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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 
minix_evict_inode(struct inode * inode)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 
minix_put_super(struct super_block * sb)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 
minix_alloc_inode(struct super_block * sb)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 
minix_i_callback(struct rcu_head * head)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 
minix_destroy_inode(struct inode * inode)77 static void minix_destroy_inode(struct inode *inode)
78 {
79 	call_rcu(&inode->i_rcu, minix_i_callback);
80 }
81 
init_once(void * foo)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 
init_inodecache(void)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 
destroy_inodecache(void)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 
minix_remount(struct super_block * sb,int * flags,char * data)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 
minix_check_superblock(struct minix_sb_info * sbi)158 static bool minix_check_superblock(struct minix_sb_info *sbi)
159 {
160 	if (sbi->s_imap_blocks == 0 || sbi->s_zmap_blocks == 0)
161 		return false;
162 
163 	/*
164 	 * s_max_size must not exceed the block mapping limitation.  This check
165 	 * is only needed for V1 filesystems, since V2/V3 support an extra level
166 	 * of indirect blocks which places the limit well above U32_MAX.
167 	 */
168 	if (sbi->s_version == MINIX_V1 &&
169 	    sbi->s_max_size > (7 + 512 + 512*512) * BLOCK_SIZE)
170 		return false;
171 
172 	return true;
173 }
174 
minix_fill_super(struct super_block * s,void * data,int silent)175 static int minix_fill_super(struct super_block *s, void *data, int silent)
176 {
177 	struct buffer_head *bh;
178 	struct buffer_head **map;
179 	struct minix_super_block *ms;
180 	struct minix3_super_block *m3s = NULL;
181 	unsigned long i, block;
182 	struct inode *root_inode;
183 	struct minix_sb_info *sbi;
184 	int ret = -EINVAL;
185 
186 	sbi = kzalloc(sizeof(struct minix_sb_info), GFP_KERNEL);
187 	if (!sbi)
188 		return -ENOMEM;
189 	s->s_fs_info = sbi;
190 
191 	BUILD_BUG_ON(32 != sizeof (struct minix_inode));
192 	BUILD_BUG_ON(64 != sizeof(struct minix2_inode));
193 
194 	if (!sb_set_blocksize(s, BLOCK_SIZE))
195 		goto out_bad_hblock;
196 
197 	if (!(bh = sb_bread(s, 1)))
198 		goto out_bad_sb;
199 
200 	ms = (struct minix_super_block *) bh->b_data;
201 	sbi->s_ms = ms;
202 	sbi->s_sbh = bh;
203 	sbi->s_mount_state = ms->s_state;
204 	sbi->s_ninodes = ms->s_ninodes;
205 	sbi->s_nzones = ms->s_nzones;
206 	sbi->s_imap_blocks = ms->s_imap_blocks;
207 	sbi->s_zmap_blocks = ms->s_zmap_blocks;
