Commit c0053903 authored Aug 17, 2017 by Christoph Hellwig Committed by Jens Axboe Aug 18, 2017

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 <hch@lst.de>
Cc: stable@vger.kernel.org
Reviewed-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

parent 6caa0503

block/blk-mq-pci.c

+7 −1

Original line number	Diff line number	Diff line
		@@ -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);