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Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/avi/kvm
[wrt350n-kernel.git] / fs / fat / dir.c
blobc16af246d245ddd45daf90a59ef0612fe5904dac
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 <linux/compat.h>
24 #include <asm/uaccess.h>
25
26 static inline loff_t fat_make_i_pos(struct super_block *sb,
27 struct buffer_head *bh,
28 struct msdos_dir_entry *de)
29 {
30 return ((loff_t)bh->b_blocknr << MSDOS_SB(sb)->dir_per_block_bits)
31 | (de - (struct msdos_dir_entry *)bh->b_data);
32 }
33
34 static inline void fat_dir_readahead(struct inode *dir, sector_t iblock,
35 sector_t phys)
36 {
37 struct super_block *sb = dir->i_sb;
38 struct msdos_sb_info *sbi = MSDOS_SB(sb);
39 struct buffer_head *bh;
40 int sec;
41
42 /* This is not a first sector of cluster, or sec_per_clus == 1 */
43 if ((iblock & (sbi->sec_per_clus - 1)) || sbi->sec_per_clus == 1)
44 return;
45 /* root dir of FAT12/FAT16 */
46 if ((sbi->fat_bits != 32) && (dir->i_ino == MSDOS_ROOT_INO))
47 return;
48
49 bh = sb_find_get_block(sb, phys);
50 if (bh == NULL || !buffer_uptodate(bh)) {
51 for (sec = 0; sec < sbi->sec_per_clus; sec++)
52 sb_breadahead(sb, phys + sec);
53 }
54 brelse(bh);
55 }
56
57 /* Returns the inode number of the directory entry at offset pos. If bh is
58 non-NULL, it is brelse'd before. Pos is incremented. The buffer header is
59 returned in bh.
60 AV. Most often we do it item-by-item. Makes sense to optimize.
61 AV. OK, there we go: if both bh and de are non-NULL we assume that we just
62 AV. want the next entry (took one explicit de=NULL in vfat/namei.c).
63 AV. It's done in fat_get_entry() (inlined), here the slow case lives.
64 AV. Additionally, when we return -1 (i.e. reached the end of directory)
65 AV. we make bh NULL.
66 */
67 static int fat__get_entry(struct inode *dir, loff_t *pos,
68 struct buffer_head **bh, struct msdos_dir_entry **de)
69 {
70 struct super_block *sb = dir->i_sb;
71 sector_t phys, iblock;
72 unsigned long mapped_blocks;
73 int err, offset;
74
75 next:
76 if (*bh)
77 brelse(*bh);
78
79 *bh = NULL;
80 iblock = *pos >> sb->s_blocksize_bits;
81 err = fat_bmap(dir, iblock, &phys, &mapped_blocks);
82 if (err || !phys)
83 return -1; /* beyond EOF or error */
84
85 fat_dir_readahead(dir, iblock, phys);
86
87 *bh = sb_bread(sb, phys);
88 if (*bh == NULL) {
89 printk(KERN_ERR "FAT: Directory bread(block %llu) failed\n",
90 (unsigned long long)phys);
91 /* skip this block */
92 *pos = (iblock + 1) << sb->s_blocksize_bits;
93 goto next;
94 }
95
96 offset = *pos & (sb->s_blocksize - 1);
97 *pos += sizeof(struct msdos_dir_entry);
98 *de = (struct msdos_dir_entry *)((*bh)->b_data + offset);
99
100 return 0;
101 }
102
103 static inline int fat_get_entry(struct inode *dir, loff_t *pos,
104 struct buffer_head **bh,
105 struct msdos_dir_entry **de)
106 {
107 /* Fast stuff first */
108 if (*bh && *de &&
109 (*de - (struct msdos_dir_entry *)(*bh)->b_data) < MSDOS_SB(dir->i_sb)->dir_per_block - 1) {
110 *pos += sizeof(struct msdos_dir_entry);
111 (*de)++;
112 return 0;
113 }
114 return fat__get_entry(dir, pos, bh, de);
115 }
116
117 /*
118 * Convert Unicode 16 to UTF-8, translated Unicode, or ASCII.
119 * If uni_xlate is enabled and we can't get a 1:1 conversion, use a
120 * colon as an escape character since it is normally invalid on the vfat
121 * filesystem. The following four characters are the hexadecimal digits
122 * of Unicode value. This lets us do a full dump and restore of Unicode
123 * filenames. We could get into some trouble with long Unicode names,
124 * but ignore that right now.
125 * Ahem... Stack smashing in ring 0 isn't fun. Fixed.
