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Pull sn-features into release branch
[deliverable/linux.git] / fs / fat / dir.c
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_getblk(sb, phys);
49 if (bh && !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 int offset;
72 int err;
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);
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 /*
226 * Return values: negative -> error, 0 -> not found, positive -> found,
227 * value is the total amount of slots, including the shortname entry.
228 */
229 int fat_search_long(struct inode *inode, const unsigned char *name,
230 int name_len, struct fat_slot_info *sinfo)
231 {
232 struct super_block *sb = inode->i_sb;
233 struct msdos_sb_info *sbi = MSDOS_SB(sb);
234 struct buffer_head *bh = NULL;
235 struct msdos_dir_entry *de;
236 struct nls_table *nls_io = sbi->nls_io;
237 struct nls_table *nls_disk = sbi->nls_disk;
238 wchar_t bufuname[14];
239 unsigned char xlate_len, nr_slots;
240 wchar_t *unicode = NULL;
241 unsigned char work[8], bufname[260]; /* 256 + 4 */
242 int uni_xlate = sbi->options.unicode_xlate;
243 int utf8 = sbi->options.utf8;
244 int anycase = (sbi->options.name_check != 's');
245 unsigned short opt_shortname = sbi->options.shortname;
246 loff_t cpos = 0;
247 int chl, i, j, last_u, err;
248
249 err = -ENOENT;
250 while(1) {
251 if (fat_get_entry(inode, &cpos, &bh, &de) == -1)
252 goto EODir;
253 parse_record:
254 nr_slots = 0;
255 if (de->name[0] == DELETED_FLAG)
256 continue;
257 if (de->attr != ATTR_EXT && (de->attr & ATTR_VOLUME))
258 continue;
259 if (de->attr != ATTR_EXT && IS_FREE(de->name))
260 continue;
261 if (de->attr == ATTR_EXT) {
262 struct msdos_dir_slot *ds;
263 unsigned char id;
264 unsigned char slot;
265 unsigned char slots;
266 unsigned char sum;
267 unsigned char alias_checksum;
268
269 if (!unicode) {
270 unicode = (wchar_t *)
271 __get_free_page(GFP_KERNEL);
272 if (!unicode) {
273 brelse(bh);
274 return -ENOMEM;
275 }
276 }
277 parse_long:
278 slots = 0;
279 ds = (struct msdos_dir_slot *) de;
280 id = ds->id;
281 if (!(id & 0x40))
282 continue;
283 slots = id & ~0x40;
284 if (slots > 20 || !slots) /* ceil(256 * 2 / 26) */
285 continue;
286 nr_slots = slots;
287 alias_checksum = ds->alias_checksum;
288
289 slot = slots;
290 while (1) {
291 int offset;
292
293 slot--;
294 offset = slot * 13;
295 fat16_towchar(unicode + offset, ds->name0_4, 5);
296 fat16_towchar(unicode + offset + 5, ds->name5_10, 6);
297 fat16_towchar(unicode + offset + 11, ds->name11_12, 2);
298
299 if (ds->id & 0x40) {
300 unicode[offset + 13] = 0;
301 }
302 if (fat_get_entry(inode, &cpos, &bh, &de) < 0)
303 goto EODir;
304 if (slot == 0)
305 break;
306 ds = (struct msdos_dir_slot *) de;
307 if (ds->attr != ATTR_EXT)
308 goto parse_record;
309 if ((ds->id & ~0x40) != slot)
310 goto parse_long;
311 if (ds->alias_checksum != alias_checksum)
312 goto parse_long;
313 }
314 if (de->name[0] == DELETED_FLAG)
315 continue;
316 if (de->attr == ATTR_EXT)
317 goto parse_long;
318 if (IS_FREE(de->name) || (de->attr & ATTR_VOLUME))
319 continue;
320 for (sum = 0, i = 0; i < 11; i++)
321 sum = (((sum&1)<<7)|((sum&0xfe)>>1)) + de->name[i];
322 if (sum != alias_checksum)
323 nr_slots = 0;
324 }
325
326 memcpy(work, de->name, sizeof(de->name));
327 /* see namei.c, msdos_format_name */
328 if (work[0] == 0x05)
329 work[0] = 0xE5;
330 for (i = 0, j = 0, last_u = 0; i < 8;) {
331 if (!work[i]) break;
332 chl = fat_shortname2uni(nls_disk, &work[i], 8 - i,
333 &bufuname[j++], opt_shortname,
334 de->lcase & CASE_LOWER_BASE);
335 if (chl <= 1) {
336 if (work[i] != ' ')
337 last_u = j;
338 } else {
339 last_u = j;
