Neil writes:
Hi Jens,
I've found a little bug for you. It was introduced by
a6f23657d3
block: add one-hit cache for disk partition lookup
and has the effect of killing my machine whenever I try to assemble
an md array :-(
One of the devices in the array has partitions, and mdadm always
deletes partitions before putting a whole-device in an array (as it
can cause confusion). The next IO to that device locks the machine.
I don't really understand exactly why it locks up, but it happens in
disk_map_sector_rcu(). This patch fixes it.
Which is due to a missing clear of the (now) stale partition lookup
data. So clear that when we delete a partition.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
54b0d12769