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;
44 * If the kernel has IPv6 support available, always listen for
45 * both AF_INET and AF_INET6 requests.
47 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
48 static const sa_family_t nfs_callback_family
= AF_INET6
;
50 static const sa_family_t nfs_callback_family
= AF_INET
;
53 static int param_set_port(const char *val
, struct kernel_param
*kp
)
56 int num
= simple_strtol(val
, &endp
, 0);
57 if (endp
== val
|| *endp
|| num
< nfs_set_port_min
|| num
> nfs_set_port_max
)
59 *((int *)kp
->arg
) = num
;
63 module_param_call(callback_tcpport
, param_set_port
, param_get_int
,
64 &nfs_callback_set_tcpport
, 0644);
67 * This is the callback kernel thread.
70 nfs_callback_svc(void *vrqstp
)
73 struct svc_rqst
*rqstp
= vrqstp
;
78 * FIXME: do we really need to run this under the BKL? If so, please
79 * add a comment about what it's intended to protect.
82 while (!kthread_should_stop()) {
84 * Listen for a request on the socket
86 err
= svc_recv(rqstp
, MAX_SCHEDULE_TIMEOUT
);
87 if (err
== -EAGAIN
|| err
== -EINTR
) {
93 printk(KERN_WARNING
"%s: unexpected error "
94 "from svc_recv (%d)\n", __func__
, err
);
97 schedule_timeout_uninterruptible(HZ
);
108 * Bring up the callback thread if it is not already up.
110 int nfs_callback_up(void)
112 struct svc_serv
*serv
= NULL
;
115 mutex_lock(&nfs_callback_mutex
);
116 if (nfs_callback_info
.users
++ || nfs_callback_info
.task
!= NULL
)
118 serv
= svc_create(&nfs4_callback_program
, NFS4_CALLBACK_BUFSIZE
,
119 nfs_callback_family
, NULL
);
124 ret
= svc_create_xprt(serv
, "tcp", nfs_callback_set_tcpport
,
128 nfs_callback_tcpport
= ret
;
129 dprintk("NFS: Callback listener port = %u (af %u)\n",
130 nfs_callback_tcpport
, nfs_callback_family
);
132 nfs_callback_info
.rqst
= svc_prepare_thread(serv
, &serv
->sv_pools
[0]);
133 if (IS_ERR(nfs_callback_info
.rqst
)) {
134 ret
= PTR_ERR(nfs_callback_info
.rqst
);
135 nfs_callback_info
.rqst
= NULL
;
139 svc_sock_update_bufs(serv
);
141 nfs_callback_info
.task
= kthread_run(nfs_callback_svc
,
142 nfs_callback_info
.rqst
,
144 if (IS_ERR(nfs_callback_info
.task
)) {
145 ret
= PTR_ERR(nfs_callback_info
.task
);
146 svc_exit_thread(nfs_callback_info
.rqst
);
147 nfs_callback_info
.rqst
= NULL
;
148 nfs_callback_info
.task
= NULL
;
153 * svc_create creates the svc_serv with sv_nrthreads == 1, and then
154 * svc_prepare_thread increments that. So we need to call svc_destroy
155 * on both success and failure so that the refcount is 1 when the
160 mutex_unlock(&nfs_callback_mutex
);
163 dprintk("NFS: Couldn't create callback socket or server thread; "
165 nfs_callback_info
.users
--;
170 * Kill the callback thread if it's no longer being used.
172 void nfs_callback_down(void)
174 mutex_lock(&nfs_callback_mutex
);
175 nfs_callback_info
.users
--;
176 if (nfs_callback_info
.users
== 0 && nfs_callback_info
.task
!= NULL
) {
177 kthread_stop(nfs_callback_info
.task
);
178 svc_exit_thread(nfs_callback_info
.rqst
);
179 nfs_callback_info
.rqst
= NULL
;
180 nfs_callback_info
.task
= NULL
;
182 mutex_unlock(&nfs_callback_mutex
);
185 static int nfs_callback_authenticate(struct svc_rqst
*rqstp
)
187 struct nfs_client
*clp
;
188 RPC_IFDEBUG(char buf
[RPC_MAX_ADDRBUFLEN
]);
190 /* Don't talk to strangers */
191 clp
= nfs_find_client(svc_addr(rqstp
), 4);
195 dprintk("%s: %s NFSv4 callback!\n", __func__
,
196 svc_print_addr(rqstp
, buf
, sizeof(buf
)));
199 switch (rqstp
->rq_authop
->flavour
) {
201 if (rqstp
->rq_proc
!= CB_NULL
)
207 /* FIXME: RPCSEC_GSS handling? */
215 * Define NFS4 callback program
217 static struct svc_version
*nfs4_callback_version
[] = {
218 [1] = &nfs4_callback_version1
,
221 static struct svc_stat nfs4_callback_stats
;
223 static struct svc_program nfs4_callback_program
= {
224 .pg_prog
= NFS4_CALLBACK
, /* RPC service number */
225 .pg_nvers
= ARRAY_SIZE(nfs4_callback_version
), /* Number of entries */
226 .pg_vers
= nfs4_callback_version
, /* version table */
227 .pg_name
= "NFSv4 callback", /* service name */
228 .pg_class
= "nfs", /* authentication class */
229 .pg_stats
= &nfs4_callback_stats
,
230 .pg_authenticate
= nfs_callback_authenticate
,