NFSv4: try lease recovery on NFS4ERR_EXPIRED

Currently, if an nfs server returns NFS4ERR_EXPIRED to open(),
we return EIO to applications without even trying to recover.

Fixes: 272289a3 ("NFSv4: nfs4_do_handle_exception() handle revoke/expiry of a single stateid")
Signed-off-by: Robert Milkowski <rmilkowski@gmail.com>
Reviewed-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

fs/nfs/nfs4proc.c

@@ -3199,6 +3199,11 @@ static struct nfs4_state *nfs4_do_open(struct inode *dir,
 			exception.retry = 1;
 			continue;
 		}
+		if (status == -NFS4ERR_EXPIRED) {
+			nfs4_schedule_lease_recovery(server->nfs_client);
+			exception.retry = 1;
+			continue;
+		}
 		if (status == -EAGAIN) {
 			/* We must have found a delegation */
 			exception.retry = 1;