xref: /openbmc/linux/fs/minix/inode.c (revision baa7eb025ab14f3cba2e35c0a8648f9c9f01d24f)
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 #include <linux/writeback.h>
21 
22 static int minix_write_inode(struct inode *inode,
23 		struct writeback_control *wbc);
24 static int minix_statfs(struct dentry *dentry, struct kstatfs *buf);
25 static int minix_remount (struct super_block * sb, int * flags, char * data);
26 
27 static void minix_evict_inode(struct inode *inode)
28 {
29 	truncate_inode_pages(&inode->i_data, 0);
30 	if (!inode->i_nlink) {
31 		inode->i_size = 0;
32 		minix_truncate(inode);
33 	}
34 	invalidate_inode_buffers(inode);
35 	end_writeback(inode);
36 	if (!inode->i_nlink)
37 		minix_free_inode(inode);
38 }
39 
40 static void minix_put_super(struct super_block *sb)
41 {
42 	int i;
43 	struct minix_sb_info *sbi = minix_sb(sb);
44 
45 	if (!(sb->s_flags & MS_RDONLY)) {
46 		if (sbi->s_version != MINIX_V3)	 /* s_state is now out from V3 sb */
47 			sbi->s_ms->s_state = sbi->s_mount_state;
48 		mark_buffer_dirty(sbi->s_sbh);
49 	}
50 	for (i = 0; i < sbi->s_imap_blocks; i++)
51 		brelse(sbi->s_imap[i]);
52 	for (i = 0; i < sbi->s_zmap_blocks; i++)
53 		brelse(sbi->s_zmap[i]);
54 	brelse (sbi->s_sbh);
55 	kfree(sbi->s_imap);
56 	sb->s_fs_info = NULL;
57 	kfree(sbi);
58 }
59 
60 static struct kmem_cache * minix_inode_cachep;
61 
62 static struct inode *minix_alloc_inode(struct super_block *sb)
63 {
64 	struct minix_inode_info *ei;
65 	ei = (struct minix_inode_info *)kmem_cache_alloc(minix_inode_cachep, GFP_KERNEL);
66 	if (!ei)
67 		return NULL;
68 	return &ei->vfs_inode;
69 }
70 
71 static void minix_destroy_inode(struct inode *inode)
72 {
73 	kmem_cache_free(minix_inode_cachep, minix_i(inode));
74 }
75 
76 static void init_once(void *foo)
77 {
78 	struct minix_inode_info *ei = (struct minix_inode_info *) foo;
79 
80 	inode_init_once(&ei->vfs_inode);
81 }
82 
83 static int init_inodecache(void)
84 {
85 	minix_inode_cachep = kmem_cache_create("minix_inode_cache",
86 					     sizeof(struct minix_inode_info),
87 					     0, (SLAB_RECLAIM_ACCOUNT|
88 						SLAB_MEM_SPREAD),
89 					     init_once);
90 	if (minix_inode_cachep == NULL)
91 		return -ENOMEM;
92 	return 0;
93 }
94 
95 static void destroy_inodecache(void)
96 {
97 	kmem_cache_destroy(minix_inode_cachep);
98 }
99 
100 static const struct super_operations minix_sops = {
101 	.alloc_inode	= minix_alloc_inode,
102 	.destroy_inode	= minix_destroy_inode,
103 	.write_inode	= minix_write_inode,
104 	.evict_inode	= minix_evict_inode,
105 	.put_super	= minix_put_super,
106 	.statfs		= minix_statfs,
107 	.remount_fs	= minix_remount,
108 };
109 
110 static int minix_remount (struct super_block * sb, int * flags, char * data)
111 {
112 	struct minix_sb_info * sbi = minix_sb(sb);
113 	struct minix_super_block * ms;
114 
115 	ms = sbi->s_ms;
116 	if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
117 		return 0;
118 	if (*flags & MS_RDONLY) {
119 		if (ms->s_state & MINIX_VALID_FS ||
120 		    !(sbi->s_mount_state & MINIX_VALID_FS))
121 			return 0;
122 		/* Mounting a rw partition read-only. */
123 		if (sbi->s_version != MINIX_V3)
124 			ms->s_state = sbi->s_mount_state;
125 		mark_buffer_dirty(sbi->s_sbh);
126 	} else {
127 	  	/* Mount a partition which is read-only, read-write. */
