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Linux v2.6.16-rc1
[linux-2.6/next.git] / fs / fat / dir.c
blobdb0de5c621c7db1eec05f9f2a875c0e559f8cdbc
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/module.h>
17 #include <linux/slab.h>
18 #include <linux/time.h>
19 #include <linux/msdos_fs.h>
20 #include <linux/dirent.h>
21 #include <linux/smp_lock.h>
22 #include <linux/buffer_head.h>
23 #include <asm/uaccess.h>
24
25 static inline loff_t fat_make_i_pos(struct super_block *sb,
26 struct buffer_head *bh,
27 struct msdos_dir_entry *de)
28 {
29 return ((loff_t)bh->b_blocknr << MSDOS_SB(sb)->dir_per_block_bits)
30 | (de - (struct msdos_dir_entry *)bh->b_data);
31 }
32
33 static inline void fat_dir_readahead(struct inode *dir, sector_t iblock,
34 sector_t phys)
35 {
36 struct super_block *sb = dir->i_sb;
37 struct msdos_sb_info *sbi = MSDOS_SB(sb);
38 struct buffer_head *bh;
39 int sec;
40
41 /* This is not a first sector of cluster, or sec_per_clus == 1 */
42 if ((iblock & (sbi->sec_per_clus - 1)) || sbi->sec_per_clus == 1)
43 return;
44 /* root dir of FAT12/FAT16 */
45 if ((sbi->fat_bits != 32) && (dir->i_ino == MSDOS_ROOT_INO))
46 return;
47
48 bh = sb_find_get_block(sb, phys);
49 if (bh == NULL || !buffer_uptodate(bh)) {
50 for (sec = 0; sec < sbi->sec_per_clus; sec++)
51 sb_breadahead(sb, phys + sec);
52 }
53 brelse(bh);
54 }
55
56 /* Returns the inode number of the directory entry at offset pos. If bh is
57 non-NULL, it is brelse'd before. Pos is incremented. The buffer header is
58 returned in bh.
59 AV. Most often we do it item-by-item. Makes sense to optimize.
60 AV. OK, there we go: if both bh and de are non-NULL we assume that we just
61 AV. want the next entry (took one explicit de=NULL in vfat/namei.c).
62 AV. It's done in fat_get_entry() (inlined), here the slow case lives.
63 AV. Additionally, when we return -1 (i.e. reached the end of directory)
64 AV. we make bh NULL.
65 */
66 static int fat__get_entry(struct inode *dir, loff_t *pos,
67 struct buffer_head **bh, struct msdos_dir_entry **de)
68 {
69 struct super_block *sb = dir->i_sb;
70 sector_t phys, iblock;
71 unsigned long mapped_blocks;
72 int err, offset;
73
74 next:
75 if (*bh)
76 brelse(*bh);
77
78 *bh = NULL;
79 iblock = *pos >> sb->s_blocksize_bits;
80 err = fat_bmap(dir, iblock, &phys, &mapped_blocks);
81 if (err || !phys)
82 return -1; /* beyond EOF or error */
83
84 fat_dir_readahead(dir, iblock, phys);
85
86 *bh = sb_bread(sb, phys);
87 if (*bh == NULL) {
88 printk(KERN_ERR "FAT: Directory bread(block %llu) failed\n",
89 (unsigned long long)phys);
90 /* skip this block */
91 *pos = (iblock + 1) << sb->s_blocksize_bits;
92 goto next;
93 }
94
95 offset = *pos & (sb->s_blocksize - 1);
96 *pos += sizeof(struct msdos_dir_entry);
97 *de = (struct msdos_dir_entry *)((*bh)->b_data + offset);
98
99 return 0;
100 }
101
102 static inline int fat_get_entry(struct inode *dir, loff_t *pos,
103 struct buffer_head **bh,
104 struct msdos_dir_entry **de)
105 {
106 /* Fast stuff first */
107 if (*bh && *de &&
108 (*de - (struct msdos_dir_entry *)(*bh)->b_data) < MSDOS_SB(dir->i_sb)->dir_per_block - 1) {
109 *pos += sizeof(struct msdos_dir_entry);
110 (*de)++;
111 return 0;
112 }
113 return fat__get_entry(dir, pos, bh, de);
114 }
115
116 /*
117 * Convert Unicode 16 to UTF8, translated Unicode, or ASCII.
118 * If uni_xlate is enabled and we can't get a 1:1 conversion, use a
119 * colon as an escape character since it is normally invalid on the vfat
120 * filesystem. The following four characters are the hexadecimal digits
121 * of Unicode value. This lets us do a full dump and restore of Unicode
122 * filenames. We could get into some trouble with long Unicode names,
123 * but ignore that right now.
124 * Ahem... Stack smashing in ring 0 isn't fun. Fixed.
