On Tue, Nov 06, 2007 at 02:33:53AM -0800, akpm@linux-foundation.org wrote:
[mmotm.git] / fs / fat / dir.c
blob530b4ca0151037ae212fe9d2d8ffb827fc970f98
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 "fat.h"
25 * Maximum buffer size of short name.
26 * [(MSDOS_NAME + '.') * max one char + nul]
27 * For msdos style, ['.' (hidden) + MSDOS_NAME + '.' + nul]
29 #define FAT_MAX_SHORT_SIZE ((MSDOS_NAME + 1) * NLS_MAX_CHARSET_SIZE + 1)
31 * Maximum buffer size of unicode chars from slots.
32 * [(max longname slots * 13 (size in a slot) + nul) * sizeof(wchar_t)]
34 #define FAT_MAX_UNI_CHARS ((MSDOS_SLOTS - 1) * 13 + 1)
35 #define FAT_MAX_UNI_SIZE (FAT_MAX_UNI_CHARS * sizeof(wchar_t))
37 static inline loff_t fat_make_i_pos(struct super_block *sb,
38 struct buffer_head *bh,
39 struct msdos_dir_entry *de)
41 return ((loff_t)bh->b_blocknr << MSDOS_SB(sb)->dir_per_block_bits)
42 | (de - (struct msdos_dir_entry *)bh->b_data);
45 static inline void fat_dir_readahead(struct inode *dir, sector_t iblock,
46 sector_t phys)
48 struct super_block *sb = dir->i_sb;
49 struct msdos_sb_info *sbi = MSDOS_SB(sb);
50 struct buffer_head *bh;
51 int sec;
53 /* This is not a first sector of cluster, or sec_per_clus == 1 */
54 if ((iblock & (sbi->sec_per_clus - 1)) || sbi->sec_per_clus == 1)
55 return;
56 /* root dir of FAT12/FAT16 */
57 if ((sbi->fat_bits != 32) && (dir->i_ino == MSDOS_ROOT_INO))
58 return;
60 bh = sb_find_get_block(sb, phys);
61 if (bh == NULL || !buffer_uptodate(bh)) {
62 for (sec = 0; sec < sbi->sec_per_clus; sec++)
63 sb_breadahead(sb, phys + sec);
65 brelse(bh);
68 /* Returns the inode number of the directory entry at offset pos. If bh is
69 non-NULL, it is brelse'd before. Pos is incremented. The buffer header is
70 returned in bh.
71 AV. Most often we do it item-by-item. Makes sense to optimize.
72 AV. OK, there we go: if both bh and de are non-NULL we assume that we just
73 AV. want the next entry (took one explicit de=NULL in vfat/namei.c).
74 AV. It's done in fat_get_entry() (inlined), here the slow case lives.
75 AV. Additionally, when we return -1 (i.e. reached the end of directory)
76 AV. we make bh NULL.
78 static int fat__get_entry(struct inode *dir, loff_t *pos,
79 struct buffer_head **bh, struct msdos_dir_entry **de)
81 struct super_block *sb = dir->i_sb;
82 sector_t phys, iblock;
83 unsigned long mapped_blocks;
84 int err, offset;
86 next:
87 if (*bh)
88 brelse(*bh);
90 *bh = NULL;
91 iblock = *pos >> sb->s_blocksize_bits;
92 err = fat_bmap(dir, iblock, &phys, &mapped_blocks, 0);
93 if (err || !phys)
94 return -1; /* beyond EOF or error */
96 fat_dir_readahead(dir, iblock, phys);
98 *bh = sb_bread(sb, phys);
99 if (*bh == NULL) {
100 printk(KERN_ERR "FAT: Directory bread(block %llu) failed\n",
101 (llu)phys);
102 /* skip this block */
103 *pos = (iblock + 1) << sb->s_blocksize_bits;
104 goto next;
107 offset = *pos & (sb->s_blocksize - 1);
108 *pos += sizeof(struct msdos_dir_entry);
109 *de = (struct msdos_dir_entry *)((*bh)->b_data + offset);
111 return 0;
114 static inline int fat_get_entry(struct inode *dir, loff_t *pos,
115 struct buffer_head **bh,
116 struct msdos_dir_entry **de)
118 /* Fast stuff first */
119 if (*bh && *de &&
120 (*de - (struct msdos_dir_entry *)(*bh)->b_data) < MSDOS_SB(dir->i_sb)->dir_per_block - 1) {
121 *pos += sizeof(struct msdos_dir_entry);
122 (*de)++;
123 return 0;
125 return fat__get_entry(dir, pos, bh, de);
129 * Convert Unicode 16 to UTF-8, translated Unicode, or ASCII.
130 * If uni_xlate is enabled and we can't get a 1:1 conversion, use a
131 * colon as an escape character since it is normally invalid on the vfat
132 * filesystem. The following four characters are the hexadecimal digits
133 * of Unicode value. This lets us do a full dump and restore of Unicode
134 * filenames. We could get into some trouble with long Unicode names,
135 * but ignore that right now.
136 * Ahem... Stack smashing in ring 0 isn't fun. Fixed.
