md: add support for raid5 to raid4 conversion

This is unlikely to be wanted, but we may as well provide it
for completeness.

Signed-off-by: NeilBrown <neilb@suse.de>
This commit is contained in:
NeilBrown 2010-03-22 16:53:49 +11:00
parent 5cac7861b2
commit a78d38a1a1

View file

@ -5788,6 +5788,18 @@ static void *raid5_takeover(mddev_t *mddev)
return ERR_PTR(-EINVAL);
}
static void *raid4_takeover(mddev_t *mddev)
{
/* raid4 can take over raid5 if layout is right.
*/
if (mddev->level == 5 &&
mddev->layout == ALGORITHM_PARITY_N) {
mddev->new_layout = 0;
mddev->new_level = 4;
return setup_conf(mddev);
}
return ERR_PTR(-EINVAL);
}
static struct mdk_personality raid5_personality;
@ -5903,6 +5915,7 @@ static struct mdk_personality raid4_personality =
.start_reshape = raid5_start_reshape,
.finish_reshape = raid5_finish_reshape,
.quiesce = raid5_quiesce,
.takeover = raid4_takeover,
};
static int __init raid5_init(void)