// SPDX-License-Identifier: GPL-2.0-only
/******************************************************************************
*******************************************************************************
**
**  Copyright (C) Sistina Software, Inc.  1997-2003  All rights reserved.
**  Copyright (C) 2004-2005 Red Hat, Inc.  All rights reserved.
**
**
*******************************************************************************
******************************************************************************/

#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
 * timeout.  This uses a timeout so it can check periodically if the wait
 * should abort due to node failure (which doesn't cause a wake_up).
 * This should only be called by the dlm_recoverd thread.
 */

int dlm_wait_function(struct dlm_ls *ls, int (*testfn) (struct dlm_ls *ls))
{
        int error = 0;
        int rv;

        while (1) {
                rv = wait_event_timeout(ls->ls_wait_general,
                                        testfn(ls) || dlm_recovery_stopped(ls),
                                        dlm_config.ci_recover_timer * HZ);
                if (rv)
                        break;
                if (test_bit(LSFL_RCOM_WAIT, &ls->ls_flags)) {
                        log_debug(ls, "dlm_wait_function timed out");
                        return -ETIMEDOUT;
                }
        }

        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_bh(&ls->ls_recover_lock);
        status = ls->ls_recover_status;
        spin_unlock_bh(&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_bh(&ls->ls_recover_lock);
        _set_recover_status(ls, status);
        spin_unlock_bh(&ls->ls_recover_lock);
}

static int wait_status_all(struct dlm_ls *ls, uint32_t wait_status,
                           int save_slots, uint64_t seq)
{
        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, seq);
                        if (error)
                                goto out;

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

                        if (le32_to_cpu(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, uint64_t seq)
{
        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, seq);
                if (error)
                        break;

                if (le32_to_cpu(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, uint64_t seq)
{
        uint32_t status_all = status << 1;
        int error;

        if (ls->ls_low_nodeid == dlm_our_nodeid()) {
                error = wait_status_all(ls, status, 0, seq);
                if (!error)
                        dlm_set_recover_status(ls, status_all);
        } else
                error = wait_status_low(ls, status_all, 0, seq);

        return error;
}

int dlm_recover_members_wait(struct dlm_ls *ls, uint64_t seq)
{
        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, seq);
                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_bh(&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_bh(&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, seq);
                if (error)
                        goto out;

                dlm_slots_copy_in(ls);
        }
 out:
        return error;
}

int dlm_recover_directory_wait(struct dlm_ls *ls, uint64_t seq)
{
        return wait_status(ls, DLM_RS_DIR, seq);
}

int dlm_recover_locks_wait(struct dlm_ls *ls, uint64_t seq)
{
        return wait_status(ls, DLM_RS_LOCKS, seq);
}

int dlm_recover_done_wait(struct dlm_ls *ls, uint64_t seq)
{
        return wait_status(ls, DLM_RS_DONE, seq);
}

/*
 * 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_bh(&ls->ls_recover_list_lock);
        empty = list_empty(&ls->ls_recover_list);
        spin_unlock_bh(&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_bh(&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_bh(&ls->ls_recover_list_lock);
}

static void recover_list_del(struct dlm_rsb *r)
{
        struct dlm_ls *ls = r->res_ls;

        spin_lock_bh(&ls->ls_recover_list_lock);
        list_del_init(&r->res_recover_list);
        ls->ls_recover_list_count--;
        spin_unlock_bh(&ls->ls_recover_list_lock);

        dlm_put_rsb(r);
}

static void recover_list_clear(struct dlm_ls *ls)
{
        struct dlm_rsb *r, *s;

        spin_lock_bh(&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_bh(&ls->ls_recover_list_lock);
}

static int recover_xa_empty(struct dlm_ls *ls)
{
        int empty = 1;

        spin_lock_bh(&ls->ls_recover_xa_lock);
        if (ls->ls_recover_list_count)
                empty = 0;
        spin_unlock_bh(&ls->ls_recover_xa_lock);

        return empty;
}

static int recover_xa_add(struct dlm_rsb *r)
{
        struct dlm_ls *ls = r->res_ls;
        struct xa_limit limit = {
                .min = 1,
                .max = UINT_MAX,
        };
        uint32_t id;
        int rv;

        spin_lock_bh(&ls->ls_recover_xa_lock);
        if (r->res_id) {
                rv = -1;
                goto out_unlock;
        }
        rv = xa_alloc(&ls->ls_recover_xa, &id, r, limit, GFP_ATOMIC);
        if (rv < 0)
                goto out_unlock;

        r->res_id = id;
        ls->ls_recover_list_count++;
        dlm_hold_rsb(r);
        rv = 0;
out_unlock:
        spin_unlock_bh(&ls->ls_recover_xa_lock);
        return rv;
}