138 static int uni16_to_x8(unsigned char *ascii, const wchar_t *uni, int len,
139 int uni_xlate, struct nls_table *nls)
141 const wchar_t *ip;
142 wchar_t ec;
143 unsigned char *op, nc;
144 int charlen;
145 int k;
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 for (k = 4; k > 0; k--) {
159 nc = ec & 0xF;
160 op[k] = nc > 9 ? nc + ('a' - 10)
161 : nc + '0';
162 ec >>= 4;
164 op += 5;
165 len -= 5;
166 } else {
167 *op++ = '?';
168 len--;
173 if (unlikely(*ip)) {
174 printk(KERN_WARNING "FAT: filename was truncated while "
175 "converting.");
178 *op = 0;
179 return (op - ascii);
182 static inline int fat_uni_to_x8(struct msdos_sb_info *sbi, const wchar_t *uni,
183 unsigned char *buf, int size)
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(buf, uni, size, sbi->options.unicode_xlate,
190 sbi->nls_io);
193 static inline int
194 fat_short2uni(struct nls_table *t, unsigned char *c, int clen, wchar_t *uni)
196 int charlen;
198 charlen = t->char2uni(c, clen, uni);
199 if (charlen < 0) {
200 *uni = 0x003f; /* a question mark */
201 charlen = 1;
203 return charlen;
206 static inline int
207 fat_short2lower_uni(struct nls_table *t, unsigned char *c, int clen, wchar_t *uni)
209 int charlen;
210 wchar_t wc;
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];
219 if (!nc)
220 nc = *c;
222 if ( (charlen = t->char2uni(&nc, 1, uni)) < 0) {
223 *uni = 0x003f; /* a question mark */
224 charlen = 1;
226 } else
227 *uni = wc;
229 return charlen;
232 static inline int
233 fat_shortname2uni(struct nls_table *nls, unsigned char *buf, int buf_size,
234 wchar_t *uni_buf, unsigned short opt, int lower)
236 int len = 0;
238 if (opt & VFAT_SFN_DISPLAY_LOWER)
239 len = fat_short2lower_uni(nls, buf, buf_size, uni_buf);
240 else if (opt & VFAT_SFN_DISPLAY_WIN95)
241 len = fat_short2uni(nls, buf, buf_size, uni_buf);
242 else if (opt & VFAT_SFN_DISPLAY_WINNT) {
243 if (lower)
244 len = fat_short2lower_uni(nls, buf, buf_size, uni_buf);
245 else
246 len = fat_short2uni(nls, buf, buf_size, uni_buf);
247 } else
248 len = fat_short2uni(nls, buf, buf_size, uni_buf);
250 return len;
253 static inline int fat_name_match(struct msdos_sb_info *sbi,
254 const unsigned char *a, int a_len,
255 const unsigned char *b, int b_len)
257 if (a_len != b_len)
258 return 0;
260 if (sbi->options.name_check != 's')
261 return !nls_strnicmp(sbi->nls_io, a, b, a_len);
262 else
263 return !memcmp(a, b, a_len);
266 enum { PARSE_INVALID = 1, PARSE_NOT_LONGNAME, PARSE_EOF, };
269 * fat_parse_long - Parse extended directory entry.
271 * This function returns zero on success, negative value on error, or one of
272 * the following:
274 * %PARSE_INVALID - Directory entry is invalid.
275 * %PARSE_NOT_LONGNAME - Directory entry does not contain longname.
276 * %PARSE_EOF - Directory has no more entries.
278 static int fat_parse_long(struct inode *dir, loff_t *pos,
279 struct buffer_head **bh, struct msdos_dir_entry **de,
280 wchar_t **unicode, unsigned char *nr_slots)
282 struct msdos_dir_slot *ds;
283 unsigned char id, slot, slots, alias_checksum;
285 if (!*unicode) {
286 *unicode = __getname();
287 if (!*unicode) {
288 brelse(*bh);
289 return -ENOMEM;
292 parse_long:
293 slots = 0;
294 ds = (struct msdos_dir_slot *)*de;
295 id = ds->id;
296 if (!(id & 0x40))
297 return PARSE_INVALID;
298 slots = id & ~0x40;
299 if (slots > 20 || !slots) /* ceil(256 * 2 / 26) */
300 return PARSE_INVALID;
301 *nr_slots = slots;
302 alias_checksum = ds->alias_checksum;
304 slot = slots;
305 while (1) {
306 int offset;
308 slot--;
309 offset = slot * 13;
310 fat16_towchar(*unicode + offset, ds->name0_4, 5);
311 fat16_towchar(*unicode + offset + 5, ds->name5_10, 6);
312 fat16_towchar(*unicode + offset + 11, ds->name11_12, 2);
314 if (ds->id & 0x40)
315 (*unicode)[offset + 13] = 0;
316 if (fat_get_entry(dir, pos, bh, de) < 0)
317 return PARSE_EOF;
318 if (slot == 0)
319 break;
320 ds = (struct msdos_dir_slot *)*de;
321 if (ds->attr != ATTR_EXT)
322 return PARSE_NOT_LONGNAME;
323 if ((ds->id & ~0x40) != slot)
324 goto parse_long;
