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14#include <linux/kernel.h>
15#include <linux/module.h>
16#include <linux/spinlock.h>
17#include <linux/fs.h>
18#include <linux/mm.h>
19#include <linux/swap.h>
20#include <linux/slab.h>
21#include <linux/pagemap.h>
22#include <linux/writeback.h>
23#include <linux/init.h>
24#include <linux/backing-dev.h>
25#include <linux/task_io_accounting_ops.h>
26#include <linux/blkdev.h>
27#include <linux/mpage.h>
28#include <linux/rmap.h>
29#include <linux/percpu.h>
30#include <linux/notifier.h>
31#include <linux/smp.h>
32#include <linux/sysctl.h>
33#include <linux/cpu.h>
34#include <linux/syscalls.h>
35#include <linux/buffer_head.h>
36#include <linux/pagevec.h>
37
38
39
40
41
42static long ratelimit_pages = 32;
43
44
45
46
47
48
49
50static inline long sync_writeback_pages(unsigned long dirtied)
51{
52 if (dirtied < ratelimit_pages)
53 dirtied = ratelimit_pages;
54
55 return dirtied + dirtied / 2;
56}
57
58
59
60
61
62
63int dirty_background_ratio = 10;
64
65
66
67
68
69unsigned long dirty_background_bytes;
70
71
72
73
74
75int vm_highmem_is_dirtyable;
76
77
78
79
80int vm_dirty_ratio = 20;
81
82
83
84
85
86unsigned long vm_dirty_bytes;
87
88
89
90
91unsigned int dirty_writeback_interval = 5 * 100;
92
93
94
95
96unsigned int dirty_expire_interval = 30 * 100;
97
98
99
100
101int block_dump;
102
103
104
105
106
107int laptop_mode;
108
109EXPORT_SYMBOL(laptop_mode);
110
111
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122
123
124
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126
127
128
129
130static struct prop_descriptor vm_completions;
131static struct prop_descriptor vm_dirties;
132
133
134
135
136
137
138static int calc_period_shift(void)
139{
140 unsigned long dirty_total;
141
142 if (vm_dirty_bytes)
143 dirty_total = vm_dirty_bytes / PAGE_SIZE;
144 else
145 dirty_total = (vm_dirty_ratio * determine_dirtyable_memory()) /
146 100;
147 return 2 + ilog2(dirty_total - 1);
148}
149
150
151
152
153static void update_completion_period(void)
154{
155 int shift = calc_period_shift();
156 prop_change_shift(&vm_completions, shift);
157 prop_change_shift(&vm_dirties, shift);
158}
159
160int dirty_background_ratio_handler(struct ctl_table *table, int write,
161 void __user *buffer, size_t *lenp,
162 loff_t *ppos)
163{
164 int ret;
165
166 ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos);
167 if (ret == 0 && write)
168 dirty_background_bytes = 0;
169 return ret;
170}
171
172int dirty_background_bytes_handler(struct ctl_table *table, int write,
173 void __user *buffer, size_t *lenp,
174 loff_t *ppos)
175{
176 int ret;
177
178 ret = proc_doulongvec_minmax(table, write, buffer, lenp, ppos);
179 if (ret == 0 && write)
180 dirty_background_ratio = 0;
181 return ret;
182}
183
184int dirty_ratio_handler(struct ctl_table *table, int write,
185 void __user *buffer, size_t *lenp,
186 loff_t *ppos)
187{
188 int old_ratio = vm_dirty_ratio;
189 int ret;
190
191 ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos);
192 if (ret == 0 && write && vm_dirty_ratio != old_ratio) {
193 update_completion_period();
