[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/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 hlist_head	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 *, unsigned int, int);
static struct nsm_handle *	nsm_find(const struct sockaddr_in *sin,
					 const char *hostname,
					 unsigned int hostname_len);

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

	dprintk("lockd: nlm_lookup_host("NIPQUAD_FMT"->"NIPQUAD_FMT
			", p=%d, v=%d, my role=%s, name=%.*s)\n",
			NIPQUAD(ssin->sin_addr.s_addr),
			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.
	 */
	chain = &nlm_hosts[hash];
	hlist_for_each_entry(host, pos, chain, h_hash) {
		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;

		if (host->h_proto != proto)
			continue;
		if (host->h_version != version)
			continue;
		if (host->h_server != server)
			continue;
		if (!nlm_cmp_addr(&host->h_saddr, ssin))
			continue;

		/* Move to head of hash chain. */
		hlist_del(&host->h_hash);
		hlist_add_head(&host->h_hash, chain);

		nlm_get_host(host);
		goto out;
	}
	if (nsm)
		atomic_inc(&nsm->sm_count);

	host = NULL;

	/* 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_saddr	   = *ssin;
	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;
	hlist_add_head(&host->h_hash, chain);
	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;
}

/*
 * Destroy a host
 */
static void
nlm_destroy_host(struct nlm_host *host)
{
	struct rpc_clnt	*clnt;

	BUG_ON(!list_empty(&host->h_lockowners));
	BUG_ON(atomic_read(&host->h_count));

	/*
	 * Release NSM handle and unmonitor host.
	 */
	nsm_unmonitor(host);

	clnt = host->h_rpcclnt;
	if (clnt != NULL)
		rpc_shutdown_client(clnt);
	kfree(host);
}

/*
 * 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, unsigned int hostname_len)
{
	struct sockaddr_in ssin = {0};

	return nlm_lookup_host(0, sin, proto, version,
			       hostname, hostname_len, &ssin);
}

/*
 * 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, unsigned int hostname_len)
{
	struct sockaddr_in ssin = {0};

	ssin.sin_addr = rqstp->rq_daddr.addr;
	return nlm_lookup_host(1, svc_addr_in(rqstp),
			       rqstp->rq_prot, rqstp->rq_vers,
			       hostname, hostname_len, &ssin);
}

/*
 * 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("NIPQUAD_FMT"->"NIPQUAD_FMT")\n",
			NIPQUAD(host->h_saddr.sin_addr),
			NIPQUAD(host->h_addr.sin_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;
		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),
			.saddress	= (struct sockaddr *)&host->h_saddr,
			.timeout	= &timeparms,
			.servername	= host->h_name,
			.program	= &nlm_program,
			.version	= host->h_version,
			.authflavor	= RPC_AUTH_UNIX,
			.flags		= (RPC_CLNT_CREATE_NOPING |
					   RPC_CLNT_CREATE_AUTOBIND),
		};

		/*
		 * lockd retries server side blocks automatically so we want
		 * those to be soft RPC calls. Client side calls need to be
		 * hard RPC tasks.
		 */
		if (!host->h_server)
			args.flags |= RPC_CLNT_CREATE_HARDRTRY;

		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 char *hostname,
				unsigned int hostname_len,
				u32 new_state)
{
	struct hlist_head *chain;
	struct hlist_node *pos;
	struct nsm_handle *nsm;
	struct nlm_host	*host;

	dprintk("lockd: nlm_host_rebooted(%s, %u.%u.%u.%u)\n",
			hostname, NIPQUAD(sin->sin_addr));

	/* Find the NSM handle for this peer */
	if (!(nsm = __nsm_find(sin, hostname, hostname_len, 0)))
		return;

	/* When reclaiming locks on this peer, make sure that
	 * we set up a new notification */
	nsm->sm_monitored = 0;

