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-rw-r--r--fs/fat/namei_vfat.c1055
1 files changed, 1055 insertions, 0 deletions
diff --git a/fs/fat/namei_vfat.c b/fs/fat/namei_vfat.c
new file mode 100644
index 000000000000..155c10b4adbd
--- /dev/null
+++ b/fs/fat/namei_vfat.c
@@ -0,0 +1,1055 @@
1/*
2 * linux/fs/vfat/namei.c
3 *
4 * Written 1992,1993 by Werner Almesberger
5 *
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.
11 *
12 * Short name translation 1999, 2001 by Wolfram Pienkoss <wp@bszh.de>
13 *
14 * Support Multibyte characters and cleanup by
15 * OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
16 */
17
18#include <linux/module.h>
19
20#include <linux/jiffies.h>
21#include <linux/msdos_fs.h>
22#include <linux/ctype.h>
23#include <linux/slab.h>
24#include <linux/smp_lock.h>
25#include <linux/buffer_head.h>
26#include <linux/namei.h>
27
28static int vfat_revalidate(struct dentry *dentry, struct nameidata *nd)
29{
30 int ret = 1;
31
32 if (!dentry->d_inode &&
33 nd && !(nd->flags & LOOKUP_CONTINUE) && (nd->flags & LOOKUP_CREATE))
34 /*
35 * negative dentry is dropped, in order to make sure
36 * to use the name which a user desires if this is
37 * create path.
38 */
39 ret = 0;
40 else {
41 spin_lock(&dentry->d_lock);
42 if (dentry->d_time != dentry->d_parent->d_inode->i_version)
43 ret = 0;
44 spin_unlock(&dentry->d_lock);
45 }
46 return ret;
47}
48
49/* returns the length of a struct qstr, ignoring trailing dots */
50static unsigned int vfat_striptail_len(struct qstr *qstr)
51{
52 unsigned int len = qstr->len;
53
54 while (len && qstr->name[len - 1] == '.')
55 len--;
56 return len;
57}
58
59/*
60 * Compute the hash for the vfat name corresponding to the dentry.
61 * Note: if the name is invalid, we leave the hash code unchanged so
62 * that the existing dentry can be used. The vfat fs routines will
63 * return ENOENT or EINVAL as appropriate.
64 */
65static int vfat_hash(struct dentry *dentry, struct qstr *qstr)
66{
67 qstr->hash = full_name_hash(qstr->name, vfat_striptail_len(qstr));
68 return 0;
69}
70
71/*
72 * Compute the hash for the vfat name corresponding to the dentry.
73 * Note: if the name is invalid, we leave the hash code unchanged so
74 * that the existing dentry can be used. The vfat fs routines will
75 * return ENOENT or EINVAL as appropriate.
76 */
77static int vfat_hashi(struct dentry *dentry, struct qstr *qstr)
78{
79 struct nls_table *t = MSDOS_SB(dentry->d_inode->i_sb)->nls_io;
80 const unsigned char *name;
81 unsigned int len;
82 unsigned long hash;
83
84 name = qstr->name;
85 len = vfat_striptail_len(qstr);
86
87 hash = init_name_hash();
88 while (len--)
89 hash = partial_name_hash(nls_tolower(t, *name++), hash);
90 qstr->hash = end_name_hash(hash);
91
92 return 0;
93}
94
95/*
96 * Case insensitive compare of two vfat names.
97 */
98static int vfat_cmpi(struct dentry *dentry, struct qstr *a, struct qstr *b)
99{
100 struct nls_table *t = MSDOS_SB(dentry->d_inode->i_sb)->nls_io;
101 unsigned int alen, blen;
102
103 /* A filename cannot end in '.' or we treat it like it has none */
104 alen = vfat_striptail_len(a);
105 blen = vfat_striptail_len(b);
106 if (alen == blen) {
107 if (nls_strnicmp(t, a->name, b->name, alen) == 0)
108 return 0;
109 }
110 return 1;
111}
112
113/*
114 * Case sensitive compare of two vfat names.
