forked from torvalds/linux
-
Notifications
You must be signed in to change notification settings - Fork 0
/
Copy pathdir.c
1196 lines (1020 loc) · 27.8 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
// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Copyright (C) 2012-2013 Samsung Electronics Co., Ltd.
*/
#include <linux/slab.h>
#include <linux/bio.h>
#include <linux/buffer_head.h>
#include "exfat_raw.h"
#include "exfat_fs.h"
static int exfat_extract_uni_name(struct exfat_dentry *ep,
unsigned short *uniname)
{
int i, len = 0;
for (i = 0; i < EXFAT_FILE_NAME_LEN; i++) {
*uniname = le16_to_cpu(ep->dentry.name.unicode_0_14[i]);
if (*uniname == 0x0)
return len;
uniname++;
len++;
}
*uniname = 0x0;
return len;
}
static void exfat_get_uniname_from_ext_entry(struct super_block *sb,
struct exfat_chain *p_dir, int entry, unsigned short *uniname)
{
int i;
struct exfat_entry_set_cache *es;
es = exfat_get_dentry_set(sb, p_dir, entry, ES_ALL_ENTRIES);
if (!es)
return;
/*
* First entry : file entry
* Second entry : stream-extension entry
* Third entry : first file-name entry
* So, the index of first file-name dentry should start from 2.
*/
for (i = 2; i < es->num_entries; i++) {
struct exfat_dentry *ep = exfat_get_dentry_cached(es, i);
/* end of name entry */
if (exfat_get_entry_type(ep) != TYPE_EXTEND)
break;
exfat_extract_uni_name(ep, uniname);
uniname += EXFAT_FILE_NAME_LEN;
}
exfat_free_dentry_set(es, false);
}
/* read a directory entry from the opened directory */
static int exfat_readdir(struct inode *inode, struct exfat_dir_entry *dir_entry)
{
int i, dentries_per_clu, dentries_per_clu_bits = 0;
unsigned int type, clu_offset;
sector_t sector;
struct exfat_chain dir, clu;
struct exfat_uni_name uni_name;
struct exfat_dentry *ep;
struct super_block *sb = inode->i_sb;
struct exfat_sb_info *sbi = EXFAT_SB(sb);
struct exfat_inode_info *ei = EXFAT_I(inode);
unsigned int dentry = ei->rwoffset & 0xFFFFFFFF;
struct buffer_head *bh;
/* check if the given file ID is opened */
if (ei->type != TYPE_DIR)
return -EPERM;
if (ei->entry == -1)
exfat_chain_set(&dir, sbi->root_dir, 0, ALLOC_FAT_CHAIN);
else
exfat_chain_set(&dir, ei->start_clu,
EXFAT_B_TO_CLU(i_size_read(inode), sbi), ei->flags);
dentries_per_clu = sbi->dentries_per_clu;
dentries_per_clu_bits = ilog2(dentries_per_clu);
clu_offset = dentry >> dentries_per_clu_bits;
exfat_chain_dup(&clu, &dir);
if (clu.flags == ALLOC_NO_FAT_CHAIN) {
clu.dir += clu_offset;
clu.size -= clu_offset;
} else {
/* hint_information */
if (clu_offset > 0 && ei->hint_bmap.off != EXFAT_EOF_CLUSTER &&
ei->hint_bmap.off > 0 && clu_offset >= ei->hint_bmap.off) {
clu_offset -= ei->hint_bmap.off;
clu.dir = ei->hint_bmap.clu;
}
while (clu_offset > 0) {
if (exfat_get_next_cluster(sb, &(clu.dir)))
return -EIO;
clu_offset--;
}
}
while (clu.dir != EXFAT_EOF_CLUSTER) {
i = dentry & (dentries_per_clu - 1);
for ( ; i < dentries_per_clu; i++, dentry++) {
