xref: /openbmc/linux/fs/minix/inode.c (revision 6abeae2a)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  *  linux/fs/minix/inode.c
4  *
5  *  Copyright (C) 1991, 1992  Linus Torvalds
6  *
7  *  Copyright (C) 1996  Gertjan van Wingerde
8  *	Minix V2 fs support.
9  *
10  *  Modified for 680x0 by Andreas Schwab
11  *  Updated to filesystem version 3 by Daniel Aragones
12  */
13 
14 #include <linux/module.h>
15 #include "minix.h"
16 #include <linux/buffer_head.h>
17 #include <linux/slab.h>
18 #include <linux/init.h>
19 #include <linux/highuid.h>
20 #include <linux/vfs.h>
21 #include <linux/writeback.h>
22 
23 static int minix_write_inode(struct inode *inode,
24 		struct writeback_control *wbc);
25 static int minix_statfs(struct dentry *dentry, struct kstatfs *buf);
26 static int minix_remount (struct super_block * sb, int * flags, char * data);
27 
28 static void minix_evict_inode(struct inode *inode)
29 {
30 	truncate_inode_pages_final(&inode->i_data);
31 	if (!inode->i_nlink) {
32 		inode->i_size = 0;
33 		minix_truncate(inode);
34 	}
35 	invalidate_inode_buffers(inode);
36 	clear_inode(inode);
37 	if (!inode->i_nlink)
38 		minix_free_inode(inode);
39 }
40 
41 static void minix_put_super(struct super_block *sb)
42 {
43 	int i;
44 	struct minix_sb_info *sbi = minix_sb(sb);
45 
46 	if (!sb_rdonly(sb)) {
47 		if (sbi->s_version != MINIX_V3)	 /* s_state is now out from V3 sb */
48 			sbi->s_ms->s_state = sbi->s_mount_state;
49 		mark_buffer_dirty(sbi->s_sbh);
50 	}
51 	for (i = 0; i < sbi->s_imap_blocks; i++)
52 		brelse(sbi->s_imap[i]);
53 	for (i = 0; i < sbi->s_zmap_blocks; i++)
54 		brelse(sbi->s_zmap[i]);
55 	brelse (sbi->s_sbh);
56 	kfree(sbi->s_imap);
57 	sb->s_fs_info = NULL;
58 	kfree(sbi);
59 }
60 
61 static struct kmem_cache * minix_inode_cachep;
62 
63 static struct inode *minix_alloc_inode(struct super_block *sb)
64 {
65 	struct minix_inode_info *ei;
66 	ei = kmem_cache_alloc(minix_inode_cachep, GFP_KERNEL);
67 	if (!ei)
68 		return NULL;
69 	return &ei->vfs_inode;
70 }
71 
72 static void minix_free_in_core_inode(struct inode *inode)
73 {
74 	kmem_cache_free(minix_inode_cachep, minix_i(inode));
75 }
76 
77 static void init_once(void *foo)
78 {
79 	struct minix_inode_info *ei = (struct minix_inode_info *) foo;
80 
81 	inode_init_once(&ei->vfs_inode);
82 }
83 
84 static int __init init_inodecache(void)
85 {
86 	minix_inode_cachep = kmem_cache_create("minix_inode_cache",
87 					     sizeof(struct minix_inode_info),
88 					     0, (SLAB_RECLAIM_ACCOUNT|
89 						SLAB_MEM_SPREAD|SLAB_ACCOUNT),
90 					     init_once);
91 	if (minix_inode_cachep == NULL)
92 		return -ENOMEM;
93 	return 0;
94 }
95 
96 static void destroy_inodecache(void)
97 {
98 	/*
99 	 * Make sure all delayed rcu free inodes are flushed before we
100 	 * destroy cache.