128 		if (sbi->s_version != MINIX_V3) {
129 			sbi->s_mount_state = ms->s_state;
130 			ms->s_state &= ~MINIX_VALID_FS;
131 		} else {
132 			sbi->s_mount_state = MINIX_VALID_FS;
133 		}
134 		mark_buffer_dirty(sbi->s_sbh);
135 
136 		if (!(sbi->s_mount_state & MINIX_VALID_FS))
137 			printk("MINIX-fs warning: remounting unchecked fs, "
138 				"running fsck is recommended\n");
139 		else if ((sbi->s_mount_state & MINIX_ERROR_FS))
140 			printk("MINIX-fs warning: remounting fs with errors, "
141 				"running fsck is recommended\n");
142 	}
143 	return 0;
144 }
145 
146 static int minix_fill_super(struct super_block *s, void *data, int silent)
147 {
148 	struct buffer_head *bh;
149 	struct buffer_head **map;
150 	struct minix_super_block *ms;
151 	struct minix3_super_block *m3s = NULL;
152 	unsigned long i, block;
153 	struct inode *root_inode;
154 	struct minix_sb_info *sbi;
155 	int ret = -EINVAL;
156 
157 	sbi = kzalloc(sizeof(struct minix_sb_info), GFP_KERNEL);
158 	if (!sbi)
159 		return -ENOMEM;
160 	s->s_fs_info = sbi;
161 
162 	BUILD_BUG_ON(32 != sizeof (struct minix_inode));
163 	BUILD_BUG_ON(64 != sizeof(struct minix2_inode));
164 
165 	if (!sb_set_blocksize(s, BLOCK_SIZE))
166 		goto out_bad_hblock;
167 
168 	if (!(bh = sb_bread(s, 1)))
169 		goto out_bad_sb;
170 
171 	ms = (struct minix_super_block *) bh->b_data;
172 	sbi->s_ms = ms;
173 	sbi->s_sbh = bh;
174 	sbi->s_mount_state = ms->s_state;
175 	sbi->s_ninodes = ms->s_ninodes;
176 	sbi->s_nzones = ms->s_nzones;
177 	sbi->s_imap_blocks = ms->s_imap_blocks;
178 	sbi->s_zmap_blocks = ms->s_zmap_blocks;
179 	sbi->s_firstdatazone = ms->s_firstdatazone;
180 	sbi->s_log_zone_size = ms->s_log_zone_size;
181 	sbi->s_max_size = ms->s_max_size;
182 	s->s_magic = ms->s_magic;
183 	if (s->s_magic == MINIX_SUPER_MAGIC) {
184 		sbi->s_version = MINIX_V1;
185 		sbi->s_dirsize = 16;
186 		sbi->s_namelen = 14;
187 		sbi->s_link_max = MINIX_LINK_MAX;
188 	} else if (s->s_magic == MINIX_SUPER_MAGIC2) {
189 		sbi->s_version = MINIX_V1;
190 		sbi->s_dirsize = 32;
191 		sbi->s_namelen = 30;
192 		sbi->s_link_max = MINIX_LINK_MAX;
193 	} else if (s->s_magic == MINIX2_SUPER_MAGIC) {
194 		sbi->s_version = MINIX_V2;
195 		sbi->s_nzones = ms->s_zones;
196 		sbi->s_dirsize = 16;
197 		sbi->s_namelen = 14;
198 		sbi->s_link_max = MINIX2_LINK_MAX;
199 	} else if (s->s_magic == MINIX2_SUPER_MAGIC2) {
200 		sbi->s_version = MINIX_V2;
201 		sbi->s_nzones = ms->s_zones;
202 		sbi->s_dirsize = 32;
203 		sbi->s_namelen = 30;
204 		sbi->s_link_max = MINIX2_LINK_MAX;
205 	} else if ( *(__u16 *)(bh->b_data + 24) == MINIX3_SUPER_MAGIC) {
206 		m3s = (struct minix3_super_block *) bh->b_data;
207 		s->s_magic = m3s->s_magic;
208 		sbi->s_imap_blocks = m3s->s_imap_blocks;
209 		sbi->s_zmap_blocks = m3s->s_zmap_blocks;
210 		sbi->s_firstdatazone = m3s->s_firstdatazone;
211 		sbi->s_log_zone_size = m3s->s_log_zone_size;
212 		sbi->s_max_size = m3s->s_max_size;
213 		sbi->s_ninodes = m3s->s_ninodes;
214 		sbi->s_nzones = m3s->s_zones;
215 		sbi->s_dirsize = 64;
216 		sbi->s_namelen = 60;
217 		sbi->s_version = MINIX_V3;
218 		sbi->s_link_max = MINIX2_LINK_MAX;
219 		sbi->s_mount_state = MINIX_VALID_FS;
220 		sb_set_blocksize(s, m3s->s_blocksize);
221 	} else
222 		goto out_no_fs;
223 
224 	/*
225 	 * Allocate the buffer map to keep the superblock small.
