acpi_pad: build only on X86
[linux-2.6/linux-acpi-2.6.git] / fs / fat / namei_vfat.c
blobcb6e83557112d74e03cf00f37d6b3bddfa66cd83
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/buffer_head.h>
23 #include <linux/namei.h>
24 #include "fat.h"
27 * If new entry was created in the parent, it could create the 8.3
28 * alias (the shortname of logname). So, the parent may have the
29 * negative-dentry which matches the created 8.3 alias.
31 * If it happened, the negative dentry isn't actually negative
32 * anymore. So, drop it.
34 static int vfat_revalidate_shortname(struct dentry *dentry)
36 int ret = 1;
37 spin_lock(&dentry->d_lock);
38 if (dentry->d_time != dentry->d_parent->d_inode->i_version)
39 ret = 0;
40 spin_unlock(&dentry->d_lock);
41 return ret;
44 static int vfat_revalidate(struct dentry *dentry, struct nameidata *nd)
46 /* This is not negative dentry. Always valid. */
47 if (dentry->d_inode)
48 return 1;
49 return vfat_revalidate_shortname(dentry);
52 static int vfat_revalidate_ci(struct dentry *dentry, struct nameidata *nd)
55 * This is not negative dentry. Always valid.
57 * Note, rename() to existing directory entry will have ->d_inode,
58 * and will use existing name which isn't specified name by user.
60 * We may be able to drop this positive dentry here. But dropping
61 * positive dentry isn't good idea. So it's unsupported like
62 * rename("filename", "FILENAME") for now.
64 if (dentry->d_inode)
65 return 1;
68 * This may be nfsd (or something), anyway, we can't see the
69 * intent of this. So, since this can be for creation, drop it.
71 if (!nd)
72 return 0;
75 * Drop the negative dentry, in order to make sure to use the
76 * case sensitive name which is specified by user if this is
77 * for creation.
79 if (!(nd->flags & (LOOKUP_CONTINUE | LOOKUP_PARENT))) {
80 if (nd->flags & (LOOKUP_CREATE | LOOKUP_RENAME_TARGET))
81 return 0;
84 return vfat_revalidate_shortname(dentry);
87 /* returns the length of a struct qstr, ignoring trailing dots */
88 static unsigned int vfat_striptail_len(struct qstr *qstr)
90 unsigned int len = qstr->len;
92 while (len && qstr->name[len - 1] == '.')
93 len--;
94 return len;
98 * Compute the hash for the vfat name corresponding to the dentry.
99 * Note: if the name is invalid, we leave the hash code unchanged so
100 * that the existing dentry can be used. The vfat fs routines will
101 * return ENOENT or EINVAL as appropriate.
103 static int vfat_hash(struct dentry *dentry, struct qstr *qstr)
105 qstr->hash = full_name_hash(qstr->name, vfat_striptail_len(qstr));
106 return 0;
110 * Compute the hash for the vfat name corresponding to the dentry.
111 * Note: if the name is invalid, we leave the hash code unchanged so
112 * that the existing dentry can be used. The vfat fs routines will
113 * return ENOENT or EINVAL as appropriate.
115 static int vfat_hashi(struct dentry *dentry, struct qstr *qstr)
117 struct nls_table *t = MSDOS_SB(dentry->d_inode->i_sb)->nls_io;
118 const unsigned char *name;
119 unsigned int len;
120 unsigned long hash;
122 name = qstr->name;
123 len = vfat_striptail_len(qstr);
125 hash = init_name_hash();
126 while (len--)
127 hash = partial_name_hash(nls_tolower(t, *name++), hash);
128 qstr->hash = end_name_hash(hash);
130 return 0;
134 * Case insensitive compare of two vfat names.
136 static int vfat_cmpi(struct dentry *dentry, struct qstr *a, struct qstr *b)
138 struct nls_table *t = MSDOS_SB(dentry->d_inode->i_sb)->nls_io;
139 unsigned int alen, blen;
141 /* A filename cannot end in '.' or we treat it like it has none */
142 alen = vfat_striptail_len(a);
143 blen = vfat_striptail_len(b);
144 if (alen == blen) {
145 if (nls_strnicmp(t, a->name, b->name, alen) == 0)
146 return 0;
148 return 1;
152 * Case sensitive compare of two vfat names.