340 }
341 i += chl;
342 }
343 j = last_u;
344 fat_short2uni(nls_disk, ".", 1, &bufuname[j++]);
345 for (i = 0; i < 3;) {
346 if (!de->ext[i]) break;
347 chl = fat_shortname2uni(nls_disk, &de->ext[i], 3 - i,
348 &bufuname[j++], opt_shortname,
349 de->lcase & CASE_LOWER_EXT);
350 if (chl <= 1) {
351 if (de->ext[i] != ' ')
352 last_u = j;
353 } else {
354 last_u = j;
355 }
356 i += chl;
357 }
358 if (!last_u)
359 continue;
360
361 bufuname[last_u] = 0x0000;
362 xlate_len = utf8
363 ?utf8_wcstombs(bufname, bufuname, sizeof(bufname))
364 :uni16_to_x8(bufname, bufuname, uni_xlate, nls_io);
365 if (xlate_len == name_len)
366 if ((!anycase && !memcmp(name, bufname, xlate_len)) ||
367 (anycase && !nls_strnicmp(nls_io, name, bufname,
368 xlate_len)))
369 goto Found;
370
371 if (nr_slots) {
372 xlate_len = utf8
373 ?utf8_wcstombs(bufname, unicode, sizeof(bufname))
374 :uni16_to_x8(bufname, unicode, uni_xlate, nls_io);
375 if (xlate_len != name_len)
376 continue;
377 if ((!anycase && !memcmp(name, bufname, xlate_len)) ||
378 (anycase && !nls_strnicmp(nls_io, name, bufname,
379 xlate_len)))
380 goto Found;
381 }
382 }
383
384 Found:
385 nr_slots++; /* include the de */
386 sinfo->slot_off = cpos - nr_slots * sizeof(*de);
387 sinfo->nr_slots = nr_slots;
388 sinfo->de = de;
389 sinfo->bh = bh;
390 sinfo->i_pos = fat_make_i_pos(sb, sinfo->bh, sinfo->de);
391 err = 0;
392 EODir:
393 if (unicode)
394 free_page((unsigned long)unicode);
395
396 return err;
397 }
398
399 EXPORT_SYMBOL(fat_search_long);
400
401 struct fat_ioctl_filldir_callback {
402 struct dirent __user *dirent;
403 int result;
404 /* for dir ioctl */
405 const char *longname;
406 int long_len;
407 const char *shortname;
408 int short_len;
409 };
410
411 static int fat_readdirx(struct inode *inode, struct file *filp, void *dirent,
412 filldir_t filldir, int short_only, int both)
413 {
414 struct super_block *sb = inode->i_sb;
415 struct msdos_sb_info *sbi = MSDOS_SB(sb);
416 struct buffer_head *bh;
417 struct msdos_dir_entry *de;
418 struct nls_table *nls_io = sbi->nls_io;
419 struct nls_table *nls_disk = sbi->nls_disk;
420 unsigned char long_slots;
421 const char *fill_name;
422 int fill_len;
423 wchar_t bufuname[14];
424 wchar_t *unicode = NULL;
425 unsigned char c, work[8], bufname[56], *ptname = bufname;
426 unsigned long lpos, dummy, *furrfu = &lpos;
427 int uni_xlate = sbi->options.unicode_xlate;
428 int isvfat = sbi->options.isvfat;
429 int utf8 = sbi->options.utf8;
430 int nocase = sbi->options.nocase;
431 unsigned short opt_shortname = sbi->options.shortname;
432 unsigned long inum;
433 int chi, chl, i, i2, j, last, last_u, dotoffset = 0;
434 loff_t cpos;
435 int ret = 0;
436
437 lock_kernel();
438
439 cpos = filp->f_pos;
440 /* Fake . and .. for the root directory. */
441 if (inode->i_ino == MSDOS_ROOT_INO) {
442 while (cpos < 2) {
443 if (filldir(dirent, "..", cpos+1, cpos, MSDOS_ROOT_INO, DT_DIR) < 0)
444 goto out;
445 cpos++;
446 filp->f_pos++;
447 }
448 if (cpos == 2) {
449 dummy = 2;
450 furrfu = &dummy;
451 cpos = 0;
452 }
453 }
454 if (cpos & (sizeof(struct msdos_dir_entry)-1)) {
455 ret = -ENOENT;
456 goto out;
457 }
458
459 bh = NULL;
460 GetNew:
461 long_slots = 0;
462 if (fat_get_entry(inode, &cpos, &bh, &de) == -1)
463 goto EODir;
464 /* Check for long filename entry */
465 if (isvfat) {
466 if (de->name[0] == DELETED_FLAG)
467 goto RecEnd;
468 if (de->attr != ATTR_EXT && (de->attr & ATTR_VOLUME))
469 goto RecEnd;
470 if (de->attr != ATTR_EXT && IS_FREE(de->name))
471 goto RecEnd;
472 } else {
473 if ((de->attr & ATTR_VOLUME) || IS_FREE(de->name))
474 goto RecEnd;
475 }
476
477 if (isvfat && de->attr == ATTR_EXT) {
