1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 *  linux/fs/fat/dir.c
4 *
5 *  directory handling functions for fat-based filesystems
6 *
7 *  Written 1992,1993 by Werner Almesberger
8 *
9 *  Hidden files 1995 by Albert Cahalan <albert@ccs.neu.edu> <adc@coe.neu.edu>
10 *
11 *  VFAT extensions by Gordon Chaffee <chaffee@plateau.cs.berkeley.edu>
12 *  Merged with msdos fs by Henrik Storner <storner@osiris.ping.dk>
13 *  Rewritten for constant inumbers. Plugged buffer overrun in readdir(). AV
14 *  Short name translation 1999, 2001 by Wolfram Pienkoss <wp@bszh.de>
15 */
16
17#include <linux/slab.h>
18#include <linux/compat.h>
19#include <linux/uaccess.h>
20#include <linux/iversion.h>
21#include "fat.h"
22
23/*
24 * Maximum buffer size of short name.
25 * [(MSDOS_NAME + '.') * max one char + nul]
26 * For msdos style, ['.' (hidden) + MSDOS_NAME + '.' + nul]
27 */
28#define FAT_MAX_SHORT_SIZE	((MSDOS_NAME + 1) * NLS_MAX_CHARSET_SIZE + 1)
29/*
30 * Maximum buffer size of unicode chars from slots.
31 * [(max longname slots * 13 (size in a slot) + nul) * sizeof(wchar_t)]
32 */
33#define FAT_MAX_UNI_CHARS	((MSDOS_SLOTS - 1) * 13 + 1)
34#define FAT_MAX_UNI_SIZE	(FAT_MAX_UNI_CHARS * sizeof(wchar_t))
35
36static inline unsigned char fat_tolower(unsigned char c)
37{
38	return ((c >= 'A') && (c <= 'Z')) ? c+32 : c;
39}
40
41static inline loff_t fat_make_i_pos(struct super_block *sb,
42				    struct buffer_head *bh,
43				    struct msdos_dir_entry *de)
44{
45	return ((loff_t)bh->b_blocknr << MSDOS_SB(sb)->dir_per_block_bits)
46		| (de - (struct msdos_dir_entry *)bh->b_data);
47}
48
49static inline void fat_dir_readahead(struct inode *dir, sector_t iblock,
50				     sector_t phys)
51{
52	struct super_block *sb = dir->i_sb;
53	struct msdos_sb_info *sbi = MSDOS_SB(sb);
54	struct buffer_head *bh;
55	int sec;
56
57	/* This is not a first sector of cluster, or sec_per_clus == 1 */
58	if ((iblock & (sbi->sec_per_clus - 1)) || sbi->sec_per_clus == 1)
59		return;
60	/* root dir of FAT12/FAT16 */
61	if (!is_fat32(sbi) && (dir->i_ino == MSDOS_ROOT_INO))
62		return;
63
64	bh = sb_find_get_block(sb, phys);
65	if (bh == NULL || !buffer_uptodate(bh)) {
66		for (sec = 0; sec < sbi->sec_per_clus; sec++)
67			sb_breadahead(sb, phys + sec);
68	}
69	brelse(bh);
70}
71
72/* Returns the inode number of the directory entry at offset pos. If bh is
73   non-NULL, it is brelse'd before. Pos is incremented. The buffer header is
74   returned in bh.
75   AV. Most often we do it item-by-item. Makes sense to optimize.
76   AV. OK, there we go: if both bh and de are non-NULL we assume that we just
77   AV. want the next entry (took one explicit de=NULL in vfat/namei.c).
78   AV. It's done in fat_get_entry() (inlined), here the slow case lives.
79   AV. Additionally, when we return -1 (i.e. reached the end of directory)
80   AV. we make bh NULL.
81 */
82static int fat__get_entry(struct inode *dir, loff_t *pos,
83			  struct buffer_head **bh, struct msdos_dir_entry **de)
84{
85	struct super_block *sb = dir->i_sb;
86	sector_t phys, iblock;
87	unsigned long mapped_blocks;
88	int err, offset;
89
90next:
91	brelse(*bh);
92	*bh = NULL;
93	iblock = *pos >> sb->s_blocksize_bits;
94	err = fat_bmap(dir, iblock, &phys, &mapped_blocks, 0, false);
95	if (err || !phys)
96		return -1;	/* beyond EOF or error */
97
98	fat_dir_readahead(dir, iblock, phys);
99
100	*bh = sb_bread(sb, phys);
101	if (*bh == NULL) {
102		fat_msg_ratelimit(sb, KERN_ERR,
103			"Directory bread(block %llu) failed", (llu)phys);
104		/* skip this block */
105		*pos = (iblock + 1) << sb->s_blocksize_bits;
106		goto next;
107	}
108
109	offset = *pos & (sb->s_blocksize - 1);
110	*pos += sizeof(struct msdos_dir_entry);
111	*de = (struct msdos_dir_entry *)((*bh)->b_data + offset);
112
113	return 0;
114}
115
116static inline int fat_get_entry(struct inode *dir, loff_t *pos,
117				struct buffer_head **bh,
118				struct msdos_dir_entry **de)
119{
120	/* Fast stuff first */
121	if (*bh && *de &&
122	   (*de - (struct msdos_dir_entry *)(*bh)->b_data) <
123				MSDOS_SB(dir->i_sb)->dir_per_block - 1) {
124		*pos += sizeof(struct msdos_dir_entry);
125		(*de)++;
126		return 0;
127	}
128	return fat__get_entry(dir, pos, bh, de);
129}
130
131/*
132 * Convert Unicode 16 to UTF-8, translated Unicode, or ASCII.
133 * If uni_xlate is enabled and we can't get a 1:1 conversion, use a
134 * colon as an escape character since it is normally invalid on the vfat
135 * filesystem. The following four characters are the hexadecimal digits
136 * of Unicode value. This lets us do a full dump and restore of Unicode
137 * filenames. We could get into some trouble with long Unicode names,
138 * but ignore that right now.
139 * Ahem... Stack smashing in ring 0 isn't fun. Fixed.
