GNU Linux-libre 5.10.219-gnu1
[releases.git] / fs / nfs / nfs4renewd.c
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
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
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
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  */
142 void nfs4_set_lease_period(struct nfs_client *clp,
143                 unsigned long lease)
144 {
145         spin_lock(&clp->cl_lock);
146         clp->cl_lease_time = lease;
147         spin_unlock(&clp->cl_lock);
148
149         /* Cap maximum reconnect timeout at 1/2 lease period */
150         rpc_set_connect_timeout(clp->cl_rpcclient, lease, lease >> 1);
151 }
152
153 /*
154  * Local variables:
155  *   c-basic-offset: 8
156  * End:
157  */