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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * fs/nfs/nfs4renewd.c
3 *
4 * Copyright (c) 2002 The Regents of the University of Michigan.
5 * All rights reserved.
6 *
7 * Kendrick Smith <kmsmith@umich.edu>
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 *
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 * 3. Neither the name of the University nor the names of its
19 * contributors may be used to endorse or promote products derived
20 * from this software without specific prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
23 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
24 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
25 * DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
27 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
28 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
29 * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
30 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
31 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
32 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
33 *
34 * Implementation of the NFSv4 "renew daemon", which wakes up periodically to
35 * send a RENEW, to keep state alive on the server. The daemon is implemented
36 * as an rpc_task, not a real kernel thread, so it always runs in rpciod's
37 * context. There is one renewd per nfs_server.
38 *
39 * TODO: If the send queue gets backlogged (e.g., if the server goes down),
40 * we will keep filling the queue with periodic RENEW requests. We need a
41 * mechanism for ensuring that if renewd successfully sends off a request,
42 * then it only wakes up when the request is finished. Maybe use the
43 * child task framework of the RPC layer?
44 */
45
46#include <linux/sched.h>
47#include <linux/smp_lock.h>
48#include <linux/mm.h>
49#include <linux/pagemap.h>
50#include <linux/sunrpc/sched.h>
51#include <linux/sunrpc/clnt.h>
52
53#include <linux/nfs.h>
54#include <linux/nfs4.h>
55#include <linux/nfs_fs.h>
Trond Myklebust4ce79712005-06-22 17:16:21 +000056#include "nfs4_fs.h"
Trond Myklebust58d97142006-01-03 09:55:24 +010057#include "delegation.h"
Linus Torvalds1da177e2005-04-16 15:20:36 -070058
59#define NFSDBG_FACILITY NFSDBG_PROC
60
61void
62nfs4_renew_state(void *data)
63{
64 struct nfs4_client *clp = (struct nfs4_client *)data;
Trond Myklebustb4454fe2006-01-03 09:55:25 +010065 struct rpc_cred *cred;
Linus Torvalds1da177e2005-04-16 15:20:36 -070066 long lease, timeout;
67 unsigned long last, now;
68
69 down_read(&clp->cl_sem);
70 dprintk("%s: start\n", __FUNCTION__);
71 /* Are there any active superblocks? */
72 if (list_empty(&clp->cl_superblocks))
Trond Myklebust58d97142006-01-03 09:55:24 +010073 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -070074 spin_lock(&clp->cl_lock);
75 lease = clp->cl_lease_time;
76 last = clp->cl_last_renewal;
77 now = jiffies;
78 timeout = (2 * lease) / 3 + (long)last - (long)now;
79 /* Are we close to a lease timeout? */
80 if (time_after(now, last + lease/3)) {
Trond Myklebustb4454fe2006-01-03 09:55:25 +010081 cred = nfs4_get_renew_cred(clp);
82 if (cred == NULL) {
Trond Myklebust58d97142006-01-03 09:55:24 +010083 set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
84 spin_unlock(&clp->cl_lock);
85 nfs_expire_all_delegations(clp);
86 goto out;
87 }
Linus Torvalds1da177e2005-04-16 15:20:36 -070088 spin_unlock(&clp->cl_lock);
89 /* Queue an asynchronous RENEW. */
Trond Myklebustb4454fe2006-01-03 09:55:25 +010090 nfs4_proc_async_renew(clp, cred);
91 put_rpccred(cred);
Linus Torvalds1da177e2005-04-16 15:20:36 -070092 timeout = (2 * lease) / 3;
93 spin_lock(&clp->cl_lock);
94 } else
95 dprintk("%s: failed to call renewd. Reason: lease not expired \n",
96 __FUNCTION__);
97 if (timeout < 5 * HZ) /* safeguard */
98 timeout = 5 * HZ;
99 dprintk("%s: requeueing work. Lease period = %ld\n",
100 __FUNCTION__, (timeout + HZ - 1) / HZ);
101 cancel_delayed_work(&clp->cl_renewd);
102 schedule_delayed_work(&clp->cl_renewd, timeout);
103 spin_unlock(&clp->cl_lock);
104out:
105 up_read(&clp->cl_sem);
106 dprintk("%s: done\n", __FUNCTION__);
107}
108
109/* Must be called with clp->cl_sem locked for writes */
110void
111nfs4_schedule_state_renewal(struct nfs4_client *clp)
112{
113 long timeout;
114
115 spin_lock(&clp->cl_lock);
116 timeout = (2 * clp->cl_lease_time) / 3 + (long)clp->cl_last_renewal
117 - (long)jiffies;
118 if (timeout < 5 * HZ)
119 timeout = 5 * HZ;
120 dprintk("%s: requeueing work. Lease period = %ld\n",
121 __FUNCTION__, (timeout + HZ - 1) / HZ);
122 cancel_delayed_work(&clp->cl_renewd);
123 schedule_delayed_work(&clp->cl_renewd, timeout);
124 spin_unlock(&clp->cl_lock);
125}
126
127void
128nfs4_renewd_prepare_shutdown(struct nfs_server *server)
129{
130 struct nfs4_client *clp = server->nfs4_state;
131
132 if (!clp)
133 return;
134 flush_scheduled_work();
135 down_write(&clp->cl_sem);
136 if (!list_empty(&server->nfs4_siblings))
137 list_del_init(&server->nfs4_siblings);
138 up_write(&clp->cl_sem);
139}
140
141/* Must be called with clp->cl_sem locked for writes */
142void
143nfs4_kill_renewd(struct nfs4_client *clp)
144{
145 down_read(&clp->cl_sem);
146 if (!list_empty(&clp->cl_superblocks)) {
147 up_read(&clp->cl_sem);
148 return;
149 }
150 cancel_delayed_work(&clp->cl_renewd);
151 up_read(&clp->cl_sem);
152 flush_scheduled_work();
153}
154
155/*
156 * Local variables:
157 * c-basic-offset: 8
158 * End:
159 */