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gro: Allow tunnel stacking in the case of FOU/GUE
[linux/fpc-iii.git] / net / ceph / crush / mapper.c
blob5b47736d27d94584bf33b2e60af56b5e76fc141c
1
2 #ifdef __KERNEL__
3 # include <linux/string.h>
4 # include <linux/slab.h>
5 # include <linux/bug.h>
6 # include <linux/kernel.h>
7 # ifndef dprintk
8 # define dprintk(args...)
9 # endif
10 #else
11 # include <string.h>
12 # include <stdio.h>
13 # include <stdlib.h>
14 # include <assert.h>
15 # define BUG_ON(x) assert(!(x))
16 # define dprintk(args...) /* printf(args) */
17 # define kmalloc(x, f) malloc(x)
18 # define kfree(x) free(x)
19 #endif
20
21 #include <linux/crush/crush.h>
22 #include <linux/crush/hash.h>
23 #include "crush_ln_table.h"
24
25 /*
26 * Implement the core CRUSH mapping algorithm.
27 */
28
29 /**
30 * crush_find_rule - find a crush_rule id for a given ruleset, type, and size.
31 * @map: the crush_map
32 * @ruleset: the storage ruleset id (user defined)
33 * @type: storage ruleset type (user defined)
34 * @size: output set size
35 */
36 int crush_find_rule(const struct crush_map *map, int ruleset, int type, int size)
37 {
38 __u32 i;
39
40 for (i = 0; i < map->max_rules; i++) {
41 if (map->rules[i] &&
42 map->rules[i]->mask.ruleset == ruleset &&
43 map->rules[i]->mask.type == type &&
44 map->rules[i]->mask.min_size <= size &&
45 map->rules[i]->mask.max_size >= size)
46 return i;
47 }
48 return -1;
49 }
50
51
52 /*
53 * bucket choose methods
54 *
55 * For each bucket algorithm, we have a "choose" method that, given a
56 * crush input @x and replica position (usually, position in output set) @r,
57 * will produce an item in the bucket.
58 */
59
60 /*
61 * Choose based on a random permutation of the bucket.
62 *
63 * We used to use some prime number arithmetic to do this, but it
64 * wasn't very random, and had some other bad behaviors. Instead, we
65 * calculate an actual random permutation of the bucket members.
66 * Since this is expensive, we optimize for the r=0 case, which
67 * captures the vast majority of calls.
68 */
69 static int bucket_perm_choose(struct crush_bucket *bucket,
70 int x, int r)
71 {
72 unsigned int pr = r % bucket->size;
73 unsigned int i, s;
74
75 /* start a new permutation if @x has changed */
76 if (bucket->perm_x != (__u32)x || bucket->perm_n == 0) {
77 dprintk("bucket %d new x=%d\n", bucket->id, x);
78 bucket->perm_x = x;
79
80 /* optimize common r=0 case */
81 if (pr == 0) {
82 s = crush_hash32_3(bucket->hash, x, bucket->id, 0) %
83 bucket->size;
84 bucket->perm[0] = s;
85 bucket->perm_n = 0xffff; /* magic value, see below */
86 goto out;
87 }
88
89 for (i = 0; i < bucket->size; i++)
90 bucket->perm[i] = i;
91 bucket->perm_n = 0;
92 } else if (bucket->perm_n == 0xffff) {
93 /* clean up after the r=0 case above */
94 for (i = 1; i < bucket->size; i++)
95 bucket->perm[i] = i;
96 bucket->perm[bucket->perm[0]] = 0;
97 bucket->perm_n = 1;
98 }
99
100 /* calculate permutation up to pr */
101 for (i = 0; i < bucket->perm_n; i++)
102 dprintk(" perm_choose have %d: %d\n", i, bucket->perm[i]);
103 while (bucket->perm_n <= pr) {
104 unsigned int p = bucket->perm_n;
105 /* no point in swapping the final entry */
