forked from torvalds/linux
-
Notifications
You must be signed in to change notification settings - Fork 0
/
Copy pathzdata.c
1361 lines (1105 loc) · 34.7 KB
/
zdata.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
/*
* Copyright (C) 2018 HUAWEI, Inc.
* https://www.huawei.com/
* Created by Gao Xiang <[email protected]>
*/
#include "zdata.h"
#include "compress.h"
#include <linux/prefetch.h>
#include <trace/events/erofs.h>
/*
* a compressed_pages[] placeholder in order to avoid
* being filled with file pages for in-place decompression.
*/
#define PAGE_UNALLOCATED ((void *)0x5F0E4B1D)
/* how to allocate cached pages for a pcluster */
enum z_erofs_cache_alloctype {
DONTALLOC, /* don't allocate any cached pages */
DELAYEDALLOC, /* delayed allocation (at the time of submitting io) */
};
/*
* tagged pointer with 1-bit tag for all compressed pages
* tag 0 - the page is just found with an extra page reference
*/
typedef tagptr1_t compressed_page_t;
#define tag_compressed_page_justfound(page) \
tagptr_fold(compressed_page_t, page, 1)
static struct workqueue_struct *z_erofs_workqueue __read_mostly;
static struct kmem_cache *pcluster_cachep __read_mostly;
void z_erofs_exit_zip_subsystem(void)
{
destroy_workqueue(z_erofs_workqueue);
kmem_cache_destroy(pcluster_cachep);
}
static inline int z_erofs_init_workqueue(void)
{
const unsigned int onlinecpus = num_possible_cpus();
/*
* no need to spawn too many threads, limiting threads could minimum
* scheduling overhead, perhaps per-CPU threads should be better?
*/
z_erofs_workqueue = alloc_workqueue("erofs_unzipd",
WQ_UNBOUND | WQ_HIGHPRI,
onlinecpus + onlinecpus / 4);
return z_erofs_workqueue ? 0 : -ENOMEM;
}
static void z_erofs_pcluster_init_once(void *ptr)
{
struct z_erofs_pcluster *pcl = ptr;
struct z_erofs_collection *cl = z_erofs_primarycollection(pcl);
unsigned int i;
mutex_init(&cl->lock);
cl->nr_pages = 0;
cl->vcnt = 0;
for (i = 0; i < Z_EROFS_CLUSTER_MAX_PAGES; ++i)
pcl->compressed_pages[i] = NULL;
}
int __init z_erofs_init_zip_subsystem(void)
{
pcluster_cachep = kmem_cache_create("erofs_compress",
Z_EROFS_WORKGROUP_SIZE, 0,
SLAB_RECLAIM_ACCOUNT,
z_erofs_pcluster_init_once);
if (pcluster_cachep) {
if (!z_erofs_init_workqueue())
return 0;
kmem_cache_destroy(pcluster_cachep);
}
return -ENOMEM;
}
enum z_erofs_collectmode {
COLLECT_SECONDARY,
COLLECT_PRIMARY,
/*
* The current collection was the tail of an exist chain, in addition
* that the previous processed chained collections are all decided to
* be hooked up to it.
