nfs4state.c

 * returns NFS4ERR_LEASE_MOVED.
 */
static int nfs4_handle_lease_moved(struct nfs_client *clp)
{
	const struct nfs4_state_maintenance_ops *ops =
				clp->cl_mvops->state_renewal_ops;
	struct nfs_server *server;
	struct rpc_cred *cred;

	dprintk("%s: lease moved reported on \"%s\"\n", __func__,
			clp->cl_hostname);

	spin_lock(&clp->cl_lock);
	cred = ops->get_state_renewal_cred_locked(clp);
	spin_unlock(&clp->cl_lock);
	if (cred == NULL)
		return -NFS4ERR_NOENT;

	clp->cl_mig_gen++;
restart:
	rcu_read_lock();
	list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
		struct inode *inode;
		int status;

		if (server->mig_gen == clp->cl_mig_gen)
			continue;
		server->mig_gen = clp->cl_mig_gen;

		rcu_read_unlock();

		inode = server->super->s_root->d_inode;
		status = nfs4_proc_fsid_present(inode, cred);
		if (status != -NFS4ERR_MOVED)
			goto restart;	/* wasn't this one */
		if (nfs4_try_migration(server, cred) == -NFS4ERR_LEASE_MOVED)
			goto restart;	/* there are more */
		goto out;
	}
	rcu_read_unlock();

out:
	put_rpccred(cred);
	return 0;
}

/**
 * nfs4_discover_server_trunking - Detect server IP address trunking
 *
 * @clp: nfs_client under test
 * @result: OUT: found nfs_client, or clp
 *
 * Returns zero or a negative errno.  If zero is returned,
 * an nfs_client pointer is planted in "result".
 *
 * Note: since we are invoked in process context, and
 * not from inside the state manager, we cannot use
 * nfs4_handle_reclaim_lease_error().
 */
int nfs4_discover_server_trunking(struct nfs_client *clp,
				  struct nfs_client **result)
{
	const struct nfs4_state_recovery_ops *ops =
				clp->cl_mvops->reboot_recovery_ops;
	struct rpc_clnt *clnt;
	struct rpc_cred *cred;
	int i, status;

	dprintk("NFS: %s: testing '%s'\n", __func__, clp->cl_hostname);

	clnt = clp->cl_rpcclient;
	i = 0;

	mutex_lock(&nfs_clid_init_mutex);
again:
	status  = -ENOENT;
	cred = nfs4_get_clid_cred(clp);
	if (cred == NULL)
		goto out_unlock;

	status = ops->detect_trunking(clp, result, cred);
	put_rpccred(cred);
	switch (status) {
	case 0:
		break;
	case -NFS4ERR_DELAY:
	case -ETIMEDOUT:
	case -EAGAIN:
		ssleep(1);
	case -NFS4ERR_STALE_CLIENTID:
		dprintk("NFS: %s after status %d, retrying\n",
			__func__, status);
		goto again;
	case -EACCES:
		if (i++ == 0) {
			nfs4_root_machine_cred(clp);
			goto again;
		}
		if (clnt->cl_auth->au_flavor == RPC_AUTH_UNIX)
			break;
	case -NFS4ERR_CLID_INUSE:
	case -NFS4ERR_WRONGSEC:
		/* No point in retrying if we already used RPC_AUTH_UNIX */
		if (clnt->cl_auth->au_flavor == RPC_AUTH_UNIX) {
			status = -EPERM;
			break;
		}
		clnt = rpc_clone_client_set_auth(clnt, RPC_AUTH_UNIX);
		if (IS_ERR(clnt)) {
			status = PTR_ERR(clnt);
			break;
		}
		/* Note: this is safe because we haven't yet marked the
		 * client as ready, so we are the only user of
		 * clp->cl_rpcclient
		 */
		clnt = xchg(&clp->cl_rpcclient, clnt);
		rpc_shutdown_client(clnt);
		clnt = clp->cl_rpcclient;
		goto again;

