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1099 lines
26 KiB
1099 lines
26 KiB
/* |
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* Ceph - scalable distributed file system |
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* |
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* Copyright (C) 2015 Intel Corporation All Rights Reserved |
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* |
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* This is free software; you can redistribute it and/or |
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* modify it under the terms of the GNU Lesser General Public |
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* License version 2.1, as published by the Free Software |
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* Foundation. See file COPYING. |
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* |
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*/ |
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|
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#ifdef __KERNEL__ |
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# include <linux/string.h> |
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# include <linux/slab.h> |
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# include <linux/bug.h> |
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# include <linux/kernel.h> |
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# include <linux/crush/crush.h> |
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# include <linux/crush/hash.h> |
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# include <linux/crush/mapper.h> |
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#else |
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# include "crush_compat.h" |
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# include "crush.h" |
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# include "hash.h" |
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# include "mapper.h" |
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#endif |
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#include "crush_ln_table.h" |
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|
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#define dprintk(args...) /* printf(args) */ |
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|
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/* |
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* Implement the core CRUSH mapping algorithm. |
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*/ |
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|
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/** |
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* crush_find_rule - find a crush_rule id for a given ruleset, type, and size. |
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* @map: the crush_map |
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* @ruleset: the storage ruleset id (user defined) |
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* @type: storage ruleset type (user defined) |
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* @size: output set size |
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*/ |
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int crush_find_rule(const struct crush_map *map, int ruleset, int type, int size) |
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{ |
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__u32 i; |
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|
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for (i = 0; i < map->max_rules; i++) { |
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if (map->rules[i] && |
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map->rules[i]->mask.ruleset == ruleset && |
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map->rules[i]->mask.type == type && |
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map->rules[i]->mask.min_size <= size && |
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map->rules[i]->mask.max_size >= size) |
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return i; |
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} |
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return -1; |
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} |
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|
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/* |
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* bucket choose methods |
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* |
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* For each bucket algorithm, we have a "choose" method that, given a |
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* crush input @x and replica position (usually, position in output set) @r, |
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* will produce an item in the bucket. |
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*/ |
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|
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/* |
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* Choose based on a random permutation of the bucket. |
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* |
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* We used to use some prime number arithmetic to do this, but it |
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* wasn't very random, and had some other bad behaviors. Instead, we |
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* calculate an actual random permutation of the bucket members. |
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* Since this is expensive, we optimize for the r=0 case, which |
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* captures the vast majority of calls. |
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*/ |
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static int bucket_perm_choose(const struct crush_bucket *bucket, |
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struct crush_work_bucket *work, |
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int x, int r) |
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{ |
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unsigned int pr = r % bucket->size; |
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unsigned int i, s; |
