-
Notifications
You must be signed in to change notification settings - Fork 87
/
dir.c
1371 lines (1232 loc) · 34.1 KB
/
dir.c
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
/*
* linux/fs/fat/dir.c
*
* directory handling functions for fat-based filesystems
*
* Written 1992,1993 by Werner Almesberger
*
* Hidden files 1995 by Albert Cahalan <[email protected]> <[email protected]>
*
* VFAT extensions by Gordon Chaffee <[email protected]>
* Merged with msdos fs by Henrik Storner <[email protected]>
* Rewritten for constant inumbers. Plugged buffer overrun in readdir(). AV
* Short name translation 1999, 2001 by Wolfram Pienkoss <[email protected]>
*/
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/time.h>
#include <linux/buffer_head.h>
#include <linux/compat.h>
#include <asm/uaccess.h>
#include <linux/kernel.h>
#include "fat.h"
/*
* Maximum buffer size of short name.
* [(MSDOS_NAME + '.') * max one char + nul]
* For msdos style, ['.' (hidden) + MSDOS_NAME + '.' + nul]
*/
#define FAT_MAX_SHORT_SIZE ((MSDOS_NAME + 1) * NLS_MAX_CHARSET_SIZE + 1)
/*
* Maximum buffer size of unicode chars from slots.
* [(max longname slots * 13 (size in a slot) + nul) * sizeof(wchar_t)]
*/
#define FAT_MAX_UNI_CHARS ((MSDOS_SLOTS - 1) * 13 + 1)
#define FAT_MAX_UNI_SIZE (FAT_MAX_UNI_CHARS * sizeof(wchar_t))
static inline loff_t fat_make_i_pos(struct super_block *sb,
struct buffer_head *bh,
struct msdos_dir_entry *de)
{
return ((loff_t)bh->b_blocknr << MSDOS_SB(sb)->dir_per_block_bits)
| (de - (struct msdos_dir_entry *)bh->b_data);
}
static inline void fat_dir_readahead(struct inode *dir, sector_t iblock,
sector_t phys)
{
struct super_block *sb = dir->i_sb;
struct msdos_sb_info *sbi = MSDOS_SB(sb);
struct buffer_head *bh;
int sec;
/* This is not a first sector of cluster, or sec_per_clus == 1 */
if ((iblock & (sbi->sec_per_clus - 1)) || sbi->sec_per_clus == 1)
return;
/* root dir of FAT12/FAT16 */
if ((sbi->fat_bits != 32) && (dir->i_ino == MSDOS_ROOT_INO))
return;
bh = sb_find_get_block(sb, phys);
if (bh == NULL || !buffer_uptodate(bh)) {
for (sec = 0; sec < sbi->sec_per_clus; sec++)
sb_breadahead(sb, phys + sec);
}
brelse(bh);
}
/* Returns the inode number of the directory entry at offset pos. If bh is
non-NULL, it is brelse'd before. Pos is incremented. The buffer header is
returned in bh.
AV. Most often we do it item-by-item. Makes sense to optimize.
AV. OK, there we go: if both bh and de are non-NULL we assume that we just
AV. want the next entry (took one explicit de=NULL in vfat/namei.c).
AV. It's done in fat_get_entry() (inlined), here the slow case lives.
AV. Additionally, when we return -1 (i.e. reached the end of directory)
AV. we make bh NULL.
