[deliverable/linux.git] / fs / lockd / host.c

/*
 * linux/fs/lockd/host.c
 *
 * Management for NLM peer hosts. The nlm_host struct is shared
 * between client and server implementation. The only reason to
 * do so is to reduce code bloat.
 *
 * Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de>
 */

#include <linux/types.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/in.h>
#include <linux/sunrpc/clnt.h>
#include <linux/sunrpc/svc.h>
#include <linux/lockd/lockd.h>
#include <linux/lockd/sm_inter.h>


#define NLMDBG_FACILITY		NLMDBG_HOSTCACHE
#define NLM_HOST_MAX		64
#define NLM_HOST_NRHASH		32
#define NLM_ADDRHASH(addr)	(ntohl(addr) & (NLM_HOST_NRHASH-1))
#define NLM_HOST_REBIND		(60 * HZ)
#define NLM_HOST_EXPIRE		((nrhosts > NLM_HOST_MAX)? 300 * HZ : 120 * HZ)
#define NLM_HOST_COLLECT	((nrhosts > NLM_HOST_MAX)? 120 * HZ :  60 * HZ)
#define NLM_HOST_ADDR(sv)	(&(sv)->s_nlmclnt->cl_xprt->addr)

static struct nlm_host *	nlm_hosts[NLM_HOST_NRHASH];
static unsigned long		next_gc;
static int			nrhosts;
static DECLARE_MUTEX(nlm_host_sema);


static void			nlm_gc_hosts(void);

/*
 * Find an NLM server handle in the cache. If there is none, create it.
 */
struct nlm_host *
nlmclnt_lookup_host(struct sockaddr_in *sin, int proto, int version)
{
	return nlm_lookup_host(0, sin, proto, version);
}

/*
 * Find an NLM client handle in the cache. If there is none, create it.
 */
struct nlm_host *
nlmsvc_lookup_host(struct svc_rqst *rqstp)
{
	return nlm_lookup_host(1, &rqstp->rq_addr,
			       rqstp->rq_prot, rqstp->rq_vers);
}

/*
 * Common host lookup routine for server & client
 */
struct nlm_host *
nlm_lookup_host(int server, struct sockaddr_in *sin,
					int proto, int version)
{
	struct nlm_host	*host, **hp;
	u32		addr;
	int		hash;

	dprintk("lockd: nlm_lookup_host(%08x, p=%d, v=%d)\n",
			(unsigned)(sin? ntohl(sin->sin_addr.s_addr) : 0), proto, version);

	hash = NLM_ADDRHASH(sin->sin_addr.s_addr);

	/* Lock hash table */
	down(&nlm_host_sema);

	if (time_after_eq(jiffies, next_gc))
		nlm_gc_hosts();

	for (hp = &nlm_hosts[hash]; (host = *hp) != 0; hp = &host->h_next) {
		if (host->h_proto != proto)
			continue;
		if (host->h_version != version)
			continue;
		if (host->h_server != server)
			continue;

		if (nlm_cmp_addr(&host->h_addr, sin)) {
			if (hp != nlm_hosts + hash) {
				*hp = host->h_next;
				host->h_next = nlm_hosts[hash];
				nlm_hosts[hash] = host;
			}
			nlm_get_host(host);
			up(&nlm_host_sema);
			return host;
		}
	}

	/* Ooops, no host found, create it */
	dprintk("lockd: creating host entry\n");

	if (!(host = (struct nlm_host *) kmalloc(sizeof(*host), GFP_KERNEL)))
		goto nohost;
	memset(host, 0, sizeof(*host));

	addr = sin->sin_addr.s_addr;
	sprintf(host->h_name, "%u.%u.%u.%u", NIPQUAD(addr));

	host->h_addr       = *sin;
	host->h_addr.sin_port = 0;	/* ouch! */
	host->h_version    = version;
	host->h_proto      = proto;
	host->h_rpcclnt    = NULL;
	init_MUTEX(&host->h_sema);
	host->h_nextrebind = jiffies + NLM_HOST_REBIND;
	host->h_expires    = jiffies + NLM_HOST_EXPIRE;
	atomic_set(&host->h_count, 1);
	init_waitqueue_head(&host->h_gracewait);
	host->h_state      = 0;			/* pseudo NSM state */
	host->h_nsmstate   = 0;			/* real NSM state */
	host->h_server	   = server;
	host->h_next       = nlm_hosts[hash];
	nlm_hosts[hash]    = host;
	INIT_LIST_HEAD(&host->h_lockowners);
	spin_lock_init(&host->h_lock);

