xref: /linux/fs/affs/super.c (revision d060296cc0300ae8ed08004ebd3994bf325fa257)
1 /*
2  *  linux/fs/affs/inode.c
3  *
4  *  (c) 1996  Hans-Joachim Widmaier - Rewritten
5  *
6  *  (C) 1993  Ray Burr - Modified for Amiga FFS filesystem.
7  *
8  *  (C) 1992  Eric Youngdale Modified for ISO 9660 filesystem.
9  *
10  *  (C) 1991  Linus Torvalds - minix filesystem
11  */
12 
13 #include <linux/module.h>
14 #include <linux/init.h>
15 #include <linux/statfs.h>
16 #include <linux/parser.h>
17 #include <linux/magic.h>
18 #include <linux/sched.h>
19 #include <linux/cred.h>
20 #include <linux/slab.h>
21 #include <linux/writeback.h>
22 #include <linux/blkdev.h>
23 #include <linux/seq_file.h>
24 #include "affs.h"
25 
26 static int affs_statfs(struct dentry *dentry, struct kstatfs *buf);
27 static int affs_show_options(struct seq_file *m, struct dentry *root);
28 static int affs_remount (struct super_block *sb, int *flags, char *data);
29 
30 static void
31 affs_commit_super(struct super_block *sb, int wait)
32 {
33 	struct affs_sb_info *sbi = AFFS_SB(sb);
34 	struct buffer_head *bh = sbi->s_root_bh;
35 	struct affs_root_tail *tail = AFFS_ROOT_TAIL(sb, bh);
36 
37 	lock_buffer(bh);
38 	affs_secs_to_datestamp(ktime_get_real_seconds(), &tail->disk_change);
39 	affs_fix_checksum(sb, bh);
40 	unlock_buffer(bh);
41 
42 	mark_buffer_dirty(bh);
43 	if (wait)
44 		sync_dirty_buffer(bh);
45 }
46 
47 static void
48 affs_put_super(struct super_block *sb)
49 {
50 	struct affs_sb_info *sbi = AFFS_SB(sb);
51 	pr_debug("%s()\n", __func__);
52 
53 	cancel_delayed_work_sync(&sbi->sb_work);
54 }
55 
56 static int
57 affs_sync_fs(struct super_block *sb, int wait)
58 {
59 	affs_commit_super(sb, wait);
60 	return 0;
61 }
62 
63 static void flush_superblock(struct work_struct *work)
64 {
65 	struct affs_sb_info *sbi;
66 	struct super_block *sb;
67 
68 	sbi = container_of(work, struct affs_sb_info, sb_work.work);
69 	sb = sbi->sb;
70 
71 	spin_lock(&sbi->work_lock);
72 	sbi->work_queued = 0;
73 	spin_unlock(&sbi->work_lock);
74 
75 	affs_commit_super(sb, 1);
76 }
77 
78 void affs_mark_sb_dirty(struct super_block *sb)
79 {
80 	struct affs_sb_info *sbi = AFFS_SB(sb);
81 	unsigned long delay;
82 
83 	if (sb->s_flags & MS_RDONLY)
84 	       return;
85 
86 	spin_lock(&sbi->work_lock);
87 	if (!sbi->work_queued) {
88 	       delay = msecs_to_jiffies(dirty_writeback_interval * 10);
89 	       queue_delayed_work(system_long_wq, &sbi->sb_work, delay);
90 	       sbi->work_queued = 1;
91 	}
92 	spin_unlock(&sbi->work_lock);
93 }
94 
95 static struct kmem_cache * affs_inode_cachep;
96 
97 static struct inode *affs_alloc_inode(struct super_block *sb)
98 {
99 	struct affs_inode_info *i;
100 
101 	i = kmem_cache_alloc(affs_inode_cachep, GFP_KERNEL);
102 	if (!i)
103 		return NULL;
104 
