[mirror_ubuntu-artful-kernel.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_HARDRTRY |
					   RPC_CLNT_CREATE_NOPING |
					   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 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,
	246	.flags = (RPC_CLNT_CREATE_HARDRTRY \|
031fd3aa	247	RPC_CLNT_CREATE_NOPING \|
e1ec7892 CL	248	RPC_CLNT_CREATE_AUTOBIND),
	249	};
	250
	251	clnt = rpc_create(&args);
	252	if (!IS_ERR(clnt))
	253	host->h_rpcclnt = clnt;
	254	else {
	255	printk("lockd: couldn't create RPC handle for %s\n", host->h_name);
	256	clnt = NULL;
	257	}
1da177e4 LT	258	}
1da177e4 LT	259
50467914	260	mutex_unlock(&host->h_mutex);
1da177e4	261	return clnt;
1da177e4 LT	262	}
	263
	264	/*
	265	* Force a portmap lookup of the remote lockd port
	266	*/
	267	void
	268	nlm_rebind_host(struct nlm_host *host)
	269	{
	270	dprintk("lockd: rebind host %s\n", host->h_name);
	271	if (host->h_rpcclnt && time_after_eq(jiffies, host->h_nextrebind)) {
35f5a422	272	rpc_force_rebind(host->h_rpcclnt);
1da177e4 LT	273	host->h_nextrebind = jiffies + NLM_HOST_REBIND;
	274	}
	275	}
	276
	277	/*
	278	* Increment NLM host count
	279	*/
	280	struct nlm_host * nlm_get_host(struct nlm_host *host)
	281	{
	282	if (host) {
	283	dprintk("lockd: get host %s\n", host->h_name);
	284	atomic_inc(&host->h_count);
	285	host->h_expires = jiffies + NLM_HOST_EXPIRE;
	286	}
	287	return host;
	288	}
	289
	290	/*
	291	* Release NLM host after use
	292	*/
	293	void nlm_release_host(struct nlm_host *host)
	294	{
	295	if (host != NULL) {
	296	dprintk("lockd: release host %s\n", host->h_name);
1da177e4	297	BUG_ON(atomic_read(&host->h_count) < 0);
4c060b53 TM	298	if (atomic_dec_and_test(&host->h_count)) {
	299	BUG_ON(!list_empty(&host->h_lockowners));
	300	BUG_ON(!list_empty(&host->h_granted));
	301	BUG_ON(!list_empty(&host->h_reclaim));
	302	}
1da177e4 LT	303	}
	304	}
	305
cf712c24 OK	306	/*
	307	* We were notified that the host indicated by address &sin
	308	* has rebooted.
	309	* Release all resources held by that peer.
	310	*/
5c8dd29c	311	void nlm_host_rebooted(const struct sockaddr_in *sin,
48df020a CL	312	const char *hostname,
48df020a CL	313	unsigned int hostname_len,
5c8dd29c	314	u32 new_state)
cf712c24	315	{
0cea3276 OK	316	struct hlist_head *chain;
0cea3276 OK	317	struct hlist_node *pos;
5c8dd29c	318	struct nsm_handle *nsm;
0cea3276	319	struct nlm_host *host;
cf712c24	320
5c8dd29c OK	321	dprintk("lockd: nlm_host_rebooted(%s, %u.%u.%u.%u)\n",
	322	hostname, NIPQUAD(sin->sin_addr));
	323
	324	/* Find the NSM handle for this peer */
	325	if (!(nsm = __nsm_find(sin, hostname, hostname_len, 0)))
db4e4c9a OK	326	return;
db4e4c9a OK	327
5c8dd29c OK	328	/* When reclaiming locks on this peer, make sure that
	329	* we set up a new notification */
	330	nsm->sm_monitored = 0;
	331
	332	/* Mark all hosts tied to this NSM state as having rebooted.
	333	* We run the loop repeatedly, because we drop the host table
	334	* lock for this.
	335	* To avoid processing a host several times, we match the nsmstate.