	if (++nrhosts > NLM_HOST_MAX)
		next_gc = 0;

nohost:
	up(&nlm_host_sema);
	return host;
}

struct nlm_host *
nlm_find_client(void)
{
	/* find a nlm_host for a client for which h_killed == 0.
	 * and return it
	 */
	int hash;
	down(&nlm_host_sema);
	for (hash = 0 ; hash < NLM_HOST_NRHASH; hash++) {
		struct nlm_host *host, **hp;
		for (hp = &nlm_hosts[hash]; (host = *hp) != 0; hp = &host->h_next) {
			if (host->h_server &&
			    host->h_killed == 0) {
				nlm_get_host(host);
				up(&nlm_host_sema);
				return host;
			}
		}
	}
	up(&nlm_host_sema);
	return NULL;
}

				
/*
 * Create the NLM RPC client for an NLM peer
 */
struct rpc_clnt *
nlm_bind_host(struct nlm_host *host)
{
	struct rpc_clnt	*clnt;
	struct rpc_xprt	*xprt;

	dprintk("lockd: nlm_bind_host(%08x)\n",
			(unsigned)ntohl(host->h_addr.sin_addr.s_addr));

	/* Lock host handle */
	down(&host->h_sema);

	/* If we've already created an RPC client, check whether
	 * RPC rebind is required
	 */
	if ((clnt = host->h_rpcclnt) != NULL) {
		xprt = clnt->cl_xprt;
		if (time_after_eq(jiffies, host->h_nextrebind)) {
			rpc_force_rebind(clnt);
			host->h_nextrebind = jiffies + NLM_HOST_REBIND;
			dprintk("lockd: next rebind in %ld jiffies\n",
					host->h_nextrebind - jiffies);
		}
	} else {
		xprt = xprt_create_proto(host->h_proto, &host->h_addr, NULL);
		if (IS_ERR(xprt))
			goto forgetit;

		xprt_set_timeout(&xprt->timeout, 5, nlmsvc_timeout);
		xprt->resvport = 1;	/* NLM requires a reserved port */

		/* Existing NLM servers accept AUTH_UNIX only */
		clnt = rpc_create_client(xprt, host->h_name, &nlm_program,
					host->h_version, RPC_AUTH_UNIX);
		if (IS_ERR(clnt))
			goto forgetit;
		clnt->cl_autobind = 1;	/* turn on pmap queries */

		host->h_rpcclnt = clnt;
	}

	up(&host->h_sema);
	return clnt;

forgetit:
	printk("lockd: couldn't create RPC handle for %s\n", host->h_name);
	up(&host->h_sema);
	return NULL;
}

/*
 * Force a portmap lookup of the remote lockd port
 */
void
nlm_rebind_host(struct nlm_host *host)
{
	dprintk("lockd: rebind host %s\n", host->h_name);
	if (host->h_rpcclnt && time_after_eq(jiffies, host->h_nextrebind)) {
		rpc_force_rebind(host->h_rpcclnt);
		host->h_nextrebind = jiffies + NLM_HOST_REBIND;
	}
}

/*
 * Increment NLM host count
 */
struct nlm_host * nlm_get_host(struct nlm_host *host)
{
	if (host) {
		dprintk("lockd: get host %s\n", host->h_name);
		atomic_inc(&host->h_count);
		host->h_expires = jiffies + NLM_HOST_EXPIRE;
	}
	return host;
}

/*
 * Release NLM host after use
 */
void nlm_release_host(struct nlm_host *host)
{
	if (host != NULL) {
		dprintk("lockd: release host %s\n", host->h_name);
		atomic_dec(&host->h_count);
		BUG_ON(atomic_read(&host->h_count) < 0);
	}
}

/*
 * Shut down the hosts module.
 * Note that this routine is called only at server shutdown time.
 */
void
nlm_shutdown_hosts(void)
{
	struct nlm_host	*host;
	int		i;

	dprintk("lockd: shutting down host module\n");
	down(&nlm_host_sema);

	/* First, make all hosts eligible for gc */
	dprintk("lockd: nuking all hosts...\n");
	for (i = 0; i < NLM_HOST_NRHASH; i++) {
		for (host = nlm_hosts[i]; host; host = host->h_next)
			host->h_expires = jiffies - 1;
	}

	/* Then, perform a garbage collection pass */
	nlm_gc_hosts();
	up(&nlm_host_sema);

