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27#include <linux/fs.h>
28#include <linux/types.h>
29#include <linux/highmem.h>
30#include <linux/bitops.h>
31#include <linux/list.h>
32
33#include <cluster/masklog.h>
34
35#include "ocfs2.h"
36#include "ocfs2_trace.h"
37
38#ifdef CONFIG_OCFS2_DEBUG_FS
39#define OCFS2_CHECK_RESERVATIONS
40#endif
41
42static DEFINE_SPINLOCK(resv_lock);
43
44#define OCFS2_MIN_RESV_WINDOW_BITS 8
45#define OCFS2_MAX_RESV_WINDOW_BITS 1024
46
47int ocfs2_dir_resv_allowed(struct ocfs2_super *osb)
48{
49 return (osb->osb_resv_level && osb->osb_dir_resv_level);
50}
51
52static unsigned int ocfs2_resv_window_bits(struct ocfs2_reservation_map *resmap,
53 struct ocfs2_alloc_reservation *resv)
54{
55 struct ocfs2_super *osb = resmap->m_osb;
56 unsigned int bits;
57
58 if (!(resv->r_flags & OCFS2_RESV_FLAG_DIR)) {
59
60 bits = 4 << osb->osb_resv_level;
61 } else {
62 bits = 4 << osb->osb_dir_resv_level;
63 }
64 return bits;
65}
66
67static inline unsigned int ocfs2_resv_end(struct ocfs2_alloc_reservation *resv)
68{
69 if (resv->r_len)
70 return resv->r_start + resv->r_len - 1;
71 return resv->r_start;
72}
73
74static inline int ocfs2_resv_empty(struct ocfs2_alloc_reservation *resv)
75{
76 return !!(resv->r_len == 0);
77}
78
79static inline int ocfs2_resmap_disabled(struct ocfs2_reservation_map *resmap)
80{
81 if (resmap->m_osb->osb_resv_level == 0)
82 return 1;
83 return 0;
84}
85
86static void ocfs2_dump_resv(struct ocfs2_reservation_map *resmap)
87{
88 struct ocfs2_super *osb = resmap->m_osb;
89 struct rb_node *node;
90 struct ocfs2_alloc_reservation *resv;
91 int i = 0;
92
93 mlog(ML_NOTICE, "Dumping resmap for device %s. Bitmap length: %u\n",
94 osb->dev_str, resmap->m_bitmap_len);
95
96 node = rb_first(&resmap->m_reservations);
97 while (node) {
98 resv = rb_entry(node, struct ocfs2_alloc_reservation, r_node);
99
100 mlog(ML_NOTICE, "start: %u\tend: %u\tlen: %u\tlast_start: %u"
101 "\tlast_len: %u\n", resv->r_start,
102 ocfs2_resv_end(resv), resv->r_len, resv->r_last_start,
103 resv->r_last_len);
104
105 node = rb_next(node);
106 i++;
107 }
108
109 mlog(ML_NOTICE, "%d reservations found. LRU follows\n", i);
110
111 i = 0;
112 list_for_each_entry(resv, &resmap->m_lru, r_lru) {
113 mlog(ML_NOTICE, "LRU(%d) start: %u\tend: %u\tlen: %u\t"
114 "last_start: %u\tlast_len: %u\n", i, resv->r_start,
115 ocfs2_resv_end(resv), resv->r_len, resv->r_last_start,
116 resv->r_last_len);
117
118 i++;
119 }
120}
121
122#ifdef OCFS2_CHECK_RESERVATIONS
123static int ocfs2_validate_resmap_bits(struct ocfs2_reservation_map *resmap,
124 int i,
125 struct ocfs2_alloc_reservation *resv)
126{
127 char *disk_bitmap = resmap->m_disk_bitmap;
128 unsigned int start = resv->r_start;
129 unsigned int end = ocfs2_resv_end(resv);
130
131 while (start <= end) {
132 if (ocfs2_test_bit(start, disk_bitmap)) {
133 mlog(ML_ERROR,
134 "reservation %d covers an allocated area "
