1 /*
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 */
40
41 #include <linux/mm.h>
42 #include <linux/pagemap.h>
43 #include <linux/sunrpc/sched.h>
44 #include <linux/sunrpc/clnt.h>
45
46 #include <linux/nfs.h>
47 #include <linux/nfs4.h>
48 #include <linux/nfs_fs.h>
49 #include "nfs4_fs.h"
50 #include "delegation.h"
51
52 #define NFSDBG_FACILITY NFSDBG_STATE
53
54 void
nfs4_renew_state(struct work_struct * work)55 nfs4_renew_state(struct work_struct *work)
56 {
57 const struct nfs4_state_maintenance_ops *ops;
58 struct nfs_client *clp =
59 container_of(work, struct nfs_client, cl_renewd.work);
60 const struct cred *cred;
61 long lease;
62 unsigned long last, now;
63 unsigned renew_flags = 0;
64
65 ops = clp->cl_mvops->state_renewal_ops;
66 dprintk("%s: start\n", __func__);
67
68 if (test_bit(NFS_CS_STOP_RENEW, &clp->cl_res_state))
69 goto out;
70
71 lease = clp->cl_lease_time;
72 last = clp->cl_last_renewal;
73 now = jiffies;
74 /* Are we close to a lease timeout? */
75 if (time_after(now, last + lease/3))
76 renew_flags |= NFS4_RENEW_TIMEOUT;
77 if (nfs_delegations_present(clp))
78 renew_flags |= NFS4_RENEW_DELEGATION_CB;
79
80 if (renew_flags != 0) {
81 cred = ops->get_state_renewal_cred(clp);
82 if (cred == NULL) {
83 if (!(renew_flags & NFS4_RENEW_DELEGATION_CB)) {
84 set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
85 goto out;
86 }
87 nfs_expire_all_delegations(clp);
88 } else {
89 int ret;
90
91 /* Queue an asynchronous RENEW. */
92 ret = ops->sched_state_renewal(clp, cred, renew_flags);
93 put_cred(cred);
94 switch (ret) {
95 default:
96 goto out_exp;
97 case -EAGAIN:
98 case -ENOMEM:
99 break;
100 }
101 }
102 } else {
103 dprintk("%s: failed to call renewd. Reason: lease not expired \n",
104 __func__);
105 }
106 nfs4_schedule_state_renewal(clp);
107 out_exp:
108 nfs_expire_unreferenced_delegations(clp);
109 out:
110 dprintk("%s: done\n", __func__);
111 }
112
113 void
nfs4_schedule_state_renewal(struct nfs_client * clp)114 nfs4_schedule_state_renewal(struct nfs_client *clp)
115 {
116 long timeout;
117
118 spin_lock(&clp->cl_lock);
119 timeout = (2 * clp->cl_lease_time) / 3 + (long)clp->cl_last_renewal
120 - (long)jiffies;
121 if (timeout < 5 * HZ)
122 timeout = 5 * HZ;
123 dprintk("%s: requeueing work. Lease period = %ld\n",
124 __func__, (timeout + HZ - 1) / HZ);
125 mod_delayed_work(system_wq, &clp->cl_renewd, timeout);
126 set_bit(NFS_CS_RENEWD, &clp->cl_res_state);
127 spin_unlock(&clp->cl_lock);
128 }
129
130 void
nfs4_kill_renewd(struct nfs_client * clp)131 nfs4_kill_renewd(struct nfs_client *clp)
132 {
133 cancel_delayed_work_sync(&clp->cl_renewd);
134 }
135
136 /**
137 * nfs4_set_lease_period - Sets the lease period on a nfs_client
138 *
139 * @clp: pointer to nfs_client
140 * @lease: new value for lease period
141 * @lastrenewed: time at which lease was last renewed
142 */
nfs4_set_lease_period(struct nfs_client * clp,unsigned long lease,unsigned long lastrenewed)143 void nfs4_set_lease_period(struct nfs_client *clp,
144 unsigned long lease,
145 unsigned long lastrenewed)
146 {
147 spin_lock(&clp->cl_lock);
148 clp->cl_lease_time = lease;
149 clp->cl_last_renewal = lastrenewed;
150 spin_unlock(&clp->cl_lock);
151
152 /* Cap maximum reconnect timeout at 1/2 lease period */
153 rpc_set_connect_timeout(clp->cl_rpcclient, lease, lease >> 1);
154 }
155
156 /*
157 * Local variables:
158 * c-basic-offset: 8
159 * End:
160 */
161
