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[linux-2.6/mini2440.git] / fs / fat / dir.c
blobcd4a0162e10d6dea7507507cf25a13fd93d93f04
1 /*
2 * linux/fs/fat/dir.c
4 * directory handling functions for fat-based filesystems
6 * Written 1992,1993 by Werner Almesberger
8 * Hidden files 1995 by Albert Cahalan <albert@ccs.neu.edu> <adc@coe.neu.edu>
10 * VFAT extensions by Gordon Chaffee <chaffee@plateau.cs.berkeley.edu>
11 * Merged with msdos fs by Henrik Storner <storner@osiris.ping.dk>
12 * Rewritten for constant inumbers. Plugged buffer overrun in readdir(). AV
13 * Short name translation 1999, 2001 by Wolfram Pienkoss <wp@bszh.de>
16 #include <linux/module.h>
17 #include <linux/slab.h>
18 #include <linux/time.h>
19 #include <linux/msdos_fs.h>
20 #include <linux/smp_lock.h>
21 #include <linux/buffer_head.h>
22 #include <linux/compat.h>
23 #include <asm/uaccess.h>
25 static inline loff_t fat_make_i_pos(struct super_block *sb,
26 struct buffer_head *bh,
27 struct msdos_dir_entry *de)
29 return ((loff_t)bh->b_blocknr << MSDOS_SB(sb)->dir_per_block_bits)
30 | (de - (struct msdos_dir_entry *)bh->b_data);
33 static inline void fat_dir_readahead(struct inode *dir, sector_t iblock,
34 sector_t phys)
36 struct super_block *sb = dir->i_sb;
37 struct msdos_sb_info *sbi = MSDOS_SB(sb);
38 struct buffer_head *bh;
39 int sec;
41 /* This is not a first sector of cluster, or sec_per_clus == 1 */
42 if ((iblock & (sbi->sec_per_clus - 1)) || sbi->sec_per_clus == 1)
43 return;
44 /* root dir of FAT12/FAT16 */
45 if ((sbi->fat_bits != 32) && (dir->i_ino == MSDOS_ROOT_INO))
46 return;
48 bh = sb_find_get_block(sb, phys);
49 if (bh == NULL || !buffer_uptodate(bh)) {
50 for (sec = 0; sec < sbi->sec_per_clus; sec++)
51 sb_breadahead(sb, phys + sec);
53 brelse(bh);
56 /* Returns the inode number of the directory entry at offset pos. If bh is
57 non-NULL, it is brelse'd before. Pos is incremented. The buffer header is
58 returned in bh.
59 AV. Most often we do it item-by-item. Makes sense to optimize.
60 AV. OK, there we go: if both bh and de are non-NULL we assume that we just
61 AV. want the next entry (took one explicit de=NULL in vfat/namei.c).
62 AV. It's done in fat_get_entry() (inlined), here the slow case lives.
63 AV. Additionally, when we return -1 (i.e. reached the end of directory)
64 AV. we make bh NULL.
66 static int fat__get_entry(struct inode *dir, loff_t *pos,
67 struct buffer_head **bh, struct msdos_dir_entry **de)
69 struct super_block *sb = dir->i_sb;
70 sector_t phys, iblock;
71 unsigned long mapped_blocks;
72 int err, offset;
74 next:
75 if (*bh)
76 brelse(*bh);
78 *bh = NULL;
79 iblock = *pos >> sb->s_blocksize_bits;
80 err = fat_bmap(dir, iblock, &phys, &mapped_blocks);
81 if (err || !phys)
82 return -1; /* beyond EOF or error */
84 fat_dir_readahead(dir, iblock, phys);
86 *bh = sb_bread(sb, phys);
87 if (*bh == NULL) {
88 printk(KERN_ERR "FAT: Directory bread(block %llu) failed\n",
89 (unsigned long long)phys);
90 /* skip this block */
91 *pos = (iblock + 1) << sb->s_blocksize_bits;
92 goto next;
95 offset = *pos & (sb->s_blocksize - 1);
96 *pos += sizeof(struct msdos_dir_entry);
97 *de = (struct msdos_dir_entry *)((*bh)->b_data + offset);
99 return 0;
102 static inline int fat_get_entry(struct inode *dir, loff_t *pos,
103 struct buffer_head **bh,
104 struct msdos_dir_entry **de)
106 /* Fast stuff first */
107 if (*bh && *de &&
108 (*de - (struct msdos_dir_entry *)(*bh)->b_data) < MSDOS_SB(dir->i_sb)->dir_per_block - 1) {
109 *pos += sizeof(struct msdos_dir_entry);
110 (*de)++;
111 return 0;
113 return fat__get_entry(dir, pos, bh, de);
117 * Convert Unicode 16 to UTF-8, translated Unicode, or ASCII.
118 * If uni_xlate is enabled and we can't get a 1:1 conversion, use a
119 * colon as an escape character since it is normally invalid on the vfat
120 * filesystem. The following four characters are the hexadecimal digits
121 * of Unicode value. This lets us do a full dump and restore of Unicode
122 * filenames. We could get into some trouble with long Unicode names,
123 * but ignore that right now.
124 * Ahem... Stack smashing in ring 0 isn't fun. Fixed.
