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[tomato.git] / release / src-rt-6.x.4708 / linux / linux-2.6.36 / fs / fat / dir.c
blobee42b9e0b16adb954e8fa1b183f01253c32f7b3c
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/buffer_head.h>
20 #include <linux/compat.h>
21 #include <asm/uaccess.h>
22 #include <linux/kernel.h>
23 #include "fat.h"
26 * Maximum buffer size of short name.
27 * [(MSDOS_NAME + '.') * max one char + nul]
28 * For msdos style, ['.' (hidden) + MSDOS_NAME + '.' + nul]
30 #define FAT_MAX_SHORT_SIZE ((MSDOS_NAME + 1) * NLS_MAX_CHARSET_SIZE + 1)
32 * Maximum buffer size of unicode chars from slots.
33 * [(max longname slots * 13 (size in a slot) + nul) * sizeof(wchar_t)]
35 #define FAT_MAX_UNI_CHARS ((MSDOS_SLOTS - 1) * 13 + 1)
36 #define FAT_MAX_UNI_SIZE (FAT_MAX_UNI_CHARS * sizeof(wchar_t))
38 static inline loff_t fat_make_i_pos(struct super_block *sb,
39 struct buffer_head *bh,
40 struct msdos_dir_entry *de)
42 return ((loff_t)bh->b_blocknr << MSDOS_SB(sb)->dir_per_block_bits)
43 | (de - (struct msdos_dir_entry *)bh->b_data);
46 static inline void fat_dir_readahead(struct inode *dir, sector_t iblock,
47 sector_t phys)
49 struct super_block *sb = dir->i_sb;
50 struct msdos_sb_info *sbi = MSDOS_SB(sb);
51 struct buffer_head *bh;
52 int sec;
54 /* This is not a first sector of cluster, or sec_per_clus == 1 */
55 if ((iblock & (sbi->sec_per_clus - 1)) || sbi->sec_per_clus == 1)
56 return;
57 /* root dir of FAT12/FAT16 */
58 if ((sbi->fat_bits != 32) && (dir->i_ino == MSDOS_ROOT_INO))
59 return;
61 bh = sb_find_get_block(sb, phys);
62 if (bh == NULL || !buffer_uptodate(bh)) {
63 for (sec = 0; sec < sbi->sec_per_clus; sec++)
64 sb_breadahead(sb, phys + sec);
66 brelse(bh);
69 /* Returns the inode number of the directory entry at offset pos. If bh is
70 non-NULL, it is brelse'd before. Pos is incremented. The buffer header is
71 returned in bh.
72 AV. Most often we do it item-by-item. Makes sense to optimize.
73 AV. OK, there we go: if both bh and de are non-NULL we assume that we just
74 AV. want the next entry (took one explicit de=NULL in vfat/namei.c).
75 AV. It's done in fat_get_entry() (inlined), here the slow case lives.
76 AV. Additionally, when we return -1 (i.e. reached the end of directory)
77 AV. we make bh NULL.
79 static int fat__get_entry(struct inode *dir, loff_t *pos,
80 struct buffer_head **bh, struct msdos_dir_entry **de)
82 struct super_block *sb = dir->i_sb;
83 sector_t phys, iblock;
84 unsigned long mapped_blocks;
85 int err, offset;
87 next:
88 if (*bh)
89 brelse(*bh);
91 *bh = NULL;
92 iblock = *pos >> sb->s_blocksize_bits;
93 err = fat_bmap(dir, iblock, &phys, &mapped_blocks, 0);
94 if (err || !phys)
95 return -1; /* beyond EOF or error */
97 fat_dir_readahead(dir, iblock, phys);
99 *bh = sb_bread(sb, phys);
100 if (*bh == NULL) {
101 printk(KERN_ERR "FAT: Directory bread(block %llu) failed\n",
102 (llu)phys);
103 /* skip this block */
104 *pos = (iblock + 1) << sb->s_blocksize_bits;
105 goto next;
108 offset = *pos & (sb->s_blocksize - 1);
109 *pos += sizeof(struct msdos_dir_entry);
110 *de = (struct msdos_dir_entry *)((*bh)->b_data + offset);
112 return 0;
115 static inline int fat_get_entry(struct inode *dir, loff_t *pos,
116 struct buffer_head **bh,
117 struct msdos_dir_entry **de)
119 /* Fast stuff first */
120 if (*bh && *de &&
121 (*de - (struct msdos_dir_entry *)(*bh)->b_data) < MSDOS_SB(dir->i_sb)->dir_per_block - 1) {
122 *pos += sizeof(struct msdos_dir_entry);
123 (*de)++;
124 return 0;
126 return fat__get_entry(dir, pos, bh, de);
130 * Convert Unicode 16 to UTF-8, translated Unicode, or ASCII.
