/******************************************************************************
  *******************************************************************************
  **
  **  Copyright (C) Sistina Software, Inc.  1997-2003  All rights reserved.
  **  Copyright (C) 2004-2005 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 "dlm_internal.h"
  #include "lockspace.h"
  #include "dir.h"
  #include "config.h"
  #include "ast.h"
  #include "memory.h"
  #include "rcom.h"
  #include "lock.h"
  #include "lowcomms.h"
  #include "member.h"
  #include "recover.h"
  
  
  /*
   * Recovery waiting routines: these functions wait for a particular reply from
   * a remote node, or for the remote node to report a certain status.  They need
   * to abort if the lockspace is stopped indicating a node has failed (perhaps
   * the one being waited for).
   */
  
  /*
   * Wait until given function returns non-zero or lockspace is stopped
   * (LS_RECOVERY_STOP set due to failure of a node in ls_nodes).  When another
   * function thinks it could have completed the waited-on task, they should wake
   * up ls_wait_general to get an immediate response rather than waiting for the
   * timer to detect the result.  A timer wakes us up periodically while waiting
   * to see if we should abort due to a node failure.  This should only be called
   * by the dlm_recoverd thread.
   */
  
  static void dlm_wait_timer_fn(unsigned long data)
  {
  	struct dlm_ls *ls = (struct dlm_ls *) data;

  	mod_timer(&ls->ls_timer, jiffies + (dlm_config.ci_recover_timer * HZ));

  	wake_up(&ls->ls_wait_general);
  }
  
  int dlm_wait_function(struct dlm_ls *ls, int (*testfn) (struct dlm_ls *ls))
  {
  	int error = 0;
  
  	init_timer(&ls->ls_timer);
  	ls->ls_timer.function = dlm_wait_timer_fn;
  	ls->ls_timer.data = (long) ls;

  	ls->ls_timer.expires = jiffies + (dlm_config.ci_recover_timer * HZ);

  	add_timer(&ls->ls_timer);
  
  	wait_event(ls->ls_wait_general, testfn(ls) || dlm_recovery_stopped(ls));
  	del_timer_sync(&ls->ls_timer);
  
  	if (dlm_recovery_stopped(ls)) {
  		log_debug(ls, "dlm_wait_function aborted");
  		error = -EINTR;
  	}
  	return error;
  }
  
  /*
   * An efficient way for all nodes to wait for all others to have a certain
   * status.  The node with the lowest nodeid polls all the others for their
   * status (wait_status_all) and all the others poll the node with the low id
   * for its accumulated result (wait_status_low).  When all nodes have set
   * status flag X, then status flag X_ALL will be set on the low nodeid.
   */
  
  uint32_t dlm_recover_status(struct dlm_ls *ls)
  {
  	uint32_t status;
  	spin_lock(&ls->ls_recover_lock);
  	status = ls->ls_recover_status;
  	spin_unlock(&ls->ls_recover_lock);
  	return status;
  }

  static void _set_recover_status(struct dlm_ls *ls, uint32_t status)
  {
  	ls->ls_recover_status |= status;
  }

  void dlm_set_recover_status(struct dlm_ls *ls, uint32_t status)
  {
  	spin_lock(&ls->ls_recover_lock);

  	_set_recover_status(ls, status);

  	spin_unlock(&ls->ls_recover_lock);
  }

  static int wait_status_all(struct dlm_ls *ls, uint32_t wait_status,
  			   int save_slots)

  {

  	struct dlm_rcom *rc = ls->ls_recover_buf;

  	struct dlm_member *memb;
  	int error = 0, delay;
  
  	list_for_each_entry(memb, &ls->ls_nodes, list) {
  		delay = 0;
  		for (;;) {
  			if (dlm_recovery_stopped(ls)) {
  				error = -EINTR;
  				goto out;
  			}

  			error = dlm_rcom_status(ls, memb->nodeid, 0);

  			if (error)
  				goto out;

  			if (save_slots)
  				dlm_slot_save(ls, rc, memb);

  			if (rc->rc_result & wait_status)
  				break;
  			if (delay < 1000)
  				delay += 20;
  			msleep(delay);
  		}
  	}
   out:
  	return error;
  }

  static int wait_status_low(struct dlm_ls *ls, uint32_t wait_status,
  			   uint32_t status_flags)