478 struct msdos_dir_slot *ds;
479 unsigned char id;
480 unsigned char slot;
481 unsigned char slots;
482 unsigned char sum;
483 unsigned char alias_checksum;
484
485 if (!unicode) {
486 unicode = (wchar_t *)__get_free_page(GFP_KERNEL);
487 if (!unicode) {
488 filp->f_pos = cpos;
489 brelse(bh);
490 ret = -ENOMEM;
491 goto out;
492 }
493 }
494 ParseLong:
495 slots = 0;
496 ds = (struct msdos_dir_slot *) de;
497 id = ds->id;
498 if (!(id & 0x40))
499 goto RecEnd;
500 slots = id & ~0x40;
501 if (slots > 20 || !slots) /* ceil(256 * 2 / 26) */
502 goto RecEnd;
503 long_slots = slots;
504 alias_checksum = ds->alias_checksum;
505
506 slot = slots;
507 while (1) {
508 int offset;
509
510 slot--;
511 offset = slot * 13;
512 fat16_towchar(unicode + offset, ds->name0_4, 5);
513 fat16_towchar(unicode + offset + 5, ds->name5_10, 6);
514 fat16_towchar(unicode + offset + 11, ds->name11_12, 2);
515
516 if (ds->id & 0x40) {
517 unicode[offset + 13] = 0;
518 }
519 if (fat_get_entry(inode, &cpos, &bh, &de) == -1)
520 goto EODir;
521 if (slot == 0)
522 break;
523 ds = (struct msdos_dir_slot *) de;
524 if (ds->attr != ATTR_EXT)
525 goto RecEnd; /* XXX */
526 if ((ds->id & ~0x40) != slot)
527 goto ParseLong;
528 if (ds->alias_checksum != alias_checksum)
529 goto ParseLong;
530 }
531 if (de->name[0] == DELETED_FLAG)
532 goto RecEnd;
533 if (de->attr == ATTR_EXT)
534 goto ParseLong;
535 if (IS_FREE(de->name) || (de->attr & ATTR_VOLUME))
536 goto RecEnd;
537 for (sum = 0, i = 0; i < 11; i++)
538 sum = (((sum&1)<<7)|((sum&0xfe)>>1)) + de->name[i];
539 if (sum != alias_checksum)
540 long_slots = 0;
541 }
542
543 if (sbi->options.dotsOK) {
544 ptname = bufname;
545 dotoffset = 0;
546 if (de->attr & ATTR_HIDDEN) {
547 *ptname++ = '.';
548 dotoffset = 1;
549 }
550 }
551
552 memcpy(work, de->name, sizeof(de->name));
553 /* see namei.c, msdos_format_name */
554 if (work[0] == 0x05)
555 work[0] = 0xE5;
556 for (i = 0, j = 0, last = 0, last_u = 0; i < 8;) {
557 if (!(c = work[i])) break;
558 chl = fat_shortname2uni(nls_disk, &work[i], 8 - i,
559 &bufuname[j++], opt_shortname,
560 de->lcase & CASE_LOWER_BASE);
561 if (chl <= 1) {
562 ptname[i++] = (!nocase && c>='A' && c<='Z') ? c+32 : c;
563 if (c != ' ') {
564 last = i;
565 last_u = j;
566 }
567 } else {
568 last_u = j;
569 for (chi = 0; chi < chl && i < 8; chi++) {
570 ptname[i] = work[i];
571 i++; last = i;
572 }
573 }
574 }
575 i = last;
576 j = last_u;
577 fat_short2uni(nls_disk, ".", 1, &bufuname[j++]);
578 ptname[i++] = '.';
579 for (i2 = 0; i2 < 3;) {
580 if (!(c = de->ext[i2])) break;
581 chl = fat_shortname2uni(nls_disk, &de->ext[i2], 3 - i2,
582 &bufuname[j++], opt_shortname,
583 de->lcase & CASE_LOWER_EXT);
584 if (chl <= 1) {
585 i2++;
586 ptname[i++] = (!nocase && c>='A' && c<='Z') ? c+32 : c;
587 if (c != ' ') {
588 last = i;
589 last_u = j;
590 }
591 } else {
592 last_u = j;
593 for (chi = 0; chi < chl && i2 < 3; chi++) {
594 ptname[i++] = de->ext[i2++];
595 last = i;
596 }
597 }
598 }
599 if (!last)
600 goto RecEnd;
601
602 i = last + dotoffset;
603 j = last_u;
604
605 lpos = cpos - (long_slots+1)*sizeof(struct msdos_dir_entry);
606 if (!memcmp(de->name, MSDOS_DOT, MSDOS_NAME))
607 inum = inode->i_ino;
608 else if (!memcmp(de->name, MSDOS_DOTDOT, MSDOS_NAME)) {
609 inum = parent_ino(filp->f_dentry);
610 } else {
611 loff_t i_pos = fat_make_i_pos(sb, bh, de);
612 struct inode *tmp = fat_iget(sb, i_pos);
613 if (tmp) {
614 inum = tmp->i_ino;
615 iput(tmp);
616 } else
617 inum = iunique(sb, MSDOS_ROOT_INO);
618 }
619
620 if (isvfat) {
621 bufuname[j] = 0x0000;
622 i = utf8 ? utf8_wcstombs(bufname, bufuname, sizeof(bufname))
623 : uni16_to_x8(bufname, bufuname, uni_xlate, nls_io);