115 */
116static int vfat_cmp(struct dentry *dentry, struct qstr *a, struct qstr *b)
117{
118 unsigned int alen, blen;
119
120 /* A filename cannot end in '.' or we treat it like it has none */
121 alen = vfat_striptail_len(a);
122 blen = vfat_striptail_len(b);
123 if (alen == blen) {
124 if (strncmp(a->name, b->name, alen) == 0)
125 return 0;
126 }
127 return 1;
128}
129
130static struct dentry_operations vfat_dentry_ops[4] = {
131 {
132 .d_hash = vfat_hashi,
133 .d_compare = vfat_cmpi,
134 },
135 {
136 .d_revalidate = vfat_revalidate,
137 .d_hash = vfat_hashi,
138 .d_compare = vfat_cmpi,
139 },
140 {
141 .d_hash = vfat_hash,
142 .d_compare = vfat_cmp,
143 },
144 {
145 .d_revalidate = vfat_revalidate,
146 .d_hash = vfat_hash,
147 .d_compare = vfat_cmp,
148 }
149};
150
151/* Characters that are undesirable in an MS-DOS file name */
152
153static inline wchar_t vfat_bad_char(wchar_t w)
154{
155 return (w < 0x0020)
156 || (w == '*') || (w == '?') || (w == '<') || (w == '>')
157 || (w == '|') || (w == '"') || (w == ':') || (w == '/')
158 || (w == '\\');
159}
160
161static inline wchar_t vfat_replace_char(wchar_t w)
162{
163 return (w == '[') || (w == ']') || (w == ';') || (w == ',')
164 || (w == '+') || (w == '=');
165}
166
167static wchar_t vfat_skip_char(wchar_t w)
168{
169 return (w == '.') || (w == ' ');
170}
171
172static inline int vfat_is_used_badchars(const wchar_t *s, int len)
173{
174 int i;
175
176 for (i = 0; i < len; i++)
177 if (vfat_bad_char(s[i]))
178 return -EINVAL;
179
180 if (s[i - 1] == ' ') /* last character cannot be space */
181 return -EINVAL;
182
183 return 0;
184}
185
186static int vfat_find_form(struct inode *dir, unsigned char *name)
187{
188 struct fat_slot_info sinfo;
189 int err = fat_scan(dir, name, &sinfo);
190 if (err)
191 return -ENOENT;
192 brelse(sinfo.bh);
193 return 0;
194}
195
196/*
197 * 1) Valid characters for the 8.3 format alias are any combination of
198 * letters, uppercase alphabets, digits, any of the
199 * following special characters:
200 * $ % ' ` - @ { } ~ ! # ( ) & _ ^
201 * In this case Longfilename is not stored in disk.
202 *
203 * WinNT's Extension:
204 * File name and extension name is contain uppercase/lowercase
205 * only. And it is expressed by CASE_LOWER_BASE and CASE_LOWER_EXT.
206 *
207 * 2) File name is 8.3 format, but it contain the uppercase and
208 * lowercase char, muliti bytes char, etc. In this case numtail is not
209 * added, but Longfilename is stored.
210 *
211 * 3) When the one except for the above, or the following special
212 * character are contained:
213 * . [ ] ; , + =
214 * numtail is added, and Longfilename must be stored in disk .
215 */
216struct shortname_info {
217 unsigned char lower:1,
218 upper:1,
219 valid:1;
220};
221#define INIT_SHORTNAME_INFO(x) do { \
222 (x)->lower = 1; \
223 (x)->upper = 1; \
224 (x)->valid = 1; \
225} while (0)
226
227static inline int to_shortname_char(struct nls_table *nls,
228 unsigned char *buf, int buf_size,
229 wchar_t *src, struct shortname_info *info)
230{
231 int len;
232
233 if (vfat_skip_char(*src)) {
234 info->valid = 0;
235 return 0;
236 }
237 if (vfat_replace_char(*src)) {
238 info->valid = 0;
239 buf[0] = '_';
240 return 1;
241 }
242
243 len = nls->uni2char(*src, buf, buf_size);
244 if (len <= 0) {
245 info->valid = 0;
246 buf[0] = '_';
247 len = 1;
248 } else if (len == 1) {
249 unsigned char prev = buf[0];
250
251 if (buf[0] >= 0x7F) {
252 info->lower = 0;