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|
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/* start a new permutation if @x has changed */ |
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if (work->perm_x != (__u32)x || work->perm_n == 0) { |
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dprintk("bucket %d new x=%d\n", bucket->id, x); |
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work->perm_x = x; |
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|
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/* optimize common r=0 case */ |
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if (pr == 0) { |
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s = crush_hash32_3(bucket->hash, x, bucket->id, 0) % |
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bucket->size; |
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work->perm[0] = s; |
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work->perm_n = 0xffff; /* magic value, see below */ |
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goto out; |
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} |
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|
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for (i = 0; i < bucket->size; i++) |
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work->perm[i] = i; |
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work->perm_n = 0; |
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} else if (work->perm_n == 0xffff) { |
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/* clean up after the r=0 case above */ |
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for (i = 1; i < bucket->size; i++) |
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work->perm[i] = i; |
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work->perm[work->perm[0]] = 0; |
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work->perm_n = 1; |
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} |
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|
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/* calculate permutation up to pr */ |
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for (i = 0; i < work->perm_n; i++) |
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dprintk(" perm_choose have %d: %d\n", i, work->perm[i]); |
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while (work->perm_n <= pr) { |
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unsigned int p = work->perm_n; |
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/* no point in swapping the final entry */ |
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if (p < bucket->size - 1) { |
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i = crush_hash32_3(bucket->hash, x, bucket->id, p) % |
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(bucket->size - p); |
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if (i) { |
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unsigned int t = work->perm[p + i]; |
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work->perm[p + i] = work->perm[p]; |
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work->perm[p] = t; |
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} |
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dprintk(" perm_choose swap %d with %d\n", p, p+i); |
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} |
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work->perm_n++; |
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} |
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for (i = 0; i < bucket->size; i++) |
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dprintk(" perm_choose %d: %d\n", i, work->perm[i]); |
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|
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s = work->perm[pr]; |
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out: |
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dprintk(" perm_choose %d sz=%d x=%d r=%d (%d) s=%d\n", bucket->id, |
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bucket->size, x, r, pr, s); |
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return bucket->items[s]; |
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} |
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|
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/* uniform */ |
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static int bucket_uniform_choose(const struct crush_bucket_uniform *bucket, |
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struct crush_work_bucket *work, int x, int r) |
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{ |
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return bucket_perm_choose(&bucket->h, work, x, r); |
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} |
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|
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/* list */ |
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static int bucket_list_choose(const struct crush_bucket_list *bucket, |
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int x, int r) |
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{ |
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int i; |
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|
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for (i = bucket->h.size-1; i >= 0; i--) { |
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__u64 w = crush_hash32_4(bucket->h.hash, x, bucket->h.items[i], |
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r, bucket->h.id); |
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w &= 0xffff; |
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dprintk("list_choose i=%d x=%d r=%d item %d weight %x " |
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"sw %x rand %llx", |
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i, x, r, bucket->h.items[i], bucket->item_weights[i], |
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bucket->sum_weights[i], w); |
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w *= bucket->sum_weights[i]; |
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w = w >> 16; |
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/*dprintk(" scaled %llx\n", w);*/ |
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if (w < bucket->item_weights[i]) { |
