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[linux-2.6/mini2440.git] / fs / fat / namei_vfat.c
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1 /*
2 * linux/fs/vfat/namei.c
4 * Written 1992,1993 by Werner Almesberger
6 * Windows95/Windows NT compatible extended MSDOS filesystem
7 * by Gordon Chaffee Copyright (C) 1995. Send bug reports for the
8 * VFAT filesystem to <chaffee@cs.berkeley.edu>. Specify
9 * what file operation caused you trouble and if you can duplicate
10 * the problem, send a script that demonstrates it.
12 * Short name translation 1999, 2001 by Wolfram Pienkoss <wp@bszh.de>
14 * Support Multibyte characters and cleanup by
15 * OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
18 #include <linux/module.h>
19 #include <linux/jiffies.h>
20 #include <linux/ctype.h>
21 #include <linux/slab.h>
22 #include <linux/smp_lock.h>
23 #include <linux/buffer_head.h>
24 #include <linux/namei.h>
25 #include "fat.h"
28 * If new entry was created in the parent, it could create the 8.3
29 * alias (the shortname of logname). So, the parent may have the
30 * negative-dentry which matches the created 8.3 alias.
32 * If it happened, the negative dentry isn't actually negative
33 * anymore. So, drop it.
35 static int vfat_revalidate_shortname(struct dentry *dentry)
37 int ret = 1;
38 spin_lock(&dentry->d_lock);
39 if (dentry->d_time != dentry->d_parent->d_inode->i_version)
40 ret = 0;
41 spin_unlock(&dentry->d_lock);
42 return ret;
45 static int vfat_revalidate(struct dentry *dentry, struct nameidata *nd)
47 /* This is not negative dentry. Always valid. */
48 if (dentry->d_inode)
49 return 1;
50 return vfat_revalidate_shortname(dentry);
53 static int vfat_revalidate_ci(struct dentry *dentry, struct nameidata *nd)
56 * This is not negative dentry. Always valid.
58 * Note, rename() to existing directory entry will have ->d_inode,
59 * and will use existing name which isn't specified name by user.
61 * We may be able to drop this positive dentry here. But dropping
62 * positive dentry isn't good idea. So it's unsupported like
63 * rename("filename", "FILENAME") for now.
65 if (dentry->d_inode)
66 return 1;
69 * This may be nfsd (or something), anyway, we can't see the
70 * intent of this. So, since this can be for creation, drop it.
72 if (!nd)
73 return 0;
76 * Drop the negative dentry, in order to make sure to use the
77 * case sensitive name which is specified by user if this is
78 * for creation.
80 if (!(nd->flags & (LOOKUP_CONTINUE | LOOKUP_PARENT))) {
81 if (nd->flags & (LOOKUP_CREATE | LOOKUP_RENAME_TARGET))
82 return 0;
85 return vfat_revalidate_shortname(dentry);
88 /* returns the length of a struct qstr, ignoring trailing dots */
89 static unsigned int vfat_striptail_len(struct qstr *qstr)
91 unsigned int len = qstr->len;
93 while (len && qstr->name[len - 1] == '.')
94 len--;
95 return len;
99 * Compute the hash for the vfat name corresponding to the dentry.
100 * Note: if the name is invalid, we leave the hash code unchanged so
101 * that the existing dentry can be used. The vfat fs routines will
102 * return ENOENT or EINVAL as appropriate.
104 static int vfat_hash(struct dentry *dentry, struct qstr *qstr)
106 qstr->hash = full_name_hash(qstr->name, vfat_striptail_len(qstr));
107 return 0;
111 * Compute the hash for the vfat name corresponding to the dentry.
112 * Note: if the name is invalid, we leave the hash code unchanged so
113 * that the existing dentry can be used. The vfat fs routines will
114 * return ENOENT or EINVAL as appropriate.
116 static int vfat_hashi(struct dentry *dentry, struct qstr *qstr)
118 struct nls_table *t = MSDOS_SB(dentry->d_inode->i_sb)->nls_io;
119 const unsigned char *name;
120 unsigned int len;
121 unsigned long hash;
123 name = qstr->name;
124 len = vfat_striptail_len(qstr);
126 hash = init_name_hash();
127 while (len--)
128 hash = partial_name_hash(nls_tolower(t, *name++), hash);
129 qstr->hash = end_name_hash(hash);
131 return 0;
135 * Case insensitive compare of two vfat names.