253 info->upper = 0;
254 }
255
256 buf[0] = nls_toupper(nls, buf[0]);
257 if (isalpha(buf[0])) {
258 if (buf[0] == prev)
259 info->lower = 0;
260 else
261 info->upper = 0;
262 }
263 } else {
264 info->lower = 0;
265 info->upper = 0;
266 }
267
268 return len;
269}
270
271/*
272 * Given a valid longname, create a unique shortname. Make sure the
273 * shortname does not exist
274 * Returns negative number on error, 0 for a normal
275 * return, and 1 for valid shortname
276 */
277static int vfat_create_shortname(struct inode *dir, struct nls_table *nls,
278 wchar_t *uname, int ulen,
279 unsigned char *name_res, unsigned char *lcase)
280{
281 struct fat_mount_options *opts = &MSDOS_SB(dir->i_sb)->options;
282 wchar_t *ip, *ext_start, *end, *name_start;
283 unsigned char base[9], ext[4], buf[8], *p;
284 unsigned char charbuf[NLS_MAX_CHARSET_SIZE];
285 int chl, chi;
286 int sz = 0, extlen, baselen, i, numtail_baselen, numtail2_baselen;
287 int is_shortname;
288 struct shortname_info base_info, ext_info;
289
290 is_shortname = 1;
291 INIT_SHORTNAME_INFO(&base_info);
292 INIT_SHORTNAME_INFO(&ext_info);
293
294 /* Now, we need to create a shortname from the long name */
295 ext_start = end = &uname[ulen];
296 while (--ext_start >= uname) {
297 if (*ext_start == 0x002E) { /* is `.' */
298 if (ext_start == end - 1) {
299 sz = ulen;
300 ext_start = NULL;
301 }
302 break;
303 }
304 }
305
306 if (ext_start == uname - 1) {
307 sz = ulen;
308 ext_start = NULL;
309 } else if (ext_start) {
310 /*
311 * Names which start with a dot could be just
312 * an extension eg. "...test". In this case Win95
313 * uses the extension as the name and sets no extension.
314 */
315 name_start = &uname[0];
316 while (name_start < ext_start) {
317 if (!vfat_skip_char(*name_start))
318 break;
319 name_start++;
320 }
321 if (name_start != ext_start) {
322 sz = ext_start - uname;
323 ext_start++;
324 } else {
325 sz = ulen;
326 ext_start = NULL;
327 }
328 }
329
330 numtail_baselen = 6;
331 numtail2_baselen = 2;
332 for (baselen = i = 0, p = base, ip = uname; i < sz; i++, ip++) {
333 chl = to_shortname_char(nls, charbuf, sizeof(charbuf),
334 ip, &base_info);
335 if (chl == 0)
336 continue;
337
338 if (baselen < 2 && (baselen + chl) > 2)
339 numtail2_baselen = baselen;
340 if (baselen < 6 && (baselen + chl) > 6)
341 numtail_baselen = baselen;
342 for (chi = 0; chi < chl; chi++) {
343 *p++ = charbuf[chi];
344 baselen++;
345 if (baselen >= 8)
346 break;
347 }
348 if (baselen >= 8) {
349 if ((chi < chl - 1) || (ip + 1) - uname < sz)
350 is_shortname = 0;
351 break;
352 }
353 }
354 if (baselen == 0) {
355 return -EINVAL;
356 }
357
358 extlen = 0;
359 if (ext_start) {
360 for (p = ext, ip = ext_start; extlen < 3 && ip < end; ip++) {
361 chl = to_shortname_char(nls, charbuf, sizeof(charbuf),
362 ip, &ext_info);
363 if (chl == 0)
364 continue;
365
366 if ((extlen + chl) > 3) {
367 is_shortname = 0;
368 break;
369 }
370 for (chi = 0; chi < chl; chi++) {
371 *p++ = charbuf[chi];
372 extlen++;
373 }
374 if (extlen >= 3) {
375 if (ip + 1 != end)
376 is_shortname = 0;
377 break;
378 }
379 }
380 }
381 ext[extlen] = '\0';
382 base[baselen] = '\0';
383
384 /* Yes, it can happen. ".\xe5" would do it. */
385 if (base[0] == DELETED_FLAG)
386 base[0] = 0x05;
387
388 /* OK, at this point we know that base is not longer than 8 symbols,
389 * ext is not longer than 3, base is nonempty, both don't contain
390 * any bad symbols (lowercase transformed to uppercase).
