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Commit da943b99 authored by NeilBrown's avatar NeilBrown Committed by Linus Torvalds
Browse files

[PATCH] md: allow md/raid_disks to be settable 



If array is active, try to reshape, else just set the value.

Signed-off-by: default avatarNeil Brown <neilb@suse.de>
Acked-by: default avatarGreg KH <greg@kroah.com>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 4dbcdc75

Documentation/md.txt

+3 −0
Original line number Diff line number Diff line
@@ -165,6 +165,9 @@ All md devices contain: 
     in a fully functional array.  If this is not yet known, the file

     will be empty.  If an array is being resized (not currently

     possible) this will contain the larger of the old and new sizes.

     Some raid level (RAID1) allow this value to be set while the

     array is active.  This will reconfigure the array.   Otherwise

     it can only be set while assembling an array.



  chunk_size

     This is the size if bytes for 'chunks' and is only relevant to

drivers/md/md.c

+51 −23
Original line number Diff line number Diff line
@@ -1843,7 +1843,27 @@ raid_disks_show(mddev_t *mddev, char *page) 
	return sprintf(page, "%d\n", mddev->raid_disks);

}



static struct md_sysfs_entry md_raid_disks = __ATTR_RO(raid_disks);

static int update_raid_disks(mddev_t *mddev, int raid_disks);



static ssize_t

raid_disks_store(mddev_t *mddev, const char *buf, size_t len)

{

	/* can only set raid_disks if array is not yet active */

	char *e;

	int rv = 0;

	unsigned long n = simple_strtoul(buf, &e, 10);



	if (!*buf || (*e && *e != '\n'))

		return -EINVAL;



	if (mddev->pers)

		rv = update_raid_disks(mddev, n);

	else

		mddev->raid_disks = n;

	return rv ? rv : len;

}

static struct md_sysfs_entry md_raid_disks =

__ATTR(raid_disks, 0644, raid_disks_show, raid_disks_store);



static ssize_t

chunk_size_show(mddev_t *mddev, char *page)
@@ -3201,6 +3221,33 @@ static int update_size(mddev_t *mddev, unsigned long size) 
	return rv;

}



static int update_raid_disks(mddev_t *mddev, int raid_disks)

{

	int rv;

	/* change the number of raid disks */

	if (mddev->pers->reshape == NULL)

		return -EINVAL;

	if (raid_disks <= 0 ||

	    raid_disks >= mddev->max_disks)

		return -EINVAL;

	if (mddev->sync_thread)

		return -EBUSY;

	rv = mddev->pers->reshape(mddev, raid_disks);

	if (!rv) {

		struct block_device *bdev;



		bdev = bdget_disk(mddev->gendisk, 0);

		if (bdev) {

			down(&bdev->bd_inode->i_sem);

			i_size_write(bdev->bd_inode, mddev->array_size << 10);

			up(&bdev->bd_inode->i_sem);

			bdput(bdev);

		}

	}

	return rv;

}





/*

 * update_array_info is used to change the configuration of an

 * on-line array.
@@ -3252,28 +3299,9 @@ static int update_array_info(mddev_t *mddev, mdu_array_info_t *info) 
	if (mddev->size != info->size)

		rv = update_size(mddev, info->size);



	if (mddev->raid_disks    != info->raid_disks) {

		/* change the number of raid disks */

		if (mddev->pers->reshape == NULL)

			return -EINVAL;

		if (info->raid_disks <= 0 ||

		    info->raid_disks >= mddev->max_disks)

			return -EINVAL;

		if (mddev->sync_thread)

			return -EBUSY;

		rv = mddev->pers->reshape(mddev, info->raid_disks);

		if (!rv) {

			struct block_device *bdev;

	if (mddev->raid_disks    != info->raid_disks)

		rv = update_raid_disks(mddev, info->raid_disks);



			bdev = bdget_disk(mddev->gendisk, 0);

			if (bdev) {

				down(&bdev->bd_inode->i_sem);

				i_size_write(bdev->bd_inode, mddev->array_size << 10);

				up(&bdev->bd_inode->i_sem);

				bdput(bdev);

			}

		}

	}

	if ((state ^ info->state) & (1<<MD_SB_BITMAP_PRESENT)) {

		if (mddev->pers->quiesce == NULL)

			return -EINVAL;