[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>
#include <linux/mutex.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)

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


static void			nlm_gc_hosts(void);
static struct nsm_handle *	__nsm_find(const struct sockaddr_in *,
					const char *, int, int);

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

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

/*
 * Common host lookup routine for server & client
 */
struct nlm_host *
nlm_lookup_host(int server, const struct sockaddr_in *sin,
					int proto, int version,
					const char *hostname,
					int hostname_len)
{
	struct nlm_host	*host, **hp;
	struct nsm_handle *nsm = NULL;
	int		hash;

	dprintk("lockd: nlm_lookup_host(%u.%u.%u.%u, p=%d, v=%d, my role=%s, name=%.*s)\n",
			NIPQUAD(sin->sin_addr.s_addr), proto, version,
			server? "server" : "client",
			hostname_len,
			hostname? hostname : "<none>");


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

	/* Lock hash table */
	mutex_lock(&nlm_host_mutex);

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

	/* We may keep several nlm_host objects for a peer, because each
	 * nlm_host is identified by
	 * (address, protocol, version, server/client)
	 * We could probably simplify this a little by putting all those
	 * different NLM rpc_clients into one single nlm_host object.
	 * This would allow us to have one nlm_host per address.
	 */
	for (hp = &nlm_hosts[hash]; (host = *hp) != 0; hp = &host->h_next) {
		if (!nlm_cmp_addr(&host->h_addr, sin))
			continue;

		/* See if we have an NSM handle for this client */
		if (!nsm && (nsm = host->h_nsmhandle) != 0)
			atomic_inc(&nsm->sm_count);

		if (host->h_proto != proto)
			continue;
		if (host->h_version != version)
			continue;
		if (host->h_server != server)
			continue;

		if (hp != nlm_hosts + hash) {
			*hp = host->h_next;
			host->h_next = nlm_hosts[hash];
			nlm_hosts[hash] = host;
		}
		nlm_get_host(host);
		goto out;
	}

	/* Sadly, the host isn't in our hash table yet. See if
	 * we have an NSM handle for it. If not, create one.
	 */
	if (!nsm && !(nsm = nsm_find(sin, hostname, hostname_len)))
		goto out;

	host = kzalloc(sizeof(*host), GFP_KERNEL);
	if (!host) {
		nsm_release(nsm);
		goto out;
	}
	host->h_name	   = nsm->sm_name;
	host->h_addr       = *sin;
	host->h_addr.sin_port = 0;	/* ouch! */
	host->h_version    = version;
	host->h_proto      = proto;
	host->h_rpcclnt    = NULL;
	mutex_init(&host->h_mutex);
	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);
	init_rwsem(&host->h_rwsem);
	host->h_state      = 0;			/* pseudo NSM state */
	host->h_nsmstate   = 0;			/* real NSM state */
	host->h_nsmhandle  = nsm;
	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);
	INIT_LIST_HEAD(&host->h_granted);
	INIT_LIST_HEAD(&host->h_reclaim);

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

out:
	mutex_unlock(&nlm_host_mutex);
	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;
	mutex_lock(&nlm_host_mutex);
	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);
				mutex_unlock(&nlm_host_mutex);
				return host;
			}
		}
	}
	mutex_unlock(&nlm_host_mutex);
	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;

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

	/* Lock host handle */
	mutex_lock(&host->h_mutex);

	/* If we've already created an RPC client, check whether
	 * RPC rebind is required
	 */
	if ((clnt = host->h_rpcclnt) != NULL) {
		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 {
		unsigned long increment = nlmsvc_timeout * HZ;
		struct rpc_timeout timeparms = {
			.to_initval	= increment,
			.to_increment	= increment,
			.to_maxval	= increment * 6UL,
			.to_retries	= 5U,
		};
		struct rpc_create_args args = {
			.protocol	= host->h_proto,
			.address	= (struct sockaddr *)&host->h_addr,
			.addrsize	= sizeof(host->h_addr),
			.timeout	= &timeparms,
			.servername	= host->h_name,
			.program	= &nlm_program,
			.version	= host->h_version,
			.authflavor	= RPC_AUTH_UNIX,
			.flags		= (RPC_CLNT_CREATE_HARDRTRY |
					   RPC_CLNT_CREATE_AUTOBIND),
		};

