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MOXA linux-2.6.x / linux-2.6.9-uc0 from sdlinux-moxaart.tgz
[linux-2.6.9-moxart.git] / fs / fat / prince-fat / fat / dir.c
blob993d50c0db39c65e690b3d6eee4cade9f49a1c91
1 /*
2 * linux/fs/fat/dir.c
3 *
4 * directory handling functions for fat-based filesystems
5 *
6 * Written 1992,1993 by Werner Almesberger
7 *
8 * Hidden files 1995 by Albert Cahalan <albert@ccs.neu.edu> <adc@coe.neu.edu>
9 *
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>
14 */
15
16 #include <linux/slab.h>
17 #include <linux/time.h>
18 #include <linux/msdos_fs.h>
19 #include <linux/dirent.h>
20 #include <linux/smp_lock.h>
21 #include <linux/buffer_head.h>
22
23 #include <asm/uaccess.h>
24
25 struct file_operations fat_dir_operations = {
26 .read = generic_read_dir,
27 .readdir = fat_readdir,
28 .ioctl = fat_dir_ioctl,
29 .fsync = file_fsync,
30 };
31
32 /*
33 * Convert Unicode 16 to UTF8, translated Unicode, or ASCII.
34 * If uni_xlate is enabled and we can't get a 1:1 conversion, use a
35 * colon as an escape character since it is normally invalid on the vfat
36 * filesystem. The following four characters are the hexadecimal digits
37 * of Unicode value. This lets us do a full dump and restore of Unicode
38 * filenames. We could get into some trouble with long Unicode names,
39 * but ignore that right now.
40 * Ahem... Stack smashing in ring 0 isn't fun. Fixed.
41 */
42 static int
43 uni16_to_x8(unsigned char *ascii, wchar_t *uni, int uni_xlate,
44 struct nls_table *nls)
45 {
46 wchar_t *ip, ec;
47 unsigned char *op, nc;
48 int charlen;
49 int k;
50
51 ip = uni;
52 op = ascii;
53
54 while (*ip) {
55 ec = *ip++;
56 if ( (charlen = nls->uni2char(ec, op, NLS_MAX_CHARSET_SIZE)) > 0) {
57 op += charlen;
58 } else {
59 if (uni_xlate == 1) {
60 *op = ':';
61 for (k = 4; k > 0; k--) {
62 nc = ec & 0xF;
63 op[k] = nc > 9 ? nc + ('a' - 10)
64 : nc + '0';
65 ec >>= 4;
66 }
67 op += 5;
68 } else {
69 *op++ = '?';
70 }
71 }
72 /* We have some slack there, so it's OK */
73 if (op>ascii+256) {
74 op = ascii + 256;
75 break;
76 }
77 }
78 *op = 0;
79 return (op - ascii);
80 }
81
82 #if 0
83 static void dump_de(struct msdos_dir_entry *de)
84 {
85 int i;
86 unsigned char *p = (unsigned char *) de;
87 printk("[");
88
89 for (i = 0; i < 32; i++, p++) {
90 printk("%02x ", *p);
91 }
92 printk("]\n");
93 }
94 #endif
95
96 static inline int
97 fat_short2uni(struct nls_table *t, unsigned char *c, int clen, wchar_t *uni)
98 {
99 int charlen;
100
101 charlen = t->char2uni(c, clen, uni);
102 if (charlen < 0) {
103 *uni = 0x003f; /* a question mark */
104 charlen = 1;
105 }
106 return charlen;
107 }
108
109 static inline int
110 fat_short2lower_uni(struct nls_table *t, unsigned char *c, int clen, wchar_t *uni)
111 {
112 int charlen;
113 wchar_t wc;
114
115 charlen = t->char2uni(c, clen, &wc);
116 if (charlen < 0) {
117 *uni = 0x003f; /* a question mark */
118 charlen = 1;
119 } else if (charlen <= 1) {
120 unsigned char nc = t->charset2lower[*c];
121
122 if (!nc)
123 nc = *c;
124
125 if ( (charlen = t->char2uni(&nc, 1, uni)) < 0) {
126 *uni = 0x003f; /* a question mark */
127 charlen = 1;
128 }
129 } else
130 *uni = wc;
131
132 return charlen;
133 }
134
135 static inline int
136 fat_shortname2uni(struct nls_table *nls, unsigned char *buf, int buf_size,
137 wchar_t *uni_buf, unsigned short opt, int lower)
138 {
139 int len = 0;
140
141 if (opt & VFAT_SFN_DISPLAY_LOWER)
142 len = fat_short2lower_uni(nls, buf, buf_size, uni_buf);
143 else if (opt & VFAT_SFN_DISPLAY_WIN95)
144 len = fat_short2uni(nls, buf, buf_size, uni_buf);
145 else if (opt & VFAT_SFN_DISPLAY_WINNT) {
146 if (lower)
147 len = fat_short2lower_uni(nls, buf, buf_size, uni_buf);
148 else
149 len = fat_short2uni(nls, buf, buf_size, uni_buf);
150 } else
151 len = fat_short2uni(nls, buf, buf_size, uni_buf);
152
153 return len;
154 }
155
156 /*
157 * Return values: negative -> error, 0 -> not found, positive -> found,
158 * value is the total amount of slots, including the shortname entry.
