root/fs/gfs2/locking/dlm/thread.c

DEFINITIONS

1. no_work
2. gdlm_thread
3. gdlm_init_threads
4. gdlm_release_threads

/*
 * 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 version 2.
 */

#include "lock_dlm.h"

static inline int no_work(struct gdlm_ls *ls)
{
        int ret;

        spin_lock(&ls->async_lock);
        ret = list_empty(&ls->submit);
        spin_unlock(&ls->async_lock);

        return ret;
}

static int gdlm_thread(void *data)
{
        struct gdlm_ls *ls = (struct gdlm_ls *) data;
        struct gdlm_lock *lp = NULL;

        while (!kthread_should_stop()) {
                wait_event_interruptible(ls->thread_wait,
                                !no_work(ls) || kthread_should_stop());

                spin_lock(&ls->async_lock);

                if (!list_empty(&ls->submit)) {
                        lp = list_entry(ls->submit.next, struct gdlm_lock,
                                        delay_list);
                        list_del_init(&lp->delay_list);
                        spin_unlock(&ls->async_lock);
                        gdlm_do_lock(lp);
                        spin_lock(&ls->async_lock);
                }
                spin_unlock(&ls->async_lock);
        }

        return 0;
}

int gdlm_init_threads(struct gdlm_ls *ls)
{
        struct task_struct *p;
        int error;

        p = kthread_run(gdlm_thread, ls, "lock_dlm");
        error = IS_ERR(p);
        if (error) {
                log_error("can't start lock_dlm thread %d", error);
                return error;
        }
        ls->thread = p;

        return 0;
}

void gdlm_release_threads(struct gdlm_ls *ls)
{
        kthread_stop(ls->thread);
}