tree 6b7b60f296779302cc70d7c79e47b4dcc440a9be
parent 37504a3be90b69438426d74ccf467a9fe192932b
author Jens Axboe <axboe@fb.com> 1410885457 -0600
committer Jens Axboe <axboe@fb.com> 1411408444 -0600

blk-mq: request deadline must be visible before marking rq as started

When we start the request, we set the deadline and flip the bits
marking the request as started and non-complete. However, it's
important that the deadline store is ordered before flipping the
bits, otherwise we could have a small window where the request is
marked started but with an invalid deadline. This can confuse the
timeout handling.

Suggested-by: Ming Lei <tom.leiming@gmail.com>
Signed-off-by: Jens Axboe <axboe@fb.com>