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Merge tag 'x86-urgent-2025-01-28' of git://git.kernel.org/pub/scm/linux/kernel/git...
[linux.git] / fs / fat / dir.c
blobacbec5bdd5210ad4bef5848165ecb858adfdee9f
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
36 static inline unsigned char fat_tolower(unsigned char c)
37 {
38 return ((c >= 'A') && (c <= 'Z')) ? c+32 : c;
39 }
40
41 static 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
49 static 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 */
82 static 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
90 next:
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
116 static 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 */
141 static 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
181 static 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
192 static inline int
193 fat_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
205 static inline int
206 fat_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
233 static inline int
234 fat_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
254 static 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
267 enum { PARSE_INVALID = 1, PARSE_NOT_LONGNAME, PARSE_EOF, };
268
269 /**
270 * fat_parse_long - Parse extended directory entry.
271 *
272 * @dir: Pointer to the inode that represents the directory.
273 * @pos: On input, contains the starting position to read from.
274 * On output, updated with the new position.
275 * @bh: Pointer to the buffer head that may be used for reading directory
276 * entries. May be updated.
277 * @de: On input, points to the current directory entry.
278 * On output, points to the next directory entry.
279 * @unicode: Pointer to a buffer where the parsed Unicode long filename will be
280 * stored.
281 * @nr_slots: Pointer to a variable that will store the number of longname
282 * slots found.
283 *
284 * This function returns zero on success, negative value on error, or one of
285 * the following:
286 *
287 * %PARSE_INVALID - Directory entry is invalid.
288 * %PARSE_NOT_LONGNAME - Directory entry does not contain longname.
289 * %PARSE_EOF - Directory has no more entries.
290 */
291 static int fat_parse_long(struct inode *dir, loff_t *pos,
292 struct buffer_head **bh, struct msdos_dir_entry **de,
293 wchar_t **unicode, unsigned char *nr_slots)
294 {
295 struct msdos_dir_slot *ds;
296 unsigned char id, slot, slots, alias_checksum;
297
298 if (!*unicode) {
299 *unicode = __getname();
300 if (!*unicode) {
301 brelse(*bh);
302 return -ENOMEM;
303 }
304 }
305 parse_long:
306 ds = (struct msdos_dir_slot *)*de;
307 id = ds->id;
308 if (!(id & 0x40))
309 return PARSE_INVALID;
310 slots = id & ~0x40;
311 if (slots > 20 || !slots) /* ceil(256 * 2 / 26) */
312 return PARSE_INVALID;
313 *nr_slots = slots;
314 alias_checksum = ds->alias_checksum;
315
316 slot = slots;
317 while (1) {
318 int offset;
319
320 slot--;
321 offset = slot * 13;
322 fat16_towchar(*unicode + offset, ds->name0_4, 5);
323 fat16_towchar(*unicode + offset + 5, ds->name5_10, 6);
324 fat16_towchar(*unicode + offset + 11, ds->name11_12, 2);
325
326 if (ds->id & 0x40)
327 (*unicode)[offset + 13] = 0;
328 if (fat_get_entry(dir, pos, bh, de) < 0)
329 return PARSE_EOF;
330 if (slot == 0)
331 break;
332 ds = (struct msdos_dir_slot *)*de;
333 if (ds->attr != ATTR_EXT)
334 return PARSE_NOT_LONGNAME;
335 if ((ds->id & ~0x40) != slot)
336 goto parse_long;
337 if (ds->alias_checksum != alias_checksum)
338 goto parse_long;
339 }
340 if ((*de)->name[0] == DELETED_FLAG)
341 return PARSE_INVALID;
342 if ((*de)->attr == ATTR_EXT)
343 goto parse_long;
344 if (IS_FREE((*de)->name) || ((*de)->attr & ATTR_VOLUME))
345 return PARSE_INVALID;
346 if (fat_checksum((*de)->name) != alias_checksum)
347 *nr_slots = 0;
348
349 return 0;
350 }
351
352 /**
353 * fat_parse_short - Parse MS-DOS (short) directory entry.
354 * @sb: superblock
355 * @de: directory entry to parse
356 * @name: FAT_MAX_SHORT_SIZE array in which to place extracted name
357 * @dot_hidden: Nonzero == prepend '.' to names with ATTR_HIDDEN
358 *
359 * Returns the number of characters extracted into 'name'.