		clnt = rpc_create(&args);
		if (!IS_ERR(clnt))
			host->h_rpcclnt = clnt;
		else {
			printk("lockd: couldn't create RPC handle for %s\n", host->h_name);
			clnt = NULL;
		}
	}

	mutex_unlock(&host->h_mutex);
	return clnt;
}

/*
 * 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);
		BUG_ON(atomic_read(&host->h_count) < 0);
		if (atomic_dec_and_test(&host->h_count)) {
			BUG_ON(!list_empty(&host->h_lockowners));
			BUG_ON(!list_empty(&host->h_granted));
			BUG_ON(!list_empty(&host->h_reclaim));
		}
	}
}

/*
 * We were notified that the host indicated by address &sin
 * has rebooted.
 * Release all resources held by that peer.
 */
void nlm_host_rebooted(const struct sockaddr_in *sin, const struct nlm_reboot *argp)
{
	struct nlm_host *host;
	int server;

	/* Obtain the host pointer for this NFS server and try to
	 * reclaim all locks we hold on this server.
	 */
	server = (argp->proto & 1)? 1 : 0;
	host = nlm_lookup_host(server, sin, argp->proto >> 1, argp->vers,
			argp->mon, argp->len);
	if (host == NULL)
		return;

	if (server == 0) {
		/* We are client, he's the server: try to reclaim all locks. */
		nlmclnt_recovery(host, argp->state);
	} else {
		/* He's the client, we're the server: delete all locks held by the client */
		nlmsvc_free_host_resources(host);
	}
	nlm_release_host(host);
}

/*
 * 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");
	mutex_lock(&nlm_host_mutex);

	/* 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();
	mutex_unlock(&nlm_host_mutex);

	/* 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;

			/*
			 * Unmonitor unless host was invalidated (i.e. lockd restarted)
			 */
			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);
				}
			}
			kfree(host);
			nrhosts--;
		}
	}

	next_gc = jiffies + NLM_HOST_COLLECT;
}


/*
 * Manage NSM handles
 */
static LIST_HEAD(nsm_handles);
static DECLARE_MUTEX(nsm_sema);

static struct nsm_handle *
__nsm_find(const struct sockaddr_in *sin,
		const char *hostname, int hostname_len,
		int create)
{
	struct nsm_handle *nsm = NULL;
	struct list_head *pos;

	if (!sin)
		return NULL;

	if (hostname && memchr(hostname, '/', hostname_len) != NULL) {
		if (printk_ratelimit()) {
			printk(KERN_WARNING "Invalid hostname \"%.*s\" "
					    "in NFS lock request\n",
				hostname_len, hostname);
		}
		return NULL;
	}

	down(&nsm_sema);
	list_for_each(pos, &nsm_handles) {
		nsm = list_entry(pos, struct nsm_handle, sm_link);

		if (!nlm_cmp_addr(&nsm->sm_addr, sin))
			continue;
		atomic_inc(&nsm->sm_count);
		goto out;
	}

	if (!create) {
		nsm = NULL;
		goto out;
	}

	nsm = kzalloc(sizeof(*nsm) + hostname_len + 1, GFP_KERNEL);
	if (nsm != NULL) {
		nsm->sm_addr = *sin;
		nsm->sm_name = (char *) (nsm + 1);
		memcpy(nsm->sm_name, hostname, hostname_len);
		nsm->sm_name[hostname_len] = '\0';
		atomic_set(&nsm->sm_count, 1);

		list_add(&nsm->sm_link, &nsm_handles);
	}

out:	up(&nsm_sema);
	return nsm;
}

struct nsm_handle *
nsm_find(const struct sockaddr_in *sin, const char *hostname, int hostname_len)
{
	return __nsm_find(sin, hostname, hostname_len, 1);
}

