[mirror_ubuntu-zesty-kernel.git] / drivers / md / linear.c

/*
   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/blkdev.h>
#include <linux/raid/md_u.h>
#include <linux/seq_file.h>
#include <linux/module.h>
#include <linux/slab.h>
#include "md.h"
#include "linear.h"

/*
 * find which device holds a particular offset 
 */
static inline struct dev_info *which_dev(struct mddev *mddev, sector_t sector)
{
	int lo, mid, hi;
	struct linear_conf *conf;

	lo = 0;
	hi = mddev->raid_disks - 1;
	conf = rcu_dereference(mddev->private);

	/*
	 * Binary Search
	 */

	while (hi > lo) {

		mid = (hi + lo) / 2;
		if (sector < conf->disks[mid].end_sector)
			hi = mid;
		else
			lo = mid + 1;
	}

	return conf->disks + lo;
}

/**
 *	linear_mergeable_bvec -- tell bio layer if two requests can be merged
 *	@q: request queue
 *	@bvm: properties of new bio
 *	@biovec: the request that could be merged to it.
 *
 *	Return amount of bytes we can take at this offset
 */
static int linear_mergeable_bvec(struct request_queue *q,
				 struct bvec_merge_data *bvm,
				 struct bio_vec *biovec)
{
	struct mddev *mddev = q->queuedata;
	struct dev_info *dev0;
	unsigned long maxsectors, bio_sectors = bvm->bi_size >> 9;
	sector_t sector = bvm->bi_sector + get_start_sect(bvm->bi_bdev);

	rcu_read_lock();
	dev0 = which_dev(mddev, sector);
	maxsectors = dev0->end_sector - sector;
	rcu_read_unlock();

	if (maxsectors < bio_sectors)
		maxsectors = 0;
	else
		maxsectors -= bio_sectors;

	if (maxsectors <= (PAGE_SIZE >> 9 ) && bio_sectors == 0)
		return biovec->bv_len;
	/* The bytes available at this offset could be really big,
	 * so we cap at 2^31 to avoid overflow */
	if (maxsectors > (1 << (31-9)))
		return 1<<31;
	return maxsectors << 9;
}

static int linear_congested(void *data, int bits)
{
	struct mddev *mddev = data;
	struct linear_conf *conf;
	int i, ret = 0;

	if (mddev_congested(mddev, bits))
		return 1;

	rcu_read_lock();
	conf = rcu_dereference(mddev->private);

	for (i = 0; i < mddev->raid_disks && !ret ; i++) {
		struct request_queue *q = bdev_get_queue(conf->disks[i].rdev->bdev);
		ret |= bdi_congested(&q->backing_dev_info, bits);
	}

	rcu_read_unlock();
	return ret;
}

static sector_t linear_size(struct mddev *mddev, sector_t sectors, int raid_disks)
{
	struct linear_conf *conf;
	sector_t array_sectors;

	rcu_read_lock();
	conf = rcu_dereference(mddev->private);
	WARN_ONCE(sectors || raid_disks,
		  "%s does not support generic reshape\n", __func__);
	array_sectors = conf->array_sectors;
	rcu_read_unlock();

	return array_sectors;
}

static struct linear_conf *linear_conf(struct mddev *mddev, int raid_disks)
{
	struct linear_conf *conf;
	struct md_rdev *rdev;
	int i, cnt;

	conf = kzalloc (sizeof (*conf) + raid_disks*sizeof(struct dev_info),
			GFP_KERNEL);
	if (!conf)
		return NULL;

	cnt = 0;
	conf->array_sectors = 0;

	list_for_each_entry(rdev, &mddev->disks, same_set) {
		int j = rdev->raid_disk;
		struct dev_info *disk = conf->disks + j;
		sector_t sectors;

		if (j < 0 || j >= raid_disks || disk->rdev) {
			printk(KERN_ERR "md/linear:%s: disk numbering problem. Aborting!\n",
			       mdname(mddev));
			goto out;
		}

