/******************************************************************************
  *******************************************************************************
  **
  **  Copyright (C) Sistina Software, Inc.  1997-2003  All rights reserved.

  **  Copyright (C) 2004-2011 Red Hat, Inc.  All rights reserved.

  **
  **  This copyrighted material is made available to anyone wishing to use,
  **  modify, copy, or redistribute it subject to the terms and conditions
  **  of the GNU General Public License v.2.
  **
  *******************************************************************************
  ******************************************************************************/
  
  #include <linux/kernel.h>
  #include <linux/module.h>
  #include <linux/configfs.h>

  #include <linux/slab.h>

  #include <linux/in.h>
  #include <linux/in6.h>

  #include <linux/dlmconstants.h>

  #include <net/ipv6.h>

  #include <net/sock.h>
  
  #include "config.h"

  #include "lowcomms.h"

  
  /*
   * /config/dlm/<cluster>/spaces/<space>/nodes/<node>/nodeid
   * /config/dlm/<cluster>/spaces/<space>/nodes/<node>/weight
   * /config/dlm/<cluster>/comms/<comm>/nodeid
   * /config/dlm/<cluster>/comms/<comm>/local

   * /config/dlm/<cluster>/comms/<comm>/addr      (write only)
   * /config/dlm/<cluster>/comms/<comm>/addr_list (read only)

   * The <cluster> level is useless, but I haven't figured out how to avoid it.
   */
  
  static struct config_group *space_list;
  static struct config_group *comm_list;

  static struct dlm_comm *local_comm;

  static uint32_t dlm_comm_count;

  struct dlm_clusters;
  struct dlm_cluster;
  struct dlm_spaces;
  struct dlm_space;
  struct dlm_comms;
  struct dlm_comm;
  struct dlm_nodes;
  struct dlm_node;

  static struct config_group *make_cluster(struct config_group *, const char *);

  static void drop_cluster(struct config_group *, struct config_item *);
  static void release_cluster(struct config_item *);

  static struct config_group *make_space(struct config_group *, const char *);

  static void drop_space(struct config_group *, struct config_item *);
  static void release_space(struct config_item *);

  static struct config_item *make_comm(struct config_group *, const char *);

  static void drop_comm(struct config_group *, struct config_item *);
  static void release_comm(struct config_item *);

  static struct config_item *make_node(struct config_group *, const char *);

  static void drop_node(struct config_group *, struct config_item *);
  static void release_node(struct config_item *);

  static ssize_t show_cluster(struct config_item *i, struct configfs_attribute *a,
  			    char *buf);
  static ssize_t store_cluster(struct config_item *i,
  			     struct configfs_attribute *a,
  			     const char *buf, size_t len);

  static ssize_t show_comm(struct config_item *i, struct configfs_attribute *a,
  			 char *buf);
  static ssize_t store_comm(struct config_item *i, struct configfs_attribute *a,
  			  const char *buf, size_t len);
  static ssize_t show_node(struct config_item *i, struct configfs_attribute *a,
  			 char *buf);
  static ssize_t store_node(struct config_item *i, struct configfs_attribute *a,
  			  const char *buf, size_t len);

  static ssize_t comm_nodeid_read(struct dlm_comm *cm, char *buf);
  static ssize_t comm_nodeid_write(struct dlm_comm *cm, const char *buf,
  				size_t len);
  static ssize_t comm_local_read(struct dlm_comm *cm, char *buf);
  static ssize_t comm_local_write(struct dlm_comm *cm, const char *buf,
  				size_t len);
  static ssize_t comm_addr_write(struct dlm_comm *cm, const char *buf,
  				size_t len);

  static ssize_t comm_addr_list_read(struct dlm_comm *cm, char *buf);

  static ssize_t node_nodeid_read(struct dlm_node *nd, char *buf);
  static ssize_t node_nodeid_write(struct dlm_node *nd, const char *buf,
  				size_t len);
  static ssize_t node_weight_read(struct dlm_node *nd, char *buf);
  static ssize_t node_weight_write(struct dlm_node *nd, const char *buf,
  				size_t len);
  
  struct dlm_cluster {

  	struct config_group group;
  	unsigned int cl_tcp_port;
  	unsigned int cl_buffer_size;
  	unsigned int cl_rsbtbl_size;

  	unsigned int cl_recover_timer;
  	unsigned int cl_toss_secs;
  	unsigned int cl_scan_secs;
  	unsigned int cl_log_debug;

  	unsigned int cl_protocol;

  	unsigned int cl_timewarn_cs;

  	unsigned int cl_waitwarn_us;

  	unsigned int cl_new_rsb_count;

  	unsigned int cl_recover_callbacks;
  	char cl_cluster_name[DLM_LOCKSPACE_LEN];