137 static int vfat_cmpi(struct dentry *dentry, struct qstr *a, struct qstr *b)
139 struct nls_table *t = MSDOS_SB(dentry->d_inode->i_sb)->nls_io;
140 unsigned int alen, blen;
142 /* A filename cannot end in '.' or we treat it like it has none */
143 alen = vfat_striptail_len(a);
144 blen = vfat_striptail_len(b);
145 if (alen == blen) {
146 if (nls_strnicmp(t, a->name, b->name, alen) == 0)
147 return 0;
149 return 1;
153 * Case sensitive compare of two vfat names.
155 static int vfat_cmp(struct dentry *dentry, struct qstr *a, struct qstr *b)
157 unsigned int alen, blen;
159 /* A filename cannot end in '.' or we treat it like it has none */
160 alen = vfat_striptail_len(a);
161 blen = vfat_striptail_len(b);
162 if (alen == blen) {
163 if (strncmp(a->name, b->name, alen) == 0)
164 return 0;
166 return 1;
169 static struct dentry_operations vfat_ci_dentry_ops = {
170 .d_revalidate = vfat_revalidate_ci,
171 .d_hash = vfat_hashi,
172 .d_compare = vfat_cmpi,
175 static struct dentry_operations vfat_dentry_ops = {
176 .d_revalidate = vfat_revalidate,
177 .d_hash = vfat_hash,
178 .d_compare = vfat_cmp,
181 /* Characters that are undesirable in an MS-DOS file name */
183 static inline wchar_t vfat_bad_char(wchar_t w)
185 return (w < 0x0020)
186 || (w == '*') || (w == '?') || (w == '<') || (w == '>')
187 || (w == '|') || (w == '"') || (w == ':') || (w == '/')
188 || (w == '\\');
191 static inline wchar_t vfat_replace_char(wchar_t w)
193 return (w == '[') || (w == ']') || (w == ';') || (w == ',')
194 || (w == '+') || (w == '=');
197 static wchar_t vfat_skip_char(wchar_t w)
199 return (w == '.') || (w == ' ');
202 static inline int vfat_is_used_badchars(const wchar_t *s, int len)
204 int i;
206 for (i = 0; i < len; i++)
207 if (vfat_bad_char(s[i]))
208 return -EINVAL;
210 if (s[i - 1] == ' ') /* last character cannot be space */
211 return -EINVAL;
213 return 0;
216 static int vfat_find_form(struct inode *dir, unsigned char *name)
218 struct fat_slot_info sinfo;
219 int err = fat_scan(dir, name, &sinfo);
220 if (err)
221 return -ENOENT;
222 brelse(sinfo.bh);
223 return 0;
227 * 1) Valid characters for the 8.3 format alias are any combination of
228 * letters, uppercase alphabets, digits, any of the
229 * following special characters:
230 * $ % ' ` - @ { } ~ ! # ( ) & _ ^
231 * In this case Longfilename is not stored in disk.
233 * WinNT's Extension:
234 * File name and extension name is contain uppercase/lowercase
235 * only. And it is expressed by CASE_LOWER_BASE and CASE_LOWER_EXT.
237 * 2) File name is 8.3 format, but it contain the uppercase and
238 * lowercase char, muliti bytes char, etc. In this case numtail is not
239 * added, but Longfilename is stored.
241 * 3) When the one except for the above, or the following special
242 * character are contained:
243 * . [ ] ; , + =
244 * numtail is added, and Longfilename must be stored in disk .
