xref: /openbmc/linux/fs/minix/inode.c (revision 10ce3cc919f50c2043b41ca968b43c26a3672600)
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_i_callback(struct rcu_head *head)
72 {
73 	struct inode *inode = container_of(head, struct inode, i_rcu);
74 	kmem_cache_free(minix_inode_cachep, minix_i(inode));
75 }
76 
77 static void minix_destroy_inode(struct inode *inode)
78 {
79 	call_rcu(&inode->i_rcu, minix_i_callback);
80 }
81 
82 static void init_once(void *foo)
83 {
84 	struct minix_inode_info *ei = (struct minix_inode_info *) foo;
85 
86 	inode_init_once(&ei->vfs_inode);
87 }
88 
89 static int init_inodecache(void)
90 {
91 	minix_inode_cachep = kmem_cache_create("minix_inode_cache",
92 					     sizeof(struct minix_inode_info),
93 					     0, (SLAB_RECLAIM_ACCOUNT|
94 						SLAB_MEM_SPREAD),
95 					     init_once);
96 	if (minix_inode_cachep == NULL)
97 		return -ENOMEM;
98 	return 0;
99 }
100 
101 static void destroy_inodecache(void)
102 {
103 	kmem_cache_destroy(minix_inode_cachep);
104 }
105 
106 static const struct super_operations minix_sops = {
107 	.alloc_inode	= minix_alloc_inode,
108 	.destroy_inode	= minix_destroy_inode,
109 	.write_inode	= minix_write_inode,
110 	.evict_inode	= minix_evict_inode,
111 	.put_super	= minix_put_super,
112 	.statfs		= minix_statfs,
113 	.remount_fs	= minix_remount,
114 };
115 
116 static int minix_remount (struct super_block * sb, int * flags, char * data)
117 {
118 	struct minix_sb_info * sbi = minix_sb(sb);
119 	struct minix_super_block * ms;
120 
121 	ms = sbi->s_ms;
122 	if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
123 		return 0;
124 	if (*flags & MS_RDONLY) {
125 		if (ms->s_state & MINIX_VALID_FS ||
126 		    !(sbi->s_mount_state & MINIX_VALID_FS))
127 			return 0;
128 		/* Mounting a rw partition read-only. */
129 		if (sbi->s_version != MINIX_V3)
130 			ms->s_state = sbi->s_mount_state;
131 		mark_buffer_dirty(sbi->s_sbh);
132 	} else {
133 	  	/* Mount a partition which is read-only, read-write. */
134 		if (sbi->s_version != MINIX_V3) {
135 			sbi->s_mount_state = ms->s_state;
136 			ms->s_state &= ~MINIX_VALID_FS;
137 		} else {
138 			sbi->s_mount_state = MINIX_VALID_FS;
139 		}
140 		mark_buffer_dirty(sbi->s_sbh);
141 
142 		if (!(sbi->s_mount_state & MINIX_VALID_FS))
143 			printk("MINIX-fs warning: remounting unchecked fs, "
144 				"running fsck is recommended\n");
145 		else if ((sbi->s_mount_state & MINIX_ERROR_FS))
146 			printk("MINIX-fs warning: remounting fs with errors, "
147 				"running fsck is recommended\n");
148 	}
149 	return 0;
150 }
151 
152 static int minix_fill_super(struct super_block *s, void *data, int silent)
153 {
154 	struct buffer_head *bh;
155 	struct buffer_head **map;
156 	struct minix_super_block *ms;
157 	struct minix3_super_block *m3s = NULL;
158 	unsigned long i, block;
159 	struct inode *root_inode;
160 	struct minix_sb_info *sbi;
161 	int ret = -EINVAL;
162 
163 	sbi = kzalloc(sizeof(struct minix_sb_info), GFP_KERNEL);
164 	if (!sbi)
165 		return -ENOMEM;
166 	s->s_fs_info = sbi;
167 
168 	BUILD_BUG_ON(32 != sizeof (struct minix_inode));
169 	BUILD_BUG_ON(64 != sizeof(struct minix2_inode));
170 
171 	if (!sb_set_blocksize(s, BLOCK_SIZE))
172 		goto out_bad_hblock;
173 
174 	if (!(bh = sb_bread(s, 1)))