135 "starting at bit %u!\n", i, start);
136 return 1;
137 }
138
139 start++;
140 }
141 return 0;
142}
143
144static void ocfs2_check_resmap(struct ocfs2_reservation_map *resmap)
145{
146 unsigned int off = 0;
147 int i = 0;
148 struct rb_node *node;
149 struct ocfs2_alloc_reservation *resv;
150
151 node = rb_first(&resmap->m_reservations);
152 while (node) {
153 resv = rb_entry(node, struct ocfs2_alloc_reservation, r_node);
154
155 if (i > 0 && resv->r_start <= off) {
156 mlog(ML_ERROR, "reservation %d has bad start off!\n",
157 i);
158 goto bad;
159 }
160
161 if (resv->r_len == 0) {
162 mlog(ML_ERROR, "reservation %d has no length!\n",
163 i);
164 goto bad;
165 }
166
167 if (resv->r_start > ocfs2_resv_end(resv)) {
168 mlog(ML_ERROR, "reservation %d has invalid range!\n",
169 i);
170 goto bad;
171 }
172
173 if (ocfs2_resv_end(resv) >= resmap->m_bitmap_len) {
174 mlog(ML_ERROR, "reservation %d extends past bitmap!\n",
175 i);
176 goto bad;
177 }
178
179 if (ocfs2_validate_resmap_bits(resmap, i, resv))
180 goto bad;
181
182 off = ocfs2_resv_end(resv);
183 node = rb_next(node);
184
185 i++;
186 }
187 return;
188
189bad:
190 ocfs2_dump_resv(resmap);
191 BUG();
192}
193#else
194static inline void ocfs2_check_resmap(struct ocfs2_reservation_map *resmap)
195{
196
197}
198#endif
199
200void ocfs2_resv_init_once(struct ocfs2_alloc_reservation *resv)
201{
202 memset(resv, 0, sizeof(*resv));
203 INIT_LIST_HEAD(&resv->r_lru);
204}
205
206void ocfs2_resv_set_type(struct ocfs2_alloc_reservation *resv,
207 unsigned int flags)
208{
209 BUG_ON(flags & ~OCFS2_RESV_TYPES);
210
211 resv->r_flags |= flags;
212}
213
214int ocfs2_resmap_init(struct ocfs2_super *osb,
215 struct ocfs2_reservation_map *resmap)
216{
217 memset(resmap, 0, sizeof(*resmap));
218
219 resmap->m_osb = osb;
220 resmap->m_reservations = RB_ROOT;
221
222 INIT_LIST_HEAD(&resmap->m_lru);
223
224 return 0;
225}
226
227static void ocfs2_resv_mark_lru(struct ocfs2_reservation_map *resmap,
228 struct ocfs2_alloc_reservation *resv)
229{
230 assert_spin_locked(&resv_lock);
231
232 if (!list_empty(&resv->r_lru))
233 list_del_init(&resv->r_lru);
234
235 list_add_tail(&resv->r_lru, &resmap->m_lru);
236}
237
238static void __ocfs2_resv_trunc(struct ocfs2_alloc_reservation *resv)
239{
240 resv->r_len = 0;
241 resv->r_start = 0;
242}
243
244static void ocfs2_resv_remove(struct ocfs2_reservation_map *resmap,
245 struct ocfs2_alloc_reservation *resv)
246{
247 if (resv->r_flags & OCFS2_RESV_FLAG_INUSE) {
248 list_del_init(&resv->r_lru);
249 rb_erase(&resv->r_node, &resmap->m_reservations);
250 resv->r_flags &= ~OCFS2_RESV_FLAG_INUSE;
251 }
252}
253
254static void __ocfs2_resv_discard(struct ocfs2_reservation_map *resmap,
255 struct ocfs2_alloc_reservation *resv)
256{
257 assert_spin_locked(&resv_lock);
258
259 __ocfs2_resv_trunc(resv);
260
261
262
263
264 resv->r_last_len = resv->r_last_start = 0;
265
266 ocfs2_resv_remove(resmap, resv);
267}
268
269
270void ocfs2_resv_discard(struct ocfs2_reservation_map *resmap,
271 struct ocfs2_alloc_reservation *resv)
272{
273 if (resv) {
274 spin_lock(&resv_lock);
275 __ocfs2_resv_discard(resmap, resv);
276 spin_unlock(&resv_lock);
277 }
278}
279
280static void ocfs2_resmap_clear_all_resv(struct ocfs2_reservation_map *resmap)
281{
282 struct rb_node *node;
283 struct ocfs2_alloc_reservation *resv;
284
285 assert_spin_locked(&resv_lock);
286
287 while ((node = rb_last(&resmap->m_reservations)) != NULL) {
288 resv = rb_entry(node, struct ocfs2_alloc_reservation, r_node);
289
290 __ocfs2_resv_discard(resmap, resv);
291 }
292}
293
294void ocfs2_resmap_restart(struct ocfs2_reservation_map *resmap,
295 unsigned int clen, char *disk_bitmap)
296{
297 if (ocfs2_resmap_disabled(resmap))
298 return;
299
300 spin_lock(&resv_lock);
301
302 ocfs2_resmap_clear_all_resv(resmap);
303 resmap->m_bitmap_len = clen;
304 resmap->m_disk_bitmap = disk_bitmap;
305
306 spin_unlock(&resv_lock);
307}
308
309void ocfs2_resmap_uninit(struct ocfs2_reservation_map *resmap)
310{
311
312}
313
314static void ocfs2_resv_insert(struct ocfs2_reservation_map *resmap,
315 struct ocfs2_alloc_reservation *new)
316{
317 struct rb_root *root = &resmap->m_reservations;
318 struct rb_node *parent = NULL;
319 struct rb_node **p = &root->rb_node;
320 struct ocfs2_alloc_reservation *tmp;
321
322 assert_spin_locked(&resv_lock);
323
324 trace_ocfs2_resv_insert(new->r_start, new->r_len);
325
326 while (*p) {
327 parent = *p;
328
329 tmp = rb_entry(parent, struct ocfs2_alloc_reservation, r_node);
330
331 if (new->r_start < tmp->r_start) {
332 p = &(*p)->rb_left;
333
334
335
336
337
338 BUG_ON(ocfs2_resv_end(new) >= tmp->r_start);
339 } else if (new->r_start > ocfs2_resv_end(tmp)) {
340 p = &(*p)->rb_right;
341 } else {
342
343 mlog(ML_ERROR, "Duplicate reservation window!\n");
344 BUG();
345 }
346 }
347
348 rb_link_node(&new->r_node, parent, p);
349 rb_insert_color(&new->r_node, root);
350 new->r_flags |= OCFS2_RESV_FLAG_INUSE;
351
352 ocfs2_resv_mark_lru(resmap, new);
353
354 ocfs2_check_resmap(resmap);
355}
356
357
358
359
360
361
362
363
364
365
366static struct ocfs2_alloc_reservation *
367ocfs2_find_resv_lhs(struct ocfs2_reservation_map *resmap, unsigned int goal)
368{
369 struct ocfs2_alloc_reservation *resv = NULL;
370 struct ocfs2_alloc_reservation *prev_resv = NULL;
371 struct rb_node *node = resmap->m_reservations.rb_node;
372
373 assert_spin_locked(&resv_lock);
374
375 if (!node)
376 return NULL;
377
378 node = rb_first(&resmap->m_reservations);
379 while (node) {
380 resv = rb_entry(node, struct ocfs2_alloc_reservation, r_node);
381
382 if (resv->r_start <= goal && ocfs2_resv_end(resv) >= goal)
383 break;
384
385
386 if (resv->r_start > goal) {
387 resv = prev_resv;
388 break;
389 }
390
391 prev_resv = resv;
392 node = rb_next(node);
393 }
394
395 return resv;
396}