391 */
392
393 memset(name_res, ' ', MSDOS_NAME);
394 memcpy(name_res, base, baselen);
395 memcpy(name_res + 8, ext, extlen);
396 *lcase = 0;
397 if (is_shortname && base_info.valid && ext_info.valid) {
398 if (vfat_find_form(dir, name_res) == 0)
399 return -EEXIST;
400
401 if (opts->shortname & VFAT_SFN_CREATE_WIN95) {
402 return (base_info.upper && ext_info.upper);
403 } else if (opts->shortname & VFAT_SFN_CREATE_WINNT) {
404 if ((base_info.upper || base_info.lower) &&
405 (ext_info.upper || ext_info.lower)) {
406 if (!base_info.upper && base_info.lower)
407 *lcase |= CASE_LOWER_BASE;
408 if (!ext_info.upper && ext_info.lower)
409 *lcase |= CASE_LOWER_EXT;
410 return 1;
411 }
412 return 0;
413 } else {
414 BUG();
415 }
416 }
417
418 if (opts->numtail == 0)
419 if (vfat_find_form(dir, name_res) < 0)
420 return 0;
421
422 /*
423 * Try to find a unique extension. This used to
424 * iterate through all possibilities sequentially,
425 * but that gave extremely bad performance. Windows
426 * only tries a few cases before using random
427 * values for part of the base.
428 */
429
430 if (baselen > 6) {
431 baselen = numtail_baselen;
432 name_res[7] = ' ';
433 }
434 name_res[baselen] = '~';
435 for (i = 1; i < 10; i++) {
436 name_res[baselen + 1] = i + '0';
437 if (vfat_find_form(dir, name_res) < 0)
438 return 0;
439 }
440
441 i = jiffies & 0xffff;
442 sz = (jiffies >> 16) & 0x7;
443 if (baselen > 2) {
444 baselen = numtail2_baselen;
445 name_res[7] = ' ';
446 }
447 name_res[baselen + 4] = '~';
448 name_res[baselen + 5] = '1' + sz;
449 while (1) {
450 sprintf(buf, "%04X", i);
451 memcpy(&name_res[baselen], buf, 4);
452 if (vfat_find_form(dir, name_res) < 0)
453 break;
454 i -= 11;
455 }
456 return 0;
457}
458
459/* Translate a string, including coded sequences into Unicode */
460static int
461xlate_to_uni(const unsigned char *name, int len, unsigned char *outname,
462 int *longlen, int *outlen, int escape, int utf8,
463 struct nls_table *nls)
464{
465 const unsigned char *ip;
466 unsigned char nc;
467 unsigned char *op;
468 unsigned int ec;
469 int i, k, fill;
470 int charlen;
471
472 if (utf8) {
473 int name_len = strlen(name);
474
475 *outlen = utf8_mbstowcs((wchar_t *)outname, name, PATH_MAX);
476
477 /*
478 * We stripped '.'s before and set len appropriately,
479 * but utf8_mbstowcs doesn't care about len
480 */
481 *outlen -= (name_len - len);
482
483 if (*outlen > 255)
484 return -ENAMETOOLONG;
485
486 op = &outname[*outlen * sizeof(wchar_t)];
487 } else {
488 if (nls) {
489 for (i = 0, ip = name, op = outname, *outlen = 0;
490 i < len && *outlen <= 255;
491 *outlen += 1)
492 {
493 if (escape && (*ip == ':')) {
494 if (i > len - 5)
495 return -EINVAL;
496 ec = 0;
497 for (k = 1; k < 5; k++) {
498 nc = ip[k];
499 ec <<= 4;
500 if (nc >= '0' && nc <= '9') {
501 ec |= nc - '0';
502 continue;
503 }
504 if (nc >= 'a' && nc <= 'f') {
505 ec |= nc - ('a' - 10);
506 continue;
507 }
508 if (nc >= 'A' && nc <= 'F') {
509 ec |= nc - ('A' - 10);
510 continue;
511 }
512 return -EINVAL;
513 }
514 *op++ = ec & 0xFF;
515 *op++ = ec >> 8;
516 ip += 5;
517 i += 5;
518 } else {
519 if ((charlen = nls->char2uni(ip, len - i, (wchar_t *)op)) < 0)
520 return -EINVAL;
521 ip += charlen;
522 i += charlen;
523 op += 2;
524 }
525 }
526 if (i < len)
527 return -ENAMETOOLONG;
528 } else {
