disk_get_part needs to be paired with a disk_put_part.
Cc: stable@vger.kernel.org Fixes: ef45fe470e1 ("blk-cgroup: show global disk stats in root cgroup io.stat") Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>