+++ /dev/null
-/*
- * Ceph - scalable distributed file system
- *
- * Copyright (C) 2015 Intel Corporation All Rights Reserved
- *
- * This is free software; you can redistribute it and/or
- * modify it under the terms of the GNU Lesser General Public
- * License version 2.1, as published by the Free Software
- * Foundation. See file COPYING.
- *
- */
-
-#ifdef __KERNEL__
-# include <linux/string.h>
-# include <linux/slab.h>
-# include <linux/bug.h>
-# include <linux/kernel.h>
-# include <linux/crush/crush.h>
-# include <linux/crush/hash.h>
-#else
-# include "crush_compat.h"
-# include "crush.h"
-# include "hash.h"
-#endif
-#include "crush_ln_table.h"
-#include "mapper.h"
-
-#define dprintk(args...) /* printf(args) */
-
-/*
- * Implement the core CRUSH mapping algorithm.
- */
-
-/**
- * crush_find_rule - find a crush_rule id for a given ruleset, type, and size.
- * @map: the crush_map
- * @ruleset: the storage ruleset id (user defined)
- * @type: storage ruleset type (user defined)
- * @size: output set size
- */
-int crush_find_rule(const struct crush_map *map, int ruleset, int type, int size)
-{
- __u32 i;
-
- for (i = 0; i < map->max_rules; i++) {
- if (map->rules[i] &&
- map->rules[i]->mask.ruleset == ruleset &&
- map->rules[i]->mask.type == type &&
- map->rules[i]->mask.min_size <= size &&
- map->rules[i]->mask.max_size >= size)
- return i;
- }
- return -1;
-}
-
-/*
- * bucket choose methods
- *
- * For each bucket algorithm, we have a "choose" method that, given a
- * crush input @x and replica position (usually, position in output set) @r,
- * will produce an item in the bucket.
- */
-
-/*
- * Choose based on a random permutation of the bucket.
- *
- * We used to use some prime number arithmetic to do this, but it
- * wasn't very random, and had some other bad behaviors. Instead, we
- * calculate an actual random permutation of the bucket members.
- * Since this is expensive, we optimize for the r=0 case, which
- * captures the vast majority of calls.
- */
-static int bucket_perm_choose(const struct crush_bucket *bucket,
- struct crush_work_bucket *work,
- int x, int r)
-{
- unsigned int pr = r % bucket->size;
- unsigned int i, s;
-
- /* start a new permutation if @x has changed */
- if (work->perm_x != (__u32)x || work->perm_n == 0) {
- dprintk("bucket %d new x=%d\n", bucket->id, x);
- work->perm_x = x;
-
- /* optimize common r=0 case */
- if (pr == 0) {
- s = crush_hash32_3(bucket->hash, x, bucket->id, 0) %
- bucket->size;
- work->perm[0] = s;
- work->perm_n = 0xffff; /* magic value, see below */
- goto out;
- }
-
- for (i = 0; i < bucket->size; i++)
- work->perm[i] = i;
- work->perm_n = 0;
- } else if (work->perm_n == 0xffff) {
- /* clean up after the r=0 case above */
- for (i = 1; i < bucket->size; i++)
- work->perm[i] = i;
- work->perm[work->perm[0]] = 0;
- work->perm_n = 1;
- }
-
- /* calculate permutation up to pr */
- for (i = 0; i < work->perm_n; i++)
- dprintk(" perm_choose have %d: %d\n", i, work->perm[i]);
- while (work->perm_n <= pr) {
- unsigned int p = work->perm_n;
- /* no point in swapping the final entry */
- if (p < bucket->size - 1) {
- i = crush_hash32_3(bucket->hash, x, bucket->id, p) %
- (bucket->size - p);
- if (i) {
- unsigned int t = work->perm[p + i];
- work->perm[p + i] = work->perm[p];
- work->perm[p] = t;
- }
- dprintk(" perm_choose swap %d with %d\n", p, p+i);
- }
- work->perm_n++;
- }
- for (i = 0; i < bucket->size; i++)
- dprintk(" perm_choose %d: %d\n", i, work->perm[i]);
-
- s = work->perm[pr];
-out:
- dprintk(" perm_choose %d sz=%d x=%d r=%d (%d) s=%d\n", bucket->id,
- bucket->size, x, r, pr, s);
- return bucket->items[s];
-}
-
-/* uniform */
-static int bucket_uniform_choose(const struct crush_bucket_uniform *bucket,
- struct crush_work_bucket *work, int x, int r)
-{
- return bucket_perm_choose(&bucket->h, work, x, r);
-}
-
-/* list */
-static int bucket_list_choose(const struct crush_bucket_list *bucket,
- int x, int r)
-{
- int i;
-
- for (i = bucket->h.size-1; i >= 0; i--) {
- __u64 w = crush_hash32_4(bucket->h.hash, x, bucket->h.items[i],
- r, bucket->h.id);
- w &= 0xffff;
- dprintk("list_choose i=%d x=%d r=%d item %d weight %x "
- "sw %x rand %llx",
- i, x, r, bucket->h.items[i], bucket->item_weights[i],
- bucket->sum_weights[i], w);
- w *= bucket->sum_weights[i];
- w = w >> 16;
- /*dprintk(" scaled %llx\n", w);*/
- if (w < bucket->item_weights[i]) {
- return bucket->h.items[i];
- }
- }
-
- dprintk("bad list sums for bucket %d\n", bucket->h.id);
- return bucket->h.items[0];
-}
-
-
-/* (binary) tree */
-static int height(int n)
-{
- int h = 0;
- while ((n & 1) == 0) {
- h++;
- n = n >> 1;
- }
- return h;
-}
-
-static int left(int x)
-{
- int h = height(x);
- return x - (1 << (h-1));
-}
-
-static int right(int x)
-{
- int h = height(x);
- return x + (1 << (h-1));
-}
-
-static int terminal(int x)
-{
- return x & 1;
-}
-
-static int bucket_tree_choose(const struct crush_bucket_tree *bucket,