  };
  
  enum {
  	CLUSTER_ATTR_TCP_PORT = 0,
  	CLUSTER_ATTR_BUFFER_SIZE,
  	CLUSTER_ATTR_RSBTBL_SIZE,

  	CLUSTER_ATTR_RECOVER_TIMER,
  	CLUSTER_ATTR_TOSS_SECS,
  	CLUSTER_ATTR_SCAN_SECS,
  	CLUSTER_ATTR_LOG_DEBUG,

  	CLUSTER_ATTR_PROTOCOL,

  	CLUSTER_ATTR_TIMEWARN_CS,

  	CLUSTER_ATTR_WAITWARN_US,

  	CLUSTER_ATTR_NEW_RSB_COUNT,

  	CLUSTER_ATTR_RECOVER_CALLBACKS,
  	CLUSTER_ATTR_CLUSTER_NAME,

  };
  
  struct cluster_attribute {
  	struct configfs_attribute attr;

  	ssize_t (*show)(struct dlm_cluster *, char *);
  	ssize_t (*store)(struct dlm_cluster *, const char *, size_t);

  };

  static ssize_t cluster_cluster_name_read(struct dlm_cluster *cl, char *buf)
  {
  	return sprintf(buf, "%s
  ", cl->cl_cluster_name);
  }
  
  static ssize_t cluster_cluster_name_write(struct dlm_cluster *cl,
  					  const char *buf, size_t len)
  {

  	strlcpy(dlm_config.ci_cluster_name, buf,
  				sizeof(dlm_config.ci_cluster_name));
  	strlcpy(cl->cl_cluster_name, buf, sizeof(cl->cl_cluster_name));

  	return len;
  }
  
  static struct cluster_attribute cluster_attr_cluster_name = {
  	.attr   = { .ca_owner = THIS_MODULE,
                      .ca_name = "cluster_name",
                      .ca_mode = S_IRUGO | S_IWUSR },
  	.show   = cluster_cluster_name_read,
  	.store  = cluster_cluster_name_write,
  };

  static ssize_t cluster_set(struct dlm_cluster *cl, unsigned int *cl_field,

  			   int *info_field, int check_zero,

  			   const char *buf, size_t len)
  {
  	unsigned int x;

  	int rc;

  
  	if (!capable(CAP_SYS_ADMIN))

  		return -EPERM;

  	rc = kstrtouint(buf, 0, &x);
  	if (rc)
  		return rc;

  
  	if (check_zero && !x)
  		return -EINVAL;
  
  	*cl_field = x;
  	*info_field = x;
  
  	return len;
  }

  #define CLUSTER_ATTR(name, check_zero)                                        \

  static ssize_t name##_write(struct dlm_cluster *cl, const char *buf, size_t len) \

  {                                                                             \
  	return cluster_set(cl, &cl->cl_##name, &dlm_config.ci_##name,         \
  			   check_zero, buf, len);                             \
  }                                                                             \

  static ssize_t name##_read(struct dlm_cluster *cl, char *buf)                 \

  {                                                                             \
  	return snprintf(buf, PAGE_SIZE, "%u
  ", cl->cl_##name);               \
  }                                                                             \
  static struct cluster_attribute cluster_attr_##name =                         \
  __CONFIGFS_ATTR(name, 0644, name##_read, name##_write)
  
  CLUSTER_ATTR(tcp_port, 1);
  CLUSTER_ATTR(buffer_size, 1);
  CLUSTER_ATTR(rsbtbl_size, 1);

  CLUSTER_ATTR(recover_timer, 1);
  CLUSTER_ATTR(toss_secs, 1);
  CLUSTER_ATTR(scan_secs, 1);
  CLUSTER_ATTR(log_debug, 0);

  CLUSTER_ATTR(protocol, 0);

  CLUSTER_ATTR(timewarn_cs, 1);

  CLUSTER_ATTR(waitwarn_us, 0);

  CLUSTER_ATTR(new_rsb_count, 0);

  CLUSTER_ATTR(recover_callbacks, 0);

  
  static struct configfs_attribute *cluster_attrs[] = {
  	[CLUSTER_ATTR_TCP_PORT] = &cluster_attr_tcp_port.attr,
  	[CLUSTER_ATTR_BUFFER_SIZE] = &cluster_attr_buffer_size.attr,
  	[CLUSTER_ATTR_RSBTBL_SIZE] = &cluster_attr_rsbtbl_size.attr,