175 		goto out_bad_sb;
176 
177 	ms = (struct minix_super_block *) bh->b_data;
178 	sbi->s_ms = ms;
179 	sbi->s_sbh = bh;
180 	sbi->s_mount_state = ms->s_state;
181 	sbi->s_ninodes = ms->s_ninodes;
182 	sbi->s_nzones = ms->s_nzones;
183 	sbi->s_imap_blocks = ms->s_imap_blocks;
184 	sbi->s_zmap_blocks = ms->s_zmap_blocks;
185 	sbi->s_firstdatazone = ms->s_firstdatazone;
186 	sbi->s_log_zone_size = ms->s_log_zone_size;
187 	sbi->s_max_size = ms->s_max_size;
188 	s->s_magic = ms->s_magic;
189 	if (s->s_magic == MINIX_SUPER_MAGIC) {
190 		sbi->s_version = MINIX_V1;
191 		sbi->s_dirsize = 16;
192 		sbi->s_namelen = 14;
193 		sbi->s_link_max = MINIX_LINK_MAX;
194 	} else if (s->s_magic == MINIX_SUPER_MAGIC2) {
195 		sbi->s_version = MINIX_V1;
196 		sbi->s_dirsize = 32;
197 		sbi->s_namelen = 30;
198 		sbi->s_link_max = MINIX_LINK_MAX;
199 	} else if (s->s_magic == MINIX2_SUPER_MAGIC) {
200 		sbi->s_version = MINIX_V2;
201 		sbi->s_nzones = ms->s_zones;
202 		sbi->s_dirsize = 16;
203 		sbi->s_namelen = 14;
204 		sbi->s_link_max = MINIX2_LINK_MAX;
205 	} else if (s->s_magic == MINIX2_SUPER_MAGIC2) {
206 		sbi->s_version = MINIX_V2;
207 		sbi->s_nzones = ms->s_zones;
208 		sbi->s_dirsize = 32;
209 		sbi->s_namelen = 30;
210 		sbi->s_link_max = MINIX2_LINK_MAX;
211 	} else if ( *(__u16 *)(bh->b_data + 24) == MINIX3_SUPER_MAGIC) {
212 		m3s = (struct minix3_super_block *) bh->b_data;
213 		s->s_magic = m3s->s_magic;
214 		sbi->s_imap_blocks = m3s->s_imap_blocks;
215 		sbi->s_zmap_blocks = m3s->s_zmap_blocks;
216 		sbi->s_firstdatazone = m3s->s_firstdatazone;
217 		sbi->s_log_zone_size = m3s->s_log_zone_size;
218 		sbi->s_max_size = m3s->s_max_size;
219 		sbi->s_ninodes = m3s->s_ninodes;
220 		sbi->s_nzones = m3s->s_zones;
221 		sbi->s_dirsize = 64;
222 		sbi->s_namelen = 60;
223 		sbi->s_version = MINIX_V3;
224 		sbi->s_link_max = MINIX2_LINK_MAX;
225 		sbi->s_mount_state = MINIX_VALID_FS;
226 		sb_set_blocksize(s, m3s->s_blocksize);
227 	} else
228 		goto out_no_fs;
229 
230 	/*
231 	 * Allocate the buffer map to keep the superblock small.
232 	 */
233 	if (sbi->s_imap_blocks == 0 || sbi->s_zmap_blocks == 0)
234 		goto out_illegal_sb;
235 	i = (sbi->s_imap_blocks + sbi->s_zmap_blocks) * sizeof(bh);
236 	map = kzalloc(i, GFP_KERNEL);
237 	if (!map)
238 		goto out_no_map;
239 	sbi->s_imap = &map[0];
240 	sbi->s_zmap = &map[sbi->s_imap_blocks];
241 
242 	block=2;
243 	for (i=0 ; i < sbi->s_imap_blocks ; i++) {
244 		if (!(sbi->s_imap[i]=sb_bread(s, block)))
245 			goto out_no_bitmap;
246 		block++;
247 	}
248 	for (i=0 ; i < sbi->s_zmap_blocks ; i++) {
249 		if (!(sbi->s_zmap[i]=sb_bread(s, block)))
250 			goto out_no_bitmap;
251 		block++;
252 	}
253 
254 	minix_set_bit(0,sbi->s_imap[0]->b_data);
255 	minix_set_bit(0,sbi->s_zmap[0]->b_data);
256 
257 	/* set up enough so that it can read an inode */
258 	s->s_op = &minix_sops;
259 	root_inode = minix_iget(s, MINIX_ROOT_INO);
260 	if (IS_ERR(root_inode)) {
261 		ret = PTR_ERR(root_inode);
262 		goto out_no_root;
263 	}
264 
265 	/* Apparently minix can create filesystems that allocate more blocks for
266 	 * the bitmaps than needed.  We simply ignore that, but verify it didn't
267 	 * create one with not enough blocks and bail out if so.
