xref: /linux/fs/affs/super.c (revision 3eb66e91a25497065c5322b1268cbc3953642227)
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 <linux/iversion.h>
25 #include "affs.h"
26 
27 static int affs_statfs(struct dentry *dentry, struct kstatfs *buf);
28 static int affs_show_options(struct seq_file *m, struct dentry *root);
29 static int affs_remount (struct super_block *sb, int *flags, char *data);
30 
31 static void
32 affs_commit_super(struct super_block *sb, int wait)
33 {
34 	struct affs_sb_info *sbi = AFFS_SB(sb);
35 	struct buffer_head *bh = sbi->s_root_bh;
36 	struct affs_root_tail *tail = AFFS_ROOT_TAIL(sb, bh);
37 
38 	lock_buffer(bh);
39 	affs_secs_to_datestamp(ktime_get_real_seconds(), &tail->disk_change);
40 	affs_fix_checksum(sb, bh);
41 	unlock_buffer(bh);
42 
43 	mark_buffer_dirty(bh);
44 	if (wait)
45 		sync_dirty_buffer(bh);
46 }
47 
48 static void
49 affs_put_super(struct super_block *sb)
50 {
51 	struct affs_sb_info *sbi = AFFS_SB(sb);
52 	pr_debug("%s()\n", __func__);
53 
54 	cancel_delayed_work_sync(&sbi->sb_work);
55 }
56 
57 static int
58 affs_sync_fs(struct super_block *sb, int wait)
59 {
60 	affs_commit_super(sb, wait);
61 	return 0;
62 }
63 
64 static void flush_superblock(struct work_struct *work)
65 {
66 	struct affs_sb_info *sbi;
67 	struct super_block *sb;
68 
69 	sbi = container_of(work, struct affs_sb_info, sb_work.work);
70 	sb = sbi->sb;
71 
72 	spin_lock(&sbi->work_lock);
73 	sbi->work_queued = 0;
74 	spin_unlock(&sbi->work_lock);
75 
76 	affs_commit_super(sb, 1);
77 }
78 
79 void affs_mark_sb_dirty(struct super_block *sb)
80 {
81 	struct affs_sb_info *sbi = AFFS_SB(sb);
82 	unsigned long delay;
83 
84 	if (sb_rdonly(sb))
85 	       return;
86 
87 	spin_lock(&sbi->work_lock);
88 	if (!sbi->work_queued) {
89 	       delay = msecs_to_jiffies(dirty_writeback_interval * 10);
90 	       queue_delayed_work(system_long_wq, &sbi->sb_work, delay);
91 	       sbi->work_queued = 1;
92 	}
93 	spin_unlock(&sbi->work_lock);
94 }
95 
96 static struct kmem_cache * affs_inode_cachep;
97 
98 static struct inode *affs_alloc_inode(struct super_block *sb)
99 {
100 	struct affs_inode_info *i;
101 
102 	i = kmem_cache_alloc(affs_inode_cachep, GFP_KERNEL);
103 	if (!i)
104 		return NULL;
105 
106 	inode_set_iversion(&i->vfs_inode, 1);
107 	i->i_lc = NULL;
108 	i->i_ext_bh = NULL;
109 	i->i_pa_cnt = 0;
110 
111 	return &i->vfs_inode;
112 }
113 
114 static void affs_i_callback(struct rcu_head *head)
115 {
116 	struct inode *inode = container_of(head, struct inode, i_rcu);
117 	kmem_cache_free(affs_inode_cachep, AFFS_I(inode));
118 }
119 
120 static void affs_destroy_inode(struct inode *inode)
121 {
122 	call_rcu(&inode->i_rcu, affs_i_callback);
123 }
124 
125 static void init_once(void *foo)
126 {
127 	struct affs_inode_info *ei = (struct affs_inode_info *) foo;
128 
129 	sema_init(&ei->i_link_lock, 1);
130 	sema_init(&ei->i_ext_lock, 1);
131 	inode_init_once(&ei->vfs_inode);
132 }
133 
134 static int __init init_inodecache(void)
135 {
136 	affs_inode_cachep = kmem_cache_create("affs_inode_cache",
137 					     sizeof(struct affs_inode_info),
138 					     0, (SLAB_RECLAIM_ACCOUNT|
139 						SLAB_MEM_SPREAD|SLAB_ACCOUNT),
140 					     init_once);
141 	if (affs_inode_cachep == NULL)
142 		return -ENOMEM;
143 	return 0;
144 }
145 
146 static void destroy_inodecache(void)
147 {
148 	/*
149 	 * Make sure all delayed rcu free inodes are flushed before we
150 	 * destroy cache.
