linux-imx

/*

 * Copyright (C) 2003 Sistina Software

 * Copyright (C) 2006 Red Hat GmbH

 *

 * This file is released under the GPL.

 */

​

#include "dm-core.h"

​

#include <linux/device-mapper.h>

​

#include <linux/bio.h>

#include <linux/completion.h>

#include <linux/mempool.h>

#include <linux/module.h>

#include <linux/sched.h>

#include <linux/slab.h>

#include <linux/dm-io.h>

​

#define DM_MSG_PREFIX "io"

​

#define DM_IO_MAX_REGIONS   BITS_PER_LONG

​

struct dm_io_client {

    mempool_t pool;

    struct bio_set bios;

};

​

/*

 * Aligning 'struct io' reduces the number of bits required to store

 * its address.  Refer to store_io_and_region_in_bio() below.

 */

struct io {

    unsigned long error_bits;

    atomic_t count;

    struct dm_io_client *client;

    io_notify_fn callback;

    void *context;

    void *vma_invalidate_address;

    unsigned long vma_invalidate_size;

} __attribute__((aligned(DM_IO_MAX_REGIONS)));

​

static struct kmem_cache *_dm_io_cache;

​

/*

 * Create a client with mempool and bioset.

 */

struct dm_io_client *dm_io_client_create(void)

{

    struct dm_io_client *client;

    unsigned min_ios = dm_get_reserved_bio_based_ios();

    int ret;

​

    client = kzalloc(sizeof(*client), GFP_KERNEL);

    if (!client)

        return ERR_PTR(-ENOMEM);

​

    ret = mempool_init_slab_pool(&client->pool, min_ios, _dm_io_cache);

    if (ret)

        goto bad;

​

    ret = bioset_init(&client->bios, min_ios, 0, BIOSET_NEED_BVECS);

    if (ret)