126 */
127 static int uni16_to_x8(unsigned char *ascii, wchar_t *uni, int uni_xlate,
128 struct nls_table *nls)
129 {
130 wchar_t *ip, ec;
131 unsigned char *op, nc;
132 int charlen;
133 int k;
134
135 ip = uni;
136 op = ascii;
137
138 while (*ip) {
139 ec = *ip++;
140 if ( (charlen = nls->uni2char(ec, op, NLS_MAX_CHARSET_SIZE)) > 0) {
141 op += charlen;
142 } else {
143 if (uni_xlate == 1) {
144 *op = ':';
145 for (k = 4; k > 0; k--) {
146 nc = ec & 0xF;
147 op[k] = nc > 9 ? nc + ('a' - 10)
148 : nc + '0';
149 ec >>= 4;
150 }
151 op += 5;
152 } else {
153 *op++ = '?';
154 }
155 }
156 /* We have some slack there, so it's OK */
157 if (op>ascii+256) {
158 op = ascii + 256;
159 break;
160 }
161 }
162 *op = 0;
163 return (op - ascii);
164 }
165
166 static inline int
167 fat_short2uni(struct nls_table *t, unsigned char *c, int clen, wchar_t *uni)
168 {
169 int charlen;
170
171 charlen = t->char2uni(c, clen, uni);
172 if (charlen < 0) {
173 *uni = 0x003f; /* a question mark */
174 charlen = 1;
175 }
176 return charlen;
177 }
178
179 static inline int
180 fat_short2lower_uni(struct nls_table *t, unsigned char *c, int clen, wchar_t *uni)
181 {
182 int charlen;
183 wchar_t wc;
184
185 charlen = t->char2uni(c, clen, &wc);
186 if (charlen < 0) {
187 *uni = 0x003f; /* a question mark */
188 charlen = 1;
189 } else if (charlen <= 1) {
190 unsigned char nc = t->charset2lower[*c];
191
192 if (!nc)
193 nc = *c;
194
195 if ( (charlen = t->char2uni(&nc, 1, uni)) < 0) {
196 *uni = 0x003f; /* a question mark */
197 charlen = 1;
198 }
199 } else
200 *uni = wc;
201
202 return charlen;
203 }
204
205 static inline int
206 fat_shortname2uni(struct nls_table *nls, unsigned char *buf, int buf_size,
207 wchar_t *uni_buf, unsigned short opt, int lower)
208 {
209 int len = 0;
210
211 if (opt & VFAT_SFN_DISPLAY_LOWER)
212 len = fat_short2lower_uni(nls, buf, buf_size, uni_buf);
213 else if (opt & VFAT_SFN_DISPLAY_WIN95)
214 len = fat_short2uni(nls, buf, buf_size, uni_buf);
215 else if (opt & VFAT_SFN_DISPLAY_WINNT) {
216 if (lower)
217 len = fat_short2lower_uni(nls, buf, buf_size, uni_buf);
218 else
219 len = fat_short2uni(nls, buf, buf_size, uni_buf);
220 } else
221 len = fat_short2uni(nls, buf, buf_size, uni_buf);
222
223 return len;
224 }
225
226 enum { PARSE_INVALID = 1, PARSE_NOT_LONGNAME, PARSE_EOF, };
227
228 /**
229 * fat_parse_long - Parse extended directory entry.
230 *
231 * This function returns zero on success, negative value on error, or one of
232 * the following:
233 *
234 * %PARSE_INVALID - Directory entry is invalid.
235 * %PARSE_NOT_LONGNAME - Directory entry does not contain longname.
236 * %PARSE_EOF - Directory has no more entries.
237 */
238 static int fat_parse_long(struct inode *dir, loff_t *pos,
239 struct buffer_head **bh, struct msdos_dir_entry **de,
240 wchar_t **unicode, unsigned char *nr_slots)
241 {
242 struct msdos_dir_slot *ds;
243 unsigned char id, slot, slots, alias_checksum;
244
245 if (!*unicode) {
246 *unicode = (wchar_t *)__get_free_page(GFP_KERNEL);
247 if (!*unicode) {
248 brelse(*bh);
249 return -ENOMEM;
250 }
251 }
252 parse_long:
253 slots = 0;
254 ds = (struct msdos_dir_slot *)*de;
255 id = ds->id;
256 if (!(id & 0x40))
257 return PARSE_INVALID;
258 slots = id & ~0x40;
259 if (slots > 20 || !slots) /* ceil(256 * 2 / 26) */
260 return PARSE_INVALID;
261 *nr_slots = slots;
262 alias_checksum = ds->alias_checksum;
263
264 slot = slots;
265 while (1) {
266 int offset;
267
268 slot--;
269 offset = slot * 13;
270 fat16_towchar(*unicode + offset, ds->name0_4, 5);
271 fat16_towchar(*unicode + offset + 5, ds->name5_10, 6);
272 fat16_towchar(*unicode + offset + 11, ds->name11_12, 2);
273
274 if (ds->id & 0x40)
275 (*unicode)[offset + 13] = 0;
276 if (fat_get_entry(dir, pos, bh, de) < 0)
277 return PARSE_EOF;
278 if (slot == 0)
279 break;
280 ds = (struct msdos_dir_slot *)*de;
281 if (ds->attr != ATTR_EXT)
282 return PARSE_NOT_LONGNAME;
283 if ((ds->id & ~0x40) != slot)
284 goto parse_long;
285 if (ds->alias_checksum != alias_checksum)
286 goto parse_long;
287 }
288 if ((*de)->name[0] == DELETED_FLAG)
289 return PARSE_INVALID;
290 if ((*de)->attr == ATTR_EXT)
291 goto parse_long;
292 if (IS_FREE((*de)->name) || ((*de)->attr & ATTR_VOLUME))
293 return PARSE_INVALID;
294 if (fat_checksum((*de)->name) != alias_checksum)
295 *nr_slots = 0;
296
297 return 0;
298 }
299
300 /*
301 * Return values: negative -> error, 0 -> not found, positive -> found,
302 * value is the total amount of slots, including the shortname entry.