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414static int ocfs2_resmap_find_free_bits(struct ocfs2_reservation_map *resmap,
415 unsigned int wanted,
416 unsigned int search_start,
417 unsigned int search_len,
418 unsigned int *rstart,
419 unsigned int *rlen)
420{
421 void *bitmap = resmap->m_disk_bitmap;
422 unsigned int best_start, best_len = 0;
423 int offset, start, found;
424
425 trace_ocfs2_resmap_find_free_bits_begin(search_start, search_len,
426 wanted, resmap->m_bitmap_len);
427
428 found = best_start = best_len = 0;
429
430 start = search_start;
431 while ((offset = ocfs2_find_next_zero_bit(bitmap, resmap->m_bitmap_len,
432 start)) != -1) {
433
434 if (offset >= (search_start + search_len))
435 break;
436
437 if (offset == start) {
438
439 found++;
440
441 start++;
442 } else {
443
444 found = 1;
445 start = offset + 1;
446 }
447 if (found > best_len) {
448 best_len = found;
449 best_start = start - found;
450 }
451
452 if (found >= wanted)
453 break;
454 }
455
456 if (best_len == 0)
457 return 0;
458
459 if (best_len >= wanted)
460 best_len = wanted;
461
462 *rlen = best_len;
463 *rstart = best_start;
464
465 trace_ocfs2_resmap_find_free_bits_end(best_start, best_len);
466
467 return *rlen;
468}
469
470static void __ocfs2_resv_find_window(struct ocfs2_reservation_map *resmap,
471 struct ocfs2_alloc_reservation *resv,
472 unsigned int goal, unsigned int wanted)
473{
474 struct rb_root *root = &resmap->m_reservations;
475 unsigned int gap_start, gap_end, gap_len;
476 struct ocfs2_alloc_reservation *prev_resv, *next_resv;
477 struct rb_node *prev, *next;
478 unsigned int cstart, clen;
479 unsigned int best_start = 0, best_len = 0;
480
481
482
483
484
485
486
487
488
489 trace_ocfs2_resv_find_window_begin(resv->r_start, ocfs2_resv_end(resv),
490 goal, wanted, RB_EMPTY_ROOT(root));
491
492 assert_spin_locked(&resv_lock);
493
494 if (RB_EMPTY_ROOT(root)) {
495
496
497
498
499 clen = ocfs2_resmap_find_free_bits(resmap, wanted, goal,
500 resmap->m_bitmap_len - goal,
501 &cstart, &clen);
502
503
504
505
506
507 BUG_ON(goal == 0 && clen == 0);
508
509 if (clen == 0)
510 return;
511
512 resv->r_start = cstart;
513 resv->r_len = clen;
514
515 ocfs2_resv_insert(resmap, resv);
516 return;
517 }
518
519 prev_resv = ocfs2_find_resv_lhs(resmap, goal);
520
521 if (prev_resv == NULL) {
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537 next = rb_first(root);
538 next_resv = rb_entry(next, struct ocfs2_alloc_reservation,
539 r_node);
540
541
542
543
544
545 if (next_resv->r_start <= goal) {
546 mlog(ML_ERROR, "goal: %u next_resv: start %u len %u\n",
547 goal, next_resv->r_start, next_resv->r_len);
548 ocfs2_dump_resv(resmap);
549 BUG();
550 }
551
552 clen = ocfs2_resmap_find_free_bits(resmap, wanted, goal,
553 next_resv->r_start - goal,
554 &cstart, &clen);
555 if (clen) {
556 best_len = clen;
557 best_start = cstart;
558 if (best_len == wanted)