/*
 * Release an NSM handle
 */
void
nsm_release(struct nsm_handle *nsm)
{
	if (!nsm)
		return;
	if (atomic_dec_and_test(&nsm->sm_count)) {
		down(&nsm_sema);
		if (atomic_read(&nsm->sm_count) == 0) {
			list_del(&nsm->sm_link);
			kfree(nsm);
		}
		up(&nsm_sema);
	}
}
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>
353ab6e9	19	#include <linux/mutex.h>
1da177e4 LT	20
	21
	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)
1da177e4 LT	29
	30	static struct nlm_host * nlm_hosts[NLM_HOST_NRHASH];
	31	static unsigned long next_gc;
	32	static int nrhosts;
353ab6e9	33	static DEFINE_MUTEX(nlm_host_mutex);
1da177e4 LT	34
	35
	36	static void nlm_gc_hosts(void);
8dead0db OK	37	static struct nsm_handle * __nsm_find(const struct sockaddr_in *,
8dead0db OK	38	const char *, int, int);
1da177e4 LT	39
	40	/*
	41	* Find an NLM server handle in the cache. If there is none, create it.
	42	*/
	43	struct nlm_host *
db4e4c9a OK	44	nlmclnt_lookup_host(const struct sockaddr_in *sin, int proto, int version,
db4e4c9a OK	45	const char *hostname, int hostname_len)
1da177e4	46	{
db4e4c9a OK	47	return nlm_lookup_host(0, sin, proto, version,
db4e4c9a OK	48	hostname, hostname_len);
1da177e4 LT	49	}
	50
	51	/*
	52	* Find an NLM client handle in the cache. If there is none, create it.
	53	*/
	54	struct nlm_host *
db4e4c9a OK	55	nlmsvc_lookup_host(struct svc_rqst *rqstp,
db4e4c9a OK	56	const char *hostname, int hostname_len)
1da177e4 LT	57	{
1da177e4 LT	58	return nlm_lookup_host(1, &rqstp->rq_addr,
db4e4c9a OK	59	rqstp->rq_prot, rqstp->rq_vers,
db4e4c9a OK	60	hostname, hostname_len);
1da177e4 LT	61	}
	62
	63	/*
	64	* Common host lookup routine for server & client
	65	*/
	66	struct nlm_host *
cf712c24	67	nlm_lookup_host(int server, const struct sockaddr_in *sin,
db4e4c9a OK	68	int proto, int version,
	69	const char *hostname,
	70	int hostname_len)
1da177e4 LT	71	{
1da177e4 LT	72	struct nlm_host host, *hp;
8dead0db	73	struct nsm_handle *nsm = NULL;
1da177e4 LT	74	int hash;
1da177e4 LT	75
db4e4c9a OK	76	dprintk("lockd: nlm_lookup_host(%u.%u.%u.%u, p=%d, v=%d, my role=%s, name=%.*s)\n",
	77	NIPQUAD(sin->sin_addr.s_addr), proto, version,
	78	server? "server" : "client",
	79	hostname_len,
	80	hostname? hostname : "<none>");
	81
1da177e4 LT	82
	83	hash = NLM_ADDRHASH(sin->sin_addr.s_addr);
	84
	85	/* Lock hash table */
353ab6e9	86	mutex_lock(&nlm_host_mutex);
1da177e4 LT	87
	88	if (time_after_eq(jiffies, next_gc))
	89	nlm_gc_hosts();
	90
8dead0db OK	91	/* We may keep several nlm_host objects for a peer, because each
	92	* nlm_host is identified by
	93	* (address, protocol, version, server/client)
	94	* We could probably simplify this a little by putting all those
	95	* different NLM rpc_clients into one single nlm_host object.
	96	* This would allow us to have one nlm_host per address.
	97	*/