303 */
304 int fat_search_long(struct inode *inode, const unsigned char *name,
305 int name_len, struct fat_slot_info *sinfo)
306 {
307 struct super_block *sb = inode->i_sb;
308 struct msdos_sb_info *sbi = MSDOS_SB(sb);
309 struct buffer_head *bh = NULL;
310 struct msdos_dir_entry *de;
311 struct nls_table *nls_io = sbi->nls_io;
312 struct nls_table *nls_disk = sbi->nls_disk;
313 wchar_t bufuname[14];
314 unsigned char xlate_len, nr_slots;
315 wchar_t *unicode = NULL;
316 unsigned char work[8], bufname[260]; /* 256 + 4 */
317 int uni_xlate = sbi->options.unicode_xlate;
318 int utf8 = sbi->options.utf8;
319 int anycase = (sbi->options.name_check != 's');
320 unsigned short opt_shortname = sbi->options.shortname;
321 loff_t cpos = 0;
322 int chl, i, j, last_u, err;
323
324 err = -ENOENT;
325 while(1) {
326 if (fat_get_entry(inode, &cpos, &bh, &de) == -1)
327 goto EODir;
328 parse_record:
329 nr_slots = 0;
330 if (de->name[0] == DELETED_FLAG)
331 continue;
332 if (de->attr != ATTR_EXT && (de->attr & ATTR_VOLUME))
333 continue;
334 if (de->attr != ATTR_EXT && IS_FREE(de->name))
335 continue;
336 if (de->attr == ATTR_EXT) {
337 int status = fat_parse_long(inode, &cpos, &bh, &de,
338 &unicode, &nr_slots);
339 if (status < 0)
340 return status;
341 else if (status == PARSE_INVALID)
342 continue;
343 else if (status == PARSE_NOT_LONGNAME)
344 goto parse_record;
345 else if (status == PARSE_EOF)
346 goto EODir;
347 }
348
349 memcpy(work, de->name, sizeof(de->name));
350 /* see namei.c, msdos_format_name */
351 if (work[0] == 0x05)
352 work[0] = 0xE5;
353 for (i = 0, j = 0, last_u = 0; i < 8;) {
354 if (!work[i]) break;
355 chl = fat_shortname2uni(nls_disk, &work[i], 8 - i,
356 &bufuname[j++], opt_shortname,
357 de->lcase & CASE_LOWER_BASE);
358 if (chl <= 1) {
359 if (work[i] != ' ')
360 last_u = j;
361 } else {
362 last_u = j;
363 }
364 i += chl;
365 }
366 j = last_u;
367 fat_short2uni(nls_disk, ".", 1, &bufuname[j++]);
368 for (i = 0; i < 3;) {
369 if (!de->ext[i]) break;
370 chl = fat_shortname2uni(nls_disk, &de->ext[i], 3 - i,
371 &bufuname[j++], opt_shortname,
372 de->lcase & CASE_LOWER_EXT);
373 if (chl <= 1) {
374 if (de->ext[i] != ' ')
375 last_u = j;
376 } else {
377 last_u = j;
378 }
379 i += chl;
380 }
381 if (!last_u)
382 continue;
383
384 bufuname[last_u] = 0x0000;
385 xlate_len = utf8
386 ?utf8_wcstombs(bufname, bufuname, sizeof(bufname))
387 :uni16_to_x8(bufname, bufuname, uni_xlate, nls_io);
388 if (xlate_len == name_len)
389 if ((!anycase && !memcmp(name, bufname, xlate_len)) ||
390 (anycase && !nls_strnicmp(nls_io, name, bufname,
391 xlate_len)))
392 goto Found;
393
394 if (nr_slots) {
395 xlate_len = utf8
396 ?utf8_wcstombs(bufname, unicode, sizeof(bufname))
397 :uni16_to_x8(bufname, unicode, uni_xlate, nls_io);
398 if (xlate_len != name_len)
399 continue;
400 if ((!anycase && !memcmp(name, bufname, xlate_len)) ||
401 (anycase && !nls_strnicmp(nls_io, name, bufname,
402 xlate_len)))
403 goto Found;
404 }
405 }
406
407 Found:
408 nr_slots++; /* include the de */
409 sinfo->slot_off = cpos - nr_slots * sizeof(*de);
410 sinfo->nr_slots = nr_slots;
411 sinfo->de = de;
412 sinfo->bh = bh;
413 sinfo->i_pos = fat_make_i_pos(sb, sinfo->bh, sinfo->de);
414 err = 0;
415 EODir:
416 if (unicode)
417 free_page((unsigned long)unicode);
418
419 return err;
420 }
421
422 EXPORT_SYMBOL_GPL(fat_search_long);
423
424 struct fat_ioctl_filldir_callback {
425 struct dirent __user *dirent;
426 int result;
427 /* for dir ioctl */
428 const char *longname;
429 int long_len;
430 const char *shortname;
431 int short_len;
432 };
433
434 static int __fat_readdir(struct inode *inode, struct file *filp, void *dirent,
435 filldir_t filldir, int short_only, int both)
436 {
437 struct super_block *sb = inode->i_sb;
438 struct msdos_sb_info *sbi = MSDOS_SB(sb);
439 struct buffer_head *bh;
440 struct msdos_dir_entry *de;
441 struct nls_table *nls_io = sbi->nls_io;
442 struct nls_table *nls_disk = sbi->nls_disk;
443 unsigned char long_slots;
444 const char *fill_name;
445 int fill_len;
446 wchar_t bufuname[14];
447 wchar_t *unicode = NULL;
448 unsigned char c, work[8], bufname[56], *ptname = bufname;
449 unsigned long lpos, dummy, *furrfu = &lpos;
450 int uni_xlate = sbi->options.unicode_xlate;
451 int isvfat = sbi->options.isvfat;
452 int utf8 = sbi->options.utf8;
453 int nocase = sbi->options.nocase;
454 unsigned short opt_shortname = sbi->options.shortname;
455 unsigned long inum;
456 int chi, chl, i, i2, j, last, last_u, dotoffset = 0;
457 loff_t cpos;
458 int ret = 0;
459
460 lock_kernel();
461
462 cpos = filp->f_pos;
463 /* Fake . and .. for the root directory. */
464 if (inode->i_ino == MSDOS_ROOT_INO) {
465 while (cpos < 2) {
