tree 688cec558495fd27078e34d5474992b5c2b6650f
parent 85b6bc9db6d5ab6980b43c38b5cbd11d24414ce4
author Tejun Heo <tj@kernel.org> 1439934919 -0700
committer Jens Axboe <axboe@fb.com> 1439938157 -0700

blk-throttle: improve queue bypass handling

If a queue is bypassing, all blkcg policies should become noops but
blk-throttle wasn't.  It only became noop if the queue was dying.
While this wouldn't lead to an oops as falling back to the root blkg
is safe in this case, this can be a bit surprising - a bypassing queue
could still be applying throttle limits.

Fix it by removing blk_queue_dying() test in throtl_lookup_create_tg()
and testing blk_queue_bypass() in blk_throtl_bio() and bypassing
before doing anything else.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Arianna Avanzini <avanzini.arianna@gmail.com>
Signed-off-by: Jens Axboe <axboe@fb.com>