106 if (p < bucket->size - 1) {
107 i = crush_hash32_3(bucket->hash, x, bucket->id, p) %
108 (bucket->size - p);
109 if (i) {
110 unsigned int t = bucket->perm[p + i];
111 bucket->perm[p + i] = bucket->perm[p];
112 bucket->perm[p] = t;
113 }
114 dprintk(" perm_choose swap %d with %d\n", p, p+i);
115 }
116 bucket->perm_n++;
117 }
118 for (i = 0; i < bucket->size; i++)
119 dprintk(" perm_choose %d: %d\n", i, bucket->perm[i]);
120
121 s = bucket->perm[pr];
122 out:
123 dprintk(" perm_choose %d sz=%d x=%d r=%d (%d) s=%d\n", bucket->id,
124 bucket->size, x, r, pr, s);
125 return bucket->items[s];
126 }
127
128 /* uniform */
129 static int bucket_uniform_choose(struct crush_bucket_uniform *bucket,
130 int x, int r)
131 {
132 return bucket_perm_choose(&bucket->h, x, r);
133 }
134
135 /* list */
136 static int bucket_list_choose(struct crush_bucket_list *bucket,
137 int x, int r)
138 {
139 int i;
140
141 for (i = bucket->h.size-1; i >= 0; i--) {
142 __u64 w = crush_hash32_4(bucket->h.hash,x, bucket->h.items[i],
143 r, bucket->h.id);
144 w &= 0xffff;
145 dprintk("list_choose i=%d x=%d r=%d item %d weight %x "
146 "sw %x rand %llx",
147 i, x, r, bucket->h.items[i], bucket->item_weights[i],
148 bucket->sum_weights[i], w);
149 w *= bucket->sum_weights[i];
150 w = w >> 16;
151 /*dprintk(" scaled %llx\n", w);*/
152 if (w < bucket->item_weights[i])
153 return bucket->h.items[i];
154 }
155
156 dprintk("bad list sums for bucket %d\n", bucket->h.id);
157 return bucket->h.items[0];
158 }
159
160
161 /* (binary) tree */
162 static int height(int n)
163 {
164 int h = 0;
165 while ((n & 1) == 0) {
166 h++;
167 n = n >> 1;
168 }
169 return h;
170 }
171
172 static int left(int x)
173 {
174 int h = height(x);
175 return x - (1 << (h-1));
176 }
177
178 static int right(int x)
179 {
180 int h = height(x);
181 return x + (1 << (h-1));
182 }
183
184 static int terminal(int x)
185 {
186 return x & 1;
187 }
188
189 static int bucket_tree_choose(struct crush_bucket_tree *bucket,
190 int x, int r)
191 {
192 int n;
193 __u32 w;
194 __u64 t;
195
196 /* start at root */
197 n = bucket->num_nodes >> 1;
198
199 while (!terminal(n)) {
200 int l;
201 /* pick point in [0, w) */
202 w = bucket->node_weights[n];
203 t = (__u64)crush_hash32_4(bucket->h.hash, x, n, r,
204 bucket->h.id) * (__u64)w;
205 t = t >> 32;
206
207 /* descend to the left or right? */
208 l = left(n);
209 if (t < bucket->node_weights[l])
210 n = l;
211 else
212 n = right(n);
213 }
214
215 return bucket->h.items[n >> 1];
216 }
217
218
219 /* straw */
220
221 static int bucket_straw_choose(struct crush_bucket_straw *bucket,
222 int x, int r)
223 {
224 __u32 i;
225 int high = 0;
226 __u64 high_draw = 0;
227 __u64 draw;
228
229 for (i = 0; i < bucket->h.size; i++) {
230 draw = crush_hash32_3(bucket->h.hash, x, bucket->h.items[i], r);
231 draw &= 0xffff;
232 draw *= bucket->straws[i];
233 if (i == 0 || draw > high_draw) {
234 high = i;
235 high_draw = draw;
236 }
237 }
238 return bucket->h.items[high];
239 }
240
241 // compute 2^44*log2(input+1)
242 uint64_t crush_ln(unsigned xin)
243 {
244 unsigned x=xin, x1;
245 int iexpon, index1, index2;
246 uint64_t RH, LH, LL, xl64, result;
247
248 x++;
249
