block: move the remaining elv.icq handling to the I/O scheduler

After the prepare side has been moved to the only I/O scheduler that
cares, do the same for the cleanup and the NULL initialization.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20211126115817.2087431-9-hch@lst.deSigned-off-by: Jens Axboe <axboe@kernel.dk>

block/bfq-iosched.c

@@ -6569,6 +6569,16 @@ static void bfq_finish_requeue_request(struct request *rq)
 	rq->elv.priv[1] = NULL;
 }
 
+static void bfq_finish_request(struct request *rq)
+{
+	bfq_finish_requeue_request(rq);
+
+	if (rq->elv.icq) {
+		put_io_context(rq->elv.icq->ioc);
+		rq->elv.icq = NULL;
+	}
+}
+
 /*
  * Removes the association between the current task and bfqq, assuming
  * that bic points to the bfq iocontext of the task.
@@ -7388,7 +7398,7 @@ static struct elevator_type iosched_bfq_mq = {
 		.limit_depth		= bfq_limit_depth,
 		.prepare_request	= bfq_prepare_request,
 		.requeue_request        = bfq_finish_requeue_request,
-		.finish_request		= bfq_finish_requeue_request,
+		.finish_request		= bfq_finish_request,
 		.exit_icq		= bfq_exit_icq,
 		.insert_requests	= bfq_insert_requests,
 		.dispatch_request	= bfq_dispatch_request,

block/blk-ioc.c

@@ -167,6 +167,7 @@ void put_io_context(struct io_context *ioc)
 	if (free_ioc)
 		kmem_cache_free(iocontext_cachep, ioc);
 }
+EXPORT_SYMBOL_GPL(put_io_context);
 
 /**
  * put_io_context_active - put active reference on ioc

block/blk-mq.c

@@ -400,7 +400,6 @@ static struct request *blk_mq_rq_ctx_init(struct blk_mq_alloc_data *data,
 	if (rq->rq_flags & RQF_ELV) {
 		struct elevator_queue *e = data->q->elevator;
 
-		rq->elv.icq = NULL;
 		INIT_HLIST_NODE(&rq->hash);
 		RB_CLEAR_NODE(&rq->rb_node);
 
@@ -631,16 +630,9 @@ void blk_mq_free_request(struct request *rq)
 	struct request_queue *q = rq->q;
 	struct blk_mq_hw_ctx *hctx = rq->mq_hctx;
 
-	if (rq->rq_flags & RQF_ELVPRIV) {
-		struct elevator_queue *e = q->elevator;
-
-		if (e->type->ops.finish_request)
-			e->type->ops.finish_request(rq);
-		if (rq->elv.icq) {
-			put_io_context(rq->elv.icq->ioc);
-			rq->elv.icq = NULL;
-		}
-	}
+	if ((rq->rq_flags & RQF_ELVPRIV) &&
+	    q->elevator->type->ops.finish_request)
+		q->elevator->type->ops.finish_request(rq);
 
 	if (rq->rq_flags & RQF_MQ_INFLIGHT)
 		__blk_mq_dec_active_requests(hctx);