194 vm_dirty_bytes = 0;
195 }
196 return ret;
197}
198
199
200int dirty_bytes_handler(struct ctl_table *table, int write,
201 void __user *buffer, size_t *lenp,
202 loff_t *ppos)
203{
204 unsigned long old_bytes = vm_dirty_bytes;
205 int ret;
206
207 ret = proc_doulongvec_minmax(table, write, buffer, lenp, ppos);
208 if (ret == 0 && write && vm_dirty_bytes != old_bytes) {
209 update_completion_period();
210 vm_dirty_ratio = 0;
211 }
212 return ret;
213}
214
215
216
217
218
219static inline void __bdi_writeout_inc(struct backing_dev_info *bdi)
220{
221 __prop_inc_percpu_max(&vm_completions, &bdi->completions,
222 bdi->max_prop_frac);
223}
224
225void bdi_writeout_inc(struct backing_dev_info *bdi)
226{
227 unsigned long flags;
228
229 local_irq_save(flags);
230 __bdi_writeout_inc(bdi);
231 local_irq_restore(flags);
232}
233EXPORT_SYMBOL_GPL(bdi_writeout_inc);
234
235void task_dirty_inc(struct task_struct *tsk)
236{
237 prop_inc_single(&vm_dirties, &tsk->dirties);
238}
239
240
241
242
243static void bdi_writeout_fraction(struct backing_dev_info *bdi,
244 long *numerator, long *denominator)
245{
246 if (bdi_cap_writeback_dirty(bdi)) {
247 prop_fraction_percpu(&vm_completions, &bdi->completions,
248 numerator, denominator);
249 } else {
250 *numerator = 0;
251 *denominator = 1;
252 }
253}
254
255
256
257
258
259
260static void clip_bdi_dirty_limit(struct backing_dev_info *bdi,
261 unsigned long dirty, unsigned long *pbdi_dirty)
262{
263 unsigned long avail_dirty;
264
265 avail_dirty = global_page_state(NR_FILE_DIRTY) +
266 global_page_state(NR_WRITEBACK) +
267 global_page_state(NR_UNSTABLE_NFS) +
268 global_page_state(NR_WRITEBACK_TEMP);
269
270 if (avail_dirty < dirty)
271 avail_dirty = dirty - avail_dirty;
272 else
273 avail_dirty = 0;
274
275 avail_dirty += bdi_stat(bdi, BDI_RECLAIMABLE) +
276 bdi_stat(bdi, BDI_WRITEBACK);
277
278 *pbdi_dirty = min(*pbdi_dirty, avail_dirty);
279}
280
281static inline void task_dirties_fraction(struct task_struct *tsk,
282 long *numerator, long *denominator)
283{
284 prop_fraction_single(&vm_dirties, &tsk->dirties,
285 numerator, denominator);
286}
287
288
289
290
291
292
293
294
295static void task_dirty_limit(struct task_struct *tsk, unsigned long *pdirty)
296{
297 long numerator, denominator;
298 unsigned long dirty = *pdirty;
299 u64 inv = dirty >> 3;
300
301 task_dirties_fraction(tsk, &numerator, &denominator);
302 inv *= numerator;
303 do_div(inv, denominator);
304
305 dirty -= inv;
306 if (dirty < *pdirty/2)
307 dirty = *pdirty/2;
308
309 *pdirty = dirty;
310}
311
312
313
314
315static unsigned int bdi_min_ratio;
316
317int bdi_set_min_ratio(struct backing_dev_info *bdi, unsigned int min_ratio)
318{
319 int ret = 0;
320
321 spin_lock_bh(&bdi_lock);
322 if (min_ratio > bdi->max_ratio) {
323 ret = -EINVAL;
324 } else {
325 min_ratio -= bdi->min_ratio;
326 if (bdi_min_ratio + min_ratio < 100) {
327 bdi_min_ratio += min_ratio;
328 bdi->min_ratio += min_ratio;
329 } else {
330 ret = -EINVAL;
331 }
332 }
333 spin_unlock_bh(&bdi_lock);
334
335 return ret;
336}
337
338int bdi_set_max_ratio(struct backing_dev_info *bdi, unsigned max_ratio)