250 // normalize input
251 iexpon = 15;
252 while(!(x&0x18000)) { x<<=1; iexpon--; }
253
254 index1 = (x>>8)<<1;
255 // RH ~ 2^56/index1
256 RH = __RH_LH_tbl[index1 - 256];
257 // LH ~ 2^48 * log2(index1/256)
258 LH = __RH_LH_tbl[index1 + 1 - 256];
259
260 // RH*x ~ 2^48 * (2^15 + xf), xf<2^8
261 xl64 = (int64_t)x * RH;
262 xl64 >>= 48;
263 x1 = xl64;
264
265 result = iexpon;
266 result <<= (12 + 32);
267
268 index2 = x1 & 0xff;
269 // LL ~ 2^48*log2(1.0+index2/2^15)
270 LL = __LL_tbl[index2];
271
272 LH = LH + LL;
273
274 LH >>= (48-12 - 32);
275 result += LH;
276
277 return result;
278 }
279
280
281 /*
282 * straw2
283 *
284 * for reference, see:
285 *
286 * http://en.wikipedia.org/wiki/Exponential_distribution#Distribution_of_the_minimum_of_exponential_random_variables
287 *
288 */
289
290 static int bucket_straw2_choose(struct crush_bucket_straw2 *bucket,
291 int x, int r)
292 {
293 unsigned i, high = 0;
294 unsigned u;
295 unsigned w;
296 __s64 ln, draw, high_draw = 0;
297
298 for (i = 0; i < bucket->h.size; i++) {
299 w = bucket->item_weights[i];
300 if (w) {
301 u = crush_hash32_3(bucket->h.hash, x,
302 bucket->h.items[i], r);
303 u &= 0xffff;
304
305 /*
306 * for some reason slightly less than 0x10000 produces
307 * a slightly more accurate distribution... probably a
308 * rounding effect.
309 *
310 * the natural log lookup table maps [0,0xffff]
311 * (corresponding to real numbers [1/0x10000, 1] to
312 * [0, 0xffffffffffff] (corresponding to real numbers
313 * [-11.090355,0]).
314 */
315 ln = crush_ln(u) - 0x1000000000000ll;
316
317 /*
318 * divide by 16.16 fixed-point weight. note
319 * that the ln value is negative, so a larger
320 * weight means a larger (less negative) value
321 * for draw.
322 */
323 draw = div64_s64(ln, w);
324 } else {
325 draw = S64_MIN;
326 }
327
328 if (i == 0 || draw > high_draw) {
329 high = i;
330 high_draw = draw;
331 }
332 }
333 return bucket->h.items[high];
334 }
335
336
337 static int crush_bucket_choose(struct crush_bucket *in, int x, int r)
338 {
339 dprintk(" crush_bucket_choose %d x=%d r=%d\n", in->id, x, r);
340 BUG_ON(in->size == 0);
341 switch (in->alg) {
342 case CRUSH_BUCKET_UNIFORM:
343 return bucket_uniform_choose((struct crush_bucket_uniform *)in,
344 x, r);
345 case CRUSH_BUCKET_LIST:
346 return bucket_list_choose((struct crush_bucket_list *)in,
347 x, r);
348 case CRUSH_BUCKET_TREE:
349 return bucket_tree_choose((struct crush_bucket_tree *)in,
350 x, r);
351 case CRUSH_BUCKET_STRAW:
352 return bucket_straw_choose((struct crush_bucket_straw *)in,
353 x, r);
354 case CRUSH_BUCKET_STRAW2:
355 return bucket_straw2_choose((struct crush_bucket_straw2 *)in,
356 x, r);
357 default:
358 dprintk("unknown bucket %d alg %d\n", in->id, in->alg);
359 return in->items[0];
360 }
361 }
362
363
364 /*
365 * true if device is marked "out" (failed, fully offloaded)
366 * of the cluster
367 */
368 static int is_out(const struct crush_map *map,
369 const __u32 *weight, int weight_max,
370 int item, int x)
371 {
372 if (item >= weight_max)
373 return 1;
374 if (weight[item] >= 0x10000)
375 return 0;
376 if (weight[item] == 0)
377 return 1;
378 if ((crush_hash32_2(CRUSH_HASH_RJENKINS1, x, item) & 0xffff)