151 	 */
152 	rcu_barrier();
153 	kmem_cache_destroy(affs_inode_cachep);
154 }
155 
156 static const struct super_operations affs_sops = {
157 	.alloc_inode	= affs_alloc_inode,
158 	.destroy_inode	= affs_destroy_inode,
159 	.write_inode	= affs_write_inode,
160 	.evict_inode	= affs_evict_inode,
161 	.put_super	= affs_put_super,
162 	.sync_fs	= affs_sync_fs,
163 	.statfs		= affs_statfs,
164 	.remount_fs	= affs_remount,
165 	.show_options	= affs_show_options,
166 };
167 
168 enum {
169 	Opt_bs, Opt_mode, Opt_mufs, Opt_notruncate, Opt_prefix, Opt_protect,
170 	Opt_reserved, Opt_root, Opt_setgid, Opt_setuid,
171 	Opt_verbose, Opt_volume, Opt_ignore, Opt_err,
172 };
173 
174 static const match_table_t tokens = {
175 	{Opt_bs, "bs=%u"},
176 	{Opt_mode, "mode=%o"},
177 	{Opt_mufs, "mufs"},
178 	{Opt_notruncate, "nofilenametruncate"},
179 	{Opt_prefix, "prefix=%s"},
180 	{Opt_protect, "protect"},
181 	{Opt_reserved, "reserved=%u"},
182 	{Opt_root, "root=%u"},
183 	{Opt_setgid, "setgid=%u"},
184 	{Opt_setuid, "setuid=%u"},
185 	{Opt_verbose, "verbose"},
186 	{Opt_volume, "volume=%s"},
187 	{Opt_ignore, "grpquota"},
188 	{Opt_ignore, "noquota"},
189 	{Opt_ignore, "quota"},
190 	{Opt_ignore, "usrquota"},
191 	{Opt_err, NULL},
192 };
193 
194 static int
195 parse_options(char *options, kuid_t *uid, kgid_t *gid, int *mode, int *reserved, s32 *root,
196 		int *blocksize, char **prefix, char *volume, unsigned long *mount_opts)
197 {
198 	char *p;
199 	substring_t args[MAX_OPT_ARGS];
200 
201 	/* Fill in defaults */
202 
203 	*uid        = current_uid();
204 	*gid        = current_gid();
205 	*reserved   = 2;
206 	*root       = -1;
207 	*blocksize  = -1;
208 	volume[0]   = ':';
209 	volume[1]   = 0;
210 	*mount_opts = 0;
211 	if (!options)
212 		return 1;
213 
214 	while ((p = strsep(&options, ",")) != NULL) {
215 		int token, n, option;
216 		if (!*p)
217 			continue;
218 
219 		token = match_token(p, tokens, args);
220 		switch (token) {
221 		case Opt_bs:
222 			if (match_int(&args[0], &n))
223 				return 0;
224 			if (n != 512 && n != 1024 && n != 2048
225 			    && n != 4096) {
226 				pr_warn("Invalid blocksize (512, 1024, 2048, 4096 allowed)\n");
227 				return 0;
228 			}
229 			*blocksize = n;
230 			break;
231 		case Opt_mode:
232 			if (match_octal(&args[0], &option))
233 				return 0;
234 			*mode = option & 0777;
235 			affs_set_opt(*mount_opts, SF_SETMODE);
236 			break;
237 		case Opt_mufs:
238 			affs_set_opt(*mount_opts, SF_MUFS);
239 			break;
240 		case Opt_notruncate:
241 			affs_set_opt(*mount_opts, SF_NO_TRUNCATE);
242 			break;
243 		case Opt_prefix:
244 			kfree(*prefix);
245 			*prefix = match_strdup(&args[0]);
246 			if (!*prefix)
247 				return 0;
248 			affs_set_opt(*mount_opts, SF_PREFIX);
249 			break;
