Commit f1b29bca authored by Dan Williams's avatar Dan Williams Committed by NeilBrown
Browse files

md/raid4: permit raid0 takeover 



For consistency allow raid4 to takeover raid0 in addition to raid5 (with a
raid4 layout).

Signed-off-by: default avatarDan Williams <dan.j.williams@intel.com>
parent e555190d

drivers/md/raid5.c

+17 −15
Original line number Diff line number Diff line
@@ -5610,10 +5610,17 @@ static void raid5_quiesce(mddev_t *mddev, int state) 
}





static void *raid5_takeover_raid0(mddev_t *mddev)

static void *raid45_takeover_raid0(mddev_t *mddev, int level)

{

	struct raid0_private_data *raid0_priv = mddev->private;



	mddev->new_level = 5;

	/* for raid0 takeover only one zone is supported */

	if (raid0_priv->nr_strip_zones > 1) {

		printk(KERN_ERR "md: cannot takeover raid0 with more than one zone.\n");

		return ERR_PTR(-EINVAL);

	}



	mddev->new_level = level;

	mddev->new_layout = ALGORITHM_PARITY_N;

	mddev->new_chunk_sectors = mddev->chunk_sectors;

	mddev->raid_disks += 1;
@@ -5749,22 +5756,13 @@ static int raid6_check_reshape(mddev_t *mddev) 
static void *raid5_takeover(mddev_t *mddev)

{

	/* raid5 can take over:

	 *  raid0 - if all devices are the same - make it a raid4 layout

	 *  raid0 - if there is only one strip zone - make it a raid4 layout

	 *  raid1 - if there are two drives.  We need to know the chunk size

	 *  raid4 - trivial - just use a raid4 layout.

	 *  raid6 - Providing it is a *_6 layout

	 */

	if (mddev->level == 0) {

		/* for raid0 takeover only one zone is supported */

		struct raid0_private_data *raid0_priv

			= mddev->private;

		if (raid0_priv->nr_strip_zones > 1) {

			printk(KERN_ERR "md: cannot takeover raid 0 with more than one zone.\n");

			return ERR_PTR(-EINVAL);

		}

		return raid5_takeover_raid0(mddev);

	}



	if (mddev->level == 0)

		return raid45_takeover_raid0(mddev, 5);

	if (mddev->level == 1)

		return raid5_takeover_raid1(mddev);

	if (mddev->level == 4) {
@@ -5780,8 +5778,12 @@ static void *raid5_takeover(mddev_t *mddev) 


static void *raid4_takeover(mddev_t *mddev)

{

	/* raid4 can take over raid5 if layout is right.

	/* raid4 can take over:

	 *  raid0 - if there is only one strip zone

	 *  raid5 - if layout is right

	 */

	if (mddev->level == 0)

		return raid45_takeover_raid0(mddev, 4);

	if (mddev->level == 5 &&

	    mddev->layout == ALGORITHM_PARITY_N) {

		mddev->new_layout = 0;