* A new chain will be created for the remaining collections which are
* not processed yet, therefore different from COLLECT_PRIMARY_FOLLOWED,
* the next collection cannot reuse the whole page safely in
* the following scenario:
* ________________________________________________________________
* | tail (partial) page | head (partial) page |
* | (belongs to the next cl) | (belongs to the current cl) |
* |_______PRIMARY_FOLLOWED_______|________PRIMARY_HOOKED___________|
*/
COLLECT_PRIMARY_HOOKED,
COLLECT_PRIMARY_FOLLOWED_NOINPLACE,
/*
* The current collection has been linked with the owned chain, and
* could also be linked with the remaining collections, which means
* if the processing page is the tail page of the collection, thus
* the current collection can safely use the whole page (since
* the previous collection is under control) for in-place I/O, as
* illustrated below:
* ________________________________________________________________
* | tail (partial) page | head (partial) page |
* | (of the current cl) | (of the previous collection) |
* | PRIMARY_FOLLOWED or | |
* |_____PRIMARY_HOOKED___|____________PRIMARY_FOLLOWED____________|
*
* [ (*) the above page can be used as inplace I/O. ]
*/
COLLECT_PRIMARY_FOLLOWED,
};
struct z_erofs_collector {
struct z_erofs_pagevec_ctor vector;
struct z_erofs_pcluster *pcl, *tailpcl;
struct z_erofs_collection *cl;
struct page **compressedpages;
z_erofs_next_pcluster_t owned_head;
enum z_erofs_collectmode mode;
};
struct z_erofs_decompress_frontend {
struct inode *const inode;
struct z_erofs_collector clt;
struct erofs_map_blocks map;
bool readahead;
/* used for applying cache strategy on the fly */
bool backmost;
erofs_off_t headoffset;
};
#define COLLECTOR_INIT() { \
.owned_head = Z_EROFS_PCLUSTER_TAIL, \
.mode = COLLECT_PRIMARY_FOLLOWED }
#define DECOMPRESS_FRONTEND_INIT(__i) { \
.inode = __i, .clt = COLLECTOR_INIT(), \
.backmost = true, }
static struct page *z_pagemap_global[Z_EROFS_VMAP_GLOBAL_PAGES];
static DEFINE_MUTEX(z_pagemap_global_lock);
static void preload_compressed_pages(struct z_erofs_collector *clt,
struct address_space *mc,
enum z_erofs_cache_alloctype type)
{
const struct z_erofs_pcluster *pcl = clt->pcl;
const unsigned int clusterpages = BIT(pcl->clusterbits);
struct page **pages = clt->compressedpages;
pgoff_t index = pcl->obj.index + (pages - pcl->compressed_pages);
bool standalone = true;
if (clt->mode < COLLECT_PRIMARY_FOLLOWED)
return;
for (; pages < pcl->compressed_pages + clusterpages; ++pages) {
struct page *page;
compressed_page_t t;
/* the compressed page was loaded before */
if (READ_ONCE(*pages))
continue;
page = find_get_page(mc, index);
if (page) {
t = tag_compressed_page_justfound(page);
} else if (type == DELAYEDALLOC) {
t = tagptr_init(compressed_page_t, PAGE_UNALLOCATED);
} else { /* DONTALLOC */
if (standalone)
clt->compressedpages = pages;
standalone = false;
continue;
}
if (!cmpxchg_relaxed(pages, NULL, tagptr_cast_ptr(t)))
continue;
if (page)
put_page(page);
}
if (standalone) /* downgrade to PRIMARY_FOLLOWED_NOINPLACE */
clt->mode = COLLECT_PRIMARY_FOLLOWED_NOINPLACE;
}
/* called by erofs_shrinker to get rid of all compressed_pages */
int erofs_try_to_free_all_cached_pages(struct erofs_sb_info *sbi,
struct erofs_workgroup *grp)
{
struct z_erofs_pcluster *const pcl =
container_of(grp, struct z_erofs_pcluster, obj);
struct address_space *const mapping = MNGD_MAPPING(sbi);
const unsigned int clusterpages = BIT(pcl->clusterbits);
int i;
/*
* refcount of workgroup is now freezed as 1,
* therefore no need to worry about available decompression users.