208 	sbi->s_firstdatazone = ms->s_firstdatazone;
209 	sbi->s_log_zone_size = ms->s_log_zone_size;
210 	sbi->s_max_size = ms->s_max_size;
211 	s->s_magic = ms->s_magic;
212 	if (s->s_magic == MINIX_SUPER_MAGIC) {
213 		sbi->s_version = MINIX_V1;
214 		sbi->s_dirsize = 16;
215 		sbi->s_namelen = 14;
216 		s->s_max_links = MINIX_LINK_MAX;
217 	} else if (s->s_magic == MINIX_SUPER_MAGIC2) {
218 		sbi->s_version = MINIX_V1;
219 		sbi->s_dirsize = 32;
220 		sbi->s_namelen = 30;
221 		s->s_max_links = MINIX_LINK_MAX;
222 	} else if (s->s_magic == MINIX2_SUPER_MAGIC) {
223 		sbi->s_version = MINIX_V2;
224 		sbi->s_nzones = ms->s_zones;
225 		sbi->s_dirsize = 16;
226 		sbi->s_namelen = 14;
227 		s->s_max_links = MINIX2_LINK_MAX;
228 	} else if (s->s_magic == MINIX2_SUPER_MAGIC2) {
229 		sbi->s_version = MINIX_V2;
230 		sbi->s_nzones = ms->s_zones;
231 		sbi->s_dirsize = 32;
232 		sbi->s_namelen = 30;
233 		s->s_max_links = MINIX2_LINK_MAX;
234 	} else if ( *(__u16 *)(bh->b_data + 24) == MINIX3_SUPER_MAGIC) {
235 		m3s = (struct minix3_super_block *) bh->b_data;
236 		s->s_magic = m3s->s_magic;
237 		sbi->s_imap_blocks = m3s->s_imap_blocks;
238 		sbi->s_zmap_blocks = m3s->s_zmap_blocks;
239 		sbi->s_firstdatazone = m3s->s_firstdatazone;
240 		sbi->s_log_zone_size = m3s->s_log_zone_size;
241 		sbi->s_max_size = m3s->s_max_size;
242 		sbi->s_ninodes = m3s->s_ninodes;
243 		sbi->s_nzones = m3s->s_zones;
244 		sbi->s_dirsize = 64;
245 		sbi->s_namelen = 60;
246 		sbi->s_version = MINIX_V3;
247 		sbi->s_mount_state = MINIX_VALID_FS;
248 		sb_set_blocksize(s, m3s->s_blocksize);
249 		s->s_max_links = MINIX2_LINK_MAX;
250 	} else
251 		goto out_no_fs;
252 
253 	if (!minix_check_superblock(sbi))
254 		goto out_illegal_sb;
255 
256 	/*
257 	 * Allocate the buffer map to keep the superblock small.
258 	 */
259 	i = (sbi->s_imap_blocks + sbi->s_zmap_blocks) * sizeof(bh);
260 	map = kzalloc(i, GFP_KERNEL);
261 	if (!map)
262 		goto out_no_map;
263 	sbi->s_imap = &map[0];
264 	sbi->s_zmap = &map[sbi->s_imap_blocks];
265 
266 	block=2;
267 	for (i=0 ; i < sbi->s_imap_blocks ; i++) {
268 		if (!(sbi->s_imap[i]=sb_bread(s, block)))
269 			goto out_no_bitmap;
270 		block++;
271 	}
272 	for (i=0 ; i < sbi->s_zmap_blocks ; i++) {
273 		if (!(sbi->s_zmap[i]=sb_bread(s, block)))
274 			goto out_no_bitmap;
275 		block++;
276 	}
277 
278 	minix_set_bit(0,sbi->s_imap[0]->b_data);
279 	minix_set_bit(0,sbi->s_zmap[0]->b_data);
280 
281 	/* Apparently minix can create filesystems that allocate more blocks for
282 	 * the bitmaps than needed.  We simply ignore that, but verify it didn't
283 	 * create one with not enough blocks and bail out if so.
