// SPDX-License-Identifier: GPL-2.0-only
/******************************************************************************
*******************************************************************************
**
**  Copyright (C) 2005-2007 Red Hat, Inc.  All rights reserved.
**
**
*******************************************************************************
******************************************************************************/

#include "dlm_internal.h"
#include "member.h"
#include "lock.h"
#include "dir.h"
#include "config.h"
#include "requestqueue.h"
#include "util.h"

struct rq_entry {
        struct list_head list;
        uint32_t recover_seq;
        int nodeid;
        struct dlm_message request;
};

/*
 * Requests received while the lockspace is in recovery get added to the
 * request queue and processed when recovery is complete.  This happens when
 * the lockspace is suspended on some nodes before it is on others, or the
 * lockspace is enabled on some while still suspended on others.
 */

void dlm_add_requestqueue(struct dlm_ls *ls, int nodeid,
                          const struct dlm_message *ms)
{
        struct rq_entry *e;
        int length = le16_to_cpu(ms->m_header.h_length) -
                sizeof(struct dlm_message);

        e = kmalloc(sizeof(struct rq_entry) + length, GFP_ATOMIC);
        if (!e) {
                log_print("dlm_add_requestqueue: out of memory len %d", length);
                return;
        }

        e->recover_seq = ls->ls_recover_seq & 0xFFFFFFFF;
        e->nodeid = nodeid;
        memcpy(&e->request, ms, sizeof(*ms));
        memcpy(&e->request.m_extra, ms->m_extra, length);

        list_add_tail(&e->list, &ls->ls_requestqueue);
}

/*
 * Called by dlm_recoverd to process normal messages saved while recovery was
 * happening.  Normal locking has been enabled before this is called.  dlm_recv
 * upon receiving a message, will wait for all saved messages to be drained
 * here before processing the message it got.  If a new dlm_ls_stop() arrives
 * while we're processing these saved messages, it may block trying to suspend
 * dlm_recv if dlm_recv is waiting for us in dlm_wait_requestqueue.  In that
 * case, we don't abort since locking_stopped is still 0.  If dlm_recv is not
 * waiting for us, then this processing may be aborted due to locking_stopped.
 */

int dlm_process_requestqueue(struct dlm_ls *ls)
{
        struct rq_entry *e;
        struct dlm_message *ms;
        int error = 0;

        write_lock_bh(&ls->ls_requestqueue_lock);
        for (;;) {
                if (list_empty(&ls->ls_requestqueue)) {
                        clear_bit(LSFL_RECV_MSG_BLOCKED, &ls->ls_flags);
                        error = 0;
                        break;
                }
                e = list_first_entry(&ls->ls_requestqueue, struct rq_entry, list);

                ms = &e->request;

                log_limit(ls, "dlm_process_requestqueue msg %d from %d "
                          "lkid %x remid %x result %d seq %u",
                          le32_to_cpu(ms->m_type),
                          le32_to_cpu(ms->m_header.h_nodeid),
                          le32_to_cpu(ms->m_lkid), le32_to_cpu(ms->m_remid),
                          from_dlm_errno(le32_to_cpu(ms->m_result)),
                          e->recover_seq);

                dlm_receive_message_saved(ls, &e->request, e->recover_seq);
                list_del(&e->list);
                kfree(e);

                if (dlm_locking_stopped(ls)) {
                        log_debug(ls, "process_requestqueue abort running");
                        error = -EINTR;
                        break;
                }
                write_unlock_bh(&ls->ls_requestqueue_lock);
                schedule();
                write_lock_bh(&ls->ls_requestqueue_lock);
        }
        write_unlock_bh(&ls->ls_requestqueue_lock);

        return error;
}

static int purge_request(struct dlm_ls *ls, struct dlm_message *ms, int nodeid)
{
        __le32 type = ms->m_type;

        /* the ls is being cleaned up and freed by release_lockspace */
        if (!atomic_read(&ls->ls_count))
                return 1;

        if (dlm_is_removed(ls, nodeid))
                return 1;

        /* directory operations are always purged because the directory is
           always rebuilt during recovery and the lookups resent */

        if (type == cpu_to_le32(DLM_MSG_REMOVE) ||
            type == cpu_to_le32(DLM_MSG_LOOKUP) ||
            type == cpu_to_le32(DLM_MSG_LOOKUP_REPLY))
                return 1;

        if (!dlm_no_directory(ls))
                return 0;

        return 1;
}

void dlm_purge_requestqueue(struct dlm_ls *ls)
{
        struct dlm_message *ms;
        struct rq_entry *e, *safe;

        write_lock_bh(&ls->ls_requestqueue_lock);
        list_for_each_entry_safe(e, safe, &ls->ls_requestqueue, list) {
                ms =  &e->request;

                if (purge_request(ls, ms, e->nodeid)) {
                        list_del(&e->list);
                        kfree(e);
                }
        }
        write_unlock_bh(&ls->ls_requestqueue_lock);
}