xref: /openbmc/linux/fs/minix/inode.c (revision 8b235f2f)
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_final(&inode->i_data);
30 	if (!inode->i_nlink) {
31 		inode->i_size = 0;
32 		minix_truncate(inode);
33 	}
34 	invalidate_inode_buffers(inode);
35 	clear_inode(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 = 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 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 	/*
104 	 * Make sure all delayed rcu free inodes are flushed before we
105 	 * destroy cache.
106 	 */
107 	rcu_barrier();
108 	kmem_cache_destroy(minix_inode_cachep);
109 }
110 
111 static const struct super_operations minix_sops = {
112 	.alloc_inode	= minix_alloc_inode,
113 	.destroy_inode	= minix_destroy_inode,
114 	.write_inode	= minix_write_inode,
115 	.evict_inode	= minix_evict_inode,
116 	.put_super	= minix_put_super,
117 	.statfs		= minix_statfs,
118 	.remount_fs	= minix_remount,
119 };
120 
121 static int minix_remount (struct super_block * sb, int * flags, char * data)
122 {
123 	struct minix_sb_info * sbi = minix_sb(sb);
124 	struct minix_super_block * ms;
125 
126 	sync_filesystem(sb);
127 	ms = sbi->s_ms;
128 	if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
129 		return 0;
130 	if (*flags & MS_RDONLY) {
131 		if (ms->s_state & MINIX_VALID_FS ||
132 		    !(sbi->s_mount_state & MINIX_VALID_FS))
133 			return 0;
134 		/* Mounting a rw partition read-only. */
135 		if (sbi->s_version != MINIX_V3)
136 			ms->s_state = sbi->s_mount_state;
137 		mark_buffer_dirty(sbi->s_sbh);
138 	} else {
139 	  	/* Mount a partition which is read-only, read-write. */
140 		if (sbi->s_version != MINIX_V3) {
141 			sbi->s_mount_state = ms->s_state;
142 			ms->s_state &= ~MINIX_VALID_FS;
143 		} else {
144 			sbi->s_mount_state = MINIX_VALID_FS;
145 		}
146 		mark_buffer_dirty(sbi->s_sbh);
147 
148 		if (!(sbi->s_mount_state & MINIX_VALID_FS))
149 			printk("MINIX-fs warning: remounting unchecked fs, "
150 				"running fsck is recommended\n");
151 		else if ((sbi->s_mount_state & MINIX_ERROR_FS))
152 			printk("MINIX-fs warning: remounting fs with errors, "
153 				"running fsck is recommended\n");
154 	}
155 	return 0;
156 }
157 
158 static int minix_fill_super(struct super_block *s, void *data, int silent)
159 {
160 	struct buffer_head *bh;
161 	struct buffer_head **map;
162 	struct minix_super_block *ms;
163 	struct minix3_super_block *m3s = NULL;
164 	unsigned long i, block;
165 	struct inode *root_inode;
166 	struct minix_sb_info *sbi;
167 	int ret = -EINVAL;
168 
169 	sbi = kzalloc(sizeof(struct minix_sb_info), GFP_KERNEL);
170 	if (!sbi)
171 		return -ENOMEM;
172 	s->s_fs_info = sbi;
173 
174 	BUILD_BUG_ON(32 != sizeof (struct minix_inode));
175 	BUILD_BUG_ON(64 != sizeof(struct minix2_inode));
176 
177 	if (!sb_set_blocksize(s, BLOCK_SIZE))
178 		goto out_bad_hblock;
179 
180 	if (!(bh = sb_bread(s, 1)))
181 		goto out_bad_sb;
182 
