From 5435c023b92ee1cfb896d924d28c6d31d8386aa0 Mon Sep 17 00:00:00 2001 From: Bart Van Assche Date: Tue, 20 Jun 2017 11:15:49 -0700 Subject: [PATCH] blk-mq: Warn when attempting to run a hardware queue that is not mapped A queue must be frozen while the mapped state of a hardware queue is changed. Additionally, any change of the mapped state is followed by a call to blk_mq_map_swqueue() (see also blk_mq_init_allocated_queue() and blk_mq_update_nr_hw_queues()). Since blk_mq_map_swqueue() does not map any unmapped hardware queue onto any software queue, no attempt will be made to run an unmapped hardware queue. Hence issue a warning upon attempts to run an unmapped hardware queue. Signed-off-by: Bart Van Assche Reviewed-by: Christoph Hellwig Cc: Hannes Reinecke Cc: Omar Sandoval Cc: Ming Lei Signed-off-by: Jens Axboe --- block/blk-mq.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/block/blk-mq.c b/block/blk-mq.c index 1d8050e49a94..1c4f1f4978c6 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -1129,8 +1129,10 @@ static int blk_mq_hctx_next_cpu(struct blk_mq_hw_ctx *hctx) static void __blk_mq_delay_run_hw_queue(struct blk_mq_hw_ctx *hctx, bool async, unsigned long msecs) { - if (unlikely(blk_mq_hctx_stopped(hctx) || - !blk_mq_hw_queue_mapped(hctx))) + if (WARN_ON_ONCE(!blk_mq_hw_queue_mapped(hctx))) + return; + + if (unlikely(blk_mq_hctx_stopped(hctx))) return; if (!async && !(hctx->flags & BLK_MQ_F_BLOCKING)) { @@ -1295,7 +1297,7 @@ static void blk_mq_run_work_fn(struct work_struct *work) void blk_mq_delay_queue(struct blk_mq_hw_ctx *hctx, unsigned long msecs) { - if (unlikely(!blk_mq_hw_queue_mapped(hctx))) + if (WARN_ON_ONCE(!blk_mq_hw_queue_mapped(hctx))) return; /* -- 2.39.2