325 if (ds->alias_checksum != alias_checksum)
326 goto parse_long;
328 if ((*de)->name[0] == DELETED_FLAG)
329 return PARSE_INVALID;
330 if ((*de)->attr == ATTR_EXT)
331 goto parse_long;
332 if (IS_FREE((*de)->name) || ((*de)->attr & ATTR_VOLUME))
333 return PARSE_INVALID;
334 if (fat_checksum((*de)->name) != alias_checksum)
335 *nr_slots = 0;
337 return 0;
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 err = status;
378 goto end_of_dir;
379 } else if (status == PARSE_INVALID)
380 continue;
381 else if (status == PARSE_NOT_LONGNAME)
382 goto parse_record;
383 else if (status == PARSE_EOF)
384 goto end_of_dir;
387 memcpy(work, de->name, sizeof(de->name));
388 /* see namei.c, msdos_format_name */
389 if (work[0] == 0x05)
390 work[0] = 0xE5;
391 for (i = 0, j = 0, last_u = 0; i < 8;) {
392 if (!work[i])
393 break;
394 chl = fat_shortname2uni(nls_disk, &work[i], 8 - i,
395 &bufuname[j++], opt_shortname,
396 de->lcase & CASE_LOWER_BASE);
397 if (chl <= 1) {
398 if (work[i] != ' ')
399 last_u = j;
400 } else {
401 last_u = j;
403 i += chl;
405 j = last_u;
406 fat_short2uni(nls_disk, ".", 1, &bufuname[j++]);
407 for (i = 8; i < MSDOS_NAME;) {
408 if (!work[i])
409 break;
410 chl = fat_shortname2uni(nls_disk, &work[i],
411 MSDOS_NAME - i,
412 &bufuname[j++], opt_shortname,
413 de->lcase & CASE_LOWER_EXT);
414 if (chl <= 1) {
415 if (work[i] != ' ')
416 last_u = j;
417 } else {
418 last_u = j;
420 i += chl;
422 if (!last_u)
423 continue;
425 /* Compare shortname */
426 bufuname[last_u] = 0x0000;
427 len = fat_uni_to_x8(sbi, bufuname, bufname, sizeof(bufname));
428 if (fat_name_match(sbi, name, name_len, bufname, len))
429 goto found;
431 if (nr_slots) {
432 void *longname = unicode + FAT_MAX_UNI_CHARS;
433 int size = PATH_MAX - FAT_MAX_UNI_SIZE;
435 /* Compare longname */
436 len = fat_uni_to_x8(sbi, unicode, longname, size);
437 if (fat_name_match(sbi, name, name_len, longname, len))
438 goto found;
442 found:
443 nr_slots++; /* include the de */
444 sinfo->slot_off = cpos - nr_slots * sizeof(*de);
445 sinfo->nr_slots = nr_slots;
446 sinfo->de = de;
447 sinfo->bh = bh;
448 sinfo->i_pos = fat_make_i_pos(sb, sinfo->bh, sinfo->de);
449 err = 0;
450 end_of_dir:
451 if (unicode)
452 __putname(unicode);
454 return err;
457 EXPORT_SYMBOL_GPL(fat_search_long);
459 struct fat_ioctl_filldir_callback {
460 void __user *dirent;
461 int result;
462 /* for dir ioctl */
463 const char *longname;
464 int long_len;
465 const char *shortname;
466 int short_len;
469 static int __fat_readdir(struct inode *inode, struct file *filp, void *dirent,
470 filldir_t filldir, int short_only, int both)
472 struct super_block *sb = inode->i_sb;
473 struct msdos_sb_info *sbi = MSDOS_SB(sb);
474 struct buffer_head *bh;
475 struct msdos_dir_entry *de;
476 struct nls_table *nls_disk = sbi->nls_disk;
477 unsigned char nr_slots;
478 wchar_t bufuname[14];
479 wchar_t *unicode = NULL;
480 unsigned char c, work[MSDOS_NAME];
481 unsigned char bufname[FAT_MAX_SHORT_SIZE], *ptname = bufname;
482 unsigned short opt_shortname = sbi->options.shortname;
483 int isvfat = sbi->options.isvfat;
484 int nocase = sbi->options.nocase;
485 const char *fill_name = NULL;
486 unsigned long inum;
487 unsigned long lpos, dummy, *furrfu = &lpos;
488 loff_t cpos;
489 int chi, chl, i, i2, j, last, last_u, dotoffset = 0, fill_len = 0;
490 int ret = 0;
492 lock_super(sb);
494 cpos = filp->f_pos;
495 /* Fake . and .. for the root directory. */
496 if (inode->i_ino == MSDOS_ROOT_INO) {
497 while (cpos < 2) {
498 if (filldir(dirent, "..", cpos+1, cpos, MSDOS_ROOT_INO, DT_DIR) < 0)
499 goto out;
500 cpos++;
501 filp->f_pos++;
503 if (cpos == 2) {
504 dummy = 2;
505 furrfu = &dummy;
506 cpos = 0;
509 if (cpos & (sizeof(struct msdos_dir_entry) - 1)) {
510 ret = -ENOENT;
511 goto out;
514 bh = NULL;
515 get_new:
516 if (fat_get_entry(inode, &cpos, &bh, &de) == -1)
517 goto end_of_dir;
518 parse_record:
519 nr_slots = 0;
521 * Check for long filename entry, but if short_only, we don't
522 * need to parse long filename.
