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