559 goto out_insert;
560 }
561
562 prev_resv = next_resv;
563 next_resv = NULL;
564 }
565
566 trace_ocfs2_resv_find_window_prev(prev_resv->r_start,
567 ocfs2_resv_end(prev_resv));
568
569 prev = &prev_resv->r_node;
570
571
572 while (1) {
573 next = rb_next(prev);
574 if (next) {
575 next_resv = rb_entry(next,
576 struct ocfs2_alloc_reservation,
577 r_node);
578
579 gap_start = ocfs2_resv_end(prev_resv) + 1;
580 gap_end = next_resv->r_start - 1;
581 gap_len = gap_end - gap_start + 1;
582 } else {
583
584
585
586
587
588 gap_start = ocfs2_resv_end(prev_resv) + 1;
589 gap_len = resmap->m_bitmap_len - gap_start;
590 gap_end = resmap->m_bitmap_len - 1;
591 }
592
593 trace_ocfs2_resv_find_window_next(next ? next_resv->r_start: -1,
594 next ? ocfs2_resv_end(next_resv) : -1);
595
596
597
598
599 if (gap_len <= best_len)
600 goto next_resv;
601
602 clen = ocfs2_resmap_find_free_bits(resmap, wanted, gap_start,
603 gap_len, &cstart, &clen);
604 if (clen == wanted) {
605 best_len = clen;
606 best_start = cstart;
607 goto out_insert;
608 } else if (clen > best_len) {
609 best_len = clen;
610 best_start = cstart;
611 }
612
613next_resv:
614 if (!next)
615 break;
616
617 prev = next;
618 prev_resv = rb_entry(prev, struct ocfs2_alloc_reservation,
619 r_node);
620 }
621
622out_insert:
623 if (best_len) {
624 resv->r_start = best_start;
625 resv->r_len = best_len;
626 ocfs2_resv_insert(resmap, resv);
627 }
628}
629
630static void ocfs2_cannibalize_resv(struct ocfs2_reservation_map *resmap,
631 struct ocfs2_alloc_reservation *resv,
632 unsigned int wanted)
633{
634 struct ocfs2_alloc_reservation *lru_resv;
635 int tmpwindow = !!(resv->r_flags & OCFS2_RESV_FLAG_TMP);
636 unsigned int min_bits;
637
638 if (!tmpwindow)
639 min_bits = ocfs2_resv_window_bits(resmap, resv) >> 1;
640 else
641 min_bits = wanted;
642
643
644
645
646
647
648
649
650 lru_resv = list_first_entry(&resmap->m_lru,
651 struct ocfs2_alloc_reservation, r_lru);
652
653 trace_ocfs2_cannibalize_resv_begin(lru_resv->r_start,
654 lru_resv->r_len,
655 ocfs2_resv_end(lru_resv));
656
657
658
659
660
661 if (lru_resv->r_len <= min_bits) {
662
663
664
665
666
667 resv->r_start = lru_resv->r_start;
668 resv->r_len = lru_resv->r_len;
669
670 __ocfs2_resv_discard(resmap, lru_resv);
671 } else {
672 unsigned int shrink;
673 if (tmpwindow)
674 shrink = min_bits;
675 else
676 shrink = lru_resv->r_len / 2;
677
678 lru_resv->r_len -= shrink;
679
680 resv->r_start = ocfs2_resv_end(lru_resv) + 1;
681 resv->r_len = shrink;
682 }
683
684 trace_ocfs2_cannibalize_resv_end(resv->r_start, ocfs2_resv_end(resv),
685 resv->r_len, resv->r_last_start,
686 resv->r_last_len);
687
688 ocfs2_resv_insert(resmap, resv);
689}
690
691static void ocfs2_resv_find_window(struct ocfs2_reservation_map *resmap,
692 struct ocfs2_alloc_reservation *resv,
693 unsigned int wanted)
694{
695 unsigned int goal = 0;
696
697 BUG_ON(!ocfs2_resv_empty(resv));
698
699