  	[CLUSTER_ATTR_RECOVER_TIMER] = &cluster_attr_recover_timer.attr,
  	[CLUSTER_ATTR_TOSS_SECS] = &cluster_attr_toss_secs.attr,
  	[CLUSTER_ATTR_SCAN_SECS] = &cluster_attr_scan_secs.attr,
  	[CLUSTER_ATTR_LOG_DEBUG] = &cluster_attr_log_debug.attr,

  	[CLUSTER_ATTR_PROTOCOL] = &cluster_attr_protocol.attr,

  	[CLUSTER_ATTR_TIMEWARN_CS] = &cluster_attr_timewarn_cs.attr,

  	[CLUSTER_ATTR_WAITWARN_US] = &cluster_attr_waitwarn_us.attr,

  	[CLUSTER_ATTR_NEW_RSB_COUNT] = &cluster_attr_new_rsb_count.attr,

  	[CLUSTER_ATTR_RECOVER_CALLBACKS] = &cluster_attr_recover_callbacks.attr,
  	[CLUSTER_ATTR_CLUSTER_NAME] = &cluster_attr_cluster_name.attr,

  	NULL,
  };

  enum {
  	COMM_ATTR_NODEID = 0,
  	COMM_ATTR_LOCAL,
  	COMM_ATTR_ADDR,

  	COMM_ATTR_ADDR_LIST,

  };
  
  struct comm_attribute {
  	struct configfs_attribute attr;

  	ssize_t (*show)(struct dlm_comm *, char *);
  	ssize_t (*store)(struct dlm_comm *, const char *, size_t);

  };
  
  static struct comm_attribute comm_attr_nodeid = {
  	.attr   = { .ca_owner = THIS_MODULE,
                      .ca_name = "nodeid",
                      .ca_mode = S_IRUGO | S_IWUSR },
  	.show   = comm_nodeid_read,
  	.store  = comm_nodeid_write,
  };
  
  static struct comm_attribute comm_attr_local = {
  	.attr   = { .ca_owner = THIS_MODULE,
                      .ca_name = "local",
                      .ca_mode = S_IRUGO | S_IWUSR },
  	.show   = comm_local_read,
  	.store  = comm_local_write,
  };
  
  static struct comm_attribute comm_attr_addr = {
  	.attr   = { .ca_owner = THIS_MODULE,
                      .ca_name = "addr",

                      .ca_mode = S_IWUSR },

  	.store  = comm_addr_write,
  };

  static struct comm_attribute comm_attr_addr_list = {
  	.attr   = { .ca_owner = THIS_MODULE,
                      .ca_name = "addr_list",
                      .ca_mode = S_IRUGO },
  	.show   = comm_addr_list_read,
  };

  static struct configfs_attribute *comm_attrs[] = {
  	[COMM_ATTR_NODEID] = &comm_attr_nodeid.attr,
  	[COMM_ATTR_LOCAL] = &comm_attr_local.attr,
  	[COMM_ATTR_ADDR] = &comm_attr_addr.attr,

  	[COMM_ATTR_ADDR_LIST] = &comm_attr_addr_list.attr,

  	NULL,
  };
  
  enum {
  	NODE_ATTR_NODEID = 0,
  	NODE_ATTR_WEIGHT,
  };
  
  struct node_attribute {
  	struct configfs_attribute attr;

  	ssize_t (*show)(struct dlm_node *, char *);
  	ssize_t (*store)(struct dlm_node *, const char *, size_t);

  };
  
  static struct node_attribute node_attr_nodeid = {
  	.attr   = { .ca_owner = THIS_MODULE,
                      .ca_name = "nodeid",
                      .ca_mode = S_IRUGO | S_IWUSR },
  	.show   = node_nodeid_read,
  	.store  = node_nodeid_write,
  };
  
  static struct node_attribute node_attr_weight = {
  	.attr   = { .ca_owner = THIS_MODULE,
                      .ca_name = "weight",
                      .ca_mode = S_IRUGO | S_IWUSR },
  	.show   = node_weight_read,
  	.store  = node_weight_write,
  };
  
  static struct configfs_attribute *node_attrs[] = {
  	[NODE_ATTR_NODEID] = &node_attr_nodeid.attr,
  	[NODE_ATTR_WEIGHT] = &node_attr_weight.attr,
  	NULL,
  };

  struct dlm_clusters {

  	struct configfs_subsystem subsys;
  };

  struct dlm_spaces {

  	struct config_group ss_group;
  };

  struct dlm_space {

  	struct config_group group;
  	struct list_head members;

  	struct mutex members_lock;

  	int members_count;
  };

  struct dlm_comms {

  	struct config_group cs_group;
  };

  struct dlm_comm {

  	struct config_item item;

  	int seq;

  	int nodeid;
  	int local;
  	int addr_count;
  	struct sockaddr_storage *addr[DLM_MAX_ADDR_COUNT];
  };

  struct dlm_nodes {

  	struct config_group ns_group;
  };

  struct dlm_node {

  	struct config_item item;
  	struct list_head list; /* space->members */
  	int nodeid;
  	int weight;

  	int new;

  	int comm_seq; /* copy of cm->seq when nd->nodeid is set */

  };
  
  static struct configfs_group_operations clusters_ops = {
  	.make_group = make_cluster,
  	.drop_item = drop_cluster,
  };
  
  static struct configfs_item_operations cluster_ops = {
  	.release = release_cluster,