*/
static int fat__get_entry(struct inode *dir, loff_t *pos,
struct buffer_head **bh, struct msdos_dir_entry **de)
{
struct super_block *sb = dir->i_sb;
sector_t phys, iblock;
unsigned long mapped_blocks;
int err, offset;
next:
if (*bh)
brelse(*bh);
*bh = NULL;
iblock = *pos >> sb->s_blocksize_bits;
err = fat_bmap(dir, iblock, &phys, &mapped_blocks, 0);
if (err || !phys)
return -1; /* beyond EOF or error */
fat_dir_readahead(dir, iblock, phys);
*bh = sb_bread(sb, phys);
if (*bh == NULL) {
fat_msg(sb, KERN_ERR, "Directory bread(block %llu) failed",
(llu)phys);
/* skip this block */
*pos = (iblock + 1) << sb->s_blocksize_bits;
goto next;
}
offset = *pos & (sb->s_blocksize - 1);
*pos += sizeof(struct msdos_dir_entry);
*de = (struct msdos_dir_entry *)((*bh)->b_data + offset);
return 0;
}
static inline int fat_get_entry(struct inode *dir, loff_t *pos,
struct buffer_head **bh,
struct msdos_dir_entry **de)
{
/* Fast stuff first */
if (*bh && *de &&
(*de - (struct msdos_dir_entry *)(*bh)->b_data) < MSDOS_SB(dir->i_sb)->dir_per_block - 1) {
*pos += sizeof(struct msdos_dir_entry);
(*de)++;
return 0;
}
return fat__get_entry(dir, pos, bh, de);
}
/*
* Convert Unicode 16 to UTF-8, translated Unicode, or ASCII.
* If uni_xlate is enabled and we can't get a 1:1 conversion, use a
* colon as an escape character since it is normally invalid on the vfat
* filesystem. The following four characters are the hexadecimal digits
* of Unicode value. This lets us do a full dump and restore of Unicode
* filenames. We could get into some trouble with long Unicode names,
* but ignore that right now.
* Ahem... Stack smashing in ring 0 isn't fun. Fixed.
*/
static int uni16_to_x8(struct super_block *sb, unsigned char *ascii,
const wchar_t *uni, int len, struct nls_table *nls)
{
int uni_xlate = MSDOS_SB(sb)->options.unicode_xlate;
const wchar_t *ip;
wchar_t ec;
unsigned char *op;
int charlen;
ip = uni;
op = ascii;
while (*ip && ((len - NLS_MAX_CHARSET_SIZE) > 0)) {
ec = *ip++;
if ((charlen = nls->uni2char(ec, op, NLS_MAX_CHARSET_SIZE)) > 0) {
op += charlen;
len -= charlen;
} else {
if (uni_xlate == 1) {
*op++ = ':';
op = hex_byte_pack(op, ec >> 8);
op = hex_byte_pack(op, ec);
len -= 5;
} else {
*op++ = '?';
len--;
}
}
}
if (unlikely(*ip)) {
fat_msg(sb, KERN_WARNING, "filename was truncated while "
"converting.");
}
*op = 0;
return (op - ascii);
}
static inline int fat_uni_to_x8(struct super_block *sb, const wchar_t *uni,
unsigned char *buf, int size)
{
struct msdos_sb_info *sbi = MSDOS_SB(sb);
if (sbi->options.utf8)
return utf16s_to_utf8s(uni, FAT_MAX_UNI_CHARS,
UTF16_HOST_ENDIAN, buf, size);
else
return uni16_to_x8(sb, buf, uni, size, sbi->nls_io);
}
static inline int
fat_short2uni(struct nls_table *t, unsigned char *c, int clen, wchar_t *uni)
{
int charlen;
charlen = t->char2uni(c, clen, uni);
if (charlen < 0) {
*uni = 0x003f; /* a question mark */
charlen = 1;
}
return charlen;
}
static inline int
fat_short2lower_uni(struct nls_table *t, unsigned char *c, int clen, wchar_t *uni)
{
int charlen;
wchar_t wc;
charlen = t->char2uni(c, clen, &wc);
if (charlen < 0) {
*uni = 0x003f; /* a question mark */
charlen = 1;
} else if (charlen <= 1) {
unsigned char nc = t->charset2lower[*c];
if (!nc)
nc = *c;
if ( (charlen = t->char2uni(&nc, 1, uni)) < 0) {
*uni = 0x003f; /* a question mark */
charlen = 1;
}
} else
*uni = wc;
return charlen;
}
static inline int
fat_shortname2uni(struct nls_table *nls, unsigned char *buf, int buf_size,
wchar_t *uni_buf, unsigned short opt, int lower)
{
int len = 0;
if (opt & VFAT_SFN_DISPLAY_LOWER)
len = fat_short2lower_uni(nls, buf, buf_size, uni_buf);
else if (opt & VFAT_SFN_DISPLAY_WIN95)
len = fat_short2uni(nls, buf, buf_size, uni_buf);
else if (opt & VFAT_SFN_DISPLAY_WINNT) {
if (lower)
len = fat_short2lower_uni(nls, buf, buf_size, uni_buf);
else
len = fat_short2uni(nls, buf, buf_size, uni_buf);
} else
len = fat_short2uni(nls, buf, buf_size, uni_buf);
return len;
}
static inline int fat_name_match(struct msdos_sb_info *sbi,
const unsigned char *a, int a_len,
const unsigned char *b, int b_len)
{
if (a_len != b_len)
return 0;
if (sbi->options.name_check != 's')
return !nls_strnicmp(sbi->nls_io, a, b, a_len);
else
return !memcmp(a, b, a_len);
}
enum { PARSE_INVALID = 1, PARSE_NOT_LONGNAME, PARSE_EOF, };
/**
* fat_parse_long - Parse extended directory entry.