140 */
141static int uni16_to_x8(struct super_block *sb, unsigned char *ascii,
142		       const wchar_t *uni, int len, struct nls_table *nls)
143{
144	int uni_xlate = MSDOS_SB(sb)->options.unicode_xlate;
145	const wchar_t *ip;
146	wchar_t ec;
147	unsigned char *op;
148	int charlen;
149
150	ip = uni;
151	op = ascii;
152
153	while (*ip && ((len - NLS_MAX_CHARSET_SIZE) > 0)) {
154		ec = *ip++;
155		charlen = nls->uni2char(ec, op, NLS_MAX_CHARSET_SIZE);
156		if (charlen > 0) {
157			op += charlen;
158			len -= charlen;
159		} else {
160			if (uni_xlate == 1) {
161				*op++ = ':';
162				op = hex_byte_pack(op, ec >> 8);
163				op = hex_byte_pack(op, ec);
164				len -= 5;
165			} else {
166				*op++ = '?';
167				len--;
168			}
169		}
170	}
171
172	if (unlikely(*ip)) {
173		fat_msg(sb, KERN_WARNING,
174			"filename was truncated while converting.");
175	}
176
177	*op = 0;
178	return op - ascii;
179}
180
181static inline int fat_uni_to_x8(struct super_block *sb, const wchar_t *uni,
182				unsigned char *buf, int size)
183{
184	struct msdos_sb_info *sbi = MSDOS_SB(sb);
185	if (sbi->options.utf8)
186		return utf16s_to_utf8s(uni, FAT_MAX_UNI_CHARS,
187				UTF16_HOST_ENDIAN, buf, size);
188	else
189		return uni16_to_x8(sb, buf, uni, size, sbi->nls_io);
190}
191
192static inline int
193fat_short2uni(struct nls_table *t, unsigned char *c, int clen, wchar_t *uni)
194{
195	int charlen;
196
197	charlen = t->char2uni(c, clen, uni);
198	if (charlen < 0) {
199		*uni = 0x003f;	/* a question mark */
200		charlen = 1;
201	}
202	return charlen;
203}
204
205static inline int
206fat_short2lower_uni(struct nls_table *t, unsigned char *c,
207		    int clen, wchar_t *uni)
208{
209	int charlen;
210	wchar_t wc;
211
212	charlen = t->char2uni(c, clen, &wc);
213	if (charlen < 0) {
214		*uni = 0x003f;	/* a question mark */
215		charlen = 1;
216	} else if (charlen <= 1) {
217		unsigned char nc = t->charset2lower[*c];
218
219		if (!nc)
220			nc = *c;
221
222		charlen = t->char2uni(&nc, 1, uni);
223		if (charlen < 0) {
224			*uni = 0x003f;	/* a question mark */
225			charlen = 1;
226		}
227	} else
228		*uni = wc;
229
230	return charlen;
231}
232
233static inline int
234fat_shortname2uni(struct nls_table *nls, unsigned char *buf, int buf_size,
235		  wchar_t *uni_buf, unsigned short opt, int lower)
236{
237	int len = 0;
238
239	if (opt & VFAT_SFN_DISPLAY_LOWER)
240		len =  fat_short2lower_uni(nls, buf, buf_size, uni_buf);
241	else if (opt & VFAT_SFN_DISPLAY_WIN95)
242		len = fat_short2uni(nls, buf, buf_size, uni_buf);
243	else if (opt & VFAT_SFN_DISPLAY_WINNT) {
244		if (lower)
245			len = fat_short2lower_uni(nls, buf, buf_size, uni_buf);
246		else
247			len = fat_short2uni(nls, buf, buf_size, uni_buf);
248	} else
249		len = fat_short2uni(nls, buf, buf_size, uni_buf);
250
251	return len;
252}
253
254static inline int fat_name_match(struct msdos_sb_info *sbi,
255				 const unsigned char *a, int a_len,
256				 const unsigned char *b, int b_len)
257{
258	if (a_len != b_len)
259		return 0;
260
261	if (sbi->options.name_check != 's')
262		return !nls_strnicmp(sbi->nls_io, a, b, a_len);
263	else
264		return !memcmp(a, b, a_len);
265}
266
267enum { PARSE_INVALID = 1, PARSE_NOT_LONGNAME, PARSE_EOF, };
268
269/**
270 * fat_parse_long - Parse extended directory entry.
271 *
272 * This function returns zero on success, negative value on error, or one of
273 * the following:
274 *
275 * %PARSE_INVALID - Directory entry is invalid.
276 * %PARSE_NOT_LONGNAME - Directory entry does not contain longname.
277 * %PARSE_EOF - Directory has no more entries.
278 */
279static int fat_parse_long(struct inode *dir, loff_t *pos,
280			  struct buffer_head **bh, struct msdos_dir_entry **de,
281			  wchar_t **unicode, unsigned char *nr_slots)
282{
283	struct msdos_dir_slot *ds;
284	unsigned char id, slot, slots, alias_checksum;
285
286	if (!*unicode) {
287		*unicode = __getname();
288		if (!*unicode) {
289			brelse(*bh);
290			return -ENOMEM;
291		}
292	}
293parse_long:
294	ds = (struct msdos_dir_slot *)*de;
295	id = ds->id;
296	if (!(id & 0x40))
297		return PARSE_INVALID;
298	slots = id & ~0x40;
299	if (slots > 20 || !slots)	/* ceil(256 * 2 / 26) */
300		return PARSE_INVALID;
301	*nr_slots = slots;
302	alias_checksum = ds->alias_checksum;
303
304	slot = slots;
305	while (1) {
306		int offset;
307
308		slot--;
309		offset = slot * 13;
310		fat16_towchar(*unicode + offset, ds->name0_4, 5);
311		fat16_towchar(*unicode + offset + 5, ds->name5_10, 6);
312		fat16_towchar(*unicode + offset + 11, ds->name11_12, 2);
313
314		if (ds->id & 0x40)
315			(*unicode)[offset + 13] = 0;
316		if (fat_get_entry(dir, pos, bh, de) < 0)
317			return PARSE_EOF;
318		if (slot == 0)
319			break;
320		ds = (struct msdos_dir_slot *)*de;
321		if (ds->attr != ATTR_EXT)
322			return PARSE_NOT_LONGNAME;
323		if ((ds->id & ~0x40) != slot)
324			goto parse_long;
325		if (ds->alias_checksum != alias_checksum)
326			goto parse_long;
327	}
328	if ((*de)->name[0] == DELETED_FLAG)
329		return PARSE_INVALID;
330	if ((*de)->attr == ATTR_EXT)
331		goto parse_long;
332	if (IS_FREE((*de)->name) || ((*de)->attr & ATTR_VOLUME))
333		return PARSE_INVALID;
334	if (fat_checksum((*de)->name) != alias_checksum)
335		*nr_slots = 0;
336
337	return 0;
338}
339
340/**
341 * fat_parse_short - Parse MS-DOS (short) directory entry.
342 * @sb:		superblock
343 * @de:		directory entry to parse
344 * @name:	FAT_MAX_SHORT_SIZE array in which to place extracted name
345 * @dot_hidden:	Nonzero == prepend '.' to names with ATTR_HIDDEN
346 *
347 * Returns the number of characters extracted into 'name'.