  	.show_attribute = show_cluster,
  	.store_attribute = store_cluster,

  };
  
  static struct configfs_group_operations spaces_ops = {
  	.make_group = make_space,
  	.drop_item = drop_space,
  };
  
  static struct configfs_item_operations space_ops = {
  	.release = release_space,
  };
  
  static struct configfs_group_operations comms_ops = {
  	.make_item = make_comm,
  	.drop_item = drop_comm,
  };
  
  static struct configfs_item_operations comm_ops = {
  	.release = release_comm,
  	.show_attribute = show_comm,
  	.store_attribute = store_comm,
  };
  
  static struct configfs_group_operations nodes_ops = {
  	.make_item = make_node,
  	.drop_item = drop_node,
  };
  
  static struct configfs_item_operations node_ops = {
  	.release = release_node,
  	.show_attribute = show_node,
  	.store_attribute = store_node,
  };
  
  static struct config_item_type clusters_type = {
  	.ct_group_ops = &clusters_ops,
  	.ct_owner = THIS_MODULE,
  };
  
  static struct config_item_type cluster_type = {
  	.ct_item_ops = &cluster_ops,

  	.ct_attrs = cluster_attrs,

  	.ct_owner = THIS_MODULE,
  };
  
  static struct config_item_type spaces_type = {
  	.ct_group_ops = &spaces_ops,
  	.ct_owner = THIS_MODULE,
  };
  
  static struct config_item_type space_type = {
  	.ct_item_ops = &space_ops,
  	.ct_owner = THIS_MODULE,
  };
  
  static struct config_item_type comms_type = {
  	.ct_group_ops = &comms_ops,
  	.ct_owner = THIS_MODULE,
  };
  
  static struct config_item_type comm_type = {
  	.ct_item_ops = &comm_ops,
  	.ct_attrs = comm_attrs,
  	.ct_owner = THIS_MODULE,
  };
  
  static struct config_item_type nodes_type = {
  	.ct_group_ops = &nodes_ops,
  	.ct_owner = THIS_MODULE,
  };
  
  static struct config_item_type node_type = {
  	.ct_item_ops = &node_ops,
  	.ct_attrs = node_attrs,
  	.ct_owner = THIS_MODULE,
  };

  static struct dlm_cluster *config_item_to_cluster(struct config_item *i)

  {

  	return i ? container_of(to_config_group(i), struct dlm_cluster, group) :
  		   NULL;

  }

  static struct dlm_space *config_item_to_space(struct config_item *i)

  {

  	return i ? container_of(to_config_group(i), struct dlm_space, group) :
  		   NULL;

  }

  static struct dlm_comm *config_item_to_comm(struct config_item *i)

  {

  	return i ? container_of(i, struct dlm_comm, item) : NULL;

  }

  static struct dlm_node *config_item_to_node(struct config_item *i)

  {

  	return i ? container_of(i, struct dlm_node, item) : NULL;

  }

  static struct config_group *make_cluster(struct config_group *g,
  					 const char *name)

  {

  	struct dlm_cluster *cl = NULL;
  	struct dlm_spaces *sps = NULL;
  	struct dlm_comms *cms = NULL;

  	void *gps = NULL;

  	cl = kzalloc(sizeof(struct dlm_cluster), GFP_NOFS);
  	gps = kcalloc(3, sizeof(struct config_group *), GFP_NOFS);
  	sps = kzalloc(sizeof(struct dlm_spaces), GFP_NOFS);
  	cms = kzalloc(sizeof(struct dlm_comms), GFP_NOFS);

  
  	if (!cl || !gps || !sps || !cms)
  		goto fail;
  
  	config_group_init_type_name(&cl->group, name, &cluster_type);
  	config_group_init_type_name(&sps->ss_group, "spaces", &spaces_type);
  	config_group_init_type_name(&cms->cs_group, "comms", &comms_type);
  
  	cl->group.default_groups = gps;
  	cl->group.default_groups[0] = &sps->ss_group;
  	cl->group.default_groups[1] = &cms->cs_group;
  	cl->group.default_groups[2] = NULL;

