xref: /linux/fs/hfsplus/super.c (revision cdb138080b78146d1cdadba9f5dadbeb97445b91)
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/fs.h>
14 #include <linux/slab.h>
15 #include <linux/smp_lock.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 struct inode *hfsplus_iget(struct super_block *sb, unsigned long ino)
25 {
26 	struct hfs_find_data fd;
27 	struct hfsplus_vh *vhdr;
28 	struct inode *inode;
29 	long err = -EIO;
30 
31 	inode = iget_locked(sb, ino);
32 	if (!inode)
33 		return ERR_PTR(-ENOMEM);
34 	if (!(inode->i_state & I_NEW))
35 		return inode;
36 
37 	INIT_LIST_HEAD(&HFSPLUS_I(inode).open_dir_list);
38 	mutex_init(&HFSPLUS_I(inode).extents_lock);
39 	HFSPLUS_I(inode).flags = 0;
40 	HFSPLUS_I(inode).rsrc_inode = NULL;
41 	atomic_set(&HFSPLUS_I(inode).opencnt, 0);
42 
43 	if (inode->i_ino >= HFSPLUS_FIRSTUSER_CNID) {
44 	read_inode:
45 		hfs_find_init(HFSPLUS_SB(inode->i_sb).cat_tree, &fd);
46 		err = hfsplus_find_cat(inode->i_sb, inode->i_ino, &fd);
47 		if (!err)
48 			err = hfsplus_cat_read_inode(inode, &fd);
49 		hfs_find_exit(&fd);
50 		if (err)
51 			goto bad_inode;
52 		goto done;
53 	}
54 	vhdr = HFSPLUS_SB(inode->i_sb).s_vhdr;
55 	switch(inode->i_ino) {
56 	case HFSPLUS_ROOT_CNID:
57 		goto read_inode;
58 	case HFSPLUS_EXT_CNID:
59 		hfsplus_inode_read_fork(inode, &vhdr->ext_file);
60 		inode->i_mapping->a_ops = &hfsplus_btree_aops;
61 		break;
62 	case HFSPLUS_CAT_CNID:
63 		hfsplus_inode_read_fork(inode, &vhdr->cat_file);
64 		inode->i_mapping->a_ops = &hfsplus_btree_aops;
65 		break;
66 	case HFSPLUS_ALLOC_CNID:
67 		hfsplus_inode_read_fork(inode, &vhdr->alloc_file);
68 		inode->i_mapping->a_ops = &hfsplus_aops;
69 		break;
70 	case HFSPLUS_START_CNID:
71 		hfsplus_inode_read_fork(inode, &vhdr->start_file);
72 		break;
73 	case HFSPLUS_ATTR_CNID:
74 		hfsplus_inode_read_fork(inode, &vhdr->attr_file);
75 		inode->i_mapping->a_ops = &hfsplus_btree_aops;
76 		break;
77 	default:
78 		goto bad_inode;
79 	}
80 
81 done:
82 	unlock_new_inode(inode);
83 	return inode;
84 
85 bad_inode:
86 	iget_failed(inode);
87 	return ERR_PTR(err);
88 }
89 
90 static int hfsplus_write_inode(struct inode *inode,
91 		struct writeback_control *wbc)
92 {
93 	struct hfsplus_vh *vhdr;
94 	int ret = 0;
95 
96 	dprint(DBG_INODE, "hfsplus_write_inode: %lu\n", inode->i_ino);
97 	hfsplus_ext_write_extent(inode);
98 	if (inode->i_ino >= HFSPLUS_FIRSTUSER_CNID) {
99 		return hfsplus_cat_write_inode(inode);
100 	}
101 	vhdr = HFSPLUS_SB(inode->i_sb).s_vhdr;
102 	switch (inode->i_ino) {
103 	case HFSPLUS_ROOT_CNID:
104 		ret = hfsplus_cat_write_inode(inode);
105 		break;
106 	case HFSPLUS_EXT_CNID:
107 		if (vhdr->ext_file.total_size != cpu_to_be64(inode->i_size)) {
108 			HFSPLUS_SB(inode->i_sb).flags |= HFSPLUS_SB_WRITEBACKUP;
109 			inode->i_sb->s_dirt = 1;
110 		}
111 		hfsplus_inode_write_fork(inode, &vhdr->ext_file);
112 		hfs_btree_write(HFSPLUS_SB(inode->i_sb).ext_tree);
113 		break;
