forked from grate-driver/linux
-
Notifications
You must be signed in to change notification settings - Fork 0
/
inode.c
1978 lines (1745 loc) · 51 KB
/
inode.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-only
/*
* linux/fs/fat/inode.c
*
* Written 1992,1993 by Werner Almesberger
* VFAT extensions by Gordon Chaffee, merged with msdos fs by Henrik Storner
* Rewritten for the constant inumbers support by Al Viro
*
* Fixes:
*
* Max Cohan: Fixed invalid FSINFO offset when info_sector is 0
*/
#include <linux/module.h>
#include <linux/pagemap.h>
#include <linux/mpage.h>
#include <linux/vfs.h>
#include <linux/seq_file.h>
#include <linux/parser.h>
#include <linux/uio.h>
#include <linux/blkdev.h>
#include <linux/backing-dev.h>
#include <asm/unaligned.h>
#include <linux/random.h>
#include <linux/iversion.h>
#include "fat.h"
#ifndef CONFIG_FAT_DEFAULT_IOCHARSET
/* if user don't select VFAT, this is undefined. */
#define CONFIG_FAT_DEFAULT_IOCHARSET ""
#endif
#define KB_IN_SECTORS 2
/* DOS dates from 1980/1/1 through 2107/12/31 */
#define FAT_DATE_MIN (0<<9 | 1<<5 | 1)
#define FAT_DATE_MAX (127<<9 | 12<<5 | 31)
#define FAT_TIME_MAX (23<<11 | 59<<5 | 29)
/*
* A deserialized copy of the on-disk structure laid out in struct
* fat_boot_sector.
*/
struct fat_bios_param_block {
u16 fat_sector_size;
u8 fat_sec_per_clus;
u16 fat_reserved;
u8 fat_fats;
u16 fat_dir_entries;
u16 fat_sectors;
u16 fat_fat_length;
u32 fat_total_sect;
u8 fat16_state;
u32 fat16_vol_id;
u32 fat32_length;
u32 fat32_root_cluster;
u16 fat32_info_sector;
u8 fat32_state;
u32 fat32_vol_id;
};
static int fat_default_codepage = CONFIG_FAT_DEFAULT_CODEPAGE;
static char fat_default_iocharset[] = CONFIG_FAT_DEFAULT_IOCHARSET;
static struct fat_floppy_defaults {
unsigned nr_sectors;
unsigned sec_per_clus;
unsigned dir_entries;
unsigned media;
unsigned fat_length;
} floppy_defaults[] = {
{
.nr_sectors = 160 * KB_IN_SECTORS,
.sec_per_clus = 1,
.dir_entries = 64,
.media = 0xFE,
.fat_length = 1,
},
{
.nr_sectors = 180 * KB_IN_SECTORS,
.sec_per_clus = 1,
.dir_entries = 64,
.media = 0xFC,
.fat_length = 2,
},
{
.nr_sectors = 320 * KB_IN_SECTORS,
.sec_per_clus = 2,
.dir_entries = 112,
.media = 0xFF,
.fat_length = 1,
},
{
.nr_sectors = 360 * KB_IN_SECTORS,
.sec_per_clus = 2,
.dir_entries = 112,
.media = 0xFD,
.fat_length = 2,
},
};
int fat_add_cluster(struct inode *inode)
{
int err, cluster;
err = fat_alloc_clusters(inode, &cluster, 1);
if (err)
return err;
/* FIXME: this cluster should be added after data of this
* cluster is writed */
err = fat_chain_add(inode, cluster, 1);
if (err)
fat_free_clusters(inode, cluster);
return err;
}
static inline int __fat_get_block(struct inode *inode, sector_t iblock,
unsigned long *max_blocks,
struct buffer_head *bh_result, int create)
{
struct super_block *sb = inode->i_sb;
struct msdos_sb_info *sbi = MSDOS_SB(sb);
unsigned long mapped_blocks;
sector_t phys, last_block;
int err, offset;
err = fat_bmap(inode, iblock, &phys, &mapped_blocks, create, false);
if (err)
return err;
if (phys) {
map_bh(bh_result, sb, phys);
*max_blocks = min(mapped_blocks, *max_blocks);
return 0;
}
if (!create)
return 0;
if (iblock != MSDOS_I(inode)->mmu_private >> sb->s_blocksize_bits) {
fat_fs_error(sb, "corrupted file size (i_pos %lld, %lld)",
MSDOS_I(inode)->i_pos, MSDOS_I(inode)->mmu_private);
return -EIO;
}
last_block = inode->i_blocks >> (sb->s_blocksize_bits - 9);
offset = (unsigned long)iblock & (sbi->sec_per_clus - 1);
/*
* allocate a cluster according to the following.