246 struct shortname_info {
247 unsigned char lower:1,
248 upper:1,
249 valid:1;
251 #define INIT_SHORTNAME_INFO(x) do { \
252 (x)->lower = 1; \
253 (x)->upper = 1; \
254 (x)->valid = 1; \
255 } while (0)
257 static inline int to_shortname_char(struct nls_table *nls,
258 unsigned char *buf, int buf_size,
259 wchar_t *src, struct shortname_info *info)
261 int len;
263 if (vfat_skip_char(*src)) {
264 info->valid = 0;
265 return 0;
267 if (vfat_replace_char(*src)) {
268 info->valid = 0;
269 buf[0] = '_';
270 return 1;
273 len = nls->uni2char(*src, buf, buf_size);
274 if (len <= 0) {
275 info->valid = 0;
276 buf[0] = '_';
277 len = 1;
278 } else if (len == 1) {
279 unsigned char prev = buf[0];
281 if (buf[0] >= 0x7F) {
282 info->lower = 0;
283 info->upper = 0;
286 buf[0] = nls_toupper(nls, buf[0]);
287 if (isalpha(buf[0])) {
288 if (buf[0] == prev)
289 info->lower = 0;
290 else
291 info->upper = 0;
293 } else {
294 info->lower = 0;
295 info->upper = 0;
298 return len;
302 * Given a valid longname, create a unique shortname. Make sure the
303 * shortname does not exist
304 * Returns negative number on error, 0 for a normal
305 * return, and 1 for valid shortname
307 static int vfat_create_shortname(struct inode *dir, struct nls_table *nls,
308 wchar_t *uname, int ulen,
309 unsigned char *name_res, unsigned char *lcase)
311 struct fat_mount_options *opts = &MSDOS_SB(dir->i_sb)->options;
312 wchar_t *ip, *ext_start, *end, *name_start;
313 unsigned char base[9], ext[4], buf[8], *p;
314 unsigned char charbuf[NLS_MAX_CHARSET_SIZE];
315 int chl, chi;
316 int sz = 0, extlen, baselen, i, numtail_baselen, numtail2_baselen;
317 int is_shortname;
318 struct shortname_info base_info, ext_info;
320 is_shortname = 1;
321 INIT_SHORTNAME_INFO(&base_info);
322 INIT_SHORTNAME_INFO(&ext_info);
324 /* Now, we need to create a shortname from the long name */
325 ext_start = end = &uname[ulen];
326 while (--ext_start >= uname) {
327 if (*ext_start == 0x002E) { /* is `.' */
328 if (ext_start == end - 1) {
329 sz = ulen;
330 ext_start = NULL;
332 break;
336 if (ext_start == uname - 1) {
337 sz = ulen;
338 ext_start = NULL;
339 } else if (ext_start) {
341 * Names which start with a dot could be just
342 * an extension eg. "...test". In this case Win95
343 * uses the extension as the name and sets no extension.
345 name_start = &uname[0];
346 while (name_start < ext_start) {
347 if (!vfat_skip_char(*name_start))
348 break;
349 name_start++;
351 if (name_start != ext_start) {
352 sz = ext_start - uname;
353 ext_start++;
354 } else {
355 sz = ulen;
356 ext_start = NULL;
360 numtail_baselen = 6;
361 numtail2_baselen = 2;
362 for (baselen = i = 0, p = base, ip = uname; i < sz; i++, ip++) {
363 chl = to_shortname_char(nls, charbuf, sizeof(charbuf),
364 ip, &base_info);
365 if (chl == 0)
366 continue;
368 if (baselen < 2 && (baselen + chl) > 2)
369 numtail2_baselen = baselen;
370 if (baselen < 6 && (baselen + chl) > 6)
371 numtail_baselen = baselen;
372 for (chi = 0; chi < chl; chi++) {
373 *p++ = charbuf[chi];
374 baselen++;
375 if (baselen >= 8)
376 break;
378 if (baselen >= 8) {
379 if ((chi < chl - 1) || (ip + 1) - uname < sz)
380 is_shortname = 0;
381 break;
384 if (baselen == 0) {
385 return -EINVAL;
388 extlen = 0;
389 if (ext_start) {
390 for (p = ext, ip = ext_start; extlen < 3 && ip < end; ip++) {
391 chl = to_shortname_char(nls, charbuf, sizeof(charbuf),
392 ip, &ext_info);
393 if (chl == 0)
394 continue;
396 if ((extlen + chl) > 3) {
397 is_shortname = 0;
398 break;
400 for (chi = 0; chi < chl; chi++) {
401 *p++ = charbuf[chi];
402 extlen++;
404 if (extlen >= 3) {
405 if (ip + 1 != end)
406 is_shortname = 0;
407 break;
411 ext[extlen] = '\0';
412 base[baselen] = '\0';
414 /* Yes, it can happen. ".\xe5" would do it. */
415 if (base[0] == DELETED_FLAG)
416 base[0] = 0x05;
418 /* OK, at this point we know that base is not longer than 8 symbols,
419 * ext is not longer than 3, base is nonempty, both don't contain
420 * any bad symbols (lowercase transformed to uppercase).