529 for (i = 0, ip = name, op = outname, *outlen = 0;
530 i < len && *outlen <= 255;
531 i++, *outlen += 1)
532 {
533 *op++ = *ip++;
534 *op++ = 0;
535 }
536 if (i < len)
537 return -ENAMETOOLONG;
538 }
539 }
540
541 *longlen = *outlen;
542 if (*outlen % 13) {
543 *op++ = 0;
544 *op++ = 0;
545 *outlen += 1;
546 if (*outlen % 13) {
547 fill = 13 - (*outlen % 13);
548 for (i = 0; i < fill; i++) {
549 *op++ = 0xff;
550 *op++ = 0xff;
551 }
552 *outlen += fill;
553 }
554 }
555
556 return 0;
557}
558
559static int vfat_build_slots(struct inode *dir, const unsigned char *name,
560 int len, int is_dir, int cluster,
561 struct timespec *ts,
562 struct msdos_dir_slot *slots, int *nr_slots)
563{
564 struct msdos_sb_info *sbi = MSDOS_SB(dir->i_sb);
565 struct fat_mount_options *opts = &sbi->options;
566 struct msdos_dir_slot *ps;
567 struct msdos_dir_entry *de;
568 unsigned char cksum, lcase;
569 unsigned char msdos_name[MSDOS_NAME];
570 wchar_t *uname;
571 __le16 time, date;
572 int err, ulen, usize, i;
573 loff_t offset;
574
575 *nr_slots = 0;
576
577 uname = __getname();
578 if (!uname)
579 return -ENOMEM;
580
581 err = xlate_to_uni(name, len, (unsigned char *)uname, &ulen, &usize,
582 opts->unicode_xlate, opts->utf8, sbi->nls_io);
583 if (err)
584 goto out_free;
585
586 err = vfat_is_used_badchars(uname, ulen);
587 if (err)
588 goto out_free;
589
590 err = vfat_create_shortname(dir, sbi->nls_disk, uname, ulen,
591 msdos_name, &lcase);
592 if (err < 0)
593 goto out_free;
594 else if (err == 1) {
595 de = (struct msdos_dir_entry *)slots;
596 err = 0;
597 goto shortname;
598 }
599
600 /* build the entry of long file name */
601 cksum = fat_checksum(msdos_name);
602
603 *nr_slots = usize / 13;
604 for (ps = slots, i = *nr_slots; i > 0; i--, ps++) {
605 ps->id = i;
606 ps->attr = ATTR_EXT;
607 ps->reserved = 0;
608 ps->alias_checksum = cksum;
609 ps->start = 0;
610 offset = (i - 1) * 13;
611 fatwchar_to16(ps->name0_4, uname + offset, 5);
612 fatwchar_to16(ps->name5_10, uname + offset + 5, 6);
613 fatwchar_to16(ps->name11_12, uname + offset + 11, 2);
614 }
615 slots[0].id |= 0x40;
616 de = (struct msdos_dir_entry *)ps;
617
618shortname:
619 /* build the entry of 8.3 alias name */
620 (*nr_slots)++;
621 memcpy(de->name, msdos_name, MSDOS_NAME);
622 de->attr = is_dir ? ATTR_DIR : ATTR_ARCH;
623 de->lcase = lcase;
624 fat_date_unix2dos(ts->tv_sec, &time, &date, sbi->options.tz_utc);
625 de->time = de->ctime = time;
626 de->date = de->cdate = de->adate = date;
627 de->ctime_cs = 0;
628 de->start = cpu_to_le16(cluster);
629 de->starthi = cpu_to_le16(cluster >> 16);
630 de->size = 0;
631out_free:
632 __putname(uname);
633 return err;
634}
635
636static int vfat_add_entry(struct inode *dir, struct qstr *qname, int is_dir,
637 int cluster, struct timespec *ts,
638 struct fat_slot_info *sinfo)
639{
640 struct msdos_dir_slot *slots;
641 unsigned int len;
642 int err, nr_slots;
643
644 len = vfat_striptail_len(qname);
645 if (len == 0)
646 return -ENOENT;
647
648 slots = kmalloc(sizeof(*slots) * MSDOS_SLOTS, GFP_NOFS);
649 if (slots == NULL)
650 return -ENOMEM;
651
652 err = vfat_build_slots(dir, qname->name, len, is_dir, cluster, ts,
653 slots, &nr_slots);
654 if (err)
655 goto cleanup;
656
657 err = fat_add_entries(dir, slots, nr_slots, sinfo);
658 if (err)
659 goto cleanup;
660