114 	case HFSPLUS_CAT_CNID:
115 		if (vhdr->cat_file.total_size != cpu_to_be64(inode->i_size)) {
116 			HFSPLUS_SB(inode->i_sb).flags |= HFSPLUS_SB_WRITEBACKUP;
117 			inode->i_sb->s_dirt = 1;
118 		}
119 		hfsplus_inode_write_fork(inode, &vhdr->cat_file);
120 		hfs_btree_write(HFSPLUS_SB(inode->i_sb).cat_tree);
121 		break;
122 	case HFSPLUS_ALLOC_CNID:
123 		if (vhdr->alloc_file.total_size != cpu_to_be64(inode->i_size)) {
124 			HFSPLUS_SB(inode->i_sb).flags |= HFSPLUS_SB_WRITEBACKUP;
125 			inode->i_sb->s_dirt = 1;
126 		}
127 		hfsplus_inode_write_fork(inode, &vhdr->alloc_file);
128 		break;
129 	case HFSPLUS_START_CNID:
130 		if (vhdr->start_file.total_size != cpu_to_be64(inode->i_size)) {
131 			HFSPLUS_SB(inode->i_sb).flags |= HFSPLUS_SB_WRITEBACKUP;
132 			inode->i_sb->s_dirt = 1;
133 		}
134 		hfsplus_inode_write_fork(inode, &vhdr->start_file);
135 		break;
136 	case HFSPLUS_ATTR_CNID:
137 		if (vhdr->attr_file.total_size != cpu_to_be64(inode->i_size)) {
138 			HFSPLUS_SB(inode->i_sb).flags |= HFSPLUS_SB_WRITEBACKUP;
139 			inode->i_sb->s_dirt = 1;
140 		}
141 		hfsplus_inode_write_fork(inode, &vhdr->attr_file);
142 		hfs_btree_write(HFSPLUS_SB(inode->i_sb).attr_tree);
143 		break;
144 	}
145 	return ret;
146 }
147 
148 static void hfsplus_evict_inode(struct inode *inode)
149 {
150 	dprint(DBG_INODE, "hfsplus_evict_inode: %lu\n", inode->i_ino);
151 	truncate_inode_pages(&inode->i_data, 0);
152 	end_writeback(inode);
153 	if (HFSPLUS_IS_RSRC(inode)) {
154 		HFSPLUS_I(HFSPLUS_I(inode).rsrc_inode).rsrc_inode = NULL;
155 		iput(HFSPLUS_I(inode).rsrc_inode);
156 	}
157 }
158 
159 int hfsplus_sync_fs(struct super_block *sb, int wait)
160 {
161 	struct hfsplus_vh *vhdr = HFSPLUS_SB(sb).s_vhdr;
162 
163 	dprint(DBG_SUPER, "hfsplus_write_super\n");
164 
165 	lock_super(sb);
166 	sb->s_dirt = 0;
167 
168 	vhdr->free_blocks = cpu_to_be32(HFSPLUS_SB(sb).free_blocks);
169 	vhdr->next_alloc = cpu_to_be32(HFSPLUS_SB(sb).next_alloc);
170 	vhdr->next_cnid = cpu_to_be32(HFSPLUS_SB(sb).next_cnid);
171 	vhdr->folder_count = cpu_to_be32(HFSPLUS_SB(sb).folder_count);
172 	vhdr->file_count = cpu_to_be32(HFSPLUS_SB(sb).file_count);
173 
174 	mark_buffer_dirty(HFSPLUS_SB(sb).s_vhbh);
175 	if (HFSPLUS_SB(sb).flags & HFSPLUS_SB_WRITEBACKUP) {
176 		if (HFSPLUS_SB(sb).sect_count) {
177 			struct buffer_head *bh;
178 			u32 block, offset;
179 
180 			block = HFSPLUS_SB(sb).blockoffset;
181 			block += (HFSPLUS_SB(sb).sect_count - 2) >> (sb->s_blocksize_bits - 9);
182 			offset = ((HFSPLUS_SB(sb).sect_count - 2) << 9) & (sb->s_blocksize - 1);
183 			printk(KERN_DEBUG "hfs: backup: %u,%u,%u,%u\n", HFSPLUS_SB(sb).blockoffset,
184 				HFSPLUS_SB(sb).sect_count, block, offset);
185 			bh = sb_bread(sb, block);
186 			if (bh) {
187 				vhdr = (struct hfsplus_vh *)(bh->b_data + offset);
188 				if (be16_to_cpu(vhdr->signature) == HFSPLUS_VOLHEAD_SIG) {
189 					memcpy(vhdr, HFSPLUS_SB(sb).s_vhdr, sizeof(*vhdr));