	/* Mark all hosts tied to this NSM state as having rebooted.
	 * We run the loop repeatedly, because we drop the host table
	 * lock for this.
	 * To avoid processing a host several times, we match the nsmstate.
	 */
again:	mutex_lock(&nlm_host_mutex);
	for (chain = nlm_hosts; chain < nlm_hosts + NLM_HOST_NRHASH; ++chain) {
		hlist_for_each_entry(host, pos, chain, h_hash) {
			if (host->h_nsmhandle == nsm
			 && host->h_nsmstate != new_state) {
				host->h_nsmstate = new_state;
				host->h_state++;

				nlm_get_host(host);
				mutex_unlock(&nlm_host_mutex);

				if (host->h_server) {
					/* We're server for this guy, just ditch
					 * all the locks he held. */
					nlmsvc_free_host_resources(host);
				} else {
					/* He's the server, initiate lock recovery. */
					nlmclnt_recovery(host);
				}

				nlm_release_host(host);
				goto again;
			}
		}
	}

	mutex_unlock(&nlm_host_mutex);
}

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

	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 (chain = nlm_hosts; chain < nlm_hosts + NLM_HOST_NRHASH; ++chain) {
		hlist_for_each_entry(host, pos, chain, h_hash) {
			host->h_expires = jiffies - 1;
			if (host->h_rpcclnt) {
				rpc_shutdown_client(host->h_rpcclnt);
				host->h_rpcclnt = NULL;
			}
		}
	}

	/* 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 (chain = nlm_hosts; chain < nlm_hosts + NLM_HOST_NRHASH; ++chain) {
			hlist_for_each_entry(host, pos, chain, h_hash) {
				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 hlist_head *chain;
	struct hlist_node *pos, *next;
	struct nlm_host	*host;

	dprintk("lockd: host garbage collection\n");
	for (chain = nlm_hosts; chain < nlm_hosts + NLM_HOST_NRHASH; ++chain) {
		hlist_for_each_entry(host, pos, chain, h_hash)
			host->h_inuse = 0;
	}

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

	for (chain = nlm_hosts; chain < nlm_hosts + NLM_HOST_NRHASH; ++chain) {
		hlist_for_each_entry_safe(host, pos, next, chain, h_hash) {
			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);
				continue;
			}
			dprintk("lockd: delete host %s\n", host->h_name);
			hlist_del_init(&host->h_hash);

			nlm_destroy_host(host);
			nrhosts--;
		}
	}

	next_gc = jiffies + NLM_HOST_COLLECT;
}


/*
 * Manage NSM handles
 */
static LIST_HEAD(nsm_handles);
static DEFINE_MUTEX(nsm_mutex);

static struct nsm_handle *
__nsm_find(const struct sockaddr_in *sin,
		const char *hostname, unsigned 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;
	}

	mutex_lock(&nsm_mutex);
	list_for_each(pos, &nsm_handles) {
		nsm = list_entry(pos, struct nsm_handle, sm_link);

		if (hostname && nsm_use_hostnames) {
			if (strlen(nsm->sm_name) != hostname_len
			 || memcmp(nsm->sm_name, hostname, hostname_len))
				continue;
		} else 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:
	mutex_unlock(&nsm_mutex);
	return nsm;
}

