/* * fs/nfs/nfs4renewd.c * * Copyright (c) 2002 The Regents of the University of Michigan. * All rights reserved. * * Kendrick Smith <kmsmith@umich.edu> * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of the University nor the names of its * contributors may be used to endorse or promote products derived * from this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE * DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. * * Implementation of the NFSv4 "renew daemon", which wakes up periodically to * send a RENEW, to keep state alive on the server. The daemon is implemented * as an rpc_task, not a real kernel thread, so it always runs in rpciod's * context. There is one renewd per nfs_server. * * TODO: If the send queue gets backlogged (e.g., if the server goes down), * we will keep filling the queue with periodic RENEW requests. We need a * mechanism for ensuring that if renewd successfully sends off a request, * then it only wakes up when the request is finished. Maybe use the * child task framework of the RPC layer? */ #include <linux/sched.h> #include <linux/smp_lock.h> #include <linux/mm.h> #include <linux/pagemap.h> #include <linux/sunrpc/sched.h> #include <linux/sunrpc/clnt.h> #include <linux/nfs.h> #include <linux/nfs4.h> #include <linux/nfs_fs.h> #include "nfs4_fs.h" #include "delegation.h" #define NFSDBG_FACILITY NFSDBG_PROC void nfs4_renew_state(void *data) { struct nfs4_client *clp = (struct nfs4_client *)data; struct rpc_cred *cred; long lease, timeout; unsigned long last, now; down_read(&clp->cl_sem); dprintk("%s: start\n", __FUNCTION__); /* Are there any active superblocks? */ if (list_empty(&clp->cl_superblocks)) goto out; spin_lock(&clp->cl_lock); lease = clp->cl_lease_time; last = clp->cl_last_renewal; now = jiffies; timeout = (2 * lease) / 3 + (long)last - (long)now; /* Are we close to a lease timeout? */ if (time_after(now, last + lease/3)) { cred = nfs4_get_renew_cred(clp); if (cred == NULL) { set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state); spin_unlock(&clp->cl_lock); nfs_expire_all_delegations(clp); goto out; } spin_unlock(&clp->cl_lock); /* Queue an asynchronous RENEW. */ nfs4_proc_async_renew(clp, cred); put_rpccred(cred); timeout = (2 * lease) / 3; spin_lock(&clp->cl_lock); } else dprintk("%s: failed to call renewd. Reason: lease not expired \n", __FUNCTION__); if (timeout < 5 * HZ) /* safeguard */ timeout = 5 * HZ; dprintk("%s: requeueing work. Lease period = %ld\n", __FUNCTION__, (timeout + HZ - 1) / HZ); cancel_delayed_work(&clp->cl_renewd); schedule_delayed_work(&clp->cl_renewd, timeout); spin_unlock(&clp->cl_lock); out: up_read(&clp->cl_sem); dprintk("%s: done\n", __FUNCTION__); } /* Must be called with clp->cl_sem locked for writes */ void nfs4_schedule_state_renewal(struct nfs4_client *clp) { long timeout; spin_lock(&clp->cl_lock); timeout = (2 * clp->cl_lease_time) / 3 + (long)clp->cl_last_renewal - (long)jiffies; if (timeout < 5 * HZ) timeout = 5 * HZ; dprintk("%s: requeueing work. Lease period = %ld\n", __FUNCTION__, (timeout + HZ - 1) / HZ); cancel_delayed_work(&clp->cl_renewd); schedule_delayed_work(&clp->cl_renewd, timeout); spin_unlock(&clp->cl_lock); } void nfs4_renewd_prepare_shutdown(struct nfs_server *server) { struct nfs4_client *clp = server->nfs4_state; if (!clp) return; flush_scheduled_work(); down_write(&clp->cl_sem); if (!list_empty(&server->nfs4_siblings)) list_del_init(&server->nfs4_siblings); up_write(&clp->cl_sem); } /* Must be called with clp->cl_sem locked for writes */ void nfs4_kill_renewd(struct nfs4_client *clp) { down_read(&clp->cl_sem); if (!list_empty(&clp->cl_superblocks)) { up_read(&clp->cl_sem); return; } cancel_delayed_work(&clp->cl_renewd); up_read(&clp->cl_sem); flush_scheduled_work(); } /* * Local variables: * c-basic-offset: 8 * End: */