1da177e4	98	for (hp = &nlm_hosts[hash]; (host = *hp) != 0; hp = &host->h_next) {
8dead0db OK	99	if (!nlm_cmp_addr(&host->h_addr, sin))
	100	continue;
	101
	102	/* See if we have an NSM handle for this client */
	103	if (!nsm && (nsm = host->h_nsmhandle) != 0)
	104	atomic_inc(&nsm->sm_count);
	105
1da177e4 LT	106	if (host->h_proto != proto)
	107	continue;
	108	if (host->h_version != version)
	109	continue;
	110	if (host->h_server != server)
	111	continue;
	112
f0737a39 OK	113	if (hp != nlm_hosts + hash) {
	114	*hp = host->h_next;
	115	host->h_next = nlm_hosts[hash];
	116	nlm_hosts[hash] = host;
1da177e4	117	}
f0737a39 OK	118	nlm_get_host(host);
f0737a39 OK	119	goto out;
1da177e4 LT	120	}
1da177e4 LT	121
8dead0db OK	122	/* Sadly, the host isn't in our hash table yet. See if
	123	* we have an NSM handle for it. If not, create one.
	124	*/
	125	if (!nsm && !(nsm = nsm_find(sin, hostname, hostname_len)))
	126	goto out;
1da177e4	127
f8314dc6	128	host = kzalloc(sizeof(*host), GFP_KERNEL);
8dead0db OK	129	if (!host) {
	130	nsm_release(nsm);
	131	goto out;
	132	}
	133	host->h_name = nsm->sm_name;
1da177e4 LT	134	host->h_addr = *sin;
	135	host->h_addr.sin_port = 0; /* ouch! */
	136	host->h_version = version;
	137	host->h_proto = proto;
	138	host->h_rpcclnt = NULL;
50467914	139	mutex_init(&host->h_mutex);
1da177e4 LT	140	host->h_nextrebind = jiffies + NLM_HOST_REBIND;
	141	host->h_expires = jiffies + NLM_HOST_EXPIRE;
	142	atomic_set(&host->h_count, 1);
	143	init_waitqueue_head(&host->h_gracewait);
28df955a	144	init_rwsem(&host->h_rwsem);
1da177e4 LT	145	host->h_state = 0; /* pseudo NSM state */
1da177e4 LT	146	host->h_nsmstate = 0; /* real NSM state */
8dead0db	147	host->h_nsmhandle = nsm;
1da177e4 LT	148	host->h_server = server;
	149	host->h_next = nlm_hosts[hash];
	150	nlm_hosts[hash] = host;
	151	INIT_LIST_HEAD(&host->h_lockowners);
	152	spin_lock_init(&host->h_lock);
26bcbf96 CH	153	INIT_LIST_HEAD(&host->h_granted);
26bcbf96 CH	154	INIT_LIST_HEAD(&host->h_reclaim);
1da177e4 LT	155
	156	if (++nrhosts > NLM_HOST_MAX)
	157	next_gc = 0;
	158
8dead0db	159	out:
353ab6e9	160	mutex_unlock(&nlm_host_mutex);
1da177e4 LT	161	return host;
	162	}
	163
	164	struct nlm_host *
	165	nlm_find_client(void)
	166	{
	167	/* find a nlm_host for a client for which h_killed == 0.
	168	* and return it
	169	*/
	170	int hash;
353ab6e9	171	mutex_lock(&nlm_host_mutex);
1da177e4 LT	172	for (hash = 0 ; hash < NLM_HOST_NRHASH; hash++) {
	173	struct nlm_host host, *hp;
	174	for (hp = &nlm_hosts[hash]; (host = *hp) != 0; hp = &host->h_next) {
	175	if (host->h_server &&
	176	host->h_killed == 0) {
	177	nlm_get_host(host);
353ab6e9	178	mutex_unlock(&nlm_host_mutex);
1da177e4 LT	179	return host;
	180	}
	181	}
	182	}
353ab6e9	183	mutex_unlock(&nlm_host_mutex);
1da177e4 LT	184	return NULL;
	185	}
	186
	187
	188	/*
