// SPDX-License-Identifier: GPL-2.0

#include <linux/ceph/ceph_debug.h>

#include <linux/module.h>
#include <linux/slab.h>

#include <linux/ceph/libceph.h>
#include <linux/ceph/osdmap.h>
#include <linux/ceph/decode.h>
#include <linux/crush/hash.h>
#include <linux/crush/mapper.h>

char *ceph_osdmap_state_str(char *str, int len, u32 state)
{
        if (!len)
                return str;

        if ((state & CEPH_OSD_EXISTS) && (state & CEPH_OSD_UP))
                snprintf(str, len, "exists, up");
        else if (state & CEPH_OSD_EXISTS)
                snprintf(str, len, "exists");
        else if (state & CEPH_OSD_UP)
                snprintf(str, len, "up");
        else
                snprintf(str, len, "doesn't exist");

        return str;
}

/* maps */

static int calc_bits_of(unsigned int t)
{
        int b = 0;
        while (t) {
                t = t >> 1;
                b++;
        }
        return b;
}

/*
 * the foo_mask is the smallest value 2^n-1 that is >= foo.
 */
static void calc_pg_masks(struct ceph_pg_pool_info *pi)
{
        pi->pg_num_mask = (1 << calc_bits_of(pi->pg_num-1)) - 1;
        pi->pgp_num_mask = (1 << calc_bits_of(pi->pgp_num-1)) - 1;
}

/*
 * decode crush map
 */
static int crush_decode_uniform_bucket(void **p, void *end,
                                       struct crush_bucket_uniform *b)
{
        dout("crush_decode_uniform_bucket %p to %p\n", *p, end);
        ceph_decode_need(p, end, (1+b->h.size) * sizeof(u32), bad);
        b->item_weight = ceph_decode_32(p);
        return 0;
bad:
        return -EINVAL;
}

static int crush_decode_list_bucket(void **p, void *end,
                                    struct crush_bucket_list *b)
{
        int j;
        dout("crush_decode_list_bucket %p to %p\n", *p, end);
        b->item_weights = kcalloc(b->h.size, sizeof(u32), GFP_NOFS);
        if (b->item_weights == NULL)
                return -ENOMEM;
        b->sum_weights = kcalloc(b->h.size, sizeof(u32), GFP_NOFS);
        if (b->sum_weights == NULL)
                return -ENOMEM;
        ceph_decode_need(p, end, 2 * b->h.size * sizeof(u32), bad);
        for (j = 0; j < b->h.size; j++) {
                b->item_weights[j] = ceph_decode_32(p);
                b->sum_weights[j] = ceph_decode_32(p);
        }
        return 0;
bad:
        return -EINVAL;
}

static int crush_decode_tree_bucket(void **p, void *end,
                                    struct crush_bucket_tree *b)
{
        int j;
        dout("crush_decode_tree_bucket %p to %p\n", *p, end);
        ceph_decode_8_safe(p, end, b->num_nodes, bad);
        b->node_weights = kcalloc(b->num_nodes, sizeof(u32), GFP_NOFS);
        if (b->node_weights == NULL)
                return -ENOMEM;
        ceph_decode_need(p, end, b->num_nodes * sizeof(u32), bad);
        for (j = 0; j < b->num_nodes; j++)
                b->node_weights[j] = ceph_decode_32(p);
        return 0;
bad:
        return -EINVAL;
}

static int crush_decode_straw_bucket(void **p, void *end,
                                     struct crush_bucket_straw *b)
{
        int j;
        dout("crush_decode_straw_bucket %p to %p\n", *p, end);
        b->item_weights = kcalloc(b->h.size, sizeof(u32), GFP_NOFS);
        if (b->item_weights == NULL)
                return -ENOMEM;
        b->straws = kcalloc(b->h.size, sizeof(u32), GFP_NOFS);
        if (b->straws == NULL)
                return -ENOMEM;
        ceph_decode_need(p, end, 2 * b->h.size * sizeof(u32), bad);
        for (j = 0; j < b->h.size; j++) {
                b->item_weights[j] = ceph_decode_32(p);
                b->straws[j] = ceph_decode_32(p);
        }
        return 0;
bad:
        return -EINVAL;
}

static int crush_decode_straw2_bucket(void **p, void *end,
                                      struct crush_bucket_straw2 *b)
{
        int j;
        dout("crush_decode_straw2_bucket %p to %p\n", *p, end);
        b->item_weights = kcalloc(b->h.size, sizeof(u32), GFP_NOFS);
        if (b->item_weights == NULL)
                return -ENOMEM;
        ceph_decode_need(p, end, b->h.size * sizeof(u32), bad);
        for (j = 0; j < b->h.size; j++)
                b->item_weights[j] = ceph_decode_32(p);
        return 0;
bad:
        return -EINVAL;
}

struct crush_name_node {
        struct rb_node cn_node;
        int cn_id;
        char cn_name[];
};

static struct crush_name_node *alloc_crush_name(size_t name_len)
{
        struct crush_name_node *cn;

        cn = kmalloc(sizeof(*cn) + name_len + 1, GFP_NOIO);
        if (!cn)
                return NULL;

        RB_CLEAR_NODE(&cn->cn_node);
        return cn;
}

static void free_crush_name(struct crush_name_node *cn)
{
        WARN_ON(!RB_EMPTY_NODE(&cn->cn_node));

        kfree(cn);
}

DEFINE_RB_FUNCS(crush_name, struct crush_name_node, cn_id, cn_node)

static int decode_crush_names(void **p, void *end, struct rb_root *root)
{
        u32 n;

        ceph_decode_32_safe(p, end, n, e_inval);
        while (n--) {
                struct crush_name_node *cn;
                int id;
                u32 name_len;

                ceph_decode_32_safe(p, end, id, e_inval);
                ceph_decode_32_safe(p, end, name_len, e_inval);
                ceph_decode_need(p, end, name_len, e_inval);

                cn = alloc_crush_name(name_len);
                if (!cn)
                        return -ENOMEM;

                cn->cn_id = id;
                memcpy(cn->cn_name, *p, name_len);
                cn->cn_name[name_len] = '\0';
                *p += name_len;

                if (!__insert_crush_name(root, cn)) {
                        free_crush_name(cn);
                        return -EEXIST;
                }
        }

        return 0;

e_inval:
        return -EINVAL;
}

void clear_crush_names(struct rb_root *root)
{
        while (!RB_EMPTY_ROOT(root)) {
                struct crush_name_node *cn =
                    rb_entry(rb_first(root), struct crush_name_node, cn_node);

                erase_crush_name(root, cn);
                free_crush_name(cn);
        }
}

static struct crush_choose_arg_map *alloc_choose_arg_map(void)
{
        struct crush_choose_arg_map *arg_map;

        arg_map = kzalloc(sizeof(*arg_map), GFP_NOIO);
        if (!arg_map)
                return NULL;

        RB_CLEAR_NODE(&arg_map->node);
        return arg_map;
}

static void free_choose_arg_map(struct crush_choose_arg_map *arg_map)
{
        if (arg_map) {
                int i, j;

                WARN_ON(!RB_EMPTY_NODE(&arg_map->node));

                for (i = 0; i < arg_map->size; i++) {
                        struct crush_choose_arg *arg = &arg_map->args[i];

                        for (j = 0; j < arg->weight_set_size; j++)
                                kfree(arg->weight_set[j].weights);
                        kfree(arg->weight_set);
                        kfree(arg->ids);
                }
                kfree(arg_map->args);
                kfree(arg_map);
        }
}

DEFINE_RB_FUNCS(choose_arg_map, struct crush_choose_arg_map, choose_args_index,
                node);

void clear_choose_args(struct crush_map *c)
{
        while (!RB_EMPTY_ROOT(&c->choose_args)) {
                struct crush_choose_arg_map *arg_map =
                    rb_entry(rb_first(&c->choose_args),
                             struct crush_choose_arg_map, node);

                erase_choose_arg_map(&c->choose_args, arg_map);
                free_choose_arg_map(arg_map);
        }
}

static u32 *decode_array_32_alloc(void **p, void *end, u32 *plen)
{
        u32 *a = NULL;
        u32 len;
        int ret;

        ceph_decode_32_safe(p, end, len, e_inval);
        if (len) {
                u32 i;

                a = kmalloc_array(len, sizeof(u32), GFP_NOIO);
                if (!a) {
                        ret = -ENOMEM;
                        goto fail;
                }

                ceph_decode_need(p, end, len * sizeof(u32), e_inval);
                for (i = 0; i < len; i++)
                        a[i] = ceph_decode_32(p);
        }

        *plen = len;
        return a;

e_inval:
        ret = -EINVAL;
fail:
        kfree(a);
        return ERR_PTR(ret);
}

/*
 * Assumes @arg is zero-initialized.
 */
static int decode_choose_arg(void **p, void *end, struct crush_choose_arg *arg)
{
        int ret;

        ceph_decode_32_safe(p, end, arg->weight_set_size, e_inval);
        if (arg->weight_set_size) {
                u32 i;

                arg->weight_set = kmalloc_array(arg->weight_set_size,
                                                sizeof(*arg->weight_set),
                                                GFP_NOIO);
                if (!arg->weight_set)
                        return -ENOMEM;

                for (i = 0; i < arg->weight_set_size; i++) {
                        struct crush_weight_set *w = &arg->weight_set[i];

                        w->weights = decode_array_32_alloc(p, end, &w->size);
                        if (IS_ERR(w->weights)) {
                                ret = PTR_ERR(w->weights);
                                w->weights = NULL;
                                return ret;
                        }
                }
        }

        arg->ids = decode_array_32_alloc(p, end, &arg->ids_size);
        if (IS_ERR(arg->ids)) {
                ret = PTR_ERR(arg->ids);
                arg->ids = NULL;
                return ret;
        }

        return 0;

e_inval:
        return -EINVAL;
}

static int decode_choose_args(void **p, void *end, struct crush_map *c)
{
        struct crush_choose_arg_map *arg_map = NULL;
        u32 num_choose_arg_maps, num_buckets;
        int ret;

        ceph_decode_32_safe(p, end, num_choose_arg_maps, e_inval);
        while (num_choose_arg_maps--) {
                arg_map = alloc_choose_arg_map();
                if (!arg_map) {
                        ret = -ENOMEM;
                        goto fail;
                }

                ceph_decode_64_safe(p, end, arg_map->choose_args_index,
                                    e_inval);
                arg_map->size = c->max_buckets;
                arg_map->args = kcalloc(arg_map->size, sizeof(*arg_map->args),
                                        GFP_NOIO);
                if (!arg_map->args) {
                        ret = -ENOMEM;
                        goto fail;
                }

                ceph_decode_32_safe(p, end, num_buckets, e_inval);
                while (num_buckets--) {
                        struct crush_choose_arg *arg;
                        u32 bucket_index;

                        ceph_decode_32_safe(p, end, bucket_index, e_inval);
                        if (bucket_index >= arg_map->size)
                                goto e_inval;

                        arg = &arg_map->args[bucket_index];
                        ret = decode_choose_arg(p, end, arg);
                        if (ret)
                                goto fail;

                        if (arg->ids_size &&
                            arg->ids_size != c->buckets[bucket_index]->size)
                                goto e_inval;
                }

                insert_choose_arg_map(&c->choose_args, arg_map);
        }

        return 0;

e_inval:
        ret = -EINVAL;
fail:
        free_choose_arg_map(arg_map);
        return ret;
}

static void crush_finalize(struct crush_map *c)
{
        __s32 b;