348 */
349static int fat_parse_short(struct super_block *sb,
350			   const struct msdos_dir_entry *de,
351			   unsigned char *name, int dot_hidden)
352{
353	const struct msdos_sb_info *sbi = MSDOS_SB(sb);
354	int isvfat = sbi->options.isvfat;
355	int nocase = sbi->options.nocase;
356	unsigned short opt_shortname = sbi->options.shortname;
357	struct nls_table *nls_disk = sbi->nls_disk;
358	wchar_t uni_name[14];
359	unsigned char c, work[MSDOS_NAME];
360	unsigned char *ptname = name;
361	int chi, chl, i, j, k;
362	int dotoffset = 0;
363	int name_len = 0, uni_len = 0;
364
365	if (!isvfat && dot_hidden && (de->attr & ATTR_HIDDEN)) {
366		*ptname++ = '.';
367		dotoffset = 1;
368	}
369
370	memcpy(work, de->name, sizeof(work));
371	/* For an explanation of the special treatment of 0x05 in
372	 * filenames, see msdos_format_name in namei_msdos.c
373	 */
374	if (work[0] == 0x05)
375		work[0] = 0xE5;
376
377	/* Filename */
378	for (i = 0, j = 0; i < 8;) {
379		c = work[i];
380		if (!c)
381			break;
382		chl = fat_shortname2uni(nls_disk, &work[i], 8 - i,
383					&uni_name[j++], opt_shortname,
384					de->lcase & CASE_LOWER_BASE);
385		if (chl <= 1) {
386			if (!isvfat)
387				ptname[i] = nocase ? c : fat_tolower(c);
388			i++;
389			if (c != ' ') {
390				name_len = i;
391				uni_len  = j;
392			}
393		} else {
394			uni_len = j;
395			if (isvfat)
396				i += min(chl, 8-i);
397			else {
398				for (chi = 0; chi < chl && i < 8; chi++, i++)
399					ptname[i] = work[i];
400			}
401			if (chl)
402				name_len = i;
403		}
404	}
405
406	i = name_len;
407	j = uni_len;
408	fat_short2uni(nls_disk, ".", 1, &uni_name[j++]);
409	if (!isvfat)
410		ptname[i] = '.';
411	i++;
412
413	/* Extension */
414	for (k = 8; k < MSDOS_NAME;) {
415		c = work[k];
416		if (!c)
417			break;
418		chl = fat_shortname2uni(nls_disk, &work[k], MSDOS_NAME - k,
419					&uni_name[j++], opt_shortname,
420					de->lcase & CASE_LOWER_EXT);
421		if (chl <= 1) {
422			k++;
423			if (!isvfat)
424				ptname[i] = nocase ? c : fat_tolower(c);
425			i++;
426			if (c != ' ') {
427				name_len = i;
428				uni_len  = j;
429			}
430		} else {
431			uni_len = j;
432			if (isvfat) {
433				int offset = min(chl, MSDOS_NAME-k);
434				k += offset;
435				i += offset;
436			} else {
437				for (chi = 0; chi < chl && k < MSDOS_NAME;
438				     chi++, i++, k++) {
439						ptname[i] = work[k];
440				}
441			}
442			if (chl)
443				name_len = i;
444		}
445	}
446
447	if (name_len > 0) {
448		name_len += dotoffset;
449
450		if (sbi->options.isvfat) {
451			uni_name[uni_len] = 0x0000;
452			name_len = fat_uni_to_x8(sb, uni_name, name,
453						 FAT_MAX_SHORT_SIZE);
454		}
455	}
456
457	return name_len;
458}
459
460/*
461 * Return values: negative -> error/not found, 0 -> found.
462 */
463int fat_search_long(struct inode *inode, const unsigned char *name,
464		    int name_len, struct fat_slot_info *sinfo)
465{
466	struct super_block *sb = inode->i_sb;
467	struct msdos_sb_info *sbi = MSDOS_SB(sb);
468	struct buffer_head *bh = NULL;
469	struct msdos_dir_entry *de;
470	unsigned char nr_slots;
471	wchar_t *unicode = NULL;
472	unsigned char bufname[FAT_MAX_SHORT_SIZE];
473	loff_t cpos = 0;
474	int err, len;
475
476	err = -ENOENT;
477	while (1) {
478		if (fat_get_entry(inode, &cpos, &bh, &de) == -1)
479			goto end_of_dir;
480parse_record:
481		nr_slots = 0;
482		if (de->name[0] == DELETED_FLAG)
483			continue;
484		if (de->attr != ATTR_EXT && (de->attr & ATTR_VOLUME))
485			continue;
486		if (de->attr != ATTR_EXT && IS_FREE(de->name))
487			continue;
488		if (de->attr == ATTR_EXT) {
489			int status = fat_parse_long(inode, &cpos, &bh, &de,
490						    &unicode, &nr_slots);
491			if (status < 0) {
492				err = status;
493				goto end_of_dir;
494			} else if (status == PARSE_INVALID)
495				continue;
496			else if (status == PARSE_NOT_LONGNAME)
497				goto parse_record;
498			else if (status == PARSE_EOF)
499				goto end_of_dir;
500		}
501
502		/* Never prepend '.' to hidden files here.
503		 * That is done only for msdos mounts (and only when
504		 * 'dotsOK=yes'); if we are executing here, it is in the
505		 * context of a vfat mount.
