2 files changed, 18 insertions, 1 deletions

diff --git a/fs/nfs/Kconfig b/fs/nfs/Kconfig
index b5e80b0af315..38c1768b4142 100644
--- a/fs/nfs/Kconfig
+++ b/fs/nfs/Kconfig
@@ -140,6 +140,17 @@ config NFS_V4_1_IMPLEMENTATION_ID_DOMAIN
           If the NFS client is unchanged from the upstream kernel, this
           option should be set to the default "kernel.org".
 
+config NFS_V4_1_MIGRATION
+        bool "NFSv4.1 client support for migration"
+        depends on NFS_V4_1
+        default n
+        help
+          This option makes the NFS client advertise to NFSv4.1 servers that
+          it can support NFSv4 migration.
+
+          The NFSv4.1 pieces of the Linux NFSv4 migration implementation are
+          still experimental.  If you are not an NFSv4 developer, say N here.
+
 config NFS_V4_SECURITY_LABEL
         bool
         depends on NFS_V4_2 && SECURITY
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 8aa8ff3fd5e7..1463c71b0862 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -6596,8 +6596,14 @@ static int _nfs4_proc_exchange_id(struct nfs_client *clp, struct rpc_cred *cred,
         struct nfs41_exchange_id_args args = {
                 .verifier = &verifier,
                 .client = clp,
+#ifdef CONFIG_NFS_V4_1_MIGRATION
                 .flags = EXCHGID4_FLAG_SUPP_MOVED_REFER |
-                        EXCHGID4_FLAG_BIND_PRINC_STATEID,
+                         EXCHGID4_FLAG_BIND_PRINC_STATEID |
+                         EXCHGID4_FLAG_SUPP_MOVED_MIGR,
+#else
+                .flags = EXCHGID4_FLAG_SUPP_MOVED_REFER |
+                         EXCHGID4_FLAG_BIND_PRINC_STATEID,
+#endif
         };
         struct nfs41_exchange_id_res res = {
                 0