// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
	// vim: ts=8 sw=2 smarttab
	
	#include "osd/osd_types.h"
	#include "common/debug.h"
	#include "common/Formatter.h"
	#include "common/errno.h"
	#include "common/TextTable.h"
	#include "include/stringify.h"
	
	#include "CrushWrapper.h"
	#include "CrushTreeDumper.h"
	
	#define dout_subsys ceph_subsys_crush
	
	using std::cout;
	using std::list;
	using std::map;
	using std::make_pair;
	using std::ostream;
	using std::ostringstream;
	using std::pair;
	using std::set;
	using std::string;
	using std::vector;
	
	using ceph::bufferlist;
	using ceph::decode;
	using ceph::decode_nohead;
	using ceph::encode;
	using ceph::Formatter;
	
	bool CrushWrapper::has_legacy_rule_ids() const
	{
	  for (unsigned i=0; i<crush->max_rules; i++) {
	    crush_rule *r = crush->rules[i];
	    if (r &&
		r->mask.ruleset != i) {
	      return true;
	    }
	  }
	  return false;
	}
	
	std::map<int, int> CrushWrapper::renumber_rules()
	{
	  std::map<int, int> result;
	  for (unsigned i=0; i<crush->max_rules; i++) {
	    crush_rule *r = crush->rules[i];
	    if (r && r->mask.ruleset != i) {
	      result[r->mask.ruleset] = i;
	      r->mask.ruleset = i;
	    }
	  }
	  return result;
	}
	
	bool CrushWrapper::has_non_straw2_buckets() const
	{
	  for (int i=0; i<crush->max_buckets; ++i) {
	    crush_bucket *b = crush->buckets[i];
	    if (!b)
	      continue;
	    if (b->alg != CRUSH_BUCKET_STRAW2)
	      return true;
	  }
	  return false;
	}
	
	bool CrushWrapper::has_v2_rules() const
	{
	  for (unsigned i=0; i<crush->max_rules; i++) {
	    if (is_v2_rule(i)) {
	      return true;
	    }
	  }
	  return false;
	}
	
	bool CrushWrapper::is_v2_rule(unsigned ruleid) const
	{
	  // check rule for use of indep or new SET_* rule steps
	  if (ruleid >= crush->max_rules)
	    return false;
	  crush_rule *r = crush->rules[ruleid];
	  if (!r)
	    return false;
	  for (unsigned j=0; j<r->len; j++) {
	    if (r->steps[j].op == CRUSH_RULE_CHOOSE_INDEP ||
		r->steps[j].op == CRUSH_RULE_CHOOSELEAF_INDEP ||
		r->steps[j].op == CRUSH_RULE_SET_CHOOSE_TRIES ||
		r->steps[j].op == CRUSH_RULE_SET_CHOOSELEAF_TRIES) {
	      return true;
	    }
	  }
	  return false;
	}
	
	bool CrushWrapper::has_v3_rules() const
	{
	  for (unsigned i=0; i<crush->max_rules; i++) {
	    if (is_v3_rule(i)) {
	      return true;
	    }
	  }
	  return false;
	}
	
	bool CrushWrapper::is_v3_rule(unsigned ruleid) const
	{
	  // check rule for use of SET_CHOOSELEAF_VARY_R step
	  if (ruleid >= crush->max_rules)
	    return false;
	  crush_rule *r = crush->rules[ruleid];
	  if (!r)
	    return false;
	  for (unsigned j=0; j<r->len; j++) {
	    if (r->steps[j].op == CRUSH_RULE_SET_CHOOSELEAF_VARY_R) {
	      return true;
	    }
	  }
	  return false;
	}
	
	bool CrushWrapper::has_v4_buckets() const
	{
	  for (int i=0; i<crush->max_buckets; ++i) {
	    crush_bucket *b = crush->buckets[i];
	    if (!b)
	      continue;
	    if (b->alg == CRUSH_BUCKET_STRAW2)
	      return true;
	  }
	  return false;
	}
	
	bool CrushWrapper::has_v5_rules() const
	{
	  for (unsigned i=0; i<crush->max_rules; i++) {
	    if (is_v5_rule(i)) {
	      return true;
	    }
	  }
	  return false;
	}
	
	bool CrushWrapper::is_v5_rule(unsigned ruleid) const
	{
	  // check rule for use of SET_CHOOSELEAF_STABLE step
	  if (ruleid >= crush->max_rules)
	    return false;
	  crush_rule *r = crush->rules[ruleid];
	  if (!r)
	    return false;
	  for (unsigned j=0; j<r->len; j++) {
	    if (r->steps[j].op == CRUSH_RULE_SET_CHOOSELEAF_STABLE) {
	      return true;
	    }
	  }
	  return false;
	}
	
	bool CrushWrapper::has_choose_args() const
	{
	  return !choose_args.empty();
	}
	
	bool CrushWrapper::has_incompat_choose_args() const
	{
	  if (choose_args.empty())
	    return false;
	  if (choose_args.size() > 1)
	    return true;
	  if (choose_args.begin()->first != DEFAULT_CHOOSE_ARGS)
	    return true;
	  crush_choose_arg_map arg_map = choose_args.begin()->second;
	  for (__u32 i = 0; i < arg_map.size; i++) {
	    crush_choose_arg *arg = &arg_map.args[i];
	    if (arg->weight_set_positions == 0 &&
		arg->ids_size == 0)
		continue;
	    if (arg->weight_set_positions != 1)
	      return true;
	    if (arg->ids_size != 0)
	      return true;
	  }
	  return false;
	}
	
	int CrushWrapper::split_id_class(int i, int *idout, int *classout) const
	{
	  if (!item_exists(i))
	    return -EINVAL;
	  string name = get_item_name(i);
	  size_t pos = name.find("~");
	  if (pos == string::npos) {
	    *idout = i;
	    *classout = -1;
	    return 0;
	  }
	  string name_no_class = name.substr(0, pos);
	  if (!name_exists(name_no_class))
	    return -ENOENT;
	  string class_name = name.substr(pos + 1);
	  if (!class_exists(class_name))
	    return -ENOENT;
	  *idout = get_item_id(name_no_class);
	  *classout = get_class_id(class_name);
	  return 0;
	}
	
	int CrushWrapper::can_rename_item(const string& srcname,
	                                  const string& dstname,
	                                  ostream *ss) const
	{
	  if (name_exists(srcname)) {
	    if (name_exists(dstname)) {
	      *ss << "dstname = '" << dstname << "' already exists";
	      return -EEXIST;
	    }
	    if (is_valid_crush_name(dstname)) {
	      return 0;
	    } else {
	      *ss << "dstname = '" << dstname << "' does not match [-_.0-9a-zA-Z]+";
	      return -EINVAL;
	    }
	  } else {
	    if (name_exists(dstname)) {
	      *ss << "srcname = '" << srcname << "' does not exist "
	          << "and dstname = '" << dstname << "' already exists";
	      return -EALREADY;
	    } else {
	      *ss << "srcname = '" << srcname << "' does not exist";
	      return -ENOENT;
	    }
	  }
	}
	
	int CrushWrapper::rename_item(const string& srcname,
	                              const string& dstname,
	                              ostream *ss)
	{
	  int ret = can_rename_item(srcname, dstname, ss);
	  if (ret < 0)
	    return ret;
	  int oldid = get_item_id(srcname);
	  return set_item_name(oldid, dstname);
	}
	
	int CrushWrapper::can_rename_bucket(const string& srcname,
	                                    const string& dstname,
	                                    ostream *ss) const
	{
	  int ret = can_rename_item(srcname, dstname, ss);
	  if (ret)
	    return ret;
	  int srcid = get_item_id(srcname);
	  if (srcid >= 0) {
	    *ss << "srcname = '" << srcname << "' is not a bucket "
	        << "because its id = " << srcid << " is >= 0";
	    return -ENOTDIR;
	  }
	  return 0;
	}
	
	int CrushWrapper::rename_bucket(const string& srcname,
	                                const string& dstname,
	                                ostream *ss)
	{
	  int ret = can_rename_bucket(srcname, dstname, ss);
	  if (ret < 0)
	    return ret;
	  int oldid = get_item_id(srcname);
	  return set_item_name(oldid, dstname);
	}
	
	int CrushWrapper::rename_rule(const string& srcname,
	                              const string& dstname,
	                              ostream *ss)
	{
	  if (!rule_exists(srcname)) {
	    if (ss) {
	      *ss << "source rule name '" << srcname << "' does not exist";
	    }
	    return -ENOENT;
	  }
	  if (rule_exists(dstname)) {
	    if (ss) {
	      *ss << "destination rule name '" << dstname << "' already exists";
	    }
	    return -EEXIST;
	  }
	  int rule_id = get_rule_id(srcname);
	  auto it = rule_name_map.find(rule_id);
	  ceph_assert(it != rule_name_map.end());
	  it->second = dstname;
	  if (have_rmaps) {
	    rule_name_rmap.erase(srcname);
	    rule_name_rmap[dstname] = rule_id;
	  }
	  return 0;
	}
	
	void CrushWrapper::find_takes(set<int> *roots) const
	{
	  for (unsigned i=0; i<crush->max_rules; i++) {
	    crush_rule *r = crush->rules[i];
	    if (!r)
	      continue;
	    for (unsigned j=0; j<r->len; j++) {
	      if (r->steps[j].op == CRUSH_RULE_TAKE)
		roots->insert(r->steps[j].arg1);
	    }
	  }
	}
	
	void CrushWrapper::find_takes_by_rule(int rule, set<int> *roots) const
	{
	  if (rule < 0 || rule >= (int)crush->max_rules)
	    return;
	  crush_rule *r = crush->rules[rule];
	  if (!r)
	    return;
	  for (unsigned i = 0; i < r->len; i++) {
	    if (r->steps[i].op == CRUSH_RULE_TAKE)
	      roots->insert(r->steps[i].arg1);
	  }
	}
	
	void CrushWrapper::find_roots(set<int> *roots) const
	{
	  for (int i = 0; i < crush->max_buckets; i++) {
	    if (!crush->buckets[i])
	      continue;
	    crush_bucket *b = crush->buckets[i];
	    if (!_search_item_exists(b->id))
	      roots->insert(b->id);
	  }
	}
	
	bool CrushWrapper::subtree_contains(int root, int item) const
	{
	  if (root == item)
	    return true;
	
	  if (root >= 0)
	    return false;  // root is a leaf
	
	  const crush_bucket *b = get_bucket(root);
	  if (IS_ERR(b))
	    return false;
	
	  for (unsigned j=0; j<b->size; j++) {
	    if (subtree_contains(b->items[j], item))
	      return true;
	  }
	  return false;
	}
	
	bool CrushWrapper::_maybe_remove_last_instance(CephContext *cct, int item, bool unlink_only)
	{
	  // last instance?
	  if (_search_item_exists(item)) {
	    return false;
	  }
	  if (item < 0 && _bucket_is_in_use(item)) {
	    return false;
	  }
	
	  if (item < 0 && !unlink_only) {
	    crush_bucket *t = get_bucket(item);
	    ldout(cct, 5) << "_maybe_remove_last_instance removing bucket " << item << dendl;
	    crush_remove_bucket(crush, t);
	    if (class_bucket.count(item) != 0)
	      class_bucket.erase(item);
	    class_remove_item(item);
	    update_choose_args(cct);
	  }
	  if ((item >= 0 || !unlink_only) && name_map.count(item)) {
	    ldout(cct, 5) << "_maybe_remove_last_instance removing name for item " << item << dendl;
	    name_map.erase(item);
	    have_rmaps = false;
	    if (item >= 0 && !unlink_only) {
	      class_remove_item(item);
	    }
	  }
	  rebuild_roots_with_classes(cct);
	  return true;
	}
	
	int CrushWrapper::remove_root(CephContext *cct, int item)
	{
	  crush_bucket *b = get_bucket(item);
	  if (IS_ERR(b)) {
	    // should be idempotent
	    // e.g.: we use 'crush link' to link same host into
	    // different roots, which as a result can cause different
	    // shadow trees reference same hosts too. This means
	    // we may need to destory the same buckets(hosts, racks, etc.)
	    // multiple times during rebuilding all shadow trees.
	    return 0;
	  }
	
	  for (unsigned n = 0; n < b->size; n++) {
	    if (b->items[n] >= 0)
	      continue;
	    int r = remove_root(cct, b->items[n]);
	    if (r < 0)
	      return r;
	  }
	
	  crush_remove_bucket(crush, b);
	  if (name_map.count(item) != 0) {
	    name_map.erase(item);
	    have_rmaps = false;
	  }
	  if (class_bucket.count(item) != 0)
	    class_bucket.erase(item);
	  class_remove_item(item);
	  update_choose_args(cct);
	  return 0;
	}
	
	void CrushWrapper::update_choose_args(CephContext *cct)
	{
	  for (auto& i : choose_args) {
	    crush_choose_arg_map &arg_map = i.second;
	    assert(arg_map.size == (unsigned)crush->max_buckets);
	    unsigned positions = get_choose_args_positions(arg_map);
	    for (int j = 0; j < crush->max_buckets; ++j) {
	      crush_bucket *b = crush->buckets[j];
	      assert(j < (int)arg_map.size);
	      auto& carg = arg_map.args[j];
	      // strip out choose_args for any buckets that no longer exist
	      if (!b || b->alg != CRUSH_BUCKET_STRAW2) {
		if (carg.ids) {
		  if (cct)
		    ldout(cct,10) << __func__ << " removing " << i.first << " bucket "
				  << (-1-j) << " ids" << dendl;
		  free(carg.ids);
		  carg.ids = 0;
		  carg.ids_size = 0;
		}
		if (carg.weight_set) {
		  if (cct)
		    ldout(cct,10) << __func__ << " removing " << i.first << " bucket "
				  << (-1-j) << " weight_sets" << dendl;
		  for (unsigned p = 0; p < carg.weight_set_positions; ++p) {
		    free(carg.weight_set[p].weights);
		  }
		  free(carg.weight_set);
		  carg.weight_set = 0;
		  carg.weight_set_positions = 0;
		}
		continue;
	      }
	      if (carg.weight_set_positions == 0) {
		continue;	// skip it
	      }
	      if (carg.weight_set_positions != positions) {
		if (cct)
		  lderr(cct) << __func__ << " " << i.first << " bucket "
			     << (-1-j) << " positions " << carg.weight_set_positions
			     << " -> " << positions << dendl;
		continue;	// wth... skip!
	      }
	      // mis-sized weight_sets?  this shouldn't ever happen.
	      for (unsigned p = 0; p < positions; ++p) {
		if (carg.weight_set[p].size != b->size) {
		  if (cct)
		    lderr(cct) << __func__ << " fixing " << i.first << " bucket "
			       << (-1-j) << " position " << p
			       << " size " << carg.weight_set[p].size << " -> "
			       << b->size << dendl;
		  auto old_ws = carg.weight_set[p];
		  carg.weight_set[p].size = b->size;
		  carg.weight_set[p].weights = (__u32*)calloc(b->size, sizeof(__u32));
		  auto max = std::min<unsigned>(old_ws.size, b->size);
		  for (unsigned k = 0; k < max; ++k) {
		    carg.weight_set[p].weights[k] = old_ws.weights[k];
		  }
		  free(old_ws.weights);
		}
	      }
	    }
	  }
	}
	
	int CrushWrapper::remove_item(CephContext *cct, int item, bool unlink_only)
	{
	  ldout(cct, 5) << "remove_item " << item
			<< (unlink_only ? " unlink_only":"") << dendl;
	
	  int ret = -ENOENT;
	
	  if (item < 0 && !unlink_only) {
	    crush_bucket *t = get_bucket(item);
	    if (IS_ERR(t)) {
	      ldout(cct, 1) << "remove_item bucket " << item << " does not exist"
			    << dendl;
	      return -ENOENT;
	    }
	
	    if (t->size) {
	      ldout(cct, 1) << "remove_item bucket " << item << " has " << t->size
			    << " items, not empty" << dendl;
	      return -ENOTEMPTY;
	    }
	    if (_bucket_is_in_use(item)) {
	      return -EBUSY;
	    }
	  }
	
	  for (int i = 0; i < crush->max_buckets; i++) {
	    if (!crush->buckets[i])
	      continue;
	    crush_bucket *b = crush->buckets[i];
	