		disk->rdev = rdev;
		if (mddev->chunk_sectors) {
			sectors = rdev->sectors;
			sector_div(sectors, mddev->chunk_sectors);
			rdev->sectors = sectors * mddev->chunk_sectors;
		}

		disk_stack_limits(mddev->gendisk, rdev->bdev,
				  rdev->data_offset << 9);
		/* as we don't honour merge_bvec_fn, we must never risk
		 * violating it, so limit max_segments to 1 lying within
		 * a single page.
		 */
		if (rdev->bdev->bd_disk->queue->merge_bvec_fn) {
			blk_queue_max_segments(mddev->queue, 1);
			blk_queue_segment_boundary(mddev->queue,
						   PAGE_CACHE_SIZE - 1);
		}

		conf->array_sectors += rdev->sectors;
		cnt++;

	}
	if (cnt != raid_disks) {
		printk(KERN_ERR "md/linear:%s: not enough drives present. Aborting!\n",
		       mdname(mddev));
		goto out;
	}

	/*
	 * Here we calculate the device offsets.
	 */
	conf->disks[0].end_sector = conf->disks[0].rdev->sectors;

	for (i = 1; i < raid_disks; i++)
		conf->disks[i].end_sector =
			conf->disks[i-1].end_sector +
			conf->disks[i].rdev->sectors;

	return conf;

out:
	kfree(conf);
	return NULL;
}

static int linear_run (struct mddev *mddev)
{
	struct linear_conf *conf;

	if (md_check_no_bitmap(mddev))
		return -EINVAL;
	conf = linear_conf(mddev, mddev->raid_disks);

	if (!conf)
		return 1;
	mddev->private = conf;
	md_set_array_sectors(mddev, linear_size(mddev, 0, 0));

	blk_queue_merge_bvec(mddev->queue, linear_mergeable_bvec);
	mddev->queue->backing_dev_info.congested_fn = linear_congested;
	mddev->queue->backing_dev_info.congested_data = mddev;
	return md_integrity_register(mddev);
}

static int linear_add(struct mddev *mddev, struct md_rdev *rdev)
{
	/* Adding a drive to a linear array allows the array to grow.
	 * It is permitted if the new drive has a matching superblock
	 * already on it, with raid_disk equal to raid_disks.
	 * It is achieved by creating a new linear_private_data structure
	 * and swapping it in in-place of the current one.
	 * The current one is never freed until the array is stopped.
	 * This avoids races.
	 */
	struct linear_conf *newconf, *oldconf;

	if (rdev->saved_raid_disk != mddev->raid_disks)
		return -EINVAL;

	rdev->raid_disk = rdev->saved_raid_disk;

	newconf = linear_conf(mddev,mddev->raid_disks+1);

	if (!newconf)
		return -ENOMEM;

	oldconf = rcu_dereference(mddev->private);
	mddev->raid_disks++;
	rcu_assign_pointer(mddev->private, newconf);
	md_set_array_sectors(mddev, linear_size(mddev, 0, 0));
	set_capacity(mddev->gendisk, mddev->array_sectors);
	revalidate_disk(mddev->gendisk);
	kfree_rcu(oldconf, rcu);
	return 0;
}

static int linear_stop (struct mddev *mddev)
{
	struct linear_conf *conf = mddev->private;