*
* This function returns zero on success, negative value on error, or one of
* the following:
*
* %PARSE_INVALID - Directory entry is invalid.
* %PARSE_NOT_LONGNAME - Directory entry does not contain longname.
* %PARSE_EOF - Directory has no more entries.
*/
static int fat_parse_long(struct inode *dir, loff_t *pos,
struct buffer_head **bh, struct msdos_dir_entry **de,
wchar_t **unicode, unsigned char *nr_slots)
{
struct msdos_dir_slot *ds;
unsigned char id, slot, slots, alias_checksum;
if (!*unicode) {
*unicode = __getname();
if (!*unicode) {
brelse(*bh);
return -ENOMEM;
}
}
parse_long:
slots = 0;
ds = (struct msdos_dir_slot *)*de;
id = ds->id;
if (!(id & 0x40))
return PARSE_INVALID;
slots = id & ~0x40;
if (slots > 20 || !slots) /* ceil(256 * 2 / 26) */
return PARSE_INVALID;
*nr_slots = slots;
alias_checksum = ds->alias_checksum;
slot = slots;
while (1) {
int offset;
slot--;
offset = slot * 13;
fat16_towchar(*unicode + offset, ds->name0_4, 5);
fat16_towchar(*unicode + offset + 5, ds->name5_10, 6);
fat16_towchar(*unicode + offset + 11, ds->name11_12, 2);
if (ds->id & 0x40)
(*unicode)[offset + 13] = 0;
if (fat_get_entry(dir, pos, bh, de) < 0)
return PARSE_EOF;
if (slot == 0)
break;
ds = (struct msdos_dir_slot *)*de;
if (ds->attr != ATTR_EXT)
return PARSE_NOT_LONGNAME;
if ((ds->id & ~0x40) != slot)
goto parse_long;
if (ds->alias_checksum != alias_checksum)
goto parse_long;
}
if ((*de)->name[0] == DELETED_FLAG)
return PARSE_INVALID;
if ((*de)->attr == ATTR_EXT)
goto parse_long;
if (IS_FREE((*de)->name) || ((*de)->attr & ATTR_VOLUME))
return PARSE_INVALID;
if (fat_checksum((*de)->name) != alias_checksum)
*nr_slots = 0;
return 0;
}
/*
* Return values: negative -> error, 0 -> not found, positive -> found,
* value is the total amount of slots, including the shortname entry.