  	cl->cl_tcp_port = dlm_config.ci_tcp_port;
  	cl->cl_buffer_size = dlm_config.ci_buffer_size;
  	cl->cl_rsbtbl_size = dlm_config.ci_rsbtbl_size;

  	cl->cl_recover_timer = dlm_config.ci_recover_timer;
  	cl->cl_toss_secs = dlm_config.ci_toss_secs;
  	cl->cl_scan_secs = dlm_config.ci_scan_secs;
  	cl->cl_log_debug = dlm_config.ci_log_debug;

  	cl->cl_protocol = dlm_config.ci_protocol;

  	cl->cl_timewarn_cs = dlm_config.ci_timewarn_cs;

  	cl->cl_waitwarn_us = dlm_config.ci_waitwarn_us;

  	cl->cl_new_rsb_count = dlm_config.ci_new_rsb_count;

  	cl->cl_recover_callbacks = dlm_config.ci_recover_callbacks;
  	memcpy(cl->cl_cluster_name, dlm_config.ci_cluster_name,
  	       DLM_LOCKSPACE_LEN);

  	space_list = &sps->ss_group;
  	comm_list = &cms->cs_group;

  	return &cl->group;

  
   fail:
  	kfree(cl);
  	kfree(gps);
  	kfree(sps);
  	kfree(cms);

  	return ERR_PTR(-ENOMEM);

  }
  
  static void drop_cluster(struct config_group *g, struct config_item *i)
  {

  	struct dlm_cluster *cl = config_item_to_cluster(i);

  	struct config_item *tmp;
  	int j;
  
  	for (j = 0; cl->group.default_groups[j]; j++) {
  		tmp = &cl->group.default_groups[j]->cg_item;
  		cl->group.default_groups[j] = NULL;
  		config_item_put(tmp);
  	}
  
  	space_list = NULL;
  	comm_list = NULL;
  
  	config_item_put(i);
  }
  
  static void release_cluster(struct config_item *i)
  {

  	struct dlm_cluster *cl = config_item_to_cluster(i);

  	kfree(cl->group.default_groups);
  	kfree(cl);
  }

  static struct config_group *make_space(struct config_group *g, const char *name)

  {

  	struct dlm_space *sp = NULL;
  	struct dlm_nodes *nds = NULL;

  	void *gps = NULL;

  	sp = kzalloc(sizeof(struct dlm_space), GFP_NOFS);
  	gps = kcalloc(2, sizeof(struct config_group *), GFP_NOFS);
  	nds = kzalloc(sizeof(struct dlm_nodes), GFP_NOFS);

  
  	if (!sp || !gps || !nds)
  		goto fail;
  
  	config_group_init_type_name(&sp->group, name, &space_type);
  	config_group_init_type_name(&nds->ns_group, "nodes", &nodes_type);
  
  	sp->group.default_groups = gps;
  	sp->group.default_groups[0] = &nds->ns_group;
  	sp->group.default_groups[1] = NULL;
  
  	INIT_LIST_HEAD(&sp->members);

  	mutex_init(&sp->members_lock);

  	sp->members_count = 0;

  	return &sp->group;

  
   fail:
  	kfree(sp);
  	kfree(gps);
  	kfree(nds);

  	return ERR_PTR(-ENOMEM);

  }
  
  static void drop_space(struct config_group *g, struct config_item *i)
  {

  	struct dlm_space *sp = config_item_to_space(i);

  	struct config_item *tmp;
  	int j;
  
  	/* assert list_empty(&sp->members) */
  
  	for (j = 0; sp->group.default_groups[j]; j++) {
  		tmp = &sp->group.default_groups[j]->cg_item;
  		sp->group.default_groups[j] = NULL;
  		config_item_put(tmp);
  	}
  
  	config_item_put(i);
  }
  
  static void release_space(struct config_item *i)
  {

  	struct dlm_space *sp = config_item_to_space(i);

  	kfree(sp->group.default_groups);
  	kfree(sp);
  }

  static struct config_item *make_comm(struct config_group *g, const char *name)

  {

  	struct dlm_comm *cm;

  	cm = kzalloc(sizeof(struct dlm_comm), GFP_NOFS);

  	if (!cm)

  		return ERR_PTR(-ENOMEM);

  
  	config_item_init_type_name(&cm->item, name, &comm_type);

  
  	cm->seq = dlm_comm_count++;
  	if (!cm->seq)
  		cm->seq = dlm_comm_count++;

  	cm->nodeid = -1;
  	cm->local = 0;
  	cm->addr_count = 0;

  	return &cm->item;