466 if (filldir(dirent, "..", cpos+1, cpos, MSDOS_ROOT_INO, DT_DIR) < 0)
467 goto out;
468 cpos++;
469 filp->f_pos++;
470 }
471 if (cpos == 2) {
472 dummy = 2;
473 furrfu = &dummy;
474 cpos = 0;
475 }
476 }
477 if (cpos & (sizeof(struct msdos_dir_entry)-1)) {
478 ret = -ENOENT;
479 goto out;
480 }
481
482 bh = NULL;
483 GetNew:
484 if (fat_get_entry(inode, &cpos, &bh, &de) == -1)
485 goto EODir;
486 parse_record:
487 long_slots = 0;
488 /* Check for long filename entry */
489 if (isvfat) {
490 if (de->name[0] == DELETED_FLAG)
491 goto RecEnd;
492 if (de->attr != ATTR_EXT && (de->attr & ATTR_VOLUME))
493 goto RecEnd;
494 if (de->attr != ATTR_EXT && IS_FREE(de->name))
495 goto RecEnd;
496 } else {
497 if ((de->attr & ATTR_VOLUME) || IS_FREE(de->name))
498 goto RecEnd;
499 }
500
501 if (isvfat && de->attr == ATTR_EXT) {
502 int status = fat_parse_long(inode, &cpos, &bh, &de,
503 &unicode, &long_slots);
504 if (status < 0) {
505 filp->f_pos = cpos;
506 ret = status;
507 goto out;
508 } else if (status == PARSE_INVALID)
509 goto RecEnd;
510 else if (status == PARSE_NOT_LONGNAME)
511 goto parse_record;
512 else if (status == PARSE_EOF)
513 goto EODir;
514 }
515
516 if (sbi->options.dotsOK) {
517 ptname = bufname;
518 dotoffset = 0;
519 if (de->attr & ATTR_HIDDEN) {
520 *ptname++ = '.';
521 dotoffset = 1;
522 }
523 }
524
525 memcpy(work, de->name, sizeof(de->name));
526 /* see namei.c, msdos_format_name */
527 if (work[0] == 0x05)
528 work[0] = 0xE5;
529 for (i = 0, j = 0, last = 0, last_u = 0; i < 8;) {
530 if (!(c = work[i])) break;
531 chl = fat_shortname2uni(nls_disk, &work[i], 8 - i,
532 &bufuname[j++], opt_shortname,
533 de->lcase & CASE_LOWER_BASE);
534 if (chl <= 1) {
535 ptname[i++] = (!nocase && c>='A' && c<='Z') ? c+32 : c;
536 if (c != ' ') {
537 last = i;
538 last_u = j;
539 }
540 } else {
541 last_u = j;
542 for (chi = 0; chi < chl && i < 8; chi++) {
543 ptname[i] = work[i];
544 i++; last = i;
545 }
546 }
547 }
548 i = last;
549 j = last_u;
550 fat_short2uni(nls_disk, ".", 1, &bufuname[j++]);
551 ptname[i++] = '.';
552 for (i2 = 0; i2 < 3;) {
553 if (!(c = de->ext[i2])) break;
554 chl = fat_shortname2uni(nls_disk, &de->ext[i2], 3 - i2,
555 &bufuname[j++], opt_shortname,
556 de->lcase & CASE_LOWER_EXT);
557 if (chl <= 1) {
558 i2++;
559 ptname[i++] = (!nocase && c>='A' && c<='Z') ? c+32 : c;
560 if (c != ' ') {
561 last = i;
562 last_u = j;
563 }
564 } else {
565 last_u = j;
566 for (chi = 0; chi < chl && i2 < 3; chi++) {
567 ptname[i++] = de->ext[i2++];
568 last = i;
569 }
570 }
571 }
572 if (!last)
573 goto RecEnd;
574
575 i = last + dotoffset;
576 j = last_u;
577
578 lpos = cpos - (long_slots+1)*sizeof(struct msdos_dir_entry);
579 if (!memcmp(de->name, MSDOS_DOT, MSDOS_NAME))
580 inum = inode->i_ino;
581 else if (!memcmp(de->name, MSDOS_DOTDOT, MSDOS_NAME)) {
582 inum = parent_ino(filp->f_path.dentry);
583 } else {
584 loff_t i_pos = fat_make_i_pos(sb, bh, de);
585 struct inode *tmp = fat_iget(sb, i_pos);
586 if (tmp) {
587 inum = tmp->i_ino;
588 iput(tmp);
589 } else
590 inum = iunique(sb, MSDOS_ROOT_INO);
591 }
592
593 if (isvfat) {
594 bufuname[j] = 0x0000;
595 i = utf8 ? utf8_wcstombs(bufname, bufuname, sizeof(bufname))
596 : uni16_to_x8(bufname, bufuname, uni_xlate, nls_io);
597 }
598
599 fill_name = bufname;
600 fill_len = i;
601 if (!short_only && long_slots) {
602 /* convert the unicode long name. 261 is maximum size
603 * of unicode buffer. (13 * slots + nul) */
604 void *longname = unicode + 261;
605 int buf_size = PAGE_SIZE - (261 * sizeof(unicode[0]));
606 int long_len = utf8
607 ? utf8_wcstombs(longname, unicode, buf_size)
608 : uni16_to_x8(longname, unicode, uni_xlate, nls_io);
609
610 if (!both) {
611 fill_name = longname;
612 fill_len = long_len;
613 } else {
614 /* hack for fat_ioctl_filldir() */
615 struct fat_ioctl_filldir_callback *p = dirent;
616
617 p->longname = longname;
618 p->long_len = long_len;
619 p->shortname = bufname;
620 p->short_len = i;
621 fill_name = NULL;
622 fill_len = 0;
623 }
624 }
625 if (filldir(dirent, fill_name, fill_len, *furrfu, inum,
626 (de->attr & ATTR_DIR) ? DT_DIR : DT_REG) < 0)
627 goto FillFailed;
628
629 RecEnd:
630 furrfu = &lpos;
631 filp->f_pos = cpos;
632 goto GetNew;
633 EODir:
634 filp->f_pos = cpos;
635 FillFailed:
636 brelse(bh);
637 if (unicode)
638 free_page((unsigned long)unicode);
639 out:
640 unlock_kernel();
641 return ret;
642 }
643
644 static int fat_readdir(struct file *filp, void *dirent, filldir_t filldir)
645 {
646 struct inode *inode = filp->f_path.dentry->d_inode;
647 return __fat_readdir(inode, filp, dirent, filldir, 0, 0);
648 }
649
650 static int fat_ioctl_filldir(void *__buf, const char *name, int name_len,
651 loff_t offset, u64 ino, unsigned int d_type)
652 {