360 */
361 static int fat_parse_short(struct super_block *sb,
362 const struct msdos_dir_entry *de,
363 unsigned char *name, int dot_hidden)
364 {
365 const struct msdos_sb_info *sbi = MSDOS_SB(sb);
366 int isvfat = sbi->options.isvfat;
367 int nocase = sbi->options.nocase;
368 unsigned short opt_shortname = sbi->options.shortname;
369 struct nls_table *nls_disk = sbi->nls_disk;
370 wchar_t uni_name[14];
371 unsigned char c, work[MSDOS_NAME];
372 unsigned char *ptname = name;
373 int chi, chl, i, j, k;
374 int dotoffset = 0;
375 int name_len = 0, uni_len = 0;
376
377 if (!isvfat && dot_hidden && (de->attr & ATTR_HIDDEN)) {
378 *ptname++ = '.';
379 dotoffset = 1;
380 }
381
382 memcpy(work, de->name, sizeof(work));
383 /* For an explanation of the special treatment of 0x05 in
384 * filenames, see msdos_format_name in namei_msdos.c
385 */
386 if (work[0] == 0x05)
387 work[0] = 0xE5;
388
389 /* Filename */
390 for (i = 0, j = 0; i < 8;) {
391 c = work[i];
392 if (!c)
393 break;
394 chl = fat_shortname2uni(nls_disk, &work[i], 8 - i,
395 &uni_name[j++], opt_shortname,
396 de->lcase & CASE_LOWER_BASE);
397 if (chl <= 1) {
398 if (!isvfat)
399 ptname[i] = nocase ? c : fat_tolower(c);
400 i++;
401 if (c != ' ') {
402 name_len = i;
403 uni_len = j;
404 }
405 } else {
406 uni_len = j;
407 if (isvfat)
408 i += min(chl, 8-i);
409 else {
410 for (chi = 0; chi < chl && i < 8; chi++, i++)
411 ptname[i] = work[i];
412 }
413 if (chl)
414 name_len = i;
415 }
416 }
417
418 i = name_len;
419 j = uni_len;
420 fat_short2uni(nls_disk, ".", 1, &uni_name[j++]);
421 if (!isvfat)
422 ptname[i] = '.';
423 i++;
424
425 /* Extension */
426 for (k = 8; k < MSDOS_NAME;) {
427 c = work[k];
428 if (!c)
429 break;
430 chl = fat_shortname2uni(nls_disk, &work[k], MSDOS_NAME - k,
431 &uni_name[j++], opt_shortname,
432 de->lcase & CASE_LOWER_EXT);
433 if (chl <= 1) {
434 k++;
435 if (!isvfat)
436 ptname[i] = nocase ? c : fat_tolower(c);
437 i++;
438 if (c != ' ') {
439 name_len = i;
440 uni_len = j;
441 }
442 } else {
443 uni_len = j;
444 if (isvfat) {
445 int offset = min(chl, MSDOS_NAME-k);
446 k += offset;
447 i += offset;
448 } else {
449 for (chi = 0; chi < chl && k < MSDOS_NAME;
450 chi++, i++, k++) {
451 ptname[i] = work[k];
452 }
453 }
454 if (chl)
455 name_len = i;
456 }
457 }
458
459 if (name_len > 0) {
460 name_len += dotoffset;
461
462 if (sbi->options.isvfat) {
463 uni_name[uni_len] = 0x0000;
464 name_len = fat_uni_to_x8(sb, uni_name, name,
465 FAT_MAX_SHORT_SIZE);
466 }
467 }
468
469 return name_len;
470 }
471
472 /*
473 * Return values: negative -> error/not found, 0 -> found.
474 */
475 int fat_search_long(struct inode *inode, const unsigned char *name,
476 int name_len, struct fat_slot_info *sinfo)
477 {
478 struct super_block *sb = inode->i_sb;
479 struct msdos_sb_info *sbi = MSDOS_SB(sb);
480 struct buffer_head *bh = NULL;
481 struct msdos_dir_entry *de;
482 unsigned char nr_slots;
483 wchar_t *unicode = NULL;
484 unsigned char bufname[FAT_MAX_SHORT_SIZE];
485 loff_t cpos = 0;
486 int err, len;
487
488 err = -ENOENT;
489 while (1) {
490 if (fat_get_entry(inode, &cpos, &bh, &de) == -1)
491 goto end_of_dir;
492 parse_record:
493 nr_slots = 0;
494 if (de->name[0] == DELETED_FLAG)
495 continue;
496 if (de->attr != ATTR_EXT && (de->attr & ATTR_VOLUME))
497 continue;
498 if (de->attr != ATTR_EXT && IS_FREE(de->name))
499 continue;
500 if (de->attr == ATTR_EXT) {
501 int status = fat_parse_long(inode, &cpos, &bh, &de,
502 &unicode, &nr_slots);
503 if (status < 0) {
504 err = status;
505 goto end_of_dir;
506 } else if (status == PARSE_INVALID)
507 continue;
508 else if (status == PARSE_NOT_LONGNAME)
509 goto parse_record;
510 else if (status == PARSE_EOF)
511 goto end_of_dir;
512 }
513
514 /* Never prepend '.' to hidden files here.
515 * That is done only for msdos mounts (and only when
516 * 'dotsOK=yes'); if we are executing here, it is in the
517 * context of a vfat mount.
