Merge git://git.kernel.org/pub/scm/linux/kernel/git/steve/gfs2-2.6-nmw
[pandora-kernel.git] / fs / hfsplus / super.c
1 /*
2  *  linux/fs/hfsplus/super.c
3  *
4  * Copyright (C) 2001
5  * Brad Boyer (flar@allandria.com)
6  * (C) 2003 Ardis Technologies <roman@ardistech.com>
7  *
8  */
9
10 #include <linux/module.h>
11 #include <linux/init.h>
12 #include <linux/pagemap.h>
13 #include <linux/blkdev.h>
14 #include <linux/fs.h>
15 #include <linux/slab.h>
16 #include <linux/vfs.h>
17 #include <linux/nls.h>
18
19 static struct inode *hfsplus_alloc_inode(struct super_block *sb);
20 static void hfsplus_destroy_inode(struct inode *inode);
21
22 #include "hfsplus_fs.h"
23
24 static int hfsplus_system_read_inode(struct inode *inode)
25 {
26         struct hfsplus_vh *vhdr = HFSPLUS_SB(inode->i_sb)->s_vhdr;
27
28         switch (inode->i_ino) {
29         case HFSPLUS_EXT_CNID:
30                 hfsplus_inode_read_fork(inode, &vhdr->ext_file);
31                 inode->i_mapping->a_ops = &hfsplus_btree_aops;
32                 break;
33         case HFSPLUS_CAT_CNID:
34                 hfsplus_inode_read_fork(inode, &vhdr->cat_file);
35                 inode->i_mapping->a_ops = &hfsplus_btree_aops;
36                 break;
37         case HFSPLUS_ALLOC_CNID:
38                 hfsplus_inode_read_fork(inode, &vhdr->alloc_file);
39                 inode->i_mapping->a_ops = &hfsplus_aops;
40                 break;
41         case HFSPLUS_START_CNID:
42                 hfsplus_inode_read_fork(inode, &vhdr->start_file);
43                 break;
44         case HFSPLUS_ATTR_CNID:
45                 hfsplus_inode_read_fork(inode, &vhdr->attr_file);
46                 inode->i_mapping->a_ops = &hfsplus_btree_aops;
47                 break;
48         default:
49                 return -EIO;
50         }
51
52         return 0;
53 }
54
55 struct inode *hfsplus_iget(struct super_block *sb, unsigned long ino)
56 {
57         struct hfs_find_data fd;
58         struct inode *inode;
59         int err;
60
61         inode = iget_locked(sb, ino);
62         if (!inode)
63                 return ERR_PTR(-ENOMEM);
64         if (!(inode->i_state & I_NEW))
65                 return inode;
66
67         INIT_LIST_HEAD(&HFSPLUS_I(inode)->open_dir_list);
68         mutex_init(&HFSPLUS_I(inode)->extents_lock);
69         HFSPLUS_I(inode)->flags = 0;
70         HFSPLUS_I(inode)->extent_state = 0;
71         HFSPLUS_I(inode)->rsrc_inode = NULL;
72         atomic_set(&HFSPLUS_I(inode)->opencnt, 0);
73
74         if (inode->i_ino >= HFSPLUS_FIRSTUSER_CNID ||
75             inode->i_ino == HFSPLUS_ROOT_CNID) {
76                 hfs_find_init(HFSPLUS_SB(inode->i_sb)->cat_tree, &fd);
77                 err = hfsplus_find_cat(inode->i_sb, inode->i_ino, &fd);
78                 if (!err)
79                         err = hfsplus_cat_read_inode(inode, &fd);
80                 hfs_find_exit(&fd);
81         } else {
82                 err = hfsplus_system_read_inode(inode);
83         }
84
85         if (err) {
86                 iget_failed(inode);
87                 return ERR_PTR(err);
88         }
89
90         unlock_new_inode(inode);
91         return inode;
92 }
93
94 static int hfsplus_system_write_inode(struct inode *inode)
95 {
96         struct hfsplus_sb_info *sbi = HFSPLUS_SB(inode->i_sb);
97         struct hfsplus_vh *vhdr = sbi->s_vhdr;
98         struct hfsplus_fork_raw *fork;
99         struct hfs_btree *tree = NULL;
100
101         switch (inode->i_ino) {
102         case HFSPLUS_EXT_CNID:
103                 fork = &vhdr->ext_file;
104                 tree = sbi->ext_tree;
105                 break;
106         case HFSPLUS_CAT_CNID:
107                 fork = &vhdr->cat_file;
108                 tree = sbi->cat_tree;
109                 break;