static void recover_xa_del(struct dlm_rsb *r)
{
        struct dlm_ls *ls = r->res_ls;

        spin_lock_bh(&ls->ls_recover_xa_lock);
        xa_erase_bh(&ls->ls_recover_xa, r->res_id);
        r->res_id = 0;
        ls->ls_recover_list_count--;
        spin_unlock_bh(&ls->ls_recover_xa_lock);

        dlm_put_rsb(r);
}

static struct dlm_rsb *recover_xa_find(struct dlm_ls *ls, uint64_t id)
{
        struct dlm_rsb *r;

        spin_lock_bh(&ls->ls_recover_xa_lock);
        r = xa_load(&ls->ls_recover_xa, (int)id);
        spin_unlock_bh(&ls->ls_recover_xa_lock);
        return r;
}

static void recover_xa_clear(struct dlm_ls *ls)
{
        struct dlm_rsb *r;
        unsigned long id;

        spin_lock_bh(&ls->ls_recover_xa_lock);

        xa_for_each(&ls->ls_recover_xa, id, r) {
                xa_erase_bh(&ls->ls_recover_xa, id);
                r->res_id = 0;
                r->res_recover_locks_count = 0;
                ls->ls_recover_list_count--;

                dlm_put_rsb(r);
        }

        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_bh(&ls->ls_recover_xa_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 (!test_bit(DLM_IFL_MSTCPY_BIT, &lkb->lkb_iflags)) {
                        lkb->lkb_nodeid = nodeid;
                        lkb->lkb_remid = 0;
                }
        }
}

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 recover_grant() which
 * rsb's to consider.
 */

static void set_new_master(struct dlm_rsb *r)
{
        set_master_lkbs(r);
        rsb_set_flag(r, RSB_NEW_MASTER);
        rsb_set_flag(r, RSB_NEW_MASTER2);
}

/*
 * 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.
 *
 * Another node recovering the master may have sent us a rcom lookup,
 * and our dlm_master_lookup() set it as the new master, along with
 * NEW_MASTER so that we'll recover it here (this implies dir_nodeid
 * equals our_nodeid below).
 */

static int recover_master(struct dlm_rsb *r, unsigned int *count, uint64_t seq)
{
        struct dlm_ls *ls = r->res_ls;
        int our_nodeid, dir_nodeid;
        int is_removed = 0;
        int error;

        if (r->res_nodeid != -1 && is_master(r))
                return 0;

        if (r->res_nodeid != -1)
                is_removed = dlm_is_removed(ls, r->res_nodeid);

        if (!is_removed && !rsb_flag(r, RSB_NEW_MASTER))
                return 0;

        our_nodeid = dlm_our_nodeid();
        dir_nodeid = dlm_dir_nodeid(r);

        if (dir_nodeid == our_nodeid) {
                if (is_removed) {
                        r->res_master_nodeid = our_nodeid;
                        r->res_nodeid = 0;
                }

                /* set master of lkbs to ourself when is_removed, or to
                   another new master which we set along with NEW_MASTER
                   in dlm_master_lookup */
                set_new_master(r);
                error = 0;
        } else {
                recover_xa_add(r);
                error = dlm_send_rcom_lookup(r, dir_nodeid, seq);
        }

        (*count)++;
        return error;
}

/*
 * All MSTCPY locks are purged and rebuilt, even if the master stayed the same.
 * This is necessary because recovery can be started, aborted and restarted,
 * causing the master nodeid to briefly change during the aborted recovery, and
 * change back to the original value in the second recovery.  The MSTCPY locks
 * may or may not have been purged during the aborted recovery.  Another node
 * with an outstanding request in waiters list and a request reply saved in the
 * requestqueue, cannot know whether it should ignore the reply and resend the
 * request, or accept the reply and complete the request.  It must do the
 * former if the remote node purged MSTCPY locks, and it must do the later if
 * the remote node did not.  This is solved by always purging MSTCPY locks, in
 * which case, the request reply would always be ignored and the request
 * resent.
 */

static int recover_master_static(struct dlm_rsb *r, unsigned int *count)
{
        int dir_nodeid = dlm_dir_nodeid(r);
        int new_master = dir_nodeid;

        if (dir_nodeid == dlm_our_nodeid())
                new_master = 0;

        dlm_purge_mstcpy_locks(r);
        r->res_master_nodeid = dir_nodeid;
        r->res_nodeid = new_master;
        set_new_master(r);
        (*count)++;
        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, uint64_t seq,
                        const struct list_head *root_list)
{
        struct dlm_rsb *r;
        unsigned int total = 0;
        unsigned int count = 0;
        int nodir = dlm_no_directory(ls);
        int error;

