linux-imx

/*

   linear.c : Multiple Devices driver for Linux

          Copyright (C) 1994-96 Marc ZYNGIER

          <zyngier@ufr-info-p7.ibp.fr> or

          <maz@gloups.fdn.fr>

​

   Linear mode management functions.

​

   This program is free software; you can redistribute it and/or modify

   it under the terms of the GNU General Public License as published by

   the Free Software Foundation; either version 2, or (at your option)

   any later version.

​

   You should have received a copy of the GNU General Public License

   (for example /usr/src/linux/COPYING); if not, write to the Free

   Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.

*/

​

#include <linux/blkdev.h>

#include <linux/raid/md_u.h>

#include <linux/seq_file.h>

#include <linux/module.h>

#include <linux/slab.h>

#include <trace/events/block.h>

#include "md.h"

#include "md-linear.h"

​

/*

 * find which device holds a particular offset

 */

static inline struct dev_info *which_dev(struct mddev *mddev, sector_t sector)

{

    int lo, mid, hi;

    struct linear_conf *conf;

​

    lo = 0;

    hi = mddev->raid_disks - 1;

    conf = mddev->private;

​

    /*

     * Binary Search

     */

​

    while (hi > lo) {

​

        mid = (hi + lo) / 2;

        if (sector < conf->disks[mid].end_sector)

            hi = mid;

        else

            lo = mid + 1;

    }

​

    return conf->disks + lo;

}

​

/*

 * In linear_congested() conf->raid_disks is used as a copy of

 * mddev->raid_disks to iterate conf->disks[], because conf->raid_disks

 * and conf->disks[] are created in linear_conf(), they are always

 * consitent with each other, but mddev->raid_disks does not.

 */

static int linear_congested(struct mddev *mddev, int bits)

{