110         case HFSPLUS_ALLOC_CNID:
111                 fork = &vhdr->alloc_file;
112                 break;
113         case HFSPLUS_START_CNID:
114                 fork = &vhdr->start_file;
115                 break;
116         case HFSPLUS_ATTR_CNID:
117                 fork = &vhdr->attr_file;
118                 tree = sbi->attr_tree;
119         default:
120                 return -EIO;
121         }
122
123         if (fork->total_size != cpu_to_be64(inode->i_size)) {
124                 set_bit(HFSPLUS_SB_WRITEBACKUP, &sbi->flags);
125                 inode->i_sb->s_dirt = 1;
126         }
127         hfsplus_inode_write_fork(inode, fork);
128         if (tree)
129                 hfs_btree_write(tree);
130         return 0;
131 }
132
133 static int hfsplus_write_inode(struct inode *inode,
134                 struct writeback_control *wbc)
135 {
136         dprint(DBG_INODE, "hfsplus_write_inode: %lu\n", inode->i_ino);
137
138         hfsplus_ext_write_extent(inode);
139
140         if (inode->i_ino >= HFSPLUS_FIRSTUSER_CNID ||
141             inode->i_ino == HFSPLUS_ROOT_CNID)
142                 return hfsplus_cat_write_inode(inode);
143         else
144                 return hfsplus_system_write_inode(inode);
145 }
146
147 static void hfsplus_evict_inode(struct inode *inode)
148 {
149         dprint(DBG_INODE, "hfsplus_evict_inode: %lu\n", inode->i_ino);
150         truncate_inode_pages(&inode->i_data, 0);
151         end_writeback(inode);
152         if (HFSPLUS_IS_RSRC(inode)) {
153                 HFSPLUS_I(HFSPLUS_I(inode)->rsrc_inode)->rsrc_inode = NULL;
154                 iput(HFSPLUS_I(inode)->rsrc_inode);
155         }
156 }
157
158 int hfsplus_sync_fs(struct super_block *sb, int wait)
159 {
160         struct hfsplus_sb_info *sbi = HFSPLUS_SB(sb);
161         struct hfsplus_vh *vhdr = sbi->s_vhdr;
162         int write_backup = 0;
163         int error, error2;
164
165         if (!wait)
166                 return 0;
167
168         dprint(DBG_SUPER, "hfsplus_write_super\n");
169
170         sb->s_dirt = 0;
171
172         /*
173          * Explicitly write out the special metadata inodes.
174          *
175          * While these special inodes are marked as hashed and written
176          * out peridocically by the flusher threads we redirty them
177          * during writeout of normal inodes, and thus the life lock
178          * prevents us from getting the latest state to disk.
179          */
180         error = filemap_write_and_wait(sbi->cat_tree->inode->i_mapping);
181         error2 = filemap_write_and_wait(sbi->ext_tree->inode->i_mapping);
182         if (!error)
183                 error = error2;
184         error2 = filemap_write_and_wait(sbi->alloc_file->i_mapping);
185         if (!error)
186                 error = error2;
187
188         mutex_lock(&sbi->vh_mutex);
189         mutex_lock(&sbi->alloc_mutex);
190         vhdr->free_blocks = cpu_to_be32(sbi->free_blocks);
191         vhdr->next_cnid = cpu_to_be32(sbi->next_cnid);
192         vhdr->folder_count = cpu_to_be32(sbi->folder_count);
193         vhdr->file_count = cpu_to_be32(sbi->file_count);
194
195         if (test_and_clear_bit(HFSPLUS_SB_WRITEBACKUP, &sbi->flags)) {
196                 memcpy(sbi->s_backup_vhdr, sbi->s_vhdr, sizeof(*sbi->s_vhdr));
197                 write_backup = 1;
198         }
199
200         error2 = hfsplus_submit_bio(sb->s_bdev,
201                                    sbi->part_start + HFSPLUS_VOLHEAD_SECTOR,
202                                    sbi->s_vhdr, WRITE_SYNC);
203         if (!error)
204                 error = error2;
205         if (!write_backup)
206                 goto out;
207
208         error2 = hfsplus_submit_bio(sb->s_bdev,
209                                   sbi->part_start + sbi->sect_count - 2,