	    for (unsigned i=0; i<b->size; ++i) {
	      int id = b->items[i];
	      if (id == item) {
		ldout(cct, 5) << "remove_item removing item " << item
			      << " from bucket " << b->id << dendl;
		adjust_item_weight_in_bucket(cct, item, 0, b->id, true);
		bucket_remove_item(b, item);
		ret = 0;
	      }
	    }
	  }
	
	  if (_maybe_remove_last_instance(cct, item, unlink_only))
	    ret = 0;
	  
	  return ret;
	}
	
	bool CrushWrapper::_search_item_exists(int item) const
	{
	  for (int i = 0; i < crush->max_buckets; i++) {
	    if (!crush->buckets[i])
	      continue;
	    crush_bucket *b = crush->buckets[i];
	    for (unsigned j=0; j<b->size; ++j) {
	      if (b->items[j] == item)
		return true;
	    }
	  }
	  return false;
	}
	
	bool CrushWrapper::_bucket_is_in_use(int item)
	{
	  for (auto &i : class_bucket)
	    for (auto &j : i.second)
	      if (j.second == item)
		return true;
	  for (unsigned i = 0; i < crush->max_rules; ++i) {
	    crush_rule *r = crush->rules[i];
	    if (!r)
	      continue;
	    for (unsigned j = 0; j < r->len; ++j) {
	      if (r->steps[j].op == CRUSH_RULE_TAKE) {
		int step_item = r->steps[j].arg1;
		int original_item;
		int c;
		int res = split_id_class(step_item, &original_item, &c);
		if (res < 0)
		  return false;
		if (step_item == item || original_item == item)
		  return true;
	      }
	    }
	  }
	  return false;
	}
	
	int CrushWrapper::_remove_item_under(
	  CephContext *cct, int item, int ancestor, bool unlink_only)
	{
	  ldout(cct, 5) << "_remove_item_under " << item << " under " << ancestor
			<< (unlink_only ? " unlink_only":"") << dendl;
	
	  if (ancestor >= 0) {
	    return -EINVAL;
	  }
	
	  if (!bucket_exists(ancestor))
	    return -EINVAL;
	
	  int ret = -ENOENT;
	
	  crush_bucket *b = get_bucket(ancestor);
	  for (unsigned i=0; i<b->size; ++i) {
	    int id = b->items[i];
	    if (id == item) {
	      ldout(cct, 5) << "_remove_item_under removing item " << item
			    << " from bucket " << b->id << dendl;
	      adjust_item_weight_in_bucket(cct, item, 0, b->id, true);
	      bucket_remove_item(b, item);
	      ret = 0;
	    } else if (id < 0) {
	      int r = remove_item_under(cct, item, id, unlink_only);
	      if (r == 0)
		ret = 0;
	    }
	  }
	  return ret;
	}
	
	int CrushWrapper::remove_item_under(
	  CephContext *cct, int item, int ancestor, bool unlink_only)
	{
	  ldout(cct, 5) << "remove_item_under " << item << " under " << ancestor
			<< (unlink_only ? " unlink_only":"") << dendl;
	
	  if (!unlink_only && _bucket_is_in_use(item)) {
	    return -EBUSY;
	  }
	
	  int ret = _remove_item_under(cct, item, ancestor, unlink_only);
	  if (ret < 0)
	    return ret;
	
	  if (item < 0 && !unlink_only) {
	    crush_bucket *t = get_bucket(item);
	    if (IS_ERR(t)) {
	      ldout(cct, 1) << "remove_item_under bucket " << item
	                    << " does not exist" << dendl;
	      return -ENOENT;
	    }
	
	    if (t->size) {
	      ldout(cct, 1) << "remove_item_under bucket " << item << " has " << t->size
			    << " items, not empty" << dendl;
	      return -ENOTEMPTY;
	    }
	  }
	
	  if (_maybe_remove_last_instance(cct, item, unlink_only))
	    ret = 0;
	
	  return ret;
	}
	
	int CrushWrapper::get_common_ancestor_distance(CephContext *cct, int id,
				       const std::multimap<string,string>& loc) const
	{
	  ldout(cct, 5) << __func__ << " " << id << " " << loc << dendl;
	  if (!item_exists(id))
	    return -ENOENT;
	  map<string,string> id_loc = get_full_location(id);
	  ldout(cct, 20) << " id is at " << id_loc << dendl;
	
	  for (map<int,string>::const_iterator p = type_map.begin();
	       p != type_map.end();
	       ++p) {
	    map<string,string>::iterator ip = id_loc.find(p->second);
	    if (ip == id_loc.end())
	      continue;
	    for (std::multimap<string,string>::const_iterator q = loc.find(p->second);
		 q != loc.end();
		 ++q) {
	      if (q->first != p->second)
		break;
	      if (q->second == ip->second)
		return p->first;
	    }
	  }
	  return -ERANGE;
	}
	
	int CrushWrapper::parse_loc_map(const std::vector<string>& args,
					std::map<string,string> *ploc)
	{
	  ploc->clear();
	  for (unsigned i = 0; i < args.size(); ++i) {
	    const char *s = args[i].c_str();
	    const char *pos = strchr(s, '=');
	    if (!pos)
	      return -EINVAL;
	    string key(s, 0, pos-s);
	    string value(pos+1);
	    if (value.length())
	      (*ploc)[key] = value;
	    else
	      return -EINVAL;
	  }
	  return 0;
	}
	
	int CrushWrapper::parse_loc_multimap(const std::vector<string>& args,
						    std::multimap<string,string> *ploc)
	{
	  ploc->clear();
	  for (unsigned i = 0; i < args.size(); ++i) {
	    const char *s = args[i].c_str();
	    const char *pos = strchr(s, '=');
	    if (!pos)
	      return -EINVAL;
	    string key(s, 0, pos-s);
	    string value(pos+1);
	    if (value.length())
	      ploc->insert(make_pair(key, value));
	    else
	      return -EINVAL;
	  }
	  return 0;
	}
	
	bool CrushWrapper::check_item_loc(CephContext *cct, int item, const map<string,string>& loc,
					  int *weight)
	{
	  ldout(cct, 5) << "check_item_loc item " << item << " loc " << loc << dendl;
	
	  for (map<int,string>::const_iterator p = type_map.begin(); p != type_map.end(); ++p) {
	    // ignore device
	    if (p->first == 0)
	      continue;
	
	    // ignore types that aren't specified in loc
	    map<string,string>::const_iterator q = loc.find(p->second);
	    if (q == loc.end()) {
	      ldout(cct, 2) << "warning: did not specify location for '" << p->second << "' level (levels are "
			    << type_map << ")" << dendl;
	      continue;
	    }
	
	    if (!name_exists(q->second)) {
	      ldout(cct, 5) << "check_item_loc bucket " << q->second << " dne" << dendl;
	      return false;
	    }
	
	    int id = get_item_id(q->second);
	    if (id >= 0) {
	      ldout(cct, 5) << "check_item_loc requested " << q->second << " for type " << p->second
			    << " is a device, not bucket" << dendl;
	      return false;
	    }
	
	    ceph_assert(bucket_exists(id));
	    crush_bucket *b = get_bucket(id);
	
	    // see if item exists in this bucket
	    for (unsigned j=0; j<b->size; j++) {
	      if (b->items[j] == item) {
		ldout(cct, 2) << "check_item_loc " << item << " exists in bucket " << b->id << dendl;
		if (weight)
		  *weight = crush_get_bucket_item_weight(b, j);
		return true;
	      }
	    }
	    return false;
	  }
	  
	  ldout(cct, 2) << __func__ << " item " << item << " loc " << loc << dendl;
	  return false;
	}
	
	map<string, string> CrushWrapper::get_full_location(int id) const
	{
	  vector<pair<string, string> > full_location_ordered;
	  map<string,string> full_location;
	
	  get_full_location_ordered(id, full_location_ordered);
	
	  std::copy(full_location_ordered.begin(),
	      full_location_ordered.end(),
	      std::inserter(full_location, full_location.begin()));
	
	  return full_location;
	}
	
	int CrushWrapper::get_full_location(const string& name,
					    map<string,string> *ploc)
	{
	  build_rmaps();
	  auto p = name_rmap.find(name);
	  if (p == name_rmap.end()) {
	    return -ENOENT;
	  }
	  *ploc = get_full_location(p->second);
	  return 0;
	}
	
	int CrushWrapper::get_full_location_ordered(int id, vector<pair<string, string> >& path) const
	{
	  if (!item_exists(id))
	    return -ENOENT;
	  int cur = id;
	  int ret;
	  while (true) {
	    pair<string, string> parent_coord = get_immediate_parent(cur, &ret);
	    if (ret != 0)
	      break;
	    path.push_back(parent_coord);
	    cur = get_item_id(parent_coord.second);
	  }
	  return 0;
	}
	
	string CrushWrapper::get_full_location_ordered_string(int id) const
	{
	  vector<pair<string, string> > full_location_ordered;
	  string full_location;
	  get_full_location_ordered(id, full_location_ordered);
	  reverse(begin(full_location_ordered), end(full_location_ordered));
	  for(auto i = full_location_ordered.begin(); i != full_location_ordered.end(); i++) {
	    full_location = full_location + i->first + "=" + i->second;
	    if (i != full_location_ordered.end() - 1) {
	      full_location = full_location + ",";
	    }
	  }
	  return full_location;
	}
	
	map<int, string> CrushWrapper::get_parent_hierarchy(int id) const
	{
	  map<int,string> parent_hierarchy;
	  pair<string, string> parent_coord = get_immediate_parent(id);
	  int parent_id;
	
	  // get the integer type for id and create a counter from there
	  int type_counter = get_bucket_type(id);
	
	  // if we get a negative type then we can assume that we have an OSD
	  // change behavior in get_item_type FIXME
	  if (type_counter < 0)
	    type_counter = 0;
	
	  // read the type map and get the name of the type with the largest ID
	  int high_type = 0;
	  if (!type_map.empty())
	    high_type = type_map.rbegin()->first;
	
	  parent_id = get_item_id(parent_coord.second);
	
	  while (type_counter < high_type) {
	    type_counter++;
	    parent_hierarchy[ type_counter ] = parent_coord.first;
	
	    if (type_counter < high_type){
	      // get the coordinate information for the next parent
	      parent_coord = get_immediate_parent(parent_id);
	      parent_id = get_item_id(parent_coord.second);
	    }
	  }
	
	  return parent_hierarchy;
	}
	
	int CrushWrapper::get_children(int id, list<int> *children) const
	{
	  // leaf?
	  if (id >= 0) {
	    return 0;
	  }
	
	  auto *b = get_bucket(id);
	  if (IS_ERR(b)) {
	    return -ENOENT;
	  }
	
	  for (unsigned n=0; n<b->size; n++) {
	    children->push_back(b->items[n]);
	  }
	  return b->size;
	}
	
	int CrushWrapper::get_all_children(int id, set<int> *children) const
	{
	  // leaf?
	  if (id >= 0) {
	    return 0;
	  }
	
	  auto *b = get_bucket(id);
	  if (IS_ERR(b)) {
	    return -ENOENT;
	  }
	
	  int c = 0;
	  for (unsigned n = 0; n < b->size; n++) {
	    children->insert(b->items[n]);
	    c++;
	    auto r = get_all_children(b->items[n], children);
	    if (r < 0)
	      return r;
	    c += r;
	  }
	  return c;
	}
	
	void CrushWrapper::get_children_of_type(int id,
	                                        int type,
						vector<int> *children,
						bool exclude_shadow) const
	{
	  if (id >= 0) {
	    if (type == 0) {
	      // want leaf?
	      children->push_back(id);
	    }
	    return;
	  }
	  auto b = get_bucket(id);
	  if (IS_ERR(b)) {
	    return;
	  }
	  if (b->type < type) {
	    // give up
	    return;
	  } else if (b->type == type) {
	    if (!is_shadow_item(b->id) || !exclude_shadow) {
	      children->push_back(b->id);
	    }
	    return;
	  }
	  for (unsigned n = 0; n < b->size; n++) {
	    get_children_of_type(b->items[n], type, children, exclude_shadow);
	  }
	}
	
	int CrushWrapper::verify_upmap(CephContext *cct,
	                               int rule_id,
	                               int pool_size,
	                               const vector<int>& up)
	{
	  auto rule = get_rule(rule_id);
	  if (IS_ERR(rule) || !rule) {
	    lderr(cct) << __func__ << " rule " << rule_id << " does not exist"
	               << dendl;
	    return -ENOENT;
	  }
	  for (unsigned step = 0; step < rule->len; ++step) {
	    auto curstep = &rule->steps[step];
	    ldout(cct, 10) << __func__ << " step " << step << dendl;
	    switch (curstep->op) {
	    case CRUSH_RULE_CHOOSELEAF_FIRSTN:
	    case CRUSH_RULE_CHOOSELEAF_INDEP:
	      {
	        int type = curstep->arg2;
	        if (type == 0) // osd
	          break;
	        map<int, set<int>> osds_by_parent; // parent_of_desired_type -> osds
	        for (auto osd : up) {
	          auto parent = get_parent_of_type(osd, type, rule_id);
	          if (parent < 0) {
	            osds_by_parent[parent].insert(osd);
	          } else {
	            ldout(cct, 1) << __func__ << " unable to get parent of osd." << osd
	                          << ", skipping for now"
	                          << dendl;
	          }
	        }
	        for (auto i : osds_by_parent) {
	          if (i.second.size() > 1) {
	            lderr(cct) << __func__ << " multiple osds " << i.second
	                       << " come from same failure domain " << i.first
	                       << dendl;
	            return -EINVAL;
	          }
	        }
	      }
	      break;
	
	    case CRUSH_RULE_CHOOSE_FIRSTN:
	    case CRUSH_RULE_CHOOSE_INDEP:
	      {
	        int numrep = curstep->arg1;
	        int type = curstep->arg2;
	        if (type == 0) // osd
	          break;
	        if (numrep <= 0)
	          numrep += pool_size;
	        set<int> parents_of_type;
	        for (auto osd : up) {
	          auto parent = get_parent_of_type(osd, type, rule_id);
	          if (parent < 0) {
	            parents_of_type.insert(parent);
	          } else {
	            ldout(cct, 1) << __func__ << " unable to get parent of osd." << osd
	                          << ", skipping for now"
	                          << dendl;
	          }
	        }
	        if ((int)parents_of_type.size() > numrep) {
	          lderr(cct) << __func__ << " number of buckets "
	                     << parents_of_type.size() << " exceeds desired " << numrep
	                     << dendl;
	          return -EINVAL;
	        }
	      }
	      break;
	
	    default:
	      // ignore
	      break;
	    }
	  }
	  return 0;
	}
	
	int CrushWrapper::_get_leaves(int id, list<int> *leaves) const
	{
	  ceph_assert(leaves);
	
	  // Already leaf?
	  if (id >= 0) {
	    leaves->push_back(id);
	    return 0;
	  }
	
	  auto b = get_bucket(id);
	  if (IS_ERR(b)) {
	    return -ENOENT;
	  }
	
	  for (unsigned n = 0; n < b->size; n++) {
	    if (b->items[n] >= 0) {
	      leaves->push_back(b->items[n]);
	    } else {
	      // is a bucket, do recursive call
	      int r = _get_leaves(b->items[n], leaves);
	      if (r < 0) {
	        return r;
	      }
	    }
	  }
	
	  return 0; // all is well
	}
	
	int CrushWrapper::get_leaves(const string &name, set<int> *leaves) const
	{
	  ceph_assert(leaves);
	  leaves->clear();
	
	  if (!name_exists(name)) {
	    return -ENOENT;
	  }
	
	  int id = get_item_id(name);
	  if (id >= 0) {
	    // already leaf
	    leaves->insert(id);
	    return 0;
	  }
	
	  list<int> unordered;
	  int r = _get_leaves(id, &unordered);
	  if (r < 0) {
	    return r;
	  }
	
	  for (auto &p : unordered) {
	    leaves->insert(p);
	  }
	
	  return 0;
	}
	
	int CrushWrapper::insert_item(
	  CephContext *cct, int item, float weight, string name,
	  const map<string,string>& loc,  // typename -> bucketname
	  bool init_weight_sets)
	{
	  ldout(cct, 5) << "insert_item item " << item << " weight " << weight
			<< " name " << name << " loc " << loc << dendl;
	
	  if (!is_valid_crush_name(name))
	    return -EINVAL;
	
	  if (!is_valid_crush_loc(cct, loc))
	    return -EINVAL;
	
	  int r = validate_weightf(weight);
	  if (r < 0) {
	    return r;
	  }
	
	  if (name_exists(name)) {
	    if (get_item_id(name) != item) {
	      ldout(cct, 10) << "device name '" << name << "' already exists as id "
			     << get_item_id(name) << dendl;
	      return -EEXIST;
	    }
	  } else {
	    set_item_name(item, name);
	  }
	
	  int cur = item;
	