131 * If uni_xlate is enabled and we can't get a 1:1 conversion, use a
132 * colon as an escape character since it is normally invalid on the vfat
133 * filesystem. The following four characters are the hexadecimal digits
134 * of Unicode value. This lets us do a full dump and restore of Unicode
135 * filenames. We could get into some trouble with long Unicode names,
136 * but ignore that right now.
137 * Ahem... Stack smashing in ring 0 isn't fun. Fixed.
139 static int uni16_to_x8(unsigned char *ascii, const wchar_t *uni, int len,
140 int uni_xlate, struct nls_table *nls)
142 const wchar_t *ip;
143 wchar_t ec;
144 unsigned char *op;
145 int charlen;
147 ip = uni;
148 op = ascii;
150 while (*ip && ((len - NLS_MAX_CHARSET_SIZE) > 0)) {
151 ec = *ip++;
152 if ((charlen = nls->uni2char(ec, op, NLS_MAX_CHARSET_SIZE)) > 0) {
153 op += charlen;
154 len -= charlen;
155 } else {
156 if (uni_xlate == 1) {
157 *op++ = ':';
158 op = pack_hex_byte(op, ec >> 8);
159 op = pack_hex_byte(op, ec);
160 len -= 5;
161 } else {
162 *op++ = '?';
163 len--;
168 if (unlikely(*ip)) {
169 printk(KERN_WARNING "FAT: filename was truncated while "
170 "converting.");
173 *op = 0;
174 return (op - ascii);
177 static inline int fat_uni_to_x8(struct msdos_sb_info *sbi, const wchar_t *uni,
178 unsigned char *buf, int size)
180 if (sbi->options.utf8)
181 return utf16s_to_utf8s(uni, FAT_MAX_UNI_CHARS,
182 UTF16_HOST_ENDIAN, buf, size);
183 else
184 return uni16_to_x8(buf, uni, size, sbi->options.unicode_xlate,
185 sbi->nls_io);
188 static inline int
189 fat_short2uni(struct nls_table *t, unsigned char *c, int clen, wchar_t *uni)
191 int charlen;
193 charlen = t->char2uni(c, clen, uni);
194 if (charlen < 0) {
195 *uni = 0x003f; /* a question mark */
196 charlen = 1;
198 return charlen;
201 static inline int
202 fat_short2lower_uni(struct nls_table *t, unsigned char *c, int clen, wchar_t *uni)
204 int charlen;
205 wchar_t wc;
207 charlen = t->char2uni(c, clen, &wc);
208 if (charlen < 0) {
209 *uni = 0x003f; /* a question mark */
210 charlen = 1;
211 } else if (charlen <= 1) {
212 unsigned char nc = t->charset2lower[*c];
214 if (!nc)
215 nc = *c;
217 if ( (charlen = t->char2uni(&nc, 1, uni)) < 0) {
218 *uni = 0x003f; /* a question mark */
219 charlen = 1;
221 } else
222 *uni = wc;
224 return charlen;
227 static inline int
228 fat_shortname2uni(struct nls_table *nls, unsigned char *buf, int buf_size,
229 wchar_t *uni_buf, unsigned short opt, int lower)
231 int len = 0;
233 if (opt & VFAT_SFN_DISPLAY_LOWER)
234 len = fat_short2lower_uni(nls, buf, buf_size, uni_buf);
235 else if (opt & VFAT_SFN_DISPLAY_WIN95)
236 len = fat_short2uni(nls, buf, buf_size, uni_buf);
237 else if (opt & VFAT_SFN_DISPLAY_WINNT) {
238 if (lower)
239 len = fat_short2lower_uni(nls, buf, buf_size, uni_buf);
240 else
241 len = fat_short2uni(nls, buf, buf_size, uni_buf);
242 } else
243 len = fat_short2uni(nls, buf, buf_size, uni_buf);
245 return len;
248 static inline int fat_name_match(struct msdos_sb_info *sbi,
249 const unsigned char *a, int a_len,
250 const unsigned char *b, int b_len)
252 if (a_len != b_len)
253 return 0;
255 if (sbi->options.name_check != 's')
256 return !nls_strnicmp(sbi->nls_io, a, b, a_len);
257 else
258 return !memcmp(a, b, a_len);
261 enum { PARSE_INVALID = 1, PARSE_NOT_LONGNAME, PARSE_EOF, };
264 * fat_parse_long - Parse extended directory entry.
266 * This function returns zero on success, negative value on error, or one of
267 * the following:
269 * %PARSE_INVALID - Directory entry is invalid.
270 * %PARSE_NOT_LONGNAME - Directory entry does not contain longname.
271 * %PARSE_EOF - Directory has no more entries.