* 1) no more available blocks
* 2) not part of fallocate region
*/
if (!offset && !(iblock < last_block)) {
/* TODO: multiple cluster allocation would be desirable. */
err = fat_add_cluster(inode);
if (err)
return err;
}
/* available blocks on this cluster */
mapped_blocks = sbi->sec_per_clus - offset;
*max_blocks = min(mapped_blocks, *max_blocks);
MSDOS_I(inode)->mmu_private += *max_blocks << sb->s_blocksize_bits;
err = fat_bmap(inode, iblock, &phys, &mapped_blocks, create, false);
if (err)
return err;
if (!phys) {
fat_fs_error(sb,
"invalid FAT chain (i_pos %lld, last_block %llu)",
MSDOS_I(inode)->i_pos,
(unsigned long long)last_block);
return -EIO;
}
BUG_ON(*max_blocks != mapped_blocks);
set_buffer_new(bh_result);
map_bh(bh_result, sb, phys);
return 0;
}
static int fat_get_block(struct inode *inode, sector_t iblock,
struct buffer_head *bh_result, int create)
{
struct super_block *sb = inode->i_sb;
unsigned long max_blocks = bh_result->b_size >> inode->i_blkbits;
int err;
err = __fat_get_block(inode, iblock, &max_blocks, bh_result, create);
if (err)
return err;
bh_result->b_size = max_blocks << sb->s_blocksize_bits;
return 0;
}
static int fat_writepage(struct page *page, struct writeback_control *wbc)
{
return block_write_full_page(page, fat_get_block, wbc);
}
static int fat_writepages(struct address_space *mapping,
struct writeback_control *wbc)
{
return mpage_writepages(mapping, wbc, fat_get_block);
}
static int fat_readpage(struct file *file, struct page *page)
{
return mpage_readpage(page, fat_get_block);
}
static void fat_readahead(struct readahead_control *rac)
{
mpage_readahead(rac, fat_get_block);
}
static void fat_write_failed(struct address_space *mapping, loff_t to)
{
struct inode *inode = mapping->host;
if (to > inode->i_size) {
truncate_pagecache(inode, inode->i_size);
fat_truncate_blocks(inode, inode->i_size);
}
}
static int fat_write_begin(struct file *file, struct address_space *mapping,
loff_t pos, unsigned len, unsigned flags,
struct page **pagep, void **fsdata)
{
int err;
*pagep = NULL;
err = cont_write_begin(file, mapping, pos, len, flags,
pagep, fsdata, fat_get_block,
&MSDOS_I(mapping->host)->mmu_private);
if (err < 0)
fat_write_failed(mapping, pos + len);
return err;
}
static int fat_write_end(struct file *file, struct address_space *mapping,
loff_t pos, unsigned len, unsigned copied,
struct page *pagep, void *fsdata)
{
struct inode *inode = mapping->host;
int err;
err = generic_write_end(file, mapping, pos, len, copied, pagep, fsdata);
if (err < len)
fat_write_failed(mapping, pos + len);
if (!(err < 0) && !(MSDOS_I(inode)->i_attrs & ATTR_ARCH)) {
fat_truncate_time(inode, NULL, S_CTIME|S_MTIME);
MSDOS_I(inode)->i_attrs |= ATTR_ARCH;
mark_inode_dirty(inode);
}
return err;
}
static ssize_t fat_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
{
struct file *file = iocb->ki_filp;
struct address_space *mapping = file->f_mapping;
struct inode *inode = mapping->host;
size_t count = iov_iter_count(iter);
loff_t offset = iocb->ki_pos;
ssize_t ret;
if (iov_iter_rw(iter) == WRITE) {
/*
* FIXME: blockdev_direct_IO() doesn't use ->write_begin(),
* so we need to update the ->mmu_private to block boundary.