	189	* Create the NLM RPC client for an NLM peer
	190	*/
	191	struct rpc_clnt *
	192	nlm_bind_host(struct nlm_host *host)
	193	{
	194	struct rpc_clnt *clnt;
1da177e4 LT	195
	196	dprintk("lockd: nlm_bind_host(%08x)\n",
	197	(unsigned)ntohl(host->h_addr.sin_addr.s_addr));
	198
	199	/* Lock host handle */
50467914	200	mutex_lock(&host->h_mutex);
1da177e4 LT	201
	202	/* If we've already created an RPC client, check whether
	203	* RPC rebind is required
1da177e4 LT	204	*/
1da177e4 LT	205	if ((clnt = host->h_rpcclnt) != NULL) {
43118c29	206	if (time_after_eq(jiffies, host->h_nextrebind)) {
35f5a422	207	rpc_force_rebind(clnt);
1da177e4 LT	208	host->h_nextrebind = jiffies + NLM_HOST_REBIND;
	209	dprintk("lockd: next rebind in %ld jiffies\n",
	210	host->h_nextrebind - jiffies);
	211	}
	212	} else {
e1ec7892 CL	213	unsigned long increment = nlmsvc_timeout * HZ;
	214	struct rpc_timeout timeparms = {
	215	.to_initval = increment,
	216	.to_increment = increment,
	217	.to_maxval = increment * 6UL,
	218	.to_retries = 5U,
	219	};
	220	struct rpc_create_args args = {
	221	.protocol = host->h_proto,
	222	.address = (struct sockaddr *)&host->h_addr,
	223	.addrsize = sizeof(host->h_addr),
	224	.timeout = &timeparms,
	225	.servername = host->h_name,
	226	.program = &nlm_program,
	227	.version = host->h_version,
	228	.authflavor = RPC_AUTH_UNIX,
	229	.flags = (RPC_CLNT_CREATE_HARDRTRY \|
	230	RPC_CLNT_CREATE_AUTOBIND),
	231	};
	232
	233	clnt = rpc_create(&args);
	234	if (!IS_ERR(clnt))
	235	host->h_rpcclnt = clnt;
	236	else {
	237	printk("lockd: couldn't create RPC handle for %s\n", host->h_name);
	238	clnt = NULL;
	239	}
1da177e4 LT	240	}
1da177e4 LT	241
50467914	242	mutex_unlock(&host->h_mutex);
1da177e4	243	return clnt;
1da177e4 LT	244	}
	245
	246	/*
	247	* Force a portmap lookup of the remote lockd port
	248	*/
	249	void
	250	nlm_rebind_host(struct nlm_host *host)
	251	{
	252	dprintk("lockd: rebind host %s\n", host->h_name);
	253	if (host->h_rpcclnt && time_after_eq(jiffies, host->h_nextrebind)) {
35f5a422	254	rpc_force_rebind(host->h_rpcclnt);
1da177e4 LT	255	host->h_nextrebind = jiffies + NLM_HOST_REBIND;
	256	}
	257	}
	258
	259	/*
	260	* Increment NLM host count
	261	*/
	262	struct nlm_host * nlm_get_host(struct nlm_host *host)
	263	{
	264	if (host) {
	265	dprintk("lockd: get host %s\n", host->h_name);
	266	atomic_inc(&host->h_count);
	267	host->h_expires = jiffies + NLM_HOST_EXPIRE;
	268	}
	269	return host;
	270	}
	271
	272	/*
	273	* Release NLM host after use
	274	*/
	275	void nlm_release_host(struct nlm_host *host)
	276	{
	277	if (host != NULL) {
	278	dprintk("lockd: release host %s\n", host->h_name);
1da177e4	279	BUG_ON(atomic_read(&host->h_count) < 0);
4c060b53 TM	280	if (atomic_dec_and_test(&host->h_count)) {
	281	BUG_ON(!list_empty(&host->h_lockowners));
	282	BUG_ON(!list_empty(&host->h_granted));