        /* Space for the array of pointers to per-bucket workspace */
        c->working_size = sizeof(struct crush_work) +
            c->max_buckets * sizeof(struct crush_work_bucket *);

        for (b = 0; b < c->max_buckets; b++) {
                if (!c->buckets[b])
                        continue;

                switch (c->buckets[b]->alg) {
                default:
                        /*
                         * The base case, permutation variables and
                         * the pointer to the permutation array.
                         */
                        c->working_size += sizeof(struct crush_work_bucket);
                        break;
                }
                /* Every bucket has a permutation array. */
                c->working_size += c->buckets[b]->size * sizeof(__u32);
        }
}

static struct crush_map *crush_decode(void *pbyval, void *end)
{
        struct crush_map *c;
        int err;
        int i, j;
        void **p = &pbyval;
        void *start = pbyval;
        u32 magic;

        dout("crush_decode %p to %p len %d\n", *p, end, (int)(end - *p));

        c = kzalloc(sizeof(*c), GFP_NOFS);
        if (c == NULL)
                return ERR_PTR(-ENOMEM);

        c->type_names = RB_ROOT;
        c->names = RB_ROOT;
        c->choose_args = RB_ROOT;

        /* set tunables to default values */
        c->choose_local_tries = 2;
        c->choose_local_fallback_tries = 5;
        c->choose_total_tries = 19;
        c->chooseleaf_descend_once = 0;

        ceph_decode_need(p, end, 4*sizeof(u32), bad);
        magic = ceph_decode_32(p);
        if (magic != CRUSH_MAGIC) {
                pr_err("crush_decode magic %x != current %x\n",
                       (unsigned int)magic, (unsigned int)CRUSH_MAGIC);
                goto bad;
        }
        c->max_buckets = ceph_decode_32(p);
        c->max_rules = ceph_decode_32(p);
        c->max_devices = ceph_decode_32(p);

        c->buckets = kcalloc(c->max_buckets, sizeof(*c->buckets), GFP_NOFS);
        if (c->buckets == NULL)
                goto badmem;
        c->rules = kcalloc(c->max_rules, sizeof(*c->rules), GFP_NOFS);
        if (c->rules == NULL)
                goto badmem;

        /* buckets */
        for (i = 0; i < c->max_buckets; i++) {
                int size = 0;
                u32 alg;
                struct crush_bucket *b;

                ceph_decode_32_safe(p, end, alg, bad);
                if (alg == 0) {
                        c->buckets[i] = NULL;
                        continue;
                }
                dout("crush_decode bucket %d off %x %p to %p\n",
                     i, (int)(*p-start), *p, end);

                switch (alg) {
                case CRUSH_BUCKET_UNIFORM:
                        size = sizeof(struct crush_bucket_uniform);
                        break;
                case CRUSH_BUCKET_LIST:
                        size = sizeof(struct crush_bucket_list);
                        break;
                case CRUSH_BUCKET_TREE:
                        size = sizeof(struct crush_bucket_tree);
                        break;
                case CRUSH_BUCKET_STRAW:
                        size = sizeof(struct crush_bucket_straw);
                        break;
                case CRUSH_BUCKET_STRAW2:
                        size = sizeof(struct crush_bucket_straw2);
                        break;
                default:
                        goto bad;
                }
                BUG_ON(size == 0);
                b = c->buckets[i] = kzalloc(size, GFP_NOFS);
                if (b == NULL)
                        goto badmem;

                ceph_decode_need(p, end, 4*sizeof(u32), bad);
                b->id = ceph_decode_32(p);
                b->type = ceph_decode_16(p);
                b->alg = ceph_decode_8(p);
                b->hash = ceph_decode_8(p);
                b->weight = ceph_decode_32(p);
                b->size = ceph_decode_32(p);

                dout("crush_decode bucket size %d off %x %p to %p\n",
                     b->size, (int)(*p-start), *p, end);

                b->items = kcalloc(b->size, sizeof(__s32), GFP_NOFS);
                if (b->items == NULL)
                        goto badmem;

                ceph_decode_need(p, end, b->size*sizeof(u32), bad);
                for (j = 0; j < b->size; j++)
                        b->items[j] = ceph_decode_32(p);

                switch (b->alg) {
                case CRUSH_BUCKET_UNIFORM:
                        err = crush_decode_uniform_bucket(p, end,
                                  (struct crush_bucket_uniform *)b);
                        if (err < 0)
                                goto fail;
                        break;
                case CRUSH_BUCKET_LIST:
                        err = crush_decode_list_bucket(p, end,
                               (struct crush_bucket_list *)b);
                        if (err < 0)
                                goto fail;
                        break;
                case CRUSH_BUCKET_TREE:
                        err = crush_decode_tree_bucket(p, end,
                                (struct crush_bucket_tree *)b);
                        if (err < 0)
                                goto fail;
                        break;
                case CRUSH_BUCKET_STRAW:
                        err = crush_decode_straw_bucket(p, end,
                                (struct crush_bucket_straw *)b);
                        if (err < 0)
                                goto fail;
                        break;
                case CRUSH_BUCKET_STRAW2:
                        err = crush_decode_straw2_bucket(p, end,
                                (struct crush_bucket_straw2 *)b);
                        if (err < 0)
                                goto fail;
                        break;
                }
        }

        /* rules */
        dout("rule vec is %p\n", c->rules);
        for (i = 0; i < c->max_rules; i++) {
                u32 yes;
                struct crush_rule *r;

                ceph_decode_32_safe(p, end, yes, bad);
                if (!yes) {
                        dout("crush_decode NO rule %d off %x %p to %p\n",
                             i, (int)(*p-start), *p, end);
                        c->rules[i] = NULL;
                        continue;
                }

                dout("crush_decode rule %d off %x %p to %p\n",
                     i, (int)(*p-start), *p, end);

                /* len */
                ceph_decode_32_safe(p, end, yes, bad);
#if BITS_PER_LONG == 32
                if (yes > (ULONG_MAX - sizeof(*r))
                          / sizeof(struct crush_rule_step))
                        goto bad;
#endif
                r = kmalloc(struct_size(r, steps, yes), GFP_NOFS);
                c->rules[i] = r;
                if (r == NULL)
                        goto badmem;
                dout(" rule %d is at %p\n", i, r);
                r->len = yes;
                ceph_decode_copy_safe(p, end, &r->mask, 4, bad); /* 4 u8's */
                ceph_decode_need(p, end, r->len*3*sizeof(u32), bad);
                for (j = 0; j < r->len; j++) {
                        r->steps[j].op = ceph_decode_32(p);
                        r->steps[j].arg1 = ceph_decode_32(p);
                        r->steps[j].arg2 = ceph_decode_32(p);
                }
        }

        err = decode_crush_names(p, end, &c->type_names);
        if (err)
                goto fail;

        err = decode_crush_names(p, end, &c->names);
        if (err)
                goto fail;

        ceph_decode_skip_map(p, end, 32, string, bad); /* rule_name_map */

        /* tunables */
        ceph_decode_need(p, end, 3*sizeof(u32), done);
        c->choose_local_tries = ceph_decode_32(p);
        c->choose_local_fallback_tries =  ceph_decode_32(p);
        c->choose_total_tries = ceph_decode_32(p);
        dout("crush decode tunable choose_local_tries = %d\n",
             c->choose_local_tries);
        dout("crush decode tunable choose_local_fallback_tries = %d\n",
             c->choose_local_fallback_tries);
        dout("crush decode tunable choose_total_tries = %d\n",
             c->choose_total_tries);

        ceph_decode_need(p, end, sizeof(u32), done);
        c->chooseleaf_descend_once = ceph_decode_32(p);
        dout("crush decode tunable chooseleaf_descend_once = %d\n",
             c->chooseleaf_descend_once);

        ceph_decode_need(p, end, sizeof(u8), done);
        c->chooseleaf_vary_r = ceph_decode_8(p);
        dout("crush decode tunable chooseleaf_vary_r = %d\n",
             c->chooseleaf_vary_r);

        /* skip straw_calc_version, allowed_bucket_algs */
        ceph_decode_need(p, end, sizeof(u8) + sizeof(u32), done);
        *p += sizeof(u8) + sizeof(u32);

        ceph_decode_need(p, end, sizeof(u8), done);
        c->chooseleaf_stable = ceph_decode_8(p);
        dout("crush decode tunable chooseleaf_stable = %d\n",
             c->chooseleaf_stable);

        if (*p != end) {
                /* class_map */
                ceph_decode_skip_map(p, end, 32, 32, bad);
                /* class_name */
                ceph_decode_skip_map(p, end, 32, string, bad);
                /* class_bucket */
                ceph_decode_skip_map_of_map(p, end, 32, 32, 32, bad);
        }

        if (*p != end) {
                err = decode_choose_args(p, end, c);
                if (err)
                        goto fail;
        }

done:
        crush_finalize(c);
        dout("crush_decode success\n");
        return c;

badmem:
        err = -ENOMEM;
fail:
        dout("crush_decode fail %d\n", err);
        crush_destroy(c);
        return ERR_PTR(err);

bad:
        err = -EINVAL;
        goto fail;
}

int ceph_pg_compare(const struct ceph_pg *lhs, const struct ceph_pg *rhs)
{
        if (lhs->pool < rhs->pool)
                return -1;
        if (lhs->pool > rhs->pool)
                return 1;
        if (lhs->seed < rhs->seed)
                return -1;
        if (lhs->seed > rhs->seed)
                return 1;

        return 0;
}

int ceph_spg_compare(const struct ceph_spg *lhs, const struct ceph_spg *rhs)
{
        int ret;

        ret = ceph_pg_compare(&lhs->pgid, &rhs->pgid);
        if (ret)
                return ret;

        if (lhs->shard < rhs->shard)
                return -1;
        if (lhs->shard > rhs->shard)
                return 1;

        return 0;
}

static struct ceph_pg_mapping *alloc_pg_mapping(size_t payload_len)
{
        struct ceph_pg_mapping *pg;

        pg = kmalloc(sizeof(*pg) + payload_len, GFP_NOIO);
        if (!pg)
                return NULL;

        RB_CLEAR_NODE(&pg->node);
        return pg;
}

static void free_pg_mapping(struct ceph_pg_mapping *pg)
{
        WARN_ON(!RB_EMPTY_NODE(&pg->node));

        kfree(pg);
}

/*
 * rbtree of pg_mapping for handling pg_temp (explicit mapping of pgid
 * to a set of osds) and primary_temp (explicit primary setting)
 */
DEFINE_RB_FUNCS2(pg_mapping, struct ceph_pg_mapping, pgid, ceph_pg_compare,
                 RB_BYPTR, const struct ceph_pg *, node)