static struct nsm_handle *
nsm_find(const struct sockaddr_in *sin, const char *hostname,
	 unsigned 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)) {
		mutex_lock(&nsm_mutex);
		if (atomic_read(&nsm->sm_count) == 0) {
			list_del(&nsm->sm_link);
			kfree(nsm);
		}
		mutex_unlock(&nsm_mutex);
	}
}
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>
1da177e4 LT	12	#include <linux/slab.h>
	13	#include <linux/in.h>
	14	#include <linux/sunrpc/clnt.h>
	15	#include <linux/sunrpc/svc.h>
	16	#include <linux/lockd/lockd.h>
	17	#include <linux/lockd/sm_inter.h>
353ab6e9	18	#include <linux/mutex.h>
1da177e4 LT	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)
1da177e4	28
0cea3276	29	static struct hlist_head nlm_hosts[NLM_HOST_NRHASH];
1da177e4 LT	30	static unsigned long next_gc;
1da177e4 LT	31	static int nrhosts;
353ab6e9	32	static DEFINE_MUTEX(nlm_host_mutex);
1da177e4 LT	33
	34
	35	static void nlm_gc_hosts(void);
8dead0db	36	static struct nsm_handle * __nsm_find(const struct sockaddr_in *,
48df020a	37	const char *, unsigned int, int);
c585646d AB	38	static struct nsm_handle * nsm_find(const struct sockaddr_in *sin,
c585646d AB	39	const char *hostname,
48df020a	40	unsigned int hostname_len);
1da177e4 LT	41
	42	/*
	43	* Common host lookup routine for server & client
	44	*/
c585646d	45	static struct nlm_host *
cf712c24	46	nlm_lookup_host(int server, const struct sockaddr_in *sin,
c98451bd	47	int proto, int version, const char *hostname,
48df020a CL	48	unsigned int hostname_len,
48df020a CL	49	const struct sockaddr_in *ssin)
1da177e4	50	{
0cea3276 OK	51	struct hlist_head *chain;
	52	struct hlist_node *pos;
	53	struct nlm_host *host;
8dead0db	54	struct nsm_handle *nsm = NULL;
1da177e4 LT	55	int hash;
1da177e4 LT	56
c98451bd FM	57	dprintk("lockd: nlm_lookup_host("NIPQUAD_FMT"->"NIPQUAD_FMT
	58	", p=%d, v=%d, my role=%s, name=%.*s)\n",
	59	NIPQUAD(ssin->sin_addr.s_addr),
db4e4c9a OK	60	NIPQUAD(sin->sin_addr.s_addr), proto, version,
	61	server? "server" : "client",
	62	hostname_len,
	63	hostname? hostname : "<none>");
	64
1da177e4 LT	65
	66	hash = NLM_ADDRHASH(sin->sin_addr.s_addr);
	67
	68	/* Lock hash table */
353ab6e9	69	mutex_lock(&nlm_host_mutex);
1da177e4 LT	70
	71	if (time_after_eq(jiffies, next_gc))
	72	nlm_gc_hosts();
	73
8dead0db OK	74	/* We may keep several nlm_host objects for a peer, because each
	75	* nlm_host is identified by
	76	* (address, protocol, version, server/client)
	77	* We could probably simplify this a little by putting all those
	78	* different NLM rpc_clients into one single nlm_host object.
	79	* This would allow us to have one nlm_host per address.
	80	*/
0cea3276 OK	81	chain = &nlm_hosts[hash];
0cea3276 OK	82	hlist_for_each_entry(host, pos, chain, h_hash) {
8dead0db OK	83	if (!nlm_cmp_addr(&host->h_addr, sin))
	84	continue;
	85
	86	/* See if we have an NSM handle for this client */
6b54dae2 N	87	if (!nsm)
6b54dae2 N	88	nsm = host->h_nsmhandle;
8dead0db	89
1da177e4 LT	90	if (host->h_proto != proto)
	91	continue;
	92	if (host->h_version != version)
	93	continue;
	94	if (host->h_server != server)
	95	continue;
c98451bd FM	96	if (!nlm_cmp_addr(&host->h_saddr, ssin))
c98451bd FM	97	continue;
1da177e4	98
0cea3276 OK	99	/* Move to head of hash chain. */
	100	hlist_del(&host->h_hash);
	101	hlist_add_head(&host->h_hash, chain);
	102
f0737a39 OK	103	nlm_get_host(host);
f0737a39 OK	104	goto out;
1da177e4	105	}
6b54dae2 N	106	if (nsm)