190 					mark_buffer_dirty(bh);
191 					brelse(bh);
192 				} else
193 					printk(KERN_WARNING "hfs: backup not found!\n");
194 			}
195 		}
196 		HFSPLUS_SB(sb).flags &= ~HFSPLUS_SB_WRITEBACKUP;
197 	}
198 	unlock_super(sb);
199 	return 0;
200 }
201 
202 static void hfsplus_write_super(struct super_block *sb)
203 {
204 	if (!(sb->s_flags & MS_RDONLY))
205 		hfsplus_sync_fs(sb, 1);
206 	else
207 		sb->s_dirt = 0;
208 }
209 
210 static void hfsplus_put_super(struct super_block *sb)
211 {
212 	dprint(DBG_SUPER, "hfsplus_put_super\n");
213 	if (!sb->s_fs_info)
214 		return;
215 
216 	lock_kernel();
217 
218 	if (sb->s_dirt)
219 		hfsplus_write_super(sb);
220 	if (!(sb->s_flags & MS_RDONLY) && HFSPLUS_SB(sb).s_vhdr) {
221 		struct hfsplus_vh *vhdr = HFSPLUS_SB(sb).s_vhdr;
222 
223 		vhdr->modify_date = hfsp_now2mt();
224 		vhdr->attributes |= cpu_to_be32(HFSPLUS_VOL_UNMNT);
225 		vhdr->attributes &= cpu_to_be32(~HFSPLUS_VOL_INCNSTNT);
226 		mark_buffer_dirty(HFSPLUS_SB(sb).s_vhbh);
227 		sync_dirty_buffer(HFSPLUS_SB(sb).s_vhbh);
228 	}
229 
230 	hfs_btree_close(HFSPLUS_SB(sb).cat_tree);
231 	hfs_btree_close(HFSPLUS_SB(sb).ext_tree);
232 	iput(HFSPLUS_SB(sb).alloc_file);
233 	iput(HFSPLUS_SB(sb).hidden_dir);
234 	brelse(HFSPLUS_SB(sb).s_vhbh);
235 	unload_nls(HFSPLUS_SB(sb).nls);
236 	kfree(sb->s_fs_info);
237 	sb->s_fs_info = NULL;
238 
239 	unlock_kernel();
240 }
241 
242 static int hfsplus_statfs(struct dentry *dentry, struct kstatfs *buf)
243 {
244 	struct super_block *sb = dentry->d_sb;
245 	u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
246 
247 	buf->f_type = HFSPLUS_SUPER_MAGIC;
248 	buf->f_bsize = sb->s_blocksize;
249 	buf->f_blocks = HFSPLUS_SB(sb).total_blocks << HFSPLUS_SB(sb).fs_shift;
250 	buf->f_bfree = HFSPLUS_SB(sb).free_blocks << HFSPLUS_SB(sb).fs_shift;
251 	buf->f_bavail = buf->f_bfree;
252 	buf->f_files = 0xFFFFFFFF;
253 	buf->f_ffree = 0xFFFFFFFF - HFSPLUS_SB(sb).next_cnid;
254 	buf->f_fsid.val[0] = (u32)id;
255 	buf->f_fsid.val[1] = (u32)(id >> 32);
256 	buf->f_namelen = HFSPLUS_MAX_STRLEN;
257 
258 	return 0;
259 }
260 
261 static int hfsplus_remount(struct super_block *sb, int *flags, char *data)
262 {
263 	if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
264 		return 0;
265 	if (!(*flags & MS_RDONLY)) {
266 		struct hfsplus_vh *vhdr = HFSPLUS_SB(sb).s_vhdr;
267 		struct hfsplus_sb_info sbi;
268 
269 		memset(&sbi, 0, sizeof(struct hfsplus_sb_info));
270 		sbi.nls = HFSPLUS_SB(sb).nls;
271 		if (!hfsplus_parse_options(data, &sbi))
272 			return -EINVAL;
273 
274 		if (!(vhdr->attributes & cpu_to_be32(HFSPLUS_VOL_UNMNT))) {
275 			printk(KERN_WARNING "hfs: filesystem was not cleanly unmounted, "
276 			       "running fsck.hfsplus is recommended.  leaving read-only.\n");
277 			sb->s_flags |= MS_RDONLY;
278 			*flags |= MS_RDONLY;
279 		} else if (sbi.flags & HFSPLUS_SB_FORCE) {
280 			/* nothing */
281 		} else if (vhdr->attributes & cpu_to_be32(HFSPLUS_VOL_SOFTLOCK)) {