126 static int uni16_to_x8(unsigned char *ascii, const wchar_t *uni, int len,
127 int uni_xlate, struct nls_table *nls)
129 const wchar_t *ip;
130 wchar_t ec;
131 unsigned char *op, nc;
132 int charlen;
133 int k;
135 ip = uni;
136 op = ascii;
138 while (*ip && ((len - NLS_MAX_CHARSET_SIZE) > 0)) {
139 ec = *ip++;
140 if ( (charlen = nls->uni2char(ec, op, NLS_MAX_CHARSET_SIZE)) > 0) {
141 op += charlen;
142 len -= charlen;
143 } else {
144 if (uni_xlate == 1) {
145 *op = ':';
146 for (k = 4; k > 0; k--) {
147 nc = ec & 0xF;
148 op[k] = nc > 9 ? nc + ('a' - 10)
149 : nc + '0';
150 ec >>= 4;
152 op += 5;
153 len -= 5;
154 } else {
155 *op++ = '?';
156 len--;
161 if (unlikely(*ip)) {
162 printk(KERN_WARNING "FAT: filename was truncated while "
163 "converting.");
166 *op = 0;
167 return (op - ascii);
170 static inline int fat_uni_to_x8(struct msdos_sb_info *sbi, const wchar_t *uni,
171 unsigned char *buf, int size)
173 if (sbi->options.utf8)
174 return utf8_wcstombs(buf, uni, size);
175 else
176 return uni16_to_x8(buf, uni, size, sbi->options.unicode_xlate,
177 sbi->nls_io);
180 static inline int
181 fat_short2uni(struct nls_table *t, unsigned char *c, int clen, wchar_t *uni)
183 int charlen;
185 charlen = t->char2uni(c, clen, uni);
186 if (charlen < 0) {
187 *uni = 0x003f; /* a question mark */
188 charlen = 1;
190 return charlen;
193 static inline int
194 fat_short2lower_uni(struct nls_table *t, unsigned char *c, int clen, wchar_t *uni)
196 int charlen;
197 wchar_t wc;
199 charlen = t->char2uni(c, clen, &wc);
200 if (charlen < 0) {
201 *uni = 0x003f; /* a question mark */
202 charlen = 1;
203 } else if (charlen <= 1) {
204 unsigned char nc = t->charset2lower[*c];
206 if (!nc)
207 nc = *c;
209 if ( (charlen = t->char2uni(&nc, 1, uni)) < 0) {
210 *uni = 0x003f; /* a question mark */
211 charlen = 1;
213 } else
214 *uni = wc;
216 return charlen;
219 static inline int
220 fat_shortname2uni(struct nls_table *nls, unsigned char *buf, int buf_size,
221 wchar_t *uni_buf, unsigned short opt, int lower)
223 int len = 0;
225 if (opt & VFAT_SFN_DISPLAY_LOWER)
226 len = fat_short2lower_uni(nls, buf, buf_size, uni_buf);
227 else if (opt & VFAT_SFN_DISPLAY_WIN95)
228 len = fat_short2uni(nls, buf, buf_size, uni_buf);
229 else if (opt & VFAT_SFN_DISPLAY_WINNT) {
230 if (lower)
231 len = fat_short2lower_uni(nls, buf, buf_size, uni_buf);
232 else
233 len = fat_short2uni(nls, buf, buf_size, uni_buf);
234 } else
235 len = fat_short2uni(nls, buf, buf_size, uni_buf);
237 return len;
240 static inline int fat_name_match(struct msdos_sb_info *sbi,
241 const unsigned char *a, int a_len,
242 const unsigned char *b, int b_len)
244 if (a_len != b_len)
245 return 0;
247 if (sbi->options.name_check != 's')
248 return !nls_strnicmp(sbi->nls_io, a, b, a_len);
249 else
250 return !memcmp(a, b, a_len);
253 enum { PARSE_INVALID = 1, PARSE_NOT_LONGNAME, PARSE_EOF, };
256 * fat_parse_long - Parse extended directory entry.
258 * This function returns zero on success, negative value on error, or one of
259 * the following:
261 * %PARSE_INVALID - Directory entry is invalid.
262 * %PARSE_NOT_LONGNAME - Directory entry does not contain longname.
263 * %PARSE_EOF - Directory has no more entries.
265 static int fat_parse_long(struct inode *dir, loff_t *pos,
266 struct buffer_head **bh, struct msdos_dir_entry **de,
267 wchar_t **unicode, unsigned char *nr_slots)
269 struct msdos_dir_slot *ds;
270 unsigned char id, slot, slots, alias_checksum;
272 if (!*unicode) {
273 *unicode = __getname();
274 if (!*unicode) {
275 brelse(*bh);
276 return -ENOMEM;
279 parse_long:
280 slots = 0;
281 ds = (struct msdos_dir_slot *)*de;
282 id = ds->id;
283 if (!(id & 0x40))
284 return PARSE_INVALID;
285 slots = id & ~0x40;
286 if (slots > 20 || !slots) /* ceil(256 * 2 / 26) */
287 return PARSE_INVALID;
288 *nr_slots = slots;
289 alias_checksum = ds->alias_checksum;
291 slot = slots;
292 while (1) {
293 int offset;
295 slot--;
296 offset = slot * 13;
297 fat16_towchar(*unicode + offset, ds->name0_4, 5);
298 fat16_towchar(*unicode + offset + 5, ds->name5_10, 6);
299 fat16_towchar(*unicode + offset + 11, ds->name11_12, 2);
301 if (ds->id & 0x40)
302 (*unicode)[offset + 13] = 0;
303 if (fat_get_entry(dir, pos, bh, de) < 0)
304 return PARSE_EOF;
305 if (slot == 0)
306 break;
307 ds = (struct msdos_dir_slot *)*de;
308 if (ds->attr != ATTR_EXT)
309 return PARSE_NOT_LONGNAME;
310 if ((ds->id & ~0x40) != slot)
311 goto parse_long;
312 if (ds->alias_checksum != alias_checksum)
313 goto parse_long;
315 if ((*de)->name[0] == DELETED_FLAG)
316 return PARSE_INVALID;
317 if ((*de)->attr == ATTR_EXT)
318 goto parse_long;
319 if (IS_FREE((*de)->name) || ((*de)->attr & ATTR_VOLUME))
320 return PARSE_INVALID;
321 if (fat_checksum((*de)->name) != alias_checksum)
322 *nr_slots = 0;
324 return 0;
328 * Maximum buffer size of short name.
329 * [(MSDOS_NAME + '.') * max one char + nul]
330 * For msdos style, ['.' (hidden) + MSDOS_NAME + '.' + nul]
332 #define FAT_MAX_SHORT_SIZE ((MSDOS_NAME + 1) * NLS_MAX_CHARSET_SIZE + 1)
334 * Maximum buffer size of unicode chars from slots.