105 	i->vfs_inode.i_version = 1;
106 	i->i_lc = NULL;
107 	i->i_ext_bh = NULL;
108 	i->i_pa_cnt = 0;
109 
110 	return &i->vfs_inode;
111 }
112 
113 static void affs_i_callback(struct rcu_head *head)
114 {
115 	struct inode *inode = container_of(head, struct inode, i_rcu);
116 	kmem_cache_free(affs_inode_cachep, AFFS_I(inode));
117 }
118 
119 static void affs_destroy_inode(struct inode *inode)
120 {
121 	call_rcu(&inode->i_rcu, affs_i_callback);
122 }
123 
124 static void init_once(void *foo)
125 {
126 	struct affs_inode_info *ei = (struct affs_inode_info *) foo;
127 
128 	sema_init(&ei->i_link_lock, 1);
129 	sema_init(&ei->i_ext_lock, 1);
130 	inode_init_once(&ei->vfs_inode);
131 }
132 
133 static int __init init_inodecache(void)
134 {
135 	affs_inode_cachep = kmem_cache_create("affs_inode_cache",
136 					     sizeof(struct affs_inode_info),
137 					     0, (SLAB_RECLAIM_ACCOUNT|
138 						SLAB_MEM_SPREAD|SLAB_ACCOUNT),
139 					     init_once);
140 	if (affs_inode_cachep == NULL)
141 		return -ENOMEM;
142 	return 0;
143 }
144 
145 static void destroy_inodecache(void)
146 {
147 	/*
148 	 * Make sure all delayed rcu free inodes are flushed before we
149 	 * destroy cache.
150 	 */
151 	rcu_barrier();
152 	kmem_cache_destroy(affs_inode_cachep);
153 }
154 
155 static const struct super_operations affs_sops = {
156 	.alloc_inode	= affs_alloc_inode,
157 	.destroy_inode	= affs_destroy_inode,
158 	.write_inode	= affs_write_inode,
159 	.evict_inode	= affs_evict_inode,
160 	.put_super	= affs_put_super,
161 	.sync_fs	= affs_sync_fs,
162 	.statfs		= affs_statfs,
163 	.remount_fs	= affs_remount,
164 	.show_options	= affs_show_options,
165 };
166 
167 enum {
168 	Opt_bs, Opt_mode, Opt_mufs, Opt_notruncate, Opt_prefix, Opt_protect,
169 	Opt_reserved, Opt_root, Opt_setgid, Opt_setuid,
170 	Opt_verbose, Opt_volume, Opt_ignore, Opt_err,
171 };
172 
173 static const match_table_t tokens = {
174 	{Opt_bs, "bs=%u"},
175 	{Opt_mode, "mode=%o"},
176 	{Opt_mufs, "mufs"},
177 	{Opt_notruncate, "nofilenametruncate"},
178 	{Opt_prefix, "prefix=%s"},
179 	{Opt_protect, "protect"},
180 	{Opt_reserved, "reserved=%u"},
181 	{Opt_root, "root=%u"},
182 	{Opt_setgid, "setgid=%u"},
183 	{Opt_setuid, "setuid=%u"},
184 	{Opt_verbose, "verbose"},
185 	{Opt_volume, "volume=%s"},
186 	{Opt_ignore, "grpquota"},
187 	{Opt_ignore, "noquota"},
188 	{Opt_ignore, "quota"},
189 	{Opt_ignore, "usrquota"},
190 	{Opt_err, NULL},
191 };
192 
193 static int
194 parse_options(char *options, kuid_t *uid, kgid_t *gid, int *mode, int *reserved, s32 *root,
195 		int *blocksize, char **prefix, char *volume, unsigned long *mount_opts)
196 {
197 	char *p;
198 	substring_t args[MAX_OPT_ARGS];
199 
200 	/* Fill in defaults */
201 
202 	*uid        = current_uid();
203 	*gid        = current_gid();