	case -NFS4ERR_MINOR_VERS_MISMATCH:
		status = -EPROTONOSUPPORT;
		break;

	case -EKEYEXPIRED:
	case -NFS4ERR_NOT_SAME: /* FixMe: implement recovery
				 * in nfs4_exchange_id */
		status = -EKEYEXPIRED;
		break;
	default:
		pr_warn("NFS: %s unhandled error %d. Exiting with error EIO\n",
				__func__, status);
		status = -EIO;
	}

out_unlock:
	mutex_unlock(&nfs_clid_init_mutex);
	dprintk("NFS: %s: status = %d\n", __func__, status);
	return status;
}

#ifdef CONFIG_NFS_V4_1
void nfs4_schedule_session_recovery(struct nfs4_session *session, int err)
{
	struct nfs_client *clp = session->clp;

	switch (err) {
	default:
		set_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state);
		break;
	case -NFS4ERR_CONN_NOT_BOUND_TO_SESSION:
		set_bit(NFS4CLNT_BIND_CONN_TO_SESSION, &clp->cl_state);
	}
	nfs4_schedule_lease_recovery(clp);
}
EXPORT_SYMBOL_GPL(nfs4_schedule_session_recovery);

static void nfs41_ping_server(struct nfs_client *clp)
{
	/* Use CHECK_LEASE to ping the server with a SEQUENCE */
	set_bit(NFS4CLNT_CHECK_LEASE, &clp->cl_state);
	nfs4_schedule_state_manager(clp);
}

void nfs41_server_notify_target_slotid_update(struct nfs_client *clp)
{
	nfs41_ping_server(clp);
}

void nfs41_server_notify_highest_slotid_update(struct nfs_client *clp)
{
	nfs41_ping_server(clp);
}

static void nfs4_reset_all_state(struct nfs_client *clp)
{
	if (test_and_set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state) == 0) {
		set_bit(NFS4CLNT_PURGE_STATE, &clp->cl_state);
		clear_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
		nfs4_state_start_reclaim_nograce(clp);
		dprintk("%s: scheduling reset of all state for server %s!\n",
				__func__, clp->cl_hostname);
		nfs4_schedule_state_manager(clp);
	}
}

static void nfs41_handle_server_reboot(struct nfs_client *clp)
{
	if (test_and_set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state) == 0) {
		nfs4_state_start_reclaim_reboot(clp);
		dprintk("%s: server %s rebooted!\n", __func__,
				clp->cl_hostname);
		nfs4_schedule_state_manager(clp);
	}
}

static void nfs41_handle_state_revoked(struct nfs_client *clp)
{
	nfs4_reset_all_state(clp);
	dprintk("%s: state revoked on server %s\n", __func__, clp->cl_hostname);
}

static void nfs41_handle_recallable_state_revoked(struct nfs_client *clp)
{
	/* This will need to handle layouts too */
	nfs_expire_all_delegations(clp);
	dprintk("%s: Recallable state revoked on server %s!\n", __func__,
			clp->cl_hostname);
}

static void nfs41_handle_backchannel_fault(struct nfs_client *clp)
{
	nfs_expire_all_delegations(clp);
	if (test_and_set_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state) == 0)
		nfs4_schedule_state_manager(clp);
	dprintk("%s: server %s declared a backchannel fault\n", __func__,
			clp->cl_hostname);
}

static void nfs41_handle_cb_path_down(struct nfs_client *clp)
{
	if (test_and_set_bit(NFS4CLNT_BIND_CONN_TO_SESSION,
		&clp->cl_state) == 0)
		nfs4_schedule_state_manager(clp);
}

void nfs41_handle_sequence_flag_errors(struct nfs_client *clp, u32 flags)
{
	if (!flags)
		return;

	dprintk("%s: \"%s\" (client ID %llx) flags=0x%08x\n",
		__func__, clp->cl_hostname, clp->cl_clientid, flags);