339{
340 int ret = 0;
341
342 if (max_ratio > 100)
343 return -EINVAL;
344
345 spin_lock_bh(&bdi_lock);
346 if (bdi->min_ratio > max_ratio) {
347 ret = -EINVAL;
348 } else {
349 bdi->max_ratio = max_ratio;
350 bdi->max_prop_frac = (PROP_FRAC_BASE * max_ratio) / 100;
351 }
352 spin_unlock_bh(&bdi_lock);
353
354 return ret;
355}
356EXPORT_SYMBOL(bdi_set_max_ratio);
357
358
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374
375
376static unsigned long highmem_dirtyable_memory(unsigned long total)
377{
378#ifdef CONFIG_HIGHMEM
379 int node;
380 unsigned long x = 0;
381
382 for_each_node_state(node, N_HIGH_MEMORY) {
383 struct zone *z =
384 &NODE_DATA(node)->node_zones[ZONE_HIGHMEM];
385
386 x += zone_page_state(z, NR_FREE_PAGES) +
387 zone_reclaimable_pages(z);
388 }
389
390
391
392
393
394
395 return min(x, total);
396#else
397 return 0;
398#endif
399}
400
401
402
403
404
405
406
407unsigned long determine_dirtyable_memory(void)
408{
409 unsigned long x;
410
411 x = global_page_state(NR_FREE_PAGES) + global_reclaimable_pages();
412
413 if (!vm_highmem_is_dirtyable)
414 x -= highmem_dirtyable_memory(x);
415
416 return x + 1;
417}
418
419void
420get_dirty_limits(unsigned long *pbackground, unsigned long *pdirty,
421 unsigned long *pbdi_dirty, struct backing_dev_info *bdi)
422{
423 unsigned long background;
424 unsigned long dirty;
425 unsigned long available_memory = determine_dirtyable_memory();
426 struct task_struct *tsk;
427
428 if (vm_dirty_bytes)
429 dirty = DIV_ROUND_UP(vm_dirty_bytes, PAGE_SIZE);
430 else {
431 int dirty_ratio;
432
433 dirty_ratio = vm_dirty_ratio;
434 if (dirty_ratio < 5)
435 dirty_ratio = 5;
436 dirty = (dirty_ratio * available_memory) / 100;
437 }
438
439 if (dirty_background_bytes)
440 background = DIV_ROUND_UP(dirty_background_bytes, PAGE_SIZE);
441 else
442 background = (dirty_background_ratio * available_memory) / 100;
443
444 if (background >= dirty)
445 background = dirty / 2;
446 tsk = current;
447 if (tsk->flags & PF_LESS_THROTTLE || rt_task(tsk)) {
448 background += background / 4;
449 dirty += dirty / 4;
450 }
451 *pbackground = background;
452 *pdirty = dirty;
453
454 if (bdi) {
455 u64 bdi_dirty;
456 long numerator, denominator;
457
458
459
460
461 bdi_writeout_fraction(bdi, &numerator, &denominator);
462
463 bdi_dirty = (dirty * (100 - bdi_min_ratio)) / 100;
464 bdi_dirty *= numerator;
465 do_div(bdi_dirty, denominator);
466 bdi_dirty += (dirty * bdi->min_ratio) / 100;
467 if (bdi_dirty > (dirty * bdi->max_ratio) / 100)
468 bdi_dirty = dirty * bdi->max_ratio / 100;
469
470 *pbdi_dirty = bdi_dirty;
471 clip_bdi_dirty_limit(bdi, dirty, pbdi_dirty);
472 task_dirty_limit(current, pbdi_dirty);
473 }
474}
475
476
477
478
479
480
481
482
483static void balance_dirty_pages(struct address_space *mapping,
484 unsigned long write_chunk)
485{
486 long nr_reclaimable, bdi_nr_reclaimable;
487 long nr_writeback, bdi_nr_writeback;
488 unsigned long background_thresh;
489 unsigned long dirty_thresh;
490 unsigned long bdi_thresh;
491 unsigned long pages_written = 0;
492 unsigned long pause = 1;