250 		case Opt_protect:
251 			affs_set_opt(*mount_opts, SF_IMMUTABLE);
252 			break;
253 		case Opt_reserved:
254 			if (match_int(&args[0], reserved))
255 				return 0;
256 			break;
257 		case Opt_root:
258 			if (match_int(&args[0], root))
259 				return 0;
260 			break;
261 		case Opt_setgid:
262 			if (match_int(&args[0], &option))
263 				return 0;
264 			*gid = make_kgid(current_user_ns(), option);
265 			if (!gid_valid(*gid))
266 				return 0;
267 			affs_set_opt(*mount_opts, SF_SETGID);
268 			break;
269 		case Opt_setuid:
270 			if (match_int(&args[0], &option))
271 				return 0;
272 			*uid = make_kuid(current_user_ns(), option);
273 			if (!uid_valid(*uid))
274 				return 0;
275 			affs_set_opt(*mount_opts, SF_SETUID);
276 			break;
277 		case Opt_verbose:
278 			affs_set_opt(*mount_opts, SF_VERBOSE);
279 			break;
280 		case Opt_volume: {
281 			char *vol = match_strdup(&args[0]);
282 			if (!vol)
283 				return 0;
284 			strlcpy(volume, vol, 32);
285 			kfree(vol);
286 			break;
287 		}
288 		case Opt_ignore:
289 		 	/* Silently ignore the quota options */
290 			break;
291 		default:
292 			pr_warn("Unrecognized mount option \"%s\" or missing value\n",
293 				p);
294 			return 0;
295 		}
296 	}
297 	return 1;
298 }
299 
300 static int affs_show_options(struct seq_file *m, struct dentry *root)
301 {
302 	struct super_block *sb = root->d_sb;
303 	struct affs_sb_info *sbi = AFFS_SB(sb);
304 
305 	if (sb->s_blocksize)
306 		seq_printf(m, ",bs=%lu", sb->s_blocksize);
307 	if (affs_test_opt(sbi->s_flags, SF_SETMODE))
308 		seq_printf(m, ",mode=%o", sbi->s_mode);
309 	if (affs_test_opt(sbi->s_flags, SF_MUFS))
310 		seq_puts(m, ",mufs");
311 	if (affs_test_opt(sbi->s_flags, SF_NO_TRUNCATE))
312 		seq_puts(m, ",nofilenametruncate");
313 	if (affs_test_opt(sbi->s_flags, SF_PREFIX))
314 		seq_printf(m, ",prefix=%s", sbi->s_prefix);
315 	if (affs_test_opt(sbi->s_flags, SF_IMMUTABLE))
316 		seq_puts(m, ",protect");
317 	if (sbi->s_reserved != 2)
318 		seq_printf(m, ",reserved=%u", sbi->s_reserved);
319 	if (sbi->s_root_block != (sbi->s_reserved + sbi->s_partition_size - 1) / 2)
320 		seq_printf(m, ",root=%u", sbi->s_root_block);
321 	if (affs_test_opt(sbi->s_flags, SF_SETGID))
322 		seq_printf(m, ",setgid=%u",
323 			   from_kgid_munged(&init_user_ns, sbi->s_gid));
324 	if (affs_test_opt(sbi->s_flags, SF_SETUID))
325 		seq_printf(m, ",setuid=%u",
326 			   from_kuid_munged(&init_user_ns, sbi->s_uid));
327 	if (affs_test_opt(sbi->s_flags, SF_VERBOSE))
328 		seq_puts(m, ",verbose");
329 	if (sbi->s_volume[0])
330 		seq_printf(m, ",volume=%s", sbi->s_volume);
331 	return 0;
332 }
333 
334 /* This function definitely needs to be split up. Some fine day I'll
335  * hopefully have the guts to do so. Until then: sorry for the mess.