653 struct fat_ioctl_filldir_callback *buf = __buf;
654 struct dirent __user *d1 = buf->dirent;
655 struct dirent __user *d2 = d1 + 1;
656
657 if (buf->result)
658 return -EINVAL;
659 buf->result++;
660
661 if (name != NULL) {
662 /* dirent has only short name */
663 if (name_len >= sizeof(d1->d_name))
664 name_len = sizeof(d1->d_name) - 1;
665
666 if (put_user(0, d2->d_name) ||
667 put_user(0, &d2->d_reclen) ||
668 copy_to_user(d1->d_name, name, name_len) ||
669 put_user(0, d1->d_name + name_len) ||
670 put_user(name_len, &d1->d_reclen))
671 goto efault;
672 } else {
673 /* dirent has short and long name */
674 const char *longname = buf->longname;
675 int long_len = buf->long_len;
676 const char *shortname = buf->shortname;
677 int short_len = buf->short_len;
678
679 if (long_len >= sizeof(d1->d_name))
680 long_len = sizeof(d1->d_name) - 1;
681 if (short_len >= sizeof(d1->d_name))
682 short_len = sizeof(d1->d_name) - 1;
683
684 if (copy_to_user(d2->d_name, longname, long_len) ||
685 put_user(0, d2->d_name + long_len) ||
686 put_user(long_len, &d2->d_reclen) ||
687 put_user(ino, &d2->d_ino) ||
688 put_user(offset, &d2->d_off) ||
689 copy_to_user(d1->d_name, shortname, short_len) ||
690 put_user(0, d1->d_name + short_len) ||
691 put_user(short_len, &d1->d_reclen))
692 goto efault;
693 }
694 return 0;
695 efault:
696 buf->result = -EFAULT;
697 return -EFAULT;
698 }
699
700 static int fat_dir_ioctl(struct inode * inode, struct file * filp,
701 unsigned int cmd, unsigned long arg)
702 {
703 struct fat_ioctl_filldir_callback buf;
704 struct dirent __user *d1;
705 int ret, short_only, both;
706
707 switch (cmd) {
708 case VFAT_IOCTL_READDIR_SHORT:
709 short_only = 1;
710 both = 0;
711 break;
712 case VFAT_IOCTL_READDIR_BOTH:
713 short_only = 0;
714 both = 1;
715 break;
716 default:
717 return fat_generic_ioctl(inode, filp, cmd, arg);
718 }
719
720 d1 = (struct dirent __user *)arg;
721 if (!access_ok(VERIFY_WRITE, d1, sizeof(struct dirent[2])))
722 return -EFAULT;
723 /*
724 * Yes, we don't need this put_user() absolutely. However old
725 * code didn't return the right value. So, app use this value,
726 * in order to check whether it is EOF.
727 */
728 if (put_user(0, &d1->d_reclen))
729 return -EFAULT;
730
731 buf.dirent = d1;
732 buf.result = 0;
733 mutex_lock(&inode->i_mutex);
734 ret = -ENOENT;
735 if (!IS_DEADDIR(inode)) {
736 ret = __fat_readdir(inode, filp, &buf, fat_ioctl_filldir,
737 short_only, both);
738 }
739 mutex_unlock(&inode->i_mutex);
740 if (ret >= 0)
741 ret = buf.result;
742 return ret;
743 }
744
745 #ifdef CONFIG_COMPAT
746 #define VFAT_IOCTL_READDIR_BOTH32 _IOR('r', 1, struct compat_dirent[2])
747 #define VFAT_IOCTL_READDIR_SHORT32 _IOR('r', 2, struct compat_dirent[2])
748
749 static long fat_compat_put_dirent32(struct dirent *d,
750 struct compat_dirent __user *d32)
751 {
752 if (!access_ok(VERIFY_WRITE, d32, sizeof(struct compat_dirent)))
753 return -EFAULT;
754
755 __put_user(d->d_ino, &d32->d_ino);
756 __put_user(d->d_off, &d32->d_off);
757 __put_user(d->d_reclen, &d32->d_reclen);
758 if (__copy_to_user(d32->d_name, d->d_name, d->d_reclen))
759 return -EFAULT;
760
761 return 0;
762 }
763
764 static long fat_compat_dir_ioctl(struct file *file, unsigned cmd,
765 unsigned long arg)
766 {
767 struct compat_dirent __user *p = compat_ptr(arg);
768 int ret;
769 mm_segment_t oldfs = get_fs();
770 struct dirent d[2];
771
772 switch (cmd) {
773 case VFAT_IOCTL_READDIR_BOTH32:
774 cmd = VFAT_IOCTL_READDIR_BOTH;
775 break;
776 case VFAT_IOCTL_READDIR_SHORT32:
777 cmd = VFAT_IOCTL_READDIR_SHORT;
778 break;
779 default:
780 return -ENOIOCTLCMD;
781 }
782
783 set_fs(KERNEL_DS);
784 lock_kernel();
785 ret = fat_dir_ioctl(file->f_path.dentry->d_inode, file,
786 cmd, (unsigned long) &d);
787 unlock_kernel();
788 set_fs(oldfs);
789 if (ret >= 0) {
790 ret |= fat_compat_put_dirent32(&d[0], p);
791 ret |= fat_compat_put_dirent32(&d[1], p + 1);
792 }
793 return ret;
794 }
795 #endif /* CONFIG_COMPAT */
796
797 const struct file_operations fat_dir_operations = {
798 .read = generic_read_dir,
799 .readdir = fat_readdir,
800 .ioctl = fat_dir_ioctl,
801 #ifdef CONFIG_COMPAT
802 .compat_ioctl = fat_compat_dir_ioctl,
803 #endif
804 .fsync = file_fsync,
805 };
806
807 static int fat_get_short_entry(struct inode *dir, loff_t *pos,
808 struct buffer_head **bh,
809 struct msdos_dir_entry **de)
810 {
811 while (fat_get_entry(dir, pos, bh, de) >= 0) {
812 /* free entry or long name entry or volume label */
813 if (!IS_FREE((*de)->name) && !((*de)->attr & ATTR_VOLUME))
814 return 0;
815 }
816 return -ENOENT;
817 }
818
819 /*
820 * The ".." entry can not provide the "struct fat_slot_info" informations
821 * for inode. So, this function provide the some informations only.
