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/slab.h>
14 #include <linux/in6.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>
23 #define NLMDBG_FACILITY NLMDBG_HOSTCACHE
24 #define NLM_HOST_NRHASH 32
25 #define NLM_HOST_REBIND (60 * HZ)
26 #define NLM_HOST_EXPIRE (300 * HZ)
27 #define NLM_HOST_COLLECT (120 * HZ)
29 static struct hlist_head nlm_hosts
[NLM_HOST_NRHASH
];
30 static unsigned long next_gc
;
32 static DEFINE_MUTEX(nlm_host_mutex
);
34 static void nlm_gc_hosts(void);
35 static struct nsm_handle
*nsm_find(const struct sockaddr
*sap
,
38 const size_t hostname_len
,
41 struct nlm_lookup_host_info
{
42 const int server
; /* search for server|client */
43 const struct sockaddr
*sap
; /* address to search for */
44 const size_t salen
; /* it's length */
45 const unsigned short protocol
; /* transport to search for*/
46 const u32 version
; /* NLM version to search for */
47 const char *hostname
; /* remote's hostname */
48 const size_t hostname_len
; /* it's length */
49 const struct sockaddr
*src_sap
; /* our address (optional) */
50 const size_t src_len
; /* it's length */
51 const int noresvport
; /* use non-priv port */
55 * Hash function must work well on big- and little-endian platforms
57 static unsigned int __nlm_hash32(const __be32 n
)
59 unsigned int hash
= (__force u32
)n
^ ((__force u32
)n
>> 16);
60 return hash
^ (hash
>> 8);
63 static unsigned int __nlm_hash_addr4(const struct sockaddr
*sap
)
65 const struct sockaddr_in
*sin
= (struct sockaddr_in
*)sap
;
66 return __nlm_hash32(sin
->sin_addr
.s_addr
);
69 static unsigned int __nlm_hash_addr6(const struct sockaddr
*sap
)
71 const struct sockaddr_in6
*sin6
= (struct sockaddr_in6
*)sap
;
72 const struct in6_addr addr
= sin6
->sin6_addr
;
73 return __nlm_hash32(addr
.s6_addr32
[0]) ^
74 __nlm_hash32(addr
.s6_addr32
[1]) ^
75 __nlm_hash32(addr
.s6_addr32
[2]) ^
76 __nlm_hash32(addr
.s6_addr32
[3]);
79 static unsigned int nlm_hash_address(const struct sockaddr
*sap
)
83 switch (sap
->sa_family
) {
85 hash
= __nlm_hash_addr4(sap
);
88 hash
= __nlm_hash_addr6(sap
);
93 return hash
& (NLM_HOST_NRHASH
- 1);
96 static void nlm_clear_port(struct sockaddr
*sap
)
98 switch (sap
->sa_family
) {
100 ((struct sockaddr_in
*)sap
)->sin_port
= 0;
103 ((struct sockaddr_in6
*)sap
)->sin6_port
= 0;
108 static void nlm_display_address(const struct sockaddr
*sap
,
109 char *buf
, const size_t len
)
111 const struct sockaddr_in
*sin
= (struct sockaddr_in
*)sap
;
112 const struct sockaddr_in6
*sin6
= (struct sockaddr_in6
*)sap
;
114 switch (sap
->sa_family
) {
116 snprintf(buf
, len
, "unspecified");
119 snprintf(buf
, len
, "%pI4", &sin
->sin_addr
.s_addr
);
122 if (ipv6_addr_v4mapped(&sin6
->sin6_addr
))
123 snprintf(buf
, len
, "%pI4",
124 &sin6
->sin6_addr
.s6_addr32
[3]);
126 snprintf(buf
, len
, "%pI6", &sin6
->sin6_addr
);
129 snprintf(buf
, len
, "unsupported address family");
135 * Common host lookup routine for server & client
137 static struct nlm_host
*nlm_lookup_host(struct nlm_lookup_host_info
*ni
)
139 struct hlist_head
*chain
;
140 struct hlist_node
*pos
;
141 struct nlm_host
*host
;
142 struct nsm_handle
*nsm
= NULL
;
144 mutex_lock(&nlm_host_mutex
);
146 if (time_after_eq(jiffies
, next_gc
))
149 /* We may keep several nlm_host objects for a peer, because each
150 * nlm_host is identified by
151 * (address, protocol, version, server/client)
152 * We could probably simplify this a little by putting all those
153 * different NLM rpc_clients into one single nlm_host object.
154 * This would allow us to have one nlm_host per address.
