From 20469a37aed12a886d0deda5a07c04037923144a Mon Sep 17 00:00:00 2001 From: Keith Busch Date: Wed, 17 Jan 2018 22:04:37 +0100 Subject: [PATCH] nvme-pci: check segement valid for SGL use The driver needs to verify there is a payload with a command before seeing if it should use SGLs to map it. Fixes: 955b1b5a00ba ("nvme-pci: move use_sgl initialization to nvme_init_iod()") Reported-by: Paul Menzel Reviewed-by: Paul Menzel Signed-off-by: Keith Busch Signed-off-by: Christoph Hellwig Signed-off-by: Jens Axboe --- drivers/nvme/host/pci.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c index d53550e612bc..a7e94cc3c70e 100644 --- a/drivers/nvme/host/pci.c +++ b/drivers/nvme/host/pci.c @@ -451,10 +451,13 @@ static void **nvme_pci_iod_list(struct request *req) static inline bool nvme_pci_use_sgls(struct nvme_dev *dev, struct request *req) { struct nvme_iod *iod = blk_mq_rq_to_pdu(req); + int nseg = blk_rq_nr_phys_segments(req); unsigned int avg_seg_size; - avg_seg_size = DIV_ROUND_UP(blk_rq_payload_bytes(req), - blk_rq_nr_phys_segments(req)); + if (nseg == 0) + return false; + + avg_seg_size = DIV_ROUND_UP(blk_rq_payload_bytes(req), nseg); if (!(dev->ctrl.sgls & ((1 << 0) | (1 << 1)))) return false; -- 2.39.2