*/
for (i = 0; i < clusterpages; ++i) {
struct page *page = pcl->compressed_pages[i];
if (!page)
continue;
/* block other users from reclaiming or migrating the page */
if (!trylock_page(page))
return -EBUSY;
if (page->mapping != mapping)
continue;
/* barrier is implied in the following 'unlock_page' */
WRITE_ONCE(pcl->compressed_pages[i], NULL);
set_page_private(page, 0);
ClearPagePrivate(page);
unlock_page(page);
put_page(page);
}
return 0;
}
int erofs_try_to_free_cached_page(struct address_space *mapping,
struct page *page)
{
struct z_erofs_pcluster *const pcl = (void *)page_private(page);
const unsigned int clusterpages = BIT(pcl->clusterbits);
int ret = 0; /* 0 - busy */
if (erofs_workgroup_try_to_freeze(&pcl->obj, 1)) {
unsigned int i;
for (i = 0; i < clusterpages; ++i) {
if (pcl->compressed_pages[i] == page) {
WRITE_ONCE(pcl->compressed_pages[i], NULL);
ret = 1;
break;
}
}
erofs_workgroup_unfreeze(&pcl->obj, 1);
if (ret) {
ClearPagePrivate(page);
put_page(page);
}
}
return ret;
}
/* page_type must be Z_EROFS_PAGE_TYPE_EXCLUSIVE */
static inline bool z_erofs_try_inplace_io(struct z_erofs_collector *clt,
struct page *page)
{
struct z_erofs_pcluster *const pcl = clt->pcl;
const unsigned int clusterpages = BIT(pcl->clusterbits);
while (clt->compressedpages < pcl->compressed_pages + clusterpages) {
if (!cmpxchg(clt->compressedpages++, NULL, page))
return true;
}
return false;
}
/* callers must be with collection lock held */
static int z_erofs_attach_page(struct z_erofs_collector *clt,
struct page *page,
enum z_erofs_page_type type)
{
int ret;
bool occupied;
/* give priority for inplaceio */
if (clt->mode >= COLLECT_PRIMARY &&
type == Z_EROFS_PAGE_TYPE_EXCLUSIVE &&
z_erofs_try_inplace_io(clt, page))
return 0;
ret = z_erofs_pagevec_enqueue(&clt->vector,
page, type, &occupied);
clt->cl->vcnt += (unsigned int)ret;
return ret ? 0 : -EAGAIN;
}
static enum z_erofs_collectmode
try_to_claim_pcluster(struct z_erofs_pcluster *pcl,
z_erofs_next_pcluster_t *owned_head)
{
/* let's claim these following types of pclusters */
retry:
if (pcl->next == Z_EROFS_PCLUSTER_NIL) {
/* type 1, nil pcluster */
if (cmpxchg(&pcl->next, Z_EROFS_PCLUSTER_NIL,
*owned_head) != Z_EROFS_PCLUSTER_NIL)
goto retry;
*owned_head = &pcl->next;
/* lucky, I am the followee :) */
return COLLECT_PRIMARY_FOLLOWED;
} else if (pcl->next == Z_EROFS_PCLUSTER_TAIL) {
/*
* type 2, link to the end of a existing open chain,
* be careful that its submission itself is governed
* by the original owned chain.
*/
if (cmpxchg(&pcl->next, Z_EROFS_PCLUSTER_TAIL,
*owned_head) != Z_EROFS_PCLUSTER_TAIL)
goto retry;
*owned_head = Z_EROFS_PCLUSTER_TAIL;
return COLLECT_PRIMARY_HOOKED;
}
return COLLECT_PRIMARY; /* :( better luck next time */
}
static int z_erofs_lookup_collection(struct z_erofs_collector *clt,
struct inode *inode,
struct erofs_map_blocks *map)
{
struct z_erofs_pcluster *pcl = clt->pcl;
struct z_erofs_collection *cl;
unsigned int length;
/* to avoid unexpected loop formed by corrupted images */
if (clt->owned_head == &pcl->next || pcl == clt->tailpcl) {
DBG_BUGON(1);
return -EFSCORRUPTED;
}
cl = z_erofs_primarycollection(pcl);
if (cl->pageofs != (map->m_la & ~PAGE_MASK)) {
DBG_BUGON(1);
return -EFSCORRUPTED;
}
length = READ_ONCE(pcl->length);
if (length & Z_EROFS_PCLUSTER_FULL_LENGTH) {
if ((map->m_llen << Z_EROFS_PCLUSTER_LENGTH_BIT) > length) {
DBG_BUGON(1);
return -EFSCORRUPTED;
}
} else {
unsigned int llen = map->m_llen << Z_EROFS_PCLUSTER_LENGTH_BIT;
if (map->m_flags & EROFS_MAP_FULL_MAPPED)