159 */
160 int fat_search_long(struct inode *inode, const unsigned char *name,
161 int name_len, int anycase, loff_t *spos, loff_t *lpos)
162 {
163 struct super_block *sb = inode->i_sb;
164 struct buffer_head *bh = NULL;
165 struct msdos_dir_entry *de;
166 struct nls_table *nls_io = MSDOS_SB(sb)->nls_io;
167 struct nls_table *nls_disk = MSDOS_SB(sb)->nls_disk;
168 wchar_t bufuname[14];
169 unsigned char xlate_len, long_slots;
170 wchar_t *unicode = NULL;
171 unsigned char work[8], bufname[260]; /* 256 + 4 */
172 int uni_xlate = MSDOS_SB(sb)->options.unicode_xlate;
173 int utf8 = MSDOS_SB(sb)->options.utf8;
174 unsigned short opt_shortname = MSDOS_SB(sb)->options.shortname;
175 int chl, i, j, last_u, res = 0;
176 loff_t i_pos, cpos = 0;
177
178 while(1) {
179 if (fat_get_entry(inode,&cpos,&bh,&de,&i_pos) == -1)
180 goto EODir;
181 parse_record:
182 long_slots = 0;
183 if (de->name[0] == DELETED_FLAG)
184 continue;
185 if (de->attr != ATTR_EXT && (de->attr & ATTR_VOLUME))
186 continue;
187 if (de->attr != ATTR_EXT && IS_FREE(de->name))
188 continue;
189 if (de->attr == ATTR_EXT) {
190 struct msdos_dir_slot *ds;
191 unsigned char id;
192 unsigned char slot;
193 unsigned char slots;
194 unsigned char sum;
195 unsigned char alias_checksum;
196
197 if (!unicode) {
198 unicode = (wchar_t *)
199 __get_free_page(GFP_KERNEL);
200 if (!unicode) {
201 brelse(bh);
202 return -ENOMEM;
203 }
204 }
205 parse_long:
206 slots = 0;
207 ds = (struct msdos_dir_slot *) de;
208 id = ds->id;
209 if (!(id & 0x40))
210 continue;
211 slots = id & ~0x40;
212 if (slots > 20 || !slots) /* ceil(256 * 2 / 26) */
213 continue;
214 long_slots = slots;
215 alias_checksum = ds->alias_checksum;
216
217 slot = slots;
218 while (1) {
219 int offset;
220
221 slot--;
222 offset = slot * 13;
223 fat16_towchar(unicode + offset, ds->name0_4, 5);
224 fat16_towchar(unicode + offset + 5, ds->name5_10, 6);
225 fat16_towchar(unicode + offset + 11, ds->name11_12, 2);
226
227 if (ds->id & 0x40) {
228 unicode[offset + 13] = 0;
229 }
230 if (fat_get_entry(inode,&cpos,&bh,&de,&i_pos)<0)
231 goto EODir;
232 if (slot == 0)
233 break;
234 ds = (struct msdos_dir_slot *) de;
235 if (ds->attr != ATTR_EXT)
236 goto parse_record;
237 if ((ds->id & ~0x40) != slot)
238 goto parse_long;
239 if (ds->alias_checksum != alias_checksum)
240 goto parse_long;
241 }
242 if (de->name[0] == DELETED_FLAG)
243 continue;
244 if (de->attr == ATTR_EXT)
245 goto parse_long;
246 if (IS_FREE(de->name) || (de->attr & ATTR_VOLUME))
247 continue;
248 for (sum = 0, i = 0; i < 11; i++)
249 sum = (((sum&1)<<7)|((sum&0xfe)>>1)) + de->name[i];
250 if (sum != alias_checksum)
251 long_slots = 0;
252 }
253
254 memcpy(work, de->name, sizeof(de->name));
255 /* see namei.c, msdos_format_name */
256 if (work[0] == 0x05)
257 work[0] = 0xE5;
258 for (i = 0, j = 0, last_u = 0; i < 8;) {
259 if (!work[i]) break;
260 chl = fat_shortname2uni(nls_disk, &work[i], 8 - i,
