blk-mq-sched: unify request prepare methods
This patch makes sure we always allocate requests in the core blk-mq
code and use a common prepare_request method to initialize them for
both mq I/O schedulers. For Kyber and additional limit_depth method
is added that is called before allocating the request.
Also because none of the intializations can really fail the new method
does not return an error - instead the bfq finish method is hardened
to deal with the no-IOC case.
Last but not least this removes the abuse of RQF_QUEUE by the blk-mq
scheduling code as RQF_ELFPRIV is all that is needed now.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c
index f037b00..60d3270 100644
--- a/block/bfq-iosched.c
+++ b/block/bfq-iosched.c
@@ -4292,8 +4292,14 @@ static void bfq_put_rq_priv_body(struct bfq_queue *bfqq)
static void bfq_finish_request(struct request *rq)
{
- struct bfq_queue *bfqq = RQ_BFQQ(rq);
- struct bfq_data *bfqd = bfqq->bfqd;
+ struct bfq_queue *bfqq;
+ struct bfq_data *bfqd;
+
+ if (!rq->elv.icq)
+ return;
+
+ bfqq = RQ_BFQQ(rq);
+ bfqd = bfqq->bfqd;
if (rq->rq_flags & RQF_STARTED)
bfqg_stats_update_completion(bfqq_group(bfqq),
@@ -4394,9 +4400,9 @@ static struct bfq_queue *bfq_get_bfqq_handle_split(struct bfq_data *bfqd,
/*
* Allocate bfq data structures associated with this request.
*/
-static int bfq_get_rq_private(struct request_queue *q, struct request *rq,
- struct bio *bio)
+static void bfq_prepare_request(struct request *rq, struct bio *bio)
{
+ struct request_queue *q = rq->q;
struct bfq_data *bfqd = q->elevator->elevator_data;
struct bfq_io_cq *bic;
const int is_sync = rq_is_sync(rq);
@@ -4405,7 +4411,7 @@ static int bfq_get_rq_private(struct request_queue *q, struct request *rq,
bool split = false;
if (!rq->elv.icq)
- return 1;
+ return;
bic = icq_to_bic(rq->elv.icq);
spin_lock_irq(&bfqd->lock);
@@ -4466,7 +4472,6 @@ static int bfq_get_rq_private(struct request_queue *q, struct request *rq,
bfq_handle_burst(bfqd, bfqq);
spin_unlock_irq(&bfqd->lock);
- return 0;
}
static void bfq_idle_slice_timer_body(struct bfq_queue *bfqq)
@@ -4945,7 +4950,7 @@ static struct elv_fs_entry bfq_attrs[] = {
static struct elevator_type iosched_bfq_mq = {
.ops.mq = {
- .get_rq_priv = bfq_get_rq_private,
+ .prepare_request = bfq_prepare_request,
.finish_request = bfq_finish_request,
.exit_icq = bfq_exit_icq,
.insert_requests = bfq_insert_requests,