125 */
126 static int uni16_to_x8(unsigned char *ascii, wchar_t *uni, int uni_xlate,
127 struct nls_table *nls)
128 {
129 wchar_t *ip, ec;
130 unsigned char *op, nc;
131 int charlen;
132 int k;
133
134 ip = uni;
135 op = ascii;
136
137 while (*ip) {
138 ec = *ip++;
139 if ( (charlen = nls->uni2char(ec, op, NLS_MAX_CHARSET_SIZE)) > 0) {
140 op += charlen;
141 } else {
142 if (uni_xlate == 1) {
143 *op = ':';
144 for (k = 4; k > 0; k--) {
145 nc = ec & 0xF;
146 op[k] = nc > 9 ? nc + ('a' - 10)
147 : nc + '0';
148 ec >>= 4;
149 }
150 op += 5;
151 } else {
152 *op++ = '?';
153 }
154 }
155 /* We have some slack there, so it's OK */
156 if (op>ascii+256) {
157 op = ascii + 256;
158 break;
159 }
160 }
161 *op = 0;
162 return (op - ascii);
163 }
164
165 static inline int
166 fat_short2uni(struct nls_table *t, unsigned char *c, int clen, wchar_t *uni)
167 {
168 int charlen;
169
170 charlen = t->char2uni(c, clen, uni);
171 if (charlen < 0) {
172 *uni = 0x003f; /* a question mark */
173 charlen = 1;
174 }
175 return charlen;
176 }
177
178 static inline int
179 fat_short2lower_uni(struct nls_table *t, unsigned char *c, int clen, wchar_t *uni)
180 {
181 int charlen;
182 wchar_t wc;
183
184 charlen = t->char2uni(c, clen, &wc);
185 if (charlen < 0) {
186 *uni = 0x003f; /* a question mark */
187 charlen = 1;
188 } else if (charlen <= 1) {
189 unsigned char nc = t->charset2lower[*c];
190
191 if (!nc)
192 nc = *c;
193
194 if ( (charlen = t->char2uni(&nc, 1, uni)) < 0) {
195 *uni = 0x003f; /* a question mark */
196 charlen = 1;
197 }
198 } else
199 *uni = wc;
200
201 return charlen;
202 }
203
204 static inline int
205 fat_shortname2uni(struct nls_table *nls, unsigned char *buf, int buf_size,
206 wchar_t *uni_buf, unsigned short opt, int lower)
207 {
208 int len = 0;
209
210 if (opt & VFAT_SFN_DISPLAY_LOWER)
211 len = fat_short2lower_uni(nls, buf, buf_size, uni_buf);
212 else if (opt & VFAT_SFN_DISPLAY_WIN95)
213 len = fat_short2uni(nls, buf, buf_size, uni_buf);
214 else if (opt & VFAT_SFN_DISPLAY_WINNT) {
215 if (lower)
216 len = fat_short2lower_uni(nls, buf, buf_size, uni_buf);
217 else
218 len = fat_short2uni(nls, buf, buf_size, uni_buf);
219 } else
220 len = fat_short2uni(nls, buf, buf_size, uni_buf);
221
222 return len;
223 }
224
225 enum { PARSE_INVALID = 1, PARSE_NOT_LONGNAME, PARSE_EOF, };
226
227 /**
228 * fat_parse_long - Parse extended directory entry.
229 *
230 * This function returns zero on success, negative value on error, or one of
231 * the following:
232 *
233 * %PARSE_INVALID - Directory entry is invalid.
234 * %PARSE_NOT_LONGNAME - Directory entry does not contain longname.
235 * %PARSE_EOF - Directory has no more entries.
236 */
237 static int fat_parse_long(struct inode *dir, loff_t *pos,
238 struct buffer_head **bh, struct msdos_dir_entry **de,
239 wchar_t **unicode, unsigned char *nr_slots)
240 {
241 struct msdos_dir_slot *ds;
242 unsigned char id, slot, slots, alias_checksum;
243
244 if (!*unicode) {
245 *unicode = (wchar_t *)__get_free_page(GFP_KERNEL);
246 if (!*unicode) {
247 brelse(*bh);
248 return -ENOMEM;
249 }
250 }
251 parse_long:
252 slots = 0;
253 ds = (struct msdos_dir_slot *)*de;
254 id = ds->id;
255 if (!(id & 0x40))
256 return PARSE_INVALID;
257 slots = id & ~0x40;
258 if (slots > 20 || !slots) /* ceil(256 * 2 / 26) */
259 return PARSE_INVALID;
260 *nr_slots = slots;
261 alias_checksum = ds->alias_checksum;
262
263 slot = slots;
264 while (1) {
265 int offset;
266
267 slot--;
268 offset = slot * 13;
269 fat16_towchar(*unicode + offset, ds->name0_4, 5);
270 fat16_towchar(*unicode + offset + 5, ds->name5_10, 6);
271 fat16_towchar(*unicode + offset + 11, ds->name11_12, 2);
272
273 if (ds->id & 0x40)
274 (*unicode)[offset + 13] = 0;
275 if (fat_get_entry(dir, pos, bh, de) < 0)
276 return PARSE_EOF;
277 if (slot == 0)
278 break;
279 ds = (struct msdos_dir_slot *)*de;
280 if (ds->attr != ATTR_EXT)
281 return PARSE_NOT_LONGNAME;
282 if ((ds->id & ~0x40) != slot)
283 goto parse_long;
284 if (ds->alias_checksum != alias_checksum)
285 goto parse_long;
286 }
287 if ((*de)->name[0] == DELETED_FLAG)
288 return PARSE_INVALID;
289 if ((*de)->attr == ATTR_EXT)
290 goto parse_long;
291 if (IS_FREE((*de)->name) || ((*de)->attr & ATTR_VOLUME))
292 return PARSE_INVALID;
293 if (fat_checksum((*de)->name) != alias_checksum)
294 *nr_slots = 0;
295
296 return 0;
297 }
298
299 /*
300 * Return values: negative -> error, 0 -> not found, positive -> found,
301 * value is the total amount of slots, including the shortname entry.