379 < weight[item])
380 return 0;
381 return 1;
382 }
383
384 /**
385 * crush_choose_firstn - choose numrep distinct items of given type
386 * @map: the crush_map
387 * @bucket: the bucket we are choose an item from
388 * @x: crush input value
389 * @numrep: the number of items to choose
390 * @type: the type of item to choose
391 * @out: pointer to output vector
392 * @outpos: our position in that vector
393 * @out_size: size of the out vector
394 * @tries: number of attempts to make
395 * @recurse_tries: number of attempts to have recursive chooseleaf make
396 * @local_retries: localized retries
397 * @local_fallback_retries: localized fallback retries
398 * @recurse_to_leaf: true if we want one device under each item of given type (chooseleaf instead of choose)
399 * @vary_r: pass r to recursive calls
400 * @out2: second output vector for leaf items (if @recurse_to_leaf)
401 * @parent_r: r value passed from the parent
402 */
403 static int crush_choose_firstn(const struct crush_map *map,
404 struct crush_bucket *bucket,
405 const __u32 *weight, int weight_max,
406 int x, int numrep, int type,
407 int *out, int outpos,
408 int out_size,
409 unsigned int tries,
410 unsigned int recurse_tries,
411 unsigned int local_retries,
412 unsigned int local_fallback_retries,
413 int recurse_to_leaf,
414 unsigned int vary_r,
415 int *out2,
416 int parent_r)
417 {
418 int rep;
419 unsigned int ftotal, flocal;
420 int retry_descent, retry_bucket, skip_rep;
421 struct crush_bucket *in = bucket;
422 int r;
423 int i;
424 int item = 0;
425 int itemtype;
426 int collide, reject;
427 int count = out_size;
428
429 dprintk("CHOOSE%s bucket %d x %d outpos %d numrep %d tries %d recurse_tries %d local_retries %d local_fallback_retries %d parent_r %d\n",
430 recurse_to_leaf ? "_LEAF" : "",
431 bucket->id, x, outpos, numrep,
432 tries, recurse_tries, local_retries, local_fallback_retries,
433 parent_r);
434
435 for (rep = outpos; rep < numrep && count > 0 ; rep++) {
436 /* keep trying until we get a non-out, non-colliding item */
437 ftotal = 0;
438 skip_rep = 0;
439 do {
440 retry_descent = 0;
441 in = bucket; /* initial bucket */
442
443 /* choose through intervening buckets */
444 flocal = 0;
445 do {
446 collide = 0;
447 retry_bucket = 0;
448 r = rep + parent_r;
449 /* r' = r + f_total */
450 r += ftotal;
451
452 /* bucket choose */
453 if (in->size == 0) {
454 reject = 1;
455 goto reject;
456 }
457 if (local_fallback_retries > 0 &&
458 flocal >= (in->size>>1) &&
459 flocal > local_fallback_retries)
460 item = bucket_perm_choose(in, x, r);
461 else
462 item = crush_bucket_choose(in, x, r);
463 if (item >= map->max_devices) {
464 dprintk(" bad item %d\n", item);
465 skip_rep = 1;
466 break;
467 }
468
469 /* desired type? */
470 if (item < 0)
471 itemtype = map->buckets[-1-item]->type;
472 else
473 itemtype = 0;
474 dprintk(" item %d type %d\n", item, itemtype);
475
476 /* keep going? */
477 if (itemtype != type) {
478 if (item >= 0 ||
479 (-1-item) >= map->max_buckets) {
480 dprintk(" bad item type %d\n", type);
481 skip_rep = 1;
482 break;
483 }
484 in = map->buckets[-1-item];
485 retry_bucket = 1;
486 continue;
487 }
488
489 /* collision? */
