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/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->s_flags & MS_RDONLY)
  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 |= MS_NODIRATIME;
 118         if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
 119                 return 0;
 120         if (!(*flags & MS_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 |= MS_RDONLY;
 124                         *flags |= MS_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 |= MS_RDONLY;
 128                         *flags |= MS_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_i_callback(struct rcu_head *head)
 171 {
 172         struct inode *inode = container_of(head, struct inode, i_rcu);
 173         kmem_cache_free(hfs_inode_cachep, HFS_I(inode));
 174 }
 175
 176 static void hfs_destroy_inode(struct inode *inode)
 177 {
 178         call_rcu(&inode->i_rcu, hfs_i_callback);
 179 }
 180
 181 static const struct super_operations hfs_super_operations = {
 182         .alloc_inode    = hfs_alloc_inode,
 183         .destroy_inode  = hfs_destroy_inode,
 184         .write_inode    = hfs_write_inode,
 185         .evict_inode    = hfs_evict_inode,
 186         .put_super      = hfs_put_super,
 187         .sync_fs        = hfs_sync_fs,
 188         .statfs         = hfs_statfs,
 189         .remount_fs     = hfs_remount,
 190         .show_options   = hfs_show_options,
 191 };
 192
 193 enum {
 194         opt_uid, opt_gid, opt_umask, opt_file_umask, opt_dir_umask,
 195         opt_part, opt_session, opt_type, opt_creator, opt_quiet,
 196         opt_codepage, opt_iocharset,
 197         opt_err
 198 };
 199
 200 static const match_table_t tokens = {
 201         { opt_uid, "uid=%u" },
 202         { opt_gid, "gid=%u" },
 203         { opt_umask, "umask=%o" },
 204         { opt_file_umask, "file_umask=%o" },
 205         { opt_dir_umask, "dir_umask=%o" },
 206         { opt_part, "part=%u" },
 207         { opt_session, "session=%u" },
 208         { opt_type, "type=%s" },
 209         { opt_creator, "creator=%s" },
 210         { opt_quiet, "quiet" },
 211         { opt_codepage, "codepage=%s" },
 212         { opt_iocharset, "iocharset=%s" },
 213         { opt_err, NULL }
 214 };
 215
 216 static inline int match_fourchar(substring_t *arg, u32 *result)
 217 {
 218         if (arg->to - arg->from != 4)
 219                 return -EINVAL;
 220         memcpy(result, arg->from, 4);
 221         return 0;
 222 }
 223
 224 /*
 225  * parse_options()
 226  *
 227  * adapted from linux/fs/msdos/inode.c written 1992,93 by Werner Almesberger
 228  * This function is called by hfs_read_super() to parse the mount options.
 229  */
 230 static int parse_options(char *options, struct hfs_sb_info *hsb)
 231 {
 232         char *p;
 233         substring_t args[MAX_OPT_ARGS];
 234         int tmp, token;
 235
 236         /* initialize the sb with defaults */
 237         hsb->s_uid = current_uid();
 238         hsb->s_gid = current_gid();
 239         hsb->s_file_umask = 0133;
 240         hsb->s_dir_umask = 0022;
 241         hsb->s_type = hsb->s_creator = cpu_to_be32(0x3f3f3f3f); /* == '????' */
 242         hsb->s_quiet = 0;
 243         hsb->part = -1;
 244         hsb->session = -1;
 245
 246         if (!options)
 247                 return 1;
 248
 249         while ((p = strsep(&options, ",")) != NULL) {
 250                 if (!*p)
 251                         continue;
 252
 253                 token = match_token(p, tokens, args);
 254                 switch (token) {
 255                 case opt_uid:
 256                         if (match_int(&args[0], &tmp)) {
 257                                 pr_err("uid requires an argument\n");
 258                                 return 0;
 259                         }
 260                         hsb->s_uid = make_kuid(current_user_ns(), (uid_t)tmp);
 261                         if (!uid_valid(hsb->s_uid)) {
 262                                 pr_err("invalid uid %d\n", tmp);
 263                                 return 0;
 264                         }
 265                         break;
 266                 case opt_gid:
 267                         if (match_int(&args[0], &tmp)) {
 268                                 pr_err("gid requires an argument\n");
 269                                 return 0;
 270                         }
 271                         hsb->s_gid = make_kgid(current_user_ns(), (gid_t)tmp);
 272                         if (!gid_valid(hsb->s_gid)) {
 273                                 pr_err("invalid gid %d\n", tmp);
 274                                 return 0;
 275                         }
 276                         break;
 277                 case opt_umask:
 278                         if (match_octal(&args[0], &tmp)) {
 279                                 pr_err("umask requires a value\n");