268 	 */
269 	block = minix_blocks_needed(sbi->s_ninodes, s->s_blocksize);
270 	if (sbi->s_imap_blocks < block) {
271 		printk("MINIX-fs: file system does not have enough "
272 				"imap blocks allocated.  Refusing to mount\n");
273 		goto out_iput;
274 	}
275 
276 	block = minix_blocks_needed(
277 			(sbi->s_nzones - (sbi->s_firstdatazone + 1)),
278 			s->s_blocksize);
279 	if (sbi->s_zmap_blocks < block) {
280 		printk("MINIX-fs: file system does not have enough "
281 				"zmap blocks allocated.  Refusing to mount.\n");
282 		goto out_iput;
283 	}
284 
285 	ret = -ENOMEM;
286 	s->s_root = d_alloc_root(root_inode);
287 	if (!s->s_root)
288 		goto out_iput;
289 
290 	if (!(s->s_flags & MS_RDONLY)) {
291 		if (sbi->s_version != MINIX_V3) /* s_state is now out from V3 sb */
292 			ms->s_state &= ~MINIX_VALID_FS;
293 		mark_buffer_dirty(bh);
294 	}
295 	if (!(sbi->s_mount_state & MINIX_VALID_FS))
296 		printk("MINIX-fs: mounting unchecked file system, "
297 			"running fsck is recommended\n");
298 	else if (sbi->s_mount_state & MINIX_ERROR_FS)
299 		printk("MINIX-fs: mounting file system with errors, "
300 			"running fsck is recommended\n");
301 
302 	return 0;
303 
304 out_iput:
305 	iput(root_inode);
306 	goto out_freemap;
307 
308 out_no_root:
309 	if (!silent)
310 		printk("MINIX-fs: get root inode failed\n");
311 	goto out_freemap;
312 
313 out_no_bitmap:
314 	printk("MINIX-fs: bad superblock or unable to read bitmaps\n");
315 out_freemap:
316 	for (i = 0; i < sbi->s_imap_blocks; i++)
317 		brelse(sbi->s_imap[i]);
318 	for (i = 0; i < sbi->s_zmap_blocks; i++)
319 		brelse(sbi->s_zmap[i]);
320 	kfree(sbi->s_imap);
321 	goto out_release;
322 
323 out_no_map:
324 	ret = -ENOMEM;
325 	if (!silent)
326 		printk("MINIX-fs: can't allocate map\n");
327 	goto out_release;
328 
329 out_illegal_sb:
330 	if (!silent)
331 		printk("MINIX-fs: bad superblock\n");
332 	goto out_release;
333 
334 out_no_fs:
335 	if (!silent)
336 		printk("VFS: Can't find a Minix filesystem V1 | V2 | V3 "
337 		       "on device %s.\n", s->s_id);
338 out_release:
339 	brelse(bh);
340 	goto out;
341 
342 out_bad_hblock:
343 	printk("MINIX-fs: blocksize too small for device\n");
344 	goto out;
345 
346 out_bad_sb:
347 	printk("MINIX-fs: unable to read superblock\n");
348 out:
349 	s->s_fs_info = NULL;
350 	kfree(sbi);
351 	return ret;
352 }
353 
354 static int minix_statfs(struct dentry *dentry, struct kstatfs *buf)
355 {
356 	struct super_block *sb = dentry->d_sb;
357 	struct minix_sb_info *sbi = minix_sb(sb);
358 	u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
359 	buf->f_type = sb->s_magic;
360 	buf->f_bsize = sb->s_blocksize;
361 	buf->f_blocks = (sbi->s_nzones - sbi->s_firstdatazone) << sbi->s_log_zone_size;
362 	buf->f_bfree = minix_count_free_blocks(sb);
363 	buf->f_bavail = buf->f_bfree;