210                                   sbi->s_backup_vhdr, WRITE_SYNC);
211         if (!error)
212                 error2 = error;
213 out:
214         mutex_unlock(&sbi->alloc_mutex);
215         mutex_unlock(&sbi->vh_mutex);
216
217         if (!test_bit(HFSPLUS_SB_NOBARRIER, &sbi->flags))
218                 blkdev_issue_flush(sb->s_bdev, GFP_KERNEL, NULL);
219
220         return error;
221 }
222
223 static void hfsplus_write_super(struct super_block *sb)
224 {
225         if (!(sb->s_flags & MS_RDONLY))
226                 hfsplus_sync_fs(sb, 1);
227         else
228                 sb->s_dirt = 0;
229 }
230
231 static void hfsplus_put_super(struct super_block *sb)
232 {
233         struct hfsplus_sb_info *sbi = HFSPLUS_SB(sb);
234
235         dprint(DBG_SUPER, "hfsplus_put_super\n");
236
237         if (!sb->s_fs_info)
238                 return;
239
240         if (!(sb->s_flags & MS_RDONLY) && sbi->s_vhdr) {
241                 struct hfsplus_vh *vhdr = sbi->s_vhdr;
242
243                 vhdr->modify_date = hfsp_now2mt();
244                 vhdr->attributes |= cpu_to_be32(HFSPLUS_VOL_UNMNT);
245                 vhdr->attributes &= cpu_to_be32(~HFSPLUS_VOL_INCNSTNT);
246
247                 hfsplus_sync_fs(sb, 1);
248         }
249
250         hfs_btree_close(sbi->cat_tree);
251         hfs_btree_close(sbi->ext_tree);
252         iput(sbi->alloc_file);
253         iput(sbi->hidden_dir);
254         kfree(sbi->s_vhdr);
255         kfree(sbi->s_backup_vhdr);
256         unload_nls(sbi->nls);
257         kfree(sb->s_fs_info);
258         sb->s_fs_info = NULL;
259 }
260
261 static int hfsplus_statfs(struct dentry *dentry, struct kstatfs *buf)
262 {
263         struct super_block *sb = dentry->d_sb;
264         struct hfsplus_sb_info *sbi = HFSPLUS_SB(sb);
265         u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
266
267         buf->f_type = HFSPLUS_SUPER_MAGIC;
268         buf->f_bsize = sb->s_blocksize;
269         buf->f_blocks = sbi->total_blocks << sbi->fs_shift;
270         buf->f_bfree = sbi->free_blocks << sbi->fs_shift;
271         buf->f_bavail = buf->f_bfree;
272         buf->f_files = 0xFFFFFFFF;
273         buf->f_ffree = 0xFFFFFFFF - sbi->next_cnid;
274         buf->f_fsid.val[0] = (u32)id;
275         buf->f_fsid.val[1] = (u32)(id >> 32);
276         buf->f_namelen = HFSPLUS_MAX_STRLEN;
277
278         return 0;
279 }
280
281 static int hfsplus_remount(struct super_block *sb, int *flags, char *data)
282 {
283         if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
284                 return 0;
285         if (!(*flags & MS_RDONLY)) {
286                 struct hfsplus_vh *vhdr = HFSPLUS_SB(sb)->s_vhdr;
287                 int force = 0;
288
289                 if (!hfsplus_parse_options_remount(data, &force))
290                         return -EINVAL;
291
292                 if (!(vhdr->attributes & cpu_to_be32(HFSPLUS_VOL_UNMNT))) {
293                         printk(KERN_WARNING "hfs: filesystem was "
294                                         "not cleanly unmounted, "
295                                         "running fsck.hfsplus is recommended.  "
296                                         "leaving read-only.\n");
297                         sb->s_flags |= MS_RDONLY;
298                         *flags |= MS_RDONLY;
299                 } else if (force) {
300                         /* nothing */
301                 } else if (vhdr->attributes &
302                                 cpu_to_be32(HFSPLUS_VOL_SOFTLOCK)) {
303                         printk(KERN_WARNING "hfs: filesystem is marked locked, "
304                                         "leaving read-only.\n");
305                         sb->s_flags |= MS_RDONLY;