ep = exfat_get_dentry(sb, &clu, i, &bh, §or);
if (!ep)
return -EIO;
type = exfat_get_entry_type(ep);
if (type == TYPE_UNUSED) {
brelse(bh);
break;
}
if (type != TYPE_FILE && type != TYPE_DIR) {
brelse(bh);
continue;
}
dir_entry->attr = le16_to_cpu(ep->dentry.file.attr);
exfat_get_entry_time(sbi, &dir_entry->crtime,
ep->dentry.file.create_tz,
ep->dentry.file.create_time,
ep->dentry.file.create_date,
ep->dentry.file.create_time_cs);
exfat_get_entry_time(sbi, &dir_entry->mtime,
ep->dentry.file.modify_tz,
ep->dentry.file.modify_time,
ep->dentry.file.modify_date,
ep->dentry.file.modify_time_cs);
exfat_get_entry_time(sbi, &dir_entry->atime,
ep->dentry.file.access_tz,
ep->dentry.file.access_time,
ep->dentry.file.access_date,
0);
*uni_name.name = 0x0;
exfat_get_uniname_from_ext_entry(sb, &dir, dentry,
uni_name.name);
exfat_utf16_to_nls(sb, &uni_name,
dir_entry->namebuf.lfn,
dir_entry->namebuf.lfnbuf_len);
brelse(bh);
ep = exfat_get_dentry(sb, &clu, i + 1, &bh, NULL);
if (!ep)
return -EIO;
dir_entry->size =
le64_to_cpu(ep->dentry.stream.valid_size);
brelse(bh);
ei->hint_bmap.off = dentry >> dentries_per_clu_bits;
ei->hint_bmap.clu = clu.dir;
ei->rwoffset = ++dentry;
return 0;
}
if (clu.flags == ALLOC_NO_FAT_CHAIN) {
if (--clu.size > 0)
clu.dir++;
else
clu.dir = EXFAT_EOF_CLUSTER;
} else {
if (exfat_get_next_cluster(sb, &(clu.dir)))
return -EIO;
}
}
dir_entry->namebuf.lfn[0] = '\0';
ei->rwoffset = dentry;
return 0;
}
static void exfat_init_namebuf(struct exfat_dentry_namebuf *nb)
{
nb->lfn = NULL;
nb->lfnbuf_len = 0;
}
static int exfat_alloc_namebuf(struct exfat_dentry_namebuf *nb)
{
nb->lfn = __getname();
if (!nb->lfn)
return -ENOMEM;
nb->lfnbuf_len = MAX_VFSNAME_BUF_SIZE;
return 0;
}
static void exfat_free_namebuf(struct exfat_dentry_namebuf *nb)
{
if (!nb->lfn)
return;
__putname(nb->lfn);
exfat_init_namebuf(nb);
}
/* skip iterating emit_dots when dir is empty */
#define ITER_POS_FILLED_DOTS (2)
static int exfat_iterate(struct file *filp, struct dir_context *ctx)
{
struct inode *inode = filp->f_path.dentry->d_inode;
struct super_block *sb = inode->i_sb;
struct inode *tmp;
struct exfat_dir_entry de;
struct exfat_dentry_namebuf *nb = &(de.namebuf);
struct exfat_inode_info *ei = EXFAT_I(inode);
unsigned long inum;
loff_t cpos, i_pos;
int err = 0, fake_offset = 0;
exfat_init_namebuf(nb);
mutex_lock(&EXFAT_SB(sb)->s_lock);
cpos = ctx->pos;
if (!dir_emit_dots(filp, ctx))
goto unlock;
if (ctx->pos == ITER_POS_FILLED_DOTS) {
cpos = 0;
fake_offset = 1;
}
if (cpos & (DENTRY_SIZE - 1)) {
err = -ENOENT;
goto unlock;
}
/* name buffer should be allocated before use */
err = exfat_alloc_namebuf(nb);
if (err)
goto unlock;
get_new:
ei->rwoffset = EXFAT_B_TO_DEN(cpos);
if (cpos >= i_size_read(inode))
goto end_of_dir;
err = exfat_readdir(inode, &de);
if (err) {
/*
* At least we tried to read a sector. Move cpos to next sector
* position (should be aligned).