226 	 */
227 	if (sbi->s_imap_blocks == 0 || sbi->s_zmap_blocks == 0)
228 		goto out_illegal_sb;
229 	i = (sbi->s_imap_blocks + sbi->s_zmap_blocks) * sizeof(bh);
230 	map = kzalloc(i, GFP_KERNEL);
231 	if (!map)
232 		goto out_no_map;
233 	sbi->s_imap = &map[0];
234 	sbi->s_zmap = &map[sbi->s_imap_blocks];
235 
236 	block=2;
237 	for (i=0 ; i < sbi->s_imap_blocks ; i++) {
238 		if (!(sbi->s_imap[i]=sb_bread(s, block)))
239 			goto out_no_bitmap;
240 		block++;
241 	}
242 	for (i=0 ; i < sbi->s_zmap_blocks ; i++) {
243 		if (!(sbi->s_zmap[i]=sb_bread(s, block)))
244 			goto out_no_bitmap;
245 		block++;
246 	}
247 
248 	minix_set_bit(0,sbi->s_imap[0]->b_data);
249 	minix_set_bit(0,sbi->s_zmap[0]->b_data);
250 
251 	/* set up enough so that it can read an inode */
252 	s->s_op = &minix_sops;
253 	root_inode = minix_iget(s, MINIX_ROOT_INO);
254 	if (IS_ERR(root_inode)) {
255 		ret = PTR_ERR(root_inode);
256 		goto out_no_root;
257 	}
258 
259 	ret = -ENOMEM;
260 	s->s_root = d_alloc_root(root_inode);
261 	if (!s->s_root)
262 		goto out_iput;
263 
264 	if (!(s->s_flags & MS_RDONLY)) {
265 		if (sbi->s_version != MINIX_V3) /* s_state is now out from V3 sb */
266 			ms->s_state &= ~MINIX_VALID_FS;
267 		mark_buffer_dirty(bh);
268 	}
269 	if (!(sbi->s_mount_state & MINIX_VALID_FS))
270 		printk("MINIX-fs: mounting unchecked file system, "
271 			"running fsck is recommended\n");
272  	else if (sbi->s_mount_state & MINIX_ERROR_FS)
273 		printk("MINIX-fs: mounting file system with errors, "
274 			"running fsck is recommended\n");
275 	return 0;
276 
277 out_iput:
278 	iput(root_inode);
279 	goto out_freemap;
280 
281 out_no_root:
282 	if (!silent)
283 		printk("MINIX-fs: get root inode failed\n");
284 	goto out_freemap;
285 
286 out_no_bitmap:
287 	printk("MINIX-fs: bad superblock or unable to read bitmaps\n");
288 out_freemap:
289 	for (i = 0; i < sbi->s_imap_blocks; i++)
290 		brelse(sbi->s_imap[i]);
291 	for (i = 0; i < sbi->s_zmap_blocks; i++)
292 		brelse(sbi->s_zmap[i]);
293 	kfree(sbi->s_imap);
294 	goto out_release;
295 
296 out_no_map:
297 	ret = -ENOMEM;
298 	if (!silent)
299 		printk("MINIX-fs: can't allocate map\n");
300 	goto out_release;
301 
302 out_illegal_sb:
303 	if (!silent)
304 		printk("MINIX-fs: bad superblock\n");
305 	goto out_release;
306 
307 out_no_fs:
308 	if (!silent)
309 		printk("VFS: Can't find a Minix filesystem V1 | V2 | V3 "
310 		       "on device %s.\n", s->s_id);
311 out_release:
312 	brelse(bh);
313 	goto out;
314 
315 out_bad_hblock:
316 	printk("MINIX-fs: blocksize too small for device\n");
317 	goto out;
318 
319 out_bad_sb:
320 	printk("MINIX-fs: unable to read superblock\n");
321 out:
322 	s->s_fs_info = NULL;
323 	kfree(sbi);
324 	return ret;
325 }
326 
327 static int minix_statfs(struct dentry *dentry, struct kstatfs *buf)
328 {
329 	struct super_block *sb = dentry->d_sb;
330 	struct minix_sb_info *sbi = minix_sb(sb);
331 	u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
332 	buf->f_type = sb->s_magic;
333 	buf->f_bsize = sb->s_blocksize;
