On 12/11/18 4:03 PM, Dennis Zhou wrote: > Between v3 [1] and v4 [2] of the blkg association series, the > association point moved from generic_make_request_checks(), which is > called after the request enters the queue, to bio_set_dev(), which is when > the bio is formed before submit_bio(). When the request_queue goes away, > the blkgs supporting the request_queue are destroyed and then the > q->root_blkg is set to %NULL. > > This patch adds a %NULL check to blkg_tryget_closest() to prevent the > NPE caused by the above. It also adds a guard to see if the > request_queue is dying when creating a blkg to prevent creating a blkg > for a dead request_queue. Applied, thanks Dennis. -- Jens Axboe
