/*
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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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#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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#define dprintk(args...) /* printf(args) */
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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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* 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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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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* 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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* 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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/* 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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/* 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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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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/* 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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|
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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/* 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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/* 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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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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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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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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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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static int terminal(int x)
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{
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return x & 1;
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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)
|
{
|
int n;
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__u32 w;
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__u64 t;
|
|
/* start at root */
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n = bucket->num_nodes >> 1;
|
|
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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/* 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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return bucket->h.items[n >> 1];
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}
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|
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/* straw */
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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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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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x++;
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/* normalize input */
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iexpon = 15;
|
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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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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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/* 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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result = iexpon;
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result <<= (12 + 32);
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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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LH = LH + LL;
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LH >>= (48 - 12 - 32);
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result += LH;
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|
return result;
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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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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)
|
{
|
if (!arg || !arg->weight_set)
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return bucket->item_weights;
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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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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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if (!arg || !arg->ids)
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return bucket->h.items;
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|
return arg->ids;
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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,
|
int position)
|
{
|
unsigned int i, high = 0;
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unsigned int u;
|
__s64 ln, draw, high_draw = 0;
|
__u32 *weights = get_choose_arg_weights(bucket, arg, position);
|
__s32 *ids = get_choose_arg_ids(bucket, arg);
|
|
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]) {
|
u = crush_hash32_3(bucket->h.hash, x, ids[i], r);
|
u &= 0xffff;
|
|
/*
|
* for some reason slightly less than 0x10000 produces
|
* a slightly more accurate distribution... probably a
|
* rounding effect.
|
*
|
* the natural log lookup table maps [0,0xffff]
|
* (corresponding to real numbers [1/0x10000, 1] to
|
* [0, 0xffffffffffff] (corresponding to real numbers
|
* [-11.090355,0]).
|
*/
|
ln = crush_ln(u) - 0x1000000000000ll;
|
|
/*
|
* divide by 16.16 fixed-point weight. note
|
* that the ln value is negative, so a larger
|
* weight means a larger (less negative) value
|
* for draw.
|
*/
|
draw = div64_s64(ln, weights[i]);
|
} else {
|
draw = S64_MIN;
|
}
|
|
if (i == 0 || draw > high_draw) {
|
high = i;
|
high_draw = draw;
|
}
|
}
|
|
return bucket->h.items[high];
|
}
|
|
|
static int crush_bucket_choose(const struct crush_bucket *in,
|
struct crush_work_bucket *work,
|
int x, int r,
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const struct crush_choose_arg *arg,
|
int position)
|
{
|
dprintk(" crush_bucket_choose %d x=%d r=%d\n", in->id, x, r);
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BUG_ON(in->size == 0);
|
switch (in->alg) {
|
case CRUSH_BUCKET_UNIFORM:
|
return bucket_uniform_choose(
|
(const struct crush_bucket_uniform *)in,
|
work, x, r);
|
case CRUSH_BUCKET_LIST:
|
return bucket_list_choose((const struct crush_bucket_list *)in,
|
x, r);
|
case CRUSH_BUCKET_TREE:
|
return bucket_tree_choose((const struct crush_bucket_tree *)in,
|
x, r);
|
case CRUSH_BUCKET_STRAW:
|
return bucket_straw_choose(
|
(const struct crush_bucket_straw *)in,
|
x, r);
|
case CRUSH_BUCKET_STRAW2:
|
return bucket_straw2_choose(
|
(const struct crush_bucket_straw2 *)in,
|
x, r, arg, position);
|
default:
|
dprintk("unknown bucket %d alg %d\n", in->id, in->alg);
|
return in->items[0];
|
}
|
}
|
|
/*
|
* true if device is marked "out" (failed, fully offloaded)
|
* of the cluster
|
*/
|
static int is_out(const struct crush_map *map,
|
const __u32 *weight, int weight_max,
|
int item, int x)
|
{
|
if (item >= weight_max)
|
return 1;
|
if (weight[item] >= 0x10000)
|
return 0;
|
if (weight[item] == 0)
|
return 1;
|
if ((crush_hash32_2(CRUSH_HASH_RJENKINS1, x, item) & 0xffff)
|
< weight[item])
|
return 0;
|
return 1;
|
}
|
|
/**
|
* crush_choose_firstn - choose numrep distinct items of given type
|
* @map: the crush_map
|
* @bucket: the bucket we are choose an item from
|
* @x: crush input value
|
* @numrep: the number of items to choose
|
* @type: the type of item to choose
|
* @out: pointer to output vector
|
* @outpos: our position in that vector
|
* @out_size: size of the out vector
|
* @tries: number of attempts to make
|
* @recurse_tries: number of attempts to have recursive chooseleaf make
|
* @local_retries: localized retries
|
* @local_fallback_retries: localized fallback retries
|
* @recurse_to_leaf: true if we want one device under each item of given type (chooseleaf instead of choose)
|
* @stable: stable mode starts rep=0 in the recursive call for all replicas
|
* @vary_r: pass r to recursive calls
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* @out2: second output vector for leaf items (if @recurse_to_leaf)
|
* @parent_r: r value passed from the parent
|
*/
|
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,
|
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,
|
unsigned int local_retries,
|
unsigned int local_fallback_retries,
|
int recurse_to_leaf,
|
unsigned int vary_r,
|
unsigned int stable,
|
int *out2,
|
int parent_r,
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const struct crush_choose_arg *choose_args)
|
{
|
int rep;
|
unsigned int ftotal, flocal;
|
int retry_descent, retry_bucket, skip_rep;
|
const struct crush_bucket *in = bucket;
|
int r;
|
int i;
|
int item = 0;
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int itemtype;
|
int collide, reject;
|
int count = out_size;
|
|
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" : "",
|
bucket->id, x, outpos, numrep,
|
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;
|
}
|