261 &bufuname[j++], opt_shortname,
262 de->lcase & CASE_LOWER_BASE);
263 if (chl <= 1) {
264 if (work[i] != ' ')
265 last_u = j;
266 } else {
267 last_u = j;
268 }
269 i += chl;
270 }
271 j = last_u;
272 fat_short2uni(nls_disk, ".", 1, &bufuname[j++]);
273 for (i = 0; i < 3;) {
274 if (!de->ext[i]) break;
275 chl = fat_shortname2uni(nls_disk, &de->ext[i], 3 - i,
276 &bufuname[j++], opt_shortname,
277 de->lcase & CASE_LOWER_EXT);
278 if (chl <= 1) {
279 if (de->ext[i] != ' ')
280 last_u = j;
281 } else {
282 last_u = j;
283 }
284 i += chl;
285 }
286 if (!last_u)
287 continue;
288
289 bufuname[last_u] = 0x0000;
290 xlate_len = utf8
291 ?utf8_wcstombs(bufname, bufuname, sizeof(bufname))
292 :uni16_to_x8(bufname, bufuname, uni_xlate, nls_io);
293 if (xlate_len == name_len)
294 if ((!anycase && !memcmp(name, bufname, xlate_len)) ||
295 (anycase && !nls_strnicmp(nls_io, name, bufname,
296 xlate_len)))
297 goto Found;
298
299 if (long_slots) {
300 xlate_len = utf8
301 ?utf8_wcstombs(bufname, unicode, sizeof(bufname))
302 :uni16_to_x8(bufname, unicode, uni_xlate, nls_io);
303 if (xlate_len != name_len)
304 continue;
305 if ((!anycase && !memcmp(name, bufname, xlate_len)) ||
306 (anycase && !nls_strnicmp(nls_io, name, bufname,
307 xlate_len)))
308 goto Found;
309 }
310 }
311
312 Found:
313 res = long_slots + 1;
314 *spos = cpos - sizeof(struct msdos_dir_entry);
315 *lpos = cpos - res*sizeof(struct msdos_dir_entry);
316 EODir:
317 brelse(bh);
318 if (unicode) {
319 free_page((unsigned long) unicode);
320 }
321 return res;
322 }
323
324 static int fat_readdirx(struct inode *inode, struct file *filp, void *dirent,
325 filldir_t filldir, int shortnames, int both)
326 {
327 struct super_block *sb = inode->i_sb;
328 struct buffer_head *bh;
329 struct msdos_dir_entry *de;
330 struct nls_table *nls_io = MSDOS_SB(sb)->nls_io;
331 struct nls_table *nls_disk = MSDOS_SB(sb)->nls_disk;
332 wchar_t bufuname[14];
333 unsigned char long_slots;
334 wchar_t *unicode = NULL;
335 unsigned char c, work[8], bufname[56], *ptname = bufname;
336 unsigned long lpos, dummy, *furrfu = &lpos;
337 int uni_xlate = MSDOS_SB(sb)->options.unicode_xlate;
338 int isvfat = MSDOS_SB(sb)->options.isvfat;
339 int utf8 = MSDOS_SB(sb)->options.utf8;
340 int nocase = MSDOS_SB(sb)->options.nocase;
341 unsigned short opt_shortname = MSDOS_SB(sb)->options.shortname;
342 unsigned long inum;
343 int chi, chl, i, i2, j, last, last_u, dotoffset = 0;
344 loff_t i_pos, cpos;
345 int ret = 0;
346
347 lock_kernel();
348
349 cpos = filp->f_pos;
350 /* Fake . and .. for the root directory. */
351 if (inode->i_ino == MSDOS_ROOT_INO) {
352 while (cpos < 2) {
353 if (filldir(dirent, "..", cpos+1, cpos, MSDOS_ROOT_INO, DT_DIR) < 0)
354 goto out;
355 cpos++;
356 filp->f_pos++;
357 }
358 if (cpos == 2) {
359 dummy = 2;
360 furrfu = &dummy;
361 cpos = 0;
362 }
363 }
364 if (cpos & (sizeof(struct msdos_dir_entry)-1)) {
365 ret = -ENOENT;