335 * [(max longname slots * 13 (size in a slot) + nul) * sizeof(wchar_t)]
337 #define FAT_MAX_UNI_CHARS ((MSDOS_SLOTS - 1) * 13 + 1)
338 #define FAT_MAX_UNI_SIZE (FAT_MAX_UNI_CHARS * sizeof(wchar_t))
341 * Return values: negative -> error, 0 -> not found, positive -> found,
342 * value is the total amount of slots, including the shortname entry.
344 int fat_search_long(struct inode *inode, const unsigned char *name,
345 int name_len, struct fat_slot_info *sinfo)
347 struct super_block *sb = inode->i_sb;
348 struct msdos_sb_info *sbi = MSDOS_SB(sb);
349 struct buffer_head *bh = NULL;
350 struct msdos_dir_entry *de;
351 struct nls_table *nls_disk = sbi->nls_disk;
352 unsigned char nr_slots;
353 wchar_t bufuname[14];
354 wchar_t *unicode = NULL;
355 unsigned char work[MSDOS_NAME];
356 unsigned char bufname[FAT_MAX_SHORT_SIZE];
357 unsigned short opt_shortname = sbi->options.shortname;
358 loff_t cpos = 0;
359 int chl, i, j, last_u, err, len;
361 err = -ENOENT;
362 while (1) {
363 if (fat_get_entry(inode, &cpos, &bh, &de) == -1)
364 goto end_of_dir;
365 parse_record:
366 nr_slots = 0;
367 if (de->name[0] == DELETED_FLAG)
368 continue;
369 if (de->attr != ATTR_EXT && (de->attr & ATTR_VOLUME))
370 continue;
371 if (de->attr != ATTR_EXT && IS_FREE(de->name))
372 continue;
373 if (de->attr == ATTR_EXT) {
374 int status = fat_parse_long(inode, &cpos, &bh, &de,
375 &unicode, &nr_slots);
376 if (status < 0)
377 return status;
378 else if (status == PARSE_INVALID)
379 continue;
380 else if (status == PARSE_NOT_LONGNAME)
381 goto parse_record;
382 else if (status == PARSE_EOF)
383 goto end_of_dir;
386 memcpy(work, de->name, sizeof(de->name));
387 /* see namei.c, msdos_format_name */
388 if (work[0] == 0x05)
389 work[0] = 0xE5;
390 for (i = 0, j = 0, last_u = 0; i < 8;) {
391 if (!work[i])
392 break;
393 chl = fat_shortname2uni(nls_disk, &work[i], 8 - i,
394 &bufuname[j++], opt_shortname,
395 de->lcase & CASE_LOWER_BASE);
396 if (chl <= 1) {
397 if (work[i] != ' ')
398 last_u = j;
399 } else {
400 last_u = j;
402 i += chl;
404 j = last_u;
405 fat_short2uni(nls_disk, ".", 1, &bufuname[j++]);
406 for (i = 8; i < MSDOS_NAME;) {
407 if (!work[i])
408 break;
409 chl = fat_shortname2uni(nls_disk, &work[i],
410 MSDOS_NAME - i,
411 &bufuname[j++], opt_shortname,
412 de->lcase & CASE_LOWER_EXT);
413 if (chl <= 1) {
414 if (work[i] != ' ')
415 last_u = j;
416 } else {
417 last_u = j;
419 i += chl;
421 if (!last_u)
422 continue;
424 /* Compare shortname */
425 bufuname[last_u] = 0x0000;
426 len = fat_uni_to_x8(sbi, bufuname, bufname, sizeof(bufname));
427 if (fat_name_match(sbi, name, name_len, bufname, len))
428 goto found;
430 if (nr_slots) {
431 void *longname = unicode + FAT_MAX_UNI_CHARS;
432 int size = PATH_MAX - FAT_MAX_UNI_SIZE;
434 /* Compare longname */
435 len = fat_uni_to_x8(sbi, unicode, longname, size);
436 if (fat_name_match(sbi, name, name_len, longname, len))
437 goto found;
441 found:
442 nr_slots++; /* include the de */
443 sinfo->slot_off = cpos - nr_slots * sizeof(*de);
444 sinfo->nr_slots = nr_slots;
445 sinfo->de = de;
446 sinfo->bh = bh;
447 sinfo->i_pos = fat_make_i_pos(sb, sinfo->bh, sinfo->de);
448 err = 0;
449 end_of_dir:
450 if (unicode)
451 __putname(unicode);
453 return err;
456 EXPORT_SYMBOL_GPL(fat_search_long);
458 struct fat_ioctl_filldir_callback {
459 void __user *dirent;
460 int result;
461 /* for dir ioctl */
462 const char *longname;
463 int long_len;
464 const char *shortname;
465 int short_len;
468 static int __fat_readdir(struct inode *inode, struct file *filp, void *dirent,
469 filldir_t filldir, int short_only, int both)
471 struct super_block *sb = inode->i_sb;
472 struct msdos_sb_info *sbi = MSDOS_SB(sb);
473 struct buffer_head *bh;
474 struct msdos_dir_entry *de;
475 struct nls_table *nls_disk = sbi->nls_disk;
476 unsigned char nr_slots;
477 wchar_t bufuname[14];
478 wchar_t *unicode = NULL;
479 unsigned char c, work[MSDOS_NAME];
480 unsigned char bufname[FAT_MAX_SHORT_SIZE], *ptname = bufname;
481 unsigned short opt_shortname = sbi->options.shortname;
482 int isvfat = sbi->options.isvfat;
483 int nocase = sbi->options.nocase;
484 const char *fill_name = NULL;
485 unsigned long inum;
486 unsigned long lpos, dummy, *furrfu = &lpos;
487 loff_t cpos;
488 int chi, chl, i, i2, j, last, last_u, dotoffset = 0, fill_len = 0;
489 int ret = 0;
491 lock_super(sb);
493 cpos = filp->f_pos;
494 /* Fake . and .. for the root directory. */
495 if (inode->i_ino == MSDOS_ROOT_INO) {
496 while (cpos < 2) {
497 if (filldir(dirent, "..", cpos+1, cpos, MSDOS_ROOT_INO, DT_DIR) < 0)
498 goto out;
499 cpos++;
500 filp->f_pos++;
502 if (cpos == 2) {
503 dummy = 2;
504 furrfu = &dummy;
505 cpos = 0;
508 if (cpos & (sizeof(struct msdos_dir_entry) - 1)) {
509 ret = -ENOENT;
510 goto out;
513 bh = NULL;
514 get_new:
515 if (fat_get_entry(inode, &cpos, &bh, &de) == -1)
516 goto end_of_dir;
517 parse_record:
518 nr_slots = 0;
520 * Check for long filename entry, but if short_only, we don't
521 * need to parse long filename.