        log_rinfo(ls, "dlm_recover_masters");

        list_for_each_entry(r, root_list, res_root_list) {
                if (dlm_recovery_stopped(ls)) {
                        error = -EINTR;
                        goto out;
                }

                lock_rsb(r);
                if (nodir)
                        error = recover_master_static(r, &count);
                else
                        error = recover_master(r, &count, seq);
                unlock_rsb(r);
                cond_resched();
                total++;

                if (error)
                        goto out;
        }

        log_rinfo(ls, "dlm_recover_masters %u of %u", count, total);

        error = dlm_wait_function(ls, &recover_xa_empty);
 out:
        if (error)
                recover_xa_clear(ls);
        return error;
}

int dlm_recover_master_reply(struct dlm_ls *ls, const struct dlm_rcom *rc)
{
        struct dlm_rsb *r;
        int ret_nodeid, new_master;

        r = recover_xa_find(ls, le64_to_cpu(rc->rc_id));
        if (!r) {
                log_error(ls, "dlm_recover_master_reply no id %llx",
                          (unsigned long long)le64_to_cpu(rc->rc_id));
                goto out;
        }

        ret_nodeid = le32_to_cpu(rc->rc_result);

        if (ret_nodeid == dlm_our_nodeid())
                new_master = 0;
        else
                new_master = ret_nodeid;

        lock_rsb(r);
        r->res_master_nodeid = ret_nodeid;
        r->res_nodeid = new_master;
        set_new_master(r);
        unlock_rsb(r);
        recover_xa_del(r);

        if (recover_xa_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,
                               uint64_t seq)
{
        struct dlm_lkb *lkb;
        int error = 0;

        list_for_each_entry(lkb, head, lkb_statequeue) {
                error = dlm_send_rcom_lock(r, lkb, seq);
                if (error)
                        break;
                r->res_recover_locks_count++;
        }

        return error;
}

static int recover_locks(struct dlm_rsb *r, uint64_t seq)
{
        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, seq);
        if (error)
                goto out;
        error = recover_locks_queue(r, &r->res_convertqueue, seq);
        if (error)
                goto out;
        error = recover_locks_queue(r, &r->res_waitqueue, seq);
        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, uint64_t seq,
                      const struct list_head *root_list)
{
        struct dlm_rsb *r;
        int error, count = 0;

        list_for_each_entry(r, root_list, res_root_list) {
                if (r->res_nodeid != -1 && 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;
                        goto out;
                }

                error = recover_locks(r, seq);
                if (error)
                        goto out;

                count += r->res_recover_locks_count;
        }

        log_rinfo(ls, "dlm_recover_locks %d out", 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 in two cases:
 *
 * 1. we are master, but not new, and we purged an EX/PW lock held by a
 * failed node (in dlm_recover_purge which set RSB_RECOVER_LVB_INVAL)
 *
 * 2. we are a new master, and there are only NL/CR locks left.
 * (We could probably improve this by only invaliding in this way when
 * the previous master left uncleanly.  VMS docs mention that.)
 *
 * 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 *big_lkb = NULL, *iter, *high_lkb = NULL;
        uint32_t high_seq = 0;
        int lock_lvb_exists = 0;
        int lvblen = r->res_ls->ls_lvblen;

        if (!rsb_flag(r, RSB_NEW_MASTER2) &&
            rsb_flag(r, RSB_RECOVER_LVB_INVAL)) {
                /* case 1 above */
                rsb_set_flag(r, RSB_VALNOTVALID);
                return;
        }

        if (!rsb_flag(r, RSB_NEW_MASTER2))
                return;

        /* we are the new master, so figure out if VALNOTVALID should
           be set, and set the rsb lvb from the best lkb available. */

        list_for_each_entry(iter, &r->res_grantqueue, lkb_statequeue) {
                if (!(iter->lkb_exflags & DLM_LKF_VALBLK))
                        continue;

                lock_lvb_exists = 1;

                if (iter->lkb_grmode > DLM_LOCK_CR) {
                        big_lkb = iter;
                        goto setflag;
                }

                if (((int)iter->lkb_lvbseq - (int)high_seq) >= 0) {
                        high_lkb = iter;
                        high_seq = iter->lkb_lvbseq;
                }
        }

        list_for_each_entry(iter, &r->res_convertqueue, lkb_statequeue) {
                if (!(iter->lkb_exflags & DLM_LKF_VALBLK))
                        continue;

                lock_lvb_exists = 1;

                if (iter->lkb_grmode > DLM_LOCK_CR) {
                        big_lkb = iter;
                        goto setflag;
                }

                if (((int)iter->lkb_lvbseq - (int)high_seq) >= 0) {
                        high_lkb = iter;
                        high_seq = iter->lkb_lvbseq;
                }
        }

 setflag:
        if (!lock_lvb_exists)
                goto out;