273 static int fat_parse_long(struct inode *dir, loff_t *pos,
274 struct buffer_head **bh, struct msdos_dir_entry **de,
275 wchar_t **unicode, unsigned char *nr_slots)
277 struct msdos_dir_slot *ds;
278 unsigned char id, slot, slots, alias_checksum;
280 if (!*unicode) {
281 *unicode = __getname();
282 if (!*unicode) {
283 brelse(*bh);
284 return -ENOMEM;
287 parse_long:
288 slots = 0;
289 ds = (struct msdos_dir_slot *)*de;
290 id = ds->id;
291 if (!(id & 0x40))
292 return PARSE_INVALID;
293 slots = id & ~0x40;
294 if (slots > 20 || !slots) /* ceil(256 * 2 / 26) */
295 return PARSE_INVALID;
296 *nr_slots = slots;
297 alias_checksum = ds->alias_checksum;
299 slot = slots;
300 while (1) {
301 int offset;
303 slot--;
304 offset = slot * 13;
305 fat16_towchar(*unicode + offset, ds->name0_4, 5);
306 fat16_towchar(*unicode + offset + 5, ds->name5_10, 6);
307 fat16_towchar(*unicode + offset + 11, ds->name11_12, 2);
309 if (ds->id & 0x40)
310 (*unicode)[offset + 13] = 0;
311 if (fat_get_entry(dir, pos, bh, de) < 0)
312 return PARSE_EOF;
313 if (slot == 0)
314 break;
315 ds = (struct msdos_dir_slot *)*de;
316 if (ds->attr != ATTR_EXT)
317 return PARSE_NOT_LONGNAME;
318 if ((ds->id & ~0x40) != slot)
319 goto parse_long;
320 if (ds->alias_checksum != alias_checksum)
321 goto parse_long;
323 if ((*de)->name[0] == DELETED_FLAG)
324 return PARSE_INVALID;
325 if ((*de)->attr == ATTR_EXT)
326 goto parse_long;
327 if (IS_FREE((*de)->name) || ((*de)->attr & ATTR_VOLUME))
328 return PARSE_INVALID;
329 if (fat_checksum((*de)->name) != alias_checksum)
330 *nr_slots = 0;
332 return 0;
336 * Return values: negative -> error, 0 -> not found, positive -> found,
337 * value is the total amount of slots, including the shortname entry.
339 int fat_search_long(struct inode *inode, const unsigned char *name,
340 int name_len, struct fat_slot_info *sinfo)
342 struct super_block *sb = inode->i_sb;
343 struct msdos_sb_info *sbi = MSDOS_SB(sb);
344 struct buffer_head *bh = NULL;
345 struct msdos_dir_entry *de;
346 struct nls_table *nls_disk = sbi->nls_disk;
347 unsigned char nr_slots;
348 wchar_t bufuname[14];
349 wchar_t *unicode = NULL;
350 unsigned char work[MSDOS_NAME];
351 unsigned char bufname[FAT_MAX_SHORT_SIZE];
352 unsigned short opt_shortname = sbi->options.shortname;
353 loff_t cpos = 0;
354 int chl, i, j, last_u, err, len;
356 err = -ENOENT;
357 while (1) {
358 if (fat_get_entry(inode, &cpos, &bh, &de) == -1)
359 goto end_of_dir;
360 parse_record:
361 nr_slots = 0;
362 if (de->name[0] == DELETED_FLAG)
363 continue;
364 if (de->attr != ATTR_EXT && (de->attr & ATTR_VOLUME))
365 continue;
366 if (de->attr != ATTR_EXT && IS_FREE(de->name))
367 continue;
368 if (de->attr == ATTR_EXT) {
369 int status = fat_parse_long(inode, &cpos, &bh, &de,
370 &unicode, &nr_slots);
371 if (status < 0) {
372 err = status;
373 goto end_of_dir;
374 } else if (status == PARSE_INVALID)
375 continue;
376 else if (status == PARSE_NOT_LONGNAME)
377 goto parse_record;
378 else if (status == PARSE_EOF)
379 goto end_of_dir;
382 memcpy(work, de->name, sizeof(de->name));
383 /* see namei.c, msdos_format_name */
384 if (work[0] == 0x05)
385 work[0] = 0xE5;
386 for (i = 0, j = 0, last_u = 0; i < 8;) {