	/* complain if any hosts are left */
	if (nrhosts) {
		printk(KERN_WARNING "lockd: couldn't shutdown host module!\n");
		dprintk("lockd: %d hosts left:\n", nrhosts);
		for (i = 0; i < NLM_HOST_NRHASH; i++) {
			for (host = nlm_hosts[i]; host; host = host->h_next) {
				dprintk("       %s (cnt %d use %d exp %ld)\n",
					host->h_name, atomic_read(&host->h_count),
					host->h_inuse, host->h_expires);
			}
		}
	}
}

/*
 * Garbage collect any unused NLM hosts.
 * This GC combines reference counting for async operations with
 * mark & sweep for resources held by remote clients.
 */
static void
nlm_gc_hosts(void)
{
	struct nlm_host	**q, *host;
	struct rpc_clnt	*clnt;
	int		i;

	dprintk("lockd: host garbage collection\n");
	for (i = 0; i < NLM_HOST_NRHASH; i++) {
		for (host = nlm_hosts[i]; host; host = host->h_next)
			host->h_inuse = 0;
	}

	/* Mark all hosts that hold locks, blocks or shares */
	nlmsvc_mark_resources();

	for (i = 0; i < NLM_HOST_NRHASH; i++) {
		q = &nlm_hosts[i];
		while ((host = *q) != NULL) {
			if (atomic_read(&host->h_count) || host->h_inuse
			 || time_before(jiffies, host->h_expires)) {
				dprintk("nlm_gc_hosts skipping %s (cnt %d use %d exp %ld)\n",
					host->h_name, atomic_read(&host->h_count),
					host->h_inuse, host->h_expires);
				q = &host->h_next;
				continue;
			}
			dprintk("lockd: delete host %s\n", host->h_name);
			*q = host->h_next;
			/* Don't unmonitor hosts that have been invalidated */
			if (host->h_monitored && !host->h_killed)
				nsm_unmonitor(host);
			if ((clnt = host->h_rpcclnt) != NULL) {
				if (atomic_read(&clnt->cl_users)) {
					printk(KERN_WARNING
						"lockd: active RPC handle\n");
					clnt->cl_dead = 1;
				} else {
					rpc_destroy_client(host->h_rpcclnt);
				}
			}
			BUG_ON(!list_empty(&host->h_lockowners));
			kfree(host);
			nrhosts--;
		}
	}