204 	*reserved   = 2;
205 	*root       = -1;
206 	*blocksize  = -1;
207 	volume[0]   = ':';
208 	volume[1]   = 0;
209 	*mount_opts = 0;
210 	if (!options)
211 		return 1;
212 
213 	while ((p = strsep(&options, ",")) != NULL) {
214 		int token, n, option;
215 		if (!*p)
216 			continue;
217 
218 		token = match_token(p, tokens, args);
219 		switch (token) {
220 		case Opt_bs:
221 			if (match_int(&args[0], &n))
222 				return 0;
223 			if (n != 512 && n != 1024 && n != 2048
224 			    && n != 4096) {
225 				pr_warn("Invalid blocksize (512, 1024, 2048, 4096 allowed)\n");
226 				return 0;
227 			}
228 			*blocksize = n;
229 			break;
230 		case Opt_mode:
231 			if (match_octal(&args[0], &option))
232 				return 0;
233 			*mode = option & 0777;
234 			affs_set_opt(*mount_opts, SF_SETMODE);
235 			break;
236 		case Opt_mufs:
237 			affs_set_opt(*mount_opts, SF_MUFS);
238 			break;
239 		case Opt_notruncate:
240 			affs_set_opt(*mount_opts, SF_NO_TRUNCATE);
241 			break;
242 		case Opt_prefix:
243 			*prefix = match_strdup(&args[0]);
244 			if (!*prefix)
245 				return 0;
246 			affs_set_opt(*mount_opts, SF_PREFIX);
247 			break;
248 		case Opt_protect:
249 			affs_set_opt(*mount_opts, SF_IMMUTABLE);
250 			break;
251 		case Opt_reserved:
252 			if (match_int(&args[0], reserved))
253 				return 0;
254 			break;
255 		case Opt_root:
256 			if (match_int(&args[0], root))
257 				return 0;
258 			break;
259 		case Opt_setgid:
260 			if (match_int(&args[0], &option))
261 				return 0;
262 			*gid = make_kgid(current_user_ns(), option);
263 			if (!gid_valid(*gid))
264 				return 0;
265 			affs_set_opt(*mount_opts, SF_SETGID);
266 			break;
267 		case Opt_setuid:
268 			if (match_int(&args[0], &option))
269 				return 0;
270 			*uid = make_kuid(current_user_ns(), option);
271 			if (!uid_valid(*uid))
272 				return 0;
273 			affs_set_opt(*mount_opts, SF_SETUID);
274 			break;
275 		case Opt_verbose:
276 			affs_set_opt(*mount_opts, SF_VERBOSE);
277 			break;
278 		case Opt_volume: {
279 			char *vol = match_strdup(&args[0]);
280 			if (!vol)
281 				return 0;
282 			strlcpy(volume, vol, 32);
283 			kfree(vol);
284 			break;
285 		}
286 		case Opt_ignore:
287 		 	/* Silently ignore the quota options */
288 			break;
289 		default:
290 			pr_warn("Unrecognized mount option \"%s\" or missing value\n",
291 				p);
292 			return 0;
293 		}
294 	}
295 	return 1;
296 }
297 
298 static int affs_show_options(struct seq_file *m, struct dentry *root)
299 {
300 	struct super_block *sb = root->d_sb;
301 	struct affs_sb_info *sbi = AFFS_SB(sb);
302 
303 	if (sb->s_blocksize)
304 		seq_printf(m, ",bs=%lu", sb->s_blocksize);
305 	if (affs_test_opt(sbi->s_flags, SF_SETMODE))
306 		seq_printf(m, ",mode=%o", sbi->s_mode);
307 	if (affs_test_opt(sbi->s_flags, SF_MUFS))
