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-rw-r--r--fs/fat/dir.c1271
1 files changed, 1271 insertions, 0 deletions
diff --git a/fs/fat/dir.c b/fs/fat/dir.c
new file mode 100644
index 000000000000..e5ae1b720dde
--- /dev/null
+++ b/fs/fat/dir.c
@@ -0,0 +1,1271 @@
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
25static 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/* Returns the inode number of the directory entry at offset pos. If bh is
34 non-NULL, it is brelse'd before. Pos is incremented. The buffer header is
35 returned in bh.
36 AV. Most often we do it item-by-item. Makes sense to optimize.
37 AV. OK, there we go: if both bh and de are non-NULL we assume that we just
38 AV. want the next entry (took one explicit de=NULL in vfat/namei.c).
39 AV. It's done in fat_get_entry() (inlined), here the slow case lives.
40 AV. Additionally, when we return -1 (i.e. reached the end of directory)
41 AV. we make bh NULL.
42 */
43static int fat__get_entry(struct inode *dir, loff_t *pos,
44 struct buffer_head **bh, struct msdos_dir_entry **de)
45{
46 struct super_block *sb = dir->i_sb;
47 sector_t phys, iblock;
48 int offset;
49 int err;
50
51next:
52 if (*bh)
53 brelse(*bh);
54
55 *bh = NULL;
56 iblock = *pos >> sb->s_blocksize_bits;
57 err = fat_bmap(dir, iblock, &phys);
58 if (err || !phys)
59 return -1; /* beyond EOF or error */
60
61 *bh = sb_bread(sb, phys);
62 if (*bh == NULL) {
63 printk(KERN_ERR "FAT: Directory bread(block %llu) failed\n",
64 (unsigned long long)phys);
65 /* skip this block */
66 *pos = (iblock + 1) << sb->s_blocksize_bits;
67 goto next;
68 }
69
70 offset = *pos & (sb->s_blocksize - 1);
71 *pos += sizeof(struct msdos_dir_entry);
72 *de = (struct msdos_dir_entry *)((*bh)->b_data + offset);
73
74 return 0;
75}
76
77static inline int fat_get_entry(struct inode *dir, loff_t *pos,
78 struct buffer_head **bh,
79 struct msdos_dir_entry **de)
80{
81 /* Fast stuff first */
82 if (*bh && *de &&
83 (*de - (struct msdos_dir_entry *)(*bh)->b_data) < MSDOS_SB(dir->i_sb)->dir_per_block - 1) {
84 *pos += sizeof(struct msdos_dir_entry);
85 (*de)++;
86 return 0;
87 }
88 return fat__get_entry(dir, pos, bh, de);
89}
90
91/*
92 * Convert Unicode 16 to UTF8, translated Unicode, or ASCII.
93 * If uni_xlate is enabled and we can't get a 1:1 conversion, use a
94 * colon as an escape character since it is normally invalid on the vfat
95 * filesystem. The following four characters are the hexadecimal digits
96 * of Unicode value. This lets us do a full dump and restore of Unicode
97 * filenames. We could get into some trouble with long Unicode names,
98 * but ignore that right now.
99 * Ahem... Stack smashing in ring 0 isn't fun. Fixed.
100 */
101static int uni16_to_x8(unsigned char *ascii, wchar_t *uni, int uni_xlate,
102 struct nls_table *nls)
103{
104 wchar_t *ip, ec;
105 unsigned char *op, nc;
106 int charlen;
107 int k;
108
109 ip = uni;
110 op = ascii;
111
112 while (*ip) {
113 ec = *ip++;
114 if ( (charlen = nls->uni2char(ec, op, NLS_MAX_CHARSET_SIZE)) > 0) {
115 op += charlen;
116 } else {
117 if (uni_xlate == 1) {
118 *op = ':';
119 for (k = 4; k > 0; k--) {
120 nc = ec & 0xF;
121 op[k] = nc > 9 ? nc + ('a' - 10)
122 : nc + '0';
123 ec >>= 4;
124 }
125 op += 5;
126 } else {
127 *op++ = '?';
128 }
129 }
130 /* We have some slack there, so it's OK */
131 if (op>ascii+256) {
132 op = ascii + 256;
133 break;
134 }
135 }
136 *op = 0;
137 return (op - ascii);
138}
139
140static inline int
141fat_short2uni(struct nls_table *t, unsigned char *c, int clen, wchar_t *uni)
142{
143 int charlen;
144
145 charlen = t->char2uni(c, clen, uni);
146 if (charlen < 0) {
147 *uni = 0x003f; /* a question mark */
148 charlen = 1;
149 }
150 return charlen;
151}
152
153static inline int
154fat_short2lower_uni(struct nls_table *t, unsigned char *c, int clen, wchar_t *uni)
155{
156 int charlen;
157 wchar_t wc;
158
159 charlen = t->char2uni(c, clen, &wc);
160 if (charlen < 0) {
161 *uni = 0x003f; /* a question mark */
162 charlen = 1;
163 } else if (charlen <= 1) {
164 unsigned char nc = t->charset2lower[*c];
165
166 if (!nc)
167 nc = *c;
168
169 if ( (charlen = t->char2uni(&nc, 1, uni)) < 0) {
170 *uni = 0x003f; /* a question mark */
171 charlen = 1;
172 }
173 } else
174 *uni = wc;
175
176 return charlen;
177}
178
179static inline int
180fat_shortname2uni(struct nls_table *nls, unsigned char *buf, int buf_size,
181 wchar_t *uni_buf, unsigned short opt, int lower)
182{
183 int len = 0;
184
185 if (opt & VFAT_SFN_DISPLAY_LOWER)
186 len = fat_short2lower_uni(nls, buf, buf_size, uni_buf);
187 else if (opt & VFAT_SFN_DISPLAY_WIN95)
188 len = fat_short2uni(nls, buf, buf_size, uni_buf);
189 else if (opt & VFAT_SFN_DISPLAY_WINNT) {
190 if (lower)
191 len = fat_short2lower_uni(nls, buf, buf_size, uni_buf);
192 else
193 len = fat_short2uni(nls, buf, buf_size, uni_buf);
194 } else
195 len = fat_short2uni(nls, buf, buf_size, uni_buf);
196
197 return len;
198}
199
200/*
201 * Return values: negative -> error, 0 -> not found, positive -> found,
202 * value is the total amount of slots, including the shortname entry.