493
494 struct backing_dev_info *bdi = mapping->backing_dev_info;
495
496 for (;;) {
497 struct writeback_control wbc = {
498 .bdi = bdi,
499 .sync_mode = WB_SYNC_NONE,
500 .older_than_this = NULL,
501 .nr_to_write = write_chunk,
502 .range_cyclic = 1,
503 };
504
505 get_dirty_limits(&background_thresh, &dirty_thresh,
506 &bdi_thresh, bdi);
507
508 nr_reclaimable = global_page_state(NR_FILE_DIRTY) +
509 global_page_state(NR_UNSTABLE_NFS);
510 nr_writeback = global_page_state(NR_WRITEBACK);
511
512 bdi_nr_reclaimable = bdi_stat(bdi, BDI_RECLAIMABLE);
513 bdi_nr_writeback = bdi_stat(bdi, BDI_WRITEBACK);
514
515 if (bdi_nr_reclaimable + bdi_nr_writeback <= bdi_thresh)
516 break;
517
518
519
520
521
522
523 if (nr_reclaimable + nr_writeback <
524 (background_thresh + dirty_thresh) / 2)
525 break;
526
527 if (!bdi->dirty_exceeded)
528 bdi->dirty_exceeded = 1;
529
530
531
532
533
534
535
536
537
538
539 if (bdi_nr_reclaimable > bdi_thresh) {
540 writeback_inodes_wbc(&wbc);
541 pages_written += write_chunk - wbc.nr_to_write;
542 get_dirty_limits(&background_thresh, &dirty_thresh,
543 &bdi_thresh, bdi);
544 }
545
546
547
548
549
550
551
552
553
554
555
556 if (bdi_thresh < 2*bdi_stat_error(bdi)) {
557 bdi_nr_reclaimable = bdi_stat_sum(bdi, BDI_RECLAIMABLE);
558 bdi_nr_writeback = bdi_stat_sum(bdi, BDI_WRITEBACK);
559 } else if (bdi_nr_reclaimable) {
560 bdi_nr_reclaimable = bdi_stat(bdi, BDI_RECLAIMABLE);
561 bdi_nr_writeback = bdi_stat(bdi, BDI_WRITEBACK);
562 }
563
564 if (bdi_nr_reclaimable + bdi_nr_writeback <= bdi_thresh)
565 break;
566 if (pages_written >= write_chunk)
567 break;
568
569 __set_current_state(TASK_INTERRUPTIBLE);
570 io_schedule_timeout(pause);
571
572
573
574
575
576 pause <<= 1;
577 if (pause > HZ / 10)
578 pause = HZ / 10;
579 }
580
581 if (bdi_nr_reclaimable + bdi_nr_writeback < bdi_thresh &&
582 bdi->dirty_exceeded)
583 bdi->dirty_exceeded = 0;
584
585 if (writeback_in_progress(bdi))
586 return;
587
588
589
590
591
592
593
594
595
596 if ((laptop_mode && pages_written) ||
597 (!laptop_mode && ((global_page_state(NR_FILE_DIRTY)
598 + global_page_state(NR_UNSTABLE_NFS))
599 > background_thresh)))
600 bdi_start_writeback(bdi, NULL, 0);
601}
602
603void set_page_dirty_balance(struct page *page, int page_mkwrite)
604{
605 if (set_page_dirty(page) || page_mkwrite) {
606 struct address_space *mapping = page_mapping(page);
607
608 if (mapping)
609 balance_dirty_pages_ratelimited(mapping);
610 }
611}
612
613static DEFINE_PER_CPU(unsigned long, bdp_ratelimits) = 0;
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629void balance_dirty_pages_ratelimited_nr(struct address_space *mapping,
630 unsigned long nr_pages_dirtied)
631{
632 unsigned long ratelimit;
633 unsigned long *p;
634
635 ratelimit = ratelimit_pages;
636 if (mapping->backing_dev_info->dirty_exceeded)
637 ratelimit = 8;
638
639
640
641
642
643 preempt_disable();
644 p = &__get_cpu_var(bdp_ratelimits);
645 *p += nr_pages_dirtied;
646 if (unlikely(*p >= ratelimit)) {
647 ratelimit = sync_writeback_pages(*p);
648 *p = 0;
649 preempt_enable();
650 balance_dirty_pages(mapping, ratelimit);