366 goto out;
367 }
368
369 bh = NULL;
370 GetNew:
371 long_slots = 0;
372 if (fat_get_entry(inode,&cpos,&bh,&de,&i_pos) == -1)
373 goto EODir;
374 /* Check for long filename entry */
375 if (isvfat) {
376 if (de->name[0] == DELETED_FLAG)
377 goto RecEnd;
378 if (de->attr != ATTR_EXT && (de->attr & ATTR_VOLUME))
379 goto RecEnd;
380 if (de->attr != ATTR_EXT && IS_FREE(de->name))
381 goto RecEnd;
382 } else {
383 if ((de->attr & ATTR_VOLUME) || IS_FREE(de->name))
384 goto RecEnd;
385 }
386
387 if (isvfat && de->attr == ATTR_EXT) {
388 struct msdos_dir_slot *ds;
389 unsigned char id;
390 unsigned char slot;
391 unsigned char slots;
392 unsigned char sum;
393 unsigned char alias_checksum;
394
395 if (!unicode) {
396 unicode = (wchar_t *)
397 __get_free_page(GFP_KERNEL);
398 if (!unicode) {
399 filp->f_pos = cpos;
400 brelse(bh);
401 ret = -ENOMEM;
402 goto out;
403 }
404 }
405 ParseLong:
406 slots = 0;
407 ds = (struct msdos_dir_slot *) de;
408 id = ds->id;
409 if (!(id & 0x40))
410 goto RecEnd;
411 slots = id & ~0x40;
412 if (slots > 20 || !slots) /* ceil(256 * 2 / 26) */
413 goto RecEnd;
414 long_slots = slots;
415 alias_checksum = ds->alias_checksum;
416
417 slot = slots;
418 while (1) {
419 int offset;
420
421 slot--;
422 offset = slot * 13;
423 fat16_towchar(unicode + offset, ds->name0_4, 5);
424 fat16_towchar(unicode + offset + 5, ds->name5_10, 6);
425 fat16_towchar(unicode + offset + 11, ds->name11_12, 2);
426
427 if (ds->id & 0x40) {
428 unicode[offset + 13] = 0;
429 }
430 if (fat_get_entry(inode,&cpos,&bh,&de,&i_pos) == -1)
431 goto EODir;
432 if (slot == 0)
433 break;
434 ds = (struct msdos_dir_slot *) de;
435 if (ds->attr != ATTR_EXT)
436 goto RecEnd; /* XXX */
437 if ((ds->id & ~0x40) != slot)
438 goto ParseLong;
439 if (ds->alias_checksum != alias_checksum)
440 goto ParseLong;
441 }
442 if (de->name[0] == DELETED_FLAG)
443 goto RecEnd;
444 if (de->attr == ATTR_EXT)
445 goto ParseLong;
446 if (IS_FREE(de->name) || (de->attr & ATTR_VOLUME))
447 goto RecEnd;
448 for (sum = 0, i = 0; i < 11; i++)
449 sum = (((sum&1)<<7)|((sum&0xfe)>>1)) + de->name[i];
450 if (sum != alias_checksum)
451 long_slots = 0;
452 }
453
454 if ((de->attr & ATTR_HIDDEN) && MSDOS_SB(sb)->options.dotsOK) {
455 *ptname++ = '.';
456 dotoffset = 1;
457 }
458
459 memcpy(work, de->name, sizeof(de->name));
460 /* see namei.c, msdos_format_name */
461 if (work[0] == 0x05)
462 work[0] = 0xE5;
463 for (i = 0, j = 0, last = 0, last_u = 0; i < 8;) {
464 if (!(c = work[i])) break;
465 chl = fat_shortname2uni(nls_disk, &work[i], 8 - i,
466 &bufuname[j++], opt_shortname,
467 de->lcase & CASE_LOWER_BASE);
468 if (chl <= 1) {
469 ptname[i++] = (!nocase && c>='A' && c<='Z') ? c+32 : c;
470 if (c != ' ') {
471 last = i;
472 last_u = j;
473 }
474 } else {
475 last_u = j;
476 for (chi = 0; chi < chl && i < 8; chi++) {
477 ptname[i] = work[i];
478 i++; last = i;
479 }
480 }
481 }
482 i = last;
