blob: a3001628ad32dff1ffce1b4174bec53031710e95 [file] [log] [blame]
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"
Linus Torvalds1da177e2005-04-16 15:20:36 -070057
58#define NFSDBG_FACILITY NFSDBG_PROC
59
60void
61nfs4_renew_state(void *data)
62{
63 struct nfs4_client *clp = (struct nfs4_client *)data;
64 long lease, timeout;
65 unsigned long last, now;
66
67 down_read(&clp->cl_sem);
68 dprintk("%s: start\n", __FUNCTION__);
69 /* Are there any active superblocks? */
70 if (list_empty(&clp->cl_superblocks))
71 goto out;
72 spin_lock(&clp->cl_lock);
73 lease = clp->cl_lease_time;
74 last = clp->cl_last_renewal;
75 now = jiffies;
76 timeout = (2 * lease) / 3 + (long)last - (long)now;
77 /* Are we close to a lease timeout? */
78 if (time_after(now, last + lease/3)) {
79 spin_unlock(&clp->cl_lock);
80 /* Queue an asynchronous RENEW. */
81 nfs4_proc_async_renew(clp);
82 timeout = (2 * lease) / 3;
83 spin_lock(&clp->cl_lock);
84 } else
85 dprintk("%s: failed to call renewd. Reason: lease not expired \n",
86 __FUNCTION__);
87 if (timeout < 5 * HZ) /* safeguard */
88 timeout = 5 * HZ;
89 dprintk("%s: requeueing work. Lease period = %ld\n",
90 __FUNCTION__, (timeout + HZ - 1) / HZ);
91 cancel_delayed_work(&clp->cl_renewd);
92 schedule_delayed_work(&clp->cl_renewd, timeout);
93 spin_unlock(&clp->cl_lock);
94out:
95 up_read(&clp->cl_sem);
96 dprintk("%s: done\n", __FUNCTION__);
97}
98
99/* Must be called with clp->cl_sem locked for writes */
100void
101nfs4_schedule_state_renewal(struct nfs4_client *clp)
102{
103 long timeout;
104
105 spin_lock(&clp->cl_lock);
106 timeout = (2 * clp->cl_lease_time) / 3 + (long)clp->cl_last_renewal
107 - (long)jiffies;
108 if (timeout < 5 * HZ)
109 timeout = 5 * HZ;
110 dprintk("%s: requeueing work. Lease period = %ld\n",
111 __FUNCTION__, (timeout + HZ - 1) / HZ);
112 cancel_delayed_work(&clp->cl_renewd);
113 schedule_delayed_work(&clp->cl_renewd, timeout);
114 spin_unlock(&clp->cl_lock);
115}
116
117void
118nfs4_renewd_prepare_shutdown(struct nfs_server *server)
119{
120 struct nfs4_client *clp = server->nfs4_state;
121
122 if (!clp)
123 return;
124 flush_scheduled_work();
125 down_write(&clp->cl_sem);
126 if (!list_empty(&server->nfs4_siblings))
127 list_del_init(&server->nfs4_siblings);
128 up_write(&clp->cl_sem);
129}
130
131/* Must be called with clp->cl_sem locked for writes */
132void
133nfs4_kill_renewd(struct nfs4_client *clp)
134{
135 down_read(&clp->cl_sem);
136 if (!list_empty(&clp->cl_superblocks)) {
137 up_read(&clp->cl_sem);
138 return;
139 }
140 cancel_delayed_work(&clp->cl_renewd);
141 up_read(&clp->cl_sem);
142 flush_scheduled_work();
143}
144
145/*
146 * Local variables:
147 * c-basic-offset: 8
148 * End:
149 */