518 */
519 len = fat_parse_short(sb, de, bufname, 0);
520 if (len == 0)
521 continue;
522
523 /* Compare shortname */
524 if (fat_name_match(sbi, name, name_len, bufname, len))
525 goto found;
526
527 if (nr_slots) {
528 void *longname = unicode + FAT_MAX_UNI_CHARS;
529 int size = PATH_MAX - FAT_MAX_UNI_SIZE;
530
531 /* Compare longname */
532 len = fat_uni_to_x8(sb, unicode, longname, size);
533 if (fat_name_match(sbi, name, name_len, longname, len))
534 goto found;
535 }
536 }
537
538 found:
539 nr_slots++; /* include the de */
540 sinfo->slot_off = cpos - nr_slots * sizeof(*de);
541 sinfo->nr_slots = nr_slots;
542 sinfo->de = de;
543 sinfo->bh = bh;
544 sinfo->i_pos = fat_make_i_pos(sb, sinfo->bh, sinfo->de);
545 err = 0;
546 end_of_dir:
547 if (unicode)
548 __putname(unicode);
549
550 return err;
551 }
552 EXPORT_SYMBOL_GPL(fat_search_long);
553
554 struct fat_ioctl_filldir_callback {
555 struct dir_context ctx;
556 void __user *dirent;
557 int result;
558 /* for dir ioctl */
559 const char *longname;
560 int long_len;
561 const char *shortname;
562 int short_len;
563 };
564
565 static int __fat_readdir(struct inode *inode, struct file *file,
566 struct dir_context *ctx, int short_only,
567 struct fat_ioctl_filldir_callback *both)
568 {
569 struct super_block *sb = inode->i_sb;
570 struct msdos_sb_info *sbi = MSDOS_SB(sb);
571 struct buffer_head *bh;
572 struct msdos_dir_entry *de;
573 unsigned char nr_slots;
574 wchar_t *unicode = NULL;
575 unsigned char bufname[FAT_MAX_SHORT_SIZE];
576 int isvfat = sbi->options.isvfat;
577 const char *fill_name = NULL;
578 int fake_offset = 0;
579 loff_t cpos;
580 int short_len = 0, fill_len = 0;
581 int ret = 0;
582
583 mutex_lock(&sbi->s_lock);
584
585 cpos = ctx->pos;
586 /* Fake . and .. for the root directory. */
587 if (inode->i_ino == MSDOS_ROOT_INO) {
588 if (!dir_emit_dots(file, ctx))
589 goto out;
590 if (ctx->pos == 2) {
591 fake_offset = 1;
592 cpos = 0;
593 }
594 }
595 if (cpos & (sizeof(struct msdos_dir_entry) - 1)) {
596 ret = -ENOENT;
597 goto out;
598 }
599
600 bh = NULL;
601 get_new:
602 if (fat_get_entry(inode, &cpos, &bh, &de) == -1)
603 goto end_of_dir;
604 parse_record:
605 nr_slots = 0;
606 /*
607 * Check for long filename entry, but if short_only, we don't
608 * need to parse long filename.
609 */
610 if (isvfat && !short_only) {
611 if (de->name[0] == DELETED_FLAG)
612 goto record_end;
613 if (de->attr != ATTR_EXT && (de->attr & ATTR_VOLUME))
614 goto record_end;
615 if (de->attr != ATTR_EXT && IS_FREE(de->name))
616 goto record_end;
617 } else {
618 if ((de->attr & ATTR_VOLUME) || IS_FREE(de->name))
619 goto record_end;
620 }
621
622 if (isvfat && de->attr == ATTR_EXT) {
623 int status = fat_parse_long(inode, &cpos, &bh, &de,
624 &unicode, &nr_slots);
625 if (status < 0) {
626 bh = NULL;
627 ret = status;
628 goto end_of_dir;
629 } else if (status == PARSE_INVALID)
630 goto record_end;
631 else if (status == PARSE_NOT_LONGNAME)
632 goto parse_record;
633 else if (status == PARSE_EOF)
634 goto end_of_dir;
635
636 if (nr_slots) {
637 void *longname = unicode + FAT_MAX_UNI_CHARS;
638 int size = PATH_MAX - FAT_MAX_UNI_SIZE;
639 int len = fat_uni_to_x8(sb, unicode, longname, size);
640
641 fill_name = longname;
642 fill_len = len;
643 /* !both && !short_only, so we don't need shortname. */
644 if (!both)
645 goto start_filldir;
646
647 short_len = fat_parse_short(sb, de, bufname,
648 sbi->options.dotsOK);
649 if (short_len == 0)
650 goto record_end;
651 /* hack for fat_ioctl_filldir() */
652 both->longname = fill_name;
653 both->long_len = fill_len;
654 both->shortname = bufname;
655 both->short_len = short_len;
656 fill_name = NULL;
657 fill_len = 0;
658 goto start_filldir;
659 }
660 }
661
662 short_len = fat_parse_short(sb, de, bufname, sbi->options.dotsOK);
663 if (short_len == 0)
664 goto record_end;
665
666 fill_name = bufname;
667 fill_len = short_len;
668
669 start_filldir:
670 ctx->pos = cpos - (nr_slots + 1) * sizeof(struct msdos_dir_entry);
671 if (fake_offset && ctx->pos < 2)
672 ctx->pos = 2;
673
674 if (!memcmp(de->name, MSDOS_DOT, MSDOS_NAME)) {
675 if (!dir_emit_dot(file, ctx))
676 goto fill_failed;
677 } else if (!memcmp(de->name, MSDOS_DOTDOT, MSDOS_NAME)) {
678 if (!dir_emit_dotdot(file, ctx))
679 goto fill_failed;
680 } else {
681 unsigned long inum;
682 loff_t i_pos = fat_make_i_pos(sb, bh, de);
683 struct inode *tmp = fat_iget(sb, i_pos);
684 if (tmp) {
685 inum = tmp->i_ino;
686 iput(tmp);
687 } else
688 inum = iunique(sb, MSDOS_ROOT_INO);
689 if (!dir_emit(ctx, fill_name, fill_len, inum,
690 (de->attr & ATTR_DIR) ? DT_DIR : DT_REG))
691 goto fill_failed;
692 }
693
694 record_end:
695 fake_offset = 0;
