summaryrefslogtreecommitdiff
path: root/fs/ceph/crush/mapper.c
diff options
context:
space:
mode:
Diffstat (limited to 'fs/ceph/crush/mapper.c')
-rw-r--r--fs/ceph/crush/mapper.c609
1 files changed, 0 insertions, 609 deletions
diff --git a/fs/ceph/crush/mapper.c b/fs/ceph/crush/mapper.c
deleted file mode 100644
index a4eec133258e..000000000000
--- a/fs/ceph/crush/mapper.c
+++ /dev/null
@@ -1,609 +0,0 @@
-
-#ifdef __KERNEL__
-# include <linux/string.h>
-# include <linux/slab.h>
-# include <linux/bug.h>
-# include <linux/kernel.h>
-# ifndef dprintk
-# define dprintk(args...)
-# endif
-#else
-# include <string.h>
-# include <stdio.h>
-# include <stdlib.h>
-# include <assert.h>
-# define BUG_ON(x) assert(!(x))
-# define dprintk(args...) /* printf(args) */
-# define kmalloc(x, f) malloc(x)
-# define kfree(x) free(x)
-#endif
-
-#include "crush.h"
-#include "hash.h"
-
-/*
- * 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(struct crush_map *map, int ruleset, int type, int size)
-{
- int 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(struct crush_bucket *bucket,
- int x, int r)
-{
- unsigned pr = r % bucket->size;
- unsigned i, s;
-
- /* start a new permutation if @x has changed */
- if (bucket->perm_x != x || bucket->perm_n == 0) {
- dprintk("bucket %d new x=%d\n", bucket->id, x);
- bucket->perm_x = x;
-
- /* optimize common r=0 case */
- if (pr == 0) {
- s = crush_hash32_3(bucket->hash, x, bucket->id, 0) %
- bucket->size;
- bucket->perm[0] = s;
- bucket->perm_n = 0xffff; /* magic value, see below */
- goto out;
- }
-
- for (i = 0; i < bucket->size; i++)
- bucket->perm[i] = i;
- bucket->perm_n = 0;
- } else if (bucket->perm_n == 0xffff) {
- /* clean up after the r=0 case above */
- for (i = 1; i < bucket->size; i++)
- bucket->perm[i] = i;
- bucket->perm[bucket->perm[0]] = 0;
- bucket->perm_n = 1;
- }
-
- /* calculate permutation up to pr */
- for (i = 0; i < bucket->perm_n; i++)
- dprintk(" perm_choose have %d: %d\n", i, bucket->perm[i]);
- while (bucket->perm_n <= pr) {
- unsigned p = bucket->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 t = bucket->perm[p + i];
- bucket->perm[p + i] = bucket->perm[p];
- bucket->perm[p] = t;
- }
- dprintk(" perm_choose swap %d with %d\n", p, p+i);
- }
- bucket->perm_n++;
- }
- for (i = 0; i < bucket->size; i++)
- dprintk(" perm_choose %d: %d\n", i, bucket->perm[i]);
-
- s = bucket->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(struct crush_bucket_uniform *bucket,
- int x, int r)
-{
- return bucket_perm_choose(&bucket->h, x, r);
-}
-
-/* list */
-static int bucket_list_choose(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];
- }
-
- BUG_ON(1);
- return 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(struct crush_bucket_tree *bucket,
- int x, int r)
-{
- int n, l;
- __u32 w;
- __u64 t;
-
- /* start at root */
- n = bucket->num_nodes >> 1;
-
- while (!terminal(n)) {
- /* 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(struct crush_bucket_straw *bucket,
- int x, int r)
-{
- int 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];
-}
-
-static int crush_bucket_choose(struct crush_bucket *in, int x, int r)
-{
- dprintk(" crush_bucket_choose %d x=%d r=%d\n", in->id, x, r);
- switch (in->alg) {
- case CRUSH_BUCKET_UNIFORM:
- return bucket_uniform_choose((struct crush_bucket_uniform *)in,
- x, r);
- case CRUSH_BUCKET_LIST:
- return bucket_list_choose((struct crush_bucket_list *)in,
- x, r);
- case CRUSH_BUCKET_TREE:
- return bucket_tree_choose((struct crush_bucket_tree *)in,
- x, r);
- case CRUSH_BUCKET_STRAW:
- return bucket_straw_choose((struct crush_bucket_straw *)in,
- x, r);
- default:
- BUG_ON(1);
- return in->items[0];
- }
-}
-
-/*
- * true if device is marked "out" (failed, fully offloaded)
- * of the cluster