	if (flags & SEQ4_STATUS_RESTART_RECLAIM_NEEDED)
		nfs41_handle_server_reboot(clp);
	if (flags & (SEQ4_STATUS_EXPIRED_ALL_STATE_REVOKED |
			    SEQ4_STATUS_EXPIRED_SOME_STATE_REVOKED |
			    SEQ4_STATUS_ADMIN_STATE_REVOKED))
		nfs41_handle_state_revoked(clp);
	if (flags & SEQ4_STATUS_LEASE_MOVED)
		nfs4_schedule_lease_moved_recovery(clp);
	if (flags & SEQ4_STATUS_RECALLABLE_STATE_REVOKED)
		nfs41_handle_recallable_state_revoked(clp);
	if (flags & SEQ4_STATUS_BACKCHANNEL_FAULT)
		nfs41_handle_backchannel_fault(clp);
	else if (flags & (SEQ4_STATUS_CB_PATH_DOWN |
				SEQ4_STATUS_CB_PATH_DOWN_SESSION))
		nfs41_handle_cb_path_down(clp);
}

static int nfs4_reset_session(struct nfs_client *clp)
{
	struct rpc_cred *cred;
	int status;

	if (!nfs4_has_session(clp))
		return 0;
	nfs4_begin_drain_session(clp);
	cred = nfs4_get_clid_cred(clp);
	status = nfs4_proc_destroy_session(clp->cl_session, cred);
	switch (status) {
	case 0:
	case -NFS4ERR_BADSESSION:
	case -NFS4ERR_DEADSESSION:
		break;
	case -NFS4ERR_BACK_CHAN_BUSY:
	case -NFS4ERR_DELAY:
		set_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state);
		status = 0;
		ssleep(1);
		goto out;
	default:
		status = nfs4_recovery_handle_error(clp, status);
		goto out;
	}

	memset(clp->cl_session->sess_id.data, 0, NFS4_MAX_SESSIONID_LEN);
	status = nfs4_proc_create_session(clp, cred);
	if (status) {
		dprintk("%s: session reset failed with status %d for server %s!\n",
			__func__, status, clp->cl_hostname);
		status = nfs4_handle_reclaim_lease_error(clp, status);
		goto out;
	}
	nfs41_finish_session_reset(clp);
	dprintk("%s: session reset was successful for server %s!\n",
			__func__, clp->cl_hostname);
out:
	if (cred)
		put_rpccred(cred);
	return status;
}

static int nfs4_bind_conn_to_session(struct nfs_client *clp)
{
	struct rpc_cred *cred;
	int ret;

	if (!nfs4_has_session(clp))
		return 0;
	nfs4_begin_drain_session(clp);
	cred = nfs4_get_clid_cred(clp);
	ret = nfs4_proc_bind_conn_to_session(clp, cred);
	if (cred)
		put_rpccred(cred);
	clear_bit(NFS4CLNT_BIND_CONN_TO_SESSION, &clp->cl_state);
	switch (ret) {
	case 0:
		dprintk("%s: bind_conn_to_session was successful for server %s!\n",
			__func__, clp->cl_hostname);
		break;
	case -NFS4ERR_DELAY:
		ssleep(1);
		set_bit(NFS4CLNT_BIND_CONN_TO_SESSION, &clp->cl_state);
		break;
	default:
		return nfs4_recovery_handle_error(clp, ret);
	}
	return 0;
}
#else /* CONFIG_NFS_V4_1 */
static int nfs4_reset_session(struct nfs_client *clp) { return 0; }

static int nfs4_bind_conn_to_session(struct nfs_client *clp)
{
	return 0;
}
#endif /* CONFIG_NFS_V4_1 */

static void nfs4_state_manager(struct nfs_client *clp)
{
	int status = 0;
	const char *section = "", *section_sep = "";