  }
  
  static void drop_comm(struct config_group *g, struct config_item *i)
  {

  	struct dlm_comm *cm = config_item_to_comm(i);

  	if (local_comm == cm)
  		local_comm = NULL;

  	dlm_lowcomms_close(cm->nodeid);

  	while (cm->addr_count--)
  		kfree(cm->addr[cm->addr_count]);
  	config_item_put(i);
  }
  
  static void release_comm(struct config_item *i)
  {

  	struct dlm_comm *cm = config_item_to_comm(i);

  	kfree(cm);
  }

  static struct config_item *make_node(struct config_group *g, const char *name)

  {

  	struct dlm_space *sp = config_item_to_space(g->cg_item.ci_parent);

  	struct dlm_node *nd;

  	nd = kzalloc(sizeof(struct dlm_node), GFP_NOFS);

  	if (!nd)

  		return ERR_PTR(-ENOMEM);

  
  	config_item_init_type_name(&nd->item, name, &node_type);
  	nd->nodeid = -1;
  	nd->weight = 1;  /* default weight of 1 if none is set */

  	nd->new = 1;     /* set to 0 once it's been read by dlm_nodeid_list() */

  	mutex_lock(&sp->members_lock);

  	list_add(&nd->list, &sp->members);
  	sp->members_count++;

  	mutex_unlock(&sp->members_lock);

  	return &nd->item;

  }
  
  static void drop_node(struct config_group *g, struct config_item *i)
  {

  	struct dlm_space *sp = config_item_to_space(g->cg_item.ci_parent);
  	struct dlm_node *nd = config_item_to_node(i);

  	mutex_lock(&sp->members_lock);

  	list_del(&nd->list);
  	sp->members_count--;

  	mutex_unlock(&sp->members_lock);

  
  	config_item_put(i);
  }
  
  static void release_node(struct config_item *i)
  {

  	struct dlm_node *nd = config_item_to_node(i);

  	kfree(nd);
  }

  static struct dlm_clusters clusters_root = {

  	.subsys = {
  		.su_group = {
  			.cg_item = {
  				.ci_namebuf = "dlm",
  				.ci_type = &clusters_type,
  			},
  		},
  	},
  };

  int __init dlm_config_init(void)

  {
  	config_group_init(&clusters_root.subsys.su_group);

  	mutex_init(&clusters_root.subsys.su_mutex);

  	return configfs_register_subsystem(&clusters_root.subsys);
  }
  
  void dlm_config_exit(void)
  {
  	configfs_unregister_subsystem(&clusters_root.subsys);
  }
  
  /*
   * Functions for user space to read/write attributes
   */

  static ssize_t show_cluster(struct config_item *i, struct configfs_attribute *a,
  			    char *buf)
  {

  	struct dlm_cluster *cl = config_item_to_cluster(i);

  	struct cluster_attribute *cla =
  			container_of(a, struct cluster_attribute, attr);
  	return cla->show ? cla->show(cl, buf) : 0;
  }
  
  static ssize_t store_cluster(struct config_item *i,
  			     struct configfs_attribute *a,
  			     const char *buf, size_t len)
  {

  	struct dlm_cluster *cl = config_item_to_cluster(i);

  	struct cluster_attribute *cla =
  		container_of(a, struct cluster_attribute, attr);
  	return cla->store ? cla->store(cl, buf, len) : -EINVAL;
  }

  static ssize_t show_comm(struct config_item *i, struct configfs_attribute *a,
  			 char *buf)
  {

  	struct dlm_comm *cm = config_item_to_comm(i);

  	struct comm_attribute *cma =
  			container_of(a, struct comm_attribute, attr);
  	return cma->show ? cma->show(cm, buf) : 0;
  }
  
  static ssize_t store_comm(struct config_item *i, struct configfs_attribute *a,
  			  const char *buf, size_t len)
  {

  	struct dlm_comm *cm = config_item_to_comm(i);

  	struct comm_attribute *cma =
  		container_of(a, struct comm_attribute, attr);
  	return cma->store ? cma->store(cm, buf, len) : -EINVAL;
  }

  static ssize_t comm_nodeid_read(struct dlm_comm *cm, char *buf)

  {
  	return sprintf(buf, "%d
  ", cm->nodeid);
  }

  static ssize_t comm_nodeid_write(struct dlm_comm *cm, const char *buf,
  				 size_t len)

  {

  	int rc = kstrtoint(buf, 0, &cm->nodeid);
  
  	if (rc)
  		return rc;

  	return len;
  }

  static ssize_t comm_local_read(struct dlm_comm *cm, char *buf)

  {
  	return sprintf(buf, "%d
  ", cm->local);
  }

  static ssize_t comm_local_write(struct dlm_comm *cm, const char *buf,
  				size_t len)

