Branch data Line data Source code
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 : 0 : nfs4_renew_state(struct work_struct *work)
56 : : {
57 : : const struct nfs4_state_maintenance_ops *ops;
58 : 0 : 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 : 0 : ops = clp->cl_mvops->state_renewal_ops;
66 : : dprintk("%s: start\n", __func__);
67 : :
68 [ # # ]: 0 : if (test_bit(NFS_CS_STOP_RENEW, &clp->cl_res_state))
69 : : goto out;
70 : :
71 : : spin_lock(&clp->cl_lock);
72 : 0 : lease = clp->cl_lease_time;
73 : 0 : last = clp->cl_last_renewal;
74 : 0 : now = jiffies;
75 : : /* Are we close to a lease timeout? */
76 [ # # ]: 0 : if (time_after(now, last + lease/3))
77 : : renew_flags |= NFS4_RENEW_TIMEOUT;
78 [ # # ]: 0 : if (nfs_delegations_present(clp))
79 : 0 : renew_flags |= NFS4_RENEW_DELEGATION_CB;
80 : :
81 [ # # ]: 0 : if (renew_flags != 0) {
82 : 0 : cred = ops->get_state_renewal_cred_locked(clp);
83 : : spin_unlock(&clp->cl_lock);
84 [ # # ]: 0 : if (cred == NULL) {
85 [ # # ]: 0 : if (!(renew_flags & NFS4_RENEW_DELEGATION_CB)) {
86 : 0 : set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
87 : 0 : goto out;
88 : : }
89 : 0 : nfs_expire_all_delegations(clp);
90 : : } else {
91 : : /* Queue an asynchronous RENEW. */
92 : 0 : ops->sched_state_renewal(clp, cred, renew_flags);
93 : 0 : put_rpccred(cred);
94 : 0 : goto out_exp;
95 : : }
96 : : } else {
97 : : dprintk("%s: failed to call renewd. Reason: lease not expired \n",
98 : : __func__);
99 : : spin_unlock(&clp->cl_lock);
100 : : }
101 : 0 : nfs4_schedule_state_renewal(clp);
102 : : out_exp:
103 : 0 : nfs_expire_unreferenced_delegations(clp);
104 : : out:
105 : : dprintk("%s: done\n", __func__);
106 : 0 : }
107 : :
108 : : void
109 : 0 : nfs4_schedule_state_renewal(struct nfs_client *clp)
110 : : {
111 : : long timeout;
112 : :
113 : : spin_lock(&clp->cl_lock);
114 : 0 : timeout = (2 * clp->cl_lease_time) / 3 + (long)clp->cl_last_renewal
115 : 0 : - (long)jiffies;
116 [ # # ]: 0 : if (timeout < 5 * HZ)
117 : : timeout = 5 * HZ;
118 : : dprintk("%s: requeueing work. Lease period = %ld\n",
119 : : __func__, (timeout + HZ - 1) / HZ);
120 : 0 : mod_delayed_work(system_wq, &clp->cl_renewd, timeout);
121 : 0 : set_bit(NFS_CS_RENEWD, &clp->cl_res_state);
122 : : spin_unlock(&clp->cl_lock);
123 : 0 : }
124 : :
125 : : void
126 : 0 : nfs4_kill_renewd(struct nfs_client *clp)
127 : : {
128 : 0 : cancel_delayed_work_sync(&clp->cl_renewd);
129 : 0 : }
130 : :
131 : : /*
132 : : * Local variables:
133 : : * c-basic-offset: 8
134 : : * End:
135 : : */
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