334 	buf->f_blocks = (sbi->s_nzones - sbi->s_firstdatazone) << sbi->s_log_zone_size;
335 	buf->f_bfree = minix_count_free_blocks(sbi);
336 	buf->f_bavail = buf->f_bfree;
337 	buf->f_files = sbi->s_ninodes;
338 	buf->f_ffree = minix_count_free_inodes(sbi);
339 	buf->f_namelen = sbi->s_namelen;
340 	buf->f_fsid.val[0] = (u32)id;
341 	buf->f_fsid.val[1] = (u32)(id >> 32);
342 
343 	return 0;
344 }
345 
346 static int minix_get_block(struct inode *inode, sector_t block,
347 		    struct buffer_head *bh_result, int create)
348 {
349 	if (INODE_VERSION(inode) == MINIX_V1)
350 		return V1_minix_get_block(inode, block, bh_result, create);
351 	else
352 		return V2_minix_get_block(inode, block, bh_result, create);
353 }
354 
355 static int minix_writepage(struct page *page, struct writeback_control *wbc)
356 {
357 	return block_write_full_page(page, minix_get_block, wbc);
358 }
359 
360 static int minix_readpage(struct file *file, struct page *page)
361 {
362 	return block_read_full_page(page,minix_get_block);
363 }
364 
365 int minix_prepare_chunk(struct page *page, loff_t pos, unsigned len)
366 {
367 	return __block_write_begin(page, pos, len, minix_get_block);
368 }
369 
370 static int minix_write_begin(struct file *file, struct address_space *mapping,
371 			loff_t pos, unsigned len, unsigned flags,
372 			struct page **pagep, void **fsdata)
373 {
374 	int ret;
375 
376 	ret = block_write_begin(mapping, pos, len, flags, pagep,
377 				minix_get_block);
378 	if (unlikely(ret)) {
379 		loff_t isize = mapping->host->i_size;
380 		if (pos + len > isize)
381 			vmtruncate(mapping->host, isize);
382 	}
383 
384 	return ret;
385 }
386 
387 static sector_t minix_bmap(struct address_space *mapping, sector_t block)
388 {
389 	return generic_block_bmap(mapping,block,minix_get_block);
390 }
391 
392 static const struct address_space_operations minix_aops = {
393 	.readpage = minix_readpage,
394 	.writepage = minix_writepage,
395 	.sync_page = block_sync_page,
396 	.write_begin = minix_write_begin,
397 	.write_end = generic_write_end,
398 	.bmap = minix_bmap
399 };
400 
401 static const struct inode_operations minix_symlink_inode_operations = {
402 	.readlink	= generic_readlink,
403 	.follow_link	= page_follow_link_light,
404 	.put_link	= page_put_link,
405 	.getattr	= minix_getattr,
406 };
407 
408 void minix_set_inode(struct inode *inode, dev_t rdev)
409 {
410 	if (S_ISREG(inode->i_mode)) {
411 		inode->i_op = &minix_file_inode_operations;
412 		inode->i_fop = &minix_file_operations;
413 		inode->i_mapping->a_ops = &minix_aops;
414 	} else if (S_ISDIR(inode->i_mode)) {
415 		inode->i_op = &minix_dir_inode_operations;
416 		inode->i_fop = &minix_dir_operations;
417 		inode->i_mapping->a_ops = &minix_aops;
418 	} else if (S_ISLNK(inode->i_mode)) {
419 		inode->i_op = &minix_symlink_inode_operations;
420 		inode->i_mapping->a_ops = &minix_aops;
421 	} else
422 		init_special_inode(inode, inode->i_mode, rdev);
423 }
424 
425 /*
426  * The minix V1 function to read an inode.