302 */
303 int fat_search_long(struct inode *inode, const unsigned char *name,
304 int name_len, struct fat_slot_info *sinfo)
305 {
306 struct super_block *sb = inode->i_sb;
307 struct msdos_sb_info *sbi = MSDOS_SB(sb);
308 struct buffer_head *bh = NULL;
309 struct msdos_dir_entry *de;
310 struct nls_table *nls_io = sbi->nls_io;
311 struct nls_table *nls_disk = sbi->nls_disk;
312 wchar_t bufuname[14];
313 unsigned char xlate_len, nr_slots;
314 wchar_t *unicode = NULL;
315 unsigned char work[8], bufname[260]; /* 256 + 4 */
316 int uni_xlate = sbi->options.unicode_xlate;
317 int utf8 = sbi->options.utf8;
318 int anycase = (sbi->options.name_check != 's');
319 unsigned short opt_shortname = sbi->options.shortname;
320 loff_t cpos = 0;
321 int chl, i, j, last_u, err;
322
323 err = -ENOENT;
324 while(1) {
325 if (fat_get_entry(inode, &cpos, &bh, &de) == -1)
326 goto EODir;
327 parse_record:
328 nr_slots = 0;
329 if (de->name[0] == DELETED_FLAG)
330 continue;
331 if (de->attr != ATTR_EXT && (de->attr & ATTR_VOLUME))
332 continue;
333 if (de->attr != ATTR_EXT && IS_FREE(de->name))
334 continue;
335 if (de->attr == ATTR_EXT) {
336 int status = fat_parse_long(inode, &cpos, &bh, &de,
337 &unicode, &nr_slots);
338 if (status < 0)
339 return status;
340 else if (status == PARSE_INVALID)
341 continue;
342 else if (status == PARSE_NOT_LONGNAME)
343 goto parse_record;
344 else if (status == PARSE_EOF)
345 goto EODir;
346 }
347
348 memcpy(work, de->name, sizeof(de->name));
349 /* see namei.c, msdos_format_name */
350 if (work[0] == 0x05)
351 work[0] = 0xE5;
352 for (i = 0, j = 0, last_u = 0; i < 8;) {
353 if (!work[i]) break;
354 chl = fat_shortname2uni(nls_disk, &work[i], 8 - i,
355 &bufuname[j++], opt_shortname,
356 de->lcase & CASE_LOWER_BASE);
357 if (chl <= 1) {
358 if (work[i] != ' ')
359 last_u = j;
360 } else {
361 last_u = j;
362 }
363 i += chl;
364 }
365 j = last_u;
366 fat_short2uni(nls_disk, ".", 1, &bufuname[j++]);
367 for (i = 0; i < 3;) {
368 if (!de->ext[i]) break;
369 chl = fat_shortname2uni(nls_disk, &de->ext[i], 3 - i,
370 &bufuname[j++], opt_shortname,
371 de->lcase & CASE_LOWER_EXT);
372 if (chl <= 1) {
373 if (de->ext[i] != ' ')
374 last_u = j;
375 } else {
376 last_u = j;
377 }
378 i += chl;
379 }
380 if (!last_u)
381 continue;
382
383 bufuname[last_u] = 0x0000;
384 xlate_len = utf8
385 ?utf8_wcstombs(bufname, bufuname, sizeof(bufname))
386 :uni16_to_x8(bufname, bufuname, uni_xlate, nls_io);
387 if (xlate_len == name_len)
388 if ((!anycase && !memcmp(name, bufname, xlate_len)) ||
389 (anycase && !nls_strnicmp(nls_io, name, bufname,
390 xlate_len)))
391 goto Found;
392
393 if (nr_slots) {
394 xlate_len = utf8
395 ?utf8_wcstombs(bufname, unicode, sizeof(bufname))
396 :uni16_to_x8(bufname, unicode, uni_xlate, nls_io);
397 if (xlate_len != name_len)
398 continue;
399 if ((!anycase && !memcmp(name, bufname, xlate_len)) ||
400 (anycase && !nls_strnicmp(nls_io, name, bufname,
401 xlate_len)))
402 goto Found;
403 }
404 }
405
406 Found:
407 nr_slots++; /* include the de */
408 sinfo->slot_off = cpos - nr_slots * sizeof(*de);
409 sinfo->nr_slots = nr_slots;
410 sinfo->de = de;
411 sinfo->bh = bh;
412 sinfo->i_pos = fat_make_i_pos(sb, sinfo->bh, sinfo->de);
413 err = 0;
414 EODir:
415 if (unicode)
416 free_page((unsigned long)unicode);
417
418 return err;
419 }
420
421 EXPORT_SYMBOL_GPL(fat_search_long);
422
423 struct fat_ioctl_filldir_callback {
424 struct dirent __user *dirent;
425 int result;
426 /* for dir ioctl */
427 const char *longname;
428 int long_len;
429 const char *shortname;
430 int short_len;
431 };
432
433 static int __fat_readdir(struct inode *inode, struct file *filp, void *dirent,
434 filldir_t filldir, int short_only, int both)
435 {
436 struct super_block *sb = inode->i_sb;
437 struct msdos_sb_info *sbi = MSDOS_SB(sb);
438 struct buffer_head *bh;
439 struct msdos_dir_entry *de;
440 struct nls_table *nls_io = sbi->nls_io;
441 struct nls_table *nls_disk = sbi->nls_disk;
442 unsigned char long_slots;
443 const char *fill_name;
444 int fill_len;
445 wchar_t bufuname[14];
446 wchar_t *unicode = NULL;
447 unsigned char c, work[8], bufname[56], *ptname = bufname;
448 unsigned long lpos, dummy, *furrfu = &lpos;
449 int uni_xlate = sbi->options.unicode_xlate;
450 int isvfat = sbi->options.isvfat;
451 int utf8 = sbi->options.utf8;
452 int nocase = sbi->options.nocase;
453 unsigned short opt_shortname = sbi->options.shortname;
454 unsigned long inum;
455 int chi, chl, i, i2, j, last, last_u, dotoffset = 0;
456 loff_t cpos;
457 int ret = 0;
458
459 lock_kernel();
460
461 cpos = filp->f_pos;