387 if (!work[i])
388 break;
389 chl = fat_shortname2uni(nls_disk, &work[i], 8 - i,
390 &bufuname[j++], opt_shortname,
391 de->lcase & CASE_LOWER_BASE);
392 if (chl <= 1) {
393 if (work[i] != ' ')
394 last_u = j;
395 } else {
396 last_u = j;
398 i += chl;
400 j = last_u;
401 fat_short2uni(nls_disk, ".", 1, &bufuname[j++]);
402 for (i = 8; i < MSDOS_NAME;) {
403 if (!work[i])
404 break;
405 chl = fat_shortname2uni(nls_disk, &work[i],
406 MSDOS_NAME - i,
407 &bufuname[j++], opt_shortname,
408 de->lcase & CASE_LOWER_EXT);
409 if (chl <= 1) {
410 if (work[i] != ' ')
411 last_u = j;
412 } else {
413 last_u = j;
415 i += chl;
417 if (!last_u)
418 continue;
420 /* Compare shortname */
421 bufuname[last_u] = 0x0000;
422 len = fat_uni_to_x8(sbi, bufuname, bufname, sizeof(bufname));
423 if (fat_name_match(sbi, name, name_len, bufname, len))
424 goto found;
426 if (nr_slots) {
427 void *longname = unicode + FAT_MAX_UNI_CHARS;
428 int size = PATH_MAX - FAT_MAX_UNI_SIZE;
430 /* Compare longname */
431 len = fat_uni_to_x8(sbi, unicode, longname, size);
432 if (fat_name_match(sbi, name, name_len, longname, len))
433 goto found;
437 found:
438 nr_slots++; /* include the de */
439 sinfo->slot_off = cpos - nr_slots * sizeof(*de);
440 sinfo->nr_slots = nr_slots;
441 sinfo->de = de;
442 sinfo->bh = bh;
443 sinfo->i_pos = fat_make_i_pos(sb, sinfo->bh, sinfo->de);
444 err = 0;
445 end_of_dir:
446 if (unicode)
447 __putname(unicode);
449 return err;
452 EXPORT_SYMBOL_GPL(fat_search_long);
454 struct fat_ioctl_filldir_callback {
455 void __user *dirent;
456 int result;
457 /* for dir ioctl */
458 const char *longname;
459 int long_len;
460 const char *shortname;
461 int short_len;
464 static int __fat_readdir(struct inode *inode, struct file *filp, void *dirent,
465 filldir_t filldir, int short_only, int both)
467 struct super_block *sb = inode->i_sb;
468 struct msdos_sb_info *sbi = MSDOS_SB(sb);
469 struct buffer_head *bh;
470 struct msdos_dir_entry *de;
471 struct nls_table *nls_disk = sbi->nls_disk;
472 unsigned char nr_slots;
473 wchar_t bufuname[14];
474 wchar_t *unicode = NULL;
475 unsigned char c, work[MSDOS_NAME];
476 unsigned char bufname[FAT_MAX_SHORT_SIZE], *ptname = bufname;
477 unsigned short opt_shortname = sbi->options.shortname;
478 int isvfat = sbi->options.isvfat;
479 int nocase = sbi->options.nocase;
480 const char *fill_name = NULL;
481 unsigned long inum;
482 unsigned long lpos, dummy, *furrfu = &lpos;
483 loff_t cpos;
484 int chi, chl, i, i2, j, last, last_u, dotoffset = 0, fill_len = 0;
485 int ret = 0;
487 lock_super(sb);
489 cpos = filp->f_pos;
490 /* Fake . and .. for the root directory. */
491 if (inode->i_ino == MSDOS_ROOT_INO) {
492 while (cpos < 2) {
493 if (filldir(dirent, "..", cpos+1, cpos, MSDOS_ROOT_INO, DT_DIR) < 0)
494 goto out;
495 cpos++;
496 filp->f_pos++;
498 if (cpos == 2) {
499 dummy = 2;
500 furrfu = &dummy;
501 cpos = 0;
504 if (cpos & (sizeof(struct msdos_dir_entry) - 1)) {
505 ret = -ENOENT;
506 goto out;
509 bh = NULL;
510 get_new:
511 if (fat_get_entry(inode, &cpos, &bh, &de) == -1)
512 goto end_of_dir;
513 parse_record:
514 nr_slots = 0;
516 * Check for long filename entry, but if short_only, we don't
517 * need to parse long filename.