308 		seq_puts(m, ",mufs");
309 	if (affs_test_opt(sbi->s_flags, SF_NO_TRUNCATE))
310 		seq_puts(m, ",nofilenametruncate");
311 	if (affs_test_opt(sbi->s_flags, SF_PREFIX))
312 		seq_printf(m, ",prefix=%s", sbi->s_prefix);
313 	if (affs_test_opt(sbi->s_flags, SF_IMMUTABLE))
314 		seq_puts(m, ",protect");
315 	if (sbi->s_reserved != 2)
316 		seq_printf(m, ",reserved=%u", sbi->s_reserved);
317 	if (sbi->s_root_block != (sbi->s_reserved + sbi->s_partition_size - 1) / 2)
318 		seq_printf(m, ",root=%u", sbi->s_root_block);
319 	if (affs_test_opt(sbi->s_flags, SF_SETGID))
320 		seq_printf(m, ",setgid=%u",
321 			   from_kgid_munged(&init_user_ns, sbi->s_gid));
322 	if (affs_test_opt(sbi->s_flags, SF_SETUID))
323 		seq_printf(m, ",setuid=%u",
324 			   from_kuid_munged(&init_user_ns, sbi->s_uid));
325 	if (affs_test_opt(sbi->s_flags, SF_VERBOSE))
326 		seq_puts(m, ",verbose");
327 	if (sbi->s_volume[0])
328 		seq_printf(m, ",volume=%s", sbi->s_volume);
329 	return 0;
330 }
331 
332 /* This function definitely needs to be split up. Some fine day I'll
333  * hopefully have the guts to do so. Until then: sorry for the mess.
334  */
335 
336 static int affs_fill_super(struct super_block *sb, void *data, int silent)
337 {
338 	struct affs_sb_info	*sbi;
339 	struct buffer_head	*root_bh = NULL;
340 	struct buffer_head	*boot_bh;
341 	struct inode		*root_inode = NULL;
342 	s32			 root_block;
343 	int			 size, blocksize;
344 	u32			 chksum;
345 	int			 num_bm;
346 	int			 i, j;
347 	kuid_t			 uid;
348 	kgid_t			 gid;
349 	int			 reserved;
350 	unsigned long		 mount_flags;
351 	int			 tmp_flags;	/* fix remount prototype... */
352 	u8			 sig[4];
353 	int			 ret;
354 
355 	pr_debug("read_super(%s)\n", data ? (const char *)data : "no options");
356 
357 	sb->s_magic             = AFFS_SUPER_MAGIC;
358 	sb->s_op                = &affs_sops;
359 	sb->s_flags |= MS_NODIRATIME;
360 
361 	sbi = kzalloc(sizeof(struct affs_sb_info), GFP_KERNEL);
362 	if (!sbi)
363 		return -ENOMEM;
364 
365 	sb->s_fs_info = sbi;
366 	sbi->sb = sb;
367 	mutex_init(&sbi->s_bmlock);
368 	spin_lock_init(&sbi->symlink_lock);
369 	spin_lock_init(&sbi->work_lock);
370 	INIT_DELAYED_WORK(&sbi->sb_work, flush_superblock);
371 
372 	if (!parse_options(data,&uid,&gid,&i,&reserved,&root_block,
373 				&blocksize,&sbi->s_prefix,
374 				sbi->s_volume, &mount_flags)) {
375 		pr_err("Error parsing options\n");
376 		return -EINVAL;
377 	}
378 	/* N.B. after this point s_prefix must be released */
379 
380 	sbi->s_flags   = mount_flags;
381 	sbi->s_mode    = i;
382 	sbi->s_uid     = uid;
383 	sbi->s_gid     = gid;
384 	sbi->s_reserved= reserved;
385 
386 	/* Get the size of the device in 512-byte blocks.
387 	 * If we later see that the partition uses bigger
388 	 * blocks, we will have to change it.