6b54dae2 N	107	atomic_inc(&nsm->sm_count);
1da177e4	108
0cea3276 OK	109	host = NULL;
0cea3276 OK	110
8dead0db OK	111	/* Sadly, the host isn't in our hash table yet. See if
	112	* we have an NSM handle for it. If not, create one.
	113	*/
	114	if (!nsm && !(nsm = nsm_find(sin, hostname, hostname_len)))
	115	goto out;
1da177e4	116
f8314dc6	117	host = kzalloc(sizeof(*host), GFP_KERNEL);
8dead0db OK	118	if (!host) {
	119	nsm_release(nsm);
	120	goto out;
	121	}
	122	host->h_name = nsm->sm_name;
1da177e4 LT	123	host->h_addr = *sin;
1da177e4 LT	124	host->h_addr.sin_port = 0; /* ouch! */
c98451bd	125	host->h_saddr = *ssin;
1da177e4 LT	126	host->h_version = version;
	127	host->h_proto = proto;
	128	host->h_rpcclnt = NULL;
50467914	129	mutex_init(&host->h_mutex);
1da177e4 LT	130	host->h_nextrebind = jiffies + NLM_HOST_REBIND;
	131	host->h_expires = jiffies + NLM_HOST_EXPIRE;
	132	atomic_set(&host->h_count, 1);
	133	init_waitqueue_head(&host->h_gracewait);
28df955a	134	init_rwsem(&host->h_rwsem);
1da177e4 LT	135	host->h_state = 0; /* pseudo NSM state */
1da177e4 LT	136	host->h_nsmstate = 0; /* real NSM state */
8dead0db	137	host->h_nsmhandle = nsm;
1da177e4	138	host->h_server = server;
0cea3276	139	hlist_add_head(&host->h_hash, chain);
1da177e4 LT	140	INIT_LIST_HEAD(&host->h_lockowners);
1da177e4 LT	141	spin_lock_init(&host->h_lock);
26bcbf96 CH	142	INIT_LIST_HEAD(&host->h_granted);
26bcbf96 CH	143	INIT_LIST_HEAD(&host->h_reclaim);
1da177e4 LT	144
	145	if (++nrhosts > NLM_HOST_MAX)
	146	next_gc = 0;
	147
8dead0db	148	out:
353ab6e9	149	mutex_unlock(&nlm_host_mutex);
1da177e4 LT	150	return host;
	151	}
	152
c53c1bb9 OK	153	/*
	154	* Destroy a host
	155	*/
	156	static void
	157	nlm_destroy_host(struct nlm_host *host)
	158	{
	159	struct rpc_clnt *clnt;
	160
	161	BUG_ON(!list_empty(&host->h_lockowners));
	162	BUG_ON(atomic_read(&host->h_count));
	163
	164	/*
	165	* Release NSM handle and unmonitor host.
	166	*/
	167	nsm_unmonitor(host);
	168
34f52e35 TM	169	clnt = host->h_rpcclnt;
	170	if (clnt != NULL)
	171	rpc_shutdown_client(clnt);
c53c1bb9 OK	172	kfree(host);
	173	}
	174
c585646d AB	175	/*
	176	* Find an NLM server handle in the cache. If there is none, create it.
	177	*/
	178	struct nlm_host *
	179	nlmclnt_lookup_host(const struct sockaddr_in *sin, int proto, int version,
48df020a	180	const char *hostname, unsigned int hostname_len)
c585646d	181	{
c98451bd FM	182	struct sockaddr_in ssin = {0};
c98451bd FM	183
c585646d	184	return nlm_lookup_host(0, sin, proto, version,
c98451bd	185	hostname, hostname_len, &ssin);
c585646d AB	186	}
	187
	188	/*
	189	* Find an NLM client handle in the cache. If there is none, create it.
	190	*/
	191	struct nlm_host *
	192	nlmsvc_lookup_host(struct svc_rqst *rqstp,
48df020a	193	const char *hostname, unsigned int hostname_len)
c585646d	194	{
c98451bd FM	195	struct sockaddr_in ssin = {0};
	196
	197	ssin.sin_addr = rqstp->rq_daddr.addr;
27459f09	198	return nlm_lookup_host(1, svc_addr_in(rqstp),
c585646d	199	rqstp->rq_prot, rqstp->rq_vers,
c98451bd	200	hostname, hostname_len, &ssin);
c585646d AB	201	}
c585646d AB	202
1da177e4 LT	203	/*
	204	* Create the NLM RPC client for an NLM peer
	205	*/
	206	struct rpc_clnt *
	207	nlm_bind_host(struct nlm_host *host)
	208	{
	209	struct rpc_clnt *clnt;
1da177e4	210
c98451bd FM	211	dprintk("lockd: nlm_bind_host("NIPQUAD_FMT"->"NIPQUAD_FMT")\n",
	212	NIPQUAD(host->h_saddr.sin_addr),
	213	NIPQUAD(host->h_addr.sin_addr));