156 chain
= &nlm_hosts
[nlm_hash_address(ni
->sap
)];
157 hlist_for_each_entry(host
, pos
, chain
, h_hash
) {
158 if (!nlm_cmp_addr(nlm_addr(host
), ni
->sap
))
161 /* See if we have an NSM handle for this client */
163 nsm
= host
->h_nsmhandle
;
165 if (host
->h_proto
!= ni
->protocol
)
167 if (host
->h_version
!= ni
->version
)
169 if (host
->h_server
!= ni
->server
)
172 !nlm_cmp_addr(nlm_srcaddr(host
), ni
->src_sap
))
175 /* Move to head of hash chain. */
176 hlist_del(&host
->h_hash
);
177 hlist_add_head(&host
->h_hash
, chain
);
180 dprintk("lockd: nlm_lookup_host found host %s (%s)\n",
181 host
->h_name
, host
->h_addrbuf
);
186 * The host wasn't in our hash table. If we don't
187 * have an NSM handle for it yet, create one.
190 atomic_inc(&nsm
->sm_count
);
193 nsm
= nsm_find(ni
->sap
, ni
->salen
,
194 ni
->hostname
, ni
->hostname_len
, 1);
196 dprintk("lockd: nlm_lookup_host failed; "
202 host
= kzalloc(sizeof(*host
), GFP_KERNEL
);
205 dprintk("lockd: nlm_lookup_host failed; no memory\n");
208 host
->h_name
= nsm
->sm_name
;
209 memcpy(nlm_addr(host
), ni
->sap
, ni
->salen
);
210 host
->h_addrlen
= ni
->salen
;
211 nlm_clear_port(nlm_addr(host
));
212 memcpy(nlm_srcaddr(host
), ni
->src_sap
, ni
->src_len
);
213 host
->h_version
= ni
->version
;
214 host
->h_proto
= ni
->protocol
;
215 host
->h_rpcclnt
= NULL
;
216 mutex_init(&host
->h_mutex
);
217 host
->h_nextrebind
= jiffies
+ NLM_HOST_REBIND
;
218 host
->h_expires
= jiffies
+ NLM_HOST_EXPIRE
;
219 atomic_set(&host
->h_count
, 1);
220 init_waitqueue_head(&host
->h_gracewait
);
221 init_rwsem(&host
->h_rwsem
);
222 host
->h_state
= 0; /* pseudo NSM state */
223 host
->h_nsmstate
= 0; /* real NSM state */
224 host
->h_nsmhandle
= nsm
;
225 host
->h_server
= ni
->server
;
226 host
->h_noresvport
= ni
->noresvport
;
227 hlist_add_head(&host
->h_hash
, chain
);
228 INIT_LIST_HEAD(&host
->h_lockowners
);
229 spin_lock_init(&host
->h_lock
);
230 INIT_LIST_HEAD(&host
->h_granted
);
231 INIT_LIST_HEAD(&host
->h_reclaim
);
235 nlm_display_address((struct sockaddr
*)&host
->h_addr
,
236 host
->h_addrbuf
, sizeof(host
->h_addrbuf
));
237 nlm_display_address((struct sockaddr
*)&host
->h_srcaddr
,
238 host
->h_srcaddrbuf
, sizeof(host
->h_srcaddrbuf
));
240 dprintk("lockd: nlm_lookup_host created host %s\n",
244 mutex_unlock(&nlm_host_mutex
);
252 nlm_destroy_host(struct nlm_host
*host
)
254 struct rpc_clnt
*clnt
;
256 BUG_ON(!list_empty(&host
->h_lockowners
));
257 BUG_ON(atomic_read(&host
->h_count
));
260 * Release NSM handle and unmonitor host.
264 clnt
= host
->h_rpcclnt
;
266 rpc_shutdown_client(clnt
);
271 * nlmclnt_lookup_host - Find an NLM host handle matching a remote server
272 * @sap: network address of server
273 * @salen: length of server address
274 * @protocol: transport protocol to use
275 * @version: NLM protocol version
276 * @hostname: '\0'-terminated hostname of server
277 * @noresvport: 1 if non-privileged port should be used
279 * Returns an nlm_host structure that matches the passed-in
280 * [server address, transport protocol, NLM version, server hostname].
281 * If one doesn't already exist in the host cache, a new handle is
282 * created and returned.
