linux-imx

/*

   md.h : kernel internal structure of the Linux MD driver

          Copyright (C) 1996-98 Ingo Molnar, Gadi Oxman

​

   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.

*/

​

#ifndef _MD_MD_H

#define _MD_MD_H

​

#include <linux/blkdev.h>

#include <linux/backing-dev.h>

#include <linux/badblocks.h>

#include <linux/kobject.h>

#include <linux/list.h>

#include <linux/mm.h>

#include <linux/mutex.h>

#include <linux/timer.h>

#include <linux/wait.h>

#include <linux/workqueue.h>

#include "md-cluster.h"

​

#define MaxSector (~(sector_t)0)

​

/*

 * These flags should really be called "NO_RETRY" rather than

 * "FAILFAST" because they don't make any promise about time lapse,

 * only about the number of retries, which will be zero.

 * REQ_FAILFAST_DRIVER is not included because

 * Commit: 4a27446f3e39 ("[SCSI] modify scsi to handle new fail fast flags.")

 * seems to suggest that the errors it avoids retrying should usually

 * be retried.

 */

#define MD_FAILFAST (REQ_FAILFAST_DEV | REQ_FAILFAST_TRANSPORT)

/*

 * MD's 'extended' device

 */

struct md_rdev {

    struct list_head same_set;  /* RAID devices within the same set */

​

    sector_t sectors;       /* Device size (in 512bytes sectors) */

    struct mddev *mddev;        /* RAID array if running */

    int last_events;        /* IO event timestamp */

​

    /*

     * If meta_bdev is non-NULL, it means that a separate device is

     * being used to store the metadata (superblock/bitmap) which

     * would otherwise be contained on the same device as the data (bdev).

     */

    struct block_device *meta_bdev;

    struct block_device *bdev;  /* block device handle */

​

    struct page *sb_page, *bb_page;

    int     sb_loaded;

    __u64       sb_events;

    sector_t    data_offset;    /* start of data in array */

    sector_t    new_data_offset;/* only relevant while reshaping */

    sector_t    sb_start;   /* offset of the super block (in 512byte sectors) */

    int     sb_size;    /* bytes in the superblock */

    int     preferred_minor;    /* autorun support */

​

    struct kobject  kobj;

​

    /* A device can be in one of three states based on two flags:

     * Not working:   faulty==1 in_sync==0

     * Fully working: faulty==0 in_sync==1

     * Working, but not

     * in sync with array

     *                faulty==0 in_sync==0

     *

     * It can never have faulty==1, in_sync==1

     * This reduces the burden of testing multiple flags in many cases

     */

​

    unsigned long   flags;  /* bit set of 'enum flag_bits' bits. */

    wait_queue_head_t blocked_wait;

​

    int desc_nr;            /* descriptor index in the superblock */

    int raid_disk;          /* role of device in array */

    int new_raid_disk;      /* role that the device will have in

                     * the array after a level-change completes.

                     */

    int saved_raid_disk;        /* role that device used to have in the

                     * array and could again if we did a partial

                     * resync from the bitmap