On Thu, 2017-04-20 at 17:09 -0600, Jens Axboe wrote: > From: Jens Axboe <axboe@xxxxxx> > Subject: [PATCH] blk-mq: add might_sleep check to blk_mq_get_driver_tag() > > If the caller passes in wait=true, it has to be able to block > for a driver tag. We just had a bug where flush insertion > would block on tag allocation, while we had preempt disabled. > Ensure that we catch cases like that earlier next time. > > Signed-off-by: Jens Axboe <axboe@xxxxxx> > > diff --git a/block/blk-mq.c b/block/blk-mq.c > index 992f09772f8a..dd6e5dd62804 100644 > --- a/block/blk-mq.c > +++ b/block/blk-mq.c > @@ -866,6 +866,8 @@ bool blk_mq_get_driver_tag(struct request *rq, struct blk_mq_hw_ctx **hctx, > .flags = wait ? 0 : BLK_MQ_REQ_NOWAIT, > }; > > + might_sleep_if(wait); > + > if (rq->tag != -1) > goto done; > > Thanks! Reviewed-by: Bart Van Assche <Bart.VanAssche@xxxxxxxxxxx>