519 if (isvfat && !short_only) {
520 if (de->name[0] == DELETED_FLAG)
521 goto record_end;
522 if (de->attr != ATTR_EXT && (de->attr & ATTR_VOLUME))
523 goto record_end;
524 if (de->attr != ATTR_EXT && IS_FREE(de->name))
525 goto record_end;
526 } else {
527 if ((de->attr & ATTR_VOLUME) || IS_FREE(de->name))
528 goto record_end;
531 if (isvfat && de->attr == ATTR_EXT) {
532 int status = fat_parse_long(inode, &cpos, &bh, &de,
533 &unicode, &nr_slots);
534 if (status < 0) {
535 filp->f_pos = cpos;
536 ret = status;
537 goto out;
538 } else if (status == PARSE_INVALID)
539 goto record_end;
540 else if (status == PARSE_NOT_LONGNAME)
541 goto parse_record;
542 else if (status == PARSE_EOF)
543 goto end_of_dir;
545 if (nr_slots) {
546 void *longname = unicode + FAT_MAX_UNI_CHARS;
547 int size = PATH_MAX - FAT_MAX_UNI_SIZE;
548 int len = fat_uni_to_x8(sbi, unicode, longname, size);
550 fill_name = longname;
551 fill_len = len;
552 /* !both && !short_only, so we don't need shortname. */
553 if (!both)
554 goto start_filldir;
558 if (sbi->options.dotsOK) {
559 ptname = bufname;
560 dotoffset = 0;
561 if (de->attr & ATTR_HIDDEN) {
562 *ptname++ = '.';
563 dotoffset = 1;
567 memcpy(work, de->name, sizeof(de->name));
568 /* see namei.c, msdos_format_name */
569 if (work[0] == 0x05)
570 work[0] = 0xE5;
571 for (i = 0, j = 0, last = 0, last_u = 0; i < 8;) {
572 if (!(c = work[i]))
573 break;
574 chl = fat_shortname2uni(nls_disk, &work[i], 8 - i,
575 &bufuname[j++], opt_shortname,
576 de->lcase & CASE_LOWER_BASE);
577 if (chl <= 1) {
578 ptname[i++] = (!nocase && c>='A' && c<='Z') ? c+32 : c;
579 if (c != ' ') {
580 last = i;
581 last_u = j;
583 } else {
584 last_u = j;
585 for (chi = 0; chi < chl && i < 8; chi++) {
586 ptname[i] = work[i];
587 i++; last = i;
591 i = last;
592 j = last_u;
593 fat_short2uni(nls_disk, ".", 1, &bufuname[j++]);
594 ptname[i++] = '.';
595 for (i2 = 8; i2 < MSDOS_NAME;) {
596 if (!(c = work[i2]))
597 break;
598 chl = fat_shortname2uni(nls_disk, &work[i2], MSDOS_NAME - i2,
599 &bufuname[j++], opt_shortname,
600 de->lcase & CASE_LOWER_EXT);
601 if (chl <= 1) {
602 i2++;
603 ptname[i++] = (!nocase && c>='A' && c<='Z') ? c+32 : c;
604 if (c != ' ') {
605 last = i;
606 last_u = j;
608 } else {
609 last_u = j;
610 for (chi = 0; chi < chl && i2 < MSDOS_NAME; chi++) {
611 ptname[i++] = work[i2++];
612 last = i;
616 if (!last)
617 goto record_end;
619 i = last + dotoffset;
620 j = last_u;
622 if (isvfat) {
623 bufuname[j] = 0x0000;
624 i = fat_uni_to_x8(sbi, bufuname, bufname, sizeof(bufname));
626 if (nr_slots) {
627 /* hack for fat_ioctl_filldir() */
628 struct fat_ioctl_filldir_callback *p = dirent;
630 p->longname = fill_name;
631 p->long_len = fill_len;
632 p->shortname = bufname;
633 p->short_len = i;
634 fill_name = NULL;
635 fill_len = 0;
636 } else {
637 fill_name = bufname;
638 fill_len = i;
641 start_filldir:
642 lpos = cpos - (nr_slots + 1) * sizeof(struct msdos_dir_entry);
643 if (!memcmp(de->name, MSDOS_DOT, MSDOS_NAME))
644 inum = inode->i_ino;
645 else if (!memcmp(de->name, MSDOS_DOTDOT, MSDOS_NAME)) {
646 inum = parent_ino(filp->f_path.dentry);
647 } else {
648 loff_t i_pos = fat_make_i_pos(sb, bh, de);
649 struct inode *tmp = fat_iget(sb, i_pos);
650 if (tmp) {
651 inum = tmp->i_ino;
652 iput(tmp);
653 } else
654 inum = iunique(sb, MSDOS_ROOT_INO);
657 if (filldir(dirent, fill_name, fill_len, *furrfu, inum,
658 (de->attr & ATTR_DIR) ? DT_DIR : DT_REG) < 0)
659 goto fill_failed;
661 record_end:
662 furrfu = &lpos;
663 filp->f_pos = cpos;
664 goto get_new;
665 end_of_dir:
666 filp->f_pos = cpos;
667 fill_failed:
668 brelse(bh);
669 if (unicode)
670 __putname(unicode);
671 out:
672 unlock_super(sb);
673 return ret;
676 static int fat_readdir(struct file *filp, void *dirent, filldir_t filldir)
678 struct inode *inode = filp->f_path.dentry->d_inode;
679 return __fat_readdir(inode, filp, dirent, filldir, 0, 0);
682 #define FAT_IOCTL_FILLDIR_FUNC(func, dirent_type) \