/*
 * rbtree of pg pool info
 */
DEFINE_RB_FUNCS(pg_pool, struct ceph_pg_pool_info, id, node)

struct ceph_pg_pool_info *ceph_pg_pool_by_id(struct ceph_osdmap *map, u64 id)
{
        return lookup_pg_pool(&map->pg_pools, id);
}

const char *ceph_pg_pool_name_by_id(struct ceph_osdmap *map, u64 id)
{
        struct ceph_pg_pool_info *pi;

        if (id == CEPH_NOPOOL)
                return NULL;

        if (WARN_ON_ONCE(id > (u64) INT_MAX))
                return NULL;

        pi = lookup_pg_pool(&map->pg_pools, id);
        return pi ? pi->name : NULL;
}
EXPORT_SYMBOL(ceph_pg_pool_name_by_id);

int ceph_pg_poolid_by_name(struct ceph_osdmap *map, const char *name)
{
        struct rb_node *rbp;

        for (rbp = rb_first(&map->pg_pools); rbp; rbp = rb_next(rbp)) {
                struct ceph_pg_pool_info *pi =
                        rb_entry(rbp, struct ceph_pg_pool_info, node);
                if (pi->name && strcmp(pi->name, name) == 0)
                        return pi->id;
        }
        return -ENOENT;
}
EXPORT_SYMBOL(ceph_pg_poolid_by_name);

u64 ceph_pg_pool_flags(struct ceph_osdmap *map, u64 id)
{
        struct ceph_pg_pool_info *pi;

        pi = lookup_pg_pool(&map->pg_pools, id);
        return pi ? pi->flags : 0;
}
EXPORT_SYMBOL(ceph_pg_pool_flags);

static void __remove_pg_pool(struct rb_root *root, struct ceph_pg_pool_info *pi)
{
        erase_pg_pool(root, pi);
        kfree(pi->name);
        kfree(pi);
}

static int decode_pool(void **p, void *end, struct ceph_pg_pool_info *pi)
{
        u8 ev, cv;
        unsigned len, num;
        void *pool_end;

        ceph_decode_need(p, end, 2 + 4, bad);
        ev = ceph_decode_8(p);  /* encoding version */
        cv = ceph_decode_8(p); /* compat version */
        if (ev < 5) {
                pr_warn("got v %d < 5 cv %d of ceph_pg_pool\n", ev, cv);
                return -EINVAL;
        }
        if (cv > 9) {
                pr_warn("got v %d cv %d > 9 of ceph_pg_pool\n", ev, cv);
                return -EINVAL;
        }
        len = ceph_decode_32(p);
        ceph_decode_need(p, end, len, bad);
        pool_end = *p + len;

        pi->type = ceph_decode_8(p);
        pi->size = ceph_decode_8(p);
        pi->crush_ruleset = ceph_decode_8(p);
        pi->object_hash = ceph_decode_8(p);

        pi->pg_num = ceph_decode_32(p);
        pi->pgp_num = ceph_decode_32(p);

        *p += 4 + 4;  /* skip lpg* */
        *p += 4;      /* skip last_change */
        *p += 8 + 4;  /* skip snap_seq, snap_epoch */

        /* skip snaps */
        num = ceph_decode_32(p);
        while (num--) {
                *p += 8;  /* snapid key */
                *p += 1 + 1; /* versions */
                len = ceph_decode_32(p);
                *p += len;
        }

        /* skip removed_snaps */
        num = ceph_decode_32(p);
        *p += num * (8 + 8);

        *p += 8;  /* skip auid */
        pi->flags = ceph_decode_64(p);
        *p += 4;  /* skip crash_replay_interval */

        if (ev >= 7)
                pi->min_size = ceph_decode_8(p);
        else
                pi->min_size = pi->size - pi->size / 2;

        if (ev >= 8)
                *p += 8 + 8;  /* skip quota_max_* */

        if (ev >= 9) {
                /* skip tiers */
                num = ceph_decode_32(p);
                *p += num * 8;

                *p += 8;  /* skip tier_of */
                *p += 1;  /* skip cache_mode */

                pi->read_tier = ceph_decode_64(p);
                pi->write_tier = ceph_decode_64(p);
        } else {
                pi->read_tier = -1;
                pi->write_tier = -1;
        }

        if (ev >= 10) {
                /* skip properties */
                num = ceph_decode_32(p);
                while (num--) {
                        len = ceph_decode_32(p);
                        *p += len; /* key */
                        len = ceph_decode_32(p);
                        *p += len; /* val */
                }
        }

        if (ev >= 11) {
                /* skip hit_set_params */
                *p += 1 + 1; /* versions */
                len = ceph_decode_32(p);
                *p += len;

                *p += 4; /* skip hit_set_period */
                *p += 4; /* skip hit_set_count */
        }

        if (ev >= 12)
                *p += 4; /* skip stripe_width */

        if (ev >= 13) {
                *p += 8; /* skip target_max_bytes */
                *p += 8; /* skip target_max_objects */
                *p += 4; /* skip cache_target_dirty_ratio_micro */
                *p += 4; /* skip cache_target_full_ratio_micro */
                *p += 4; /* skip cache_min_flush_age */
                *p += 4; /* skip cache_min_evict_age */
        }

        if (ev >=  14) {
                /* skip erasure_code_profile */
                len = ceph_decode_32(p);
                *p += len;
        }

        /*
         * last_force_op_resend_preluminous, will be overridden if the
         * map was encoded with RESEND_ON_SPLIT
         */
        if (ev >= 15)
                pi->last_force_request_resend = ceph_decode_32(p);
        else
                pi->last_force_request_resend = 0;

        if (ev >= 16)
                *p += 4; /* skip min_read_recency_for_promote */

        if (ev >= 17)
                *p += 8; /* skip expected_num_objects */

        if (ev >= 19)
                *p += 4; /* skip cache_target_dirty_high_ratio_micro */

        if (ev >= 20)
                *p += 4; /* skip min_write_recency_for_promote */

        if (ev >= 21)
                *p += 1; /* skip use_gmt_hitset */

        if (ev >= 22)
                *p += 1; /* skip fast_read */

        if (ev >= 23) {
                *p += 4; /* skip hit_set_grade_decay_rate */
                *p += 4; /* skip hit_set_search_last_n */
        }

        if (ev >= 24) {
                /* skip opts */
                *p += 1 + 1; /* versions */
                len = ceph_decode_32(p);
                *p += len;
        }

        if (ev >= 25)
                pi->last_force_request_resend = ceph_decode_32(p);

        /* ignore the rest */

        *p = pool_end;
        calc_pg_masks(pi);
        return 0;

bad:
        return -EINVAL;
}

static int decode_pool_names(void **p, void *end, struct ceph_osdmap *map)
{
        struct ceph_pg_pool_info *pi;
        u32 num, len;
        u64 pool;

        ceph_decode_32_safe(p, end, num, bad);
        dout(" %d pool names\n", num);
        while (num--) {
                ceph_decode_64_safe(p, end, pool, bad);
                ceph_decode_32_safe(p, end, len, bad);
                dout("  pool %llu len %d\n", pool, len);
                ceph_decode_need(p, end, len, bad);
                pi = lookup_pg_pool(&map->pg_pools, pool);
                if (pi) {
                        char *name = kstrndup(*p, len, GFP_NOFS);

                        if (!name)
                                return -ENOMEM;
                        kfree(pi->name);
                        pi->name = name;
                        dout("  name is %s\n", pi->name);
                }
                *p += len;
        }
        return 0;

bad:
        return -EINVAL;
}

/*
 * CRUSH workspaces
 *
 * workspace_manager framework borrowed from fs/btrfs/compression.c.
 * Two simplifications: there is only one type of workspace and there
 * is always at least one workspace.
 */
static struct crush_work *alloc_workspace(const struct crush_map *c)
{
        struct crush_work *work;
        size_t work_size;

        WARN_ON(!c->working_size);
        work_size = crush_work_size(c, CEPH_PG_MAX_SIZE);
        dout("%s work_size %zu bytes\n", __func__, work_size);

        work = ceph_kvmalloc(work_size, GFP_NOIO);
        if (!work)
                return NULL;

        INIT_LIST_HEAD(&work->item);
        crush_init_workspace(c, work);
        return work;
}

static void free_workspace(struct crush_work *work)
{
        WARN_ON(!list_empty(&work->item));
        kvfree(work);
}

static void init_workspace_manager(struct workspace_manager *wsm)
{
        INIT_LIST_HEAD(&wsm->idle_ws);

        spin_lock_init(&wsm->ws_lock);
        atomic_set(&wsm->total_ws, 0);
        wsm->free_ws = 0;
        init_waitqueue_head(&wsm->ws_wait);
}

static void add_initial_workspace(struct workspace_manager *wsm,
                                  struct crush_work *work)
{
        WARN_ON(!list_empty(&wsm->idle_ws));

        list_add(&work->item, &wsm->idle_ws);
        atomic_set(&wsm->total_ws, 1);
        wsm->free_ws = 1;
}

static void cleanup_workspace_manager(struct workspace_manager *wsm)
{
        struct crush_work *work;

        while (!list_empty(&wsm->idle_ws)) {
                work = list_first_entry(&wsm->idle_ws, struct crush_work,
                                        item);
                list_del_init(&work->item);
                free_workspace(work);
        }
        atomic_set(&wsm->total_ws, 0);
        wsm->free_ws = 0;
}

/*
 * Finds an available workspace or allocates a new one.  If it's not
 * possible to allocate a new one, waits until there is one.
 */
static struct crush_work *get_workspace(struct workspace_manager *wsm,
                                        const struct crush_map *c)
{
        struct crush_work *work;
        int cpus = num_online_cpus();

again:
        spin_lock(&wsm->ws_lock);
        if (!list_empty(&wsm->idle_ws)) {
                work = list_first_entry(&wsm->idle_ws, struct crush_work,
                                        item);
                list_del_init(&work->item);
                wsm->free_ws--;
                spin_unlock(&wsm->ws_lock);
                return work;

        }
        if (atomic_read(&wsm->total_ws) > cpus) {
                DEFINE_WAIT(wait);

                spin_unlock(&wsm->ws_lock);
                prepare_to_wait(&wsm->ws_wait, &wait, TASK_UNINTERRUPTIBLE);
                if (atomic_read(&wsm->total_ws) > cpus && !wsm->free_ws)
                        schedule();
                finish_wait(&wsm->ws_wait, &wait);
                goto again;
        }
        atomic_inc(&wsm->total_ws);
        spin_unlock(&wsm->ws_lock);

        work = alloc_workspace(c);
        if (!work) {
                atomic_dec(&wsm->total_ws);
                wake_up(&wsm->ws_wait);

                /*
                 * Do not return the error but go back to waiting.  We
                 * have the initial workspace and the CRUSH computation
                 * time is bounded so we will get it eventually.
                 */
                WARN_ON(atomic_read(&wsm->total_ws) < 1);
                goto again;
        }
        return work;
}

/*
 * Puts a workspace back on the list or frees it if we have enough
 * idle ones sitting around.
 */
static void put_workspace(struct workspace_manager *wsm,
                          struct crush_work *work)
{
        spin_lock(&wsm->ws_lock);
        if (wsm->free_ws <= num_online_cpus()) {
                list_add(&work->item, &wsm->idle_ws);
                wsm->free_ws++;
                spin_unlock(&wsm->ws_lock);
                goto wake;
        }
        spin_unlock(&wsm->ws_lock);

        free_workspace(work);
        atomic_dec(&wsm->total_ws);
wake:
        if (wq_has_sleeper(&wsm->ws_wait))
                wake_up(&wsm->ws_wait);
}