624 }
625
626 fill_name = bufname;
627 fill_len = i;
628 if (!short_only && long_slots) {
629 /* convert the unicode long name. 261 is maximum size
630 * of unicode buffer. (13 * slots + nul) */
631 void *longname = unicode + 261;
632 int buf_size = PAGE_SIZE - (261 * sizeof(unicode[0]));
633 int long_len = utf8
634 ? utf8_wcstombs(longname, unicode, buf_size)
635 : uni16_to_x8(longname, unicode, uni_xlate, nls_io);
636
637 if (!both) {
638 fill_name = longname;
639 fill_len = long_len;
640 } else {
641 /* hack for fat_ioctl_filldir() */
642 struct fat_ioctl_filldir_callback *p = dirent;
643
644 p->longname = longname;
645 p->long_len = long_len;
646 p->shortname = bufname;
647 p->short_len = i;
648 fill_name = NULL;
649 fill_len = 0;
650 }
651 }
652 if (filldir(dirent, fill_name, fill_len, *furrfu, inum,
653 (de->attr & ATTR_DIR) ? DT_DIR : DT_REG) < 0)
654 goto FillFailed;
655
656 RecEnd:
657 furrfu = &lpos;
658 filp->f_pos = cpos;
659 goto GetNew;
660 EODir:
661 filp->f_pos = cpos;
662 FillFailed:
663 brelse(bh);
664 if (unicode)
665 free_page((unsigned long)unicode);
666 out:
667 unlock_kernel();
668 return ret;
669 }
670
671 static int fat_readdir(struct file *filp, void *dirent, filldir_t filldir)
672 {
673 struct inode *inode = filp->f_dentry->d_inode;
674 return fat_readdirx(inode, filp, dirent, filldir, 0, 0);
675 }
676
677 static int fat_ioctl_filldir(void *__buf, const char *name, int name_len,
678 loff_t offset, ino_t ino, unsigned int d_type)
679 {
680 struct fat_ioctl_filldir_callback *buf = __buf;
681 struct dirent __user *d1 = buf->dirent;
682 struct dirent __user *d2 = d1 + 1;
683
684 if (buf->result)
685 return -EINVAL;
686 buf->result++;
687
688 if (name != NULL) {
689 /* dirent has only short name */
690 if (name_len >= sizeof(d1->d_name))
691 name_len = sizeof(d1->d_name) - 1;
692
693 if (put_user(0, d2->d_name) ||
694 put_user(0, &d2->d_reclen) ||
695 copy_to_user(d1->d_name, name, name_len) ||
696 put_user(0, d1->d_name + name_len) ||
697 put_user(name_len, &d1->d_reclen))
698 goto efault;
699 } else {
700 /* dirent has short and long name */
701 const char *longname = buf->longname;
702 int long_len = buf->long_len;
703 const char *shortname = buf->shortname;
704 int short_len = buf->short_len;
705
706 if (long_len >= sizeof(d1->d_name))
707 long_len = sizeof(d1->d_name) - 1;
708 if (short_len >= sizeof(d1->d_name))
709 short_len = sizeof(d1->d_name) - 1;
710
711 if (copy_to_user(d2->d_name, longname, long_len) ||
712 put_user(0, d2->d_name + long_len) ||
713 put_user(long_len, &d2->d_reclen) ||
714 put_user(ino, &d2->d_ino) ||
715 put_user(offset, &d2->d_off) ||
716 copy_to_user(d1->d_name, shortname, short_len) ||
717 put_user(0, d1->d_name + short_len) ||
718 put_user(short_len, &d1->d_reclen))
719 goto efault;
720 }
721 return 0;
722 efault:
723 buf->result = -EFAULT;
724 return -EFAULT;
725 }
726
727 static int fat_dir_ioctl(struct inode * inode, struct file * filp,
728 unsigned int cmd, unsigned long arg)
729 {
730 struct fat_ioctl_filldir_callback buf;
731 struct dirent __user *d1;
732 int ret, short_only, both;
733
734 switch (cmd) {
735 case VFAT_IOCTL_READDIR_SHORT:
736 short_only = 1;
737 both = 0;
738 break;
739 case VFAT_IOCTL_READDIR_BOTH:
740 short_only = 0;
741 both = 1;
742 break;
743 default:
744 return fat_generic_ioctl(inode, filp, cmd, arg);
745 }
746
747 d1 = (struct dirent __user *)arg;
748 if (!access_ok(VERIFY_WRITE, d1, sizeof(struct dirent[2])))
749 return -EFAULT;
750 /*
751 * Yes, we don't need this put_user() absolutely. However old
752 * code didn't return the right value. So, app use this value,
753 * in order to check whether it is EOF.