423 memset(name_res, ' ', MSDOS_NAME);
424 memcpy(name_res, base, baselen);
425 memcpy(name_res + 8, ext, extlen);
426 *lcase = 0;
427 if (is_shortname && base_info.valid && ext_info.valid) {
428 if (vfat_find_form(dir, name_res) == 0)
429 return -EEXIST;
431 if (opts->shortname & VFAT_SFN_CREATE_WIN95) {
432 return (base_info.upper && ext_info.upper);
433 } else if (opts->shortname & VFAT_SFN_CREATE_WINNT) {
434 if ((base_info.upper || base_info.lower) &&
435 (ext_info.upper || ext_info.lower)) {
436 if (!base_info.upper && base_info.lower)
437 *lcase |= CASE_LOWER_BASE;
438 if (!ext_info.upper && ext_info.lower)
439 *lcase |= CASE_LOWER_EXT;
440 return 1;
442 return 0;
443 } else {
444 BUG();
448 if (opts->numtail == 0)
449 if (vfat_find_form(dir, name_res) < 0)
450 return 0;
453 * Try to find a unique extension. This used to
454 * iterate through all possibilities sequentially,
455 * but that gave extremely bad performance. Windows
456 * only tries a few cases before using random
457 * values for part of the base.
460 if (baselen > 6) {
461 baselen = numtail_baselen;
462 name_res[7] = ' ';
464 name_res[baselen] = '~';
465 for (i = 1; i < 10; i++) {
466 name_res[baselen + 1] = i + '0';
467 if (vfat_find_form(dir, name_res) < 0)
468 return 0;
471 i = jiffies & 0xffff;
472 sz = (jiffies >> 16) & 0x7;
473 if (baselen > 2) {
474 baselen = numtail2_baselen;
475 name_res[7] = ' ';
477 name_res[baselen + 4] = '~';
478 name_res[baselen + 5] = '1' + sz;
479 while (1) {
480 sprintf(buf, "%04X", i);
481 memcpy(&name_res[baselen], buf, 4);
482 if (vfat_find_form(dir, name_res) < 0)
483 break;
484 i -= 11;
486 return 0;
489 /* Translate a string, including coded sequences into Unicode */
490 static int
491 xlate_to_uni(const unsigned char *name, int len, unsigned char *outname,
492 int *longlen, int *outlen, int escape, int utf8,
493 struct nls_table *nls)
495 const unsigned char *ip;
496 unsigned char nc;
497 unsigned char *op;
498 unsigned int ec;
499 int i, k, fill;
500 int charlen;
502 if (utf8) {
503 int name_len = strlen(name);
505 *outlen = utf8_mbstowcs((wchar_t *)outname, name, PATH_MAX);
508 * We stripped '.'s before and set len appropriately,
509 * but utf8_mbstowcs doesn't care about len
511 *outlen -= (name_len - len);
513 if (*outlen > 255)
514 return -ENAMETOOLONG;
516 op = &outname[*outlen * sizeof(wchar_t)];
517 } else {
518 if (nls) {
519 for (i = 0, ip = name, op = outname, *outlen = 0;
520 i < len && *outlen <= 255;
521 *outlen += 1)
523 if (escape && (*ip == ':')) {
524 if (i > len - 5)
525 return -EINVAL;
526 ec = 0;
527 for (k = 1; k < 5; k++) {
528 nc = ip[k];
529 ec <<= 4;
530 if (nc >= '0' && nc <= '9') {
531 ec |= nc - '0';
532 continue;
534 if (nc >= 'a' && nc <= 'f') {
535 ec |= nc - ('a' - 10);
536 continue;
538 if (nc >= 'A' && nc <= 'F') {
539 ec |= nc - ('A' - 10);
540 continue;
542 return -EINVAL;
544 *op++ = ec & 0xFF;
545 *op++ = ec >> 8;
546 ip += 5;
547 i += 5;
548 } else {
549 if ((charlen = nls->char2uni(ip, len - i, (wchar_t *)op)) < 0)
550 return -EINVAL;
551 ip += charlen;
552 i += charlen;
553 op += 2;
556 if (i < len)
557 return -ENAMETOOLONG;
558 } else {
559 for (i = 0, ip = name, op = outname, *outlen = 0;