661 /* update timestamp */
662 dir->i_ctime = dir->i_mtime = dir->i_atime = *ts;
663 if (IS_DIRSYNC(dir))
664 (void)fat_sync_inode(dir);
665 else
666 mark_inode_dirty(dir);
667cleanup:
668 kfree(slots);
669 return err;
670}
671
672static int vfat_find(struct inode *dir, struct qstr *qname,
673 struct fat_slot_info *sinfo)
674{
675 unsigned int len = vfat_striptail_len(qname);
676 if (len == 0)
677 return -ENOENT;
678 return fat_search_long(dir, qname->name, len, sinfo);
679}
680
681static struct dentry *vfat_lookup(struct inode *dir, struct dentry *dentry,
682 struct nameidata *nd)
683{
684 struct super_block *sb = dir->i_sb;
685 struct fat_slot_info sinfo;
686 struct inode *inode = NULL;
687 struct dentry *alias;
688 int err, table;
689
690 lock_super(sb);
691 table = (MSDOS_SB(sb)->options.name_check == 's') ? 2 : 0;
692 dentry->d_op = &vfat_dentry_ops[table];
693
694 err = vfat_find(dir, &dentry->d_name, &sinfo);
695 if (err) {
696 table++;
697 goto error;
698 }
699 inode = fat_build_inode(sb, sinfo.de, sinfo.i_pos);
700 brelse(sinfo.bh);
701 if (IS_ERR(inode)) {
702 unlock_super(sb);
703 return ERR_CAST(inode);
704 }
705 alias = d_find_alias(inode);
706 if (alias) {
707 if (d_invalidate(alias) == 0)
708 dput(alias);
709 else {
710 iput(inode);
711 unlock_super(sb);
712 return alias;
713 }
714
715 }
716error:
717 unlock_super(sb);
718 dentry->d_op = &vfat_dentry_ops[table];
719 dentry->d_time = dentry->d_parent->d_inode->i_version;
720 dentry = d_splice_alias(inode, dentry);
721 if (dentry) {
722 dentry->d_op = &vfat_dentry_ops[table];
723 dentry->d_time = dentry->d_parent->d_inode->i_version;
724 }
725 return dentry;
726}
727
728static int vfat_create(struct inode *dir, struct dentry *dentry, int mode,
729 struct nameidata *nd)
730{
731 struct super_block *sb = dir->i_sb;
732 struct inode *inode;
733 struct fat_slot_info sinfo;
734 struct timespec ts;
735 int err;
736
737 lock_super(sb);
738
739 ts = CURRENT_TIME_SEC;
740 err = vfat_add_entry(dir, &dentry->d_name, 0, 0, &ts, &sinfo);
741 if (err)
742 goto out;
743 dir->i_version++;
744
745 inode = fat_build_inode(sb, sinfo.de, sinfo.i_pos);
746 brelse(sinfo.bh);
747 if (IS_ERR(inode)) {
748 err = PTR_ERR(inode);
749 goto out;
750 }
751 inode->i_version++;
752 inode->i_mtime = inode->i_atime = inode->i_ctime = ts;
753 /* timestamp is already written, so mark_inode_dirty() is unneeded. */
754
755 dentry->d_time = dentry->d_parent->d_inode->i_version;
756 d_instantiate(dentry, inode);
757out:
758 unlock_super(sb);
759 return err;
760}
761
762static int vfat_rmdir(struct inode *dir, struct dentry *dentry)
763{
764 struct inode *inode = dentry->d_inode;
765 struct super_block *sb = dir->i_sb;
766 struct fat_slot_info sinfo;
767 int err;
768
769 lock_super(sb);
770
771 err = fat_dir_empty(inode);
772 if (err)
773 goto out;
774 err = vfat_find(dir, &dentry->d_name, &sinfo);
775 if (err)
776 goto out;
777
778 err = fat_remove_entries(dir, &sinfo); /* and releases bh */
779 if (err)
780 goto out;
781 drop_nlink(dir);
782
783 clear_nlink(inode);
784 inode->i_mtime = inode->i_atime = CURRENT_TIME_SEC;
785 fat_detach(inode);
786out:
787 unlock_super(sb);
788
789 return err;
790}
791
792static int vfat_unlink(struct inode *dir, struct dentry *dentry)
793{
794 struct inode *inode = dentry->d_inode;
795 struct super_block *sb = dir->i_sb;