	  // create locations if locations don't exist and add child in
	  // location with 0 weight the more detail in the insert_item method
	  // declaration in CrushWrapper.h
	  for (auto p = type_map.begin(); p != type_map.end(); ++p) {
	    // ignore device type
	    if (p->first == 0)
	      continue;
	
	    // skip types that are unspecified
	    map<string,string>::const_iterator q = loc.find(p->second);
	    if (q == loc.end()) {
	      ldout(cct, 2) << "warning: did not specify location for '"
			    << p->second << "' level (levels are "
			    << type_map << ")" << dendl;
	      continue;
	    }
	
	    if (!name_exists(q->second)) {
	      ldout(cct, 5) << "insert_item creating bucket " << q->second << dendl;
	      int empty = 0, newid;
	      int r = add_bucket(0, 0,
				 CRUSH_HASH_DEFAULT, p->first, 1, &cur, &empty, &newid);
	      if (r < 0) {
	        ldout(cct, 1) << "add_bucket failure error: " << cpp_strerror(r)
			      << dendl;
	        return r;
	      }
	      set_item_name(newid, q->second);
	      
	      cur = newid;
	      continue;
	    }
	
	    // add to an existing bucket
	    int id = get_item_id(q->second);
	    if (!bucket_exists(id)) {
	      ldout(cct, 1) << "insert_item doesn't have bucket " << id << dendl;
	      return -EINVAL;
	    }
	
	    // check that we aren't creating a cycle.
	    if (subtree_contains(id, cur)) {
	      ldout(cct, 1) << "insert_item item " << cur << " already exists beneath "
			    << id << dendl;
	      return -EINVAL;
	    }
	
	    // we have done sanity check above
	    crush_bucket *b = get_bucket(id);
	
	    if (p->first != b->type) {
	      ldout(cct, 1) << "insert_item existing bucket has type "
		<< "'" << type_map[b->type] << "' != "
		<< "'" << type_map[p->first] << "'" << dendl;
	      return -EINVAL;
	    }
	
	    // are we forming a loop?
	    if (subtree_contains(cur, b->id)) {
	      ldout(cct, 1) << "insert_item " << cur << " already contains " << b->id
			    << "; cannot form loop" << dendl;
	      return -ELOOP;
	    }
	
	    ldout(cct, 5) << "insert_item adding " << cur << " weight " << weight
			  << " to bucket " << id << dendl;
	    [[maybe_unused]] int r = bucket_add_item(b, cur, 0);
	    ceph_assert(!r);
	    break;
	  }
	
	  // adjust the item's weight in location
	  if (adjust_item_weightf_in_loc(cct, item, weight, loc,
					 item >= 0 && init_weight_sets) > 0) {
	    if (item >= crush->max_devices) {
	      crush->max_devices = item + 1;
	      ldout(cct, 5) << "insert_item max_devices now " << crush->max_devices
			    << dendl;
	    }
	    r = rebuild_roots_with_classes(cct);
	    if (r < 0) {
	      ldout(cct, 0) << __func__ << " unable to rebuild roots with classes: "
	                    << cpp_strerror(r) << dendl;
	      return r;
	    }
	    return 0;
	  }
	
	  ldout(cct, 1) << "error: didn't find anywhere to add item " << item
			<< " in " << loc << dendl;
	  return -EINVAL;
	}
	
	
	int CrushWrapper::move_bucket(
	  CephContext *cct, int id, const map<string,string>& loc)
	{
	  // sorry this only works for buckets
	  if (id >= 0)
	    return -EINVAL;
	
	  if (!item_exists(id))
	    return -ENOENT;
	
	  // get the name of the bucket we are trying to move for later
	  string id_name = get_item_name(id);
	
	  // detach the bucket
	  int bucket_weight = detach_bucket(cct, id);
	
	  // insert the bucket back into the hierarchy
	  return insert_item(cct, id, bucket_weight / (float)0x10000, id_name, loc,
			     false);
	}
	
	int CrushWrapper::detach_bucket(CephContext *cct, int item)
	{
	  if (!crush)
	    return (-EINVAL);
	
	  if (item >= 0)
	    return (-EINVAL);
	
	  // check that the bucket that we want to detach exists
	  ceph_assert(bucket_exists(item));
	
	  // get the bucket's weight
	  crush_bucket *b = get_bucket(item);
	  unsigned bucket_weight = b->weight;
	
	  // get where the bucket is located
	  pair<string, string> bucket_location = get_immediate_parent(item);
	
	  // get the id of the parent bucket
	  int parent_id = get_item_id(bucket_location.second);
	
	  // get the parent bucket
	  crush_bucket *parent_bucket = get_bucket(parent_id);
	
	  if (!IS_ERR(parent_bucket)) {
	    // zero out the bucket weight
	    adjust_item_weight_in_bucket(cct, item, 0, parent_bucket->id, true);
	
	    // remove the bucket from the parent
	    bucket_remove_item(parent_bucket, item);
	  } else if (PTR_ERR(parent_bucket) != -ENOENT) {
	    return PTR_ERR(parent_bucket);
	  }
	
	  // check that we're happy
	  int test_weight = 0;
	  map<string,string> test_location;
	  test_location[ bucket_location.first ] = (bucket_location.second);
	
	  bool successful_detach = !(check_item_loc(cct, item, test_location,
						    &test_weight));
	  ceph_assert(successful_detach);
	  ceph_assert(test_weight == 0);
	
	  return bucket_weight;
	}
	
	bool CrushWrapper::is_parent_of(int child, int p) const
	{
	  int parent = 0;
	  while (!get_immediate_parent_id(child, &parent)) {
	    if (parent == p) {
	      return true;
	    }
	    child = parent;
	  }
	  return false;
	}
	
	int CrushWrapper::swap_bucket(CephContext *cct, int src, int dst)
	{
	  if (src >= 0 || dst >= 0)
	    return -EINVAL;
	  if (!item_exists(src) || !item_exists(dst))
	    return -EINVAL;
	  crush_bucket *a = get_bucket(src);
	  crush_bucket *b = get_bucket(dst);
	  if (is_parent_of(a->id, b->id) || is_parent_of(b->id, a->id)) {
	    return -EINVAL;
	  }
	  unsigned aw = a->weight;
	  unsigned bw = b->weight;
	
	  // swap weights
	  adjust_item_weight(cct, a->id, bw);
	  adjust_item_weight(cct, b->id, aw);
	
	  // swap items
	  map<int,unsigned> tmp;
	  unsigned as = a->size;
	  unsigned bs = b->size;
	  for (unsigned i = 0; i < as; ++i) {
	    int item = a->items[0];
	    int itemw = crush_get_bucket_item_weight(a, 0);
	    tmp[item] = itemw;
	    bucket_remove_item(a, item);
	  }
	  ceph_assert(a->size == 0);
	  ceph_assert(b->size == bs);
	  for (unsigned i = 0; i < bs; ++i) {
	    int item = b->items[0];
	    int itemw = crush_get_bucket_item_weight(b, 0);
	    bucket_remove_item(b, item);
	    bucket_add_item(a, item, itemw);
	  }
	  ceph_assert(a->size == bs);
	  ceph_assert(b->size == 0);
	  for (auto t : tmp) {
	    bucket_add_item(b, t.first, t.second);
	  }
	  ceph_assert(a->size == bs);
	  ceph_assert(b->size == as);
	
	  // swap names
	  swap_names(src, dst);
	  return rebuild_roots_with_classes(cct);
	}
	
	int CrushWrapper::link_bucket(
	  CephContext *cct, int id, const map<string,string>& loc)
	{
	  // sorry this only works for buckets
	  if (id >= 0)
	    return -EINVAL;
	
	  if (!item_exists(id))
	    return -ENOENT;
	
	  // get the name of the bucket we are trying to move for later
	  string id_name = get_item_name(id);
	
	  crush_bucket *b = get_bucket(id);
	  unsigned bucket_weight = b->weight;
	
	  return insert_item(cct, id, bucket_weight / (float)0x10000, id_name, loc);
	}
	
	int CrushWrapper::create_or_move_item(
	  CephContext *cct, int item, float weight, string name,
	  const map<string,string>& loc,  // typename -> bucketname
	  bool init_weight_sets)
	{
	  int ret = 0;
	  int old_iweight;
	
	  if (!is_valid_crush_name(name))
	    return -EINVAL;
	
	  if (check_item_loc(cct, item, loc, &old_iweight)) {
	    ldout(cct, 5) << "create_or_move_item " << item << " already at " << loc
			  << dendl;
	  } else {
	    if (_search_item_exists(item)) {
	      weight = get_item_weightf(item);
	      ldout(cct, 10) << "create_or_move_item " << item
			     << " exists with weight " << weight << dendl;
	      remove_item(cct, item, true);
	    }
	    ldout(cct, 5) << "create_or_move_item adding " << item
			  << " weight " << weight
			  << " at " << loc << dendl;
	    ret = insert_item(cct, item, weight, name, loc,
			      item >= 0 && init_weight_sets);
	    if (ret == 0)
	      ret = 1;  // changed
	  }
	  return ret;
	}
	
	int CrushWrapper::update_item(
	  CephContext *cct, int item, float weight, string name,
	  const map<string,string>& loc)  // typename -> bucketname
	{
	  ldout(cct, 5) << "update_item item " << item << " weight " << weight
			<< " name " << name << " loc " << loc << dendl;
	  int ret = 0;
	
	  if (!is_valid_crush_name(name))
	    return -EINVAL;
	
	  if (!is_valid_crush_loc(cct, loc))
	    return -EINVAL;
	
	  ret = validate_weightf(weight);
	  if (ret < 0) {
	    return ret;
	  }
	
	  // compare quantized (fixed-point integer) weights!  
	  int iweight = (int)(weight * (float)0x10000);
	  int old_iweight;
	  if (check_item_loc(cct, item, loc, &old_iweight)) {
	    ldout(cct, 5) << "update_item " << item << " already at " << loc << dendl;
	    if (old_iweight != iweight) {
	      ldout(cct, 5) << "update_item " << item << " adjusting weight "
			    << ((float)old_iweight/(float)0x10000) << " -> " << weight
			    << dendl;
	      adjust_item_weight_in_loc(cct, item, iweight, loc);
	      ret = 1;
	    }
	    if (get_item_name(item) != name) {
	      ldout(cct, 5) << "update_item setting " << item << " name to " << name
			    << dendl;
	      set_item_name(item, name);
	      ret = 1;
	    }
	  } else {
	    if (item_exists(item)) {
	      remove_item(cct, item, true);
	    }
	    ldout(cct, 5) << "update_item adding " << item << " weight " << weight
			  << " at " << loc << dendl;
	    ret = insert_item(cct, item, weight, name, loc);
	    if (ret == 0)
	      ret = 1;  // changed
	  }
	  return ret;
	}
	
	int CrushWrapper::get_item_weight(int id) const
	{
	  for (int bidx = 0; bidx < crush->max_buckets; bidx++) {
	    crush_bucket *b = crush->buckets[bidx];
	    if (b == NULL)
	      continue;
	    if (b->id == id)
	      return b->weight;
	    for (unsigned i = 0; i < b->size; i++)
	      if (b->items[i] == id)
		return crush_get_bucket_item_weight(b, i);
	  }
	  return -ENOENT;
	}
	
	int CrushWrapper::get_item_weight_in_loc(int id, const map<string,string> &loc)
	{
	  for (map<string,string>::const_iterator l = loc.begin(); l != loc.end(); ++l) {
	
	    int bid = get_item_id(l->second);
	    if (!bucket_exists(bid))
	      continue;
	    crush_bucket *b = get_bucket(bid);
	    for (unsigned int i = 0; i < b->size; i++) {
	      if (b->items[i] == id) {
		return crush_get_bucket_item_weight(b, i);
	      }
	    }
	  }
	  return -ENOENT;
	}
	
	int CrushWrapper::adjust_item_weight(CephContext *cct, int id, int weight,
					     bool update_weight_sets)
	{
	  ldout(cct, 5) << __func__ << " " << id << " weight " << weight
			<< " update_weight_sets=" << (int)update_weight_sets
			<< dendl;
	  int changed = 0;
	  for (int bidx = 0; bidx < crush->max_buckets; bidx++) {
	    if (!crush->buckets[bidx]) {
	      continue;
	    }
	    int r = adjust_item_weight_in_bucket(cct, id, weight, -1-bidx,
						 update_weight_sets);
	    if (r > 0) {
	      ++changed;
	    }
	  }
	  if (!changed) {
	    return -ENOENT;
	  }
	  return changed;
	}
	
	int CrushWrapper::adjust_item_weight_in_bucket(
	  CephContext *cct, int id, int weight,
	  int bucket_id,
	  bool update_weight_sets)
	{
	  ldout(cct, 5) << __func__ << " " << id << " weight " << weight
			<< " in bucket " << bucket_id
			<< " update_weight_sets=" << (int)update_weight_sets
			<< dendl;
	  int changed = 0;
	  if (!bucket_exists(bucket_id)) {
	    return -ENOENT;
	  }
	  crush_bucket *b = get_bucket(bucket_id);
	  for (unsigned int i = 0; i < b->size; i++) {
	    if (b->items[i] == id) {
	      int diff = bucket_adjust_item_weight(cct, b, id, weight,
						   update_weight_sets);
	      ldout(cct, 5) << __func__ << " " << id << " diff " << diff
			    << " in bucket " << bucket_id << dendl;
	      adjust_item_weight(cct, bucket_id, b->weight, false);
	      changed++;
	    }
	  }
	  // update weight-sets so they continue to sum
	  for (auto& p : choose_args) {
	    auto &cmap = p.second;
	    if (!cmap.args) {
	      continue;
	    }
	    crush_choose_arg *arg = &cmap.args[-1 - bucket_id];
	    if (!arg->weight_set) {
	      continue;
	    }
	    ceph_assert(arg->weight_set_positions > 0);
	    vector<int> w(arg->weight_set_positions);
	    for (unsigned i = 0; i < b->size; ++i) {
	      for (unsigned j = 0; j < arg->weight_set_positions; ++j) {
		crush_weight_set *weight_set = &arg->weight_set[j];
		w[j] += weight_set->weights[i];
	      }
	    }
	    ldout(cct,5) << __func__ << "  adjusting bucket " << bucket_id
			 << " cmap " << p.first << " weights to " << w << dendl;
	    ostringstream ss;
	    choose_args_adjust_item_weight(cct, cmap, bucket_id, w, &ss);
	  }
	  if (!changed) {
	    return -ENOENT;
	  }
	  return changed;
	}
	
	int CrushWrapper::adjust_item_weight_in_loc(
	  CephContext *cct, int id, int weight,
	  const map<string,string>& loc,
	  bool update_weight_sets)
	{
	  ldout(cct, 5) << "adjust_item_weight_in_loc " << id << " weight " << weight
			<< " in " << loc
			<< " update_weight_sets=" << (int)update_weight_sets
			<< dendl;
	  int changed = 0;
	  for (auto l = loc.begin(); l != loc.end(); ++l) {
	    int bid = get_item_id(l->second);
	    if (!bucket_exists(bid))
	      continue;
	    int r = adjust_item_weight_in_bucket(cct, id, weight, bid,
						 update_weight_sets);
	    if (r > 0) {
	      ++changed;
	    }
	  }
	  if (!changed) {
	    return -ENOENT;
	  }
	  return changed;
	}
	
	int CrushWrapper::adjust_subtree_weight(CephContext *cct, int id, int weight,
						bool update_weight_sets)
	{
	  ldout(cct, 5) << __func__ << " " << id << " weight " << weight << dendl;
	  crush_bucket *b = get_bucket(id);
	  if (IS_ERR(b))
	    return PTR_ERR(b);
	  int changed = 0;
	  list<crush_bucket*> q;
	  q.push_back(b);
	  while (!q.empty()) {
	    b = q.front();
	    q.pop_front();
	    int local_changed = 0;
	    for (unsigned i=0; i<b->size; ++i) {
	      int n = b->items[i];
	      if (n >= 0) {
		adjust_item_weight_in_bucket(cct, n, weight, b->id, update_weight_sets);
		++changed;
		++local_changed;
	      } else {
		crush_bucket *sub = get_bucket(n);
		if (IS_ERR(sub))
		  continue;
		q.push_back(sub);
	      }
	    }
	  }
	  return changed;
	}
	