*/
if (err == -EIO) {
cpos += 1 << (sb->s_blocksize_bits);
cpos &= ~(sb->s_blocksize - 1);
}
err = -EIO;
goto end_of_dir;
}
cpos = EXFAT_DEN_TO_B(ei->rwoffset);
if (!nb->lfn[0])
goto end_of_dir;
i_pos = ((loff_t)ei->start_clu << 32) |
((ei->rwoffset - 1) & 0xffffffff);
tmp = exfat_iget(sb, i_pos);
if (tmp) {
inum = tmp->i_ino;
iput(tmp);
} else {
inum = iunique(sb, EXFAT_ROOT_INO);
}
/*
* Before calling dir_emit(), sb_lock should be released.
* Because page fault can occur in dir_emit() when the size
* of buffer given from user is larger than one page size.
*/
mutex_unlock(&EXFAT_SB(sb)->s_lock);
if (!dir_emit(ctx, nb->lfn, strlen(nb->lfn), inum,
(de.attr & ATTR_SUBDIR) ? DT_DIR : DT_REG))
goto out_unlocked;
mutex_lock(&EXFAT_SB(sb)->s_lock);
ctx->pos = cpos;
goto get_new;
end_of_dir:
if (!cpos && fake_offset)
cpos = ITER_POS_FILLED_DOTS;
ctx->pos = cpos;
unlock:
mutex_unlock(&EXFAT_SB(sb)->s_lock);
out_unlocked:
/*
* To improve performance, free namebuf after unlock sb_lock.
* If namebuf is not allocated, this function do nothing
*/
exfat_free_namebuf(nb);
return err;
}
const struct file_operations exfat_dir_operations = {
.llseek = generic_file_llseek,
.read = generic_read_dir,
.iterate = exfat_iterate,
.fsync = exfat_file_fsync,
};
int exfat_alloc_new_dir(struct inode *inode, struct exfat_chain *clu)
{
int ret;
exfat_chain_set(clu, EXFAT_EOF_CLUSTER, 0, ALLOC_NO_FAT_CHAIN);
ret = exfat_alloc_cluster(inode, 1, clu);
if (ret)
return ret;
return exfat_zeroed_cluster(inode, clu->dir);
}
int exfat_calc_num_entries(struct exfat_uni_name *p_uniname)
{
int len;
len = p_uniname->name_len;
if (len == 0)
return -EINVAL;
/* 1 file entry + 1 stream entry + name entries */
return ((len - 1) / EXFAT_FILE_NAME_LEN + 3);
}
unsigned int exfat_get_entry_type(struct exfat_dentry *ep)
{
if (ep->type == EXFAT_UNUSED)
return TYPE_UNUSED;
if (IS_EXFAT_DELETED(ep->type))
return TYPE_DELETED;
if (ep->type == EXFAT_INVAL)
return TYPE_INVALID;
if (IS_EXFAT_CRITICAL_PRI(ep->type)) {
if (ep->type == EXFAT_BITMAP)
return TYPE_BITMAP;
if (ep->type == EXFAT_UPCASE)
return TYPE_UPCASE;
if (ep->type == EXFAT_VOLUME)
return TYPE_VOLUME;
if (ep->type == EXFAT_FILE) {
if (le16_to_cpu(ep->dentry.file.attr) & ATTR_SUBDIR)
return TYPE_DIR;
return TYPE_FILE;
}
return TYPE_CRITICAL_PRI;
}
if (IS_EXFAT_BENIGN_PRI(ep->type)) {
if (ep->type == EXFAT_GUID)
return TYPE_GUID;
if (ep->type == EXFAT_PADDING)
return TYPE_PADDING;
if (ep->type == EXFAT_ACLTAB)
return TYPE_ACLTAB;
return TYPE_BENIGN_PRI;
}
if (IS_EXFAT_CRITICAL_SEC(ep->type)) {
if (ep->type == EXFAT_STREAM)
return TYPE_STREAM;
if (ep->type == EXFAT_NAME)
return TYPE_EXTEND;
if (ep->type == EXFAT_ACL)
return TYPE_ACL;
return TYPE_CRITICAL_SEC;
}
return TYPE_BENIGN_SEC;
}
static void exfat_set_entry_type(struct exfat_dentry *ep, unsigned int type)
{
if (type == TYPE_UNUSED) {
