// SPDX-License-Identifier: GPL-2.0

  #include <linux/ceph/ceph_debug.h>

  #include <linux/module.h>

  #include <linux/slab.h>

  #include <asm/div64.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
  ", *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
  ", *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
  ", *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
  ", *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
  ", *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;
  }

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

  	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
  ",

  		       (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
  ",
  		     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
  ",
  		     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
  ", 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
  ",
  			     i, (int)(*p-start), *p, end);
  			c->rules[i] = NULL;
  			continue;
  		}
  
  		dout("crush_decode rule %d off %x %p to %p
  ",
  		     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 = c->rules[i] = kmalloc(sizeof(*r) +
  					  yes*sizeof(struct crush_rule_step),
  					  GFP_NOFS);
  		if (r == NULL)
  			goto badmem;
  		dout(" rule %d is at %p
  ", 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);

  		}
  	}

  	ceph_decode_skip_map(p, end, 32, string, bad); /* type_map */
  	ceph_decode_skip_map(p, end, 32, string, bad); /* name_map */
  	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
  ",

               c->choose_local_tries);

          dout("crush decode tunable choose_local_fallback_tries = %d
  ",

               c->choose_local_fallback_tries);

          dout("crush decode tunable choose_total_tries = %d
  ",

               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
  ",

  	     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
  ",

  	     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
  ",
  	     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
  ");
  	return c;
  
  badmem:
  	err = -ENOMEM;

  fail:

  	dout("crush_decode fail %d
  ", 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
   */
  static int __insert_pg_pool(struct rb_root *root, struct ceph_pg_pool_info *new)
  {
  	struct rb_node **p = &root->rb_node;
  	struct rb_node *parent = NULL;
  	struct ceph_pg_pool_info *pi = NULL;
  
  	while (*p) {
  		parent = *p;
  		pi = rb_entry(parent, struct ceph_pg_pool_info, node);
  		if (new->id < pi->id)
  			p = &(*p)->rb_left;
  		else if (new->id > pi->id)
  			p = &(*p)->rb_right;
  		else
  			return -EEXIST;
  	}
  
  	rb_link_node(&new->node, parent, p);
  	rb_insert_color(&new->node, root);
  	return 0;
  }

  static struct ceph_pg_pool_info *__lookup_pg_pool(struct rb_root *root, u64 id)

  {
  	struct ceph_pg_pool_info *pi;
  	struct rb_node *n = root->rb_node;
  
  	while (n) {
  		pi = rb_entry(n, struct ceph_pg_pool_info, node);
  		if (id < pi->id)
  			n = n->rb_left;
  		else if (id > pi->id)
  			n = n->rb_right;
  		else
  			return pi;
  	}
  	return NULL;
  }

  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, (int) 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);

  static void __remove_pg_pool(struct rb_root *root, struct ceph_pg_pool_info *pi)
  {
  	rb_erase(&pi->node, root);
  	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
  ", ev, cv);

  		return -EINVAL;
  	}

  	if (cv > 9) {

  		pr_warn("got v %d cv %d > 9 of ceph_pg_pool
  ", 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
  ", num);
  	while (num--) {

  		ceph_decode_64_safe(p, end, pool, bad);

  		ceph_decode_32_safe(p, end, len, bad);

  		dout("  pool %llu len %d
  ", 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
  ", pi->name);

  		}
  		*p += len;
  	}
  	return 0;
  
  bad:
  	return -EINVAL;
  }
  
  /*
   * 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;

  	mutex_init(&map->crush_workspace_mutex);

  
  	return map;
  }

  void ceph_osdmap_destroy(struct ceph_osdmap *map)
  {
  	dout("osdmap_destroy %p
  ", map);
  	if (map->crush)
  		crush_destroy(map->crush);
  	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);
  	}
  	kfree(map->osd_state);
  	kfree(map->osd_weight);
  	kfree(map->osd_addr);

  	kfree(map->osd_primary_affinity);

  	kfree(map->crush_workspace);

  	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, int max)
  {

  	u32 *state;

  	u32 *weight;

  	struct ceph_entity_addr *addr;
  	int i;

  	state = krealloc(map->osd_state, max*sizeof(*state), GFP_NOFS);

  	if (!state)
  		return -ENOMEM;
  	map->osd_state = state;

  	weight = krealloc(map->osd_weight, max*sizeof(*weight), GFP_NOFS);

  	if (!weight)
  		return -ENOMEM;
  	map->osd_weight = weight;

  	addr = krealloc(map->osd_addr, max*sizeof(*addr), GFP_NOFS);
  	if (!addr)

  		return -ENOMEM;

  	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 = krealloc(map->osd_primary_affinity,
  				    max*sizeof(*affinity), GFP_NOFS);
  		if (!affinity)
  			return -ENOMEM;

  		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)
  {

  	void *workspace;

  	size_t work_size;

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

  	work_size = crush_work_size(crush, CEPH_PG_MAX_SIZE);
  	dout("%s work_size %zu bytes
  ", __func__, work_size);
  	workspace = kmalloc(work_size, GFP_NOIO);

  	if (!workspace) {
  		crush_destroy(crush);
  		return -ENOMEM;
  	}
  	crush_init_workspace(crush, workspace);

  	if (map->crush)
  		crush_destroy(map->crush);

  	kfree(map->crush_workspace);

  	map->crush = crush;

  	map->crush_workspace = workspace;

