On 8/24/21 2:35 PM, Niklas Cassel wrote:
> Reviewed-by: Niklas Cassel <niklas.cassel@xxxxxxx>
> Tested-by: Niklas Cassel <niklas.cassel@xxxxxxx>
Hi Niklas,
Thank you for the help, that's really appreciated. Earlier today I discovered
that this patch does not handle requeuing correctly so I have started testing
the patch below.
---
block/mq-deadline.c | 19 ++++++++++++++-----
1 file changed, 14 insertions(+), 5 deletions(-)
diff --git a/block/mq-deadline.c b/block/mq-deadline.c
index dbd74bae9f11..c4c3c2e3f446 100644
--- a/block/mq-deadline.c
+++ b/block/mq-deadline.c
@@ -712,7 +712,10 @@ static void dd_insert_request(struct blk_mq_hw_ctx *hctx, struct request *rq,
blk_req_zone_write_unlock(rq);
prio = ioprio_class_to_prio[ioprio_class];
- dd_count(dd, inserted, prio);
+ if (!rq->elv.priv[0]) {
+ dd_count(dd, inserted, prio);
+ rq->elv.priv[0] = (void *)(uintptr_t)1;
+ }
if (blk_mq_sched_try_insert_merge(q, rq, &free)) {
blk_mq_free_requests(&free);
@@ -761,12 +764,10 @@ static void dd_insert_requests(struct blk_mq_hw_ctx *hctx,
spin_unlock(&dd->lock);
}
-/*
- * Nothing to do here. This is defined only to ensure that .finish_request
- * method is called upon request completion.
- */
+/* Callback from inside blk_mq_rq_ctx_init(). */
static void dd_prepare_request(struct request *rq)
{
+ rq->elv.priv[0] = NULL;
}
/*
@@ -793,6 +794,14 @@ static void dd_finish_request(struct request *rq)
const enum dd_prio prio = ioprio_class_to_prio[ioprio_class];
struct dd_per_prio *per_prio = &dd->per_prio[prio];
+ /*
+ * The block layer core may call dd_finish_request() without having
+ * called dd_insert_requests(). Skip requests that bypassed I/O
+ * scheduling. See also blk_mq_request_bypass_insert().
+ */
+ if (!rq->elv.priv[0])
+ return;
+
dd_count(dd, completed, prio);
if (blk_queue_is_zoned(q)) {