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return bucket->h.items[i]; |
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} |
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} |
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|
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dprintk("bad list sums for bucket %d\n", bucket->h.id); |
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return bucket->h.items[0]; |
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} |
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|
|
|
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/* (binary) tree */ |
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static int height(int n) |
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{ |
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int h = 0; |
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while ((n & 1) == 0) { |
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h++; |
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n = n >> 1; |
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} |
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return h; |
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} |
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|
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static int left(int x) |
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{ |
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int h = height(x); |
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return x - (1 << (h-1)); |
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} |
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|
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static int right(int x) |
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{ |
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int h = height(x); |
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return x + (1 << (h-1)); |
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} |
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|
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static int terminal(int x) |
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{ |
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return x & 1; |
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} |
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|
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static int bucket_tree_choose(const struct crush_bucket_tree *bucket, |
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int x, int r) |
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{ |
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int n; |
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__u32 w; |
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__u64 t; |
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|
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/* start at root */ |
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n = bucket->num_nodes >> 1; |
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|
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while (!terminal(n)) { |
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int l; |
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/* pick point in [0, w) */ |
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w = bucket->node_weights[n]; |
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t = (__u64)crush_hash32_4(bucket->h.hash, x, n, r, |
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bucket->h.id) * (__u64)w; |
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t = t >> 32; |
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|
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/* descend to the left or right? */ |
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l = left(n); |
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if (t < bucket->node_weights[l]) |
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n = l; |
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else |
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n = right(n); |
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} |
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|
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return bucket->h.items[n >> 1]; |
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} |
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|
|
|
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/* straw */ |
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|
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static int bucket_straw_choose(const struct crush_bucket_straw *bucket, |
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int x, int r) |
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{ |
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__u32 i; |
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int high = 0; |
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__u64 high_draw = 0; |
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__u64 draw; |
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|
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for (i = 0; i < bucket->h.size; i++) { |
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draw = crush_hash32_3(bucket->h.hash, x, bucket->h.items[i], r); |
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draw &= 0xffff; |
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draw *= bucket->straws[i]; |
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if (i == 0 || draw > high_draw) { |
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high = i; |
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high_draw = draw; |
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} |
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} |
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return bucket->h.items[high]; |
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} |
|
|
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/* compute 2^44*log2(input+1) */ |
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static __u64 crush_ln(unsigned int xin) |
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{ |
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unsigned int x = xin; |
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int iexpon, index1, index2; |