	/*
	 * We do not require rcu protection here since
	 * we hold reconfig_mutex for both linear_add and
	 * linear_stop, so they cannot race.
	 * We should make sure any old 'conf's are properly
	 * freed though.
	 */
	rcu_barrier();
	blk_sync_queue(mddev->queue); /* the unplug fn references 'conf'*/
	kfree(conf);
	mddev->private = NULL;

	return 0;
}

static void linear_make_request(struct mddev *mddev, struct bio *bio)
{
	struct dev_info *tmp_dev;
	sector_t start_sector;

	if (unlikely(bio->bi_rw & REQ_FLUSH)) {
		md_flush_request(mddev, bio);
		return;
	}

	rcu_read_lock();
	tmp_dev = which_dev(mddev, bio->bi_sector);
	start_sector = tmp_dev->end_sector - tmp_dev->rdev->sectors;


	if (unlikely(bio->bi_sector >= (tmp_dev->end_sector)
		     || (bio->bi_sector < start_sector))) {
		char b[BDEVNAME_SIZE];

		printk(KERN_ERR
		       "md/linear:%s: make_request: Sector %llu out of bounds on "
		       "dev %s: %llu sectors, offset %llu\n",
		       mdname(mddev),
		       (unsigned long long)bio->bi_sector,
		       bdevname(tmp_dev->rdev->bdev, b),
		       (unsigned long long)tmp_dev->rdev->sectors,
		       (unsigned long long)start_sector);
		rcu_read_unlock();
		bio_io_error(bio);
		return;
	}
	if (unlikely(bio->bi_sector + (bio->bi_size >> 9) >
		     tmp_dev->end_sector)) {
		/* This bio crosses a device boundary, so we have to
		 * split it.
		 */
		struct bio_pair *bp;
		sector_t end_sector = tmp_dev->end_sector;

		rcu_read_unlock();

		bp = bio_split(bio, end_sector - bio->bi_sector);

		linear_make_request(mddev, &bp->bio1);
		linear_make_request(mddev, &bp->bio2);
		bio_pair_release(bp);
		return;
	}
		    
	bio->bi_bdev = tmp_dev->rdev->bdev;
	bio->bi_sector = bio->bi_sector - start_sector
		+ tmp_dev->rdev->data_offset;
	rcu_read_unlock();
	generic_make_request(bio);
}

static void linear_status (struct seq_file *seq, struct mddev *mddev)
{

	seq_printf(seq, " %dk rounding", mddev->chunk_sectors / 2);
}


static struct md_personality linear_personality =
{
	.name		= "linear",
	.level		= LEVEL_LINEAR,
	.owner		= THIS_MODULE,
	.make_request	= linear_make_request,
	.run		= linear_run,
	.stop		= linear_stop,
	.status		= linear_status,
	.hot_add_disk	= linear_add,
	.size		= linear_size,
};

static int __init linear_init (void)
{
	return register_md_personality (&linear_personality);
}

static void linear_exit (void)
{
	unregister_md_personality (&linear_personality);
}