183 	ms = (struct minix_super_block *) bh->b_data;
184 	sbi->s_ms = ms;
185 	sbi->s_sbh = bh;
186 	sbi->s_mount_state = ms->s_state;
187 	sbi->s_ninodes = ms->s_ninodes;
188 	sbi->s_nzones = ms->s_nzones;
189 	sbi->s_imap_blocks = ms->s_imap_blocks;
190 	sbi->s_zmap_blocks = ms->s_zmap_blocks;
191 	sbi->s_firstdatazone = ms->s_firstdatazone;
192 	sbi->s_log_zone_size = ms->s_log_zone_size;
193 	sbi->s_max_size = ms->s_max_size;
194 	s->s_magic = ms->s_magic;
195 	if (s->s_magic == MINIX_SUPER_MAGIC) {
196 		sbi->s_version = MINIX_V1;
197 		sbi->s_dirsize = 16;
198 		sbi->s_namelen = 14;
199 		s->s_max_links = MINIX_LINK_MAX;
200 	} else if (s->s_magic == MINIX_SUPER_MAGIC2) {
201 		sbi->s_version = MINIX_V1;
202 		sbi->s_dirsize = 32;
203 		sbi->s_namelen = 30;
204 		s->s_max_links = MINIX_LINK_MAX;
205 	} else if (s->s_magic == MINIX2_SUPER_MAGIC) {
206 		sbi->s_version = MINIX_V2;
207 		sbi->s_nzones = ms->s_zones;
208 		sbi->s_dirsize = 16;
209 		sbi->s_namelen = 14;
210 		s->s_max_links = MINIX2_LINK_MAX;
211 	} else if (s->s_magic == MINIX2_SUPER_MAGIC2) {
212 		sbi->s_version = MINIX_V2;
213 		sbi->s_nzones = ms->s_zones;
214 		sbi->s_dirsize = 32;
215 		sbi->s_namelen = 30;
216 		s->s_max_links = MINIX2_LINK_MAX;
217 	} else if ( *(__u16 *)(bh->b_data + 24) == MINIX3_SUPER_MAGIC) {
218 		m3s = (struct minix3_super_block *) bh->b_data;
219 		s->s_magic = m3s->s_magic;
220 		sbi->s_imap_blocks = m3s->s_imap_blocks;
221 		sbi->s_zmap_blocks = m3s->s_zmap_blocks;
222 		sbi->s_firstdatazone = m3s->s_firstdatazone;
223 		sbi->s_log_zone_size = m3s->s_log_zone_size;
224 		sbi->s_max_size = m3s->s_max_size;
225 		sbi->s_ninodes = m3s->s_ninodes;
226 		sbi->s_nzones = m3s->s_zones;
227 		sbi->s_dirsize = 64;
228 		sbi->s_namelen = 60;
229 		sbi->s_version = MINIX_V3;
230 		sbi->s_mount_state = MINIX_VALID_FS;
231 		sb_set_blocksize(s, m3s->s_blocksize);
232 		s->s_max_links = MINIX2_LINK_MAX;
233 	} else
234 		goto out_no_fs;
235 
236 	/*
237 	 * Allocate the buffer map to keep the superblock small.
238 	 */
239 	if (sbi->s_imap_blocks == 0 || sbi->s_zmap_blocks == 0)
240 		goto out_illegal_sb;
241 	i = (sbi->s_imap_blocks + sbi->s_zmap_blocks) * sizeof(bh);
242 	map = kzalloc(i, GFP_KERNEL);
243 	if (!map)
244 		goto out_no_map;
245 	sbi->s_imap = &map[0];
246 	sbi->s_zmap = &map[sbi->s_imap_blocks];
247 
248 	block=2;
249 	for (i=0 ; i < sbi->s_imap_blocks ; i++) {
250 		if (!(sbi->s_imap[i]=sb_bread(s, block)))
251 			goto out_no_bitmap;
252 		block++;
253 	}
254 	for (i=0 ; i < sbi->s_zmap_blocks ; i++) {
255 		if (!(sbi->s_zmap[i]=sb_bread(s, block)))
256 			goto out_no_bitmap;
257 		block++;
258 	}
259 
260 	minix_set_bit(0,sbi->s_imap[0]->b_data);
261 	minix_set_bit(0,sbi->s_zmap[0]->b_data);
262 
263 	/* Apparently minix can create filesystems that allocate more blocks for
264 	 * the bitmaps than needed.  We simply ignore that, but verify it didn't
265 	 * create one with not enough blocks and bail out if so.