282 			printk(KERN_WARNING "hfs: filesystem is marked locked, leaving read-only.\n");
283 			sb->s_flags |= MS_RDONLY;
284 			*flags |= MS_RDONLY;
285 		} else if (vhdr->attributes & cpu_to_be32(HFSPLUS_VOL_JOURNALED)) {
286 			printk(KERN_WARNING "hfs: filesystem is marked journaled, leaving read-only.\n");
287 			sb->s_flags |= MS_RDONLY;
288 			*flags |= MS_RDONLY;
289 		}
290 	}
291 	return 0;
292 }
293 
294 static const struct super_operations hfsplus_sops = {
295 	.alloc_inode	= hfsplus_alloc_inode,
296 	.destroy_inode	= hfsplus_destroy_inode,
297 	.write_inode	= hfsplus_write_inode,
298 	.evict_inode	= hfsplus_evict_inode,
299 	.put_super	= hfsplus_put_super,
300 	.write_super	= hfsplus_write_super,
301 	.sync_fs	= hfsplus_sync_fs,
302 	.statfs		= hfsplus_statfs,
303 	.remount_fs	= hfsplus_remount,
304 	.show_options	= hfsplus_show_options,
305 };
306 
307 static int hfsplus_fill_super(struct super_block *sb, void *data, int silent)
308 {
309 	struct hfsplus_vh *vhdr;
310 	struct hfsplus_sb_info *sbi;
311 	hfsplus_cat_entry entry;
312 	struct hfs_find_data fd;
313 	struct inode *root, *inode;
314 	struct qstr str;
315 	struct nls_table *nls = NULL;
316 	int err = -EINVAL;
317 
318 	sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
319 	if (!sbi)
320 		return -ENOMEM;
321 
322 	sb->s_fs_info = sbi;
323 	INIT_HLIST_HEAD(&sbi->rsrc_inodes);
324 	hfsplus_fill_defaults(sbi);
325 	if (!hfsplus_parse_options(data, sbi)) {
326 		printk(KERN_ERR "hfs: unable to parse mount options\n");
327 		err = -EINVAL;
328 		goto cleanup;
329 	}
330 
331 	/* temporarily use utf8 to correctly find the hidden dir below */
332 	nls = sbi->nls;
333 	sbi->nls = load_nls("utf8");
334 	if (!sbi->nls) {
335 		printk(KERN_ERR "hfs: unable to load nls for utf8\n");
336 		err = -EINVAL;
337 		goto cleanup;
338 	}
339 
340 	/* Grab the volume header */
341 	if (hfsplus_read_wrapper(sb)) {
342 		if (!silent)
343 			printk(KERN_WARNING "hfs: unable to find HFS+ superblock\n");
344 		err = -EINVAL;
345 		goto cleanup;
346 	}
347 	vhdr = HFSPLUS_SB(sb).s_vhdr;
348 
349 	/* Copy parts of the volume header into the superblock */
350 	sb->s_magic = HFSPLUS_VOLHEAD_SIG;
351 	if (be16_to_cpu(vhdr->version) < HFSPLUS_MIN_VERSION ||
352 	    be16_to_cpu(vhdr->version) > HFSPLUS_CURRENT_VERSION) {
353 		printk(KERN_ERR "hfs: wrong filesystem version\n");
354 		goto cleanup;
355 	}
356 	HFSPLUS_SB(sb).total_blocks = be32_to_cpu(vhdr->total_blocks);
357 	HFSPLUS_SB(sb).free_blocks = be32_to_cpu(vhdr->free_blocks);
358 	HFSPLUS_SB(sb).next_alloc = be32_to_cpu(vhdr->next_alloc);
359 	HFSPLUS_SB(sb).next_cnid = be32_to_cpu(vhdr->next_cnid);
360 	HFSPLUS_SB(sb).file_count = be32_to_cpu(vhdr->file_count);
361 	HFSPLUS_SB(sb).folder_count = be32_to_cpu(vhdr->folder_count);
362 	HFSPLUS_SB(sb).data_clump_blocks = be32_to_cpu(vhdr->data_clump_sz) >> HFSPLUS_SB(sb).alloc_blksz_shift;