1da177e4 LT	214
1da177e4 LT	215	/* Lock host handle */
50467914	216	mutex_lock(&host->h_mutex);
1da177e4 LT	217
	218	/* If we've already created an RPC client, check whether
	219	* RPC rebind is required
1da177e4 LT	220	*/
1da177e4 LT	221	if ((clnt = host->h_rpcclnt) != NULL) {
43118c29	222	if (time_after_eq(jiffies, host->h_nextrebind)) {
35f5a422	223	rpc_force_rebind(clnt);
1da177e4 LT	224	host->h_nextrebind = jiffies + NLM_HOST_REBIND;
	225	dprintk("lockd: next rebind in %ld jiffies\n",
	226	host->h_nextrebind - jiffies);
	227	}
	228	} else {
21051ba6	229	unsigned long increment = nlmsvc_timeout;
e1ec7892 CL	230	struct rpc_timeout timeparms = {
	231	.to_initval = increment,
	232	.to_increment = increment,
	233	.to_maxval = increment * 6UL,
	234	.to_retries = 5U,
	235	};
	236	struct rpc_create_args args = {
	237	.protocol = host->h_proto,
	238	.address = (struct sockaddr *)&host->h_addr,
	239	.addrsize = sizeof(host->h_addr),
c98451bd	240	.saddress = (struct sockaddr *)&host->h_saddr,
e1ec7892 CL	241	.timeout = &timeparms,
	242	.servername = host->h_name,
	243	.program = &nlm_program,
	244	.version = host->h_version,
	245	.authflavor = RPC_AUTH_UNIX,
90bd17c8	246	.flags = (RPC_CLNT_CREATE_NOPING \|
e1ec7892 CL	247	RPC_CLNT_CREATE_AUTOBIND),
	248	};
	249
90bd17c8 JL	250	/*
	251	* lockd retries server side blocks automatically so we want
	252	* those to be soft RPC calls. Client side calls need to be
	253	* hard RPC tasks.
	254	*/
	255	if (!host->h_server)
	256	args.flags \|= RPC_CLNT_CREATE_HARDRTRY;
	257
e1ec7892 CL	258	clnt = rpc_create(&args);
	259	if (!IS_ERR(clnt))
	260	host->h_rpcclnt = clnt;
	261	else {
	262	printk("lockd: couldn't create RPC handle for %s\n", host->h_name);
	263	clnt = NULL;
	264	}
1da177e4 LT	265	}
1da177e4 LT	266
50467914	267	mutex_unlock(&host->h_mutex);
1da177e4	268	return clnt;
1da177e4 LT	269	}
	270
	271	/*
	272	* Force a portmap lookup of the remote lockd port
	273	*/
	274	void
	275	nlm_rebind_host(struct nlm_host *host)
	276	{
	277	dprintk("lockd: rebind host %s\n", host->h_name);
	278	if (host->h_rpcclnt && time_after_eq(jiffies, host->h_nextrebind)) {
35f5a422	279	rpc_force_rebind(host->h_rpcclnt);
1da177e4 LT	280	host->h_nextrebind = jiffies + NLM_HOST_REBIND;
	281	}
	282	}
	283
	284	/*
	285	* Increment NLM host count
	286	*/
	287	struct nlm_host * nlm_get_host(struct nlm_host *host)
	288	{
	289	if (host) {
	290	dprintk("lockd: get host %s\n", host->h_name);
	291	atomic_inc(&host->h_count);
	292	host->h_expires = jiffies + NLM_HOST_EXPIRE;
	293	}
	294	return host;
	295	}
	296
	297	/*
	298	* Release NLM host after use
	299	*/
	300	void nlm_release_host(struct nlm_host *host)
	301	{
	302	if (host != NULL) {
	303	dprintk("lockd: release host %s\n", host->h_name);
1da177e4	304	BUG_ON(atomic_read(&host->h_count) < 0);
4c060b53 TM	305	if (atomic_dec_and_test(&host->h_count)) {
	306	BUG_ON(!list_empty(&host->h_lockowners));
	307	BUG_ON(!list_empty(&host->h_granted));
	308	BUG_ON(!list_empty(&host->h_reclaim));
	309	}
1da177e4 LT	310	}
	311	}
	312
cf712c24 OK	313	/*
	314	* We were notified that the host indicated by address &sin
	315	* has rebooted.
	316	* Release all resources held by that peer.
	317	*/
5c8dd29c	318	void nlm_host_rebooted(const struct sockaddr_in *sin,
48df020a CL	319	const char *hostname,
48df020a CL	320	unsigned int hostname_len,
5c8dd29c	321	u32 new_state)
cf712c24	322	{
0cea3276 OK	323	struct hlist_head *chain;