754 */
755 if (put_user(0, &d1->d_reclen))
756 return -EFAULT;
757
758 buf.dirent = d1;
759 buf.result = 0;
760 down(&inode->i_sem);
761 ret = -ENOENT;
762 if (!IS_DEADDIR(inode)) {
763 ret = fat_readdirx(inode, filp, &buf, fat_ioctl_filldir,
764 short_only, both);
765 }
766 up(&inode->i_sem);
767 if (ret >= 0)
768 ret = buf.result;
769 return ret;
770 }
771
772 struct file_operations fat_dir_operations = {
773 .read = generic_read_dir,
774 .readdir = fat_readdir,
775 .ioctl = fat_dir_ioctl,
776 .fsync = file_fsync,
777 };
778
779 static int fat_get_short_entry(struct inode *dir, loff_t *pos,
780 struct buffer_head **bh,
781 struct msdos_dir_entry **de)
782 {
783 while (fat_get_entry(dir, pos, bh, de) >= 0) {
784 /* free entry or long name entry or volume label */
785 if (!IS_FREE((*de)->name) && !((*de)->attr & ATTR_VOLUME))
786 return 0;
787 }
788 return -ENOENT;
789 }
790
791 /*
792 * The ".." entry can not provide the "struct fat_slot_info" informations
793 * for inode. So, this function provide the some informations only.
794 */
795 int fat_get_dotdot_entry(struct inode *dir, struct buffer_head **bh,
796 struct msdos_dir_entry **de, loff_t *i_pos)
797 {
798 loff_t offset;
799
800 offset = 0;
801 *bh = NULL;
802 while (fat_get_short_entry(dir, &offset, bh, de) >= 0) {
803 if (!strncmp((*de)->name, MSDOS_DOTDOT, MSDOS_NAME)) {
804 *i_pos = fat_make_i_pos(dir->i_sb, *bh, *de);
805 return 0;
806 }
807 }
808 return -ENOENT;
809 }
810
811 EXPORT_SYMBOL(fat_get_dotdot_entry);
812
813 /* See if directory is empty */
814 int fat_dir_empty(struct inode *dir)
815 {
816 struct buffer_head *bh;
817 struct msdos_dir_entry *de;
818 loff_t cpos;
819 int result = 0;
820
821 bh = NULL;
822 cpos = 0;
823 while (fat_get_short_entry(dir, &cpos, &bh, &de) >= 0) {
824 if (strncmp(de->name, MSDOS_DOT , MSDOS_NAME) &&
825 strncmp(de->name, MSDOS_DOTDOT, MSDOS_NAME)) {
826 result = -ENOTEMPTY;
827 break;
828 }
829 }
830 brelse(bh);
831 return result;
832 }
833
834 EXPORT_SYMBOL(fat_dir_empty);
835
836 /*
837 * fat_subdirs counts the number of sub-directories of dir. It can be run
838 * on directories being created.
839 */
840 int fat_subdirs(struct inode *dir)
841 {
842 struct buffer_head *bh;
843 struct msdos_dir_entry *de;
844 loff_t cpos;
845 int count = 0;
846
847 bh = NULL;
848 cpos = 0;
849 while (fat_get_short_entry(dir, &cpos, &bh, &de) >= 0) {
850 if (de->attr & ATTR_DIR)
851 count++;
852 }
853 brelse(bh);
854 return count;
855 }
856
857 /*
858 * Scans a directory for a given file (name points to its formatted name).
859 * Returns an error code or zero.
860 */
861 int fat_scan(struct inode *dir, const unsigned char *name,
862 struct fat_slot_info *sinfo)
863 {
864 struct super_block *sb = dir->i_sb;
865
866 sinfo->slot_off = 0;
867 sinfo->bh = NULL;
868 while (fat_get_short_entry(dir, &sinfo->slot_off, &sinfo->bh,
869 &sinfo->de) >= 0) {
870 if (!strncmp(sinfo->de->name, name, MSDOS_NAME)) {
871 sinfo->slot_off -= sizeof(*sinfo->de);
872 sinfo->nr_slots = 1;
873 sinfo->i_pos = fat_make_i_pos(sb, sinfo->bh, sinfo->de);
874 return 0;
875 }
876 }
877 return -ENOENT;
878 }
879
880 EXPORT_SYMBOL(fat_scan);
881
882 static int __fat_remove_entries(struct inode *dir, loff_t pos, int nr_slots)
883 {
884 struct super_block *sb = dir->i_sb;
885 struct buffer_head *bh;
886 struct msdos_dir_entry *de, *endp;
887 int err = 0, orig_slots;
888
889 while (nr_slots) {
890 bh = NULL;
891 if (fat_get_entry(dir, &pos, &bh, &de) < 0) {
892 err = -EIO;
893 break;
894 }
895
896 orig_slots = nr_slots;
897 endp = (struct msdos_dir_entry *)(bh->b_data + sb->s_blocksize);
898 while (nr_slots && de < endp) {
899 de->name[0] = DELETED_FLAG;
900 de++;
901 nr_slots--;
902 }
903 mark_buffer_dirty(bh);
904 if (IS_DIRSYNC(dir))
905 err = sync_dirty_buffer(bh);
906 brelse(bh);
907 if (err)
908 break;
909
910 /* pos is *next* de's position, so this does `- sizeof(de)' */
911 pos += ((orig_slots - nr_slots) * sizeof(*de)) - sizeof(*de);
912 }
913
914 return err;
915 }
916
917 int fat_remove_entries(struct inode *dir, struct fat_slot_info *sinfo)
918 {
919 struct msdos_dir_entry *de;
920 struct buffer_head *bh;
921 int err = 0, nr_slots;
922
923 /*
924 * First stage: Remove the shortname. By this, the directory
925 * entry is removed.
