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 <bart.vanassche@xxxxxxxxxxx>
Cc: Christoph Hellwig <hch@xxxxxx>
Cc: Hannes Reinecke <hare@xxxxxxxx>
Cc: Omar Sandoval <osandov@xxxxxx>
Cc: Ming Lei <ming.lei@xxxxxxxxxx>
---
block/blk-mq.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)
diff --git a/block/blk-mq.c b/block/blk-mq.c
index b56cb3d9060f..12a627743842 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -1091,8 +1091,9 @@ 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)))
+ WARN_ON_ONCE(!blk_mq_hw_queue_mapped(hctx));
+
+ if (unlikely(blk_mq_hctx_stopped(hctx)))
return;
if (!async && !(hctx->flags & BLK_MQ_F_BLOCKING)) {
@@ -1252,7 +1253,7 @@ 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;
/*
--
2.12.2
