| /* |
| * 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 nfs_client *clp = (struct nfs_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 nfs_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) |
| { |
| flush_scheduled_work(); |
| } |
| |
| void |
| nfs4_kill_renewd(struct nfs_client *clp) |
| { |
| down_read(&clp->cl_sem); |
| cancel_delayed_work(&clp->cl_renewd); |
| up_read(&clp->cl_sem); |
| flush_scheduled_work(); |
| } |
| |
| /* |
| * Local variables: |
| * c-basic-offset: 8 |
| * End: |
| */ |