203 */
204int fat_search_long(struct inode *inode, const unsigned char *name,
205 int name_len, struct fat_slot_info *sinfo)
206{
207 struct super_block *sb = inode->i_sb;
208 struct msdos_sb_info *sbi = MSDOS_SB(sb);
209 struct buffer_head *bh = NULL;
210 struct msdos_dir_entry *de;
211 struct nls_table *nls_io = sbi->nls_io;
212 struct nls_table *nls_disk = sbi->nls_disk;
213 wchar_t bufuname[14];
214 unsigned char xlate_len, nr_slots;
215 wchar_t *unicode = NULL;
216 unsigned char work[8], bufname[260]; /* 256 + 4 */
217 int uni_xlate = sbi->options.unicode_xlate;
218 int utf8 = sbi->options.utf8;
219 int anycase = (sbi->options.name_check != 's');
220 unsigned short opt_shortname = sbi->options.shortname;
221 loff_t cpos = 0;
222 int chl, i, j, last_u, err;
223
224 err = -ENOENT;
225 while(1) {
226 if (fat_get_entry(inode, &cpos, &bh, &de) == -1)
227 goto EODir;
228parse_record:
229 nr_slots = 0;
230 if (de->name[0] == DELETED_FLAG)
231 continue;
232 if (de->attr != ATTR_EXT && (de->attr & ATTR_VOLUME))
233 continue;
234 if (de->attr != ATTR_EXT && IS_FREE(de->name))
235 continue;
236 if (de->attr == ATTR_EXT) {
237 struct msdos_dir_slot *ds;
238 unsigned char id;
239 unsigned char slot;
240 unsigned char slots;
241 unsigned char sum;
242 unsigned char alias_checksum;
243
244 if (!unicode) {
245 unicode = (wchar_t *)
246 __get_free_page(GFP_KERNEL);
247 if (!unicode) {
248 brelse(bh);
249 return -ENOMEM;
250 }
251 }
252parse_long:
253 slots = 0;
254 ds = (struct msdos_dir_slot *) de;
255 id = ds->id;
256 if (!(id & 0x40))
257 continue;
258 slots = id & ~0x40;
259 if (slots > 20 || !slots) /* ceil(256 * 2 / 26) */
260 continue;
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 }
277 if (fat_get_entry(inode, &cpos, &bh, &de) < 0)
278 goto EODir;
279 if (slot == 0)
280 break;
281 ds = (struct msdos_dir_slot *) de;
282 if (ds->attr != ATTR_EXT)
283 goto parse_record;
284 if ((ds->id & ~0x40) != slot)
285 goto parse_long;
286 if (ds->alias_checksum != alias_checksum)
287 goto parse_long;
288 }
289 if (de->name[0] == DELETED_FLAG)
290 continue;
291 if (de->attr == ATTR_EXT)
292 goto parse_long;
293 if (IS_FREE(de->name) || (de->attr & ATTR_VOLUME))
294 continue;
295 for (sum = 0, i = 0; i < 11; i++)
296 sum = (((sum&1)<<7)|((sum&0xfe)>>1)) + de->name[i];
297 if (sum != alias_checksum)
298 nr_slots = 0;
299 }
300
301 memcpy(work, de->name, sizeof(de->name));
302 /* see namei.c, msdos_format_name */
303 if (work[0] == 0x05)
304 work[0] = 0xE5;
305 for (i = 0, j = 0, last_u = 0; i < 8;) {
306 if (!work[i]) break;
307 chl = fat_shortname2uni(nls_disk, &work[i], 8 - i,
308 &bufuname[j++], opt_shortname,
309 de->lcase & CASE_LOWER_BASE);
310 if (chl <= 1) {
311 if (work[i] != ' ')
312 last_u = j;
313 } else {
314 last_u = j;
315 }
316 i += chl;
317 }
318 j = last_u;
319 fat_short2uni(nls_disk, ".", 1, &bufuname[j++]);
320 for (i = 0; i < 3;) {
321 if (!de->ext[i]) break;
322 chl = fat_shortname2uni(nls_disk, &de->ext[i], 3 - i,
323 &bufuname[j++], opt_shortname,
324 de->lcase & CASE_LOWER_EXT);
325 if (chl <= 1) {
326 if (de->ext[i] != ' ')
327 last_u = j;
328 } else {
329 last_u = j;
330 }
331 i += chl;
332 }
333 if (!last_u)
334 continue;
335
336 bufuname[last_u] = 0x0000;
337 xlate_len = utf8
338 ?utf8_wcstombs(bufname, bufuname, sizeof(bufname))
339 :uni16_to_x8(bufname, bufuname, uni_xlate, nls_io);
340 if (xlate_len == name_len)
341 if ((!anycase && !memcmp(name, bufname, xlate_len)) ||
342 (anycase && !nls_strnicmp(nls_io, name, bufname,
343 xlate_len)))
344 goto Found;
345
346 if (nr_slots) {
347 xlate_len = utf8
348 ?utf8_wcstombs(bufname, unicode, sizeof(bufname))
349 :uni16_to_x8(bufname, unicode, uni_xlate, nls_io);
350 if (xlate_len != name_len)
351 continue;
352 if ((!anycase && !memcmp(name, bufname, xlate_len)) ||
353 (anycase && !nls_strnicmp(nls_io, name, bufname,
354 xlate_len)))
355 goto Found;
356 }
357 }
358
359Found:
360 nr_slots++; /* include the de */