796 struct fat_slot_info sinfo;
797 int err;
798
799 lock_super(sb);
800
801 err = vfat_find(dir, &dentry->d_name, &sinfo);
802 if (err)
803 goto out;
804
805 err = fat_remove_entries(dir, &sinfo); /* and releases bh */
806 if (err)
807 goto out;
808 clear_nlink(inode);
809 inode->i_mtime = inode->i_atime = CURRENT_TIME_SEC;
810 fat_detach(inode);
811out:
812 unlock_super(sb);
813
814 return err;
815}
816
817static int vfat_mkdir(struct inode *dir, struct dentry *dentry, int mode)
818{
819 struct super_block *sb = dir->i_sb;
820 struct inode *inode;
821 struct fat_slot_info sinfo;
822 struct timespec ts;
823 int err, cluster;
824
825 lock_super(sb);
826
827 ts = CURRENT_TIME_SEC;
828 cluster = fat_alloc_new_dir(dir, &ts);
829 if (cluster < 0) {
830 err = cluster;
831 goto out;
832 }
833 err = vfat_add_entry(dir, &dentry->d_name, 1, cluster, &ts, &sinfo);
834 if (err)
835 goto out_free;
836 dir->i_version++;
837 inc_nlink(dir);
838
839 inode = fat_build_inode(sb, sinfo.de, sinfo.i_pos);
840 brelse(sinfo.bh);
841 if (IS_ERR(inode)) {
842 err = PTR_ERR(inode);
843 /* the directory was completed, just return a error */
844 goto out;
845 }
846 inode->i_version++;
847 inode->i_nlink = 2;
848 inode->i_mtime = inode->i_atime = inode->i_ctime = ts;
849 /* timestamp is already written, so mark_inode_dirty() is unneeded. */
850
851 dentry->d_time = dentry->d_parent->d_inode->i_version;
852 d_instantiate(dentry, inode);
853
854 unlock_super(sb);
855 return 0;
856
857out_free:
858 fat_free_clusters(dir, cluster);
859out:
860 unlock_super(sb);
861 return err;
862}
863
864static int vfat_rename(struct inode *old_dir, struct dentry *old_dentry,
865 struct inode *new_dir, struct dentry *new_dentry)
866{
867 struct buffer_head *dotdot_bh;
868 struct msdos_dir_entry *dotdot_de;
869 struct inode *old_inode, *new_inode;
870 struct fat_slot_info old_sinfo, sinfo;
871 struct timespec ts;
872 loff_t dotdot_i_pos, new_i_pos;
873 int err, is_dir, update_dotdot, corrupt = 0;
874 struct super_block *sb = old_dir->i_sb;
875
876 old_sinfo.bh = sinfo.bh = dotdot_bh = NULL;
877 old_inode = old_dentry->d_inode;
878 new_inode = new_dentry->d_inode;
879 lock_super(sb);
880 err = vfat_find(old_dir, &old_dentry->d_name, &old_sinfo);
881 if (err)
882 goto out;
883
884 is_dir = S_ISDIR(old_inode->i_mode);
885 update_dotdot = (is_dir && old_dir != new_dir);
886 if (update_dotdot) {
887 if (fat_get_dotdot_entry(old_inode, &dotdot_bh, &dotdot_de,
888 &dotdot_i_pos) < 0) {
889 err = -EIO;
890 goto out;
891 }
892 }
893
894 ts = CURRENT_TIME_SEC;
895 if (new_inode) {
896 if (is_dir) {
897 err = fat_dir_empty(new_inode);
898 if (err)
899 goto out;
900 }
901 new_i_pos = MSDOS_I(new_inode)->i_pos;
902 fat_detach(new_inode);
903 } else {
904 err = vfat_add_entry(new_dir, &new_dentry->d_name, is_dir, 0,
905 &ts, &sinfo);
906 if (err)
907 goto out;
908 new_i_pos = sinfo.i_pos;
909 }
910 new_dir->i_version++;
911
912 fat_detach(old_inode);
913 fat_attach(old_inode, new_i_pos);
914 if (IS_DIRSYNC(new_dir)) {
915 err = fat_sync_inode(old_inode);
916 if (err)
917 goto error_inode;
918 } else
919 mark_inode_dirty(old_inode);
920
921 if (update_dotdot) {
922 int start = MSDOS_I(new_dir)->i_logstart;
923 dotdot_de->start = cpu_to_le16(start);
924 dotdot_de->starthi = cpu_to_le16(start >> 16);