683 static int func(void *__buf, const char *name, int name_len, \
684 loff_t offset, u64 ino, unsigned int d_type) \
686 struct fat_ioctl_filldir_callback *buf = __buf; \
687 struct dirent_type __user *d1 = buf->dirent; \
688 struct dirent_type __user *d2 = d1 + 1; \
690 if (buf->result) \
691 return -EINVAL; \
692 buf->result++; \
694 if (name != NULL) { \
695 /* dirent has only short name */ \
696 if (name_len >= sizeof(d1->d_name)) \
697 name_len = sizeof(d1->d_name) - 1; \
699 if (put_user(0, d2->d_name) || \
700 put_user(0, &d2->d_reclen) || \
701 copy_to_user(d1->d_name, name, name_len) || \
702 put_user(0, d1->d_name + name_len) || \
703 put_user(name_len, &d1->d_reclen)) \
704 goto efault; \
705 } else { \
706 /* dirent has short and long name */ \
707 const char *longname = buf->longname; \
708 int long_len = buf->long_len; \
709 const char *shortname = buf->shortname; \
710 int short_len = buf->short_len; \
712 if (long_len >= sizeof(d1->d_name)) \
713 long_len = sizeof(d1->d_name) - 1; \
714 if (short_len >= sizeof(d1->d_name)) \
715 short_len = sizeof(d1->d_name) - 1; \
717 if (copy_to_user(d2->d_name, longname, long_len) || \
718 put_user(0, d2->d_name + long_len) || \
719 put_user(long_len, &d2->d_reclen) || \
720 put_user(ino, &d2->d_ino) || \
721 put_user(offset, &d2->d_off) || \
722 copy_to_user(d1->d_name, shortname, short_len) || \
723 put_user(0, d1->d_name + short_len) || \
724 put_user(short_len, &d1->d_reclen)) \
725 goto efault; \
727 return 0; \
728 efault: \
729 buf->result = -EFAULT; \
730 return -EFAULT; \
733 FAT_IOCTL_FILLDIR_FUNC(fat_ioctl_filldir, __fat_dirent)
735 static int fat_ioctl_readdir(struct inode *inode, struct file *filp,
736 void __user *dirent, filldir_t filldir,
737 int short_only, int both)
739 struct fat_ioctl_filldir_callback buf;
740 int ret;
742 buf.dirent = dirent;
743 buf.result = 0;
744 mutex_lock(&inode->i_mutex);
745 ret = -ENOENT;
746 if (!IS_DEADDIR(inode)) {
747 ret = __fat_readdir(inode, filp, &buf, filldir,
748 short_only, both);
750 mutex_unlock(&inode->i_mutex);
751 if (ret >= 0)
752 ret = buf.result;
753 return ret;
756 static long fat_dir_ioctl(struct file *filp, unsigned int cmd,
757 unsigned long arg)
759 struct inode *inode = filp->f_path.dentry->d_inode;
760 struct __fat_dirent __user *d1 = (struct __fat_dirent __user *)arg;
761 int short_only, both;
763 switch (cmd) {
764 case VFAT_IOCTL_READDIR_SHORT:
765 short_only = 1;
766 both = 0;
767 break;
768 case VFAT_IOCTL_READDIR_BOTH:
769 short_only = 0;
770 both = 1;
771 break;
772 default:
773 return fat_generic_ioctl(filp, cmd, arg);
776 if (!access_ok(VERIFY_WRITE, d1, sizeof(struct __fat_dirent[2])))
777 return -EFAULT;
779 * Yes, we don't need this put_user() absolutely. However old
780 * code didn't return the right value. So, app use this value,
781 * in order to check whether it is EOF.
783 if (put_user(0, &d1->d_reclen))
784 return -EFAULT;
786 return fat_ioctl_readdir(inode, filp, d1, fat_ioctl_filldir,
787 short_only, both);
790 #ifdef CONFIG_COMPAT
791 #define VFAT_IOCTL_READDIR_BOTH32 _IOR('r', 1, struct compat_dirent[2])
792 #define VFAT_IOCTL_READDIR_SHORT32 _IOR('r', 2, struct compat_dirent[2])
794 FAT_IOCTL_FILLDIR_FUNC(fat_compat_ioctl_filldir, compat_dirent)
796 static long fat_compat_dir_ioctl(struct file *filp, unsigned cmd,
797 unsigned long arg)
799 struct inode *inode = filp->f_path.dentry->d_inode;
800 struct compat_dirent __user *d1 = compat_ptr(arg);
801 int short_only, both;
803 switch (cmd) {
804 case VFAT_IOCTL_READDIR_SHORT32:
805 short_only = 1;
806 both = 0;
807 break;
808 case VFAT_IOCTL_READDIR_BOTH32:
809 short_only = 0;
810 both = 1;
811 break;
812 default:
813 return fat_generic_ioctl(filp, cmd, (unsigned long)arg);
816 if (!access_ok(VERIFY_WRITE, d1, sizeof(struct compat_dirent[2])))
817 return -EFAULT;
819 * Yes, we don't need this put_user() absolutely. However old
820 * code didn't return the right value. So, app use this value,
821 * in order to check whether it is EOF.