284 	 */
285 	block = minix_blocks_needed(sbi->s_ninodes, s->s_blocksize);
286 	if (sbi->s_imap_blocks < block) {
287 		printk("MINIX-fs: file system does not have enough "
288 				"imap blocks allocated.  Refusing to mount.\n");
289 		goto out_no_bitmap;
290 	}
291 
292 	block = minix_blocks_needed(
293 			(sbi->s_nzones - sbi->s_firstdatazone + 1),
294 			s->s_blocksize);
295 	if (sbi->s_zmap_blocks < block) {
296 		printk("MINIX-fs: file system does not have enough "
297 				"zmap blocks allocated.  Refusing to mount.\n");
298 		goto out_no_bitmap;
299 	}
300 
301 	/* set up enough so that it can read an inode */
302 	s->s_op = &minix_sops;
303 	root_inode = minix_iget(s, MINIX_ROOT_INO);
304 	if (IS_ERR(root_inode)) {
305 		ret = PTR_ERR(root_inode);
306 		goto out_no_root;
307 	}
308 
309 	ret = -ENOMEM;
310 	s->s_root = d_make_root(root_inode);
311 	if (!s->s_root)
312 		goto out_no_root;
313 
314 	if (!(s->s_flags & MS_RDONLY)) {
315 		if (sbi->s_version != MINIX_V3) /* s_state is now out from V3 sb */
316 			ms->s_state &= ~MINIX_VALID_FS;
317 		mark_buffer_dirty(bh);
318 	}
319 	if (!(sbi->s_mount_state & MINIX_VALID_FS))
320 		printk("MINIX-fs: mounting unchecked file system, "
321 			"running fsck is recommended\n");
322 	else if (sbi->s_mount_state & MINIX_ERROR_FS)
323 		printk("MINIX-fs: mounting file system with errors, "
324 			"running fsck is recommended\n");
325 
326 	return 0;
327 
328 out_no_root:
329 	if (!silent)
330 		printk("MINIX-fs: get root inode failed\n");
331 	goto out_freemap;
332 
333 out_no_bitmap:
334 	printk("MINIX-fs: bad superblock or unable to read bitmaps\n");
335 out_freemap:
336 	for (i = 0; i < sbi->s_imap_blocks; i++)
337 		brelse(sbi->s_imap[i]);
338 	for (i = 0; i < sbi->s_zmap_blocks; i++)
339 		brelse(sbi->s_zmap[i]);
340 	kfree(sbi->s_imap);
341 	goto out_release;
342 
343 out_no_map:
344 	ret = -ENOMEM;
345 	if (!silent)
346 		printk("MINIX-fs: can't allocate map\n");
347 	goto out_release;
348 
349 out_illegal_sb:
350 	if (!silent)
351 		printk("MINIX-fs: bad superblock\n");
352 	goto out_release;
353 
354 out_no_fs:
355 	if (!silent)
356 		printk("VFS: Can't find a Minix filesystem V1 | V2 | V3 "
357 		       "on device %s.\n", s->s_id);
358 out_release:
359 	brelse(bh);
360 	goto out;
361 
362 out_bad_hblock:
363 	printk("MINIX-fs: blocksize too small for device\n");
364 	goto out;
365 
366 out_bad_sb:
367 	printk("MINIX-fs: unable to read superblock\n");
368 out:
369 	s->s_fs_info = NULL;
370 	kfree(sbi);
371 	return ret;
372 }
373 
minix_statfs(struct dentry * dentry,struct kstatfs * buf)374 static int minix_statfs(struct dentry *dentry, struct kstatfs *buf)
375 {
376 	struct super_block *sb = dentry->d_sb;
377 	struct minix_sb_info *sbi = minix_sb(sb);
378 	u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
379 	buf->f_type = sb->s_magic;
380 	buf->f_bsize = sb->s_blocksize;
381 	buf->f_blocks = (sbi->s_nzones - sbi->s_firstdatazone) << sbi->s_log_zone_size;
382 	buf->f_bfree = minix_count_free_blocks(sb);
383 	buf->f_bavail = buf->f_bfree;
384 	buf->f_files = sbi->s_ninodes;
385 	buf->f_ffree = minix_count_free_inodes(sb);
386 	buf->f_namelen = sbi->s_namelen;
387 	buf->f_fsid.val[0] = (u32)id;
388 	buf->f_fsid.val[1] = (u32)(id >> 32);
389 
390 	return 0;
391 }
392 