 280                                 return 0;
 281                         }
 282                         hsb->s_file_umask = (umode_t)tmp;
 283                         hsb->s_dir_umask = (umode_t)tmp;
 284                         break;
 285                 case opt_file_umask:
 286                         if (match_octal(&args[0], &tmp)) {
 287                                 pr_err("file_umask requires a value\n");
 288                                 return 0;
 289                         }
 290                         hsb->s_file_umask = (umode_t)tmp;
 291                         break;
 292                 case opt_dir_umask:
 293                         if (match_octal(&args[0], &tmp)) {
 294                                 pr_err("dir_umask requires a value\n");
 295                                 return 0;
 296                         }
 297                         hsb->s_dir_umask = (umode_t)tmp;
 298                         break;
 299                 case opt_part:
 300                         if (match_int(&args[0], &hsb->part)) {
 301                                 pr_err("part requires an argument\n");
 302                                 return 0;
 303                         }
 304                         break;
 305                 case opt_session:
 306                         if (match_int(&args[0], &hsb->session)) {
 307                                 pr_err("session requires an argument\n");
 308                                 return 0;
 309                         }
 310                         break;
 311                 case opt_type:
 312                         if (match_fourchar(&args[0], &hsb->s_type)) {
 313                                 pr_err("type requires a 4 character value\n");
 314                                 return 0;
 315                         }
 316                         break;
 317                 case opt_creator:
 318                         if (match_fourchar(&args[0], &hsb->s_creator)) {
 319                                 pr_err("creator requires a 4 character value\n");
 320                                 return 0;
 321                         }
 322                         break;
 323                 case opt_quiet:
 324                         hsb->s_quiet = 1;
 325                         break;
 326                 case opt_codepage:
 327                         if (hsb->nls_disk) {
 328                                 pr_err("unable to change codepage\n");
 329                                 return 0;
 330                         }
 331                         p = match_strdup(&args[0]);
 332                         if (p)
 333                                 hsb->nls_disk = load_nls(p);
 334                         if (!hsb->nls_disk) {
 335                                 pr_err("unable to load codepage \"%s\"\n", p);
 336                                 kfree(p);
 337                                 return 0;
 338                         }
 339                         kfree(p);
 340                         break;
 341                 case opt_iocharset:
 342                         if (hsb->nls_io) {
 343                                 pr_err("unable to change iocharset\n");
 344                                 return 0;
 345                         }
 346                         p = match_strdup(&args[0]);
 347                         if (p)
 348                                 hsb->nls_io = load_nls(p);
 349                         if (!hsb->nls_io) {
 350                                 pr_err("unable to load iocharset \"%s\"\n", p);
 351                                 kfree(p);
 352                                 return 0;
 353                         }
 354                         kfree(p);
 355                         break;
 356                 default:
 357                         return 0;
 358                 }
 359         }
 360
 361         if (hsb->nls_disk && !hsb->nls_io) {
 362                 hsb->nls_io = load_nls_default();
 363                 if (!hsb->nls_io) {
 364                         pr_err("unable to load default iocharset\n");
 365                         return 0;
 366                 }
 367         }
 368         hsb->s_dir_umask &= 0777;
 369         hsb->s_file_umask &= 0577;
 370
 371         return 1;
 372 }
 373
 374 /*
 375  * hfs_read_super()
 376  *
 377  * This is the function that is responsible for mounting an HFS
 378  * filesystem.  It performs all the tasks necessary to get enough data
 379  * from the disk to read the root inode.  This includes parsing the
 380  * mount options, dealing with Macintosh partitions, reading the
 381  * superblock and the allocation bitmap blocks, calling
 382  * hfs_btree_init() to get the necessary data about the extents and
 383  * catalog B-trees and, finally, reading the root inode into memory.
