xref: /openbmc/linux/fs/minix/inode.c (revision b627b4ed)
1 /*
2  *  linux/fs/minix/inode.c
3  *
4  *  Copyright (C) 1991, 1992  Linus Torvalds
5  *
6  *  Copyright (C) 1996  Gertjan van Wingerde
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 super_block *sb = dentry->d_sb;
325 	struct minix_sb_info *sbi = minix_sb(sb);
326 	u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
327 	buf->f_type = sb->s_magic;
328 	buf->f_bsize = sb->s_blocksize;
329 	buf->f_blocks = (sbi->s_nzones - sbi->s_firstdatazone) << sbi->s_log_zone_size;
330 	buf->f_bfree = minix_count_free_blocks(sbi);
331 	buf->f_bavail = buf->f_bfree;
332 	buf->f_files = sbi->s_ninodes;
333 	buf->f_ffree = minix_count_free_inodes(sbi);
334 	buf->f_namelen = sbi->s_namelen;
335 	buf->f_fsid.val[0] = (u32)id;
336 	buf->f_fsid.val[1] = (u32)(id >> 32);
337 
338 	return 0;
339 }
340 
341 static int minix_get_block(struct inode *inode, sector_t block,
342 		    struct buffer_head *bh_result, int create)
343 {
344 	if (INODE_VERSION(inode) == MINIX_V1)
345 		return V1_minix_get_block(inode, block, bh_result, create);
346 	else
347 		return V2_minix_get_block(inode, block, bh_result, create);
348 }
349 
350 static int minix_writepage(struct page *page, struct writeback_control *wbc)
351 {
352 	return block_write_full_page(page, minix_get_block, wbc);
353 }
354 
355 static int minix_readpage(struct file *file, struct page *page)
356 {
357 	return block_read_full_page(page,minix_get_block);
358 }
359 
360 int __minix_write_begin(struct file *file, struct address_space *mapping,
361 			loff_t pos, unsigned len, unsigned flags,
362 			struct page **pagep, void **fsdata)
363 {
364 	return block_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
365 				minix_get_block);
366 }
367 
368 static int minix_write_begin(struct file *file, struct address_space *mapping,
369 			loff_t pos, unsigned len, unsigned flags,
370 			struct page **pagep, void **fsdata)
371 {
372 	*pagep = NULL;
373 	return __minix_write_begin(file, mapping, pos, len, flags, pagep, fsdata);
374 }
375 
376 static sector_t minix_bmap(struct address_space *mapping, sector_t block)
377 {
378 	return generic_block_bmap(mapping,block,minix_get_block);
379 }
380 
381 static const struct address_space_operations minix_aops = {
382 	.readpage = minix_readpage,
383 	.writepage = minix_writepage,
384 	.sync_page = block_sync_page,
385 	.write_begin = minix_write_begin,
386 	.write_end = generic_write_end,
387 	.bmap = minix_bmap
388 };
389 
390 static const struct inode_operations minix_symlink_inode_operations = {
391 	.readlink	= generic_readlink,
392 	.follow_link	= page_follow_link_light,
393 	.put_link	= page_put_link,
394 	.getattr	= minix_getattr,
395 };
396 
397 void minix_set_inode(struct inode *inode, dev_t rdev)
398 {
399 	if (S_ISREG(inode->i_mode)) {
400 		inode->i_op = &minix_file_inode_operations;
401 		inode->i_fop = &minix_file_operations;
402 		inode->i_mapping->a_ops = &minix_aops;
403 	} else if (S_ISDIR(inode->i_mode)) {
404 		inode->i_op = &minix_dir_inode_operations;
405 		inode->i_fop = &minix_dir_operations;
406 		inode->i_mapping->a_ops = &minix_aops;
407 	} else if (S_ISLNK(inode->i_mode)) {
408 		inode->i_op = &minix_symlink_inode_operations;
409 		inode->i_mapping->a_ops = &minix_aops;
410 	} else
411 		init_special_inode(inode, inode->i_mode, rdev);
412 }
413 
414 /*
415  * The minix V1 function to read an inode.
