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: 955b1b5a00 ("nvme-pci: move use_sgl initialization to nvme_init_iod()")
Reported-by: Paul Menzel <pmenzel+linux-nvme@molgen.mpg.de>
Reviewed-by: Paul Menzel <pmenzel+linux-nvme@molgen.mpg.de>
Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Keith Busch 2018-01-17 22:04:37 +01:00 committed by Jens Axboe
parent 32835a0741
commit 20469a37ae

View file

@ -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;