154 static int vfat_cmp(struct dentry *dentry, struct qstr *a, struct qstr *b)
156 unsigned int alen, blen;
158 /* A filename cannot end in '.' or we treat it like it has none */
159 alen = vfat_striptail_len(a);
160 blen = vfat_striptail_len(b);
161 if (alen == blen) {
162 if (strncmp(a->name, b->name, alen) == 0)
163 return 0;
165 return 1;
168 static const struct dentry_operations vfat_ci_dentry_ops = {
169 .d_revalidate = vfat_revalidate_ci,
170 .d_hash = vfat_hashi,
171 .d_compare = vfat_cmpi,
174 static const struct dentry_operations vfat_dentry_ops = {
175 .d_revalidate = vfat_revalidate,
176 .d_hash = vfat_hash,
177 .d_compare = vfat_cmp,
180 /* Characters that are undesirable in an MS-DOS file name */
182 static inline wchar_t vfat_bad_char(wchar_t w)
184 return (w < 0x0020)
185 || (w == '*') || (w == '?') || (w == '<') || (w == '>')
186 || (w == '|') || (w == '"') || (w == ':') || (w == '/')
187 || (w == '\\');
190 static inline wchar_t vfat_replace_char(wchar_t w)
192 return (w == '[') || (w == ']') || (w == ';') || (w == ',')
193 || (w == '+') || (w == '=');
196 static wchar_t vfat_skip_char(wchar_t w)
198 return (w == '.') || (w == ' ');
201 static inline int vfat_is_used_badchars(const wchar_t *s, int len)
203 int i;
205 for (i = 0; i < len; i++)
206 if (vfat_bad_char(s[i]))
207 return -EINVAL;
209 if (s[i - 1] == ' ') /* last character cannot be space */
210 return -EINVAL;
212 return 0;
215 static int vfat_find_form(struct inode *dir, unsigned char *name)
217 struct fat_slot_info sinfo;
218 int err = fat_scan(dir, name, &sinfo);
219 if (err)
220 return -ENOENT;
221 brelse(sinfo.bh);
222 return 0;
226 * 1) Valid characters for the 8.3 format alias are any combination of
227 * letters, uppercase alphabets, digits, any of the
228 * following special characters:
229 * $ % ' ` - @ { } ~ ! # ( ) & _ ^
230 * In this case Longfilename is not stored in disk.
232 * WinNT's Extension:
233 * File name and extension name is contain uppercase/lowercase
234 * only. And it is expressed by CASE_LOWER_BASE and CASE_LOWER_EXT.
236 * 2) File name is 8.3 format, but it contain the uppercase and
237 * lowercase char, muliti bytes char, etc. In this case numtail is not
238 * added, but Longfilename is stored.
240 * 3) When the one except for the above, or the following special
241 * character are contained:
242 * . [ ] ; , + =
243 * numtail is added, and Longfilename must be stored in disk .
245 struct shortname_info {
246 unsigned char lower:1,
247 upper:1,
248 valid:1;
250 #define INIT_SHORTNAME_INFO(x) do { \
251 (x)->lower = 1; \
252 (x)->upper = 1; \
253 (x)->valid = 1; \
254 } while (0)
256 static inline int to_shortname_char(struct nls_table *nls,
257 unsigned char *buf, int buf_size,
258 wchar_t *src, struct shortname_info *info)
260 int len;
262 if (vfat_skip_char(*src)) {
263 info->valid = 0;
264 return 0;
266 if (vfat_replace_char(*src)) {
267 info->valid = 0;
268 buf[0] = '_';
269 return 1;
272 len = nls->uni2char(*src, buf, buf_size);
273 if (len <= 0) {
274 info->valid = 0;
275 buf[0] = '_';
276 len = 1;
277 } else if (len == 1) {
278 unsigned char prev = buf[0];
280 if (buf[0] >= 0x7F) {
281 info->lower = 0;
282 info->upper = 0;
285 buf[0] = nls_toupper(nls, buf[0]);