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__u64 RH, LH, LL, xl64, result; |
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|
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x++; |
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|
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/* normalize input */ |
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iexpon = 15; |
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|
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/* |
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* figure out number of bits we need to shift and |
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* do it in one step instead of iteratively |
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*/ |
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if (!(x & 0x18000)) { |
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int bits = __builtin_clz(x & 0x1FFFF) - 16; |
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x <<= bits; |
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iexpon = 15 - bits; |
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} |
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|
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index1 = (x >> 8) << 1; |
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/* RH ~ 2^56/index1 */ |
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RH = __RH_LH_tbl[index1 - 256]; |
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/* LH ~ 2^48 * log2(index1/256) */ |
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LH = __RH_LH_tbl[index1 + 1 - 256]; |
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|
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/* RH*x ~ 2^48 * (2^15 + xf), xf<2^8 */ |
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xl64 = (__s64)x * RH; |
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xl64 >>= 48; |
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|
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result = iexpon; |
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result <<= (12 + 32); |
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|
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index2 = xl64 & 0xff; |
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/* LL ~ 2^48*log2(1.0+index2/2^15) */ |
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LL = __LL_tbl[index2]; |
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|
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LH = LH + LL; |
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|
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LH >>= (48 - 12 - 32); |
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result += LH; |
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|
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return result; |
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} |
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|
|
|
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/* |
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* straw2 |
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* |
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* for reference, see: |
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* |
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* https://en.wikipedia.org/wiki/Exponential_distribution#Distribution_of_the_minimum_of_exponential_random_variables |
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* |
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*/ |
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|
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static __u32 *get_choose_arg_weights(const struct crush_bucket_straw2 *bucket, |
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const struct crush_choose_arg *arg, |
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int position) |
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{ |
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if (!arg || !arg->weight_set) |
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return bucket->item_weights; |
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|
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if (position >= arg->weight_set_size) |
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position = arg->weight_set_size - 1; |
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return arg->weight_set[position].weights; |
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} |
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|
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static __s32 *get_choose_arg_ids(const struct crush_bucket_straw2 *bucket, |
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const struct crush_choose_arg *arg) |
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{ |
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if (!arg || !arg->ids) |
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return bucket->h.items; |
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|
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return arg->ids; |
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} |
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|
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static int bucket_straw2_choose(const struct crush_bucket_straw2 *bucket, |
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int x, int r, |
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const struct crush_choose_arg *arg, |
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int position) |
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{ |
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unsigned int i, high = 0; |
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unsigned int u; |
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__s64 ln, draw, high_draw = 0; |
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__u32 *weights = get_choose_arg_weights(bucket, arg, position); |
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__s32 *ids = get_choose_arg_ids(bucket, arg); |
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|
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for (i = 0; i < bucket->h.size; i++) { |
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dprintk("weight 0x%x item %d\n", weights[i], ids[i]); |
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if (weights[i]) { |
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u = crush_hash32_3(bucket->h.hash, x, ids[i], r); |
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u &= 0xffff; |
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|
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/* |
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* for some reason slightly less than 0x10000 produces |
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* a slightly more accurate distribution... probably a |
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* rounding effect. |
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* |
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* the natural log lookup table maps [0,0xffff] |
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* (corresponding to real numbers [1/0x10000, 1] to |
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* [0, 0xffffffffffff] (corresponding to real numbers |
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* [-11.090355,0]). |
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*/ |
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ln = crush_ln(u) - 0x1000000000000ll; |
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|
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/* |
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* divide by 16.16 fixed-point weight. note |
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* that the ln value is negative, so a larger |
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* weight means a larger (less negative) value |
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* for draw. |
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*/ |
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draw = div64_s64(ln, weights[i]); |
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} else { |
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draw = S64_MIN; |
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} |
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|
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if (i == 0 || draw > high_draw) { |
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high = i; |
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high_draw = draw; |
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} |
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} |
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|
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return bucket->h.items[high]; |
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} |
|
|
|
|
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static int crush_bucket_choose(const struct crush_bucket *in, |
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struct crush_work_bucket *work, |
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int x, int r, |
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const struct crush_choose_arg *arg, |
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int position) |
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{ |
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dprintk(" crush_bucket_choose %d x=%d r=%d\n", in->id, x, r); |
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BUG_ON(in->size == 0); |
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switch (in->alg) { |
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case CRUSH_BUCKET_UNIFORM: |
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return bucket_uniform_choose( |
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(const struct crush_bucket_uniform *)in, |
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work, x, r); |
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case CRUSH_BUCKET_LIST: |
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return bucket_list_choose((const struct crush_bucket_list *)in, |
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x, r); |
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case CRUSH_BUCKET_TREE: |
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return bucket_tree_choose((const struct crush_bucket_tree *)in, |
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x, r); |
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case CRUSH_BUCKET_STRAW: |
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return bucket_straw_choose( |
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(const struct crush_bucket_straw *)in, |
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x, r); |
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case CRUSH_BUCKET_STRAW2: |
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return bucket_straw2_choose( |
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(const struct crush_bucket_straw2 *)in, |
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x, r, arg, position); |
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default: |
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dprintk("unknown bucket %d alg %d\n", in->id, in->alg); |
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return in->items[0]; |
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} |
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} |
|
|
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/* |
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* true if device is marked "out" (failed, fully offloaded) |
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* of the cluster |
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*/ |
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static int is_out(const struct crush_map *map, |
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const __u32 *weight, int weight_max, |
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int item, int x) |
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{ |
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if (item >= weight_max) |
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return 1; |
|
if (weight[item] >= 0x10000) |
|
return 0; |
|
if (weight[item] == 0) |
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return 1; |
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if ((crush_hash32_2(CRUSH_HASH_RJENKINS1, x, item) & 0xffff) |
|
< weight[item]) |
|
return 0; |
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return 1; |