minix_get_block(struct inode * inode,sector_t block,struct buffer_head * bh_result,int create)393 static int minix_get_block(struct inode *inode, sector_t block,
394 		    struct buffer_head *bh_result, int create)
395 {
396 	if (INODE_VERSION(inode) == MINIX_V1)
397 		return V1_minix_get_block(inode, block, bh_result, create);
398 	else
399 		return V2_minix_get_block(inode, block, bh_result, create);
400 }
401 
minix_writepage(struct page * page,struct writeback_control * wbc)402 static int minix_writepage(struct page *page, struct writeback_control *wbc)
403 {
404 	return block_write_full_page(page, minix_get_block, wbc);
405 }
406 
minix_readpage(struct file * file,struct page * page)407 static int minix_readpage(struct file *file, struct page *page)
408 {
409 	return block_read_full_page(page,minix_get_block);
410 }
411 
minix_prepare_chunk(struct page * page,loff_t pos,unsigned len)412 int minix_prepare_chunk(struct page *page, loff_t pos, unsigned len)
413 {
414 	return __block_write_begin(page, pos, len, minix_get_block);
415 }
416 
minix_write_failed(struct address_space * mapping,loff_t to)417 static void minix_write_failed(struct address_space *mapping, loff_t to)
418 {
419 	struct inode *inode = mapping->host;
420 
421 	if (to > inode->i_size) {
422 		truncate_pagecache(inode, inode->i_size);
423 		minix_truncate(inode);
424 	}
425 }
426 
minix_write_begin(struct file * file,struct address_space * mapping,loff_t pos,unsigned len,unsigned flags,struct page ** pagep,void ** fsdata)427 static int minix_write_begin(struct file *file, struct address_space *mapping,
428 			loff_t pos, unsigned len, unsigned flags,
429 			struct page **pagep, void **fsdata)
430 {
431 	int ret;
432 
433 	ret = block_write_begin(mapping, pos, len, flags, pagep,
434 				minix_get_block);
435 	if (unlikely(ret))
436 		minix_write_failed(mapping, pos + len);
437 
438 	return ret;
439 }
440 
minix_bmap(struct address_space * mapping,sector_t block)441 static sector_t minix_bmap(struct address_space *mapping, sector_t block)
442 {
443 	return generic_block_bmap(mapping,block,minix_get_block);
444 }
445 
446 static const struct address_space_operations minix_aops = {
447 	.readpage = minix_readpage,
448 	.writepage = minix_writepage,
449 	.write_begin = minix_write_begin,
450 	.write_end = generic_write_end,
451 	.bmap = minix_bmap
452 };
453 
454 static const struct inode_operations minix_symlink_inode_operations = {
455 	.readlink	= generic_readlink,
456 	.follow_link	= page_follow_link_light,
457 	.put_link	= page_put_link,
458 	.getattr	= minix_getattr,
459 };
460 
minix_set_inode(struct inode * inode,dev_t rdev)461 void minix_set_inode(struct inode *inode, dev_t rdev)
462 {
463 	if (S_ISREG(inode->i_mode)) {
464 		inode->i_op = &minix_file_inode_operations;
465 		inode->i_fop = &minix_file_operations;
466 		inode->i_mapping->a_ops = &minix_aops;
467 	} else if (S_ISDIR(inode->i_mode)) {
468 		inode->i_op = &minix_dir_inode_operations;
469 		inode->i_fop = &minix_dir_operations;
470 		inode->i_mapping->a_ops = &minix_aops;
471 	} else if (S_ISLNK(inode->i_mode)) {
472 		inode->i_op = &minix_symlink_inode_operations;
473 		inode->i_mapping->a_ops = &minix_aops;
474 	} else
475 		init_special_inode(inode, inode->i_mode, rdev);
476 }
477 
478 /*
479  * The minix V1 function to read an inode.