925 mark_buffer_dirty(dotdot_bh);
926 if (IS_DIRSYNC(new_dir)) {
927 err = sync_dirty_buffer(dotdot_bh);
928 if (err)
929 goto error_dotdot;
930 }
931 drop_nlink(old_dir);
932 if (!new_inode)
933 inc_nlink(new_dir);
934 }
935
936 err = fat_remove_entries(old_dir, &old_sinfo); /* and releases bh */
937 old_sinfo.bh = NULL;
938 if (err)
939 goto error_dotdot;
940 old_dir->i_version++;
941 old_dir->i_ctime = old_dir->i_mtime = ts;
942 if (IS_DIRSYNC(old_dir))
943 (void)fat_sync_inode(old_dir);
944 else
945 mark_inode_dirty(old_dir);
946
947 if (new_inode) {
948 drop_nlink(new_inode);
949 if (is_dir)
950 drop_nlink(new_inode);
951 new_inode->i_ctime = ts;
952 }
953out:
954 brelse(sinfo.bh);
955 brelse(dotdot_bh);
956 brelse(old_sinfo.bh);
957 unlock_super(sb);
958
959 return err;
960
961error_dotdot:
962 /* data cluster is shared, serious corruption */
963 corrupt = 1;
964
965 if (update_dotdot) {
966 int start = MSDOS_I(old_dir)->i_logstart;
967 dotdot_de->start = cpu_to_le16(start);
968 dotdot_de->starthi = cpu_to_le16(start >> 16);
969 mark_buffer_dirty(dotdot_bh);
970 corrupt |= sync_dirty_buffer(dotdot_bh);
971 }
972error_inode:
973 fat_detach(old_inode);
974 fat_attach(old_inode, old_sinfo.i_pos);
975 if (new_inode) {
976 fat_attach(new_inode, new_i_pos);
977 if (corrupt)
978 corrupt |= fat_sync_inode(new_inode);
979 } else {
980 /*
981 * If new entry was not sharing the data cluster, it
982 * shouldn't be serious corruption.
983 */
984 int err2 = fat_remove_entries(new_dir, &sinfo);
985 if (corrupt)
986 corrupt |= err2;
987 sinfo.bh = NULL;
988 }
989 if (corrupt < 0) {
990 fat_fs_panic(new_dir->i_sb,
991 "%s: Filesystem corrupted (i_pos %lld)",
992 __func__, sinfo.i_pos);
993 }
994 goto out;
995}
996
997static const struct inode_operations vfat_dir_inode_operations = {
998 .create = vfat_create,
999 .lookup = vfat_lookup,
1000 .unlink = vfat_unlink,
1001 .mkdir = vfat_mkdir,
1002 .rmdir = vfat_rmdir,
1003 .rename = vfat_rename,
1004 .setattr = fat_setattr,
1005 .getattr = fat_getattr,
1006};
1007
1008static int vfat_fill_super(struct super_block *sb, void *data, int silent)
1009{
1010 int res;
1011
1012 res = fat_fill_super(sb, data, silent, &vfat_dir_inode_operations, 1);
1013 if (res)
1014 return res;
1015
1016 if (MSDOS_SB(sb)->options.name_check != 's')
1017 sb->s_root->d_op = &vfat_dentry_ops[0];
1018 else
1019 sb->s_root->d_op = &vfat_dentry_ops[2];
1020
1021 return 0;
1022}
1023
1024static int vfat_get_sb(struct file_system_type *fs_type,
1025 int flags, const char *dev_name,
1026 void *data, struct vfsmount *mnt)
1027{
1028 return get_sb_bdev(fs_type, flags, dev_name, data, vfat_fill_super,
1029 mnt);
1030}
1031
1032static struct file_system_type vfat_fs_type = {
1033 .owner = THIS_MODULE,
1034 .name = "vfat",
1035 .get_sb = vfat_get_sb,
1036 .kill_sb = kill_block_super,
1037 .fs_flags = FS_REQUIRES_DEV,
1038};
1039
1040static int __init init_vfat_fs(void)
1041{
1042 return register_filesystem(&vfat_fs_type);
1043}
1044
1045static void __exit exit_vfat_fs(void)
1046{
1047 unregister_filesystem(&vfat_fs_type);
1048}
1049
1050MODULE_LICENSE("GPL");
1051MODULE_DESCRIPTION("VFAT filesystem support");
1052MODULE_AUTHOR("Gordon Chaffee");
1053
1054module_init(init_vfat_fs)
1055module_exit(exit_vfat_fs)
generated by cgit v1.2.2 (git 2.25.0) at 2024-11-19 02:10:25 -0500