651 return;
652 }
653 preempt_enable();
654}
655EXPORT_SYMBOL(balance_dirty_pages_ratelimited_nr);
656
657void throttle_vm_writeout(gfp_t gfp_mask)
658{
659 unsigned long background_thresh;
660 unsigned long dirty_thresh;
661
662 for ( ; ; ) {
663 get_dirty_limits(&background_thresh, &dirty_thresh, NULL, NULL);
664
665
666
667
668
669 dirty_thresh += dirty_thresh / 10;
670
671 if (global_page_state(NR_UNSTABLE_NFS) +
672 global_page_state(NR_WRITEBACK) <= dirty_thresh)
673 break;
674 congestion_wait(BLK_RW_ASYNC, HZ/10);
675
676
677
678
679
680
681 if ((gfp_mask & (__GFP_FS|__GFP_IO)) != (__GFP_FS|__GFP_IO))
682 break;
683 }
684}
685
686static void laptop_timer_fn(unsigned long unused);
687
688static DEFINE_TIMER(laptop_mode_wb_timer, laptop_timer_fn, 0, 0);
689
690
691
692
693int dirty_writeback_centisecs_handler(ctl_table *table, int write,
694 void __user *buffer, size_t *length, loff_t *ppos)
695{
696 proc_dointvec(table, write, buffer, length, ppos);
697 return 0;
698}
699
700static void do_laptop_sync(struct work_struct *work)
701{
702 wakeup_flusher_threads(0);
703 kfree(work);
704}
705
706static void laptop_timer_fn(unsigned long unused)
707{
708 struct work_struct *work;
709
710 work = kmalloc(sizeof(*work), GFP_ATOMIC);
711 if (work) {
712 INIT_WORK(work, do_laptop_sync);
713 schedule_work(work);
714 }
715}
716
717
718
719
720
721
722void laptop_io_completion(void)
723{
724 mod_timer(&laptop_mode_wb_timer, jiffies + laptop_mode);
725}
726
727
728
729
730
731
732void laptop_sync_completion(void)
733{
734 del_timer(&laptop_mode_wb_timer);
735}
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754void writeback_set_ratelimit(void)
755{
756 ratelimit_pages = vm_total_pages / (num_online_cpus() * 32);
757 if (ratelimit_pages < 16)
758 ratelimit_pages = 16;
759 if (ratelimit_pages * PAGE_CACHE_SIZE > 4096 * 1024)
760 ratelimit_pages = (4096 * 1024) / PAGE_CACHE_SIZE;
761}
762
763static int __cpuinit
764ratelimit_handler(struct notifier_block *self, unsigned long u, void *v)
765{
766 writeback_set_ratelimit();
767 return NOTIFY_DONE;
768}
769
770static struct notifier_block __cpuinitdata ratelimit_nb = {
771 .notifier_call = ratelimit_handler,
772 .next = NULL,
773};
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793void __init page_writeback_init(void)
794{
795 int shift;
796
797 writeback_set_ratelimit();
798 register_cpu_notifier(&ratelimit_nb);
799
800 shift = calc_period_shift();
801 prop_descriptor_init(&vm_completions, shift);
802 prop_descriptor_init(&vm_dirties, shift);
803}
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820int write_cache_pages(struct address_space *mapping,
821 struct writeback_control *wbc, writepage_t writepage,
822 void *data)
823{
824 struct backing_dev_info *bdi = mapping->backing_dev_info;
825 int ret = 0;
826 int done = 0;
827 struct pagevec pvec;
828 int nr_pages;
829 pgoff_t uninitialized_var(writeback_index);
830 pgoff_t index;
831 pgoff_t end;
832 pgoff_t done_index;
833 int cycled;
834 int range_whole = 0;
835 long nr_to_write = wbc->nr_to_write;
836