/*
 * osd map
 */
struct ceph_osdmap *ceph_osdmap_alloc(void)
{
        struct ceph_osdmap *map;

        map = kzalloc(sizeof(*map), GFP_NOIO);
        if (!map)
                return NULL;

        map->pg_pools = RB_ROOT;
        map->pool_max = -1;
        map->pg_temp = RB_ROOT;
        map->primary_temp = RB_ROOT;
        map->pg_upmap = RB_ROOT;
        map->pg_upmap_items = RB_ROOT;

        init_workspace_manager(&map->crush_wsm);

        return map;
}

void ceph_osdmap_destroy(struct ceph_osdmap *map)
{
        dout("osdmap_destroy %p\n", map);

        if (map->crush)
                crush_destroy(map->crush);
        cleanup_workspace_manager(&map->crush_wsm);

        while (!RB_EMPTY_ROOT(&map->pg_temp)) {
                struct ceph_pg_mapping *pg =
                        rb_entry(rb_first(&map->pg_temp),
                                 struct ceph_pg_mapping, node);
                erase_pg_mapping(&map->pg_temp, pg);
                free_pg_mapping(pg);
        }
        while (!RB_EMPTY_ROOT(&map->primary_temp)) {
                struct ceph_pg_mapping *pg =
                        rb_entry(rb_first(&map->primary_temp),
                                 struct ceph_pg_mapping, node);
                erase_pg_mapping(&map->primary_temp, pg);
                free_pg_mapping(pg);
        }
        while (!RB_EMPTY_ROOT(&map->pg_upmap)) {
                struct ceph_pg_mapping *pg =
                        rb_entry(rb_first(&map->pg_upmap),
                                 struct ceph_pg_mapping, node);
                rb_erase(&pg->node, &map->pg_upmap);
                kfree(pg);
        }
        while (!RB_EMPTY_ROOT(&map->pg_upmap_items)) {
                struct ceph_pg_mapping *pg =
                        rb_entry(rb_first(&map->pg_upmap_items),
                                 struct ceph_pg_mapping, node);
                rb_erase(&pg->node, &map->pg_upmap_items);
                kfree(pg);
        }
        while (!RB_EMPTY_ROOT(&map->pg_pools)) {
                struct ceph_pg_pool_info *pi =
                        rb_entry(rb_first(&map->pg_pools),
                                 struct ceph_pg_pool_info, node);
                __remove_pg_pool(&map->pg_pools, pi);
        }
        kvfree(map->osd_state);
        kvfree(map->osd_weight);
        kvfree(map->osd_addr);
        kvfree(map->osd_primary_affinity);
        kfree(map);
}

/*
 * Adjust max_osd value, (re)allocate arrays.
 *
 * The new elements are properly initialized.
 */
static int osdmap_set_max_osd(struct ceph_osdmap *map, u32 max)
{
        u32 *state;
        u32 *weight;
        struct ceph_entity_addr *addr;
        u32 to_copy;
        int i;

        dout("%s old %u new %u\n", __func__, map->max_osd, max);
        if (max == map->max_osd)
                return 0;

        state = ceph_kvmalloc(array_size(max, sizeof(*state)), GFP_NOFS);
        weight = ceph_kvmalloc(array_size(max, sizeof(*weight)), GFP_NOFS);
        addr = ceph_kvmalloc(array_size(max, sizeof(*addr)), GFP_NOFS);
        if (!state || !weight || !addr) {
                kvfree(state);
                kvfree(weight);
                kvfree(addr);
                return -ENOMEM;
        }

        to_copy = min(map->max_osd, max);
        if (map->osd_state) {
                memcpy(state, map->osd_state, to_copy * sizeof(*state));
                memcpy(weight, map->osd_weight, to_copy * sizeof(*weight));
                memcpy(addr, map->osd_addr, to_copy * sizeof(*addr));
                kvfree(map->osd_state);
                kvfree(map->osd_weight);
                kvfree(map->osd_addr);
        }

        map->osd_state = state;
        map->osd_weight = weight;
        map->osd_addr = addr;
        for (i = map->max_osd; i < max; i++) {
                map->osd_state[i] = 0;
                map->osd_weight[i] = CEPH_OSD_OUT;
                memset(map->osd_addr + i, 0, sizeof(*map->osd_addr));
        }

        if (map->osd_primary_affinity) {
                u32 *affinity;

                affinity = ceph_kvmalloc(array_size(max, sizeof(*affinity)),
                                         GFP_NOFS);
                if (!affinity)
                        return -ENOMEM;

                memcpy(affinity, map->osd_primary_affinity,
                       to_copy * sizeof(*affinity));
                kvfree(map->osd_primary_affinity);

                map->osd_primary_affinity = affinity;
                for (i = map->max_osd; i < max; i++)
                        map->osd_primary_affinity[i] =
                            CEPH_OSD_DEFAULT_PRIMARY_AFFINITY;
        }

        map->max_osd = max;

        return 0;
}

static int osdmap_set_crush(struct ceph_osdmap *map, struct crush_map *crush)
{
        struct crush_work *work;

        if (IS_ERR(crush))
                return PTR_ERR(crush);

        work = alloc_workspace(crush);
        if (!work) {
                crush_destroy(crush);
                return -ENOMEM;
        }

        if (map->crush)
                crush_destroy(map->crush);
        cleanup_workspace_manager(&map->crush_wsm);
        map->crush = crush;
        add_initial_workspace(&map->crush_wsm, work);
        return 0;
}

#define OSDMAP_WRAPPER_COMPAT_VER       7
#define OSDMAP_CLIENT_DATA_COMPAT_VER   1

/*
 * Return 0 or error.  On success, *v is set to 0 for old (v6) osdmaps,
 * to struct_v of the client_data section for new (v7 and above)
 * osdmaps.
 */
static int get_osdmap_client_data_v(void **p, void *end,
                                    const char *prefix, u8 *v)
{
        u8 struct_v;

        ceph_decode_8_safe(p, end, struct_v, e_inval);
        if (struct_v >= 7) {
                u8 struct_compat;

                ceph_decode_8_safe(p, end, struct_compat, e_inval);
                if (struct_compat > OSDMAP_WRAPPER_COMPAT_VER) {
                        pr_warn("got v %d cv %d > %d of %s ceph_osdmap\n",
                                struct_v, struct_compat,
                                OSDMAP_WRAPPER_COMPAT_VER, prefix);
                        return -EINVAL;
                }
                *p += 4; /* ignore wrapper struct_len */

                ceph_decode_8_safe(p, end, struct_v, e_inval);
                ceph_decode_8_safe(p, end, struct_compat, e_inval);
                if (struct_compat > OSDMAP_CLIENT_DATA_COMPAT_VER) {
                        pr_warn("got v %d cv %d > %d of %s ceph_osdmap client data\n",
                                struct_v, struct_compat,
                                OSDMAP_CLIENT_DATA_COMPAT_VER, prefix);
                        return -EINVAL;
                }
                *p += 4; /* ignore client data struct_len */
        } else {
                u16 version;

                *p -= 1;
                ceph_decode_16_safe(p, end, version, e_inval);
                if (version < 6) {
                        pr_warn("got v %d < 6 of %s ceph_osdmap\n",
                                version, prefix);
                        return -EINVAL;
                }

                /* old osdmap encoding */
                struct_v = 0;
        }

        *v = struct_v;
        return 0;

e_inval:
        return -EINVAL;
}

static int __decode_pools(void **p, void *end, struct ceph_osdmap *map,
                          bool incremental)
{
        u32 n;

        ceph_decode_32_safe(p, end, n, e_inval);
        while (n--) {
                struct ceph_pg_pool_info *pi;
                u64 pool;
                int ret;

                ceph_decode_64_safe(p, end, pool, e_inval);

                pi = lookup_pg_pool(&map->pg_pools, pool);
                if (!incremental || !pi) {
                        pi = kzalloc(sizeof(*pi), GFP_NOFS);
                        if (!pi)
                                return -ENOMEM;

                        RB_CLEAR_NODE(&pi->node);
                        pi->id = pool;

                        if (!__insert_pg_pool(&map->pg_pools, pi)) {
                                kfree(pi);
                                return -EEXIST;
                        }
                }

                ret = decode_pool(p, end, pi);
                if (ret)
                        return ret;
        }

        return 0;

e_inval:
        return -EINVAL;
}

static int decode_pools(void **p, void *end, struct ceph_osdmap *map)
{
        return __decode_pools(p, end, map, false);
}

static int decode_new_pools(void **p, void *end, struct ceph_osdmap *map)
{
        return __decode_pools(p, end, map, true);
}

typedef struct ceph_pg_mapping *(*decode_mapping_fn_t)(void **, void *, bool);

static int decode_pg_mapping(void **p, void *end, struct rb_root *mapping_root,
                             decode_mapping_fn_t fn, bool incremental)
{
        u32 n;

        WARN_ON(!incremental && !fn);

        ceph_decode_32_safe(p, end, n, e_inval);
        while (n--) {
                struct ceph_pg_mapping *pg;
                struct ceph_pg pgid;
                int ret;

                ret = ceph_decode_pgid(p, end, &pgid);
                if (ret)
                        return ret;

                pg = lookup_pg_mapping(mapping_root, &pgid);
                if (pg) {
                        WARN_ON(!incremental);
                        erase_pg_mapping(mapping_root, pg);
                        free_pg_mapping(pg);
                }

                if (fn) {
                        pg = fn(p, end, incremental);
                        if (IS_ERR(pg))
                                return PTR_ERR(pg);

                        if (pg) {
                                pg->pgid = pgid; /* struct */
                                insert_pg_mapping(mapping_root, pg);
                        }
                }
        }

        return 0;

e_inval:
        return -EINVAL;
}

static struct ceph_pg_mapping *__decode_pg_temp(void **p, void *end,
                                                bool incremental)
{
        struct ceph_pg_mapping *pg;
        u32 len, i;

        ceph_decode_32_safe(p, end, len, e_inval);
        if (len == 0 && incremental)
                return NULL;    /* new_pg_temp: [] to remove */
        if (len > (SIZE_MAX - sizeof(*pg)) / sizeof(u32))
                return ERR_PTR(-EINVAL);

        ceph_decode_need(p, end, len * sizeof(u32), e_inval);
        pg = alloc_pg_mapping(len * sizeof(u32));
        if (!pg)
                return ERR_PTR(-ENOMEM);

        pg->pg_temp.len = len;
        for (i = 0; i < len; i++)
                pg->pg_temp.osds[i] = ceph_decode_32(p);

        return pg;

e_inval:
        return ERR_PTR(-EINVAL);
}

static int decode_pg_temp(void **p, void *end, struct ceph_osdmap *map)
{
        return decode_pg_mapping(p, end, &map->pg_temp, __decode_pg_temp,
                                 false);
}

static int decode_new_pg_temp(void **p, void *end, struct ceph_osdmap *map)
{
        return decode_pg_mapping(p, end, &map->pg_temp, __decode_pg_temp,
                                 true);
}

static struct ceph_pg_mapping *__decode_primary_temp(void **p, void *end,
                                                     bool incremental)
{
        struct ceph_pg_mapping *pg;
        u32 osd;

        ceph_decode_32_safe(p, end, osd, e_inval);
        if (osd == (u32)-1 && incremental)
                return NULL;    /* new_primary_temp: -1 to remove */

        pg = alloc_pg_mapping(0);
        if (!pg)
                return ERR_PTR(-ENOMEM);

        pg->primary_temp.osd = osd;
        return pg;

e_inval:
        return ERR_PTR(-EINVAL);
}

static int decode_primary_temp(void **p, void *end, struct ceph_osdmap *map)
{
        return decode_pg_mapping(p, end, &map->primary_temp,
                                 __decode_primary_temp, false);
}

static int decode_new_primary_temp(void **p, void *end,
                                   struct ceph_osdmap *map)
{
        return decode_pg_mapping(p, end, &map->primary_temp,
                                 __decode_primary_temp, true);
}

u32 ceph_get_primary_affinity(struct ceph_osdmap *map, int osd)
{
        BUG_ON(osd >= map->max_osd);

        if (!map->osd_primary_affinity)
                return CEPH_OSD_DEFAULT_PRIMARY_AFFINITY;

        return map->osd_primary_affinity[osd];
}

static int set_primary_affinity(struct ceph_osdmap *map, int osd, u32 aff)
{
        BUG_ON(osd >= map->max_osd);

        if (!map->osd_primary_affinity) {
                int i;

                map->osd_primary_affinity = ceph_kvmalloc(
                    array_size(map->max_osd, sizeof(*map->osd_primary_affinity)),
                    GFP_NOFS);
                if (!map->osd_primary_affinity)
                        return -ENOMEM;