822 */
823 int fat_get_dotdot_entry(struct inode *dir, struct buffer_head **bh,
824 struct msdos_dir_entry **de, loff_t *i_pos)
825 {
826 loff_t offset;
827
828 offset = 0;
829 *bh = NULL;
830 while (fat_get_short_entry(dir, &offset, bh, de) >= 0) {
831 if (!strncmp((*de)->name, MSDOS_DOTDOT, MSDOS_NAME)) {
832 *i_pos = fat_make_i_pos(dir->i_sb, *bh, *de);
833 return 0;
834 }
835 }
836 return -ENOENT;
837 }
838
839 EXPORT_SYMBOL_GPL(fat_get_dotdot_entry);
840
841 /* See if directory is empty */
842 int fat_dir_empty(struct inode *dir)
843 {
844 struct buffer_head *bh;
845 struct msdos_dir_entry *de;
846 loff_t cpos;
847 int result = 0;
848
849 bh = NULL;
850 cpos = 0;
851 while (fat_get_short_entry(dir, &cpos, &bh, &de) >= 0) {
852 if (strncmp(de->name, MSDOS_DOT , MSDOS_NAME) &&
853 strncmp(de->name, MSDOS_DOTDOT, MSDOS_NAME)) {
854 result = -ENOTEMPTY;
855 break;
856 }
857 }
858 brelse(bh);
859 return result;
860 }
861
862 EXPORT_SYMBOL_GPL(fat_dir_empty);
863
864 /*
865 * fat_subdirs counts the number of sub-directories of dir. It can be run
866 * on directories being created.
867 */
868 int fat_subdirs(struct inode *dir)
869 {
870 struct buffer_head *bh;
871 struct msdos_dir_entry *de;
872 loff_t cpos;
873 int count = 0;
874
875 bh = NULL;
876 cpos = 0;
877 while (fat_get_short_entry(dir, &cpos, &bh, &de) >= 0) {
878 if (de->attr & ATTR_DIR)
879 count++;
880 }
881 brelse(bh);
882 return count;
883 }
884
885 /*
886 * Scans a directory for a given file (name points to its formatted name).
887 * Returns an error code or zero.
888 */
889 int fat_scan(struct inode *dir, const unsigned char *name,
890 struct fat_slot_info *sinfo)
891 {
892 struct super_block *sb = dir->i_sb;
893
894 sinfo->slot_off = 0;
895 sinfo->bh = NULL;
896 while (fat_get_short_entry(dir, &sinfo->slot_off, &sinfo->bh,
897 &sinfo->de) >= 0) {
898 if (!strncmp(sinfo->de->name, name, MSDOS_NAME)) {
899 sinfo->slot_off -= sizeof(*sinfo->de);
900 sinfo->nr_slots = 1;
901 sinfo->i_pos = fat_make_i_pos(sb, sinfo->bh, sinfo->de);
902 return 0;
903 }
904 }
905 return -ENOENT;
906 }
907
908 EXPORT_SYMBOL_GPL(fat_scan);
909
910 static int __fat_remove_entries(struct inode *dir, loff_t pos, int nr_slots)
911 {
912 struct super_block *sb = dir->i_sb;
913 struct buffer_head *bh;
914 struct msdos_dir_entry *de, *endp;
915 int err = 0, orig_slots;
916
917 while (nr_slots) {
918 bh = NULL;
919 if (fat_get_entry(dir, &pos, &bh, &de) < 0) {
920 err = -EIO;
921 break;
922 }
923
924 orig_slots = nr_slots;
925 endp = (struct msdos_dir_entry *)(bh->b_data + sb->s_blocksize);
926 while (nr_slots && de < endp) {
927 de->name[0] = DELETED_FLAG;
928 de++;
929 nr_slots--;
930 }
931 mark_buffer_dirty(bh);
932 if (IS_DIRSYNC(dir))
933 err = sync_dirty_buffer(bh);
934 brelse(bh);
935 if (err)
936 break;
937
938 /* pos is *next* de's position, so this does `- sizeof(de)' */
939 pos += ((orig_slots - nr_slots) * sizeof(*de)) - sizeof(*de);
940 }
941
942 return err;
943 }
944
945 int fat_remove_entries(struct inode *dir, struct fat_slot_info *sinfo)
946 {
947 struct msdos_dir_entry *de;
948 struct buffer_head *bh;
949 int err = 0, nr_slots;
950
951 /*
952 * First stage: Remove the shortname. By this, the directory
953 * entry is removed.
954 */
955 nr_slots = sinfo->nr_slots;
956 de = sinfo->de;
957 sinfo->de = NULL;
958 bh = sinfo->bh;
959 sinfo->bh = NULL;
960 while (nr_slots && de >= (struct msdos_dir_entry *)bh->b_data) {
961 de->name[0] = DELETED_FLAG;
962 de--;
963 nr_slots--;
964 }
965 mark_buffer_dirty(bh);
966 if (IS_DIRSYNC(dir))
967 err = sync_dirty_buffer(bh);
968 brelse(bh);
969 if (err)
970 return err;
971 dir->i_version++;
972
973 if (nr_slots) {
974 /*
975 * Second stage: remove the remaining longname slots.
