2 * linux/fs/lockd/host.c
4 * Management for NLM peer hosts. The nlm_host struct is shared
5 * between client and server implementation. The only reason to
6 * do so is to reduce code bloat.
8 * Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de>
11 #include <linux/types.h>
12 #include <linux/sched.h>
13 #include <linux/slab.h>
15 #include <linux/sunrpc/clnt.h>
16 #include <linux/sunrpc/svc.h>
17 #include <linux/lockd/lockd.h>
18 #include <linux/lockd/sm_inter.h>
21 #define NLMDBG_FACILITY NLMDBG_HOSTCACHE
22 #define NLM_HOST_MAX 64
23 #define NLM_HOST_NRHASH 32
24 #define NLM_ADDRHASH(addr) (ntohl(addr) & (NLM_HOST_NRHASH-1))
25 #define NLM_HOST_REBIND (60 * HZ)
26 #define NLM_HOST_EXPIRE ((nrhosts > NLM_HOST_MAX)? 300 * HZ : 120 * HZ)
27 #define NLM_HOST_COLLECT ((nrhosts > NLM_HOST_MAX)? 120 * HZ : 60 * HZ)
28 #define NLM_HOST_ADDR(sv) (&(sv)->s_nlmclnt->cl_xprt->addr)
30 static struct nlm_host
* nlm_hosts
[NLM_HOST_NRHASH
];
31 static unsigned long next_gc
;
33 static DECLARE_MUTEX(nlm_host_sema
);
36 static void nlm_gc_hosts(void);
39 * Find an NLM server handle in the cache. If there is none, create it.
42 nlmclnt_lookup_host(struct sockaddr_in
*sin
, int proto
, int version
)
44 return nlm_lookup_host(0, sin
, proto
, version
);
48 * Find an NLM client handle in the cache. If there is none, create it.
51 nlmsvc_lookup_host(struct svc_rqst
*rqstp
)
53 return nlm_lookup_host(1, &rqstp
->rq_addr
,
54 rqstp
->rq_prot
, rqstp
->rq_vers
);
58 * Common host lookup routine for server & client
61 nlm_lookup_host(int server
, struct sockaddr_in
*sin
,
62 int proto
, int version
)
64 struct nlm_host
*host
, **hp
;
68 dprintk("lockd: nlm_lookup_host(%08x, p=%d, v=%d)\n",
69 (unsigned)(sin
? ntohl(sin
->sin_addr
.s_addr
) : 0), proto
, version
);
71 hash
= NLM_ADDRHASH(sin
->sin_addr
.s_addr
);
76 if (time_after_eq(jiffies
, next_gc
))
79 for (hp
= &nlm_hosts
[hash
]; (host
= *hp
) != 0; hp
= &host
->h_next
) {
80 if (host
->h_proto
!= proto
)
82 if (host
->h_version
!= version
)
84 if (host
->h_server
!= server
)
87 if (nlm_cmp_addr(&host
->h_addr
, sin
)) {
88 if (hp
!= nlm_hosts
+ hash
) {
90 host
->h_next
= nlm_hosts
[hash
];
91 nlm_hosts
[hash
] = host
;
99 /* Ooops, no host found, create it */
100 dprintk("lockd: creating host entry\n");
102 if (!(host
= (struct nlm_host
*) kmalloc(sizeof(*host
), GFP_KERNEL
)))
104 memset(host
, 0, sizeof(*host
));
106 addr
= sin
->sin_addr
.s_addr
;
107 sprintf(host
->h_name
, "%d.%d.%d.%d",
108 (unsigned char) (ntohl(addr
) >> 24),
109 (unsigned char) (ntohl(addr
) >> 16),
110 (unsigned char) (ntohl(addr
) >> 8),
111 (unsigned char) (ntohl(addr
) >> 0));
114 host
->h_addr
.sin_port
= 0; /* ouch! */
115 host
->h_version
= version
;
116 host
->h_proto
= proto
;
117 host
->h_authflavor
= RPC_AUTH_UNIX
;
118 host
->h_rpcclnt
= NULL
;
119 init_MUTEX(&host
->h_sema
);
120 host
->h_nextrebind
= jiffies
+ NLM_HOST_REBIND
;
121 host
->h_expires
= jiffies
+ NLM_HOST_EXPIRE
;
122 atomic_set(&host
->h_count
, 1);
123 init_waitqueue_head(&host
->h_gracewait
);
124 host
->h_state
= 0; /* pseudo NSM state */
125 host
->h_nsmstate
= 0; /* real NSM state */
126 host
->h_server
= server
;
127 host
->h_next
= nlm_hosts
[hash
];
128 nlm_hosts
[hash
] = host
;
129 INIT_LIST_HEAD(&host
->h_lockowners
);
130 spin_lock_init(&host
->h_lock
);
132 if (++nrhosts
> NLM_HOST_MAX
)
141 nlm_find_client(void)
143 /* find a nlm_host for a client for which h_killed == 0.
147 down(&nlm_host_sema
);
148 for (hash
= 0 ; hash
< NLM_HOST_NRHASH
; hash
++) {
149 struct nlm_host
*host
, **hp
;
150 for (hp
= &nlm_hosts
[hash
]; (host
= *hp
) != 0; hp
= &host
->h_next
) {
151 if (host
->h_server
&&
152 host
->h_killed
== 0) {
165 * Create the NLM RPC client for an NLM peer
168 nlm_bind_host(struct nlm_host
*host
)
170 struct rpc_clnt
*clnt
;
171 struct rpc_xprt
*xprt
;
173 dprintk("lockd: nlm_bind_host(%08x)\n",
174 (unsigned)ntohl(host
->h_addr
.sin_addr
.s_addr
));
176 /* Lock host handle */
179 /* If we've already created an RPC client, check whether
180 * RPC rebind is required
181 * Note: why keep rebinding if we're on a tcp connection?