483 j = last_u;
484 fat_short2uni(nls_disk, ".", 1, &bufuname[j++]);
485 ptname[i++] = '.';
486 for (i2 = 0; i2 < 3;) {
487 if (!(c = de->ext[i2])) break;
488 chl = fat_shortname2uni(nls_disk, &de->ext[i2], 3 - i2,
489 &bufuname[j++], opt_shortname,
490 de->lcase & CASE_LOWER_EXT);
491 if (chl <= 1) {
492 i2++;
493 ptname[i++] = (!nocase && c>='A' && c<='Z') ? c+32 : c;
494 if (c != ' ') {
495 last = i;
496 last_u = j;
497 }
498 } else {
499 last_u = j;
500 for (chi = 0; chi < chl && i2 < 3; chi++) {
501 ptname[i++] = de->ext[i2++];
502 last = i;
503 }
504 }
505 }
506 if (!last)
507 goto RecEnd;
508
509 i = last + dotoffset;
510 j = last_u;
511
512 lpos = cpos - (long_slots+1)*sizeof(struct msdos_dir_entry);
513 if (!memcmp(de->name,MSDOS_DOT,11))
514 inum = inode->i_ino;
515 else if (!memcmp(de->name,MSDOS_DOTDOT,11)) {
516 inum = parent_ino(filp->f_dentry);
517 } else {
518 struct inode *tmp = fat_iget(sb, i_pos);
519 if (tmp) {
520 inum = tmp->i_ino;
521 iput(tmp);
522 } else
523 inum = iunique(sb, MSDOS_ROOT_INO);
524 }
525
526 if (isvfat) {
527 bufuname[j] = 0x0000;
528 i = utf8 ? utf8_wcstombs(bufname, bufuname, sizeof(bufname))
529 : uni16_to_x8(bufname, bufuname, uni_xlate, nls_io);
530 }
531
532 if (!long_slots||shortnames) {
533 if (both)
534 bufname[i] = '\0';
535 if (filldir(dirent, bufname, i, *furrfu, inum,
536 (de->attr & ATTR_DIR) ? DT_DIR : DT_REG) < 0)
537 goto FillFailed;
538 } else {
539 unsigned char longname[275];
540 int long_len = utf8
541 ? utf8_wcstombs(longname, unicode, sizeof(longname))
542 : uni16_to_x8(longname, unicode, uni_xlate,
543 nls_io);
544 if (both) {
545 memcpy(&longname[long_len+1], bufname, i);
546 long_len += i;
547 }
548 if (filldir(dirent, longname, long_len, *furrfu, inum,
549 (de->attr & ATTR_DIR) ? DT_DIR : DT_REG) < 0)
550 goto FillFailed;
551 }
552
553 RecEnd:
554 furrfu = &lpos;
555 filp->f_pos = cpos;
556 goto GetNew;
557 EODir:
558 filp->f_pos = cpos;
559 FillFailed:
560 if (bh)
561 brelse(bh);
562 if (unicode) {
563 free_page((unsigned long) unicode);
564 }
565 out:
566 unlock_kernel();
567 return ret;
568 }
569
570 int fat_readdir(struct file *filp, void *dirent, filldir_t filldir)
571 {
572 struct inode *inode = filp->f_dentry->d_inode;
573 return fat_readdirx(inode, filp, dirent, filldir, 0, 0);
574 }
575
576 struct fat_ioctl_filldir_callback {
577 struct dirent __user *dirent;
578 int result;
579 };
580
581 static int fat_ioctl_filldir(void *__buf, const char * name, int name_len,
582 loff_t offset, ino_t ino, unsigned int d_type)
583 {
584 struct fat_ioctl_filldir_callback *buf = __buf;
585 struct dirent __user *d1 = buf->dirent;
586 struct dirent __user *d2 = d1 + 1;
587 int len, slen;
588 int dotdir;
589
590 if (buf->result)
591 return -EINVAL;
592 buf->result++;
593
594 if ((name_len == 1 && name[0] == '.') ||
595 (name_len == 2 && name[0] == '.' && name[1] == '.')) {
596 dotdir = 1;
597 len = name_len;