976 * (This directory entry is already removed, and so return
977 * the success)
978 */
979 err = __fat_remove_entries(dir, sinfo->slot_off, nr_slots);
980 if (err) {
981 printk(KERN_WARNING
982 "FAT: Couldn't remove the long name slots\n");
983 }
984 }
985
986 dir->i_mtime = dir->i_atime = CURRENT_TIME_SEC;
987 if (IS_DIRSYNC(dir))
988 (void)fat_sync_inode(dir);
989 else
990 mark_inode_dirty(dir);
991
992 return 0;
993 }
994
995 EXPORT_SYMBOL_GPL(fat_remove_entries);
996
997 static int fat_zeroed_cluster(struct inode *dir, sector_t blknr, int nr_used,
998 struct buffer_head **bhs, int nr_bhs)
999 {
1000 struct super_block *sb = dir->i_sb;
1001 sector_t last_blknr = blknr + MSDOS_SB(sb)->sec_per_clus;
1002 int err, i, n;
1003
1004 /* Zeroing the unused blocks on this cluster */
1005 blknr += nr_used;
1006 n = nr_used;
1007 while (blknr < last_blknr) {
1008 bhs[n] = sb_getblk(sb, blknr);
1009 if (!bhs[n]) {
1010 err = -ENOMEM;
1011 goto error;
1012 }
1013 memset(bhs[n]->b_data, 0, sb->s_blocksize);
1014 set_buffer_uptodate(bhs[n]);
1015 mark_buffer_dirty(bhs[n]);
1016
1017 n++;
1018 blknr++;
1019 if (n == nr_bhs) {
1020 if (IS_DIRSYNC(dir)) {
1021 err = fat_sync_bhs(bhs, n);
1022 if (err)
1023 goto error;
1024 }
1025 for (i = 0; i < n; i++)
1026 brelse(bhs[i]);
1027 n = 0;
1028 }
1029 }
1030 if (IS_DIRSYNC(dir)) {
1031 err = fat_sync_bhs(bhs, n);
1032 if (err)
1033 goto error;
1034 }
1035 for (i = 0; i < n; i++)
1036 brelse(bhs[i]);
1037
1038 return 0;
1039
1040 error:
1041 for (i = 0; i < n; i++)
1042 bforget(bhs[i]);
1043 return err;
1044 }
1045
1046 int fat_alloc_new_dir(struct inode *dir, struct timespec *ts)
1047 {
1048 struct super_block *sb = dir->i_sb;
1049 struct msdos_sb_info *sbi = MSDOS_SB(sb);
1050 struct buffer_head *bhs[MAX_BUF_PER_PAGE];
1051 struct msdos_dir_entry *de;
1052 sector_t blknr;
1053 __le16 date, time;
1054 int err, cluster;
1055
1056 err = fat_alloc_clusters(dir, &cluster, 1);
1057 if (err)
1058 goto error;
1059
1060 blknr = fat_clus_to_blknr(sbi, cluster);
1061 bhs[0] = sb_getblk(sb, blknr);
1062 if (!bhs[0]) {
1063 err = -ENOMEM;
1064 goto error_free;
1065 }
1066
1067 fat_date_unix2dos(ts->tv_sec, &time, &date);
1068
1069 de = (struct msdos_dir_entry *)bhs[0]->b_data;
1070 /* filling the new directory slots ("." and ".." entries) */
1071 memcpy(de[0].name, MSDOS_DOT, MSDOS_NAME);
1072 memcpy(de[1].name, MSDOS_DOTDOT, MSDOS_NAME);
1073 de->attr = de[1].attr = ATTR_DIR;
1074 de[0].lcase = de[1].lcase = 0;
1075 de[0].time = de[1].time = time;
1076 de[0].date = de[1].date = date;
1077 de[0].ctime_cs = de[1].ctime_cs = 0;
1078 if (sbi->options.isvfat) {
1079 /* extra timestamps */
1080 de[0].ctime = de[1].ctime = time;
1081 de[0].adate = de[0].cdate = de[1].adate = de[1].cdate = date;
1082 } else {
1083 de[0].ctime = de[1].ctime = 0;
1084 de[0].adate = de[0].cdate = de[1].adate = de[1].cdate = 0;
1085 }
1086 de[0].start = cpu_to_le16(cluster);
1087 de[0].starthi = cpu_to_le16(cluster >> 16);
1088 de[1].start = cpu_to_le16(MSDOS_I(dir)->i_logstart);
1089 de[1].starthi = cpu_to_le16(MSDOS_I(dir)->i_logstart >> 16);
1090 de[0].size = de[1].size = 0;
1091 memset(de + 2, 0, sb->s_blocksize - 2 * sizeof(*de));
1092 set_buffer_uptodate(bhs[0]);
1093 mark_buffer_dirty(bhs[0]);
1094
1095 err = fat_zeroed_cluster(dir, blknr, 1, bhs, MAX_BUF_PER_PAGE);
1096 if (err)
1097 goto error_free;
1098
1099 return cluster;
1100
1101 error_free:
1102 fat_free_clusters(dir, cluster);
1103 error:
1104 return err;
1105 }
1106
1107 EXPORT_SYMBOL_GPL(fat_alloc_new_dir);
1108
1109 static int fat_add_new_entries(struct inode *dir, void *slots, int nr_slots,
1110 int *nr_cluster, struct msdos_dir_entry **de,
1111 struct buffer_head **bh, loff_t *i_pos)
1112 {
1113 struct super_block *sb = dir->i_sb;
1114 struct msdos_sb_info *sbi = MSDOS_SB(sb);
1115 struct buffer_head *bhs[MAX_BUF_PER_PAGE];
1116 sector_t blknr, start_blknr, last_blknr;
1117 unsigned long size, copy;
1118 int err, i, n, offset, cluster[2];
1119
1120 /*
1121 * The minimum cluster size is 512bytes, and maximum entry
1122 * size is 32*slots (672bytes). So, iff the cluster size is
1123 * 512bytes, we may need two clusters.
1124 */
1125 size = nr_slots * sizeof(struct msdos_dir_entry);
1126 *nr_cluster = (size + (sbi->cluster_size - 1)) >> sbi->cluster_bits;
1127 BUG_ON(*nr_cluster > 2);
1128
1129 err = fat_alloc_clusters(dir, cluster, *nr_cluster);
1130 if (err)
1131 goto error;
1132
1133 /*
1134 * First stage: Fill the directory entry. NOTE: This cluster
1135 * is not referenced from any inode yet, so updates order is
1136 * not important.