524 if (isvfat && !short_only) {
525 if (de->name[0] == DELETED_FLAG)
526 goto record_end;
527 if (de->attr != ATTR_EXT && (de->attr & ATTR_VOLUME))
528 goto record_end;
529 if (de->attr != ATTR_EXT && IS_FREE(de->name))
530 goto record_end;
531 } else {
532 if ((de->attr & ATTR_VOLUME) || IS_FREE(de->name))
533 goto record_end;
536 if (isvfat && de->attr == ATTR_EXT) {
537 int status = fat_parse_long(inode, &cpos, &bh, &de,
538 &unicode, &nr_slots);
539 if (status < 0) {
540 filp->f_pos = cpos;
541 ret = status;
542 goto out;
543 } else if (status == PARSE_INVALID)
544 goto record_end;
545 else if (status == PARSE_NOT_LONGNAME)
546 goto parse_record;
547 else if (status == PARSE_EOF)
548 goto end_of_dir;
550 if (nr_slots) {
551 void *longname = unicode + FAT_MAX_UNI_CHARS;
552 int size = PATH_MAX - FAT_MAX_UNI_SIZE;
553 int len = fat_uni_to_x8(sbi, unicode, longname, size);
555 fill_name = longname;
556 fill_len = len;
557 /* !both && !short_only, so we don't need shortname. */
558 if (!both)
559 goto start_filldir;
563 if (sbi->options.dotsOK) {
564 ptname = bufname;
565 dotoffset = 0;
566 if (de->attr & ATTR_HIDDEN) {
567 *ptname++ = '.';
568 dotoffset = 1;
572 memcpy(work, de->name, sizeof(de->name));
573 /* see namei.c, msdos_format_name */
574 if (work[0] == 0x05)
575 work[0] = 0xE5;
576 for (i = 0, j = 0, last = 0, last_u = 0; i < 8;) {
577 if (!(c = work[i]))
578 break;
579 chl = fat_shortname2uni(nls_disk, &work[i], 8 - i,
580 &bufuname[j++], opt_shortname,
581 de->lcase & CASE_LOWER_BASE);
582 if (chl <= 1) {
583 ptname[i++] = (!nocase && c>='A' && c<='Z') ? c+32 : c;
584 if (c != ' ') {
585 last = i;
586 last_u = j;
588 } else {
589 last_u = j;
590 for (chi = 0; chi < chl && i < 8; chi++) {
591 ptname[i] = work[i];
592 i++; last = i;
596 i = last;
597 j = last_u;
598 fat_short2uni(nls_disk, ".", 1, &bufuname[j++]);
599 ptname[i++] = '.';
600 for (i2 = 8; i2 < MSDOS_NAME;) {
601 if (!(c = work[i2]))
602 break;
603 chl = fat_shortname2uni(nls_disk, &work[i2], MSDOS_NAME - i2,
604 &bufuname[j++], opt_shortname,
605 de->lcase & CASE_LOWER_EXT);
606 if (chl <= 1) {
607 i2++;
608 ptname[i++] = (!nocase && c>='A' && c<='Z') ? c+32 : c;
609 if (c != ' ') {
610 last = i;
611 last_u = j;
613 } else {
614 last_u = j;
615 for (chi = 0; chi < chl && i2 < MSDOS_NAME; chi++) {
616 ptname[i++] = work[i2++];
617 last = i;
621 if (!last)
622 goto record_end;
624 i = last + dotoffset;
625 j = last_u;
627 if (isvfat) {
628 bufuname[j] = 0x0000;
629 i = fat_uni_to_x8(sbi, bufuname, bufname, sizeof(bufname));
631 if (nr_slots) {
632 /* hack for fat_ioctl_filldir() */
633 struct fat_ioctl_filldir_callback *p = dirent;
635 p->longname = fill_name;
636 p->long_len = fill_len;
637 p->shortname = bufname;
638 p->short_len = i;
639 fill_name = NULL;
640 fill_len = 0;
641 } else {
642 fill_name = bufname;
643 fill_len = i;
646 start_filldir:
647 lpos = cpos - (nr_slots + 1) * sizeof(struct msdos_dir_entry);
648 if (!memcmp(de->name, MSDOS_DOT, MSDOS_NAME))
649 inum = inode->i_ino;
650 else if (!memcmp(de->name, MSDOS_DOTDOT, MSDOS_NAME)) {
651 inum = parent_ino(filp->f_path.dentry);
652 } else {
653 loff_t i_pos = fat_make_i_pos(sb, bh, de);
654 struct inode *tmp = fat_iget(sb, i_pos);
655 if (tmp) {
656 inum = tmp->i_ino;
657 iput(tmp);
658 } else
659 inum = iunique(sb, MSDOS_ROOT_INO);
662 if (filldir(dirent, fill_name, fill_len, *furrfu, inum,
663 (de->attr & ATTR_DIR) ? DT_DIR : DT_REG) < 0)
664 goto fill_failed;
666 record_end:
667 furrfu = &lpos;
668 filp->f_pos = cpos;
669 goto get_new;
670 end_of_dir:
671 filp->f_pos = cpos;
672 fill_failed:
673 brelse(bh);
674 if (unicode)
675 __putname(unicode);
676 out:
677 unlock_super(sb);
678 return ret;
681 static int fat_readdir(struct file *filp, void *dirent, filldir_t filldir)
683 struct inode *inode = filp->f_path.dentry->d_inode;
684 return __fat_readdir(inode, filp, dirent, filldir, 0, 0);
687 #define FAT_IOCTL_FILLDIR_FUNC(func, dirent_type) \
688 static int func(void *__buf, const char *name, int name_len, \
689 loff_t offset, u64 ino, unsigned int d_type) \
691 struct fat_ioctl_filldir_callback *buf = __buf; \
692 struct dirent_type __user *d1 = buf->dirent; \
693 struct dirent_type __user *d2 = d1 + 1; \
695 if (buf->result) \
696 return -EINVAL; \
697 buf->result++; \
699 if (name != NULL) { \
700 /* dirent has only short name */ \
701 if (name_len >= sizeof(d1->d_name)) \
702 name_len = sizeof(d1->d_name) - 1; \
704 if (put_user(0, d2->d_name) || \
705 put_user(0, &d2->d_reclen) || \
706 copy_to_user(d1->d_name, name, name_len) || \
707 put_user(0, d1->d_name + name_len) || \
708 put_user(name_len, &d1->d_reclen)) \
709 goto efault; \
710 } else { \
711 /* dirent has short and long name */ \
712 const char *longname = buf->longname; \
713 int long_len = buf->long_len; \
714 const char *shortname = buf->shortname; \
715 int short_len = buf->short_len; \
717 if (long_len >= sizeof(d1->d_name)) \