926 */
927 nr_slots = sinfo->nr_slots;
928 de = sinfo->de;
929 sinfo->de = NULL;
930 bh = sinfo->bh;
931 sinfo->bh = NULL;
932 while (nr_slots && de >= (struct msdos_dir_entry *)bh->b_data) {
933 de->name[0] = DELETED_FLAG;
934 de--;
935 nr_slots--;
936 }
937 mark_buffer_dirty(bh);
938 if (IS_DIRSYNC(dir))
939 err = sync_dirty_buffer(bh);
940 brelse(bh);
941 if (err)
942 return err;
943 dir->i_version++;
944
945 if (nr_slots) {
946 /*
947 * Second stage: remove the remaining longname slots.
948 * (This directory entry is already removed, and so return
949 * the success)
950 */
951 err = __fat_remove_entries(dir, sinfo->slot_off, nr_slots);
952 if (err) {
953 printk(KERN_WARNING
954 "FAT: Couldn't remove the long name slots\n");
955 }
956 }
957
958 dir->i_mtime = dir->i_atime = CURRENT_TIME_SEC;
959 if (IS_DIRSYNC(dir))
960 (void)fat_sync_inode(dir);
961 else
962 mark_inode_dirty(dir);
963
964 return 0;
965 }
966
967 EXPORT_SYMBOL(fat_remove_entries);
968
969 static int fat_zeroed_cluster(struct inode *dir, sector_t blknr, int nr_used,
970 struct buffer_head **bhs, int nr_bhs)
971 {
972 struct super_block *sb = dir->i_sb;
973 sector_t last_blknr = blknr + MSDOS_SB(sb)->sec_per_clus;
974 int err, i, n;
975
976 /* Zeroing the unused blocks on this cluster */
977 blknr += nr_used;
978 n = nr_used;
979 while (blknr < last_blknr) {
980 bhs[n] = sb_getblk(sb, blknr);
981 if (!bhs[n]) {
982 err = -ENOMEM;
983 goto error;
984 }
985 memset(bhs[n]->b_data, 0, sb->s_blocksize);
986 set_buffer_uptodate(bhs[n]);
987 mark_buffer_dirty(bhs[n]);
988
989 n++;
990 blknr++;
991 if (n == nr_bhs) {
992 if (IS_DIRSYNC(dir)) {
993 err = fat_sync_bhs(bhs, n);
994 if (err)
995 goto error;
996 }
997 for (i = 0; i < n; i++)
998 brelse(bhs[i]);
999 n = 0;
1000 }
1001 }
1002 if (IS_DIRSYNC(dir)) {
1003 err = fat_sync_bhs(bhs, n);
1004 if (err)
1005 goto error;
1006 }
1007 for (i = 0; i < n; i++)
1008 brelse(bhs[i]);
1009
1010 return 0;
1011
1012 error:
1013 for (i = 0; i < n; i++)
1014 bforget(bhs[i]);
1015 return err;
1016 }
1017
1018 int fat_alloc_new_dir(struct inode *dir, struct timespec *ts)
1019 {
1020 struct super_block *sb = dir->i_sb;
1021 struct msdos_sb_info *sbi = MSDOS_SB(sb);
1022 struct buffer_head *bhs[MAX_BUF_PER_PAGE];
1023 struct msdos_dir_entry *de;
1024 sector_t blknr;
1025 __le16 date, time;
1026 int err, cluster;
1027
1028 err = fat_alloc_clusters(dir, &cluster, 1);
1029 if (err)
1030 goto error;
1031
1032 blknr = fat_clus_to_blknr(sbi, cluster);
1033 bhs[0] = sb_getblk(sb, blknr);
1034 if (!bhs[0]) {
1035 err = -ENOMEM;
1036 goto error_free;
1037 }
1038
1039 fat_date_unix2dos(ts->tv_sec, &time, &date);
1040
1041 de = (struct msdos_dir_entry *)bhs[0]->b_data;
1042 /* filling the new directory slots ("." and ".." entries) */
1043 memcpy(de[0].name, MSDOS_DOT, MSDOS_NAME);
1044 memcpy(de[1].name, MSDOS_DOTDOT, MSDOS_NAME);
1045 de->attr = de[1].attr = ATTR_DIR;
1046 de[0].lcase = de[1].lcase = 0;
1047 de[0].time = de[1].time = time;
1048 de[0].date = de[1].date = date;
1049 de[0].ctime_cs = de[1].ctime_cs = 0;
1050 if (sbi->options.isvfat) {
1051 /* extra timestamps */
1052 de[0].ctime = de[1].ctime = time;
1053 de[0].adate = de[0].cdate = de[1].adate = de[1].cdate = date;
1054 } else {
1055 de[0].ctime = de[1].ctime = 0;
1056 de[0].adate = de[0].cdate = de[1].adate = de[1].cdate = 0;
1057 }
1058 de[0].start = cpu_to_le16(cluster);