module_init(linear_init);
module_exit(linear_exit);
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Linear device concatenation personality for MD");
MODULE_ALIAS("md-personality-1"); /* LINEAR - deprecated*/
MODULE_ALIAS("md-linear");
MODULE_ALIAS("md-level--1");
Commit	Line	Data
1da177e4 LT	1	/*
	2	linear.c : Multiple Devices driver for Linux
	3	Copyright (C) 1994-96 Marc ZYNGIER
	4	<zyngier@ufr-info-p7.ibp.fr> or
	5	<maz@gloups.fdn.fr>
	6
	7	Linear mode management functions.
	8
	9	This program is free software; you can redistribute it and/or modify
	10	it under the terms of the GNU General Public License as published by
	11	the Free Software Foundation; either version 2, or (at your option)
	12	any later version.
	13
	14	You should have received a copy of the GNU General Public License
	15	(for example /usr/src/linux/COPYING); if not, write to the Free
	16	Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
	17	*/
	18
bff61975 N	19	#include <linux/blkdev.h>
bff61975 N	20	#include <linux/raid/md_u.h>
bff61975	21	#include <linux/seq_file.h>
056075c7	22	#include <linux/module.h>
5a0e3ad6	23	#include <linux/slab.h>
43b2e5d8	24	#include "md.h"
ef740c37	25	#include "linear.h"
1da177e4	26
1da177e4 LT	27	/*
	28	* find which device holds a particular offset
	29	*/
a7120771	30	static inline struct dev_info which_dev(struct mddev mddev, sector_t sector)
1da177e4	31	{
aece3d1f	32	int lo, mid, hi;
e849b938	33	struct linear_conf *conf;
1da177e4	34
aece3d1f SS	35	lo = 0;
aece3d1f SS	36	hi = mddev->raid_disks - 1;
af11c397	37	conf = rcu_dereference(mddev->private);
1da177e4	38
aece3d1f SS	39	/*
	40	* Binary Search
	41	*/
	42
	43	while (hi > lo) {
	44
	45	mid = (hi + lo) / 2;
	46	if (sector < conf->disks[mid].end_sector)
	47	hi = mid;
	48	else
	49	lo = mid + 1;
	50	}
	51
	52	return conf->disks + lo;
1da177e4 LT	53	}
	54
	55	/**
15945fee	56	* linear_mergeable_bvec -- tell bio layer if two requests can be merged
1da177e4	57	* @q: request queue
cc371e66	58	* @bvm: properties of new bio
1da177e4 LT	59	* @biovec: the request that could be merged to it.
	60	*
	61	* Return amount of bytes we can take at this offset
	62	*/
cc371e66 AK	63	static int linear_mergeable_bvec(struct request_queue *q,
	64	struct bvec_merge_data *bvm,
	65	struct bio_vec *biovec)
1da177e4	66	{
fd01b88c	67	struct mddev *mddev = q->queuedata;
a7120771	68	struct dev_info *dev0;
cc371e66 AK	69	unsigned long maxsectors, bio_sectors = bvm->bi_size >> 9;
cc371e66 AK	70	sector_t sector = bvm->bi_sector + get_start_sect(bvm->bi_bdev);
1da177e4	71
af11c397	72	rcu_read_lock();
1da177e4	73	dev0 = which_dev(mddev, sector);
4db7cdc8	74	maxsectors = dev0->end_sector - sector;
af11c397	75	rcu_read_unlock();
1da177e4 LT	76
	77	if (maxsectors < bio_sectors)
	78	maxsectors = 0;
	79	else
	80	maxsectors -= bio_sectors;
	81
	82	if (maxsectors <= (PAGE_SIZE >> 9 ) && bio_sectors == 0)
	83	return biovec->bv_len;
	84	/* The bytes available at this offset could be really big,
	85	* so we cap at 2^31 to avoid overflow */
	86	if (maxsectors > (1 << (31-9)))
	87	return 1<<31;
	88	return maxsectors << 9;
	89	}
	90