	283	BUG_ON(!list_empty(&host->h_reclaim));
	284	}
1da177e4 LT	285	}
	286	}
	287
cf712c24 OK	288	/*
	289	* We were notified that the host indicated by address &sin
	290	* has rebooted.
	291	* Release all resources held by that peer.
	292	*/
	293	void nlm_host_rebooted(const struct sockaddr_in sin, const struct nlm_reboot argp)
	294	{
	295	struct nlm_host *host;
db4e4c9a	296	int server;
cf712c24 OK	297
	298	/* Obtain the host pointer for this NFS server and try to
	299	* reclaim all locks we hold on this server.
	300	*/
db4e4c9a OK	301	server = (argp->proto & 1)? 1 : 0;
	302	host = nlm_lookup_host(server, sin, argp->proto >> 1, argp->vers,
	303	argp->mon, argp->len);
	304	if (host == NULL)
	305	return;
	306
	307	if (server == 0) {
cf712c24	308	/* We are client, he's the server: try to reclaim all locks. */
cf712c24 OK	309	nlmclnt_recovery(host, argp->state);
	310	} else {
	311	/* He's the client, we're the server: delete all locks held by the client */
cf712c24 OK	312	nlmsvc_free_host_resources(host);
	313	}
	314	nlm_release_host(host);
	315	}
	316
1da177e4 LT	317	/*
	318	* Shut down the hosts module.
	319	* Note that this routine is called only at server shutdown time.
	320	*/
	321	void
	322	nlm_shutdown_hosts(void)
	323	{
	324	struct nlm_host *host;
	325	int i;
	326
	327	dprintk("lockd: shutting down host module\n");
353ab6e9	328	mutex_lock(&nlm_host_mutex);
1da177e4 LT	329
	330	/* First, make all hosts eligible for gc */
	331	dprintk("lockd: nuking all hosts...\n");
	332	for (i = 0; i < NLM_HOST_NRHASH; i++) {
	333	for (host = nlm_hosts[i]; host; host = host->h_next)
	334	host->h_expires = jiffies - 1;
	335	}
	336
	337	/* Then, perform a garbage collection pass */
	338	nlm_gc_hosts();
353ab6e9	339	mutex_unlock(&nlm_host_mutex);
1da177e4 LT	340
	341	/* complain if any hosts are left */
	342	if (nrhosts) {
	343	printk(KERN_WARNING "lockd: couldn't shutdown host module!\n");
	344	dprintk("lockd: %d hosts left:\n", nrhosts);
	345	for (i = 0; i < NLM_HOST_NRHASH; i++) {
	346	for (host = nlm_hosts[i]; host; host = host->h_next) {
	347	dprintk(" %s (cnt %d use %d exp %ld)\n",
	348	host->h_name, atomic_read(&host->h_count),
	349	host->h_inuse, host->h_expires);
	350	}
	351	}
	352	}
	353	}
	354
	355	/*
	356	* Garbage collect any unused NLM hosts.
	357	* This GC combines reference counting for async operations with
	358	* mark & sweep for resources held by remote clients.
	359	*/
	360	static void
	361	nlm_gc_hosts(void)
	362	{
	363	struct nlm_host *q, host;
	364	struct rpc_clnt *clnt;
	365	int i;
	366
	367	dprintk("lockd: host garbage collection\n");
	368	for (i = 0; i < NLM_HOST_NRHASH; i++) {
	369	for (host = nlm_hosts[i]; host; host = host->h_next)
	370	host->h_inuse = 0;
	371	}
	372
	373	/* Mark all hosts that hold locks, blocks or shares */
	374	nlmsvc_mark_resources();
	375
