kernel_optimize_test/include/linux/raid/md_u.h
NeilBrown 32a7627cf3 [PATCH] md: optimised resync using Bitmap based intent logging
With this patch, the intent to write to some block in the array can be logged
to a bitmap file.  Each bit represents some number of sectors and is set
before any update happens, and only cleared when all writes relating to all
sectors are complete.

After an unclean shutdown, information in this bitmap can be used to optimise
resync - only sectors which could be out-of-sync need to be updated.

Also if a drive is removed and then added back into an array, the recovery can
make use of the bitmap to optimise reconstruction.  This is not implemented in
this patch.

Currently the bitmap is stored in a file which must (obviously) be stored on a
separate device.

The patch only provided infrastructure.  It does not update any personalities
to bitmap intent logging.

Md arrays can still be used with no bitmap file.  This patch has minimal
impact on such arrays.

Signed-off-by: Neil Brown <neilb@cse.unsw.edu.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-21 19:07:43 -07:00

125 lines
3.2 KiB
C

/*
md_u.h : user <=> kernel API between Linux raidtools and RAID drivers
Copyright (C) 1998 Ingo Molnar
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_U_H
#define _MD_U_H
/* ioctls */
/* status */
#define RAID_VERSION _IOR (MD_MAJOR, 0x10, mdu_version_t)
#define GET_ARRAY_INFO _IOR (MD_MAJOR, 0x11, mdu_array_info_t)
#define GET_DISK_INFO _IOR (MD_MAJOR, 0x12, mdu_disk_info_t)
#define PRINT_RAID_DEBUG _IO (MD_MAJOR, 0x13)
#define RAID_AUTORUN _IO (MD_MAJOR, 0x14)
#define GET_BITMAP_FILE _IOR (MD_MAJOR, 0x15, mdu_bitmap_file_t)
/* configuration */
#define CLEAR_ARRAY _IO (MD_MAJOR, 0x20)
#define ADD_NEW_DISK _IOW (MD_MAJOR, 0x21, mdu_disk_info_t)
#define HOT_REMOVE_DISK _IO (MD_MAJOR, 0x22)
#define SET_ARRAY_INFO _IOW (MD_MAJOR, 0x23, mdu_array_info_t)
#define SET_DISK_INFO _IO (MD_MAJOR, 0x24)
#define WRITE_RAID_INFO _IO (MD_MAJOR, 0x25)
#define UNPROTECT_ARRAY _IO (MD_MAJOR, 0x26)
#define PROTECT_ARRAY _IO (MD_MAJOR, 0x27)
#define HOT_ADD_DISK _IO (MD_MAJOR, 0x28)
#define SET_DISK_FAULTY _IO (MD_MAJOR, 0x29)
#define HOT_GENERATE_ERROR _IO (MD_MAJOR, 0x2a)
#define SET_BITMAP_FILE _IOW (MD_MAJOR, 0x2b, int)
/* usage */
#define RUN_ARRAY _IOW (MD_MAJOR, 0x30, mdu_param_t)
#define START_ARRAY _IO (MD_MAJOR, 0x31)
#define STOP_ARRAY _IO (MD_MAJOR, 0x32)
#define STOP_ARRAY_RO _IO (MD_MAJOR, 0x33)
#define RESTART_ARRAY_RW _IO (MD_MAJOR, 0x34)
typedef struct mdu_version_s {
int major;
int minor;
int patchlevel;
} mdu_version_t;
typedef struct mdu_array_info_s {
/*
* Generic constant information
*/
int major_version;
int minor_version;
int patch_version;
int ctime;
int level;
int size;
int nr_disks;
int raid_disks;
int md_minor;
int not_persistent;
/*
* Generic state information
*/
int utime; /* 0 Superblock update time */
int state; /* 1 State bits (clean, ...) */
int active_disks; /* 2 Number of currently active disks */
int working_disks; /* 3 Number of working disks */
int failed_disks; /* 4 Number of failed disks */
int spare_disks; /* 5 Number of spare disks */
/*
* Personality information
*/
int layout; /* 0 the array's physical layout */
int chunk_size; /* 1 chunk size in bytes */
} mdu_array_info_t;
typedef struct mdu_disk_info_s {
/*
* configuration/status of one particular disk
*/
int number;
int major;
int minor;
int raid_disk;
int state;
} mdu_disk_info_t;
typedef struct mdu_start_info_s {
/*
* configuration/status of one particular disk
*/
int major;
int minor;
int raid_disk;
int state;
} mdu_start_info_t;
typedef struct mdu_bitmap_file_s
{
char pathname[4096];
} mdu_bitmap_file_t;
typedef struct mdu_param_s
{
int personality; /* 1,2,3,4 */
int chunk_size; /* in bytes */
int max_fault; /* unused for now */
} mdu_param_t;
#endif