266 	 */
267 	block = minix_blocks_needed(sbi->s_ninodes, s->s_blocksize);
268 	if (sbi->s_imap_blocks < block) {
269 		printk("MINIX-fs: file system does not have enough "
270 				"imap blocks allocated.  Refusing to mount.\n");
271 		goto out_no_bitmap;
272 	}
273 
274 	block = minix_blocks_needed(
275 			(sbi->s_nzones - sbi->s_firstdatazone + 1),
276 			s->s_blocksize);
277 	if (sbi->s_zmap_blocks < block) {
278 		printk("MINIX-fs: file system does not have enough "
279 				"zmap blocks allocated.  Refusing to mount.\n");
280 		goto out_no_bitmap;
281 	}
282 
283 	/* set up enough so that it can read an inode */
284 	s->s_op = &minix_sops;
285 	root_inode = minix_iget(s, MINIX_ROOT_INO);
286 	if (IS_ERR(root_inode)) {
287 		ret = PTR_ERR(root_inode);
288 		goto out_no_root;
289 	}
290 
291 	ret = -ENOMEM;
292 	s->s_root = d_make_root(root_inode);
293 	if (!s->s_root)
294 		goto out_no_root;
295 
296 	if (!(s->s_flags & MS_RDONLY)) {
297 		if (sbi->s_version != MINIX_V3) /* s_state is now out from V3 sb */
298 			ms->s_state &= ~MINIX_VALID_FS;
299 		mark_buffer_dirty(bh);
300 	}
301 	if (!(sbi->s_mount_state & MINIX_VALID_FS))
302 		printk("MINIX-fs: mounting unchecked file system, "
303 			"running fsck is recommended\n");
304 	else if (sbi->s_mount_state & MINIX_ERROR_FS)
305 		printk("MINIX-fs: mounting file system with errors, "
306 			"running fsck is recommended\n");
307 
308 	return 0;
309 
310 out_no_root:
311 	if (!silent)
312 		printk("MINIX-fs: get root inode failed\n");
313 	goto out_freemap;
314 
315 out_no_bitmap:
316 	printk("MINIX-fs: bad superblock or unable to read bitmaps\n");
317 out_freemap:
318 	for (i = 0; i < sbi->s_imap_blocks; i++)
319 		brelse(sbi->s_imap[i]);
320 	for (i = 0; i < sbi->s_zmap_blocks; i++)
321 		brelse(sbi->s_zmap[i]);
322 	kfree(sbi->s_imap);
323 	goto out_release;
324 
325 out_no_map:
326 	ret = -ENOMEM;
327 	if (!silent)
328 		printk("MINIX-fs: can't allocate map\n");
329 	goto out_release;
330 
331 out_illegal_sb:
332 	if (!silent)
333 		printk("MINIX-fs: bad superblock\n");
334 	goto out_release;
335 
336 out_no_fs:
337 	if (!silent)
338 		printk("VFS: Can't find a Minix filesystem V1 | V2 | V3 "
339 		       "on device %s.\n", s->s_id);
340 out_release:
341 	brelse(bh);
342 	goto out;
343 
344 out_bad_hblock:
345 	printk("MINIX-fs: blocksize too small for device\n");
346 	goto out;
347 
348 out_bad_sb:
349 	printk("MINIX-fs: unable to read superblock\n");
350 out:
351 	s->s_fs_info = NULL;
352 	kfree(sbi);
353 	return ret;
354 }
355 
356 static int minix_statfs(struct dentry *dentry, struct kstatfs *buf)
357 {
358 	struct super_block *sb = dentry->d_sb;
359 	struct minix_sb_info *sbi = minix_sb(sb);
360 	u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
361 	buf->f_type = sb->s_magic;
362 	buf->f_bsize = sb->s_blocksize;
363 	buf->f_blocks = (sbi->s_nzones - sbi->s_firstdatazone) << sbi->s_log_zone_size;
364 	buf->f_bfree = minix_count_free_blocks(sb);
365 	buf->f_bavail = buf->f_bfree;
366 	buf->f_files = sbi->s_ninodes;
367 	buf->f_ffree = minix_count_free_inodes(sb);
368 	buf->f_namelen = sbi->s_namelen;
369 	buf->f_fsid.val[0] = (u32)id;
370 	buf->f_fsid.val[1] = (u32)(id >> 32);
371 
372 	return 0;
373 }
374 
375 static int minix_get_block(struct inode *inode, sector_t block,
376 		    struct buffer_head *bh_result, int create)
377 {
378 	if (INODE_VERSION(inode) == MINIX_V1)
379 		return V1_minix_get_block(inode, block, bh_result, create);
380 	else
381 		return V2_minix_get_block(inode, block, bh_result, create);
382 }
383 
384 static int minix_writepage(struct page *page, struct writeback_control *wbc)
385 {
386 	return block_write_full_page(page, minix_get_block, wbc);
387 }
388 
389 static int minix_readpage(struct file *file, struct page *page)
390 {
391 	return block_read_full_page(page,minix_get_block);
392 }
393 
394 int minix_prepare_chunk(struct page *page, loff_t pos, unsigned len)
395 {
396 	return __block_write_begin(page, pos, len, minix_get_block);
397 }
398 
399 static void minix_write_failed(struct address_space *mapping, loff_t to)
400 {
401 	struct inode *inode = mapping->host;
402 
403 	if (to > inode->i_size) {
404 		truncate_pagecache(inode, inode->i_size);
405 		minix_truncate(inode);
406 	}
407 }
408 
409 static int minix_write_begin(struct file *file, struct address_space *mapping,
410 			loff_t pos, unsigned len, unsigned flags,
411 			struct page **pagep, void **fsdata)
412 {
413 	int ret;
414 
415 	ret = block_write_begin(mapping, pos, len, flags, pagep,
416 				minix_get_block);
417 	if (unlikely(ret))
418 		minix_write_failed(mapping, pos + len);
419 
420 	return ret;
421 }
422 
423 static sector_t minix_bmap(struct address_space *mapping, sector_t block)
424 {
425 	return generic_block_bmap(mapping,block,minix_get_block);
426 }
427 
428 static const struct address_space_operations minix_aops = {
429 	.readpage = minix_readpage,
430 	.writepage = minix_writepage,
431 	.write_begin = minix_write_begin,
432 	.write_end = generic_write_end,
433 	.bmap = minix_bmap
434 };
435 
436 static const struct inode_operations minix_symlink_inode_operations = {
437 	.readlink	= generic_readlink,
438 	.follow_link	= page_follow_link_light,
439 	.put_link	= page_put_link,
440 	.getattr	= minix_getattr,
441 };
442 
443 void minix_set_inode(struct inode *inode, dev_t rdev)
444 {
445 	if (S_ISREG(inode->i_mode)) {
446 		inode->i_op = &minix_file_inode_operations;
447 		inode->i_fop = &minix_file_operations;
448 		inode->i_mapping->a_ops = &minix_aops;
449 	} else if (S_ISDIR(inode->i_mode)) {
450 		inode->i_op = &minix_dir_inode_operations;
451 		inode->i_fop = &minix_dir_operations;
452 		inode->i_mapping->a_ops = &minix_aops;
453 	} else if (S_ISLNK(inode->i_mode)) {
454 		inode->i_op = &minix_symlink_inode_operations;
455 		inode->i_mapping->a_ops = &minix_aops;
456 	} else
457 		init_special_inode(inode, inode->i_mode, rdev);
458 }
459 
460 /*
461  * The minix V1 function to read an inode.
462  */
463 static struct inode *V1_minix_iget(struct inode *inode)
464 {
465 	struct buffer_head * bh;
466 	struct minix_inode * raw_inode;
467 	struct minix_inode_info *minix_inode = minix_i(inode);
468 	int i;
469 
470 	raw_inode = minix_V1_raw_inode(inode->i_sb, inode->i_ino, &bh);
471 	if (!raw_inode) {
472 		iget_failed(inode);
473 		return ERR_PTR(-EIO);
474 	}
475 	inode->i_mode = raw_inode->i_mode;
476 	i_uid_write(inode, raw_inode->i_uid);
477 	i_gid_write(inode, raw_inode->i_gid);
478 	set_nlink(inode, raw_inode->i_nlinks);
479 	inode->i_size = raw_inode->i_size;
480 	inode->i_mtime.tv_sec = inode->i_atime.tv_sec = inode->i_ctime.tv_sec = raw_inode->i_time;
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 < 9; i++)
486 		minix_inode->u.i1_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 minix V2 function to read an inode.