286 if (isalpha(buf[0])) {
287 if (buf[0] == prev)
288 info->lower = 0;
289 else
290 info->upper = 0;
292 } else {
293 info->lower = 0;
294 info->upper = 0;
297 return len;
301 * Given a valid longname, create a unique shortname. Make sure the
302 * shortname does not exist
303 * Returns negative number on error, 0 for a normal
304 * return, and 1 for valid shortname
306 static int vfat_create_shortname(struct inode *dir, struct nls_table *nls,
307 wchar_t *uname, int ulen,
308 unsigned char *name_res, unsigned char *lcase)
310 struct fat_mount_options *opts = &MSDOS_SB(dir->i_sb)->options;
311 wchar_t *ip, *ext_start, *end, *name_start;
312 unsigned char base[9], ext[4], buf[8], *p;
313 unsigned char charbuf[NLS_MAX_CHARSET_SIZE];
314 int chl, chi;
315 int sz = 0, extlen, baselen, i, numtail_baselen, numtail2_baselen;
316 int is_shortname;
317 struct shortname_info base_info, ext_info;
319 is_shortname = 1;
320 INIT_SHORTNAME_INFO(&base_info);
321 INIT_SHORTNAME_INFO(&ext_info);
323 /* Now, we need to create a shortname from the long name */
324 ext_start = end = &uname[ulen];
325 while (--ext_start >= uname) {
326 if (*ext_start == 0x002E) { /* is `.' */
327 if (ext_start == end - 1) {
328 sz = ulen;
329 ext_start = NULL;
331 break;
335 if (ext_start == uname - 1) {
336 sz = ulen;
337 ext_start = NULL;
338 } else if (ext_start) {
340 * Names which start with a dot could be just
341 * an extension eg. "...test". In this case Win95
342 * uses the extension as the name and sets no extension.
344 name_start = &uname[0];
345 while (name_start < ext_start) {
346 if (!vfat_skip_char(*name_start))
347 break;
348 name_start++;
350 if (name_start != ext_start) {
351 sz = ext_start - uname;
352 ext_start++;
353 } else {
354 sz = ulen;
355 ext_start = NULL;
359 numtail_baselen = 6;
360 numtail2_baselen = 2;
361 for (baselen = i = 0, p = base, ip = uname; i < sz; i++, ip++) {
362 chl = to_shortname_char(nls, charbuf, sizeof(charbuf),
363 ip, &base_info);
364 if (chl == 0)
365 continue;
367 if (baselen < 2 && (baselen + chl) > 2)
368 numtail2_baselen = baselen;
369 if (baselen < 6 && (baselen + chl) > 6)
370 numtail_baselen = baselen;
371 for (chi = 0; chi < chl; chi++) {
372 *p++ = charbuf[chi];
373 baselen++;
374 if (baselen >= 8)
375 break;
377 if (baselen >= 8) {
378 if ((chi < chl - 1) || (ip + 1) - uname < sz)
379 is_shortname = 0;
380 break;
383 if (baselen == 0) {
384 return -EINVAL;
387 extlen = 0;
388 if (ext_start) {
389 for (p = ext, ip = ext_start; extlen < 3 && ip < end; ip++) {
390 chl = to_shortname_char(nls, charbuf, sizeof(charbuf),
391 ip, &ext_info);
392 if (chl == 0)
393 continue;
395 if ((extlen + chl) > 3) {
396 is_shortname = 0;
397 break;
399 for (chi = 0; chi < chl; chi++) {
400 *p++ = charbuf[chi];
401 extlen++;
403 if (extlen >= 3) {
404 if (ip + 1 != end)
405 is_shortname = 0;
406 break;
410 ext[extlen] = '\0';
411 base[baselen] = '\0';
413 /* Yes, it can happen. ".\xe5" would do it. */
414 if (base[0] == DELETED_FLAG)
415 base[0] = 0x05;
417 /* OK, at this point we know that base is not longer than 8 symbols,
418 * ext is not longer than 3, base is nonempty, both don't contain
419 * any bad symbols (lowercase transformed to uppercase).