306                         *flags |= MS_RDONLY;
307                 } else if (vhdr->attributes &
308                                 cpu_to_be32(HFSPLUS_VOL_JOURNALED)) {
309                         printk(KERN_WARNING "hfs: filesystem is "
310                                         "marked journaled, "
311                                         "leaving read-only.\n");
312                         sb->s_flags |= MS_RDONLY;
313                         *flags |= MS_RDONLY;
314                 }
315         }
316         return 0;
317 }
318
319 static const struct super_operations hfsplus_sops = {
320         .alloc_inode    = hfsplus_alloc_inode,
321         .destroy_inode  = hfsplus_destroy_inode,
322         .write_inode    = hfsplus_write_inode,
323         .evict_inode    = hfsplus_evict_inode,
324         .put_super      = hfsplus_put_super,
325         .write_super    = hfsplus_write_super,
326         .sync_fs        = hfsplus_sync_fs,
327         .statfs         = hfsplus_statfs,
328         .remount_fs     = hfsplus_remount,
329         .show_options   = hfsplus_show_options,
330 };
331
332 static int hfsplus_fill_super(struct super_block *sb, void *data, int silent)
333 {
334         struct hfsplus_vh *vhdr;
335         struct hfsplus_sb_info *sbi;
336         hfsplus_cat_entry entry;
337         struct hfs_find_data fd;
338         struct inode *root, *inode;
339         struct qstr str;
340         struct nls_table *nls = NULL;
341         int err;
342
343         err = -EINVAL;
344         sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
345         if (!sbi)
346                 goto out;
347
348         sb->s_fs_info = sbi;
349         mutex_init(&sbi->alloc_mutex);
350         mutex_init(&sbi->vh_mutex);
351         hfsplus_fill_defaults(sbi);
352
353         err = -EINVAL;
354         if (!hfsplus_parse_options(data, sbi)) {
355                 printk(KERN_ERR "hfs: unable to parse mount options\n");
356                 goto out_unload_nls;
357         }
358
359         /* temporarily use utf8 to correctly find the hidden dir below */
360         nls = sbi->nls;
361         sbi->nls = load_nls("utf8");
362         if (!sbi->nls) {
363                 printk(KERN_ERR "hfs: unable to load nls for utf8\n");
364                 goto out_unload_nls;
365         }
366
367         /* Grab the volume header */
368         if (hfsplus_read_wrapper(sb)) {
369                 if (!silent)
370                         printk(KERN_WARNING "hfs: unable to find HFS+ superblock\n");
371                 goto out_unload_nls;
372         }
373         vhdr = sbi->s_vhdr;
374
375         /* Copy parts of the volume header into the superblock */
376         sb->s_magic = HFSPLUS_VOLHEAD_SIG;
377         if (be16_to_cpu(vhdr->version) < HFSPLUS_MIN_VERSION ||
378             be16_to_cpu(vhdr->version) > HFSPLUS_CURRENT_VERSION) {
379                 printk(KERN_ERR "hfs: wrong filesystem version\n");
380                 goto out_free_vhdr;
381         }
382         sbi->total_blocks = be32_to_cpu(vhdr->total_blocks);
383         sbi->free_blocks = be32_to_cpu(vhdr->free_blocks);
384         sbi->next_cnid = be32_to_cpu(vhdr->next_cnid);
385         sbi->file_count = be32_to_cpu(vhdr->file_count);
386         sbi->folder_count = be32_to_cpu(vhdr->folder_count);
387         sbi->data_clump_blocks =
388                 be32_to_cpu(vhdr->data_clump_sz) >> sbi->alloc_blksz_shift;
389         if (!sbi->data_clump_blocks)
390                 sbi->data_clump_blocks = 1;
391         sbi->rsrc_clump_blocks =
392                 be32_to_cpu(vhdr->rsrc_clump_sz) >> sbi->alloc_blksz_shift;
393         if (!sbi->rsrc_clump_blocks)
394                 sbi->rsrc_clump_blocks = 1;
395
396         /* Set up operations so we can load metadata */