	376	for (i = 0; i < NLM_HOST_NRHASH; i++) {
	377	q = &nlm_hosts[i];
	378	while ((host = *q) != NULL) {
	379	if (atomic_read(&host->h_count) \|\| host->h_inuse
	380	\|\| time_before(jiffies, host->h_expires)) {
	381	dprintk("nlm_gc_hosts skipping %s (cnt %d use %d exp %ld)\n",
	382	host->h_name, atomic_read(&host->h_count),
	383	host->h_inuse, host->h_expires);
	384	q = &host->h_next;
	385	continue;
	386	}
	387	dprintk("lockd: delete host %s\n", host->h_name);
	388	*q = host->h_next;
977faf39 OK	389
	390	/*
	391	* Unmonitor unless host was invalidated (i.e. lockd restarted)
	392	*/
	393	nsm_unmonitor(host);
	394
1da177e4 LT	395	if ((clnt = host->h_rpcclnt) != NULL) {
	396	if (atomic_read(&clnt->cl_users)) {
	397	printk(KERN_WARNING
	398	"lockd: active RPC handle\n");
	399	clnt->cl_dead = 1;
	400	} else {
	401	rpc_destroy_client(host->h_rpcclnt);
	402	}
	403	}
1da177e4 LT	404	kfree(host);
	405	nrhosts--;
	406	}
	407	}
	408
	409	next_gc = jiffies + NLM_HOST_COLLECT;
	410	}
	411
8dead0db OK	412
	413	/*
	414	* Manage NSM handles
	415	*/
	416	static LIST_HEAD(nsm_handles);
	417	static DECLARE_MUTEX(nsm_sema);
	418
	419	static struct nsm_handle *
	420	__nsm_find(const struct sockaddr_in *sin,
	421	const char *hostname, int hostname_len,
	422	int create)
	423	{
	424	struct nsm_handle *nsm = NULL;
	425	struct list_head *pos;
	426
	427	if (!sin)
	428	return NULL;
	429
	430	if (hostname && memchr(hostname, '/', hostname_len) != NULL) {
	431	if (printk_ratelimit()) {
	432	printk(KERN_WARNING "Invalid hostname \"%.*s\" "
	433	"in NFS lock request\n",
	434	hostname_len, hostname);
	435	}
	436	return NULL;
	437	}
	438
	439	down(&nsm_sema);
	440	list_for_each(pos, &nsm_handles) {
	441	nsm = list_entry(pos, struct nsm_handle, sm_link);
	442
	443	if (!nlm_cmp_addr(&nsm->sm_addr, sin))
	444	continue;
	445	atomic_inc(&nsm->sm_count);
	446	goto out;
	447	}
	448
	449	if (!create) {
	450	nsm = NULL;
	451	goto out;
	452	}
	453
	454	nsm = kzalloc(sizeof(*nsm) + hostname_len + 1, GFP_KERNEL);
	455	if (nsm != NULL) {
	456	nsm->sm_addr = *sin;
	457	nsm->sm_name = (char *) (nsm + 1);
	458	memcpy(nsm->sm_name, hostname, hostname_len);
	459	nsm->sm_name[hostname_len] = '\0';
	460	atomic_set(&nsm->sm_count, 1);
	461
	462	list_add(&nsm->sm_link, &nsm_handles);
	463	}
	464
	465	out: up(&nsm_sema);
	466	return nsm;
	467	}
	468
	469	struct nsm_handle *
	470	nsm_find(const struct sockaddr_in sin, const char hostname, int hostname_len)
	471	{
	472	return __nsm_find(sin, hostname, hostname_len, 1);
	473	}
	474
	475	/*
476	* Release an NSM handle
477	*/
478	void
479	nsm_release(struct nsm_handle *nsm)
480	{
481	if (!nsm)
482	return;
483	if (atomic_dec_and_test(&nsm->sm_count)) {
484	down(&nsm_sema);
485	if (atomic_read(&nsm->sm_count) == 0) {
486	list_del(&nsm->sm_link);
487	kfree(nsm);
488	}
489	up(&nsm_sema);
490	}
491	}