101 	 */
102 	rcu_barrier();
103 	kmem_cache_destroy(minix_inode_cachep);
104 }
105 
106 static const struct super_operations minix_sops = {
107 	.alloc_inode	= minix_alloc_inode,
108 	.free_inode	= minix_free_in_core_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 	sync_filesystem(sb);
122 	ms = sbi->s_ms;
123 	if ((bool)(*flags & SB_RDONLY) == sb_rdonly(sb))
124 		return 0;
125 	if (*flags & SB_RDONLY) {
126 		if (ms->s_state & MINIX_VALID_FS ||
127 		    !(sbi->s_mount_state & MINIX_VALID_FS))
128 			return 0;
129 		/* Mounting a rw partition read-only. */
130 		if (sbi->s_version != MINIX_V3)
131 			ms->s_state = sbi->s_mount_state;
132 		mark_buffer_dirty(sbi->s_sbh);
133 	} else {
134 	  	/* Mount a partition which is read-only, read-write. */
135 		if (sbi->s_version != MINIX_V3) {
136 			sbi->s_mount_state = ms->s_state;
137 			ms->s_state &= ~MINIX_VALID_FS;
138 		} else {
139 			sbi->s_mount_state = MINIX_VALID_FS;
140 		}
141 		mark_buffer_dirty(sbi->s_sbh);
142 
143 		if (!(sbi->s_mount_state & MINIX_VALID_FS))
144 			printk("MINIX-fs warning: remounting unchecked fs, "
145 				"running fsck is recommended\n");
146 		else if ((sbi->s_mount_state & MINIX_ERROR_FS))
147 			printk("MINIX-fs warning: remounting fs with errors, "
148 				"running fsck is recommended\n");
149 	}
150 	return 0;
151 }
152 
153 static bool minix_check_superblock(struct super_block *sb)
154 {
155 	struct minix_sb_info *sbi = minix_sb(sb);
156 
157 	if (sbi->s_imap_blocks == 0 || sbi->s_zmap_blocks == 0)
158 		return false;
159 
160 	/*
161 	 * s_max_size must not exceed the block mapping limitation.  This check
162 	 * is only needed for V1 filesystems, since V2/V3 support an extra level
163 	 * of indirect blocks which places the limit well above U32_MAX.
164 	 */
165 	if (sbi->s_version == MINIX_V1 &&
166 	    sb->s_maxbytes > (7 + 512 + 512*512) * BLOCK_SIZE)
167 		return false;
168 
169 	return true;
170 }
171 
172 static int minix_fill_super(struct super_block *s, void *data, int silent)
173 {
174 	struct buffer_head *bh;
175 	struct buffer_head **map;
176 	struct minix_super_block *ms;
177 	struct minix3_super_block *m3s = NULL;
178 	unsigned long i, block;
179 	struct inode *root_inode;
180 	struct minix_sb_info *sbi;
181 	int ret = -EINVAL;
182 
183 	sbi = kzalloc(sizeof(struct minix_sb_info), GFP_KERNEL);
184 	if (!sbi)
185 		return -ENOMEM;
186 	s->s_fs_info = sbi;
187 
188 	BUILD_BUG_ON(32 != sizeof (struct minix_inode));
189 	BUILD_BUG_ON(64 != sizeof(struct minix2_inode));
190 
191 	if (!sb_set_blocksize(s, BLOCK_SIZE))
192 		goto out_bad_hblock;
193 
194 	if (!(bh = sb_bread(s, 1)))
195 		goto out_bad_sb;
196 
197 	ms = (struct minix_super_block *) bh->b_data;
198 	sbi->s_ms = ms;
199 	sbi->s_sbh = bh;
200 	sbi->s_mount_state = ms->s_state;