ep->type = EXFAT_UNUSED;
} else if (type == TYPE_DELETED) {
ep->type &= EXFAT_DELETE;
} else if (type == TYPE_STREAM) {
ep->type = EXFAT_STREAM;
} else if (type == TYPE_EXTEND) {
ep->type = EXFAT_NAME;
} else if (type == TYPE_BITMAP) {
ep->type = EXFAT_BITMAP;
} else if (type == TYPE_UPCASE) {
ep->type = EXFAT_UPCASE;
} else if (type == TYPE_VOLUME) {
ep->type = EXFAT_VOLUME;
} else if (type == TYPE_DIR) {
ep->type = EXFAT_FILE;
ep->dentry.file.attr = cpu_to_le16(ATTR_SUBDIR);
} else if (type == TYPE_FILE) {
ep->type = EXFAT_FILE;
ep->dentry.file.attr = cpu_to_le16(ATTR_ARCHIVE);
}
}
static void exfat_init_stream_entry(struct exfat_dentry *ep,
unsigned char flags, unsigned int start_clu,
unsigned long long size)
{
exfat_set_entry_type(ep, TYPE_STREAM);
ep->dentry.stream.flags = flags;
ep->dentry.stream.start_clu = cpu_to_le32(start_clu);
ep->dentry.stream.valid_size = cpu_to_le64(size);
ep->dentry.stream.size = cpu_to_le64(size);
}
static void exfat_init_name_entry(struct exfat_dentry *ep,
unsigned short *uniname)
{
int i;
exfat_set_entry_type(ep, TYPE_EXTEND);
ep->dentry.name.flags = 0x0;
for (i = 0; i < EXFAT_FILE_NAME_LEN; i++) {
if (*uniname != 0x0) {
ep->dentry.name.unicode_0_14[i] = cpu_to_le16(*uniname);
uniname++;
} else {
ep->dentry.name.unicode_0_14[i] = 0x0;
}
}
}
int exfat_init_dir_entry(struct inode *inode, struct exfat_chain *p_dir,
int entry, unsigned int type, unsigned int start_clu,
unsigned long long size)
{
struct super_block *sb = inode->i_sb;
struct exfat_sb_info *sbi = EXFAT_SB(sb);
struct timespec64 ts = current_time(inode);
sector_t sector;
struct exfat_dentry *ep;
struct buffer_head *bh;
/*
* We cannot use exfat_get_dentry_set here because file ep is not
* initialized yet.
*/
ep = exfat_get_dentry(sb, p_dir, entry, &bh, §or);
if (!ep)
return -EIO;
exfat_set_entry_type(ep, type);
exfat_set_entry_time(sbi, &ts,
&ep->dentry.file.create_tz,
&ep->dentry.file.create_time,
&ep->dentry.file.create_date,
&ep->dentry.file.create_time_cs);
exfat_set_entry_time(sbi, &ts,
&ep->dentry.file.modify_tz,
&ep->dentry.file.modify_time,
&ep->dentry.file.modify_date,
&ep->dentry.file.modify_time_cs);
exfat_set_entry_time(sbi, &ts,
&ep->dentry.file.access_tz,
&ep->dentry.file.access_time,
&ep->dentry.file.access_date,
NULL);
exfat_update_bh(bh, IS_DIRSYNC(inode));
brelse(bh);
ep = exfat_get_dentry(sb, p_dir, entry + 1, &bh, §or);
if (!ep)
return -EIO;
exfat_init_stream_entry(ep,
(type == TYPE_FILE) ? ALLOC_FAT_CHAIN : ALLOC_NO_FAT_CHAIN,
start_clu, size);
exfat_update_bh(bh, IS_DIRSYNC(inode));
brelse(bh);
return 0;
}
int exfat_update_dir_chksum(struct inode *inode, struct exfat_chain *p_dir,
int entry)
{
struct super_block *sb = inode->i_sb;
int ret = 0;
int i, num_entries;
sector_t sector;
u16 chksum;
struct exfat_dentry *ep, *fep;
struct buffer_head *fbh, *bh;
fep = exfat_get_dentry(sb, p_dir, entry, &fbh, §or);
