[net-next-2.6.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_NRHASH		32
#define NLM_ADDRHASH(addr)	(ntohl(addr) & (NLM_HOST_NRHASH-1))
#define NLM_HOST_REBIND		(60 * HZ)
#define NLM_HOST_EXPIRE		(300 * HZ)
#define NLM_HOST_COLLECT	(120 * 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, u32 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=%u, 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);

	nrhosts++;
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, u32 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_SPINLOCK(nsm_lock);

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 nsm_handle *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;
	}

retry:
	spin_lock(&nsm_lock);
	list_for_each_entry(pos, &nsm_handles, sm_link) {

		if (hostname && nsm_use_hostnames) {
			if (strlen(pos->sm_name) != hostname_len
			 || memcmp(pos->sm_name, hostname, hostname_len))
				continue;
		} else if (!nlm_cmp_addr(&pos->sm_addr, sin))
			continue;
		atomic_inc(&pos->sm_count);
		kfree(nsm);
		nsm = pos;
		goto found;
	}
	if (nsm) {
		list_add(&nsm->sm_link, &nsm_handles);
		goto found;
	}
	spin_unlock(&nsm_lock);

	if (!create)
		return NULL;

	nsm = kzalloc(sizeof(*nsm) + hostname_len + 1, GFP_KERNEL);
	if (nsm == NULL)
		return 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);
	goto retry;