26be34dc N	91	static int linear_congested(void *data, int bits)
26be34dc N	92	{
fd01b88c	93	struct mddev *mddev = data;
e849b938	94	struct linear_conf *conf;
26be34dc N	95	int i, ret = 0;
26be34dc N	96
3fa841d7 N	97	if (mddev_congested(mddev, bits))
	98	return 1;
	99
af11c397 S	100	rcu_read_lock();
	101	conf = rcu_dereference(mddev->private);
	102
26be34dc	103	for (i = 0; i < mddev->raid_disks && !ret ; i++) {
165125e1	104	struct request_queue *q = bdev_get_queue(conf->disks[i].rdev->bdev);
26be34dc N	105	ret \|= bdi_congested(&q->backing_dev_info, bits);
26be34dc N	106	}
af11c397 S	107
af11c397 S	108	rcu_read_unlock();
26be34dc N	109	return ret;
	110	}
	111
fd01b88c	112	static sector_t linear_size(struct mddev *mddev, sector_t sectors, int raid_disks)
80c3a6ce	113	{
e849b938	114	struct linear_conf *conf;
af11c397	115	sector_t array_sectors;
80c3a6ce	116
af11c397 S	117	rcu_read_lock();
af11c397 S	118	conf = rcu_dereference(mddev->private);
80c3a6ce DW	119	WARN_ONCE(sectors \|\| raid_disks,
80c3a6ce DW	120	"%s does not support generic reshape\n", __func__);
af11c397 S	121	array_sectors = conf->array_sectors;
af11c397 S	122	rcu_read_unlock();
80c3a6ce	123
af11c397	124	return array_sectors;
80c3a6ce DW	125	}
80c3a6ce DW	126
e849b938	127	static struct linear_conf linear_conf(struct mddev mddev, int raid_disks)
1da177e4	128	{
e849b938	129	struct linear_conf *conf;
3cb03002	130	struct md_rdev *rdev;
45d4582f	131	int i, cnt;
1da177e4	132
a7120771	133	conf = kzalloc (sizeof (conf) + raid_diskssizeof(struct dev_info),
1da177e4 LT	134	GFP_KERNEL);
1da177e4 LT	135	if (!conf)
7c7546cc N	136	return NULL;
7c7546cc N	137
1da177e4	138	cnt = 0;
d6e22150	139	conf->array_sectors = 0;
1da177e4	140
159ec1fc	141	list_for_each_entry(rdev, &mddev->disks, same_set) {
1da177e4	142	int j = rdev->raid_disk;
a7120771	143	struct dev_info *disk = conf->disks + j;
13f2682b	144	sector_t sectors;
1da177e4	145
13864515	146	if (j < 0 \|\| j >= raid_disks \|\| disk->rdev) {
2dc40f80 N	147	printk(KERN_ERR "md/linear:%s: disk numbering problem. Aborting!\n",
2dc40f80 N	148	mdname(mddev));
1da177e4 LT	149	goto out;
	150	}
	151
	152	disk->rdev = rdev;
13f2682b N	153	if (mddev->chunk_sectors) {
	154	sectors = rdev->sectors;
	155	sector_div(sectors, mddev->chunk_sectors);
	156	rdev->sectors = sectors * mddev->chunk_sectors;
	157	}
1da177e4	158
8f6c2e4b MP	159	disk_stack_limits(mddev->gendisk, rdev->bdev,
8f6c2e4b MP	160	rdev->data_offset << 9);
1da177e4	161	/* as we don't honour merge_bvec_fn, we must never risk
627a2d3c N	162	* violating it, so limit max_segments to 1 lying within
627a2d3c N	163	* a single page.
1da177e4	164	*/
627a2d3c N	165	if (rdev->bdev->bd_disk->queue->merge_bvec_fn) {
	166	blk_queue_max_segments(mddev->queue, 1);
	167	blk_queue_segment_boundary(mddev->queue,
	168	PAGE_CACHE_SIZE - 1);
	169	}
1da177e4	170
dd8ac336	171	conf->array_sectors += rdev->sectors;
1da177e4	172	cnt++;
4db7cdc8	173
1da177e4	174	}
7c7546cc	175	if (cnt != raid_disks) {
2dc40f80 N	176	printk(KERN_ERR "md/linear:%s: not enough drives present. Aborting!\n",
2dc40f80 N	177	mdname(mddev));
1da177e4 LT	178	goto out;
	179	}
	180
	181	/*