490 for (i = 0; i < outpos; i++) {
491 if (out[i] == item) {
492 collide = 1;
493 break;
494 }
495 }
496
497 reject = 0;
498 if (!collide && recurse_to_leaf) {
499 if (item < 0) {
500 int sub_r;
501 if (vary_r)
502 sub_r = r >> (vary_r-1);
503 else
504 sub_r = 0;
505 if (crush_choose_firstn(map,
506 map->buckets[-1-item],
507 weight, weight_max,
508 x, outpos+1, 0,
509 out2, outpos, count,
510 recurse_tries, 0,
511 local_retries,
512 local_fallback_retries,
513 0,
514 vary_r,
515 NULL,
516 sub_r) <= outpos)
517 /* didn't get leaf */
518 reject = 1;
519 } else {
520 /* we already have a leaf! */
521 out2[outpos] = item;
522 }
523 }
524
525 if (!reject) {
526 /* out? */
527 if (itemtype == 0)
528 reject = is_out(map, weight,
529 weight_max,
530 item, x);
531 else
532 reject = 0;
533 }
534
535 reject:
536 if (reject || collide) {
537 ftotal++;
538 flocal++;
539
540 if (collide && flocal <= local_retries)
541 /* retry locally a few times */
542 retry_bucket = 1;
543 else if (local_fallback_retries > 0 &&
544 flocal <= in->size + local_fallback_retries)
545 /* exhaustive bucket search */
546 retry_bucket = 1;
547 else if (ftotal < tries)
548 /* then retry descent */
549 retry_descent = 1;
550 else
551 /* else give up */
552 skip_rep = 1;
553 dprintk(" reject %d collide %d "
554 "ftotal %u flocal %u\n",
555 reject, collide, ftotal,
556 flocal);
557 }
558 } while (retry_bucket);
559 } while (retry_descent);
560
561 if (skip_rep) {
562 dprintk("skip rep\n");
563 continue;
564 }
565
566 dprintk("CHOOSE got %d\n", item);
567 out[outpos] = item;
568 outpos++;
569 count--;
570 }
571
572 dprintk("CHOOSE returns %d\n", outpos);
573 return outpos;
574 }
575
576
577 /**
578 * crush_choose_indep: alternative breadth-first positionally stable mapping
579 *
580 */
581 static void crush_choose_indep(const struct crush_map *map,
582 struct crush_bucket *bucket,
583 const __u32 *weight, int weight_max,
584 int x, int left, int numrep, int type,
585 int *out, int outpos,
586 unsigned int tries,
587 unsigned int recurse_tries,
588 int recurse_to_leaf,
589 int *out2,
590 int parent_r)
591 {
592 struct crush_bucket *in = bucket;
593 int endpos = outpos + left;
594 int rep;
595 unsigned int ftotal;
596 int r;
597 int i;
598 int item = 0;
599 int itemtype;
600 int collide;
601
602 dprintk("CHOOSE%s INDEP bucket %d x %d outpos %d numrep %d\n", recurse_to_leaf ? "_LEAF" : "",
603 bucket->id, x, outpos, numrep);
604
605 /* initially my result is undefined */
606 for (rep = outpos; rep < endpos; rep++) {
607 out[rep] = CRUSH_ITEM_UNDEF;
608 if (out2)
609 out2[rep] = CRUSH_ITEM_UNDEF;
610 }
611
612 for (ftotal = 0; left > 0 && ftotal < tries; ftotal++) {
613 for (rep = outpos; rep < endpos; rep++) {
614 if (out[rep] != CRUSH_ITEM_UNDEF)
615 continue;
616
617 in = bucket; /* initial bucket */
618
619 /* choose through intervening buckets */
620 for (;;) {
621 /* note: we base the choice on the position
622 * even in the nested call. that means that
623 * if the first layer chooses the same bucket
624 * in a different position, we will tend to
625 * choose a different item in that bucket.
626 * this will involve more devices in data
627 * movement and tend to distribute the load.