718 long_len = sizeof(d1->d_name) - 1; \
719 if (short_len >= sizeof(d1->d_name)) \
720 short_len = sizeof(d1->d_name) - 1; \
722 if (copy_to_user(d2->d_name, longname, long_len) || \
723 put_user(0, d2->d_name + long_len) || \
724 put_user(long_len, &d2->d_reclen) || \
725 put_user(ino, &d2->d_ino) || \
726 put_user(offset, &d2->d_off) || \
727 copy_to_user(d1->d_name, shortname, short_len) || \
728 put_user(0, d1->d_name + short_len) || \
729 put_user(short_len, &d1->d_reclen)) \
730 goto efault; \
732 return 0; \
733 efault: \
734 buf->result = -EFAULT; \
735 return -EFAULT; \
738 FAT_IOCTL_FILLDIR_FUNC(fat_ioctl_filldir, __fat_dirent)
740 static int fat_ioctl_readdir(struct inode *inode, struct file *filp,
741 void __user *dirent, filldir_t filldir,
742 int short_only, int both)
744 struct fat_ioctl_filldir_callback buf;
745 int ret;
747 buf.dirent = dirent;
748 buf.result = 0;
749 mutex_lock(&inode->i_mutex);
750 ret = -ENOENT;
751 if (!IS_DEADDIR(inode)) {
752 ret = __fat_readdir(inode, filp, &buf, filldir,
753 short_only, both);
755 mutex_unlock(&inode->i_mutex);
756 if (ret >= 0)
757 ret = buf.result;
758 return ret;
761 static int fat_dir_ioctl(struct inode *inode, struct file *filp,
762 unsigned int cmd, unsigned long arg)
764 struct __fat_dirent __user *d1 = (struct __fat_dirent __user *)arg;
765 int short_only, both;
767 switch (cmd) {
768 case VFAT_IOCTL_READDIR_SHORT:
769 short_only = 1;
770 both = 0;
771 break;
772 case VFAT_IOCTL_READDIR_BOTH:
773 short_only = 0;
774 both = 1;
775 break;
776 default:
777 return fat_generic_ioctl(inode, filp, cmd, arg);
780 if (!access_ok(VERIFY_WRITE, d1, sizeof(struct __fat_dirent[2])))
781 return -EFAULT;
783 * Yes, we don't need this put_user() absolutely. However old
784 * code didn't return the right value. So, app use this value,
785 * in order to check whether it is EOF.
787 if (put_user(0, &d1->d_reclen))
788 return -EFAULT;
790 return fat_ioctl_readdir(inode, filp, d1, fat_ioctl_filldir,
791 short_only, both);
794 #ifdef CONFIG_COMPAT
795 #define VFAT_IOCTL_READDIR_BOTH32 _IOR('r', 1, struct compat_dirent[2])
796 #define VFAT_IOCTL_READDIR_SHORT32 _IOR('r', 2, struct compat_dirent[2])
798 FAT_IOCTL_FILLDIR_FUNC(fat_compat_ioctl_filldir, compat_dirent)
800 static long fat_compat_dir_ioctl(struct file *filp, unsigned cmd,
801 unsigned long arg)
803 struct inode *inode = filp->f_path.dentry->d_inode;
804 struct compat_dirent __user *d1 = compat_ptr(arg);
805 int short_only, both;
807 switch (cmd) {
808 case VFAT_IOCTL_READDIR_SHORT32:
809 short_only = 1;
810 both = 0;
811 break;
812 case VFAT_IOCTL_READDIR_BOTH32:
813 short_only = 0;
814 both = 1;
815 break;
816 default:
817 return -ENOIOCTLCMD;
820 if (!access_ok(VERIFY_WRITE, d1, sizeof(struct compat_dirent[2])))
821 return -EFAULT;
823 * Yes, we don't need this put_user() absolutely. However old
824 * code didn't return the right value. So, app use this value,
825 * in order to check whether it is EOF.
827 if (put_user(0, &d1->d_reclen))
828 return -EFAULT;
830 return fat_ioctl_readdir(inode, filp, d1, fat_compat_ioctl_filldir,
831 short_only, both);
833 #endif /* CONFIG_COMPAT */
835 const struct file_operations fat_dir_operations = {
836 .llseek = generic_file_llseek,
837 .read = generic_read_dir,
838 .readdir = fat_readdir,
839 .ioctl = fat_dir_ioctl,
840 #ifdef CONFIG_COMPAT
841 .compat_ioctl = fat_compat_dir_ioctl,
842 #endif
843 .fsync = fat_file_fsync,
846 static int fat_get_short_entry(struct inode *dir, loff_t *pos,
847 struct buffer_head **bh,
848 struct msdos_dir_entry **de)
850 while (fat_get_entry(dir, pos, bh, de) >= 0) {
851 /* free entry or long name entry or volume label */
852 if (!IS_FREE((*de)->name) && !((*de)->attr & ATTR_VOLUME))
853 return 0;
855 return -ENOENT;
859 * The ".." entry can not provide the "struct fat_slot_info" informations
860 * for inode. So, this function provide the some informations only.
862 int fat_get_dotdot_entry(struct inode *dir, struct buffer_head **bh,
863 struct msdos_dir_entry **de, loff_t *i_pos)
865 loff_t offset;
867 offset = 0;
868 *bh = NULL;
869 while (fat_get_short_entry(dir, &offset, bh, de) >= 0) {
870 if (!strncmp((*de)->name, MSDOS_DOTDOT, MSDOS_NAME)) {
871 *i_pos = fat_make_i_pos(dir->i_sb, *bh, *de);
872 return 0;
875 return -ENOENT;
878 EXPORT_SYMBOL_GPL(fat_get_dotdot_entry);
880 /* See if directory is empty */
881 int fat_dir_empty(struct inode *dir)
883 struct buffer_head *bh;
884 struct msdos_dir_entry *de;
885 loff_t cpos;
886 int result = 0;
888 bh = NULL;
889 cpos = 0;
890 while (fat_get_short_entry(dir, &cpos, &bh, &de) >= 0) {
891 if (strncmp(de->name, MSDOS_DOT , MSDOS_NAME) &&
892 strncmp(de->name, MSDOS_DOTDOT, MSDOS_NAME)) {
893 result = -ENOTEMPTY;
894 break;
897 brelse(bh);
898 return result;
901 EXPORT_SYMBOL_GPL(fat_dir_empty);
904 * fat_subdirs counts the number of sub-directories of dir. It can be run
905 * on directories being created.