336  */
337 
338 static int affs_fill_super(struct super_block *sb, void *data, int silent)
339 {
340 	struct affs_sb_info	*sbi;
341 	struct buffer_head	*root_bh = NULL;
342 	struct buffer_head	*boot_bh;
343 	struct inode		*root_inode = NULL;
344 	s32			 root_block;
345 	int			 size, blocksize;
346 	u32			 chksum;
347 	int			 num_bm;
348 	int			 i, j;
349 	kuid_t			 uid;
350 	kgid_t			 gid;
351 	int			 reserved;
352 	unsigned long		 mount_flags;
353 	int			 tmp_flags;	/* fix remount prototype... */
354 	u8			 sig[4];
355 	int			 ret;
356 
357 	pr_debug("read_super(%s)\n", data ? (const char *)data : "no options");
358 
359 	sb->s_magic             = AFFS_SUPER_MAGIC;
360 	sb->s_op                = &affs_sops;
361 	sb->s_flags |= SB_NODIRATIME;
362 
363 	sbi = kzalloc(sizeof(struct affs_sb_info), GFP_KERNEL);
364 	if (!sbi)
365 		return -ENOMEM;
366 
367 	sb->s_fs_info = sbi;
368 	sbi->sb = sb;
369 	mutex_init(&sbi->s_bmlock);
370 	spin_lock_init(&sbi->symlink_lock);
371 	spin_lock_init(&sbi->work_lock);
372 	INIT_DELAYED_WORK(&sbi->sb_work, flush_superblock);
373 
374 	if (!parse_options(data,&uid,&gid,&i,&reserved,&root_block,
375 				&blocksize,&sbi->s_prefix,
376 				sbi->s_volume, &mount_flags)) {
377 		pr_err("Error parsing options\n");
378 		return -EINVAL;
379 	}
380 	/* N.B. after this point s_prefix must be released */
381 
382 	sbi->s_flags   = mount_flags;
383 	sbi->s_mode    = i;
384 	sbi->s_uid     = uid;
385 	sbi->s_gid     = gid;
386 	sbi->s_reserved= reserved;
387 
388 	/* Get the size of the device in 512-byte blocks.
389 	 * If we later see that the partition uses bigger
390 	 * blocks, we will have to change it.
391 	 */
392 
393 	size = i_size_read(sb->s_bdev->bd_inode) >> 9;
394 	pr_debug("initial blocksize=%d, #blocks=%d\n", 512, size);
395 
396 	affs_set_blocksize(sb, PAGE_SIZE);
397 	/* Try to find root block. Its location depends on the block size. */
398 
399 	i = bdev_logical_block_size(sb->s_bdev);
400 	j = PAGE_SIZE;
401 	if (blocksize > 0) {
402 		i = j = blocksize;
403 		size = size / (blocksize / 512);
404 	}
405 
406 	for (blocksize = i; blocksize <= j; blocksize <<= 1, size >>= 1) {
407 		sbi->s_root_block = root_block;
408 		if (root_block < 0)
409 			sbi->s_root_block = (reserved + size - 1) / 2;
410 		pr_debug("setting blocksize to %d\n", blocksize);
411 		affs_set_blocksize(sb, blocksize);
412 		sbi->s_partition_size = size;
413 
414 		/* The root block location that was calculated above is not
415 		 * correct if the partition size is an odd number of 512-
416 		 * byte blocks, which will be rounded down to a number of
417 		 * 1024-byte blocks, and if there were an even number of
418 		 * reserved blocks. Ideally, all partition checkers should
419 		 * report the real number of blocks of the real blocksize,
420 		 * but since this just cannot be done, we have to try to
421 		 * find the root block anyways. In the above case, it is one
422 		 * block behind the calculated one. So we check this one, too.
423 		 */
424 		for (num_bm = 0; num_bm < 2; num_bm++) {
425 			pr_debug("Dev %s, trying root=%u, bs=%d, "
426 				"size=%d, reserved=%d\n",
427 				sb->s_id,
428 				sbi->s_root_block + num_bm,
429 				blocksize, size, reserved);
430 			root_bh = affs_bread(sb, sbi->s_root_block + num_bm);
431 			if (!root_bh)
432 				continue;
433 			if (!affs_checksum_block(sb, root_bh) &&
434 			    be32_to_cpu(AFFS_ROOT_HEAD(root_bh)->ptype) == T_SHORT &&
435 			    be32_to_cpu(AFFS_ROOT_TAIL(sb, root_bh)->stype) == ST_ROOT) {
436 				sbi->s_hashsize    = blocksize / 4 - 56;
437 				sbi->s_root_block += num_bm;
438 				goto got_root;
439 			}
440 			affs_brelse(root_bh);
441 			root_bh = NULL;
442 		}
443 	}
444 	if (!silent)
445 		pr_err("No valid root block on device %s\n", sb->s_id);
446 	return -EINVAL;
447 
448 	/* N.B. after this point bh must be released */
449 got_root:
450 	/* Keep super block in cache */
451 	sbi->s_root_bh = root_bh;
452 	root_block = sbi->s_root_block;
453 
454 	/* Find out which kind of FS we have */
455 	boot_bh = sb_bread(sb, 0);
456 	if (!boot_bh) {
457 		pr_err("Cannot read boot block\n");
458 		return -EINVAL;
459 	}
460 	memcpy(sig, boot_bh->b_data, 4);
461 	brelse(boot_bh);
462 	chksum = be32_to_cpu(*(__be32 *)sig);
463 
464 	/* Dircache filesystems are compatible with non-dircache ones
465 	 * when reading. As long as they aren't supported, writing is
466 	 * not recommended.