201 	sbi->s_ninodes = ms->s_ninodes;
202 	sbi->s_nzones = ms->s_nzones;
203 	sbi->s_imap_blocks = ms->s_imap_blocks;
204 	sbi->s_zmap_blocks = ms->s_zmap_blocks;
205 	sbi->s_firstdatazone = ms->s_firstdatazone;
206 	sbi->s_log_zone_size = ms->s_log_zone_size;
207 	s->s_maxbytes = ms->s_max_size;
208 	s->s_magic = ms->s_magic;
209 	if (s->s_magic == MINIX_SUPER_MAGIC) {
210 		sbi->s_version = MINIX_V1;
211 		sbi->s_dirsize = 16;
212 		sbi->s_namelen = 14;
213 		s->s_max_links = MINIX_LINK_MAX;
214 	} else if (s->s_magic == MINIX_SUPER_MAGIC2) {
215 		sbi->s_version = MINIX_V1;
216 		sbi->s_dirsize = 32;
217 		sbi->s_namelen = 30;
218 		s->s_max_links = MINIX_LINK_MAX;
219 	} else if (s->s_magic == MINIX2_SUPER_MAGIC) {
220 		sbi->s_version = MINIX_V2;
221 		sbi->s_nzones = ms->s_zones;
222 		sbi->s_dirsize = 16;
223 		sbi->s_namelen = 14;
224 		s->s_max_links = MINIX2_LINK_MAX;
225 	} else if (s->s_magic == MINIX2_SUPER_MAGIC2) {
226 		sbi->s_version = MINIX_V2;
227 		sbi->s_nzones = ms->s_zones;
228 		sbi->s_dirsize = 32;
229 		sbi->s_namelen = 30;
230 		s->s_max_links = MINIX2_LINK_MAX;
231 	} else if ( *(__u16 *)(bh->b_data + 24) == MINIX3_SUPER_MAGIC) {
232 		m3s = (struct minix3_super_block *) bh->b_data;
233 		s->s_magic = m3s->s_magic;
234 		sbi->s_imap_blocks = m3s->s_imap_blocks;
235 		sbi->s_zmap_blocks = m3s->s_zmap_blocks;
236 		sbi->s_firstdatazone = m3s->s_firstdatazone;
237 		sbi->s_log_zone_size = m3s->s_log_zone_size;
238 		s->s_maxbytes = m3s->s_max_size;
239 		sbi->s_ninodes = m3s->s_ninodes;
240 		sbi->s_nzones = m3s->s_zones;
241 		sbi->s_dirsize = 64;
242 		sbi->s_namelen = 60;
243 		sbi->s_version = MINIX_V3;
244 		sbi->s_mount_state = MINIX_VALID_FS;
245 		sb_set_blocksize(s, m3s->s_blocksize);
246 		s->s_max_links = MINIX2_LINK_MAX;
247 	} else
248 		goto out_no_fs;
249 
250 	if (!minix_check_superblock(s))
251 		goto out_illegal_sb;
252 
253 	/*
254 	 * Allocate the buffer map to keep the superblock small.
255 	 */
256 	i = (sbi->s_imap_blocks + sbi->s_zmap_blocks) * sizeof(bh);
257 	map = kzalloc(i, GFP_KERNEL);
258 	if (!map)
259 		goto out_no_map;
260 	sbi->s_imap = &map[0];
261 	sbi->s_zmap = &map[sbi->s_imap_blocks];
262 
263 	block=2;
264 	for (i=0 ; i < sbi->s_imap_blocks ; i++) {
265 		if (!(sbi->s_imap[i]=sb_bread(s, block)))
266 			goto out_no_bitmap;
267 		block++;
268 	}
269 	for (i=0 ; i < sbi->s_zmap_blocks ; i++) {
270 		if (!(sbi->s_zmap[i]=sb_bread(s, block)))
271 			goto out_no_bitmap;
272 		block++;
273 	}
274 
275 	minix_set_bit(0,sbi->s_imap[0]->b_data);
276 	minix_set_bit(0,sbi->s_zmap[0]->b_data);
277 
278 	/* Apparently minix can create filesystems that allocate more blocks for
279 	 * the bitmaps than needed.  We simply ignore that, but verify it didn't
280 	 * create one with not enough blocks and bail out if so.