361 sinfo->slot_off = cpos - nr_slots * sizeof(*de);
362 sinfo->nr_slots = nr_slots;
363 sinfo->de = de;
364 sinfo->bh = bh;
365 sinfo->i_pos = fat_make_i_pos(sb, sinfo->bh, sinfo->de);
366 err = 0;
367EODir:
368 if (unicode)
369 free_page((unsigned long)unicode);
370
371 return err;
372}
373
374EXPORT_SYMBOL(fat_search_long);
375
376struct fat_ioctl_filldir_callback {
377 struct dirent __user *dirent;
378 int result;
379 /* for dir ioctl */
380 const char *longname;
381 int long_len;
382 const char *shortname;
383 int short_len;
384};
385
386static int fat_readdirx(struct inode *inode, struct file *filp, void *dirent,
387 filldir_t filldir, int short_only, int both)
388{
389 struct super_block *sb = inode->i_sb;
390 struct msdos_sb_info *sbi = MSDOS_SB(sb);
391 struct buffer_head *bh;
392 struct msdos_dir_entry *de;
393 struct nls_table *nls_io = sbi->nls_io;
394 struct nls_table *nls_disk = sbi->nls_disk;
395 unsigned char long_slots;
396 const char *fill_name;
397 int fill_len;
398 wchar_t bufuname[14];
399 wchar_t *unicode = NULL;
400 unsigned char c, work[8], bufname[56], *ptname = bufname;
401 unsigned long lpos, dummy, *furrfu = &lpos;
402 int uni_xlate = sbi->options.unicode_xlate;
403 int isvfat = sbi->options.isvfat;
404 int utf8 = sbi->options.utf8;
405 int nocase = sbi->options.nocase;
406 unsigned short opt_shortname = sbi->options.shortname;
407 unsigned long inum;
408 int chi, chl, i, i2, j, last, last_u, dotoffset = 0;
409 loff_t cpos;
410 int ret = 0;
411
412 lock_kernel();
413
414 cpos = filp->f_pos;
415 /* Fake . and .. for the root directory. */
416 if (inode->i_ino == MSDOS_ROOT_INO) {
417 while (cpos < 2) {
418 if (filldir(dirent, "..", cpos+1, cpos, MSDOS_ROOT_INO, DT_DIR) < 0)
419 goto out;
420 cpos++;
421 filp->f_pos++;
422 }
423 if (cpos == 2) {
424 dummy = 2;
425 furrfu = &dummy;
426 cpos = 0;
427 }
428 }
429 if (cpos & (sizeof(struct msdos_dir_entry)-1)) {
430 ret = -ENOENT;
431 goto out;
432 }
433
434 bh = NULL;
435GetNew:
436 long_slots = 0;
437 if (fat_get_entry(inode, &cpos, &bh, &de) == -1)
438 goto EODir;
439 /* Check for long filename entry */
440 if (isvfat) {
441 if (de->name[0] == DELETED_FLAG)
442 goto RecEnd;
443 if (de->attr != ATTR_EXT && (de->attr & ATTR_VOLUME))
444 goto RecEnd;
445 if (de->attr != ATTR_EXT && IS_FREE(de->name))
446 goto RecEnd;
447 } else {
448 if ((de->attr & ATTR_VOLUME) || IS_FREE(de->name))
449 goto RecEnd;
450 }
451
452 if (isvfat && de->attr == ATTR_EXT) {
453 struct msdos_dir_slot *ds;
454 unsigned char id;
455 unsigned char slot;
456 unsigned char slots;
457 unsigned char sum;
458 unsigned char alias_checksum;
459
460 if (!unicode) {
461 unicode = (wchar_t *)__get_free_page(GFP_KERNEL);
462 if (!unicode) {
463 filp->f_pos = cpos;
464 brelse(bh);
465 ret = -ENOMEM;
466 goto out;
467 }
468 }
469ParseLong:
470 slots = 0;
471 ds = (struct msdos_dir_slot *) de;
472 id = ds->id;
473 if (!(id & 0x40))
474 goto RecEnd;
475 slots = id & ~0x40;
476 if (slots > 20 || !slots) /* ceil(256 * 2 / 26) */
477 goto RecEnd;
478 long_slots = slots;
479 alias_checksum = ds->alias_checksum;
480
481 slot = slots;
482 while (1) {
483 int offset;
484
485 slot--;
486 offset = slot * 13;
487 fat16_towchar(unicode + offset, ds->name0_4, 5);
488 fat16_towchar(unicode + offset + 5, ds->name5_10, 6);
489 fat16_towchar(unicode + offset + 11, ds->name11_12, 2);
490
491 if (ds->id & 0x40) {
492 unicode[offset + 13] = 0;
493 }
494 if (fat_get_entry(inode, &cpos, &bh, &de) == -1)
495 goto EODir;
496 if (slot == 0)
497 break;
498 ds = (struct msdos_dir_slot *) de;
499 if (ds->attr != ATTR_EXT)
500 goto RecEnd; /* XXX */
501 if ((ds->id & ~0x40) != slot)
502 goto ParseLong;
503 if (ds->alias_checksum != alias_checksum)
504 goto ParseLong;
505 }
506 if (de->name[0] == DELETED_FLAG)
507 goto RecEnd;
508 if (de->attr == ATTR_EXT)
509 goto ParseLong;
510 if (IS_FREE(de->name) || (de->attr & ATTR_VOLUME))
511 goto RecEnd;
512 for (sum = 0, i = 0; i < 11; i++)