907 int fat_subdirs(struct inode *dir)
909 struct buffer_head *bh;
910 struct msdos_dir_entry *de;
911 loff_t cpos;
912 int count = 0;
914 bh = NULL;
915 cpos = 0;
916 while (fat_get_short_entry(dir, &cpos, &bh, &de) >= 0) {
917 if (de->attr & ATTR_DIR)
918 count++;
920 brelse(bh);
921 return count;
925 * Scans a directory for a given file (name points to its formatted name).
926 * Returns an error code or zero.
928 int fat_scan(struct inode *dir, const unsigned char *name,
929 struct fat_slot_info *sinfo)
931 struct super_block *sb = dir->i_sb;
933 sinfo->slot_off = 0;
934 sinfo->bh = NULL;
935 while (fat_get_short_entry(dir, &sinfo->slot_off, &sinfo->bh,
936 &sinfo->de) >= 0) {
937 if (!strncmp(sinfo->de->name, name, MSDOS_NAME)) {
938 sinfo->slot_off -= sizeof(*sinfo->de);
939 sinfo->nr_slots = 1;
940 sinfo->i_pos = fat_make_i_pos(sb, sinfo->bh, sinfo->de);
941 return 0;
944 return -ENOENT;
947 EXPORT_SYMBOL_GPL(fat_scan);
949 static int __fat_remove_entries(struct inode *dir, loff_t pos, int nr_slots)
951 struct super_block *sb = dir->i_sb;
952 struct buffer_head *bh;
953 struct msdos_dir_entry *de, *endp;
954 int err = 0, orig_slots;
956 while (nr_slots) {
957 bh = NULL;
958 if (fat_get_entry(dir, &pos, &bh, &de) < 0) {
959 err = -EIO;
960 break;
963 orig_slots = nr_slots;
964 endp = (struct msdos_dir_entry *)(bh->b_data + sb->s_blocksize);
965 while (nr_slots && de < endp) {
966 de->name[0] = DELETED_FLAG;
967 de++;
968 nr_slots--;
970 mark_buffer_dirty_inode(bh, dir);
971 if (IS_DIRSYNC(dir))
972 err = sync_dirty_buffer(bh);
973 brelse(bh);
974 if (err)
975 break;
977 /* pos is *next* de's position, so this does `- sizeof(de)' */
978 pos += ((orig_slots - nr_slots) * sizeof(*de)) - sizeof(*de);
981 return err;
984 int fat_remove_entries(struct inode *dir, struct fat_slot_info *sinfo)
986 struct msdos_dir_entry *de;
987 struct buffer_head *bh;
988 int err = 0, nr_slots;
991 * First stage: Remove the shortname. By this, the directory
992 * entry is removed.
994 nr_slots = sinfo->nr_slots;
995 de = sinfo->de;
996 sinfo->de = NULL;
997 bh = sinfo->bh;
998 sinfo->bh = NULL;
999 while (nr_slots && de >= (struct msdos_dir_entry *)bh->b_data) {
1000 de->name[0] = DELETED_FLAG;
1001 de--;
1002 nr_slots--;
1004 mark_buffer_dirty_inode(bh, dir);
1005 if (IS_DIRSYNC(dir))
1006 err = sync_dirty_buffer(bh);
1007 brelse(bh);
1008 if (err)
1009 return err;
1010 dir->i_version++;
1012 if (nr_slots) {
1014 * Second stage: remove the remaining longname slots.
1015 * (This directory entry is already removed, and so return
1016 * the success)
1018 err = __fat_remove_entries(dir, sinfo->slot_off, nr_slots);
1019 if (err) {
1020 printk(KERN_WARNING
1021 "FAT: Couldn't remove the long name slots\n");
1025 dir->i_mtime = dir->i_atime = CURRENT_TIME_SEC;
1026 if (IS_DIRSYNC(dir))
1027 (void)fat_sync_inode(dir);
1028 else
1029 mark_inode_dirty(dir);
1031 return 0;
1034 EXPORT_SYMBOL_GPL(fat_remove_entries);
1036 static int fat_zeroed_cluster(struct inode *dir, sector_t blknr, int nr_used,
1037 struct buffer_head **bhs, int nr_bhs)
1039 struct super_block *sb = dir->i_sb;
1040 sector_t last_blknr = blknr + MSDOS_SB(sb)->sec_per_clus;
1041 int err, i, n;
1043 /* Zeroing the unused blocks on this cluster */
1044 blknr += nr_used;
1045 n = nr_used;
1046 while (blknr < last_blknr) {
1047 bhs[n] = sb_getblk(sb, blknr);
1048 if (!bhs[n]) {
1049 err = -ENOMEM;
1050 goto error;
1052 memset(bhs[n]->b_data, 0, sb->s_blocksize);
