On 6/6/19 6:29 PM, Sagi Grimberg wrote:
if the rdma device supports sg gaps, we don't need to set a virtual
boundary but we then need to explicitly set the max_segment_size, otherwise
scsi takes BLK_MAX_SEGMENT_SIZE and sets it using dma_set_max_seg_size()
and this affects all the rdma device consumers.
Fix it by setting shost max_segment_size according to the device
capability if SG_GAPS are not supported.
Reported-by: Jason Gunthorpe <jgg@xxxxxxxx>
Suggested-by: Christoph Hellwig <hch@xxxxxx>
Signed-off-by: Sagi Grimberg <sagi@xxxxxxxxxxx>
---
Changes from v1:
- set max_segment_size only for non virtual boundary devices
drivers/infiniband/ulp/iser/iscsi_iser.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/infiniband/ulp/iser/iscsi_iser.c b/drivers/infiniband/ulp/iser/iscsi_iser.c
index 841b66397a57..a3a4b956bbb9 100644
--- a/drivers/infiniband/ulp/iser/iscsi_iser.c
+++ b/drivers/infiniband/ulp/iser/iscsi_iser.c
@@ -653,7 +653,9 @@ iscsi_iser_session_create(struct iscsi_endpoint *ep,
SHOST_DIX_GUARD_CRC);
}
- if (!(ib_dev->attrs.device_cap_flags & IB_DEVICE_SG_GAPS_REG))
+ if (ib_dev->attrs.device_cap_flags & IB_DEVICE_SG_GAPS_REG)
+ shost->max_segment_size = ib_dma_max_seg_size(ib_dev);
+ else
shost->virt_boundary_mask = ~MASK_4K;
if (iscsi_host_add(shost, ib_dev->dev.parent)) {
This is incomprehensible without a big comment that explains why
max_segment_size is only set if the IB_DEVICE_SG_GAPS_REG feature is
available.
Bart.
