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>
19 #include <linux/mutex.h>
22 #define NLMDBG_FACILITY NLMDBG_HOSTCACHE
23 #define NLM_HOST_MAX 64
24 #define NLM_HOST_NRHASH 32
25 #define NLM_ADDRHASH(addr) (ntohl(addr) & (NLM_HOST_NRHASH-1))
26 #define NLM_HOST_REBIND (60 * HZ)
27 #define NLM_HOST_EXPIRE ((nrhosts > NLM_HOST_MAX)? 300 * HZ : 120 * HZ)
28 #define NLM_HOST_COLLECT ((nrhosts > NLM_HOST_MAX)? 120 * HZ : 60 * HZ)
30 static struct nlm_host
* nlm_hosts
[NLM_HOST_NRHASH
];
31 static unsigned long next_gc
;
33 static DEFINE_MUTEX(nlm_host_mutex
);
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
);
74 mutex_lock(&nlm_host_mutex
);
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
;
94 mutex_unlock(&nlm_host_mutex
);
99 /* Ooops, no host found, create it */
100 dprintk("lockd: creating host entry\n");
102 host
= kzalloc(sizeof(*host
), GFP_KERNEL
);
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 mutex_init(&host
->h_mutex
);
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 init_rwsem(&host
->h_rwsem
);
120 host
->h_state
= 0; /* pseudo NSM state */
121 host
->h_nsmstate
= 0; /* real NSM state */
122 host
->h_server
= server
;
123 host
->h_next
= nlm_hosts
[hash
];
124 nlm_hosts
[hash
] = host
;
125 INIT_LIST_HEAD(&host
->h_lockowners
);
126 spin_lock_init(&host
->h_lock
);
127 INIT_LIST_HEAD(&host
->h_granted
);
128 INIT_LIST_HEAD(&host
->h_reclaim
);
130 if (++nrhosts
> NLM_HOST_MAX
)
134 mutex_unlock(&nlm_host_mutex
);
139 nlm_find_client(void)
141 /* find a nlm_host for a client for which h_killed == 0.
145 mutex_lock(&nlm_host_mutex
);
146 for (hash
= 0 ; hash
< NLM_HOST_NRHASH
; hash
++) {
147 struct nlm_host
*host
, **hp
;
148 for (hp
= &nlm_hosts
[hash
]; (host
= *hp
) != 0; hp
= &host
->h_next
) {
149 if (host
->h_server
&&
150 host
->h_killed
== 0) {
152 mutex_unlock(&nlm_host_mutex
);
157 mutex_unlock(&nlm_host_mutex
);
163 * Create the NLM RPC client for an NLM peer
166 nlm_bind_host(struct nlm_host
*host
)
168 struct rpc_clnt
*clnt
;
170 dprintk("lockd: nlm_bind_host(%08x)\n",
171 (unsigned)ntohl(host
->h_addr
.sin_addr
.s_addr
));
173 /* Lock host handle */
174 mutex_lock(&host
->h_mutex
);
176 /* If we've already created an RPC client, check whether
177 * RPC rebind is required
179 if ((clnt
= host
->h_rpcclnt
) != NULL
) {
180 if (time_after_eq(jiffies
, host
->h_nextrebind
)) {
181 rpc_force_rebind(clnt
);
182 host
->h_nextrebind
= jiffies
+ NLM_HOST_REBIND
;
183 dprintk("lockd: next rebind in %ld jiffies\n",
184 host
->h_nextrebind
- jiffies
);
187 unsigned long increment
= nlmsvc_timeout
* HZ
;
188 struct rpc_timeout timeparms
= {
189 .to_initval
= increment
,
190 .to_increment
= increment
,
191 .to_maxval
= increment
* 6UL,
194 struct rpc_create_args args
= {
195 .protocol
= host
->h_proto
,
196 .address
= (struct sockaddr
*)&host
->h_addr
,
197 .addrsize
= sizeof(host
->h_addr
),
198 .timeout
= &timeparms
,
199 .servername
= host
->h_name
,
200 .program
= &nlm_program
,
201 .version
= host
->h_version
,
202 .authflavor
= RPC_AUTH_UNIX
,
203 .flags
= (RPC_CLNT_CREATE_HARDRTRY
|
204 RPC_CLNT_CREATE_AUTOBIND
),
207 clnt
= rpc_create(&args
);
209 host
->h_rpcclnt
= clnt
;
211 printk("lockd: couldn't create RPC handle for %s\n", host
->h_name
);
216 mutex_unlock(&host
->h_mutex
);
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 rpc_force_rebind(host
->h_rpcclnt
);
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 BUG_ON(atomic_read(&host
->h_count
) < 0);
254 if (atomic_dec_and_test(&host
->h_count
)) {
255 BUG_ON(!list_empty(&host
->h_lockowners
));
256 BUG_ON(!list_empty(&host
->h_granted
));
257 BUG_ON(!list_empty(&host
->h_reclaim
));
263 * Shut down the hosts module.