422 memset(name_res, ' ', MSDOS_NAME);
423 memcpy(name_res, base, baselen);
424 memcpy(name_res + 8, ext, extlen);
425 *lcase = 0;
426 if (is_shortname && base_info.valid && ext_info.valid) {
427 if (vfat_find_form(dir, name_res) == 0)
428 return -EEXIST;
430 if (opts->shortname & VFAT_SFN_CREATE_WIN95) {
431 return (base_info.upper && ext_info.upper);
432 } else if (opts->shortname & VFAT_SFN_CREATE_WINNT) {
433 if ((base_info.upper || base_info.lower) &&
434 (ext_info.upper || ext_info.lower)) {
435 if (!base_info.upper && base_info.lower)
436 *lcase |= CASE_LOWER_BASE;
437 if (!ext_info.upper && ext_info.lower)
438 *lcase |= CASE_LOWER_EXT;
439 return 1;
441 return 0;
442 } else {
443 BUG();
447 if (opts->numtail == 0)
448 if (vfat_find_form(dir, name_res) < 0)
449 return 0;
452 * Try to find a unique extension. This used to
453 * iterate through all possibilities sequentially,
454 * but that gave extremely bad performance. Windows
455 * only tries a few cases before using random
456 * values for part of the base.
459 if (baselen > 6) {
460 baselen = numtail_baselen;
461 name_res[7] = ' ';
463 name_res[baselen] = '~';
464 for (i = 1; i < 10; i++) {
465 name_res[baselen + 1] = i + '0';
466 if (vfat_find_form(dir, name_res) < 0)
467 return 0;
470 i = jiffies & 0xffff;
471 sz = (jiffies >> 16) & 0x7;
472 if (baselen > 2) {
473 baselen = numtail2_baselen;
474 name_res[7] = ' ';
476 name_res[baselen + 4] = '~';
477 name_res[baselen + 5] = '1' + sz;
478 while (1) {
479 sprintf(buf, "%04X", i);
480 memcpy(&name_res[baselen], buf, 4);
481 if (vfat_find_form(dir, name_res) < 0)
482 break;
483 i -= 11;
485 return 0;
488 /* Translate a string, including coded sequences into Unicode */
489 static int
490 xlate_to_uni(const unsigned char *name, int len, unsigned char *outname,
491 int *longlen, int *outlen, int escape, int utf8,
492 struct nls_table *nls)
494 const unsigned char *ip;
495 unsigned char nc;
496 unsigned char *op;
497 unsigned int ec;
498 int i, k, fill;
499 int charlen;
501 if (utf8) {
502 int name_len = strlen(name);
504 *outlen = utf8s_to_utf16s(name, PATH_MAX, (wchar_t *) outname);
507 * We stripped '.'s before and set len appropriately,
508 * but utf8s_to_utf16s doesn't care about len
510 *outlen -= (name_len - len);
512 if (*outlen > 255)
513 return -ENAMETOOLONG;
515 op = &outname[*outlen * sizeof(wchar_t)];
516 } else {
517 if (nls) {
518 for (i = 0, ip = name, op = outname, *outlen = 0;
519 i < len && *outlen <= 255;
520 *outlen += 1)
522 if (escape && (*ip == ':')) {
523 if (i > len - 5)
524 return -EINVAL;
525 ec = 0;
526 for (k = 1; k < 5; k++) {
527 nc = ip[k];
528 ec <<= 4;
529 if (nc >= '0' && nc <= '9') {
530 ec |= nc - '0';
531 continue;
533 if (nc >= 'a' && nc <= 'f') {
534 ec |= nc - ('a' - 10);
535 continue;
537 if (nc >= 'A' && nc <= 'F') {
538 ec |= nc - ('A' - 10);
539 continue;
541 return -EINVAL;
543 *op++ = ec & 0xFF;
544 *op++ = ec >> 8;
545 ip += 5;
546 i += 5;
547 } else {
548 if ((charlen = nls->char2uni(ip, len - i, (wchar_t *)op)) < 0)
549 return -EINVAL;
550 ip += charlen;
551 i += charlen;
552 op += 2;
555 if (i < len)
556 return -ENAMETOOLONG;
557 } else {
558 for (i = 0, ip = name, op = outname, *outlen = 0;
559 i < len && *outlen <= 255;
560 i++, *outlen += 1)
562 *op++ = *ip++;
563 *op++ = 0;
565 if (i < len)
566 return -ENAMETOOLONG;
570 *longlen = *outlen;
571 if (*outlen % 13) {
572 *op++ = 0;
573 *op++ = 0;
574 *outlen += 1;
575 if (*outlen % 13) {
576 fill = 13 - (*outlen % 13);
577 for (i = 0; i < fill; i++) {
578 *op++ = 0xff;
579 *op++ = 0xff;
581 *outlen += fill;
585 return 0;
588 static int vfat_build_slots(struct inode *dir, const unsigned char *name,
589 int len, int is_dir, int cluster,
590 struct timespec *ts,
591 struct msdos_dir_slot *slots, int *nr_slots)