45d4582f	182	* Here we calculate the device offsets.
1da177e4	183	*/
4db7cdc8 SS	184	conf->disks[0].end_sector = conf->disks[0].rdev->sectors;
4db7cdc8 SS	185
a778b73f	186	for (i = 1; i < raid_disks; i++)
4db7cdc8 SS	187	conf->disks[i].end_sector =
	188	conf->disks[i-1].end_sector +
	189	conf->disks[i].rdev->sectors;
15945fee	190
7c7546cc N	191	return conf;
	192
	193	out:
	194	kfree(conf);
	195	return NULL;
	196	}
	197
fd01b88c	198	static int linear_run (struct mddev *mddev)
7c7546cc	199	{
e849b938	200	struct linear_conf *conf;
7c7546cc	201
0894cc30 AN	202	if (md_check_no_bitmap(mddev))
0894cc30 AN	203	return -EINVAL;
7c7546cc N	204	conf = linear_conf(mddev, mddev->raid_disks);
	205
	206	if (!conf)
	207	return 1;
	208	mddev->private = conf;
1f403624	209	md_set_array_sectors(mddev, linear_size(mddev, 0, 0));
7c7546cc	210
1da177e4	211	blk_queue_merge_bvec(mddev->queue, linear_mergeable_bvec);
26be34dc N	212	mddev->queue->backing_dev_info.congested_fn = linear_congested;
26be34dc N	213	mddev->queue->backing_dev_info.congested_data = mddev;
a91a2785	214	return md_integrity_register(mddev);
7c7546cc	215	}
1da177e4	216
fd01b88c	217	static int linear_add(struct mddev mddev, struct md_rdev rdev)
7c7546cc N	218	{
	219	/* Adding a drive to a linear array allows the array to grow.
	220	* It is permitted if the new drive has a matching superblock
	221	* already on it, with raid_disk equal to raid_disks.
	222	* It is achieved by creating a new linear_private_data structure
	223	* and swapping it in in-place of the current one.
	224	* The current one is never freed until the array is stopped.
	225	* This avoids races.
	226	*/
e849b938	227	struct linear_conf newconf, oldconf;
7c7546cc	228
a778b73f	229	if (rdev->saved_raid_disk != mddev->raid_disks)
7c7546cc N	230	return -EINVAL;
7c7546cc N	231
a778b73f N	232	rdev->raid_disk = rdev->saved_raid_disk;
a778b73f N	233
7c7546cc N	234	newconf = linear_conf(mddev,mddev->raid_disks+1);
	235
	236	if (!newconf)
	237	return -ENOMEM;
	238
495d3573	239	oldconf = rcu_dereference(mddev->private);
7c7546cc	240	mddev->raid_disks++;
af11c397	241	rcu_assign_pointer(mddev->private, newconf);
1f403624	242	md_set_array_sectors(mddev, linear_size(mddev, 0, 0));
f233ea5c	243	set_capacity(mddev->gendisk, mddev->array_sectors);
449aad3e	244	revalidate_disk(mddev->gendisk);
b119cbab	245	kfree_rcu(oldconf, rcu);
7c7546cc	246	return 0;
1da177e4 LT	247	}
1da177e4 LT	248
fd01b88c	249	static int linear_stop (struct mddev *mddev)
1da177e4	250	{
e849b938	251	struct linear_conf *conf = mddev->private;
af11c397 S	252
	253	/*
	254	* We do not require rcu protection here since
	255	* we hold reconfig_mutex for both linear_add and
	256	* linear_stop, so they cannot race.
495d3573 N	257	* We should make sure any old 'conf's are properly
495d3573 N	258	* freed though.
af11c397	259	*/
495d3573	260	rcu_barrier();
1da177e4	261	blk_sync_queue(mddev->queue); /* the unplug fn references 'conf'*/
495d3573	262	kfree(conf);
ef2f80ff	263	mddev->private = NULL;
1da177e4 LT	264
	265	return 0;
	266	}
	267
b4fdcb02	268	static void linear_make_request(struct mddev mddev, struct bio bio)
1da177e4	269	{
