[PATCH 1/2] RDMA/srp: don't set a max_segment_size when virt_boundary_mask is set

[Christoph Hellwig <hch@lst.de>]

virt_boundary_mask implies an unlimited max_segment_size.  Setting both
can lead to data corruption because __blk_rq_map_sg() can split requests
so that the virt_boundary_mask is not respected if max_segment_size is
not UINT_MAX.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
---
 drivers/infiniband/ulp/srp/ib_srp.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/infiniband/ulp/srp/ib_srp.c b/drivers/infiniband/ulp/srp/ib_srp.c
index 1378651735f6..23ed2fc688f0 100644
--- a/drivers/infiniband/ulp/srp/ib_srp.c
+++ b/drivers/infiniband/ulp/srp/ib_srp.c
@@ -3705,9 +3705,10 @@ static ssize_t add_target_store(struct device *dev,
 	target_host->max_id      = 1;
 	target_host->max_lun     = -1LL;
 	target_host->max_cmd_len = sizeof ((struct srp_cmd *) (void *) 0L)->cdb;
-	target_host->max_segment_size = ib_dma_max_seg_size(ibdev);
 
-	if (!(ibdev->attrs.kernel_cap_flags & IBK_SG_GAPS_REG))
+	if (ibdev->attrs.kernel_cap_flags & IBK_SG_GAPS_REG)
+		target_host->max_segment_size = ib_dma_max_seg_size(ibdev);
+	else
 		target_host->virt_boundary_mask = ~srp_dev->mr_page_mask;
 
 	target = host_to_target(target_host);
-- 
2.47.2