513 sum = (((sum&1)<<7)|((sum&0xfe)>>1)) + de->name[i];
514 if (sum != alias_checksum)
515 long_slots = 0;
516 }
517
518 if (sbi->options.dotsOK) {
519 ptname = bufname;
520 dotoffset = 0;
521 if (de->attr & ATTR_HIDDEN) {
522 *ptname++ = '.';
523 dotoffset = 1;
524 }
525 }
526
527 memcpy(work, de->name, sizeof(de->name));
528 /* see namei.c, msdos_format_name */
529 if (work[0] == 0x05)
530 work[0] = 0xE5;
531 for (i = 0, j = 0, last = 0, last_u = 0; i < 8;) {
532 if (!(c = work[i])) break;
533 chl = fat_shortname2uni(nls_disk, &work[i], 8 - i,
534 &bufuname[j++], opt_shortname,
535 de->lcase & CASE_LOWER_BASE);
536 if (chl <= 1) {
537 ptname[i++] = (!nocase && c>='A' && c<='Z') ? c+32 : c;
538 if (c != ' ') {
539 last = i;
540 last_u = j;
541 }
542 } else {
543 last_u = j;
544 for (chi = 0; chi < chl && i < 8; chi++) {
545 ptname[i] = work[i];
546 i++; last = i;
547 }
548 }
549 }
550 i = last;
551 j = last_u;
552 fat_short2uni(nls_disk, ".", 1, &bufuname[j++]);
553 ptname[i++] = '.';
554 for (i2 = 0; i2 < 3;) {
555 if (!(c = de->ext[i2])) break;
556 chl = fat_shortname2uni(nls_disk, &de->ext[i2], 3 - i2,
557 &bufuname[j++], opt_shortname,
558 de->lcase & CASE_LOWER_EXT);
559 if (chl <= 1) {
560 i2++;
561 ptname[i++] = (!nocase && c>='A' && c<='Z') ? c+32 : c;
562 if (c != ' ') {
563 last = i;
564 last_u = j;
565 }
566 } else {
567 last_u = j;
568 for (chi = 0; chi < chl && i2 < 3; chi++) {
569 ptname[i++] = de->ext[i2++];
570 last = i;
571 }
572 }
573 }
574 if (!last)
575 goto RecEnd;
576
577 i = last + dotoffset;
578 j = last_u;
579
580 lpos = cpos - (long_slots+1)*sizeof(struct msdos_dir_entry);
581 if (!memcmp(de->name, MSDOS_DOT, MSDOS_NAME))
582 inum = inode->i_ino;
583 else if (!memcmp(de->name, MSDOS_DOTDOT, MSDOS_NAME)) {
584 inum = parent_ino(filp->f_dentry);
585 } else {
586 loff_t i_pos = fat_make_i_pos(sb, bh, de);
587 struct inode *tmp = fat_iget(sb, i_pos);
588 if (tmp) {
589 inum = tmp->i_ino;
590 iput(tmp);
591 } else
592 inum = iunique(sb, MSDOS_ROOT_INO);
593 }
594
595 if (isvfat) {
596 bufuname[j] = 0x0000;
597 i = utf8 ? utf8_wcstombs(bufname, bufuname, sizeof(bufname))
598 : uni16_to_x8(bufname, bufuname, uni_xlate, nls_io);
599 }
600
601 fill_name = bufname;
602 fill_len = i;
603 if (!short_only && long_slots) {
604 /* convert the unicode long name. 261 is maximum size
605 * of unicode buffer. (13 * slots + nul) */
606 void *longname = unicode + 261;
607 int buf_size = PAGE_SIZE - (261 * sizeof(unicode[0]));
608 int long_len = utf8
609 ? utf8_wcstombs(longname, unicode, buf_size)
610 : uni16_to_x8(longname, unicode, uni_xlate, nls_io);
611
612 if (!both) {
613 fill_name = longname;
614 fill_len = long_len;
615 } else {
616 /* hack for fat_ioctl_filldir() */
617 struct fat_ioctl_filldir_callback *p = dirent;
618
619 p->longname = longname;
620 p->long_len = long_len;
621 p->shortname = bufname;
622 p->short_len = i;
623 fill_name = NULL;
624 fill_len = 0;
625 }
626 }
627 if (filldir(dirent, fill_name, fill_len, *furrfu, inum,
628 (de->attr & ATTR_DIR) ? DT_DIR : DT_REG) < 0)
629 goto FillFailed;
630
631RecEnd:
632 furrfu = &lpos;
633 filp->f_pos = cpos;
634 goto GetNew;
635EODir:
636 filp->f_pos = cpos;
637FillFailed:
638 if (bh)
639 brelse(bh);
640 if (unicode)
641 free_page((unsigned long)unicode);
642out:
643 unlock_kernel();
644 return ret;
645}
646
647static int fat_readdir(struct file *filp, void *dirent, filldir_t filldir)
648{
649 struct inode *inode = filp->f_dentry->d_inode;
650 return fat_readdirx(inode, filp, dirent, filldir, 0, 0);
651}
652
653static int fat_ioctl_filldir(void *__buf, const char *name, int name_len,
654 loff_t offset, ino_t ino, unsigned int d_type)
655{
656 struct fat_ioctl_filldir_callback *buf = __buf;
657 struct dirent __user *d1 = buf->dirent;
658 struct dirent __user *d2 = d1 + 1;
659
660 if (buf->result)
661 return -EINVAL;
662 buf->result++;
663
664 if (name != NULL) {
665 /* dirent has only short name */
666 if (name_len >= sizeof(d1->d_name))