837 if (wbc->nonblocking && bdi_write_congested(bdi)) {
838 wbc->encountered_congestion = 1;
839 return 0;
840 }
841
842 pagevec_init(&pvec, 0);
843 if (wbc->range_cyclic) {
844 writeback_index = mapping->writeback_index;
845 index = writeback_index;
846 if (index == 0)
847 cycled = 1;
848 else
849 cycled = 0;
850 end = -1;
851 } else {
852 index = wbc->range_start >> PAGE_CACHE_SHIFT;
853 end = wbc->range_end >> PAGE_CACHE_SHIFT;
854 if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX)
855 range_whole = 1;
856 cycled = 1;
857 }
858retry:
859 done_index = index;
860 while (!done && (index <= end)) {
861 int i;
862
863 nr_pages = pagevec_lookup_tag(&pvec, mapping, &index,
864 PAGECACHE_TAG_DIRTY,
865 min(end - index, (pgoff_t)PAGEVEC_SIZE-1) + 1);
866 if (nr_pages == 0)
867 break;
868
869 for (i = 0; i < nr_pages; i++) {
870 struct page *page = pvec.pages[i];
871
872
873
874
875
876
877
878
879 if (page->index > end) {
880
881
882
883
884 done = 1;
885 break;
886 }
887
888 done_index = page->index + 1;
889
890 lock_page(page);
891
892
893
894
895
896
897
898
899
900 if (unlikely(page->mapping != mapping)) {
901continue_unlock:
902 unlock_page(page);
903 continue;
904 }
905
906 if (!PageDirty(page)) {
907
908 goto continue_unlock;
909 }
910
911 if (PageWriteback(page)) {
912 if (wbc->sync_mode != WB_SYNC_NONE)
913 wait_on_page_writeback(page);
914 else
915 goto continue_unlock;
916 }
917
918 BUG_ON(PageWriteback(page));
919 if (!clear_page_dirty_for_io(page))
920 goto continue_unlock;
921
922 ret = (*writepage)(page, wbc, data);
923 if (unlikely(ret)) {
924 if (ret == AOP_WRITEPAGE_ACTIVATE) {
925 unlock_page(page);
926 ret = 0;
927 } else {
928
929
930
931
932
933
934
935
936
937 done = 1;
938 break;
939 }
940 }
941
942 if (nr_to_write > 0) {
943 nr_to_write--;
944 if (nr_to_write == 0 &&
945 wbc->sync_mode == WB_SYNC_NONE) {
946
947
948
949
950
951
952
953
954
955
956 done = 1;
957 break;
958 }
959 }
960
961 if (wbc->nonblocking && bdi_write_congested(bdi)) {
962 wbc->encountered_congestion = 1;
963 done = 1;
964 break;
965 }
966 }
967 pagevec_release(&pvec);
968 cond_resched();
969 }
970 if (!cycled && !done) {
971
972
973
974
975
976 cycled = 1;
977 index = 0;
978 end = writeback_index - 1;
979 goto retry;
980 }
981 if (!wbc->no_nrwrite_index_update) {
982 if (wbc->range_cyclic || (range_whole && nr_to_write > 0))
983 mapping->writeback_index = done_index;
984 wbc->nr_to_write = nr_to_write;
985 }
986
987 return ret;
988}
989EXPORT_SYMBOL(write_cache_pages);
990
991
992
993
994
995static int __writepage(struct page *page, struct writeback_control *wbc,
996 void *data)
997{
998 struct address_space *mapping = data;
999 int ret = mapping->a_ops->writepage(page, wbc);
1000 mapping_set_error(mapping, ret);
1001 return ret;
1002}
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012int generic_writepages(struct address_space *mapping,
1013 struct writeback_control *wbc)
1014{
1015
1016 if (!mapping->a_ops->writepage)
1017 return 0;
1018
1019 return write_cache_pages(mapping, wbc, __writepage, mapping);
1020}
1021
1022EXPORT_SYMBOL(generic_writepages);