593 struct msdos_sb_info *sbi = MSDOS_SB(dir->i_sb);
594 struct fat_mount_options *opts = &sbi->options;
595 struct msdos_dir_slot *ps;
596 struct msdos_dir_entry *de;
597 unsigned char cksum, lcase;
598 unsigned char msdos_name[MSDOS_NAME];
599 wchar_t *uname;
600 __le16 time, date;
601 u8 time_cs;
602 int err, ulen, usize, i;
603 loff_t offset;
605 *nr_slots = 0;
607 uname = __getname();
608 if (!uname)
609 return -ENOMEM;
611 err = xlate_to_uni(name, len, (unsigned char *)uname, &ulen, &usize,
612 opts->unicode_xlate, opts->utf8, sbi->nls_io);
613 if (err)
614 goto out_free;
616 err = vfat_is_used_badchars(uname, ulen);
617 if (err)
618 goto out_free;
620 err = vfat_create_shortname(dir, sbi->nls_disk, uname, ulen,
621 msdos_name, &lcase);
622 if (err < 0)
623 goto out_free;
624 else if (err == 1) {
625 de = (struct msdos_dir_entry *)slots;
626 err = 0;
627 goto shortname;
630 /* build the entry of long file name */
631 cksum = fat_checksum(msdos_name);
633 *nr_slots = usize / 13;
634 for (ps = slots, i = *nr_slots; i > 0; i--, ps++) {
635 ps->id = i;
636 ps->attr = ATTR_EXT;
637 ps->reserved = 0;
638 ps->alias_checksum = cksum;
639 ps->start = 0;
640 offset = (i - 1) * 13;
641 fatwchar_to16(ps->name0_4, uname + offset, 5);
642 fatwchar_to16(ps->name5_10, uname + offset + 5, 6);
643 fatwchar_to16(ps->name11_12, uname + offset + 11, 2);
645 slots[0].id |= 0x40;
646 de = (struct msdos_dir_entry *)ps;
648 shortname:
649 /* build the entry of 8.3 alias name */
650 (*nr_slots)++;
651 memcpy(de->name, msdos_name, MSDOS_NAME);
652 de->attr = is_dir ? ATTR_DIR : ATTR_ARCH;
653 de->lcase = lcase;
654 fat_time_unix2fat(sbi, ts, &time, &date, &time_cs);
655 de->time = de->ctime = time;
656 de->date = de->cdate = de->adate = date;
657 de->ctime_cs = time_cs;
658 de->start = cpu_to_le16(cluster);
659 de->starthi = cpu_to_le16(cluster >> 16);
660 de->size = 0;
661 out_free:
662 __putname(uname);
663 return err;
666 static int vfat_add_entry(struct inode *dir, struct qstr *qname, int is_dir,
667 int cluster, struct timespec *ts,
668 struct fat_slot_info *sinfo)
670 struct msdos_dir_slot *slots;
671 unsigned int len;
672 int err, nr_slots;
674 len = vfat_striptail_len(qname);
675 if (len == 0)
676 return -ENOENT;
678 slots = kmalloc(sizeof(*slots) * MSDOS_SLOTS, GFP_NOFS);
679 if (slots == NULL)
680 return -ENOMEM;
682 err = vfat_build_slots(dir, qname->name, len, is_dir, cluster, ts,
683 slots, &nr_slots);
684 if (err)
685 goto cleanup;
687 err = fat_add_entries(dir, slots, nr_slots, sinfo);
688 if (err)
689 goto cleanup;
691 /* update timestamp */
692 dir->i_ctime = dir->i_mtime = dir->i_atime = *ts;
693 if (IS_DIRSYNC(dir))
694 (void)fat_sync_inode(dir);
695 else
696 mark_inode_dirty(dir);
697 cleanup:
698 kfree(slots);
699 return err;
702 static int vfat_find(struct inode *dir, struct qstr *qname,
703 struct fat_slot_info *sinfo)
705 unsigned int len = vfat_striptail_len(qname);
706 if (len == 0)
707 return -ENOENT;
708 return fat_search_long(dir, qname->name, len, sinfo);
711 static struct dentry *vfat_lookup(struct inode *dir, struct dentry *dentry,
712 struct nameidata *nd)
714 struct super_block *sb = dir->i_sb;
715 struct fat_slot_info sinfo;
716 struct inode *inode;
717 struct dentry *alias;
718 int err;
720 lock_super(sb);
722 err = vfat_find(dir, &dentry->d_name, &sinfo);
723 if (err) {
724 if (err == -ENOENT) {
725 inode = NULL;
726 goto out;
728 goto error;
731 inode = fat_build_inode(sb, sinfo.de, sinfo.i_pos);
732 brelse(sinfo.bh);
733 if (IS_ERR(inode)) {
734 err = PTR_ERR(inode);
735 goto error;
738 alias = d_find_alias(inode);
739 if (alias && !(alias->d_flags & DCACHE_DISCONNECTED)) {
741 * This inode has non DCACHE_DISCONNECTED dentry. This
742 * means, the user did ->lookup() by an another name
743 * (longname vs 8.3 alias of it) in past.