281 	 */
282 	block = minix_blocks_needed(sbi->s_ninodes, s->s_blocksize);
283 	if (sbi->s_imap_blocks < block) {
284 		printk("MINIX-fs: file system does not have enough "
285 				"imap blocks allocated.  Refusing to mount.\n");
286 		goto out_no_bitmap;
287 	}
288 
289 	block = minix_blocks_needed(
290 			(sbi->s_nzones - sbi->s_firstdatazone + 1),
291 			s->s_blocksize);
292 	if (sbi->s_zmap_blocks < block) {
293 		printk("MINIX-fs: file system does not have enough "
294 				"zmap blocks allocated.  Refusing to mount.\n");
295 		goto out_no_bitmap;
296 	}
297 
298 	/* set up enough so that it can read an inode */
299 	s->s_op = &minix_sops;
300 	s->s_time_min = 0;
301 	s->s_time_max = U32_MAX;
302 	root_inode = minix_iget(s, MINIX_ROOT_INO);
303 	if (IS_ERR(root_inode)) {
304 		ret = PTR_ERR(root_inode);
305 		goto out_no_root;
306 	}
307 
308 	ret = -ENOMEM;
309 	s->s_root = d_make_root(root_inode);
310 	if (!s->s_root)
311 		goto out_no_root;
312 
313 	if (!sb_rdonly(s)) {
314 		if (sbi->s_version != MINIX_V3) /* s_state is now out from V3 sb */
315 			ms->s_state &= ~MINIX_VALID_FS;
316 		mark_buffer_dirty(bh);
317 	}
318 	if (!(sbi->s_mount_state & MINIX_VALID_FS))
319 		printk("MINIX-fs: mounting unchecked file system, "
320 			"running fsck is recommended\n");
321 	else if (sbi->s_mount_state & MINIX_ERROR_FS)
322 		printk("MINIX-fs: mounting file system with errors, "
323 			"running fsck is recommended\n");
324 
325 	return 0;
326 
327 out_no_root:
328 	if (!silent)
329 		printk("MINIX-fs: get root inode failed\n");
330 	goto out_freemap;
331 
332 out_no_bitmap:
333 	printk("MINIX-fs: bad superblock or unable to read bitmaps\n");
334 out_freemap:
335 	for (i = 0; i < sbi->s_imap_blocks; i++)
336 		brelse(sbi->s_imap[i]);
337 	for (i = 0; i < sbi->s_zmap_blocks; i++)
338 		brelse(sbi->s_zmap[i]);
339 	kfree(sbi->s_imap);
340 	goto out_release;
341 
342 out_no_map:
343 	ret = -ENOMEM;
344 	if (!silent)
345 		printk("MINIX-fs: can't allocate map\n");
346 	goto out_release;
347 
348 out_illegal_sb:
349 	if (!silent)
350 		printk("MINIX-fs: bad superblock\n");
351 	goto out_release;
352 
353 out_no_fs:
354 	if (!silent)
355 		printk("VFS: Can't find a Minix filesystem V1 | V2 | V3 "
356 		       "on device %s.\n", s->s_id);
357 out_release:
358 	brelse(bh);
359 	goto out;
360 
361 out_bad_hblock:
362 	printk("MINIX-fs: blocksize too small for device\n");
363 	goto out;
364 
365 out_bad_sb:
366 	printk("MINIX-fs: unable to read superblock\n");
367 out:
368 	s->s_fs_info = NULL;
369 	kfree(sbi);
370 	return ret;
371 }
372 
373 static int minix_statfs(struct dentry *dentry, struct kstatfs *buf)
374 {
375 	struct super_block *sb = dentry->d_sb;
376 	struct minix_sb_info *sbi = minix_sb(sb);
377 	u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
378 	buf->f_type = sb->s_magic;
379 	buf->f_bsize = sb->s_blocksize;
380 	buf->f_blocks = (sbi->s_nzones - sbi->s_firstdatazone) << sbi->s_log_zone_size;
381 	buf->f_bfree = minix_count_free_blocks(sb);
382 	buf->f_bavail = buf->f_bfree;
383 	buf->f_files = sbi->s_ninodes;
384 	buf->f_ffree = minix_count_free_inodes(sb);
385 	buf->f_namelen = sbi->s_namelen;
386 	buf->f_fsid = u64_to_fsid(id);
387 
388 	return 0;
389 }
390 
391 static int minix_get_block(struct inode *inode, sector_t block,
392 		    struct buffer_head *bh_result, int create)
393 {
394 	if (INODE_VERSION(inode) == MINIX_V1)
395 		return V1_minix_get_block(inode, block, bh_result, create);
396 	else
397 		return V2_minix_get_block(inode, block, bh_result, create);
398 }
399 
400 static int minix_writepage(struct page *page, struct writeback_control *wbc)