a7120771	270	struct dev_info *tmp_dev;
4db7cdc8	271	sector_t start_sector;
1da177e4	272
e9c7469b TH	273	if (unlikely(bio->bi_rw & REQ_FLUSH)) {
e9c7469b TH	274	md_flush_request(mddev, bio);
5a7bbad2	275	return;
e5dcdd80 N	276	}
e5dcdd80 N	277
af11c397	278	rcu_read_lock();
1da177e4	279	tmp_dev = which_dev(mddev, bio->bi_sector);
4db7cdc8 SS	280	start_sector = tmp_dev->end_sector - tmp_dev->rdev->sectors;
4db7cdc8 SS	281
af11c397	282
4db7cdc8 SS	283	if (unlikely(bio->bi_sector >= (tmp_dev->end_sector)
4db7cdc8 SS	284	\|\| (bio->bi_sector < start_sector))) {
1da177e4 LT	285	char b[BDEVNAME_SIZE];
1da177e4 LT	286
2dc40f80 N	287	printk(KERN_ERR
	288	"md/linear:%s: make_request: Sector %llu out of bounds on "
	289	"dev %s: %llu sectors, offset %llu\n",
	290	mdname(mddev),
	291	(unsigned long long)bio->bi_sector,
	292	bdevname(tmp_dev->rdev->bdev, b),
	293	(unsigned long long)tmp_dev->rdev->sectors,
	294	(unsigned long long)start_sector);
af11c397	295	rcu_read_unlock();
6712ecf8	296	bio_io_error(bio);
5a7bbad2	297	return;
1da177e4 LT	298	}
1da177e4 LT	299	if (unlikely(bio->bi_sector + (bio->bi_size >> 9) >
4db7cdc8	300	tmp_dev->end_sector)) {
1da177e4 LT	301	/* This bio crosses a device boundary, so we have to
	302	* split it.
	303	*/
	304	struct bio_pair *bp;
af11c397 S	305	sector_t end_sector = tmp_dev->end_sector;
	306
	307	rcu_read_unlock();
6283815d	308
af11c397	309	bp = bio_split(bio, end_sector - bio->bi_sector);
6283815d	310
5a7bbad2 CH	311	linear_make_request(mddev, &bp->bio1);
5a7bbad2 CH	312	linear_make_request(mddev, &bp->bio2);
1da177e4	313	bio_pair_release(bp);
5a7bbad2	314	return;
1da177e4 LT	315	}
	316
	317	bio->bi_bdev = tmp_dev->rdev->bdev;
4db7cdc8	318	bio->bi_sector = bio->bi_sector - start_sector
6283815d	319	+ tmp_dev->rdev->data_offset;
af11c397	320	rcu_read_unlock();
5a7bbad2	321	generic_make_request(bio);
1da177e4 LT	322	}
1da177e4 LT	323
fd01b88c	324	static void linear_status (struct seq_file seq, struct mddev mddev)
1da177e4 LT	325	{
1da177e4 LT	326
9d8f0363	327	seq_printf(seq, " %dk rounding", mddev->chunk_sectors / 2);
1da177e4 LT	328	}
	329
	330
84fc4b56	331	static struct md_personality linear_personality =
1da177e4 LT	332	{
1da177e4 LT	333	.name = "linear",
2604b703	334	.level = LEVEL_LINEAR,
1da177e4 LT	335	.owner = THIS_MODULE,
	336	.make_request = linear_make_request,
	337	.run = linear_run,
	338	.stop = linear_stop,
	339	.status = linear_status,
7c7546cc	340	.hot_add_disk = linear_add,
80c3a6ce	341	.size = linear_size,
1da177e4 LT	342	};
	343
	344	static int __init linear_init (void)
	345	{
2604b703	346	return register_md_personality (&linear_personality);
1da177e4 LT	347	}
	348
	349	static void linear_exit (void)
	350	{
2604b703	351	unregister_md_personality (&linear_personality);
1da177e4 LT	352	}
	353
	354
	355	module_init(linear_init);
	356	module_exit(linear_exit);
	357	MODULE_LICENSE("GPL");
0efb9e61	358	MODULE_DESCRIPTION("Linear device concatenation personality for MD");
d9d166c2 N	359	MODULE_ALIAS("md-personality-1"); /* LINEAR - deprecated*/
d9d166c2 N	360	MODULE_ALIAS("md-linear");
2604b703	361	MODULE_ALIAS("md-level--1");