389 	 */
390 
391 	size = i_size_read(sb->s_bdev->bd_inode) >> 9;
392 	pr_debug("initial blocksize=%d, #blocks=%d\n", 512, size);
393 
394 	affs_set_blocksize(sb, PAGE_SIZE);
395 	/* Try to find root block. Its location depends on the block size. */
396 
397 	i = bdev_logical_block_size(sb->s_bdev);
398 	j = PAGE_SIZE;
399 	if (blocksize > 0) {
400 		i = j = blocksize;
401 		size = size / (blocksize / 512);
402 	}
403 
404 	for (blocksize = i; blocksize <= j; blocksize <<= 1, size >>= 1) {
405 		sbi->s_root_block = root_block;
406 		if (root_block < 0)
407 			sbi->s_root_block = (reserved + size - 1) / 2;
408 		pr_debug("setting blocksize to %d\n", blocksize);
409 		affs_set_blocksize(sb, blocksize);
410 		sbi->s_partition_size = size;
411 
412 		/* The root block location that was calculated above is not
413 		 * correct if the partition size is an odd number of 512-
414 		 * byte blocks, which will be rounded down to a number of
415 		 * 1024-byte blocks, and if there were an even number of
416 		 * reserved blocks. Ideally, all partition checkers should
417 		 * report the real number of blocks of the real blocksize,
418 		 * but since this just cannot be done, we have to try to
419 		 * find the root block anyways. In the above case, it is one
420 		 * block behind the calculated one. So we check this one, too.
421 		 */
422 		for (num_bm = 0; num_bm < 2; num_bm++) {
423 			pr_debug("Dev %s, trying root=%u, bs=%d, "
424 				"size=%d, reserved=%d\n",
425 				sb->s_id,
426 				sbi->s_root_block + num_bm,
427 				blocksize, size, reserved);
428 			root_bh = affs_bread(sb, sbi->s_root_block + num_bm);
429 			if (!root_bh)
430 				continue;
431 			if (!affs_checksum_block(sb, root_bh) &&
432 			    be32_to_cpu(AFFS_ROOT_HEAD(root_bh)->ptype) == T_SHORT &&
433 			    be32_to_cpu(AFFS_ROOT_TAIL(sb, root_bh)->stype) == ST_ROOT) {
434 				sbi->s_hashsize    = blocksize / 4 - 56;
435 				sbi->s_root_block += num_bm;
436 				goto got_root;
437 			}
438 			affs_brelse(root_bh);
439 			root_bh = NULL;
440 		}
441 	}
442 	if (!silent)
443 		pr_err("No valid root block on device %s\n", sb->s_id);
444 	return -EINVAL;
445 
446 	/* N.B. after this point bh must be released */
447 got_root:
448 	/* Keep super block in cache */
449 	sbi->s_root_bh = root_bh;
450 	root_block = sbi->s_root_block;
451 
452 	/* Find out which kind of FS we have */
453 	boot_bh = sb_bread(sb, 0);
454 	if (!boot_bh) {
455 		pr_err("Cannot read boot block\n");
456 		return -EINVAL;
457 	}
458 	memcpy(sig, boot_bh->b_data, 4);
459 	brelse(boot_bh);
460 	chksum = be32_to_cpu(*(__be32 *)sig);
461 
462 	/* Dircache filesystems are compatible with non-dircache ones
463 	 * when reading. As long as they aren't supported, writing is
464 	 * not recommended.
465 	 */
466 	if ((chksum == FS_DCFFS || chksum == MUFS_DCFFS || chksum == FS_DCOFS
467 	     || chksum == MUFS_DCOFS) && !(sb->s_flags & MS_RDONLY)) {
468 		pr_notice("Dircache FS - mounting %s read only\n", sb->s_id);
469 		sb->s_flags |= MS_RDONLY;
470 	}
471 	switch (chksum) {
472 	case MUFS_FS:
473 	case MUFS_INTLFFS:
474 	case MUFS_DCFFS:
475 		affs_set_opt(sbi->s_flags, SF_MUFS);
476 		/* fall thru */
477 	case FS_INTLFFS:
478 	case FS_DCFFS:
479 		affs_set_opt(sbi->s_flags, SF_INTL);
480 		break;
481 	case MUFS_FFS:
482 		affs_set_opt(sbi->s_flags, SF_MUFS);
483 		break;
484 	case FS_FFS:
485 		break;
486 	case MUFS_OFS:
487 		affs_set_opt(sbi->s_flags, SF_MUFS);
488 		/* fall thru */
489 	case FS_OFS:
490 		affs_set_opt(sbi->s_flags, SF_OFS);
491 		sb->s_flags |= MS_NOEXEC;
492 		break;
493 	case MUFS_DCOFS:
494 	case MUFS_INTLOFS:
495 		affs_set_opt(sbi->s_flags, SF_MUFS);
496 	case FS_DCOFS:
497 	case FS_INTLOFS:
498 		affs_set_opt(sbi->s_flags, SF_INTL);
499 		affs_set_opt(sbi->s_flags, SF_OFS);
500 		sb->s_flags |= MS_NOEXEC;
501 		break;
502 	default:
503 		pr_err("Unknown filesystem on device %s: %08X\n",
504 		       sb->s_id, chksum);
505 		return -EINVAL;
506 	}
507 
508 	if (affs_test_opt(mount_flags, SF_VERBOSE)) {
509 		u8 len = AFFS_ROOT_TAIL(sb, root_bh)->disk_name[0];
510 		pr_notice("Mounting volume \"%.*s\": Type=%.3s\\%c, Blocksize=%d\n",
511 			len > 31 ? 31 : len,
512 			AFFS_ROOT_TAIL(sb, root_bh)->disk_name + 1,
513 			sig, sig[3] + '0', blocksize);
514 	}
515 
516 	sb->s_flags |= MS_NODEV | MS_NOSUID;
517 
518 	sbi->s_data_blksize = sb->s_blocksize;
519 	if (affs_test_opt(sbi->s_flags, SF_OFS))
520 		sbi->s_data_blksize -= 24;
521 
522 	tmp_flags = sb->s_flags;
523 	ret = affs_init_bitmap(sb, &tmp_flags);
524 	if (ret)
525 		return ret;
526 	sb->s_flags = tmp_flags;
527 
528 	/* set up enough so that it can read an inode */
529 
530 	root_inode = affs_iget(sb, root_block);
531 	if (IS_ERR(root_inode))
532 		return PTR_ERR(root_inode);
533 
534 	if (affs_test_opt(AFFS_SB(sb)->s_flags, SF_INTL))
535 		sb->s_d_op = &affs_intl_dentry_operations;
536 	else
537 		sb->s_d_op = &affs_dentry_operations;
538 
539 	sb->s_root = d_make_root(root_inode);
540 	if (!sb->s_root) {
541 		pr_err("AFFS: Get root inode failed\n");
542 		return -ENOMEM;
543 	}
544 
545 	sb->s_export_op = &affs_export_ops;
546 	pr_debug("s_flags=%lX\n", sb->s_flags);
547 	return 0;
548 }
549 
550 static int
551 affs_remount(struct super_block *sb, int *flags, char *data)
552 {
553 	struct affs_sb_info	*sbi = AFFS_SB(sb);
554 	int			 blocksize;
555 	kuid_t			 uid;
556 	kgid_t			 gid;
557 	int			 mode;
558 	int			 reserved;
559 	int			 root_block;
560 	unsigned long		 mount_flags;
561 	int			 res = 0;
562 	char			*new_opts;
563 	char			 volume[32];
564 	char			*prefix = NULL;
565 
566 	new_opts = kstrdup(data, GFP_KERNEL);
567 	if (data && !new_opts)
568 		return -ENOMEM;
569 
570 	pr_debug("%s(flags=0x%x,opts=\"%s\")\n", __func__, *flags, data);