427  */
428 static struct inode *V1_minix_iget(struct inode *inode)
429 {
430 	struct buffer_head * bh;
431 	struct minix_inode * raw_inode;
432 	struct minix_inode_info *minix_inode = minix_i(inode);
433 	int i;
434 
435 	raw_inode = minix_V1_raw_inode(inode->i_sb, inode->i_ino, &bh);
436 	if (!raw_inode) {
437 		iget_failed(inode);
438 		return ERR_PTR(-EIO);
439 	}
440 	inode->i_mode = raw_inode->i_mode;
441 	inode->i_uid = (uid_t)raw_inode->i_uid;
442 	inode->i_gid = (gid_t)raw_inode->i_gid;
443 	inode->i_nlink = raw_inode->i_nlinks;
444 	inode->i_size = raw_inode->i_size;
445 	inode->i_mtime.tv_sec = inode->i_atime.tv_sec = inode->i_ctime.tv_sec = raw_inode->i_time;
446 	inode->i_mtime.tv_nsec = 0;
447 	inode->i_atime.tv_nsec = 0;
448 	inode->i_ctime.tv_nsec = 0;
449 	inode->i_blocks = 0;
450 	for (i = 0; i < 9; i++)
451 		minix_inode->u.i1_data[i] = raw_inode->i_zone[i];
452 	minix_set_inode(inode, old_decode_dev(raw_inode->i_zone[0]));
453 	brelse(bh);
454 	unlock_new_inode(inode);
455 	return inode;
456 }
457 
458 /*
459  * The minix V2 function to read an inode.
460  */
461 static struct inode *V2_minix_iget(struct inode *inode)
462 {
463 	struct buffer_head * bh;
464 	struct minix2_inode * raw_inode;
465 	struct minix_inode_info *minix_inode = minix_i(inode);
466 	int i;
467 
468 	raw_inode = minix_V2_raw_inode(inode->i_sb, inode->i_ino, &bh);
469 	if (!raw_inode) {
470 		iget_failed(inode);
471 		return ERR_PTR(-EIO);
472 	}
473 	inode->i_mode = raw_inode->i_mode;
474 	inode->i_uid = (uid_t)raw_inode->i_uid;
475 	inode->i_gid = (gid_t)raw_inode->i_gid;
476 	inode->i_nlink = raw_inode->i_nlinks;
477 	inode->i_size = raw_inode->i_size;
478 	inode->i_mtime.tv_sec = raw_inode->i_mtime;
479 	inode->i_atime.tv_sec = raw_inode->i_atime;
480 	inode->i_ctime.tv_sec = raw_inode->i_ctime;
481 	inode->i_mtime.tv_nsec = 0;
482 	inode->i_atime.tv_nsec = 0;
483 	inode->i_ctime.tv_nsec = 0;
484 	inode->i_blocks = 0;
485 	for (i = 0; i < 10; i++)
486 		minix_inode->u.i2_data[i] = raw_inode->i_zone[i];
487 	minix_set_inode(inode, old_decode_dev(raw_inode->i_zone[0]));
488 	brelse(bh);
489 	unlock_new_inode(inode);
490 	return inode;
491 }
492 
493 /*
494  * The global function to read an inode.
495  */
496 struct inode *minix_iget(struct super_block *sb, unsigned long ino)
497 {
498 	struct inode *inode;
499 
500 	inode = iget_locked(sb, ino);
501 	if (!inode)
502 		return ERR_PTR(-ENOMEM);
503 	if (!(inode->i_state & I_NEW))
504 		return inode;
505 
506 	if (INODE_VERSION(inode) == MINIX_V1)
507 		return V1_minix_iget(inode);
508 	else
509 		return V2_minix_iget(inode);
510 }
511 
512 /*
513  * The minix V1 function to synchronize an inode.
514  */
515 static struct buffer_head * V1_minix_update_inode(struct inode * inode)
516 {
517 	struct buffer_head * bh;
518 	struct minix_inode * raw_inode;
519 	struct minix_inode_info *minix_inode = minix_i(inode);
520 	int i;
521 
522 	raw_inode = minix_V1_raw_inode(inode->i_sb, inode->i_ino, &bh);
523 	if (!raw_inode)
524 		return NULL;
525 	raw_inode->i_mode = inode->i_mode;
526 	raw_inode->i_uid = fs_high2lowuid(inode->i_uid);
527 	raw_inode->i_gid = fs_high2lowgid(inode->i_gid);
528 	raw_inode->i_nlinks = inode->i_nlink;
529 	raw_inode->i_size = inode->i_size;
530 	raw_inode->i_time = inode->i_mtime.tv_sec;
531 	if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode))
532 		raw_inode->i_zone[0] = old_encode_dev(inode->i_rdev);
533 	else for (i = 0; i < 9; i++)
534 		raw_inode->i_zone[i] = minix_inode->u.i1_data[i];
535 	mark_buffer_dirty(bh);
536 	return bh;
537 }
538 
539 /*
540  * The minix V2 function to synchronize an inode.