560 i < len && *outlen <= 255;
561 i++, *outlen += 1)
563 *op++ = *ip++;
564 *op++ = 0;
566 if (i < len)
567 return -ENAMETOOLONG;
571 *longlen = *outlen;
572 if (*outlen % 13) {
573 *op++ = 0;
574 *op++ = 0;
575 *outlen += 1;
576 if (*outlen % 13) {
577 fill = 13 - (*outlen % 13);
578 for (i = 0; i < fill; i++) {
579 *op++ = 0xff;
580 *op++ = 0xff;
582 *outlen += fill;
586 return 0;
589 static int vfat_build_slots(struct inode *dir, const unsigned char *name,
590 int len, int is_dir, int cluster,
591 struct timespec *ts,
592 struct msdos_dir_slot *slots, int *nr_slots)
594 struct msdos_sb_info *sbi = MSDOS_SB(dir->i_sb);
595 struct fat_mount_options *opts = &sbi->options;
596 struct msdos_dir_slot *ps;
597 struct msdos_dir_entry *de;
598 unsigned char cksum, lcase;
599 unsigned char msdos_name[MSDOS_NAME];
600 wchar_t *uname;
601 __le16 time, date;
602 u8 time_cs;
603 int err, ulen, usize, i;
604 loff_t offset;
606 *nr_slots = 0;
608 uname = __getname();
609 if (!uname)
610 return -ENOMEM;
612 err = xlate_to_uni(name, len, (unsigned char *)uname, &ulen, &usize,
613 opts->unicode_xlate, opts->utf8, sbi->nls_io);
614 if (err)
615 goto out_free;
617 err = vfat_is_used_badchars(uname, ulen);
618 if (err)
619 goto out_free;
621 err = vfat_create_shortname(dir, sbi->nls_disk, uname, ulen,
622 msdos_name, &lcase);
623 if (err < 0)
624 goto out_free;
625 else if (err == 1) {
626 de = (struct msdos_dir_entry *)slots;
627 err = 0;
628 goto shortname;
631 /* build the entry of long file name */
632 cksum = fat_checksum(msdos_name);
634 *nr_slots = usize / 13;
635 for (ps = slots, i = *nr_slots; i > 0; i--, ps++) {
636 ps->id = i;
637 ps->attr = ATTR_EXT;
638 ps->reserved = 0;
639 ps->alias_checksum = cksum;
640 ps->start = 0;
641 offset = (i - 1) * 13;
642 fatwchar_to16(ps->name0_4, uname + offset, 5);
643 fatwchar_to16(ps->name5_10, uname + offset + 5, 6);
644 fatwchar_to16(ps->name11_12, uname + offset + 11, 2);
646 slots[0].id |= 0x40;
647 de = (struct msdos_dir_entry *)ps;
649 shortname:
650 /* build the entry of 8.3 alias name */
651 (*nr_slots)++;
652 memcpy(de->name, msdos_name, MSDOS_NAME);
653 de->attr = is_dir ? ATTR_DIR : ATTR_ARCH;
654 de->lcase = lcase;
655 fat_time_unix2fat(sbi, ts, &time, &date, &time_cs);
656 de->time = de->ctime = time;
657 de->date = de->cdate = de->adate = date;
658 de->ctime_cs = time_cs;
659 de->start = cpu_to_le16(cluster);
660 de->starthi = cpu_to_le16(cluster >> 16);
661 de->size = 0;
662 out_free:
663 __putname(uname);
664 return err;
667 static int vfat_add_entry(struct inode *dir, struct qstr *qname, int is_dir,
668 int cluster, struct timespec *ts,
669 struct fat_slot_info *sinfo)
671 struct msdos_dir_slot *slots;
672 unsigned int len;
673 int err, nr_slots;
675 len = vfat_striptail_len(qname);
676 if (len == 0)
677 return -ENOENT;
679 slots = kmalloc(sizeof(*slots) * MSDOS_SLOTS, GFP_NOFS);
680 if (slots == NULL)
681 return -ENOMEM;
683 err = vfat_build_slots(dir, qname->name, len, is_dir, cluster, ts,
684 slots, &nr_slots);
685 if (err)
686 goto cleanup;
688 err = fat_add_entries(dir, slots, nr_slots, sinfo);
689 if (err)
690 goto cleanup;
692 /* update timestamp */
693 dir->i_ctime = dir->i_mtime = dir->i_atime = *ts;
694 if (IS_DIRSYNC(dir))
