1 files changed, 6 insertions, 3 deletions

diff --git a/net/sunrpc/xdr.c b/net/sunrpc/xdr.c
index 75edcfad6e26..1504bb11e4f3 100644
--- a/net/sunrpc/xdr.c
+++ b/net/sunrpc/xdr.c
@@ -207,10 +207,13 @@ _shift_data_right_pages(struct page **pages, size_t pgto_base,
                 pgfrom_base -= copy;
 
                 vto = kmap_atomic(*pgto);
-                vfrom = kmap_atomic(*pgfrom);
-                memmove(vto + pgto_base, vfrom + pgfrom_base, copy);
+                if (*pgto != *pgfrom) {
+                        vfrom = kmap_atomic(*pgfrom);
+                        memcpy(vto + pgto_base, vfrom + pgfrom_base, copy);
+                        kunmap_atomic(vfrom);
+                } else
+                        memmove(vto + pgto_base, vto + pgfrom_base, copy);
                 flush_dcache_page(*pgto);
-                kunmap_atomic(vfrom);
                 kunmap_atomic(vto);
 
         } while ((len -= copy) != 0);