667 name_len = sizeof(d1->d_name) - 1;
668
669 if (put_user(0, d2->d_name) ||
670 put_user(0, &d2->d_reclen) ||
671 copy_to_user(d1->d_name, name, name_len) ||
672 put_user(0, d1->d_name + name_len) ||
673 put_user(name_len, &d1->d_reclen))
674 goto efault;
675 } else {
676 /* dirent has short and long name */
677 const char *longname = buf->longname;
678 int long_len = buf->long_len;
679 const char *shortname = buf->shortname;
680 int short_len = buf->short_len;
681
682 if (long_len >= sizeof(d1->d_name))
683 long_len = sizeof(d1->d_name) - 1;
684 if (short_len >= sizeof(d1->d_name))
685 short_len = sizeof(d1->d_name) - 1;
686
687 if (copy_to_user(d2->d_name, longname, long_len) ||
688 put_user(0, d2->d_name + long_len) ||
689 put_user(long_len, &d2->d_reclen) ||
690 put_user(ino, &d2->d_ino) ||
691 put_user(offset, &d2->d_off) ||
692 copy_to_user(d1->d_name, shortname, short_len) ||
693 put_user(0, d1->d_name + short_len) ||
694 put_user(short_len, &d1->d_reclen))
695 goto efault;
696 }
697 return 0;
698efault:
699 buf->result = -EFAULT;
700 return -EFAULT;
701}
702
703static int fat_dir_ioctl(struct inode * inode, struct file * filp,
704 unsigned int cmd, unsigned long arg)
705{
706 struct fat_ioctl_filldir_callback buf;
707 struct dirent __user *d1;
708 int ret, short_only, both;
709
710 switch (cmd) {
711 case VFAT_IOCTL_READDIR_SHORT:
712 short_only = 1;
713 both = 0;
714 break;
715 case VFAT_IOCTL_READDIR_BOTH:
716 short_only = 0;
717 both = 1;
718 break;
719 default:
720 return fat_generic_ioctl(inode, filp, cmd, arg);
721 }
722
723 d1 = (struct dirent __user *)arg;
724 if (!access_ok(VERIFY_WRITE, d1, sizeof(struct dirent[2])))
725 return -EFAULT;
726 /*
727 * Yes, we don't need this put_user() absolutely. However old
728 * code didn't return the right value. So, app use this value,
729 * in order to check whether it is EOF.
730 */
731 if (put_user(0, &d1->d_reclen))
732 return -EFAULT;
733
734 buf.dirent = d1;
735 buf.result = 0;
736 down(&inode->i_sem);
737 ret = -ENOENT;
738 if (!IS_DEADDIR(inode)) {
739 ret = fat_readdirx(inode, filp, &buf, fat_ioctl_filldir,
740 short_only, both);
741 }
742 up(&inode->i_sem);
743 if (ret >= 0)
744 ret = buf.result;
745 return ret;
746}
747
748struct file_operations fat_dir_operations = {
749 .read = generic_read_dir,
750 .readdir = fat_readdir,
751 .ioctl = fat_dir_ioctl,
752 .fsync = file_fsync,
753};
754
755static int fat_get_short_entry(struct inode *dir, loff_t *pos,
756 struct buffer_head **bh,
757 struct msdos_dir_entry **de)
758{
759 while (fat_get_entry(dir, pos, bh, de) >= 0) {
760 /* free entry or long name entry or volume label */
761 if (!IS_FREE((*de)->name) && !((*de)->attr & ATTR_VOLUME))
762 return 0;
763 }
764 return -ENOENT;
765}
766
767/*
768 * The ".." entry can not provide the "struct fat_slot_info" informations
769 * for inode. So, this function provide the some informations only.
770 */
771int fat_get_dotdot_entry(struct inode *dir, struct buffer_head **bh,
772 struct msdos_dir_entry **de, loff_t *i_pos)
773{
774 loff_t offset;
775
776 offset = 0;
777 *bh = NULL;
778 while (fat_get_short_entry(dir, &offset, bh, de) >= 0) {
779 if (!strncmp((*de)->name, MSDOS_DOTDOT, MSDOS_NAME)) {
780 *i_pos = fat_make_i_pos(dir->i_sb, *bh, *de);
781 return 0;
782 }
783 }
784 return -ENOENT;
785}
786
787EXPORT_SYMBOL(fat_get_dotdot_entry);
788
789/* See if directory is empty */
790int fat_dir_empty(struct inode *dir)
791{
792 struct buffer_head *bh;
793 struct msdos_dir_entry *de;
794 loff_t cpos;
795 int result = 0;
796
797 bh = NULL;
798 cpos = 0;
799 while (fat_get_short_entry(dir, &cpos, &bh, &de) >= 0) {
800 if (strncmp(de->name, MSDOS_DOT , MSDOS_NAME) &&
801 strncmp(de->name, MSDOS_DOTDOT, MSDOS_NAME)) {
802 result = -ENOTEMPTY;
803 break;
804 }
805 }
806 brelse(bh);
807 return result;
808}
809
810EXPORT_SYMBOL(fat_dir_empty);
811
812/*
813 * fat_subdirs counts the number of sub-directories of dir. It can be run
814 * on directories being created.