llen |= Z_EROFS_PCLUSTER_FULL_LENGTH;
while (llen > length &&
length != cmpxchg_relaxed(&pcl->length, length, llen)) {
cpu_relax();
length = READ_ONCE(pcl->length);
}
}
mutex_lock(&cl->lock);
/* used to check tail merging loop due to corrupted images */
if (clt->owned_head == Z_EROFS_PCLUSTER_TAIL)
clt->tailpcl = pcl;
clt->mode = try_to_claim_pcluster(pcl, &clt->owned_head);
/* clean tailpcl if the current owned_head is Z_EROFS_PCLUSTER_TAIL */
if (clt->owned_head == Z_EROFS_PCLUSTER_TAIL)
clt->tailpcl = NULL;
clt->cl = cl;
return 0;
}
static int z_erofs_register_collection(struct z_erofs_collector *clt,
struct inode *inode,
struct erofs_map_blocks *map)
{
struct z_erofs_pcluster *pcl;
struct z_erofs_collection *cl;
struct erofs_workgroup *grp;
int err;
/* no available workgroup, let's allocate one */
pcl = kmem_cache_alloc(pcluster_cachep, GFP_NOFS);
if (!pcl)
return -ENOMEM;
atomic_set(&pcl->obj.refcount, 1);
pcl->obj.index = map->m_pa >> PAGE_SHIFT;
pcl->length = (map->m_llen << Z_EROFS_PCLUSTER_LENGTH_BIT) |
(map->m_flags & EROFS_MAP_FULL_MAPPED ?
Z_EROFS_PCLUSTER_FULL_LENGTH : 0);
if (map->m_flags & EROFS_MAP_ZIPPED)
pcl->algorithmformat = Z_EROFS_COMPRESSION_LZ4;
else
pcl->algorithmformat = Z_EROFS_COMPRESSION_SHIFTED;
pcl->clusterbits = EROFS_I(inode)->z_physical_clusterbits[0];
pcl->clusterbits -= PAGE_SHIFT;
/* new pclusters should be claimed as type 1, primary and followed */
pcl->next = clt->owned_head;
clt->mode = COLLECT_PRIMARY_FOLLOWED;
cl = z_erofs_primarycollection(pcl);
/* must be cleaned before freeing to slab */
DBG_BUGON(cl->nr_pages);
DBG_BUGON(cl->vcnt);
cl->pageofs = map->m_la & ~PAGE_MASK;
/*
* lock all primary followed works before visible to others
* and mutex_trylock *never* fails for a new pcluster.
*/
DBG_BUGON(!mutex_trylock(&cl->lock));
grp = erofs_insert_workgroup(inode->i_sb, &pcl->obj);
if (IS_ERR(grp)) {
err = PTR_ERR(grp);
goto err_out;
}
if (grp != &pcl->obj) {
clt->pcl = container_of(grp, struct z_erofs_pcluster, obj);
err = -EEXIST;
goto err_out;
}
/* used to check tail merging loop due to corrupted images */
if (clt->owned_head == Z_EROFS_PCLUSTER_TAIL)
clt->tailpcl = pcl;
clt->owned_head = &pcl->next;
clt->pcl = pcl;
clt->cl = cl;
return 0;
err_out:
mutex_unlock(&cl->lock);
kmem_cache_free(pcluster_cachep, pcl);
return err;
}
static int z_erofs_collector_begin(struct z_erofs_collector *clt,
struct inode *inode,
struct erofs_map_blocks *map)
{
struct erofs_workgroup *grp;
int ret;
DBG_BUGON(clt->cl);
/* must be Z_EROFS_PCLUSTER_TAIL or pointed to previous collection */
DBG_BUGON(clt->owned_head == Z_EROFS_PCLUSTER_NIL);
DBG_BUGON(clt->owned_head == Z_EROFS_PCLUSTER_TAIL_CLOSED);
if (!PAGE_ALIGNED(map->m_pa)) {
DBG_BUGON(1);
return -EINVAL;
}
grp = erofs_find_workgroup(inode->i_sb, map->m_pa >> PAGE_SHIFT);
if (grp) {
clt->pcl = container_of(grp, struct z_erofs_pcluster, obj);
} else {
ret = z_erofs_register_collection(clt, inode, map);
if (!ret)
goto out;
if (ret != -EEXIST)
return ret;
}
ret = z_erofs_lookup_collection(clt, inode, map);
if (ret) {
erofs_workgroup_put(&clt->pcl->obj);
return ret;
}
out:
z_erofs_pagevec_ctor_init(&clt->vector, Z_EROFS_NR_INLINE_PAGEVECS,
clt->cl->pagevec, clt->cl->vcnt);
clt->compressedpages = clt->pcl->compressed_pages;
if (clt->mode <= COLLECT_PRIMARY) /* cannot do in-place I/O */
clt->compressedpages += Z_EROFS_CLUSTER_MAX_PAGES;
return 0;
}
/*
* keep in mind that no referenced pclusters will be freed
* only after a RCU grace period.