*/
int fat_search_long(struct inode *inode, const unsigned char *name,
int name_len, struct fat_slot_info *sinfo)
{
struct super_block *sb = inode->i_sb;
struct msdos_sb_info *sbi = MSDOS_SB(sb);
struct buffer_head *bh = NULL;
struct msdos_dir_entry *de;
struct nls_table *nls_disk = sbi->nls_disk;
unsigned char nr_slots;
wchar_t bufuname[14];
wchar_t *unicode = NULL;
unsigned char work[MSDOS_NAME];
unsigned char bufname[FAT_MAX_SHORT_SIZE];
unsigned short opt_shortname = sbi->options.shortname;
loff_t cpos = 0;
int chl, i, j, last_u, err, len;
err = -ENOENT;
while (1) {
if (fat_get_entry(inode, &cpos, &bh, &de) == -1)
goto end_of_dir;
parse_record:
nr_slots = 0;
if (de->name[0] == DELETED_FLAG)
continue;
if (de->attr != ATTR_EXT && (de->attr & ATTR_VOLUME))
continue;
if (de->attr != ATTR_EXT && IS_FREE(de->name))
continue;
if (de->attr == ATTR_EXT) {
int status = fat_parse_long(inode, &cpos, &bh, &de,
&unicode, &nr_slots);
if (status < 0) {
err = status;
goto end_of_dir;
} else if (status == PARSE_INVALID)
continue;
else if (status == PARSE_NOT_LONGNAME)
goto parse_record;
else if (status == PARSE_EOF)
goto end_of_dir;
}
memcpy(work, de->name, sizeof(de->name));
/* see namei.c, msdos_format_name */
if (work[0] == 0x05)
work[0] = 0xE5;
for (i = 0, j = 0, last_u = 0; i < 8;) {
if (!work[i])
break;
chl = fat_shortname2uni(nls_disk, &work[i], 8 - i,
&bufuname[j++], opt_shortname,
de->lcase & CASE_LOWER_BASE);
if (chl <= 1) {
if (work[i] != ' ')
last_u = j;
} else {
last_u = j;
}
i += chl;
}
j = last_u;
fat_short2uni(nls_disk, ".", 1, &bufuname[j++]);
for (i = 8; i < MSDOS_NAME;) {
if (!work[i])
break;
chl = fat_shortname2uni(nls_disk, &work[i],
MSDOS_NAME - i,
&bufuname[j++], opt_shortname,
de->lcase & CASE_LOWER_EXT);
if (chl <= 1) {
if (work[i] != ' ')
last_u = j;
} else {
last_u = j;
}
i += chl;
}
if (!last_u)
continue;
/* Compare shortname */
bufuname[last_u] = 0x0000;
len = fat_uni_to_x8(sb, bufuname, bufname, sizeof(bufname));
if (fat_name_match(sbi, name, name_len, bufname, len))
goto found;
if (nr_slots) {
void *longname = unicode + FAT_MAX_UNI_CHARS;
int size = PATH_MAX - FAT_MAX_UNI_SIZE;
/* Compare longname */
len = fat_uni_to_x8(sb, unicode, longname, size);
if (fat_name_match(sbi, name, name_len, longname, len))
goto found;
}
}
found:
nr_slots++; /* include the de */
sinfo->slot_off = cpos - nr_slots * sizeof(*de);
sinfo->nr_slots = nr_slots;
sinfo->de = de;
sinfo->bh = bh;
sinfo->i_pos = fat_make_i_pos(sb, sinfo->bh, sinfo->de);
err = 0;
end_of_dir:
if (unicode)
__putname(unicode);
return err;
}
EXPORT_SYMBOL_GPL(fat_search_long);
struct fat_ioctl_filldir_callback {
void __user *dirent;
int result;
/* for dir ioctl */
const char *longname;
int long_len;
const char *shortname;
int short_len;
};
static int __fat_readdir(struct inode *inode, struct file *filp, void *dirent,
filldir_t filldir, int short_only, int both)
{
struct super_block *sb = inode->i_sb;
struct msdos_sb_info *sbi = MSDOS_SB(sb);
struct buffer_head *bh;
struct msdos_dir_entry *de;
struct nls_table *nls_disk = sbi->nls_disk;
unsigned char nr_slots;
wchar_t bufuname[14];
wchar_t *unicode = NULL;
unsigned char c, work[MSDOS_NAME];
unsigned char bufname[FAT_MAX_SHORT_SIZE], *ptname = bufname;
unsigned short opt_shortname = sbi->options.shortname;
int isvfat = sbi->options.isvfat;
int nocase = sbi->options.nocase;
const char *fill_name = NULL;
unsigned long inum;
unsigned long lpos, dummy, *furrfu = &lpos;
loff_t cpos;
int chi, chl, i, i2, j, last, last_u, dotoffset = 0, fill_len = 0;
int ret = 0;
lock_super(sb);
cpos = filp->f_pos;
/* Fake . and .. for the root directory. */
if (inode->i_ino == MSDOS_ROOT_INO) {
while (cpos < 2) {
if (filldir(dirent, "..", cpos+1, cpos, MSDOS_ROOT_INO, DT_DIR) < 0)
goto out;
cpos++;
filp->f_pos++;
}
if (cpos == 2) {
dummy = 2;
furrfu = &dummy;
cpos = 0;
}
}
if (cpos & (sizeof(struct msdos_dir_entry) - 1)) {
ret = -ENOENT;
goto out;
}
bh = NULL;
get_new:
if (fat_get_entry(inode, &cpos, &bh, &de) == -1)
goto end_of_dir;
parse_record:
nr_slots = 0;
/*
* Check for long filename entry, but if short_only, we don't
* need to parse long filename.