696 ctx->pos = cpos;
697 goto get_new;
698
699 end_of_dir:
700 if (fake_offset && cpos < 2)
701 ctx->pos = 2;
702 else
703 ctx->pos = cpos;
704 fill_failed:
705 brelse(bh);
706 if (unicode)
707 __putname(unicode);
708 out:
709 mutex_unlock(&sbi->s_lock);
710
711 return ret;
712 }
713
714 static int fat_readdir(struct file *file, struct dir_context *ctx)
715 {
716 return __fat_readdir(file_inode(file), file, ctx, 0, NULL);
717 }
718
719 #define FAT_IOCTL_FILLDIR_FUNC(func, dirent_type) \
720 static bool func(struct dir_context *ctx, const char *name, int name_len, \
721 loff_t offset, u64 ino, unsigned int d_type) \
722 { \
723 struct fat_ioctl_filldir_callback *buf = \
724 container_of(ctx, struct fat_ioctl_filldir_callback, ctx); \
725 struct dirent_type __user *d1 = buf->dirent; \
726 struct dirent_type __user *d2 = d1 + 1; \
727 \
728 if (buf->result) \
729 return false; \
730 buf->result++; \
731 \
732 if (name != NULL) { \
733 /* dirent has only short name */ \
734 if (name_len >= sizeof(d1->d_name)) \
735 name_len = sizeof(d1->d_name) - 1; \
736 \
737 if (put_user(0, &d2->d_name[0]) || \
738 put_user(0, &d2->d_reclen) || \
739 copy_to_user(d1->d_name, name, name_len) || \
740 put_user(0, d1->d_name + name_len) || \
741 put_user(name_len, &d1->d_reclen)) \
742 goto efault; \
743 } else { \
744 /* dirent has short and long name */ \
745 const char *longname = buf->longname; \
746 int long_len = buf->long_len; \
747 const char *shortname = buf->shortname; \
748 int short_len = buf->short_len; \
749 \
750 if (long_len >= sizeof(d1->d_name)) \
751 long_len = sizeof(d1->d_name) - 1; \
752 if (short_len >= sizeof(d1->d_name)) \
753 short_len = sizeof(d1->d_name) - 1; \
754 \
755 if (copy_to_user(d2->d_name, longname, long_len) || \
756 put_user(0, d2->d_name + long_len) || \
757 put_user(long_len, &d2->d_reclen) || \
758 put_user(ino, &d2->d_ino) || \
759 put_user(offset, &d2->d_off) || \
760 copy_to_user(d1->d_name, shortname, short_len) || \
761 put_user(0, d1->d_name + short_len) || \
762 put_user(short_len, &d1->d_reclen)) \
763 goto efault; \
764 } \
765 return true; \
766 efault: \
767 buf->result = -EFAULT; \
768 return false; \
769 }
770
771 FAT_IOCTL_FILLDIR_FUNC(fat_ioctl_filldir, __fat_dirent)
772
773 static int fat_ioctl_readdir(struct inode *inode, struct file *file,
774 void __user *dirent, filldir_t filldir,
775 int short_only, int both)
776 {
777 struct fat_ioctl_filldir_callback buf = {
778 .ctx.actor = filldir,
779 .dirent = dirent
780 };
781 int ret;
782
783 buf.dirent = dirent;
784 buf.result = 0;
785 inode_lock_shared(inode);
786 buf.ctx.pos = file->f_pos;
787 ret = -ENOENT;
788 if (!IS_DEADDIR(inode)) {
789 ret = __fat_readdir(inode, file, &buf.ctx,
790 short_only, both ? &buf : NULL);
791 file->f_pos = buf.ctx.pos;
792 }
793 inode_unlock_shared(inode);
794 if (ret >= 0)
795 ret = buf.result;
796 return ret;
797 }
798
799 static long fat_dir_ioctl(struct file *filp, unsigned int cmd,
800 unsigned long arg)
801 {
802 struct inode *inode = file_inode(filp);
803 struct __fat_dirent __user *d1 = (struct __fat_dirent __user *)arg;
804 int short_only, both;
805
806 switch (cmd) {
807 case VFAT_IOCTL_READDIR_SHORT:
808 short_only = 1;
809 both = 0;
810 break;
811 case VFAT_IOCTL_READDIR_BOTH:
812 short_only = 0;
813 both = 1;
814 break;
815 default:
816 return fat_generic_ioctl(filp, cmd, arg);
817 }
818
819 /*
820 * Yes, we don't need this put_user() absolutely. However old
821 * code didn't return the right value. So, app use this value,
822 * in order to check whether it is EOF.
823 */
824 if (put_user(0, &d1->d_reclen))
825 return -EFAULT;
826
827 return fat_ioctl_readdir(inode, filp, d1, fat_ioctl_filldir,
828 short_only, both);
829 }
830
831 #ifdef CONFIG_COMPAT
832 #define VFAT_IOCTL_READDIR_BOTH32 _IOR('r', 1, struct compat_dirent[2])
833 #define VFAT_IOCTL_READDIR_SHORT32 _IOR('r', 2, struct compat_dirent[2])
834
835 FAT_IOCTL_FILLDIR_FUNC(fat_compat_ioctl_filldir, compat_dirent)
836
837 static long fat_compat_dir_ioctl(struct file *filp, unsigned cmd,
838 unsigned long arg)
839 {
840 struct inode *inode = file_inode(filp);
841 struct compat_dirent __user *d1 = compat_ptr(arg);
842 int short_only, both;
843
844 switch (cmd) {
845 case VFAT_IOCTL_READDIR_SHORT32:
846 short_only = 1;
847 both = 0;
848 break;
849 case VFAT_IOCTL_READDIR_BOTH32:
850 short_only = 0;
851 both = 1;
852 break;
853 default:
854 return fat_generic_ioctl(filp, cmd, (unsigned long)arg);
855 }
856
857 /*
858 * Yes, we don't need this put_user() absolutely. However old
859 * code didn't return the right value. So, app use this value,
860 * in order to check whether it is EOF.