695 (void)fat_sync_inode(dir);
696 else
697 mark_inode_dirty(dir);
698 cleanup:
699 kfree(slots);
700 return err;
703 static int vfat_find(struct inode *dir, struct qstr *qname,
704 struct fat_slot_info *sinfo)
706 unsigned int len = vfat_striptail_len(qname);
707 if (len == 0)
708 return -ENOENT;
709 return fat_search_long(dir, qname->name, len, sinfo);
712 static struct dentry *vfat_lookup(struct inode *dir, struct dentry *dentry,
713 struct nameidata *nd)
715 struct super_block *sb = dir->i_sb;
716 struct fat_slot_info sinfo;
717 struct inode *inode;
718 struct dentry *alias;
719 int err;
721 lock_super(sb);
723 err = vfat_find(dir, &dentry->d_name, &sinfo);
724 if (err) {
725 if (err == -ENOENT) {
726 inode = NULL;
727 goto out;
729 goto error;
732 inode = fat_build_inode(sb, sinfo.de, sinfo.i_pos);
733 brelse(sinfo.bh);
734 if (IS_ERR(inode)) {
735 err = PTR_ERR(inode);
736 goto error;
739 alias = d_find_alias(inode);
740 if (alias && !(alias->d_flags & DCACHE_DISCONNECTED)) {
742 * This inode has non DCACHE_DISCONNECTED dentry. This
743 * means, the user did ->lookup() by an another name
744 * (longname vs 8.3 alias of it) in past.
746 * Switch to new one for reason of locality if possible.
748 BUG_ON(d_unhashed(alias));
749 if (!S_ISDIR(inode->i_mode))
750 d_move(alias, dentry);
751 iput(inode);
752 unlock_super(sb);
753 return alias;
755 out:
756 unlock_super(sb);
757 dentry->d_op = sb->s_root->d_op;
758 dentry->d_time = dentry->d_parent->d_inode->i_version;
759 dentry = d_splice_alias(inode, dentry);
760 if (dentry) {
761 dentry->d_op = sb->s_root->d_op;
762 dentry->d_time = dentry->d_parent->d_inode->i_version;
764 return dentry;
766 error:
767 unlock_super(sb);
768 return ERR_PTR(err);
771 static int vfat_create(struct inode *dir, struct dentry *dentry, int mode,
772 struct nameidata *nd)
774 struct super_block *sb = dir->i_sb;
775 struct inode *inode;
776 struct fat_slot_info sinfo;
777 struct timespec ts;
778 int err;
780 lock_super(sb);
782 ts = CURRENT_TIME_SEC;
783 err = vfat_add_entry(dir, &dentry->d_name, 0, 0, &ts, &sinfo);
784 if (err)
785 goto out;
786 dir->i_version++;
788 inode = fat_build_inode(sb, sinfo.de, sinfo.i_pos);
789 brelse(sinfo.bh);
790 if (IS_ERR(inode)) {
791 err = PTR_ERR(inode);
792 goto out;
794 inode->i_version++;
795 inode->i_mtime = inode->i_atime = inode->i_ctime = ts;
796 /* timestamp is already written, so mark_inode_dirty() is unneeded. */
798 dentry->d_time = dentry->d_parent->d_inode->i_version;
799 d_instantiate(dentry, inode);
800 out:
801 unlock_super(sb);
802 return err;
805 static int vfat_rmdir(struct inode *dir, struct dentry *dentry)
807 struct inode *inode = dentry->d_inode;
808 struct super_block *sb = dir->i_sb;
809 struct fat_slot_info sinfo;
810 int err;
812 lock_super(sb);
814 err = fat_dir_empty(inode);
815 if (err)
816 goto out;
817 err = vfat_find(dir, &dentry->d_name, &sinfo);
818 if (err)
819 goto out;
821 err = fat_remove_entries(dir, &sinfo); /* and releases bh */
822 if (err)
823 goto out;
824 drop_nlink(dir);
826 clear_nlink(inode);
827 inode->i_mtime = inode->i_atime = CURRENT_TIME_SEC;
828 fat_detach(inode);
829 out:
830 unlock_super(sb);
832 return err;
