staging: msm/lcdc.c: Convert IS_ERR result to PTR_ERR
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / fs / nfs / nfs4renewd.c
blob402143d75fc5c598da1efee03478a2ea1a3726f2
1 /*
2 * fs/nfs/nfs4renewd.c
4 * Copyright (c) 2002 The Regents of the University of Michigan.
5 * All rights reserved.
7 * Kendrick Smith <kmsmith@umich.edu>
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
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.
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.
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.
41 #include <linux/mm.h>
42 #include <linux/pagemap.h>
43 #include <linux/sunrpc/sched.h>
44 #include <linux/sunrpc/clnt.h>
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"
52 #define NFSDBG_FACILITY NFSDBG_PROC
54 void
55 nfs4_renew_state(struct work_struct *work)
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;
64 ops = clp->cl_mvops->state_renewal_ops;
65 dprintk("%s: start\n", __func__);
67 rcu_read_lock();
68 if (list_empty(&clp->cl_superblocks)) {
69 rcu_read_unlock();
70 goto out;
72 rcu_read_unlock();
74 spin_lock(&clp->cl_lock);
75 lease = clp->cl_lease_time;
76 last = clp->cl_last_renewal;
77 now = jiffies;
78 /* Are we close to a lease timeout? */
79 if (time_after(now, last + lease/3)) {
80 cred = ops->get_state_renewal_cred_locked(clp);
81 spin_unlock(&clp->cl_lock);
82 if (cred == NULL) {
83 if (!nfs_delegations_present(clp)) {
84 set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
85 goto out;
87 nfs_expire_all_delegations(clp);
88 } else {
89 /* Queue an asynchronous RENEW. */
90 ops->sched_state_renewal(clp, cred);
91 put_rpccred(cred);
92 goto out_exp;
94 } else {
95 dprintk("%s: failed to call renewd. Reason: lease not expired \n",
96 __func__);
97 spin_unlock(&clp->cl_lock);
99 nfs4_schedule_state_renewal(clp);
100 out_exp:
101 nfs_expire_unreferenced_delegations(clp);
102 out:
103 dprintk("%s: done\n", __func__);
106 void
107 nfs4_schedule_state_renewal(struct nfs_client *clp)
109 long timeout;
111 spin_lock(&clp->cl_lock);
112 timeout = (2 * clp->cl_lease_time) / 3 + (long)clp->cl_last_renewal
113 - (long)jiffies;
114 if (timeout < 5 * HZ)
115 timeout = 5 * HZ;
116 dprintk("%s: requeueing work. Lease period = %ld\n",
117 __func__, (timeout + HZ - 1) / HZ);
118 cancel_delayed_work(&clp->cl_renewd);
119 schedule_delayed_work(&clp->cl_renewd, timeout);
120 set_bit(NFS_CS_RENEWD, &clp->cl_res_state);
121 spin_unlock(&clp->cl_lock);
124 void
125 nfs4_kill_renewd(struct nfs_client *clp)
127 cancel_delayed_work_sync(&clp->cl_renewd);
131 * Local variables:
132 * c-basic-offset: 8
133 * End: