From c005390374957baacbc38eef96ea360559510aa7 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Thu, 17 Aug 2017 12:24:47 +0200 Subject: [PATCH] blk-mq-pci: add a fallback when pci_irq_get_affinity returns NULL While pci_irq_get_affinity should never fail for SMP kernel that implement the affinity mapping, it will always return NULL in the UP case, so provide a fallback mapping of all queues to CPU 0 in that case. Signed-off-by: Christoph Hellwig Cc: stable@vger.kernel.org Reviewed-by: Omar Sandoval Signed-off-by: Jens Axboe --- block/blk-mq-pci.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/block/blk-mq-pci.c b/block/blk-mq-pci.c index 0c3354cf3552..76944e3271bf 100644 --- a/block/blk-mq-pci.c +++ b/block/blk-mq-pci.c @@ -36,12 +36,18 @@ int blk_mq_pci_map_queues(struct blk_mq_tag_set *set, struct pci_dev *pdev) for (queue = 0; queue < set->nr_hw_queues; queue++) { mask = pci_irq_get_affinity(pdev, queue); if (!mask) - return -EINVAL; + goto fallback; for_each_cpu(cpu, mask) set->mq_map[cpu] = queue; } return 0; + +fallback: + WARN_ON_ONCE(set->nr_hw_queues > 1); + for_each_possible_cpu(cpu) + set->mq_map[cpu] = 0; + return 0; } EXPORT_SYMBOL_GPL(blk_mq_pci_map_queues); -- 2.20.1