506		 */
507		len = fat_parse_short(sb, de, bufname, 0);
508		if (len == 0)
509			continue;
510
511		/* Compare shortname */
512		if (fat_name_match(sbi, name, name_len, bufname, len))
513			goto found;
514
515		if (nr_slots) {
516			void *longname = unicode + FAT_MAX_UNI_CHARS;
517			int size = PATH_MAX - FAT_MAX_UNI_SIZE;
518
519			/* Compare longname */
520			len = fat_uni_to_x8(sb, unicode, longname, size);
521			if (fat_name_match(sbi, name, name_len, longname, len))
522				goto found;
523		}
524	}
525
526found:
527	nr_slots++;	/* include the de */
528	sinfo->slot_off = cpos - nr_slots * sizeof(*de);
529	sinfo->nr_slots = nr_slots;
530	sinfo->de = de;
531	sinfo->bh = bh;
532	sinfo->i_pos = fat_make_i_pos(sb, sinfo->bh, sinfo->de);
533	err = 0;
534end_of_dir:
535	if (unicode)
536		__putname(unicode);
537
538	return err;
539}
540EXPORT_SYMBOL_GPL(fat_search_long);
541
542struct fat_ioctl_filldir_callback {
543	struct dir_context ctx;
544	void __user *dirent;
545	int result;
546	/* for dir ioctl */
547	const char *longname;
548	int long_len;
549	const char *shortname;
550	int short_len;
551};
552
553static int __fat_readdir(struct inode *inode, struct file *file,
554			 struct dir_context *ctx, int short_only,
555			 struct fat_ioctl_filldir_callback *both)
556{
557	struct super_block *sb = inode->i_sb;
558	struct msdos_sb_info *sbi = MSDOS_SB(sb);
559	struct buffer_head *bh;
560	struct msdos_dir_entry *de;
561	unsigned char nr_slots;
562	wchar_t *unicode = NULL;
563	unsigned char bufname[FAT_MAX_SHORT_SIZE];
564	int isvfat = sbi->options.isvfat;
565	const char *fill_name = NULL;
566	int fake_offset = 0;
567	loff_t cpos;
568	int short_len = 0, fill_len = 0;
569	int ret = 0;
570
571	mutex_lock(&sbi->s_lock);
572
573	cpos = ctx->pos;
574	/* Fake . and .. for the root directory. */
575	if (inode->i_ino == MSDOS_ROOT_INO) {
576		if (!dir_emit_dots(file, ctx))
577			goto out;
578		if (ctx->pos == 2) {
579			fake_offset = 1;
580			cpos = 0;
581		}
582	}
583	if (cpos & (sizeof(struct msdos_dir_entry) - 1)) {
584		ret = -ENOENT;
585		goto out;
586	}
587
588	bh = NULL;
589get_new:
590	if (fat_get_entry(inode, &cpos, &bh, &de) == -1)
591		goto end_of_dir;
592parse_record:
593	nr_slots = 0;
594	/*
595	 * Check for long filename entry, but if short_only, we don't
596	 * need to parse long filename.
597	 */
598	if (isvfat && !short_only) {
599		if (de->name[0] == DELETED_FLAG)
600			goto record_end;
601		if (de->attr != ATTR_EXT && (de->attr & ATTR_VOLUME))
602			goto record_end;
603		if (de->attr != ATTR_EXT && IS_FREE(de->name))
604			goto record_end;
605	} else {
606		if ((de->attr & ATTR_VOLUME) || IS_FREE(de->name))
607			goto record_end;
608	}
609
610	if (isvfat && de->attr == ATTR_EXT) {
611		int status = fat_parse_long(inode, &cpos, &bh, &de,
612					    &unicode, &nr_slots);
613		if (status < 0) {
614			bh = NULL;
615			ret = status;
616			goto end_of_dir;
617		} else if (status == PARSE_INVALID)
618			goto record_end;
619		else if (status == PARSE_NOT_LONGNAME)
620			goto parse_record;
621		else if (status == PARSE_EOF)
622			goto end_of_dir;
623
624		if (nr_slots) {
625			void *longname = unicode + FAT_MAX_UNI_CHARS;
626			int size = PATH_MAX - FAT_MAX_UNI_SIZE;
627			int len = fat_uni_to_x8(sb, unicode, longname, size);
628
629			fill_name = longname;
630			fill_len = len;
631			/* !both && !short_only, so we don't need shortname. */
632			if (!both)
633				goto start_filldir;
634
635			short_len = fat_parse_short(sb, de, bufname,
636						    sbi->options.dotsOK);
637			if (short_len == 0)
638				goto record_end;
639			/* hack for fat_ioctl_filldir() */
640			both->longname = fill_name;
641			both->long_len = fill_len;
642			both->shortname = bufname;
643			both->short_len = short_len;
644			fill_name = NULL;
645			fill_len = 0;
646			goto start_filldir;
647		}
648	}
649
650	short_len = fat_parse_short(sb, de, bufname, sbi->options.dotsOK);
651	if (short_len == 0)
652		goto record_end;
653
654	fill_name = bufname;
655	fill_len = short_len;
656
657start_filldir:
658	ctx->pos = cpos - (nr_slots + 1) * sizeof(struct msdos_dir_entry);
659	if (fake_offset && ctx->pos < 2)
660		ctx->pos = 2;
661
662	if (!memcmp(de->name, MSDOS_DOT, MSDOS_NAME)) {
663		if (!dir_emit_dot(file, ctx))
664			goto fill_failed;
665	} else if (!memcmp(de->name, MSDOS_DOTDOT, MSDOS_NAME)) {
666		if (!dir_emit_dotdot(file, ctx))
667			goto fill_failed;
668	} else {
669		unsigned long inum;
670		loff_t i_pos = fat_make_i_pos(sb, bh, de);
671		struct inode *tmp = fat_iget(sb, i_pos);
672		if (tmp) {
673			inum = tmp->i_ino;
674			iput(tmp);
675		} else
676			inum = iunique(sb, MSDOS_ROOT_INO);
677		if (!dir_emit(ctx, fill_name, fill_len, inum,
678			    (de->attr & ATTR_DIR) ? DT_DIR : DT_REG))
679			goto fill_failed;
680	}
681
682record_end:
683	fake_offset = 0;
684	ctx->pos = cpos;
685	goto get_new;
686
687end_of_dir:
688	if (fake_offset && cpos < 2)
689		ctx->pos = 2;
690	else
691		ctx->pos = cpos;
692fill_failed:
693	brelse(bh);
694	if (unicode)
695		__putname(unicode);
696out:
697	mutex_unlock(&sbi->s_lock);
698
699	return ret;
700}
701
702static int fat_readdir(struct file *file, struct dir_context *ctx)
703{
704	return __fat_readdir(file_inode(file), file, ctx, 0, NULL);
705}
706
707#define FAT_IOCTL_FILLDIR_FUNC(func, dirent_type)			   \
708static bool func(struct dir_context *ctx, const char *name, int name_len,  \
709			     loff_t offset, u64 ino, unsigned int d_type)  \
710{									   \
711	struct fat_ioctl_filldir_callback *buf =			   \
712		container_of(ctx, struct fat_ioctl_filldir_callback, ctx); \