745 * Switch to new one for reason of locality if possible.
747 BUG_ON(d_unhashed(alias));
748 if (!S_ISDIR(inode->i_mode))
749 d_move(alias, dentry);
750 iput(inode);
751 unlock_super(sb);
752 return alias;
754 out:
755 unlock_super(sb);
756 dentry->d_op = sb->s_root->d_op;
757 dentry->d_time = dentry->d_parent->d_inode->i_version;
758 dentry = d_splice_alias(inode, dentry);
759 if (dentry) {
760 dentry->d_op = sb->s_root->d_op;
761 dentry->d_time = dentry->d_parent->d_inode->i_version;
763 return dentry;
765 error:
766 unlock_super(sb);
767 return ERR_PTR(err);
770 static int vfat_create(struct inode *dir, struct dentry *dentry, int mode,
771 struct nameidata *nd)
773 struct super_block *sb = dir->i_sb;
774 struct inode *inode;
775 struct fat_slot_info sinfo;
776 struct timespec ts;
777 int err;
779 lock_super(sb);
781 ts = CURRENT_TIME_SEC;
782 err = vfat_add_entry(dir, &dentry->d_name, 0, 0, &ts, &sinfo);
783 if (err)
784 goto out;
785 dir->i_version++;
787 inode = fat_build_inode(sb, sinfo.de, sinfo.i_pos);
788 brelse(sinfo.bh);
789 if (IS_ERR(inode)) {
790 err = PTR_ERR(inode);
791 goto out;
793 inode->i_version++;
794 inode->i_mtime = inode->i_atime = inode->i_ctime = ts;
795 /* timestamp is already written, so mark_inode_dirty() is unneeded. */
797 dentry->d_time = dentry->d_parent->d_inode->i_version;
798 d_instantiate(dentry, inode);
799 out:
800 unlock_super(sb);
801 return err;
804 static int vfat_rmdir(struct inode *dir, struct dentry *dentry)
806 struct inode *inode = dentry->d_inode;
807 struct super_block *sb = dir->i_sb;
808 struct fat_slot_info sinfo;
809 int err;
811 lock_super(sb);
813 err = fat_dir_empty(inode);
814 if (err)
815 goto out;
816 err = vfat_find(dir, &dentry->d_name, &sinfo);
817 if (err)
818 goto out;
820 err = fat_remove_entries(dir, &sinfo); /* and releases bh */
821 if (err)
822 goto out;
823 drop_nlink(dir);
825 clear_nlink(inode);
826 inode->i_mtime = inode->i_atime = CURRENT_TIME_SEC;
827 fat_detach(inode);
828 out:
829 unlock_super(sb);
831 return err;
834 static int vfat_unlink(struct inode *dir, struct dentry *dentry)
836 struct inode *inode = dentry->d_inode;
837 struct super_block *sb = dir->i_sb;
838 struct fat_slot_info sinfo;
839 int err;
841 lock_super(sb);
843 err = vfat_find(dir, &dentry->d_name, &sinfo);
844 if (err)
845 goto out;
847 err = fat_remove_entries(dir, &sinfo); /* and releases bh */
848 if (err)
849 goto out;
850 clear_nlink(inode);
851 inode->i_mtime = inode->i_atime = CURRENT_TIME_SEC;
852 fat_detach(inode);
853 out:
854 unlock_super(sb);
856 return err;
859 static int vfat_mkdir(struct inode *dir, struct dentry *dentry, int mode)
861 struct super_block *sb = dir->i_sb;
862 struct inode *inode;
863 struct fat_slot_info sinfo;
864 struct timespec ts;
865 int err, cluster;
867 lock_super(sb);
869 ts = CURRENT_TIME_SEC;