*/
static void z_erofs_rcu_callback(struct rcu_head *head)
{
struct z_erofs_collection *const cl =
container_of(head, struct z_erofs_collection, rcu);
kmem_cache_free(pcluster_cachep,
container_of(cl, struct z_erofs_pcluster,
primary_collection));
}
void erofs_workgroup_free_rcu(struct erofs_workgroup *grp)
{
struct z_erofs_pcluster *const pcl =
container_of(grp, struct z_erofs_pcluster, obj);
struct z_erofs_collection *const cl = z_erofs_primarycollection(pcl);
call_rcu(&cl->rcu, z_erofs_rcu_callback);
}
static void z_erofs_collection_put(struct z_erofs_collection *cl)
{
struct z_erofs_pcluster *const pcl =
container_of(cl, struct z_erofs_pcluster, primary_collection);
erofs_workgroup_put(&pcl->obj);
}
static bool z_erofs_collector_end(struct z_erofs_collector *clt)
{
struct z_erofs_collection *cl = clt->cl;
if (!cl)
return false;
z_erofs_pagevec_ctor_exit(&clt->vector, false);
mutex_unlock(&cl->lock);
/*
* if all pending pages are added, don't hold its reference
* any longer if the pcluster isn't hosted by ourselves.
*/
if (clt->mode < COLLECT_PRIMARY_FOLLOWED_NOINPLACE)
z_erofs_collection_put(cl);
clt->cl = NULL;
return true;
}
static bool should_alloc_managed_pages(struct z_erofs_decompress_frontend *fe,
unsigned int cachestrategy,
erofs_off_t la)
{
if (cachestrategy <= EROFS_ZIP_CACHE_DISABLED)
return false;
if (fe->backmost)
return true;
return cachestrategy >= EROFS_ZIP_CACHE_READAROUND &&
la < fe->headoffset;
}
static int z_erofs_do_read_page(struct z_erofs_decompress_frontend *fe,
struct page *page)
{
struct inode *const inode = fe->inode;
struct erofs_sb_info *const sbi = EROFS_I_SB(inode);
struct erofs_map_blocks *const map = &fe->map;
struct z_erofs_collector *const clt = &fe->clt;
const loff_t offset = page_offset(page);
bool tight = true;
enum z_erofs_cache_alloctype cache_strategy;
enum z_erofs_page_type page_type;
unsigned int cur, end, spiltted, index;
int err = 0;
/* register locked file pages as online pages in pack */
z_erofs_onlinepage_init(page);
spiltted = 0;
end = PAGE_SIZE;
repeat:
cur = end - 1;
/* lucky, within the range of the current map_blocks */
if (offset + cur >= map->m_la &&
offset + cur < map->m_la + map->m_llen) {
/* didn't get a valid collection previously (very rare) */
if (!clt->cl)
goto restart_now;
goto hitted;
}
/* go ahead the next map_blocks */
erofs_dbg("%s: [out-of-range] pos %llu", __func__, offset + cur);
if (z_erofs_collector_end(clt))
fe->backmost = false;
map->m_la = offset + cur;
map->m_llen = 0;
err = z_erofs_map_blocks_iter(inode, map, 0);
if (err)
goto err_out;
restart_now:
if (!(map->m_flags & EROFS_MAP_MAPPED))
goto hitted;
err = z_erofs_collector_begin(clt, inode, map);
if (err)
goto err_out;
/* preload all compressed pages (maybe downgrade role if necessary) */
if (should_alloc_managed_pages(fe, sbi->ctx.cache_strategy, map->m_la))
cache_strategy = DELAYEDALLOC;
else
cache_strategy = DONTALLOC;
preload_compressed_pages(clt, MNGD_MAPPING(sbi), cache_strategy);
hitted:
/*
* Ensure the current partial page belongs to this submit chain rather
* than other concurrent submit chains or the noio(bypass) chain since
* those chains are handled asynchronously thus the page cannot be used
* for inplace I/O or pagevec (should be processed in strict order.)