	bool CrushWrapper::check_item_present(int id) const
	{
	  bool found = false;
	
	  for (int bidx = 0; bidx < crush->max_buckets; bidx++) {
	    crush_bucket *b = crush->buckets[bidx];
	    if (b == 0)
	      continue;
	    for (unsigned i = 0; i < b->size; i++)
	      if (b->items[i] == id)
		found = true;
	  }
	  return found;
	}
	
	
	pair<string,string> CrushWrapper::get_immediate_parent(int id, int *_ret) const
	{
	
	  for (int bidx = 0; bidx < crush->max_buckets; bidx++) {
	    crush_bucket *b = crush->buckets[bidx];
	    if (b == 0)
	      continue;
	   if (is_shadow_item(b->id))
	      continue;
	    for (unsigned i = 0; i < b->size; i++)
	      if (b->items[i] == id) {
	        string parent_id = name_map.at(b->id);
	        string parent_bucket_type = type_map.at(b->type);
	        if (_ret)
	          *_ret = 0;
	        return make_pair(parent_bucket_type, parent_id);
	      }
	  }
	
	  if (_ret)
	    *_ret = -ENOENT;
	
	  return pair<string, string>();
	}
	
	int CrushWrapper::get_immediate_parent_id(int id, int *parent) const
	{
	  for (int bidx = 0; bidx < crush->max_buckets; bidx++) {
	    crush_bucket *b = crush->buckets[bidx];
	    if (b == 0)
	      continue;
	    if (is_shadow_item(b->id))
	      continue;
	    for (unsigned i = 0; i < b->size; i++) {
	      if (b->items[i] == id) {
		*parent = b->id;
		return 0;
	      }
	    }
	  }
	  return -ENOENT;
	}
	
	int CrushWrapper::get_parent_of_type(int item, int type, int rule) const
	{
	  if (rule < 0) {
	    // no rule specified
	    do {
	      int r = get_immediate_parent_id(item, &item);
	      if (r < 0) {
	        return 0;
	      }
	    } while (get_bucket_type(item) != type);
	    return item;
	  }
	  set<int> roots;
	  find_takes_by_rule(rule, &roots);
	  for (auto root : roots) {
	    vector<int> candidates;
	    get_children_of_type(root, type, &candidates, false);
	    for (auto candidate : candidates) {
	      if (subtree_contains(candidate, item)) {
		// note that here we assure that no two different buckets
		// from a single crush rule will share a same device,
		// which should generally be true.
	        return candidate;
	      }
	    }
	  }
	  return 0; // not found
	}
	
	void CrushWrapper::get_subtree_of_type(int type, vector<int> *subtrees)
	{
	  set<int> roots;
	  find_roots(&roots);
	  for (auto r: roots) {
	    crush_bucket *b = get_bucket(r);
	    if (IS_ERR(b))
	      continue;
	    get_children_of_type(b->id, type, subtrees);
	  }
	}
	
	bool CrushWrapper::class_is_in_use(int class_id, ostream *ss)
	{
	  list<unsigned> rules;
	  for (unsigned i = 0; i < crush->max_rules; ++i) {
	    crush_rule *r = crush->rules[i];
	    if (!r)
	      continue;
	    for (unsigned j = 0; j < r->len; ++j) {
	      if (r->steps[j].op == CRUSH_RULE_TAKE) {
	        int root = r->steps[j].arg1;
	        for (auto &p : class_bucket) {
	          auto& q = p.second;
	          if (q.count(class_id) && q[class_id] == root) {
	            rules.push_back(i);
	          }
	        }
	      }
	    }
	  }
	  if (rules.empty()) {
	    return false;
	  }
	  if (ss) {
	    ostringstream os;
	    for (auto &p: rules) {
	      os << "'" << get_rule_name(p) <<"',";
	    }
	    string out(os.str());
	    out.resize(out.size() - 1); // drop last ','
	    *ss << "still referenced by crush_rule(s): " << out;
	  }
	  return true;
	}
	
	int CrushWrapper::rename_class(const string& srcname, const string& dstname)
	{
	  auto i = class_rname.find(srcname);
	  if (i == class_rname.end())
	    return -ENOENT;
	  auto j = class_rname.find(dstname);
	  if (j != class_rname.end())
	    return -EEXIST;
	
	  int class_id = i->second;
	  ceph_assert(class_name.count(class_id));
	  // rename any shadow buckets of old class name
	  for (auto &it: class_map) {
	    if (it.first < 0 && it.second == class_id) {
	        string old_name = get_item_name(it.first);
	        size_t pos = old_name.find("~");
	        ceph_assert(pos != string::npos);
	        string name_no_class = old_name.substr(0, pos);
	        string old_class_name = old_name.substr(pos + 1);
	        ceph_assert(old_class_name == srcname);
	        string new_name = name_no_class + "~" + dstname;
	        // we do not use set_item_name
	        // because the name is intentionally invalid
	        name_map[it.first] = new_name;
	        have_rmaps = false;
	    }
	  }
	
	  // rename class
	  class_rname.erase(srcname);
	  class_name.erase(class_id);
	  class_rname[dstname] = class_id;
	  class_name[class_id] = dstname;
	  return 0;
	}
	
	int CrushWrapper::populate_classes(
	  const std::map<int32_t, map<int32_t, int32_t>>& old_class_bucket)
	{
	  // build set of previous used shadow ids
	  set<int32_t> used_ids;
	  for (auto& p : old_class_bucket) {
	    for (auto& q : p.second) {
	      used_ids.insert(q.second);
	    }
	  }
	  // accumulate weight values for each carg and bucket as we go. because it is
	  // depth first, we will have the nested bucket weights we need when we
	  // finish constructing the containing buckets.
	  map<int,map<int,vector<int>>> cmap_item_weight; // cargs -> bno -> [bucket weight for each position]
	  set<int> roots;
	  find_nonshadow_roots(&roots);
	  for (auto &r : roots) {
	    if (r >= 0)
	      continue;
	    for (auto &c : class_name) {
	      int clone;
	      int res = device_class_clone(r, c.first, old_class_bucket, used_ids,
					   &clone, &cmap_item_weight);
	      if (res < 0)
		return res;
	    }
	  }
	  return 0;
	}
	
	int CrushWrapper::trim_roots_with_class(CephContext *cct)
	{
	  set<int> roots;
	  find_shadow_roots(&roots);
	  for (auto &r : roots) {
	    if (r >= 0)
	      continue;
	    int res = remove_root(cct, r);
	    if (res)
	      return res;
	  }
	  // there is no need to reweight because we only remove from the
	  // root and down
	  return 0;
	}
	
	int32_t CrushWrapper::_alloc_class_id() const {
	  if (class_name.empty()) {
	    return 0;
	  }
	  int32_t class_id = class_name.rbegin()->first + 1;
	  if (class_id >= 0) {
	    return class_id;
	  }
	  // wrapped, pick a random start and do exhaustive search
	  uint32_t upperlimit = std::numeric_limits<int32_t>::max();
	  upperlimit++;
	  class_id = rand() % upperlimit;
	  const auto start = class_id;
	  do {
	    if (!class_name.count(class_id)) {
	      return class_id;
	    } else {
	      class_id++;
	      if (class_id < 0) {
	        class_id = 0;
	      }
	    }
	  } while (class_id != start);
	  ceph_abort_msg("no available class id");
	}
	
	int CrushWrapper::set_subtree_class(
	  const string& subtree,
	  const string& new_class)
	{
	  if (!name_exists(subtree)) {
	    return -ENOENT;
	  }
	
	  int new_class_id = get_or_create_class_id(new_class);
	  int id = get_item_id(subtree);
	  list<int> q = { id };
	  while (!q.empty()) {
	    int id = q.front();
	    q.pop_front();
	    crush_bucket *b = get_bucket(id);
	    if (IS_ERR(b)) {
	      return PTR_ERR(b);
	    }
	    for (unsigned i = 0; i < b->size; ++i) {
	      int item = b->items[i];
	      if (item >= 0) {
		class_map[item] = new_class_id;
	      } else {
		q.push_back(item);
	      }
	    }
	  }
	  return 0;
	}
	
	int CrushWrapper::reclassify(
	  CephContext *cct,
	  ostream& out,
	  const map<string,string>& classify_root,
	  const map<string,pair<string,string>>& classify_bucket
	  )
	{
	  map<int,string> reclassified_bucket; // orig_id -> class
	
	  // classify_root
	  for (auto& i : classify_root) {
	    string root = i.first;
	    if (!name_exists(root)) {
	      out << "root " << root << " does not exist" << std::endl;
	      return -EINVAL;
	    }
	    int root_id = get_item_id(root);
	    string new_class = i.second;
	    int new_class_id = get_or_create_class_id(new_class);
	    out << "classify_root " << root << " (" << root_id
		<< ") as " << new_class << std::endl;
	
	    // validate rules
	    for (unsigned j = 0; j < crush->max_rules; j++) {
	      if (crush->rules[j]) {
		auto rule = crush->rules[j];
		for (unsigned k = 0; k < rule->len; ++k) {
		  if (rule->steps[k].op == CRUSH_RULE_TAKE) {
		    int step_item = get_rule_arg1(j, k);
		    int original_item;
		    int c;
		    int res = split_id_class(step_item, &original_item, &c);
		    if (res < 0)
		      return res;
		    if (c >= 0) {
		      if (original_item == root_id) {
			out << "  rule " << j << " includes take on root "
			    << root << " class " << c << std::endl;
			return -EINVAL;
		      }
		    }
		  }
		}
	      }
	    }
	
	    // rebuild new buckets for root
	    //cout << "before class_bucket: " << class_bucket << std::endl;
	    map<int,int> renumber;
	    list<int> q;
	    q.push_back(root_id);
	    while (!q.empty()) {
	      int id = q.front();
	      q.pop_front();
	      crush_bucket *bucket = get_bucket(id);
	      if (IS_ERR(bucket)) {
		out << "cannot find bucket " << id
		    << ": " << cpp_strerror(PTR_ERR(bucket)) << std::endl;
		return PTR_ERR(bucket);
	      }
	
	      // move bucket
	      int new_id = get_new_bucket_id();
	      out << "  renumbering bucket " << id << " -> " << new_id << std::endl;
	      renumber[id] = new_id;
	      crush->buckets[-1-new_id] = bucket;
	      bucket->id = new_id;
	      crush->buckets[-1-id] = crush_make_bucket(crush,
							bucket->alg,
							bucket->hash,
							bucket->type,
							0, NULL, NULL);
	      crush->buckets[-1-id]->id = id;
	      for (auto& i : choose_args) {
		i.second.args[-1-new_id] = i.second.args[-1-id];
		memset(&i.second.args[-1-id], 0, sizeof(i.second.args[0]));
	      }
	      class_bucket.erase(id);
	      class_bucket[new_id][new_class_id] = id;
	      name_map[new_id] = string(get_item_name(id));
	      name_map[id] = string(get_item_name(id)) + "~" + new_class;
	
	      for (unsigned j = 0; j < bucket->size; ++j) {
		if (bucket->items[j] < 0) {
		  q.push_front(bucket->items[j]);
		} else {
		  // we don't reclassify the device here; if the users wants that,
		  // they can pass --set-subtree-class separately.
		}
	      }
	    }
	    //cout << "mid class_bucket: " << class_bucket << std::endl;
	
	    for (int i = 0; i < crush->max_buckets; ++i) {
	      crush_bucket *b = crush->buckets[i];
	      if (!b) {
		continue;
	      }
	      for (unsigned j = 0; j < b->size; ++j) {
		if (renumber.count(b->items[j])) {
		  b->items[j] = renumber[b->items[j]];
		}
	      }
	    }
	
	    int r = rebuild_roots_with_classes(cct);
	    if (r < 0) {
	      out << "failed to rebuild_roots_with_classes: " << cpp_strerror(r)
		  << std::endl;
	      return r;
	    }
	    //cout << "final class_bucket: " << class_bucket << std::endl;
	  }
	
	  // classify_bucket
	  map<int,int> send_to;  // source bucket -> dest bucket
	  map<int,map<int,int>> new_class_bucket;
	  map<int,string> new_bucket_names;
	  map<int,map<string,string>> new_buckets;
	  map<string,int> new_bucket_by_name;
	  for (auto& i : classify_bucket) {
	    const string& match = i.first;  // prefix% or %suffix
	    const string& new_class = i.second.first;
	    const string& default_parent = i.second.second;
	    if (!name_exists(default_parent)) {
	      out << "default parent " << default_parent << " does not exist"
		  << std::endl;
	      return -EINVAL;
	    }
	    int default_parent_id = get_item_id(default_parent);
	    crush_bucket *default_parent_bucket = get_bucket(default_parent_id);
	    assert(default_parent_bucket);
	    string default_parent_type_name = get_type_name(default_parent_bucket->type);
	
	    out << "classify_bucket " << match << " as " << new_class
		<< " default bucket " << default_parent
		<< " (" << default_parent_type_name << ")" << std::endl;
	
	    int new_class_id = get_or_create_class_id(new_class);
	    for (int j = 0; j < crush->max_buckets; ++j) {
	      crush_bucket *b = crush->buckets[j];
	      if (!b || is_shadow_item(b->id)) {
		continue;
	      }
	      string name = get_item_name(b->id);
	      if (name.length() < match.length()) {
		continue;
	      }
	      string basename;
	      if (match[0] == '%') {
		if (match.substr(1) != name.substr(name.size() - match.size() + 1)) {
		  continue;
		}
		basename = name.substr(0, name.size() - match.size() + 1);
	      } else if (match[match.size() - 1] == '%') {
		if (match.substr(0, match.size() - 1) !=
		    name.substr(0, match.size() - 1)) {
		  continue;
		}
		basename = name.substr(match.size() - 1);
	      } else if (match == name) {
		basename = default_parent;
	      } else {
		continue;
	      }
	      cout << "match " << match << " to " << name << " basename " << basename
		   << std::endl;
	      // look up or create basename bucket
	      int base_id;
	      if (name_exists(basename)) {
		base_id = get_item_id(basename);
		cout << "  have base " << base_id << std::endl;
	      } else if (new_bucket_by_name.count(basename)) {
		base_id = new_bucket_by_name[basename];
		cout << "  already creating base " << base_id << std::endl;
	      } else {
		base_id = get_new_bucket_id();
		crush->buckets[-1-base_id] = crush_make_bucket(crush,
							       b->alg,
							       b->hash,
							       b->type,
							       0, NULL, NULL);
		crush->buckets[-1-base_id]->id = base_id;
		name_map[base_id] = basename;
		new_bucket_by_name[basename] = base_id;
		cout << "  created base " << base_id << std::endl;
	
		new_buckets[base_id][default_parent_type_name] = default_parent;
	      }
	      send_to[b->id] = base_id;
	      new_class_bucket[base_id][new_class_id] = b->id;
	      new_bucket_names[b->id] = basename + "~" + get_class_name(new_class_id);
	
	      // make sure devices are classified
	      for (unsigned i = 0; i < b->size; ++i) {
		int item = b->items[i];
		if (item >= 0) {
		  class_map[item] = new_class_id;
		}
	      }
	    }
	  }
	
	  // no name_exists() works below,
	  have_rmaps = false;
	
	  // copy items around
	  //cout << "send_to " << send_to << std::endl;
	  set<int> roots;
	  find_roots(&roots);
	  for (auto& i : send_to) {
	    crush_bucket *from = get_bucket(i.first);
	    crush_bucket *to = get_bucket(i.second);
	    cout << "moving items from " << from->id << " (" << get_item_name(from->id)
		 << ") to " << to->id << " (" << get_item_name(to->id) << ")"
		 << std::endl;
	    for (unsigned j = 0; j < from->size; ++j) {
	      int item = from->items[j];
	      int r;
	      map<string,string> to_loc;
	      to_loc[get_type_name(to->type)] = get_item_name(to->id);
	      if (item >= 0) {
		if (subtree_contains(to->id, item)) {
		  continue;
		}
		map<string,string> from_loc;
		from_loc[get_type_name(from->type)] = get_item_name(from->id);
		auto w = get_item_weightf_in_loc(item, from_loc);
		r = insert_item(cct, item,
				w,
				get_item_name(item),
				to_loc);
	      } else {
		if (!send_to.count(item)) {
		  lderr(cct) << "item " << item << " in bucket " << from->id
		       << " is not also a reclassified bucket" << dendl;
		  return -EINVAL;
		}
		int newitem = send_to[item];
		if (subtree_contains(to->id, newitem)) {
		  continue;
		}
		r = link_bucket(cct, newitem, to_loc);
	      }
	      if (r != 0) {
		cout << __func__ << " err from insert_item: " << cpp_strerror(r)
		     << std::endl;
		return r;
	      }
	    }
	  }
	
