1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
|
/*
* fs/nfs/nfs4renewd.c
*
* Copyright (c) 2002 The Regents of the University of Michigan.
* All rights reserved.
*
* Kendrick Smith <kmsmith@umich.edu>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the University nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
* BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* Implementation of the NFSv4 "renew daemon", which wakes up periodically to
* send a RENEW, to keep state alive on the server. The daemon is implemented
* as an rpc_task, not a real kernel thread, so it always runs in rpciod's
* context. There is one renewd per nfs_server.
*
* TODO: If the send queue gets backlogged (e.g., if the server goes down),
* we will keep filling the queue with periodic RENEW requests. We need a
* mechanism for ensuring that if renewd successfully sends off a request,
* then it only wakes up when the request is finished. Maybe use the
* child task framework of the RPC layer?
*/
#include <linux/mm.h>
#include <linux/pagemap.h>
#include <linux/sunrpc/sched.h>
#include <linux/sunrpc/clnt.h>
#include <linux/nfs.h>
#include <linux/nfs4.h>
#include <linux/nfs_fs.h>
#include "nfs4_fs.h"
#include "delegation.h"
#define NFSDBG_FACILITY NFSDBG_PROC
void
nfs4_renew_state(struct work_struct *work)
{
struct nfs_client *clp =
container_of(work, struct nfs_client, cl_renewd.work);
struct rpc_cred *cred;
long lease, timeout;
unsigned long last, now;
dprintk("%s: start\n", __func__);
/* Are there any active superblocks? */
if (list_empty(&clp->cl_superblocks))
goto out;
spin_lock(&clp->cl_lock);
lease = clp->cl_lease_time;
last = clp->cl_last_renewal;
now = jiffies;
timeout = (2 * lease) / 3 + (long)last - (long)now;
/* Are we close to a lease timeout? */
if (time_after(now, last + lease/3)) {
cred = nfs4_get_renew_cred_locked(clp);
spin_unlock(&clp->cl_lock);
if (cred == NULL) {
if (list_empty(&clp->cl_delegations)) {
set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
goto out;
}
nfs_expire_all_delegations(clp);
} else {
/* Queue an asynchronous RENEW. */
nfs4_proc_async_renew(clp, cred);
put_rpccred(cred);
}
timeout = (2 * lease) / 3;
spin_lock(&clp->cl_lock);
} else
dprintk("%s: failed to call renewd. Reason: lease not expired \n",
__func__);
if (timeout < 5 * HZ) /* safeguard */
timeout = 5 * HZ;
dprintk("%s: requeueing work. Lease period = %ld\n",
__func__, (timeout + HZ - 1) / HZ);
cancel_delayed_work(&clp->cl_renewd);
schedule_delayed_work(&clp->cl_renewd, timeout);
spin_unlock(&clp->cl_lock);
out:
dprintk("%s: done\n", __func__);
}
void
nfs4_schedule_state_renewal(struct nfs_client *clp)
{
long timeout;
spin_lock(&clp->cl_lock);
timeout = (2 * clp->cl_lease_time) / 3 + (long)clp->cl_last_renewal
- (long)jiffies;
if (timeout < 5 * HZ)
timeout = 5 * HZ;
dprintk("%s: requeueing work. Lease period = %ld\n",
__func__, (timeout + HZ - 1) / HZ);
cancel_delayed_work(&clp->cl_renewd);
schedule_delayed_work(&clp->cl_renewd, timeout);
set_bit(NFS_CS_RENEWD, &clp->cl_res_state);
spin_unlock(&clp->cl_lock);
}
void
nfs4_renewd_prepare_shutdown(struct nfs_server *server)
{
cancel_delayed_work(&server->nfs_client->cl_renewd);
}
void
nfs4_kill_renewd(struct nfs_client *clp)
{
cancel_delayed_work_sync(&clp->cl_renewd);
}
/*
* Local variables:
* c-basic-offset: 8
* End:
*/
|
