xref: /openbmc/linux/fs/fat/namei_msdos.c (revision e18275ae)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  *  linux/fs/msdos/namei.c
4  *
5  *  Written 1992,1993 by Werner Almesberger
6  *  Hidden files 1995 by Albert Cahalan <albert@ccs.neu.edu> <adc@coe.neu.edu>
7  *  Rewritten for constant inumbers 1999 by Al Viro
8  */
9 
10 #include <linux/module.h>
11 #include <linux/iversion.h>
12 #include "fat.h"
13 
14 /* Characters that are undesirable in an MS-DOS file name */
15 static unsigned char bad_chars[] = "*?<>|\"";
16 static unsigned char bad_if_strict[] = "+=,; ";
17 
18 /***** Formats an MS-DOS file name. Rejects invalid names. */
msdos_format_name(const unsigned char * name,int len,unsigned char * res,struct fat_mount_options * opts)19 static int msdos_format_name(const unsigned char *name, int len,
20 			     unsigned char *res, struct fat_mount_options *opts)
21 	/*
22 	 * name is the proposed name, len is its length, res is
23 	 * the resulting name, opts->name_check is either (r)elaxed,
24 	 * (n)ormal or (s)trict, opts->dotsOK allows dots at the
25 	 * beginning of name (for hidden files)
26 	 */
27 {
28 	unsigned char *walk;
29 	unsigned char c;
30 	int space;
31 
32 	if (name[0] == '.') {	/* dotfile because . and .. already done */
33 		if (opts->dotsOK) {
34 			/* Get rid of dot - test for it elsewhere */
35 			name++;
36 			len--;
37 		} else
38 			return -EINVAL;
39 	}
40 	/*
41 	 * disallow names that _really_ start with a dot
42 	 */
43 	space = 1;
44 	c = 0;
45 	for (walk = res; len && walk - res < 8; walk++) {
46 		c = *name++;
47 		len--;
48 		if (opts->name_check != 'r' && strchr(bad_chars, c))
49 			return -EINVAL;
50 		if (opts->name_check == 's' && strchr(bad_if_strict, c))
51 			return -EINVAL;
52 		if (c >= 'A' && c <= 'Z' && opts->name_check == 's')
53 			return -EINVAL;
54 		if (c < ' ' || c == ':' || c == '\\')
55 			return -EINVAL;
56 	/*
57 	 * 0xE5 is legal as a first character, but we must substitute
58 	 * 0x05 because 0xE5 marks deleted files.  Yes, DOS really
59 	 * does this.
60 	 * It seems that Microsoft hacked DOS to support non-US
61 	 * characters after the 0xE5 character was already in use to
62 	 * mark deleted files.
63 	 */
64 		if ((res == walk) && (c == 0xE5))
65 			c = 0x05;
66 		if (c == '.')
67 			break;
68 		space = (c == ' ');
69 		*walk = (!opts->nocase && c >= 'a' && c <= 'z') ? c - 32 : c;
70 	}
71 	if (space)
72 		return -EINVAL;
73 	if (opts->name_check == 's' && len && c != '.') {
74 		c = *name++;
75 		len--;
76 		if (c != '.')