401 {
402 	return block_write_full_page(page, minix_get_block, wbc);
403 }
404 
405 static int minix_readpage(struct file *file, struct page *page)
406 {
407 	return block_read_full_page(page,minix_get_block);
408 }
409 
410 int minix_prepare_chunk(struct page *page, loff_t pos, unsigned len)
411 {
412 	return __block_write_begin(page, pos, len, minix_get_block);
413 }
414 
415 static void minix_write_failed(struct address_space *mapping, loff_t to)
416 {
417 	struct inode *inode = mapping->host;
418 
419 	if (to > inode->i_size) {
420 		truncate_pagecache(inode, inode->i_size);
421 		minix_truncate(inode);
422 	}
423 }
424 
425 static int minix_write_begin(struct file *file, struct address_space *mapping,
426 			loff_t pos, unsigned len, unsigned flags,
427 			struct page **pagep, void **fsdata)
428 {
429 	int ret;
430 
431 	ret = block_write_begin(mapping, pos, len, flags, pagep,
432 				minix_get_block);
433 	if (unlikely(ret))
434 		minix_write_failed(mapping, pos + len);
435 
436 	return ret;
437 }
438 
439 static sector_t minix_bmap(struct address_space *mapping, sector_t block)
440 {
441 	return generic_block_bmap(mapping,block,minix_get_block);
442 }
443 
444 static const struct address_space_operations minix_aops = {
445 	.readpage = minix_readpage,
446 	.writepage = minix_writepage,
447 	.write_begin = minix_write_begin,
448 	.write_end = generic_write_end,
449 	.bmap = minix_bmap
450 };
451 
452 static const struct inode_operations minix_symlink_inode_operations = {
453 	.get_link	= page_get_link,
454 	.getattr	= minix_getattr,
455 };
456 
457 void minix_set_inode(struct inode *inode, dev_t rdev)
458 {
459 	if (S_ISREG(inode->i_mode)) {
460 		inode->i_op = &minix_file_inode_operations;
461 		inode->i_fop = &minix_file_operations;
462 		inode->i_mapping->a_ops = &minix_aops;
463 	} else if (S_ISDIR(inode->i_mode)) {
464 		inode->i_op = &minix_dir_inode_operations;
465 		inode->i_fop = &minix_dir_operations;
466 		inode->i_mapping->a_ops = &minix_aops;
467 	} else if (S_ISLNK(inode->i_mode)) {
468 		inode->i_op = &minix_symlink_inode_operations;
469 		inode_nohighmem(inode);
470 		inode->i_mapping->a_ops = &minix_aops;
471 	} else
472 		init_special_inode(inode, inode->i_mode, rdev);
473 }
474 
475 /*
476  * The minix V1 function to read an inode.
477  */
478 static struct inode *V1_minix_iget(struct inode *inode)
479 {
480 	struct buffer_head * bh;
481 	struct minix_inode * raw_inode;
482 	struct minix_inode_info *minix_inode = minix_i(inode);
483 	int i;
484 
485 	raw_inode = minix_V1_raw_inode(inode->i_sb, inode->i_ino, &bh);
486 	if (!raw_inode) {
487 		iget_failed(inode);
488 		return ERR_PTR(-EIO);
489 	}
490 	if (raw_inode->i_nlinks == 0) {
491 		printk("MINIX-fs: deleted inode referenced: %lu\n",
492 		       inode->i_ino);
493 		brelse(bh);
494 		iget_failed(inode);
495 		return ERR_PTR(-ESTALE);
496 	}
497 	inode->i_mode = raw_inode->i_mode;
498 	i_uid_write(inode, raw_inode->i_uid);
499 	i_gid_write(inode, raw_inode->i_gid);
500 	set_nlink(inode, raw_inode->i_nlinks);
501 	inode->i_size = raw_inode->i_size;
502 	inode->i_mtime.tv_sec = inode->i_atime.tv_sec = inode->i_ctime.tv_sec = raw_inode->i_time;
503 	inode->i_mtime.tv_nsec = 0;
504 	inode->i_atime.tv_nsec = 0;
505 	inode->i_ctime.tv_nsec = 0;
506 	inode->i_blocks = 0;
507 	for (i = 0; i < 9; i++)
508 		minix_inode->u.i1_data[i] = raw_inode->i_zone[i];
509 	minix_set_inode(inode, old_decode_dev(raw_inode->i_zone[0]));
510 	brelse(bh);
511 	unlock_new_inode(inode);
512 	return inode;
513 }
514 
515 /*
516  * The minix V2 function to read an inode.
