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Diffstat (limited to 'block/blk-mq.c')
-rw-r--r--block/blk-mq.c50
1 files changed, 18 insertions, 32 deletions
diff --git a/block/blk-mq.c b/block/blk-mq.c
index 7e9f7d00452f..c3de03217f4f 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -2506,37 +2506,26 @@ out:
blk_mq_run_hw_queue(hctx, run_queue_async);
}
-static bool blk_mq_sched_bypass_insert(struct blk_mq_hw_ctx *hctx,
- struct request *rq)
-{
- /*
- * dispatch flush and passthrough rq directly
- *
- * passthrough request has to be added to hctx->dispatch directly.
- * For some reason, device may be in one situation which can't
- * handle FS request, so STS_RESOURCE is always returned and the
- * FS request will be added to hctx->dispatch. However passthrough
- * request may be required at that time for fixing the problem. If
- * passthrough request is added to scheduler queue, there isn't any
- * chance to dispatch it given we prioritize requests in hctx->dispatch.
- */
- if ((rq->rq_flags & RQF_FLUSH_SEQ) || blk_rq_is_passthrough(rq))
- return true;
-
- return false;
-}
-
static void blk_mq_insert_request(struct request *rq, bool at_head,
bool run_queue, bool async)
{
struct request_queue *q = rq->q;
- struct elevator_queue *e = q->elevator;
struct blk_mq_ctx *ctx = rq->mq_ctx;
struct blk_mq_hw_ctx *hctx = rq->mq_hctx;
- WARN_ON(e && (rq->tag != BLK_MQ_NO_TAG));
-
- if (blk_mq_sched_bypass_insert(hctx, rq)) {
+ if (blk_rq_is_passthrough(rq)) {
+ /*
+ * Passthrough request have to be added to hctx->dispatch
+ * directly. The device may be in a situation where it can't
+ * handle FS request, and always returns BLK_STS_RESOURCE for
+ * them, which gets them added to hctx->dispatch.
+ *
+ * If a passthrough request is required to unblock the queues,
+ * and it is added to the scheduler queue, there is no chance to
+ * dispatch it given we prioritize requests in hctx->dispatch.
+ */
+ blk_mq_request_bypass_insert(rq, at_head, false);
+ } else if (rq->rq_flags & RQF_FLUSH_SEQ) {
/*
* Firstly normal IO request is inserted to scheduler queue or
* sw queue, meantime we add flush request to dispatch queue(
@@ -2558,16 +2547,14 @@ static void blk_mq_insert_request(struct request *rq, bool at_head,
* Simply queue flush rq to the front of hctx->dispatch so that
* intensive flush workloads can benefit in case of NCQ HW.
*/
- at_head = (rq->rq_flags & RQF_FLUSH_SEQ) ? true : at_head;
- blk_mq_request_bypass_insert(rq, at_head, false);
- goto run;
- }
-
- if (e) {
+ blk_mq_request_bypass_insert(rq, true, false);
+ } else if (q->elevator) {
LIST_HEAD(list);
+ WARN_ON_ONCE(rq->tag != BLK_MQ_NO_TAG);
+
list_add(&rq->queuelist, &list);
- e->type->ops.insert_requests(hctx, &list, at_head);
+ q->elevator->type->ops.insert_requests(hctx, &list, at_head);
} else {
trace_block_rq_insert(rq);
@@ -2581,7 +2568,6 @@ static void blk_mq_insert_request(struct request *rq, bool at_head,
spin_unlock(&ctx->lock);
}
-run:
if (run_queue)
blk_mq_run_hw_queue(hctx, async);
}