713	struct dirent_type __user *d1 = buf->dirent;			   \
714	struct dirent_type __user *d2 = d1 + 1;				   \
715									   \
716	if (buf->result)						   \
717		return false;						   \
718	buf->result++;							   \
719									   \
720	if (name != NULL) {						   \
721		/* dirent has only short name */			   \
722		if (name_len >= sizeof(d1->d_name))			   \
723			name_len = sizeof(d1->d_name) - 1;		   \
724									   \
725		if (put_user(0, &d2->d_name[0])			||	   \
726		    put_user(0, &d2->d_reclen)			||	   \
727		    copy_to_user(d1->d_name, name, name_len)	||	   \
728		    put_user(0, d1->d_name + name_len)		||	   \
729		    put_user(name_len, &d1->d_reclen))			   \
730			goto efault;					   \
731	} else {							   \
732		/* dirent has short and long name */			   \
733		const char *longname = buf->longname;			   \
734		int long_len = buf->long_len;				   \
735		const char *shortname = buf->shortname;			   \
736		int short_len = buf->short_len;				   \
737									   \
738		if (long_len >= sizeof(d1->d_name))			   \
739			long_len = sizeof(d1->d_name) - 1;		   \
740		if (short_len >= sizeof(d1->d_name))			   \
741			short_len = sizeof(d1->d_name) - 1;		   \
742									   \
743		if (copy_to_user(d2->d_name, longname, long_len)	|| \
744		    put_user(0, d2->d_name + long_len)			|| \
745		    put_user(long_len, &d2->d_reclen)			|| \
746		    put_user(ino, &d2->d_ino)				|| \
747		    put_user(offset, &d2->d_off)			|| \
748		    copy_to_user(d1->d_name, shortname, short_len)	|| \
749		    put_user(0, d1->d_name + short_len)			|| \
750		    put_user(short_len, &d1->d_reclen))			   \
751			goto efault;					   \
752	}								   \
753	return true;							   \
754efault:									   \
755	buf->result = -EFAULT;						   \
756	return false;							   \
757}
758
759FAT_IOCTL_FILLDIR_FUNC(fat_ioctl_filldir, __fat_dirent)
760
761static int fat_ioctl_readdir(struct inode *inode, struct file *file,
762			     void __user *dirent, filldir_t filldir,
763			     int short_only, int both)
764{
765	struct fat_ioctl_filldir_callback buf = {
766		.ctx.actor = filldir,
767		.dirent = dirent
768	};
769	int ret;
770
771	buf.dirent = dirent;
772	buf.result = 0;
773	inode_lock_shared(inode);
774	buf.ctx.pos = file->f_pos;
775	ret = -ENOENT;
776	if (!IS_DEADDIR(inode)) {
777		ret = __fat_readdir(inode, file, &buf.ctx,
778				    short_only, both ? &buf : NULL);
779		file->f_pos = buf.ctx.pos;
780	}
781	inode_unlock_shared(inode);
782	if (ret >= 0)
783		ret = buf.result;
784	return ret;
785}
786
787static long fat_dir_ioctl(struct file *filp, unsigned int cmd,
788			  unsigned long arg)
789{
790	struct inode *inode = file_inode(filp);
791	struct __fat_dirent __user *d1 = (struct __fat_dirent __user *)arg;
792	int short_only, both;
793
794	switch (cmd) {
795	case VFAT_IOCTL_READDIR_SHORT:
796		short_only = 1;
797		both = 0;
798		break;
799	case VFAT_IOCTL_READDIR_BOTH:
800		short_only = 0;
801		both = 1;
802		break;
803	default:
804		return fat_generic_ioctl(filp, cmd, arg);
805	}
806
807	/*
808	 * Yes, we don't need this put_user() absolutely. However old
809	 * code didn't return the right value. So, app use this value,
810	 * in order to check whether it is EOF.
811	 */
812	if (put_user(0, &d1->d_reclen))
813		return -EFAULT;
814
815	return fat_ioctl_readdir(inode, filp, d1, fat_ioctl_filldir,
816				 short_only, both);
817}
818
819#ifdef CONFIG_COMPAT
820#define	VFAT_IOCTL_READDIR_BOTH32	_IOR('r', 1, struct compat_dirent[2])
821#define	VFAT_IOCTL_READDIR_SHORT32	_IOR('r', 2, struct compat_dirent[2])
822
823FAT_IOCTL_FILLDIR_FUNC(fat_compat_ioctl_filldir, compat_dirent)
824
825static long fat_compat_dir_ioctl(struct file *filp, unsigned cmd,
826				 unsigned long arg)
827{
828	struct inode *inode = file_inode(filp);
829	struct compat_dirent __user *d1 = compat_ptr(arg);
830	int short_only, both;
831
832	switch (cmd) {
833	case VFAT_IOCTL_READDIR_SHORT32:
834		short_only = 1;
835		both = 0;
836		break;
837	case VFAT_IOCTL_READDIR_BOTH32:
838		short_only = 0;
839		both = 1;
840		break;
841	default:
842		return fat_generic_ioctl(filp, cmd, (unsigned long)arg);
843	}
844
845	/*
846	 * Yes, we don't need this put_user() absolutely. However old
847	 * code didn't return the right value. So, app use this value,
848	 * in order to check whether it is EOF.
849	 */
850	if (put_user(0, &d1->d_reclen))
851		return -EFAULT;
852
853	return fat_ioctl_readdir(inode, filp, d1, fat_compat_ioctl_filldir,
854				 short_only, both);
855}
856#endif /* CONFIG_COMPAT */
857
858const struct file_operations fat_dir_operations = {
859	.llseek		= generic_file_llseek,
860	.read		= generic_read_dir,
861	.iterate_shared	= fat_readdir,
862	.unlocked_ioctl	= fat_dir_ioctl,
863#ifdef CONFIG_COMPAT
864	.compat_ioctl	= fat_compat_dir_ioctl,
865#endif
866	.fsync		= fat_file_fsync,
867};
868
869static int fat_get_short_entry(struct inode *dir, loff_t *pos,
870			       struct buffer_head **bh,
871			       struct msdos_dir_entry **de)
872{
873	while (fat_get_entry(dir, pos, bh, de) >= 0) {
874		/* free entry or long name entry or volume label */
875		if (!IS_FREE((*de)->name) && !((*de)->attr & ATTR_VOLUME))
876			return 0;
877	}
878	return -ENOENT;
879}
880
881/*
882 * The ".." entry can not provide the "struct fat_slot_info" information
883 * for inode, nor a usable i_pos. So, this function provides some information
884 * only.
885 *
886 * Since this function walks through the on-disk inodes within a directory,
887 * callers are responsible for taking any locks necessary to prevent the
888 * directory from changing.