	336	*/
	337	again: mutex_lock(&nlm_host_mutex);
0cea3276 OK	338	for (chain = nlm_hosts; chain < nlm_hosts + NLM_HOST_NRHASH; ++chain) {
0cea3276 OK	339	hlist_for_each_entry(host, pos, chain, h_hash) {
5c8dd29c OK	340	if (host->h_nsmhandle == nsm
	341	&& host->h_nsmstate != new_state) {
	342	host->h_nsmstate = new_state;
	343	host->h_state++;
	344
	345	nlm_get_host(host);
	346	mutex_unlock(&nlm_host_mutex);
	347
	348	if (host->h_server) {
	349	/* We're server for this guy, just ditch
	350	* all the locks he held. */
	351	nlmsvc_free_host_resources(host);
	352	} else {
	353	/* He's the server, initiate lock recovery. */
	354	nlmclnt_recovery(host);
	355	}
	356
	357	nlm_release_host(host);
	358	goto again;
	359	}
	360	}
cf712c24	361	}
5c8dd29c OK	362
5c8dd29c OK	363	mutex_unlock(&nlm_host_mutex);
cf712c24 OK	364	}
cf712c24 OK	365
1da177e4 LT	366	/*
	367	* Shut down the hosts module.
	368	* Note that this routine is called only at server shutdown time.
	369	*/
	370	void
	371	nlm_shutdown_hosts(void)
	372	{
0cea3276 OK	373	struct hlist_head *chain;
0cea3276 OK	374	struct hlist_node *pos;
1da177e4	375	struct nlm_host *host;
1da177e4 LT	376
1da177e4 LT	377	dprintk("lockd: shutting down host module\n");
353ab6e9	378	mutex_lock(&nlm_host_mutex);
1da177e4 LT	379
	380	/* First, make all hosts eligible for gc */
	381	dprintk("lockd: nuking all hosts...\n");
0cea3276	382	for (chain = nlm_hosts; chain < nlm_hosts + NLM_HOST_NRHASH; ++chain) {
d801b861	383	hlist_for_each_entry(host, pos, chain, h_hash) {
1da177e4	384	host->h_expires = jiffies - 1;
d801b861 JL	385	if (host->h_rpcclnt) {
	386	rpc_shutdown_client(host->h_rpcclnt);
	387	host->h_rpcclnt = NULL;
	388	}
	389	}
1da177e4 LT	390	}
	391
	392	/* Then, perform a garbage collection pass */
	393	nlm_gc_hosts();
353ab6e9	394	mutex_unlock(&nlm_host_mutex);
1da177e4 LT	395
	396	/* complain if any hosts are left */
	397	if (nrhosts) {
	398	printk(KERN_WARNING "lockd: couldn't shutdown host module!\n");
	399	dprintk("lockd: %d hosts left:\n", nrhosts);
0cea3276 OK	400	for (chain = nlm_hosts; chain < nlm_hosts + NLM_HOST_NRHASH; ++chain) {
0cea3276 OK	401	hlist_for_each_entry(host, pos, chain, h_hash) {
1da177e4 LT	402	dprintk(" %s (cnt %d use %d exp %ld)\n",
	403	host->h_name, atomic_read(&host->h_count),
	404	host->h_inuse, host->h_expires);
	405	}
	406	}
	407	}
	408	}
	409
	410	/*
	411	* Garbage collect any unused NLM hosts.
	412	* This GC combines reference counting for async operations with
	413	* mark & sweep for resources held by remote clients.
