xref: /openbmc/linux/fs/minix/inode.c (revision 9ac8d3fb)
1 /*
2  *  linux/fs/minix/inode.c
3  *
4  *  Copyright (C) 1991, 1992  Linus Torvalds
5  *
6  *  Copyright (C) 1996  Gertjan van Wingerde    (gertjan@cs.vu.nl)
7  *	Minix V2 fs support.
8  *
9  *  Modified for 680x0 by Andreas Schwab
10  *  Updated to filesystem version 3 by Daniel Aragones
11  */
12 
13 #include <linux/module.h>
14 #include "minix.h"
15 #include <linux/buffer_head.h>
16 #include <linux/slab.h>
17 #include <linux/init.h>
18 #include <linux/highuid.h>
19 #include <linux/vfs.h>
20 
21 static int minix_write_inode(struct inode * inode, int wait);
22 static int minix_statfs(struct dentry *dentry, struct kstatfs *buf);
23 static int minix_remount (struct super_block * sb, int * flags, char * data);
24 
25 static void minix_delete_inode(struct inode *inode)
26 {
27 	truncate_inode_pages(&inode->i_data, 0);
28 	inode->i_size = 0;
29 	minix_truncate(inode);
30 	minix_free_inode(inode);
31 }
32 
33 static void minix_put_super(struct super_block *sb)
34 {
35 	int i;
36 	struct minix_sb_info *sbi = minix_sb(sb);
37 
38 	if (!(sb->s_flags & MS_RDONLY)) {
39 		if (sbi->s_version != MINIX_V3)	 /* s_state is now out from V3 sb */
40 			sbi->s_ms->s_state = sbi->s_mount_state;
41 		mark_buffer_dirty(sbi->s_sbh);
42 	}
43 	for (i = 0; i < sbi->s_imap_blocks; i++)
44 		brelse(sbi->s_imap[i]);
45 	for (i = 0; i < sbi->s_zmap_blocks; i++)
46 		brelse(sbi->s_zmap[i]);
47 	brelse (sbi->s_sbh);
48 	kfree(sbi->s_imap);
49 	sb->s_fs_info = NULL;
50 	kfree(sbi);
51 
52 	return;
53 }
54 
55 static struct kmem_cache * minix_inode_cachep;
56 
57 static struct inode *minix_alloc_inode(struct super_block *sb)
58 {
59 	struct minix_inode_info *ei;
60 	ei = (struct minix_inode_info *)kmem_cache_alloc(minix_inode_cachep, GFP_KERNEL);
61 	if (!ei)
62 		return NULL;
63 	return &ei->vfs_inode;
64 }
65 
66 static void minix_destroy_inode(struct inode *inode)
67 {
68 	kmem_cache_free(minix_inode_cachep, minix_i(inode));
69 }
70 
71 static void init_once(void *foo)
72 {
73 	struct minix_inode_info *ei = (struct minix_inode_info *) foo;
74 
75 	inode_init_once(&ei->vfs_inode);
76 }
77 
78 static int init_inodecache(void)
79 {
80 	minix_inode_cachep = kmem_cache_create("minix_inode_cache",
81 					     sizeof(struct minix_inode_info),
82 					     0, (SLAB_RECLAIM_ACCOUNT|
83 						SLAB_MEM_SPREAD),
84 					     init_once);
85 	if (minix_inode_cachep == NULL)
86 		return -ENOMEM;
87 	return 0;
88 }
89 
90 static void destroy_inodecache(void)
91 {
92 	kmem_cache_destroy(minix_inode_cachep);
93 }
94 
95 static const struct super_operations minix_sops = {
96 	.alloc_inode	= minix_alloc_inode,
97 	.destroy_inode	= minix_destroy_inode,
98 	.write_inode	= minix_write_inode,
99 	.delete_inode	= minix_delete_inode,
100 	.put_super	= minix_put_super,
101 	.statfs		= minix_statfs,
102 	.remount_fs	= minix_remount,
103 };
104 
105 static int minix_remount (struct super_block * sb, int * flags, char * data)
106 {
107 	struct minix_sb_info * sbi = minix_sb(sb);
108 	struct minix_super_block * ms;
109 
110 	ms = sbi->s_ms;
111 	if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
112 		return 0;
113 	if (*flags & MS_RDONLY) {
114 		if (ms->s_state & MINIX_VALID_FS ||
115 		    !(sbi->s_mount_state & MINIX_VALID_FS))
116 			return 0;
117 		/* Mounting a rw partition read-only. */
118 		if (sbi->s_version != MINIX_V3)
119 			ms->s_state = sbi->s_mount_state;