- int x, int r)
-{
- int n;
- __u32 w;
- __u64 t;
-
- /* start at root */
- n = bucket->num_nodes >> 1;
-
- while (!terminal(n)) {
- int l;
- /* pick point in [0, w) */
- w = bucket->node_weights[n];
- t = (__u64)crush_hash32_4(bucket->h.hash, x, n, r,
- bucket->h.id) * (__u64)w;
- t = t >> 32;
-
- /* descend to the left or right? */
- l = left(n);
- if (t < bucket->node_weights[l])
- n = l;
- else
- n = right(n);
- }
-
- return bucket->h.items[n >> 1];
-}
-
-
-/* straw */
-
-static int bucket_straw_choose(const struct crush_bucket_straw *bucket,
- int x, int r)
-{
- __u32 i;
- int high = 0;
- __u64 high_draw = 0;
- __u64 draw;
-
- for (i = 0; i < bucket->h.size; i++) {
- draw = crush_hash32_3(bucket->h.hash, x, bucket->h.items[i], r);
- draw &= 0xffff;
- draw *= bucket->straws[i];
- if (i == 0 || draw > high_draw) {
- high = i;
- high_draw = draw;
- }
- }
- return bucket->h.items[high];
-}
-
-/* compute 2^44*log2(input+1) */
-static __u64 crush_ln(unsigned int xin)
-{
- unsigned int x = xin;
- int iexpon, index1, index2;
- __u64 RH, LH, LL, xl64, result;
-
- x++;
-
- /* normalize input */
- iexpon = 15;
-
- // figure out number of bits we need to shift and
- // do it in one step instead of iteratively
- if (!(x & 0x18000)) {
- int bits = __builtin_clz(x & 0x1FFFF) - 16;
- x <<= bits;
- iexpon = 15 - bits;
- }
-
- index1 = (x >> 8) << 1;
- /* RH ~ 2^56/index1 */
- RH = __RH_LH_tbl[index1 - 256];
- /* LH ~ 2^48 * log2(index1/256) */
- LH = __RH_LH_tbl[index1 + 1 - 256];
-
- /* RH*x ~ 2^48 * (2^15 + xf), xf<2^8 */
- xl64 = (__s64)x * RH;
- xl64 >>= 48;
-
- result = iexpon;
- result <<= (12 + 32);
-
- index2 = xl64 & 0xff;
- /* LL ~ 2^48*log2(1.0+index2/2^15) */
- LL = __LL_tbl[index2];
-
- LH = LH + LL;
-
- LH >>= (48 - 12 - 32);
- result += LH;
-
- return result;
-}
-
-
-/*
- * straw2
- *
- * for reference, see:
- *
- * http://en.wikipedia.org/wiki/Exponential_distribution#Distribution_of_the_minimum_of_exponential_random_variables
- *
- */
-
-static inline __u32 *get_choose_arg_weights(const struct crush_bucket_straw2 *bucket,
- const struct crush_choose_arg *arg,
- int position)
-{
- if ((arg == NULL) ||
- (arg->weight_set == NULL))
- return bucket->item_weights;
- if (position >= arg->weight_set_size)
- position = arg->weight_set_size - 1;
- return arg->weight_set[position].weights;
-}
-
-static inline __s32 *get_choose_arg_ids(const struct crush_bucket_straw2 *bucket,
- const struct crush_choose_arg *arg)
-{
- if ((arg == NULL) || (arg->ids == NULL))
- return bucket->h.items;
- return arg->ids;
-}
-
-static int bucket_straw2_choose(const struct crush_bucket_straw2 *bucket,
- int x, int r, const struct crush_choose_arg *arg,
- int position)
-{
- unsigned int i, high = 0;
- 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++) {
- dprintk("weight 0x%x item %d\n", weights[i], ids[i]);
- 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,
- const struct crush_choose_arg *arg,
- int position)
-{
- dprintk(" crush_bucket_choose %d x=%d r=%d\n", in->id, x, r);
- 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
- * @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,
- struct crush_work *work,
- const struct crush_bucket *bucket,
- const __u32 *weight, int weight_max,
- int x, int numrep, int type,
- int *out, int outpos,
- int out_size,
- unsigned int tries,
- 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,
- 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;
- 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",
- 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] : 0),
- 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] : 0),
- 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. If you reinstitute the locking I've spent so much
- time getting rid of, I will be very unhappy with you. */
-
-void crush_init_workspace(const struct crush_map *m, void *v) {
- /* 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. */
- struct crush_work *w = (struct crush_work *)v;
- char *point = (char *)v;
- __s32 b;
- point += sizeof(struct crush_work);
- w->work = (struct crush_work_bucket **)point;
- point += m->max_buckets * sizeof(struct crush_work_bucket *);
- for (b = 0; b < m->max_buckets; ++b) {
- if (m->buckets[b] == 0)
- continue;
-
- w->work[b] = (struct crush_work_bucket *) point;
- switch (m->buckets[b]->alg) {
- default:
- point += sizeof(struct crush_work_bucket);
- break;
- }
- w->work[b]->perm_x = 0;
- w->work[b]->perm_n = 0;
- w->work[b]->perm = (__u32 *)point;
- point += m->buckets[b]->size * sizeof(__u32);
- }
- BUG_ON((char *)point - (char *)w != m->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 map->working_size bytes of memory or NULL.
- */
-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 = (int *)((char *)cw + 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;
- /* fall through */
- 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;
-}
Code Review / stor4nfv.git / blobdiff