	  // make sure new buckets have parents
	  for (auto& i : new_buckets) {
	    int parent;
	    if (get_immediate_parent_id(i.first, &parent) < 0) {
	      cout << "new bucket " << i.first << " missing parent, adding at "
		   << i.second << std::endl;
	      int r = link_bucket(cct, i.first, i.second);
	      if (r != 0) {
		cout << __func__ << " err from insert_item: " << cpp_strerror(r)
		     << std::endl;
		return r;
	      }
	    }
	  }
	
	  // set class mappings
	  //cout << "pre class_bucket: " << class_bucket << std::endl;
	  for (auto& i : new_class_bucket) {
	    for (auto& j : i.second) {
	      class_bucket[i.first][j.first] = j.second;
	    }
	
	  }
	  //cout << "post class_bucket: " << class_bucket << std::endl;
	  for (auto& i : new_bucket_names) {
	    name_map[i.first] = i.second;
	  }
	
	  int r = rebuild_roots_with_classes(cct);
	  if (r < 0) {
	    out << "failed to rebuild_roots_with_classes: " << cpp_strerror(r)
		<< std::endl;
	    return r;
	  }
	  //cout << "final class_bucket: " << class_bucket << std::endl;
	
	  return 0;
	}
	
	int CrushWrapper::get_new_bucket_id()
	{
	  int id = -1;
	  while (crush->buckets[-1-id] &&
		 -1-id < crush->max_buckets) {
	    id--;
	  }
	  if (-1-id == crush->max_buckets) {
	    ++crush->max_buckets;
	    crush->buckets = (struct crush_bucket**)realloc(
	      crush->buckets,
	      sizeof(crush->buckets[0]) * crush->max_buckets);
	    for (auto& i : choose_args) {
	      assert(i.second.size == (__u32)crush->max_buckets - 1);
	      ++i.second.size;
	      i.second.args = (struct crush_choose_arg*)realloc(
		i.second.args,
		sizeof(i.second.args[0]) * i.second.size);
	    }
	  }
	  return id;
	}
	
	void CrushWrapper::reweight(CephContext *cct)
	{
	  set<int> roots;
	  find_nonshadow_roots(&roots);
	  for (auto id : roots) {
	    if (id >= 0)
	      continue;
	    crush_bucket *b = get_bucket(id);
	    ldout(cct, 5) << "reweight root bucket " << id << dendl;
	    int r = crush_reweight_bucket(crush, b);
	    ceph_assert(r == 0);
	
	    for (auto& i : choose_args) {
	      //cout << "carg " << i.first << std::endl;
	      vector<uint32_t> w;  // discard top-level weights
	      reweight_bucket(b, i.second, &w);
	    }
	  }
	  int r = rebuild_roots_with_classes(cct);
	  ceph_assert(r == 0);
	}
	
	void CrushWrapper::reweight_bucket(
	  crush_bucket *b,
	  crush_choose_arg_map& arg_map,
	  vector<uint32_t> *weightv)
	{
	  int idx = -1 - b->id;
	  unsigned npos = arg_map.args[idx].weight_set_positions;
	  //cout << __func__ << " " << b->id << " npos " << npos << std::endl;
	  weightv->resize(npos);
	  for (unsigned i = 0; i < b->size; ++i) {
	    int item = b->items[i];
	    if (item >= 0) {
	      for (unsigned pos = 0; pos < npos; ++pos) {
		(*weightv)[pos] += arg_map.args[idx].weight_set->weights[i];
	      }
	    } else {
	      vector<uint32_t> subw(npos);
	      crush_bucket *sub = get_bucket(item);
	      assert(sub);
	      reweight_bucket(sub, arg_map, &subw);
	      for (unsigned pos = 0; pos < npos; ++pos) {
		(*weightv)[pos] += subw[pos];
		// strash the real bucket weight as the weights for this reference
		arg_map.args[idx].weight_set->weights[i] = subw[pos];
	      }
	    }
	  }
	  //cout << __func__ << " finish " << b->id << " " << *weightv << std::endl;
	}
	
	int CrushWrapper::add_simple_rule_at(
	  string name, string root_name,
	  string failure_domain_name,
	  string device_class,
	  string mode, int rule_type,
	  int rno,
	  ostream *err)
	{
	  if (rule_exists(name)) {
	    if (err)
	      *err << "rule " << name << " exists";
	    return -EEXIST;
	  }
	  if (rno >= 0) {
	    if (rule_exists(rno)) {
	      if (err)
	        *err << "rule with ruleno " << rno << " exists";
	      return -EEXIST;
	    }
	    if (ruleset_exists(rno)) {
	      if (err)
	        *err << "ruleset " << rno << " exists";
	      return -EEXIST;
	    }
	  } else {
	    for (rno = 0; rno < get_max_rules(); rno++) {
	      if (!rule_exists(rno) && !ruleset_exists(rno))
	        break;
	    }
	  }
	  if (!name_exists(root_name)) {
	    if (err)
	      *err << "root item " << root_name << " does not exist";
	    return -ENOENT;
	  }
	  int root = get_item_id(root_name);
	  int type = 0;
	  if (failure_domain_name.length()) {
	    type = get_type_id(failure_domain_name);
	    if (type < 0) {
	      if (err)
		*err << "unknown type " << failure_domain_name;
	      return -EINVAL;
	    }
	  }
	  if (device_class.size()) {
	    if (!class_exists(device_class)) {
	      if (err)
		*err << "device class " << device_class << " does not exist";
	      return -EINVAL;
	    }
	    int c = get_class_id(device_class);
	    if (class_bucket.count(root) == 0 ||
		class_bucket[root].count(c) == 0) {
	      if (err)
		*err << "root " << root_name << " has no devices with class "
		     << device_class;
	      return -EINVAL;
	    }
	    root = class_bucket[root][c];
	  }
	  if (mode != "firstn" && mode != "indep") {
	    if (err)
	      *err << "unknown mode " << mode;
	    return -EINVAL;
	  }
	
	  int steps = 3;
	  if (mode == "indep")
	    steps = 5;
	  int min_rep = mode == "firstn" ? 1 : 3;
	  int max_rep = mode == "firstn" ? 10 : 20;
	  //set the ruleset the same as rule_id(rno)
	  crush_rule *rule = crush_make_rule(steps, rno, rule_type, min_rep, max_rep);
	  ceph_assert(rule);
	  int step = 0;
	  if (mode == "indep") {
	    crush_rule_set_step(rule, step++, CRUSH_RULE_SET_CHOOSELEAF_TRIES, 5, 0);
	    crush_rule_set_step(rule, step++, CRUSH_RULE_SET_CHOOSE_TRIES, 100, 0);
	  }
	  crush_rule_set_step(rule, step++, CRUSH_RULE_TAKE, root, 0);
	  if (type)
	    crush_rule_set_step(rule, step++,
				mode == "firstn" ? CRUSH_RULE_CHOOSELEAF_FIRSTN :
				CRUSH_RULE_CHOOSELEAF_INDEP,
				CRUSH_CHOOSE_N,
				type);
	  else
	    crush_rule_set_step(rule, step++,
				mode == "firstn" ? CRUSH_RULE_CHOOSE_FIRSTN :
				CRUSH_RULE_CHOOSE_INDEP,
				CRUSH_CHOOSE_N,
				0);
	  crush_rule_set_step(rule, step++, CRUSH_RULE_EMIT, 0, 0);
	
	  int ret = crush_add_rule(crush, rule, rno);
	  if(ret < 0) {
	    *err << "failed to add rule " << rno << " because " << cpp_strerror(ret);
	    return ret;
	  }
	  set_rule_name(rno, name);
	  have_rmaps = false;
	  return rno;
	}
	
	int CrushWrapper::add_simple_rule(
	  string name, string root_name,
	  string failure_domain_name,
	  string device_class,
	  string mode, int rule_type,
	  ostream *err)
	{
	  return add_simple_rule_at(name, root_name, failure_domain_name, device_class,
				    mode,
				    rule_type, -1, err);
	}
	
	float CrushWrapper::_get_take_weight_osd_map(int root,
						     map<int,float> *pmap) const
	{
	  float sum = 0.0;
	  list<int> q;
	  q.push_back(root);
	  //breadth first iterate the OSD tree
	  while (!q.empty()) {
	    int bno = q.front();
	    q.pop_front();
	    crush_bucket *b = crush->buckets[-1-bno];
	    ceph_assert(b);
	    for (unsigned j=0; j<b->size; ++j) {
	      int item_id = b->items[j];
	      if (item_id >= 0) { //it's an OSD
		float w = crush_get_bucket_item_weight(b, j);
		(*pmap)[item_id] = w;
		sum += w;
	      } else { //not an OSD, expand the child later
		q.push_back(item_id);
	      }
	    }
	  }
	  return sum;
	}
	
	void CrushWrapper::_normalize_weight_map(float sum,
						 const map<int,float>& m,
						 map<int,float> *pmap) const
	{
	  for (auto& p : m) {
	    map<int,float>::iterator q = pmap->find(p.first);
	    if (q == pmap->end()) {
	      (*pmap)[p.first] = p.second / sum;
	    } else {
	      q->second += p.second / sum;
	    }
	  }
	}
	
	int CrushWrapper::get_take_weight_osd_map(int root, map<int,float> *pmap) const
	{
	  map<int,float> m;
	  float sum = _get_take_weight_osd_map(root, &m);
	  _normalize_weight_map(sum, m, pmap);
	  return 0;
	}
	
	int CrushWrapper::get_rule_weight_osd_map(unsigned ruleno,
						  map<int,float> *pmap) const
	{
	  if (ruleno >= crush->max_rules)
	    return -ENOENT;
	  if (crush->rules[ruleno] == NULL)
	    return -ENOENT;
	  crush_rule *rule = crush->rules[ruleno];
	
	  // build a weight map for each TAKE in the rule, and then merge them
	
	  // FIXME: if there are multiple takes that place a different number of
	  // objects we do not take that into account.  (Also, note that doing this
	  // right is also a function of the pool, since the crush rule
	  // might choose 2 + choose 2 but pool size may only be 3.)
	  for (unsigned i=0; i<rule->len; ++i) {
	    map<int,float> m;
	    float sum = 0;
	    if (rule->steps[i].op == CRUSH_RULE_TAKE) {
	      int n = rule->steps[i].arg1;
	      if (n >= 0) {
		m[n] = 1.0;
		sum = 1.0;
	      } else {
		sum += _get_take_weight_osd_map(n, &m);
	      }
	    }
	    _normalize_weight_map(sum, m, pmap);
	  }
	
	  return 0;
	}
	
	int CrushWrapper::remove_rule(int ruleno)
	{
	  if (ruleno >= (int)crush->max_rules)
	    return -ENOENT;
	  if (crush->rules[ruleno] == NULL)
	    return -ENOENT;
	  crush_destroy_rule(crush->rules[ruleno]);
	  crush->rules[ruleno] = NULL;
	  rule_name_map.erase(ruleno);
	  have_rmaps = false;
	  return rebuild_roots_with_classes(nullptr);
	}
	
	int CrushWrapper::bucket_adjust_item_weight(
	  CephContext *cct, crush_bucket *bucket, int item, int weight,
	  bool adjust_weight_sets)
	{
	  if (adjust_weight_sets) {
	    unsigned position;
	    for (position = 0; position < bucket->size; position++)
	      if (bucket->items[position] == item)
		break;
	    ceph_assert(position != bucket->size);
	    for (auto &w : choose_args) {
	      crush_choose_arg_map &arg_map = w.second;
	      crush_choose_arg *arg = &arg_map.args[-1-bucket->id];
	      for (__u32 j = 0; j < arg->weight_set_positions; j++) {
		crush_weight_set *weight_set = &arg->weight_set[j];
		weight_set->weights[position] = weight;
	      }
	    }
	  }
	  return crush_bucket_adjust_item_weight(crush, bucket, item, weight);
	}
	
	int CrushWrapper::add_bucket(
	  int bucketno, int alg, int hash, int type, int size,
	  int *items, int *weights, int *idout)
	{
	  if (alg == 0) {
	    alg = get_default_bucket_alg();
	    if (alg == 0)
	      return -EINVAL;
	  }
	  crush_bucket *b = crush_make_bucket(crush, alg, hash, type, size, items,
					      weights);
	  ceph_assert(b);
	  ceph_assert(idout);
	  int r = crush_add_bucket(crush, bucketno, b, idout);
	  int pos = -1 - *idout;
	  for (auto& p : choose_args) {
	    crush_choose_arg_map& cmap = p.second;
	    unsigned new_size = crush->max_buckets;
	    if (cmap.args) {
	      if ((int)cmap.size < crush->max_buckets) {
		cmap.args = static_cast<crush_choose_arg*>(realloc(
		  cmap.args,
		  sizeof(crush_choose_arg) * new_size));
	        ceph_assert(cmap.args);
		memset(&cmap.args[cmap.size], 0,
		       sizeof(crush_choose_arg) * (new_size - cmap.size));
		cmap.size = new_size;
	      }
	    } else {
	      cmap.args = static_cast<crush_choose_arg*>(calloc(sizeof(crush_choose_arg),
								new_size));
	      ceph_assert(cmap.args);
	      cmap.size = new_size;
	    }
	    if (size > 0) {
	      int positions = get_choose_args_positions(cmap);
	      crush_choose_arg& carg = cmap.args[pos];
	      carg.weight_set = static_cast<crush_weight_set*>(calloc(sizeof(crush_weight_set),
							  size));
	      carg.weight_set_positions = positions;
	      for (int ppos = 0; ppos < positions; ++ppos) {
		carg.weight_set[ppos].weights = (__u32*)calloc(sizeof(__u32), size);
		carg.weight_set[ppos].size = size;
		for (int bpos = 0; bpos < size; ++bpos) {
		  carg.weight_set[ppos].weights[bpos] = weights[bpos];
		}
	      }
	    }
	    assert(crush->max_buckets == (int)cmap.size);
	  }
	  return r;
	}
	
	int CrushWrapper::bucket_add_item(crush_bucket *bucket, int item, int weight)
	{
	  __u32 new_size = bucket->size + 1;
	  int r = crush_bucket_add_item(crush, bucket, item, weight);
	  if (r < 0) {
	    return r;
	  }
	  for (auto &w : choose_args) {
	    crush_choose_arg_map &arg_map = w.second;
	    crush_choose_arg *arg = &arg_map.args[-1-bucket->id];
	    for (__u32 j = 0; j < arg->weight_set_positions; j++) {
	      crush_weight_set *weight_set = &arg->weight_set[j];
	      weight_set->weights = (__u32*)realloc(weight_set->weights,
						    new_size * sizeof(__u32));
	      ceph_assert(weight_set->size + 1 == new_size);
	      weight_set->weights[weight_set->size] = weight;
	      weight_set->size = new_size;
	    }
	    if (arg->ids_size) {
	      arg->ids = (__s32 *)realloc(arg->ids, new_size * sizeof(__s32));
	      ceph_assert(arg->ids_size + 1 == new_size);
	      arg->ids[arg->ids_size] = item;
	      arg->ids_size = new_size;
	    }
	  }
	  return 0;
	}
	