if (!fep)
return -EIO;
num_entries = fep->dentry.file.num_ext + 1;
chksum = exfat_calc_chksum16(fep, DENTRY_SIZE, 0, CS_DIR_ENTRY);
for (i = 1; i < num_entries; i++) {
ep = exfat_get_dentry(sb, p_dir, entry + i, &bh, NULL);
if (!ep) {
ret = -EIO;
goto release_fbh;
}
chksum = exfat_calc_chksum16(ep, DENTRY_SIZE, chksum,
CS_DEFAULT);
brelse(bh);
}
fep->dentry.file.checksum = cpu_to_le16(chksum);
exfat_update_bh(fbh, IS_DIRSYNC(inode));
release_fbh:
brelse(fbh);
return ret;
}
int exfat_init_ext_entry(struct inode *inode, struct exfat_chain *p_dir,
int entry, int num_entries, struct exfat_uni_name *p_uniname)
{
struct super_block *sb = inode->i_sb;
int i;
sector_t sector;
unsigned short *uniname = p_uniname->name;
struct exfat_dentry *ep;
struct buffer_head *bh;
int sync = IS_DIRSYNC(inode);
ep = exfat_get_dentry(sb, p_dir, entry, &bh, §or);
if (!ep)
return -EIO;
ep->dentry.file.num_ext = (unsigned char)(num_entries - 1);
exfat_update_bh(bh, sync);
brelse(bh);
ep = exfat_get_dentry(sb, p_dir, entry + 1, &bh, §or);
if (!ep)
return -EIO;
ep->dentry.stream.name_len = p_uniname->name_len;
ep->dentry.stream.name_hash = cpu_to_le16(p_uniname->name_hash);
exfat_update_bh(bh, sync);
brelse(bh);
for (i = EXFAT_FIRST_CLUSTER; i < num_entries; i++) {
ep = exfat_get_dentry(sb, p_dir, entry + i, &bh, §or);
if (!ep)
return -EIO;
exfat_init_name_entry(ep, uniname);
exfat_update_bh(bh, sync);
brelse(bh);
uniname += EXFAT_FILE_NAME_LEN;
}
exfat_update_dir_chksum(inode, p_dir, entry);
return 0;
}
int exfat_remove_entries(struct inode *inode, struct exfat_chain *p_dir,
int entry, int order, int num_entries)
{
struct super_block *sb = inode->i_sb;
int i;
sector_t sector;
struct exfat_dentry *ep;
struct buffer_head *bh;
for (i = order; i < num_entries; i++) {
ep = exfat_get_dentry(sb, p_dir, entry + i, &bh, §or);
if (!ep)
return -EIO;
exfat_set_entry_type(ep, TYPE_DELETED);
exfat_update_bh(bh, IS_DIRSYNC(inode));
brelse(bh);
}
return 0;
}
void exfat_update_dir_chksum_with_entry_set(struct exfat_entry_set_cache *es)
{
int chksum_type = CS_DIR_ENTRY, i;
unsigned short chksum = 0;
struct exfat_dentry *ep;
for (i = 0; i < es->num_entries; i++) {
ep = exfat_get_dentry_cached(es, i);
chksum = exfat_calc_chksum16(ep, DENTRY_SIZE, chksum,
chksum_type);
chksum_type = CS_DEFAULT;
}
ep = exfat_get_dentry_cached(es, 0);
ep->dentry.file.checksum = cpu_to_le16(chksum);
es->modified = true;
}
int exfat_free_dentry_set(struct exfat_entry_set_cache *es, int sync)
{
int i, err = 0;
if (es->modified)
err = exfat_update_bhs(es->bh, es->num_bh, sync);
for (i = 0; i < es->num_bh; i++)
if (err)
bforget(es->bh[i]);
else
brelse(es->bh[i]);
kfree(es);
return err;
}
static int exfat_walk_fat_chain(struct super_block *sb,
struct exfat_chain *p_dir, unsigned int byte_offset,
unsigned int *clu)
{
struct exfat_sb_info *sbi = EXFAT_SB(sb);
