target: Don't allocate pages for NULLIO devices

Signed-off-by: Andy Grover <agrover@redhat.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

diff --git a/drivers/target/target_core_rd.c b/drivers/target/target_core_rd.c
index 0921a64..51127d1 100644 (file)
--- a/drivers/target/target_core_rd.c
+++ b/drivers/target/target_core_rd.c
@@ -139,6 +139,11 @@ static int rd_build_device_space(struct rd_dev *rd_dev)
                        rd_dev->rd_page_count);
                return -EINVAL;
        }
+
+       /* Don't need backing pages for NULLIO */
+       if (rd_dev->rd_flags & RDF_NULLIO)
+               return 0;
+
        total_sg_needed = rd_dev->rd_page_count;
 
        sg_tables = (total_sg_needed / max_sg_per_table) + 1;