284 struct nlm_host
*nlmclnt_lookup_host(const struct sockaddr
*sap
,
286 const unsigned short protocol
,
288 const char *hostname
,
291 const struct sockaddr source
= {
292 .sa_family
= AF_UNSPEC
,
294 struct nlm_lookup_host_info ni
= {
298 .protocol
= protocol
,
300 .hostname
= hostname
,
301 .hostname_len
= strlen(hostname
),
303 .src_len
= sizeof(source
),
304 .noresvport
= noresvport
,
307 dprintk("lockd: %s(host='%s', vers=%u, proto=%s)\n", __func__
,
308 (hostname
? hostname
: "<none>"), version
,
309 (protocol
== IPPROTO_UDP
? "udp" : "tcp"));
311 return nlm_lookup_host(&ni
);
315 * nlmsvc_lookup_host - Find an NLM host handle matching a remote client
316 * @rqstp: incoming NLM request
317 * @hostname: name of client host
318 * @hostname_len: length of client hostname
320 * Returns an nlm_host structure that matches the [client address,
321 * transport protocol, NLM version, client hostname] of the passed-in
322 * NLM request. If one doesn't already exist in the host cache, a
323 * new handle is created and returned.
325 * Before possibly creating a new nlm_host, construct a sockaddr
326 * for a specific source address in case the local system has
327 * multiple network addresses. The family of the address in
328 * rq_daddr is guaranteed to be the same as the family of the
329 * address in rq_addr, so it's safe to use the same family for
330 * the source address.
332 struct nlm_host
*nlmsvc_lookup_host(const struct svc_rqst
*rqstp
,
333 const char *hostname
,
334 const size_t hostname_len
)
336 struct sockaddr_in sin
= {
337 .sin_family
= AF_INET
,
339 struct sockaddr_in6 sin6
= {
340 .sin6_family
= AF_INET6
,
342 struct nlm_lookup_host_info ni
= {
344 .sap
= svc_addr(rqstp
),
345 .salen
= rqstp
->rq_addrlen
,
346 .protocol
= rqstp
->rq_prot
,
347 .version
= rqstp
->rq_vers
,
348 .hostname
= hostname
,
349 .hostname_len
= hostname_len
,
350 .src_len
= rqstp
->rq_addrlen
,
353 dprintk("lockd: %s(host='%*s', vers=%u, proto=%s)\n", __func__
,
354 (int)hostname_len
, hostname
, rqstp
->rq_vers
,
355 (rqstp
->rq_prot
== IPPROTO_UDP
? "udp" : "tcp"));
357 switch (ni
.sap
->sa_family
) {
359 sin
.sin_addr
.s_addr
= rqstp
->rq_daddr
.addr
.s_addr
;
360 ni
.src_sap
= (struct sockaddr
*)&sin
;
363 ipv6_addr_copy(&sin6
.sin6_addr
, &rqstp
->rq_daddr
.addr6
);
364 ni
.src_sap
= (struct sockaddr
*)&sin6
;
370 return nlm_lookup_host(&ni
);
374 * Create the NLM RPC client for an NLM peer
377 nlm_bind_host(struct nlm_host
*host
)
379 struct rpc_clnt
*clnt
;
381 dprintk("lockd: nlm_bind_host %s (%s), my addr=%s\n",
382 host
->h_name
, host
->h_addrbuf
, host
->h_srcaddrbuf
);
384 /* Lock host handle */
385 mutex_lock(&host
->h_mutex
);
387 /* If we've already created an RPC client, check whether
388 * RPC rebind is required
390 if ((clnt
= host
->h_rpcclnt
) != NULL
) {
391 if (time_after_eq(jiffies
, host
->h_nextrebind
)) {
392 rpc_force_rebind(clnt
);
393 host
->h_nextrebind
= jiffies
+ NLM_HOST_REBIND
;
394 dprintk("lockd: next rebind in %lu jiffies\n",
395 host
->h_nextrebind
- jiffies
);
398 unsigned long increment
= nlmsvc_timeout
;
399 struct rpc_timeout timeparms
= {
400 .to_initval
= increment
,
401 .to_increment
= increment
,
402 .to_maxval
= increment
* 6UL,
405 struct rpc_create_args args
= {
406 .protocol
= host
->h_proto
,
407 .address
= nlm_addr(host
),
