linux-imx

/*

 * Copyright (C) 2012 Red Hat, Inc.

 *

 * This file is released under the GPL.

 */

​

#include "dm.h"

#include "dm-bio-prison-v1.h"

#include "dm-bio-prison-v2.h"

​

#include <linux/spinlock.h>

#include <linux/mempool.h>

#include <linux/module.h>

#include <linux/slab.h>

​

/*----------------------------------------------------------------*/

​

#define MIN_CELLS 1024

​

struct dm_bio_prison {

    spinlock_t lock;

    struct rb_root cells;

    mempool_t cell_pool;

};

​

static struct kmem_cache *_cell_cache;

​

/*----------------------------------------------------------------*/

​

/*

 * @nr_cells should be the number of cells you want in use _concurrently_.

 * Don't confuse it with the number of distinct keys.

 */

struct dm_bio_prison *dm_bio_prison_create(void)

{

    struct dm_bio_prison *prison = kzalloc(sizeof(*prison), GFP_KERNEL);

    int ret;

​

    if (!prison)

        return NULL;

​

    spin_lock_init(&prison->lock);

​

    ret = mempool_init_slab_pool(&prison->cell_pool, MIN_CELLS, _cell_cache);

    if (ret) {

        kfree(prison);

        return NULL;

    }

​

    prison->cells = RB_ROOT;

​

    return prison;

}

EXPORT_SYMBOL_GPL(dm_bio_prison_create);

​

void dm_bio_prison_destroy(struct dm_bio_prison *prison)

{

    mempool_exit(&prison->cell_pool);

    kfree(prison);

}

EXPORT_SYMBOL_GPL(dm_bio_prison_destroy);

​

struct dm_bio_prison_cell *dm_bio_prison_alloc_cell(struct dm_bio_prison *prison, gfp_t gfp)