*/
tight &= (clt->mode >= COLLECT_PRIMARY_HOOKED &&
clt->mode != COLLECT_PRIMARY_FOLLOWED_NOINPLACE);
cur = end - min_t(unsigned int, offset + end - map->m_la, end);
if (!(map->m_flags & EROFS_MAP_MAPPED)) {
zero_user_segment(page, cur, end);
goto next_part;
}
/* let's derive page type */
page_type = cur ? Z_EROFS_VLE_PAGE_TYPE_HEAD :
(!spiltted ? Z_EROFS_PAGE_TYPE_EXCLUSIVE :
(tight ? Z_EROFS_PAGE_TYPE_EXCLUSIVE :
Z_EROFS_VLE_PAGE_TYPE_TAIL_SHARED));
if (cur)
tight &= (clt->mode >= COLLECT_PRIMARY_FOLLOWED);
retry:
err = z_erofs_attach_page(clt, page, page_type);
/* should allocate an additional staging page for pagevec */
if (err == -EAGAIN) {
struct page *const newpage =
alloc_page(GFP_NOFS | __GFP_NOFAIL);
newpage->mapping = Z_EROFS_MAPPING_STAGING;
err = z_erofs_attach_page(clt, newpage,
Z_EROFS_PAGE_TYPE_EXCLUSIVE);
if (!err)
goto retry;
}
if (err)
goto err_out;
index = page->index - (map->m_la >> PAGE_SHIFT);
z_erofs_onlinepage_fixup(page, index, true);
/* bump up the number of spiltted parts of a page */
++spiltted;
/* also update nr_pages */
clt->cl->nr_pages = max_t(pgoff_t, clt->cl->nr_pages, index + 1);
next_part:
/* can be used for verification */
map->m_llen = offset + cur - map->m_la;
end = cur;
if (end > 0)
goto repeat;
out:
z_erofs_onlinepage_endio(page);
erofs_dbg("%s, finish page: %pK spiltted: %u map->m_llen %llu",
__func__, page, spiltted, map->m_llen);
return err;
/* if some error occurred while processing this page */
err_out:
SetPageError(page);
goto out;
}
static void z_erofs_decompress_kickoff(struct z_erofs_decompressqueue *io,
bool sync, int bios)
{
/* wake up the caller thread for sync decompression */
if (sync) {
unsigned long flags;
spin_lock_irqsave(&io->u.wait.lock, flags);
if (!atomic_add_return(bios, &io->pending_bios))
wake_up_locked(&io->u.wait);
spin_unlock_irqrestore(&io->u.wait.lock, flags);
return;
}
if (!atomic_add_return(bios, &io->pending_bios))
queue_work(z_erofs_workqueue, &io->u.work);
}
static void z_erofs_decompressqueue_endio(struct bio *bio)
{
tagptr1_t t = tagptr_init(tagptr1_t, bio->bi_private);
struct z_erofs_decompressqueue *q = tagptr_unfold_ptr(t);
blk_status_t err = bio->bi_status;