unsigned int clu_offset;
unsigned int cur_clu;
clu_offset = EXFAT_B_TO_CLU(byte_offset, sbi);
cur_clu = p_dir->dir;
if (p_dir->flags == ALLOC_NO_FAT_CHAIN) {
cur_clu += clu_offset;
} else {
while (clu_offset > 0) {
if (exfat_get_next_cluster(sb, &cur_clu))
return -EIO;
if (cur_clu == EXFAT_EOF_CLUSTER) {
exfat_fs_error(sb,
"invalid dentry access beyond EOF (clu : %u, eidx : %d)",
p_dir->dir,
EXFAT_B_TO_DEN(byte_offset));
return -EIO;
}
clu_offset--;
}
}
*clu = cur_clu;
return 0;
}
int exfat_find_location(struct super_block *sb, struct exfat_chain *p_dir,
int entry, sector_t *sector, int *offset)
{
int ret;
unsigned int off, clu = 0;
struct exfat_sb_info *sbi = EXFAT_SB(sb);
off = EXFAT_DEN_TO_B(entry);
ret = exfat_walk_fat_chain(sb, p_dir, off, &clu);
if (ret)
return ret;
/* byte offset in cluster */
off = EXFAT_CLU_OFFSET(off, sbi);
/* byte offset in sector */
*offset = EXFAT_BLK_OFFSET(off, sb);
/* sector offset in cluster */
*sector = EXFAT_B_TO_BLK(off, sb);
*sector += exfat_cluster_to_sector(sbi, clu);
return 0;
}
#define EXFAT_MAX_RA_SIZE (128*1024)
static int exfat_dir_readahead(struct super_block *sb, sector_t sec)
{
struct exfat_sb_info *sbi = EXFAT_SB(sb);
struct buffer_head *bh;
unsigned int max_ra_count = EXFAT_MAX_RA_SIZE >> sb->s_blocksize_bits;
unsigned int page_ra_count = PAGE_SIZE >> sb->s_blocksize_bits;
unsigned int adj_ra_count = max(sbi->sect_per_clus, page_ra_count);
unsigned int ra_count = min(adj_ra_count, max_ra_count);
/* Read-ahead is not required */
if (sbi->sect_per_clus == 1)
return 0;
if (sec < sbi->data_start_sector) {
exfat_err(sb, "requested sector is invalid(sect:%llu, root:%llu)",
(unsigned long long)sec, sbi->data_start_sector);
return -EIO;
}
/* Not sector aligned with ra_count, resize ra_count to page size */
if ((sec - sbi->data_start_sector) & (ra_count - 1))
ra_count = page_ra_count;
bh = sb_find_get_block(sb, sec);
if (!bh || !buffer_uptodate(bh)) {
unsigned int i;
for (i = 0; i < ra_count; i++)
sb_breadahead(sb, (sector_t)(sec + i));
}
brelse(bh);
return 0;
}
struct exfat_dentry *exfat_get_dentry(struct super_block *sb,
struct exfat_chain *p_dir, int entry, struct buffer_head **bh,
sector_t *sector)
{
unsigned int dentries_per_page = EXFAT_B_TO_DEN(PAGE_SIZE);
int off;
sector_t sec;
if (p_dir->dir == DIR_DELETED) {
exfat_err(sb, "abnormal access to deleted dentry");
return NULL;
}
if (exfat_find_location(sb, p_dir, entry, &sec, &off))
return NULL;
if (p_dir->dir != EXFAT_FREE_CLUSTER &&
!(entry & (dentries_per_page - 1)))
exfat_dir_readahead(sb, sec);
*bh = sb_bread(sb, sec);
if (!*bh)
return NULL;
if (sector)
*sector = sec;
return (struct exfat_dentry *)((*bh)->b_data + off);
}
enum exfat_validate_dentry_mode {
ES_MODE_STARTED,
ES_MODE_GET_FILE_ENTRY,
ES_MODE_GET_STRM_ENTRY,
ES_MODE_GET_NAME_ENTRY,
ES_MODE_GET_CRITICAL_SEC_ENTRY,
};