408 .addrsize
= host
->h_addrlen
,
409 .saddress
= nlm_srcaddr(host
),
410 .timeout
= &timeparms
,
411 .servername
= host
->h_name
,
412 .program
= &nlm_program
,
413 .version
= host
->h_version
,
414 .authflavor
= RPC_AUTH_UNIX
,
415 .flags
= (RPC_CLNT_CREATE_NOPING
|
416 RPC_CLNT_CREATE_AUTOBIND
),
420 * lockd retries server side blocks automatically so we want
421 * those to be soft RPC calls. Client side calls need to be
425 args
.flags
|= RPC_CLNT_CREATE_HARDRTRY
;
426 if (host
->h_noresvport
)
427 args
.flags
|= RPC_CLNT_CREATE_NONPRIVPORT
;
429 clnt
= rpc_create(&args
);
431 host
->h_rpcclnt
= clnt
;
433 printk("lockd: couldn't create RPC handle for %s\n", host
->h_name
);
438 mutex_unlock(&host
->h_mutex
);
443 * Force a portmap lookup of the remote lockd port
446 nlm_rebind_host(struct nlm_host
*host
)
448 dprintk("lockd: rebind host %s\n", host
->h_name
);
449 if (host
->h_rpcclnt
&& time_after_eq(jiffies
, host
->h_nextrebind
)) {
450 rpc_force_rebind(host
->h_rpcclnt
);
451 host
->h_nextrebind
= jiffies
+ NLM_HOST_REBIND
;
456 * Increment NLM host count
458 struct nlm_host
* nlm_get_host(struct nlm_host
*host
)
461 dprintk("lockd: get host %s\n", host
->h_name
);
462 atomic_inc(&host
->h_count
);
463 host
->h_expires
= jiffies
+ NLM_HOST_EXPIRE
;
469 * Release NLM host after use
471 void nlm_release_host(struct nlm_host
*host
)
474 dprintk("lockd: release host %s\n", host
->h_name
);
475 BUG_ON(atomic_read(&host
->h_count
) < 0);
476 if (atomic_dec_and_test(&host
->h_count
)) {
477 BUG_ON(!list_empty(&host
->h_lockowners
));
478 BUG_ON(!list_empty(&host
->h_granted
));
479 BUG_ON(!list_empty(&host
->h_reclaim
));
485 * We were notified that the host indicated by address &sin
487 * Release all resources held by that peer.
489 void nlm_host_rebooted(const struct sockaddr_in
*sin
,
490 const char *hostname
,
491 unsigned int hostname_len
,
494 struct hlist_head
*chain
;
495 struct hlist_node
*pos
;
496 struct nsm_handle
*nsm
;
497 struct nlm_host
*host
;
499 nsm
= nsm_find((struct sockaddr
*)sin
, sizeof(*sin
),
500 hostname
, hostname_len
, 0);
502 dprintk("lockd: never saw rebooted peer '%.*s' before\n",
503 hostname_len
, hostname
);
507 dprintk("lockd: nlm_host_rebooted(%.*s, %s)\n",
508 hostname_len
, hostname
, nsm
->sm_addrbuf
);
510 /* When reclaiming locks on this peer, make sure that
511 * we set up a new notification */
512 nsm
->sm_monitored
= 0;
514 /* Mark all hosts tied to this NSM state as having rebooted.
515 * We run the loop repeatedly, because we drop the host table
517 * To avoid processing a host several times, we match the nsmstate.
519 again
: mutex_lock(&nlm_host_mutex
);
520 for (chain
= nlm_hosts
; chain
< nlm_hosts
+ NLM_HOST_NRHASH
; ++chain
) {
521 hlist_for_each_entry(host
, pos
, chain
, h_hash
) {
522 if (host
->h_nsmhandle
== nsm
523 && host
->h_nsmstate
!= new_state
) {
524 host
->h_nsmstate
= new_state
;
528 mutex_unlock(&nlm_host_mutex
);
530 if (host
->h_server
) {
531 /* We're server for this guy, just ditch
532 * all the locks he held. */
533 nlmsvc_free_host_resources(host
);
535 /* He's the server, initiate lock recovery. */
536 nlmclnt_recovery(host
);
539 nlm_release_host(host
);
545 mutex_unlock(&nlm_host_mutex
);
549 * Shut down the hosts module.
550 * Note that this routine is called only at server shutdown time.