861 */
862 if (put_user(0, &d1->d_reclen))
863 return -EFAULT;
864
865 return fat_ioctl_readdir(inode, filp, d1, fat_compat_ioctl_filldir,
866 short_only, both);
867 }
868 #endif /* CONFIG_COMPAT */
869
870 const struct file_operations fat_dir_operations = {
871 .llseek = generic_file_llseek,
872 .read = generic_read_dir,
873 .iterate_shared = fat_readdir,
874 .unlocked_ioctl = fat_dir_ioctl,
875 #ifdef CONFIG_COMPAT
876 .compat_ioctl = fat_compat_dir_ioctl,
877 #endif
878 .fsync = fat_file_fsync,
879 };
880
881 static int fat_get_short_entry(struct inode *dir, loff_t *pos,
882 struct buffer_head **bh,
883 struct msdos_dir_entry **de)
884 {
885 while (fat_get_entry(dir, pos, bh, de) >= 0) {
886 /* free entry or long name entry or volume label */
887 if (!IS_FREE((*de)->name) && !((*de)->attr & ATTR_VOLUME))
888 return 0;
889 }
890 return -ENOENT;
891 }
892
893 /*
894 * The ".." entry can not provide the "struct fat_slot_info" information
895 * for inode, nor a usable i_pos. So, this function provides some information
896 * only.
897 *
898 * Since this function walks through the on-disk inodes within a directory,
899 * callers are responsible for taking any locks necessary to prevent the
900 * directory from changing.
901 */
902 int fat_get_dotdot_entry(struct inode *dir, struct buffer_head **bh,
903 struct msdos_dir_entry **de)
904 {
905 loff_t offset = 0;
906
907 *de = NULL;
908 while (fat_get_short_entry(dir, &offset, bh, de) >= 0) {
909 if (!strncmp((*de)->name, MSDOS_DOTDOT, MSDOS_NAME))
910 return 0;
911 }
912 return -ENOENT;
913 }
914 EXPORT_SYMBOL_GPL(fat_get_dotdot_entry);
915
916 /* See if directory is empty */
917 int fat_dir_empty(struct inode *dir)
918 {
919 struct buffer_head *bh;
920 struct msdos_dir_entry *de;
921 loff_t cpos;
922 int result = 0;
923
924 bh = NULL;
925 cpos = 0;
926 while (fat_get_short_entry(dir, &cpos, &bh, &de) >= 0) {
927 if (strncmp(de->name, MSDOS_DOT , MSDOS_NAME) &&
928 strncmp(de->name, MSDOS_DOTDOT, MSDOS_NAME)) {
929 result = -ENOTEMPTY;
930 break;
931 }
932 }
933 brelse(bh);
934 return result;
935 }
936 EXPORT_SYMBOL_GPL(fat_dir_empty);
937
938 /*
939 * fat_subdirs counts the number of sub-directories of dir. It can be run
940 * on directories being created.
941 */
942 int fat_subdirs(struct inode *dir)
943 {
944 struct buffer_head *bh;
945 struct msdos_dir_entry *de;
946 loff_t cpos;
947 int count = 0;
948
949 bh = NULL;
950 cpos = 0;
951 while (fat_get_short_entry(dir, &cpos, &bh, &de) >= 0) {
952 if (de->attr & ATTR_DIR)
953 count++;
954 }
955 brelse(bh);
956 return count;
957 }
958
959 /*
960 * Scans a directory for a given file (name points to its formatted name).
961 * Returns an error code or zero.
962 */
963 int fat_scan(struct inode *dir, const unsigned char *name,
964 struct fat_slot_info *sinfo)
965 {
966 struct super_block *sb = dir->i_sb;
967
968 sinfo->slot_off = 0;
969 sinfo->bh = NULL;
970 while (fat_get_short_entry(dir, &sinfo->slot_off, &sinfo->bh,
971 &sinfo->de) >= 0) {
972 if (!strncmp(sinfo->de->name, name, MSDOS_NAME)) {
973 sinfo->slot_off -= sizeof(*sinfo->de);
974 sinfo->nr_slots = 1;
975 sinfo->i_pos = fat_make_i_pos(sb, sinfo->bh, sinfo->de);
976 return 0;
977 }
978 }
979 return -ENOENT;
980 }
981 EXPORT_SYMBOL_GPL(fat_scan);
982
983 /*
984 * Scans a directory for a given logstart.
985 * Returns an error code or zero.