	next_gc = jiffies + NLM_HOST_COLLECT;
}
Commit	Line	Data
1da177e4 LT	1	/*
	2	* linux/fs/lockd/host.c
	3	*
	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.
	7	*
	8	* Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de>
	9	*/
	10
	11	#include <linux/types.h>
	12	#include <linux/sched.h>
	13	#include <linux/slab.h>
	14	#include <linux/in.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
	20
	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)
	29
	30	static struct nlm_host * nlm_hosts[NLM_HOST_NRHASH];
	31	static unsigned long next_gc;
	32	static int nrhosts;
	33	static DECLARE_MUTEX(nlm_host_sema);
	34
	35
	36	static void nlm_gc_hosts(void);
	37
	38	/*
	39	* Find an NLM server handle in the cache. If there is none, create it.
	40	*/
	41	struct nlm_host *
	42	nlmclnt_lookup_host(struct sockaddr_in *sin, int proto, int version)
	43	{
	44	return nlm_lookup_host(0, sin, proto, version);
	45	}
	46
	47	/*
	48	* Find an NLM client handle in the cache. If there is none, create it.
	49	*/
	50	struct nlm_host *
	51	nlmsvc_lookup_host(struct svc_rqst *rqstp)
	52	{
	53	return nlm_lookup_host(1, &rqstp->rq_addr,
	54	rqstp->rq_prot, rqstp->rq_vers);
	55	}
	56
	57	/*
	58	* Common host lookup routine for server & client
	59	*/
	60	struct nlm_host *
	61	nlm_lookup_host(int server, struct sockaddr_in *sin,
	62	int proto, int version)
	63	{
	64	struct nlm_host host, *hp;
65	u32 addr;
66	int hash;
67
68	dprintk("lockd: nlm_lookup_host(%08x, p=%d, v=%d)\n",
69	(unsigned)(sin? ntohl(sin->sin_addr.s_addr) : 0), proto, version);
70
71	hash = NLM_ADDRHASH(sin->sin_addr.s_addr);
72
73	/* Lock hash table */
74	down(&nlm_host_sema);
75
76	if (time_after_eq(jiffies, next_gc))
77	nlm_gc_hosts();
78
79	for (hp = &nlm_hosts[hash]; (host = *hp) != 0; hp = &host->h_next) {
80	if (host->h_proto != proto)
81	continue;
82	if (host->h_version != version)
83	continue;
84	if (host->h_server != server)
85	continue;
86
87	if (nlm_cmp_addr(&host->h_addr, sin)) {
88	if (hp != nlm_hosts + hash) {
89	*hp = host->h_next;
90	host->h_next = nlm_hosts[hash];
91	nlm_hosts[hash] = host;
92	}
93	nlm_get_host(host);
94	up(&nlm_host_sema);
95	return host;
96	}
97	}
98
99	/* Ooops, no host found, create it */
100	dprintk("lockd: creating host entry\n");
101
102	if (!(host = (struct nlm_host ) kmalloc(sizeof(host), GFP_KERNEL)))
103	goto nohost;
104	memset(host, 0, sizeof(*host));
105
106	addr = sin->sin_addr.s_addr;
107	sprintf(host->h_name, "%u.%u.%u.%u", NIPQUAD(addr));
108
109	host->h_addr = *sin;
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
127	if (++nrhosts > NLM_HOST_MAX)
128	next_gc = 0;
129
130	nohost:
131	up(&nlm_host_sema);
132	return host;
133	}
134
135	struct nlm_host *
136	nlm_find_client(void)
137	{
138	/* find a nlm_host for a client for which h_killed == 0.
139	* and return it
140	*/
141	int hash;
142	down(&nlm_host_sema);
143	for (hash = 0 ; hash < NLM_HOST_NRHASH; hash++) {
144	struct nlm_host host, *hp;
145	for (hp = &nlm_hosts[hash]; (host = *hp) != 0; hp = &host->h_next) {
146	if (host->h_server &&
147	host->h_killed == 0) {
148	nlm_get_host(host);
149	up(&nlm_host_sema);
150	return host;
151	}
152	}
153	}
154	up(&nlm_host_sema);
155	return NULL;
156	}
157
158
159	/*
160	* Create the NLM RPC client for an NLM peer
161	*/
162	struct rpc_clnt *
163	nlm_bind_host(struct nlm_host *host)
164	{
165	struct rpc_clnt *clnt;
166	struct rpc_xprt *xprt;
167
168	dprintk("lockd: nlm_bind_host(%08x)\n",
169	(unsigned)ntohl(host->h_addr.sin_addr.s_addr));
170
171	/* Lock host handle */
172	down(&host->h_sema);
173
174	/* If we've already created an RPC client, check whether
175	* RPC rebind is required
1da177e4 LT	176	*/
	177	if ((clnt = host->h_rpcclnt) != NULL) {
	178	xprt = clnt->cl_xprt;
43118c29	179	if (time_after_eq(jiffies, host->h_nextrebind)) {
35f5a422	180	rpc_force_rebind(clnt);
1da177e4 LT	181	host->h_nextrebind = jiffies + NLM_HOST_REBIND;
	182	dprintk("lockd: next rebind in %ld jiffies\n",
	183	host->h_nextrebind - jiffies);
	184	}
	185	} else {
	186	xprt = xprt_create_proto(host->h_proto, &host->h_addr, NULL);
	187	if (IS_ERR(xprt))
	188	goto forgetit;
	189
	190	xprt_set_timeout(&xprt->timeout, 5, nlmsvc_timeout);