815 */
816int fat_subdirs(struct inode *dir)
817{
818 struct buffer_head *bh;
819 struct msdos_dir_entry *de;
820 loff_t cpos;
821 int count = 0;
822
823 bh = NULL;
824 cpos = 0;
825 while (fat_get_short_entry(dir, &cpos, &bh, &de) >= 0) {
826 if (de->attr & ATTR_DIR)
827 count++;
828 }
829 brelse(bh);
830 return count;
831}
832
833/*
834 * Scans a directory for a given file (name points to its formatted name).
835 * Returns an error code or zero.
836 */
837int fat_scan(struct inode *dir, const unsigned char *name,
838 struct fat_slot_info *sinfo)
839{
840 struct super_block *sb = dir->i_sb;
841
842 sinfo->slot_off = 0;
843 sinfo->bh = NULL;
844 while (fat_get_short_entry(dir, &sinfo->slot_off, &sinfo->bh,
845 &sinfo->de) >= 0) {
846 if (!strncmp(sinfo->de->name, name, MSDOS_NAME)) {
847 sinfo->slot_off -= sizeof(*sinfo->de);
848 sinfo->nr_slots = 1;
849 sinfo->i_pos = fat_make_i_pos(sb, sinfo->bh, sinfo->de);
850 return 0;
851 }
852 }
853 return -ENOENT;
854}
855
856EXPORT_SYMBOL(fat_scan);
857
858static int __fat_remove_entries(struct inode *dir, loff_t pos, int nr_slots)
859{
860 struct super_block *sb = dir->i_sb;
861 struct buffer_head *bh;
862 struct msdos_dir_entry *de, *endp;
863 int err = 0, orig_slots;
864
865 while (nr_slots) {
866 bh = NULL;
867 if (fat_get_entry(dir, &pos, &bh, &de) < 0) {
868 err = -EIO;
869 break;
870 }
871
872 orig_slots = nr_slots;
873 endp = (struct msdos_dir_entry *)(bh->b_data + sb->s_blocksize);
874 while (nr_slots && de < endp) {
875 de->name[0] = DELETED_FLAG;
876 de++;
877 nr_slots--;
878 }
879 mark_buffer_dirty(bh);
880 if (IS_DIRSYNC(dir))
881 err = sync_dirty_buffer(bh);
882 brelse(bh);
883 if (err)
884 break;
885
886 /* pos is *next* de's position, so this does `- sizeof(de)' */
887 pos += ((orig_slots - nr_slots) * sizeof(*de)) - sizeof(*de);
888 }
889
890 return err;
891}
892
893int fat_remove_entries(struct inode *dir, struct fat_slot_info *sinfo)
894{
895 struct msdos_dir_entry *de;
896 struct buffer_head *bh;
897 int err = 0, nr_slots;
898
899 /*
900 * First stage: Remove the shortname. By this, the directory
901 * entry is removed.
902 */
903 nr_slots = sinfo->nr_slots;
904 de = sinfo->de;
905 sinfo->de = NULL;
906 bh = sinfo->bh;
907 sinfo->bh = NULL;
908 while (nr_slots && de >= (struct msdos_dir_entry *)bh->b_data) {
909 de->name[0] = DELETED_FLAG;
910 de--;
911 nr_slots--;
912 }
913 mark_buffer_dirty(bh);
914 if (IS_DIRSYNC(dir))
915 err = sync_dirty_buffer(bh);
916 brelse(bh);
917 if (err)
918 return err;
919 dir->i_version++;
920
921 if (nr_slots) {
922 /*
923 * Second stage: remove the remaining longname slots.
924 * (This directory entry is already removed, and so return
925 * the success)
926 */
927 err = __fat_remove_entries(dir, sinfo->slot_off, nr_slots);
928 if (err) {
929 printk(KERN_WARNING
930 "FAT: Couldn't remove the long name slots\n");
931 }
932 }
933
934 dir->i_mtime = dir->i_atime = CURRENT_TIME_SEC;
935 if (IS_DIRSYNC(dir))
936 (void)fat_sync_inode(dir);
937 else
938 mark_inode_dirty(dir);
939
940 return 0;
941}
942
943EXPORT_SYMBOL(fat_remove_entries);
944
945static int fat_zeroed_cluster(struct inode *dir, sector_t blknr, int nr_used,
946 struct buffer_head **bhs, int nr_bhs)
947{
948 struct super_block *sb = dir->i_sb;
949 sector_t last_blknr = blknr + MSDOS_SB(sb)->sec_per_clus;
950 int err, i, n;
951
952 /* Zeroing the unused blocks on this cluster */
953 blknr += nr_used;
954 n = nr_used;
955 while (blknr < last_blknr) {
956 bhs[n] = sb_getblk(sb, blknr);
957 if (!bhs[n]) {
958 err = -ENOMEM;
959 goto error;
960 }
