On 8/9/21 9:47 AM, Jan Kara wrote: > On Mon 09-08-21 16:17:43, Christoph Hellwig wrote: >> The backing device information only makes sense for file system I/O, >> and thus belongs into the gendisk and not the lower level request_queue >> structure. Move it there. >> >> Signed-off-by: Christoph Hellwig <hch@xxxxxx> > > Looks mostly good. I'm just unsure whether some queue_to_disk() calls are > safe. > >> diff --git a/block/blk-mq.c b/block/blk-mq.c >> index 2c4ac51e54eb..d2725f94491d 100644 >> --- a/block/blk-mq.c >> +++ b/block/blk-mq.c >> @@ -525,7 +525,7 @@ void blk_mq_free_request(struct request *rq) >> __blk_mq_dec_active_requests(hctx); >> >> if (unlikely(laptop_mode && !blk_rq_is_passthrough(rq))) >> - laptop_io_completion(q->backing_dev_info); >> + laptop_io_completion(queue_to_disk(q)->bdi); >> > > E.g. cannot this get called for a queue that is without a disk? Should be fine, as it's checking for passthrough. Maybe famous last words, but we should not be seeing regular IO before disk is setup. >> @@ -359,8 +359,8 @@ static void wb_timer_fn(struct blk_stat_callback *cb) >> >> status = latency_exceeded(rwb, cb->stat); >> >> - trace_wbt_timer(rwb->rqos.q->backing_dev_info, status, rqd->scale_step, >> - inflight); >> + trace_wbt_timer(queue_to_disk(rwb->rqos.q)->bdi, status, >> + rqd->scale_step, inflight); >> >> /* >> * If we exceeded the latency target, step down. If we did not, > > Or all these calls - is wbt guaranteed to only be setup for a queue with > disk? Same for this one. -- Jens Axboe