986 */
987 int fat_scan_logstart(struct inode *dir, int i_logstart,
988 struct fat_slot_info *sinfo)
989 {
990 struct super_block *sb = dir->i_sb;
991
992 sinfo->slot_off = 0;
993 sinfo->bh = NULL;
994 while (fat_get_short_entry(dir, &sinfo->slot_off, &sinfo->bh,
995 &sinfo->de) >= 0) {
996 if (fat_get_start(MSDOS_SB(sb), sinfo->de) == i_logstart) {
997 sinfo->slot_off -= sizeof(*sinfo->de);
998 sinfo->nr_slots = 1;
999 sinfo->i_pos = fat_make_i_pos(sb, sinfo->bh, sinfo->de);
1000 return 0;
1001 }
1002 }
1003 return -ENOENT;
1004 }
1005
1006 static int __fat_remove_entries(struct inode *dir, loff_t pos, int nr_slots)
1007 {
1008 struct super_block *sb = dir->i_sb;
1009 struct buffer_head *bh;
1010 struct msdos_dir_entry *de, *endp;
1011 int err = 0, orig_slots;
1012
1013 while (nr_slots) {
1014 bh = NULL;
1015 if (fat_get_entry(dir, &pos, &bh, &de) < 0) {
1016 err = -EIO;
1017 break;
1018 }
1019
1020 orig_slots = nr_slots;
1021 endp = (struct msdos_dir_entry *)(bh->b_data + sb->s_blocksize);
1022 while (nr_slots && de < endp) {
1023 de->name[0] = DELETED_FLAG;
1024 de++;
1025 nr_slots--;
1026 }
1027 mark_buffer_dirty_inode(bh, dir);
1028 if (IS_DIRSYNC(dir))
1029 err = sync_dirty_buffer(bh);
1030 brelse(bh);
1031 if (err)
1032 break;
1033
1034 /* pos is *next* de's position, so this does `- sizeof(de)' */
1035 pos += ((orig_slots - nr_slots) * sizeof(*de)) - sizeof(*de);
1036 }
1037
1038 return err;
1039 }
1040
1041 int fat_remove_entries(struct inode *dir, struct fat_slot_info *sinfo)
1042 {
1043 struct super_block *sb = dir->i_sb;
1044 struct msdos_dir_entry *de;
1045 struct buffer_head *bh;
1046 int err = 0, nr_slots;
1047
1048 /*
1049 * First stage: Remove the shortname. By this, the directory
1050 * entry is removed.
1051 */
1052 nr_slots = sinfo->nr_slots;
1053 de = sinfo->de;
1054 sinfo->de = NULL;
1055 bh = sinfo->bh;
1056 sinfo->bh = NULL;
1057 while (nr_slots && de >= (struct msdos_dir_entry *)bh->b_data) {
1058 de->name[0] = DELETED_FLAG;
1059 de--;
1060 nr_slots--;
1061 }
1062 mark_buffer_dirty_inode(bh, dir);
1063 if (IS_DIRSYNC(dir))
1064 err = sync_dirty_buffer(bh);
1065 brelse(bh);
1066 if (err)
1067 return err;
1068 inode_inc_iversion(dir);
1069
1070 if (nr_slots) {
1071 /*
1072 * Second stage: remove the remaining longname slots.
1073 * (This directory entry is already removed, and so return
1074 * the success)
1075 */
1076 err = __fat_remove_entries(dir, sinfo->slot_off, nr_slots);
1077 if (err) {
1078 fat_msg(sb, KERN_WARNING,
1079 "Couldn't remove the long name slots");
1080 }
1081 }
1082
1083 fat_truncate_time(dir, NULL, S_ATIME|S_MTIME);
1084 if (IS_DIRSYNC(dir))
1085 (void)fat_sync_inode(dir);
1086 else
1087 mark_inode_dirty(dir);
1088
1089 return 0;
1090 }
1091 EXPORT_SYMBOL_GPL(fat_remove_entries);
1092
1093 static int fat_zeroed_cluster(struct inode *dir, sector_t blknr, int nr_used,
1094 struct buffer_head **bhs, int nr_bhs)
1095 {
1096 struct super_block *sb = dir->i_sb;
1097 sector_t last_blknr = blknr + MSDOS_SB(sb)->sec_per_clus;
1098 int err, i, n;
1099
1100 /* Zeroing the unused blocks on this cluster */
1101 blknr += nr_used;
1102 n = nr_used;
1103 while (blknr < last_blknr) {
1104 bhs[n] = sb_getblk(sb, blknr);
1105 if (!bhs[n]) {
1106 err = -ENOMEM;
1107 goto error;
1108 }
1109 /* Avoid race with userspace read via bdev */
1110 lock_buffer(bhs[n]);
1111 memset(bhs[n]->b_data, 0, sb->s_blocksize);
1112 set_buffer_uptodate(bhs[n]);
1113 unlock_buffer(bhs[n]);
1114 mark_buffer_dirty_inode(bhs[n], dir);
1115
1116 n++;
1117 blknr++;
1118 if (n == nr_bhs) {
1119 if (IS_DIRSYNC(dir)) {
1120 err = fat_sync_bhs(bhs, n);
1121 if (err)
1122 goto error;
1123 }
1124 for (i = 0; i < n; i++)
1125 brelse(bhs[i]);
1126 n = 0;
1127 }
1128 }
1129 if (IS_DIRSYNC(dir)) {
1130 err = fat_sync_bhs(bhs, n);
1131 if (err)
1132 goto error;
1133 }
1134 for (i = 0; i < n; i++)
1135 brelse(bhs[i]);
1136
1137 return 0;
1138
1139 error:
1140 for (i = 0; i < n; i++)
1141 bforget(bhs[i]);
1142 return err;
1143 }
1144
1145 int fat_alloc_new_dir(struct inode *dir, struct timespec64 *ts)
1146 {
1147 struct super_block *sb = dir->i_sb;