571 
572 	sync_filesystem(sb);
573 	*flags |= MS_NODIRATIME;
574 
575 	memcpy(volume, sbi->s_volume, 32);
576 	if (!parse_options(data, &uid, &gid, &mode, &reserved, &root_block,
577 			   &blocksize, &prefix, volume,
578 			   &mount_flags)) {
579 		kfree(prefix);
580 		kfree(new_opts);
581 		return -EINVAL;
582 	}
583 
584 	flush_delayed_work(&sbi->sb_work);
585 
586 	sbi->s_flags = mount_flags;
587 	sbi->s_mode  = mode;
588 	sbi->s_uid   = uid;
589 	sbi->s_gid   = gid;
590 	/* protect against readers */
591 	spin_lock(&sbi->symlink_lock);
592 	if (prefix) {
593 		kfree(sbi->s_prefix);
594 		sbi->s_prefix = prefix;
595 	}
596 	memcpy(sbi->s_volume, volume, 32);
597 	spin_unlock(&sbi->symlink_lock);
598 
599 	if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
600 		return 0;
601 
602 	if (*flags & MS_RDONLY)
603 		affs_free_bitmap(sb);
604 	else
605 		res = affs_init_bitmap(sb, flags);
606 
607 	return res;
608 }
609 
610 static int
611 affs_statfs(struct dentry *dentry, struct kstatfs *buf)
612 {
613 	struct super_block *sb = dentry->d_sb;
614 	int		 free;
615 	u64		 id = huge_encode_dev(sb->s_bdev->bd_dev);
616 
617 	pr_debug("%s() partsize=%d, reserved=%d\n",
618 		 __func__, AFFS_SB(sb)->s_partition_size,
619 		 AFFS_SB(sb)->s_reserved);
620 
621 	free          = affs_count_free_blocks(sb);
622 	buf->f_type    = AFFS_SUPER_MAGIC;
623 	buf->f_bsize   = sb->s_blocksize;
624 	buf->f_blocks  = AFFS_SB(sb)->s_partition_size - AFFS_SB(sb)->s_reserved;
625 	buf->f_bfree   = free;
626 	buf->f_bavail  = free;
627 	buf->f_fsid.val[0] = (u32)id;
628 	buf->f_fsid.val[1] = (u32)(id >> 32);
629 	buf->f_namelen = AFFSNAMEMAX;
630 	return 0;
631 }
632 
633 static struct dentry *affs_mount(struct file_system_type *fs_type,
634 	int flags, const char *dev_name, void *data)
635 {
636 	return mount_bdev(fs_type, flags, dev_name, data, affs_fill_super);
637 }
638 
639 static void affs_kill_sb(struct super_block *sb)
640 {
641 	struct affs_sb_info *sbi = AFFS_SB(sb);
642 	kill_block_super(sb);
643 	if (sbi) {
644 		affs_free_bitmap(sb);
645 		affs_brelse(sbi->s_root_bh);
646 		kfree(sbi->s_prefix);
647 		mutex_destroy(&sbi->s_bmlock);
648 		kfree(sbi);
649 	}
650 }
651 
652 static struct file_system_type affs_fs_type = {
653 	.owner		= THIS_MODULE,
654 	.name		= "affs",
655 	.mount		= affs_mount,
656 	.kill_sb	= affs_kill_sb,
657 	.fs_flags	= FS_REQUIRES_DEV,
658 };
659 MODULE_ALIAS_FS("affs");
660 
661 static int __init init_affs_fs(void)
662 {
663 	int err = init_inodecache();
664 	if (err)
665 		goto out1;
666 	err = register_filesystem(&affs_fs_type);
667 	if (err)
668 		goto out;
669 	return 0;
670 out:
671 	destroy_inodecache();
672 out1:
673 	return err;
674 }
675 
676 static void __exit exit_affs_fs(void)
677 {
678 	unregister_filesystem(&affs_fs_type);
679 	destroy_inodecache();
680 }
681 
682 MODULE_DESCRIPTION("Amiga filesystem support for Linux");
683 MODULE_LICENSE("GPL");
684 
685 module_init(init_affs_fs)
686 module_exit(exit_affs_fs)
687