|
} |
|
|
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/** |
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* crush_choose_firstn - choose numrep distinct items of given type |
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* @map: the crush_map |
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* @bucket: the bucket we are choose an item from |
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* @x: crush input value |
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* @numrep: the number of items to choose |
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* @type: the type of item to choose |
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* @out: pointer to output vector |
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* @outpos: our position in that vector |
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* @out_size: size of the out vector |
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* @tries: number of attempts to make |
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* @recurse_tries: number of attempts to have recursive chooseleaf make |
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* @local_retries: localized retries |
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* @local_fallback_retries: localized fallback retries |
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* @recurse_to_leaf: true if we want one device under each item of given type (chooseleaf instead of choose) |
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* @stable: stable mode starts rep=0 in the recursive call for all replicas |
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* @vary_r: pass r to recursive calls |
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* @out2: second output vector for leaf items (if @recurse_to_leaf) |
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* @parent_r: r value passed from the parent |
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*/ |
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static int crush_choose_firstn(const struct crush_map *map, |
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struct crush_work *work, |
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const struct crush_bucket *bucket, |
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const __u32 *weight, int weight_max, |
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int x, int numrep, int type, |
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int *out, int outpos, |
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int out_size, |
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unsigned int tries, |
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unsigned int recurse_tries, |
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unsigned int local_retries, |
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unsigned int local_fallback_retries, |
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int recurse_to_leaf, |
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unsigned int vary_r, |
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unsigned int stable, |
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int *out2, |
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int parent_r, |
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const struct crush_choose_arg *choose_args) |
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{ |
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int rep; |
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unsigned int ftotal, flocal; |
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int retry_descent, retry_bucket, skip_rep; |
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const struct crush_bucket *in = bucket; |
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int r; |
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int i; |
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int item = 0; |
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int itemtype; |
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int collide, reject; |
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int count = out_size; |
|
|
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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 stable %d\n", |
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recurse_to_leaf ? "_LEAF" : "", |
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bucket->id, x, outpos, numrep, |
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tries, recurse_tries, local_retries, local_fallback_retries, |
|
parent_r, stable); |
|
|
|
for (rep = stable ? 0 : outpos; rep < numrep && count > 0 ; rep++) { |
|
/* keep trying until we get a non-out, non-colliding item */ |
|
ftotal = 0; |
|
skip_rep = 0; |
|
do { |
|
retry_descent = 0; |
|
in = bucket; /* initial bucket */ |
|
|
|
/* choose through intervening buckets */ |
|
flocal = 0; |
|
do { |
|
collide = 0; |
|
retry_bucket = 0; |
|
r = rep + parent_r; |
|
/* r' = r + f_total */ |
|
r += ftotal; |
|
|
|
/* bucket choose */ |
|
if (in->size == 0) { |
|
reject = 1; |
|
goto reject; |
|
} |
|
if (local_fallback_retries > 0 && |
|
flocal >= (in->size>>1) && |
|
flocal > local_fallback_retries) |
|
item = bucket_perm_choose( |
|
in, work->work[-1-in->id], |
|
x, r); |
|
else |
|
item = crush_bucket_choose( |
|
in, work->work[-1-in->id], |
|
x, r, |
|
(choose_args ? |
|
&choose_args[-1-in->id] : NULL), |
|
outpos); |
|
if (item >= map->max_devices) { |
|
dprintk(" bad item %d\n", item); |
|
skip_rep = 1; |
|
break; |
|
} |
|
|
|
/* desired type? */ |
|
if (item < 0) |
|
itemtype = map->buckets[-1-item]->type; |
|
else |
|
itemtype = 0; |
|
dprintk(" item %d type %d\n", item, itemtype); |
|
|
|
/* keep going? */ |
|
if (itemtype != type) { |
|
if (item >= 0 || |
|
(-1-item) >= map->max_buckets) { |
|
dprintk(" bad item type %d\n", type); |
|
skip_rep = 1; |
|
break; |
|
} |
|
in = map->buckets[-1-item]; |
|
retry_bucket = 1; |
|
continue; |
|
} |
|
|
|
/* collision? */ |
|
for (i = 0; i < outpos; i++) { |
|
if (out[i] == item) { |
|
collide = 1; |
|
break; |
|
} |
|
} |
|
|
|
reject = 0; |
|
if (!collide && recurse_to_leaf) { |
|
if (item < 0) { |
|
int sub_r; |
|
if (vary_r) |
|
sub_r = r >> (vary_r-1); |
|
else |
|
sub_r = 0; |
|
if (crush_choose_firstn( |
|
map, |
|
work, |
|
map->buckets[-1-item], |
|