 384  */
 385 static int hfs_fill_super(struct super_block *sb, void *data, int silent)
 386 {
 387         struct hfs_sb_info *sbi;
 388         struct hfs_find_data fd;
 389         hfs_cat_rec rec;
 390         struct inode *root_inode;
 391         int res;
 392
 393         sbi = kzalloc(sizeof(struct hfs_sb_info), GFP_KERNEL);
 394         if (!sbi)
 395                 return -ENOMEM;
 396
 397         sbi->sb = sb;
 398         sb->s_fs_info = sbi;
 399         spin_lock_init(&sbi->work_lock);
 400         INIT_DELAYED_WORK(&sbi->mdb_work, flush_mdb);
 401
 402         res = -EINVAL;
 403         if (!parse_options((char *)data, sbi)) {
 404                 pr_err("unable to parse mount options\n");
 405                 goto bail;
 406         }
 407
 408         sb->s_op = &hfs_super_operations;
 409         sb->s_flags |= MS_NODIRATIME;
 410         mutex_init(&sbi->bitmap_lock);
 411
 412         res = hfs_mdb_get(sb);
 413         if (res) {
 414                 if (!silent)
 415                         pr_warn("can't find a HFS filesystem on dev %s\n",
 416                                 hfs_mdb_name(sb));
 417                 res = -EINVAL;
 418                 goto bail;
 419         }
 420
 421         /* try to get the root inode */
 422         res = hfs_find_init(HFS_SB(sb)->cat_tree, &fd);
 423         if (res)
 424                 goto bail_no_root;
 425         res = hfs_cat_find_brec(sb, HFS_ROOT_CNID, &fd);
 426         if (!res) {
 427                 if (fd.entrylength > sizeof(rec) || fd.entrylength < 0) {
 428                         res =  -EIO;
 429                         goto bail;
 430                 }
 431                 hfs_bnode_read(fd.bnode, &rec, fd.entryoffset, fd.entrylength);
 432         }
 433         if (res) {
 434                 hfs_find_exit(&fd);
 435                 goto bail_no_root;
 436         }
 437         res = -EINVAL;
 438         root_inode = hfs_iget(sb, &fd.search_key->cat, &rec);
 439         hfs_find_exit(&fd);
 440         if (!root_inode)
 441                 goto bail_no_root;
 442
 443         sb->s_d_op = &hfs_dentry_operations;
 444         res = -ENOMEM;
 445         sb->s_root = d_make_root(root_inode);
 446         if (!sb->s_root)
 447                 goto bail_no_root;
 448
 449         /* everything's okay */
 450         return 0;
 451
 452 bail_no_root:
 453         pr_err("get root inode failed\n");
 454 bail:
 455         hfs_mdb_put(sb);
 456         return res;
 457 }
 458
 459 static struct dentry *hfs_mount(struct file_system_type *fs_type,
 460                       int flags, const char *dev_name, void *data)
 461 {
 462         return mount_bdev(fs_type, flags, dev_name, data, hfs_fill_super);
 463 }
 464
 465 static struct file_system_type hfs_fs_type = {
 466         .owner          = THIS_MODULE,
 467         .name           = "hfs",
 468         .mount          = hfs_mount,
 469         .kill_sb        = kill_block_super,
 470         .fs_flags       = FS_REQUIRES_DEV,
 471 };
 472 MODULE_ALIAS_FS("hfs");
 473
 474 static void hfs_init_once(void *p)
 475 {
 476         struct hfs_inode_info *i = p;
 477
 478         inode_init_once(&i->vfs_inode);
 479 }
 480
 481 static int __init init_hfs_fs(void)
 482 {
 483         int err;
 484
 485         hfs_inode_cachep = kmem_cache_create("hfs_inode_cache",
 486                 sizeof(struct hfs_inode_info), 0, SLAB_HWCACHE_ALIGN,
 487                 hfs_init_once);
 488         if (!hfs_inode_cachep)
 489                 return -ENOMEM;
 490         err = register_filesystem(&hfs_fs_type);
 491         if (err)
 492                 kmem_cache_destroy(hfs_inode_cachep);
 493         return err;
 494 }
 495
 496 static void __exit exit_hfs_fs(void)
 497 {
 498         unregister_filesystem(&hfs_fs_type);
 499
 500         /*
 501          * Make sure all delayed rcu free inodes are flushed before we
 502          * destroy cache.
 503          */
 504         rcu_barrier();
 505         kmem_cache_destroy(hfs_inode_cachep);
 506 }
 507
 508 module_init(init_hfs_fs)
 509 module_exit(exit_hfs_fs)