                for (i = 0; i < map->max_osd; i++)
                        map->osd_primary_affinity[i] =
                            CEPH_OSD_DEFAULT_PRIMARY_AFFINITY;
        }

        map->osd_primary_affinity[osd] = aff;

        return 0;
}

static int decode_primary_affinity(void **p, void *end,
                                   struct ceph_osdmap *map)
{
        u32 len, i;

        ceph_decode_32_safe(p, end, len, e_inval);
        if (len == 0) {
                kvfree(map->osd_primary_affinity);
                map->osd_primary_affinity = NULL;
                return 0;
        }
        if (len != map->max_osd)
                goto e_inval;

        ceph_decode_need(p, end, map->max_osd*sizeof(u32), e_inval);

        for (i = 0; i < map->max_osd; i++) {
                int ret;

                ret = set_primary_affinity(map, i, ceph_decode_32(p));
                if (ret)
                        return ret;
        }

        return 0;

e_inval:
        return -EINVAL;
}

static int decode_new_primary_affinity(void **p, void *end,
                                       struct ceph_osdmap *map)
{
        u32 n;

        ceph_decode_32_safe(p, end, n, e_inval);
        while (n--) {
                u32 osd, aff;
                int ret;

                ceph_decode_32_safe(p, end, osd, e_inval);
                ceph_decode_32_safe(p, end, aff, e_inval);

                ret = set_primary_affinity(map, osd, aff);
                if (ret)
                        return ret;

                pr_info("osd%d primary-affinity 0x%x\n", osd, aff);
        }

        return 0;

e_inval:
        return -EINVAL;
}

static struct ceph_pg_mapping *__decode_pg_upmap(void **p, void *end,
                                                 bool __unused)
{
        return __decode_pg_temp(p, end, false);
}

static int decode_pg_upmap(void **p, void *end, struct ceph_osdmap *map)
{
        return decode_pg_mapping(p, end, &map->pg_upmap, __decode_pg_upmap,
                                 false);
}

static int decode_new_pg_upmap(void **p, void *end, struct ceph_osdmap *map)
{
        return decode_pg_mapping(p, end, &map->pg_upmap, __decode_pg_upmap,
                                 true);
}

static int decode_old_pg_upmap(void **p, void *end, struct ceph_osdmap *map)
{
        return decode_pg_mapping(p, end, &map->pg_upmap, NULL, true);
}

static struct ceph_pg_mapping *__decode_pg_upmap_items(void **p, void *end,
                                                       bool __unused)
{
        struct ceph_pg_mapping *pg;
        u32 len, i;

        ceph_decode_32_safe(p, end, len, e_inval);
        if (len > (SIZE_MAX - sizeof(*pg)) / (2 * sizeof(u32)))
                return ERR_PTR(-EINVAL);

        ceph_decode_need(p, end, 2 * len * sizeof(u32), e_inval);
        pg = alloc_pg_mapping(2 * len * sizeof(u32));
        if (!pg)
                return ERR_PTR(-ENOMEM);

        pg->pg_upmap_items.len = len;
        for (i = 0; i < len; i++) {
                pg->pg_upmap_items.from_to[i][0] = ceph_decode_32(p);
                pg->pg_upmap_items.from_to[i][1] = ceph_decode_32(p);
        }

        return pg;

e_inval:
        return ERR_PTR(-EINVAL);
}

static int decode_pg_upmap_items(void **p, void *end, struct ceph_osdmap *map)
{
        return decode_pg_mapping(p, end, &map->pg_upmap_items,
                                 __decode_pg_upmap_items, false);
}

static int decode_new_pg_upmap_items(void **p, void *end,
                                     struct ceph_osdmap *map)
{
        return decode_pg_mapping(p, end, &map->pg_upmap_items,
                                 __decode_pg_upmap_items, true);
}

static int decode_old_pg_upmap_items(void **p, void *end,
                                     struct ceph_osdmap *map)
{
        return decode_pg_mapping(p, end, &map->pg_upmap_items, NULL, true);
}

/*
 * decode a full map.
 */
static int osdmap_decode(void **p, void *end, bool msgr2,
                         struct ceph_osdmap *map)
{
        u8 struct_v;
        u32 epoch = 0;
        void *start = *p;
        u32 max;
        u32 len, i;
        int err;

        dout("%s %p to %p len %d\n", __func__, *p, end, (int)(end - *p));

        err = get_osdmap_client_data_v(p, end, "full", &struct_v);
        if (err)
                goto bad;

        /* fsid, epoch, created, modified */
        ceph_decode_need(p, end, sizeof(map->fsid) + sizeof(u32) +
                         sizeof(map->created) + sizeof(map->modified), e_inval);
        ceph_decode_copy(p, &map->fsid, sizeof(map->fsid));
        epoch = map->epoch = ceph_decode_32(p);
        ceph_decode_copy(p, &map->created, sizeof(map->created));
        ceph_decode_copy(p, &map->modified, sizeof(map->modified));

        /* pools */
        err = decode_pools(p, end, map);
        if (err)
                goto bad;

        /* pool_name */
        err = decode_pool_names(p, end, map);
        if (err)
                goto bad;

        ceph_decode_32_safe(p, end, map->pool_max, e_inval);

        ceph_decode_32_safe(p, end, map->flags, e_inval);

        /* max_osd */
        ceph_decode_32_safe(p, end, max, e_inval);

        /* (re)alloc osd arrays */
        err = osdmap_set_max_osd(map, max);
        if (err)
                goto bad;

        /* osd_state, osd_weight, osd_addrs->client_addr */
        ceph_decode_need(p, end, 3*sizeof(u32) +
                         map->max_osd*(struct_v >= 5 ? sizeof(u32) :
                                                       sizeof(u8)) +
                                       sizeof(*map->osd_weight), e_inval);
        if (ceph_decode_32(p) != map->max_osd)
                goto e_inval;

        if (struct_v >= 5) {
                for (i = 0; i < map->max_osd; i++)
                        map->osd_state[i] = ceph_decode_32(p);
        } else {
                for (i = 0; i < map->max_osd; i++)
                        map->osd_state[i] = ceph_decode_8(p);
        }

        if (ceph_decode_32(p) != map->max_osd)
                goto e_inval;

        for (i = 0; i < map->max_osd; i++)
                map->osd_weight[i] = ceph_decode_32(p);

        if (ceph_decode_32(p) != map->max_osd)
                goto e_inval;

        for (i = 0; i < map->max_osd; i++) {
                struct ceph_entity_addr *addr = &map->osd_addr[i];

                if (struct_v >= 8)
                        err = ceph_decode_entity_addrvec(p, end, msgr2, addr);
                else
                        err = ceph_decode_entity_addr(p, end, addr);
                if (err)
                        goto bad;

                dout("%s osd%d addr %s\n", __func__, i, ceph_pr_addr(addr));
        }

        /* pg_temp */
        err = decode_pg_temp(p, end, map);
        if (err)
                goto bad;

        /* primary_temp */
        if (struct_v >= 1) {
                err = decode_primary_temp(p, end, map);
                if (err)
                        goto bad;
        }

        /* primary_affinity */
        if (struct_v >= 2) {
                err = decode_primary_affinity(p, end, map);
                if (err)
                        goto bad;
        } else {
                WARN_ON(map->osd_primary_affinity);
        }

        /* crush */
        ceph_decode_32_safe(p, end, len, e_inval);
        err = osdmap_set_crush(map, crush_decode(*p, min(*p + len, end)));
        if (err)
                goto bad;

        *p += len;
        if (struct_v >= 3) {
                /* erasure_code_profiles */
                ceph_decode_skip_map_of_map(p, end, string, string, string,
                                            e_inval);
        }

        if (struct_v >= 4) {
                err = decode_pg_upmap(p, end, map);
                if (err)
                        goto bad;

                err = decode_pg_upmap_items(p, end, map);
                if (err)
                        goto bad;
        } else {
                WARN_ON(!RB_EMPTY_ROOT(&map->pg_upmap));
                WARN_ON(!RB_EMPTY_ROOT(&map->pg_upmap_items));
        }

        /* ignore the rest */
        *p = end;

        dout("full osdmap epoch %d max_osd %d\n", map->epoch, map->max_osd);
        return 0;

e_inval:
        err = -EINVAL;
bad:
        pr_err("corrupt full osdmap (%d) epoch %d off %d (%p of %p-%p)\n",
               err, epoch, (int)(*p - start), *p, start, end);
        print_hex_dump(KERN_DEBUG, "osdmap: ",
                       DUMP_PREFIX_OFFSET, 16, 1,
                       start, end - start, true);
        return err;
}

/*
 * Allocate and decode a full map.
 */
struct ceph_osdmap *ceph_osdmap_decode(void **p, void *end, bool msgr2)
{
        struct ceph_osdmap *map;
        int ret;

        map = ceph_osdmap_alloc();
        if (!map)
                return ERR_PTR(-ENOMEM);

        ret = osdmap_decode(p, end, msgr2, map);
        if (ret) {
                ceph_osdmap_destroy(map);
                return ERR_PTR(ret);
        }

        return map;
}

/*
 * Encoding order is (new_up_client, new_state, new_weight).  Need to
 * apply in the (new_weight, new_state, new_up_client) order, because
 * an incremental map may look like e.g.
 *
 *     new_up_client: { osd=6, addr=... } # set osd_state and addr
 *     new_state: { osd=6, xorstate=EXISTS } # clear osd_state
 */
static int decode_new_up_state_weight(void **p, void *end, u8 struct_v,
                                      bool msgr2, struct ceph_osdmap *map)
{
        void *new_up_client;
        void *new_state;
        void *new_weight_end;
        u32 len;
        int ret;
        int i;

        new_up_client = *p;
        ceph_decode_32_safe(p, end, len, e_inval);
        for (i = 0; i < len; ++i) {
                struct ceph_entity_addr addr;

                ceph_decode_skip_32(p, end, e_inval);
                if (struct_v >= 7)
                        ret = ceph_decode_entity_addrvec(p, end, msgr2, &addr);
                else
                        ret = ceph_decode_entity_addr(p, end, &addr);
                if (ret)
                        return ret;
        }

        new_state = *p;
        ceph_decode_32_safe(p, end, len, e_inval);
        len *= sizeof(u32) + (struct_v >= 5 ? sizeof(u32) : sizeof(u8));
        ceph_decode_need(p, end, len, e_inval);
        *p += len;

        /* new_weight */
        ceph_decode_32_safe(p, end, len, e_inval);
        while (len--) {
                s32 osd;
                u32 w;

                ceph_decode_need(p, end, 2*sizeof(u32), e_inval);
                osd = ceph_decode_32(p);
                w = ceph_decode_32(p);
                BUG_ON(osd >= map->max_osd);
                pr_info("osd%d weight 0x%x %s\n", osd, w,
                     w == CEPH_OSD_IN ? "(in)" :
                     (w == CEPH_OSD_OUT ? "(out)" : ""));
                map->osd_weight[osd] = w;

                /*
                 * If we are marking in, set the EXISTS, and clear the
                 * AUTOOUT and NEW bits.
                 */
                if (w) {
                        map->osd_state[osd] |= CEPH_OSD_EXISTS;
                        map->osd_state[osd] &= ~(CEPH_OSD_AUTOOUT |
                                                 CEPH_OSD_NEW);
                }
        }
        new_weight_end = *p;