	414	*/
	415	static void
	416	nlm_gc_hosts(void)
	417	{
0cea3276 OK	418	struct hlist_head *chain;
	419	struct hlist_node pos, next;
	420	struct nlm_host *host;
1da177e4 LT	421
1da177e4 LT	422	dprintk("lockd: host garbage collection\n");
0cea3276 OK	423	for (chain = nlm_hosts; chain < nlm_hosts + NLM_HOST_NRHASH; ++chain) {
0cea3276 OK	424	hlist_for_each_entry(host, pos, chain, h_hash)
1da177e4 LT	425	host->h_inuse = 0;
	426	}
	427
	428	/* Mark all hosts that hold locks, blocks or shares */
	429	nlmsvc_mark_resources();
	430
0cea3276 OK	431	for (chain = nlm_hosts; chain < nlm_hosts + NLM_HOST_NRHASH; ++chain) {
0cea3276 OK	432	hlist_for_each_entry_safe(host, pos, next, chain, h_hash) {
1da177e4 LT	433	if (atomic_read(&host->h_count) \|\| host->h_inuse
	434	\|\| time_before(jiffies, host->h_expires)) {
	435	dprintk("nlm_gc_hosts skipping %s (cnt %d use %d exp %ld)\n",
	436	host->h_name, atomic_read(&host->h_count),
	437	host->h_inuse, host->h_expires);
1da177e4 LT	438	continue;
	439	}
	440	dprintk("lockd: delete host %s\n", host->h_name);
0cea3276	441	hlist_del_init(&host->h_hash);
977faf39	442
c53c1bb9	443	nlm_destroy_host(host);
1da177e4 LT	444	nrhosts--;
	445	}
	446	}
	447
	448	next_gc = jiffies + NLM_HOST_COLLECT;
	449	}
	450
8dead0db OK	451
	452	/*
	453	* Manage NSM handles
	454	*/
	455	static LIST_HEAD(nsm_handles);
89e63ef6	456	static DEFINE_MUTEX(nsm_mutex);
8dead0db OK	457
	458	static struct nsm_handle *
	459	__nsm_find(const struct sockaddr_in *sin,
48df020a	460	const char *hostname, unsigned int hostname_len,
8dead0db OK	461	int create)
	462	{
	463	struct nsm_handle *nsm = NULL;
	464	struct list_head *pos;
	465
	466	if (!sin)
	467	return NULL;
	468
	469	if (hostname && memchr(hostname, '/', hostname_len) != NULL) {
	470	if (printk_ratelimit()) {
	471	printk(KERN_WARNING "Invalid hostname \"%.*s\" "
	472	"in NFS lock request\n",
	473	hostname_len, hostname);
	474	}
	475	return NULL;
	476	}
	477
89e63ef6	478	mutex_lock(&nsm_mutex);
8dead0db OK	479	list_for_each(pos, &nsm_handles) {
	480	nsm = list_entry(pos, struct nsm_handle, sm_link);
	481
abd1f500 OK	482	if (hostname && nsm_use_hostnames) {
	483	if (strlen(nsm->sm_name) != hostname_len
	484	\|\| memcmp(nsm->sm_name, hostname, hostname_len))
	485	continue;
	486	} else if (!nlm_cmp_addr(&nsm->sm_addr, sin))
8dead0db OK	487	continue;
	488	atomic_inc(&nsm->sm_count);
	489	goto out;
	490	}
	491
	492	if (!create) {
	493	nsm = NULL;
	494	goto out;
	495	}
	496
	497	nsm = kzalloc(sizeof(*nsm) + hostname_len + 1, GFP_KERNEL);
	498	if (nsm != NULL) {
	499	nsm->sm_addr = *sin;
	500	nsm->sm_name = (char *) (nsm + 1);
	501	memcpy(nsm->sm_name, hostname, hostname_len);
	502	nsm->sm_name[hostname_len] = '\0';
	503	atomic_set(&nsm->sm_count, 1);
	504
	505	list_add(&nsm->sm_link, &nsm_handles);
	506	}
	507
89e63ef6 NB	508	out:
89e63ef6 NB	509	mutex_unlock(&nsm_mutex);
8dead0db OK	510	return nsm;
	511	}
	512
c585646d	513	static struct nsm_handle *
48df020a CL	514	nsm_find(const struct sockaddr_in sin, const char hostname,
48df020a CL	515	unsigned int hostname_len)
8dead0db OK	516	{
	517	return __nsm_find(sin, hostname, hostname_len, 1);
	518	}
	519
	520	/*
	521	* Release an NSM handle
	522	*/
	523	void
	524	nsm_release(struct nsm_handle *nsm)
	525	{
	526	if (!nsm)
	527	return;
	528	if (atomic_dec_and_test(&nsm->sm_count)) {
89e63ef6	529	mutex_lock(&nsm_mutex);
8dead0db OK	530	if (atomic_read(&nsm->sm_count) == 0) {
	531	list_del(&nsm->sm_link);
	532	kfree(nsm);
	533	}
89e63ef6	534	mutex_unlock(&nsm_mutex);
8dead0db OK	535	}
8dead0db OK	536	}