77 			return -EINVAL;
78 	}
79 	while (c != '.' && len--)
80 		c = *name++;
81 	if (c == '.') {
82 		while (walk - res < 8)
83 			*walk++ = ' ';
84 		while (len > 0 && walk - res < MSDOS_NAME) {
85 			c = *name++;
86 			len--;
87 			if (opts->name_check != 'r' && strchr(bad_chars, c))
88 				return -EINVAL;
89 			if (opts->name_check == 's' &&
90 			    strchr(bad_if_strict, c))
91 				return -EINVAL;
92 			if (c < ' ' || c == ':' || c == '\\')
93 				return -EINVAL;
94 			if (c == '.') {
95 				if (opts->name_check == 's')
96 					return -EINVAL;
97 				break;
98 			}
99 			if (c >= 'A' && c <= 'Z' && opts->name_check == 's')
100 				return -EINVAL;
101 			space = c == ' ';
102 			if (!opts->nocase && c >= 'a' && c <= 'z')
103 				*walk++ = c - 32;
104 			else
105 				*walk++ = c;
106 		}
107 		if (space)
108 			return -EINVAL;
109 		if (opts->name_check == 's' && len)
110 			return -EINVAL;
111 	}
112 	while (walk - res < MSDOS_NAME)
113 		*walk++ = ' ';
114 
115 	return 0;
116 }
117 
118 /***** Locates a directory entry.  Uses unformatted name. */
msdos_find(struct inode * dir,const unsigned char * name,int len,struct fat_slot_info * sinfo)119 static int msdos_find(struct inode *dir, const unsigned char *name, int len,
120 		      struct fat_slot_info *sinfo)
121 {
122 	struct msdos_sb_info *sbi = MSDOS_SB(dir->i_sb);
123 	unsigned char msdos_name[MSDOS_NAME];
124 	int err;
125 
126 	err = msdos_format_name(name, len, msdos_name, &sbi->options);
127 	if (err)
128 		return -ENOENT;
129 
130 	err = fat_scan(dir, msdos_name, sinfo);
131 	if (!err && sbi->options.dotsOK) {
132 		if (name[0] == '.') {
133 			if (!(sinfo->de->attr & ATTR_HIDDEN))
134 				err = -ENOENT;
135 		} else {
136 			if (sinfo->de->attr & ATTR_HIDDEN)
137 				err = -ENOENT;
138 		}
139 		if (err)
140 			brelse(sinfo->bh);
141 	}
142 	return err;
143 }
144 
145 /*
146  * Compute the hash for the msdos name corresponding to the dentry.
147  * Note: if the name is invalid, we leave the hash code unchanged so
148  * that the existing dentry can be used. The msdos fs routines will
149  * return ENOENT or EINVAL as appropriate.
150  */
msdos_hash(const struct dentry * dentry,struct qstr * qstr)151 static int msdos_hash(const struct dentry *dentry, struct qstr *qstr)
152 {
153 	struct fat_mount_options *options = &MSDOS_SB(dentry->d_sb)->options;
154 	unsigned char msdos_name[MSDOS_NAME];
155 	int error;
156 
157 	error = msdos_format_name(qstr->name, qstr->len, msdos_name, options);
158 	if (!error)
159 		qstr->hash = full_name_hash(dentry, msdos_name, MSDOS_NAME);
160 	return 0;
161 }
162 
163 /*
164  * Compare two msdos names. If either of the names are invalid,
165  * we fall back to doing the standard name comparison.
166  */
msdos_cmp(const struct dentry * dentry,unsigned int len,const char * str,const struct qstr * name)167 static int msdos_cmp(const struct dentry *dentry,
168 		unsigned int len, const char *str, const struct qstr *name)
169 {
170 	struct fat_mount_options *options = &MSDOS_SB(dentry->d_sb)->options;
171 	unsigned char a_msdos_name[MSDOS_NAME], b_msdos_name[MSDOS_NAME];
172 	int error;
173 
174 	error = msdos_format_name(name->name, name->len, a_msdos_name, options);
175 	if (error)
176 		goto old_compare;
177 	error = msdos_format_name(str, len, b_msdos_name, options);
178 	if (error)
179 		goto old_compare;
180 	error = memcmp(a_msdos_name, b_msdos_name, MSDOS_NAME);
181 out:
182 	return error;
183 
184 old_compare:
185 	error = 1;
186 	if (name->len == len)
187 		error = memcmp(name->name, str, len);
188 	goto out;
189 }
190 
191 static const struct dentry_operations msdos_dentry_operations = {
192 	.d_hash		= msdos_hash,
193 	.d_compare	= msdos_cmp,
194 };
195 
196 /*
197  * AV. Wrappers for FAT sb operations. Is it wise?