weight, weight_max, |
|
x, stable ? 1 : outpos+1, 0, |
|
out2, outpos, count, |
|
recurse_tries, 0, |
|
local_retries, |
|
local_fallback_retries, |
|
0, |
|
vary_r, |
|
stable, |
|
NULL, |
|
sub_r, |
|
choose_args) <= outpos) |
|
/* didn't get leaf */ |
|
reject = 1; |
|
} else { |
|
/* we already have a leaf! */ |
|
out2[outpos] = item; |
|
} |
|
} |
|
|
|
if (!reject && !collide) { |
|
/* out? */ |
|
if (itemtype == 0) |
|
reject = is_out(map, weight, |
|
weight_max, |
|
item, x); |
|
} |
|
|
|
reject: |
|
if (reject || collide) { |
|
ftotal++; |
|
flocal++; |
|
|
|
if (collide && flocal <= local_retries) |
|
/* retry locally a few times */ |
|
retry_bucket = 1; |
|
else if (local_fallback_retries > 0 && |
|
flocal <= in->size + local_fallback_retries) |
|
/* exhaustive bucket search */ |
|
retry_bucket = 1; |
|
else if (ftotal < tries) |
|
/* then retry descent */ |
|
retry_descent = 1; |
|
else |
|
/* else give up */ |
|
skip_rep = 1; |
|
dprintk(" reject %d collide %d " |
|
"ftotal %u flocal %u\n", |
|
reject, collide, ftotal, |
|
flocal); |
|
} |
|
} while (retry_bucket); |
|
} while (retry_descent); |
|
|
|
if (skip_rep) { |
|
dprintk("skip rep\n"); |
|
continue; |
|
} |
|
|
|
dprintk("CHOOSE got %d\n", item); |
|
out[outpos] = item; |
|
outpos++; |
|
count--; |
|
#ifndef __KERNEL__ |
|
if (map->choose_tries && ftotal <= map->choose_total_tries) |
|
map->choose_tries[ftotal]++; |
|
#endif |
|
} |
|
|
|
dprintk("CHOOSE returns %d\n", outpos); |
|
return outpos; |
|
} |
|
|
|
|
|
/** |
|
* crush_choose_indep: alternative breadth-first positionally stable mapping |
|
* |
|
*/ |
|
static void crush_choose_indep(const struct crush_map *map, |
|
struct crush_work *work, |
|
const struct crush_bucket *bucket, |
|
const __u32 *weight, int weight_max, |
|
int x, int left, int numrep, int type, |
|
int *out, int outpos, |
|
unsigned int tries, |
|
unsigned int recurse_tries, |
|
int recurse_to_leaf, |
|
int *out2, |
|
int parent_r, |
|
const struct crush_choose_arg *choose_args) |
|
{ |
|
const struct crush_bucket *in = bucket; |
|
int endpos = outpos + left; |
|
int rep; |
|
unsigned int ftotal; |
|
int r; |
|
int i; |
|
int item = 0; |
|
int itemtype; |
|
int collide; |
|
|
|
dprintk("CHOOSE%s INDEP bucket %d x %d outpos %d numrep %d\n", recurse_to_leaf ? "_LEAF" : "", |
|
bucket->id, x, outpos, numrep); |
|
|
|
/* initially my result is undefined */ |
|
for (rep = outpos; rep < endpos; rep++) { |
|
out[rep] = CRUSH_ITEM_UNDEF; |
|
if (out2) |
|
out2[rep] = CRUSH_ITEM_UNDEF; |
|
} |
|
|
|
for (ftotal = 0; left > 0 && ftotal < tries; ftotal++) { |
|
#ifdef DEBUG_INDEP |
|
if (out2 && ftotal) { |
|
dprintk("%u %d a: ", ftotal, left); |
|
for (rep = outpos; rep < endpos; rep++) { |
|
dprintk(" %d", out[rep]); |
|
} |
|
dprintk("\n"); |
|
dprintk("%u %d b: ", ftotal, left); |
|
for (rep = outpos; rep < endpos; rep++) { |
|
dprintk(" %d", out2[rep]); |
|
} |
|
dprintk("\n"); |
|
} |
|
#endif |
|
for (rep = outpos; rep < endpos; rep++) { |
|
if (out[rep] != CRUSH_ITEM_UNDEF) |
|
continue; |
|
|
|
in = bucket; /* initial bucket */ |
|
|
|
/* choose through intervening buckets */ |
|
for (;;) { |
|
/* note: we base the choice on the position |
|
* even in the nested call. that means that |
|
* if the first layer chooses the same bucket |
|
* in a different position, we will tend to |
|
* choose a different item in that bucket. |
|
* this will involve more devices in data |
|
* movement and tend to distribute the load. |
|
*/ |
|
r = rep + parent_r; |
|
|
|
/* be careful */ |
|
if (in->alg == CRUSH_BUCKET_UNIFORM && |
|
in->size % numrep == 0) |
|
/* r'=r+(n+1)*f_total */ |
|
r += (numrep+1) * ftotal; |
|
else |
|
/* r' = r + n*f_total */ |
|
r += numrep * ftotal; |
|
|
|
/* bucket choose */ |
|
if (in->size == 0) { |
|
dprintk(" empty bucket\n"); |
|
break; |
|
} |
|
|
|
item = crush_bucket_choose( |
|
in, work->work[-1-in->id], |
|
x, r, |
|
(choose_args ? |
|
&choose_args[-1-in->id] : NULL), |
|
outpos); |
|
if (item >= map->max_devices) { |
|
dprintk(" bad item %d\n", item); |
|
out[rep] = CRUSH_ITEM_NONE; |
|
if (out2) |
|
out2[rep] = CRUSH_ITEM_NONE; |
|
left--; |
|
break; |
|
} |
|
|
|
/* desired type? */ |
|
if (item < 0) |
|
itemtype = map->buckets[-1-item]->type; |
|
else |
|
itemtype = 0; |
|
dprintk(" item %d type %d\n", item, itemtype); |
|
|
|
/* keep going? */ |
|
if (itemtype != type) { |
|
if (item >= 0 || |
|
(-1-item) >= map->max_buckets) { |
|
dprintk(" bad item type %d\n", type); |
|
out[rep] = CRUSH_ITEM_NONE; |
|
if (out2) |
|
out2[rep] = |
|
CRUSH_ITEM_NONE; |
|
left--; |
|
break; |
|
} |
|
in = map->buckets[-1-item]; |
|
continue; |
|
} |
|
|
|
/* collision? */ |
|
collide = 0; |
|
for (i = outpos; i < endpos; i++) { |
|
if (out[i] == item) { |
|
collide = 1; |
|
break; |
|
} |
|
} |
|
if (collide) |
|
break; |
|
|
|
if (recurse_to_leaf) { |
|
if (item < 0) { |
|
crush_choose_indep( |
|
map, |
|
work, |
|
map->buckets[-1-item], |
|
weight, weight_max, |
|
x, 1, numrep, 0, |
|
out2, rep, |
|
recurse_tries, 0, |
|
0, NULL, r, |
|
choose_args); |
|
if (out2[rep] == CRUSH_ITEM_NONE) { |
|
/* placed nothing; no leaf */ |
|
break; |
|
} |
|
} else { |
|
/* we already have a leaf! */ |
|
out2[rep] = item; |
|
} |
|
} |
|
|
|
/* out? */ |
|
if (itemtype == 0 && |
|
is_out(map, weight, weight_max, item, x)) |
|
break; |
|
|
|
/* yay! */ |
|
out[rep] = item; |
|
left--; |
|
break; |
|
} |
|
} |
|
} |
|
for (rep = outpos; rep < endpos; rep++) { |
|
if (out[rep] == CRUSH_ITEM_UNDEF) { |
|
out[rep] = CRUSH_ITEM_NONE; |
|
} |
|
if (out2 && out2[rep] == CRUSH_ITEM_UNDEF) { |
|
out2[rep] = CRUSH_ITEM_NONE; |
|
} |
|
} |
|
#ifndef __KERNEL__ |
|
if (map->choose_tries && ftotal <= map->choose_total_tries) |
|
map->choose_tries[ftotal]++; |
|
#endif |
|
#ifdef DEBUG_INDEP |
|
if (out2) { |
|
dprintk("%u %d a: ", ftotal, left); |
|
for (rep = outpos; rep < endpos; rep++) { |
|
dprintk(" %d", out[rep]); |
|
} |
|
dprintk("\n"); |
|
dprintk("%u %d b: ", ftotal, left); |
|
for (rep = outpos; rep < endpos; rep++) { |
|
dprintk(" %d", out2[rep]); |
|
} |
|
dprintk("\n"); |
|
} |
|
#endif |
|
} |
|
|
|
|
|
/* |
|
* This takes a chunk of memory and sets it up to be a shiny new |
|
* working area for a CRUSH placement computation. It must be called |
|
* on any newly allocated memory before passing it in to |
|
* crush_do_rule. It may be used repeatedly after that, so long as the |
|
