/*        $NetBSD: dm_target_linear.c,v 1.37 2020/01/21 16:27:53 tkusumi Exp $      */

/*
* Copyright (c) 2008 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_linear.c,v 1.37 2020/01/21 16:27:53 tkusumi Exp $");

/*
* This file implements initial version of device-mapper linear target.
*/

#include <sys/types.h>
#include <sys/param.h>
#include <sys/buf.h>
#include <sys/kmem.h>
#include <sys/lwp.h>

#include <machine/int_fmtio.h>

#include "dm.h"

/*
* Allocate target specific config data, and link them to table.
* This function is called only when, flags is not READONLY and
* therefore we can add things to pdev list. This should not a
* problem because this routine is called only from dm_table_load_ioctl.
* @argv[0] is name,
* @argv[1] is physical data offset.
*/
int
dm_target_linear_init(dm_table_entry_t *table_en, int argc, char **argv)
{
       dm_target_linear_config_t *tlc;
       dm_pdev_t *dmp;

       if (argc != 2) {
               printf("Linear target takes 2 args, %d given\n", argc);
               return EINVAL;
       }

       aprint_debug("Linear target init function called %s--%s!!\n",
           argv[0], argv[1]);

       /* Insert dmp to global pdev list */
       if ((dmp = dm_pdev_insert(argv[0])) == NULL)
               return ENOENT;

       tlc = kmem_alloc(sizeof(dm_target_linear_config_t), KM_SLEEP);
       tlc->pdev = dmp;
       tlc->offset = atoi64(argv[1]);

       dm_table_add_deps(table_en, dmp);
       table_en->target_config = tlc;

       return 0;
}

/*
* Table routine is called to get params string, which is target
* specific. When dm_table_status_ioctl is called with flag
* DM_STATUS_TABLE_FLAG I have to sent params string back.
*/
char *
dm_target_linear_table(void *target_config)
{
       dm_target_linear_config_t *tlc;
       char *params;
       tlc = target_config;

       aprint_debug("Linear target table function called\n");

       params = kmem_alloc(DM_MAX_PARAMS_SIZE, KM_SLEEP);
       snprintf(params, DM_MAX_PARAMS_SIZE, "%s %" PRIu64,
           tlc->pdev->udev_name, tlc->offset);

       return params;
}

/*
* Do IO operation, called from dmstrategy routine.
*/
int
dm_target_linear_strategy(dm_table_entry_t *table_en, struct buf *bp)
{
       dm_target_linear_config_t *tlc;

       tlc = table_en->target_config;

       bp->b_blkno += tlc->offset;

       VOP_STRATEGY(tlc->pdev->pdev_vnode, bp);

       return 0;
}

/*
* Sync underlying disk caches.
*/
int
dm_target_linear_sync(dm_table_entry_t *table_en)
{
       int cmd;
       dm_target_linear_config_t *tlc;

       tlc = table_en->target_config;

       cmd = 1;

       return VOP_IOCTL(tlc->pdev->pdev_vnode,  DIOCCACHESYNC, &cmd,
           FREAD|FWRITE, kauth_cred_get());
}

/*
* Destroy target specific data. Decrement table pdevs.
*/
int
dm_target_linear_destroy(dm_table_entry_t *table_en)
{

       /*
        * Destroy function is called for every target even if it
        * doesn't have target_config.
        */
       if (table_en->target_config == NULL)
               goto out;

       dm_target_linear_config_t *tlc = table_en->target_config;

       /* Decrement pdev ref counter if 0 remove it */
       dm_pdev_decr(tlc->pdev);

       kmem_free(tlc, sizeof(*tlc));

out:
       /* Unbusy target so we can unload it */
       dm_target_unbusy(table_en->target);
       return 0;
}

#if 0
/*
* Register upcall device.
* Linear target doesn't need any upcall devices but other targets like
* mirror, snapshot, multipath, stripe will use this functionality.
*/
int
dm_target_linear_upcall(dm_table_entry_t *table_en, struct buf *bp)
{

       return 0;
}
#endif

/*
* Query physical block size of this target
* For a linear target this is just the sector size of the underlying device
*/
int
dm_target_linear_secsize(dm_table_entry_t *table_en, unsigned int *secsizep)
{
       dm_target_linear_config_t *tlc;
       unsigned int secsize;

       secsize = 0;

       tlc = table_en->target_config;
       if (tlc != NULL)
               secsize = tlc->pdev->pdev_secsize;

       *secsizep = secsize;

       return 0;
}