	int CrushWrapper::bucket_remove_item(crush_bucket *bucket, int item)
	{
	  __u32 new_size = bucket->size - 1;
	  unsigned position;
	  for (position = 0; position < bucket->size; position++)
	    if (bucket->items[position] == item)
	      break;
	  ceph_assert(position != bucket->size);
	  int r = crush_bucket_remove_item(crush, bucket, item);
	  if (r < 0) {
	    return r;
	  }
	  for (auto &w : choose_args) {
	    crush_choose_arg_map &arg_map = w.second;
	    crush_choose_arg *arg = &arg_map.args[-1-bucket->id];
	    for (__u32 j = 0; j < arg->weight_set_positions; j++) {
	      crush_weight_set *weight_set = &arg->weight_set[j];
	      ceph_assert(weight_set->size - 1 == new_size);
	      for (__u32 k = position; k < new_size; k++)
		weight_set->weights[k] = weight_set->weights[k+1];
	      if (new_size) {
		weight_set->weights = (__u32*)realloc(weight_set->weights,
						      new_size * sizeof(__u32));
	      } else {
	        free(weight_set->weights);
		weight_set->weights = NULL;
	      }
	      weight_set->size = new_size;
	    }
	    if (arg->ids_size) {
	      ceph_assert(arg->ids_size - 1 == new_size);
	      for (__u32 k = position; k < new_size; k++)
		arg->ids[k] = arg->ids[k+1];
	      if (new_size) {
		arg->ids = (__s32 *)realloc(arg->ids, new_size * sizeof(__s32));
	      } else {
	        free(arg->ids);
		arg->ids = NULL;
	      }
	      arg->ids_size = new_size;
	    }
	  }
	  return 0;
	}
	
	int CrushWrapper::bucket_set_alg(int bid, int alg)
	{
	  crush_bucket *b = get_bucket(bid);
	  if (!b) {
	    return -ENOENT;
	  }
	  b->alg = alg;
	  return 0;
	}
	
	int CrushWrapper::update_device_class(int id,
	                                      const string& class_name,
	                                      const string& name,
	                                      ostream *ss)
	{
	  ceph_assert(item_exists(id));
	  auto old_class_name = get_item_class(id);
	  if (old_class_name && old_class_name != class_name) {
	    *ss << "osd." << id << " has already bound to class '" << old_class_name
	        << "', can not reset class to '" << class_name  << "'; "
	        << "use 'ceph osd crush rm-device-class <id>' to "
	        << "remove old class first";
	    return -EBUSY;
	  }
	
	  int class_id = get_or_create_class_id(class_name);
	  if (id < 0) {
	    *ss << name << " id " << id << " is negative";
	    return -EINVAL;
	  }
	
	  if (class_map.count(id) != 0 && class_map[id] == class_id) {
	    *ss << name << " already set to class " << class_name << ". ";
	    return 0;
	  }
	
	  set_item_class(id, class_id);
	
	  int r = rebuild_roots_with_classes(nullptr);
	  if (r < 0)
	    return r;
	  return 1;
	}
	
	int CrushWrapper::remove_device_class(CephContext *cct, int id, ostream *ss)
	{
	  ceph_assert(ss);
	  const char *name = get_item_name(id);
	  if (!name) {
	    *ss << "osd." << id << " does not have a name";
	    return -ENOENT;
	  }
	
	  const char *class_name = get_item_class(id);
	  if (!class_name) {
	    *ss << "osd." << id << " has not been bound to a specific class yet";
	    return 0;
	  }
	  class_remove_item(id);
	
	  int r = rebuild_roots_with_classes(cct);
	  if (r < 0) {
	    *ss << "unable to rebuild roots with class '" << class_name << "' "
	        << "of osd." << id << ": " << cpp_strerror(r);
	    return r;
	  }
	  return 0;
	}
	
	int CrushWrapper::device_class_clone(
	  int original_id, int device_class,
	  const std::map<int32_t, map<int32_t, int32_t>>& old_class_bucket,
	  const std::set<int32_t>& used_ids,
	  int *clone,
	  map<int,map<int,vector<int>>> *cmap_item_weight)
	{
	  const char *item_name = get_item_name(original_id);
	  if (item_name == NULL)
	    return -ECHILD;
	  const char *class_name = get_class_name(device_class);
	  if (class_name == NULL)
	    return -EBADF;
	  string copy_name = item_name + string("~") + class_name;
	  if (name_exists(copy_name)) {
	    *clone = get_item_id(copy_name);
	    return 0;
	  }
	
	  crush_bucket *original = get_bucket(original_id);
	  ceph_assert(!IS_ERR(original));
	  crush_bucket *copy = crush_make_bucket(crush,
						 original->alg,
						 original->hash,
						 original->type,
						 0, NULL, NULL);
	  ceph_assert(copy);
	
	  vector<unsigned> item_orig_pos;  // new item pos -> orig item pos
	  for (unsigned i = 0; i < original->size; i++) {
	    int item = original->items[i];
	    int weight = crush_get_bucket_item_weight(original, i);
	    if (item >= 0) {
	      if (class_map.count(item) != 0 && class_map[item] == device_class) {
		int res = crush_bucket_add_item(crush, copy, item, weight);
		if (res)
		  return res;
	      } else {
		continue;
	      }
	    } else {
	      int child_copy_id;
	      int res = device_class_clone(item, device_class, old_class_bucket,
					   used_ids, &child_copy_id,
					   cmap_item_weight);
	      if (res < 0)
		return res;
	      crush_bucket *child_copy = get_bucket(child_copy_id);
	      ceph_assert(!IS_ERR(child_copy));
	      res = crush_bucket_add_item(crush, copy, child_copy_id,
					  child_copy->weight);
	      if (res)
		return res;
	    }
	    item_orig_pos.push_back(i);
	  }
	  ceph_assert(item_orig_pos.size() == copy->size);
	
	  int bno = 0;
	  if (old_class_bucket.count(original_id) &&
	      old_class_bucket.at(original_id).count(device_class)) {
	    bno = old_class_bucket.at(original_id).at(device_class);
	  } else {
	    // pick a new shadow bucket id that is not used by the current map
	    // *or* any previous shadow buckets.
	    bno = -1;
	    while (((-1-bno) < crush->max_buckets && crush->buckets[-1-bno]) ||
		   used_ids.count(bno)) {
	      --bno;
	    }
	  }
	  int res = crush_add_bucket(crush, bno, copy, clone);
	  if (res)
	    return res;
	  ceph_assert(!bno || bno == *clone);
	
	  res = set_item_class(*clone, device_class);
	  if (res < 0)
	    return res;
	
	  // we do not use set_item_name because the name is intentionally invalid
	  name_map[*clone] = copy_name;
	  if (have_rmaps)
	    name_rmap[copy_name] = *clone;
	  class_bucket[original_id][device_class] = *clone;
	
	  // set up choose_args for the new bucket.
	  for (auto& w : choose_args) {
	    crush_choose_arg_map& cmap = w.second;
	    if (crush->max_buckets > (int)cmap.size) {
	      unsigned new_size = crush->max_buckets;
	      cmap.args = static_cast<crush_choose_arg*>(realloc(cmap.args,
						     new_size * sizeof(cmap.args[0])));
	      ceph_assert(cmap.args);
	      memset(cmap.args + cmap.size, 0,
		     (new_size - cmap.size) * sizeof(cmap.args[0]));
	      cmap.size = new_size;
	    }
	    auto& o = cmap.args[-1-original_id];
	    auto& n = cmap.args[-1-bno];
	    n.ids_size = 0; // FIXME: implement me someday
	    n.weight_set_positions = o.weight_set_positions;
	    n.weight_set = static_cast<crush_weight_set*>(calloc(
	      n.weight_set_positions, sizeof(crush_weight_set)));
	    for (size_t s = 0; s < n.weight_set_positions; ++s) {
	      n.weight_set[s].size = copy->size;
	      n.weight_set[s].weights = (__u32*)calloc(copy->size, sizeof(__u32));
	    }
	    for (size_t s = 0; s < n.weight_set_positions; ++s) {
	      vector<int> bucket_weights(n.weight_set_positions);
	      for (size_t i = 0; i < copy->size; ++i) {
		int item = copy->items[i];
		if (item >= 0) {
		  n.weight_set[s].weights[i] = o.weight_set[s].weights[item_orig_pos[i]];
		} else if ((*cmap_item_weight)[w.first].count(item)) {
		  n.weight_set[s].weights[i] = (*cmap_item_weight)[w.first][item][s];
		} else {
		  n.weight_set[s].weights[i] = 0;
		}
		bucket_weights[s] += n.weight_set[s].weights[i];
	      }
	      (*cmap_item_weight)[w.first][bno] = bucket_weights;
	    }
	  }
	  return 0;
	}
	
	int CrushWrapper::get_rules_by_class(const string &class_name, set<int> *rules)
	{
	  ceph_assert(rules);
	  rules->clear();
	  if (!class_exists(class_name)) {
	    return -ENOENT;
	  }
	  int class_id = get_class_id(class_name);
	  for (unsigned i = 0; i < crush->max_rules; ++i) {
	    crush_rule *r = crush->rules[i];
	    if (!r)
	      continue;
	    for (unsigned j = 0; j < r->len; ++j) {
	      if (r->steps[j].op == CRUSH_RULE_TAKE) {
	        int step_item = r->steps[j].arg1;
	        int original_item;
	        int c;
	        int res = split_id_class(step_item, &original_item, &c);
	        if (res < 0) {
	          return res;
	        }
	        if (c != -1 && c == class_id) {
	          rules->insert(i);
	          break;
	        }
	      }
	    }
	  }
	  return 0;
	}
	
	// return rules that might reference the given osd
	int CrushWrapper::get_rules_by_osd(int osd, set<int> *rules)
	{
	  ceph_assert(rules);
	  rules->clear();
	  if (osd < 0) {
	    return -EINVAL;
	  }
	  for (unsigned i = 0; i < crush->max_rules; ++i) {
	    crush_rule *r = crush->rules[i];
	    if (!r)
	      continue;
	    for (unsigned j = 0; j < r->len; ++j) {
	      if (r->steps[j].op == CRUSH_RULE_TAKE) {
	        int step_item = r->steps[j].arg1;
	        list<int> unordered;
	        int rc = _get_leaves(step_item, &unordered);
	        if (rc < 0) {
	          return rc; // propagate fatal errors!
	        }
	        bool match = false;
	        for (auto &o: unordered) {
	          ceph_assert(o >= 0);
	          if (o == osd) {
	            match = true;
	            break;
	          }
	        }
	        if (match) {
	          rules->insert(i);
	          break;
	        }
	      }
	    }
	  }
	  return 0;
	}
	
	bool CrushWrapper::_class_is_dead(int class_id)
	{
	  for (auto &p: class_map) {
	    if (p.first >= 0 && p.second == class_id) {
	      return false;
	    }
	  }
	  for (unsigned i = 0; i < crush->max_rules; ++i) {
	    crush_rule *r = crush->rules[i];
	    if (!r)
	      continue;
	    for (unsigned j = 0; j < r->len; ++j) {
	      if (r->steps[j].op == CRUSH_RULE_TAKE) {
	        int root = r->steps[j].arg1;
	        for (auto &p : class_bucket) {
	          auto& q = p.second;
	          if (q.count(class_id) && q[class_id] == root) {
	            return false;
	          }
	        }
	      }
	    }
	  }
	  // no more referenced by any devices or crush rules
	  return true;
	}
	
	void CrushWrapper::cleanup_dead_classes()
	{
	  auto p = class_name.begin();
	  while (p != class_name.end()) {
	    if (_class_is_dead(p->first)) {
	      string n = p->second;
	      ++p;
	      remove_class_name(n);
	    } else {
	      ++p;
	    }
	  }
	}
	
	int CrushWrapper::rebuild_roots_with_classes(CephContext *cct)
	{
	  std::map<int32_t, map<int32_t, int32_t> > old_class_bucket = class_bucket;
	  cleanup_dead_classes();
	  int r = trim_roots_with_class(cct);
	  if (r < 0)
	    return r;
	  class_bucket.clear();
	  return populate_classes(old_class_bucket);
	}
	
	void CrushWrapper::encode(bufferlist& bl, uint64_t features) const
	{
	  using ceph::encode;
	  ceph_assert(crush);
	
	  __u32 magic = CRUSH_MAGIC;
	  encode(magic, bl);
	
	  encode(crush->max_buckets, bl);
	  encode(crush->max_rules, bl);
	  encode(crush->max_devices, bl);
	
	  bool encode_compat_choose_args = false;
	  crush_choose_arg_map arg_map;
	  memset(&arg_map, '\0', sizeof(arg_map));
	  if (has_choose_args() &&
	      !HAVE_FEATURE(features, CRUSH_CHOOSE_ARGS)) {
	    ceph_assert(!has_incompat_choose_args());
	    encode_compat_choose_args = true;
	    arg_map = choose_args.begin()->second;
	  }
	
	  // buckets
	  for (int i=0; i<crush->max_buckets; i++) {
	    __u32 alg = 0;
	    if (crush->buckets[i]) alg = crush->buckets[i]->alg;
	    encode(alg, bl);
	    if (!alg)
	      continue;
	
	    encode(crush->buckets[i]->id, bl);
	    encode(crush->buckets[i]->type, bl);
	    encode(crush->buckets[i]->alg, bl);
	    encode(crush->buckets[i]->hash, bl);
	    encode(crush->buckets[i]->weight, bl);
	    encode(crush->buckets[i]->size, bl);
	    for (unsigned j=0; j<crush->buckets[i]->size; j++)
	      encode(crush->buckets[i]->items[j], bl);
	
	    switch (crush->buckets[i]->alg) {
	    case CRUSH_BUCKET_UNIFORM:
	      encode((reinterpret_cast<crush_bucket_uniform*>(crush->buckets[i]))->item_weight, bl);
	      break;
	
	    case CRUSH_BUCKET_LIST:
	      for (unsigned j=0; j<crush->buckets[i]->size; j++) {
		encode((reinterpret_cast<crush_bucket_list*>(crush->buckets[i]))->item_weights[j], bl);
		encode((reinterpret_cast<crush_bucket_list*>(crush->buckets[i]))->sum_weights[j], bl);
	      }
	      break;
	
	    case CRUSH_BUCKET_TREE:
	      encode((reinterpret_cast<crush_bucket_tree*>(crush->buckets[i]))->num_nodes, bl);
	      for (unsigned j=0; j<(reinterpret_cast<crush_bucket_tree*>(crush->buckets[i]))->num_nodes; j++)
		encode((reinterpret_cast<crush_bucket_tree*>(crush->buckets[i]))->node_weights[j], bl);
	      break;
	
	    case CRUSH_BUCKET_STRAW:
	      for (unsigned j=0; j<crush->buckets[i]->size; j++) {
		encode((reinterpret_cast<crush_bucket_straw*>(crush->buckets[i]))->item_weights[j], bl);
		encode((reinterpret_cast<crush_bucket_straw*>(crush->buckets[i]))->straws[j], bl);
	      }
	      break;
	
	    case CRUSH_BUCKET_STRAW2:
	      {
		__u32 *weights;
		if (encode_compat_choose_args &&
		    arg_map.args[i].weight_set_positions > 0) {
		  weights = arg_map.args[i].weight_set[0].weights;
		} else {
		  weights = (reinterpret_cast<crush_bucket_straw2*>(crush->buckets[i]))->item_weights;
		}
		for (unsigned j=0; j<crush->buckets[i]->size; j++) {
		  encode(weights[j], bl);
		}
	      }
	      break;
	
	    default:
	      ceph_abort();
	      break;
	    }
	  }
	
	  // rules
	  for (unsigned i=0; i<crush->max_rules; i++) {
	    __u32 yes = crush->rules[i] ? 1:0;
	    encode(yes, bl);
	    if (!yes)
	      continue;
	
	    encode(crush->rules[i]->len, bl);
	    encode(crush->rules[i]->mask, bl);
	    for (unsigned j=0; j<crush->rules[i]->len; j++)
	      encode(crush->rules[i]->steps[j], bl);
	  }
	
	  // name info
	  encode(type_map, bl);
	  encode(name_map, bl);
	  encode(rule_name_map, bl);
	
	  // tunables
	  encode(crush->choose_local_tries, bl);
	  encode(crush->choose_local_fallback_tries, bl);
	  encode(crush->choose_total_tries, bl);
	  encode(crush->chooseleaf_descend_once, bl);
	  encode(crush->chooseleaf_vary_r, bl);
	  encode(crush->straw_calc_version, bl);
	  encode(crush->allowed_bucket_algs, bl);
	  if (features & CEPH_FEATURE_CRUSH_TUNABLES5) {
	    encode(crush->chooseleaf_stable, bl);
	  }
	
	  if (HAVE_FEATURE(features, SERVER_LUMINOUS)) {
	    // device classes
	    encode(class_map, bl);
	    encode(class_name, bl);
	    encode(class_bucket, bl);
	