  {

  	struct dlm_rcom *rc = ls->ls_recover_buf;

  	int error = 0, delay = 0, nodeid = ls->ls_low_nodeid;
  
  	for (;;) {
  		if (dlm_recovery_stopped(ls)) {
  			error = -EINTR;
  			goto out;
  		}

  		error = dlm_rcom_status(ls, nodeid, status_flags);

  		if (error)
  			break;
  
  		if (rc->rc_result & wait_status)
  			break;
  		if (delay < 1000)
  			delay += 20;
  		msleep(delay);
  	}
   out:
  	return error;
  }
  
  static int wait_status(struct dlm_ls *ls, uint32_t status)
  {
  	uint32_t status_all = status << 1;
  	int error;
  
  	if (ls->ls_low_nodeid == dlm_our_nodeid()) {

  		error = wait_status_all(ls, status, 0);

  		if (!error)
  			dlm_set_recover_status(ls, status_all);
  	} else

  		error = wait_status_low(ls, status_all, 0);

  
  	return error;
  }
  
  int dlm_recover_members_wait(struct dlm_ls *ls)
  {

  	struct dlm_member *memb;
  	struct dlm_slot *slots;
  	int num_slots, slots_size;
  	int error, rv;
  	uint32_t gen;
  
  	list_for_each_entry(memb, &ls->ls_nodes, list) {
  		memb->slot = -1;
  		memb->generation = 0;
  	}
  
  	if (ls->ls_low_nodeid == dlm_our_nodeid()) {
  		error = wait_status_all(ls, DLM_RS_NODES, 1);
  		if (error)
  			goto out;
  
  		/* slots array is sparse, slots_size may be > num_slots */
  
  		rv = dlm_slots_assign(ls, &num_slots, &slots_size, &slots, &gen);
  		if (!rv) {
  			spin_lock(&ls->ls_recover_lock);
  			_set_recover_status(ls, DLM_RS_NODES_ALL);
  			ls->ls_num_slots = num_slots;
  			ls->ls_slots_size = slots_size;
  			ls->ls_slots = slots;
  			ls->ls_generation = gen;
  			spin_unlock(&ls->ls_recover_lock);
  		} else {
  			dlm_set_recover_status(ls, DLM_RS_NODES_ALL);
  		}
  	} else {
  		error = wait_status_low(ls, DLM_RS_NODES_ALL, DLM_RSF_NEED_SLOTS);
  		if (error)
  			goto out;
  
  		dlm_slots_copy_in(ls);
  	}
   out:
  	return error;

  }
  
  int dlm_recover_directory_wait(struct dlm_ls *ls)
  {
  	return wait_status(ls, DLM_RS_DIR);
  }
  
  int dlm_recover_locks_wait(struct dlm_ls *ls)
  {
  	return wait_status(ls, DLM_RS_LOCKS);
  }
  
  int dlm_recover_done_wait(struct dlm_ls *ls)
  {
  	return wait_status(ls, DLM_RS_DONE);
  }
  
  /*
   * The recover_list contains all the rsb's for which we've requested the new
   * master nodeid.  As replies are returned from the resource directories the
   * rsb's are removed from the list.  When the list is empty we're done.
   *
   * The recover_list is later similarly used for all rsb's for which we've sent
   * new lkb's and need to receive new corresponding lkid's.
   *
   * We use the address of the rsb struct as a simple local identifier for the
   * rsb so we can match an rcom reply with the rsb it was sent for.
   */
  
  static int recover_list_empty(struct dlm_ls *ls)
  {
  	int empty;
  
  	spin_lock(&ls->ls_recover_list_lock);
  	empty = list_empty(&ls->ls_recover_list);
  	spin_unlock(&ls->ls_recover_list_lock);
  