517  */
518 static struct inode *V2_minix_iget(struct inode *inode)
519 {
520 	struct buffer_head * bh;
521 	struct minix2_inode * raw_inode;
522 	struct minix_inode_info *minix_inode = minix_i(inode);
523 	int i;
524 
525 	raw_inode = minix_V2_raw_inode(inode->i_sb, inode->i_ino, &bh);
526 	if (!raw_inode) {
527 		iget_failed(inode);
528 		return ERR_PTR(-EIO);
529 	}
530 	if (raw_inode->i_nlinks == 0) {
531 		printk("MINIX-fs: deleted inode referenced: %lu\n",
532 		       inode->i_ino);
533 		brelse(bh);
534 		iget_failed(inode);
535 		return ERR_PTR(-ESTALE);
536 	}
537 	inode->i_mode = raw_inode->i_mode;
538 	i_uid_write(inode, raw_inode->i_uid);
539 	i_gid_write(inode, raw_inode->i_gid);
540 	set_nlink(inode, raw_inode->i_nlinks);
541 	inode->i_size = raw_inode->i_size;
542 	inode->i_mtime.tv_sec = raw_inode->i_mtime;
543 	inode->i_atime.tv_sec = raw_inode->i_atime;
544 	inode->i_ctime.tv_sec = raw_inode->i_ctime;
545 	inode->i_mtime.tv_nsec = 0;
546 	inode->i_atime.tv_nsec = 0;
547 	inode->i_ctime.tv_nsec = 0;
548 	inode->i_blocks = 0;
549 	for (i = 0; i < 10; i++)
550 		minix_inode->u.i2_data[i] = raw_inode->i_zone[i];
551 	minix_set_inode(inode, old_decode_dev(raw_inode->i_zone[0]));
552 	brelse(bh);
553 	unlock_new_inode(inode);
554 	return inode;
555 }
556 
557 /*
558  * The global function to read an inode.
559  */
560 struct inode *minix_iget(struct super_block *sb, unsigned long ino)
561 {
562 	struct inode *inode;
563 
564 	inode = iget_locked(sb, ino);
565 	if (!inode)
566 		return ERR_PTR(-ENOMEM);
567 	if (!(inode->i_state & I_NEW))
568 		return inode;
569 
570 	if (INODE_VERSION(inode) == MINIX_V1)
571 		return V1_minix_iget(inode);
572 	else
573 		return V2_minix_iget(inode);
574 }
575 
576 /*
577  * The minix V1 function to synchronize an inode.
578  */
579 static struct buffer_head * V1_minix_update_inode(struct inode * inode)
580 {
581 	struct buffer_head * bh;
582 	struct minix_inode * raw_inode;
583 	struct minix_inode_info *minix_inode = minix_i(inode);
584 	int i;
585 
586 	raw_inode = minix_V1_raw_inode(inode->i_sb, inode->i_ino, &bh);
587 	if (!raw_inode)
588 		return NULL;
589 	raw_inode->i_mode = inode->i_mode;
590 	raw_inode->i_uid = fs_high2lowuid(i_uid_read(inode));
591 	raw_inode->i_gid = fs_high2lowgid(i_gid_read(inode));
592 	raw_inode->i_nlinks = inode->i_nlink;
593 	raw_inode->i_size = inode->i_size;
594 	raw_inode->i_time = inode->i_mtime.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 < 9; i++)
598 		raw_inode->i_zone[i] = minix_inode->u.i1_data[i];
599 	mark_buffer_dirty(bh);
600 	return bh;
601 }
602 
603 /*
604  * The minix V2 function to synchronize an inode.