462 /* Fake . and .. for the root directory. */
463 if (inode->i_ino == MSDOS_ROOT_INO) {
464 while (cpos < 2) {
465 if (filldir(dirent, "..", cpos+1, cpos, MSDOS_ROOT_INO, DT_DIR) < 0)
466 goto out;
467 cpos++;
468 filp->f_pos++;
469 }
470 if (cpos == 2) {
471 dummy = 2;
472 furrfu = &dummy;
473 cpos = 0;
474 }
475 }
476 if (cpos & (sizeof(struct msdos_dir_entry)-1)) {
477 ret = -ENOENT;
478 goto out;
479 }
480
481 bh = NULL;
482 GetNew:
483 if (fat_get_entry(inode, &cpos, &bh, &de) == -1)
484 goto EODir;
485 parse_record:
486 long_slots = 0;
487 /* Check for long filename entry */
488 if (isvfat) {
489 if (de->name[0] == DELETED_FLAG)
490 goto RecEnd;
491 if (de->attr != ATTR_EXT && (de->attr & ATTR_VOLUME))
492 goto RecEnd;
493 if (de->attr != ATTR_EXT && IS_FREE(de->name))
494 goto RecEnd;
495 } else {
496 if ((de->attr & ATTR_VOLUME) || IS_FREE(de->name))
497 goto RecEnd;
498 }
499
500 if (isvfat && de->attr == ATTR_EXT) {
501 int status = fat_parse_long(inode, &cpos, &bh, &de,
502 &unicode, &long_slots);
503 if (status < 0) {
504 filp->f_pos = cpos;
505 ret = status;
506 goto out;
507 } else if (status == PARSE_INVALID)
508 goto RecEnd;
509 else if (status == PARSE_NOT_LONGNAME)
510 goto parse_record;
511 else if (status == PARSE_EOF)
512 goto EODir;
513 }
514
515 if (sbi->options.dotsOK) {
516 ptname = bufname;
517 dotoffset = 0;
518 if (de->attr & ATTR_HIDDEN) {
519 *ptname++ = '.';
520 dotoffset = 1;
521 }
522 }
523
524 memcpy(work, de->name, sizeof(de->name));
525 /* see namei.c, msdos_format_name */
526 if (work[0] == 0x05)
527 work[0] = 0xE5;
528 for (i = 0, j = 0, last = 0, last_u = 0; i < 8;) {
529 if (!(c = work[i])) break;
530 chl = fat_shortname2uni(nls_disk, &work[i], 8 - i,
531 &bufuname[j++], opt_shortname,
532 de->lcase & CASE_LOWER_BASE);
533 if (chl <= 1) {
534 ptname[i++] = (!nocase && c>='A' && c<='Z') ? c+32 : c;
535 if (c != ' ') {
536 last = i;
537 last_u = j;
538 }
539 } else {
540 last_u = j;
541 for (chi = 0; chi < chl && i < 8; chi++) {
542 ptname[i] = work[i];
543 i++; last = i;
544 }
545 }
546 }
547 i = last;
548 j = last_u;
549 fat_short2uni(nls_disk, ".", 1, &bufuname[j++]);
550 ptname[i++] = '.';
551 for (i2 = 0; i2 < 3;) {
552 if (!(c = de->ext[i2])) break;
553 chl = fat_shortname2uni(nls_disk, &de->ext[i2], 3 - i2,
554 &bufuname[j++], opt_shortname,
555 de->lcase & CASE_LOWER_EXT);
556 if (chl <= 1) {
557 i2++;
558 ptname[i++] = (!nocase && c>='A' && c<='Z') ? c+32 : c;
559 if (c != ' ') {
560 last = i;
561 last_u = j;
562 }
563 } else {
564 last_u = j;
565 for (chi = 0; chi < chl && i2 < 3; chi++) {
566 ptname[i++] = de->ext[i2++];
567 last = i;
568 }
569 }
570 }
571 if (!last)
572 goto RecEnd;
573
574 i = last + dotoffset;
575 j = last_u;
576
577 lpos = cpos - (long_slots+1)*sizeof(struct msdos_dir_entry);
578 if (!memcmp(de->name, MSDOS_DOT, MSDOS_NAME))
579 inum = inode->i_ino;
580 else if (!memcmp(de->name, MSDOS_DOTDOT, MSDOS_NAME)) {
581 inum = parent_ino(filp->f_dentry);
582 } else {
583 loff_t i_pos = fat_make_i_pos(sb, bh, de);
584 struct inode *tmp = fat_iget(sb, i_pos);
585 if (tmp) {
586 inum = tmp->i_ino;
587 iput(tmp);
588 } else
589 inum = iunique(sb, MSDOS_ROOT_INO);
590 }
591
592 if (isvfat) {
593 bufuname[j] = 0x0000;
594 i = utf8 ? utf8_wcstombs(bufname, bufuname, sizeof(bufname))
595 : uni16_to_x8(bufname, bufuname, uni_xlate, nls_io);
596 }
597
598 fill_name = bufname;
599 fill_len = i;
600 if (!short_only && long_slots) {
601 /* convert the unicode long name. 261 is maximum size
602 * of unicode buffer. (13 * slots + nul) */
603 void *longname = unicode + 261;
604 int buf_size = PAGE_SIZE - (261 * sizeof(unicode[0]));
605 int long_len = utf8
606 ? utf8_wcstombs(longname, unicode, buf_size)
607 : uni16_to_x8(longname, unicode, uni_xlate, nls_io);
608
609 if (!both) {
610 fill_name = longname;
611 fill_len = long_len;
612 } else {
613 /* hack for fat_ioctl_filldir() */
614 struct fat_ioctl_filldir_callback *p = dirent;
615
616 p->longname = longname;
617 p->long_len = long_len;
618 p->shortname = bufname;
619 p->short_len = i;
620 fill_name = NULL;
621 fill_len = 0;
622 }
623 }
624 if (filldir(dirent, fill_name, fill_len, *furrfu, inum,
625 (de->attr & ATTR_DIR) ? DT_DIR : DT_REG) < 0)
626 goto FillFailed;
627
628 RecEnd:
629 furrfu = &lpos;
630 filp->f_pos = cpos;
631 goto GetNew;
632 EODir:
633 filp->f_pos = cpos;
634 FillFailed:
635 brelse(bh);
636 if (unicode)
637 free_page((unsigned long)unicode);
638 out:
639 unlock_kernel();
640 return ret;
641 }
642
643 static int fat_readdir(struct file *filp, void *dirent, filldir_t filldir)
644 {