523 if (isvfat && !short_only) {
524 if (de->name[0] == DELETED_FLAG)
525 goto record_end;
526 if (de->attr != ATTR_EXT && (de->attr & ATTR_VOLUME))
527 goto record_end;
528 if (de->attr != ATTR_EXT && IS_FREE(de->name))
529 goto record_end;
530 } else {
531 if ((de->attr & ATTR_VOLUME) || IS_FREE(de->name))
532 goto record_end;
535 if (isvfat && de->attr == ATTR_EXT) {
536 int status = fat_parse_long(inode, &cpos, &bh, &de,
537 &unicode, &nr_slots);
538 if (status < 0) {
539 filp->f_pos = cpos;
540 ret = status;
541 goto out;
542 } else if (status == PARSE_INVALID)
543 goto record_end;
544 else if (status == PARSE_NOT_LONGNAME)
545 goto parse_record;
546 else if (status == PARSE_EOF)
547 goto end_of_dir;
549 if (nr_slots) {
550 void *longname = unicode + FAT_MAX_UNI_CHARS;
551 int size = PATH_MAX - FAT_MAX_UNI_SIZE;
552 int len = fat_uni_to_x8(sbi, unicode, longname, size);
554 fill_name = longname;
555 fill_len = len;
556 /* !both && !short_only, so we don't need shortname. */
557 if (!both)
558 goto start_filldir;
562 if (sbi->options.dotsOK) {
563 ptname = bufname;
564 dotoffset = 0;
565 if (de->attr & ATTR_HIDDEN) {
566 *ptname++ = '.';
567 dotoffset = 1;
571 memcpy(work, de->name, sizeof(de->name));
572 /* see namei.c, msdos_format_name */
573 if (work[0] == 0x05)
574 work[0] = 0xE5;
575 for (i = 0, j = 0, last = 0, last_u = 0; i < 8;) {
576 if (!(c = work[i]))
577 break;
578 chl = fat_shortname2uni(nls_disk, &work[i], 8 - i,
579 &bufuname[j++], opt_shortname,
580 de->lcase & CASE_LOWER_BASE);
581 if (chl <= 1) {
582 ptname[i++] = (!nocase && c>='A' && c<='Z') ? c+32 : c;
583 if (c != ' ') {
584 last = i;
585 last_u = j;
587 } else {
588 last_u = j;
589 for (chi = 0; chi < chl && i < 8; chi++) {
590 ptname[i] = work[i];
591 i++; last = i;
595 i = last;
596 j = last_u;
597 fat_short2uni(nls_disk, ".", 1, &bufuname[j++]);
598 ptname[i++] = '.';
599 for (i2 = 8; i2 < MSDOS_NAME;) {
600 if (!(c = work[i2]))
601 break;
602 chl = fat_shortname2uni(nls_disk, &work[i2], MSDOS_NAME - i2,
603 &bufuname[j++], opt_shortname,
604 de->lcase & CASE_LOWER_EXT);
605 if (chl <= 1) {
606 i2++;
607 ptname[i++] = (!nocase && c>='A' && c<='Z') ? c+32 : c;
608 if (c != ' ') {
609 last = i;
610 last_u = j;
612 } else {
613 last_u = j;
614 for (chi = 0; chi < chl && i2 < MSDOS_NAME; chi++) {
615 ptname[i++] = work[i2++];
616 last = i;
620 if (!last)
621 goto record_end;
623 i = last + dotoffset;
624 j = last_u;
626 if (isvfat) {
627 bufuname[j] = 0x0000;
628 i = fat_uni_to_x8(sbi, bufuname, bufname, sizeof(bufname));
630 if (nr_slots) {
631 /* hack for fat_ioctl_filldir() */
632 struct fat_ioctl_filldir_callback *p = dirent;
634 p->longname = fill_name;
635 p->long_len = fill_len;
636 p->shortname = bufname;
637 p->short_len = i;
638 fill_name = NULL;
639 fill_len = 0;
640 } else {
641 fill_name = bufname;
642 fill_len = i;
645 start_filldir:
646 lpos = cpos - (nr_slots + 1) * sizeof(struct msdos_dir_entry);
647 if (!memcmp(de->name, MSDOS_DOT, MSDOS_NAME))
648 inum = inode->i_ino;
649 else if (!memcmp(de->name, MSDOS_DOTDOT, MSDOS_NAME)) {
650 inum = parent_ino(filp->f_path.dentry);
651 } else {
652 loff_t i_pos = fat_make_i_pos(sb, bh, de);
653 struct inode *tmp = fat_iget(sb, i_pos);
654 if (tmp) {
655 inum = tmp->i_ino;
656 iput(tmp);
657 } else
658 inum = iunique(sb, MSDOS_ROOT_INO);
661 if (filldir(dirent, fill_name, fill_len, *furrfu, inum,
662 (de->attr & ATTR_DIR) ? DT_DIR : DT_REG) < 0)
663 goto fill_failed;
665 record_end:
666 furrfu = &lpos;
667 filp->f_pos = cpos;
668 goto get_new;
669 end_of_dir:
670 filp->f_pos = cpos;
671 fill_failed:
672 brelse(bh);
673 if (unicode)
674 __putname(unicode);
675 out:
676 unlock_super(sb);
677 return ret;
680 static int fat_readdir(struct file *filp, void *dirent, filldir_t filldir)
682 struct inode *inode = filp->f_path.dentry->d_inode;
683 return __fat_readdir(inode, filp, dirent, filldir, 0, 0);
686 #define FAT_IOCTL_FILLDIR_FUNC(func, dirent_type) \
687 static int func(void *__buf, const char *name, int name_len, \
688 loff_t offset, u64 ino, unsigned int d_type) \
690 struct fat_ioctl_filldir_callback *buf = __buf; \
691 struct dirent_type __user *d1 = buf->dirent; \
692 struct dirent_type __user *d2 = d1 + 1; \
694 if (buf->result) \
695 return -EINVAL; \
696 buf->result++; \
698 if (name != NULL) { \
699 /* dirent has only short name */ \
700 if (name_len >= sizeof(d1->d_name)) \
