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
, "%u.%u.%u.%u", NIPQUAD(addr
));
110 host
->h_addr
.sin_port
= 0; /* ouch! */
111 host
->h_version
= version
;
112 host
->h_proto
= proto
;
113 host
->h_rpcclnt
= NULL
;
114 init_MUTEX(&host
->h_sema
);
115 host
->h_nextrebind
= jiffies
+ NLM_HOST_REBIND
;
116 host
->h_expires
= jiffies
+ NLM_HOST_EXPIRE
;
117 atomic_set(&host
->h_count
, 1);
118 init_waitqueue_head(&host
->h_gracewait
);
119 host
->h_state
= 0; /* pseudo NSM state */
120 host
->h_nsmstate
= 0; /* real NSM state */
121 host
->h_server
= server
;
122 host
->h_next
= nlm_hosts
[hash
];
123 nlm_hosts
[hash
] = host
;
124 INIT_LIST_HEAD(&host
->h_lockowners
);
125 spin_lock_init(&host
->h_lock
);
126 INIT_LIST_HEAD(&host
->h_granted
);
127 INIT_LIST_HEAD(&host
->h_reclaim
);
129 if (++nrhosts
> NLM_HOST_MAX
)
138 nlm_find_client(void)
140 /* find a nlm_host for a client for which h_killed == 0.
144 down(&nlm_host_sema
);
145 for (hash
= 0 ; hash
< NLM_HOST_NRHASH
; hash
++) {
146 struct nlm_host
*host
, **hp
;
147 for (hp
= &nlm_hosts
[hash
]; (host
= *hp
) != 0; hp
= &host
->h_next
) {
148 if (host
->h_server
&&
149 host
->h_killed
== 0) {
162 * Create the NLM RPC client for an NLM peer
165 nlm_bind_host(struct nlm_host
*host
)
167 struct rpc_clnt
*clnt
;
168 struct rpc_xprt
*xprt
;
170 dprintk("lockd: nlm_bind_host(%08x)\n",
171 (unsigned)ntohl(host
->h_addr
.sin_addr
.s_addr
));
173 /* Lock host handle */
176 /* If we've already created an RPC client, check whether
177 * RPC rebind is required
179 if ((clnt
= host
->h_rpcclnt
) != NULL
) {
180 xprt
= clnt
->cl_xprt
;
181 if (time_after_eq(jiffies
, host
->h_nextrebind
)) {
182 rpc_force_rebind(clnt
);
183 host
->h_nextrebind
= jiffies
+ NLM_HOST_REBIND
;
184 dprintk("lockd: next rebind in %ld jiffies\n",
185 host
->h_nextrebind
- jiffies
);
188 xprt
= xprt_create_proto(host
->h_proto
, &host
->h_addr
, NULL
);
192 xprt_set_timeout(&xprt
->timeout
, 5, nlmsvc_timeout
);
193 xprt
->resvport
= 1; /* NLM requires a reserved port */
195 /* Existing NLM servers accept AUTH_UNIX only */
196 clnt
= rpc_new_client(xprt
, host
->h_name
, &nlm_program
,
197 host
->h_version
, RPC_AUTH_UNIX
);
200 clnt
->cl_autobind
= 1; /* turn on pmap queries */
201 clnt
->cl_softrtry
= 1; /* All queries are soft */
203 host
->h_rpcclnt
= clnt
;
210 printk("lockd: couldn't create RPC handle for %s\n", host
->h_name
);
216 * Force a portmap lookup of the remote lockd port
219 nlm_rebind_host(struct nlm_host
*host
)
221 dprintk("lockd: rebind host %s\n", host
->h_name
);
222 if (host
->h_rpcclnt
&& time_after_eq(jiffies
, host
->h_nextrebind
)) {
223 rpc_force_rebind(host
->h_rpcclnt
);
224 host
->h_nextrebind
= jiffies
+ NLM_HOST_REBIND
;
229 * Increment NLM host count
231 struct nlm_host
* nlm_get_host(struct nlm_host
*host
)
234 dprintk("lockd: get host %s\n", host
->h_name
);
235 atomic_inc(&host
->h_count
);
236 host
->h_expires
= jiffies
+ NLM_HOST_EXPIRE
;
242 * Release NLM host after use
244 void nlm_release_host(struct nlm_host
*host
)
247 dprintk("lockd: release host %s\n", host
->h_name
);
248 atomic_dec(&host
->h_count
);
249 BUG_ON(atomic_read(&host
->h_count
) < 0);
254 * Shut down the hosts module.
255 * Note that this routine is called only at server shutdown time.
258 nlm_shutdown_hosts(void)
260 struct nlm_host
*host
;
263 dprintk("lockd: shutting down host module\n");
264 down(&nlm_host_sema
);
266 /* First, make all hosts eligible for gc */
267 dprintk("lockd: nuking all hosts...\n");
268 for (i
= 0; i
< NLM_HOST_NRHASH
; i
++) {
269 for (host
= nlm_hosts
[i
]; host
; host
= host
->h_next
)
270 host
->h_expires
= jiffies
- 1;
273 /* Then, perform a garbage collection pass */
277 /* complain if any hosts are left */
279 printk(KERN_WARNING
"lockd: couldn't shutdown host module!\n");
280 dprintk("lockd: %d hosts left:\n", nrhosts
);
281 for (i
= 0; i
< NLM_HOST_NRHASH
; i
++) {
282 for (host
= nlm_hosts
[i
]; host
; host
= host
->h_next
) {
283 dprintk(" %s (cnt %d use %d exp %ld)\n",
284 host
->h_name
, atomic_read(&host
->h_count
),
285 host
->h_inuse
, host
->h_expires
);
292 * Garbage collect any unused NLM hosts.
293 * This GC combines reference counting for async operations with
294 * mark & sweep for resources held by remote clients.
299 struct nlm_host
**q
, *host
;
300 struct rpc_clnt
*clnt
;
303 dprintk("lockd: host garbage collection\n");
304 for (i
= 0; i
< NLM_HOST_NRHASH
; i
++) {
305 for (host
= nlm_hosts
[i
]; host
; host
= host
->h_next
)
309 /* Mark all hosts that hold locks, blocks or shares */
310 nlmsvc_mark_resources();
312 for (i
= 0; i
< NLM_HOST_NRHASH
; i
++) {
314 while ((host
= *q
) != NULL
) {
315 if (atomic_read(&host
->h_count
) || host
->h_inuse
316 || time_before(jiffies
, host
->h_expires
)) {
317 dprintk("nlm_gc_hosts skipping %s (cnt %d use %d exp %ld)\n",
318 host
->h_name
, atomic_read(&host
->h_count
),
319 host
->h_inuse
, host
->h_expires
);
323 dprintk("lockd: delete host %s\n", host
->h_name
);
325 /* Don't unmonitor hosts that have been invalidated */
326 if (host
->h_monitored
&& !host
->h_killed
)
328 if ((clnt
= host
->h_rpcclnt
) != NULL
) {
329 if (atomic_read(&clnt
->cl_users
)) {
331 "lockd: active RPC handle\n");
334 rpc_destroy_client(host
->h_rpcclnt
);
337 BUG_ON(!list_empty(&host
->h_lockowners
));
343 next_gc
= jiffies
+ NLM_HOST_COLLECT
;