struct bio_vec *bvec;
struct bvec_iter_all iter_all;
bio_for_each_segment_all(bvec, bio, iter_all) {
struct page *page = bvec->bv_page;
DBG_BUGON(PageUptodate(page));
DBG_BUGON(!page->mapping);
if (err)
SetPageError(page);
if (erofs_page_is_managed(EROFS_SB(q->sb), page)) {
if (!err)
SetPageUptodate(page);
unlock_page(page);
}
}
z_erofs_decompress_kickoff(q, tagptr_unfold_tags(t), -1);
bio_put(bio);
}
static int z_erofs_decompress_pcluster(struct super_block *sb,
struct z_erofs_pcluster *pcl,
struct list_head *pagepool)
{
struct erofs_sb_info *const sbi = EROFS_SB(sb);
const unsigned int clusterpages = BIT(pcl->clusterbits);
struct z_erofs_pagevec_ctor ctor;
unsigned int i, outputsize, llen, nr_pages;
struct page *pages_onstack[Z_EROFS_VMAP_ONSTACK_PAGES];
struct page **pages, **compressed_pages, *page;
enum z_erofs_page_type page_type;
bool overlapped, partial;
struct z_erofs_collection *cl;
int err;
might_sleep();
cl = z_erofs_primarycollection(pcl);
DBG_BUGON(!READ_ONCE(cl->nr_pages));
mutex_lock(&cl->lock);
nr_pages = cl->nr_pages;
if (nr_pages <= Z_EROFS_VMAP_ONSTACK_PAGES) {
pages = pages_onstack;
} else if (nr_pages <= Z_EROFS_VMAP_GLOBAL_PAGES &&
mutex_trylock(&z_pagemap_global_lock)) {
pages = z_pagemap_global;
} else {
gfp_t gfp_flags = GFP_KERNEL;
if (nr_pages > Z_EROFS_VMAP_GLOBAL_PAGES)
gfp_flags |= __GFP_NOFAIL;
pages = kvmalloc_array(nr_pages, sizeof(struct page *),
gfp_flags);
/* fallback to global pagemap for the lowmem scenario */
if (!pages) {
mutex_lock(&z_pagemap_global_lock);
pages = z_pagemap_global;
}
}
for (i = 0; i < nr_pages; ++i)
pages[i] = NULL;
err = 0;
z_erofs_pagevec_ctor_init(&ctor, Z_EROFS_NR_INLINE_PAGEVECS,
cl->pagevec, 0);
for (i = 0; i < cl->vcnt; ++i) {
unsigned int pagenr;
page = z_erofs_pagevec_dequeue(&ctor, &page_type);
/* all pages in pagevec ought to be valid */
DBG_BUGON(!page);
DBG_BUGON(!page->mapping);
if (z_erofs_put_stagingpage(pagepool, page))
continue;
if (page_type == Z_EROFS_VLE_PAGE_TYPE_HEAD)
pagenr = 0;
else
pagenr = z_erofs_onlinepage_index(page);
DBG_BUGON(pagenr >= nr_pages);
/*
* currently EROFS doesn't support multiref(dedup),
* so here erroring out one multiref page.