628 */
629 r = rep + parent_r;
630
631 /* be careful */
632 if (in->alg == CRUSH_BUCKET_UNIFORM &&
633 in->size % numrep == 0)
634 /* r'=r+(n+1)*f_total */
635 r += (numrep+1) * ftotal;
636 else
637 /* r' = r + n*f_total */
638 r += numrep * ftotal;
639
640 /* bucket choose */
641 if (in->size == 0) {
642 dprintk(" empty bucket\n");
643 break;
644 }
645
646 item = crush_bucket_choose(in, x, r);
647 if (item >= map->max_devices) {
648 dprintk(" bad item %d\n", item);
649 out[rep] = CRUSH_ITEM_NONE;
650 if (out2)
651 out2[rep] = CRUSH_ITEM_NONE;
652 left--;
653 break;
654 }
655
656 /* desired type? */
657 if (item < 0)
658 itemtype = map->buckets[-1-item]->type;
659 else
660 itemtype = 0;
661 dprintk(" item %d type %d\n", item, itemtype);
662
663 /* keep going? */
664 if (itemtype != type) {
665 if (item >= 0 ||
666 (-1-item) >= map->max_buckets) {
667 dprintk(" bad item type %d\n", type);
668 out[rep] = CRUSH_ITEM_NONE;
669 if (out2)
670 out2[rep] =
671 CRUSH_ITEM_NONE;
672 left--;
673 break;
674 }
675 in = map->buckets[-1-item];
676 continue;
677 }
678
679 /* collision? */
680 collide = 0;
681 for (i = outpos; i < endpos; i++) {
682 if (out[i] == item) {
683 collide = 1;
684 break;
685 }
686 }
687 if (collide)
688 break;
689
690 if (recurse_to_leaf) {
691 if (item < 0) {
692 crush_choose_indep(map,
693 map->buckets[-1-item],
694 weight, weight_max,
695 x, 1, numrep, 0,
696 out2, rep,
697 recurse_tries, 0,
698 0, NULL, r);
699 if (out2[rep] == CRUSH_ITEM_NONE) {
700 /* placed nothing; no leaf */
701 break;
702 }
703 } else {
704 /* we already have a leaf! */
705 out2[rep] = item;
706 }
707 }
708
709 /* out? */
710 if (itemtype == 0 &&
711 is_out(map, weight, weight_max, item, x))
712 break;
713
714 /* yay! */
715 out[rep] = item;
716 left--;
717 break;
718 }
719 }
720 }
721 for (rep = outpos; rep < endpos; rep++) {
722 if (out[rep] == CRUSH_ITEM_UNDEF) {
723 out[rep] = CRUSH_ITEM_NONE;
724 }
725 if (out2 && out2[rep] == CRUSH_ITEM_UNDEF) {
726 out2[rep] = CRUSH_ITEM_NONE;
727 }
728 }
729 }
730
731 /**
732 * crush_do_rule - calculate a mapping with the given input and rule
733 * @map: the crush_map
734 * @ruleno: the rule id
735 * @x: hash input
736 * @result: pointer to result vector
737 * @result_max: maximum result size
738 * @weight: weight vector (for map leaves)
739 * @weight_max: size of weight vector
740 * @scratch: scratch vector for private use; must be >= 3 * result_max
741 */
742 int crush_do_rule(const struct crush_map *map,
743 int ruleno, int x, int *result, int result_max,
744 const __u32 *weight, int weight_max,
745 int *scratch)
746 {
747 int result_len;
748 int *a = scratch;
749 int *b = scratch + result_max;
750 int *c = scratch + result_max*2;
751 int recurse_to_leaf;
752 int *w;
753 int wsize = 0;
754 int *o;
755 int osize;
756 int *tmp;
757 struct crush_rule *rule;
758 __u32 step;
759 int i, j;
760 int numrep;
761 int out_size;
762 /*
763 * the original choose_total_tries value was off by one (it
764 * counted "retries" and not "tries"). add one.