*/
if (isvfat && !short_only) {
if (de->name[0] == DELETED_FLAG)
goto record_end;
if (de->attr != ATTR_EXT && (de->attr & ATTR_VOLUME))
goto record_end;
if (de->attr != ATTR_EXT && IS_FREE(de->name))
goto record_end;
} else {
if ((de->attr & ATTR_VOLUME) || IS_FREE(de->name))
goto record_end;
}
if (isvfat && de->attr == ATTR_EXT) {
int status = fat_parse_long(inode, &cpos, &bh, &de,
&unicode, &nr_slots);
if (status < 0) {
filp->f_pos = cpos;
ret = status;
goto out;
} else if (status == PARSE_INVALID)
goto record_end;
else if (status == PARSE_NOT_LONGNAME)
goto parse_record;
else if (status == PARSE_EOF)
goto end_of_dir;
if (nr_slots) {
void *longname = unicode + FAT_MAX_UNI_CHARS;
int size = PATH_MAX - FAT_MAX_UNI_SIZE;
int len = fat_uni_to_x8(sb, unicode, longname, size);
fill_name = longname;
fill_len = len;
/* !both && !short_only, so we don't need shortname. */
if (!both)
goto start_filldir;
}
}
if (sbi->options.dotsOK) {
ptname = bufname;
dotoffset = 0;
if (de->attr & ATTR_HIDDEN) {
*ptname++ = '.';
dotoffset = 1;
}
}
memcpy(work, de->name, sizeof(de->name));
/* see namei.c, msdos_format_name */
if (work[0] == 0x05)
work[0] = 0xE5;
for (i = 0, j = 0, last = 0, last_u = 0; i < 8;) {
if (!(c = work[i]))
break;
chl = fat_shortname2uni(nls_disk, &work[i], 8 - i,
&bufuname[j++], opt_shortname,
de->lcase & CASE_LOWER_BASE);
if (chl <= 1) {
ptname[i++] = (!nocase && c>='A' && c<='Z') ? c+32 : c;
if (c != ' ') {
last = i;
last_u = j;
}
} else {
last_u = j;
for (chi = 0; chi < chl && i < 8; chi++) {
ptname[i] = work[i];
i++; last = i;
}
}
}
i = last;
j = last_u;
fat_short2uni(nls_disk, ".", 1, &bufuname[j++]);
ptname[i++] = '.';
for (i2 = 8; i2 < MSDOS_NAME;) {
if (!(c = work[i2]))
break;
chl = fat_shortname2uni(nls_disk, &work[i2], MSDOS_NAME - i2,
&bufuname[j++], opt_shortname,
de->lcase & CASE_LOWER_EXT);
if (chl <= 1) {
i2++;
ptname[i++] = (!nocase && c>='A' && c<='Z') ? c+32 : c;
if (c != ' ') {
last = i;
last_u = j;
}
} else {
last_u = j;
for (chi = 0; chi < chl && i2 < MSDOS_NAME; chi++) {
ptname[i++] = work[i2++];
last = i;
}
}
}
if (!last)
goto record_end;
i = last + dotoffset;
j = last_u;
if (isvfat) {
bufuname[j] = 0x0000;
i = fat_uni_to_x8(sb, bufuname, bufname, sizeof(bufname));
}
if (nr_slots) {
/* hack for fat_ioctl_filldir() */
struct fat_ioctl_filldir_callback *p = dirent;
p->longname = fill_name;
p->long_len = fill_len;
p->shortname = bufname;
p->short_len = i;
fill_name = NULL;
fill_len = 0;
} else {
fill_name = bufname;
fill_len = i;
}
start_filldir:
lpos = cpos - (nr_slots + 1) * sizeof(struct msdos_dir_entry);
if (!memcmp(de->name, MSDOS_DOT, MSDOS_NAME))
inum = inode->i_ino;
else if (!memcmp(de->name, MSDOS_DOTDOT, MSDOS_NAME)) {
inum = parent_ino(filp->f_path.dentry);