        /* new_state (up/down) */
        *p = new_state;
        len = ceph_decode_32(p);
        while (len--) {
                s32 osd;
                u32 xorstate;

                osd = ceph_decode_32(p);
                if (struct_v >= 5)
                        xorstate = ceph_decode_32(p);
                else
                        xorstate = ceph_decode_8(p);
                if (xorstate == 0)
                        xorstate = CEPH_OSD_UP;
                BUG_ON(osd >= map->max_osd);
                if ((map->osd_state[osd] & CEPH_OSD_UP) &&
                    (xorstate & CEPH_OSD_UP))
                        pr_info("osd%d down\n", osd);
                if ((map->osd_state[osd] & CEPH_OSD_EXISTS) &&
                    (xorstate & CEPH_OSD_EXISTS)) {
                        pr_info("osd%d does not exist\n", osd);
                        ret = set_primary_affinity(map, osd,
                                                   CEPH_OSD_DEFAULT_PRIMARY_AFFINITY);
                        if (ret)
                                return ret;
                        memset(map->osd_addr + osd, 0, sizeof(*map->osd_addr));
                        map->osd_state[osd] = 0;
                } else {
                        map->osd_state[osd] ^= xorstate;
                }
        }

        /* new_up_client */
        *p = new_up_client;
        len = ceph_decode_32(p);
        while (len--) {
                s32 osd;
                struct ceph_entity_addr addr;

                osd = ceph_decode_32(p);
                BUG_ON(osd >= map->max_osd);
                if (struct_v >= 7)
                        ret = ceph_decode_entity_addrvec(p, end, msgr2, &addr);
                else
                        ret = ceph_decode_entity_addr(p, end, &addr);
                if (ret)
                        return ret;

                dout("%s osd%d addr %s\n", __func__, osd, ceph_pr_addr(&addr));

                pr_info("osd%d up\n", osd);
                map->osd_state[osd] |= CEPH_OSD_EXISTS | CEPH_OSD_UP;
                map->osd_addr[osd] = addr;
        }

        *p = new_weight_end;
        return 0;

e_inval:
        return -EINVAL;
}

/*
 * decode and apply an incremental map update.
 */
struct ceph_osdmap *osdmap_apply_incremental(void **p, void *end, bool msgr2,
                                             struct ceph_osdmap *map)
{
        struct ceph_fsid fsid;
        u32 epoch = 0;
        struct ceph_timespec modified;
        s32 len;
        u64 pool;
        __s64 new_pool_max;
        __s32 new_flags, max;
        void *start = *p;
        int err;
        u8 struct_v;

        dout("%s %p to %p len %d\n", __func__, *p, end, (int)(end - *p));

        err = get_osdmap_client_data_v(p, end, "inc", &struct_v);
        if (err)
                goto bad;

        /* fsid, epoch, modified, new_pool_max, new_flags */
        ceph_decode_need(p, end, sizeof(fsid) + sizeof(u32) + sizeof(modified) +
                         sizeof(u64) + sizeof(u32), e_inval);
        ceph_decode_copy(p, &fsid, sizeof(fsid));
        epoch = ceph_decode_32(p);
        BUG_ON(epoch != map->epoch+1);
        ceph_decode_copy(p, &modified, sizeof(modified));
        new_pool_max = ceph_decode_64(p);
        new_flags = ceph_decode_32(p);

        /* full map? */
        ceph_decode_32_safe(p, end, len, e_inval);
        if (len > 0) {
                dout("apply_incremental full map len %d, %p to %p\n",
                     len, *p, end);
                return ceph_osdmap_decode(p, min(*p+len, end), msgr2);
        }

        /* new crush? */
        ceph_decode_32_safe(p, end, len, e_inval);
        if (len > 0) {
                err = osdmap_set_crush(map,
                                       crush_decode(*p, min(*p + len, end)));
                if (err)
                        goto bad;
                *p += len;
        }

        /* new flags? */
        if (new_flags >= 0)
                map->flags = new_flags;
        if (new_pool_max >= 0)

                map->pool_max = new_pool_max;

        /* new max? */
        ceph_decode_32_safe(p, end, max, e_inval);
        if (max >= 0) {
                err = osdmap_set_max_osd(map, max);
                if (err)
                        goto bad;
        }

        map->epoch++;
        map->modified = modified;

        /* new_pools */
        err = decode_new_pools(p, end, map);
        if (err)
                goto bad;

        /* new_pool_names */
        err = decode_pool_names(p, end, map);
        if (err)
                goto bad;

        /* old_pool */
        ceph_decode_32_safe(p, end, len, e_inval);
        while (len--) {
                struct ceph_pg_pool_info *pi;

                ceph_decode_64_safe(p, end, pool, e_inval);
                pi = lookup_pg_pool(&map->pg_pools, pool);
                if (pi)
                        __remove_pg_pool(&map->pg_pools, pi);
        }

        /* new_up_client, new_state, new_weight */
        err = decode_new_up_state_weight(p, end, struct_v, msgr2, map);
        if (err)
                goto bad;

        /* new_pg_temp */
        err = decode_new_pg_temp(p, end, map);
        if (err)
                goto bad;

        /* new_primary_temp */
        if (struct_v >= 1) {
                err = decode_new_primary_temp(p, end, map);
                if (err)
                        goto bad;
        }

        /* new_primary_affinity */
        if (struct_v >= 2) {
                err = decode_new_primary_affinity(p, end, map);
                if (err)
                        goto bad;
        }

        if (struct_v >= 3) {
                /* new_erasure_code_profiles */
                ceph_decode_skip_map_of_map(p, end, string, string, string,
                                            e_inval);
                /* old_erasure_code_profiles */
                ceph_decode_skip_set(p, end, string, e_inval);
        }

        if (struct_v >= 4) {
                err = decode_new_pg_upmap(p, end, map);
                if (err)
                        goto bad;

                err = decode_old_pg_upmap(p, end, map);
                if (err)
                        goto bad;

                err = decode_new_pg_upmap_items(p, end, map);
                if (err)
                        goto bad;

                err = decode_old_pg_upmap_items(p, end, map);
                if (err)
                        goto bad;
        }

        /* ignore the rest */
        *p = end;

        dout("inc osdmap epoch %d max_osd %d\n", map->epoch, map->max_osd);
        return map;

e_inval:
        err = -EINVAL;
bad:
        pr_err("corrupt inc osdmap (%d) epoch %d off %d (%p of %p-%p)\n",
               err, epoch, (int)(*p - start), *p, start, end);
        print_hex_dump(KERN_DEBUG, "osdmap: ",
                       DUMP_PREFIX_OFFSET, 16, 1,
                       start, end - start, true);
        return ERR_PTR(err);
}

void ceph_oloc_copy(struct ceph_object_locator *dest,
                    const struct ceph_object_locator *src)
{
        ceph_oloc_destroy(dest);

        dest->pool = src->pool;
        if (src->pool_ns)
                dest->pool_ns = ceph_get_string(src->pool_ns);
        else
                dest->pool_ns = NULL;
}
EXPORT_SYMBOL(ceph_oloc_copy);

void ceph_oloc_destroy(struct ceph_object_locator *oloc)
{
        ceph_put_string(oloc->pool_ns);
}
EXPORT_SYMBOL(ceph_oloc_destroy);

void ceph_oid_copy(struct ceph_object_id *dest,
                   const struct ceph_object_id *src)
{
        ceph_oid_destroy(dest);

        if (src->name != src->inline_name) {
                /* very rare, see ceph_object_id definition */
                dest->name = kmalloc(src->name_len + 1,
                                     GFP_NOIO | __GFP_NOFAIL);
        } else {
                dest->name = dest->inline_name;
        }
        memcpy(dest->name, src->name, src->name_len + 1);
        dest->name_len = src->name_len;
}
EXPORT_SYMBOL(ceph_oid_copy);

static __printf(2, 0)
int oid_printf_vargs(struct ceph_object_id *oid, const char *fmt, va_list ap)
{
        int len;

        WARN_ON(!ceph_oid_empty(oid));

        len = vsnprintf(oid->inline_name, sizeof(oid->inline_name), fmt, ap);
        if (len >= sizeof(oid->inline_name))
                return len;

        oid->name_len = len;
        return 0;
}

/*
 * If oid doesn't fit into inline buffer, BUG.
 */
void ceph_oid_printf(struct ceph_object_id *oid, const char *fmt, ...)
{
        va_list ap;

        va_start(ap, fmt);
        BUG_ON(oid_printf_vargs(oid, fmt, ap));
        va_end(ap);
}
EXPORT_SYMBOL(ceph_oid_printf);

static __printf(3, 0)
int oid_aprintf_vargs(struct ceph_object_id *oid, gfp_t gfp,
                      const char *fmt, va_list ap)
{
        va_list aq;
        int len;

        va_copy(aq, ap);
        len = oid_printf_vargs(oid, fmt, aq);
        va_end(aq);

        if (len) {
                char *external_name;

                external_name = kmalloc(len + 1, gfp);
                if (!external_name)
                        return -ENOMEM;

                oid->name = external_name;
                WARN_ON(vsnprintf(oid->name, len + 1, fmt, ap) != len);
                oid->name_len = len;
        }

        return 0;
}

/*
 * If oid doesn't fit into inline buffer, allocate.
 */
int ceph_oid_aprintf(struct ceph_object_id *oid, gfp_t gfp,
                     const char *fmt, ...)
{
        va_list ap;
        int ret;

        va_start(ap, fmt);
        ret = oid_aprintf_vargs(oid, gfp, fmt, ap);
        va_end(ap);

        return ret;
}
EXPORT_SYMBOL(ceph_oid_aprintf);

void ceph_oid_destroy(struct ceph_object_id *oid)
{
        if (oid->name != oid->inline_name)
                kfree(oid->name);
}
EXPORT_SYMBOL(ceph_oid_destroy);

/*
 * osds only
 */
static bool __osds_equal(const struct ceph_osds *lhs,
                         const struct ceph_osds *rhs)
{
        if (lhs->size == rhs->size &&
            !memcmp(lhs->osds, rhs->osds, rhs->size * sizeof(rhs->osds[0])))
                return true;

        return false;
}

/*
 * osds + primary
 */
static bool osds_equal(const struct ceph_osds *lhs,
                       const struct ceph_osds *rhs)
{
        if (__osds_equal(lhs, rhs) &&
            lhs->primary == rhs->primary)
                return true;

        return false;
}

static bool osds_valid(const struct ceph_osds *set)
{
        /* non-empty set */
        if (set->size > 0 && set->primary >= 0)
                return true;

        /* empty can_shift_osds set */
        if (!set->size && set->primary == -1)
                return true;

        /* empty !can_shift_osds set - all NONE */
        if (set->size > 0 && set->primary == -1) {
                int i;

                for (i = 0; i < set->size; i++) {
                        if (set->osds[i] != CRUSH_ITEM_NONE)
                                break;
                }
                if (i == set->size)
                        return true;
        }

        return false;
}

void ceph_osds_copy(struct ceph_osds *dest, const struct ceph_osds *src)
{
        memcpy(dest->osds, src->osds, src->size * sizeof(src->osds[0]));
        dest->size = src->size;
        dest->primary = src->primary;
}

bool ceph_pg_is_split(const struct ceph_pg *pgid, u32 old_pg_num,
                      u32 new_pg_num)
{
        int old_bits = calc_bits_of(old_pg_num);
        int old_mask = (1 << old_bits) - 1;
        int n;

