linux-imx

/*

 * Copyright (C) 2017 Intel Corporation.

 *

 * This file is released under the GPL.

 */

​

#include "dm.h"

​

#include <linux/module.h>

​

struct unstripe_c {

    struct dm_dev *dev;

    sector_t physical_start;

​

    uint32_t stripes;

​

    uint32_t unstripe;

    sector_t unstripe_width;

    sector_t unstripe_offset;

​

    uint32_t chunk_size;

    u8 chunk_shift;

};

​

#define DM_MSG_PREFIX "unstriped"

​

static void cleanup_unstripe(struct unstripe_c *uc, struct dm_target *ti)

{

    if (uc->dev)

        dm_put_device(ti, uc->dev);

    kfree(uc);

}

​

/*

 * Contruct an unstriped mapping.

 * <number of stripes> <chunk size> <stripe #> <dev_path> <offset>

 */

static int unstripe_ctr(struct dm_target *ti, unsigned int argc, char **argv)

{

    struct unstripe_c *uc;

    sector_t tmp_len;

    unsigned long long start;

    char dummy;

​

    if (argc != 5) {

        ti->error = "Invalid number of arguments";

        return -EINVAL;

    }

​

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

    if (!uc) {

        ti->error = "Memory allocation for unstriped context failed";

        return -ENOMEM;

    }

​

    if (kstrtouint(argv[0], 10, &uc->stripes) || !uc->stripes) {

        ti->error = "Invalid stripe count";

        goto err;

    }

​

    if (kstrtouint(argv[1], 10, &uc->chunk_size) || !uc->chunk_size) {

        ti->error = "Invalid chunk_size";

        goto err;

    }

​

    if (kstrtouint(argv[2], 10, &uc->unstripe)) {

        ti->error = "Invalid stripe number";

        goto err;

    }

​

    if (uc->unstripe > uc->stripes && uc->stripes > 1) {

        ti->error = "Please provide stripe between [0, # of stripes]";

        goto err;

    }

​

    if (dm_get_device(ti, argv[3], dm_table_get_mode(ti->table), &uc->dev)) {

        ti->error = "Couldn't get striped device";

        goto err;

    }

​

    if (sscanf(argv[4], "%llu%c", &start, &dummy) != 1 || start != (sector_t)start) {

        ti->error = "Invalid striped device offset";

        goto err;

    }

    uc->physical_start = start;

​

    uc->unstripe_offset = uc->unstripe * uc->chunk_size;

    uc->unstripe_width = (uc->stripes - 1) * uc->chunk_size;

    uc->chunk_shift = is_power_of_2(uc->chunk_size) ? fls(uc->chunk_size) - 1 : 0;

​

    tmp_len = ti->len;

    if (sector_div(tmp_len, uc->chunk_size)) {