416  */
417 static struct inode *V1_minix_iget(struct inode *inode)
418 {
419 	struct buffer_head * bh;
420 	struct minix_inode * raw_inode;
421 	struct minix_inode_info *minix_inode = minix_i(inode);
422 	int i;
423 
424 	raw_inode = minix_V1_raw_inode(inode->i_sb, inode->i_ino, &bh);
425 	if (!raw_inode) {
426 		iget_failed(inode);
427 		return ERR_PTR(-EIO);
428 	}
429 	inode->i_mode = raw_inode->i_mode;
430 	inode->i_uid = (uid_t)raw_inode->i_uid;
431 	inode->i_gid = (gid_t)raw_inode->i_gid;
432 	inode->i_nlink = raw_inode->i_nlinks;
433 	inode->i_size = raw_inode->i_size;
434 	inode->i_mtime.tv_sec = inode->i_atime.tv_sec = inode->i_ctime.tv_sec = raw_inode->i_time;
435 	inode->i_mtime.tv_nsec = 0;
436 	inode->i_atime.tv_nsec = 0;
437 	inode->i_ctime.tv_nsec = 0;
438 	inode->i_blocks = 0;
439 	for (i = 0; i < 9; i++)
440 		minix_inode->u.i1_data[i] = raw_inode->i_zone[i];
441 	minix_set_inode(inode, old_decode_dev(raw_inode->i_zone[0]));
442 	brelse(bh);
443 	unlock_new_inode(inode);
444 	return inode;
445 }
446 
447 /*
448  * The minix V2 function to read an inode.
449  */
450 static struct inode *V2_minix_iget(struct inode *inode)
451 {
452 	struct buffer_head * bh;
453 	struct minix2_inode * raw_inode;
454 	struct minix_inode_info *minix_inode = minix_i(inode);
455 	int i;
456 
457 	raw_inode = minix_V2_raw_inode(inode->i_sb, inode->i_ino, &bh);
458 	if (!raw_inode) {
459 		iget_failed(inode);
460 		return ERR_PTR(-EIO);
461 	}
462 	inode->i_mode = raw_inode->i_mode;
463 	inode->i_uid = (uid_t)raw_inode->i_uid;
464 	inode->i_gid = (gid_t)raw_inode->i_gid;
465 	inode->i_nlink = raw_inode->i_nlinks;
466 	inode->i_size = raw_inode->i_size;
467 	inode->i_mtime.tv_sec = raw_inode->i_mtime;
468 	inode->i_atime.tv_sec = raw_inode->i_atime;
469 	inode->i_ctime.tv_sec = raw_inode->i_ctime;
470 	inode->i_mtime.tv_nsec = 0;
471 	inode->i_atime.tv_nsec = 0;
472 	inode->i_ctime.tv_nsec = 0;
473 	inode->i_blocks = 0;
474 	for (i = 0; i < 10; i++)
475 		minix_inode->u.i2_data[i] = raw_inode->i_zone[i];
476 	minix_set_inode(inode, old_decode_dev(raw_inode->i_zone[0]));
477 	brelse(bh);
478 	unlock_new_inode(inode);
479 	return inode;
480 }
481 
482 /*
483  * The global function to read an inode.
484  */
485 struct inode *minix_iget(struct super_block *sb, unsigned long ino)
486 {
487 	struct inode *inode;
488 
489 	inode = iget_locked(sb, ino);
490 	if (!inode)
491 		return ERR_PTR(-ENOMEM);
492 	if (!(inode->i_state & I_NEW))
493 		return inode;
494 
495 	if (INODE_VERSION(inode) == MINIX_V1)
496 		return V1_minix_iget(inode);
497 	else
498 		return V2_minix_iget(inode);
499 }
500 
501 /*
502  * The minix V1 function to synchronize an inode.
503  */
504 static struct buffer_head * V1_minix_update_inode(struct inode * inode)
505 {
506 	struct buffer_head * bh;
507 	struct minix_inode * raw_inode;
508 	struct minix_inode_info *minix_inode = minix_i(inode);
509 	int i;
510 
511 	raw_inode = minix_V1_raw_inode(inode->i_sb, inode->i_ino, &bh);
512 	if (!raw_inode)
513 		return NULL;
514 	raw_inode->i_mode = inode->i_mode;
515 	raw_inode->i_uid = fs_high2lowuid(inode->i_uid);
516 	raw_inode->i_gid = fs_high2lowgid(inode->i_gid);
517 	raw_inode->i_nlinks = inode->i_nlink;
518 	raw_inode->i_size = inode->i_size;
519 	raw_inode->i_time = inode->i_mtime.tv_sec;
520 	if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode))
521 		raw_inode->i_zone[0] = old_encode_dev(inode->i_rdev);
522 	else for (i = 0; i < 9; i++)
523 		raw_inode->i_zone[i] = minix_inode->u.i1_data[i];
524 	mark_buffer_dirty(bh);
525 	return bh;
526 }
527 
528 /*
529  * The minix V2 function to synchronize an inode.
