NFSv4: Treat ENETUNREACH errors as fatal for state recovery

If a containerised process is killed and causes an ENETUNREACH or
ENETDOWN error to be propagated to the state manager, then mark the
nfs_client as being dead so that we don't loop in functions that are
expecting recovery to succeed.

Reviewed-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Benjamin Coddington <bcodding@redhat.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

Author: Trond Myklebust

fs/nfs/nfs4state.c

@@ -2739,7 +2739,15 @@ static void nfs4_state_manager(struct nfs_client *clp)
 	pr_warn_ratelimited("NFS: state manager%s%s failed on NFSv4 server %s"
 			" with error %d\n", section_sep, section,
 			clp->cl_hostname, -status);
-	ssleep(1);
+	switch (status) {
+	case -ENETDOWN:
+	case -ENETUNREACH:
+		nfs_mark_client_ready(clp, -EIO);
+		break;
+	default:
+		ssleep(1);
+		break;
+	}
 out_drain:
 	memalloc_nofs_restore(memflags);
 	nfs4_end_drain_session(clp);