1053 set_buffer_uptodate(bhs[n]);
1054 mark_buffer_dirty_inode(bhs[n], dir);
1056 n++;
1057 blknr++;
1058 if (n == nr_bhs) {
1059 if (IS_DIRSYNC(dir)) {
1060 err = fat_sync_bhs(bhs, n);
1061 if (err)
1062 goto error;
1064 for (i = 0; i < n; i++)
1065 brelse(bhs[i]);
1066 n = 0;
1069 if (IS_DIRSYNC(dir)) {
1070 err = fat_sync_bhs(bhs, n);
1071 if (err)
1072 goto error;
1074 for (i = 0; i < n; i++)
1075 brelse(bhs[i]);
1077 return 0;
1079 error:
1080 for (i = 0; i < n; i++)
1081 bforget(bhs[i]);
1082 return err;
1085 int fat_alloc_new_dir(struct inode *dir, struct timespec *ts)
1087 struct super_block *sb = dir->i_sb;
1088 struct msdos_sb_info *sbi = MSDOS_SB(sb);
1089 struct buffer_head *bhs[MAX_BUF_PER_PAGE];
1090 struct msdos_dir_entry *de;
1091 sector_t blknr;
1092 __le16 date, time;
1093 u8 time_cs;
1094 int err, cluster;
1096 err = fat_alloc_clusters(dir, &cluster, 1);
1097 if (err)
1098 goto error;
1100 blknr = fat_clus_to_blknr(sbi, cluster);
1101 bhs[0] = sb_getblk(sb, blknr);
1102 if (!bhs[0]) {
1103 err = -ENOMEM;
1104 goto error_free;
1107 fat_time_unix2fat(sbi, ts, &time, &date, &time_cs);
1109 de = (struct msdos_dir_entry *)bhs[0]->b_data;
1110 /* filling the new directory slots ("." and ".." entries) */
1111 memcpy(de[0].name, MSDOS_DOT, MSDOS_NAME);
1112 memcpy(de[1].name, MSDOS_DOTDOT, MSDOS_NAME);
1113 de->attr = de[1].attr = ATTR_DIR;
1114 de[0].lcase = de[1].lcase = 0;
1115 de[0].time = de[1].time = time;
1116 de[0].date = de[1].date = date;
1117 if (sbi->options.isvfat) {
1118 /* extra timestamps */
1119 de[0].ctime = de[1].ctime = time;
1120 de[0].ctime_cs = de[1].ctime_cs = time_cs;
1121 de[0].adate = de[0].cdate = de[1].adate = de[1].cdate = date;
1122 } else {
1123 de[0].ctime = de[1].ctime = 0;
1124 de[0].ctime_cs = de[1].ctime_cs = 0;
1125 de[0].adate = de[0].cdate = de[1].adate = de[1].cdate = 0;
1127 de[0].start = cpu_to_le16(cluster);
1128 de[0].starthi = cpu_to_le16(cluster >> 16);
1129 de[1].start = cpu_to_le16(MSDOS_I(dir)->i_logstart);
1130 de[1].starthi = cpu_to_le16(MSDOS_I(dir)->i_logstart >> 16);
1131 de[0].size = de[1].size = 0;
1132 memset(de + 2, 0, sb->s_blocksize - 2 * sizeof(*de));
1133 set_buffer_uptodate(bhs[0]);
1134 mark_buffer_dirty_inode(bhs[0], dir);
1136 err = fat_zeroed_cluster(dir, blknr, 1, bhs, MAX_BUF_PER_PAGE);
1137 if (err)
1138 goto error_free;
1140 return cluster;
1142 error_free:
1143 fat_free_clusters(dir, cluster);
1144 error:
1145 return err;
1148 EXPORT_SYMBOL_GPL(fat_alloc_new_dir);
1150 static int fat_add_new_entries(struct inode *dir, void *slots, int nr_slots,
1151 int *nr_cluster, struct msdos_dir_entry **de,
1152 struct buffer_head **bh, loff_t *i_pos)
1154 struct super_block *sb = dir->i_sb;
1155 struct msdos_sb_info *sbi = MSDOS_SB(sb);
1156 struct buffer_head *bhs[MAX_BUF_PER_PAGE];
1157 sector_t blknr, start_blknr, last_blknr;
1158 unsigned long size, copy;
1159 int err, i, n, offset, cluster[2];
1162 * The minimum cluster size is 512bytes, and maximum entry
1163 * size is 32*slots (672bytes). So, iff the cluster size is
1164 * 512bytes, we may need two clusters.
1166 size = nr_slots * sizeof(struct msdos_dir_entry);
1167 *nr_cluster = (size + (sbi->cluster_size - 1)) >> sbi->cluster_bits;
1168 BUG_ON(*nr_cluster > 2);
1170 err = fat_alloc_clusters(dir, cluster, *nr_cluster);
1171 if (err)
1172 goto error;
1175 * First stage: Fill the directory entry. NOTE: This cluster
1176 * is not referenced from any inode yet, so updates order is
1177 * not important.