1137 */
1138 i = n = copy = 0;
1139 do {
1140 start_blknr = blknr = fat_clus_to_blknr(sbi, cluster[i]);
1141 last_blknr = start_blknr + sbi->sec_per_clus;
1142 while (blknr < last_blknr) {
1143 bhs[n] = sb_getblk(sb, blknr);
1144 if (!bhs[n]) {
1145 err = -ENOMEM;
1146 goto error_nomem;
1147 }
1148
1149 /* fill the directory entry */
1150 copy = min(size, sb->s_blocksize);
1151 memcpy(bhs[n]->b_data, slots, copy);
1152 slots += copy;
1153 size -= copy;
1154 set_buffer_uptodate(bhs[n]);
1155 mark_buffer_dirty(bhs[n]);
1156 if (!size)
1157 break;
1158 n++;
1159 blknr++;
1160 }
1161 } while (++i < *nr_cluster);
1162
1163 memset(bhs[n]->b_data + copy, 0, sb->s_blocksize - copy);
1164 offset = copy - sizeof(struct msdos_dir_entry);
1165 get_bh(bhs[n]);
1166 *bh = bhs[n];
1167 *de = (struct msdos_dir_entry *)((*bh)->b_data + offset);
1168 *i_pos = fat_make_i_pos(sb, *bh, *de);
1169
1170 /* Second stage: clear the rest of cluster, and write outs */
1171 err = fat_zeroed_cluster(dir, start_blknr, ++n, bhs, MAX_BUF_PER_PAGE);
1172 if (err)
1173 goto error_free;
1174
1175 return cluster[0];
1176
1177 error_free:
1178 brelse(*bh);
1179 *bh = NULL;
1180 n = 0;
1181 error_nomem:
1182 for (i = 0; i < n; i++)
1183 bforget(bhs[i]);
1184 fat_free_clusters(dir, cluster[0]);
1185 error:
1186 return err;
1187 }
1188
1189 int fat_add_entries(struct inode *dir, void *slots, int nr_slots,
1190 struct fat_slot_info *sinfo)
1191 {
1192 struct super_block *sb = dir->i_sb;
1193 struct msdos_sb_info *sbi = MSDOS_SB(sb);
1194 struct buffer_head *bh, *prev, *bhs[3]; /* 32*slots (672bytes) */
1195 struct msdos_dir_entry *de;
1196 int err, free_slots, i, nr_bhs;
1197 loff_t pos, i_pos;
1198
1199 sinfo->nr_slots = nr_slots;
1200
1201 /* First stage: search free direcotry entries */
1202 free_slots = nr_bhs = 0;
1203 bh = prev = NULL;
1204 pos = 0;
1205 err = -ENOSPC;
1206 while (fat_get_entry(dir, &pos, &bh, &de) > -1) {
1207 /* check the maximum size of directory */
1208 if (pos >= FAT_MAX_DIR_SIZE)
1209 goto error;
1210
1211 if (IS_FREE(de->name)) {
1212 if (prev != bh) {
1213 get_bh(bh);
1214 bhs[nr_bhs] = prev = bh;
1215 nr_bhs++;
1216 }
1217 free_slots++;
1218 if (free_slots == nr_slots)
1219 goto found;
1220 } else {
1221 for (i = 0; i < nr_bhs; i++)
1222 brelse(bhs[i]);
1223 prev = NULL;
1224 free_slots = nr_bhs = 0;
1225 }
1226 }
1227 if (dir->i_ino == MSDOS_ROOT_INO) {
1228 if (sbi->fat_bits != 32)
1229 goto error;
1230 } else if (MSDOS_I(dir)->i_start == 0) {
1231 printk(KERN_ERR "FAT: Corrupted directory (i_pos %lld)\n",
1232 MSDOS_I(dir)->i_pos);
1233 err = -EIO;
1234 goto error;
1235 }
1236
1237 found:
1238 err = 0;
1239 pos -= free_slots * sizeof(*de);
1240 nr_slots -= free_slots;
1241 if (free_slots) {
1242 /*
1243 * Second stage: filling the free entries with new entries.
1244 * NOTE: If this slots has shortname, first, we write
1245 * the long name slots, then write the short name.
1246 */
1247 int size = free_slots * sizeof(*de);
1248 int offset = pos & (sb->s_blocksize - 1);
1249 int long_bhs = nr_bhs - (nr_slots == 0);
1250
1251 /* Fill the long name slots. */
1252 for (i = 0; i < long_bhs; i++) {
1253 int copy = min_t(int, sb->s_blocksize - offset, size);
1254 memcpy(bhs[i]->b_data + offset, slots, copy);
1255 mark_buffer_dirty(bhs[i]);
1256 offset = 0;
1257 slots += copy;
1258 size -= copy;
1259 }
1260 if (long_bhs && IS_DIRSYNC(dir))
1261 err = fat_sync_bhs(bhs, long_bhs);
1262 if (!err && i < nr_bhs) {
1263 /* Fill the short name slot. */
1264 int copy = min_t(int, sb->s_blocksize - offset, size);
1265 memcpy(bhs[i]->b_data + offset, slots, copy);
1266 mark_buffer_dirty(bhs[i]);
1267 if (IS_DIRSYNC(dir))
1268 err = sync_dirty_buffer(bhs[i]);
1269 }
1270 for (i = 0; i < nr_bhs; i++)
1271 brelse(bhs[i]);
1272 if (err)
1273 goto error_remove;
1274 }
1275
1276 if (nr_slots) {
1277 int cluster, nr_cluster;
1278
1279 /*
1280 * Third stage: allocate the cluster for new entries.
1281 * And initialize the cluster with new entries, then
1282 * add the cluster to dir.
1283 */
1284 cluster = fat_add_new_entries(dir, slots, nr_slots, &nr_cluster,
1285 &de, &bh, &i_pos);
1286 if (cluster < 0) {
1287 err = cluster;
1288 goto error_remove;
1289 }
1290 err = fat_chain_add(dir, cluster, nr_cluster);
1291 if (err) {
1292 fat_free_clusters(dir, cluster);
1293 goto error_remove;
1294 }
1295 if (dir->i_size & (sbi->cluster_size - 1)) {
1296 fat_fs_panic(sb, "Odd directory size");
1297 dir->i_size = (dir->i_size + sbi->cluster_size - 1)
1298 & ~((loff_t)sbi->cluster_size - 1);
1299 }
1300 dir->i_size += nr_cluster << sbi->cluster_bits;
1301 MSDOS_I(dir)->mmu_private += nr_cluster << sbi->cluster_bits;
1302 }
1303 sinfo->slot_off = pos;
1304 sinfo->de = de;
1305 sinfo->bh = bh;
1306 sinfo->i_pos = fat_make_i_pos(sb, sinfo->bh, sinfo->de);
1307
1308 return 0;
1309
1310 error:
1311 brelse(bh);
1312 for (i = 0; i < nr_bhs; i++)
1313 brelse(bhs[i]);
1314 return err;
1315
1316 error_remove:
1317 brelse(bh);
1318 if (free_slots)
1319 __fat_remove_entries(dir, pos, free_slots);
1320 return err;
1321 }
1322
1323 EXPORT_SYMBOL_GPL(fat_add_entries);
WRT350N Kernel Patches