  	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
  ",
  				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
  ",
  				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
  ",
  				version, prefix);

  			return -EINVAL;
  		}
  
  		/* old osdmap enconding */
  		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;
  
  			pi->id = pool;
  
  			ret = __insert_pg_pool(&map->pg_pools, pi);
  			if (ret) {
  				kfree(pi);
  				return ret;
  			}
  		}
  
  		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 = kmalloc(map->max_osd*sizeof(u32),
  						    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) {
  		kfree(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
  ", 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, 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
  ", __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) +

  				       sizeof(*map->osd_addr)), 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;

  	ceph_decode_copy(p, map->osd_addr, map->max_osd*sizeof(*map->osd_addr));

  	for (i = 0; i < map->max_osd; i++)
  		ceph_decode_addr(&map->osd_addr[i]);

  
  	/* 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
  ", 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)
  ",
  	       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)
  {
  	struct ceph_osdmap *map;
  	int ret;

  	map = ceph_osdmap_alloc();

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

  	ret = osdmap_decode(p, end, 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,

  				      struct ceph_osdmap *map)
  {
  	void *new_up_client;
  	void *new_state;
  	void *new_weight_end;
  	u32 len;
  
  	new_up_client = *p;
  	ceph_decode_32_safe(p, end, len, e_inval);
  	len *= sizeof(u32) + sizeof(struct ceph_entity_addr);
  	ceph_decode_need(p, end, len, e_inval);
  	*p += len;
  
  	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
  ", 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;

  		int ret;
  
  		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
  ", osd);
  		if ((map->osd_state[osd] & CEPH_OSD_EXISTS) &&
  		    (xorstate & CEPH_OSD_EXISTS)) {
  			pr_info("osd%d does not exist
  ", 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);
  		ceph_decode_copy(p, &addr, sizeof(addr));
  		ceph_decode_addr(&addr);
  		BUG_ON(osd >= map->max_osd);
  		pr_info("osd%d up
  ", 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,

  					     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
  ", __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
  ",
  		     len, *p, end);

  		return ceph_osdmap_decode(p, min(*p+len, end));

  	}
  
  	/* 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, 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
  ", 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)
  ",
  	       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;
  }

  /*
   * calculate file layout from given offset, length.
   * fill in correct oid, logical length, and object extent
   * offset, length.
   *
   * for now, we write only a single su, until we can
   * pass a stride back to the caller.
   */

  int ceph_calc_file_object_mapping(struct ceph_file_layout *layout,

  				   u64 off, u64 len,

  				   u64 *ono,

  				   u64 *oxoff, u64 *oxlen)
  {

  	u32 osize = layout->object_size;
  	u32 su = layout->stripe_unit;
  	u32 sc = layout->stripe_count;

  	u32 bl, stripeno, stripepos, objsetno;
  	u32 su_per_object;

  	u64 t, su_offset;

  	dout("mapping %llu~%llu  osize %u fl_su %u
  ", off, len,

  	     osize, su);

  	if (su == 0 || sc == 0)
  		goto invalid;

  	su_per_object = osize / su;

  	if (su_per_object == 0)
  		goto invalid;

  	dout("osize %u / su %u = su_per_object %u
  ", osize, su,
  	     su_per_object);

  	if ((su & ~PAGE_MASK) != 0)
  		goto invalid;

  	/* bl = *off / su; */
  	t = off;
  	do_div(t, su);
  	bl = t;
  	dout("off %llu / su %u = bl %u
  ", off, su, bl);
  
  	stripeno = bl / sc;
  	stripepos = bl % sc;
  	objsetno = stripeno / su_per_object;

  	*ono = objsetno * sc + stripepos;

  	dout("objset %u * sc %u = ono %u
  ", objsetno, sc, (unsigned int)*ono);

  
  	/* *oxoff = *off % layout->fl_stripe_unit;  # offset in su */

  	t = off;

  	su_offset = do_div(t, su);
  	*oxoff = su_offset + (stripeno % su_per_object) * su;
  
  	/*
  	 * Calculate the length of the extent being written to the selected

  	 * object. This is the minimum of the full length requested (len) or

  	 * the remainder of the current stripe being written to.
  	 */

  	*oxlen = min_t(u64, len, su - su_offset);

  
  	dout(" obj extent %llu~%llu
  ", *oxoff, *oxlen);

  	return 0;
  
  invalid:
  	dout(" invalid layout
  ");
  	*ono = 0;
  	*oxoff = 0;
  	*oxlen = 0;
  	return -EINVAL;

  }

  EXPORT_SYMBOL(ceph_calc_file_object_mapping);

  
  /*

   * 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.

   */

  int __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
  ", __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);
  			if (!buf)
  				return -ENOMEM;
  		}
  		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
  ", __func__,
  		     oid->name, nsl, oloc->pool_ns->str,
  		     raw_pgid->pool, raw_pgid->seed);
  	}

  	return 0;
  }

  
  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;
  
  	return __ceph_object_locator_to_pg(pi, oid, oloc, raw_pgid);
  }

  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;

  	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);

  	mutex_lock(&map->crush_workspace_mutex);

  	r = crush_do_rule(map->crush, ruleno, x, result, result_max,

  			  weight, weight_max, map->crush_workspace,
  			  arg_map ? arg_map->args : NULL);

  	mutex_unlock(&map->crush_workspace_mutex);

  	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
  ",

  		       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
  ",
  		       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
  ",

  		       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);