645 struct inode *inode = filp->f_dentry->d_inode;
646 return __fat_readdir(inode, filp, dirent, filldir, 0, 0);
647 }
648
649 static int fat_ioctl_filldir(void *__buf, const char *name, int name_len,
650 loff_t offset, ino_t ino, unsigned int d_type)
651 {
652 struct fat_ioctl_filldir_callback *buf = __buf;
653 struct dirent __user *d1 = buf->dirent;
654 struct dirent __user *d2 = d1 + 1;
655
656 if (buf->result)
657 return -EINVAL;
658 buf->result++;
659
660 if (name != NULL) {
661 /* dirent has only short name */
662 if (name_len >= sizeof(d1->d_name))
663 name_len = sizeof(d1->d_name) - 1;
664
665 if (put_user(0, d2->d_name) ||
666 put_user(0, &d2->d_reclen) ||
667 copy_to_user(d1->d_name, name, name_len) ||
668 put_user(0, d1->d_name + name_len) ||
669 put_user(name_len, &d1->d_reclen))
670 goto efault;
671 } else {
672 /* dirent has short and long name */
673 const char *longname = buf->longname;
674 int long_len = buf->long_len;
675 const char *shortname = buf->shortname;
676 int short_len = buf->short_len;
677
678 if (long_len >= sizeof(d1->d_name))
679 long_len = sizeof(d1->d_name) - 1;
680 if (short_len >= sizeof(d1->d_name))
681 short_len = sizeof(d1->d_name) - 1;
682
683 if (copy_to_user(d2->d_name, longname, long_len) ||
684 put_user(0, d2->d_name + long_len) ||
685 put_user(long_len, &d2->d_reclen) ||
686 put_user(ino, &d2->d_ino) ||
687 put_user(offset, &d2->d_off) ||
688 copy_to_user(d1->d_name, shortname, short_len) ||
689 put_user(0, d1->d_name + short_len) ||
690 put_user(short_len, &d1->d_reclen))
691 goto efault;
692 }
693 return 0;
694 efault:
695 buf->result = -EFAULT;
696 return -EFAULT;
697 }
698
699 static int fat_dir_ioctl(struct inode * inode, struct file * filp,
700 unsigned int cmd, unsigned long arg)
701 {
702 struct fat_ioctl_filldir_callback buf;
703 struct dirent __user *d1;
704 int ret, short_only, both;
705
706 switch (cmd) {
707 case VFAT_IOCTL_READDIR_SHORT:
708 short_only = 1;
709 both = 0;
710 break;
711 case VFAT_IOCTL_READDIR_BOTH:
712 short_only = 0;
713 both = 1;
714 break;
715 default:
716 return fat_generic_ioctl(inode, filp, cmd, arg);
717 }
718
719 d1 = (struct dirent __user *)arg;
720 if (!access_ok(VERIFY_WRITE, d1, sizeof(struct dirent[2])))
721 return -EFAULT;
722 /*
723 * Yes, we don't need this put_user() absolutely. However old
724 * code didn't return the right value. So, app use this value,
725 * in order to check whether it is EOF.
726 */
727 if (put_user(0, &d1->d_reclen))
728 return -EFAULT;
729
730 buf.dirent = d1;
731 buf.result = 0;
732 mutex_lock(&inode->i_mutex);
733 ret = -ENOENT;
734 if (!IS_DEADDIR(inode)) {
735 ret = __fat_readdir(inode, filp, &buf, fat_ioctl_filldir,
736 short_only, both);
737 }
738 mutex_unlock(&inode->i_mutex);
739 if (ret >= 0)
740 ret = buf.result;
741 return ret;
742 }
743
744 struct file_operations fat_dir_operations = {
745 .read = generic_read_dir,
746 .readdir = fat_readdir,
747 .ioctl = fat_dir_ioctl,
748 .fsync = file_fsync,
749 };
750
751 static int fat_get_short_entry(struct inode *dir, loff_t *pos,
752 struct buffer_head **bh,
753 struct msdos_dir_entry **de)
754 {
755 while (fat_get_entry(dir, pos, bh, de) >= 0) {
756 /* free entry or long name entry or volume label */
757 if (!IS_FREE((*de)->name) && !((*de)->attr & ATTR_VOLUME))
758 return 0;
759 }
760 return -ENOENT;
761 }
762
763 /*
764 * The ".." entry can not provide the "struct fat_slot_info" informations
765 * for inode. So, this function provide the some informations only.
766 */
767 int fat_get_dotdot_entry(struct inode *dir, struct buffer_head **bh,
768 struct msdos_dir_entry **de, loff_t *i_pos)
769 {
770 loff_t offset;
771
772 offset = 0;
773 *bh = NULL;
774 while (fat_get_short_entry(dir, &offset, bh, de) >= 0) {
775 if (!strncmp((*de)->name, MSDOS_DOTDOT, MSDOS_NAME)) {
776 *i_pos = fat_make_i_pos(dir->i_sb, *bh, *de);
777 return 0;
778 }
779 }
780 return -ENOENT;
781 }
782
783 EXPORT_SYMBOL_GPL(fat_get_dotdot_entry);
784
785 /* See if directory is empty */
786 int fat_dir_empty(struct inode *dir)
787 {
788 struct buffer_head *bh;
789 struct msdos_dir_entry *de;
790 loff_t cpos;
791 int result = 0;
792
793 bh = NULL;
794 cpos = 0;
795 while (fat_get_short_entry(dir, &cpos, &bh, &de) >= 0) {
796 if (strncmp(de->name, MSDOS_DOT , MSDOS_NAME) &&
797 strncmp(de->name, MSDOS_DOTDOT, MSDOS_NAME)) {
798 result = -ENOTEMPTY;
799 break;
800 }
801 }
802 brelse(bh);
803 return result;
804 }
805
806 EXPORT_SYMBOL_GPL(fat_dir_empty);
807
808 /*
809 * fat_subdirs counts the number of sub-directories of dir. It can be run
810 * on directories being created.