961 memset(bhs[n]->b_data, 0, sb->s_blocksize);
962 set_buffer_uptodate(bhs[n]);
963 mark_buffer_dirty(bhs[n]);
964
965 n++;
966 blknr++;
967 if (n == nr_bhs) {
968 if (IS_DIRSYNC(dir)) {
969 err = fat_sync_bhs(bhs, n);
970 if (err)
971 goto error;
972 }
973 for (i = 0; i < n; i++)
974 brelse(bhs[i]);
975 n = 0;
976 }
977 }
978 if (IS_DIRSYNC(dir)) {
979 err = fat_sync_bhs(bhs, n);
980 if (err)
981 goto error;
982 }
983 for (i = 0; i < n; i++)
984 brelse(bhs[i]);
985
986 return 0;
987
988error:
989 for (i = 0; i < n; i++)
990 bforget(bhs[i]);
991 return err;
992}
993
994int fat_alloc_new_dir(struct inode *dir, struct timespec *ts)
995{
996 struct super_block *sb = dir->i_sb;
997 struct msdos_sb_info *sbi = MSDOS_SB(sb);
998 struct buffer_head *bhs[MAX_BUF_PER_PAGE];
999 struct msdos_dir_entry *de;
1000 sector_t blknr;
1001 __le16 date, time;
1002 int err, cluster;
1003
1004 err = fat_alloc_clusters(dir, &cluster, 1);
1005 if (err)
1006 goto error;
1007
1008 blknr = fat_clus_to_blknr(sbi, cluster);
1009 bhs[0] = sb_getblk(sb, blknr);
1010 if (!bhs[0]) {
1011 err = -ENOMEM;
1012 goto error_free;
1013 }
1014
1015 fat_date_unix2dos(ts->tv_sec, &time, &date);
1016
1017 de = (struct msdos_dir_entry *)bhs[0]->b_data;
1018 /* filling the new directory slots ("." and ".." entries) */
1019 memcpy(de[0].name, MSDOS_DOT, MSDOS_NAME);
1020 memcpy(de[1].name, MSDOS_DOTDOT, MSDOS_NAME);
1021 de->attr = de[1].attr = ATTR_DIR;
1022 de[0].lcase = de[1].lcase = 0;
1023 de[0].time = de[1].time = time;
1024 de[0].date = de[1].date = date;
1025 de[0].ctime_cs = de[1].ctime_cs = 0;
1026 if (sbi->options.isvfat) {
1027 /* extra timestamps */
1028 de[0].ctime = de[1].ctime = time;
1029 de[0].adate = de[0].cdate = de[1].adate = de[1].cdate = date;
1030 } else {
1031 de[0].ctime = de[1].ctime = 0;
1032 de[0].adate = de[0].cdate = de[1].adate = de[1].cdate = 0;
1033 }
1034 de[0].start = cpu_to_le16(cluster);
1035 de[0].starthi = cpu_to_le16(cluster >> 16);
1036 de[1].start = cpu_to_le16(MSDOS_I(dir)->i_logstart);
1037 de[1].starthi = cpu_to_le16(MSDOS_I(dir)->i_logstart >> 16);
1038 de[0].size = de[1].size = 0;
1039 memset(de + 2, 0, sb->s_blocksize - 2 * sizeof(*de));
1040 set_buffer_uptodate(bhs[0]);
1041 mark_buffer_dirty(bhs[0]);
1042
1043 err = fat_zeroed_cluster(dir, blknr, 1, bhs, MAX_BUF_PER_PAGE);
1044 if (err)
1045 goto error_free;
1046
1047 return cluster;
1048
1049error_free:
1050 fat_free_clusters(dir, cluster);
1051error:
1052 return err;
1053}
1054
1055EXPORT_SYMBOL(fat_alloc_new_dir);
1056
1057static int fat_add_new_entries(struct inode *dir, void *slots, int nr_slots,
1058 int *nr_cluster, struct msdos_dir_entry **de,
1059 struct buffer_head **bh, loff_t *i_pos)
1060{
1061 struct super_block *sb = dir->i_sb;
1062 struct msdos_sb_info *sbi = MSDOS_SB(sb);
1063 struct buffer_head *bhs[MAX_BUF_PER_PAGE];
1064 sector_t blknr, start_blknr, last_blknr;
1065 unsigned long size, copy;
1066 int err, i, n, offset, cluster[2];
1067
1068 /*
1069 * The minimum cluster size is 512bytes, and maximum entry
1070 * size is 32*slots (672bytes). So, iff the cluster size is
1071 * 512bytes, we may need two clusters.
1072 */
1073 size = nr_slots * sizeof(struct msdos_dir_entry);
1074 *nr_cluster = (size + (sbi->cluster_size - 1)) >> sbi->cluster_bits;
1075 BUG_ON(*nr_cluster > 2);
1076
1077 err = fat_alloc_clusters(dir, cluster, *nr_cluster);
1078 if (err)
1079 goto error;
1080
1081 /*
1082 * First stage: Fill the directory entry. NOTE: This cluster
1083 * is not referenced from any inode yet, so updates order is
1084 * not important.