1023
1024int do_writepages(struct address_space *mapping, struct writeback_control *wbc)
1025{
1026 int ret;
1027
1028 if (wbc->nr_to_write <= 0)
1029 return 0;
1030 if (mapping->a_ops->writepages)
1031 ret = mapping->a_ops->writepages(mapping, wbc);
1032 else
1033 ret = generic_writepages(mapping, wbc);
1034 return ret;
1035}
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046int write_one_page(struct page *page, int wait)
1047{
1048 struct address_space *mapping = page->mapping;
1049 int ret = 0;
1050 struct writeback_control wbc = {
1051 .sync_mode = WB_SYNC_ALL,
1052 .nr_to_write = 1,
1053 };
1054
1055 BUG_ON(!PageLocked(page));
1056
1057 if (wait)
1058 wait_on_page_writeback(page);
1059
1060 if (clear_page_dirty_for_io(page)) {
1061 page_cache_get(page);
1062 ret = mapping->a_ops->writepage(page, &wbc);
1063 if (ret == 0 && wait) {
1064 wait_on_page_writeback(page);
1065 if (PageError(page))
1066 ret = -EIO;
1067 }
1068 page_cache_release(page);
1069 } else {
1070 unlock_page(page);
1071 }
1072 return ret;
1073}
1074EXPORT_SYMBOL(write_one_page);
1075
1076
1077
1078
1079int __set_page_dirty_no_writeback(struct page *page)
1080{
1081 if (!PageDirty(page))
1082 SetPageDirty(page);
1083 return 0;
1084}
1085
1086
1087
1088
1089
1090void account_page_dirtied(struct page *page, struct address_space *mapping)
1091{
1092 if (mapping_cap_account_dirty(mapping)) {
1093 __inc_zone_page_state(page, NR_FILE_DIRTY);
1094 __inc_bdi_stat(mapping->backing_dev_info, BDI_RECLAIMABLE);
1095 task_dirty_inc(current);
1096 task_io_account_write(PAGE_CACHE_SIZE);
1097 }
1098}
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115int __set_page_dirty_nobuffers(struct page *page)
1116{
1117 if (!TestSetPageDirty(page)) {
1118 struct address_space *mapping = page_mapping(page);
1119 struct address_space *mapping2;
1120
1121 if (!mapping)
1122 return 1;
1123
1124 spin_lock_irq(&mapping->tree_lock);
1125 mapping2 = page_mapping(page);
1126 if (mapping2) {
1127 BUG_ON(mapping2 != mapping);
1128 WARN_ON_ONCE(!PagePrivate(page) && !PageUptodate(page));
1129 account_page_dirtied(page, mapping);
1130 radix_tree_tag_set(&mapping->page_tree,
1131 page_index(page), PAGECACHE_TAG_DIRTY);
1132 }
1133 spin_unlock_irq(&mapping->tree_lock);
1134 if (mapping->host) {
1135
1136 __mark_inode_dirty(mapping->host, I_DIRTY_PAGES);
1137 }
1138 return 1;
1139 }
1140 return 0;
1141}
1142EXPORT_SYMBOL(__set_page_dirty_nobuffers);
1143
1144
1145
1146
1147
1148
1149int redirty_page_for_writepage(struct writeback_control *wbc, struct page *page)
1150{
1151 wbc->pages_skipped++;
1152 return __set_page_dirty_nobuffers(page);
1153}
1154EXPORT_SYMBOL(redirty_page_for_writepage);
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167int set_page_dirty(struct page *page)
1168{
1169 struct address_space *mapping = page_mapping(page);
1170
1171 if (likely(mapping)) {
1172 int (*spd)(struct page *) = mapping->a_ops->set_page_dirty;
1173#ifdef CONFIG_BLOCK
1174 if (!spd)
1175 spd = __set_page_dirty_buffers;
1176#endif
1177 return (*spd)(page);
1178 }
1179 if (!PageDirty(page)) {