811 */
812 int fat_subdirs(struct inode *dir)
813 {
814 struct buffer_head *bh;
815 struct msdos_dir_entry *de;
816 loff_t cpos;
817 int count = 0;
818
819 bh = NULL;
820 cpos = 0;
821 while (fat_get_short_entry(dir, &cpos, &bh, &de) >= 0) {
822 if (de->attr & ATTR_DIR)
823 count++;
824 }
825 brelse(bh);
826 return count;
827 }
828
829 /*
830 * Scans a directory for a given file (name points to its formatted name).
831 * Returns an error code or zero.
832 */
833 int fat_scan(struct inode *dir, const unsigned char *name,
834 struct fat_slot_info *sinfo)
835 {
836 struct super_block *sb = dir->i_sb;
837
838 sinfo->slot_off = 0;
839 sinfo->bh = NULL;
840 while (fat_get_short_entry(dir, &sinfo->slot_off, &sinfo->bh,
841 &sinfo->de) >= 0) {
842 if (!strncmp(sinfo->de->name, name, MSDOS_NAME)) {
843 sinfo->slot_off -= sizeof(*sinfo->de);
844 sinfo->nr_slots = 1;
845 sinfo->i_pos = fat_make_i_pos(sb, sinfo->bh, sinfo->de);
846 return 0;
847 }
848 }
849 return -ENOENT;
850 }
851
852 EXPORT_SYMBOL_GPL(fat_scan);
853
854 static int __fat_remove_entries(struct inode *dir, loff_t pos, int nr_slots)
855 {
856 struct super_block *sb = dir->i_sb;
857 struct buffer_head *bh;
858 struct msdos_dir_entry *de, *endp;
859 int err = 0, orig_slots;
860
861 while (nr_slots) {
862 bh = NULL;
863 if (fat_get_entry(dir, &pos, &bh, &de) < 0) {
864 err = -EIO;
865 break;
866 }
867
868 orig_slots = nr_slots;
869 endp = (struct msdos_dir_entry *)(bh->b_data + sb->s_blocksize);
870 while (nr_slots && de < endp) {
871 de->name[0] = DELETED_FLAG;
872 de++;
873 nr_slots--;
874 }
875 mark_buffer_dirty(bh);
876 if (IS_DIRSYNC(dir))
877 err = sync_dirty_buffer(bh);
878 brelse(bh);
879 if (err)
880 break;
881
882 /* pos is *next* de's position, so this does `- sizeof(de)' */
883 pos += ((orig_slots - nr_slots) * sizeof(*de)) - sizeof(*de);
884 }
885
886 return err;
887 }
888
889 int fat_remove_entries(struct inode *dir, struct fat_slot_info *sinfo)
890 {
891 struct msdos_dir_entry *de;
892 struct buffer_head *bh;
893 int err = 0, nr_slots;
894
895 /*
896 * First stage: Remove the shortname. By this, the directory
897 * entry is removed.
898 */
899 nr_slots = sinfo->nr_slots;
900 de = sinfo->de;
901 sinfo->de = NULL;
902 bh = sinfo->bh;
903 sinfo->bh = NULL;
904 while (nr_slots && de >= (struct msdos_dir_entry *)bh->b_data) {
905 de->name[0] = DELETED_FLAG;
906 de--;
907 nr_slots--;
908 }
909 mark_buffer_dirty(bh);
910 if (IS_DIRSYNC(dir))
911 err = sync_dirty_buffer(bh);
912 brelse(bh);
913 if (err)
914 return err;
915 dir->i_version++;
916
917 if (nr_slots) {
918 /*
919 * Second stage: remove the remaining longname slots.
920 * (This directory entry is already removed, and so return
921 * the success)
922 */
923 err = __fat_remove_entries(dir, sinfo->slot_off, nr_slots);
924 if (err) {
925 printk(KERN_WARNING
926 "FAT: Couldn't remove the long name slots\n");
927 }
928 }
929
930 dir->i_mtime = dir->i_atime = CURRENT_TIME_SEC;
931 if (IS_DIRSYNC(dir))
932 (void)fat_sync_inode(dir);
933 else
934 mark_inode_dirty(dir);
935
936 return 0;
937 }
938
939 EXPORT_SYMBOL_GPL(fat_remove_entries);
940
941 static int fat_zeroed_cluster(struct inode *dir, sector_t blknr, int nr_used,
942 struct buffer_head **bhs, int nr_bhs)
943 {
944 struct super_block *sb = dir->i_sb;
945 sector_t last_blknr = blknr + MSDOS_SB(sb)->sec_per_clus;
946 int err, i, n;
947
948 /* Zeroing the unused blocks on this cluster */
949 blknr += nr_used;
950 n = nr_used;
951 while (blknr < last_blknr) {
952 bhs[n] = sb_getblk(sb, blknr);
953 if (!bhs[n]) {
954 err = -ENOMEM;
955 goto error;
956 }
