/*$NetBSD: dm_target_mirror.c,v 1.24 2020/01/21 16:27:53 tkusumi Exp $*/

/*$NetBSD: dm_target_mirror.c,v 1.24 2020/01/21 16:27:53 tkusumi Exp $*/

/*
* Copyright (c) 2009 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Adam Hamsik.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: dm_target_mirror.c,v 1.24 2020/01/21 16:27:53 tkusumi Exp $");

/*
* This file implements initial version of device-mapper mirror target.
*/
#include <sys/types.h>
#include <sys/param.h>
#include <sys/buf.h>

#include "dm.h"

/* dm_target_mirror.c */
int dm_target_mirror_init(dm_table_entry_t *, int, char **);
char *dm_target_mirror_table(void *);
int dm_target_mirror_strategy(dm_table_entry_t *, struct buf *);
int dm_target_mirror_sync(dm_table_entry_t *);
int dm_target_mirror_destroy(dm_table_entry_t *);
//int dm_target_mirror_upcall(dm_table_entry_t *, struct buf *);

typedef struct target_mirror_config {
#define MAX_MIRROR_COPIES 4
dm_pdev_t *orig;
dm_pdev_t *copies[MAX_MIRROR_COPIES];

/* copied blocks bitmaps administration etc*/
dm_pdev_t *log_pdev; /* for administration */
uint64_t log_regionsize; /* blocksize of mirror */

/* list of parts that still need copied etc.; run length encoded? */
} dm_target_mirror_config_t;

#ifdef DM_TARGET_MODULE
/*
* Every target can be compiled directly to dm driver or as a
* separate module this part of target is used for loading targets
* to dm driver.
* Target can be unloaded from kernel only if there are no users of
* it e.g. there are no devices which uses that target.
*/
#include <sys/kernel.h>
#include <sys/module.h>

MODULE(MODULE_CLASS_MISC, dm_target_mirror, "dm");

static int
dm_target_mirror_modcmd(modcmd_t cmd, void *arg)
{
dm_target_t *dmt;
int r;

switch (cmd) {
case MODULE_CMD_INIT:
if ((dmt = dm_target_lookup("mirror")) != NULL) {
dm_target_unbusy(dmt);
return EEXIST;
}
dmt = dm_target_alloc("mirror");

dmt->version[0] = 1;
dmt->version[1] = 0;
dmt->version[2] = 0;
dmt->init = &dm_target_mirror_init;
dmt->table = &dm_target_mirror_table;
dmt->strategy = &dm_target_mirror_strategy;
dmt->sync = &dm_target_mirror_sync;
dmt->destroy = &dm_target_mirror_destroy;
//dmt->upcall = &dm_target_mirror_upcall;

r = dm_target_insert(dmt);

break;

case MODULE_CMD_FINI:
r = dm_target_rem("mirror");
break;

case MODULE_CMD_STAT:
return ENOTTY;

default:
return ENOTTY;
}

return r;
}
#endif

/*
* Init function called from dm_table_load_ioctl.
* start length mirror log_type #logargs logarg1 ... logargN #devs device1 offset1 ... deviceN offsetN
* 0 52428800 mirror clustered_disk 4 253:2 1024 UUID block_on_error 3 253:3 0 253:4 0 253:5 0
*/
int
dm_target_mirror_init(dm_table_entry_t *table_en, int argc, char **argv)
{

printf("Mirror target init function called!!\n");

table_en->target_config = NULL;

return ENOSYS;
}

/* Table routine called to get params string. */
char *
dm_target_mirror_table(void *target_config)
{

return NULL;
}

/* Strategy routine called from dm_strategy. */
int
dm_target_mirror_strategy(dm_table_entry_t *table_en, struct buf *bp)
{

bp->b_error = EIO;
bp->b_resid = 0;

biodone(bp);

return 0;
}

/* Sync underlying disk caches. */
int
dm_target_mirror_sync(dm_table_entry_t *table_en)
{

return 0;
}

/* Doesn't do anything here. */
int
dm_target_mirror_destroy(dm_table_entry_t *table_en)
{

/* Unbusy target so we can unload it */
dm_target_unbusy(table_en->target);

return 0;
}

#if 0
/* Unsupported for this target. */
int
dm_target_mirror_upcall(dm_table_entry_t *table_en, struct buf *bp)
{

return 0;
}
#endif