  	return empty;
  }
  
  static void recover_list_add(struct dlm_rsb *r)
  {
  	struct dlm_ls *ls = r->res_ls;
  
  	spin_lock(&ls->ls_recover_list_lock);
  	if (list_empty(&r->res_recover_list)) {
  		list_add_tail(&r->res_recover_list, &ls->ls_recover_list);
  		ls->ls_recover_list_count++;
  		dlm_hold_rsb(r);
  	}
  	spin_unlock(&ls->ls_recover_list_lock);
  }
  
  static void recover_list_del(struct dlm_rsb *r)
  {
  	struct dlm_ls *ls = r->res_ls;
  
  	spin_lock(&ls->ls_recover_list_lock);
  	list_del_init(&r->res_recover_list);
  	ls->ls_recover_list_count--;
  	spin_unlock(&ls->ls_recover_list_lock);
  
  	dlm_put_rsb(r);
  }
  
  static struct dlm_rsb *recover_list_find(struct dlm_ls *ls, uint64_t id)
  {
  	struct dlm_rsb *r = NULL;
  
  	spin_lock(&ls->ls_recover_list_lock);
  
  	list_for_each_entry(r, &ls->ls_recover_list, res_recover_list) {
  		if (id == (unsigned long) r)
  			goto out;
  	}
  	r = NULL;
   out:
  	spin_unlock(&ls->ls_recover_list_lock);
  	return r;
  }
  
  static void recover_list_clear(struct dlm_ls *ls)
  {
  	struct dlm_rsb *r, *s;
  
  	spin_lock(&ls->ls_recover_list_lock);
  	list_for_each_entry_safe(r, s, &ls->ls_recover_list, res_recover_list) {
  		list_del_init(&r->res_recover_list);

  		r->res_recover_locks_count = 0;

  		dlm_put_rsb(r);
  		ls->ls_recover_list_count--;
  	}
  
  	if (ls->ls_recover_list_count != 0) {
  		log_error(ls, "warning: recover_list_count %d",
  			  ls->ls_recover_list_count);
  		ls->ls_recover_list_count = 0;
  	}
  	spin_unlock(&ls->ls_recover_list_lock);
  }
  
  
  /* Master recovery: find new master node for rsb's that were
     mastered on nodes that have been removed.
  
     dlm_recover_masters
     recover_master
     dlm_send_rcom_lookup            ->  receive_rcom_lookup
                                         dlm_dir_lookup
     receive_rcom_lookup_reply       <-
     dlm_recover_master_reply
     set_new_master
     set_master_lkbs
     set_lock_master
  */
  
  /*
   * Set the lock master for all LKBs in a lock queue
   * If we are the new master of the rsb, we may have received new
   * MSTCPY locks from other nodes already which we need to ignore
   * when setting the new nodeid.
   */
  
  static void set_lock_master(struct list_head *queue, int nodeid)
  {
  	struct dlm_lkb *lkb;
  
  	list_for_each_entry(lkb, queue, lkb_statequeue)
  		if (!(lkb->lkb_flags & DLM_IFL_MSTCPY))
  			lkb->lkb_nodeid = nodeid;
  }
  
  static void set_master_lkbs(struct dlm_rsb *r)
  {
  	set_lock_master(&r->res_grantqueue, r->res_nodeid);
  	set_lock_master(&r->res_convertqueue, r->res_nodeid);
  	set_lock_master(&r->res_waitqueue, r->res_nodeid);
  }
  
  /*

   * Propagate the new master nodeid to locks

   * The NEW_MASTER flag tells dlm_recover_locks() which rsb's to consider.

   * The NEW_MASTER2 flag tells recover_lvb() and set_locks_purged() which
   * rsb's to consider.

