>From 7e849dd9cf37 ("nvme-pci: don't share queue maps"), the mapping table won't be initialized actually if map->nr_queues is zero, so we can't use blk_mq_map_queue_type() to retrieve hctx any more. This way still may cause broken mapping, fix it by skipping zero-queues maps in blk_mq_map_swqueue(). Cc: Jeff Moyer <jmoyer@xxxxxxxxxx> Cc: Mike Snitzer <snitzer@xxxxxxxxxx> Cc: Christoph Hellwig <hch@xxxxxx> Signed-off-by: Ming Lei <ming.lei@xxxxxxxxxx> --- block/blk-mq.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/block/blk-mq.c b/block/blk-mq.c index 17de117be019..8075b16c5228 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -2433,6 +2433,9 @@ static void blk_mq_map_swqueue(struct request_queue *q) ctx = per_cpu_ptr(q->queue_ctx, i); for (j = 0; j < set->nr_maps; j++) { + if (!set->map[j].nr_queues) + continue; + hctx = blk_mq_map_queue_type(q, j, i); /* -- 2.9.5