1148 struct msdos_sb_info *sbi = MSDOS_SB(sb);
1149 struct buffer_head *bhs[MAX_BUF_PER_PAGE];
1150 struct msdos_dir_entry *de;
1151 sector_t blknr;
1152 __le16 date, time;
1153 u8 time_cs;
1154 int err, cluster;
1155
1156 err = fat_alloc_clusters(dir, &cluster, 1);
1157 if (err)
1158 goto error;
1159
1160 blknr = fat_clus_to_blknr(sbi, cluster);
1161 bhs[0] = sb_getblk(sb, blknr);
1162 if (!bhs[0]) {
1163 err = -ENOMEM;
1164 goto error_free;
1165 }
1166
1167 fat_time_unix2fat(sbi, ts, &time, &date, &time_cs);
1168
1169 de = (struct msdos_dir_entry *)bhs[0]->b_data;
1170 /* Avoid race with userspace read via bdev */
1171 lock_buffer(bhs[0]);
1172 /* filling the new directory slots ("." and ".." entries) */
1173 memcpy(de[0].name, MSDOS_DOT, MSDOS_NAME);
1174 memcpy(de[1].name, MSDOS_DOTDOT, MSDOS_NAME);
1175 de->attr = de[1].attr = ATTR_DIR;
1176 de[0].lcase = de[1].lcase = 0;
1177 de[0].time = de[1].time = time;
1178 de[0].date = de[1].date = date;
1179 if (sbi->options.isvfat) {
1180 /* extra timestamps */
1181 de[0].ctime = de[1].ctime = time;
1182 de[0].ctime_cs = de[1].ctime_cs = time_cs;
1183 de[0].adate = de[0].cdate = de[1].adate = de[1].cdate = date;
1184 } else {
1185 de[0].ctime = de[1].ctime = 0;
1186 de[0].ctime_cs = de[1].ctime_cs = 0;
1187 de[0].adate = de[0].cdate = de[1].adate = de[1].cdate = 0;
1188 }
1189 fat_set_start(&de[0], cluster);
1190 fat_set_start(&de[1], MSDOS_I(dir)->i_logstart);
1191 de[0].size = de[1].size = 0;
1192 memset(de + 2, 0, sb->s_blocksize - 2 * sizeof(*de));
1193 set_buffer_uptodate(bhs[0]);
1194 unlock_buffer(bhs[0]);
1195 mark_buffer_dirty_inode(bhs[0], dir);
1196
1197 err = fat_zeroed_cluster(dir, blknr, 1, bhs, MAX_BUF_PER_PAGE);
1198 if (err)
1199 goto error_free;
1200
1201 return cluster;
1202
1203 error_free:
1204 fat_free_clusters(dir, cluster);
1205 error:
1206 return err;
1207 }
1208 EXPORT_SYMBOL_GPL(fat_alloc_new_dir);
1209
1210 static int fat_add_new_entries(struct inode *dir, void *slots, int nr_slots,
1211 int *nr_cluster, struct msdos_dir_entry **de,
1212 struct buffer_head **bh, loff_t *i_pos)
1213 {
1214 struct super_block *sb = dir->i_sb;
1215 struct msdos_sb_info *sbi = MSDOS_SB(sb);
1216 struct buffer_head *bhs[MAX_BUF_PER_PAGE];
1217 sector_t blknr, start_blknr, last_blknr;
1218 unsigned long size, copy;
1219 int err, i, n, offset, cluster[2];
1220
1221 /*
1222 * The minimum cluster size is 512bytes, and maximum entry
1223 * size is 32*slots (672bytes). So, iff the cluster size is
1224 * 512bytes, we may need two clusters.
1225 */
1226 size = nr_slots * sizeof(struct msdos_dir_entry);
1227 *nr_cluster = (size + (sbi->cluster_size - 1)) >> sbi->cluster_bits;
1228 BUG_ON(*nr_cluster > 2);
1229
1230 err = fat_alloc_clusters(dir, cluster, *nr_cluster);
1231 if (err)
1232 goto error;
1233
1234 /*
1235 * First stage: Fill the directory entry. NOTE: This cluster
1236 * is not referenced from any inode yet, so updates order is
1237 * not important.
1238 */
1239 i = n = copy = 0;
1240 do {
1241 start_blknr = blknr = fat_clus_to_blknr(sbi, cluster[i]);
1242 last_blknr = start_blknr + sbi->sec_per_clus;
1243 while (blknr < last_blknr) {
1244 bhs[n] = sb_getblk(sb, blknr);
1245 if (!bhs[n]) {
1246 err = -ENOMEM;
1247 goto error_nomem;
1248 }
1249
1250 /* fill the directory entry */
1251 copy = min(size, sb->s_blocksize);
1252 /* Avoid race with userspace read via bdev */
1253 lock_buffer(bhs[n]);
1254 memcpy(bhs[n]->b_data, slots, copy);
1255 set_buffer_uptodate(bhs[n]);
1256 unlock_buffer(bhs[n]);
1257 mark_buffer_dirty_inode(bhs[n], dir);
1258 slots += copy;
1259 size -= copy;
1260 if (!size)
1261 break;
1262 n++;
1263 blknr++;
1264 }
1265 } while (++i < *nr_cluster);
1266
1267 memset(bhs[n]->b_data + copy, 0, sb->s_blocksize - copy);
1268 offset = copy - sizeof(struct msdos_dir_entry);
1269 get_bh(bhs[n]);
1270 *bh = bhs[n];
1271 *de = (struct msdos_dir_entry *)((*bh)->b_data + offset);
1272 *i_pos = fat_make_i_pos(sb, *bh, *de);
1273
1274 /* Second stage: clear the rest of cluster, and write outs */
1275 err = fat_zeroed_cluster(dir, start_blknr, ++n, bhs, MAX_BUF_PER_PAGE);