	    // choose args
	    __u32 size = (__u32)choose_args.size();
	    encode(size, bl);
	    for (auto c : choose_args) {
	      encode(c.first, bl);
	      crush_choose_arg_map arg_map = c.second;
	      size = 0;
	      for (__u32 i = 0; i < arg_map.size; i++) {
		crush_choose_arg *arg = &arg_map.args[i];
		if (arg->weight_set_positions == 0 &&
		    arg->ids_size == 0)
		  continue;
		size++;
	      }
	      encode(size, bl);
	      for (__u32 i = 0; i < arg_map.size; i++) {
		crush_choose_arg *arg = &arg_map.args[i];
		if (arg->weight_set_positions == 0 &&
		    arg->ids_size == 0)
		  continue;
		encode(i, bl);
		encode(arg->weight_set_positions, bl);
		for (__u32 j = 0; j < arg->weight_set_positions; j++) {
		  crush_weight_set *weight_set = &arg->weight_set[j];
		  encode(weight_set->size, bl);
		  for (__u32 k = 0; k < weight_set->size; k++)
		    encode(weight_set->weights[k], bl);
		}
		encode(arg->ids_size, bl);
		for (__u32 j = 0; j < arg->ids_size; j++)
		  encode(arg->ids[j], bl);
	      }
	    }
	  }
	}
	
	static void decode_32_or_64_string_map(map<int32_t,string>& m, bufferlist::const_iterator& blp)
	{
	  m.clear();
	  __u32 n;
	  decode(n, blp);
	  while (n--) {
	    __s32 key;
	    decode(key, blp);
	
	    __u32 strlen;
	    decode(strlen, blp);
	    if (strlen == 0) {
	      // der, key was actually 64-bits!
	      decode(strlen, blp);
	    }
	    decode_nohead(strlen, m[key], blp);
	  }
	}
	
	void CrushWrapper::decode(bufferlist::const_iterator& blp)
	{
	  using ceph::decode;
	  create();
	
	  __u32 magic;
	  decode(magic, blp);
	  if (magic != CRUSH_MAGIC)
	    throw ceph::buffer::malformed_input("bad magic number");
	
	  decode(crush->max_buckets, blp);
	  decode(crush->max_rules, blp);
	  decode(crush->max_devices, blp);
	
	  // legacy tunables, unless we decode something newer
	  set_tunables_legacy();
	
	  try {
	    // buckets
	    crush->buckets = (crush_bucket**)calloc(1, crush->max_buckets * sizeof(crush_bucket*));
	    for (int i=0; i<crush->max_buckets; i++) {
	      decode_crush_bucket(&crush->buckets[i], blp);
	    }
	
	    // rules
	    crush->rules = (crush_rule**)calloc(1, crush->max_rules * sizeof(crush_rule*));
	    for (unsigned i = 0; i < crush->max_rules; ++i) {
	      __u32 yes;
	      decode(yes, blp);
	      if (!yes) {
		crush->rules[i] = NULL;
		continue;
	      }
	
	      __u32 len;
	      decode(len, blp);
	      crush->rules[i] = reinterpret_cast<crush_rule*>(calloc(1, crush_rule_size(len)));
	      crush->rules[i]->len = len;
	      decode(crush->rules[i]->mask, blp);
	      for (unsigned j=0; j<crush->rules[i]->len; j++)
		decode(crush->rules[i]->steps[j], blp);
	    }
	
	    // name info
	    // NOTE: we had a bug where we were incoding int instead of int32, which means the
	    // 'key' field for these maps may be either 32 or 64 bits, depending.  tolerate
	    // both by assuming the string is always non-empty.
	    decode_32_or_64_string_map(type_map, blp);
	    decode_32_or_64_string_map(name_map, blp);
	    decode_32_or_64_string_map(rule_name_map, blp);
	
	    // tunables
	    if (!blp.end()) {
	      decode(crush->choose_local_tries, blp);
	      decode(crush->choose_local_fallback_tries, blp);
	      decode(crush->choose_total_tries, blp);
	    }
	    if (!blp.end()) {
	      decode(crush->chooseleaf_descend_once, blp);
	    }
	    if (!blp.end()) {
	      decode(crush->chooseleaf_vary_r, blp);
	    }
	    if (!blp.end()) {
	      decode(crush->straw_calc_version, blp);
	    }
	    if (!blp.end()) {
	      decode(crush->allowed_bucket_algs, blp);
	    }
	    if (!blp.end()) {
	      decode(crush->chooseleaf_stable, blp);
	    }
	    if (!blp.end()) {
	      decode(class_map, blp);
	      decode(class_name, blp);
	      for (auto &c : class_name)
		class_rname[c.second] = c.first;
	      decode(class_bucket, blp);
	    }
	    if (!blp.end()) {
	      __u32 choose_args_size;
	      decode(choose_args_size, blp);
	      for (__u32 i = 0; i < choose_args_size; i++) {
	        typename decltype(choose_args)::key_type choose_args_index;
		decode(choose_args_index, blp);
		crush_choose_arg_map arg_map;
		arg_map.size = crush->max_buckets;
		arg_map.args = static_cast<crush_choose_arg*>(calloc(
		  arg_map.size, sizeof(crush_choose_arg)));
		__u32 size;
		decode(size, blp);
		for (__u32 j = 0; j < size; j++) {
		  __u32 bucket_index;
		  decode(bucket_index, blp);
		  ceph_assert(bucket_index < arg_map.size);
		  crush_choose_arg *arg = &arg_map.args[bucket_index];
		  decode(arg->weight_set_positions, blp);
		  if (arg->weight_set_positions) {
		    arg->weight_set = static_cast<crush_weight_set*>(calloc(
		      arg->weight_set_positions, sizeof(crush_weight_set)));
		    for (__u32 k = 0; k < arg->weight_set_positions; k++) {
		      crush_weight_set *weight_set = &arg->weight_set[k];
		      decode(weight_set->size, blp);
		      weight_set->weights = (__u32*)calloc(
			weight_set->size, sizeof(__u32));
		      for (__u32 l = 0; l < weight_set->size; l++)
			decode(weight_set->weights[l], blp);
		    }
		  }
		  decode(arg->ids_size, blp);
		  if (arg->ids_size) {
		    ceph_assert(arg->ids_size == crush->buckets[bucket_index]->size);
		    arg->ids = (__s32 *)calloc(arg->ids_size, sizeof(__s32));
		    for (__u32 k = 0; k < arg->ids_size; k++)
		      decode(arg->ids[k], blp);
		  }
		}
		choose_args[choose_args_index] = arg_map;
	      }
	    }
	    update_choose_args(nullptr); // in case we decode a legacy "corrupted" map
	    finalize();
	  }
	  catch (...) {
	    crush_destroy(crush);
	    throw;
	  }
	}
	
	void CrushWrapper::decode_crush_bucket(crush_bucket** bptr, bufferlist::const_iterator &blp)
	{
	  using ceph::decode;
	  __u32 alg;
	  decode(alg, blp);
	  if (!alg) {
	    *bptr = NULL;
	    return;
	  }
	
	  int size = 0;
	  switch (alg) {
	  case CRUSH_BUCKET_UNIFORM:
	    size = sizeof(crush_bucket_uniform);
	    break;
	  case CRUSH_BUCKET_LIST:
	    size = sizeof(crush_bucket_list);
	    break;
	  case CRUSH_BUCKET_TREE:
	    size = sizeof(crush_bucket_tree);
	    break;
	  case CRUSH_BUCKET_STRAW:
	    size = sizeof(crush_bucket_straw);
	    break;
	  case CRUSH_BUCKET_STRAW2:
	    size = sizeof(crush_bucket_straw2);
	    break;
	  default:
	    {
	      char str[128];
	      snprintf(str, sizeof(str), "unsupported bucket algorithm: %d", alg);
	      throw ceph::buffer::malformed_input(str);
	    }
	  }
	  crush_bucket *bucket = reinterpret_cast<crush_bucket*>(calloc(1, size));
	  *bptr = bucket;
	    
	  decode(bucket->id, blp);
	  decode(bucket->type, blp);
	  decode(bucket->alg, blp);
	  decode(bucket->hash, blp);
	  decode(bucket->weight, blp);
	  decode(bucket->size, blp);
	
	  bucket->items = (__s32*)calloc(1, bucket->size * sizeof(__s32));
	  for (unsigned j = 0; j < bucket->size; ++j) {
	    decode(bucket->items[j], blp);
	  }
	
	  switch (bucket->alg) {
	  case CRUSH_BUCKET_UNIFORM:
	    decode((reinterpret_cast<crush_bucket_uniform*>(bucket))->item_weight, blp);
	    break;
	
	  case CRUSH_BUCKET_LIST: {
	    crush_bucket_list* cbl = reinterpret_cast<crush_bucket_list*>(bucket);
	    cbl->item_weights = (__u32*)calloc(1, bucket->size * sizeof(__u32));
	    cbl->sum_weights = (__u32*)calloc(1, bucket->size * sizeof(__u32));
	
	    for (unsigned j = 0; j < bucket->size; ++j) {
	      decode(cbl->item_weights[j], blp);
	      decode(cbl->sum_weights[j], blp);
	    }
	    break;
	  }
	
	  case CRUSH_BUCKET_TREE: {
	    crush_bucket_tree* cbt = reinterpret_cast<crush_bucket_tree*>(bucket);
	    decode(cbt->num_nodes, blp);
	    cbt->node_weights = (__u32*)calloc(1, cbt->num_nodes * sizeof(__u32));
	    for (unsigned j=0; j<cbt->num_nodes; j++) {
	      decode(cbt->node_weights[j], blp);
	    }
	    break;
	  }
	
	  case CRUSH_BUCKET_STRAW: {
	    crush_bucket_straw* cbs = reinterpret_cast<crush_bucket_straw*>(bucket);
	    cbs->straws = (__u32*)calloc(1, bucket->size * sizeof(__u32));
	    cbs->item_weights = (__u32*)calloc(1, bucket->size * sizeof(__u32));
	    for (unsigned j = 0; j < bucket->size; ++j) {
	      decode(cbs->item_weights[j], blp);
	      decode(cbs->straws[j], blp);
	    }
	    break;
	  }
	
	  case CRUSH_BUCKET_STRAW2: {
	    crush_bucket_straw2* cbs = reinterpret_cast<crush_bucket_straw2*>(bucket);
	    cbs->item_weights = (__u32*)calloc(1, bucket->size * sizeof(__u32));
	    for (unsigned j = 0; j < bucket->size; ++j) {
	      decode(cbs->item_weights[j], blp);
	    }
	    break;
	  }
	
	  default:
	    // We should have handled this case in the first switch statement
	    ceph_abort();
	    break;
	  }
	}
	
	  
	void CrushWrapper::dump(Formatter *f) const
	{
	  f->open_array_section("devices");
	  for (int i=0; i<get_max_devices(); i++) {
	    f->open_object_section("device");
	    f->dump_int("id", i);
	    const char *n = get_item_name(i);
	    if (n) {
	      f->dump_string("name", n);
	    } else {
	      char name[20];
	      sprintf(name, "device%d", i);
	      f->dump_string("name", name);
	    }
	    const char *device_class = get_item_class(i);
	    if (device_class != NULL)
	      f->dump_string("class", device_class);
	    f->close_section();
	  }
	  f->close_section();
	
	  f->open_array_section("types");
	  int n = get_num_type_names();
	  for (int i=0; n; i++) {
	    const char *name = get_type_name(i);
	    if (!name) {
	      if (i == 0) {
		f->open_object_section("type");
		f->dump_int("type_id", 0);
		f->dump_string("name", "device");
		f->close_section();
	      }
	      continue;
	    }
	    n--;
	    f->open_object_section("type");
	    f->dump_int("type_id", i);
	    f->dump_string("name", name);
	    f->close_section();
	  }
	  f->close_section();
	
	  f->open_array_section("buckets");
	  for (int bucket = -1; bucket > -1-get_max_buckets(); --bucket) {
	    if (!bucket_exists(bucket))
	      continue;
	    f->open_object_section("bucket");
	    f->dump_int("id", bucket);
	    if (get_item_name(bucket))
	      f->dump_string("name", get_item_name(bucket));
	    f->dump_int("type_id", get_bucket_type(bucket));
	    if (get_type_name(get_bucket_type(bucket)))
	      f->dump_string("type_name", get_type_name(get_bucket_type(bucket)));
	    f->dump_int("weight", get_bucket_weight(bucket));
	    f->dump_string("alg", crush_bucket_alg_name(get_bucket_alg(bucket)));
	    f->dump_string("hash", crush_hash_name(get_bucket_hash(bucket)));
	    f->open_array_section("items");
	    for (int j=0; j<get_bucket_size(bucket); j++) {
	      f->open_object_section("item");
	      f->dump_int("id", get_bucket_item(bucket, j));
	      f->dump_int("weight", get_bucket_item_weight(bucket, j));
	      f->dump_int("pos", j);
	      f->close_section();
	    }
	    f->close_section();
	    f->close_section();
	  }
	  f->close_section();
	
	  f->open_array_section("rules");
	  dump_rules(f);
	  f->close_section();
	
	  f->open_object_section("tunables");
	  dump_tunables(f);
	  f->close_section();
	
	  dump_choose_args(f);
	}
	
	namespace {
	  // depth first walker
	  class TreeDumper {
	    typedef CrushTreeDumper::Item Item;
	    const CrushWrapper *crush;
	    const CrushTreeDumper::name_map_t& weight_set_names;
	  public:
	    explicit TreeDumper(const CrushWrapper *crush,
				const CrushTreeDumper::name_map_t& wsnames)
	      : crush(crush), weight_set_names(wsnames) {}
	
	    void dump(Formatter *f) {
	      set<int> roots;
	      crush->find_roots(&roots);
	      for (set<int>::iterator root = roots.begin(); root != roots.end(); ++root) {
		dump_item(Item(*root, 0, 0, crush->get_bucket_weightf(*root)), f);
	      }
	    }
	
	  private:
	    void dump_item(const Item& qi, Formatter* f) {
	      if (qi.is_bucket()) {
		f->open_object_section("bucket");
		CrushTreeDumper::dump_item_fields(crush, weight_set_names, qi, f);
		dump_bucket_children(qi, f);
		f->close_section();
	      } else {
		f->open_object_section("device");
		CrushTreeDumper::dump_item_fields(crush, weight_set_names, qi, f);
		f->close_section();
	      }
	    }
	
	    void dump_bucket_children(const Item& parent, Formatter* f) {
	      f->open_array_section("items");
	      const int max_pos = crush->get_bucket_size(parent.id);
	      for (int pos = 0; pos < max_pos; pos++) {
		int id = crush->get_bucket_item(parent.id, pos);
		float weight = crush->get_bucket_item_weightf(parent.id, pos);
		dump_item(Item(id, parent.id, parent.depth + 1, weight), f);
	      }
	      f->close_section();
	    }
	  };
	}
	
	void CrushWrapper::dump_tree(
	  Formatter *f,
	  const CrushTreeDumper::name_map_t& weight_set_names) const
	{
	  ceph_assert(f);
	  TreeDumper(this, weight_set_names).dump(f);
	}
	
	void CrushWrapper::dump_tunables(Formatter *f) const
	{
	  f->dump_int("choose_local_tries", get_choose_local_tries());
	  f->dump_int("choose_local_fallback_tries", get_choose_local_fallback_tries());
	  f->dump_int("choose_total_tries", get_choose_total_tries());
	  f->dump_int("chooseleaf_descend_once", get_chooseleaf_descend_once());
	  f->dump_int("chooseleaf_vary_r", get_chooseleaf_vary_r());
	  f->dump_int("chooseleaf_stable", get_chooseleaf_stable());
	  f->dump_int("straw_calc_version", get_straw_calc_version());
	  f->dump_int("allowed_bucket_algs", get_allowed_bucket_algs());
	
	  // be helpful about it
	  if (has_jewel_tunables())
	    f->dump_string("profile", "jewel");
	  else if (has_hammer_tunables())
	    f->dump_string("profile", "hammer");
	  else if (has_firefly_tunables())
	    f->dump_string("profile", "firefly");
	  else if (has_bobtail_tunables())
	    f->dump_string("profile", "bobtail");
	  else if (has_argonaut_tunables())
	    f->dump_string("profile", "argonaut");
	  else
	    f->dump_string("profile", "unknown");
	  f->dump_int("optimal_tunables", (int)has_optimal_tunables());
	  f->dump_int("legacy_tunables", (int)has_legacy_tunables());
	