364 	buf->f_files = sbi->s_ninodes;
365 	buf->f_ffree = minix_count_free_inodes(sb);
366 	buf->f_namelen = sbi->s_namelen;
367 	buf->f_fsid.val[0] = (u32)id;
368 	buf->f_fsid.val[1] = (u32)(id >> 32);
369 
370 	return 0;
371 }
372 
373 static int minix_get_block(struct inode *inode, sector_t block,
374 		    struct buffer_head *bh_result, int create)
375 {
376 	if (INODE_VERSION(inode) == MINIX_V1)
377 		return V1_minix_get_block(inode, block, bh_result, create);
378 	else
379 		return V2_minix_get_block(inode, block, bh_result, create);
380 }
381 
382 static int minix_writepage(struct page *page, struct writeback_control *wbc)
383 {
384 	return block_write_full_page(page, minix_get_block, wbc);
385 }
386 
387 static int minix_readpage(struct file *file, struct page *page)
388 {
389 	return block_read_full_page(page,minix_get_block);
390 }
391 
392 int minix_prepare_chunk(struct page *page, loff_t pos, unsigned len)
393 {
394 	return __block_write_begin(page, pos, len, minix_get_block);
395 }
396 
397 static int minix_write_begin(struct file *file, struct address_space *mapping,
398 			loff_t pos, unsigned len, unsigned flags,
399 			struct page **pagep, void **fsdata)
400 {
401 	int ret;
402 
403 	ret = block_write_begin(mapping, pos, len, flags, pagep,
404 				minix_get_block);
405 	if (unlikely(ret)) {
406 		loff_t isize = mapping->host->i_size;
407 		if (pos + len > isize)
408 			vmtruncate(mapping->host, isize);
409 	}
410 
411 	return ret;
412 }
413 
414 static sector_t minix_bmap(struct address_space *mapping, sector_t block)
415 {
416 	return generic_block_bmap(mapping,block,minix_get_block);
417 }
418 
419 static const struct address_space_operations minix_aops = {
420 	.readpage = minix_readpage,
421 	.writepage = minix_writepage,
422 	.write_begin = minix_write_begin,
423 	.write_end = generic_write_end,
424 	.bmap = minix_bmap
425 };
426 
427 static const struct inode_operations minix_symlink_inode_operations = {
428 	.readlink	= generic_readlink,
429 	.follow_link	= page_follow_link_light,
430 	.put_link	= page_put_link,
431 	.getattr	= minix_getattr,
432 };
433 
434 void minix_set_inode(struct inode *inode, dev_t rdev)
435 {
436 	if (S_ISREG(inode->i_mode)) {
437 		inode->i_op = &minix_file_inode_operations;
438 		inode->i_fop = &minix_file_operations;
439 		inode->i_mapping->a_ops = &minix_aops;
440 	} else if (S_ISDIR(inode->i_mode)) {
441 		inode->i_op = &minix_dir_inode_operations;
442 		inode->i_fop = &minix_dir_operations;
443 		inode->i_mapping->a_ops = &minix_aops;
444 	} else if (S_ISLNK(inode->i_mode)) {
445 		inode->i_op = &minix_symlink_inode_operations;
446 		inode->i_mapping->a_ops = &minix_aops;
447 	} else
448 		init_special_inode(inode, inode->i_mode, rdev);
449 }
450 
451 /*
452  * The minix V1 function to read an inode.
