsb->nls_io = load_nls_default();
 361                 if (!hsb->nls_io) {
 362                         pr_err("unable to load default iocharset\n");
 363                         return 0;
 364                 }
 365         }
 366         hsb->s_dir_umask &= 0777;
 367         hsb->s_file_umask &= 0577;
 368
 369         return 1;
 370 }
 371
 372 /*
 373  * hfs_read_super()
 374  *
 375  * This is the function that is responsible for mounting an HFS
 376  * filesystem.  It performs all the tasks necessary to get enough data
 377  * from the disk to read the root inode.  This includes parsing the
 378  * mount options, dealing with Macintosh partitions, reading the
 379  * superblock and the allocation bitmap blocks, calling
 380  * hfs_btree_init() to get the necessary data about the extents and
 381  * catalog B-trees and, finally, reading the root inode into memory.
 382  */
 383 static int hfs_fill_super(struct super_block *sb, void *data, int silent)
 384 {
 385         struct hfs_sb_info *sbi;
 386         struct hfs_find_data fd;
 387         hfs_cat_rec rec;
 388         struct inode *root_inode;
 389         int res;
 390
 391         sbi = kzalloc(sizeof(struct hfs_sb_info), GFP_KERNEL);
 392         if (!sbi)
 393                 return -ENOMEM;
 394
 395         sbi->sb = sb;
 396         sb->s_fs_info = sbi;
 397         spin_lock_init(&sbi->work_lock);
 398         INIT_DELAYED_WORK(&sbi->mdb_work, flush_mdb);
 399
 400         res = -EINVAL;
 401         if (!parse_options((char *)data, sbi)) {
 402                 pr_err("unable to parse mount options\n");
 403                 goto bail;
 404         }
 405
 406         sb->s_op = &hfs_super_operations;
 407         sb->s_flags |= MS_NODIRATIME;
 408         mutex_init(&sbi->bitmap_lock);
 409
 410         res = hfs_mdb_get(sb);
 411         if (res) {
 412                 if (!silent)
 413                         pr_warn("can't find a HFS filesystem on dev %s\n",
 414                                 hfs_mdb_name(sb));
 415                 res = -EINVAL;
 416                 goto bail;
 417         }
 418
 419         /* try to get the root inode */
 420         res = hfs_find_init(HFS_SB(sb)->cat_tree, &fd);
 421         if (res)
 422                 goto bail_no_root;
 423         res = hfs_cat_find_brec(sb, HFS_ROOT_CNID, &fd);
 424         if (!res) {
 425                 if (fd.entrylength > sizeof(rec) || fd.entrylength < 0) {
 426                         res =  -EIO;
 427                         goto bail;
 428                 }
 429                 hfs_bnode_read(fd.bnode, &rec, fd.entryoffset, fd.entrylength);
 430         }
 431         if (res) {
 432                 hfs_find_exit(&fd);
 433                 goto bail_no_root;
 434         }
 435         res = -EINVAL;
 436         root_inode = hfs_iget(sb, &fd.search_key->cat, &rec);
 437         hfs_find_exit(&fd);
 438         if (!root_inode)
 439                 goto bail_no_root;
 440
 441         sb->s_d_op = &hfs_dentry_operations;
 442         res = -ENOMEM;
 443         sb->s_root = d_make_root(root_inode);
 444         if (!sb->s_root)
 445                 goto bail_no_root;
 446
 447         /* everything's okay */
 448         return 0;
 449
 450 bail_no_root:
 451         pr_err("get root inode failed\n");
 452 bail:
 453         hfs_mdb_put(sb);
 454         return res;
 455 }
 456
 457 static struct dentry *hfs_mount(struct file_system_type *fs_type,
 458                       int flags, const char *dev_name, void *data)
 459 {
 460         return mount_bdev(fs_type, flags, dev_name, data, hfs_fill_super);
 461 }
 462
 463 static struct file_system_type hfs_fs_type = {
 464         .owner          = THIS_MODULE,
 465         .name           = "hfs",
 466         .mount          = hfs_mount,
 467         .kill_sb        = kill_block_super,
 468         .fs_flags       = FS_REQUIRES_DEV,
 469 };
 470 MODULE_ALIAS_FS("hfs");
 471
 472 static void hfs_init_once(void *p)
 473 {
 474         struct hfs_inode_info *i = p;
 475
 476         inode_init_once(&i->vfs_inode);
 477 }
 478
 479 static int __init init_hfs_fs(void)
 480 {
 481         int err;
 482
 483         hfs_inode_cachep = kmem_cache_create("hfs_inode_cache",
 484                 sizeof(struct hfs_inode_info), 0, SLAB_HWCACHE_ALIGN,
 485                 hfs_init_once);
 486         if (!hfs_inode_cachep)
 487                 return -ENOMEM;
 488         err = register_filesystem(&hfs_fs_type);
 489         if (err)
 490                 kmem_cache_destroy(hfs_inode_cachep);
 491         return err;
 492 }
 493
 494 static void __exit exit_hfs_fs(void)
 495 {
 496         unregister_filesystem(&hfs_fs_type);
 497
 498         /*
 499          * Make sure all delayed rcu free inodes are flushed before we
 500          * destroy cache.
 501          */
 502         rcu_barrier();
 503         kmem_cache_destroy(hfs_inode_cachep);
 504 }
 505
 506 module_init(init_hfs_fs)
 507 module_exit(exit_hfs_fs)