1059 de[0].starthi = cpu_to_le16(cluster >> 16);
1060 de[1].start = cpu_to_le16(MSDOS_I(dir)->i_logstart);
1061 de[1].starthi = cpu_to_le16(MSDOS_I(dir)->i_logstart >> 16);
1062 de[0].size = de[1].size = 0;
1063 memset(de + 2, 0, sb->s_blocksize - 2 * sizeof(*de));
1064 set_buffer_uptodate(bhs[0]);
1065 mark_buffer_dirty(bhs[0]);
1066
1067 err = fat_zeroed_cluster(dir, blknr, 1, bhs, MAX_BUF_PER_PAGE);
1068 if (err)
1069 goto error_free;
1070
1071 return cluster;
1072
1073 error_free:
1074 fat_free_clusters(dir, cluster);
1075 error:
1076 return err;
1077 }
1078
1079 EXPORT_SYMBOL(fat_alloc_new_dir);
1080
1081 static int fat_add_new_entries(struct inode *dir, void *slots, int nr_slots,
1082 int *nr_cluster, struct msdos_dir_entry **de,
1083 struct buffer_head **bh, loff_t *i_pos)
1084 {
1085 struct super_block *sb = dir->i_sb;
1086 struct msdos_sb_info *sbi = MSDOS_SB(sb);
1087 struct buffer_head *bhs[MAX_BUF_PER_PAGE];
1088 sector_t blknr, start_blknr, last_blknr;
1089 unsigned long size, copy;
1090 int err, i, n, offset, cluster[2];
1091
1092 /*
1093 * The minimum cluster size is 512bytes, and maximum entry
1094 * size is 32*slots (672bytes). So, iff the cluster size is
1095 * 512bytes, we may need two clusters.
1096 */
1097 size = nr_slots * sizeof(struct msdos_dir_entry);
1098 *nr_cluster = (size + (sbi->cluster_size - 1)) >> sbi->cluster_bits;
1099 BUG_ON(*nr_cluster > 2);
1100
1101 err = fat_alloc_clusters(dir, cluster, *nr_cluster);
1102 if (err)
1103 goto error;
1104
1105 /*
1106 * First stage: Fill the directory entry. NOTE: This cluster
1107 * is not referenced from any inode yet, so updates order is
1108 * not important.
1109 */
1110 i = n = copy = 0;
1111 do {
1112 start_blknr = blknr = fat_clus_to_blknr(sbi, cluster[i]);
1113 last_blknr = start_blknr + sbi->sec_per_clus;
1114 while (blknr < last_blknr) {
1115 bhs[n] = sb_getblk(sb, blknr);
1116 if (!bhs[n]) {
1117 err = -ENOMEM;
1118 goto error_nomem;
1119 }
1120
1121 /* fill the directory entry */
1122 copy = min(size, sb->s_blocksize);
1123 memcpy(bhs[n]->b_data, slots, copy);
1124 slots += copy;
1125 size -= copy;
1126 set_buffer_uptodate(bhs[n]);
1127 mark_buffer_dirty(bhs[n]);
1128 if (!size)
1129 break;
1130 n++;
1131 blknr++;
1132 }
1133 } while (++i < *nr_cluster);
1134
1135 memset(bhs[n]->b_data + copy, 0, sb->s_blocksize - copy);
1136 offset = copy - sizeof(struct msdos_dir_entry);
1137 get_bh(bhs[n]);
1138 *bh = bhs[n];
1139 *de = (struct msdos_dir_entry *)((*bh)->b_data + offset);
1140 *i_pos = fat_make_i_pos(sb, *bh, *de);
1141
1142 /* Second stage: clear the rest of cluster, and write outs */
1143 err = fat_zeroed_cluster(dir, start_blknr, ++n, bhs, MAX_BUF_PER_PAGE);
1144 if (err)
1145 goto error_free;
1146
1147 return cluster[0];
1148
1149 error_free:
1150 brelse(*bh);
1151 *bh = NULL;
1152 n = 0;
1153 error_nomem:
1154 for (i = 0; i < n; i++)
1155 bforget(bhs[i]);
1156 fat_free_clusters(dir, cluster[0]);
1157 error:
1158 return err;
1159 }
1160
1161 int fat_add_entries(struct inode *dir, void *slots, int nr_slots,
1162 struct fat_slot_info *sinfo)
1163 {
1164 struct super_block *sb = dir->i_sb;
1165 struct msdos_sb_info *sbi = MSDOS_SB(sb);
1166 struct buffer_head *bh, *prev, *bhs[3]; /* 32*slots (672bytes) */
1167 struct msdos_dir_entry *de;
1168 int err, free_slots, i, nr_bhs;
1169 loff_t pos, i_pos;
1170
1171 sinfo->nr_slots = nr_slots;
1172
1173 /* First stage: search free direcotry entries */