5ee0ed7d	191	xprt->resvport = 1; /* NLM requires a reserved port */
1da177e4 LT	192
	193	/* Existing NLM servers accept AUTH_UNIX only */
	194	clnt = rpc_create_client(xprt, host->h_name, &nlm_program,
	195	host->h_version, RPC_AUTH_UNIX);
5b616f5d	196	if (IS_ERR(clnt))
1da177e4	197	goto forgetit;
1da177e4	198	clnt->cl_autobind = 1; /* turn on pmap queries */
1da177e4 LT	199
	200	host->h_rpcclnt = clnt;
	201	}
	202
	203	up(&host->h_sema);
	204	return clnt;
	205
	206	forgetit:
	207	printk("lockd: couldn't create RPC handle for %s\n", host->h_name);
	208	up(&host->h_sema);
	209	return NULL;
	210	}
	211
	212	/*
	213	* Force a portmap lookup of the remote lockd port
	214	*/
	215	void
	216	nlm_rebind_host(struct nlm_host *host)
	217	{
	218	dprintk("lockd: rebind host %s\n", host->h_name);
	219	if (host->h_rpcclnt && time_after_eq(jiffies, host->h_nextrebind)) {
35f5a422	220	rpc_force_rebind(host->h_rpcclnt);
1da177e4 LT	221	host->h_nextrebind = jiffies + NLM_HOST_REBIND;
	222	}
	223	}
	224
	225	/*
	226	* Increment NLM host count
	227	*/
	228	struct nlm_host * nlm_get_host(struct nlm_host *host)
	229	{
	230	if (host) {
	231	dprintk("lockd: get host %s\n", host->h_name);
	232	atomic_inc(&host->h_count);
	233	host->h_expires = jiffies + NLM_HOST_EXPIRE;
	234	}
	235	return host;
	236	}
	237
	238	/*
	239	* Release NLM host after use
	240	*/
	241	void nlm_release_host(struct nlm_host *host)
	242	{
	243	if (host != NULL) {
	244	dprintk("lockd: release host %s\n", host->h_name);
	245	atomic_dec(&host->h_count);
	246	BUG_ON(atomic_read(&host->h_count) < 0);
	247	}
	248	}
	249
	250	/*
	251	* Shut down the hosts module.
	252	* Note that this routine is called only at server shutdown time.
	253	*/
	254	void
	255	nlm_shutdown_hosts(void)
	256	{
	257	struct nlm_host *host;
	258	int i;
	259
	260	dprintk("lockd: shutting down host module\n");
	261	down(&nlm_host_sema);
	262
	263	/* First, make all hosts eligible for gc */
	264	dprintk("lockd: nuking all hosts...\n");
	265	for (i = 0; i < NLM_HOST_NRHASH; i++) {
	266	for (host = nlm_hosts[i]; host; host = host->h_next)
	267	host->h_expires = jiffies - 1;
	268	}
	269
	270	/* Then, perform a garbage collection pass */
	271	nlm_gc_hosts();
	272	up(&nlm_host_sema);
	273
	274	/* complain if any hosts are left */
	275	if (nrhosts) {
	276	printk(KERN_WARNING "lockd: couldn't shutdown host module!\n");
	277	dprintk("lockd: %d hosts left:\n", nrhosts);
	278	for (i = 0; i < NLM_HOST_NRHASH; i++) {
	279	for (host = nlm_hosts[i]; host; host = host->h_next) {
	280	dprintk(" %s (cnt %d use %d exp %ld)\n",
	281	host->h_name, atomic_read(&host->h_count),
	282	host->h_inuse, host->h_expires);
	283	}
	284	}
285	}
286	}
287
288	/*
289	* Garbage collect any unused NLM hosts.
290	* This GC combines reference counting for async operations with
291	* mark & sweep for resources held by remote clients.
292	*/
293	static void
294	nlm_gc_hosts(void)
295	{
296	struct nlm_host *q, host;
297	struct rpc_clnt *clnt;
298	int i;
299
300	dprintk("lockd: host garbage collection\n");
301	for (i = 0; i < NLM_HOST_NRHASH; i++) {
302	for (host = nlm_hosts[i]; host; host = host->h_next)
303	host->h_inuse = 0;
304	}
305
306	/* Mark all hosts that hold locks, blocks or shares */
307	nlmsvc_mark_resources();
308
309	for (i = 0; i < NLM_HOST_NRHASH; i++) {
310	q = &nlm_hosts[i];
311	while ((host = *q) != NULL) {
312	if (atomic_read(&host->h_count) \|\| host->h_inuse
313	\|\| time_before(jiffies, host->h_expires)) {
314	dprintk("nlm_gc_hosts skipping %s (cnt %d use %d exp %ld)\n",
315	host->h_name, atomic_read(&host->h_count),
316	host->h_inuse, host->h_expires);
317	q = &host->h_next;
318	continue;
319	}
320	dprintk("lockd: delete host %s\n", host->h_name);
321	*q = host->h_next;
322	/* Don't unmonitor hosts that have been invalidated */
323	if (host->h_monitored && !host->h_killed)
324	nsm_unmonitor(host);
325	if ((clnt = host->h_rpcclnt) != NULL) {
326	if (atomic_read(&clnt->cl_users)) {
327	printk(KERN_WARNING
328	"lockd: active RPC handle\n");
329	clnt->cl_dead = 1;
330	} else {
331	rpc_destroy_client(host->h_rpcclnt);
332	}
333	}
334	BUG_ON(!list_empty(&host->h_lockowners));
335	kfree(host);
336	nrhosts--;
337	}
338	}
339
340	next_gc = jiffies + NLM_HOST_COLLECT;
341	}
342