183 if ((clnt
= host
->h_rpcclnt
) != NULL
) {
184 xprt
= clnt
->cl_xprt
;
185 if (!xprt
->stream
&& time_after_eq(jiffies
, host
->h_nextrebind
)) {
187 host
->h_nextrebind
= jiffies
+ NLM_HOST_REBIND
;
188 dprintk("lockd: next rebind in %ld jiffies\n",
189 host
->h_nextrebind
- jiffies
);
192 xprt
= xprt_create_proto(host
->h_proto
, &host
->h_addr
, NULL
);
196 xprt_set_timeout(&xprt
->timeout
, 5, nlmsvc_timeout
);
198 clnt
= rpc_create_client(xprt
, host
->h_name
, &nlm_program
,
199 host
->h_version
, host
->h_authflavor
);
204 clnt
->cl_autobind
= 1; /* turn on pmap queries */
205 xprt
->nocong
= 1; /* No congestion control for NLM */
206 xprt
->resvport
= 1; /* NLM requires a reserved port */
208 host
->h_rpcclnt
= clnt
;
215 printk("lockd: couldn't create RPC handle for %s\n", host
->h_name
);
221 * Force a portmap lookup of the remote lockd port
224 nlm_rebind_host(struct nlm_host
*host
)
226 dprintk("lockd: rebind host %s\n", host
->h_name
);
227 if (host
->h_rpcclnt
&& time_after_eq(jiffies
, host
->h_nextrebind
)) {
228 host
->h_rpcclnt
->cl_port
= 0;
229 host
->h_nextrebind
= jiffies
+ NLM_HOST_REBIND
;
234 * Increment NLM host count
236 struct nlm_host
* nlm_get_host(struct nlm_host
*host
)
239 dprintk("lockd: get host %s\n", host
->h_name
);
240 atomic_inc(&host
->h_count
);
241 host
->h_expires
= jiffies
+ NLM_HOST_EXPIRE
;
247 * Release NLM host after use
249 void nlm_release_host(struct nlm_host
*host
)
252 dprintk("lockd: release host %s\n", host
->h_name
);
253 atomic_dec(&host
->h_count
);
254 BUG_ON(atomic_read(&host
->h_count
) < 0);
259 * Shut down the hosts module.
260 * Note that this routine is called only at server shutdown time.
263 nlm_shutdown_hosts(void)
265 struct nlm_host
*host
;
268 dprintk("lockd: shutting down host module\n");
269 down(&nlm_host_sema
);
271 /* First, make all hosts eligible for gc */
272 dprintk("lockd: nuking all hosts...\n");
273 for (i
= 0; i
< NLM_HOST_NRHASH
; i
++) {
274 for (host
= nlm_hosts
[i
]; host
; host
= host
->h_next
)
275 host
->h_expires
= jiffies
- 1;
278 /* Then, perform a garbage collection pass */
282 /* complain if any hosts are left */
284 printk(KERN_WARNING
"lockd: couldn't shutdown host module!\n");
285 dprintk("lockd: %d hosts left:\n", nrhosts
);
286 for (i
= 0; i
< NLM_HOST_NRHASH
; i
++) {
287 for (host
= nlm_hosts
[i
]; host
; host
= host
->h_next
) {
288 dprintk(" %s (cnt %d use %d exp %ld)\n",
289 host
->h_name
, atomic_read(&host
->h_count
),
290 host
->h_inuse
, host
->h_expires
);
297 * Garbage collect any unused NLM hosts.
298 * This GC combines reference counting for async operations with
299 * mark & sweep for resources held by remote clients.
304 struct nlm_host
**q
, *host
;
305 struct rpc_clnt
*clnt
;
308 dprintk("lockd: host garbage collection\n");
309 for (i
= 0; i
< NLM_HOST_NRHASH
; i
++) {
310 for (host
= nlm_hosts
[i
]; host
; host
= host
->h_next
)
314 /* Mark all hosts that hold locks, blocks or shares */
315 nlmsvc_mark_resources();
317 for (i
= 0; i
< NLM_HOST_NRHASH
; i
++) {
319 while ((host
= *q
) != NULL
) {
320 if (atomic_read(&host
->h_count
) || host
->h_inuse
321 || time_before(jiffies
, host
->h_expires
)) {
322 dprintk("nlm_gc_hosts skipping %s (cnt %d use %d exp %ld)\n",
323 host
->h_name
, atomic_read(&host
->h_count
),
324 host
->h_inuse
, host
->h_expires
);
328 dprintk("lockd: delete host %s\n", host
->h_name
);
330 /* Don't unmonitor hosts that have been invalidated */
331 if (host
->h_monitored
&& !host
->h_killed
)
333 if ((clnt
= host
->h_rpcclnt
) != NULL
) {
334 if (atomic_read(&clnt
->cl_users
)) {
336 "lockd: active RPC handle\n");
339 rpc_destroy_client(host
->h_rpcclnt
);
342 BUG_ON(!list_empty(&host
->h_lockowners
));
348 next_gc
= jiffies
+ NLM_HOST_COLLECT
;