495  */
496 static struct inode *V2_minix_iget(struct inode *inode)
497 {
498 	struct buffer_head * bh;
499 	struct minix2_inode * raw_inode;
500 	struct minix_inode_info *minix_inode = minix_i(inode);
501 	int i;
502 
503 	raw_inode = minix_V2_raw_inode(inode->i_sb, inode->i_ino, &bh);
504 	if (!raw_inode) {
505 		iget_failed(inode);
506 		return ERR_PTR(-EIO);
507 	}
508 	inode->i_mode = raw_inode->i_mode;
509 	i_uid_write(inode, raw_inode->i_uid);
510 	i_gid_write(inode, raw_inode->i_gid);
511 	set_nlink(inode, raw_inode->i_nlinks);
512 	inode->i_size = raw_inode->i_size;
513 	inode->i_mtime.tv_sec = raw_inode->i_mtime;
514 	inode->i_atime.tv_sec = raw_inode->i_atime;
515 	inode->i_ctime.tv_sec = raw_inode->i_ctime;
516 	inode->i_mtime.tv_nsec = 0;
517 	inode->i_atime.tv_nsec = 0;
518 	inode->i_ctime.tv_nsec = 0;
519 	inode->i_blocks = 0;
520 	for (i = 0; i < 10; i++)
521 		minix_inode->u.i2_data[i] = raw_inode->i_zone[i];
522 	minix_set_inode(inode, old_decode_dev(raw_inode->i_zone[0]));
523 	brelse(bh);
524 	unlock_new_inode(inode);
525 	return inode;
526 }
527 
528 /*
529  * The global function to read an inode.
530  */
531 struct inode *minix_iget(struct super_block *sb, unsigned long ino)
532 {
533 	struct inode *inode;
534 
535 	inode = iget_locked(sb, ino);
536 	if (!inode)
537 		return ERR_PTR(-ENOMEM);
538 	if (!(inode->i_state & I_NEW))
539 		return inode;
540 
541 	if (INODE_VERSION(inode) == MINIX_V1)
542 		return V1_minix_iget(inode);
543 	else
544 		return V2_minix_iget(inode);
545 }
546 
547 /*
548  * The minix V1 function to synchronize an inode.
549  */
550 static struct buffer_head * V1_minix_update_inode(struct inode * inode)
551 {
552 	struct buffer_head * bh;
553 	struct minix_inode * raw_inode;
554 	struct minix_inode_info *minix_inode = minix_i(inode);
555 	int i;
556 
557 	raw_inode = minix_V1_raw_inode(inode->i_sb, inode->i_ino, &bh);
558 	if (!raw_inode)
559 		return NULL;
560 	raw_inode->i_mode = inode->i_mode;
561 	raw_inode->i_uid = fs_high2lowuid(i_uid_read(inode));
562 	raw_inode->i_gid = fs_high2lowgid(i_gid_read(inode));
563 	raw_inode->i_nlinks = inode->i_nlink;
564 	raw_inode->i_size = inode->i_size;
565 	raw_inode->i_time = inode->i_mtime.tv_sec;
566 	if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode))
567 		raw_inode->i_zone[0] = old_encode_dev(inode->i_rdev);
568 	else for (i = 0; i < 9; i++)
569 		raw_inode->i_zone[i] = minix_inode->u.i1_data[i];
570 	mark_buffer_dirty(bh);
571 	return bh;
572 }
573 
574 /*
575  * The minix V2 function to synchronize an inode.