* map has not changed. If the map /has/ changed, you must make sure |
|
* the working size is no smaller than what was allocated and re-run |
|
* crush_init_workspace. |
|
* |
|
* If you do retain the working space between calls to crush, make it |
|
* thread-local. |
|
*/ |
|
void crush_init_workspace(const struct crush_map *map, void *v) |
|
{ |
|
struct crush_work *w = v; |
|
__s32 b; |
|
|
|
/* |
|
* We work by moving through the available space and setting |
|
* values and pointers as we go. |
|
* |
|
* It's a bit like Forth's use of the 'allot' word since we |
|
* set the pointer first and then reserve the space for it to |
|
* point to by incrementing the point. |
|
*/ |
|
v += sizeof(struct crush_work); |
|
w->work = v; |
|
v += map->max_buckets * sizeof(struct crush_work_bucket *); |
|
for (b = 0; b < map->max_buckets; ++b) { |
|
if (!map->buckets[b]) |
|
continue; |
|
|
|
w->work[b] = v; |
|
switch (map->buckets[b]->alg) { |
|
default: |
|
v += sizeof(struct crush_work_bucket); |
|
break; |
|
} |
|
w->work[b]->perm_x = 0; |
|
w->work[b]->perm_n = 0; |
|
w->work[b]->perm = v; |
|
v += map->buckets[b]->size * sizeof(__u32); |
|
} |
|
BUG_ON(v - (void *)w != map->working_size); |
|
} |
|
|
|
/** |
|
* crush_do_rule - calculate a mapping with the given input and rule |
|
* @map: the crush_map |
|
* @ruleno: the rule id |
|
* @x: hash input |
|
* @result: pointer to result vector |
|
* @result_max: maximum result size |
|
* @weight: weight vector (for map leaves) |
|
* @weight_max: size of weight vector |
|
* @cwin: pointer to at least crush_work_size() bytes of memory |
|
* @choose_args: weights and ids for each known bucket |
|
*/ |
|
int crush_do_rule(const struct crush_map *map, |
|
int ruleno, int x, int *result, int result_max, |
|
const __u32 *weight, int weight_max, |
|
void *cwin, const struct crush_choose_arg *choose_args) |
|
{ |
|
int result_len; |
|
struct crush_work *cw = cwin; |
|
int *a = cwin + map->working_size; |
|
int *b = a + result_max; |
|
int *c = b + result_max; |
|
int *w = a; |
|
int *o = b; |
|
int recurse_to_leaf; |
|
int wsize = 0; |
|
int osize; |
|
int *tmp; |
|
const struct crush_rule *rule; |
|
__u32 step; |
|
int i, j; |
|
int numrep; |
|
int out_size; |
|
/* |
|
* the original choose_total_tries value was off by one (it |
|
* counted "retries" and not "tries"). add one. |
|
*/ |
|
int choose_tries = map->choose_total_tries + 1; |
|
int choose_leaf_tries = 0; |
|
/* |
|
* the local tries values were counted as "retries", though, |
|
* and need no adjustment |
|
*/ |
|
int choose_local_retries = map->choose_local_tries; |
|
int choose_local_fallback_retries = map->choose_local_fallback_tries; |
|
|
|
int vary_r = map->chooseleaf_vary_r; |
|
int stable = map->chooseleaf_stable; |
|
|
|
if ((__u32)ruleno >= map->max_rules) { |
|
dprintk(" bad ruleno %d\n", ruleno); |
|
return 0; |
|
} |
|
|
|
rule = map->rules[ruleno]; |
|
result_len = 0; |
|
|
|
for (step = 0; step < rule->len; step++) { |
|
int firstn = 0; |
|
const struct crush_rule_step *curstep = &rule->steps[step]; |
|
|
|
switch (curstep->op) { |
|
case CRUSH_RULE_TAKE: |
|
if ((curstep->arg1 >= 0 && |
|
curstep->arg1 < map->max_devices) || |
|
(-1-curstep->arg1 >= 0 && |
|
-1-curstep->arg1 < map->max_buckets && |
|
map->buckets[-1-curstep->arg1])) { |
|
w[0] = curstep->arg1; |
|
wsize = 1; |
|
} else { |
|
dprintk(" bad take value %d\n", curstep->arg1); |
|
} |
|
break; |
|
|
|
case CRUSH_RULE_SET_CHOOSE_TRIES: |
|
if (curstep->arg1 > 0) |
|
choose_tries = curstep->arg1; |
|
break; |
|
|
|
case CRUSH_RULE_SET_CHOOSELEAF_TRIES: |
|
if (curstep->arg1 > 0) |
|
choose_leaf_tries = curstep->arg1; |
|
break; |
|
|
|
case CRUSH_RULE_SET_CHOOSE_LOCAL_TRIES: |
|
if (curstep->arg1 >= 0) |
|
choose_local_retries = curstep->arg1; |
|
break; |
|
|
|
case CRUSH_RULE_SET_CHOOSE_LOCAL_FALLBACK_TRIES: |
|
if (curstep->arg1 >= 0) |
|
choose_local_fallback_retries = curstep->arg1; |
|
break; |
|
|
|
case CRUSH_RULE_SET_CHOOSELEAF_VARY_R: |
|
if (curstep->arg1 >= 0) |
|
vary_r = curstep->arg1; |
|
break; |
|
|
|
case CRUSH_RULE_SET_CHOOSELEAF_STABLE: |
|
if (curstep->arg1 >= 0) |
|
stable = curstep->arg1; |
|
break; |
|
|
|
case CRUSH_RULE_CHOOSELEAF_FIRSTN: |
|
case CRUSH_RULE_CHOOSE_FIRSTN: |
|
firstn = 1; |
|
fallthrough; |
|
case CRUSH_RULE_CHOOSELEAF_INDEP: |
|
case CRUSH_RULE_CHOOSE_INDEP: |
|
if (wsize == 0) |
|
break; |
|
|
|
recurse_to_leaf = |
|
curstep->op == |
|
CRUSH_RULE_CHOOSELEAF_FIRSTN || |
|
curstep->op == |
|
CRUSH_RULE_CHOOSELEAF_INDEP; |
|
|
|
/* reset output */ |
|
osize = 0; |
|
|
|
for (i = 0; i < wsize; i++) { |
|
int bno; |
|
numrep = curstep->arg1; |
|
if (numrep <= 0) { |
|
numrep += result_max; |
|
if (numrep <= 0) |
|
continue; |
|
} |
|
j = 0; |
|
/* make sure bucket id is valid */ |
|
bno = -1 - w[i]; |
|
if (bno < 0 || bno >= map->max_buckets) { |
|
/* w[i] is probably CRUSH_ITEM_NONE */ |
|
dprintk(" bad w[i] %d\n", w[i]); |
|
continue; |
|
} |
|
if (firstn) { |
|
int recurse_tries; |
|
if (choose_leaf_tries) |
|
recurse_tries = |
|
choose_leaf_tries; |
|
else if (map->chooseleaf_descend_once) |
|
recurse_tries = 1; |
|
else |
|
recurse_tries = choose_tries; |
|
osize += crush_choose_firstn( |
|
map, |
|
cw, |
|
map->buckets[bno], |
|
weight, weight_max, |
|
x, numrep, |
|
curstep->arg2, |
|
o+osize, j, |
|
result_max-osize, |
|
choose_tries, |
|
recurse_tries, |
|
choose_local_retries, |
|
choose_local_fallback_retries, |
|
recurse_to_leaf, |
|
vary_r, |
|
stable, |
|
c+osize, |
|
0, |
|
choose_args); |
|
} else { |
|
out_size = ((numrep < (result_max-osize)) ? |
|
numrep : (result_max-osize)); |
|
crush_choose_indep( |
|
map, |
|
cw, |
|
map->buckets[bno], |
|
weight, weight_max, |
|
x, out_size, numrep, |
|
curstep->arg2, |
|
o+osize, j, |
|
choose_tries, |
|
choose_leaf_tries ? |
|
choose_leaf_tries : 1, |
|
recurse_to_leaf, |
|
c+osize, |
|
0, |
|
choose_args); |
|
osize += out_size; |
|
} |
|
} |
|
|
|
if (recurse_to_leaf) |
|
/* copy final _leaf_ values to output set */ |
|
memcpy(o, c, osize*sizeof(*o)); |
|
|
|
/* swap o and w arrays */ |
|
tmp = o; |
|
o = w; |
|
w = tmp; |
|
wsize = osize; |
|
break; |
|
|
|
|
|
case CRUSH_RULE_EMIT: |
|
for (i = 0; i < wsize && result_len < result_max; i++) { |
|
result[result_len] = w[i]; |
|
result_len++; |
|
} |
|
wsize = 0; |
|
break; |
|
|
|
default: |
|
dprintk(" unknown op %d at step %d\n", |
|
curstep->op, step); |
|
break; |
|
} |
|
} |
|
|
|
return result_len; |
|
}
|
|
|