        /* lvb is invalidated if only NL/CR locks remain */
        if (!big_lkb)
                rsb_set_flag(r, RSB_VALNOTVALID);

        if (!r->res_lvbptr) {
                r->res_lvbptr = dlm_allocate_lvb(r->res_ls);
                if (!r->res_lvbptr)
                        goto out;
        }

        if (big_lkb) {
                r->res_lvbseq = big_lkb->lkb_lvbseq;
                memcpy(r->res_lvbptr, big_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 may need to have their lkb_grmode changed.
 */

static void recover_conversion(struct dlm_rsb *r)
{
        struct dlm_ls *ls = r->res_ls;
        uint32_t other_lkid = 0;
        int other_grmode = -1;
        struct dlm_lkb *lkb;

        list_for_each_entry(lkb, &r->res_grantqueue, lkb_statequeue) {
                if (lkb->lkb_grmode == DLM_LOCK_PR ||
                    lkb->lkb_grmode == DLM_LOCK_CW) {
                        other_grmode = lkb->lkb_grmode;
                        other_lkid = lkb->lkb_id;
                        break;
                }
        }

        if (other_grmode == -1)
                return;

        list_for_each_entry(lkb, &r->res_convertqueue, lkb_statequeue) {
                /* Lock recovery created incompatible granted modes, so
                 * change the granted mode of the converting lock to
                 * NL. The rqmode of the converting lock should be CW,
                 * which means the converting lock should be granted at
                 * the end of recovery.
                 */
                if (((lkb->lkb_grmode == DLM_LOCK_PR) && (other_grmode == DLM_LOCK_CW)) ||
                    ((lkb->lkb_grmode == DLM_LOCK_CW) && (other_grmode == DLM_LOCK_PR))) {
                        log_rinfo(ls, "%s %x gr %d rq %d, remote %d %x, other_lkid %u, other gr %d, set gr=NL",
                                  __func__, lkb->lkb_id, lkb->lkb_grmode,
                                  lkb->lkb_rqmode, lkb->lkb_nodeid,
                                  lkb->lkb_remid, other_lkid, other_grmode);
                        lkb->lkb_grmode = DLM_LOCK_NL;
                }
        }
}

/* We've become the new master for this rsb and waiting/converting locks may
   need to be granted in dlm_recover_grant() due to locks that may have
   existed from a removed node. */

static void recover_grant(struct dlm_rsb *r)
{
        if (!list_empty(&r->res_waitqueue) || !list_empty(&r->res_convertqueue))
                rsb_set_flag(r, RSB_RECOVER_GRANT);
}

void dlm_recover_rsbs(struct dlm_ls *ls, const struct list_head *root_list)
{
        struct dlm_rsb *r;
        unsigned int count = 0;

        list_for_each_entry(r, root_list, res_root_list) {
                lock_rsb(r);
                if (r->res_nodeid != -1 && is_master(r)) {
                        if (rsb_flag(r, RSB_RECOVER_CONVERT))
                                recover_conversion(r);

                        /* recover lvb before granting locks so the updated
                           lvb/VALNOTVALID is presented in the completion */
                        recover_lvb(r);

                        if (rsb_flag(r, RSB_NEW_MASTER2))
                                recover_grant(r);
                        count++;
                } else {
                        rsb_clear_flag(r, RSB_VALNOTVALID);
                }
                rsb_clear_flag(r, RSB_RECOVER_CONVERT);
                rsb_clear_flag(r, RSB_RECOVER_LVB_INVAL);
                rsb_clear_flag(r, RSB_NEW_MASTER2);
                unlock_rsb(r);
        }

        if (count)
                log_rinfo(ls, "dlm_recover_rsbs %d done", count);
}

void dlm_clear_inactive(struct dlm_ls *ls)
{
        struct dlm_rsb *r, *safe;
        unsigned int count = 0;

        write_lock_bh(&ls->ls_rsbtbl_lock);
        list_for_each_entry_safe(r, safe, &ls->ls_slow_inactive, res_slow_list) {
                list_del(&r->res_slow_list);
                rhashtable_remove_fast(&ls->ls_rsbtbl, &r->res_node,
                                       dlm_rhash_rsb_params);

                if (!list_empty(&r->res_scan_list))
                        list_del_init(&r->res_scan_list);

                free_inactive_rsb(r);
                count++;
        }
        write_unlock_bh(&ls->ls_rsbtbl_lock);

        if (count)
                log_rinfo(ls, "dlm_clear_inactive %u done", count);
}