linux-imx

/*

 * Copyright (C) 2001 Sistina Software (UK) Limited

 *

 * This file is released under the GPL.

 */

​

#include "dm-core.h"

​

#include <linux/module.h>

#include <linux/init.h>

#include <linux/kmod.h>

#include <linux/bio.h>

​

#define DM_MSG_PREFIX "target"

​

static LIST_HEAD(_targets);

static DECLARE_RWSEM(_lock);

​

static inline struct target_type *__find_target_type(const char *name)

{

    struct target_type *tt;

​

    list_for_each_entry(tt, &_targets, list)

        if (!strcmp(name, tt->name))

            return tt;

​

    return NULL;

}

​

static struct target_type *get_target_type(const char *name)

{

    struct target_type *tt;

​

    down_read(&_lock);

​

    tt = __find_target_type(name);

    if (tt && !try_module_get(tt->module))

        tt = NULL;

​

    up_read(&_lock);

    return tt;

}

​

static void load_module(const char *name)

{

    request_module("dm-%s", name);

}

​

struct target_type *dm_get_target_type(const char *name)

{

    struct target_type *tt = get_target_type(name);

​

    if (!tt) {

        load_module(name);

        tt = get_target_type(name);

    }

​

    return tt;

}

​

void dm_put_target_type(struct target_type *tt)

{

    down_read(&_lock);