541  */
542 static struct buffer_head * V2_minix_update_inode(struct inode * inode)
543 {
544 	struct buffer_head * bh;
545 	struct minix2_inode * raw_inode;
546 	struct minix_inode_info *minix_inode = minix_i(inode);
547 	int i;
548 
549 	raw_inode = minix_V2_raw_inode(inode->i_sb, inode->i_ino, &bh);
550 	if (!raw_inode)
551 		return NULL;
552 	raw_inode->i_mode = inode->i_mode;
553 	raw_inode->i_uid = fs_high2lowuid(inode->i_uid);
554 	raw_inode->i_gid = fs_high2lowgid(inode->i_gid);
555 	raw_inode->i_nlinks = inode->i_nlink;
556 	raw_inode->i_size = inode->i_size;
557 	raw_inode->i_mtime = inode->i_mtime.tv_sec;
558 	raw_inode->i_atime = inode->i_atime.tv_sec;
559 	raw_inode->i_ctime = inode->i_ctime.tv_sec;
560 	if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode))
561 		raw_inode->i_zone[0] = old_encode_dev(inode->i_rdev);
562 	else for (i = 0; i < 10; i++)
563 		raw_inode->i_zone[i] = minix_inode->u.i2_data[i];
564 	mark_buffer_dirty(bh);
565 	return bh;
566 }
567 
568 static int minix_write_inode(struct inode *inode, struct writeback_control *wbc)
569 {
570 	int err = 0;
571 	struct buffer_head *bh;
572 
573 	if (INODE_VERSION(inode) == MINIX_V1)
574 		bh = V1_minix_update_inode(inode);
575 	else
576 		bh = V2_minix_update_inode(inode);
577 	if (!bh)
578 		return -EIO;
579 	if (wbc->sync_mode == WB_SYNC_ALL && buffer_dirty(bh)) {
580 		sync_dirty_buffer(bh);
581 		if (buffer_req(bh) && !buffer_uptodate(bh)) {
582 			printk("IO error syncing minix inode [%s:%08lx]\n",
583 				inode->i_sb->s_id, inode->i_ino);
584 			err = -EIO;
585 		}
586 	}
587 	brelse (bh);
588 	return err;
589 }
590 
591 int minix_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
592 {
593 	struct inode *dir = dentry->d_parent->d_inode;
594 	struct super_block *sb = dir->i_sb;
595 	generic_fillattr(dentry->d_inode, stat);
596 	if (INODE_VERSION(dentry->d_inode) == MINIX_V1)
597 		stat->blocks = (BLOCK_SIZE / 512) * V1_minix_blocks(stat->size, sb);
598 	else
599 		stat->blocks = (sb->s_blocksize / 512) * V2_minix_blocks(stat->size, sb);
600 	stat->blksize = sb->s_blocksize;
601 	return 0;
602 }
603 
604 /*
605  * The function that is called for file truncation.
606  */
607 void minix_truncate(struct inode * inode)
608 {
609 	if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode)))
610 		return;
611 	if (INODE_VERSION(inode) == MINIX_V1)
612 		V1_minix_truncate(inode);
613 	else
614 		V2_minix_truncate(inode);
615 }
616 
617 static struct dentry *minix_mount(struct file_system_type *fs_type,
618 	int flags, const char *dev_name, void *data)
619 {
620 	return mount_bdev(fs_type, flags, dev_name, data, minix_fill_super);
621 }
622 
623 static struct file_system_type minix_fs_type = {
624 	.owner		= THIS_MODULE,
625 	.name		= "minix",
626 	.mount		= minix_mount,
627 	.kill_sb	= kill_block_super,
628 	.fs_flags	= FS_REQUIRES_DEV,
629 };
630 
631 static int __init init_minix_fs(void)
632 {
633 	int err = init_inodecache();
634 	if (err)
635 		goto out1;
636 	err = register_filesystem(&minix_fs_type);
637 	if (err)
638 		goto out;
639 	return 0;
640 out:
641 	destroy_inodecache();
642 out1:
643 	return err;
644 }
645 
646 static void __exit exit_minix_fs(void)
647 {
648         unregister_filesystem(&minix_fs_type);
649 	destroy_inodecache();
650 }
651 
652 module_init(init_minix_fs)
653 module_exit(exit_minix_fs)
654 MODULE_LICENSE("GPL");
655 
656