120 		mark_buffer_dirty(sbi->s_sbh);
121 	} else {
122 	  	/* Mount a partition which is read-only, read-write. */
123 		if (sbi->s_version != MINIX_V3) {
124 			sbi->s_mount_state = ms->s_state;
125 			ms->s_state &= ~MINIX_VALID_FS;
126 		} else {
127 			sbi->s_mount_state = MINIX_VALID_FS;
128 		}
129 		mark_buffer_dirty(sbi->s_sbh);
130 
131 		if (!(sbi->s_mount_state & MINIX_VALID_FS))
132 			printk("MINIX-fs warning: remounting unchecked fs, "
133 				"running fsck is recommended\n");
134 		else if ((sbi->s_mount_state & MINIX_ERROR_FS))
135 			printk("MINIX-fs warning: remounting fs with errors, "
136 				"running fsck is recommended\n");
137 	}
138 	return 0;
139 }
140 
141 static int minix_fill_super(struct super_block *s, void *data, int silent)
142 {
143 	struct buffer_head *bh;
144 	struct buffer_head **map;
145 	struct minix_super_block *ms;
146 	struct minix3_super_block *m3s = NULL;
147 	unsigned long i, block;
148 	struct inode *root_inode;
149 	struct minix_sb_info *sbi;
150 	int ret = -EINVAL;
151 
152 	sbi = kzalloc(sizeof(struct minix_sb_info), GFP_KERNEL);
153 	if (!sbi)
154 		return -ENOMEM;
155 	s->s_fs_info = sbi;
156 
157 	BUILD_BUG_ON(32 != sizeof (struct minix_inode));
158 	BUILD_BUG_ON(64 != sizeof(struct minix2_inode));
159 
160 	if (!sb_set_blocksize(s, BLOCK_SIZE))
161 		goto out_bad_hblock;
162 
163 	if (!(bh = sb_bread(s, 1)))
164 		goto out_bad_sb;
165 
166 	ms = (struct minix_super_block *) bh->b_data;
167 	sbi->s_ms = ms;
168 	sbi->s_sbh = bh;
169 	sbi->s_mount_state = ms->s_state;
170 	sbi->s_ninodes = ms->s_ninodes;
171 	sbi->s_nzones = ms->s_nzones;
172 	sbi->s_imap_blocks = ms->s_imap_blocks;
173 	sbi->s_zmap_blocks = ms->s_zmap_blocks;
174 	sbi->s_firstdatazone = ms->s_firstdatazone;
175 	sbi->s_log_zone_size = ms->s_log_zone_size;
176 	sbi->s_max_size = ms->s_max_size;
177 	s->s_magic = ms->s_magic;
178 	if (s->s_magic == MINIX_SUPER_MAGIC) {
179 		sbi->s_version = MINIX_V1;
180 		sbi->s_dirsize = 16;
181 		sbi->s_namelen = 14;
182 		sbi->s_link_max = MINIX_LINK_MAX;
183 	} else if (s->s_magic == MINIX_SUPER_MAGIC2) {
184 		sbi->s_version = MINIX_V1;
185 		sbi->s_dirsize = 32;
186 		sbi->s_namelen = 30;
187 		sbi->s_link_max = MINIX_LINK_MAX;
188 	} else if (s->s_magic == MINIX2_SUPER_MAGIC) {
189 		sbi->s_version = MINIX_V2;
190 		sbi->s_nzones = ms->s_zones;
191 		sbi->s_dirsize = 16;
192 		sbi->s_namelen = 14;
193 		sbi->s_link_max = MINIX2_LINK_MAX;
194 	} else if (s->s_magic == MINIX2_SUPER_MAGIC2) {
195 		sbi->s_version = MINIX_V2;
196 		sbi->s_nzones = ms->s_zones;
197 		sbi->s_dirsize = 32;
198 		sbi->s_namelen = 30;
199 		sbi->s_link_max = MINIX2_LINK_MAX;
200 	} else if ( *(__u16 *)(bh->b_data + 24) == MINIX3_SUPER_MAGIC) {
201 		m3s = (struct minix3_super_block *) bh->b_data;
202 		s->s_magic = m3s->s_magic;
203 		sbi->s_imap_blocks = m3s->s_imap_blocks;
204 		sbi->s_zmap_blocks = m3s->s_zmap_blocks;
205 		sbi->s_firstdatazone = m3s->s_firstdatazone;
206 		sbi->s_log_zone_size = m3s->s_log_zone_size;
207 		sbi->s_max_size = m3s->s_max_size;
208 		sbi->s_ninodes = m3s->s_ninodes;
209 		sbi->s_nzones = m3s->s_zones;
210 		sbi->s_dirsize = 64;
211 		sbi->s_namelen = 60;
212 		sbi->s_version = MINIX_V3;
213 		sbi->s_link_max = MINIX2_LINK_MAX;
214 		sbi->s_mount_state = MINIX_VALID_FS;
215 		sb_set_blocksize(s, m3s->s_blocksize);
216 	} else
217 		goto out_no_fs;
218 
219 	/*
220 	 * Allocate the buffer map to keep the superblock small.