	/* Ensure exclusive access to NFSv4 state */
	do {
		if (test_bit(NFS4CLNT_PURGE_STATE, &clp->cl_state)) {
			section = "purge state";
			status = nfs4_purge_lease(clp);
			if (status < 0)
				goto out_error;
			continue;
		}

		if (test_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state)) {
			section = "lease expired";
			/* We're going to have to re-establish a clientid */
			status = nfs4_reclaim_lease(clp);
			if (status < 0)
				goto out_error;
			continue;
		}

		/* Initialize or reset the session */
		if (test_and_clear_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state)) {
			section = "reset session";
			status = nfs4_reset_session(clp);
			if (test_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state))
				continue;
			if (status < 0)
				goto out_error;
		}

		/* Send BIND_CONN_TO_SESSION */
		if (test_and_clear_bit(NFS4CLNT_BIND_CONN_TO_SESSION,
				&clp->cl_state)) {
			section = "bind conn to session";
			status = nfs4_bind_conn_to_session(clp);
			if (status < 0)
				goto out_error;
			continue;
		}

		if (test_and_clear_bit(NFS4CLNT_CHECK_LEASE, &clp->cl_state)) {
			section = "check lease";
			status = nfs4_check_lease(clp);
			if (status < 0)
				goto out_error;
		}

		if (test_and_clear_bit(NFS4CLNT_MOVED, &clp->cl_state)) {
			section = "migration";
			status = nfs4_handle_migration(clp);
			if (status < 0)
				goto out_error;
		}

		if (test_and_clear_bit(NFS4CLNT_LEASE_MOVED, &clp->cl_state)) {
			section = "lease moved";
			status = nfs4_handle_lease_moved(clp);
			if (status < 0)
				goto out_error;
		}

		/* First recover reboot state... */
		if (test_bit(NFS4CLNT_RECLAIM_REBOOT, &clp->cl_state)) {
			section = "reclaim reboot";
			status = nfs4_do_reclaim(clp,
				clp->cl_mvops->reboot_recovery_ops);
			if (test_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state) ||
			    test_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state))
				continue;
			nfs4_state_end_reclaim_reboot(clp);
			if (test_bit(NFS4CLNT_RECLAIM_NOGRACE, &clp->cl_state))
				continue;
			if (status < 0)
				goto out_error;
		}

		/* Now recover expired state... */
		if (test_and_clear_bit(NFS4CLNT_RECLAIM_NOGRACE, &clp->cl_state)) {
			section = "reclaim nograce";
			status = nfs4_do_reclaim(clp,
				clp->cl_mvops->nograce_recovery_ops);
			if (test_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state) ||
			    test_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state) ||
			    test_bit(NFS4CLNT_RECLAIM_REBOOT, &clp->cl_state))
				continue;
			if (status < 0)
				goto out_error;
		}

		nfs4_end_drain_session(clp);
		if (test_and_clear_bit(NFS4CLNT_DELEGRETURN, &clp->cl_state)) {
			nfs_client_return_marked_delegations(clp);
			continue;
		}

		nfs4_clear_state_manager_bit(clp);
		/* Did we race with an attempt to give us more work? */
		if (clp->cl_state == 0)
			break;
		if (test_and_set_bit(NFS4CLNT_MANAGER_RUNNING, &clp->cl_state) != 0)
			break;
	} while (atomic_read(&clp->cl_count) > 1);
	return;
out_error:
	if (strlen(section))
		section_sep = ": ";
	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);
	nfs4_end_drain_session(clp);
	nfs4_clear_state_manager_bit(clp);
}

static int nfs4_run_state_manager(void *ptr)
{
	struct nfs_client *clp = ptr;

	allow_signal(SIGKILL);
	nfs4_state_manager(clp);
	nfs_put_client(clp);
	module_put_and_exit(0);
	return 0;
}

/*
 * Local variables:
 *  c-basic-offset: 8
 * End:
 */