700
701
702
703
704 if (resv->r_last_len) {
705 goal = resv->r_last_start + resv->r_last_len;
706 if (goal >= resmap->m_bitmap_len)
707 goal = 0;
708 }
709
710 __ocfs2_resv_find_window(resmap, resv, goal, wanted);
711
712
713 if (ocfs2_resv_empty(resv) && goal != 0)
714 __ocfs2_resv_find_window(resmap, resv, 0, wanted);
715
716 if (ocfs2_resv_empty(resv)) {
717
718
719
720
721 ocfs2_cannibalize_resv(resmap, resv, wanted);
722 }
723
724 BUG_ON(ocfs2_resv_empty(resv));
725}
726
727int ocfs2_resmap_resv_bits(struct ocfs2_reservation_map *resmap,
728 struct ocfs2_alloc_reservation *resv,
729 int *cstart, int *clen)
730{
731 if (resv == NULL || ocfs2_resmap_disabled(resmap))
732 return -ENOSPC;
733
734 spin_lock(&resv_lock);
735
736 if (ocfs2_resv_empty(resv)) {
737
738
739
740
741
742 unsigned int wanted = ocfs2_resv_window_bits(resmap, resv);
743
744 if ((resv->r_flags & OCFS2_RESV_FLAG_TMP) || wanted < *clen)
745 wanted = *clen;
746
747
748
749
750
751
752
753
754 ocfs2_resv_find_window(resmap, resv, wanted);
755 trace_ocfs2_resmap_resv_bits(resv->r_start, resv->r_len);
756 }
757
758 BUG_ON(ocfs2_resv_empty(resv));
759
760 *cstart = resv->r_start;
761 *clen = resv->r_len;
762
763 spin_unlock(&resv_lock);
764 return 0;
765}
766
767static void
768 ocfs2_adjust_resv_from_alloc(struct ocfs2_reservation_map *resmap,
769 struct ocfs2_alloc_reservation *resv,
770 unsigned int start, unsigned int end)
771{
772 unsigned int rhs = 0;
773 unsigned int old_end = ocfs2_resv_end(resv);
774
775 BUG_ON(start != resv->r_start || old_end < end);
776
777
778
779
780 if (old_end == end) {
781 __ocfs2_resv_discard(resmap, resv);
782 return;
783 }
784
785 rhs = old_end - end;
786
787
788
789
790 BUG_ON(rhs == 0);
791
792 resv->r_start = end + 1;
793 resv->r_len = old_end - resv->r_start + 1;
794}
795
796void ocfs2_resmap_claimed_bits(struct ocfs2_reservation_map *resmap,
797 struct ocfs2_alloc_reservation *resv,
798 u32 cstart, u32 clen)
799{
800 unsigned int cend = cstart + clen - 1;
801
802 if (resmap == NULL || ocfs2_resmap_disabled(resmap))
803 return;
804
805 if (resv == NULL)
806 return;
807
808 BUG_ON(cstart != resv->r_start);
809
810 spin_lock(&resv_lock);
811
812 trace_ocfs2_resmap_claimed_bits_begin(cstart, cend, clen, resv->r_start,
813 ocfs2_resv_end(resv), resv->r_len,
814 resv->r_last_start,
815 resv->r_last_len);
816
817 BUG_ON(cstart < resv->r_start);
818 BUG_ON(cstart > ocfs2_resv_end(resv));
819 BUG_ON(cend > ocfs2_resv_end(resv));
820
821 ocfs2_adjust_resv_from_alloc(resmap, resv, cstart, cend);
822 resv->r_last_start = cstart;
823 resv->r_last_len = clen;
824
825
826
827
828
829 if (!ocfs2_resv_empty(resv))
830 ocfs2_resv_mark_lru(resmap, resv);
831
832 trace_ocfs2_resmap_claimed_bits_end(resv->r_start, ocfs2_resv_end(resv),
833 resv->r_len, resv->r_last_start,
834 resv->r_last_len);
835
836 ocfs2_check_resmap(resmap);
837
838 spin_unlock(&resv_lock);
839}
840