static bool exfat_validate_entry(unsigned int type,
enum exfat_validate_dentry_mode *mode)
{
if (type == TYPE_UNUSED || type == TYPE_DELETED)
return false;
switch (*mode) {
case ES_MODE_STARTED:
if (type != TYPE_FILE && type != TYPE_DIR)
return false;
*mode = ES_MODE_GET_FILE_ENTRY;
return true;
case ES_MODE_GET_FILE_ENTRY:
if (type != TYPE_STREAM)
return false;
*mode = ES_MODE_GET_STRM_ENTRY;
return true;
case ES_MODE_GET_STRM_ENTRY:
if (type != TYPE_EXTEND)
return false;
*mode = ES_MODE_GET_NAME_ENTRY;
return true;
case ES_MODE_GET_NAME_ENTRY:
if (type == TYPE_STREAM)
return false;
if (type != TYPE_EXTEND) {
if (!(type & TYPE_CRITICAL_SEC))
return false;
*mode = ES_MODE_GET_CRITICAL_SEC_ENTRY;
}
return true;
case ES_MODE_GET_CRITICAL_SEC_ENTRY:
if (type == TYPE_EXTEND || type == TYPE_STREAM)
return false;
if ((type & TYPE_CRITICAL_SEC) != TYPE_CRITICAL_SEC)
return false;
return true;
default:
WARN_ON_ONCE(1);
return false;
}
}
struct exfat_dentry *exfat_get_dentry_cached(
struct exfat_entry_set_cache *es, int num)
{
int off = es->start_off + num * DENTRY_SIZE;
struct buffer_head *bh = es->bh[EXFAT_B_TO_BLK(off, es->sb)];
char *p = bh->b_data + EXFAT_BLK_OFFSET(off, es->sb);
return (struct exfat_dentry *)p;
}
/*
* Returns a set of dentries for a file or dir.
*
* Note It provides a direct pointer to bh->data via exfat_get_dentry_cached().
* User should call exfat_get_dentry_set() after setting 'modified' to apply
* changes made in this entry set to the real device.
*
* in:
* sb+p_dir+entry: indicates a file/dir
* type: specifies how many dentries should be included.
* return:
* pointer of entry set on success,
* NULL on failure.
*/
struct exfat_entry_set_cache *exfat_get_dentry_set(struct super_block *sb,
struct exfat_chain *p_dir, int entry, unsigned int type)
{
int ret, i, num_bh;
unsigned int off, byte_offset, clu = 0;
sector_t sec;
struct exfat_sb_info *sbi = EXFAT_SB(sb);
struct exfat_entry_set_cache *es;
struct exfat_dentry *ep;
int num_entries;
enum exfat_validate_dentry_mode mode = ES_MODE_STARTED;
struct buffer_head *bh;
if (p_dir->dir == DIR_DELETED) {
exfat_err(sb, "access to deleted dentry");
return NULL;
}
byte_offset = EXFAT_DEN_TO_B(entry);
ret = exfat_walk_fat_chain(sb, p_dir, byte_offset, &clu);
if (ret)
return NULL;
es = kzalloc(sizeof(*es), GFP_KERNEL);
if (!es)
return NULL;
es->sb = sb;
es->modified = false;
/* byte offset in cluster */
byte_offset = EXFAT_CLU_OFFSET(byte_offset, sbi);
/* byte offset in sector */
off = EXFAT_BLK_OFFSET(byte_offset, sb);
es->start_off = off;
/* sector offset in cluster */
sec = EXFAT_B_TO_BLK(byte_offset, sb);
sec += exfat_cluster_to_sector(sbi, clu);
bh = sb_bread(sb, sec);
if (!bh)
goto free_es;
es->bh[es->num_bh++] = bh;
ep = exfat_get_dentry_cached(es, 0);
if (!exfat_validate_entry(exfat_get_entry_type(ep), &mode))
goto free_es;
num_entries = type == ES_ALL_ENTRIES ?