889 */
890int fat_get_dotdot_entry(struct inode *dir, struct buffer_head **bh,
891			 struct msdos_dir_entry **de)
892{
893	loff_t offset = 0;
894
895	*de = NULL;
896	while (fat_get_short_entry(dir, &offset, bh, de) >= 0) {
897		if (!strncmp((*de)->name, MSDOS_DOTDOT, MSDOS_NAME))
898			return 0;
899	}
900	return -ENOENT;
901}
902EXPORT_SYMBOL_GPL(fat_get_dotdot_entry);
903
904/* See if directory is empty */
905int fat_dir_empty(struct inode *dir)
906{
907	struct buffer_head *bh;
908	struct msdos_dir_entry *de;
909	loff_t cpos;
910	int result = 0;
911
912	bh = NULL;
913	cpos = 0;
914	while (fat_get_short_entry(dir, &cpos, &bh, &de) >= 0) {
915		if (strncmp(de->name, MSDOS_DOT   , MSDOS_NAME) &&
916		    strncmp(de->name, MSDOS_DOTDOT, MSDOS_NAME)) {
917			result = -ENOTEMPTY;
918			break;
919		}
920	}
921	brelse(bh);
922	return result;
923}
924EXPORT_SYMBOL_GPL(fat_dir_empty);
925
926/*
927 * fat_subdirs counts the number of sub-directories of dir. It can be run
928 * on directories being created.
929 */
930int fat_subdirs(struct inode *dir)
931{
932	struct buffer_head *bh;
933	struct msdos_dir_entry *de;
934	loff_t cpos;
935	int count = 0;
936
937	bh = NULL;
938	cpos = 0;
939	while (fat_get_short_entry(dir, &cpos, &bh, &de) >= 0) {
940		if (de->attr & ATTR_DIR)
941			count++;
942	}
943	brelse(bh);
944	return count;
945}
946
947/*
948 * Scans a directory for a given file (name points to its formatted name).
949 * Returns an error code or zero.
950 */
951int fat_scan(struct inode *dir, const unsigned char *name,
952	     struct fat_slot_info *sinfo)
953{
954	struct super_block *sb = dir->i_sb;
955
956	sinfo->slot_off = 0;
957	sinfo->bh = NULL;
958	while (fat_get_short_entry(dir, &sinfo->slot_off, &sinfo->bh,
959				   &sinfo->de) >= 0) {
960		if (!strncmp(sinfo->de->name, name, MSDOS_NAME)) {
961			sinfo->slot_off -= sizeof(*sinfo->de);
962			sinfo->nr_slots = 1;
963			sinfo->i_pos = fat_make_i_pos(sb, sinfo->bh, sinfo->de);
964			return 0;
965		}
966	}
967	return -ENOENT;
968}
969EXPORT_SYMBOL_GPL(fat_scan);
970
971/*
972 * Scans a directory for a given logstart.
973 * Returns an error code or zero.
974 */
975int fat_scan_logstart(struct inode *dir, int i_logstart,
976		      struct fat_slot_info *sinfo)
977{
978	struct super_block *sb = dir->i_sb;
979
980	sinfo->slot_off = 0;
981	sinfo->bh = NULL;
982	while (fat_get_short_entry(dir, &sinfo->slot_off, &sinfo->bh,
983				   &sinfo->de) >= 0) {
984		if (fat_get_start(MSDOS_SB(sb), sinfo->de) == i_logstart) {
985			sinfo->slot_off -= sizeof(*sinfo->de);
986			sinfo->nr_slots = 1;
987			sinfo->i_pos = fat_make_i_pos(sb, sinfo->bh, sinfo->de);
988			return 0;
989		}
990	}
991	return -ENOENT;
992}
993
994static int __fat_remove_entries(struct inode *dir, loff_t pos, int nr_slots)
995{
996	struct super_block *sb = dir->i_sb;
997	struct buffer_head *bh;
998	struct msdos_dir_entry *de, *endp;
999	int err = 0, orig_slots;
1000
1001	while (nr_slots) {
1002		bh = NULL;
1003		if (fat_get_entry(dir, &pos, &bh, &de) < 0) {
1004			err = -EIO;
1005			break;
1006		}
1007
1008		orig_slots = nr_slots;
1009		endp = (struct msdos_dir_entry *)(bh->b_data + sb->s_blocksize);
1010		while (nr_slots && de < endp) {
1011			de->name[0] = DELETED_FLAG;
1012			de++;
1013			nr_slots--;
1014		}
1015		mark_buffer_dirty_inode(bh, dir);
1016		if (IS_DIRSYNC(dir))
1017			err = sync_dirty_buffer(bh);
1018		brelse(bh);
1019		if (err)
1020			break;
1021
1022		/* pos is *next* de's position, so this does `- sizeof(de)' */
1023		pos += ((orig_slots - nr_slots) * sizeof(*de)) - sizeof(*de);
1024	}
1025
1026	return err;
1027}
1028
1029int fat_remove_entries(struct inode *dir, struct fat_slot_info *sinfo)
1030{
1031	struct super_block *sb = dir->i_sb;
1032	struct msdos_dir_entry *de;
1033	struct buffer_head *bh;
1034	int err = 0, nr_slots;
1035
1036	/*
1037	 * First stage: Remove the shortname. By this, the directory
1038	 * entry is removed.
1039	 */
1040	nr_slots = sinfo->nr_slots;
1041	de = sinfo->de;
1042	sinfo->de = NULL;
1043	bh = sinfo->bh;
1044	sinfo->bh = NULL;
1045	while (nr_slots && de >= (struct msdos_dir_entry *)bh->b_data) {
1046		de->name[0] = DELETED_FLAG;
1047		de--;
1048		nr_slots--;
1049	}
1050	mark_buffer_dirty_inode(bh, dir);
1051	if (IS_DIRSYNC(dir))
1052		err = sync_dirty_buffer(bh);
1053	brelse(bh);
1054	if (err)
1055		return err;
1056	inode_inc_iversion(dir);
1057
1058	if (nr_slots) {
1059		/*
1060		 * Second stage: remove the remaining longname slots.