- */
-static int is_out(struct crush_map *map, __u32 *weight, int item, int x)
-{
- 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 - 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
- * @firstn: true if choosing "first n" items, false if choosing "indep"
- * @recurse_to_leaf: true if we want one device under each item of given type
- * @out2: second output vector for leaf items (if @recurse_to_leaf)
- */
-static int crush_choose(struct crush_map *map,
- struct crush_bucket *bucket,
- __u32 *weight,
- int x, int numrep, int type,
- int *out, int outpos,
- int firstn, int recurse_to_leaf,
- int *out2)
-{
- int rep;
- int ftotal, flocal;
- int retry_descent, retry_bucket, skip_rep;
- struct crush_bucket *in = bucket;
- int r;
- int i;
- int item = 0;
- int itemtype;
- int collide, reject;
- const int orig_tries = 5; /* attempts before we fall back to search */
-
- dprintk("CHOOSE%s bucket %d x %d outpos %d numrep %d\n", recurse_to_leaf ? "_LEAF" : "",
- bucket->id, x, outpos, numrep);
-
- for (rep = outpos; rep < numrep; 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;
- if (in->alg == CRUSH_BUCKET_UNIFORM) {
- /* be careful */
- if (firstn || numrep >= in->size)
- /* r' = r + f_total */
- r += ftotal;
- else if (in->size % numrep == 0)
- /* r'=r+(n+1)*f_local */
- r += (numrep+1) *
- (flocal+ftotal);
- else
- /* r' = r + n*f_local */
- r += numrep * (flocal+ftotal);
- } else {
- if (firstn)
- /* r' = r + f_total */
- r += ftotal;
- else
- /* r' = r + n*f_local */
- r += numrep * (flocal+ftotal);
- }
-
- /* bucket choose */
- if (in->size == 0) {
- reject = 1;
- goto reject;
- }
- if (flocal >= (in->size>>1) &&
- flocal > orig_tries)
- item = bucket_perm_choose(in, x, r);
- else
- item = crush_bucket_choose(in, x, r);
- BUG_ON(item >= map->max_devices);
-
- /* 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) {
- BUG_ON(item >= 0 ||
- (-1-item) >= map->max_buckets);
- 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 (recurse_to_leaf) {
- if (item < 0) {
- if (crush_choose(map,
- map->buckets[-1-item],
- weight,
- x, outpos+1, 0,
- out2, outpos,
- firstn, 0,
- NULL) <= outpos)
- /* didn't get leaf */
- reject = 1;
- } else {
- /* we already have a leaf! */
- out2[outpos] = item;
- }
- }
-
- if (!reject) {
- /* out? */
- if (itemtype == 0)
- reject = is_out(map, weight,
- item, x);
- else
- reject = 0;
- }
-
-reject:
- if (reject || collide) {
- ftotal++;
- flocal++;
-
- if (collide && flocal < 3)
- /* retry locally a few times */
- retry_bucket = 1;
- else if (flocal < in->size + orig_tries)
- /* exhaustive bucket search */
- retry_bucket = 1;
- else if (ftotal < 20)
- /* then retry descent */
- retry_descent = 1;
- else
- /* else give up */
- skip_rep = 1;
- dprintk(" reject %d collide %d "
- "ftotal %d flocal %d\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++;
- }
-
- dprintk("CHOOSE returns %d\n", outpos);
- return outpos;
-}
-
-
-/**
- * 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
- * @force: force initial replica choice; -1 for none
- */
-int crush_do_rule(struct crush_map *map,
- int ruleno, int x, int *result, int result_max,
- int force, __u32 *weight)
-{
- int result_len;
- int force_context[CRUSH_MAX_DEPTH];
- int force_pos = -1;
- int a[CRUSH_MAX_SET];
- int b[CRUSH_MAX_SET];
- int c[CRUSH_MAX_SET];
- int recurse_to_leaf;
- int *w;
- int wsize = 0;
- int *o;
- int osize;
- int *tmp;
- struct crush_rule *rule;
- int step;
- int i, j;
- int numrep;
- int firstn;
- int rc = -1;
-
- BUG_ON(ruleno >= map->max_rules);
-
- rule = map->rules[ruleno];
- result_len = 0;
- w = a;
- o = b;
-
- /*
- * determine hierarchical context of force, if any. note
- * that this may or may not correspond to the specific types
- * referenced by the crush rule.