198  */
199 
200 /***** Get inode using directory and name */
msdos_lookup(struct inode * dir,struct dentry * dentry,unsigned int flags)201 static struct dentry *msdos_lookup(struct inode *dir, struct dentry *dentry,
202 				   unsigned int flags)
203 {
204 	struct super_block *sb = dir->i_sb;
205 	struct fat_slot_info sinfo;
206 	struct inode *inode;
207 	int err;
208 
209 	mutex_lock(&MSDOS_SB(sb)->s_lock);
210 	err = msdos_find(dir, dentry->d_name.name, dentry->d_name.len, &sinfo);
211 	switch (err) {
212 	case -ENOENT:
213 		inode = NULL;
214 		break;
215 	case 0:
216 		inode = fat_build_inode(sb, sinfo.de, sinfo.i_pos);
217 		brelse(sinfo.bh);
218 		break;
219 	default:
220 		inode = ERR_PTR(err);
221 	}
222 	mutex_unlock(&MSDOS_SB(sb)->s_lock);
223 	return d_splice_alias(inode, dentry);
224 }
225 
226 /***** Creates a directory entry (name is already formatted). */
msdos_add_entry(struct inode * dir,const unsigned char * name,int is_dir,int is_hid,int cluster,struct timespec64 * ts,struct fat_slot_info * sinfo)227 static int msdos_add_entry(struct inode *dir, const unsigned char *name,
228 			   int is_dir, int is_hid, int cluster,
229 			   struct timespec64 *ts, struct fat_slot_info *sinfo)
230 {
231 	struct msdos_sb_info *sbi = MSDOS_SB(dir->i_sb);
232 	struct msdos_dir_entry de;
233 	__le16 time, date;
234 	int err;
235 
236 	memcpy(de.name, name, MSDOS_NAME);
237 	de.attr = is_dir ? ATTR_DIR : ATTR_ARCH;
238 	if (is_hid)
239 		de.attr |= ATTR_HIDDEN;
240 	de.lcase = 0;
241 	fat_time_unix2fat(sbi, ts, &time, &date, NULL);
242 	de.cdate = de.adate = 0;
243 	de.ctime = 0;
244 	de.ctime_cs = 0;
245 	de.time = time;
246 	de.date = date;
247 	fat_set_start(&de, cluster);
248 	de.size = 0;
249 
250 	err = fat_add_entries(dir, &de, 1, sinfo);
251 	if (err)
252 		return err;
253 
254 	fat_truncate_time(dir, ts, S_CTIME|S_MTIME);
255 	if (IS_DIRSYNC(dir))
256 		(void)fat_sync_inode(dir);
257 	else
258 		mark_inode_dirty(dir);
259 
260 	return 0;
261 }
262 
263 /***** Create a file */
msdos_create(struct mnt_idmap * idmap,struct inode * dir,struct dentry * dentry,umode_t mode,bool excl)264 static int msdos_create(struct mnt_idmap *idmap, struct inode *dir,
265 			struct dentry *dentry, umode_t mode, bool excl)
266 {
267 	struct super_block *sb = dir->i_sb;
268 	struct inode *inode = NULL;
269 	struct fat_slot_info sinfo;
270 	struct timespec64 ts;
271 	unsigned char msdos_name[MSDOS_NAME];
272 	int err, is_hid;
273 
274 	mutex_lock(&MSDOS_SB(sb)->s_lock);
275 
276 	err = msdos_format_name(dentry->d_name.name, dentry->d_name.len,
277 				msdos_name, &MSDOS_SB(sb)->options);
278 	if (err)
279 		goto out;
280 	is_hid = (dentry->d_name.name[0] == '.') && (msdos_name[0] != '.');
281 	/* Have to do it due to foo vs. .foo conflicts */
282 	if (!fat_scan(dir, msdos_name, &sinfo)) {
283 		brelse(sinfo.bh);
284 		err = -EINVAL;
285 		goto out;
