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Commit 7c7546cc authored by NeilBrown's avatar NeilBrown Committed by Linus Torvalds
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[PATCH] md: allow a linear array to have drives added while active 



Signed-off-by: default avatarNeil Brown <neilb@suse.de>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 5fd6c1dc

drivers/md/linear.c

+61 −13
Original line number Diff line number Diff line
@@ -111,7 +111,7 @@ static int linear_issue_flush(request_queue_t *q, struct gendisk *disk, 
	return ret;

}



static int linear_run (mddev_t *mddev)

static linear_conf_t *linear_conf(mddev_t *mddev, int raid_disks)

{

	linear_conf_t *conf;

	dev_info_t **table;
@@ -121,20 +121,21 @@ static int linear_run (mddev_t *mddev) 
	sector_t curr_offset;

	struct list_head *tmp;



	conf = kzalloc (sizeof (*conf) + mddev->raid_disks*sizeof(dev_info_t),

	conf = kzalloc (sizeof (*conf) + raid_disks*sizeof(dev_info_t),

			GFP_KERNEL);

	if (!conf)

		goto out;

		return NULL;



	mddev->private = conf;



	cnt = 0;

	mddev->array_size = 0;

	conf->array_size = 0;



	ITERATE_RDEV(mddev,rdev,tmp) {

		int j = rdev->raid_disk;

		dev_info_t *disk = conf->disks + j;



		if (j < 0 || j > mddev->raid_disks || disk->rdev) {

		if (j < 0 || j > raid_disks || disk->rdev) {

			printk("linear: disk numbering problem. Aborting!\n");

			goto out;

		}
@@ -152,11 +153,11 @@ static int linear_run (mddev_t *mddev) 
			blk_queue_max_sectors(mddev->queue, PAGE_SIZE>>9);



		disk->size = rdev->size;

		mddev->array_size += rdev->size;

		conf->array_size += rdev->size;



		cnt++;

	}

	if (cnt != mddev->raid_disks) {

	if (cnt != raid_disks) {

		printk("linear: not enough drives present. Aborting!\n");

		goto out;

	}
@@ -200,7 +201,7 @@ static int linear_run (mddev_t *mddev) 
		unsigned round;

		unsigned long base;



		sz = mddev->array_size >> conf->preshift;

		sz = conf->array_size >> conf->preshift;

		sz += 1; /* force round-up */

		base = conf->hash_spacing >> conf->preshift;

		round = sector_div(sz, base);
@@ -247,14 +248,56 @@ static int linear_run (mddev_t *mddev) 


	BUG_ON(table - conf->hash_table > nb_zone);



	return conf;



out:

	kfree(conf);

	return NULL;

}



static int linear_run (mddev_t *mddev)

{

	linear_conf_t *conf;



	conf = linear_conf(mddev, mddev->raid_disks);



	if (!conf)

		return 1;

	mddev->private = conf;

	mddev->array_size = conf->array_size;



	blk_queue_merge_bvec(mddev->queue, linear_mergeable_bvec);

	mddev->queue->unplug_fn = linear_unplug;

	mddev->queue->issue_flush_fn = linear_issue_flush;

	return 0;

}



out:

	kfree(conf);

	return 1;

static int linear_add(mddev_t *mddev, mdk_rdev_t *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.

	 */

	linear_conf_t *newconf;



	if (rdev->raid_disk != mddev->raid_disks)

		return -EINVAL;



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



	if (!newconf)

		return -ENOMEM;



	newconf->prev = mddev_to_conf(mddev);

	mddev->private = newconf;

	mddev->raid_disks++;

	mddev->array_size = newconf->array_size;

	set_capacity(mddev->gendisk, mddev->array_size << 1);

	return 0;

}



static int linear_stop (mddev_t *mddev)
@@ -262,8 +305,12 @@ static int linear_stop (mddev_t *mddev) 
	linear_conf_t *conf = mddev_to_conf(mddev);

  

	blk_sync_queue(mddev->queue); /* the unplug fn references 'conf'*/

	do {

		linear_conf_t *t = conf->prev;

		kfree(conf->hash_table);

		kfree(conf);

		conf = t;

	} while (conf);



	return 0;

}
@@ -360,6 +407,7 @@ static struct mdk_personality linear_personality = 
	.run		= linear_run,

	.stop		= linear_stop,

	.status		= linear_status,

	.hot_add_disk	= linear_add,

};



static int __init linear_init (void)

drivers/md/md.c

+13 −2
Original line number Diff line number Diff line
@@ -817,8 +817,8 @@ static int super_90_validate(mddev_t *mddev, mdk_rdev_t *rdev) 


		if (desc->state & (1<<MD_DISK_FAULTY))

			set_bit(Faulty, &rdev->flags);

		else if (desc->state & (1<<MD_DISK_SYNC) &&

			 desc->raid_disk < mddev->raid_disks) {

		else if (desc->state & (1<<MD_DISK_SYNC) /* &&

			    desc->raid_disk < mddev->raid_disks */) {

			set_bit(In_sync, &rdev->flags);

			rdev->raid_disk = desc->raid_disk;

		}
@@ -3359,6 +3359,17 @@ static int add_new_disk(mddev_t * mddev, mdu_disk_info_t *info) 


		rdev->raid_disk = -1;

		err = bind_rdev_to_array(rdev, mddev);

		if (!err && !mddev->pers->hot_remove_disk) {

			/* If there is hot_add_disk but no hot_remove_disk

			 * then added disks for geometry changes,

			 * and should be added immediately.

			 */

			super_types[mddev->major_version].

				validate_super(mddev, rdev);

			err = mddev->pers->hot_add_disk(mddev, rdev);

			if (err)

				unbind_rdev_from_array(rdev);

		}

		if (err)

			export_rdev(rdev);

include/linux/raid/linear.h

+2 −0
Original line number Diff line number Diff line
@@ -13,8 +13,10 @@ typedef struct dev_info dev_info_t; 


struct linear_private_data

{

	struct linear_private_data *prev;	/* earlier version */

	dev_info_t		**hash_table;

	sector_t		hash_spacing;

	sector_t		array_size;

	int			preshift; /* shift before dividing by hash_spacing */

	dev_info_t		disks[0];

};