1276 if (err)
1277 goto error_free;
1278
1279 return cluster[0];
1280
1281 error_free:
1282 brelse(*bh);
1283 *bh = NULL;
1284 n = 0;
1285 error_nomem:
1286 for (i = 0; i < n; i++)
1287 bforget(bhs[i]);
1288 fat_free_clusters(dir, cluster[0]);
1289 error:
1290 return err;
1291 }
1292
1293 int fat_add_entries(struct inode *dir, void *slots, int nr_slots,
1294 struct fat_slot_info *sinfo)
1295 {
1296 struct super_block *sb = dir->i_sb;
1297 struct msdos_sb_info *sbi = MSDOS_SB(sb);
1298 struct buffer_head *bh, *prev, *bhs[3]; /* 32*slots (672bytes) */
1299 struct msdos_dir_entry *de;
1300 int err, free_slots, i, nr_bhs;
1301 loff_t pos, i_pos;
1302
1303 sinfo->nr_slots = nr_slots;
1304
1305 /* First stage: search free directory entries */
1306 free_slots = nr_bhs = 0;
1307 bh = prev = NULL;
1308 pos = 0;
1309 err = -ENOSPC;
1310 while (fat_get_entry(dir, &pos, &bh, &de) > -1) {
1311 /* check the maximum size of directory */
1312 if (pos >= FAT_MAX_DIR_SIZE)
1313 goto error;
1314
1315 if (IS_FREE(de->name)) {
1316 if (prev != bh) {
1317 get_bh(bh);
1318 bhs[nr_bhs] = prev = bh;
1319 nr_bhs++;
1320 }
1321 free_slots++;
1322 if (free_slots == nr_slots)
1323 goto found;
1324 } else {
1325 for (i = 0; i < nr_bhs; i++)
1326 brelse(bhs[i]);
1327 prev = NULL;
1328 free_slots = nr_bhs = 0;
1329 }
1330 }
1331 if (dir->i_ino == MSDOS_ROOT_INO) {
1332 if (!is_fat32(sbi))
1333 goto error;
1334 } else if (MSDOS_I(dir)->i_start == 0) {
1335 fat_msg(sb, KERN_ERR, "Corrupted directory (i_pos %lld)",
1336 MSDOS_I(dir)->i_pos);
1337 err = -EIO;
1338 goto error;
1339 }
1340
1341 found:
1342 err = 0;
1343 pos -= free_slots * sizeof(*de);
1344 nr_slots -= free_slots;
1345 if (free_slots) {
1346 /*
1347 * Second stage: filling the free entries with new entries.
1348 * NOTE: If this slots has shortname, first, we write
1349 * the long name slots, then write the short name.
1350 */
1351 int size = free_slots * sizeof(*de);
1352 int offset = pos & (sb->s_blocksize - 1);
1353 int long_bhs = nr_bhs - (nr_slots == 0);
1354
1355 /* Fill the long name slots. */
1356 for (i = 0; i < long_bhs; i++) {
1357 int copy = min_t(int, sb->s_blocksize - offset, size);
1358 memcpy(bhs[i]->b_data + offset, slots, copy);
1359 mark_buffer_dirty_inode(bhs[i], dir);
1360 offset = 0;
1361 slots += copy;
1362 size -= copy;
1363 }
1364 if (long_bhs && IS_DIRSYNC(dir))
1365 err = fat_sync_bhs(bhs, long_bhs);
1366 if (!err && i < nr_bhs) {
1367 /* Fill the short name slot. */
1368 int copy = min_t(int, sb->s_blocksize - offset, size);
1369 memcpy(bhs[i]->b_data + offset, slots, copy);
1370 mark_buffer_dirty_inode(bhs[i], dir);
1371 if (IS_DIRSYNC(dir))
1372 err = sync_dirty_buffer(bhs[i]);
1373 }
1374 for (i = 0; i < nr_bhs; i++)
1375 brelse(bhs[i]);
1376 if (err)
1377 goto error_remove;
1378 }
1379
1380 if (nr_slots) {
1381 int cluster, nr_cluster;
1382
1383 /*
1384 * Third stage: allocate the cluster for new entries.
1385 * And initialize the cluster with new entries, then
1386 * add the cluster to dir.
1387 */
1388 cluster = fat_add_new_entries(dir, slots, nr_slots, &nr_cluster,
1389 &de, &bh, &i_pos);
1390 if (cluster < 0) {
1391 err = cluster;
1392 goto error_remove;
1393 }
1394 err = fat_chain_add(dir, cluster, nr_cluster);
1395 if (err) {
1396 fat_free_clusters(dir, cluster);
1397 goto error_remove;
1398 }
1399 if (dir->i_size & (sbi->cluster_size - 1)) {
1400 fat_fs_error(sb, "Odd directory size");
1401 dir->i_size = (dir->i_size + sbi->cluster_size - 1)
1402 & ~((loff_t)sbi->cluster_size - 1);
1403 }
1404 dir->i_size += nr_cluster << sbi->cluster_bits;
1405 MSDOS_I(dir)->mmu_private += nr_cluster << sbi->cluster_bits;
1406 }
1407 sinfo->slot_off = pos;
1408 sinfo->de = de;
1409 sinfo->bh = bh;
1410 sinfo->i_pos = fat_make_i_pos(sb, sinfo->bh, sinfo->de);
1411
1412 return 0;
1413
1414 error:
1415 brelse(bh);
1416 for (i = 0; i < nr_bhs; i++)
1417 brelse(bhs[i]);
1418 return err;
1419
1420 error_remove:
1421 brelse(bh);
1422 if (free_slots)
1423 __fat_remove_entries(dir, pos, free_slots);
1424 return err;
1425 }
1426 EXPORT_SYMBOL_GPL(fat_add_entries);
Linux Kernel