Commit 6508fdbf authored by NeilBrown's avatar NeilBrown
Browse files

md/raid10: set dev_sectors properly when resizing devices in array. 



raid10 stores dev_sectors in 'conf' separately from the one in
'mddev' because it can have a very significant effect on block
addressing and so need to be updated carefully.

However raid10_resize isn't updating it at all!

To update it correctly, we need to make sure it is a proper
multiple of the chunksize taking various details of the layout
in to account.
This calculation is currently done in setup_conf.   So split it
out from there and call it from raid10_resize as well.
Then set conf->dev_sectors properly.

Signed-off-by: default avatarNeilBrown <neilb@suse.de>
parent b16b1b6c

drivers/md/raid10.c

+32 −24
Original line number Diff line number Diff line
@@ -3164,12 +3164,40 @@ raid10_size(struct mddev *mddev, sector_t sectors, int raid_disks) 
	return size << conf->chunk_shift;

}



static void calc_sectors(struct r10conf *conf, sector_t size)

{

	/* Calculate the number of sectors-per-device that will

	 * actually be used, and set conf->dev_sectors and

	 * conf->stride

	 */



	size = size >> conf->chunk_shift;

	sector_div(size, conf->far_copies);

	size = size * conf->raid_disks;

	sector_div(size, conf->near_copies);

	/* 'size' is now the number of chunks in the array */

	/* calculate "used chunks per device" */

	size = size * conf->copies;



	/* We need to round up when dividing by raid_disks to

	 * get the stride size.

	 */

	size = DIV_ROUND_UP_SECTOR_T(size, conf->raid_disks);



	conf->dev_sectors = size << conf->chunk_shift;



	if (conf->far_offset)

		conf->stride = 1 << conf->chunk_shift;

	else {

		sector_div(size, conf->near_copies);

		conf->stride = size << conf->chunk_shift;

	}

}



static struct r10conf *setup_conf(struct mddev *mddev)

{

	struct r10conf *conf = NULL;

	int nc, fc, fo;

	sector_t stride, size;

	int err = -EINVAL;



	if (mddev->new_chunk_sectors < (PAGE_SIZE >> 9) ||
@@ -3219,28 +3247,7 @@ static struct r10conf *setup_conf(struct mddev *mddev) 
	if (!conf->r10bio_pool)

		goto out;



	size = mddev->dev_sectors >> conf->chunk_shift;

	sector_div(size, fc);

	size = size * conf->raid_disks;

	sector_div(size, nc);

	/* 'size' is now the number of chunks in the array */

	/* calculate "used chunks per device" in 'stride' */

	stride = size * conf->copies;



	/* We need to round up when dividing by raid_disks to

	 * get the stride size.

	 */

	stride += conf->raid_disks - 1;

	sector_div(stride, conf->raid_disks);



	conf->dev_sectors = stride << conf->chunk_shift;



	if (fo)

		stride = 1;

	else

		sector_div(stride, fc);

	conf->stride = stride << conf->chunk_shift;



	calc_sectors(conf, mddev->dev_sectors);



	spin_lock_init(&conf->device_lock);

	INIT_LIST_HEAD(&conf->retry_list);
@@ -3468,7 +3475,8 @@ static int raid10_resize(struct mddev *mddev, sector_t sectors) 
		mddev->recovery_cp = oldsize;

		set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);

	}

	mddev->dev_sectors = sectors;

	calc_sectors(conf, sectors);

	mddev->dev_sectors = conf->dev_sectors;

	mddev->resync_max_sectors = size;

	return 0;

}

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