221 	 */
222 	if (sbi->s_imap_blocks == 0 || sbi->s_zmap_blocks == 0)
223 		goto out_illegal_sb;
224 	i = (sbi->s_imap_blocks + sbi->s_zmap_blocks) * sizeof(bh);
225 	map = kzalloc(i, GFP_KERNEL);
226 	if (!map)
227 		goto out_no_map;
228 	sbi->s_imap = &map[0];
229 	sbi->s_zmap = &map[sbi->s_imap_blocks];
230 
231 	block=2;
232 	for (i=0 ; i < sbi->s_imap_blocks ; i++) {
233 		if (!(sbi->s_imap[i]=sb_bread(s, block)))
234 			goto out_no_bitmap;
235 		block++;
236 	}
237 	for (i=0 ; i < sbi->s_zmap_blocks ; i++) {
238 		if (!(sbi->s_zmap[i]=sb_bread(s, block)))
239 			goto out_no_bitmap;
240 		block++;
241 	}
242 
243 	minix_set_bit(0,sbi->s_imap[0]->b_data);
244 	minix_set_bit(0,sbi->s_zmap[0]->b_data);
245 
246 	/* set up enough so that it can read an inode */
247 	s->s_op = &minix_sops;
248 	root_inode = minix_iget(s, MINIX_ROOT_INO);
249 	if (IS_ERR(root_inode)) {
250 		ret = PTR_ERR(root_inode);
251 		goto out_no_root;
252 	}
253 
254 	ret = -ENOMEM;
255 	s->s_root = d_alloc_root(root_inode);
256 	if (!s->s_root)
257 		goto out_iput;
258 
259 	if (!(s->s_flags & MS_RDONLY)) {
260 		if (sbi->s_version != MINIX_V3) /* s_state is now out from V3 sb */
261 			ms->s_state &= ~MINIX_VALID_FS;
262 		mark_buffer_dirty(bh);
263 	}
264 	if (!(sbi->s_mount_state & MINIX_VALID_FS))
265 		printk("MINIX-fs: mounting unchecked file system, "
266 			"running fsck is recommended\n");
267  	else if (sbi->s_mount_state & MINIX_ERROR_FS)
268 		printk("MINIX-fs: mounting file system with errors, "
269 			"running fsck is recommended\n");
270 	return 0;
271 
272 out_iput:
273 	iput(root_inode);
274 	goto out_freemap;
275 
276 out_no_root:
277 	if (!silent)
278 		printk("MINIX-fs: get root inode failed\n");
279 	goto out_freemap;
280 
281 out_no_bitmap:
282 	printk("MINIX-fs: bad superblock or unable to read bitmaps\n");
283 out_freemap:
284 	for (i = 0; i < sbi->s_imap_blocks; i++)
285 		brelse(sbi->s_imap[i]);
286 	for (i = 0; i < sbi->s_zmap_blocks; i++)
287 		brelse(sbi->s_zmap[i]);
288 	kfree(sbi->s_imap);
289 	goto out_release;
290 
291 out_no_map:
292 	ret = -ENOMEM;
293 	if (!silent)
294 		printk("MINIX-fs: can't allocate map\n");
295 	goto out_release;
296 
297 out_illegal_sb:
298 	if (!silent)
299 		printk("MINIX-fs: bad superblock\n");
300 	goto out_release;
301 
302 out_no_fs:
303 	if (!silent)
304 		printk("VFS: Can't find a Minix filesystem V1 | V2 | V3 "
305 		       "on device %s.\n", s->s_id);
306 out_release:
307 	brelse(bh);
308 	goto out;
309 
310 out_bad_hblock:
311 	printk("MINIX-fs: blocksize too small for device\n");
312 	goto out;
313 
314 out_bad_sb:
315 	printk("MINIX-fs: unable to read superblock\n");
316 out:
317 	s->s_fs_info = NULL;
318 	kfree(sbi);
319 	return ret;
320 }
321 
322 static int minix_statfs(struct dentry *dentry, struct kstatfs *buf)
323 {
324 	struct minix_sb_info *sbi = minix_sb(dentry->d_sb);
325 	buf->f_type = dentry->d_sb->s_magic;