*
* But we must fill the remaining area or hole by nul for
* updating ->mmu_private.
*
* Return 0, and fallback to normal buffered write.
*/
loff_t size = offset + count;
if (MSDOS_I(inode)->mmu_private < size)
return 0;
}
/*
* FAT need to use the DIO_LOCKING for avoiding the race
* condition of fat_get_block() and ->truncate().
*/
ret = blockdev_direct_IO(iocb, inode, iter, fat_get_block);
if (ret < 0 && iov_iter_rw(iter) == WRITE)
fat_write_failed(mapping, offset + count);
return ret;
}
static int fat_get_block_bmap(struct inode *inode, sector_t iblock,
struct buffer_head *bh_result, int create)
{
struct super_block *sb = inode->i_sb;
unsigned long max_blocks = bh_result->b_size >> inode->i_blkbits;
int err;
sector_t bmap;
unsigned long mapped_blocks;
BUG_ON(create != 0);
err = fat_bmap(inode, iblock, &bmap, &mapped_blocks, create, true);
if (err)
return err;
if (bmap) {
map_bh(bh_result, sb, bmap);
max_blocks = min(mapped_blocks, max_blocks);
}
bh_result->b_size = max_blocks << sb->s_blocksize_bits;
return 0;
}
static sector_t _fat_bmap(struct address_space *mapping, sector_t block)
{
sector_t blocknr;
/* fat_get_cluster() assumes the requested blocknr isn't truncated. */
down_read(&MSDOS_I(mapping->host)->truncate_lock);
blocknr = generic_block_bmap(mapping, block, fat_get_block_bmap);
up_read(&MSDOS_I(mapping->host)->truncate_lock);
return blocknr;
}
/*
* fat_block_truncate_page() zeroes out a mapping from file offset `from'
* up to the end of the block which corresponds to `from'.
* This is required during truncate to physically zeroout the tail end
* of that block so it doesn't yield old data if the file is later grown.
* Also, avoid causing failure from fsx for cases of "data past EOF"
*/
int fat_block_truncate_page(struct inode *inode, loff_t from)
{
return block_truncate_page(inode->i_mapping, from, fat_get_block);
}
static const struct address_space_operations fat_aops = {
.dirty_folio = block_dirty_folio,
.invalidate_folio = block_invalidate_folio,
.readpage = fat_readpage,
.readahead = fat_readahead,
.writepage = fat_writepage,
.writepages = fat_writepages,
.write_begin = fat_write_begin,
.write_end = fat_write_end,
.direct_IO = fat_direct_IO,
.bmap = _fat_bmap
};
/*
* New FAT inode stuff. We do the following:
* a) i_ino is constant and has nothing with on-disk location.
* b) FAT manages its own cache of directory entries.
* c) *This* cache is indexed by on-disk location.
* d) inode has an associated directory entry, all right, but
* it may be unhashed.
* e) currently entries are stored within struct inode. That should
* change.
* f) we deal with races in the following way:
* 1. readdir() and lookup() do FAT-dir-cache lookup.
* 2. rename() unhashes the F-d-c entry and rehashes it in
* a new place.
* 3. unlink() and rmdir() unhash F-d-c entry.
* 4. fat_write_inode() checks whether the thing is unhashed.
* If it is we silently return. If it isn't we do bread(),
* check if the location is still valid and retry if it
* isn't. Otherwise we do changes.
* 5. Spinlock is used to protect hash/unhash/location check/lookup
* 6. fat_evict_inode() unhashes the F-d-c entry.
* 7. lookup() and readdir() do igrab() if they find a F-d-c entry
* and consider negative result as cache miss.