- */
- if (force >= 0) {
- if (force >= map->max_devices ||
- map->device_parents[force] == 0) {
- /*dprintk("CRUSH: forcefed device dne\n");*/
- rc = -1; /* force fed device dne */
- goto out;
- }
- if (!is_out(map, weight, force, x)) {
- while (1) {
- force_context[++force_pos] = force;
- if (force >= 0)
- force = map->device_parents[force];
- else
- force = map->bucket_parents[-1-force];
- if (force == 0)
- break;
- }
- }
- }
-
- for (step = 0; step < rule->len; step++) {
- firstn = 0;
- switch (rule->steps[step].op) {
- case CRUSH_RULE_TAKE:
- w[0] = rule->steps[step].arg1;
- if (force_pos >= 0) {
- BUG_ON(force_context[force_pos] != w[0]);
- force_pos--;
- }
- wsize = 1;
- break;
-
- case CRUSH_RULE_CHOOSE_LEAF_FIRSTN:
- case CRUSH_RULE_CHOOSE_FIRSTN:
- firstn = 1;
- case CRUSH_RULE_CHOOSE_LEAF_INDEP:
- case CRUSH_RULE_CHOOSE_INDEP:
- BUG_ON(wsize == 0);
-
- recurse_to_leaf =
- rule->steps[step].op ==
- CRUSH_RULE_CHOOSE_LEAF_FIRSTN ||
- rule->steps[step].op ==
- CRUSH_RULE_CHOOSE_LEAF_INDEP;
-
- /* reset output */
- osize = 0;
-
- for (i = 0; i < wsize; i++) {
- /*
- * see CRUSH_N, CRUSH_N_MINUS macros.
- * basically, numrep <= 0 means relative to
- * the provided result_max
- */
- numrep = rule->steps[step].arg1;
- if (numrep <= 0) {
- numrep += result_max;
- if (numrep <= 0)
- continue;
- }
- j = 0;
- if (osize == 0 && force_pos >= 0) {
- /* skip any intermediate types */
- while (force_pos &&
- force_context[force_pos] < 0 &&
- rule->steps[step].arg2 !=
- map->buckets[-1 -
- force_context[force_pos]]->type)
- force_pos--;
- o[osize] = force_context[force_pos];
- if (recurse_to_leaf)
- c[osize] = force_context[0];
- j++;
- force_pos--;
- }
- osize += crush_choose(map,
- map->buckets[-1-w[i]],
- weight,
- x, numrep,
- rule->steps[step].arg2,
- o+osize, j,
- firstn,
- recurse_to_leaf, c+osize);
- }
-
- if (recurse_to_leaf)
- /* copy final _leaf_ values to output set */
- memcpy(o, c, osize*sizeof(*o));
-
- /* swap t 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:
- BUG_ON(1);
- }
- }
- rc = result_len;
-
-out:
- return rc;
-}
-
-
generated by cgit v1.2.3 (git 2.39.0) at 2024-12-21 20:21:53 +0300