453  */
454 static struct inode *V1_minix_iget(struct inode *inode)
455 {
456 	struct buffer_head * bh;
457 	struct minix_inode * raw_inode;
458 	struct minix_inode_info *minix_inode = minix_i(inode);
459 	int i;
460 
461 	raw_inode = minix_V1_raw_inode(inode->i_sb, inode->i_ino, &bh);
462 	if (!raw_inode) {
463 		iget_failed(inode);
464 		return ERR_PTR(-EIO);
465 	}
466 	inode->i_mode = raw_inode->i_mode;
467 	inode->i_uid = (uid_t)raw_inode->i_uid;
468 	inode->i_gid = (gid_t)raw_inode->i_gid;
469 	set_nlink(inode, raw_inode->i_nlinks);
470 	inode->i_size = raw_inode->i_size;
471 	inode->i_mtime.tv_sec = inode->i_atime.tv_sec = inode->i_ctime.tv_sec = raw_inode->i_time;
472 	inode->i_mtime.tv_nsec = 0;
473 	inode->i_atime.tv_nsec = 0;
474 	inode->i_ctime.tv_nsec = 0;
475 	inode->i_blocks = 0;
476 	for (i = 0; i < 9; i++)
477 		minix_inode->u.i1_data[i] = raw_inode->i_zone[i];
478 	minix_set_inode(inode, old_decode_dev(raw_inode->i_zone[0]));
479 	brelse(bh);
480 	unlock_new_inode(inode);
481 	return inode;
482 }
483 
484 /*
485  * The minix V2 function to read an inode.
486  */
487 static struct inode *V2_minix_iget(struct inode *inode)
488 {
489 	struct buffer_head * bh;
490 	struct minix2_inode * raw_inode;
491 	struct minix_inode_info *minix_inode = minix_i(inode);
492 	int i;
493 
494 	raw_inode = minix_V2_raw_inode(inode->i_sb, inode->i_ino, &bh);
495 	if (!raw_inode) {
496 		iget_failed(inode);
497 		return ERR_PTR(-EIO);
498 	}
499 	inode->i_mode = raw_inode->i_mode;
500 	inode->i_uid = (uid_t)raw_inode->i_uid;
501 	inode->i_gid = (gid_t)raw_inode->i_gid;
502 	set_nlink(inode, raw_inode->i_nlinks);
503 	inode->i_size = raw_inode->i_size;
504 	inode->i_mtime.tv_sec = raw_inode->i_mtime;
505 	inode->i_atime.tv_sec = raw_inode->i_atime;
506 	inode->i_ctime.tv_sec = raw_inode->i_ctime;
507 	inode->i_mtime.tv_nsec = 0;
508 	inode->i_atime.tv_nsec = 0;
509 	inode->i_ctime.tv_nsec = 0;
510 	inode->i_blocks = 0;
511 	for (i = 0; i < 10; i++)
512 		minix_inode->u.i2_data[i] = raw_inode->i_zone[i];
513 	minix_set_inode(inode, old_decode_dev(raw_inode->i_zone[0]));
514 	brelse(bh);
515 	unlock_new_inode(inode);
516 	return inode;
517 }
518 
519 /*
520  * The global function to read an inode.
521  */
522 struct inode *minix_iget(struct super_block *sb, unsigned long ino)
523 {
524 	struct inode *inode;
525 
526 	inode = iget_locked(sb, ino);
527 	if (!inode)
528 		return ERR_PTR(-ENOMEM);
529 	if (!(inode->i_state & I_NEW))
530 		return inode;
531 
532 	if (INODE_VERSION(inode) == MINIX_V1)
533 		return V1_minix_iget(inode);
534 	else
535 		return V2_minix_iget(inode);
536 }
537 
538 /*
539  * The minix V1 function to synchronize an inode.
540  */
541 static struct buffer_head * V1_minix_update_inode(struct inode * inode)
542 {
543 	struct buffer_head * bh;
544 	struct minix_inode * raw_inode;
545 	struct minix_inode_info *minix_inode = minix_i(inode);
546 	int i;
547 
548 	raw_inode = minix_V1_raw_inode(inode->i_sb, inode->i_ino, &bh);
549 	if (!raw_inode)
550 		return NULL;
551 	raw_inode->i_mode = inode->i_mode;
552 	raw_inode->i_uid = fs_high2lowuid(inode->i_uid);
553 	raw_inode->i_gid = fs_high2lowgid(inode->i_gid);
554 	raw_inode->i_nlinks = inode->i_nlink;
555 	raw_inode->i_size = inode->i_size;
556 	raw_inode->i_time = inode->i_mtime.tv_sec;
557 	if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode))
558 		raw_inode->i_zone[0] = old_encode_dev(inode->i_rdev);
559 	else for (i = 0; i < 9; i++)
560 		raw_inode->i_zone[i] = minix_inode->u.i1_data[i];
561 	mark_buffer_dirty(bh);
562 	return bh;
563 }
564 
565 /*
566  * The minix V2 function to synchronize an inode.