286 	}
287 
288 	ts = current_time(dir);
289 	err = msdos_add_entry(dir, msdos_name, 0, is_hid, 0, &ts, &sinfo);
290 	if (err)
291 		goto out;
292 	inode = fat_build_inode(sb, sinfo.de, sinfo.i_pos);
293 	brelse(sinfo.bh);
294 	if (IS_ERR(inode)) {
295 		err = PTR_ERR(inode);
296 		goto out;
297 	}
298 	fat_truncate_time(inode, &ts, S_ATIME|S_CTIME|S_MTIME);
299 	/* timestamp is already written, so mark_inode_dirty() is unneeded. */
300 
301 	d_instantiate(dentry, inode);
302 out:
303 	mutex_unlock(&MSDOS_SB(sb)->s_lock);
304 	if (!err)
305 		err = fat_flush_inodes(sb, dir, inode);
306 	return err;
307 }
308 
309 /***** Remove a directory */
msdos_rmdir(struct inode * dir,struct dentry * dentry)310 static int msdos_rmdir(struct inode *dir, struct dentry *dentry)
311 {
312 	struct super_block *sb = dir->i_sb;
313 	struct inode *inode = d_inode(dentry);
314 	struct fat_slot_info sinfo;
315 	int err;
316 
317 	mutex_lock(&MSDOS_SB(sb)->s_lock);
318 	err = fat_dir_empty(inode);
319 	if (err)
320 		goto out;
321 	err = msdos_find(dir, dentry->d_name.name, dentry->d_name.len, &sinfo);
322 	if (err)
323 		goto out;
324 
325 	err = fat_remove_entries(dir, &sinfo);	/* and releases bh */
326 	if (err)
327 		goto out;
328 	drop_nlink(dir);
329 
330 	clear_nlink(inode);
331 	fat_truncate_time(inode, NULL, S_CTIME);
332 	fat_detach(inode);
333 out:
334 	mutex_unlock(&MSDOS_SB(sb)->s_lock);
335 	if (!err)
336 		err = fat_flush_inodes(sb, dir, inode);
337 
338 	return err;
339 }
340 
341 /***** Make a directory */
msdos_mkdir(struct mnt_idmap * idmap,struct inode * dir,struct dentry * dentry,umode_t mode)342 static int msdos_mkdir(struct mnt_idmap *idmap, struct inode *dir,
343 		       struct dentry *dentry, umode_t mode)
344 {
345 	struct super_block *sb = dir->i_sb;
346 	struct fat_slot_info sinfo;
347 	struct inode *inode;
348 	unsigned char msdos_name[MSDOS_NAME];
349 	struct timespec64 ts;
350 	int err, is_hid, cluster;
351 
352 	mutex_lock(&MSDOS_SB(sb)->s_lock);
353 
354 	err = msdos_format_name(dentry->d_name.name, dentry->d_name.len,
355 				msdos_name, &MSDOS_SB(sb)->options);
356 	if (err)
357 		goto out;
358 	is_hid = (dentry->d_name.name[0] == '.') && (msdos_name[0] != '.');
359 	/* foo vs .foo situation */
360 	if (!fat_scan(dir, msdos_name, &sinfo)) {
361 		brelse(sinfo.bh);
362 		err = -EINVAL;
363 		goto out;
364 	}
365 
366 	ts = current_time(dir);
367 	cluster = fat_alloc_new_dir(dir, &ts);
368 	if (cluster < 0) {
369 		err = cluster;
370 		goto out;
371 	}
372 	err = msdos_add_entry(dir, msdos_name, 1, is_hid, cluster, &ts, &sinfo);
373 	if (err)
374 		goto out_free;
375 	inc_nlink(dir);
376 
377 	inode = fat_build_inode(sb, sinfo.de, sinfo.i_pos);
378 	brelse(sinfo.bh);
379 	if (IS_ERR(inode)) {
380 		err = PTR_ERR(inode);
381 		/* the directory was completed, just return a error */
382 		goto out;
383 	}