} else {
loff_t i_pos = fat_make_i_pos(sb, bh, de);
struct inode *tmp = fat_iget(sb, i_pos);
if (tmp) {
inum = tmp->i_ino;
iput(tmp);
} else
inum = iunique(sb, MSDOS_ROOT_INO);
}
if (filldir(dirent, fill_name, fill_len, *furrfu, inum,
(de->attr & ATTR_DIR) ? DT_DIR : DT_REG) < 0)
goto fill_failed;
record_end:
furrfu = &lpos;
filp->f_pos = cpos;
goto get_new;
end_of_dir:
filp->f_pos = cpos;
fill_failed:
brelse(bh);
if (unicode)
__putname(unicode);
out:
unlock_super(sb);
return ret;
}
static int fat_readdir(struct file *filp, void *dirent, filldir_t filldir)
{
struct inode *inode = filp->f_path.dentry->d_inode;
return __fat_readdir(inode, filp, dirent, filldir, 0, 0);
}
#define FAT_IOCTL_FILLDIR_FUNC(func, dirent_type) \
static int func(void *__buf, const char *name, int name_len, \
loff_t offset, u64 ino, unsigned int d_type) \
{ \
struct fat_ioctl_filldir_callback *buf = __buf; \
struct dirent_type __user *d1 = buf->dirent; \
struct dirent_type __user *d2 = d1 + 1; \
\
if (buf->result) \
return -EINVAL; \
buf->result++; \
\
if (name != NULL) { \
/* dirent has only short name */ \
if (name_len >= sizeof(d1->d_name)) \
name_len = sizeof(d1->d_name) - 1; \
\
if (put_user(0, d2->d_name) || \
put_user(0, &d2->d_reclen) || \
copy_to_user(d1->d_name, name, name_len) || \
put_user(0, d1->d_name + name_len) || \
put_user(name_len, &d1->d_reclen)) \
goto efault; \
} else { \
/* dirent has short and long name */ \
const char *longname = buf->longname; \
int long_len = buf->long_len; \
const char *shortname = buf->shortname; \
int short_len = buf->short_len; \
\
if (long_len >= sizeof(d1->d_name)) \
long_len = sizeof(d1->d_name) - 1; \
if (short_len >= sizeof(d1->d_name)) \
short_len = sizeof(d1->d_name) - 1; \
\
if (copy_to_user(d2->d_name, longname, long_len) || \
put_user(0, d2->d_name + long_len) || \
put_user(long_len, &d2->d_reclen) || \
put_user(ino, &d2->d_ino) || \
put_user(offset, &d2->d_off) || \
copy_to_user(d1->d_name, shortname, short_len) || \
put_user(0, d1->d_name + short_len) || \
put_user(short_len, &d1->d_reclen)) \
goto efault; \
} \
return 0; \
efault: \
buf->result = -EFAULT; \
return -EFAULT; \
}
FAT_IOCTL_FILLDIR_FUNC(fat_ioctl_filldir, __fat_dirent)
static int fat_ioctl_readdir(struct inode *inode, struct file *filp,
void __user *dirent, filldir_t filldir,
int short_only, int both)
{
struct fat_ioctl_filldir_callback buf;
int ret;
buf.dirent = dirent;
buf.result = 0;
mutex_lock(&inode->i_mutex);
ret = -ENOENT;
if (!IS_DEADDIR(inode)) {
ret = __fat_readdir(inode, filp, &buf, filldir,
short_only, both);
}
mutex_unlock(&inode->i_mutex);
if (ret >= 0)
ret = buf.result;
return ret;
}
static int fat_ioctl_volume_id(struct inode *dir)
{
struct super_block *sb = dir->i_sb;
