2 * linux/fs/nfs/callback.c
4 * Copyright (C) 2004 Trond Myklebust
6 * NFSv4 callback handling
9 #include <linux/completion.h>
11 #include <linux/module.h>
12 #include <linux/smp_lock.h>
13 #include <linux/sunrpc/svc.h>
14 #include <linux/sunrpc/svcsock.h>
15 #include <linux/nfs_fs.h>
16 #include <linux/mutex.h>
17 #include <linux/freezer.h>
18 #include <linux/kthread.h>
20 #include <net/inet_sock.h>
26 #define NFSDBG_FACILITY NFSDBG_CALLBACK
28 struct nfs_callback_data
{
30 struct svc_rqst
*rqst
;
31 struct task_struct
*task
;
34 static struct nfs_callback_data nfs_callback_info
;
35 static DEFINE_MUTEX(nfs_callback_mutex
);
36 static struct svc_program nfs4_callback_program
;
38 unsigned int nfs_callback_set_tcpport
;
39 unsigned short nfs_callback_tcpport
;
40 static const int nfs_set_port_min
= 0;
41 static const int nfs_set_port_max
= 65535;
43 static int param_set_port(const char *val
, struct kernel_param
*kp
)
46 int num
= simple_strtol(val
, &endp
, 0);
47 if (endp
== val
|| *endp
|| num
< nfs_set_port_min
|| num
> nfs_set_port_max
)
49 *((int *)kp
->arg
) = num
;
53 module_param_call(callback_tcpport
, param_set_port
, param_get_int
,
54 &nfs_callback_set_tcpport
, 0644);
57 * This is the callback kernel thread.
60 nfs_callback_svc(void *vrqstp
)
63 struct svc_rqst
*rqstp
= vrqstp
;
68 * FIXME: do we really need to run this under the BKL? If so, please
69 * add a comment about what it's intended to protect.
72 while (!kthread_should_stop()) {
74 * Listen for a request on the socket
76 err
= svc_recv(rqstp
, MAX_SCHEDULE_TIMEOUT
);
77 if (err
== -EAGAIN
|| err
== -EINTR
) {
83 printk(KERN_WARNING
"%s: unexpected error "
84 "from svc_recv (%d)\n", __func__
, err
);
87 schedule_timeout_uninterruptible(HZ
);
98 * Bring up the callback thread if it is not already up.
100 int nfs_callback_up(void)
102 struct svc_serv
*serv
= NULL
;
105 mutex_lock(&nfs_callback_mutex
);
106 if (nfs_callback_info
.users
++ || nfs_callback_info
.task
!= NULL
)
108 serv
= svc_create(&nfs4_callback_program
, NFS4_CALLBACK_BUFSIZE
,
114 ret
= svc_create_xprt(serv
, "tcp", nfs_callback_set_tcpport
,
118 nfs_callback_tcpport
= ret
;
119 dprintk("Callback port = 0x%x\n", nfs_callback_tcpport
);
121 nfs_callback_info
.rqst
= svc_prepare_thread(serv
, &serv
->sv_pools
[0]);
122 if (IS_ERR(nfs_callback_info
.rqst
)) {
123 ret
= PTR_ERR(nfs_callback_info
.rqst
);
124 nfs_callback_info
.rqst
= NULL
;
128 svc_sock_update_bufs(serv
);
130 nfs_callback_info
.task
= kthread_run(nfs_callback_svc
,
131 nfs_callback_info
.rqst
,
133 if (IS_ERR(nfs_callback_info
.task
)) {
134 ret
= PTR_ERR(nfs_callback_info
.task
);
135 svc_exit_thread(nfs_callback_info
.rqst
);
136 nfs_callback_info
.rqst
= NULL
;
137 nfs_callback_info
.task
= NULL
;
142 * svc_create creates the svc_serv with sv_nrthreads == 1, and then
143 * svc_prepare_thread increments that. So we need to call svc_destroy
144 * on both success and failure so that the refcount is 1 when the
149 mutex_unlock(&nfs_callback_mutex
);
152 dprintk("Couldn't create callback socket or server thread; err = %d\n",
154 nfs_callback_info
.users
--;
159 * Kill the callback thread if it's no longer being used.
161 void nfs_callback_down(void)
163 mutex_lock(&nfs_callback_mutex
);
164 nfs_callback_info
.users
--;
165 if (nfs_callback_info
.users
== 0 && nfs_callback_info
.task
!= NULL
) {
166 kthread_stop(nfs_callback_info
.task
);
167 svc_exit_thread(nfs_callback_info
.rqst
);
168 nfs_callback_info
.rqst
= NULL
;
169 nfs_callback_info
.task
= NULL
;
171 mutex_unlock(&nfs_callback_mutex
);
174 static int nfs_callback_authenticate(struct svc_rqst
*rqstp
)
176 struct nfs_client
*clp
;
177 RPC_IFDEBUG(char buf
[RPC_MAX_ADDRBUFLEN
]);
179 /* Don't talk to strangers */
180 clp
= nfs_find_client(svc_addr(rqstp
), 4);
184 dprintk("%s: %s NFSv4 callback!\n", __func__
,
185 svc_print_addr(rqstp
, buf
, sizeof(buf
)));
188 switch (rqstp
->rq_authop
->flavour
) {
190 if (rqstp
->rq_proc
!= CB_NULL
)
196 /* FIXME: RPCSEC_GSS handling? */
204 * Define NFS4 callback program
206 static struct svc_version
*nfs4_callback_version
[] = {
207 [1] = &nfs4_callback_version1
,
210 static struct svc_stat nfs4_callback_stats
;
212 static struct svc_program nfs4_callback_program
= {
213 .pg_prog
= NFS4_CALLBACK
, /* RPC service number */
214 .pg_nvers
= ARRAY_SIZE(nfs4_callback_version
), /* Number of entries */
215 .pg_vers
= nfs4_callback_version
, /* version table */
216 .pg_name
= "NFSv4 callback", /* service name */
217 .pg_class
= "nfs", /* authentication class */
218 .pg_stats
= &nfs4_callback_stats
,
219 .pg_authenticate
= nfs_callback_authenticate
,