   */
  
  static void set_new_master(struct dlm_rsb *r, int nodeid)
  {
  	lock_rsb(r);
  	r->res_nodeid = nodeid;
  	set_master_lkbs(r);
  	rsb_set_flag(r, RSB_NEW_MASTER);
  	rsb_set_flag(r, RSB_NEW_MASTER2);
  	unlock_rsb(r);
  }
  
  /*
   * We do async lookups on rsb's that need new masters.  The rsb's
   * waiting for a lookup reply are kept on the recover_list.
   */
  
  static int recover_master(struct dlm_rsb *r)
  {
  	struct dlm_ls *ls = r->res_ls;
  	int error, dir_nodeid, ret_nodeid, our_nodeid = dlm_our_nodeid();
  
  	dir_nodeid = dlm_dir_nodeid(r);
  
  	if (dir_nodeid == our_nodeid) {
  		error = dlm_dir_lookup(ls, our_nodeid, r->res_name,
  				       r->res_length, &ret_nodeid);
  		if (error)
  			log_error(ls, "recover dir lookup error %d", error);
  
  		if (ret_nodeid == our_nodeid)
  			ret_nodeid = 0;
  		set_new_master(r, ret_nodeid);
  	} else {
  		recover_list_add(r);
  		error = dlm_send_rcom_lookup(r, dir_nodeid);
  	}
  
  	return error;
  }
  
  /*
   * When not using a directory, most resource names will hash to a new static
   * master nodeid and the resource will need to be remastered.
   */
  
  static int recover_master_static(struct dlm_rsb *r)
  {
  	int master = dlm_dir_nodeid(r);
  
  	if (master == dlm_our_nodeid())
  		master = 0;
  
  	if (r->res_nodeid != master) {
  		if (is_master(r))
  			dlm_purge_mstcpy_locks(r);
  		set_new_master(r, master);
  		return 1;
  	}
  	return 0;
  }
  
  /*
   * Go through local root resources and for each rsb which has a master which
   * has departed, get the new master nodeid from the directory.  The dir will
   * assign mastery to the first node to look up the new master.  That means
   * we'll discover in this lookup if we're the new master of any rsb's.
   *
   * We fire off all the dir lookup requests individually and asynchronously to
   * the correct dir node.
   */
  
  int dlm_recover_masters(struct dlm_ls *ls)
  {
  	struct dlm_rsb *r;
  	int error = 0, count = 0;
  
  	log_debug(ls, "dlm_recover_masters");
  
  	down_read(&ls->ls_root_sem);
  	list_for_each_entry(r, &ls->ls_root_list, res_root_list) {
  		if (dlm_recovery_stopped(ls)) {
  			up_read(&ls->ls_root_sem);
  			error = -EINTR;
  			goto out;
  		}
  
  		if (dlm_no_directory(ls))
  			count += recover_master_static(r);

  		else if (!is_master(r) &&
  			 (dlm_is_removed(ls, r->res_nodeid) ||
  			  rsb_flag(r, RSB_NEW_MASTER))) {

  			recover_master(r);
  			count++;
  		}
  
  		schedule();
  	}
  	up_read(&ls->ls_root_sem);
  
  	log_debug(ls, "dlm_recover_masters %d resources", count);
  
  	error = dlm_wait_function(ls, &recover_list_empty);
   out:
  	if (error)
  		recover_list_clear(ls);
  	return error;
  }
  
  int dlm_recover_master_reply(struct dlm_ls *ls, struct dlm_rcom *rc)
  {
  	struct dlm_rsb *r;
  	int nodeid;
  
  	r = recover_list_find(ls, rc->rc_id);
  	if (!r) {

  		log_error(ls, "dlm_recover_master_reply no id %llx",

  			  (unsigned long long)rc->rc_id);

  		goto out;
  	}
  
  	nodeid = rc->rc_result;
  	if (nodeid == dlm_our_nodeid())
  		nodeid = 0;
  
  	set_new_master(r, nodeid);
  	recover_list_del(r);
  
  	if (recover_list_empty(ls))
  		wake_up(&ls->ls_wait_general);
   out:
  	return 0;
  }
  
  
  /* Lock recovery: rebuild the process-copy locks we hold on a
     remastered rsb on the new rsb master.
  