870 cluster = fat_alloc_new_dir(dir, &ts);
871 if (cluster < 0) {
872 err = cluster;
873 goto out;
875 err = vfat_add_entry(dir, &dentry->d_name, 1, cluster, &ts, &sinfo);
876 if (err)
877 goto out_free;
878 dir->i_version++;
879 inc_nlink(dir);
881 inode = fat_build_inode(sb, sinfo.de, sinfo.i_pos);
882 brelse(sinfo.bh);
883 if (IS_ERR(inode)) {
884 err = PTR_ERR(inode);
885 /* the directory was completed, just return a error */
886 goto out;
888 inode->i_version++;
889 inode->i_nlink = 2;
890 inode->i_mtime = inode->i_atime = inode->i_ctime = ts;
891 /* timestamp is already written, so mark_inode_dirty() is unneeded. */
893 dentry->d_time = dentry->d_parent->d_inode->i_version;
894 d_instantiate(dentry, inode);
896 unlock_super(sb);
897 return 0;
899 out_free:
900 fat_free_clusters(dir, cluster);
901 out:
902 unlock_super(sb);
903 return err;
906 static int vfat_rename(struct inode *old_dir, struct dentry *old_dentry,
907 struct inode *new_dir, struct dentry *new_dentry)
909 struct buffer_head *dotdot_bh;
910 struct msdos_dir_entry *dotdot_de;
911 struct inode *old_inode, *new_inode;
912 struct fat_slot_info old_sinfo, sinfo;
913 struct timespec ts;
914 loff_t dotdot_i_pos, new_i_pos;
915 int err, is_dir, update_dotdot, corrupt = 0;
916 struct super_block *sb = old_dir->i_sb;
918 old_sinfo.bh = sinfo.bh = dotdot_bh = NULL;
919 old_inode = old_dentry->d_inode;
920 new_inode = new_dentry->d_inode;
921 lock_super(sb);
922 err = vfat_find(old_dir, &old_dentry->d_name, &old_sinfo);
923 if (err)
924 goto out;
926 is_dir = S_ISDIR(old_inode->i_mode);
927 update_dotdot = (is_dir && old_dir != new_dir);
928 if (update_dotdot) {
929 if (fat_get_dotdot_entry(old_inode, &dotdot_bh, &dotdot_de,
930 &dotdot_i_pos) < 0) {
931 err = -EIO;
932 goto out;
936 ts = CURRENT_TIME_SEC;
937 if (new_inode) {
938 if (is_dir) {
939 err = fat_dir_empty(new_inode);
940 if (err)
941 goto out;
943 new_i_pos = MSDOS_I(new_inode)->i_pos;
944 fat_detach(new_inode);
945 } else {
946 err = vfat_add_entry(new_dir, &new_dentry->d_name, is_dir, 0,
947 &ts, &sinfo);
948 if (err)
949 goto out;
950 new_i_pos = sinfo.i_pos;
952 new_dir->i_version++;
954 fat_detach(old_inode);
955 fat_attach(old_inode, new_i_pos);
956 if (IS_DIRSYNC(new_dir)) {
957 err = fat_sync_inode(old_inode);
958 if (err)
959 goto error_inode;
960 } else
961 mark_inode_dirty(old_inode);
963 if (update_dotdot) {
964 int start = MSDOS_I(new_dir)->i_logstart;
965 dotdot_de->start = cpu_to_le16(start);
966 dotdot_de->starthi = cpu_to_le16(start >> 16);
967 mark_buffer_dirty_inode(dotdot_bh, old_inode);
968 if (IS_DIRSYNC(new_dir)) {
969 err = sync_dirty_buffer(dotdot_bh);
970 if (err)
971 goto error_dotdot;
973 drop_nlink(old_dir);
974 if (!new_inode)
975 inc_nlink(new_dir);
978 err = fat_remove_entries(old_dir, &old_sinfo); /* and releases bh */
979 old_sinfo.bh = NULL;
