/*   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/raid/md.h>#include <linux/malloc.h>#include <linux/raid/linear.h>#define MAJOR_NR MD_MAJOR#define MD_DRIVER#define MD_PERSONALITYstatic int linear_run (mddev_t *mddev){	linear_conf_t *conf;	struct linear_hash *table;	mdk_rdev_t *rdev;	int size, i, j, nb_zone;	unsigned int curr_offset;	MOD_INC_USE_COUNT;	conf = kmalloc (sizeof (*conf), GFP_KERNEL);	if (!conf)		goto out;	mddev->private = conf;	if (md_check_ordering(mddev)) {		printk("linear: disks are not ordered, aborting!\n");		goto out;	}	/*	 * Find the smallest device.	 */	conf->smallest = NULL;	curr_offset = 0;	ITERATE_RDEV_ORDERED(mddev,rdev,j) {		dev_info_t *disk = conf->disks + j;		disk->dev = rdev->dev;		disk->size = rdev->size;		disk->offset = curr_offset;		curr_offset += disk->size;		if (!conf->smallest || (disk->size < conf->smallest->size))			conf->smallest = disk;	}	nb_zone = conf->nr_zones =		md_size[mdidx(mddev)] / conf->smallest->size +		((md_size[mdidx(mddev)] % conf->smallest->size) ? 1 : 0);  	conf->hash_table = kmalloc (sizeof (struct linear_hash) * nb_zone,					GFP_KERNEL);	if (!conf->hash_table)		goto out;	/*	 * Here we generate the linear hash table	 */	table = conf->hash_table;	i = 0;	size = 0;	for (j = 0; j < mddev->nb_dev; j++) {		dev_info_t *disk = conf->disks + j;		if (size < 0) {			table[-1].dev1 = disk;		}		size += disk->size;		while (size>0) {			table->dev0 = disk;			table->dev1 = NULL;			size -= conf->smallest->size;			table++;		}	}	if (table-conf->hash_table != nb_zone)		BUG();	return 0;out:	if (conf)		kfree(conf);	MOD_DEC_USE_COUNT;	return 1;}static int linear_stop (mddev_t *mddev){	linear_conf_t *conf = mddev_to_conf(mddev);  	kfree(conf->hash_table);	kfree(conf);	MOD_DEC_USE_COUNT;	return 0;}static int linear_make_request (mddev_t *mddev,			int rw, struct buffer_head * bh){        linear_conf_t *conf = mddev_to_conf(mddev);        struct linear_hash *hash;        dev_info_t *tmp_dev;        long block;	block = bh->b_rsector >> 1;	hash = conf->hash_table + (block / conf->smallest->size);  	if (block >= (hash->dev0->size + hash->dev0->offset)) {		if (!hash->dev1) {			printk ("linear_make_request : hash->dev1==NULL for block %ld\n",						block);			buffer_IO_error(bh);			return 0;		}		tmp_dev = hash->dev1;	} else		tmp_dev = hash->dev0;    	if (block >= (tmp_dev->size + tmp_dev->offset)				|| block < tmp_dev->offset) {		printk ("linear_make_request: Block %ld out of bounds on dev %s size %ld offset %ld\n", block, kdevname(tmp_dev->dev), tmp_dev->size, tmp_dev->offset);		buffer_IO_error(bh);		return 0;	}	bh->b_rdev = tmp_dev->dev;	bh->b_rsector = bh->b_rsector - (tmp_dev->offset << 1);	return 1;}static int linear_status (char *page, mddev_t *mddev){	int sz = 0;#undef MD_DEBUG#ifdef MD_DEBUG	int j;	linear_conf_t *conf = mddev_to_conf(mddev);  	sz += sprintf(page+sz, "      ");	for (j = 0; j < conf->nr_zones; j++)	{		sz += sprintf(page+sz, "[%s",			partition_name(conf->hash_table[j].dev0->dev));		if (conf->hash_table[j].dev1)			sz += sprintf(page+sz, "/%s] ",			  partition_name(conf->hash_table[j].dev1->dev));		else			sz += sprintf(page+sz, "] ");	}	sz += sprintf(page+sz, "\n");#endif	sz += sprintf(page+sz, " %dk rounding", mddev->param.chunk_size/1024);	return sz;}static mdk_personality_t linear_personality={	name:		"linear",	make_request:	linear_make_request,	run:		linear_run,	stop:		linear_stop,	status:		linear_status,};static int md__init linear_init (void){	return register_md_personality (LINEAR, &linear_personality);}static void linear_exit (void){	unregister_md_personality (LINEAR);}module_init(linear_init);module_exit(linear_exit);