struct msdos_sb_info *sbi = MSDOS_SB(sb);
return sbi->vol_id;
}
static long fat_dir_ioctl(struct file *filp, unsigned int cmd,
unsigned long arg)
{
struct inode *inode = filp->f_path.dentry->d_inode;
struct __fat_dirent __user *d1 = (struct __fat_dirent __user *)arg;
int short_only, both;
switch (cmd) {
case VFAT_IOCTL_READDIR_SHORT:
short_only = 1;
both = 0;
break;
case VFAT_IOCTL_READDIR_BOTH:
short_only = 0;
both = 1;
break;
case VFAT_IOCTL_GET_VOLUME_ID:
return fat_ioctl_volume_id(inode);
default:
return fat_generic_ioctl(filp, cmd, arg);
}
if (!access_ok(VERIFY_WRITE, d1, sizeof(struct __fat_dirent[2])))
return -EFAULT;
/*
* Yes, we don't need this put_user() absolutely. However old
* code didn't return the right value. So, app use this value,
* in order to check whether it is EOF.
*/
if (put_user(0, &d1->d_reclen))
return -EFAULT;
return fat_ioctl_readdir(inode, filp, d1, fat_ioctl_filldir,
short_only, both);
}
#ifdef CONFIG_COMPAT
#define VFAT_IOCTL_READDIR_BOTH32 _IOR('r', 1, struct compat_dirent[2])
#define VFAT_IOCTL_READDIR_SHORT32 _IOR('r', 2, struct compat_dirent[2])
FAT_IOCTL_FILLDIR_FUNC(fat_compat_ioctl_filldir, compat_dirent)
static long fat_compat_dir_ioctl(struct file *filp, unsigned cmd,
unsigned long arg)
{
struct inode *inode = filp->f_path.dentry->d_inode;
struct compat_dirent __user *d1 = compat_ptr(arg);
int short_only, both;
switch (cmd) {
case VFAT_IOCTL_READDIR_SHORT32:
short_only = 1;
both = 0;
break;
case VFAT_IOCTL_READDIR_BOTH32:
short_only = 0;
both = 1;
break;
default:
return fat_generic_ioctl(filp, cmd, (unsigned long)arg);
}
if (!access_ok(VERIFY_WRITE, d1, sizeof(struct compat_dirent[2])))
return -EFAULT;
/*
* Yes, we don't need this put_user() absolutely. However old
* code didn't return the right value. So, app use this value,
* in order to check whether it is EOF.
*/
if (put_user(0, &d1->d_reclen))
return -EFAULT;
return fat_ioctl_readdir(inode, filp, d1, fat_compat_ioctl_filldir,
short_only, both);
}
#endif /* CONFIG_COMPAT */
const struct file_operations fat_dir_operations = {
.llseek = generic_file_llseek,
.read = generic_read_dir,
.readdir = fat_readdir,
.unlocked_ioctl = fat_dir_ioctl,
#ifdef CONFIG_COMPAT
.compat_ioctl = fat_compat_dir_ioctl,
#endif
.fsync = fat_file_fsync,
};
static int fat_get_short_entry(struct inode *dir, loff_t *pos,
struct buffer_head **bh,
struct msdos_dir_entry **de)
{
while (fat_get_entry(dir, pos, bh, de) >= 0) {
/* free entry or long name entry or volume label */
if (!IS_FREE((*de)->name) && !((*de)->attr & ATTR_VOLUME))
return 0;
}
return -ENOENT;
}
/*
* The ".." entry can not provide the "struct fat_slot_info" informations
* for inode. So, this function provide the some informations only.