384 	set_nlink(inode, 2);
385 	fat_truncate_time(inode, &ts, S_ATIME|S_CTIME|S_MTIME);
386 	/* timestamp is already written, so mark_inode_dirty() is unneeded. */
387 
388 	d_instantiate(dentry, inode);
389 
390 	mutex_unlock(&MSDOS_SB(sb)->s_lock);
391 	fat_flush_inodes(sb, dir, inode);
392 	return 0;
393 
394 out_free:
395 	fat_free_clusters(dir, cluster);
396 out:
397 	mutex_unlock(&MSDOS_SB(sb)->s_lock);
398 	return err;
399 }
400 
401 /***** Unlink a file */
msdos_unlink(struct inode * dir,struct dentry * dentry)402 static int msdos_unlink(struct inode *dir, struct dentry *dentry)
403 {
404 	struct inode *inode = d_inode(dentry);
405 	struct super_block *sb = inode->i_sb;
406 	struct fat_slot_info sinfo;
407 	int err;
408 
409 	mutex_lock(&MSDOS_SB(sb)->s_lock);
410 	err = msdos_find(dir, dentry->d_name.name, dentry->d_name.len, &sinfo);
411 	if (err)
412 		goto out;
413 
414 	err = fat_remove_entries(dir, &sinfo);	/* and releases bh */
415 	if (err)
416 		goto out;
417 	clear_nlink(inode);
418 	fat_truncate_time(inode, NULL, S_CTIME);
419 	fat_detach(inode);
420 out:
421 	mutex_unlock(&MSDOS_SB(sb)->s_lock);
422 	if (!err)
423 		err = fat_flush_inodes(sb, dir, inode);
424 
425 	return err;
426 }
427 
do_msdos_rename(struct inode * old_dir,unsigned char * old_name,struct dentry * old_dentry,struct inode * new_dir,unsigned char * new_name,struct dentry * new_dentry,int is_hid)428 static int do_msdos_rename(struct inode *old_dir, unsigned char *old_name,
429 			   struct dentry *old_dentry,
430 			   struct inode *new_dir, unsigned char *new_name,
431 			   struct dentry *new_dentry, int is_hid)
432 {
433 	struct buffer_head *dotdot_bh;
434 	struct msdos_dir_entry *dotdot_de;
435 	struct inode *old_inode, *new_inode;
436 	struct fat_slot_info old_sinfo, sinfo;
437 	struct timespec64 ts;
438 	loff_t new_i_pos;
439 	int err, old_attrs, is_dir, update_dotdot, corrupt = 0;
440 
441 	old_sinfo.bh = sinfo.bh = dotdot_bh = NULL;
442 	old_inode = d_inode(old_dentry);
443 	new_inode = d_inode(new_dentry);
444 
445 	err = fat_scan(old_dir, old_name, &old_sinfo);
446 	if (err) {
447 		err = -EIO;
448 		goto out;
449 	}
450 
451 	is_dir = S_ISDIR(old_inode->i_mode);
452 	update_dotdot = (is_dir && old_dir != new_dir);
453 	if (update_dotdot) {
454 		if (fat_get_dotdot_entry(old_inode, &dotdot_bh, &dotdot_de)) {
455 			err = -EIO;
456 			goto out;
457 		}
458 	}
459 
460 	old_attrs = MSDOS_I(old_inode)->i_attrs;
461 	err = fat_scan(new_dir, new_name, &sinfo);
462 	if (!err) {
463 		if (!new_inode) {
464 			/* "foo" -> ".foo" case. just change the ATTR_HIDDEN */
465 			if (sinfo.de != old_sinfo.de) {
466 				err = -EINVAL;
467 				goto out;
468 			}
469 			if (is_hid)
470 				MSDOS_I(old_inode)->i_attrs |= ATTR_HIDDEN;
471 			else
472 				MSDOS_I(old_inode)->i_attrs &= ~ATTR_HIDDEN;
473 			if (IS_DIRSYNC(old_dir)) {
474 				err = fat_sync_inode(old_inode);