598 } else {
599 dotdir = 0;
600 len = strlen(name);
601 }
602 if (len != name_len) {
603 slen = name_len - len;
604 if (copy_to_user(d2->d_name, name, len) ||
605 put_user(0, d2->d_name + len) ||
606 put_user(len, &d2->d_reclen) ||
607 put_user(ino, &d2->d_ino) ||
608 put_user(offset, &d2->d_off) ||
609 copy_to_user(d1->d_name, name+len+1, slen) ||
610 put_user(0, d1->d_name+slen) ||
611 put_user(slen, &d1->d_reclen))
612 goto efault;
613 } else {
614 if (put_user(0, d2->d_name) ||
615 put_user(0, &d2->d_reclen) ||
616 copy_to_user(d1->d_name, name, len) ||
617 put_user(0, d1->d_name+len) ||
618 put_user(len, &d1->d_reclen))
619 goto efault;
620 }
621 return 0;
622 efault:
623 buf->result = -EFAULT;
624 return -EFAULT;
625 }
626
627 int fat_dir_ioctl(struct inode * inode, struct file * filp,
628 unsigned int cmd, unsigned long arg)
629 {
630 struct fat_ioctl_filldir_callback buf;
631 struct dirent __user *d1;
632 int ret, shortname, both;
633
634 switch (cmd) {
635 case VFAT_IOCTL_READDIR_SHORT:
636 shortname = 1;
637 both = 1;
638 break;
639 case VFAT_IOCTL_READDIR_BOTH:
640 shortname = 0;
641 both = 1;
642 break;
643 default:
644 return -EINVAL;
645 }
646
647 d1 = (struct dirent __user *)arg;
648 if (!access_ok(VERIFY_WRITE, d1, sizeof(struct dirent[2])))
649 return -EFAULT;
650 /*
651 * Yes, we don't need this put_user() absolutely. However old
652 * code didn't return the right value. So, app use this value,
653 * in order to check whether it is EOF.
654 */
655 if (put_user(0, &d1->d_reclen))
656 return -EFAULT;
657
658 buf.dirent = d1;
659 buf.result = 0;
660 down(&inode->i_sem);
661 ret = -ENOENT;
662 if (!IS_DEADDIR(inode)) {
663 ret = fat_readdirx(inode, filp, &buf, fat_ioctl_filldir,
664 shortname, both);
665 }
666 up(&inode->i_sem);
667 if (ret >= 0)
668 ret = buf.result;
669 return ret;
670 }
671
672 /* This assumes that size of cluster is above the 32*slots */
673
674 int fat_add_entries(struct inode *dir,int slots, struct buffer_head **bh,
675 struct msdos_dir_entry **de, loff_t *i_pos)
676 {
677 struct super_block *sb = dir->i_sb;
678 loff_t offset, curr;
679 int row;
680 struct buffer_head *new_bh;
681
682 offset = curr = 0;
683 *bh = NULL;
684 row = 0;
685 while (fat_get_entry(dir, &curr, bh, de, i_pos) > -1) {
686 /* check the maximum size of directory */
687 if (curr >= FAT_MAX_DIR_SIZE) {
688 brelse(*bh);
689 return -ENOSPC;
690 }
691
692 if (IS_FREE((*de)->name)) {
693 if (++row == slots)
694 return offset;
695 } else {
696 row = 0;
697 offset = curr;
698 }
699 }
700 if ((dir->i_ino == MSDOS_ROOT_INO) && (MSDOS_SB(sb)->fat_bits != 32))
701 return -ENOSPC;
702 new_bh = fat_extend_dir(dir);
703 if (IS_ERR(new_bh))
704 return PTR_ERR(new_bh);
705 brelse(new_bh);
706 do {
707 fat_get_entry(dir, &curr, bh, de, i_pos);
708 } while (++row < slots);
709
710 return offset;
711 }
712
713 int fat_new_dir(struct inode *dir, struct inode *parent, int is_vfat)
