[PATCH] knfsd: nfsd4: simplify lease changing

/* Globals */

static time_t lease_time = 90;     /* default lease time */

static time_t old_lease_time = 90; /* past incarnation lease time */

static time_t user_lease_time = 90;

static u32 nfs4_reclaim_init = 0;

time_t boot_time;

static time_t grace_end = 0;

	INIT_LIST_HEAD(&del_recall_lru);

	spin_lock_init(&recall_lock);

	boot_time = get_seconds();

	grace_time = max(old_lease_time, lease_time);

	if (reclaim_str_hashtbl_size == 0)

		grace_time = 0;

	if (grace_time)

	grace_time = max(user_lease_time, lease_time);

	lease_time = user_lease_time;

	printk("NFSD: starting %ld-second grace period\n", grace_time);

	grace_end = boot_time + grace_time;

	INIT_WORK(&laundromat_work,laundromat_main, NULL);

/*

 * Called when leasetime is changed.

 *

 * if nfsd is not started, simply set the global lease.

 *

 * if nfsd(s) are running, lease change requires nfsv4 state to be reset.

 * e.g: boot_time is reset, existing nfs4_client structs are

 * used to fill reclaim_str_hashtbl, then all state (except for the

 * reclaim_str_hashtbl) is re-initialized.

 *

 * if the old lease time is greater than the new lease time, the grace

 * period needs to be set to the old lease time to allow clients to reclaim

 * their state. XXX - we may want to set the grace period == lease time

 * after an initial grace period == old lease time

 *

 * if an error occurs in this process, the new lease is set, but the server

 * will not honor OPEN or LOCK reclaims, and will return nfserr_no_grace

 * which means OPEN/LOCK/READ/WRITE will fail during grace period.

 *

 * clients will attempt to reset all state with SETCLIENTID/CONFIRM, and

 * OPEN and LOCK reclaims.

 * The only way the protocol gives us to handle on-the-fly lease changes is to

 * simulate a reboot.  Instead of doing that, we just wait till the next time

 * we start to register any changes in lease time.  If the administrator

 * really wants to change the lease time *now*, they can go ahead and bring

 * nfsd down and then back up again after changing the lease time.

 */

void

nfs4_reset_lease(time_t leasetime)

{

	struct nfs4_client *clp;

	int i;

	printk("NFSD: New leasetime %ld\n",leasetime);

	if (!nfs4_init)

		return;

	nfs4_lock_state();

	old_lease_time = lease_time;

	lease_time = leasetime;

	nfs4_release_reclaim();

	/* populate reclaim_str_hashtbl with current confirmed nfs4_clientid */

	for (i = 0; i < CLIENT_HASH_SIZE; i++) {

		list_for_each_entry(clp, &conf_id_hashtbl[i], cl_idhash) {

			if (!nfs4_client_to_reclaim(clp->cl_name.data,

						clp->cl_name.len)) {

				nfs4_release_reclaim();

				goto init_state;

			}

		}

	}

init_state:

	__nfs4_state_shutdown();

	__nfs4_state_init();

	nfs4_unlock_state();

	lock_kernel();

	user_lease_time = leasetime;

	unlock_kernel();

}