NFSv4/pNFS: Handle server reboots in pnfs_poc_release()

If the server reboots, then handle it by deferring the layout return.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

fs/nfs/pnfs.c

@@ -1586,8 +1586,7 @@ int pnfs_roc_done(struct rpc_task *task, struct nfs4_layoutreturn_args **argpp,
 }
 
 void pnfs_roc_release(struct nfs4_layoutreturn_args *args,
-		struct nfs4_layoutreturn_res *res,
-		int ret)
+		      struct nfs4_layoutreturn_res *res, int ret)
 {
 	struct pnfs_layout_hdr *lo = args->layout;
 	struct inode *inode = args->inode;
@@ -1595,6 +1594,9 @@ void pnfs_roc_release(struct nfs4_layoutreturn_args *args,
 	struct nfs4_xdr_opaque_data *ld_private = args->ld_private;
 
 	switch (ret) {
+	case -NFS4ERR_BADSESSION:
+	case -NFS4ERR_DEADSESSION:
+	case -NFS4ERR_CONN_NOT_BOUND_TO_SESSION:
 	case -NFS4ERR_NOMATCHING_LAYOUT:
 		spin_lock(&inode->i_lock);
 		pnfs_layoutreturn_retry_later_locked(lo, &args->stateid,