701 name_len = sizeof(d1->d_name) - 1; \
703 if (put_user(0, d2->d_name) || \
704 put_user(0, &d2->d_reclen) || \
705 copy_to_user(d1->d_name, name, name_len) || \
706 put_user(0, d1->d_name + name_len) || \
707 put_user(name_len, &d1->d_reclen)) \
708 goto efault; \
709 } else { \
710 /* dirent has short and long name */ \
711 const char *longname = buf->longname; \
712 int long_len = buf->long_len; \
713 const char *shortname = buf->shortname; \
714 int short_len = buf->short_len; \
716 if (long_len >= sizeof(d1->d_name)) \
717 long_len = sizeof(d1->d_name) - 1; \
718 if (short_len >= sizeof(d1->d_name)) \
719 short_len = sizeof(d1->d_name) - 1; \
721 if (copy_to_user(d2->d_name, longname, long_len) || \
722 put_user(0, d2->d_name + long_len) || \
723 put_user(long_len, &d2->d_reclen) || \
724 put_user(ino, &d2->d_ino) || \
725 put_user(offset, &d2->d_off) || \
726 copy_to_user(d1->d_name, shortname, short_len) || \
727 put_user(0, d1->d_name + short_len) || \
728 put_user(short_len, &d1->d_reclen)) \
729 goto efault; \
731 return 0; \
732 efault: \
733 buf->result = -EFAULT; \
734 return -EFAULT; \
737 FAT_IOCTL_FILLDIR_FUNC(fat_ioctl_filldir, __fat_dirent)
739 static int fat_ioctl_readdir(struct inode *inode, struct file *filp,
740 void __user *dirent, filldir_t filldir,
741 int short_only, int both)
743 struct fat_ioctl_filldir_callback buf;
744 int ret;
746 buf.dirent = dirent;
747 buf.result = 0;
748 mutex_lock(&inode->i_mutex);
749 ret = -ENOENT;
750 if (!IS_DEADDIR(inode)) {
751 ret = __fat_readdir(inode, filp, &buf, filldir,
752 short_only, both);
754 mutex_unlock(&inode->i_mutex);
755 if (ret >= 0)
756 ret = buf.result;
757 return ret;
760 static int fat_dir_ioctl(struct inode *inode, struct file *filp,
761 unsigned int cmd, unsigned long arg)
763 struct __fat_dirent __user *d1 = (struct __fat_dirent __user *)arg;
764 int short_only, both;
766 switch (cmd) {
767 case VFAT_IOCTL_READDIR_SHORT:
768 short_only = 1;
769 both = 0;
770 break;
771 case VFAT_IOCTL_READDIR_BOTH:
772 short_only = 0;
773 both = 1;
774 break;
775 default:
776 return fat_generic_ioctl(inode, filp, cmd, arg);
779 if (!access_ok(VERIFY_WRITE, d1, sizeof(struct __fat_dirent[2])))
780 return -EFAULT;
782 * Yes, we don't need this put_user() absolutely. However old
783 * code didn't return the right value. So, app use this value,
784 * in order to check whether it is EOF.
786 if (put_user(0, &d1->d_reclen))
787 return -EFAULT;
789 return fat_ioctl_readdir(inode, filp, d1, fat_ioctl_filldir,
790 short_only, both);
793 #ifdef CONFIG_COMPAT
794 #define VFAT_IOCTL_READDIR_BOTH32 _IOR('r', 1, struct compat_dirent[2])
795 #define VFAT_IOCTL_READDIR_SHORT32 _IOR('r', 2, struct compat_dirent[2])
797 FAT_IOCTL_FILLDIR_FUNC(fat_compat_ioctl_filldir, compat_dirent)
799 static long fat_compat_dir_ioctl(struct file *filp, unsigned cmd,
800 unsigned long arg)
802 struct inode *inode = filp->f_path.dentry->d_inode;
803 struct compat_dirent __user *d1 = compat_ptr(arg);
804 int short_only, both;
806 switch (cmd) {
807 case VFAT_IOCTL_READDIR_SHORT32:
808 short_only = 1;
809 both = 0;
810 break;
811 case VFAT_IOCTL_READDIR_BOTH32:
812 short_only = 0;
813 both = 1;
814 break;
815 default:
816 return -ENOIOCTLCMD;
819 if (!access_ok(VERIFY_WRITE, d1, sizeof(struct compat_dirent[2])))
820 return -EFAULT;
822 * Yes, we don't need this put_user() absolutely. However old
823 * code didn't return the right value. So, app use this value,
824 * in order to check whether it is EOF.
826 if (put_user(0, &d1->d_reclen))
827 return -EFAULT;
829 return fat_ioctl_readdir(inode, filp, d1, fat_compat_ioctl_filldir,
830 short_only, both);
832 #endif /* CONFIG_COMPAT */
834 const struct file_operations fat_dir_operations = {
835 .read = generic_read_dir,
836 .readdir = fat_readdir,
837 .ioctl = fat_dir_ioctl,
838 #ifdef CONFIG_COMPAT
839 .compat_ioctl = fat_compat_dir_ioctl,
840 #endif
841 .fsync = file_fsync,
844 static int fat_get_short_entry(struct inode *dir, loff_t *pos,
845 struct buffer_head **bh,
846 struct msdos_dir_entry **de)
848 while (fat_get_entry(dir, pos, bh, de) >= 0) {
849 /* free entry or long name entry or volume label */
850 if (!IS_FREE((*de)->name) && !((*de)->attr & ATTR_VOLUME))
851 return 0;
853 return -ENOENT;
857 * The ".." entry can not provide the "struct fat_slot_info" informations
858 * for inode. So, this function provide the some informations only.