714 {
715 struct buffer_head *bh;
716 struct msdos_dir_entry *de;
717 __le16 date, time;
718
719 bh = fat_extend_dir(dir);
720 if (IS_ERR(bh))
721 return PTR_ERR(bh);
722
723 /* zeroed out, so... */
724 fat_date_unix2dos(dir->i_mtime.tv_sec,&time,&date);
725 de = (struct msdos_dir_entry*)&bh->b_data[0];
726 memcpy(de[0].name,MSDOS_DOT,MSDOS_NAME);
727 memcpy(de[1].name,MSDOS_DOTDOT,MSDOS_NAME);
728 de[0].attr = de[1].attr = ATTR_DIR;
729 de[0].time = de[1].time = time;
730 de[0].date = de[1].date = date;
731 if (is_vfat) { /* extra timestamps */
732 de[0].ctime = de[1].ctime = time;
733 de[0].adate = de[0].cdate =
734 de[1].adate = de[1].cdate = date;
735 }
736 de[0].start = CT_LE_W(MSDOS_I(dir)->i_logstart);
737 de[0].starthi = CT_LE_W(MSDOS_I(dir)->i_logstart>>16);
738 de[1].start = CT_LE_W(MSDOS_I(parent)->i_logstart);
739 de[1].starthi = CT_LE_W(MSDOS_I(parent)->i_logstart>>16);
740 mark_buffer_dirty(bh);
741 brelse(bh);
742 dir->i_atime = dir->i_ctime = dir->i_mtime = CURRENT_TIME;
743 mark_inode_dirty(dir);
744
745 return 0;
746 }
747
748 static int fat_get_short_entry(struct inode *dir, loff_t *pos,
749 struct buffer_head **bh,
750 struct msdos_dir_entry **de, loff_t *i_pos)
751 {
752 while (fat_get_entry(dir, pos, bh, de, i_pos) >= 0) {
753 /* free entry or long name entry or volume label */
754 if (!IS_FREE((*de)->name) && !((*de)->attr & ATTR_VOLUME))
755 return 0;
756 }
757 return -ENOENT;
758 }
759
760 /* See if directory is empty */
761 int fat_dir_empty(struct inode *dir)
762 {
763 struct buffer_head *bh;
764 struct msdos_dir_entry *de;
765 loff_t cpos, i_pos;
766 int result = 0;
767
768 bh = NULL;
769 cpos = 0;
770 while (fat_get_short_entry(dir, &cpos, &bh, &de, &i_pos) >= 0) {
771 if (strncmp(de->name, MSDOS_DOT , MSDOS_NAME) &&
772 strncmp(de->name, MSDOS_DOTDOT, MSDOS_NAME)) {
773 result = -ENOTEMPTY;
774 break;
775 }
776 }
777 brelse(bh);
778 return result;
779 }
780
781 /*
782 * fat_subdirs counts the number of sub-directories of dir. It can be run
783 * on directories being created.
784 */
785 int fat_subdirs(struct inode *dir)
786 {
787 struct buffer_head *bh;
788 struct msdos_dir_entry *de;
789 loff_t cpos, i_pos;
790 int count = 0;
791
792 bh = NULL;
793 cpos = 0;
794 while (fat_get_short_entry(dir, &cpos, &bh, &de, &i_pos) >= 0) {
795 if (de->attr & ATTR_DIR)
796 count++;
797 }
798 brelse(bh);
799 return count;
800 }
801
802 /*
803 * Scans a directory for a given file (name points to its formatted name).
804 * Returns an error code or zero.
805 */
806 int fat_scan(struct inode *dir, const unsigned char *name,
807 struct buffer_head **bh, struct msdos_dir_entry **de,
808 loff_t *i_pos)
809 {
810 loff_t cpos;
811
812 *bh = NULL;
813 cpos = 0;
814 while (fat_get_short_entry(dir, &cpos, bh, de, i_pos) >= 0) {
815 if (!strncmp((*de)->name, name, MSDOS_NAME))
816 return 0;
817 }
818 return -ENOENT;
819 }
MOXA 2.6.9 from sdlinux-moxaart.tgz