823 if (put_user(0, &d1->d_reclen))
824 return -EFAULT;
826 return fat_ioctl_readdir(inode, filp, d1, fat_compat_ioctl_filldir,
827 short_only, both);
829 #endif /* CONFIG_COMPAT */
831 const struct file_operations fat_dir_operations = {
832 .llseek = generic_file_llseek,
833 .read = generic_read_dir,
834 .readdir = fat_readdir,
835 .unlocked_ioctl = fat_dir_ioctl,
836 #ifdef CONFIG_COMPAT
837 .compat_ioctl = fat_compat_dir_ioctl,
838 #endif
839 .fsync = fat_file_fsync,
842 static int fat_get_short_entry(struct inode *dir, loff_t *pos,
843 struct buffer_head **bh,
844 struct msdos_dir_entry **de)
846 while (fat_get_entry(dir, pos, bh, de) >= 0) {
847 /* free entry or long name entry or volume label */
848 if (!IS_FREE((*de)->name) && !((*de)->attr & ATTR_VOLUME))
849 return 0;
851 return -ENOENT;
855 * The ".." entry can not provide the "struct fat_slot_info" informations
856 * for inode. So, this function provide the some informations only.
858 int fat_get_dotdot_entry(struct inode *dir, struct buffer_head **bh,
859 struct msdos_dir_entry **de, loff_t *i_pos)
861 loff_t offset;
863 offset = 0;
864 *bh = NULL;
865 while (fat_get_short_entry(dir, &offset, bh, de) >= 0) {
866 if (!strncmp((*de)->name, MSDOS_DOTDOT, MSDOS_NAME)) {
867 *i_pos = fat_make_i_pos(dir->i_sb, *bh, *de);
868 return 0;
871 return -ENOENT;
874 EXPORT_SYMBOL_GPL(fat_get_dotdot_entry);
876 /* See if directory is empty */
877 int fat_dir_empty(struct inode *dir)
879 struct buffer_head *bh;
880 struct msdos_dir_entry *de;
881 loff_t cpos;
882 int result = 0;
884 bh = NULL;
885 cpos = 0;
886 while (fat_get_short_entry(dir, &cpos, &bh, &de) >= 0) {
887 if (strncmp(de->name, MSDOS_DOT , MSDOS_NAME) &&
888 strncmp(de->name, MSDOS_DOTDOT, MSDOS_NAME)) {
889 result = -ENOTEMPTY;
890 break;
893 brelse(bh);
894 return result;
897 EXPORT_SYMBOL_GPL(fat_dir_empty);
900 * fat_subdirs counts the number of sub-directories of dir. It can be run
901 * on directories being created.
903 int fat_subdirs(struct inode *dir)
905 struct buffer_head *bh;
906 struct msdos_dir_entry *de;
907 loff_t cpos;
908 int count = 0;
910 bh = NULL;
911 cpos = 0;
912 while (fat_get_short_entry(dir, &cpos, &bh, &de) >= 0) {
913 if (de->attr & ATTR_DIR)
914 count++;
916 brelse(bh);
917 return count;
921 * Scans a directory for a given file (name points to its formatted name).
922 * Returns an error code or zero.
924 int fat_scan(struct inode *dir, const unsigned char *name,
925 struct fat_slot_info *sinfo)
927 struct super_block *sb = dir->i_sb;
929 sinfo->slot_off = 0;
930 sinfo->bh = NULL;
931 while (fat_get_short_entry(dir, &sinfo->slot_off, &sinfo->bh,
932 &sinfo->de) >= 0) {
933 if (!strncmp(sinfo->de->name, name, MSDOS_NAME)) {
934 sinfo->slot_off -= sizeof(*sinfo->de);
935 sinfo->nr_slots = 1;
936 sinfo->i_pos = fat_make_i_pos(sb, sinfo->bh, sinfo->de);
937 return 0;
940 return -ENOENT;
943 EXPORT_SYMBOL_GPL(fat_scan);
945 static int __fat_remove_entries(struct inode *dir, loff_t pos, int nr_slots)
947 struct super_block *sb = dir->i_sb;
948 struct buffer_head *bh;
949 struct msdos_dir_entry *de, *endp;
950 int err = 0, orig_slots;
952 while (nr_slots) {
953 bh = NULL;
954 if (fat_get_entry(dir, &pos, &bh, &de) < 0) {
955 err = -EIO;
956 break;
959 orig_slots = nr_slots;
960 endp = (struct msdos_dir_entry *)(bh->b_data + sb->s_blocksize);
961 while (nr_slots && de < endp) {
962 de->name[0] = DELETED_FLAG;
963 de++;
964 nr_slots--;
966 mark_buffer_dirty_inode(bh, dir);
967 if (IS_DIRSYNC(dir))
968 err = sync_dirty_buffer(bh);
969 brelse(bh);
970 if (err)
971 break;
973 /* pos is *next* de's position, so this does `- sizeof(de)' */
974 pos += ((orig_slots - nr_slots) * sizeof(*de)) - sizeof(*de);
977 return err;
980 int fat_remove_entries(struct inode *dir, struct fat_slot_info *sinfo)
982 struct msdos_dir_entry *de;
983 struct buffer_head *bh;
984 int err = 0, nr_slots;
987 * First stage: Remove the shortname. By this, the directory
988 * entry is removed.