480  */
V1_minix_iget(struct inode * inode)481 static struct inode *V1_minix_iget(struct inode *inode)
482 {
483 	struct buffer_head * bh;
484 	struct minix_inode * raw_inode;
485 	struct minix_inode_info *minix_inode = minix_i(inode);
486 	int i;
487 
488 	raw_inode = minix_V1_raw_inode(inode->i_sb, inode->i_ino, &bh);
489 	if (!raw_inode) {
490 		iget_failed(inode);
491 		return ERR_PTR(-EIO);
492 	}
493 	if (raw_inode->i_nlinks == 0) {
494 		printk("MINIX-fs: deleted inode referenced: %lu\n",
495 		       inode->i_ino);
496 		brelse(bh);
497 		iget_failed(inode);
498 		return ERR_PTR(-ESTALE);
499 	}
500 	inode->i_mode = raw_inode->i_mode;
501 	i_uid_write(inode, raw_inode->i_uid);
502 	i_gid_write(inode, raw_inode->i_gid);
503 	set_nlink(inode, raw_inode->i_nlinks);
504 	inode->i_size = raw_inode->i_size;
505 	inode->i_mtime.tv_sec = inode->i_atime.tv_sec = inode->i_ctime.tv_sec = raw_inode->i_time;
506 	inode->i_mtime.tv_nsec = 0;
507 	inode->i_atime.tv_nsec = 0;
508 	inode->i_ctime.tv_nsec = 0;
509 	inode->i_blocks = 0;
510 	for (i = 0; i < 9; i++)
511 		minix_inode->u.i1_data[i] = raw_inode->i_zone[i];
512 	minix_set_inode(inode, old_decode_dev(raw_inode->i_zone[0]));
513 	brelse(bh);
514 	unlock_new_inode(inode);
515 	return inode;
516 }
517 
518 /*
519  * The minix V2 function to read an inode.
520  */
V2_minix_iget(struct inode * inode)521 static struct inode *V2_minix_iget(struct inode *inode)
522 {
523 	struct buffer_head * bh;
524 	struct minix2_inode * raw_inode;
525 	struct minix_inode_info *minix_inode = minix_i(inode);
526 	int i;
527 
528 	raw_inode = minix_V2_raw_inode(inode->i_sb, inode->i_ino, &bh);
529 	if (!raw_inode) {
530 		iget_failed(inode);
531 		return ERR_PTR(-EIO);
532 	}
533 	if (raw_inode->i_nlinks == 0) {
534 		printk("MINIX-fs: deleted inode referenced: %lu\n",
535 		       inode->i_ino);
536 		brelse(bh);
537 		iget_failed(inode);
538 		return ERR_PTR(-ESTALE);
539 	}
540 	inode->i_mode = raw_inode->i_mode;
541 	i_uid_write(inode, raw_inode->i_uid);
542 	i_gid_write(inode, raw_inode->i_gid);
543 	set_nlink(inode, raw_inode->i_nlinks);
544 	inode->i_size = raw_inode->i_size;
545 	inode->i_mtime.tv_sec = raw_inode->i_mtime;
546 	inode->i_atime.tv_sec = raw_inode->i_atime;
547 	inode->i_ctime.tv_sec = raw_inode->i_ctime;
548 	inode->i_mtime.tv_nsec = 0;
549 	inode->i_atime.tv_nsec = 0;
550 	inode->i_ctime.tv_nsec = 0;
551 	inode->i_blocks = 0;
552 	for (i = 0; i < 10; i++)
553 		minix_inode->u.i2_data[i] = raw_inode->i_zone[i];
554 	minix_set_inode(inode, old_decode_dev(raw_inode->i_zone[0]));
555 	brelse(bh);
556 	unlock_new_inode(inode);
557 	return inode;
558 }
559 
560 /*
561  * The global function to read an inode.
562  */
minix_iget(struct super_block * sb,unsigned long ino)563 struct inode *minix_iget(struct super_block *sb, unsigned long ino)
564 {
565 	struct inode *inode;
566 
567 	inode = iget_locked(sb, ino);
568 	if (!inode)
569 		return ERR_PTR(-ENOMEM);
570 	if (!(inode->i_state & I_NEW))
571 		return inode;
572 
573 	if (INODE_VERSION(inode) == MINIX_V1)
574 		return V1_minix_iget(inode);
575 	else
576 		return V2_minix_iget(inode);
577 }
578 
579 /*
580  * The minix V1 function to synchronize an inode.