     dlm_recover_locks
     recover_locks
     recover_locks_queue
     dlm_send_rcom_lock              ->  receive_rcom_lock
                                         dlm_recover_master_copy
     receive_rcom_lock_reply         <-
     dlm_recover_process_copy
  */
  
  
  /*
   * keep a count of the number of lkb's we send to the new master; when we get
   * an equal number of replies then recovery for the rsb is done
   */
  
  static int recover_locks_queue(struct dlm_rsb *r, struct list_head *head)
  {
  	struct dlm_lkb *lkb;
  	int error = 0;
  
  	list_for_each_entry(lkb, head, lkb_statequeue) {
  	   	error = dlm_send_rcom_lock(r, lkb);
  		if (error)
  			break;
  		r->res_recover_locks_count++;
  	}
  
  	return error;
  }

  static int recover_locks(struct dlm_rsb *r)
  {
  	int error = 0;
  
  	lock_rsb(r);

  	DLM_ASSERT(!r->res_recover_locks_count, dlm_dump_rsb(r););

  
  	error = recover_locks_queue(r, &r->res_grantqueue);
  	if (error)
  		goto out;
  	error = recover_locks_queue(r, &r->res_convertqueue);
  	if (error)
  		goto out;
  	error = recover_locks_queue(r, &r->res_waitqueue);
  	if (error)
  		goto out;
  
  	if (r->res_recover_locks_count)
  		recover_list_add(r);
  	else
  		rsb_clear_flag(r, RSB_NEW_MASTER);
   out:
  	unlock_rsb(r);
  	return error;
  }
  
  int dlm_recover_locks(struct dlm_ls *ls)
  {
  	struct dlm_rsb *r;
  	int error, count = 0;
  
  	log_debug(ls, "dlm_recover_locks");
  
  	down_read(&ls->ls_root_sem);
  	list_for_each_entry(r, &ls->ls_root_list, res_root_list) {
  		if (is_master(r)) {
  			rsb_clear_flag(r, RSB_NEW_MASTER);
  			continue;
  		}
  
  		if (!rsb_flag(r, RSB_NEW_MASTER))
  			continue;
  
  		if (dlm_recovery_stopped(ls)) {
  			error = -EINTR;
  			up_read(&ls->ls_root_sem);
  			goto out;
  		}
  
  		error = recover_locks(r);
  		if (error) {
  			up_read(&ls->ls_root_sem);
  			goto out;
  		}
  
  		count += r->res_recover_locks_count;
  	}
  	up_read(&ls->ls_root_sem);
  
  	log_debug(ls, "dlm_recover_locks %d locks", count);
  
  	error = dlm_wait_function(ls, &recover_list_empty);
   out:
  	if (error)
  		recover_list_clear(ls);

  	return error;
  }
  
  void dlm_recovered_lock(struct dlm_rsb *r)
  {

  	DLM_ASSERT(rsb_flag(r, RSB_NEW_MASTER), dlm_dump_rsb(r););

  
  	r->res_recover_locks_count--;
  	if (!r->res_recover_locks_count) {
  		rsb_clear_flag(r, RSB_NEW_MASTER);
  		recover_list_del(r);
  	}
  
  	if (recover_list_empty(r->res_ls))
  		wake_up(&r->res_ls->ls_wait_general);
  }
  
  /*
   * The lvb needs to be recovered on all master rsb's.  This includes setting
   * the VALNOTVALID flag if necessary, and determining the correct lvb contents
   * based on the lvb's of the locks held on the rsb.
   *
   * RSB_VALNOTVALID is set if there are only NL/CR locks on the rsb.  If it
   * was already set prior to recovery, it's not cleared, regardless of locks.
   *
   * The LVB contents are only considered for changing when this is a new master
   * of the rsb (NEW_MASTER2).  Then, the rsb's lvb is taken from any lkb with
   * mode > CR.  If no lkb's exist with mode above CR, the lvb contents are taken
   * from the lkb with the largest lvb sequence number.
   */
  
  static void recover_lvb(struct dlm_rsb *r)
  {
  	struct dlm_lkb *lkb, *high_lkb = NULL;
  	uint32_t high_seq = 0;

