[PATCH] sem2mutex: fs/
[linux-2.6.git] / fs / nfs / callback.c
1 /*
2  * linux/fs/nfs/callback.c
3  *
4  * Copyright (C) 2004 Trond Myklebust
5  *
6  * NFSv4 callback handling
7  */
8
9 #include <linux/config.h>
10 #include <linux/completion.h>
11 #include <linux/ip.h>
12 #include <linux/module.h>
13 #include <linux/smp_lock.h>
14 #include <linux/sunrpc/svc.h>
15 #include <linux/sunrpc/svcsock.h>
16 #include <linux/nfs_fs.h>
17 #include <linux/mutex.h>
18
19 #include <net/inet_sock.h>
20
21 #include "nfs4_fs.h"
22 #include "callback.h"
23
24 #define NFSDBG_FACILITY NFSDBG_CALLBACK
25
26 struct nfs_callback_data {
27         unsigned int users;
28         struct svc_serv *serv;
29         pid_t pid;
30         struct completion started;
31         struct completion stopped;
32 };
33
34 static struct nfs_callback_data nfs_callback_info;
35 static DEFINE_MUTEX(nfs_callback_mutex);
36 static struct svc_program nfs4_callback_program;
37
38 unsigned int nfs_callback_set_tcpport;
39 unsigned short nfs_callback_tcpport;
40
41 /*
42  * This is the callback kernel thread.
43  */
44 static void nfs_callback_svc(struct svc_rqst *rqstp)
45 {
46         struct svc_serv *serv = rqstp->rq_server;
47         int err;
48
49         __module_get(THIS_MODULE);
50         lock_kernel();
51
52         nfs_callback_info.pid = current->pid;
53         daemonize("nfsv4-svc");
54         /* Process request with signals blocked, but allow SIGKILL.  */
55         allow_signal(SIGKILL);
56
57         complete(&nfs_callback_info.started);
58
59         for(;;) {
60                 if (signalled()) {
61                         if (nfs_callback_info.users == 0)
62                                 break;
63                         flush_signals(current);
64                 }
65                 /*
66                  * Listen for a request on the socket
67                  */
68                 err = svc_recv(serv, rqstp, MAX_SCHEDULE_TIMEOUT);
69                 if (err == -EAGAIN || err == -EINTR)
70                         continue;
71                 if (err < 0) {
72                         printk(KERN_WARNING
73                                         "%s: terminating on error %d\n",
74                                         __FUNCTION__, -err);
75                         break;
76                 }
77                 dprintk("%s: request from %u.%u.%u.%u\n", __FUNCTION__,
78                                 NIPQUAD(rqstp->rq_addr.sin_addr.s_addr));
79                 svc_process(serv, rqstp);
80         }
81
82         svc_exit_thread(rqstp);
83         nfs_callback_info.pid = 0;
84         complete(&nfs_callback_info.stopped);
85         unlock_kernel();
86         module_put_and_exit(0);
87 }
88
89 /*
90  * Bring up the server process if it is not already up.
91  */
92 int nfs_callback_up(void)
93 {
94         struct svc_serv *serv;
95         struct svc_sock *svsk;
96         int ret = 0;
97
98         lock_kernel();
99         mutex_lock(&nfs_callback_mutex);
100         if (nfs_callback_info.users++ || nfs_callback_info.pid != 0)
101                 goto out;
102         init_completion(&nfs_callback_info.started);
103         init_completion(&nfs_callback_info.stopped);
104         serv = svc_create(&nfs4_callback_program, NFS4_CALLBACK_BUFSIZE);
105         ret = -ENOMEM;
106         if (!serv)
107                 goto out_err;
108         /* FIXME: We don't want to register this socket with the portmapper */
109         ret = svc_makesock(serv, IPPROTO_TCP, nfs_callback_set_tcpport);
110         if (ret < 0)
111                 goto out_destroy;
112         if (!list_empty(&serv->sv_permsocks)) {
113                 svsk = list_entry(serv->sv_permsocks.next,
114                                 struct svc_sock, sk_list);
115                 nfs_callback_tcpport = ntohs(inet_sk(svsk->sk_sk)->sport);
116                 dprintk ("Callback port = 0x%x\n", nfs_callback_tcpport);
117         } else
118                 BUG();
119         ret = svc_create_thread(nfs_callback_svc, serv);
120         if (ret < 0)
121                 goto out_destroy;
122         nfs_callback_info.serv = serv;
123         wait_for_completion(&nfs_callback_info.started);
124 out:
125         mutex_unlock(&nfs_callback_mutex);
126         unlock_kernel();
127         return ret;
128 out_destroy:
129         svc_destroy(serv);
130 out_err:
131         nfs_callback_info.users--;
132         goto out;
133 }
134
135 /*
136  * Kill the server process if it is not already up.
137  */
138 int nfs_callback_down(void)
139 {
140         int ret = 0;
141
142         lock_kernel();
143         mutex_lock(&nfs_callback_mutex);
144         nfs_callback_info.users--;
145         do {
146                 if (nfs_callback_info.users != 0 || nfs_callback_info.pid == 0)
147                         break;
148                 if (kill_proc(nfs_callback_info.pid, SIGKILL, 1) < 0)
149                         break;
150         } while (wait_for_completion_timeout(&nfs_callback_info.stopped, 5*HZ) == 0);
151         mutex_unlock(&nfs_callback_mutex);
152         unlock_kernel();
153         return ret;
154 }
155
156 static int nfs_callback_authenticate(struct svc_rqst *rqstp)
157 {
158         struct in_addr *addr = &rqstp->rq_addr.sin_addr;
159         struct nfs4_client *clp;
160
161         /* Don't talk to strangers */
162         clp = nfs4_find_client(addr);
163         if (clp == NULL)
164                 return SVC_DROP;
165         dprintk("%s: %u.%u.%u.%u NFSv4 callback!\n", __FUNCTION__, NIPQUAD(addr));
166         nfs4_put_client(clp);
167         switch (rqstp->rq_authop->flavour) {
168                 case RPC_AUTH_NULL:
169                         if (rqstp->rq_proc != CB_NULL)
170                                 return SVC_DENIED;
171                         break;
172                 case RPC_AUTH_UNIX:
173                         break;
174                 case RPC_AUTH_GSS:
175                         /* FIXME: RPCSEC_GSS handling? */
176                 default:
177                         return SVC_DENIED;
178         }
179         return SVC_OK;
180 }
181
182 /*
183  * Define NFS4 callback program
184  */
185 extern struct svc_version nfs4_callback_version1;
186
187 static struct svc_version *nfs4_callback_version[] = {
188         [1] = &nfs4_callback_version1,
189 };
190
191 static struct svc_stat nfs4_callback_stats;
192
193 static struct svc_program nfs4_callback_program = {
194         .pg_prog = NFS4_CALLBACK,                       /* RPC service number */
195         .pg_nvers = ARRAY_SIZE(nfs4_callback_version),  /* Number of entries */
196         .pg_vers = nfs4_callback_version,               /* version table */
197         .pg_name = "NFSv4 callback",                    /* service name */
198         .pg_class = "nfs",                              /* authentication class */
199         .pg_stats = &nfs4_callback_stats,
200         .pg_authenticate = nfs_callback_authenticate,
201 };