From: Logan Gunthorpe logang@deltatee.com
[ Upstream commit df06047d54276f73782c9d97882b305fca745d3f ]
nvmet_passthru_map_sg() only supports mapping a single BIO, not a chain so the effective maximum transfer should also be limitted by BIO_MAX_PAGES (presently this works out to 1MB).
For PCI passthru devices the max_sectors would typically be more limitting than BIO_MAX_PAGES, but this may not be true for all passthru devices.
Fixes: c1fef73f793b ("nvmet: add passthru code to process commands") Suggested-by: Christoph Hellwig hch@lst.de Signed-off-by: Logan Gunthorpe logang@deltatee.com Cc: Christoph Hellwig hch@lst.de Cc: Sagi Grimberg sagi@grimberg.me Cc: Chaitanya Kulkarni chaitanya.kulkarni@wdc.com Signed-off-by: Christoph Hellwig hch@lst.de Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/nvme/target/passthru.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-)
diff --git a/drivers/nvme/target/passthru.c b/drivers/nvme/target/passthru.c index dacfa7435d0b2..1ab88df3310f6 100644 --- a/drivers/nvme/target/passthru.c +++ b/drivers/nvme/target/passthru.c @@ -26,7 +26,7 @@ static u16 nvmet_passthru_override_id_ctrl(struct nvmet_req *req) struct nvme_ctrl *pctrl = ctrl->subsys->passthru_ctrl; u16 status = NVME_SC_SUCCESS; struct nvme_id_ctrl *id; - u32 max_hw_sectors; + int max_hw_sectors; int page_shift;
id = kzalloc(sizeof(*id), GFP_KERNEL); @@ -48,6 +48,13 @@ static u16 nvmet_passthru_override_id_ctrl(struct nvmet_req *req) max_hw_sectors = min_not_zero(pctrl->max_segments << (PAGE_SHIFT - 9), pctrl->max_hw_sectors);
+ /* + * nvmet_passthru_map_sg is limitted to using a single bio so limit + * the mdts based on BIO_MAX_PAGES as well + */ + max_hw_sectors = min_not_zero(BIO_MAX_PAGES << (PAGE_SHIFT - 9), + max_hw_sectors); + page_shift = NVME_CAP_MPSMIN(ctrl->cap) + 12;
id->mdts = ilog2(max_hw_sectors) + 9 - page_shift;