363 	if (!HFSPLUS_SB(sb).data_clump_blocks)
364 		HFSPLUS_SB(sb).data_clump_blocks = 1;
365 	HFSPLUS_SB(sb).rsrc_clump_blocks = be32_to_cpu(vhdr->rsrc_clump_sz) >> HFSPLUS_SB(sb).alloc_blksz_shift;
366 	if (!HFSPLUS_SB(sb).rsrc_clump_blocks)
367 		HFSPLUS_SB(sb).rsrc_clump_blocks = 1;
368 
369 	/* Set up operations so we can load metadata */
370 	sb->s_op = &hfsplus_sops;
371 	sb->s_maxbytes = MAX_LFS_FILESIZE;
372 
373 	if (!(vhdr->attributes & cpu_to_be32(HFSPLUS_VOL_UNMNT))) {
374 		printk(KERN_WARNING "hfs: Filesystem was not cleanly unmounted, "
375 		       "running fsck.hfsplus is recommended.  mounting read-only.\n");
376 		sb->s_flags |= MS_RDONLY;
377 	} else if (sbi->flags & HFSPLUS_SB_FORCE) {
378 		/* nothing */
379 	} else if (vhdr->attributes & cpu_to_be32(HFSPLUS_VOL_SOFTLOCK)) {
380 		printk(KERN_WARNING "hfs: Filesystem is marked locked, mounting read-only.\n");
381 		sb->s_flags |= MS_RDONLY;
382 	} else if ((vhdr->attributes & cpu_to_be32(HFSPLUS_VOL_JOURNALED)) && !(sb->s_flags & MS_RDONLY)) {
383 		printk(KERN_WARNING "hfs: write access to a journaled filesystem is not supported, "
384 		       "use the force option at your own risk, mounting read-only.\n");
385 		sb->s_flags |= MS_RDONLY;
386 	}
387 	sbi->flags &= ~HFSPLUS_SB_FORCE;
388 
389 	/* Load metadata objects (B*Trees) */
390 	HFSPLUS_SB(sb).ext_tree = hfs_btree_open(sb, HFSPLUS_EXT_CNID);
391 	if (!HFSPLUS_SB(sb).ext_tree) {
392 		printk(KERN_ERR "hfs: failed to load extents file\n");
393 		goto cleanup;
394 	}
395 	HFSPLUS_SB(sb).cat_tree = hfs_btree_open(sb, HFSPLUS_CAT_CNID);
396 	if (!HFSPLUS_SB(sb).cat_tree) {
397 		printk(KERN_ERR "hfs: failed to load catalog file\n");
398 		goto cleanup;
399 	}
400 
401 	inode = hfsplus_iget(sb, HFSPLUS_ALLOC_CNID);
402 	if (IS_ERR(inode)) {
403 		printk(KERN_ERR "hfs: failed to load allocation file\n");
404 		err = PTR_ERR(inode);
405 		goto cleanup;
406 	}
407 	HFSPLUS_SB(sb).alloc_file = inode;
408 
409 	/* Load the root directory */
410 	root = hfsplus_iget(sb, HFSPLUS_ROOT_CNID);
411 	if (IS_ERR(root)) {
412 		printk(KERN_ERR "hfs: failed to load root directory\n");
413 		err = PTR_ERR(root);
414 		goto cleanup;
415 	}
416 	sb->s_root = d_alloc_root(root);
417 	if (!sb->s_root) {
418 		iput(root);
419 		err = -ENOMEM;
420 		goto cleanup;
421 	}
422 	sb->s_root->d_op = &hfsplus_dentry_operations;
423 
424 	str.len = sizeof(HFSP_HIDDENDIR_NAME) - 1;
425 	str.name = HFSP_HIDDENDIR_NAME;
426 	hfs_find_init(HFSPLUS_SB(sb).cat_tree, &fd);
427 	hfsplus_cat_build_key(sb, fd.search_key, HFSPLUS_ROOT_CNID, &str);
428 	if (!hfs_brec_read(&fd, &entry, sizeof(entry))) {
429 		hfs_find_exit(&fd);
430 		if (entry.type != cpu_to_be16(HFSPLUS_FOLDER))
431 			goto cleanup;
432 		inode = hfsplus_iget(sb, be32_to_cpu(entry.folder.id));
433 		if (IS_ERR(inode)) {
434 			err = PTR_ERR(inode);
435 			goto cleanup;
436 		}
437 		HFSPLUS_SB(sb).hidden_dir = inode;
438 	} else
439 		hfs_find_exit(&fd);