860 int fat_get_dotdot_entry(struct inode *dir, struct buffer_head **bh,
861 struct msdos_dir_entry **de, loff_t *i_pos)
863 loff_t offset;
865 offset = 0;
866 *bh = NULL;
867 while (fat_get_short_entry(dir, &offset, bh, de) >= 0) {
868 if (!strncmp((*de)->name, MSDOS_DOTDOT, MSDOS_NAME)) {
869 *i_pos = fat_make_i_pos(dir->i_sb, *bh, *de);
870 return 0;
873 return -ENOENT;
876 EXPORT_SYMBOL_GPL(fat_get_dotdot_entry);
878 /* See if directory is empty */
879 int fat_dir_empty(struct inode *dir)
881 struct buffer_head *bh;
882 struct msdos_dir_entry *de;
883 loff_t cpos;
884 int result = 0;
886 bh = NULL;
887 cpos = 0;
888 while (fat_get_short_entry(dir, &cpos, &bh, &de) >= 0) {
889 if (strncmp(de->name, MSDOS_DOT , MSDOS_NAME) &&
890 strncmp(de->name, MSDOS_DOTDOT, MSDOS_NAME)) {
891 result = -ENOTEMPTY;
892 break;
895 brelse(bh);
896 return result;
899 EXPORT_SYMBOL_GPL(fat_dir_empty);
902 * fat_subdirs counts the number of sub-directories of dir. It can be run
903 * on directories being created.
905 int fat_subdirs(struct inode *dir)
907 struct buffer_head *bh;
908 struct msdos_dir_entry *de;
909 loff_t cpos;
910 int count = 0;
912 bh = NULL;
913 cpos = 0;
914 while (fat_get_short_entry(dir, &cpos, &bh, &de) >= 0) {
915 if (de->attr & ATTR_DIR)
916 count++;
918 brelse(bh);
919 return count;
923 * Scans a directory for a given file (name points to its formatted name).
924 * Returns an error code or zero.
926 int fat_scan(struct inode *dir, const unsigned char *name,
927 struct fat_slot_info *sinfo)
929 struct super_block *sb = dir->i_sb;
931 sinfo->slot_off = 0;
932 sinfo->bh = NULL;
933 while (fat_get_short_entry(dir, &sinfo->slot_off, &sinfo->bh,
934 &sinfo->de) >= 0) {
935 if (!strncmp(sinfo->de->name, name, MSDOS_NAME)) {
936 sinfo->slot_off -= sizeof(*sinfo->de);
937 sinfo->nr_slots = 1;
938 sinfo->i_pos = fat_make_i_pos(sb, sinfo->bh, sinfo->de);
939 return 0;
942 return -ENOENT;
945 EXPORT_SYMBOL_GPL(fat_scan);
947 static int __fat_remove_entries(struct inode *dir, loff_t pos, int nr_slots)
949 struct super_block *sb = dir->i_sb;
950 struct buffer_head *bh;
951 struct msdos_dir_entry *de, *endp;
952 int err = 0, orig_slots;
954 while (nr_slots) {
955 bh = NULL;
956 if (fat_get_entry(dir, &pos, &bh, &de) < 0) {
957 err = -EIO;
958 break;
961 orig_slots = nr_slots;
962 endp = (struct msdos_dir_entry *)(bh->b_data + sb->s_blocksize);
963 while (nr_slots && de < endp) {
964 de->name[0] = DELETED_FLAG;
965 de++;
966 nr_slots--;
968 mark_buffer_dirty(bh);
969 if (IS_DIRSYNC(dir))
970 err = sync_dirty_buffer(bh);
971 brelse(bh);
972 if (err)
973 break;
975 /* pos is *next* de's position, so this does `- sizeof(de)' */
976 pos += ((orig_slots - nr_slots) * sizeof(*de)) - sizeof(*de);
979 return err;
982 int fat_remove_entries(struct inode *dir, struct fat_slot_info *sinfo)
984 struct msdos_dir_entry *de;
985 struct buffer_head *bh;
986 int err = 0, nr_slots;
989 * First stage: Remove the shortname. By this, the directory
990 * entry is removed.
992 nr_slots = sinfo->nr_slots;
993 de = sinfo->de;
994 sinfo->de = NULL;
995 bh = sinfo->bh;
996 sinfo->bh = NULL;
997 while (nr_slots && de >= (struct msdos_dir_entry *)bh->b_data) {
998 de->name[0] = DELETED_FLAG;
999 de--;
1000 nr_slots--;
1002 mark_buffer_dirty(bh);
1003 if (IS_DIRSYNC(dir))
1004 err = sync_dirty_buffer(bh);
1005 brelse(bh);
1006 if (err)
1007 return err;
1008 dir->i_version++;
1010 if (nr_slots) {
1012 * Second stage: remove the remaining longname slots.
