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/*
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/module.h>
#include <linux/md.h>
#include <linux/malloc.h>
#include <linux/init.h>
#include "linear.h"
#define MAJOR_NR MD_MAJOR
#define MD_DRIVER
#define MD_PERSONALITY
static int linear_run (int minor, struct md_dev *mddev)
{
int cur=0, i, size, dev0_size, nb_zone;
struct linear_data *data;
MOD_INC_USE_COUNT;
mddev->private=kmalloc (sizeof (struct linear_data), GFP_KERNEL);
data=(struct linear_data *) mddev->private;
/*
Find out the smallest device. This was previously done
at registry time, but since it violates modularity,
I moved it here... Any comment ? ;-)
*/
data->smallest=mddev->devices;
for (i=1; i<mddev->nb_dev; i++)
if (data->smallest->size > mddev->devices[i].size)
data->smallest=mddev->devices+i;
nb_zone=data->nr_zones=
md_size[minor]/data->smallest->size +
(md_size[minor]%data->smallest->size ? 1 : 0);
data->hash_table=kmalloc (sizeof (struct linear_hash)*nb_zone, GFP_KERNEL);
size=mddev->devices[cur].size;
i=0;
while (cur<mddev->nb_dev)
{
data->hash_table[i].dev0=mddev->devices+cur;
if (size>=data->smallest->size) /* If we completely fill the slot */
{
data->hash_table[i++].dev1=NULL;
size-=data->smallest->size;
if (!size)
{
if (++cur==mddev->nb_dev) continue;
size=mddev->devices[cur].size;
}
continue;
}
if (++cur==mddev->nb_dev) /* Last dev, set dev1 as NULL */
{
data->hash_table[i].dev1=NULL;
continue;
}
dev0_size=size; /* Here, we use a 2nd dev to fill the slot */
size=mddev->devices[cur].size;
data->hash_table[i++].dev1=mddev->devices+cur;
size-=(data->smallest->size - dev0_size);
}
return 0;
}
static int linear_stop (int minor, struct md_dev *mddev)
{
struct linear_data *data=(struct linear_data *) mddev->private;
kfree (data->hash_table);
kfree (data);
MOD_DEC_USE_COUNT;
return 0;
}
static int linear_map (struct md_dev *mddev, kdev_t *rdev,
unsigned long *rsector, unsigned long size)
{
struct linear_data *data=(struct linear_data *) mddev->private;
struct linear_hash *hash;
struct real_dev *tmp_dev;
long block;
block=*rsector >> 1;
hash=data->hash_table+(block/data->smallest->size);
if (block >= (hash->dev0->size + hash->dev0->offset))
{
if (!hash->dev1)
{
printk ("linear_map : hash->dev1==NULL for block %ld\n", block);
return (-1);
}
tmp_dev=hash->dev1;
}
else
tmp_dev=hash->dev0;
if (block >= (tmp_dev->size + tmp_dev->offset) || block < tmp_dev->offset)
printk ("Block %ld out of bounds on dev %s size %d offset %d\n",
block, kdevname(tmp_dev->dev), tmp_dev->size, tmp_dev->offset);
*rdev=tmp_dev->dev;
*rsector=(block-(tmp_dev->offset)) << 1;
return (0);
}
static int linear_status (char *page, int minor, struct md_dev *mddev)
{
int sz=0;
#undef MD_DEBUG
#ifdef MD_DEBUG
int j;
struct linear_data *data=(struct linear_data *) mddev->private;
sz+=sprintf (page+sz, " ");
for (j=0; j<data->nr_zones; j++)
{
sz+=sprintf (page+sz, "[%s",
partition_name (data->hash_table[j].dev0->dev));
if (data->hash_table[j].dev1)
sz+=sprintf (page+sz, "/%s] ",
partition_name(data->hash_table[j].dev1->dev));
else
sz+=sprintf (page+sz, "] ");
}
sz+=sprintf (page+sz, "\n");
#endif
return sz;
}
static struct md_personality linear_personality=
{
"linear",
linear_map,
linear_run,
linear_stop,
linear_status,
NULL, /* no ioctls */
0
};
#ifndef MODULE
__initfunc(void linear_init (void))
{
register_md_personality (LINEAR, &linear_personality);
}
#else
int init_module (void)
{
return (register_md_personality (LINEAR, &linear_personality));
}
void cleanup_module (void)
{
unregister_md_personality (LINEAR);
}
#endif
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