*/
static void fat_hash_init(struct super_block *sb)
{
struct msdos_sb_info *sbi = MSDOS_SB(sb);
int i;
spin_lock_init(&sbi->inode_hash_lock);
for (i = 0; i < FAT_HASH_SIZE; i++)
INIT_HLIST_HEAD(&sbi->inode_hashtable[i]);
}
static inline unsigned long fat_hash(loff_t i_pos)
{
return hash_32(i_pos, FAT_HASH_BITS);
}
static void dir_hash_init(struct super_block *sb)
{
struct msdos_sb_info *sbi = MSDOS_SB(sb);
int i;
spin_lock_init(&sbi->dir_hash_lock);
for (i = 0; i < FAT_HASH_SIZE; i++)
INIT_HLIST_HEAD(&sbi->dir_hashtable[i]);
}
void fat_attach(struct inode *inode, loff_t i_pos)
{
struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
if (inode->i_ino != MSDOS_ROOT_INO) {
struct hlist_head *head = sbi->inode_hashtable
+ fat_hash(i_pos);
spin_lock(&sbi->inode_hash_lock);
MSDOS_I(inode)->i_pos = i_pos;
hlist_add_head(&MSDOS_I(inode)->i_fat_hash, head);
spin_unlock(&sbi->inode_hash_lock);
}
/* If NFS support is enabled, cache the mapping of start cluster
* to directory inode. This is used during reconnection of
* dentries to the filesystem root.
*/
if (S_ISDIR(inode->i_mode) && sbi->options.nfs) {
struct hlist_head *d_head = sbi->dir_hashtable;
d_head += fat_dir_hash(MSDOS_I(inode)->i_logstart);
spin_lock(&sbi->dir_hash_lock);
hlist_add_head(&MSDOS_I(inode)->i_dir_hash, d_head);
spin_unlock(&sbi->dir_hash_lock);
}
}
EXPORT_SYMBOL_GPL(fat_attach);
void fat_detach(struct inode *inode)
{
struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
spin_lock(&sbi->inode_hash_lock);
MSDOS_I(inode)->i_pos = 0;
hlist_del_init(&MSDOS_I(inode)->i_fat_hash);
spin_unlock(&sbi->inode_hash_lock);
if (S_ISDIR(inode->i_mode) && sbi->options.nfs) {
spin_lock(&sbi->dir_hash_lock);
hlist_del_init(&MSDOS_I(inode)->i_dir_hash);
spin_unlock(&sbi->dir_hash_lock);
}
}
EXPORT_SYMBOL_GPL(fat_detach);
struct inode *fat_iget(struct super_block *sb, loff_t i_pos)
{
struct msdos_sb_info *sbi = MSDOS_SB(sb);
struct hlist_head *head = sbi->inode_hashtable + fat_hash(i_pos);
struct msdos_inode_info *i;
struct inode *inode = NULL;
spin_lock(&sbi->inode_hash_lock);
hlist_for_each_entry(i, head, i_fat_hash) {
BUG_ON(i->vfs_inode.i_sb != sb);
if (i->i_pos != i_pos)
continue;
inode = igrab(&i->vfs_inode);
if (inode)
break;
}
spin_unlock(&sbi->inode_hash_lock);
return inode;
}
static int is_exec(unsigned char *extension)
{
unsigned char exe_extensions[] = "EXECOMBAT", *walk;
for (walk = exe_extensions; *walk; walk += 3)
if (!strncmp(extension, walk, 3))
return 1;
return 0;
}
static int fat_calc_dir_size(struct inode *inode)
{
struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
int ret, fclus, dclus;
inode->i_size = 0;
if (MSDOS_I(inode)->i_start == 0)
return 0;
ret = fat_get_cluster(inode, FAT_ENT_EOF, &fclus, &dclus);
if (ret < 0)
return ret;
inode->i_size = (fclus + 1) << sbi->cluster_bits;
return 0;
}
static int fat_validate_dir(struct inode *dir)
{
struct super_block *sb = dir->i_sb;
if (dir->i_nlink < 2) {
/* Directory should have "."/".." entries at least. */
fat_fs_error(sb, "corrupted directory (invalid entries)");
return -EIO;
}
if (MSDOS_I(dir)->i_start == 0 ||
MSDOS_I(dir)->i_start == MSDOS_SB(sb)->root_cluster) {
/* Directory should point valid cluster. */
fat_fs_error(sb, "corrupted directory (invalid i_start)");
return -EIO;
}
return 0;
}
/* doesn't deal with root inode */