  {

  	int rc = kstrtoint(buf, 0, &cm->local);
  
  	if (rc)
  		return rc;

  	if (cm->local && !local_comm)
  		local_comm = cm;
  	return len;
  }

  static ssize_t comm_addr_write(struct dlm_comm *cm, const char *buf, size_t len)

  {
  	struct sockaddr_storage *addr;

  	int rv;

  
  	if (len != sizeof(struct sockaddr_storage))
  		return -EINVAL;
  
  	if (cm->addr_count >= DLM_MAX_ADDR_COUNT)
  		return -ENOSPC;

  	addr = kzalloc(sizeof(*addr), GFP_NOFS);

  	if (!addr)
  		return -ENOMEM;
  
  	memcpy(addr, buf, len);

  
  	rv = dlm_lowcomms_addr(cm->nodeid, addr, len);
  	if (rv) {
  		kfree(addr);
  		return rv;
  	}

  	cm->addr[cm->addr_count++] = addr;
  	return len;
  }

  static ssize_t comm_addr_list_read(struct dlm_comm *cm, char *buf)
  {
  	ssize_t s;
  	ssize_t allowance;
  	int i;
  	struct sockaddr_storage *addr;
  	struct sockaddr_in *addr_in;
  	struct sockaddr_in6 *addr_in6;
  	
  	/* Taken from ip6_addr_string() defined in lib/vsprintf.c */
  	char buf0[sizeof("AF_INET6	xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255
  ")];
  	
  
  	/* Derived from SIMPLE_ATTR_SIZE of fs/configfs/file.c */
  	allowance = 4096;
  	buf[0] = '\0';
  
  	for (i = 0; i < cm->addr_count; i++) {
  		addr = cm->addr[i];
  
  		switch(addr->ss_family) {
  		case AF_INET:
  			addr_in = (struct sockaddr_in *)addr;
  			s = sprintf(buf0, "AF_INET	%pI4
  ", &addr_in->sin_addr.s_addr);
  			break;
  		case AF_INET6:
  			addr_in6 = (struct sockaddr_in6 *)addr;
  			s = sprintf(buf0, "AF_INET6	%pI6
  ", &addr_in6->sin6_addr);
  			break;
  		default:
  			s = sprintf(buf0, "%s
  ", "<UNKNOWN>");
  			break;
  		}
  		allowance -= s;
  		if (allowance >= 0)
  			strcat(buf, buf0);
  		else {
  			allowance += s;
  			break;
  		}
  	}
  	return 4096 - allowance;
  }

  static ssize_t show_node(struct config_item *i, struct configfs_attribute *a,
  			 char *buf)
  {

  	struct dlm_node *nd = config_item_to_node(i);

  	struct node_attribute *nda =
  			container_of(a, struct node_attribute, attr);
  	return nda->show ? nda->show(nd, buf) : 0;
  }
  
  static ssize_t store_node(struct config_item *i, struct configfs_attribute *a,
  			  const char *buf, size_t len)
  {

  	struct dlm_node *nd = config_item_to_node(i);

  	struct node_attribute *nda =
  		container_of(a, struct node_attribute, attr);
  	return nda->store ? nda->store(nd, buf, len) : -EINVAL;
  }

  static ssize_t node_nodeid_read(struct dlm_node *nd, char *buf)

  {
  	return sprintf(buf, "%d
  ", nd->nodeid);
  }

  static ssize_t node_nodeid_write(struct dlm_node *nd, const char *buf,
  				 size_t len)

  {

  	uint32_t seq = 0;

  	int rc = kstrtoint(buf, 0, &nd->nodeid);
  
  	if (rc)
  		return rc;

  	dlm_comm_seq(nd->nodeid, &seq);
  	nd->comm_seq = seq;

  	return len;
  }

  static ssize_t node_weight_read(struct dlm_node *nd, char *buf)

  {
  	return sprintf(buf, "%d
  ", nd->weight);
  }

  static ssize_t node_weight_write(struct dlm_node *nd, const char *buf,
  				 size_t len)

  {

  	int rc = kstrtoint(buf, 0, &nd->weight);
  
  	if (rc)
  		return rc;

  	return len;
  }
  
  /*
   * Functions for the dlm to get the info that's been configured
   */

  static struct dlm_space *get_space(char *name)

  {

  	struct config_item *i;

  	if (!space_list)
  		return NULL;

  	mutex_lock(&space_list->cg_subsys->su_mutex);

  	i = config_group_find_item(space_list, name);

  	mutex_unlock(&space_list->cg_subsys->su_mutex);

  	return config_item_to_space(i);

  }

  static void put_space(struct dlm_space *sp)

  {
  	config_item_put(&sp->group.cg_item);
  }

  static struct dlm_comm *get_comm(int nodeid)