1013 * (This directory entry is already removed, and so return
1014 * the success)
1016 err = __fat_remove_entries(dir, sinfo->slot_off, nr_slots);
1017 if (err) {
1018 printk(KERN_WARNING
1019 "FAT: Couldn't remove the long name slots\n");
1023 dir->i_mtime = dir->i_atime = CURRENT_TIME_SEC;
1024 if (IS_DIRSYNC(dir))
1025 (void)fat_sync_inode(dir);
1026 else
1027 mark_inode_dirty(dir);
1029 return 0;
1032 EXPORT_SYMBOL_GPL(fat_remove_entries);
1034 static int fat_zeroed_cluster(struct inode *dir, sector_t blknr, int nr_used,
1035 struct buffer_head **bhs, int nr_bhs)
1037 struct super_block *sb = dir->i_sb;
1038 sector_t last_blknr = blknr + MSDOS_SB(sb)->sec_per_clus;
1039 int err, i, n;
1041 /* Zeroing the unused blocks on this cluster */
1042 blknr += nr_used;
1043 n = nr_used;
1044 while (blknr < last_blknr) {
1045 bhs[n] = sb_getblk(sb, blknr);
1046 if (!bhs[n]) {
1047 err = -ENOMEM;
1048 goto error;
1050 memset(bhs[n]->b_data, 0, sb->s_blocksize);
1051 set_buffer_uptodate(bhs[n]);
1052 mark_buffer_dirty(bhs[n]);
1054 n++;
1055 blknr++;
1056 if (n == nr_bhs) {
1057 if (IS_DIRSYNC(dir)) {
1058 err = fat_sync_bhs(bhs, n);
1059 if (err)
1060 goto error;
1062 for (i = 0; i < n; i++)
1063 brelse(bhs[i]);
1064 n = 0;
1067 if (IS_DIRSYNC(dir)) {
1068 err = fat_sync_bhs(bhs, n);
1069 if (err)
1070 goto error;
1072 for (i = 0; i < n; i++)
1073 brelse(bhs[i]);
1075 return 0;
1077 error:
1078 for (i = 0; i < n; i++)
1079 bforget(bhs[i]);
1080 return err;
1083 int fat_alloc_new_dir(struct inode *dir, struct timespec *ts)
1085 struct super_block *sb = dir->i_sb;
1086 struct msdos_sb_info *sbi = MSDOS_SB(sb);
1087 struct buffer_head *bhs[MAX_BUF_PER_PAGE];
1088 struct msdos_dir_entry *de;
1089 sector_t blknr;
1090 __le16 date, time;
1091 int err, cluster;
1093 err = fat_alloc_clusters(dir, &cluster, 1);
1094 if (err)
1095 goto error;
1097 blknr = fat_clus_to_blknr(sbi, cluster);
1098 bhs[0] = sb_getblk(sb, blknr);
1099 if (!bhs[0]) {
1100 err = -ENOMEM;
1101 goto error_free;
1104 fat_date_unix2dos(ts->tv_sec, &time, &date, sbi->options.tz_utc);
1106 de = (struct msdos_dir_entry *)bhs[0]->b_data;
1107 /* filling the new directory slots ("." and ".." entries) */
1108 memcpy(de[0].name, MSDOS_DOT, MSDOS_NAME);
1109 memcpy(de[1].name, MSDOS_DOTDOT, MSDOS_NAME);
1110 de->attr = de[1].attr = ATTR_DIR;
1111 de[0].lcase = de[1].lcase = 0;
1112 de[0].time = de[1].time = time;
1113 de[0].date = de[1].date = date;
1114 de[0].ctime_cs = de[1].ctime_cs = 0;
1115 if (sbi->options.isvfat) {
1116 /* extra timestamps */
1117 de[0].ctime = de[1].ctime = time;
1118 de[0].adate = de[0].cdate = de[1].adate = de[1].cdate = date;
1119 } else {
1120 de[0].ctime = de[1].ctime = 0;
1121 de[0].adate = de[0].cdate = de[1].adate = de[1].cdate = 0;
1123 de[0].start = cpu_to_le16(cluster);
1124 de[0].starthi = cpu_to_le16(cluster >> 16);
1125 de[1].start = cpu_to_le16(MSDOS_I(dir)->i_logstart);
1126 de[1].starthi = cpu_to_le16(MSDOS_I(dir)->i_logstart >> 16);
1127 de[0].size = de[1].size = 0;
1128 memset(de + 2, 0, sb->s_blocksize - 2 * sizeof(*de));
1129 set_buffer_uptodate(bhs[0]);
1130 mark_buffer_dirty(bhs[0]);
1132 err = fat_zeroed_cluster(dir, blknr, 1, bhs, MAX_BUF_PER_PAGE);
1133 if (err)
1134 goto error_free;
1136 return cluster;
1138 error_free:
1139 fat_free_clusters(dir, cluster);
1140 error:
1141 return err;
1144 EXPORT_SYMBOL_GPL(fat_alloc_new_dir);
1146 static int fat_add_new_entries(struct inode *dir, void *slots, int nr_slots,
1147 int *nr_cluster, struct msdos_dir_entry **de,
1148 struct buffer_head **bh, loff_t *i_pos)
1150 struct super_block *sb = dir->i_sb;
1151 struct msdos_sb_info *sbi = MSDOS_SB(sb);
1152 struct buffer_head *bhs[MAX_BUF_PER_PAGE];
1153 sector_t blknr, start_blknr, last_blknr;
1154 unsigned long size, copy;
1155 int err, i, n, offset, cluster[2];
1158 * The minimum cluster size is 512bytes, and maximum entry
1159 * size is 32*slots (672bytes). So, iff the cluster size is
1160 * 512bytes, we may need two clusters.
1162 size = nr_slots * sizeof(struct msdos_dir_entry);
1163 *nr_cluster = (size + (sbi->cluster_size - 1)) >> sbi->cluster_bits;
1164 BUG_ON(*nr_cluster > 2);
1166 err = fat_alloc_clusters(dir, cluster, *nr_cluster);
1167 if (err)
1168 goto error;
1171 * First stage: Fill the directory entry. NOTE: This cluster
1172 * is not referenced from any inode yet, so updates order is
1173 * not important.