397         sb->s_op = &hfsplus_sops;
398         sb->s_maxbytes = MAX_LFS_FILESIZE;
399
400         if (!(vhdr->attributes & cpu_to_be32(HFSPLUS_VOL_UNMNT))) {
401                 printk(KERN_WARNING "hfs: Filesystem was "
402                                 "not cleanly unmounted, "
403                                 "running fsck.hfsplus is recommended.  "
404                                 "mounting read-only.\n");
405                 sb->s_flags |= MS_RDONLY;
406         } else if (test_and_clear_bit(HFSPLUS_SB_FORCE, &sbi->flags)) {
407                 /* nothing */
408         } else if (vhdr->attributes & cpu_to_be32(HFSPLUS_VOL_SOFTLOCK)) {
409                 printk(KERN_WARNING "hfs: Filesystem is marked locked, mounting read-only.\n");
410                 sb->s_flags |= MS_RDONLY;
411         } else if ((vhdr->attributes & cpu_to_be32(HFSPLUS_VOL_JOURNALED)) &&
412                         !(sb->s_flags & MS_RDONLY)) {
413                 printk(KERN_WARNING "hfs: write access to "
414                                 "a journaled filesystem is not supported, "
415                                 "use the force option at your own risk, "
416                                 "mounting read-only.\n");
417                 sb->s_flags |= MS_RDONLY;
418         }
419
420         /* Load metadata objects (B*Trees) */
421         sbi->ext_tree = hfs_btree_open(sb, HFSPLUS_EXT_CNID);
422         if (!sbi->ext_tree) {
423                 printk(KERN_ERR "hfs: failed to load extents file\n");
424                 goto out_free_vhdr;
425         }
426         sbi->cat_tree = hfs_btree_open(sb, HFSPLUS_CAT_CNID);
427         if (!sbi->cat_tree) {
428                 printk(KERN_ERR "hfs: failed to load catalog file\n");
429                 goto out_close_ext_tree;
430         }
431
432         inode = hfsplus_iget(sb, HFSPLUS_ALLOC_CNID);
433         if (IS_ERR(inode)) {
434                 printk(KERN_ERR "hfs: failed to load allocation file\n");
435                 err = PTR_ERR(inode);
436                 goto out_close_cat_tree;
437         }
438         sbi->alloc_file = inode;
439
440         /* Load the root directory */
441         root = hfsplus_iget(sb, HFSPLUS_ROOT_CNID);
442         if (IS_ERR(root)) {
443                 printk(KERN_ERR "hfs: failed to load root directory\n");
444                 err = PTR_ERR(root);
445                 goto out_put_alloc_file;
446         }
447
448         str.len = sizeof(HFSP_HIDDENDIR_NAME) - 1;
449         str.name = HFSP_HIDDENDIR_NAME;
450         hfs_find_init(sbi->cat_tree, &fd);
451         hfsplus_cat_build_key(sb, fd.search_key, HFSPLUS_ROOT_CNID, &str);
452         if (!hfs_brec_read(&fd, &entry, sizeof(entry))) {
453                 hfs_find_exit(&fd);
454                 if (entry.type != cpu_to_be16(HFSPLUS_FOLDER))
455                         goto out_put_root;
456                 inode = hfsplus_iget(sb, be32_to_cpu(entry.folder.id));
457                 if (IS_ERR(inode)) {
458                         err = PTR_ERR(inode);
459                         goto out_put_root;
460                 }
461                 sbi->hidden_dir = inode;
462         } else
463                 hfs_find_exit(&fd);
464
465         if (!(sb->s_flags & MS_RDONLY)) {
466                 /*
467                  * H+LX == hfsplusutils, H+Lx == this driver, H+lx is unused
468                  * all three are registered with Apple for our use
469                  */
470                 vhdr->last_mount_vers = cpu_to_be32(HFSP_MOUNT_VERSION);
471                 vhdr->modify_date = hfsp_now2mt();
472                 be32_add_cpu(&vhdr->write_count, 1);
473                 vhdr->attributes &= cpu_to_be32(~HFSPLUS_VOL_UNMNT);
474                 vhdr->attributes |= cpu_to_be32(HFSPLUS_VOL_INCNSTNT);