1174 free_slots = nr_bhs = 0;
1175 bh = prev = NULL;
1176 pos = 0;
1177 err = -ENOSPC;
1178 while (fat_get_entry(dir, &pos, &bh, &de) > -1) {
1179 /* check the maximum size of directory */
1180 if (pos >= FAT_MAX_DIR_SIZE)
1181 goto error;
1182
1183 if (IS_FREE(de->name)) {
1184 if (prev != bh) {
1185 get_bh(bh);
1186 bhs[nr_bhs] = prev = bh;
1187 nr_bhs++;
1188 }
1189 free_slots++;
1190 if (free_slots == nr_slots)
1191 goto found;
1192 } else {
1193 for (i = 0; i < nr_bhs; i++)
1194 brelse(bhs[i]);
1195 prev = NULL;
1196 free_slots = nr_bhs = 0;
1197 }
1198 }
1199 if (dir->i_ino == MSDOS_ROOT_INO) {
1200 if (sbi->fat_bits != 32)
1201 goto error;
1202 } else if (MSDOS_I(dir)->i_start == 0) {
1203 printk(KERN_ERR "FAT: Corrupted directory (i_pos %lld)\n",
1204 MSDOS_I(dir)->i_pos);
1205 err = -EIO;
1206 goto error;
1207 }
1208
1209 found:
1210 err = 0;
1211 pos -= free_slots * sizeof(*de);
1212 nr_slots -= free_slots;
1213 if (free_slots) {
1214 /*
1215 * Second stage: filling the free entries with new entries.
1216 * NOTE: If this slots has shortname, first, we write
1217 * the long name slots, then write the short name.
1218 */
1219 int size = free_slots * sizeof(*de);
1220 int offset = pos & (sb->s_blocksize - 1);
1221 int long_bhs = nr_bhs - (nr_slots == 0);
1222
1223 /* Fill the long name slots. */
1224 for (i = 0; i < long_bhs; i++) {
1225 int copy = min_t(int, sb->s_blocksize - offset, size);
1226 memcpy(bhs[i]->b_data + offset, slots, copy);
1227 mark_buffer_dirty(bhs[i]);
1228 offset = 0;
1229 slots += copy;
1230 size -= copy;
1231 }
1232 if (long_bhs && IS_DIRSYNC(dir))
1233 err = fat_sync_bhs(bhs, long_bhs);
1234 if (!err && i < nr_bhs) {
1235 /* Fill the short name slot. */
1236 int copy = min_t(int, sb->s_blocksize - offset, size);
1237 memcpy(bhs[i]->b_data + offset, slots, copy);
1238 mark_buffer_dirty(bhs[i]);
1239 if (IS_DIRSYNC(dir))
1240 err = sync_dirty_buffer(bhs[i]);
1241 }
1242 for (i = 0; i < nr_bhs; i++)
1243 brelse(bhs[i]);
1244 if (err)
1245 goto error_remove;
1246 }
1247
1248 if (nr_slots) {
1249 int cluster, nr_cluster;
1250
1251 /*
1252 * Third stage: allocate the cluster for new entries.
1253 * And initialize the cluster with new entries, then
1254 * add the cluster to dir.
1255 */
1256 cluster = fat_add_new_entries(dir, slots, nr_slots, &nr_cluster,
1257 &de, &bh, &i_pos);
1258 if (cluster < 0) {
1259 err = cluster;
1260 goto error_remove;
1261 }
1262 err = fat_chain_add(dir, cluster, nr_cluster);
1263 if (err) {
1264 fat_free_clusters(dir, cluster);
1265 goto error_remove;
1266 }
1267 if (dir->i_size & (sbi->cluster_size - 1)) {
1268 fat_fs_panic(sb, "Odd directory size");
1269 dir->i_size = (dir->i_size + sbi->cluster_size - 1)
1270 & ~((loff_t)sbi->cluster_size - 1);
1271 }
1272 dir->i_size += nr_cluster << sbi->cluster_bits;
1273 MSDOS_I(dir)->mmu_private += nr_cluster << sbi->cluster_bits;
1274 }
1275 sinfo->slot_off = pos;
1276 sinfo->de = de;
1277 sinfo->bh = bh;
1278 sinfo->i_pos = fat_make_i_pos(sb, sinfo->bh, sinfo->de);
1279
1280 return 0;
1281
1282 error:
1283 brelse(bh);
1284 for (i = 0; i < nr_bhs; i++)
1285 brelse(bhs[i]);
1286 return err;
1287
1288 error_remove:
1289 brelse(bh);
1290 if (free_slots)
1291 __fat_remove_entries(dir, pos, free_slots);
1292 return err;
1293 }
1294
1295 EXPORT_SYMBOL(fat_add_entries);
Linux kernel - Deliverables
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