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 struct rpc_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 spin_lock(&clp->cl_lock);
72 lease = clp->cl_lease_time;
73 last = clp->cl_last_renewal;
74 now = jiffies;
75 /* Are we close to a lease timeout? */
76 if (time_after(now, last + lease/3))
77 renew_flags |= NFS4_RENEW_TIMEOUT;
78 if (nfs_delegations_present(clp))
79 renew_flags |= NFS4_RENEW_DELEGATION_CB;
80
81 if (renew_flags != 0) {
82 cred = ops->get_state_renewal_cred_locked(clp);
83 spin_unlock(&clp->cl_lock);
84 if (cred == NULL) {
85 if (!(renew_flags & NFS4_RENEW_DELEGATION_CB)) {
86 set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
87 goto out;
88 }
89 nfs_expire_all_delegations(clp);
90 } else {
91 int ret;
92
93 /* Queue an asynchronous RENEW. */
94 ret = ops->sched_state_renewal(clp, cred, renew_flags);
95 put_rpccred(cred);
96 switch (ret) {
97 default:
98 goto out_exp;
99 case -EAGAIN:
100 case -ENOMEM:
101 break;
102 }
103 }
104 } else {
105 dprintk("%s: failed to call renewd. Reason: lease not expired \n",
106 __func__);
107 spin_unlock(&clp->cl_lock);
108 }
109 nfs4_schedule_state_renewal(clp);
110 out_exp:
111 nfs_expire_unreferenced_delegations(clp);
112 out:
113 dprintk("%s: done\n", __func__);
114 }
115
116 void
nfs4_schedule_state_renewal(struct nfs_client * clp)117 nfs4_schedule_state_renewal(struct nfs_client *clp)
118 {
119 long timeout;
120
121 spin_lock(&clp->cl_lock);
122 timeout = (2 * clp->cl_lease_time) / 3 + (long)clp->cl_last_renewal
123 - (long)jiffies;
124 if (timeout < 5 * HZ)
125 timeout = 5 * HZ;
126 dprintk("%s: requeueing work. Lease period = %ld\n",
127 __func__, (timeout + HZ - 1) / HZ);
128 mod_delayed_work(system_wq, &clp->cl_renewd, timeout);
129 set_bit(NFS_CS_RENEWD, &clp->cl_res_state);
130 spin_unlock(&clp->cl_lock);
131 }
132
133 void
nfs4_kill_renewd(struct nfs_client * clp)134 nfs4_kill_renewd(struct nfs_client *clp)
135 {
136 cancel_delayed_work_sync(&clp->cl_renewd);
137 }
138
139 /**
140 * nfs4_set_lease_period - Sets the lease period on a nfs_client
141 *
142 * @clp: pointer to nfs_client
143 * @lease: new value for lease period
144 * @lastrenewed: time at which lease was last renewed
145 */
nfs4_set_lease_period(struct nfs_client * clp,unsigned long lease,unsigned long lastrenewed)146 void nfs4_set_lease_period(struct nfs_client *clp,
147 unsigned long lease,
148 unsigned long lastrenewed)
149 {
150 spin_lock(&clp->cl_lock);
151 clp->cl_lease_time = lease;
152 clp->cl_last_renewal = lastrenewed;
153 spin_unlock(&clp->cl_lock);
154
155 /* Cap maximum reconnect timeout at 1/2 lease period */
156 rpc_set_connect_timeout(clp->cl_rpcclient, lease, lease >> 1);
157 }
158
159 /*
160 * Local variables:
161 * c-basic-offset: 8
162 * End:
163 */
164