980 if (err)
981 goto error_dotdot;
982 old_dir->i_version++;
983 old_dir->i_ctime = old_dir->i_mtime = ts;
984 if (IS_DIRSYNC(old_dir))
985 (void)fat_sync_inode(old_dir);
986 else
987 mark_inode_dirty(old_dir);
989 if (new_inode) {
990 drop_nlink(new_inode);
991 if (is_dir)
992 drop_nlink(new_inode);
993 new_inode->i_ctime = ts;
995 out:
996 brelse(sinfo.bh);
997 brelse(dotdot_bh);
998 brelse(old_sinfo.bh);
999 unlock_super(sb);
1001 return err;
1003 error_dotdot:
1004 /* data cluster is shared, serious corruption */
1005 corrupt = 1;
1007 if (update_dotdot) {
1008 int start = MSDOS_I(old_dir)->i_logstart;
1009 dotdot_de->start = cpu_to_le16(start);
1010 dotdot_de->starthi = cpu_to_le16(start >> 16);
1011 mark_buffer_dirty_inode(dotdot_bh, old_inode);
1012 corrupt |= sync_dirty_buffer(dotdot_bh);
1014 error_inode:
1015 fat_detach(old_inode);
1016 fat_attach(old_inode, old_sinfo.i_pos);
1017 if (new_inode) {
1018 fat_attach(new_inode, new_i_pos);
1019 if (corrupt)
1020 corrupt |= fat_sync_inode(new_inode);
1021 } else {
1023 * If new entry was not sharing the data cluster, it
1024 * shouldn't be serious corruption.
1026 int err2 = fat_remove_entries(new_dir, &sinfo);
1027 if (corrupt)
1028 corrupt |= err2;
1029 sinfo.bh = NULL;
1031 if (corrupt < 0) {
1032 fat_fs_error(new_dir->i_sb,
1033 "%s: Filesystem corrupted (i_pos %lld)",
1034 __func__, sinfo.i_pos);
1036 goto out;
1039 static const struct inode_operations vfat_dir_inode_operations = {
1040 .create = vfat_create,
1041 .lookup = vfat_lookup,
1042 .unlink = vfat_unlink,
1043 .mkdir = vfat_mkdir,
1044 .rmdir = vfat_rmdir,
1045 .rename = vfat_rename,
1046 .setattr = fat_setattr,
1047 .getattr = fat_getattr,
1050 static int vfat_fill_super(struct super_block *sb, void *data, int silent)
1052 int res;
1054 res = fat_fill_super(sb, data, silent, &vfat_dir_inode_operations, 1);
1055 if (res)
1056 return res;
1058 if (MSDOS_SB(sb)->options.name_check != 's')
1059 sb->s_root->d_op = &vfat_ci_dentry_ops;
1060 else
1061 sb->s_root->d_op = &vfat_dentry_ops;
1063 return 0;
1066 static int vfat_get_sb(struct file_system_type *fs_type,
1067 int flags, const char *dev_name,
1068 void *data, struct vfsmount *mnt)
1070 return get_sb_bdev(fs_type, flags, dev_name, data, vfat_fill_super,
1071 mnt);
1074 static struct file_system_type vfat_fs_type = {
1075 .owner = THIS_MODULE,
1076 .name = "vfat",
1077 .get_sb = vfat_get_sb,
1078 .kill_sb = kill_block_super,
1079 .fs_flags = FS_REQUIRES_DEV,
1082 static int __init init_vfat_fs(void)
1084 return register_filesystem(&vfat_fs_type);
1087 static void __exit exit_vfat_fs(void)
1089 unregister_filesystem(&vfat_fs_type);
1092 MODULE_LICENSE("GPL");
1093 MODULE_DESCRIPTION("VFAT filesystem support");
1094 MODULE_AUTHOR("Gordon Chaffee");
1096 module_init(init_vfat_fs)
1097 module_exit(exit_vfat_fs)