1180 if (!TestSetPageDirty(page))
1181 return 1;
1182 }
1183 return 0;
1184}
1185EXPORT_SYMBOL(set_page_dirty);
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197int set_page_dirty_lock(struct page *page)
1198{
1199 int ret;
1200
1201 lock_page_nosync(page);
1202 ret = set_page_dirty(page);
1203 unlock_page(page);
1204 return ret;
1205}
1206EXPORT_SYMBOL(set_page_dirty_lock);
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222int clear_page_dirty_for_io(struct page *page)
1223{
1224 struct address_space *mapping = page_mapping(page);
1225
1226 BUG_ON(!PageLocked(page));
1227
1228 ClearPageReclaim(page);
1229 if (mapping && mapping_cap_account_dirty(mapping)) {
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255 if (page_mkclean(page))
1256 set_page_dirty(page);
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267 if (TestClearPageDirty(page)) {
1268 dec_zone_page_state(page, NR_FILE_DIRTY);
1269 dec_bdi_stat(mapping->backing_dev_info,
1270 BDI_RECLAIMABLE);
1271 return 1;
1272 }
1273 return 0;
1274 }
1275 return TestClearPageDirty(page);
1276}
1277EXPORT_SYMBOL(clear_page_dirty_for_io);
1278
1279int test_clear_page_writeback(struct page *page)
1280{
1281 struct address_space *mapping = page_mapping(page);
1282 int ret;
1283
1284 if (mapping) {
1285 struct backing_dev_info *bdi = mapping->backing_dev_info;
1286 unsigned long flags;
1287
1288 spin_lock_irqsave(&mapping->tree_lock, flags);
1289 ret = TestClearPageWriteback(page);
1290 if (ret) {
1291 radix_tree_tag_clear(&mapping->page_tree,
1292 page_index(page),
1293 PAGECACHE_TAG_WRITEBACK);
1294 if (bdi_cap_account_writeback(bdi)) {
1295 __dec_bdi_stat(bdi, BDI_WRITEBACK);
1296 __bdi_writeout_inc(bdi);
1297 }
1298 }
1299 spin_unlock_irqrestore(&mapping->tree_lock, flags);
1300 } else {
1301 ret = TestClearPageWriteback(page);
1302 }
1303 if (ret)
1304 dec_zone_page_state(page, NR_WRITEBACK);
1305 return ret;
1306}
1307
1308int test_set_page_writeback(struct page *page)
1309{
1310 struct address_space *mapping = page_mapping(page);
1311 int ret;
1312
1313 if (mapping) {
1314 struct backing_dev_info *bdi = mapping->backing_dev_info;
1315 unsigned long flags;
1316
1317 spin_lock_irqsave(&mapping->tree_lock, flags);
1318 ret = TestSetPageWriteback(page);
1319 if (!ret) {
1320 radix_tree_tag_set(&mapping->page_tree,
1321 page_index(page),
1322 PAGECACHE_TAG_WRITEBACK);
1323 if (bdi_cap_account_writeback(bdi))
1324 __inc_bdi_stat(bdi, BDI_WRITEBACK);
1325 }
1326 if (!PageDirty(page))
1327 radix_tree_tag_clear(&mapping->page_tree,
1328 page_index(page),
1329 PAGECACHE_TAG_DIRTY);
1330 spin_unlock_irqrestore(&mapping->tree_lock, flags);
1331 } else {
1332 ret = TestSetPageWriteback(page);
1333 }
1334 if (!ret)
1335 inc_zone_page_state(page, NR_WRITEBACK);
1336 return ret;
1337
1338}
1339EXPORT_SYMBOL(test_set_page_writeback);
1340
1341
1342
1343
1344
1345int mapping_tagged(struct address_space *mapping, int tag)
1346{
1347 int ret;
1348 rcu_read_lock();
1349 ret = radix_tree_tagged(&mapping->page_tree, tag);
1350 rcu_read_unlock();
1351 return ret;
1352}
1353EXPORT_SYMBOL(mapping_tagged);
1354