int fat_fill_inode(struct inode *inode, struct msdos_dir_entry *de)
{
struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
int error;
MSDOS_I(inode)->i_pos = 0;
inode->i_uid = sbi->options.fs_uid;
inode->i_gid = sbi->options.fs_gid;
inode_inc_iversion(inode);
inode->i_generation = prandom_u32();
if ((de->attr & ATTR_DIR) && !IS_FREE(de->name)) {
inode->i_generation &= ~1;
inode->i_mode = fat_make_mode(sbi, de->attr, S_IRWXUGO);
inode->i_op = sbi->dir_ops;
inode->i_fop = &fat_dir_operations;
MSDOS_I(inode)->i_start = fat_get_start(sbi, de);
MSDOS_I(inode)->i_logstart = MSDOS_I(inode)->i_start;
error = fat_calc_dir_size(inode);
if (error < 0)
return error;
MSDOS_I(inode)->mmu_private = inode->i_size;
set_nlink(inode, fat_subdirs(inode));
error = fat_validate_dir(inode);
if (error < 0)
return error;
} else { /* not a directory */
inode->i_generation |= 1;
inode->i_mode = fat_make_mode(sbi, de->attr,
((sbi->options.showexec && !is_exec(de->name + 8))
? S_IRUGO|S_IWUGO : S_IRWXUGO));
MSDOS_I(inode)->i_start = fat_get_start(sbi, de);
MSDOS_I(inode)->i_logstart = MSDOS_I(inode)->i_start;
inode->i_size = le32_to_cpu(de->size);
inode->i_op = &fat_file_inode_operations;
inode->i_fop = &fat_file_operations;
inode->i_mapping->a_ops = &fat_aops;
MSDOS_I(inode)->mmu_private = inode->i_size;
}
if (de->attr & ATTR_SYS) {
if (sbi->options.sys_immutable)
inode->i_flags |= S_IMMUTABLE;
}
fat_save_attrs(inode, de->attr);
inode->i_blocks = ((inode->i_size + (sbi->cluster_size - 1))
& ~((loff_t)sbi->cluster_size - 1)) >> 9;
fat_time_fat2unix(sbi, &inode->i_mtime, de->time, de->date, 0);
if (sbi->options.isvfat) {
fat_time_fat2unix(sbi, &inode->i_ctime, de->ctime,
de->cdate, de->ctime_cs);
fat_time_fat2unix(sbi, &inode->i_atime, 0, de->adate, 0);
} else
fat_truncate_time(inode, &inode->i_mtime, S_ATIME|S_CTIME);
return 0;
}
static inline void fat_lock_build_inode(struct msdos_sb_info *sbi)
{
if (sbi->options.nfs == FAT_NFS_NOSTALE_RO)
mutex_lock(&sbi->nfs_build_inode_lock);
}
static inline void fat_unlock_build_inode(struct msdos_sb_info *sbi)
{
if (sbi->options.nfs == FAT_NFS_NOSTALE_RO)
mutex_unlock(&sbi->nfs_build_inode_lock);
}
struct inode *fat_build_inode(struct super_block *sb,
struct msdos_dir_entry *de, loff_t i_pos)
{
struct inode *inode;
int err;
fat_lock_build_inode(MSDOS_SB(sb));
inode = fat_iget(sb, i_pos);
if (inode)
goto out;
inode = new_inode(sb);
if (!inode) {
inode = ERR_PTR(-ENOMEM);
goto out;
}
inode->i_ino = iunique(sb, MSDOS_ROOT_INO);
inode_set_iversion(inode, 1);
err = fat_fill_inode(inode, de);
if (err) {
iput(inode);
inode = ERR_PTR(err);
goto out;
}
fat_attach(inode, i_pos);
insert_inode_hash(inode);
out:
fat_unlock_build_inode(MSDOS_SB(sb));
return inode;
}
EXPORT_SYMBOL_GPL(fat_build_inode);
static int __fat_write_inode(struct inode *inode, int wait);
static void fat_free_eofblocks(struct inode *inode)
{
/* Release unwritten fallocated blocks on inode eviction. */
if ((inode->i_blocks << 9) >
round_up(MSDOS_I(inode)->mmu_private,
MSDOS_SB(inode->i_sb)->cluster_size)) {
int err;
fat_truncate_blocks(inode, MSDOS_I(inode)->mmu_private);
/* Fallocate results in updating the i_start/iogstart
* for the zero byte file. So, make it return to
* original state during evict and commit it to avoid
* any corruption on the next access to the cluster
* chain for the file.