567  */
568 static struct buffer_head * V2_minix_update_inode(struct inode * inode)
569 {
570 	struct buffer_head * bh;
571 	struct minix2_inode * raw_inode;
572 	struct minix_inode_info *minix_inode = minix_i(inode);
573 	int i;
574 
575 	raw_inode = minix_V2_raw_inode(inode->i_sb, inode->i_ino, &bh);
576 	if (!raw_inode)
577 		return NULL;
578 	raw_inode->i_mode = inode->i_mode;
579 	raw_inode->i_uid = fs_high2lowuid(inode->i_uid);
580 	raw_inode->i_gid = fs_high2lowgid(inode->i_gid);
581 	raw_inode->i_nlinks = inode->i_nlink;
582 	raw_inode->i_size = inode->i_size;
583 	raw_inode->i_mtime = inode->i_mtime.tv_sec;
584 	raw_inode->i_atime = inode->i_atime.tv_sec;
585 	raw_inode->i_ctime = inode->i_ctime.tv_sec;
586 	if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode))
587 		raw_inode->i_zone[0] = old_encode_dev(inode->i_rdev);
588 	else for (i = 0; i < 10; i++)
589 		raw_inode->i_zone[i] = minix_inode->u.i2_data[i];
590 	mark_buffer_dirty(bh);
591 	return bh;
592 }
593 
594 static int minix_write_inode(struct inode *inode, struct writeback_control *wbc)
595 {
596 	int err = 0;
597 	struct buffer_head *bh;
598 
599 	if (INODE_VERSION(inode) == MINIX_V1)
600 		bh = V1_minix_update_inode(inode);
601 	else
602 		bh = V2_minix_update_inode(inode);
603 	if (!bh)
604 		return -EIO;
605 	if (wbc->sync_mode == WB_SYNC_ALL && buffer_dirty(bh)) {
606 		sync_dirty_buffer(bh);
607 		if (buffer_req(bh) && !buffer_uptodate(bh)) {
608 			printk("IO error syncing minix inode [%s:%08lx]\n",
609 				inode->i_sb->s_id, inode->i_ino);
610 			err = -EIO;
611 		}
612 	}
613 	brelse (bh);
614 	return err;
615 }
616 
617 int minix_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
618 {
619 	struct super_block *sb = dentry->d_sb;
620 	generic_fillattr(dentry->d_inode, stat);
621 	if (INODE_VERSION(dentry->d_inode) == MINIX_V1)
622 		stat->blocks = (BLOCK_SIZE / 512) * V1_minix_blocks(stat->size, sb);
623 	else
624 		stat->blocks = (sb->s_blocksize / 512) * V2_minix_blocks(stat->size, sb);
625 	stat->blksize = sb->s_blocksize;
626 	return 0;
627 }
628 
629 /*
630  * The function that is called for file truncation.
631  */
632 void minix_truncate(struct inode * inode)
633 {
634 	if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode)))
635 		return;
636 	if (INODE_VERSION(inode) == MINIX_V1)
637 		V1_minix_truncate(inode);
638 	else
639 		V2_minix_truncate(inode);
640 }
641 
642 static struct dentry *minix_mount(struct file_system_type *fs_type,
643 	int flags, const char *dev_name, void *data)
644 {
645 	return mount_bdev(fs_type, flags, dev_name, data, minix_fill_super);
646 }
647 
648 static struct file_system_type minix_fs_type = {
649 	.owner		= THIS_MODULE,
650 	.name		= "minix",
651 	.mount		= minix_mount,
652 	.kill_sb	= kill_block_super,
653 	.fs_flags	= FS_REQUIRES_DEV,
654 };
655 
656 static int __init init_minix_fs(void)
657 {
658 	int err = init_inodecache();
659 	if (err)
660 		goto out1;
661 	err = register_filesystem(&minix_fs_type);
662 	if (err)
663 		goto out;
664 	return 0;
665 out:
666 	destroy_inodecache();
667 out1:
668 	return err;
669 }
670 
671 static void __exit exit_minix_fs(void)
672 {
673         unregister_filesystem(&minix_fs_type);
674 	destroy_inodecache();
675 }
676 
677 module_init(init_minix_fs)
678 module_exit(exit_minix_fs)
679 MODULE_LICENSE("GPL");
680 
681