ep->dentry.file.num_ext + 1 : type;
es->num_entries = num_entries;
num_bh = EXFAT_B_TO_BLK_ROUND_UP(off + num_entries * DENTRY_SIZE, sb);
for (i = 1; i < num_bh; i++) {
/* get the next sector */
if (exfat_is_last_sector_in_cluster(sbi, sec)) {
if (p_dir->flags == ALLOC_NO_FAT_CHAIN)
clu++;
else if (exfat_get_next_cluster(sb, &clu))
goto free_es;
sec = exfat_cluster_to_sector(sbi, clu);
} else {
sec++;
}
bh = sb_bread(sb, sec);
if (!bh)
goto free_es;
es->bh[es->num_bh++] = bh;
}
/* validiate cached dentries */
for (i = 1; i < num_entries; i++) {
ep = exfat_get_dentry_cached(es, i);
if (!exfat_validate_entry(exfat_get_entry_type(ep), &mode))
goto free_es;
}
return es;
free_es:
exfat_free_dentry_set(es, false);
return NULL;
}
enum {
DIRENT_STEP_FILE,
DIRENT_STEP_STRM,
DIRENT_STEP_NAME,
DIRENT_STEP_SECD,
};
/*
* return values:
* >= 0 : return dir entiry position with the name in dir
* -EEXIST : (root dir, ".") it is the root dir itself
* -ENOENT : entry with the name does not exist
* -EIO : I/O error
*/
int exfat_find_dir_entry(struct super_block *sb, struct exfat_inode_info *ei,
struct exfat_chain *p_dir, struct exfat_uni_name *p_uniname,
int num_entries, unsigned int type)
{
int i, rewind = 0, dentry = 0, end_eidx = 0, num_ext = 0, len;
int order, step, name_len = 0;
int dentries_per_clu, num_empty = 0;
unsigned int entry_type;
unsigned short *uniname = NULL;
struct exfat_chain clu;
struct exfat_hint *hint_stat = &ei->hint_stat;
struct exfat_hint_femp candi_empty;
struct exfat_sb_info *sbi = EXFAT_SB(sb);
dentries_per_clu = sbi->dentries_per_clu;
exfat_chain_dup(&clu, p_dir);
if (hint_stat->eidx) {
clu.dir = hint_stat->clu;
dentry = hint_stat->eidx;
end_eidx = dentry;
}
candi_empty.eidx = EXFAT_HINT_NONE;
rewind:
order = 0;
step = DIRENT_STEP_FILE;
while (clu.dir != EXFAT_EOF_CLUSTER) {
i = dentry & (dentries_per_clu - 1);
for (; i < dentries_per_clu; i++, dentry++) {
struct exfat_dentry *ep;
struct buffer_head *bh;
if (rewind && dentry == end_eidx)
goto not_found;
ep = exfat_get_dentry(sb, &clu, i, &bh, NULL);
if (!ep)
return -EIO;
entry_type = exfat_get_entry_type(ep);
if (entry_type == TYPE_UNUSED ||
entry_type == TYPE_DELETED) {
step = DIRENT_STEP_FILE;
num_empty++;
if (candi_empty.eidx == EXFAT_HINT_NONE &&
num_empty == 1) {
exfat_chain_set(&candi_empty.cur,
clu.dir, clu.size, clu.flags);
}
if (candi_empty.eidx == EXFAT_HINT_NONE &&
num_empty >= num_entries) {
candi_empty.eidx =
dentry - (num_empty - 1);
WARN_ON(candi_empty.eidx < 0);
candi_empty.count = num_empty;
if (ei->hint_femp.eidx ==
EXFAT_HINT_NONE ||
candi_empty.eidx <=
ei->hint_femp.eidx) {
memcpy(&ei->hint_femp,
&candi_empty,
sizeof(candi_empty));
}
}
brelse(bh);
if (entry_type == TYPE_UNUSED)
goto not_found;
continue;
}
num_empty = 0;
candi_empty.eidx = EXFAT_HINT_NONE;
if (entry_type == TYPE_FILE || entry_type == TYPE_DIR) {
step = DIRENT_STEP_FILE;
if (type == TYPE_ALL || type == entry_type) {