475 				if (err) {
476 					MSDOS_I(old_inode)->i_attrs = old_attrs;
477 					goto out;
478 				}
479 			} else
480 				mark_inode_dirty(old_inode);
481 
482 			inode_inc_iversion(old_dir);
483 			fat_truncate_time(old_dir, NULL, S_CTIME|S_MTIME);
484 			if (IS_DIRSYNC(old_dir))
485 				(void)fat_sync_inode(old_dir);
486 			else
487 				mark_inode_dirty(old_dir);
488 			goto out;
489 		}
490 	}
491 
492 	ts = current_time(old_inode);
493 	if (new_inode) {
494 		if (err)
495 			goto out;
496 		if (is_dir) {
497 			err = fat_dir_empty(new_inode);
498 			if (err)
499 				goto out;
500 		}
501 		new_i_pos = MSDOS_I(new_inode)->i_pos;
502 		fat_detach(new_inode);
503 	} else {
504 		err = msdos_add_entry(new_dir, new_name, is_dir, is_hid, 0,
505 				      &ts, &sinfo);
506 		if (err)
507 			goto out;
508 		new_i_pos = sinfo.i_pos;
509 	}
510 	inode_inc_iversion(new_dir);
511 
512 	fat_detach(old_inode);
513 	fat_attach(old_inode, new_i_pos);
514 	if (is_hid)
515 		MSDOS_I(old_inode)->i_attrs |= ATTR_HIDDEN;
516 	else
517 		MSDOS_I(old_inode)->i_attrs &= ~ATTR_HIDDEN;
518 	if (IS_DIRSYNC(new_dir)) {
519 		err = fat_sync_inode(old_inode);
520 		if (err)
521 			goto error_inode;
522 	} else
523 		mark_inode_dirty(old_inode);
524 
525 	if (update_dotdot) {
526 		fat_set_start(dotdot_de, MSDOS_I(new_dir)->i_logstart);
527 		mark_buffer_dirty_inode(dotdot_bh, old_inode);
528 		if (IS_DIRSYNC(new_dir)) {
529 			err = sync_dirty_buffer(dotdot_bh);
530 			if (err)
531 				goto error_dotdot;
532 		}
533 		drop_nlink(old_dir);
534 		if (!new_inode)
535 			inc_nlink(new_dir);
536 	}
537 
538 	err = fat_remove_entries(old_dir, &old_sinfo);	/* and releases bh */
539 	old_sinfo.bh = NULL;
540 	if (err)
541 		goto error_dotdot;
542 	inode_inc_iversion(old_dir);
543 	fat_truncate_time(old_dir, &ts, S_CTIME|S_MTIME);
544 	if (IS_DIRSYNC(old_dir))
545 		(void)fat_sync_inode(old_dir);
546 	else
547 		mark_inode_dirty(old_dir);
548 
549 	if (new_inode) {
550 		drop_nlink(new_inode);
551 		if (is_dir)
552 			drop_nlink(new_inode);
553 		fat_truncate_time(new_inode, &ts, S_CTIME);
554 	}
555 out:
556 	brelse(sinfo.bh);
557 	brelse(dotdot_bh);
558 	brelse(old_sinfo.bh);
559 	return err;
560 
561 error_dotdot:
562 	/* data cluster is shared, serious corruption */
563 	corrupt = 1;
564 
565 	if (update_dotdot) {
566 		fat_set_start(dotdot_de, MSDOS_I(old_dir)->i_logstart);
567 		mark_buffer_dirty_inode(dotdot_bh, old_inode);
568 		corrupt |= sync_dirty_buffer(dotdot_bh);
569 	}
570 error_inode:
571 	fat_detach(old_inode);
572 	fat_attach(old_inode, old_sinfo.i_pos);
573 	MSDOS_I(old_inode)->i_attrs = old_attrs;
574 	if (new_inode) {
575 		fat_attach(new_inode, new_i_pos);
576 		if (corrupt)
577 			corrupt |= fat_sync_inode(new_inode);
578 	} else {
579 		/*
580 		 * If new entry was not sharing the data cluster, it
581 		 * shouldn't be serious corruption.