957 memset(bhs[n]->b_data, 0, sb->s_blocksize);
958 set_buffer_uptodate(bhs[n]);
959 mark_buffer_dirty(bhs[n]);
960
961 n++;
962 blknr++;
963 if (n == nr_bhs) {
964 if (IS_DIRSYNC(dir)) {
965 err = fat_sync_bhs(bhs, n);
966 if (err)
967 goto error;
968 }
969 for (i = 0; i < n; i++)
970 brelse(bhs[i]);
971 n = 0;
972 }
973 }
974 if (IS_DIRSYNC(dir)) {
975 err = fat_sync_bhs(bhs, n);
976 if (err)
977 goto error;
978 }
979 for (i = 0; i < n; i++)
980 brelse(bhs[i]);
981
982 return 0;
983
984 error:
985 for (i = 0; i < n; i++)
986 bforget(bhs[i]);
987 return err;
988 }
989
990 int fat_alloc_new_dir(struct inode *dir, struct timespec *ts)
991 {
992 struct super_block *sb = dir->i_sb;
993 struct msdos_sb_info *sbi = MSDOS_SB(sb);
994 struct buffer_head *bhs[MAX_BUF_PER_PAGE];
995 struct msdos_dir_entry *de;
996 sector_t blknr;
997 __le16 date, time;
998 int err, cluster;
999
1000 err = fat_alloc_clusters(dir, &cluster, 1);
1001 if (err)
1002 goto error;
1003
1004 blknr = fat_clus_to_blknr(sbi, cluster);
1005 bhs[0] = sb_getblk(sb, blknr);
1006 if (!bhs[0]) {
1007 err = -ENOMEM;
1008 goto error_free;
1009 }
1010
1011 fat_date_unix2dos(ts->tv_sec, &time, &date);
1012
1013 de = (struct msdos_dir_entry *)bhs[0]->b_data;
1014 /* filling the new directory slots ("." and ".." entries) */
1015 memcpy(de[0].name, MSDOS_DOT, MSDOS_NAME);
1016 memcpy(de[1].name, MSDOS_DOTDOT, MSDOS_NAME);
1017 de->attr = de[1].attr = ATTR_DIR;
1018 de[0].lcase = de[1].lcase = 0;
1019 de[0].time = de[1].time = time;
1020 de[0].date = de[1].date = date;
1021 de[0].ctime_cs = de[1].ctime_cs = 0;
1022 if (sbi->options.isvfat) {
1023 /* extra timestamps */
1024 de[0].ctime = de[1].ctime = time;
1025 de[0].adate = de[0].cdate = de[1].adate = de[1].cdate = date;
1026 } else {
1027 de[0].ctime = de[1].ctime = 0;
1028 de[0].adate = de[0].cdate = de[1].adate = de[1].cdate = 0;
1029 }
1030 de[0].start = cpu_to_le16(cluster);
1031 de[0].starthi = cpu_to_le16(cluster >> 16);
1032 de[1].start = cpu_to_le16(MSDOS_I(dir)->i_logstart);
1033 de[1].starthi = cpu_to_le16(MSDOS_I(dir)->i_logstart >> 16);
1034 de[0].size = de[1].size = 0;
1035 memset(de + 2, 0, sb->s_blocksize - 2 * sizeof(*de));
1036 set_buffer_uptodate(bhs[0]);
1037 mark_buffer_dirty(bhs[0]);
1038
1039 err = fat_zeroed_cluster(dir, blknr, 1, bhs, MAX_BUF_PER_PAGE);
1040 if (err)
1041 goto error_free;
1042
1043 return cluster;
1044
1045 error_free:
1046 fat_free_clusters(dir, cluster);
1047 error:
1048 return err;
1049 }
1050
1051 EXPORT_SYMBOL_GPL(fat_alloc_new_dir);
1052
1053 static int fat_add_new_entries(struct inode *dir, void *slots, int nr_slots,
1054 int *nr_cluster, struct msdos_dir_entry **de,
1055 struct buffer_head **bh, loff_t *i_pos)
1056 {
1057 struct super_block *sb = dir->i_sb;
1058 struct msdos_sb_info *sbi = MSDOS_SB(sb);
1059 struct buffer_head *bhs[MAX_BUF_PER_PAGE];
1060 sector_t blknr, start_blknr, last_blknr;
1061 unsigned long size, copy;
1062 int err, i, n, offset, cluster[2];
1063
1064 /*
1065 * The minimum cluster size is 512bytes, and maximum entry
1066 * size is 32*slots (672bytes). So, iff the cluster size is
1067 * 512bytes, we may need two clusters.
1068 */
1069 size = nr_slots * sizeof(struct msdos_dir_entry);
1070 *nr_cluster = (size + (sbi->cluster_size - 1)) >> sbi->cluster_bits;
1071 BUG_ON(*nr_cluster > 2);
1072
1073 err = fat_alloc_clusters(dir, cluster, *nr_cluster);
1074 if (err)
1075 goto error;
1076
1077 /*
1078 * First stage: Fill the directory entry. NOTE: This cluster
1079 * is not referenced from any inode yet, so updates order is
1080 * not important.