467 	 */
468 	if ((chksum == FS_DCFFS || chksum == MUFS_DCFFS || chksum == FS_DCOFS
469 	     || chksum == MUFS_DCOFS) && !sb_rdonly(sb)) {
470 		pr_notice("Dircache FS - mounting %s read only\n", sb->s_id);
471 		sb->s_flags |= SB_RDONLY;
472 	}
473 	switch (chksum) {
474 	case MUFS_FS:
475 	case MUFS_INTLFFS:
476 	case MUFS_DCFFS:
477 		affs_set_opt(sbi->s_flags, SF_MUFS);
478 		/* fall thru */
479 	case FS_INTLFFS:
480 	case FS_DCFFS:
481 		affs_set_opt(sbi->s_flags, SF_INTL);
482 		break;
483 	case MUFS_FFS:
484 		affs_set_opt(sbi->s_flags, SF_MUFS);
485 		break;
486 	case FS_FFS:
487 		break;
488 	case MUFS_OFS:
489 		affs_set_opt(sbi->s_flags, SF_MUFS);
490 		/* fall thru */
491 	case FS_OFS:
492 		affs_set_opt(sbi->s_flags, SF_OFS);
493 		sb->s_flags |= SB_NOEXEC;
494 		break;
495 	case MUFS_DCOFS:
496 	case MUFS_INTLOFS:
497 		affs_set_opt(sbi->s_flags, SF_MUFS);
498 	case FS_DCOFS:
499 	case FS_INTLOFS:
500 		affs_set_opt(sbi->s_flags, SF_INTL);
501 		affs_set_opt(sbi->s_flags, SF_OFS);
502 		sb->s_flags |= SB_NOEXEC;
503 		break;
504 	default:
505 		pr_err("Unknown filesystem on device %s: %08X\n",
506 		       sb->s_id, chksum);
507 		return -EINVAL;
508 	}
509 
510 	if (affs_test_opt(mount_flags, SF_VERBOSE)) {
511 		u8 len = AFFS_ROOT_TAIL(sb, root_bh)->disk_name[0];
512 		pr_notice("Mounting volume \"%.*s\": Type=%.3s\\%c, Blocksize=%d\n",
513 			len > 31 ? 31 : len,
514 			AFFS_ROOT_TAIL(sb, root_bh)->disk_name + 1,
515 			sig, sig[3] + '0', blocksize);
516 	}
517 
518 	sb->s_flags |= SB_NODEV | SB_NOSUID;
519 
520 	sbi->s_data_blksize = sb->s_blocksize;
521 	if (affs_test_opt(sbi->s_flags, SF_OFS))
522 		sbi->s_data_blksize -= 24;
523 
524 	tmp_flags = sb->s_flags;
525 	ret = affs_init_bitmap(sb, &tmp_flags);
526 	if (ret)
527 		return ret;
528 	sb->s_flags = tmp_flags;
529 
530 	/* set up enough so that it can read an inode */
531 
532 	root_inode = affs_iget(sb, root_block);
533 	if (IS_ERR(root_inode))
534 		return PTR_ERR(root_inode);
535 
536 	if (affs_test_opt(AFFS_SB(sb)->s_flags, SF_INTL))
537 		sb->s_d_op = &affs_intl_dentry_operations;
538 	else
539 		sb->s_d_op = &affs_dentry_operations;
540 
541 	sb->s_root = d_make_root(root_inode);
542 	if (!sb->s_root) {
543 		pr_err("AFFS: Get root inode failed\n");
544 		return -ENOMEM;
545 	}
546 
547 	sb->s_export_op = &affs_export_ops;
548 	pr_debug("s_flags=%lX\n", sb->s_flags);
549 	return 0;
550 }
551 
552 static int
553 affs_remount(struct super_block *sb, int *flags, char *data)
554 {
555 	struct affs_sb_info	*sbi = AFFS_SB(sb);
556 	int			 blocksize;
557 	kuid_t			 uid;
558 	kgid_t			 gid;
559 	int			 mode;
560 	int			 reserved;
561 	int			 root_block;
562 	unsigned long		 mount_flags;
563 	int			 res = 0;
564 	char			*new_opts;
565 	char			 volume[32];
566 	char			*prefix = NULL;
567 
568 	new_opts = kstrdup(data, GFP_KERNEL);
569 	if (data && !new_opts)
570 		return -ENOMEM;
571 
572 	pr_debug("%s(flags=0x%x,opts=\"%s\")\n", __func__, *flags, data);
573 