440 
441 	if (sb->s_flags & MS_RDONLY)
442 		goto out;
443 
444 	/* H+LX == hfsplusutils, H+Lx == this driver, H+lx is unused
445 	 * all three are registered with Apple for our use
446 	 */
447 	vhdr->last_mount_vers = cpu_to_be32(HFSP_MOUNT_VERSION);
448 	vhdr->modify_date = hfsp_now2mt();
449 	be32_add_cpu(&vhdr->write_count, 1);
450 	vhdr->attributes &= cpu_to_be32(~HFSPLUS_VOL_UNMNT);
451 	vhdr->attributes |= cpu_to_be32(HFSPLUS_VOL_INCNSTNT);
452 	mark_buffer_dirty(HFSPLUS_SB(sb).s_vhbh);
453 	sync_dirty_buffer(HFSPLUS_SB(sb).s_vhbh);
454 
455 	if (!HFSPLUS_SB(sb).hidden_dir) {
456 		printk(KERN_DEBUG "hfs: create hidden dir...\n");
457 		HFSPLUS_SB(sb).hidden_dir = hfsplus_new_inode(sb, S_IFDIR);
458 		hfsplus_create_cat(HFSPLUS_SB(sb).hidden_dir->i_ino, sb->s_root->d_inode,
459 				   &str, HFSPLUS_SB(sb).hidden_dir);
460 		mark_inode_dirty(HFSPLUS_SB(sb).hidden_dir);
461 	}
462 out:
463 	unload_nls(sbi->nls);
464 	sbi->nls = nls;
465 	return 0;
466 
467 cleanup:
468 	hfsplus_put_super(sb);
469 	unload_nls(nls);
470 	return err;
471 }
472 
473 MODULE_AUTHOR("Brad Boyer");
474 MODULE_DESCRIPTION("Extended Macintosh Filesystem");
475 MODULE_LICENSE("GPL");
476 
477 static struct kmem_cache *hfsplus_inode_cachep;
478 
479 static struct inode *hfsplus_alloc_inode(struct super_block *sb)
480 {
481 	struct hfsplus_inode_info *i;
482 
483 	i = kmem_cache_alloc(hfsplus_inode_cachep, GFP_KERNEL);
484 	return i ? &i->vfs_inode : NULL;
485 }
486 
487 static void hfsplus_destroy_inode(struct inode *inode)
488 {
489 	kmem_cache_free(hfsplus_inode_cachep, &HFSPLUS_I(inode));
490 }
491 
492 #define HFSPLUS_INODE_SIZE	sizeof(struct hfsplus_inode_info)
493 
494 static int hfsplus_get_sb(struct file_system_type *fs_type,
495 			  int flags, const char *dev_name, void *data,
496 			  struct vfsmount *mnt)
497 {
498 	return get_sb_bdev(fs_type, flags, dev_name, data, hfsplus_fill_super,
499 			   mnt);
500 }
501 
502 static struct file_system_type hfsplus_fs_type = {
503 	.owner		= THIS_MODULE,
504 	.name		= "hfsplus",
505 	.get_sb		= hfsplus_get_sb,
506 	.kill_sb	= kill_block_super,
507 	.fs_flags	= FS_REQUIRES_DEV,
508 };
509 
510 static void hfsplus_init_once(void *p)
511 {
512 	struct hfsplus_inode_info *i = p;
513 
514 	inode_init_once(&i->vfs_inode);
515 }
516 
517 static int __init init_hfsplus_fs(void)
518 {
519 	int err;
520 
521 	hfsplus_inode_cachep = kmem_cache_create("hfsplus_icache",
522 		HFSPLUS_INODE_SIZE, 0, SLAB_HWCACHE_ALIGN,
523 		hfsplus_init_once);
524 	if (!hfsplus_inode_cachep)
525 		return -ENOMEM;
526 	err = register_filesystem(&hfsplus_fs_type);
527 	if (err)
528 		kmem_cache_destroy(hfsplus_inode_cachep);
529 	return err;
530 }
531 
532 static void __exit exit_hfsplus_fs(void)
533 {
534 	unregister_filesystem(&hfsplus_fs_type);
535 	kmem_cache_destroy(hfsplus_inode_cachep);
536 }
537 
538 module_init(init_hfsplus_fs)
539 module_exit(exit_hfsplus_fs)
540