576  */
577 static struct buffer_head * V2_minix_update_inode(struct inode * inode)
578 {
579 	struct buffer_head * bh;
580 	struct minix2_inode * raw_inode;
581 	struct minix_inode_info *minix_inode = minix_i(inode);
582 	int i;
583 
584 	raw_inode = minix_V2_raw_inode(inode->i_sb, inode->i_ino, &bh);
585 	if (!raw_inode)
586 		return NULL;
587 	raw_inode->i_mode = inode->i_mode;
588 	raw_inode->i_uid = fs_high2lowuid(i_uid_read(inode));
589 	raw_inode->i_gid = fs_high2lowgid(i_gid_read(inode));
590 	raw_inode->i_nlinks = inode->i_nlink;
591 	raw_inode->i_size = inode->i_size;
592 	raw_inode->i_mtime = inode->i_mtime.tv_sec;
593 	raw_inode->i_atime = inode->i_atime.tv_sec;
594 	raw_inode->i_ctime = inode->i_ctime.tv_sec;
595 	if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode))
596 		raw_inode->i_zone[0] = old_encode_dev(inode->i_rdev);
597 	else for (i = 0; i < 10; i++)
598 		raw_inode->i_zone[i] = minix_inode->u.i2_data[i];
599 	mark_buffer_dirty(bh);
600 	return bh;
601 }
602 
603 static int minix_write_inode(struct inode *inode, struct writeback_control *wbc)
604 {
605 	int err = 0;
606 	struct buffer_head *bh;
607 
608 	if (INODE_VERSION(inode) == MINIX_V1)
609 		bh = V1_minix_update_inode(inode);
610 	else
611 		bh = V2_minix_update_inode(inode);
612 	if (!bh)
613 		return -EIO;
614 	if (wbc->sync_mode == WB_SYNC_ALL && buffer_dirty(bh)) {
615 		sync_dirty_buffer(bh);
616 		if (buffer_req(bh) && !buffer_uptodate(bh)) {
617 			printk("IO error syncing minix inode [%s:%08lx]\n",
618 				inode->i_sb->s_id, inode->i_ino);
619 			err = -EIO;
620 		}
621 	}
622 	brelse (bh);
623 	return err;
624 }
625 
626 int minix_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
627 {
628 	struct super_block *sb = dentry->d_sb;
629 	generic_fillattr(d_inode(dentry), stat);
630 	if (INODE_VERSION(d_inode(dentry)) == MINIX_V1)
631 		stat->blocks = (BLOCK_SIZE / 512) * V1_minix_blocks(stat->size, sb);
632 	else
633 		stat->blocks = (sb->s_blocksize / 512) * V2_minix_blocks(stat->size, sb);
634 	stat->blksize = sb->s_blocksize;
635 	return 0;
636 }
637 
638 /*
639  * The function that is called for file truncation.
640  */
641 void minix_truncate(struct inode * inode)
642 {
643 	if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode)))
644 		return;
645 	if (INODE_VERSION(inode) == MINIX_V1)
646 		V1_minix_truncate(inode);
647 	else
648 		V2_minix_truncate(inode);
649 }
650 
651 static struct dentry *minix_mount(struct file_system_type *fs_type,
652 	int flags, const char *dev_name, void *data)
653 {
654 	return mount_bdev(fs_type, flags, dev_name, data, minix_fill_super);
655 }
656 
657 static struct file_system_type minix_fs_type = {
658 	.owner		= THIS_MODULE,
659 	.name		= "minix",
660 	.mount		= minix_mount,
661 	.kill_sb	= kill_block_super,
662 	.fs_flags	= FS_REQUIRES_DEV,
663 };
664 MODULE_ALIAS_FS("minix");
665 
666 static int __init init_minix_fs(void)
667 {
668 	int err = init_inodecache();
669 	if (err)
670 		goto out1;
671 	err = register_filesystem(&minix_fs_type);
672 	if (err)
673 		goto out;
674 	return 0;
675 out:
676 	destroy_inodecache();
677 out1:
678 	return err;
679 }
680 
681 static void __exit exit_minix_fs(void)
682 {
683         unregister_filesystem(&minix_fs_type);
684 	destroy_inodecache();
685 }
686 
687 module_init(init_minix_fs)
688 module_exit(exit_minix_fs)
689 MODULE_LICENSE("GPL");
690 
691