  {
  	struct config_item *i;

  	struct dlm_comm *cm = NULL;

  	int found = 0;
  
  	if (!comm_list)
  		return NULL;

  	mutex_lock(&clusters_root.subsys.su_mutex);

  
  	list_for_each_entry(i, &comm_list->cg_children, ci_entry) {

  		cm = config_item_to_comm(i);

  		if (cm->nodeid != nodeid)
  			continue;
  		found = 1;
  		config_item_get(i);
  		break;

  	}

  	mutex_unlock(&clusters_root.subsys.su_mutex);

  	if (!found)

  		cm = NULL;
  	return cm;
  }

  static void put_comm(struct dlm_comm *cm)

  {
  	config_item_put(&cm->item);
  }
  
  /* caller must free mem */

  int dlm_config_nodes(char *lsname, struct dlm_config_node **nodes_out,
  		     int *count_out)

  {

  	struct dlm_space *sp;
  	struct dlm_node *nd;

  	struct dlm_config_node *nodes, *node;
  	int rv, count;

  
  	sp = get_space(lsname);
  	if (!sp)
  		return -EEXIST;

  	mutex_lock(&sp->members_lock);

  	if (!sp->members_count) {

  		rv = -EINVAL;
  		printk(KERN_ERR "dlm: zero members_count
  ");

  		goto out;
  	}

  	count = sp->members_count;

  	nodes = kcalloc(count, sizeof(struct dlm_config_node), GFP_NOFS);
  	if (!nodes) {

  		rv = -ENOMEM;
  		goto out;
  	}

  	node = nodes;

  	list_for_each_entry(nd, &sp->members, list) {

  		node->nodeid = nd->nodeid;
  		node->weight = nd->weight;
  		node->new = nd->new;
  		node->comm_seq = nd->comm_seq;
  		node++;

  		nd->new = 0;

  	}

  	*count_out = count;
  	*nodes_out = nodes;
  	rv = 0;

   out:

  	mutex_unlock(&sp->members_lock);

  	put_space(sp);
  	return rv;
  }

  int dlm_comm_seq(int nodeid, uint32_t *seq)

  {

  	struct dlm_comm *cm = get_comm(nodeid);

  	if (!cm)
  		return -EEXIST;
  	*seq = cm->seq;
  	put_comm(cm);
  	return 0;

  }

  int dlm_our_nodeid(void)
  {
  	return local_comm ? local_comm->nodeid : 0;
  }
  
  /* num 0 is first addr, num 1 is second addr */
  int dlm_our_addr(struct sockaddr_storage *addr, int num)
  {
  	if (!local_comm)
  		return -1;
  	if (num + 1 > local_comm->addr_count)
  		return -1;
  	memcpy(addr, local_comm->addr[num], sizeof(*addr));
  	return 0;
  }
  
  /* Config file defaults */
  #define DEFAULT_TCP_PORT       21064
  #define DEFAULT_BUFFER_SIZE     4096

  #define DEFAULT_RSBTBL_SIZE     1024

  #define DEFAULT_RECOVER_TIMER      5
  #define DEFAULT_TOSS_SECS         10
  #define DEFAULT_SCAN_SECS          5

  #define DEFAULT_LOG_DEBUG          0

  #define DEFAULT_PROTOCOL           0

  #define DEFAULT_TIMEWARN_CS      500 /* 5 sec = 500 centiseconds */

  #define DEFAULT_WAITWARN_US	   0

  #define DEFAULT_NEW_RSB_COUNT    128

  #define DEFAULT_RECOVER_CALLBACKS  0
  #define DEFAULT_CLUSTER_NAME      ""

  
  struct dlm_config_info dlm_config = {

  	.ci_tcp_port = DEFAULT_TCP_PORT,
  	.ci_buffer_size = DEFAULT_BUFFER_SIZE,
  	.ci_rsbtbl_size = DEFAULT_RSBTBL_SIZE,

  	.ci_recover_timer = DEFAULT_RECOVER_TIMER,
  	.ci_toss_secs = DEFAULT_TOSS_SECS,

  	.ci_scan_secs = DEFAULT_SCAN_SECS,

  	.ci_log_debug = DEFAULT_LOG_DEBUG,

  	.ci_protocol = DEFAULT_PROTOCOL,

  	.ci_timewarn_cs = DEFAULT_TIMEWARN_CS,

  	.ci_waitwarn_us = DEFAULT_WAITWARN_US,

  	.ci_new_rsb_count = DEFAULT_NEW_RSB_COUNT,
  	.ci_recover_callbacks = DEFAULT_RECOVER_CALLBACKS,
  	.ci_cluster_name = DEFAULT_CLUSTER_NAME

  };