0cea3276 OK	324	struct hlist_node *pos;
5c8dd29c	325	struct nsm_handle *nsm;
0cea3276	326	struct nlm_host *host;
cf712c24	327
5c8dd29c OK	328	dprintk("lockd: nlm_host_rebooted(%s, %u.%u.%u.%u)\n",
	329	hostname, NIPQUAD(sin->sin_addr));
	330
	331	/* Find the NSM handle for this peer */
	332	if (!(nsm = __nsm_find(sin, hostname, hostname_len, 0)))
db4e4c9a OK	333	return;
db4e4c9a OK	334
5c8dd29c OK	335	/* When reclaiming locks on this peer, make sure that
	336	* we set up a new notification */
	337	nsm->sm_monitored = 0;
	338
	339	/* Mark all hosts tied to this NSM state as having rebooted.
	340	* We run the loop repeatedly, because we drop the host table
	341	* lock for this.
	342	* To avoid processing a host several times, we match the nsmstate.
	343	*/
	344	again: mutex_lock(&nlm_host_mutex);
0cea3276 OK	345	for (chain = nlm_hosts; chain < nlm_hosts + NLM_HOST_NRHASH; ++chain) {
0cea3276 OK	346	hlist_for_each_entry(host, pos, chain, h_hash) {
5c8dd29c OK	347	if (host->h_nsmhandle == nsm
	348	&& host->h_nsmstate != new_state) {
	349	host->h_nsmstate = new_state;
	350	host->h_state++;
	351
	352	nlm_get_host(host);
	353	mutex_unlock(&nlm_host_mutex);
	354
	355	if (host->h_server) {
	356	/* We're server for this guy, just ditch
	357	* all the locks he held. */
	358	nlmsvc_free_host_resources(host);
	359	} else {
	360	/* He's the server, initiate lock recovery. */
	361	nlmclnt_recovery(host);
	362	}
	363
	364	nlm_release_host(host);
	365	goto again;
	366	}
	367	}
cf712c24	368	}
5c8dd29c OK	369
5c8dd29c OK	370	mutex_unlock(&nlm_host_mutex);
cf712c24 OK	371	}
cf712c24 OK	372
1da177e4 LT	373	/*
	374	* Shut down the hosts module.
	375	* Note that this routine is called only at server shutdown time.
	376	*/
	377	void
	378	nlm_shutdown_hosts(void)
	379	{
0cea3276 OK	380	struct hlist_head *chain;
0cea3276 OK	381	struct hlist_node *pos;
1da177e4	382	struct nlm_host *host;
1da177e4 LT	383
1da177e4 LT	384	dprintk("lockd: shutting down host module\n");
353ab6e9	385	mutex_lock(&nlm_host_mutex);
1da177e4 LT	386
	387	/* First, make all hosts eligible for gc */
	388	dprintk("lockd: nuking all hosts...\n");
0cea3276	389	for (chain = nlm_hosts; chain < nlm_hosts + NLM_HOST_NRHASH; ++chain) {
d801b861	390	hlist_for_each_entry(host, pos, chain, h_hash) {
1da177e4	391	host->h_expires = jiffies - 1;
d801b861 JL	392	if (host->h_rpcclnt) {
	393	rpc_shutdown_client(host->h_rpcclnt);
	394	host->h_rpcclnt = NULL;
	395	}
	396	}
1da177e4 LT	397	}
	398
	399	/* Then, perform a garbage collection pass */
	400	nlm_gc_hosts();
353ab6e9	401	mutex_unlock(&nlm_host_mutex);
1da177e4 LT	402
	403	/* complain if any hosts are left */
	404	if (nrhosts) {
	405	printk(KERN_WARNING "lockd: couldn't shutdown host module!\n");
	406	dprintk("lockd: %d hosts left:\n", nrhosts);
0cea3276 OK	407	for (chain = nlm_hosts; chain < nlm_hosts + NLM_HOST_NRHASH; ++chain) {
0cea3276 OK	408	hlist_for_each_entry(host, pos, chain, h_hash) {
1da177e4 LT	409	dprintk(" %s (cnt %d use %d exp %ld)\n",
	410	host->h_name, atomic_read(&host->h_count),
	411	host->h_inuse, host->h_expires);
	412	}
	413	}
	414	}
	415	}
	416
	417	/*
	418	* Garbage collect any unused NLM hosts.
	419	* This GC combines reference counting for async operations with
	420	* mark & sweep for resources held by remote clients.
	421	*/
	422	static void
	423	nlm_gc_hosts(void)
	424	{
0cea3276 OK	425	struct hlist_head *chain;
	426	struct hlist_node pos, next;