574 	sync_filesystem(sb);
575 	*flags |= SB_NODIRATIME;
576 
577 	memcpy(volume, sbi->s_volume, 32);
578 	if (!parse_options(data, &uid, &gid, &mode, &reserved, &root_block,
579 			   &blocksize, &prefix, volume,
580 			   &mount_flags)) {
581 		kfree(prefix);
582 		kfree(new_opts);
583 		return -EINVAL;
584 	}
585 
586 	flush_delayed_work(&sbi->sb_work);
587 
588 	sbi->s_flags = mount_flags;
589 	sbi->s_mode  = mode;
590 	sbi->s_uid   = uid;
591 	sbi->s_gid   = gid;
592 	/* protect against readers */
593 	spin_lock(&sbi->symlink_lock);
594 	if (prefix) {
595 		kfree(sbi->s_prefix);
596 		sbi->s_prefix = prefix;
597 	}
598 	memcpy(sbi->s_volume, volume, 32);
599 	spin_unlock(&sbi->symlink_lock);
600 
601 	if ((bool)(*flags & SB_RDONLY) == sb_rdonly(sb))
602 		return 0;
603 
604 	if (*flags & SB_RDONLY)
605 		affs_free_bitmap(sb);
606 	else
607 		res = affs_init_bitmap(sb, flags);
608 
609 	return res;
610 }
611 
612 static int
613 affs_statfs(struct dentry *dentry, struct kstatfs *buf)
614 {
615 	struct super_block *sb = dentry->d_sb;
616 	int		 free;
617 	u64		 id = huge_encode_dev(sb->s_bdev->bd_dev);
618 
619 	pr_debug("%s() partsize=%d, reserved=%d\n",
620 		 __func__, AFFS_SB(sb)->s_partition_size,
621 		 AFFS_SB(sb)->s_reserved);
622 
623 	free          = affs_count_free_blocks(sb);
624 	buf->f_type    = AFFS_SUPER_MAGIC;
625 	buf->f_bsize   = sb->s_blocksize;
626 	buf->f_blocks  = AFFS_SB(sb)->s_partition_size - AFFS_SB(sb)->s_reserved;
627 	buf->f_bfree   = free;
628 	buf->f_bavail  = free;
629 	buf->f_fsid.val[0] = (u32)id;
630 	buf->f_fsid.val[1] = (u32)(id >> 32);
631 	buf->f_namelen = AFFSNAMEMAX;
632 	return 0;
633 }
634 
635 static struct dentry *affs_mount(struct file_system_type *fs_type,
636 	int flags, const char *dev_name, void *data)
637 {
638 	return mount_bdev(fs_type, flags, dev_name, data, affs_fill_super);
639 }
640 
641 static void affs_kill_sb(struct super_block *sb)
642 {
643 	struct affs_sb_info *sbi = AFFS_SB(sb);
644 	kill_block_super(sb);
645 	if (sbi) {
646 		affs_free_bitmap(sb);
647 		affs_brelse(sbi->s_root_bh);
648 		kfree(sbi->s_prefix);
649 		mutex_destroy(&sbi->s_bmlock);
650 		kfree(sbi);
651 	}
652 }
653 
654 static struct file_system_type affs_fs_type = {
655 	.owner		= THIS_MODULE,
656 	.name		= "affs",
657 	.mount		= affs_mount,
658 	.kill_sb	= affs_kill_sb,
659 	.fs_flags	= FS_REQUIRES_DEV,
660 };
661 MODULE_ALIAS_FS("affs");
662 
663 static int __init init_affs_fs(void)
664 {
665 	int err = init_inodecache();
666 	if (err)
667 		goto out1;
668 	err = register_filesystem(&affs_fs_type);
669 	if (err)
670 		goto out;
671 	return 0;
672 out:
673 	destroy_inodecache();
674 out1:
675 	return err;
676 }
677 
678 static void __exit exit_affs_fs(void)
679 {
680 	unregister_filesystem(&affs_fs_type);
681 	destroy_inodecache();
682 }
683 
684 MODULE_DESCRIPTION("Amiga filesystem support for Linux");
685 MODULE_LICENSE("GPL");
686 
687 module_init(init_affs_fs)
688 module_exit(exit_affs_fs)
689