*/
err = __fat_write_inode(inode, inode_needs_sync(inode));
if (err) {
fat_msg(inode->i_sb, KERN_WARNING, "Failed to "
"update on disk inode for unused "
"fallocated blocks, inode could be "
"corrupted. Please run fsck");
}
}
}
static void fat_evict_inode(struct inode *inode)
{
truncate_inode_pages_final(&inode->i_data);
if (!inode->i_nlink) {
inode->i_size = 0;
fat_truncate_blocks(inode, 0);
} else
fat_free_eofblocks(inode);
invalidate_inode_buffers(inode);
clear_inode(inode);
fat_cache_inval_inode(inode);
fat_detach(inode);
}
static void fat_set_state(struct super_block *sb,
unsigned int set, unsigned int force)
{
struct buffer_head *bh;
struct fat_boot_sector *b;
struct msdos_sb_info *sbi = MSDOS_SB(sb);
/* do not change any thing if mounted read only */
if (sb_rdonly(sb) && !force)
return;
/* do not change state if fs was dirty */
if (sbi->dirty) {
/* warn only on set (mount). */
if (set)
fat_msg(sb, KERN_WARNING, "Volume was not properly "
"unmounted. Some data may be corrupt. "
"Please run fsck.");
return;
}
bh = sb_bread(sb, 0);
if (bh == NULL) {
fat_msg(sb, KERN_ERR, "unable to read boot sector "
"to mark fs as dirty");
return;
}
b = (struct fat_boot_sector *) bh->b_data;
if (is_fat32(sbi)) {
if (set)
b->fat32.state |= FAT_STATE_DIRTY;
else
b->fat32.state &= ~FAT_STATE_DIRTY;
} else /* fat 16 and 12 */ {
if (set)
b->fat16.state |= FAT_STATE_DIRTY;
else
b->fat16.state &= ~FAT_STATE_DIRTY;
}
mark_buffer_dirty(bh);
sync_dirty_buffer(bh);
brelse(bh);
}
static void fat_reset_iocharset(struct fat_mount_options *opts)
{
if (opts->iocharset != fat_default_iocharset) {
/* Note: opts->iocharset can be NULL here */
kfree(opts->iocharset);
opts->iocharset = fat_default_iocharset;
}
}
static void delayed_free(struct rcu_head *p)
{
struct msdos_sb_info *sbi = container_of(p, struct msdos_sb_info, rcu);
unload_nls(sbi->nls_disk);
unload_nls(sbi->nls_io);
fat_reset_iocharset(&sbi->options);
kfree(sbi);
}
static void fat_put_super(struct super_block *sb)
{
struct msdos_sb_info *sbi = MSDOS_SB(sb);
fat_set_state(sb, 0, 0);
iput(sbi->fsinfo_inode);
iput(sbi->fat_inode);
call_rcu(&sbi->rcu, delayed_free);
}
static struct kmem_cache *fat_inode_cachep;
static struct inode *fat_alloc_inode(struct super_block *sb)
{
struct msdos_inode_info *ei;
ei = alloc_inode_sb(sb, fat_inode_cachep, GFP_NOFS);
if (!ei)
return NULL;
init_rwsem(&ei->truncate_lock);
/* Zeroing to allow iput() even if partial initialized inode. */
ei->mmu_private = 0;
ei->i_start = 0;
ei->i_logstart = 0;
ei->i_attrs = 0;
ei->i_pos = 0;
return &ei->vfs_inode;
}
static void fat_free_inode(struct inode *inode)
{
kmem_cache_free(fat_inode_cachep, MSDOS_I(inode));
}
static void init_once(void *foo)
{
struct msdos_inode_info *ei = (struct msdos_inode_info *)foo;
spin_lock_init(&ei->cache_lru_lock);
ei->nr_caches = 0;
ei->cache_valid_id = FAT_CACHE_VALID + 1;
INIT_LIST_HEAD(&ei->cache_lru);
INIT_HLIST_NODE(&ei->i_fat_hash);
INIT_HLIST_NODE(&ei->i_dir_hash);
inode_init_once(&ei->vfs_inode);
}
static int __init fat_init_inodecache(void)
{
fat_inode_cachep = kmem_cache_create("fat_inode_cache",
sizeof(struct msdos_inode_info),
0, (SLAB_RECLAIM_ACCOUNT|
SLAB_MEM_SPREAD|SLAB_ACCOUNT),
init_once);
if (fat_inode_cachep == NULL)
return -ENOMEM;
return 0;
}
static void __exit fat_destroy_inodecache(void)
{
/*
* Make sure all delayed rcu free inodes are flushed before we
* destroy cache.