1061		 * (This directory entry is already removed, and so return
1062		 * the success)
1063		 */
1064		err = __fat_remove_entries(dir, sinfo->slot_off, nr_slots);
1065		if (err) {
1066			fat_msg(sb, KERN_WARNING,
1067			       "Couldn't remove the long name slots");
1068		}
1069	}
1070
1071	fat_truncate_time(dir, NULL, S_ATIME|S_MTIME);
1072	if (IS_DIRSYNC(dir))
1073		(void)fat_sync_inode(dir);
1074	else
1075		mark_inode_dirty(dir);
1076
1077	return 0;
1078}
1079EXPORT_SYMBOL_GPL(fat_remove_entries);
1080
1081static int fat_zeroed_cluster(struct inode *dir, sector_t blknr, int nr_used,
1082			      struct buffer_head **bhs, int nr_bhs)
1083{
1084	struct super_block *sb = dir->i_sb;
1085	sector_t last_blknr = blknr + MSDOS_SB(sb)->sec_per_clus;
1086	int err, i, n;
1087
1088	/* Zeroing the unused blocks on this cluster */
1089	blknr += nr_used;
1090	n = nr_used;
1091	while (blknr < last_blknr) {
1092		bhs[n] = sb_getblk(sb, blknr);
1093		if (!bhs[n]) {
1094			err = -ENOMEM;
1095			goto error;
1096		}
1097		/* Avoid race with userspace read via bdev */
1098		lock_buffer(bhs[n]);
1099		memset(bhs[n]->b_data, 0, sb->s_blocksize);
1100		set_buffer_uptodate(bhs[n]);
1101		unlock_buffer(bhs[n]);
1102		mark_buffer_dirty_inode(bhs[n], dir);
1103
1104		n++;
1105		blknr++;
1106		if (n == nr_bhs) {
1107			if (IS_DIRSYNC(dir)) {
1108				err = fat_sync_bhs(bhs, n);
1109				if (err)
1110					goto error;
1111			}
1112			for (i = 0; i < n; i++)
1113				brelse(bhs[i]);
1114			n = 0;
1115		}
1116	}
1117	if (IS_DIRSYNC(dir)) {
1118		err = fat_sync_bhs(bhs, n);
1119		if (err)
1120			goto error;
1121	}
1122	for (i = 0; i < n; i++)
1123		brelse(bhs[i]);
1124
1125	return 0;
1126
1127error:
1128	for (i = 0; i < n; i++)
1129		bforget(bhs[i]);
1130	return err;
1131}
1132
1133int fat_alloc_new_dir(struct inode *dir, struct timespec64 *ts)
1134{
1135	struct super_block *sb = dir->i_sb;
1136	struct msdos_sb_info *sbi = MSDOS_SB(sb);
1137	struct buffer_head *bhs[MAX_BUF_PER_PAGE];
1138	struct msdos_dir_entry *de;
1139	sector_t blknr;
1140	__le16 date, time;
1141	u8 time_cs;
1142	int err, cluster;
1143
1144	err = fat_alloc_clusters(dir, &cluster, 1);
1145	if (err)
1146		goto error;
1147
1148	blknr = fat_clus_to_blknr(sbi, cluster);
1149	bhs[0] = sb_getblk(sb, blknr);
1150	if (!bhs[0]) {
1151		err = -ENOMEM;
1152		goto error_free;
1153	}
1154
1155	fat_time_unix2fat(sbi, ts, &time, &date, &time_cs);
1156
1157	de = (struct msdos_dir_entry *)bhs[0]->b_data;
1158	/* Avoid race with userspace read via bdev */
1159	lock_buffer(bhs[0]);
1160	/* filling the new directory slots ("." and ".." entries) */
1161	memcpy(de[0].name, MSDOS_DOT, MSDOS_NAME);
1162	memcpy(de[1].name, MSDOS_DOTDOT, MSDOS_NAME);
1163	de->attr = de[1].attr = ATTR_DIR;
1164	de[0].lcase = de[1].lcase = 0;
1165	de[0].time = de[1].time = time;
1166	de[0].date = de[1].date = date;
1167	if (sbi->options.isvfat) {
1168		/* extra timestamps */
1169		de[0].ctime = de[1].ctime = time;
1170		de[0].ctime_cs = de[1].ctime_cs = time_cs;
1171		de[0].adate = de[0].cdate = de[1].adate = de[1].cdate = date;
1172	} else {
1173		de[0].ctime = de[1].ctime = 0;
1174		de[0].ctime_cs = de[1].ctime_cs = 0;
1175		de[0].adate = de[0].cdate = de[1].adate = de[1].cdate = 0;
1176	}
1177	fat_set_start(&de[0], cluster);
1178	fat_set_start(&de[1], MSDOS_I(dir)->i_logstart);
1179	de[0].size = de[1].size = 0;
1180	memset(de + 2, 0, sb->s_blocksize - 2 * sizeof(*de));
1181	set_buffer_uptodate(bhs[0]);
1182	unlock_buffer(bhs[0]);
1183	mark_buffer_dirty_inode(bhs[0], dir);
1184
1185	err = fat_zeroed_cluster(dir, blknr, 1, bhs, MAX_BUF_PER_PAGE);
1186	if (err)
1187		goto error_free;
1188
1189	return cluster;
1190
1191error_free:
1192	fat_free_clusters(dir, cluster);
1193error:
1194	return err;
1195}
1196EXPORT_SYMBOL_GPL(fat_alloc_new_dir);
1197
1198static int fat_add_new_entries(struct inode *dir, void *slots, int nr_slots,
1199			       int *nr_cluster, struct msdos_dir_entry **de,
1200			       struct buffer_head **bh, loff_t *i_pos)
1201{
1202	struct super_block *sb = dir->i_sb;
1203	struct msdos_sb_info *sbi = MSDOS_SB(sb);
1204	struct buffer_head *bhs[MAX_BUF_PER_PAGE];
1205	sector_t blknr, start_blknr, last_blknr;
1206	unsigned long size, copy;
1207	int err, i, n, offset, cluster[2];
1208
1209	/*
1210	 * The minimum cluster size is 512bytes, and maximum entry
1211	 * size is 32*slots (672bytes).  So, iff the cluster size is
1212	 * 512bytes, we may need two clusters.
1213	 */
1214	size = nr_slots * sizeof(struct msdos_dir_entry);
1215	*nr_cluster = (size + (sbi->cluster_size - 1)) >> sbi->cluster_bits;
1216	BUG_ON(*nr_cluster > 2);
1217
1218	err = fat_alloc_clusters(dir, cluster, *nr_cluster);
1219	if (err)
1220		goto error;
1221
1222	/*
1223	 * First stage: Fill the directory entry.  NOTE: This cluster
1224	 * is not referenced from any inode yet, so updates order is
1225	 * not important.