1081 */
1082 i = n = copy = 0;
1083 do {
1084 start_blknr = blknr = fat_clus_to_blknr(sbi, cluster[i]);
1085 last_blknr = start_blknr + sbi->sec_per_clus;
1086 while (blknr < last_blknr) {
1087 bhs[n] = sb_getblk(sb, blknr);
1088 if (!bhs[n]) {
1089 err = -ENOMEM;
1090 goto error_nomem;
1091 }
1092
1093 /* fill the directory entry */
1094 copy = min(size, sb->s_blocksize);
1095 memcpy(bhs[n]->b_data, slots, copy);
1096 slots += copy;
1097 size -= copy;
1098 set_buffer_uptodate(bhs[n]);
1099 mark_buffer_dirty(bhs[n]);
1100 if (!size)
1101 break;
1102 n++;
1103 blknr++;
1104 }
1105 } while (++i < *nr_cluster);
1106
1107 memset(bhs[n]->b_data + copy, 0, sb->s_blocksize - copy);
1108 offset = copy - sizeof(struct msdos_dir_entry);
1109 get_bh(bhs[n]);
1110 *bh = bhs[n];
1111 *de = (struct msdos_dir_entry *)((*bh)->b_data + offset);
1112 *i_pos = fat_make_i_pos(sb, *bh, *de);
1113
1114 /* Second stage: clear the rest of cluster, and write outs */
1115 err = fat_zeroed_cluster(dir, start_blknr, ++n, bhs, MAX_BUF_PER_PAGE);
1116 if (err)
1117 goto error_free;
1118
1119 return cluster[0];
1120
1121 error_free:
1122 brelse(*bh);
1123 *bh = NULL;
1124 n = 0;
1125 error_nomem:
1126 for (i = 0; i < n; i++)
1127 bforget(bhs[i]);
1128 fat_free_clusters(dir, cluster[0]);
1129 error:
1130 return err;
1131 }
1132
1133 int fat_add_entries(struct inode *dir, void *slots, int nr_slots,
1134 struct fat_slot_info *sinfo)
1135 {
1136 struct super_block *sb = dir->i_sb;
1137 struct msdos_sb_info *sbi = MSDOS_SB(sb);
1138 struct buffer_head *bh, *prev, *bhs[3]; /* 32*slots (672bytes) */
1139 struct msdos_dir_entry *de;
1140 int err, free_slots, i, nr_bhs;
1141 loff_t pos, i_pos;
1142
1143 sinfo->nr_slots = nr_slots;
1144
1145 /* First stage: search free direcotry entries */
1146 free_slots = nr_bhs = 0;
1147 bh = prev = NULL;
1148 pos = 0;
1149 err = -ENOSPC;
1150 while (fat_get_entry(dir, &pos, &bh, &de) > -1) {
1151 /* check the maximum size of directory */
1152 if (pos >= FAT_MAX_DIR_SIZE)
1153 goto error;
1154
1155 if (IS_FREE(de->name)) {
1156 if (prev != bh) {
1157 get_bh(bh);
1158 bhs[nr_bhs] = prev = bh;
1159 nr_bhs++;
1160 }
1161 free_slots++;
1162 if (free_slots == nr_slots)
1163 goto found;
1164 } else {
1165 for (i = 0; i < nr_bhs; i++)
1166 brelse(bhs[i]);
1167 prev = NULL;
1168 free_slots = nr_bhs = 0;
1169 }
1170 }
1171 if (dir->i_ino == MSDOS_ROOT_INO) {
1172 if (sbi->fat_bits != 32)
1173 goto error;
1174 } else if (MSDOS_I(dir)->i_start == 0) {
1175 printk(KERN_ERR "FAT: Corrupted directory (i_pos %lld)\n",
1176 MSDOS_I(dir)->i_pos);
1177 err = -EIO;
1178 goto error;
1179 }
1180
1181 found:
1182 err = 0;
1183 pos -= free_slots * sizeof(*de);
1184 nr_slots -= free_slots;
1185 if (free_slots) {
1186 /*
1187 * Second stage: filling the free entries with new entries.
1188 * NOTE: If this slots has shortname, first, we write
1189 * the long name slots, then write the short name.
1190 */
1191 int size = free_slots * sizeof(*de);
1192 int offset = pos & (sb->s_blocksize - 1);
1193 int long_bhs = nr_bhs - (nr_slots == 0);
1194
1195 /* Fill the long name slots. */
1196 for (i = 0; i < long_bhs; i++) {
1197 int copy = min_t(int, sb->s_blocksize - offset, size);
1198 memcpy(bhs[i]->b_data + offset, slots, copy);
1199 mark_buffer_dirty(bhs[i]);
1200 offset = 0;
1201 slots += copy;
1202 size -= copy;
1203 }
1204 if (long_bhs && IS_DIRSYNC(dir))
1205 err = fat_sync_bhs(bhs, long_bhs);
1206 if (!err && i < nr_bhs) {
1207 /* Fill the short name slot. */
1208 int copy = min_t(int, sb->s_blocksize - offset, size);
1209 memcpy(bhs[i]->b_data + offset, slots, copy);
1210 mark_buffer_dirty(bhs[i]);
1211 if (IS_DIRSYNC(dir))
1212 err = sync_dirty_buffer(bhs[i]);
1213 }
1214 for (i = 0; i < nr_bhs; i++)
1215 brelse(bhs[i]);
1216 if (err)
1217 goto error_remove;
1218 }
1219
1220 if (nr_slots) {
1221 int cluster, nr_cluster;
1222
1223 /*
1224 * Third stage: allocate the cluster for new entries.
1225 * And initialize the cluster with new entries, then
1226 * add the cluster to dir.
1227 */
1228 cluster = fat_add_new_entries(dir, slots, nr_slots, &nr_cluster,
1229 &de, &bh, &i_pos);
1230 if (cluster < 0) {
1231 err = cluster;
1232 goto error_remove;
1233 }
1234 err = fat_chain_add(dir, cluster, nr_cluster);
1235 if (err) {
1236 fat_free_clusters(dir, cluster);
1237 goto error_remove;
1238 }
1239 if (dir->i_size & (sbi->cluster_size - 1)) {
1240 fat_fs_panic(sb, "Odd directory size");
1241 dir->i_size = (dir->i_size + sbi->cluster_size - 1)
1242 & ~((loff_t)sbi->cluster_size - 1);
1243 }
1244 dir->i_size += nr_cluster << sbi->cluster_bits;
1245 MSDOS_I(dir)->mmu_private += nr_cluster << sbi->cluster_bits;
1246 }
1247 sinfo->slot_off = pos;
1248 sinfo->de = de;
1249 sinfo->bh = bh;
1250 sinfo->i_pos = fat_make_i_pos(sb, sinfo->bh, sinfo->de);
1251
1252 return 0;
1253
1254 error:
1255 brelse(bh);
1256 for (i = 0; i < nr_bhs; i++)
1257 brelse(bhs[i]);
1258 return err;
1259
1260 error_remove:
1261 brelse(bh);
1262 if (free_slots)
1263 __fat_remove_entries(dir, pos, free_slots);
1264 return err;
1265 }
1266
1267 EXPORT_SYMBOL_GPL(fat_add_entries);
linux-next