553 nlm_shutdown_hosts(void)
555 struct hlist_head
*chain
;
556 struct hlist_node
*pos
;
557 struct nlm_host
*host
;
559 dprintk("lockd: shutting down host module\n");
560 mutex_lock(&nlm_host_mutex
);
562 /* First, make all hosts eligible for gc */
563 dprintk("lockd: nuking all hosts...\n");
564 for (chain
= nlm_hosts
; chain
< nlm_hosts
+ NLM_HOST_NRHASH
; ++chain
) {
565 hlist_for_each_entry(host
, pos
, chain
, h_hash
) {
566 host
->h_expires
= jiffies
- 1;
567 if (host
->h_rpcclnt
) {
568 rpc_shutdown_client(host
->h_rpcclnt
);
569 host
->h_rpcclnt
= NULL
;
574 /* Then, perform a garbage collection pass */
576 mutex_unlock(&nlm_host_mutex
);
578 /* complain if any hosts are left */
580 printk(KERN_WARNING
"lockd: couldn't shutdown host module!\n");
581 dprintk("lockd: %d hosts left:\n", nrhosts
);
582 for (chain
= nlm_hosts
; chain
< nlm_hosts
+ NLM_HOST_NRHASH
; ++chain
) {
583 hlist_for_each_entry(host
, pos
, chain
, h_hash
) {
584 dprintk(" %s (cnt %d use %d exp %ld)\n",
585 host
->h_name
, atomic_read(&host
->h_count
),
586 host
->h_inuse
, host
->h_expires
);
593 * Garbage collect any unused NLM hosts.
594 * This GC combines reference counting for async operations with
595 * mark & sweep for resources held by remote clients.
600 struct hlist_head
*chain
;
601 struct hlist_node
*pos
, *next
;
602 struct nlm_host
*host
;
604 dprintk("lockd: host garbage collection\n");
605 for (chain
= nlm_hosts
; chain
< nlm_hosts
+ NLM_HOST_NRHASH
; ++chain
) {
606 hlist_for_each_entry(host
, pos
, chain
, h_hash
)
610 /* Mark all hosts that hold locks, blocks or shares */
611 nlmsvc_mark_resources();
613 for (chain
= nlm_hosts
; chain
< nlm_hosts
+ NLM_HOST_NRHASH
; ++chain
) {
614 hlist_for_each_entry_safe(host
, pos
, next
, chain
, h_hash
) {
615 if (atomic_read(&host
->h_count
) || host
->h_inuse
616 || time_before(jiffies
, host
->h_expires
)) {
617 dprintk("nlm_gc_hosts skipping %s (cnt %d use %d exp %ld)\n",
618 host
->h_name
, atomic_read(&host
->h_count
),
619 host
->h_inuse
, host
->h_expires
);
622 dprintk("lockd: delete host %s\n", host
->h_name
);
623 hlist_del_init(&host
->h_hash
);
625 nlm_destroy_host(host
);
630 next_gc
= jiffies
+ NLM_HOST_COLLECT
;
637 static LIST_HEAD(nsm_handles
);
638 static DEFINE_SPINLOCK(nsm_lock
);
640 static struct nsm_handle
*nsm_find(const struct sockaddr
*sap
,
642 const char *hostname
,
643 const size_t hostname_len
,
646 struct nsm_handle
*nsm
= NULL
;
647 struct nsm_handle
*pos
;
652 if (hostname
&& memchr(hostname
, '/', hostname_len
) != NULL
) {
653 if (printk_ratelimit()) {
654 printk(KERN_WARNING
"Invalid hostname \"%.*s\" "
655 "in NFS lock request\n",
656 (int)hostname_len
, hostname
);
662 spin_lock(&nsm_lock
);
663 list_for_each_entry(pos
, &nsm_handles
, sm_link
) {
665 if (hostname
&& nsm_use_hostnames
) {
666 if (strlen(pos
->sm_name
) != hostname_len
667 || memcmp(pos
->sm_name
, hostname
, hostname_len
))
669 } else if (!nlm_cmp_addr(nsm_addr(pos
), sap
))
671 atomic_inc(&pos
->sm_count
);
677 list_add(&nsm
->sm_link
, &nsm_handles
);
680 spin_unlock(&nsm_lock
);
685 nsm
= kzalloc(sizeof(*nsm
) + hostname_len
+ 1, GFP_KERNEL
);
689 memcpy(nsm_addr(nsm
), sap
, salen
);
690 nsm
->sm_addrlen
= salen
;
691 nsm
->sm_name
= (char *) (nsm
+ 1);
692 memcpy(nsm
->sm_name
, hostname
, hostname_len
);
693 nsm
->sm_name
[hostname_len
] = '\0';
694 nlm_display_address((struct sockaddr
*)&nsm
->sm_addr
,
695 nsm
->sm_addrbuf
, sizeof(nsm
->sm_addrbuf
));
696 atomic_set(&nsm
->sm_count
, 1);
700 spin_unlock(&nsm_lock
);
705 * Release an NSM handle
708 nsm_release(struct nsm_handle
*nsm
)
712 if (atomic_dec_and_lock(&nsm
->sm_count
, &nsm_lock
)) {
713 list_del(&nsm
->sm_link
);
714 spin_unlock(&nsm_lock
);