        WARN_ON(pgid->seed >= old_pg_num);
        if (new_pg_num <= old_pg_num)
                return false;

        for (n = 1; ; n++) {
                int next_bit = n << (old_bits - 1);
                u32 s = next_bit | pgid->seed;

                if (s < old_pg_num || s == pgid->seed)
                        continue;
                if (s >= new_pg_num)
                        break;

                s = ceph_stable_mod(s, old_pg_num, old_mask);
                if (s == pgid->seed)
                        return true;
        }

        return false;
}

bool ceph_is_new_interval(const struct ceph_osds *old_acting,
                          const struct ceph_osds *new_acting,
                          const struct ceph_osds *old_up,
                          const struct ceph_osds *new_up,
                          int old_size,
                          int new_size,
                          int old_min_size,
                          int new_min_size,
                          u32 old_pg_num,
                          u32 new_pg_num,
                          bool old_sort_bitwise,
                          bool new_sort_bitwise,
                          bool old_recovery_deletes,
                          bool new_recovery_deletes,
                          const struct ceph_pg *pgid)
{
        return !osds_equal(old_acting, new_acting) ||
               !osds_equal(old_up, new_up) ||
               old_size != new_size ||
               old_min_size != new_min_size ||
               ceph_pg_is_split(pgid, old_pg_num, new_pg_num) ||
               old_sort_bitwise != new_sort_bitwise ||
               old_recovery_deletes != new_recovery_deletes;
}

static int calc_pg_rank(int osd, const struct ceph_osds *acting)
{
        int i;

        for (i = 0; i < acting->size; i++) {
                if (acting->osds[i] == osd)
                        return i;
        }

        return -1;
}

static bool primary_changed(const struct ceph_osds *old_acting,
                            const struct ceph_osds *new_acting)
{
        if (!old_acting->size && !new_acting->size)
                return false; /* both still empty */

        if (!old_acting->size ^ !new_acting->size)
                return true; /* was empty, now not, or vice versa */

        if (old_acting->primary != new_acting->primary)
                return true; /* primary changed */

        if (calc_pg_rank(old_acting->primary, old_acting) !=
            calc_pg_rank(new_acting->primary, new_acting))
                return true;

        return false; /* same primary (tho replicas may have changed) */
}

bool ceph_osds_changed(const struct ceph_osds *old_acting,
                       const struct ceph_osds *new_acting,
                       bool any_change)
{
        if (primary_changed(old_acting, new_acting))
                return true;

        if (any_change && !__osds_equal(old_acting, new_acting))
                return true;

        return false;
}

/*
 * Map an object into a PG.
 *
 * Should only be called with target_oid and target_oloc (as opposed to
 * base_oid and base_oloc), since tiering isn't taken into account.
 */
void __ceph_object_locator_to_pg(struct ceph_pg_pool_info *pi,
                                 const struct ceph_object_id *oid,
                                 const struct ceph_object_locator *oloc,
                                 struct ceph_pg *raw_pgid)
{
        WARN_ON(pi->id != oloc->pool);

        if (!oloc->pool_ns) {
                raw_pgid->pool = oloc->pool;
                raw_pgid->seed = ceph_str_hash(pi->object_hash, oid->name,
                                             oid->name_len);
                dout("%s %s -> raw_pgid %llu.%x\n", __func__, oid->name,
                     raw_pgid->pool, raw_pgid->seed);
        } else {
                char stack_buf[256];
                char *buf = stack_buf;
                int nsl = oloc->pool_ns->len;
                size_t total = nsl + 1 + oid->name_len;

                if (total > sizeof(stack_buf))
                        buf = kmalloc(total, GFP_NOIO | __GFP_NOFAIL);
                memcpy(buf, oloc->pool_ns->str, nsl);
                buf[nsl] = '\037';
                memcpy(buf + nsl + 1, oid->name, oid->name_len);
                raw_pgid->pool = oloc->pool;
                raw_pgid->seed = ceph_str_hash(pi->object_hash, buf, total);
                if (buf != stack_buf)
                        kfree(buf);
                dout("%s %s ns %.*s -> raw_pgid %llu.%x\n", __func__,
                     oid->name, nsl, oloc->pool_ns->str,
                     raw_pgid->pool, raw_pgid->seed);
        }
}

int ceph_object_locator_to_pg(struct ceph_osdmap *osdmap,
                              const struct ceph_object_id *oid,
                              const struct ceph_object_locator *oloc,
                              struct ceph_pg *raw_pgid)
{
        struct ceph_pg_pool_info *pi;

        pi = ceph_pg_pool_by_id(osdmap, oloc->pool);
        if (!pi)
                return -ENOENT;

        __ceph_object_locator_to_pg(pi, oid, oloc, raw_pgid);
        return 0;
}
EXPORT_SYMBOL(ceph_object_locator_to_pg);

/*
 * Map a raw PG (full precision ps) into an actual PG.
 */
static void raw_pg_to_pg(struct ceph_pg_pool_info *pi,
                         const struct ceph_pg *raw_pgid,
                         struct ceph_pg *pgid)
{
        pgid->pool = raw_pgid->pool;
        pgid->seed = ceph_stable_mod(raw_pgid->seed, pi->pg_num,
                                     pi->pg_num_mask);
}

/*
 * Map a raw PG (full precision ps) into a placement ps (placement
 * seed).  Include pool id in that value so that different pools don't
 * use the same seeds.
 */
static u32 raw_pg_to_pps(struct ceph_pg_pool_info *pi,
                         const struct ceph_pg *raw_pgid)
{
        if (pi->flags & CEPH_POOL_FLAG_HASHPSPOOL) {
                /* hash pool id and seed so that pool PGs do not overlap */
                return crush_hash32_2(CRUSH_HASH_RJENKINS1,
                                      ceph_stable_mod(raw_pgid->seed,
                                                      pi->pgp_num,
                                                      pi->pgp_num_mask),
                                      raw_pgid->pool);
        } else {
                /*
                 * legacy behavior: add ps and pool together.  this is
                 * not a great approach because the PGs from each pool
                 * will overlap on top of each other: 0.5 == 1.4 ==
                 * 2.3 == ...
                 */
                return ceph_stable_mod(raw_pgid->seed, pi->pgp_num,
                                       pi->pgp_num_mask) +
                       (unsigned)raw_pgid->pool;
        }
}

/*
 * Magic value used for a "default" fallback choose_args, used if the
 * crush_choose_arg_map passed to do_crush() does not exist.  If this
 * also doesn't exist, fall back to canonical weights.
 */
#define CEPH_DEFAULT_CHOOSE_ARGS        -1

static int do_crush(struct ceph_osdmap *map, int ruleno, int x,
                    int *result, int result_max,
                    const __u32 *weight, int weight_max,
                    s64 choose_args_index)
{
        struct crush_choose_arg_map *arg_map;
        struct crush_work *work;
        int r;

        BUG_ON(result_max > CEPH_PG_MAX_SIZE);

        arg_map = lookup_choose_arg_map(&map->crush->choose_args,
                                        choose_args_index);
        if (!arg_map)
                arg_map = lookup_choose_arg_map(&map->crush->choose_args,
                                                CEPH_DEFAULT_CHOOSE_ARGS);

        work = get_workspace(&map->crush_wsm, map->crush);
        r = crush_do_rule(map->crush, ruleno, x, result, result_max,
                          weight, weight_max, work,
                          arg_map ? arg_map->args : NULL);
        put_workspace(&map->crush_wsm, work);
        return r;
}

static void remove_nonexistent_osds(struct ceph_osdmap *osdmap,
                                    struct ceph_pg_pool_info *pi,
                                    struct ceph_osds *set)
{
        int i;

        if (ceph_can_shift_osds(pi)) {
                int removed = 0;

                /* shift left */
                for (i = 0; i < set->size; i++) {
                        if (!ceph_osd_exists(osdmap, set->osds[i])) {
                                removed++;
                                continue;
                        }
                        if (removed)
                                set->osds[i - removed] = set->osds[i];
                }
                set->size -= removed;
        } else {
                /* set dne devices to NONE */
                for (i = 0; i < set->size; i++) {
                        if (!ceph_osd_exists(osdmap, set->osds[i]))
                                set->osds[i] = CRUSH_ITEM_NONE;
                }
        }
}

/*
 * Calculate raw set (CRUSH output) for given PG and filter out
 * nonexistent OSDs.  ->primary is undefined for a raw set.
 *
 * Placement seed (CRUSH input) is returned through @ppps.
 */
static void pg_to_raw_osds(struct ceph_osdmap *osdmap,
                           struct ceph_pg_pool_info *pi,
                           const struct ceph_pg *raw_pgid,
                           struct ceph_osds *raw,
                           u32 *ppps)
{
        u32 pps = raw_pg_to_pps(pi, raw_pgid);
        int ruleno;
        int len;

        ceph_osds_init(raw);
        if (ppps)
                *ppps = pps;

        ruleno = crush_find_rule(osdmap->crush, pi->crush_ruleset, pi->type,
                                 pi->size);
        if (ruleno < 0) {
                pr_err("no crush rule: pool %lld ruleset %d type %d size %d\n",
                       pi->id, pi->crush_ruleset, pi->type, pi->size);
                return;
        }

        if (pi->size > ARRAY_SIZE(raw->osds)) {
                pr_err_ratelimited("pool %lld ruleset %d type %d too wide: size %d > %zu\n",
                       pi->id, pi->crush_ruleset, pi->type, pi->size,
                       ARRAY_SIZE(raw->osds));
                return;
        }

        len = do_crush(osdmap, ruleno, pps, raw->osds, pi->size,
                       osdmap->osd_weight, osdmap->max_osd, pi->id);
        if (len < 0) {
                pr_err("error %d from crush rule %d: pool %lld ruleset %d type %d size %d\n",
                       len, ruleno, pi->id, pi->crush_ruleset, pi->type,
                       pi->size);
                return;
        }

        raw->size = len;
        remove_nonexistent_osds(osdmap, pi, raw);
}

/* apply pg_upmap[_items] mappings */
static void apply_upmap(struct ceph_osdmap *osdmap,
                        const struct ceph_pg *pgid,
                        struct ceph_osds *raw)
{
        struct ceph_pg_mapping *pg;
        int i, j;

        pg = lookup_pg_mapping(&osdmap->pg_upmap, pgid);
        if (pg) {
                /* make sure targets aren't marked out */
                for (i = 0; i < pg->pg_upmap.len; i++) {
                        int osd = pg->pg_upmap.osds[i];

                        if (osd != CRUSH_ITEM_NONE &&
                            osd < osdmap->max_osd &&
                            osdmap->osd_weight[osd] == 0) {
                                /* reject/ignore explicit mapping */
                                return;
                        }
                }
                for (i = 0; i < pg->pg_upmap.len; i++)
                        raw->osds[i] = pg->pg_upmap.osds[i];
                raw->size = pg->pg_upmap.len;
                /* check and apply pg_upmap_items, if any */
        }

        pg = lookup_pg_mapping(&osdmap->pg_upmap_items, pgid);
        if (pg) {
                /*
                 * Note: this approach does not allow a bidirectional swap,
                 * e.g., [[1,2],[2,1]] applied to [0,1,2] -> [0,2,1].
                 */
                for (i = 0; i < pg->pg_upmap_items.len; i++) {
                        int from = pg->pg_upmap_items.from_to[i][0];
                        int to = pg->pg_upmap_items.from_to[i][1];
                        int pos = -1;
                        bool exists = false;

                        /* make sure replacement doesn't already appear */
                        for (j = 0; j < raw->size; j++) {
                                int osd = raw->osds[j];

                                if (osd == to) {
                                        exists = true;
                                        break;
                                }
                                /* ignore mapping if target is marked out */
                                if (osd == from && pos < 0 &&
                                    !(to != CRUSH_ITEM_NONE &&
                                      to < osdmap->max_osd &&
                                      osdmap->osd_weight[to] == 0)) {
                                        pos = j;
                                }
                        }
                        if (!exists && pos >= 0)
                                raw->osds[pos] = to;
                }
        }
}