*/
rcu_barrier();
kmem_cache_destroy(fat_inode_cachep);
}
static int fat_remount(struct super_block *sb, int *flags, char *data)
{
bool new_rdonly;
struct msdos_sb_info *sbi = MSDOS_SB(sb);
*flags |= SB_NODIRATIME | (sbi->options.isvfat ? 0 : SB_NOATIME);
sync_filesystem(sb);
/* make sure we update state on remount. */
new_rdonly = *flags & SB_RDONLY;
if (new_rdonly != sb_rdonly(sb)) {
if (new_rdonly)
fat_set_state(sb, 0, 0);
else
fat_set_state(sb, 1, 1);
}
return 0;
}
static int fat_statfs(struct dentry *dentry, struct kstatfs *buf)
{
struct super_block *sb = dentry->d_sb;
struct msdos_sb_info *sbi = MSDOS_SB(sb);
u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
/* If the count of free cluster is still unknown, counts it here. */
if (sbi->free_clusters == -1 || !sbi->free_clus_valid) {
int err = fat_count_free_clusters(dentry->d_sb);
if (err)
return err;
}
buf->f_type = dentry->d_sb->s_magic;
buf->f_bsize = sbi->cluster_size;
buf->f_blocks = sbi->max_cluster - FAT_START_ENT;
buf->f_bfree = sbi->free_clusters;
buf->f_bavail = sbi->free_clusters;
buf->f_fsid = u64_to_fsid(id);
buf->f_namelen =
(sbi->options.isvfat ? FAT_LFN_LEN : 12) * NLS_MAX_CHARSET_SIZE;
return 0;
}
static int __fat_write_inode(struct inode *inode, int wait)
{
struct super_block *sb = inode->i_sb;
struct msdos_sb_info *sbi = MSDOS_SB(sb);
struct buffer_head *bh;
struct msdos_dir_entry *raw_entry;
loff_t i_pos;
sector_t blocknr;
int err, offset;
if (inode->i_ino == MSDOS_ROOT_INO)
return 0;
retry:
i_pos = fat_i_pos_read(sbi, inode);
if (!i_pos)
return 0;
fat_get_blknr_offset(sbi, i_pos, &blocknr, &offset);
bh = sb_bread(sb, blocknr);
if (!bh) {
fat_msg(sb, KERN_ERR, "unable to read inode block "
"for updating (i_pos %lld)", i_pos);
return -EIO;
}
spin_lock(&sbi->inode_hash_lock);
if (i_pos != MSDOS_I(inode)->i_pos) {
spin_unlock(&sbi->inode_hash_lock);
brelse(bh);
goto retry;
}
raw_entry = &((struct msdos_dir_entry *) (bh->b_data))[offset];
if (S_ISDIR(inode->i_mode))
raw_entry->size = 0;
else
raw_entry->size = cpu_to_le32(inode->i_size);
raw_entry->attr = fat_make_attrs(inode);
fat_set_start(raw_entry, MSDOS_I(inode)->i_logstart);
fat_time_unix2fat(sbi, &inode->i_mtime, &raw_entry->time,
&raw_entry->date, NULL);
if (sbi->options.isvfat) {
__le16 atime;
fat_time_unix2fat(sbi, &inode->i_ctime, &raw_entry->ctime,
&raw_entry->cdate, &raw_entry->ctime_cs);
fat_time_unix2fat(sbi, &inode->i_atime, &atime,
&raw_entry->adate, NULL);
}
spin_unlock(&sbi->inode_hash_lock);
mark_buffer_dirty(bh);
err = 0;
if (wait)
err = sync_dirty_buffer(bh);