1175 i = n = copy = 0;
1176 do {
1177 start_blknr = blknr = fat_clus_to_blknr(sbi, cluster[i]);
1178 last_blknr = start_blknr + sbi->sec_per_clus;
1179 while (blknr < last_blknr) {
1180 bhs[n] = sb_getblk(sb, blknr);
1181 if (!bhs[n]) {
1182 err = -ENOMEM;
1183 goto error_nomem;
1186 /* fill the directory entry */
1187 copy = min(size, sb->s_blocksize);
1188 memcpy(bhs[n]->b_data, slots, copy);
1189 slots += copy;
1190 size -= copy;
1191 set_buffer_uptodate(bhs[n]);
1192 mark_buffer_dirty(bhs[n]);
1193 if (!size)
1194 break;
1195 n++;
1196 blknr++;
1198 } while (++i < *nr_cluster);
1200 memset(bhs[n]->b_data + copy, 0, sb->s_blocksize - copy);
1201 offset = copy - sizeof(struct msdos_dir_entry);
1202 get_bh(bhs[n]);
1203 *bh = bhs[n];
1204 *de = (struct msdos_dir_entry *)((*bh)->b_data + offset);
1205 *i_pos = fat_make_i_pos(sb, *bh, *de);
1207 /* Second stage: clear the rest of cluster, and write outs */
1208 err = fat_zeroed_cluster(dir, start_blknr, ++n, bhs, MAX_BUF_PER_PAGE);
1209 if (err)
1210 goto error_free;
1212 return cluster[0];
1214 error_free:
1215 brelse(*bh);
1216 *bh = NULL;
1217 n = 0;
1218 error_nomem:
1219 for (i = 0; i < n; i++)
1220 bforget(bhs[i]);
1221 fat_free_clusters(dir, cluster[0]);
1222 error:
1223 return err;
1226 int fat_add_entries(struct inode *dir, void *slots, int nr_slots,
1227 struct fat_slot_info *sinfo)
1229 struct super_block *sb = dir->i_sb;
1230 struct msdos_sb_info *sbi = MSDOS_SB(sb);
1231 struct buffer_head *bh, *prev, *bhs[3]; /* 32*slots (672bytes) */
1232 struct msdos_dir_entry *de;
1233 int err, free_slots, i, nr_bhs;
1234 loff_t pos, i_pos;
1236 sinfo->nr_slots = nr_slots;
1238 /* First stage: search free direcotry entries */
1239 free_slots = nr_bhs = 0;
1240 bh = prev = NULL;
1241 pos = 0;
1242 err = -ENOSPC;
1243 while (fat_get_entry(dir, &pos, &bh, &de) > -1) {
1244 /* check the maximum size of directory */
1245 if (pos >= FAT_MAX_DIR_SIZE)
1246 goto error;
1248 if (IS_FREE(de->name)) {
1249 if (prev != bh) {
1250 get_bh(bh);
1251 bhs[nr_bhs] = prev = bh;
1252 nr_bhs++;
1254 free_slots++;
1255 if (free_slots == nr_slots)
1256 goto found;
1257 } else {
1258 for (i = 0; i < nr_bhs; i++)
1259 brelse(bhs[i]);
1260 prev = NULL;
1261 free_slots = nr_bhs = 0;
1264 if (dir->i_ino == MSDOS_ROOT_INO) {
1265 if (sbi->fat_bits != 32)
1266 goto error;
1267 } else if (MSDOS_I(dir)->i_start == 0) {
1268 printk(KERN_ERR "FAT: Corrupted directory (i_pos %lld)\n",
1269 MSDOS_I(dir)->i_pos);
1270 err = -EIO;
1271 goto error;
1274 found:
1275 err = 0;
1276 pos -= free_slots * sizeof(*de);
1277 nr_slots -= free_slots;
1278 if (free_slots) {
1280 * Second stage: filling the free entries with new entries.
1281 * NOTE: If this slots has shortname, first, we write
1282 * the long name slots, then write the short name.
1284 int size = free_slots * sizeof(*de);
1285 int offset = pos & (sb->s_blocksize - 1);
1286 int long_bhs = nr_bhs - (nr_slots == 0);
1288 /* Fill the long name slots. */
1289 for (i = 0; i < long_bhs; i++) {
1290 int copy = min_t(int, sb->s_blocksize - offset, size);
1291 memcpy(bhs[i]->b_data + offset, slots, copy);
1292 mark_buffer_dirty(bhs[i]);
1293 offset = 0;
1294 slots += copy;
1295 size -= copy;
1297 if (long_bhs && IS_DIRSYNC(dir))
1298 err = fat_sync_bhs(bhs, long_bhs);
1299 if (!err && i < nr_bhs) {
1300 /* Fill the short name slot. */
1301 int copy = min_t(int, sb->s_blocksize - offset, size);
1302 memcpy(bhs[i]->b_data + offset, slots, copy);
1303 mark_buffer_dirty(bhs[i]);
1304 if (IS_DIRSYNC(dir))
1305 err = sync_dirty_buffer(bhs[i]);
1307 for (i = 0; i < nr_bhs; i++)
1308 brelse(bhs[i]);
1309 if (err)
1310 goto error_remove;
1313 if (nr_slots) {
1314 int cluster, nr_cluster;
1317 * Third stage: allocate the cluster for new entries.
1318 * And initialize the cluster with new entries, then
1319 * add the cluster to dir.
1321 cluster = fat_add_new_entries(dir, slots, nr_slots, &nr_cluster,
1322 &de, &bh, &i_pos);
1323 if (cluster < 0) {
1324 err = cluster;
1325 goto error_remove;
1327 err = fat_chain_add(dir, cluster, nr_cluster);
1328 if (err) {
1329 fat_free_clusters(dir, cluster);
1330 goto error_remove;
1332 if (dir->i_size & (sbi->cluster_size - 1)) {
1333 fat_fs_panic(sb, "Odd directory size");
1334 dir->i_size = (dir->i_size + sbi->cluster_size - 1)
1335 & ~((loff_t)sbi->cluster_size - 1);
1337 dir->i_size += nr_cluster << sbi->cluster_bits;
1338 MSDOS_I(dir)->mmu_private += nr_cluster << sbi->cluster_bits;
1340 sinfo->slot_off = pos;
1341 sinfo->de = de;
1342 sinfo->bh = bh;
1343 sinfo->i_pos = fat_make_i_pos(sb, sinfo->bh, sinfo->de);
1345 return 0;
1347 error:
1348 brelse(bh);
1349 for (i = 0; i < nr_bhs; i++)
1350 brelse(bhs[i]);
1351 return err;
1353 error_remove:
1354 brelse(bh);
1355 if (free_slots)
1356 __fat_remove_entries(dir, pos, free_slots);
1357 return err;
1360 EXPORT_SYMBOL_GPL(fat_add_entries);