From 5aceaeb26394538858a9dbae5830d628469a44cf Mon Sep 17 00:00:00 2001
From: Christoph Hellwig <hch@lst.de>
Date: Mon, 17 Dec 2018 12:16:26 +0100
Subject: [PATCH] blk-mq: only dispatch to non-defauly queue maps if they have
queues
We should check if a given queue map actually has queues enabled before
dispatching to it. This allows drivers to not initialize optional but
not used map types, which subsequently will allow fixing problems with
queue map rebuilds for that case.
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
---
block/blk-mq.h | 13 ++++++++-----
1 file changed, 8 insertions(+), 5 deletions(-)
diff --git a/block/blk-mq.h b/block/blk-mq.h
index b63a0de8a07a3..d1ed096723fb0 100644
--- a/block/blk-mq.h
+++ b/block/blk-mq.h
@@ -105,14 +105,17 @@ static inline struct blk_mq_hw_ctx *blk_mq_map_queue(struct request_queue *q,
{
enum hctx_type type = HCTX_TYPE_DEFAULT;
- if (q->tag_set->nr_maps > HCTX_TYPE_POLL &&
- ((flags & REQ_HIPRI) && test_bit(QUEUE_FLAG_POLL, &q->queue_flags)))
+ if ((flags & REQ_HIPRI) &&
+ q->tag_set->nr_maps > HCTX_TYPE_POLL &&
+ q->tag_set->map[HCTX_TYPE_POLL].nr_queues &&
+ test_bit(QUEUE_FLAG_POLL, &q->queue_flags))
type = HCTX_TYPE_POLL;
- else if (q->tag_set->nr_maps > HCTX_TYPE_READ &&
- ((flags & REQ_OP_MASK) == REQ_OP_READ))
+ else if (((flags & REQ_OP_MASK) == REQ_OP_READ) &&
+ q->tag_set->nr_maps > HCTX_TYPE_READ &&
+ q->tag_set->map[HCTX_TYPE_READ].nr_queues)
type = HCTX_TYPE_READ;
-
+
return blk_mq_map_queue_type(q, type, cpu);
}
--
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