brelse(bh);
return err;
}
static int fat_write_inode(struct inode *inode, struct writeback_control *wbc)
{
int err;
if (inode->i_ino == MSDOS_FSINFO_INO) {
struct super_block *sb = inode->i_sb;
mutex_lock(&MSDOS_SB(sb)->s_lock);
err = fat_clusters_flush(sb);
mutex_unlock(&MSDOS_SB(sb)->s_lock);
} else
err = __fat_write_inode(inode, wbc->sync_mode == WB_SYNC_ALL);
return err;
}
int fat_sync_inode(struct inode *inode)
{
return __fat_write_inode(inode, 1);
}
EXPORT_SYMBOL_GPL(fat_sync_inode);
static int fat_show_options(struct seq_file *m, struct dentry *root);
static const struct super_operations fat_sops = {
.alloc_inode = fat_alloc_inode,
.free_inode = fat_free_inode,
.write_inode = fat_write_inode,
.evict_inode = fat_evict_inode,
.put_super = fat_put_super,
.statfs = fat_statfs,
.remount_fs = fat_remount,
.show_options = fat_show_options,
};
static int fat_show_options(struct seq_file *m, struct dentry *root)
{
struct msdos_sb_info *sbi = MSDOS_SB(root->d_sb);
struct fat_mount_options *opts = &sbi->options;
int isvfat = opts->isvfat;
if (!uid_eq(opts->fs_uid, GLOBAL_ROOT_UID))
seq_printf(m, ",uid=%u",
from_kuid_munged(&init_user_ns, opts->fs_uid));
if (!gid_eq(opts->fs_gid, GLOBAL_ROOT_GID))
seq_printf(m, ",gid=%u",
from_kgid_munged(&init_user_ns, opts->fs_gid));
seq_printf(m, ",fmask=%04o", opts->fs_fmask);
seq_printf(m, ",dmask=%04o", opts->fs_dmask);
if (opts->allow_utime)
seq_printf(m, ",allow_utime=%04o", opts->allow_utime);
if (sbi->nls_disk)
/* strip "cp" prefix from displayed option */
seq_printf(m, ",codepage=%s", &sbi->nls_disk->charset[2]);
if (isvfat) {
if (sbi->nls_io)
seq_printf(m, ",iocharset=%s", sbi->nls_io->charset);
switch (opts->shortname) {
case VFAT_SFN_DISPLAY_WIN95 | VFAT_SFN_CREATE_WIN95:
seq_puts(m, ",shortname=win95");
break;
case VFAT_SFN_DISPLAY_WINNT | VFAT_SFN_CREATE_WINNT:
seq_puts(m, ",shortname=winnt");
break;
case VFAT_SFN_DISPLAY_WINNT | VFAT_SFN_CREATE_WIN95:
seq_puts(m, ",shortname=mixed");
break;
case VFAT_SFN_DISPLAY_LOWER | VFAT_SFN_CREATE_WIN95:
seq_puts(m, ",shortname=lower");
break;
default:
seq_puts(m, ",shortname=unknown");
break;
}
}
if (opts->name_check != 'n')
seq_printf(m, ",check=%c", opts->name_check);
if (opts->usefree)
seq_puts(m, ",usefree");
if (opts->quiet)
seq_puts(m, ",quiet");
if (opts->showexec)
seq_puts(m, ",showexec");
if (opts->sys_immutable)
seq_puts(m, ",sys_immutable");
if (!isvfat) {
if (opts->dotsOK)
seq_puts(m, ",dotsOK=yes");
if (opts->nocase)
seq_puts(m, ",nocase");
} else {
if (opts->utf8)
seq_puts(m, ",utf8");
if (opts->unicode_xlate)