*/
int fat_get_dotdot_entry(struct inode *dir, struct buffer_head **bh,
struct msdos_dir_entry **de, loff_t *i_pos)
{
loff_t offset;
offset = 0;
*bh = NULL;
while (fat_get_short_entry(dir, &offset, bh, de) >= 0) {
if (!strncmp((*de)->name, MSDOS_DOTDOT, MSDOS_NAME)) {
*i_pos = fat_make_i_pos(dir->i_sb, *bh, *de);
return 0;
}
}
return -ENOENT;
}
EXPORT_SYMBOL_GPL(fat_get_dotdot_entry);
/* See if directory is empty */
int fat_dir_empty(struct inode *dir)
{
struct buffer_head *bh;
struct msdos_dir_entry *de;
loff_t cpos;
int result = 0;
bh = NULL;
cpos = 0;
while (fat_get_short_entry(dir, &cpos, &bh, &de) >= 0) {
if (strncmp(de->name, MSDOS_DOT , MSDOS_NAME) &&
strncmp(de->name, MSDOS_DOTDOT, MSDOS_NAME)) {
result = -ENOTEMPTY;
break;
}
}
brelse(bh);
return result;
}
EXPORT_SYMBOL_GPL(fat_dir_empty);
/*
* fat_subdirs counts the number of sub-directories of dir. It can be run
* on directories being created.
*/
int fat_subdirs(struct inode *dir)
{
struct buffer_head *bh;
struct msdos_dir_entry *de;
loff_t cpos;
int count = 0;
bh = NULL;
cpos = 0;
while (fat_get_short_entry(dir, &cpos, &bh, &de) >= 0) {
if (de->attr & ATTR_DIR)
count++;
}
brelse(bh);
return count;
}
/*
* Scans a directory for a given file (name points to its formatted name).
* Returns an error code or zero.
*/
int fat_scan(struct inode *dir, const unsigned char *name,
struct fat_slot_info *sinfo)
{
struct super_block *sb = dir->i_sb;
sinfo->slot_off = 0;
sinfo->bh = NULL;
while (fat_get_short_entry(dir, &sinfo->slot_off, &sinfo->bh,
&sinfo->de) >= 0) {
if (!strncmp(sinfo->de->name, name, MSDOS_NAME)) {
sinfo->slot_off -= sizeof(*sinfo->de);
sinfo->nr_slots = 1;
sinfo->i_pos = fat_make_i_pos(sb, sinfo->bh, sinfo->de);
return 0;
}
}
return -ENOENT;
}
EXPORT_SYMBOL_GPL(fat_scan);
static int __fat_remove_entries(struct inode *dir, loff_t pos, int nr_slots)
{
struct super_block *sb = dir->i_sb;
struct buffer_head *bh;
struct msdos_dir_entry *de, *endp;
int err = 0, orig_slots;
while (nr_slots) {
bh = NULL;
if (fat_get_entry(dir, &pos, &bh, &de) < 0) {
err = -EIO;
break;
}
orig_slots = nr_slots;
endp = (struct msdos_dir_entry *)(bh->b_data + sb->s_blocksize);
while (nr_slots && de < endp) {
de->name[0] = DELETED_FLAG;
de++;
nr_slots--;
}
mark_buffer_dirty_inode(bh, dir);
if (IS_DIRSYNC(dir))
err = sync_dirty_buffer(bh);
brelse(bh);
if (err)
break;
/* pos is *next* de's position, so this does `- sizeof(de)' */
pos += ((orig_slots - nr_slots) * sizeof(*de)) - sizeof(*de);
}
return err;
}
int fat_remove_entries(struct inode *dir, struct fat_slot_info *sinfo)
{
struct super_block *sb = dir->i_sb;
struct msdos_dir_entry *de;
struct buffer_head *bh;
int err = 0, nr_slots;
/*
* First stage: Remove the shortname. By this, the directory
* entry is removed.
*/