530  */
531 static struct buffer_head * V2_minix_update_inode(struct inode * inode)
532 {
533 	struct buffer_head * bh;
534 	struct minix2_inode * raw_inode;
535 	struct minix_inode_info *minix_inode = minix_i(inode);
536 	int i;
537 
538 	raw_inode = minix_V2_raw_inode(inode->i_sb, inode->i_ino, &bh);
539 	if (!raw_inode)
540 		return NULL;
541 	raw_inode->i_mode = inode->i_mode;
542 	raw_inode->i_uid = fs_high2lowuid(inode->i_uid);
543 	raw_inode->i_gid = fs_high2lowgid(inode->i_gid);
544 	raw_inode->i_nlinks = inode->i_nlink;
545 	raw_inode->i_size = inode->i_size;
546 	raw_inode->i_mtime = inode->i_mtime.tv_sec;
547 	raw_inode->i_atime = inode->i_atime.tv_sec;
548 	raw_inode->i_ctime = inode->i_ctime.tv_sec;
549 	if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode))
550 		raw_inode->i_zone[0] = old_encode_dev(inode->i_rdev);
551 	else for (i = 0; i < 10; i++)
552 		raw_inode->i_zone[i] = minix_inode->u.i2_data[i];
553 	mark_buffer_dirty(bh);
554 	return bh;
555 }
556 
557 static struct buffer_head *minix_update_inode(struct inode *inode)
558 {
559 	if (INODE_VERSION(inode) == MINIX_V1)
560 		return V1_minix_update_inode(inode);
561 	else
562 		return V2_minix_update_inode(inode);
563 }
564 
565 static int minix_write_inode(struct inode * inode, int wait)
566 {
567 	brelse(minix_update_inode(inode));
568 	return 0;
569 }
570 
571 int minix_sync_inode(struct inode * inode)
572 {
573 	int err = 0;
574 	struct buffer_head *bh;
575 
576 	bh = minix_update_inode(inode);
577 	if (bh && buffer_dirty(bh))
578 	{
579 		sync_dirty_buffer(bh);
580 		if (buffer_req(bh) && !buffer_uptodate(bh))
581 		{
582 			printk("IO error syncing minix inode [%s:%08lx]\n",
583 				inode->i_sb->s_id, inode->i_ino);
584 			err = -1;
585 		}
586 	}
587 	else if (!bh)
588 		err = -1;
589 	brelse (bh);
590 	return err;
591 }
592 
593 int minix_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
594 {
595 	struct inode *dir = dentry->d_parent->d_inode;
596 	struct super_block *sb = dir->i_sb;
597 	generic_fillattr(dentry->d_inode, stat);
598 	if (INODE_VERSION(dentry->d_inode) == MINIX_V1)
599 		stat->blocks = (BLOCK_SIZE / 512) * V1_minix_blocks(stat->size, sb);
600 	else
601 		stat->blocks = (sb->s_blocksize / 512) * V2_minix_blocks(stat->size, sb);
602 	stat->blksize = sb->s_blocksize;
603 	return 0;
604 }
605 
606 /*
607  * The function that is called for file truncation.
608  */
609 void minix_truncate(struct inode * inode)
610 {
611 	if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode)))
612 		return;
613 	if (INODE_VERSION(inode) == MINIX_V1)
614 		V1_minix_truncate(inode);
615 	else
616 		V2_minix_truncate(inode);
617 }
618 
619 static int minix_get_sb(struct file_system_type *fs_type,
620 	int flags, const char *dev_name, void *data, struct vfsmount *mnt)
621 {
622 	return get_sb_bdev(fs_type, flags, dev_name, data, minix_fill_super,
623 			   mnt);
624 }
625 
626 static struct file_system_type minix_fs_type = {
627 	.owner		= THIS_MODULE,
628 	.name		= "minix",
629 	.get_sb		= minix_get_sb,
630 	.kill_sb	= kill_block_super,
631 	.fs_flags	= FS_REQUIRES_DEV,
632 };
633 
634 static int __init init_minix_fs(void)
635 {
636 	int err = init_inodecache();
637 	if (err)
638 		goto out1;
639 	err = register_filesystem(&minix_fs_type);
640 	if (err)
641 		goto out;
642 	return 0;
643 out:
644 	destroy_inodecache();
645 out1:
646 	return err;
647 }
648 
649 static void __exit exit_minix_fs(void)
650 {
651         unregister_filesystem(&minix_fs_type);
652 	destroy_inodecache();
653 }
654 
655 module_init(init_minix_fs)
656 module_exit(exit_minix_fs)
657 MODULE_LICENSE("GPL");
658 
659