  	int lock_lvb_exists = 0;
  	int big_lock_exists = 0;

  	int lvblen = r->res_ls->ls_lvblen;
  
  	list_for_each_entry(lkb, &r->res_grantqueue, lkb_statequeue) {
  		if (!(lkb->lkb_exflags & DLM_LKF_VALBLK))
  			continue;

  		lock_lvb_exists = 1;

  
  		if (lkb->lkb_grmode > DLM_LOCK_CR) {

  			big_lock_exists = 1;

  			goto setflag;
  		}
  
  		if (((int)lkb->lkb_lvbseq - (int)high_seq) >= 0) {
  			high_lkb = lkb;
  			high_seq = lkb->lkb_lvbseq;
  		}
  	}
  
  	list_for_each_entry(lkb, &r->res_convertqueue, lkb_statequeue) {
  		if (!(lkb->lkb_exflags & DLM_LKF_VALBLK))
  			continue;

  		lock_lvb_exists = 1;

  
  		if (lkb->lkb_grmode > DLM_LOCK_CR) {

  			big_lock_exists = 1;

  			goto setflag;
  		}
  
  		if (((int)lkb->lkb_lvbseq - (int)high_seq) >= 0) {
  			high_lkb = lkb;
  			high_seq = lkb->lkb_lvbseq;
  		}
  	}
  
   setflag:
  	if (!lock_lvb_exists)
  		goto out;
  
  	if (!big_lock_exists)
  		rsb_set_flag(r, RSB_VALNOTVALID);
  
  	/* don't mess with the lvb unless we're the new master */
  	if (!rsb_flag(r, RSB_NEW_MASTER2))
  		goto out;
  
  	if (!r->res_lvbptr) {

  		r->res_lvbptr = dlm_allocate_lvb(r->res_ls);

  		if (!r->res_lvbptr)
  			goto out;
  	}
  
  	if (big_lock_exists) {
  		r->res_lvbseq = lkb->lkb_lvbseq;
  		memcpy(r->res_lvbptr, lkb->lkb_lvbptr, lvblen);
  	} else if (high_lkb) {
  		r->res_lvbseq = high_lkb->lkb_lvbseq;
  		memcpy(r->res_lvbptr, high_lkb->lkb_lvbptr, lvblen);
  	} else {
  		r->res_lvbseq = 0;
  		memset(r->res_lvbptr, 0, lvblen);
  	}
   out:
  	return;
  }
  
  /* All master rsb's flagged RECOVER_CONVERT need to be looked at.  The locks
     converting PR->CW or CW->PR need to have their lkb_grmode set. */
  
  static void recover_conversion(struct dlm_rsb *r)
  {
  	struct dlm_lkb *lkb;
  	int grmode = -1;
  
  	list_for_each_entry(lkb, &r->res_grantqueue, lkb_statequeue) {
  		if (lkb->lkb_grmode == DLM_LOCK_PR ||
  		    lkb->lkb_grmode == DLM_LOCK_CW) {
  			grmode = lkb->lkb_grmode;
  			break;
  		}
  	}
  
  	list_for_each_entry(lkb, &r->res_convertqueue, lkb_statequeue) {
  		if (lkb->lkb_grmode != DLM_LOCK_IV)
  			continue;
  		if (grmode == -1)
  			lkb->lkb_grmode = lkb->lkb_rqmode;
  		else
  			lkb->lkb_grmode = grmode;
  	}
  }