*/
if (pages[pagenr]) {
DBG_BUGON(1);
SetPageError(pages[pagenr]);
z_erofs_onlinepage_endio(pages[pagenr]);
err = -EFSCORRUPTED;
}
pages[pagenr] = page;
}
z_erofs_pagevec_ctor_exit(&ctor, true);
overlapped = false;
compressed_pages = pcl->compressed_pages;
for (i = 0; i < clusterpages; ++i) {
unsigned int pagenr;
page = compressed_pages[i];
/* all compressed pages ought to be valid */
DBG_BUGON(!page);
DBG_BUGON(!page->mapping);
if (!z_erofs_page_is_staging(page)) {
if (erofs_page_is_managed(sbi, page)) {
if (!PageUptodate(page))
err = -EIO;
continue;
}
/*
* only if non-head page can be selected
* for inplace decompression
*/
pagenr = z_erofs_onlinepage_index(page);
DBG_BUGON(pagenr >= nr_pages);
if (pages[pagenr]) {
DBG_BUGON(1);
SetPageError(pages[pagenr]);
z_erofs_onlinepage_endio(pages[pagenr]);
err = -EFSCORRUPTED;
}
pages[pagenr] = page;
overlapped = true;
}
/* PG_error needs checking for inplaced and staging pages */
if (PageError(page)) {
DBG_BUGON(PageUptodate(page));
err = -EIO;
}
}
if (err)
goto out;
llen = pcl->length >> Z_EROFS_PCLUSTER_LENGTH_BIT;
if (nr_pages << PAGE_SHIFT >= cl->pageofs + llen) {
outputsize = llen;
partial = !(pcl->length & Z_EROFS_PCLUSTER_FULL_LENGTH);
} else {
outputsize = (nr_pages << PAGE_SHIFT) - cl->pageofs;
partial = true;
}
err = z_erofs_decompress(&(struct z_erofs_decompress_req) {
.sb = sb,
.in = compressed_pages,
.out = pages,
.pageofs_out = cl->pageofs,
.inputsize = PAGE_SIZE,
.outputsize = outputsize,
.alg = pcl->algorithmformat,
.inplace_io = overlapped,
.partial_decoding = partial
}, pagepool);
out:
/* must handle all compressed pages before endding pages */
for (i = 0; i < clusterpages; ++i) {
page = compressed_pages[i];
if (erofs_page_is_managed(sbi, page))
continue;
/* recycle all individual staging pages */
(void)z_erofs_put_stagingpage(pagepool, page);
WRITE_ONCE(compressed_pages[i], NULL);
}
for (i = 0; i < nr_pages; ++i) {
page = pages[i];
if (!page)
continue;
DBG_BUGON(!page->mapping);
/* recycle all individual staging pages */
if (z_erofs_put_stagingpage(pagepool, page))
continue;
if (err < 0)
SetPageError(page);
z_erofs_onlinepage_endio(page);
}
if (pages == z_pagemap_global)
mutex_unlock(&z_pagemap_global_lock);
else if (pages != pages_onstack)
kvfree(pages);
cl->nr_pages = 0;
cl->vcnt = 0;
/* all cl locks MUST be taken before the following line */
WRITE_ONCE(pcl->next, Z_EROFS_PCLUSTER_NIL);
/* all cl locks SHOULD be released right now */
mutex_unlock(&cl->lock);
z_erofs_collection_put(cl);
return err;
}
static void z_erofs_decompress_queue(const struct z_erofs_decompressqueue *io,
struct list_head *pagepool)
{
z_erofs_next_pcluster_t owned = io->head;
while (owned != Z_EROFS_PCLUSTER_TAIL_CLOSED) {
struct z_erofs_pcluster *pcl;
/* no possible that 'owned' equals Z_EROFS_WORK_TPTR_TAIL */
DBG_BUGON(owned == Z_EROFS_PCLUSTER_TAIL);
/* no possible that 'owned' equals NULL */
DBG_BUGON(owned == Z_EROFS_PCLUSTER_NIL);
pcl = container_of(owned, struct z_erofs_pcluster, next);
owned = READ_ONCE(pcl->next);
z_erofs_decompress_pcluster(io->sb, pcl, pagepool);
}
}
static void z_erofs_decompressqueue_work(struct work_struct *work)
{
struct z_erofs_decompressqueue *bgq =
container_of(work, struct z_erofs_decompressqueue, u.work);
LIST_HEAD(pagepool);
DBG_BUGON(bgq->head == Z_EROFS_PCLUSTER_TAIL_CLOSED);
z_erofs_decompress_queue(bgq, &pagepool);
put_pages_list(&pagepool);
kvfree(bgq);
}
static struct page *pickup_page_for_submission(struct z_erofs_pcluster *pcl,
unsigned int nr,
struct list_head *pagepool,
struct address_space *mc,
gfp_t gfp)
{
const pgoff_t index = pcl->obj.index;
bool tocache = false;
struct address_space *mapping;
struct page *oldpage, *page;
compressed_page_t t;
int justfound;
repeat:
page = READ_ONCE(pcl->compressed_pages[nr]);
oldpage = page;
if (!page)
goto out_allocpage;
/*
* the cached page has not been allocated and
* an placeholder is out there, prepare it now.
*/