aboutsummaryrefslogtreecommitdiff
path: root/fs/nfs/nfs4renewd.c
blob: 82e77198d17efdf656315f39c3d50c4d9aa568a9 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
/*
 *  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.
 *
 */

#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_STATE

void
nfs4_renew_state(struct work_struct *work)
{
	const struct nfs4_state_maintenance_ops *ops;
	struct nfs_client *clp =
		container_of(work, struct nfs_client, cl_renewd.work);
	struct rpc_cred *cred;
	long lease;
	unsigned long last, now;
	unsigned renew_flags = 0;

	ops = clp->cl_mvops->state_renewal_ops;
	dprintk("%s: start\n", __func__);

	if (test_bit(NFS_CS_STOP_RENEW, &clp->cl_res_state))
		goto out;

	spin_lock(&clp->cl_lock);
	lease = clp->cl_lease_time;
	last = clp->cl_last_renewal;
	now = jiffies;
	/* Are we close to a lease timeout? */
	if (time_after(now, last + lease/3))
		renew_flags |= NFS4_RENEW_TIMEOUT;
	if (nfs_delegations_present(clp))
		renew_flags |= NFS4_RENEW_DELEGATION_CB;

	if (renew_flags != 0) {
		cred = ops->get_state_renewal_cred_locked(clp);
		spin_unlock(&clp->cl_lock);
		if (cred == NULL) {
			if (!(renew_flags & NFS4_RENEW_DELEGATION_CB)) {
				set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
				goto out;
			}
			nfs_expire_all_delegations(clp);
		} else {
			int ret;

			/* Queue an asynchronous RENEW. */
			ret = ops->sched_state_renewal(clp, cred, renew_flags);
			put_rpccred(cred);
			switch (ret) {
			default:
				goto out_exp;
			case -EAGAIN:
			case -ENOMEM:
				break;
			}
		}
	} else {
		dprintk("%s: failed to call renewd. Reason: lease not expired \n",
				__func__);
		spin_unlock(&clp->cl_lock);
	}
	nfs4_schedule_state_renewal(clp);
out_exp:
	nfs_expire_unreferenced_delegations(clp);
out:
	dprintk("%s: done\n", __func__);
}

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",
			__func__, (timeout + HZ - 1) / HZ);
	mod_delayed_work(system_wq, &clp->cl_renewd, timeout);
	set_bit(NFS_CS_RENEWD, &clp->cl_res_state);
	spin_unlock(&clp->cl_lock);
}

void
nfs4_kill_renewd(struct nfs_client *clp)
{
	cancel_delayed_work_sync(&clp->cl_renewd);
}

/**
 * nfs4_set_lease_period - Sets the lease period on a nfs_client
 *
 * @clp: pointer to nfs_client
 * @lease: new value for lease period
 * @lastrenewed: time at which lease was last renewed
 */
void nfs4_set_lease_period(struct nfs_client *clp,
		unsigned long lease,
		unsigned long lastrenewed)
{
	spin_lock(&clp->cl_lock);
	clp->cl_lease_time = lease;
	clp->cl_last_renewal = lastrenewed;
	spin_unlock(&clp->cl_lock);

	/* Cap maximum reconnect timeout at 1/2 lease period */
	rpc_cap_max_reconnect_timeout(clp->cl_rpcclient, lease >> 1);
}

/*
 * Local variables:
 *   c-basic-offset: 8
 * End:
 */