  /* We've become the new master for this rsb and waiting/converting locks may
     need to be granted in dlm_grant_after_purge() due to locks that may have
     existed from a removed node. */
  
  static void set_locks_purged(struct dlm_rsb *r)
  {
  	if (!list_empty(&r->res_waitqueue) || !list_empty(&r->res_convertqueue))
  		rsb_set_flag(r, RSB_LOCKS_PURGED);
  }

  void dlm_recover_rsbs(struct dlm_ls *ls)
  {
  	struct dlm_rsb *r;
  	int count = 0;
  
  	log_debug(ls, "dlm_recover_rsbs");
  
  	down_read(&ls->ls_root_sem);
  	list_for_each_entry(r, &ls->ls_root_list, res_root_list) {
  		lock_rsb(r);
  		if (is_master(r)) {
  			if (rsb_flag(r, RSB_RECOVER_CONVERT))
  				recover_conversion(r);

  			if (rsb_flag(r, RSB_NEW_MASTER2))
  				set_locks_purged(r);

  			recover_lvb(r);
  			count++;
  		}
  		rsb_clear_flag(r, RSB_RECOVER_CONVERT);

  		rsb_clear_flag(r, RSB_NEW_MASTER2);

  		unlock_rsb(r);
  	}
  	up_read(&ls->ls_root_sem);
  
  	log_debug(ls, "dlm_recover_rsbs %d rsbs", count);
  }
  
  /* Create a single list of all root rsb's to be used during recovery */
  
  int dlm_create_root_list(struct dlm_ls *ls)
  {

  	struct rb_node *n;

  	struct dlm_rsb *r;
  	int i, error = 0;
  
  	down_write(&ls->ls_root_sem);
  	if (!list_empty(&ls->ls_root_list)) {
  		log_error(ls, "root list not empty");
  		error = -EINVAL;
  		goto out;
  	}
  
  	for (i = 0; i < ls->ls_rsbtbl_size; i++) {

  		spin_lock(&ls->ls_rsbtbl[i].lock);

  		for (n = rb_first(&ls->ls_rsbtbl[i].keep); n; n = rb_next(n)) {
  			r = rb_entry(n, struct dlm_rsb, res_hashnode);

  			list_add(&r->res_root_list, &ls->ls_root_list);
  			dlm_hold_rsb(r);
  		}

  
  		/* If we're using a directory, add tossed rsbs to the root
  		   list; they'll have entries created in the new directory,
  		   but no other recovery steps should do anything with them. */
  
  		if (dlm_no_directory(ls)) {

  			spin_unlock(&ls->ls_rsbtbl[i].lock);

  			continue;
  		}

  		for (n = rb_first(&ls->ls_rsbtbl[i].toss); n; n = rb_next(n)) {
  			r = rb_entry(n, struct dlm_rsb, res_hashnode);

  			list_add(&r->res_root_list, &ls->ls_root_list);
  			dlm_hold_rsb(r);
  		}

  		spin_unlock(&ls->ls_rsbtbl[i].lock);

  	}
   out:
  	up_write(&ls->ls_root_sem);
  	return error;
  }
  
  void dlm_release_root_list(struct dlm_ls *ls)
  {
  	struct dlm_rsb *r, *safe;
  
  	down_write(&ls->ls_root_sem);
  	list_for_each_entry_safe(r, safe, &ls->ls_root_list, res_root_list) {
  		list_del_init(&r->res_root_list);
  		dlm_put_rsb(r);
  	}
  	up_write(&ls->ls_root_sem);
  }

  /* If not using a directory, clear the entire toss list, there's no benefit to
     caching the master value since it's fixed.  If we are using a dir, keep the
     rsb's we're the master of.  Recovery will add them to the root list and from
     there they'll be entered in the rebuilt directory. */

  void dlm_clear_toss_list(struct dlm_ls *ls)
  {

  	struct rb_node *n, *next;
  	struct dlm_rsb *rsb;

  	int i;
  
  	for (i = 0; i < ls->ls_rsbtbl_size; i++) {

  		spin_lock(&ls->ls_rsbtbl[i].lock);

  		for (n = rb_first(&ls->ls_rsbtbl[i].toss); n; n = next) {
  			next = rb_next(n);;
  			rsb = rb_entry(n, struct dlm_rsb, res_hashnode);
  			if (dlm_no_directory(ls) || !is_master(rsb)) {
  				rb_erase(n, &ls->ls_rsbtbl[i].toss);
  				dlm_free_rsb(rsb);

  			}

  		}

  		spin_unlock(&ls->ls_rsbtbl[i].lock);

  	}
  }