605  */
606 static struct buffer_head * V2_minix_update_inode(struct inode * inode)
607 {
608 	struct buffer_head * bh;
609 	struct minix2_inode * raw_inode;
610 	struct minix_inode_info *minix_inode = minix_i(inode);
611 	int i;
612 
613 	raw_inode = minix_V2_raw_inode(inode->i_sb, inode->i_ino, &bh);
614 	if (!raw_inode)
615 		return NULL;
616 	raw_inode->i_mode = inode->i_mode;
617 	raw_inode->i_uid = fs_high2lowuid(i_uid_read(inode));
618 	raw_inode->i_gid = fs_high2lowgid(i_gid_read(inode));
619 	raw_inode->i_nlinks = inode->i_nlink;
620 	raw_inode->i_size = inode->i_size;
621 	raw_inode->i_mtime = inode->i_mtime.tv_sec;
622 	raw_inode->i_atime = inode->i_atime.tv_sec;
623 	raw_inode->i_ctime = inode->i_ctime.tv_sec;
624 	if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode))
625 		raw_inode->i_zone[0] = old_encode_dev(inode->i_rdev);
626 	else for (i = 0; i < 10; i++)
627 		raw_inode->i_zone[i] = minix_inode->u.i2_data[i];
628 	mark_buffer_dirty(bh);
629 	return bh;
630 }
631 
632 static int minix_write_inode(struct inode *inode, struct writeback_control *wbc)
633 {
634 	int err = 0;
635 	struct buffer_head *bh;
636 
637 	if (INODE_VERSION(inode) == MINIX_V1)
638 		bh = V1_minix_update_inode(inode);
639 	else
640 		bh = V2_minix_update_inode(inode);
641 	if (!bh)
642 		return -EIO;
643 	if (wbc->sync_mode == WB_SYNC_ALL && buffer_dirty(bh)) {
644 		sync_dirty_buffer(bh);
645 		if (buffer_req(bh) && !buffer_uptodate(bh)) {
646 			printk("IO error syncing minix inode [%s:%08lx]\n",
647 				inode->i_sb->s_id, inode->i_ino);
648 			err = -EIO;
649 		}
650 	}
651 	brelse (bh);
652 	return err;
653 }
654 
655 int minix_getattr(const struct path *path, struct kstat *stat,
656 		  u32 request_mask, unsigned int flags)
657 {
658 	struct super_block *sb = path->dentry->d_sb;
659 	struct inode *inode = d_inode(path->dentry);
660 
661 	generic_fillattr(inode, stat);
662 	if (INODE_VERSION(inode) == MINIX_V1)
663 		stat->blocks = (BLOCK_SIZE / 512) * V1_minix_blocks(stat->size, sb);
664 	else
665 		stat->blocks = (sb->s_blocksize / 512) * V2_minix_blocks(stat->size, sb);
666 	stat->blksize = sb->s_blocksize;
667 	return 0;
668 }
669 
670 /*
671  * The function that is called for file truncation.
672  */
673 void minix_truncate(struct inode * inode)
674 {
675 	if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode)))
676 		return;
677 	if (INODE_VERSION(inode) == MINIX_V1)
678 		V1_minix_truncate(inode);
679 	else
680 		V2_minix_truncate(inode);
681 }
682 
683 static struct dentry *minix_mount(struct file_system_type *fs_type,
684 	int flags, const char *dev_name, void *data)
685 {
686 	return mount_bdev(fs_type, flags, dev_name, data, minix_fill_super);
687 }
688 
689 static struct file_system_type minix_fs_type = {
690 	.owner		= THIS_MODULE,
691 	.name		= "minix",
692 	.mount		= minix_mount,
693 	.kill_sb	= kill_block_super,
694 	.fs_flags	= FS_REQUIRES_DEV,
695 };
696 MODULE_ALIAS_FS("minix");
697 
698 static int __init init_minix_fs(void)
699 {
700 	int err = init_inodecache();
701 	if (err)
702 		goto out1;
703 	err = register_filesystem(&minix_fs_type);
704 	if (err)
705 		goto out;
706 	return 0;
707 out:
708 	destroy_inodecache();
709 out1:
710 	return err;
711 }
712 
713 static void __exit exit_minix_fs(void)
714 {
715         unregister_filesystem(&minix_fs_type);
716 	destroy_inodecache();
717 }
718 
719 module_init(init_minix_fs)
720 module_exit(exit_minix_fs)
721 MODULE_LICENSE("GPL");
722 
723