On Fri, May 19, 2017 at 11:30:05AM -0700, Bart Van Assche wrote: > Several block drivers need to initialize the driver-private data > after having called blk_get_request() and before .prep_rq_fn() is > called, e.g. when submitting a REQ_OP_SCSI_* request. Avoid that > that initialization code has to be repeated after every > blk_get_request() call by adding a new callback function to struct > request_queue. > > Signed-off-by: Bart Van Assche <bart.vanassche@xxxxxxxxxxx> > Cc: Jens Axboe <axboe@xxxxxx> > Cc: Christoph Hellwig <hch@xxxxxx> > Cc: Omar Sandoval <osandov@xxxxxx> > Cc: Hannes Reinecke <hare@xxxxxxxx> > Cc: linux-block@xxxxxxxxxxxxxxx > --- > block/blk-core.c | 3 +++ > block/blk-mq.c | 3 +++ > include/linux/blkdev.h | 4 ++++ > 3 files changed, 10 insertions(+) > > diff --git a/block/blk-core.c b/block/blk-core.c > index a69d420b7ff0..f2540d164679 100644 > --- a/block/blk-core.c > +++ b/block/blk-core.c > @@ -126,6 +126,9 @@ void blk_rq_init(struct request_queue *q, struct request *rq) > rq->start_time = jiffies; > set_start_time_ns(rq); > rq->part = NULL; > + > + if (q->initialize_rq_fn) > + q->initialize_rq_fn(rq); Can we keep this out of the fast path and only do it from the blk_get_request / blk_mq_alloc_request path? And while were at it I think those two should be merged as far as the public interface goes, that is we should also expose the flags argument for the legacy path.