990 nr_slots = sinfo->nr_slots;
991 de = sinfo->de;
992 sinfo->de = NULL;
993 bh = sinfo->bh;
994 sinfo->bh = NULL;
995 while (nr_slots && de >= (struct msdos_dir_entry *)bh->b_data) {
996 de->name[0] = DELETED_FLAG;
997 de--;
998 nr_slots--;
1000 mark_buffer_dirty_inode(bh, dir);
1001 if (IS_DIRSYNC(dir))
1002 err = sync_dirty_buffer(bh);
1003 brelse(bh);
1004 if (err)
1005 return err;
1006 dir->i_version++;
1008 if (nr_slots) {
1010 * Second stage: remove the remaining longname slots.
1011 * (This directory entry is already removed, and so return
1012 * the success)
1014 err = __fat_remove_entries(dir, sinfo->slot_off, nr_slots);
1015 if (err) {
1016 printk(KERN_WARNING
1017 "FAT: Couldn't remove the long name slots\n");
1021 dir->i_mtime = dir->i_atime = CURRENT_TIME_SEC;
1022 if (IS_DIRSYNC(dir))
1023 (void)fat_sync_inode(dir);
1024 else
1025 mark_inode_dirty(dir);
1027 return 0;
1030 EXPORT_SYMBOL_GPL(fat_remove_entries);
1032 static int fat_zeroed_cluster(struct inode *dir, sector_t blknr, int nr_used,
1033 struct buffer_head **bhs, int nr_bhs)
1035 struct super_block *sb = dir->i_sb;
1036 sector_t last_blknr = blknr + MSDOS_SB(sb)->sec_per_clus;
1037 int err, i, n;
1039 /* Zeroing the unused blocks on this cluster */
1040 blknr += nr_used;
1041 n = nr_used;
1042 while (blknr < last_blknr) {
1043 bhs[n] = sb_getblk(sb, blknr);
1044 if (!bhs[n]) {
1045 err = -ENOMEM;
1046 goto error;
1048 memset(bhs[n]->b_data, 0, sb->s_blocksize);
1049 set_buffer_uptodate(bhs[n]);
1050 mark_buffer_dirty_inode(bhs[n], dir);
1052 n++;
1053 blknr++;
1054 if (n == nr_bhs) {
1055 if (IS_DIRSYNC(dir)) {
1056 err = fat_sync_bhs(bhs, n);
1057 if (err)
1058 goto error;
1060 for (i = 0; i < n; i++)
1061 brelse(bhs[i]);
1062 n = 0;
1065 if (IS_DIRSYNC(dir)) {
1066 err = fat_sync_bhs(bhs, n);
1067 if (err)
1068 goto error;
1070 for (i = 0; i < n; i++)
1071 brelse(bhs[i]);
1073 return 0;
1075 error:
1076 for (i = 0; i < n; i++)
1077 bforget(bhs[i]);
1078 return err;
1081 int fat_alloc_new_dir(struct inode *dir, struct timespec *ts)
1083 struct super_block *sb = dir->i_sb;
1084 struct msdos_sb_info *sbi = MSDOS_SB(sb);
1085 struct buffer_head *bhs[MAX_BUF_PER_PAGE];
1086 struct msdos_dir_entry *de;
1087 sector_t blknr;
1088 __le16 date, time;
1089 u8 time_cs;
1090 int err, cluster;
1092 err = fat_alloc_clusters(dir, &cluster, 1);
1093 if (err)
1094 goto error;
1096 blknr = fat_clus_to_blknr(sbi, cluster);
1097 bhs[0] = sb_getblk(sb, blknr);
1098 if (!bhs[0]) {
1099 err = -ENOMEM;
1100 goto error_free;
1103 fat_time_unix2fat(sbi, ts, &time, &date, &time_cs);
1105 de = (struct msdos_dir_entry *)bhs[0]->b_data;
1106 /* filling the new directory slots ("." and ".." entries) */
1107 memcpy(de[0].name, MSDOS_DOT, MSDOS_NAME);
1108 memcpy(de[1].name, MSDOS_DOTDOT, MSDOS_NAME);
1109 de->attr = de[1].attr = ATTR_DIR;
1110 de[0].lcase = de[1].lcase = 0;
1111 de[0].time = de[1].time = time;
1112 de[0].date = de[1].date = date;
1113 if (sbi->options.isvfat) {
1114 /* extra timestamps */
1115 de[0].ctime = de[1].ctime = time;
1116 de[0].ctime_cs = de[1].ctime_cs = time_cs;
1117 de[0].adate = de[0].cdate = de[1].adate = de[1].cdate = date;
1118 } else {
1119 de[0].ctime = de[1].ctime = 0;
1120 de[0].ctime_cs = de[1].ctime_cs = 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_inode(bhs[0], dir);
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_inode(bhs[n], dir);
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_inode(bhs[i], dir);
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_inode(bhs[i], dir);
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_error(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);