1179 i = n = copy = 0;
1180 do {
1181 start_blknr = blknr = fat_clus_to_blknr(sbi, cluster[i]);
1182 last_blknr = start_blknr + sbi->sec_per_clus;
1183 while (blknr < last_blknr) {
1184 bhs[n] = sb_getblk(sb, blknr);
1185 if (!bhs[n]) {
1186 err = -ENOMEM;
1187 goto error_nomem;
1190 /* fill the directory entry */
1191 copy = min(size, sb->s_blocksize);
1192 memcpy(bhs[n]->b_data, slots, copy);
1193 slots += copy;
1194 size -= copy;
1195 set_buffer_uptodate(bhs[n]);
1196 mark_buffer_dirty_inode(bhs[n], dir);
1197 if (!size)
1198 break;
1199 n++;
1200 blknr++;
1202 } while (++i < *nr_cluster);
1204 memset(bhs[n]->b_data + copy, 0, sb->s_blocksize - copy);
1205 offset = copy - sizeof(struct msdos_dir_entry);
1206 get_bh(bhs[n]);
1207 *bh = bhs[n];
1208 *de = (struct msdos_dir_entry *)((*bh)->b_data + offset);
1209 *i_pos = fat_make_i_pos(sb, *bh, *de);
1211 /* Second stage: clear the rest of cluster, and write outs */
1212 err = fat_zeroed_cluster(dir, start_blknr, ++n, bhs, MAX_BUF_PER_PAGE);
1213 if (err)
1214 goto error_free;
1216 return cluster[0];
1218 error_free:
1219 brelse(*bh);
1220 *bh = NULL;
1221 n = 0;
1222 error_nomem:
1223 for (i = 0; i < n; i++)
1224 bforget(bhs[i]);
1225 fat_free_clusters(dir, cluster[0]);
1226 error:
1227 return err;
1230 int fat_add_entries(struct inode *dir, void *slots, int nr_slots,
1231 struct fat_slot_info *sinfo)
1233 struct super_block *sb = dir->i_sb;
1234 struct msdos_sb_info *sbi = MSDOS_SB(sb);
1235 struct buffer_head *bh, *prev, *bhs[3]; /* 32*slots (672bytes) */
1236 struct msdos_dir_entry *de;
1237 int err, free_slots, i, nr_bhs;
1238 loff_t pos, i_pos;
1240 sinfo->nr_slots = nr_slots;
1242 /* First stage: search free direcotry entries */
1243 free_slots = nr_bhs = 0;
1244 bh = prev = NULL;
1245 pos = 0;
1246 err = -ENOSPC;
1247 while (fat_get_entry(dir, &pos, &bh, &de) > -1) {
1248 /* check the maximum size of directory */
1249 if (pos >= FAT_MAX_DIR_SIZE)
1250 goto error;
1252 if (IS_FREE(de->name)) {
1253 if (prev != bh) {
1254 get_bh(bh);
1255 bhs[nr_bhs] = prev = bh;
1256 nr_bhs++;
1258 free_slots++;
1259 if (free_slots == nr_slots)
1260 goto found;
1261 } else {
1262 for (i = 0; i < nr_bhs; i++)
1263 brelse(bhs[i]);
1264 prev = NULL;
1265 free_slots = nr_bhs = 0;
1268 if (dir->i_ino == MSDOS_ROOT_INO) {
1269 if (sbi->fat_bits != 32)
1270 goto error;
1271 } else if (MSDOS_I(dir)->i_start == 0) {
1272 printk(KERN_ERR "FAT: Corrupted directory (i_pos %lld)\n",
1273 MSDOS_I(dir)->i_pos);
1274 err = -EIO;
1275 goto error;
1278 found:
1279 err = 0;
1280 pos -= free_slots * sizeof(*de);
1281 nr_slots -= free_slots;
1282 if (free_slots) {
1284 * Second stage: filling the free entries with new entries.
1285 * NOTE: If this slots has shortname, first, we write
1286 * the long name slots, then write the short name.
1288 int size = free_slots * sizeof(*de);
1289 int offset = pos & (sb->s_blocksize - 1);
1290 int long_bhs = nr_bhs - (nr_slots == 0);
1292 /* Fill the long name slots. */
1293 for (i = 0; i < long_bhs; i++) {
1294 int copy = min_t(int, sb->s_blocksize - offset, size);
1295 memcpy(bhs[i]->b_data + offset, slots, copy);
1296 mark_buffer_dirty_inode(bhs[i], dir);
1297 offset = 0;
1298 slots += copy;
1299 size -= copy;
1301 if (long_bhs && IS_DIRSYNC(dir))
1302 err = fat_sync_bhs(bhs, long_bhs);
1303 if (!err && i < nr_bhs) {
1304 /* Fill the short name slot. */
1305 int copy = min_t(int, sb->s_blocksize - offset, size);
1306 memcpy(bhs[i]->b_data + offset, slots, copy);
1307 mark_buffer_dirty_inode(bhs[i], dir);
1308 if (IS_DIRSYNC(dir))
1309 err = sync_dirty_buffer(bhs[i]);
1311 for (i = 0; i < nr_bhs; i++)
1312 brelse(bhs[i]);
1313 if (err)
1314 goto error_remove;
1317 if (nr_slots) {
1318 int cluster, nr_cluster;
1321 * Third stage: allocate the cluster for new entries.
1322 * And initialize the cluster with new entries, then
1323 * add the cluster to dir.
1325 cluster = fat_add_new_entries(dir, slots, nr_slots, &nr_cluster,
1326 &de, &bh, &i_pos);
1327 if (cluster < 0) {
1328 err = cluster;
1329 goto error_remove;
1331 err = fat_chain_add(dir, cluster, nr_cluster);
1332 if (err) {
1333 fat_free_clusters(dir, cluster);
1334 goto error_remove;
1336 if (dir->i_size & (sbi->cluster_size - 1)) {
1337 fat_fs_error(sb, "Odd directory size");
1338 dir->i_size = (dir->i_size + sbi->cluster_size - 1)
1339 & ~((loff_t)sbi->cluster_size - 1);
1341 dir->i_size += nr_cluster << sbi->cluster_bits;
1342 MSDOS_I(dir)->mmu_private += nr_cluster << sbi->cluster_bits;
1344 sinfo->slot_off = pos;
1345 sinfo->de = de;
1346 sinfo->bh = bh;
1347 sinfo->i_pos = fat_make_i_pos(sb, sinfo->bh, sinfo->de);
1349 return 0;
1351 error:
1352 brelse(bh);
1353 for (i = 0; i < nr_bhs; i++)
1354 brelse(bhs[i]);
1355 return err;
1357 error_remove:
1358 brelse(bh);
1359 if (free_slots)
1360 __fat_remove_entries(dir, pos, free_slots);
1361 return err;
1364 EXPORT_SYMBOL_GPL(fat_add_entries);