835 static int vfat_unlink(struct inode *dir, struct dentry *dentry)
837 struct inode *inode = dentry->d_inode;
838 struct super_block *sb = dir->i_sb;
839 struct fat_slot_info sinfo;
840 int err;
842 lock_super(sb);
844 err = vfat_find(dir, &dentry->d_name, &sinfo);
845 if (err)
846 goto out;
848 err = fat_remove_entries(dir, &sinfo); /* and releases bh */
849 if (err)
850 goto out;
851 clear_nlink(inode);
852 inode->i_mtime = inode->i_atime = CURRENT_TIME_SEC;
853 fat_detach(inode);
854 out:
855 unlock_super(sb);
857 return err;
860 static int vfat_mkdir(struct inode *dir, struct dentry *dentry, int mode)
862 struct super_block *sb = dir->i_sb;
863 struct inode *inode;
864 struct fat_slot_info sinfo;
865 struct timespec ts;
866 int err, cluster;
868 lock_super(sb);
870 ts = CURRENT_TIME_SEC;
871 cluster = fat_alloc_new_dir(dir, &ts);
872 if (cluster < 0) {
873 err = cluster;
874 goto out;
876 err = vfat_add_entry(dir, &dentry->d_name, 1, cluster, &ts, &sinfo);
877 if (err)
878 goto out_free;
879 dir->i_version++;
880 inc_nlink(dir);
882 inode = fat_build_inode(sb, sinfo.de, sinfo.i_pos);
883 brelse(sinfo.bh);
884 if (IS_ERR(inode)) {
885 err = PTR_ERR(inode);
886 /* the directory was completed, just return a error */
887 goto out;
889 inode->i_version++;
890 inode->i_nlink = 2;
891 inode->i_mtime = inode->i_atime = inode->i_ctime = ts;
892 /* timestamp is already written, so mark_inode_dirty() is unneeded. */
894 dentry->d_time = dentry->d_parent->d_inode->i_version;
895 d_instantiate(dentry, inode);
897 unlock_super(sb);
898 return 0;
900 out_free:
901 fat_free_clusters(dir, cluster);
902 out:
903 unlock_super(sb);
904 return err;
907 static int vfat_rename(struct inode *old_dir, struct dentry *old_dentry,
908 struct inode *new_dir, struct dentry *new_dentry)
910 struct buffer_head *dotdot_bh;
911 struct msdos_dir_entry *dotdot_de;
912 struct inode *old_inode, *new_inode;
913 struct fat_slot_info old_sinfo, sinfo;
914 struct timespec ts;
915 loff_t dotdot_i_pos, new_i_pos;
916 int err, is_dir, update_dotdot, corrupt = 0;
917 struct super_block *sb = old_dir->i_sb;
919 old_sinfo.bh = sinfo.bh = dotdot_bh = NULL;
920 old_inode = old_dentry->d_inode;
921 new_inode = new_dentry->d_inode;
922 lock_super(sb);
923 err = vfat_find(old_dir, &old_dentry->d_name, &old_sinfo);
924 if (err)
925 goto out;
927 is_dir = S_ISDIR(old_inode->i_mode);
928 update_dotdot = (is_dir && old_dir != new_dir);
929 if (update_dotdot) {
930 if (fat_get_dotdot_entry(old_inode, &dotdot_bh, &dotdot_de,
931 &dotdot_i_pos) < 0) {
932 err = -EIO;
933 goto out;
937 ts = CURRENT_TIME_SEC;
938 if (new_inode) {
939 if (is_dir) {
940 err = fat_dir_empty(new_inode);
941 if (err)
942 goto out;
944 new_i_pos = MSDOS_I(new_inode)->i_pos;
945 fat_detach(new_inode);
946 } else {
947 err = vfat_add_entry(new_dir, &new_dentry->d_name, is_dir, 0,
948 &ts, &sinfo);
949 if (err)
950 goto out;
951 new_i_pos = sinfo.i_pos;
953 new_dir->i_version++;
955 fat_detach(old_inode);
956 fat_attach(old_inode, new_i_pos);
957 if (IS_DIRSYNC(new_dir)) {
958 err = fat_sync_inode(old_inode);
959 if (err)
960 goto error_inode;
961 } else
962 mark_inode_dirty(old_inode);
964 if (update_dotdot) {
965 int start = MSDOS_I(new_dir)->i_logstart;
