scsi: RDMA/srp: Don't set a max_segment_size when virt_boundary_mask is set

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>
Link: https://lore.kernel.org/r/20250624125233.219635-2-hch@lst.de
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: John Garry <john.g.garry@oracle.com>
Acked-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

diff --git a/drivers/infiniband/ulp/srp/ib_srp.c b/drivers/infiniband/ulp/srp/ib_srp.c
index 1378651735f6a3917d6d0ecc8033d6b44f9c2fa4..23ed2fc688f0b398bb63856aa6a604a4ff1e2c41 100644 (file)
--- 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);