/*
 * Given raw set, calculate up set and up primary.  By definition of an
 * up set, the result won't contain nonexistent or down OSDs.
 *
 * This is done in-place - on return @set is the up set.  If it's
 * empty, ->primary will remain undefined.
 */
static void raw_to_up_osds(struct ceph_osdmap *osdmap,
                           struct ceph_pg_pool_info *pi,
                           struct ceph_osds *set)
{
        int i;

        /* ->primary is undefined for a raw set */
        BUG_ON(set->primary != -1);

        if (ceph_can_shift_osds(pi)) {
                int removed = 0;

                /* shift left */
                for (i = 0; i < set->size; i++) {
                        if (ceph_osd_is_down(osdmap, set->osds[i])) {
                                removed++;
                                continue;
                        }
                        if (removed)
                                set->osds[i - removed] = set->osds[i];
                }
                set->size -= removed;
                if (set->size > 0)
                        set->primary = set->osds[0];
        } else {
                /* set down/dne devices to NONE */
                for (i = set->size - 1; i >= 0; i--) {
                        if (ceph_osd_is_down(osdmap, set->osds[i]))
                                set->osds[i] = CRUSH_ITEM_NONE;
                        else
                                set->primary = set->osds[i];
                }
        }
}

static void apply_primary_affinity(struct ceph_osdmap *osdmap,
                                   struct ceph_pg_pool_info *pi,
                                   u32 pps,
                                   struct ceph_osds *up)
{
        int i;
        int pos = -1;

        /*
         * Do we have any non-default primary_affinity values for these
         * osds?
         */
        if (!osdmap->osd_primary_affinity)
                return;

        for (i = 0; i < up->size; i++) {
                int osd = up->osds[i];

                if (osd != CRUSH_ITEM_NONE &&
                    osdmap->osd_primary_affinity[osd] !=
                                        CEPH_OSD_DEFAULT_PRIMARY_AFFINITY) {
                        break;
                }
        }
        if (i == up->size)
                return;

        /*
         * Pick the primary.  Feed both the seed (for the pg) and the
         * osd into the hash/rng so that a proportional fraction of an
         * osd's pgs get rejected as primary.
         */
        for (i = 0; i < up->size; i++) {
                int osd = up->osds[i];
                u32 aff;

                if (osd == CRUSH_ITEM_NONE)
                        continue;

                aff = osdmap->osd_primary_affinity[osd];
                if (aff < CEPH_OSD_MAX_PRIMARY_AFFINITY &&
                    (crush_hash32_2(CRUSH_HASH_RJENKINS1,
                                    pps, osd) >> 16) >= aff) {
                        /*
                         * We chose not to use this primary.  Note it
                         * anyway as a fallback in case we don't pick
                         * anyone else, but keep looking.
                         */
                        if (pos < 0)
                                pos = i;
                } else {
                        pos = i;
                        break;
                }
        }
        if (pos < 0)
                return;

        up->primary = up->osds[pos];

        if (ceph_can_shift_osds(pi) && pos > 0) {
                /* move the new primary to the front */
                for (i = pos; i > 0; i--)
                        up->osds[i] = up->osds[i - 1];
                up->osds[0] = up->primary;
        }
}

/*
 * Get pg_temp and primary_temp mappings for given PG.
 *
 * Note that a PG may have none, only pg_temp, only primary_temp or
 * both pg_temp and primary_temp mappings.  This means @temp isn't
 * always a valid OSD set on return: in the "only primary_temp" case,
 * @temp will have its ->primary >= 0 but ->size == 0.
 */
static void get_temp_osds(struct ceph_osdmap *osdmap,
                          struct ceph_pg_pool_info *pi,
                          const struct ceph_pg *pgid,
                          struct ceph_osds *temp)
{
        struct ceph_pg_mapping *pg;
        int i;

        ceph_osds_init(temp);

        /* pg_temp? */
        pg = lookup_pg_mapping(&osdmap->pg_temp, pgid);
        if (pg) {
                for (i = 0; i < pg->pg_temp.len; i++) {
                        if (ceph_osd_is_down(osdmap, pg->pg_temp.osds[i])) {
                                if (ceph_can_shift_osds(pi))
                                        continue;

                                temp->osds[temp->size++] = CRUSH_ITEM_NONE;
                        } else {
                                temp->osds[temp->size++] = pg->pg_temp.osds[i];
                        }
                }

                /* apply pg_temp's primary */
                for (i = 0; i < temp->size; i++) {
                        if (temp->osds[i] != CRUSH_ITEM_NONE) {
                                temp->primary = temp->osds[i];
                                break;
                        }
                }
        }

        /* primary_temp? */
        pg = lookup_pg_mapping(&osdmap->primary_temp, pgid);
        if (pg)
                temp->primary = pg->primary_temp.osd;
}

/*
 * Map a PG to its acting set as well as its up set.
 *
 * Acting set is used for data mapping purposes, while up set can be
 * recorded for detecting interval changes and deciding whether to
 * resend a request.
 */
void ceph_pg_to_up_acting_osds(struct ceph_osdmap *osdmap,
                               struct ceph_pg_pool_info *pi,
                               const struct ceph_pg *raw_pgid,
                               struct ceph_osds *up,
                               struct ceph_osds *acting)
{
        struct ceph_pg pgid;
        u32 pps;

        WARN_ON(pi->id != raw_pgid->pool);
        raw_pg_to_pg(pi, raw_pgid, &pgid);

        pg_to_raw_osds(osdmap, pi, raw_pgid, up, &pps);
        apply_upmap(osdmap, &pgid, up);
        raw_to_up_osds(osdmap, pi, up);
        apply_primary_affinity(osdmap, pi, pps, up);
        get_temp_osds(osdmap, pi, &pgid, acting);
        if (!acting->size) {
                memcpy(acting->osds, up->osds, up->size * sizeof(up->osds[0]));
                acting->size = up->size;
                if (acting->primary == -1)
                        acting->primary = up->primary;
        }
        WARN_ON(!osds_valid(up) || !osds_valid(acting));
}

bool ceph_pg_to_primary_shard(struct ceph_osdmap *osdmap,
                              struct ceph_pg_pool_info *pi,
                              const struct ceph_pg *raw_pgid,
                              struct ceph_spg *spgid)
{
        struct ceph_pg pgid;
        struct ceph_osds up, acting;
        int i;

        WARN_ON(pi->id != raw_pgid->pool);
        raw_pg_to_pg(pi, raw_pgid, &pgid);

        if (ceph_can_shift_osds(pi)) {
                spgid->pgid = pgid; /* struct */
                spgid->shard = CEPH_SPG_NOSHARD;
                return true;
        }

        ceph_pg_to_up_acting_osds(osdmap, pi, &pgid, &up, &acting);
        for (i = 0; i < acting.size; i++) {
                if (acting.osds[i] == acting.primary) {
                        spgid->pgid = pgid; /* struct */
                        spgid->shard = i;
                        return true;
                }
        }

        return false;
}

/*
 * Return acting primary for given PG, or -1 if none.
 */
int ceph_pg_to_acting_primary(struct ceph_osdmap *osdmap,
                              const struct ceph_pg *raw_pgid)
{
        struct ceph_pg_pool_info *pi;
        struct ceph_osds up, acting;

        pi = ceph_pg_pool_by_id(osdmap, raw_pgid->pool);
        if (!pi)
                return -1;

        ceph_pg_to_up_acting_osds(osdmap, pi, raw_pgid, &up, &acting);
        return acting.primary;
}
EXPORT_SYMBOL(ceph_pg_to_acting_primary);

static struct crush_loc_node *alloc_crush_loc(size_t type_name_len,
                                              size_t name_len)
{
        struct crush_loc_node *loc;

        loc = kmalloc(sizeof(*loc) + type_name_len + name_len + 2, GFP_NOIO);
        if (!loc)
                return NULL;

        RB_CLEAR_NODE(&loc->cl_node);
        return loc;
}

static void free_crush_loc(struct crush_loc_node *loc)
{
        WARN_ON(!RB_EMPTY_NODE(&loc->cl_node));

        kfree(loc);
}

static int crush_loc_compare(const struct crush_loc *loc1,
                             const struct crush_loc *loc2)
{
        return strcmp(loc1->cl_type_name, loc2->cl_type_name) ?:
               strcmp(loc1->cl_name, loc2->cl_name);
}

DEFINE_RB_FUNCS2(crush_loc, struct crush_loc_node, cl_loc, crush_loc_compare,
                 RB_BYPTR, const struct crush_loc *, cl_node)

/*
 * Parses a set of <bucket type name>':'<bucket name> pairs separated
 * by '|', e.g. "rack:foo1|rack:foo2|datacenter:bar".
 *
 * Note that @crush_location is modified by strsep().
 */
int ceph_parse_crush_location(char *crush_location, struct rb_root *locs)
{
        struct crush_loc_node *loc;
        const char *type_name, *name, *colon;
        size_t type_name_len, name_len;

        dout("%s '%s'\n", __func__, crush_location);
        while ((type_name = strsep(&crush_location, "|"))) {
                colon = strchr(type_name, ':');
                if (!colon)
                        return -EINVAL;

                type_name_len = colon - type_name;
                if (type_name_len == 0)
                        return -EINVAL;

                name = colon + 1;
                name_len = strlen(name);
                if (name_len == 0)
                        return -EINVAL;

                loc = alloc_crush_loc(type_name_len, name_len);
                if (!loc)
                        return -ENOMEM;

                loc->cl_loc.cl_type_name = loc->cl_data;
                memcpy(loc->cl_loc.cl_type_name, type_name, type_name_len);
                loc->cl_loc.cl_type_name[type_name_len] = '\0';

                loc->cl_loc.cl_name = loc->cl_data + type_name_len + 1;
                memcpy(loc->cl_loc.cl_name, name, name_len);
                loc->cl_loc.cl_name[name_len] = '\0';

                if (!__insert_crush_loc(locs, loc)) {
                        free_crush_loc(loc);
                        return -EEXIST;
                }

                dout("%s type_name '%s' name '%s'\n", __func__,
                     loc->cl_loc.cl_type_name, loc->cl_loc.cl_name);
        }

        return 0;
}

int ceph_compare_crush_locs(struct rb_root *locs1, struct rb_root *locs2)
{
        struct rb_node *n1 = rb_first(locs1);
        struct rb_node *n2 = rb_first(locs2);
        int ret;

        for ( ; n1 && n2; n1 = rb_next(n1), n2 = rb_next(n2)) {
                struct crush_loc_node *loc1 =
                    rb_entry(n1, struct crush_loc_node, cl_node);
                struct crush_loc_node *loc2 =
                    rb_entry(n2, struct crush_loc_node, cl_node);

                ret = crush_loc_compare(&loc1->cl_loc, &loc2->cl_loc);
                if (ret)
                        return ret;
        }

        if (!n1 && n2)
                return -1;
        if (n1 && !n2)
                return 1;
        return 0;
}

void ceph_clear_crush_locs(struct rb_root *locs)
{
        while (!RB_EMPTY_ROOT(locs)) {
                struct crush_loc_node *loc =
                    rb_entry(rb_first(locs), struct crush_loc_node, cl_node);

                erase_crush_loc(locs, loc);
                free_crush_loc(loc);
        }
}

/*
 * [a-zA-Z0-9-_.]+
 */
static bool is_valid_crush_name(const char *name)
{
        do {
                if (!('a' <= *name && *name <= 'z') &&
                    !('A' <= *name && *name <= 'Z') &&
                    !('0' <= *name && *name <= '9') &&
                    *name != '-' && *name != '_' && *name != '.')
                        return false;