966 dotdot_de->start = cpu_to_le16(start);
967 dotdot_de->starthi = cpu_to_le16(start >> 16);
968 mark_buffer_dirty(dotdot_bh);
969 if (IS_DIRSYNC(new_dir)) {
970 err = sync_dirty_buffer(dotdot_bh);
971 if (err)
972 goto error_dotdot;
974 drop_nlink(old_dir);
975 if (!new_inode)
976 inc_nlink(new_dir);
979 err = fat_remove_entries(old_dir, &old_sinfo); /* and releases bh */
980 old_sinfo.bh = NULL;
981 if (err)
982 goto error_dotdot;
983 old_dir->i_version++;
984 old_dir->i_ctime = old_dir->i_mtime = ts;
985 if (IS_DIRSYNC(old_dir))
986 (void)fat_sync_inode(old_dir);
987 else
988 mark_inode_dirty(old_dir);
990 if (new_inode) {
991 drop_nlink(new_inode);
992 if (is_dir)
993 drop_nlink(new_inode);
994 new_inode->i_ctime = ts;
996 out:
997 brelse(sinfo.bh);
998 brelse(dotdot_bh);
999 brelse(old_sinfo.bh);
1000 unlock_super(sb);
1002 return err;
1004 error_dotdot:
1005 /* data cluster is shared, serious corruption */
1006 corrupt = 1;
1008 if (update_dotdot) {
1009 int start = MSDOS_I(old_dir)->i_logstart;
1010 dotdot_de->start = cpu_to_le16(start);
1011 dotdot_de->starthi = cpu_to_le16(start >> 16);
1012 mark_buffer_dirty(dotdot_bh);
1013 corrupt |= sync_dirty_buffer(dotdot_bh);
1015 error_inode:
1016 fat_detach(old_inode);
1017 fat_attach(old_inode, old_sinfo.i_pos);
1018 if (new_inode) {
1019 fat_attach(new_inode, new_i_pos);
1020 if (corrupt)
1021 corrupt |= fat_sync_inode(new_inode);
1022 } else {
1024 * If new entry was not sharing the data cluster, it
1025 * shouldn't be serious corruption.
1027 int err2 = fat_remove_entries(new_dir, &sinfo);
1028 if (corrupt)
1029 corrupt |= err2;
1030 sinfo.bh = NULL;
1032 if (corrupt < 0) {
1033 fat_fs_panic(new_dir->i_sb,
1034 "%s: Filesystem corrupted (i_pos %lld)",
1035 __func__, sinfo.i_pos);
1037 goto out;
1040 static const struct inode_operations vfat_dir_inode_operations = {
1041 .create = vfat_create,
1042 .lookup = vfat_lookup,
1043 .unlink = vfat_unlink,
1044 .mkdir = vfat_mkdir,
1045 .rmdir = vfat_rmdir,
1046 .rename = vfat_rename,
1047 .setattr = fat_setattr,
1048 .getattr = fat_getattr,
1051 static int vfat_fill_super(struct super_block *sb, void *data, int silent)
1053 int res;
1055 res = fat_fill_super(sb, data, silent, &vfat_dir_inode_operations, 1);
1056 if (res)
1057 return res;
1059 if (MSDOS_SB(sb)->options.name_check != 's')
1060 sb->s_root->d_op = &vfat_ci_dentry_ops;
1061 else
1062 sb->s_root->d_op = &vfat_dentry_ops;
1064 return 0;
1067 static int vfat_get_sb(struct file_system_type *fs_type,
1068 int flags, const char *dev_name,
1069 void *data, struct vfsmount *mnt)
1071 return get_sb_bdev(fs_type, flags, dev_name, data, vfat_fill_super,
1072 mnt);
1075 static struct file_system_type vfat_fs_type = {
1076 .owner = THIS_MODULE,
1077 .name = "vfat",
1078 .get_sb = vfat_get_sb,
1079 .kill_sb = kill_block_super,
1080 .fs_flags = FS_REQUIRES_DEV,
1083 static int __init init_vfat_fs(void)
1085 return register_filesystem(&vfat_fs_type);
1088 static void __exit exit_vfat_fs(void)
1090 unregister_filesystem(&vfat_fs_type);
1093 MODULE_LICENSE("GPL");
1094 MODULE_DESCRIPTION("VFAT filesystem support");
1095 MODULE_AUTHOR("Gordon Chaffee");
1097 module_init(init_vfat_fs)
1098 module_exit(exit_vfat_fs)