475                 hfsplus_sync_fs(sb, 1);
476
477                 if (!sbi->hidden_dir) {
478                         mutex_lock(&sbi->vh_mutex);
479                         sbi->hidden_dir = hfsplus_new_inode(sb, S_IFDIR);
480                         hfsplus_create_cat(sbi->hidden_dir->i_ino, root, &str,
481                                            sbi->hidden_dir);
482                         mutex_unlock(&sbi->vh_mutex);
483
484                         hfsplus_mark_inode_dirty(sbi->hidden_dir,
485                                                  HFSPLUS_I_CAT_DIRTY);
486                 }
487         }
488
489         sb->s_d_op = &hfsplus_dentry_operations;
490         sb->s_root = d_alloc_root(root);
491         if (!sb->s_root) {
492                 err = -ENOMEM;
493                 goto out_put_hidden_dir;
494         }
495
496         unload_nls(sbi->nls);
497         sbi->nls = nls;
498         return 0;
499
500 out_put_hidden_dir:
501         iput(sbi->hidden_dir);
502 out_put_root:
503         iput(root);
504 out_put_alloc_file:
505         iput(sbi->alloc_file);
506 out_close_cat_tree:
507         hfs_btree_close(sbi->cat_tree);
508 out_close_ext_tree:
509         hfs_btree_close(sbi->ext_tree);
510 out_free_vhdr:
511         kfree(sbi->s_vhdr);
512         kfree(sbi->s_backup_vhdr);
513 out_unload_nls:
514         unload_nls(sbi->nls);
515         unload_nls(nls);
516         kfree(sbi);
517 out:
518         return err;
519 }
520
521 MODULE_AUTHOR("Brad Boyer");
522 MODULE_DESCRIPTION("Extended Macintosh Filesystem");
523 MODULE_LICENSE("GPL");
524
525 static struct kmem_cache *hfsplus_inode_cachep;
526
527 static struct inode *hfsplus_alloc_inode(struct super_block *sb)
528 {
529         struct hfsplus_inode_info *i;
530
531         i = kmem_cache_alloc(hfsplus_inode_cachep, GFP_KERNEL);
532         return i ? &i->vfs_inode : NULL;
533 }
534
535 static void hfsplus_i_callback(struct rcu_head *head)
536 {
537         struct inode *inode = container_of(head, struct inode, i_rcu);
538
539         INIT_LIST_HEAD(&inode->i_dentry);
540         kmem_cache_free(hfsplus_inode_cachep, HFSPLUS_I(inode));
541 }
542
543 static void hfsplus_destroy_inode(struct inode *inode)
544 {
545         call_rcu(&inode->i_rcu, hfsplus_i_callback);
546 }
547
548 #define HFSPLUS_INODE_SIZE      sizeof(struct hfsplus_inode_info)
549
550 static struct dentry *hfsplus_mount(struct file_system_type *fs_type,
551                           int flags, const char *dev_name, void *data)
552 {
553         return mount_bdev(fs_type, flags, dev_name, data, hfsplus_fill_super);
554 }
555
556 static struct file_system_type hfsplus_fs_type = {
557         .owner          = THIS_MODULE,
558         .name           = "hfsplus",
559         .mount          = hfsplus_mount,
560         .kill_sb        = kill_block_super,
561         .fs_flags       = FS_REQUIRES_DEV,
562 };
563
564 static void hfsplus_init_once(void *p)
565 {
566         struct hfsplus_inode_info *i = p;
567
568         inode_init_once(&i->vfs_inode);
569 }
570
571 static int __init init_hfsplus_fs(void)
572 {
573         int err;
574
575         hfsplus_inode_cachep = kmem_cache_create("hfsplus_icache",
576                 HFSPLUS_INODE_SIZE, 0, SLAB_HWCACHE_ALIGN,
577                 hfsplus_init_once);
578         if (!hfsplus_inode_cachep)
579                 return -ENOMEM;
580         err = register_filesystem(&hfsplus_fs_type);
581         if (err)
582                 kmem_cache_destroy(hfsplus_inode_cachep);
583         return err;
584 }
585
586 static void __exit exit_hfsplus_fs(void)
587 {
588         unregister_filesystem(&hfsplus_fs_type);
589         kmem_cache_destroy(hfsplus_inode_cachep);
590 }
591
592 module_init(init_hfsplus_fs)
593 module_exit(exit_hfsplus_fs)