	  // be helpful about minimum version required
	  f->dump_string("minimum_required_version", get_min_required_version());
	
	  f->dump_int("require_feature_tunables", (int)has_nondefault_tunables());
	  f->dump_int("require_feature_tunables2", (int)has_nondefault_tunables2());
	  f->dump_int("has_v2_rules", (int)has_v2_rules());
	  f->dump_int("require_feature_tunables3", (int)has_nondefault_tunables3());
	  f->dump_int("has_v3_rules", (int)has_v3_rules());
	  f->dump_int("has_v4_buckets", (int)has_v4_buckets());
	  f->dump_int("require_feature_tunables5", (int)has_nondefault_tunables5());
	  f->dump_int("has_v5_rules", (int)has_v5_rules());
	}
	
	void CrushWrapper::dump_choose_args(Formatter *f) const
	{
	  f->open_object_section("choose_args");
	  for (auto c : choose_args) {
	    crush_choose_arg_map arg_map = c.second;
	    f->open_array_section(stringify(c.first).c_str());
	    for (__u32 i = 0; i < arg_map.size; i++) {
	      crush_choose_arg *arg = &arg_map.args[i];
	      if (arg->weight_set_positions == 0 &&
		  arg->ids_size == 0)
		continue;
	      f->open_object_section("choose_args");
	      int bucket_index = i;
	      f->dump_int("bucket_id", -1-bucket_index);
	      if (arg->weight_set_positions > 0) {
		f->open_array_section("weight_set");
		for (__u32 j = 0; j < arg->weight_set_positions; j++) {
		  f->open_array_section("weights");
		  __u32 *weights = arg->weight_set[j].weights;
		  __u32 size = arg->weight_set[j].size;
		  for (__u32 k = 0; k < size; k++) {
		    f->dump_float("weight", (float)weights[k]/(float)0x10000);
		  }
		  f->close_section();
		}
		f->close_section();
	      }
	      if (arg->ids_size > 0) {
		f->open_array_section("ids");
		for (__u32 j = 0; j < arg->ids_size; j++)
		  f->dump_int("id", arg->ids[j]);
		f->close_section();
	      }
	      f->close_section();
	    }
	    f->close_section();
	  }
	  f->close_section();
	}
	
	void CrushWrapper::dump_rules(Formatter *f) const
	{
	  for (int i=0; i<get_max_rules(); i++) {
	    if (!rule_exists(i))
	      continue;
	    dump_rule(i, f);
	  }
	}
	
	void CrushWrapper::dump_rule(int ruleset, Formatter *f) const
	{
	  f->open_object_section("rule");
	  f->dump_int("rule_id", ruleset);
	  if (get_rule_name(ruleset))
	    f->dump_string("rule_name", get_rule_name(ruleset));
	  f->dump_int("ruleset", get_rule_mask_ruleset(ruleset));
	  f->dump_int("type", get_rule_mask_type(ruleset));
	  f->dump_int("min_size", get_rule_mask_min_size(ruleset));
	  f->dump_int("max_size", get_rule_mask_max_size(ruleset));
	  f->open_array_section("steps");
	  for (int j=0; j<get_rule_len(ruleset); j++) {
	    f->open_object_section("step");
	    switch (get_rule_op(ruleset, j)) {
	    case CRUSH_RULE_NOOP:
	      f->dump_string("op", "noop");
	      break;
	    case CRUSH_RULE_TAKE:
	      f->dump_string("op", "take");
	      {
	        int item = get_rule_arg1(ruleset, j);
	        f->dump_int("item", item);
	
	        const char *name = get_item_name(item);
	        f->dump_string("item_name", name ? name : "");
	      }
	      break;
	    case CRUSH_RULE_EMIT:
	      f->dump_string("op", "emit");
	      break;
	    case CRUSH_RULE_CHOOSE_FIRSTN:
	      f->dump_string("op", "choose_firstn");
	      f->dump_int("num", get_rule_arg1(ruleset, j));
	      f->dump_string("type", get_type_name(get_rule_arg2(ruleset, j)));
	      break;
	    case CRUSH_RULE_CHOOSE_INDEP:
	      f->dump_string("op", "choose_indep");
	      f->dump_int("num", get_rule_arg1(ruleset, j));
	      f->dump_string("type", get_type_name(get_rule_arg2(ruleset, j)));
	      break;
	    case CRUSH_RULE_CHOOSELEAF_FIRSTN:
	      f->dump_string("op", "chooseleaf_firstn");
	      f->dump_int("num", get_rule_arg1(ruleset, j));
	      f->dump_string("type", get_type_name(get_rule_arg2(ruleset, j)));
	      break;
	    case CRUSH_RULE_CHOOSELEAF_INDEP:
	      f->dump_string("op", "chooseleaf_indep");
	      f->dump_int("num", get_rule_arg1(ruleset, j));
	      f->dump_string("type", get_type_name(get_rule_arg2(ruleset, j)));
	      break;
	    case CRUSH_RULE_SET_CHOOSE_TRIES:
	      f->dump_string("op", "set_choose_tries");
	      f->dump_int("num", get_rule_arg1(ruleset, j));
	      break;
	    case CRUSH_RULE_SET_CHOOSELEAF_TRIES:
	      f->dump_string("op", "set_chooseleaf_tries");
	      f->dump_int("num", get_rule_arg1(ruleset, j));
	      break;
	    default:
	      f->dump_int("opcode", get_rule_op(ruleset, j));
	      f->dump_int("arg1", get_rule_arg1(ruleset, j));
	      f->dump_int("arg2", get_rule_arg2(ruleset, j));
	    }
	    f->close_section();
	  }
	  f->close_section();
	  f->close_section();
	}
	
	void CrushWrapper::list_rules(Formatter *f) const
	{
	  for (int rule = 0; rule < get_max_rules(); rule++) {
	    if (!rule_exists(rule))
	      continue;
	    f->dump_string("name", get_rule_name(rule));
	  }
	}
	
	void CrushWrapper::list_rules(ostream *ss) const
	{
	  for (int rule = 0; rule < get_max_rules(); rule++) {
	    if (!rule_exists(rule))
	      continue;
	    *ss << get_rule_name(rule) << "\n";
	  }
	}
	
	class CrushTreePlainDumper : public CrushTreeDumper::Dumper<TextTable> {
	public:
	  typedef CrushTreeDumper::Dumper<TextTable> Parent;
	
	  explicit CrushTreePlainDumper(const CrushWrapper *crush,
					const CrushTreeDumper::name_map_t& wsnames)
	    : Parent(crush, wsnames) {}
	  explicit CrushTreePlainDumper(const CrushWrapper *crush,
	                                const CrushTreeDumper::name_map_t& wsnames,
	                                bool show_shadow)
	    : Parent(crush, wsnames, show_shadow) {}
	
	
	  void dump(TextTable *tbl) {
	    tbl->define_column("ID", TextTable::LEFT, TextTable::RIGHT);
	    tbl->define_column("CLASS", TextTable::LEFT, TextTable::RIGHT);
	    tbl->define_column("WEIGHT", TextTable::LEFT, TextTable::RIGHT);
	    for (auto& p : crush->choose_args) {
	      if (p.first == CrushWrapper::DEFAULT_CHOOSE_ARGS) {
		tbl->define_column("(compat)", TextTable::LEFT, TextTable::RIGHT);
	      } else {
		string name;
		auto q = weight_set_names.find(p.first);
		name = q != weight_set_names.end() ? q->second :
		  stringify(p.first);
		tbl->define_column(name.c_str(), TextTable::LEFT, TextTable::RIGHT);
	      }
	    }
	    tbl->define_column("TYPE NAME", TextTable::LEFT, TextTable::LEFT);
	    Parent::dump(tbl);
	  }
	
	protected:
	  void dump_item(const CrushTreeDumper::Item &qi, TextTable *tbl) override {
	    const char *c = crush->get_item_class(qi.id);
	    if (!c)
	      c = "";
	    *tbl << qi.id
		 << c
		 << weightf_t(qi.weight);
	    for (auto& p : crush->choose_args) {
	      if (qi.parent < 0) {
		const crush_choose_arg_map cmap = crush->choose_args_get(p.first);
		int bidx = -1 - qi.parent;
		const crush_bucket *b = crush->get_bucket(qi.parent);
		if (b &&
		    bidx < (int)cmap.size &&
		    cmap.args[bidx].weight_set &&
		    cmap.args[bidx].weight_set_positions >= 1) {
		  int pos;
		  for (pos = 0;
		       pos < (int)cmap.args[bidx].weight_set[0].size &&
			 b->items[pos] != qi.id;
		       ++pos) ;
		  *tbl << weightf_t((float)cmap.args[bidx].weight_set[0].weights[pos] /
				    (float)0x10000);
		  continue;
		}
	      }
	      *tbl << "";
	    }
	    ostringstream ss;
	    for (int k=0; k < qi.depth; k++) {
	      ss << "    ";
	    }
	    if (qi.is_bucket()) {
	      ss << crush->get_type_name(crush->get_bucket_type(qi.id)) << " "
		 << crush->get_item_name(qi.id);
	    } else {
	      ss << "osd." << qi.id;
	    }
	    *tbl << ss.str();
	    *tbl << TextTable::endrow;
	  }
	};
	
	
	class CrushTreeFormattingDumper : public CrushTreeDumper::FormattingDumper {
	public:
	  typedef CrushTreeDumper::FormattingDumper Parent;
	
	  explicit CrushTreeFormattingDumper(
	    const CrushWrapper *crush,
	    const CrushTreeDumper::name_map_t& wsnames)
	    : Parent(crush, wsnames) {}
	
	  explicit CrushTreeFormattingDumper(
	    const CrushWrapper *crush,
	    const CrushTreeDumper::name_map_t& wsnames,
	    bool show_shadow)
	    : Parent(crush, wsnames, show_shadow) {}
	
	  void dump(Formatter *f) {
	    f->open_array_section("nodes");
	    Parent::dump(f);
	    f->close_section();
	
	    // There is no stray bucket whose id is a negative number, so just get
	    // the max_id and iterate from 0 to max_id to dump stray osds.
	    f->open_array_section("stray");
	    int32_t max_id = -1;
	    if (!crush->name_map.empty()) {
	      max_id = crush->name_map.rbegin()->first;
	    }
	    for (int32_t i = 0; i <= max_id; i++) {
	      if (crush->item_exists(i) && !is_touched(i) && should_dump(i)) {
	        dump_item(CrushTreeDumper::Item(i, 0, 0, 0), f);
	      }
	    }
	    f->close_section();
	  }
	};
	
	
	void CrushWrapper::dump_tree(
	  ostream *out,
	  Formatter *f,
	  const CrushTreeDumper::name_map_t& weight_set_names,
	  bool show_shadow) const
	{
	  if (out) {
	    TextTable tbl;
	    CrushTreePlainDumper(this, weight_set_names, show_shadow).dump(&tbl);
	    *out << tbl;
	  }
	  if (f) {
	    CrushTreeFormattingDumper(this, weight_set_names, show_shadow).dump(f);
	  }
	}
	
	void CrushWrapper::generate_test_instances(list<CrushWrapper*>& o)
	{
	  o.push_back(new CrushWrapper);
	  // fixme
	}
	
	/**
	 * Determine the default CRUSH ruleset ID to be used with
	 * newly created replicated pools.
	 *
	 * @returns a ruleset ID (>=0) or -1 if no suitable ruleset found
	 */
	int CrushWrapper::get_osd_pool_default_crush_replicated_ruleset(CephContext *cct)
	{
	  int crush_ruleset = cct->_conf.get_val<int64_t>("osd_pool_default_crush_rule");
	  if (crush_ruleset < 0) {
	    crush_ruleset = find_first_ruleset(pg_pool_t::TYPE_REPLICATED);
	  } else if (!ruleset_exists(crush_ruleset)) {
	    crush_ruleset = -1; // match find_first_ruleset() retval
	  }
	  return crush_ruleset;
	}
	
	bool CrushWrapper::is_valid_crush_name(const string& s)
	{
	  if (s.empty())
	    return false;
	  for (string::const_iterator p = s.begin(); p != s.end(); ++p) {
	    if (!(*p == '-') &&
		!(*p == '_') &&
		!(*p == '.') &&
		!(*p >= '0' && *p <= '9') &&
		!(*p >= 'A' && *p <= 'Z') &&
		!(*p >= 'a' && *p <= 'z'))
	      return false;
	  }
	  return true;
	}
	
	bool CrushWrapper::is_valid_crush_loc(CephContext *cct,
	                                      const map<string,string>& loc)
	{
	  for (map<string,string>::const_iterator l = loc.begin(); l != loc.end(); ++l) {
	    if (!is_valid_crush_name(l->first) ||
	        !is_valid_crush_name(l->second)) {
	      ldout(cct, 1) << "loc["
	                    << l->first << "] = '"
	                    << l->second << "' not a valid crush name ([A-Za-z0-9_-.]+)"
	                    << dendl;
	      return false;
	    }
	  }
	  return true;
	}
	
	int CrushWrapper::_choose_type_stack(
	  CephContext *cct,
	  const vector<pair<int,int>>& stack,
	  const set<int>& overfull,
	  const vector<int>& underfull,
	  const vector<int>& orig,
	  vector<int>::const_iterator& i,
	  set<int>& used,
	  vector<int> *pw,
	  int root_bucket) const
	{
	  vector<int> w = *pw;
	  vector<int> o;
	

	  ldout(cct, 10) << __func__ << " stack " << stack
			 << " orig " << orig
			 << " at " << *i
			 << " pw " << *pw
			 << dendl;

	  ceph_assert(root_bucket < 0);
	  vector<int> cumulative_fanout(stack.size());
	  int f = 1;

	  for (int j = (int)stack.size() - 1; j >= 0; --j) {
	    cumulative_fanout[j] = f;
	    f *= stack[j].second;

	  }

	  ldout(cct, 10) << __func__ << " cumulative_fanout " << cumulative_fanout
			 << dendl;
	
	  // identify underfull targets for each intermediate level.
	  // this serves two purposes:
	  //   1. we can tell when we are selecting a bucket that does not have any underfull
	  //      devices beneath it.  that means that if the current input includes an overfull
	  //      device, we won't be able to find an underfull device with this parent to
	  //      swap for it.
	  //   2. when we decide we should reject a bucket due to the above, this list gives us
	  //      a list of peers to consider that *do* have underfull devices available..  (we
	  //      are careful to pick one that has the same parent.)
	  vector<set<int>> underfull_buckets; // level -> set of buckets with >0 underfull item(s)
	  underfull_buckets.resize(stack.size() - 1);

	  for (auto osd : underfull) {
	    int item = osd;
	    for (int j = (int)stack.size() - 2; j >= 0; --j) {
	      int type = stack[j].first;
	      item = get_parent_of_type(item, type);
	      ldout(cct, 10) << __func__ << " underfull " << osd << " type " << type
			     << " is " << item << dendl;
	      if (!subtree_contains(root_bucket, item)) {
	        ldout(cct, 20) << __func__ << " not in root subtree " << root_bucket << dendl;
	        continue;
	      }
	      underfull_buckets[j].insert(item);
	    }

	  }

	  ldout(cct, 20) << __func__ << " underfull_buckets " << underfull_buckets << dendl;
	

	  for (unsigned j = 0; j < stack.size(); ++j) {
	    int type = stack[j].first;
	    int fanout = stack[j].second;
	    int cum_fanout = cumulative_fanout[j];

	    ldout(cct, 10) << " level " << j << ": type " << type << " fanout " << fanout
			   << " cumulative " << cum_fanout
			   << " w " << w << dendl;
	    vector<int> o;
	    auto tmpi = i;

	    if (i == orig.end()) {
	      ldout(cct, 10) << __func__ << " end of orig, break 0" << dendl;
	      break;

	    }

	    for (auto from : w) {

	      ldout(cct, 10) << " from " << from << dendl;
	      // identify leaves under each choice.  we use this to check whether any of these
	      // leaves are overfull.  (if so, we need to make sure there are underfull candidates
	      // to swap for them.)
	      vector<set<int>> leaves;
	      leaves.resize(fanout);

	      for (int pos = 0; pos < fanout; ++pos) {

		if (type > 0) {
		  // non-leaf
		  int item = get_parent_of_type(*tmpi, type);
		  o.push_back(item);
		  int n = cum_fanout;