264 * Note that this routine is called only at server shutdown time.
267 nlm_shutdown_hosts(void)
269 struct nlm_host
*host
;
272 dprintk("lockd: shutting down host module\n");
273 mutex_lock(&nlm_host_mutex
);
275 /* First, make all hosts eligible for gc */
276 dprintk("lockd: nuking all hosts...\n");
277 for (i
= 0; i
< NLM_HOST_NRHASH
; i
++) {
278 for (host
= nlm_hosts
[i
]; host
; host
= host
->h_next
)
279 host
->h_expires
= jiffies
- 1;
282 /* Then, perform a garbage collection pass */
284 mutex_unlock(&nlm_host_mutex
);
286 /* complain if any hosts are left */
288 printk(KERN_WARNING
"lockd: couldn't shutdown host module!\n");
289 dprintk("lockd: %d hosts left:\n", nrhosts
);
290 for (i
= 0; i
< NLM_HOST_NRHASH
; i
++) {
291 for (host
= nlm_hosts
[i
]; host
; host
= host
->h_next
) {
292 dprintk(" %s (cnt %d use %d exp %ld)\n",
293 host
->h_name
, atomic_read(&host
->h_count
),
294 host
->h_inuse
, host
->h_expires
);
301 * Garbage collect any unused NLM hosts.
302 * This GC combines reference counting for async operations with
303 * mark & sweep for resources held by remote clients.
308 struct nlm_host
**q
, *host
;
309 struct rpc_clnt
*clnt
;
312 dprintk("lockd: host garbage collection\n");
313 for (i
= 0; i
< NLM_HOST_NRHASH
; i
++) {
314 for (host
= nlm_hosts
[i
]; host
; host
= host
->h_next
)
318 /* Mark all hosts that hold locks, blocks or shares */
319 nlmsvc_mark_resources();
321 for (i
= 0; i
< NLM_HOST_NRHASH
; i
++) {
323 while ((host
= *q
) != NULL
) {
324 if (atomic_read(&host
->h_count
) || host
->h_inuse
325 || time_before(jiffies
, host
->h_expires
)) {
326 dprintk("nlm_gc_hosts skipping %s (cnt %d use %d exp %ld)\n",
327 host
->h_name
, atomic_read(&host
->h_count
),
328 host
->h_inuse
, host
->h_expires
);
332 dprintk("lockd: delete host %s\n", host
->h_name
);
334 /* Don't unmonitor hosts that have been invalidated */
335 if (host
->h_monitored
&& !host
->h_killed
)
337 if ((clnt
= host
->h_rpcclnt
) != NULL
) {
338 if (atomic_read(&clnt
->cl_users
)) {
340 "lockd: active RPC handle\n");
343 rpc_destroy_client(host
->h_rpcclnt
);
351 next_gc
= jiffies
+ NLM_HOST_COLLECT
;