1085 */
1086 i = n = copy = 0;
1087 do {
1088 start_blknr = blknr = fat_clus_to_blknr(sbi, cluster[i]);
1089 last_blknr = start_blknr + sbi->sec_per_clus;
1090 while (blknr < last_blknr) {
1091 bhs[n] = sb_getblk(sb, blknr);
1092 if (!bhs[n]) {
1093 err = -ENOMEM;
1094 goto error_nomem;
1095 }
1096
1097 /* fill the directory entry */
1098 copy = min(size, sb->s_blocksize);
1099 memcpy(bhs[n]->b_data, slots, copy);
1100 slots += copy;
1101 size -= copy;
1102 set_buffer_uptodate(bhs[n]);
1103 mark_buffer_dirty(bhs[n]);
1104 if (!size)
1105 break;
1106 n++;
1107 blknr++;
1108 }
1109 } while (++i < *nr_cluster);
1110
1111 memset(bhs[n]->b_data + copy, 0, sb->s_blocksize - copy);
1112 offset = copy - sizeof(struct msdos_dir_entry);
1113 get_bh(bhs[n]);
1114 *bh = bhs[n];
1115 *de = (struct msdos_dir_entry *)((*bh)->b_data + offset);
1116 *i_pos = fat_make_i_pos(sb, *bh, *de);
1117
1118 /* Second stage: clear the rest of cluster, and write outs */
1119 err = fat_zeroed_cluster(dir, start_blknr, ++n, bhs, MAX_BUF_PER_PAGE);
1120 if (err)
1121 goto error_free;
1122
1123 return cluster[0];
1124
1125error_free:
1126 brelse(*bh);
1127 *bh = NULL;
1128 n = 0;
1129error_nomem:
1130 for (i = 0; i < n; i++)
1131 bforget(bhs[i]);
1132 fat_free_clusters(dir, cluster[0]);
1133error:
1134 return err;
1135}
1136
1137int fat_add_entries(struct inode *dir, void *slots, int nr_slots,
1138 struct fat_slot_info *sinfo)
1139{
1140 struct super_block *sb = dir->i_sb;
1141 struct msdos_sb_info *sbi = MSDOS_SB(sb);
1142 struct buffer_head *bh, *prev, *bhs[3]; /* 32*slots (672bytes) */
1143 struct msdos_dir_entry *de;
1144 int err, free_slots, i, nr_bhs;
1145 loff_t pos, i_pos;
1146
1147 sinfo->nr_slots = nr_slots;
1148
1149 /* First stage: search free direcotry entries */
1150 free_slots = nr_bhs = 0;
1151 bh = prev = NULL;
1152 pos = 0;
1153 err = -ENOSPC;
1154 while (fat_get_entry(dir, &pos, &bh, &de) > -1) {
1155 /* check the maximum size of directory */
1156 if (pos >= FAT_MAX_DIR_SIZE)
1157 goto error;
1158
1159 if (IS_FREE(de->name)) {
1160 if (prev != bh) {
1161 get_bh(bh);
1162 bhs[nr_bhs] = prev = bh;
1163 nr_bhs++;
1164 }
1165 free_slots++;
1166 if (free_slots == nr_slots)
1167 goto found;
1168 } else {
1169 for (i = 0; i < nr_bhs; i++)
1170 brelse(bhs[i]);
1171 prev = NULL;
1172 free_slots = nr_bhs = 0;
1173 }
1174 }
1175 if (dir->i_ino == MSDOS_ROOT_INO) {
1176 if (sbi->fat_bits != 32)
1177 goto error;
1178 } else if (MSDOS_I(dir)->i_start == 0) {
1179 printk(KERN_ERR "FAT: Corrupted directory (i_pos %lld)\n",
1180 MSDOS_I(dir)->i_pos);
1181 err = -EIO;
1182 goto error;
1183 }
1184
1185found:
1186 err = 0;
1187 pos -= free_slots * sizeof(*de);
1188 nr_slots -= free_slots;
1189 if (free_slots) {
1190 /*
1191 * Second stage: filling the free entries with new entries.
1192 * NOTE: If this slots has shortname, first, we write
1193 * the long name slots, then write the short name.
1194 */
1195 int size = free_slots * sizeof(*de);
1196 int offset = pos & (sb->s_blocksize - 1);
1197 int long_bhs = nr_bhs - (nr_slots == 0);
1198
1199 /* Fill the long name slots. */
1200 for (i = 0; i < long_bhs; i++) {
1201 int copy = min_t(int, sb->s_blocksize - offset, size);
1202 memcpy(bhs[i]->b_data + offset, slots, copy);
1203 mark_buffer_dirty(bhs[i]);
1204 offset = 0;
1205 slots += copy;
1206 size -= copy;
1207 }
1208 if (long_bhs && IS_DIRSYNC(dir))
1209 err = fat_sync_bhs(bhs, long_bhs);
1210 if (!err && i < nr_bhs) {
1211 /* Fill the short name slot. */
1212 int copy = min_t(int, sb->s_blocksize - offset, size);
1213 memcpy(bhs[i]->b_data + offset, slots, copy);
1214 mark_buffer_dirty(bhs[i]);
1215 if (IS_DIRSYNC(dir))
1216 err = sync_dirty_buffer(bhs[i]);
1217 }
1218 for (i = 0; i < nr_bhs; i++)
1219 brelse(bhs[i]);
1220 if (err)
1221 goto error_remove;
1222 }
1223
1224 if (nr_slots) {
1225 int cluster, nr_cluster;
1226
1227 /*
1228 * Third stage: allocate the cluster for new entries.
1229 * And initialize the cluster with new entries, then
1230 * add the cluster to dir.
1231 */
1232 cluster = fat_add_new_entries(dir, slots, nr_slots, &nr_cluster,
1233 &de, &bh, &i_pos);
1234 if (cluster < 0) {
1235 err = cluster;
1236 goto error_remove;
1237 }
1238 err = fat_chain_add(dir, cluster, nr_cluster);
1239 if (err) {
1240 fat_free_clusters(dir, cluster);
1241 goto error_remove;
1242 }
1243 if (dir->i_size & (sbi->cluster_size - 1)) {
1244 fat_fs_panic(sb, "Odd directory size");
1245 dir->i_size = (dir->i_size + sbi->cluster_size - 1)
1246 & ~((loff_t)sbi->cluster_size - 1);
1247 }
1248 dir->i_size += nr_cluster << sbi->cluster_bits;
1249 MSDOS_I(dir)->mmu_private += nr_cluster << sbi->cluster_bits;
1250 }
1251 sinfo->slot_off = pos;
1252 sinfo->de = de;
1253 sinfo->bh = bh;
1254 sinfo->i_pos = fat_make_i_pos(sb, sinfo->bh, sinfo->de);
1255
1256 return 0;
1257
1258error:
1259 brelse(bh);
1260 for (i = 0; i < nr_bhs; i++)
1261 brelse(bhs[i]);
1262 return err;
1263
1264error_remove:
1265 brelse(bh);
1266 if (free_slots)
1267 __fat_remove_entries(dir, pos, free_slots);
1268 return err;
1269}
1270
1271EXPORT_SYMBOL(fat_add_entries);
generated by cgit v1.2.2 (git 2.25.0) at 2024-11-21 09:38:29 -0500