326 	buf->f_bsize = dentry->d_sb->s_blocksize;
327 	buf->f_blocks = (sbi->s_nzones - sbi->s_firstdatazone) << sbi->s_log_zone_size;
328 	buf->f_bfree = minix_count_free_blocks(sbi);
329 	buf->f_bavail = buf->f_bfree;
330 	buf->f_files = sbi->s_ninodes;
331 	buf->f_ffree = minix_count_free_inodes(sbi);
332 	buf->f_namelen = sbi->s_namelen;
333 	return 0;
334 }
335 
336 static int minix_get_block(struct inode *inode, sector_t block,
337 		    struct buffer_head *bh_result, int create)
338 {
339 	if (INODE_VERSION(inode) == MINIX_V1)
340 		return V1_minix_get_block(inode, block, bh_result, create);
341 	else
342 		return V2_minix_get_block(inode, block, bh_result, create);
343 }
344 
345 static int minix_writepage(struct page *page, struct writeback_control *wbc)
346 {
347 	return block_write_full_page(page, minix_get_block, wbc);
348 }
349 
350 static int minix_readpage(struct file *file, struct page *page)
351 {
352 	return block_read_full_page(page,minix_get_block);
353 }
354 
355 int __minix_write_begin(struct file *file, struct address_space *mapping,
356 			loff_t pos, unsigned len, unsigned flags,
357 			struct page **pagep, void **fsdata)
358 {
359 	return block_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
360 				minix_get_block);
361 }
362 
363 static int minix_write_begin(struct file *file, struct address_space *mapping,
364 			loff_t pos, unsigned len, unsigned flags,
365 			struct page **pagep, void **fsdata)
366 {
367 	*pagep = NULL;
368 	return __minix_write_begin(file, mapping, pos, len, flags, pagep, fsdata);
369 }
370 
371 static sector_t minix_bmap(struct address_space *mapping, sector_t block)
372 {
373 	return generic_block_bmap(mapping,block,minix_get_block);
374 }
375 
376 static const struct address_space_operations minix_aops = {
377 	.readpage = minix_readpage,
378 	.writepage = minix_writepage,
379 	.sync_page = block_sync_page,
380 	.write_begin = minix_write_begin,
381 	.write_end = generic_write_end,
382 	.bmap = minix_bmap
383 };
384 
385 static const struct inode_operations minix_symlink_inode_operations = {
386 	.readlink	= generic_readlink,
387 	.follow_link	= page_follow_link_light,
388 	.put_link	= page_put_link,
389 	.getattr	= minix_getattr,
390 };
391 
392 void minix_set_inode(struct inode *inode, dev_t rdev)
393 {
394 	if (S_ISREG(inode->i_mode)) {
395 		inode->i_op = &minix_file_inode_operations;
396 		inode->i_fop = &minix_file_operations;
397 		inode->i_mapping->a_ops = &minix_aops;
398 	} else if (S_ISDIR(inode->i_mode)) {
399 		inode->i_op = &minix_dir_inode_operations;
400 		inode->i_fop = &minix_dir_operations;
401 		inode->i_mapping->a_ops = &minix_aops;
402 	} else if (S_ISLNK(inode->i_mode)) {
403 		inode->i_op = &minix_symlink_inode_operations;
404 		inode->i_mapping->a_ops = &minix_aops;
405 	} else
406 		init_special_inode(inode, inode->i_mode, rdev);
407 }
408 
409 /*
410  * The minix V1 function to read an inode.