582 		 */
583 		int err2 = fat_remove_entries(new_dir, &sinfo);
584 		if (corrupt)
585 			corrupt |= err2;
586 		sinfo.bh = NULL;
587 	}
588 	if (corrupt < 0) {
589 		fat_fs_error(new_dir->i_sb,
590 			     "%s: Filesystem corrupted (i_pos %lld)",
591 			     __func__, sinfo.i_pos);
592 	}
593 	goto out;
594 }
595 
596 /***** Rename, a wrapper for rename_same_dir & rename_diff_dir */
msdos_rename(struct mnt_idmap * idmap,struct inode * old_dir,struct dentry * old_dentry,struct inode * new_dir,struct dentry * new_dentry,unsigned int flags)597 static int msdos_rename(struct mnt_idmap *idmap,
598 			struct inode *old_dir, struct dentry *old_dentry,
599 			struct inode *new_dir, struct dentry *new_dentry,
600 			unsigned int flags)
601 {
602 	struct super_block *sb = old_dir->i_sb;
603 	unsigned char old_msdos_name[MSDOS_NAME], new_msdos_name[MSDOS_NAME];
604 	int err, is_hid;
605 
606 	if (flags & ~RENAME_NOREPLACE)
607 		return -EINVAL;
608 
609 	mutex_lock(&MSDOS_SB(sb)->s_lock);
610 
611 	err = msdos_format_name(old_dentry->d_name.name,
612 				old_dentry->d_name.len, old_msdos_name,
613 				&MSDOS_SB(old_dir->i_sb)->options);
614 	if (err)
615 		goto out;
616 	err = msdos_format_name(new_dentry->d_name.name,
617 				new_dentry->d_name.len, new_msdos_name,
618 				&MSDOS_SB(new_dir->i_sb)->options);
619 	if (err)
620 		goto out;
621 
622 	is_hid =
623 	     (new_dentry->d_name.name[0] == '.') && (new_msdos_name[0] != '.');
624 
625 	err = do_msdos_rename(old_dir, old_msdos_name, old_dentry,
626 			      new_dir, new_msdos_name, new_dentry, is_hid);
627 out:
628 	mutex_unlock(&MSDOS_SB(sb)->s_lock);
629 	if (!err)
630 		err = fat_flush_inodes(sb, old_dir, new_dir);
631 	return err;
632 }
633 
634 static const struct inode_operations msdos_dir_inode_operations = {
635 	.create		= msdos_create,
636 	.lookup		= msdos_lookup,
637 	.unlink		= msdos_unlink,
638 	.mkdir		= msdos_mkdir,
639 	.rmdir		= msdos_rmdir,
640 	.rename		= msdos_rename,
641 	.setattr	= fat_setattr,
642 	.getattr	= fat_getattr,
643 	.update_time	= fat_update_time,
644 };
645 
setup(struct super_block * sb)646 static void setup(struct super_block *sb)
647 {
648 	MSDOS_SB(sb)->dir_ops = &msdos_dir_inode_operations;
649 	sb->s_d_op = &msdos_dentry_operations;
650 	sb->s_flags |= SB_NOATIME;
651 }
652 
msdos_fill_super(struct super_block * sb,void * data,int silent)653 static int msdos_fill_super(struct super_block *sb, void *data, int silent)
654 {
655 	return fat_fill_super(sb, data, silent, 0, setup);
656 }
657 
msdos_mount(struct file_system_type * fs_type,int flags,const char * dev_name,void * data)658 static struct dentry *msdos_mount(struct file_system_type *fs_type,
659 			int flags, const char *dev_name,
660 			void *data)
661 {
662 	return mount_bdev(fs_type, flags, dev_name, data, msdos_fill_super);
663 }
664 
665 static struct file_system_type msdos_fs_type = {
666 	.owner		= THIS_MODULE,
667 	.name		= "msdos",
668 	.mount		= msdos_mount,
669 	.kill_sb	= kill_block_super,
670 	.fs_flags	= FS_REQUIRES_DEV | FS_ALLOW_IDMAP,
671 };
672 MODULE_ALIAS_FS("msdos");
673 
init_msdos_fs(void)674 static int __init init_msdos_fs(void)
675 {
676 	return register_filesystem(&msdos_fs_type);
677 }
678 
exit_msdos_fs(void)679 static void __exit exit_msdos_fs(void)
680 {
681 	unregister_filesystem(&msdos_fs_type);
682 }
683 
684 MODULE_LICENSE("GPL");
685 MODULE_AUTHOR("Werner Almesberger");
686 MODULE_DESCRIPTION("MS-DOS filesystem support");
687 
688 module_init(init_msdos_fs)
689 module_exit(exit_msdos_fs)
690