	427	struct nlm_host *host;
1da177e4 LT	428
1da177e4 LT	429	dprintk("lockd: host garbage collection\n");
0cea3276 OK	430	for (chain = nlm_hosts; chain < nlm_hosts + NLM_HOST_NRHASH; ++chain) {
0cea3276 OK	431	hlist_for_each_entry(host, pos, chain, h_hash)
1da177e4 LT	432	host->h_inuse = 0;
	433	}
	434
	435	/* Mark all hosts that hold locks, blocks or shares */
	436	nlmsvc_mark_resources();
	437
0cea3276 OK	438	for (chain = nlm_hosts; chain < nlm_hosts + NLM_HOST_NRHASH; ++chain) {
0cea3276 OK	439	hlist_for_each_entry_safe(host, pos, next, chain, h_hash) {
1da177e4 LT	440	if (atomic_read(&host->h_count) \|\| host->h_inuse
	441	\|\| time_before(jiffies, host->h_expires)) {
	442	dprintk("nlm_gc_hosts skipping %s (cnt %d use %d exp %ld)\n",
	443	host->h_name, atomic_read(&host->h_count),
	444	host->h_inuse, host->h_expires);
1da177e4 LT	445	continue;
	446	}
	447	dprintk("lockd: delete host %s\n", host->h_name);
0cea3276	448	hlist_del_init(&host->h_hash);
977faf39	449
c53c1bb9	450	nlm_destroy_host(host);
1da177e4 LT	451	nrhosts--;
	452	}
	453	}
	454
	455	next_gc = jiffies + NLM_HOST_COLLECT;
	456	}
	457
8dead0db OK	458
	459	/*
	460	* Manage NSM handles
	461	*/
	462	static LIST_HEAD(nsm_handles);
89e63ef6	463	static DEFINE_MUTEX(nsm_mutex);
8dead0db OK	464
	465	static struct nsm_handle *
	466	__nsm_find(const struct sockaddr_in *sin,
48df020a	467	const char *hostname, unsigned int hostname_len,
8dead0db OK	468	int create)
	469	{
	470	struct nsm_handle *nsm = NULL;
	471	struct list_head *pos;
	472
	473	if (!sin)
	474	return NULL;
	475
	476	if (hostname && memchr(hostname, '/', hostname_len) != NULL) {
	477	if (printk_ratelimit()) {
	478	printk(KERN_WARNING "Invalid hostname \"%.*s\" "
	479	"in NFS lock request\n",
	480	hostname_len, hostname);
	481	}
	482	return NULL;
	483	}
	484
89e63ef6	485	mutex_lock(&nsm_mutex);
8dead0db OK	486	list_for_each(pos, &nsm_handles) {
	487	nsm = list_entry(pos, struct nsm_handle, sm_link);
	488
abd1f500 OK	489	if (hostname && nsm_use_hostnames) {
	490	if (strlen(nsm->sm_name) != hostname_len
	491	\|\| memcmp(nsm->sm_name, hostname, hostname_len))
	492	continue;
	493	} else if (!nlm_cmp_addr(&nsm->sm_addr, sin))
8dead0db OK	494	continue;
	495	atomic_inc(&nsm->sm_count);
	496	goto out;
	497	}
	498
	499	if (!create) {
	500	nsm = NULL;
	501	goto out;
	502	}
	503
	504	nsm = kzalloc(sizeof(*nsm) + hostname_len + 1, GFP_KERNEL);
	505	if (nsm != NULL) {
	506	nsm->sm_addr = *sin;
	507	nsm->sm_name = (char *) (nsm + 1);
	508	memcpy(nsm->sm_name, hostname, hostname_len);
	509	nsm->sm_name[hostname_len] = '\0';
	510	atomic_set(&nsm->sm_count, 1);
	511
	512	list_add(&nsm->sm_link, &nsm_handles);
	513	}
	514
89e63ef6 NB	515	out:
89e63ef6 NB	516	mutex_unlock(&nsm_mutex);
8dead0db OK	517	return nsm;
	518	}
	519
c585646d	520	static struct nsm_handle *
48df020a CL	521	nsm_find(const struct sockaddr_in sin, const char hostname,
48df020a CL	522	unsigned int hostname_len)
8dead0db OK	523	{
	524	return __nsm_find(sin, hostname, hostname_len, 1);
	525	}
	526
	527	/*
	528	* Release an NSM handle
	529	*/
	530	void
	531	nsm_release(struct nsm_handle *nsm)
	532	{
	533	if (!nsm)
	534	return;
	535	if (atomic_dec_and_test(&nsm->sm_count)) {
89e63ef6	536	mutex_lock(&nsm_mutex);
8dead0db OK	537	if (atomic_read(&nsm->sm_count) == 0) {
	538	list_del(&nsm->sm_link);
	539	kfree(nsm);
	540	}
89e63ef6	541	mutex_unlock(&nsm_mutex);
8dead0db OK	542	}
8dead0db OK	543	}