411  */
412 static struct inode *V1_minix_iget(struct inode *inode)
413 {
414 	struct buffer_head * bh;
415 	struct minix_inode * raw_inode;
416 	struct minix_inode_info *minix_inode = minix_i(inode);
417 	int i;
418 
419 	raw_inode = minix_V1_raw_inode(inode->i_sb, inode->i_ino, &bh);
420 	if (!raw_inode) {
421 		iget_failed(inode);
422 		return ERR_PTR(-EIO);
423 	}
424 	inode->i_mode = raw_inode->i_mode;
425 	inode->i_uid = (uid_t)raw_inode->i_uid;
426 	inode->i_gid = (gid_t)raw_inode->i_gid;
427 	inode->i_nlink = raw_inode->i_nlinks;
428 	inode->i_size = raw_inode->i_size;
429 	inode->i_mtime.tv_sec = inode->i_atime.tv_sec = inode->i_ctime.tv_sec = raw_inode->i_time;
430 	inode->i_mtime.tv_nsec = 0;
431 	inode->i_atime.tv_nsec = 0;
432 	inode->i_ctime.tv_nsec = 0;
433 	inode->i_blocks = 0;
434 	for (i = 0; i < 9; i++)
435 		minix_inode->u.i1_data[i] = raw_inode->i_zone[i];
436 	minix_set_inode(inode, old_decode_dev(raw_inode->i_zone[0]));
437 	brelse(bh);
438 	unlock_new_inode(inode);
439 	return inode;
440 }
441 
442 /*
443  * The minix V2 function to read an inode.
444  */
445 static struct inode *V2_minix_iget(struct inode *inode)
446 {
447 	struct buffer_head * bh;
448 	struct minix2_inode * raw_inode;
449 	struct minix_inode_info *minix_inode = minix_i(inode);
450 	int i;
451 
452 	raw_inode = minix_V2_raw_inode(inode->i_sb, inode->i_ino, &bh);
453 	if (!raw_inode) {
454 		iget_failed(inode);
455 		return ERR_PTR(-EIO);
456 	}
457 	inode->i_mode = raw_inode->i_mode;
458 	inode->i_uid = (uid_t)raw_inode->i_uid;
459 	inode->i_gid = (gid_t)raw_inode->i_gid;
460 	inode->i_nlink = raw_inode->i_nlinks;
461 	inode->i_size = raw_inode->i_size;
462 	inode->i_mtime.tv_sec = raw_inode->i_mtime;
463 	inode->i_atime.tv_sec = raw_inode->i_atime;
464 	inode->i_ctime.tv_sec = raw_inode->i_ctime;
465 	inode->i_mtime.tv_nsec = 0;
466 	inode->i_atime.tv_nsec = 0;
467 	inode->i_ctime.tv_nsec = 0;
468 	inode->i_blocks = 0;
469 	for (i = 0; i < 10; i++)
470 		minix_inode->u.i2_data[i] = raw_inode->i_zone[i];
471 	minix_set_inode(inode, old_decode_dev(raw_inode->i_zone[0]));
472 	brelse(bh);
473 	unlock_new_inode(inode);
474 	return inode;
475 }
476 
477 /*
478  * The global function to read an inode.
479  */
480 struct inode *minix_iget(struct super_block *sb, unsigned long ino)
481 {
482 	struct inode *inode;
483 
484 	inode = iget_locked(sb, ino);
485 	if (!inode)
486 		return ERR_PTR(-ENOMEM);
487 	if (!(inode->i_state & I_NEW))
488 		return inode;
489 
490 	if (INODE_VERSION(inode) == MINIX_V1)
491 		return V1_minix_iget(inode);
492 	else
493 		return V2_minix_iget(inode);
494 }
495 
496 /*
497  * The minix V1 function to synchronize an inode.
498  */
499 static struct buffer_head * V1_minix_update_inode(struct inode * inode)
500 {
501 	struct buffer_head * bh;
502 	struct minix_inode * raw_inode;
503 	struct minix_inode_info *minix_inode = minix_i(inode);
504 	int i;
505 
506 	raw_inode = minix_V1_raw_inode(inode->i_sb, inode->i_ino, &bh);
507 	if (!raw_inode)
508 		return NULL;
509 	raw_inode->i_mode = inode->i_mode;
510 	raw_inode->i_uid = fs_high2lowuid(inode->i_uid);
511 	raw_inode->i_gid = fs_high2lowgid(inode->i_gid);
512 	raw_inode->i_nlinks = inode->i_nlink;
513 	raw_inode->i_size = inode->i_size;
514 	raw_inode->i_time = inode->i_mtime.tv_sec;
515 	if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode))
516 		raw_inode->i_zone[0] = old_encode_dev(inode->i_rdev);
517 	else for (i = 0; i < 9; i++)
518 		raw_inode->i_zone[i] = minix_inode->u.i1_data[i];
519 	mark_buffer_dirty(bh);
520 	return bh;
521 }
522 
523 /*
524  * The minix V2 function to synchronize an inode.