1226	 */
1227	i = n = copy = 0;
1228	do {
1229		start_blknr = blknr = fat_clus_to_blknr(sbi, cluster[i]);
1230		last_blknr = start_blknr + sbi->sec_per_clus;
1231		while (blknr < last_blknr) {
1232			bhs[n] = sb_getblk(sb, blknr);
1233			if (!bhs[n]) {
1234				err = -ENOMEM;
1235				goto error_nomem;
1236			}
1237
1238			/* fill the directory entry */
1239			copy = min(size, sb->s_blocksize);
1240			/* Avoid race with userspace read via bdev */
1241			lock_buffer(bhs[n]);
1242			memcpy(bhs[n]->b_data, slots, copy);
1243			set_buffer_uptodate(bhs[n]);
1244			unlock_buffer(bhs[n]);
1245			mark_buffer_dirty_inode(bhs[n], dir);
1246			slots += copy;
1247			size -= copy;
1248			if (!size)
1249				break;
1250			n++;
1251			blknr++;
1252		}
1253	} while (++i < *nr_cluster);
1254
1255	memset(bhs[n]->b_data + copy, 0, sb->s_blocksize - copy);
1256	offset = copy - sizeof(struct msdos_dir_entry);
1257	get_bh(bhs[n]);
1258	*bh = bhs[n];
1259	*de = (struct msdos_dir_entry *)((*bh)->b_data + offset);
1260	*i_pos = fat_make_i_pos(sb, *bh, *de);
1261
1262	/* Second stage: clear the rest of cluster, and write outs */
1263	err = fat_zeroed_cluster(dir, start_blknr, ++n, bhs, MAX_BUF_PER_PAGE);
1264	if (err)
1265		goto error_free;
1266
1267	return cluster[0];
1268
1269error_free:
1270	brelse(*bh);
1271	*bh = NULL;
1272	n = 0;
1273error_nomem:
1274	for (i = 0; i < n; i++)
1275		bforget(bhs[i]);
1276	fat_free_clusters(dir, cluster[0]);
1277error:
1278	return err;
1279}
1280
1281int fat_add_entries(struct inode *dir, void *slots, int nr_slots,
1282		    struct fat_slot_info *sinfo)
1283{
1284	struct super_block *sb = dir->i_sb;
1285	struct msdos_sb_info *sbi = MSDOS_SB(sb);
1286	struct buffer_head *bh, *prev, *bhs[3]; /* 32*slots (672bytes) */
1287	struct msdos_dir_entry *de;
1288	int err, free_slots, i, nr_bhs;
1289	loff_t pos, i_pos;
1290
1291	sinfo->nr_slots = nr_slots;
1292
1293	/* First stage: search free directory entries */
1294	free_slots = nr_bhs = 0;
1295	bh = prev = NULL;
1296	pos = 0;
1297	err = -ENOSPC;
1298	while (fat_get_entry(dir, &pos, &bh, &de) > -1) {
1299		/* check the maximum size of directory */
1300		if (pos >= FAT_MAX_DIR_SIZE)
1301			goto error;
1302
1303		if (IS_FREE(de->name)) {
1304			if (prev != bh) {
1305				get_bh(bh);
1306				bhs[nr_bhs] = prev = bh;
1307				nr_bhs++;
1308			}
1309			free_slots++;
1310			if (free_slots == nr_slots)
1311				goto found;
1312		} else {
1313			for (i = 0; i < nr_bhs; i++)
1314				brelse(bhs[i]);
1315			prev = NULL;
1316			free_slots = nr_bhs = 0;
1317		}
1318	}
1319	if (dir->i_ino == MSDOS_ROOT_INO) {
1320		if (!is_fat32(sbi))
1321			goto error;
1322	} else if (MSDOS_I(dir)->i_start == 0) {
1323		fat_msg(sb, KERN_ERR, "Corrupted directory (i_pos %lld)",
1324		       MSDOS_I(dir)->i_pos);
1325		err = -EIO;
1326		goto error;
1327	}
1328
1329found:
1330	err = 0;
1331	pos -= free_slots * sizeof(*de);
1332	nr_slots -= free_slots;
1333	if (free_slots) {
1334		/*
1335		 * Second stage: filling the free entries with new entries.
1336		 * NOTE: If this slots has shortname, first, we write
1337		 * the long name slots, then write the short name.
1338		 */
1339		int size = free_slots * sizeof(*de);
1340		int offset = pos & (sb->s_blocksize - 1);
1341		int long_bhs = nr_bhs - (nr_slots == 0);
1342
1343		/* Fill the long name slots. */
1344		for (i = 0; i < long_bhs; i++) {
1345			int copy = min_t(int, sb->s_blocksize - offset, size);
1346			memcpy(bhs[i]->b_data + offset, slots, copy);
1347			mark_buffer_dirty_inode(bhs[i], dir);
1348			offset = 0;
1349			slots += copy;
1350			size -= copy;
1351		}
1352		if (long_bhs && IS_DIRSYNC(dir))
1353			err = fat_sync_bhs(bhs, long_bhs);
1354		if (!err && i < nr_bhs) {
1355			/* Fill the short name slot. */
1356			int copy = min_t(int, sb->s_blocksize - offset, size);
1357			memcpy(bhs[i]->b_data + offset, slots, copy);
1358			mark_buffer_dirty_inode(bhs[i], dir);
1359			if (IS_DIRSYNC(dir))
1360				err = sync_dirty_buffer(bhs[i]);
1361		}
1362		for (i = 0; i < nr_bhs; i++)
1363			brelse(bhs[i]);
1364		if (err)
1365			goto error_remove;
1366	}
1367
1368	if (nr_slots) {
1369		int cluster, nr_cluster;
1370
1371		/*
1372		 * Third stage: allocate the cluster for new entries.
1373		 * And initialize the cluster with new entries, then
1374		 * add the cluster to dir.
1375		 */
1376		cluster = fat_add_new_entries(dir, slots, nr_slots, &nr_cluster,
1377					      &de, &bh, &i_pos);
1378		if (cluster < 0) {
1379			err = cluster;
1380			goto error_remove;
1381		}
1382		err = fat_chain_add(dir, cluster, nr_cluster);
1383		if (err) {
1384			fat_free_clusters(dir, cluster);
1385			goto error_remove;
1386		}
1387		if (dir->i_size & (sbi->cluster_size - 1)) {
1388			fat_fs_error(sb, "Odd directory size");
1389			dir->i_size = (dir->i_size + sbi->cluster_size - 1)
1390				& ~((loff_t)sbi->cluster_size - 1);
1391		}
1392		dir->i_size += nr_cluster << sbi->cluster_bits;
1393		MSDOS_I(dir)->mmu_private += nr_cluster << sbi->cluster_bits;
1394	}
1395	sinfo->slot_off = pos;
1396	sinfo->de = de;
1397	sinfo->bh = bh;
1398	sinfo->i_pos = fat_make_i_pos(sb, sinfo->bh, sinfo->de);
1399
1400	return 0;
1401
1402error:
1403	brelse(bh);
1404	for (i = 0; i < nr_bhs; i++)
1405		brelse(bhs[i]);
1406	return err;
1407
1408error_remove:
1409	brelse(bh);
1410	if (free_slots)
1411		__fat_remove_entries(dir, pos, free_slots);
1412	return err;
1413}
1414EXPORT_SYMBOL_GPL(fat_add_entries);
1415