diff --git a/fs/nfs/client.c b/fs/nfs/client.c
index 17ba6b9..f005b5b 100644
--- a/fs/nfs/client.c
+++ b/fs/nfs/client.c
@@ -207,7 +207,6 @@
 static void nfs4_shutdown_session(struct nfs_client *clp)
 {
 	if (nfs4_has_session(clp)) {
-		nfs4_deviceid_purge_client(clp);
 		nfs4_destroy_session(clp->cl_session);
 		nfs4_destroy_clientid(clp);
 	}
diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c
index b8323aa..bdf7e52 100644
--- a/fs/nfs/pnfs.c
+++ b/fs/nfs/pnfs.c
@@ -80,6 +80,9 @@
 	if (nfss->pnfs_curr_ld) {
 		if (nfss->pnfs_curr_ld->clear_layoutdriver)
 			nfss->pnfs_curr_ld->clear_layoutdriver(nfss);
+		/* Decrement the MDS count. Purge the deviceid cache if zero */
+		if (atomic_dec_and_test(&nfss->nfs_client->cl_mds_count))
+			nfs4_deviceid_purge_client(nfss->nfs_client);
 		module_put(nfss->pnfs_curr_ld->owner);
 	}
 	nfss->pnfs_curr_ld = NULL;
@@ -127,6 +130,8 @@
 		module_put(ld_type->owner);
 		goto out_no_driver;
 	}
+	/* Bump the MDS count */
+	atomic_inc(&server->nfs_client->cl_mds_count);
 
 	dprintk("%s: pNFS module for %u set\n", __func__, id);
 	return;
diff --git a/include/linux/nfs_fs_sb.h b/include/linux/nfs_fs_sb.h
index fbb78fb..f58325a 100644
--- a/include/linux/nfs_fs_sb.h
+++ b/include/linux/nfs_fs_sb.h
@@ -25,6 +25,7 @@
  */
 struct nfs_client {
 	atomic_t		cl_count;
+	atomic_t		cl_mds_count;
 	int			cl_cons_state;	/* current construction state (-ve: init error) */
 #define NFS_CS_READY		0		/* ready to be used */
 #define NFS_CS_INITING		1		/* busy initialising */