525  */
526 static struct buffer_head * V2_minix_update_inode(struct inode * inode)
527 {
528 	struct buffer_head * bh;
529 	struct minix2_inode * raw_inode;
530 	struct minix_inode_info *minix_inode = minix_i(inode);
531 	int i;
532 
533 	raw_inode = minix_V2_raw_inode(inode->i_sb, inode->i_ino, &bh);
534 	if (!raw_inode)
535 		return NULL;
536 	raw_inode->i_mode = inode->i_mode;
537 	raw_inode->i_uid = fs_high2lowuid(inode->i_uid);
538 	raw_inode->i_gid = fs_high2lowgid(inode->i_gid);
539 	raw_inode->i_nlinks = inode->i_nlink;
540 	raw_inode->i_size = inode->i_size;
541 	raw_inode->i_mtime = inode->i_mtime.tv_sec;
542 	raw_inode->i_atime = inode->i_atime.tv_sec;
543 	raw_inode->i_ctime = inode->i_ctime.tv_sec;
544 	if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode))
545 		raw_inode->i_zone[0] = old_encode_dev(inode->i_rdev);
546 	else for (i = 0; i < 10; i++)
547 		raw_inode->i_zone[i] = minix_inode->u.i2_data[i];
548 	mark_buffer_dirty(bh);
549 	return bh;
550 }
551 
552 static struct buffer_head *minix_update_inode(struct inode *inode)
553 {
554 	if (INODE_VERSION(inode) == MINIX_V1)
555 		return V1_minix_update_inode(inode);
556 	else
557 		return V2_minix_update_inode(inode);
558 }
559 
560 static int minix_write_inode(struct inode * inode, int wait)
561 {
562 	brelse(minix_update_inode(inode));
563 	return 0;
564 }
565 
566 int minix_sync_inode(struct inode * inode)
567 {
568 	int err = 0;
569 	struct buffer_head *bh;
570 
571 	bh = minix_update_inode(inode);
572 	if (bh && buffer_dirty(bh))
573 	{
574 		sync_dirty_buffer(bh);
575 		if (buffer_req(bh) && !buffer_uptodate(bh))
576 		{
577 			printk("IO error syncing minix inode [%s:%08lx]\n",
578 				inode->i_sb->s_id, inode->i_ino);
579 			err = -1;
580 		}
581 	}
582 	else if (!bh)
583 		err = -1;
584 	brelse (bh);
585 	return err;
586 }
587 
588 int minix_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
589 {
590 	struct inode *dir = dentry->d_parent->d_inode;
591 	struct super_block *sb = dir->i_sb;
592 	generic_fillattr(dentry->d_inode, stat);
593 	if (INODE_VERSION(dentry->d_inode) == MINIX_V1)
594 		stat->blocks = (BLOCK_SIZE / 512) * V1_minix_blocks(stat->size, sb);
595 	else
596 		stat->blocks = (sb->s_blocksize / 512) * V2_minix_blocks(stat->size, sb);
597 	stat->blksize = sb->s_blocksize;
598 	return 0;
599 }
600 
601 /*
602  * The function that is called for file truncation.
603  */
604 void minix_truncate(struct inode * inode)
605 {
606 	if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode)))
607 		return;
608 	if (INODE_VERSION(inode) == MINIX_V1)
609 		V1_minix_truncate(inode);
610 	else
611 		V2_minix_truncate(inode);
612 }
613 
614 static int minix_get_sb(struct file_system_type *fs_type,
615 	int flags, const char *dev_name, void *data, struct vfsmount *mnt)
616 {
617 	return get_sb_bdev(fs_type, flags, dev_name, data, minix_fill_super,
618 			   mnt);
619 }
620 
621 static struct file_system_type minix_fs_type = {
622 	.owner		= THIS_MODULE,
623 	.name		= "minix",
624 	.get_sb		= minix_get_sb,
625 	.kill_sb	= kill_block_super,
626 	.fs_flags	= FS_REQUIRES_DEV,
627 };
628 
629 static int __init init_minix_fs(void)
630 {
631 	int err = init_inodecache();
632 	if (err)
633 		goto out1;
634 	err = register_filesystem(&minix_fs_type);
635 	if (err)
636 		goto out;
637 	return 0;
638 out:
639 	destroy_inodecache();
640 out1:
641 	return err;
642 }
643 
644 static void __exit exit_minix_fs(void)
645 {
646         unregister_filesystem(&minix_fs_type);
647 	destroy_inodecache();
648 }
649 
650 module_init(init_minix_fs)
651 module_exit(exit_minix_fs)
652 MODULE_LICENSE("GPL");
653 
654