765 */
766 int choose_tries = map->choose_total_tries + 1;
767 int choose_leaf_tries = 0;
768 /*
769 * the local tries values were counted as "retries", though,
770 * and need no adjustment
771 */
772 int choose_local_retries = map->choose_local_tries;
773 int choose_local_fallback_retries = map->choose_local_fallback_tries;
774
775 int vary_r = map->chooseleaf_vary_r;
776
777 if ((__u32)ruleno >= map->max_rules) {
778 dprintk(" bad ruleno %d\n", ruleno);
779 return 0;
780 }
781
782 rule = map->rules[ruleno];
783 result_len = 0;
784 w = a;
785 o = b;
786
787 for (step = 0; step < rule->len; step++) {
788 int firstn = 0;
789 struct crush_rule_step *curstep = &rule->steps[step];
790
791 switch (curstep->op) {
792 case CRUSH_RULE_TAKE:
793 w[0] = curstep->arg1;
794 wsize = 1;
795 break;
796
797 case CRUSH_RULE_SET_CHOOSE_TRIES:
798 if (curstep->arg1 > 0)
799 choose_tries = curstep->arg1;
800 break;
801
802 case CRUSH_RULE_SET_CHOOSELEAF_TRIES:
803 if (curstep->arg1 > 0)
804 choose_leaf_tries = curstep->arg1;
805 break;
806
807 case CRUSH_RULE_SET_CHOOSE_LOCAL_TRIES:
808 if (curstep->arg1 >= 0)
809 choose_local_retries = curstep->arg1;
810 break;
811
812 case CRUSH_RULE_SET_CHOOSE_LOCAL_FALLBACK_TRIES:
813 if (curstep->arg1 >= 0)
814 choose_local_fallback_retries = curstep->arg1;
815 break;
816
817 case CRUSH_RULE_SET_CHOOSELEAF_VARY_R:
818 if (curstep->arg1 >= 0)
819 vary_r = curstep->arg1;
820 break;
821
822 case CRUSH_RULE_CHOOSELEAF_FIRSTN:
823 case CRUSH_RULE_CHOOSE_FIRSTN:
824 firstn = 1;
825 /* fall through */
826 case CRUSH_RULE_CHOOSELEAF_INDEP:
827 case CRUSH_RULE_CHOOSE_INDEP:
828 if (wsize == 0)
829 break;
830
831 recurse_to_leaf =
832 curstep->op ==
833 CRUSH_RULE_CHOOSELEAF_FIRSTN ||
834 curstep->op ==
835 CRUSH_RULE_CHOOSELEAF_INDEP;
836
837 /* reset output */
838 osize = 0;
839
840 for (i = 0; i < wsize; i++) {
841 /*
842 * see CRUSH_N, CRUSH_N_MINUS macros.
843 * basically, numrep <= 0 means relative to
844 * the provided result_max
845 */
846 numrep = curstep->arg1;
847 if (numrep <= 0) {
848 numrep += result_max;
849 if (numrep <= 0)
850 continue;
851 }
852 j = 0;
853 if (firstn) {
854 int recurse_tries;
855 if (choose_leaf_tries)
856 recurse_tries =
857 choose_leaf_tries;
858 else if (map->chooseleaf_descend_once)
859 recurse_tries = 1;
860 else
861 recurse_tries = choose_tries;
862 osize += crush_choose_firstn(
863 map,
864 map->buckets[-1-w[i]],
865 weight, weight_max,
866 x, numrep,
867 curstep->arg2,
868 o+osize, j,
869 result_max-osize,
870 choose_tries,
871 recurse_tries,
872 choose_local_retries,
873 choose_local_fallback_retries,
874 recurse_to_leaf,
875 vary_r,
876 c+osize,
877 0);
878 } else {
879 out_size = ((numrep < (result_max-osize)) ?
880 numrep : (result_max-osize));
881 crush_choose_indep(
882 map,
883 map->buckets[-1-w[i]],
884 weight, weight_max,
885 x, out_size, numrep,
886 curstep->arg2,
887 o+osize, j,
888 choose_tries,
889 choose_leaf_tries ?
890 choose_leaf_tries : 1,
891 recurse_to_leaf,
892 c+osize,
893 0);
894 osize += out_size;
895 }
896 }
897
898 if (recurse_to_leaf)
899 /* copy final _leaf_ values to output set */
900 memcpy(o, c, osize*sizeof(*o));
901
902 /* swap o and w arrays */
903 tmp = o;
904 o = w;
905 w = tmp;
906 wsize = osize;
907 break;
908
909
910 case CRUSH_RULE_EMIT:
911 for (i = 0; i < wsize && result_len < result_max; i++) {
912 result[result_len] = w[i];
913 result_len++;
914 }
915 wsize = 0;
916 break;
917
918 default:
919 dprintk(" unknown op %d at step %d\n",
920 curstep->op, step);
921 break;
922 }
923 }
924 return result_len;
925 }
926
927
Linux with added FPC-III support