581  */
V1_minix_update_inode(struct inode * inode)582 static struct buffer_head * V1_minix_update_inode(struct inode * inode)
583 {
584 	struct buffer_head * bh;
585 	struct minix_inode * raw_inode;
586 	struct minix_inode_info *minix_inode = minix_i(inode);
587 	int i;
588 
589 	raw_inode = minix_V1_raw_inode(inode->i_sb, inode->i_ino, &bh);
590 	if (!raw_inode)
591 		return NULL;
592 	raw_inode->i_mode = inode->i_mode;
593 	raw_inode->i_uid = fs_high2lowuid(i_uid_read(inode));
594 	raw_inode->i_gid = fs_high2lowgid(i_gid_read(inode));
595 	raw_inode->i_nlinks = inode->i_nlink;
596 	raw_inode->i_size = inode->i_size;
597 	raw_inode->i_time = inode->i_mtime.tv_sec;
598 	if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode))
599 		raw_inode->i_zone[0] = old_encode_dev(inode->i_rdev);
600 	else for (i = 0; i < 9; i++)
601 		raw_inode->i_zone[i] = minix_inode->u.i1_data[i];
602 	mark_buffer_dirty(bh);
603 	return bh;
604 }
605 
606 /*
607  * The minix V2 function to synchronize an inode.
608  */
V2_minix_update_inode(struct inode * inode)609 static struct buffer_head * V2_minix_update_inode(struct inode * inode)
610 {
611 	struct buffer_head * bh;
612 	struct minix2_inode * raw_inode;
613 	struct minix_inode_info *minix_inode = minix_i(inode);
614 	int i;
615 
616 	raw_inode = minix_V2_raw_inode(inode->i_sb, inode->i_ino, &bh);
617 	if (!raw_inode)
618 		return NULL;
619 	raw_inode->i_mode = inode->i_mode;
620 	raw_inode->i_uid = fs_high2lowuid(i_uid_read(inode));
621 	raw_inode->i_gid = fs_high2lowgid(i_gid_read(inode));
622 	raw_inode->i_nlinks = inode->i_nlink;
623 	raw_inode->i_size = inode->i_size;
624 	raw_inode->i_mtime = inode->i_mtime.tv_sec;
625 	raw_inode->i_atime = inode->i_atime.tv_sec;
626 	raw_inode->i_ctime = inode->i_ctime.tv_sec;
627 	if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode))
628 		raw_inode->i_zone[0] = old_encode_dev(inode->i_rdev);
629 	else for (i = 0; i < 10; i++)
630 		raw_inode->i_zone[i] = minix_inode->u.i2_data[i];
631 	mark_buffer_dirty(bh);
632 	return bh;
633 }
634 
minix_write_inode(struct inode * inode,struct writeback_control * wbc)635 static int minix_write_inode(struct inode *inode, struct writeback_control *wbc)
636 {
637 	int err = 0;
638 	struct buffer_head *bh;
639 
640 	if (INODE_VERSION(inode) == MINIX_V1)
641 		bh = V1_minix_update_inode(inode);
642 	else
643 		bh = V2_minix_update_inode(inode);
644 	if (!bh)
645 		return -EIO;
646 	if (wbc->sync_mode == WB_SYNC_ALL && buffer_dirty(bh)) {
647 		sync_dirty_buffer(bh);
648 		if (buffer_req(bh) && !buffer_uptodate(bh)) {
649 			printk("IO error syncing minix inode [%s:%08lx]\n",
650 				inode->i_sb->s_id, inode->i_ino);
651 			err = -EIO;
652 		}
653 	}
654 	brelse (bh);
655 	return err;
656 }
657 
minix_getattr(struct vfsmount * mnt,struct dentry * dentry,struct kstat * stat)658 int minix_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
659 {
660 	struct super_block *sb = dentry->d_sb;
661 	generic_fillattr(d_inode(dentry), stat);
662 	if (INODE_VERSION(d_inode(dentry)) == 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  */
minix_truncate(struct inode * inode)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 
minix_mount(struct file_system_type * fs_type,int flags,const char * dev_name,void * data)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 
init_minix_fs(void)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 
exit_minix_fs(void)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