found:
	spin_unlock(&nsm_lock);
	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_lock(&nsm->sm_count, &nsm_lock)) {
		list_del(&nsm->sm_link);
		spin_unlock(&nsm_lock);
		kfree(nsm);
	}
}
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
1da177e4 LT	22	#define NLM_HOST_NRHASH 32
	23	#define NLM_ADDRHASH(addr) (ntohl(addr) & (NLM_HOST_NRHASH-1))
	24	#define NLM_HOST_REBIND (60 * HZ)
1447d25e N	25	#define NLM_HOST_EXPIRE (300 * HZ)
1447d25e N	26	#define NLM_HOST_COLLECT (120 * HZ)
1da177e4	27
0cea3276	28	static struct hlist_head nlm_hosts[NLM_HOST_NRHASH];
1da177e4 LT	29	static unsigned long next_gc;
1da177e4 LT	30	static int nrhosts;
353ab6e9	31	static DEFINE_MUTEX(nlm_host_mutex);
1da177e4 LT	32
	33
	34	static void nlm_gc_hosts(void);
8dead0db	35	static struct nsm_handle * __nsm_find(const struct sockaddr_in *,
48df020a	36	const char *, unsigned int, int);
c585646d AB	37	static struct nsm_handle * nsm_find(const struct sockaddr_in *sin,
c585646d AB	38	const char *hostname,
48df020a	39	unsigned int hostname_len);
1da177e4 LT	40
	41	/*
	42	* Common host lookup routine for server & client
	43	*/
eb18860e CL	44	static struct nlm_host *nlm_lookup_host(int server,
	45	const struct sockaddr_in *sin,
	46	int proto, u32 version,
	47	const char *hostname,
	48	unsigned int hostname_len,
	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	57	dprintk("lockd: nlm_lookup_host("NIPQUAD_FMT"->"NIPQUAD_FMT
eb18860e	58	", p=%d, v=%u, my role=%s, name=%.*s)\n",
c98451bd	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	144
1447d25e	145	nrhosts++;
8dead0db	146	out:
353ab6e9	147	mutex_unlock(&nlm_host_mutex);
1da177e4 LT	148	return host;
	149	}
	150
c53c1bb9 OK	151	/*
	152	* Destroy a host
	153	*/
	154	static void
	155	nlm_destroy_host(struct nlm_host *host)
	156	{
	157	struct rpc_clnt *clnt;
	158
	159	BUG_ON(!list_empty(&host->h_lockowners));
	160	BUG_ON(atomic_read(&host->h_count));
	161
	162	/*
	163	* Release NSM handle and unmonitor host.
	164	*/
	165	nsm_unmonitor(host);
	166
34f52e35 TM	167	clnt = host->h_rpcclnt;
	168	if (clnt != NULL)
	169	rpc_shutdown_client(clnt);
c53c1bb9 OK	170	kfree(host);
	171	}
	172
c585646d AB	173	/*
	174	* Find an NLM server handle in the cache. If there is none, create it.
	175	*/
eb18860e CL	176	struct nlm_host nlmclnt_lookup_host(const struct sockaddr_in sin,
	177	int proto, u32 version,
	178	const char *hostname,
	179	unsigned int hostname_len)
c585646d	180	{
c98451bd FM	181	struct sockaddr_in ssin = {0};
c98451bd FM	182
c585646d	183	return nlm_lookup_host(0, sin, proto, version,
c98451bd	184	hostname, hostname_len, &ssin);
c585646d AB	185	}
	186
	187	/*
	188	* Find an NLM client handle in the cache. If there is none, create it.
	189	*/
	190	struct nlm_host *
	191	nlmsvc_lookup_host(struct svc_rqst *rqstp,
48df020a	192	const char *hostname, unsigned int hostname_len)
c585646d	193	{
c98451bd FM	194	struct sockaddr_in ssin = {0};
	195
	196	ssin.sin_addr = rqstp->rq_daddr.addr;
27459f09	197	return nlm_lookup_host(1, svc_addr_in(rqstp),
c585646d	198	rqstp->rq_prot, rqstp->rq_vers,
c98451bd	199	hostname, hostname_len, &ssin);
c585646d AB	200	}
c585646d AB	201
1da177e4 LT	202	/*
	203	* Create the NLM RPC client for an NLM peer
	204	*/
	205	struct rpc_clnt *
	206	nlm_bind_host(struct nlm_host *host)
	207	{
	208	struct rpc_clnt *clnt;
1da177e4	209
c98451bd FM	210	dprintk("lockd: nlm_bind_host("NIPQUAD_FMT"->"NIPQUAD_FMT")\n",
	211	NIPQUAD(host->h_saddr.sin_addr),
	212	NIPQUAD(host->h_addr.sin_addr));
1da177e4 LT	213
1da177e4 LT	214	/* Lock host handle */
50467914	215	mutex_lock(&host->h_mutex);
1da177e4 LT	216
	217	/* If we've already created an RPC client, check whether
	218	* RPC rebind is required
1da177e4 LT	219	*/
1da177e4 LT	220	if ((clnt = host->h_rpcclnt) != NULL) {
43118c29	221	if (time_after_eq(jiffies, host->h_nextrebind)) {
35f5a422	222	rpc_force_rebind(clnt);
1da177e4 LT	223	host->h_nextrebind = jiffies + NLM_HOST_REBIND;
	224	dprintk("lockd: next rebind in %ld jiffies\n",
	225	host->h_nextrebind - jiffies);
	226	}
	227	} else {
21051ba6	228	unsigned long increment = nlmsvc_timeout;
e1ec7892 CL	229	struct rpc_timeout timeparms = {
	230	.to_initval = increment,
	231	.to_increment = increment,
	232	.to_maxval = increment * 6UL,
	233	.to_retries = 5U,
	234	};
	235	struct rpc_create_args args = {
	236	.protocol = host->h_proto,
	237	.address = (struct sockaddr *)&host->h_addr,
	238	.addrsize = sizeof(host->h_addr),
c98451bd	239	.saddress = (struct sockaddr *)&host->h_saddr,
e1ec7892 CL	240	.timeout = &timeparms,
	241	.servername = host->h_name,
	242	.program = &nlm_program,
	243	.version = host->h_version,
	244	.authflavor = RPC_AUTH_UNIX,
90bd17c8	245	.flags = (RPC_CLNT_CREATE_NOPING \|
e1ec7892 CL	246	RPC_CLNT_CREATE_AUTOBIND),
	247	};
	248
90bd17c8 JL	249	/*
	250	* lockd retries server side blocks automatically so we want
	251	* those to be soft RPC calls. Client side calls need to be
	252	* hard RPC tasks.
	253	*/
	254	if (!host->h_server)
	255	args.flags \|= RPC_CLNT_CREATE_HARDRTRY;
	256
e1ec7892 CL	257	clnt = rpc_create(&args);
	258	if (!IS_ERR(clnt))
	259	host->h_rpcclnt = clnt;
	260	else {
	261	printk("lockd: couldn't create RPC handle for %s\n", host->h_name);
	262	clnt = NULL;
	263	}
1da177e4 LT	264	}
1da177e4 LT	265
50467914	266	mutex_unlock(&host->h_mutex);
1da177e4	267	return clnt;
1da177e4 LT	268	}
	269
	270	/*
	271	* Force a portmap lookup of the remote lockd port
	272	*/
	273	void
	274	nlm_rebind_host(struct nlm_host *host)
	275	{
	276	dprintk("lockd: rebind host %s\n", host->h_name);
	277	if (host->h_rpcclnt && time_after_eq(jiffies, host->h_nextrebind)) {
35f5a422	278	rpc_force_rebind(host->h_rpcclnt);
1da177e4 LT	279	host->h_nextrebind = jiffies + NLM_HOST_REBIND;
	280	}
	281	}
	282
	283	/*
	284	* Increment NLM host count
	285	*/
	286	struct nlm_host * nlm_get_host(struct nlm_host *host)
	287	{
	288	if (host) {
	289	dprintk("lockd: get host %s\n", host->h_name);
	290	atomic_inc(&host->h_count);
	291	host->h_expires = jiffies + NLM_HOST_EXPIRE;
	292	}
	293	return host;
	294	}
	295
	296	/*
	297	* Release NLM host after use
	298	*/
	299	void nlm_release_host(struct nlm_host *host)
	300	{
	301	if (host != NULL) {
	302	dprintk("lockd: release host %s\n", host->h_name);
1da177e4	303	BUG_ON(atomic_read(&host->h_count) < 0);
4c060b53 TM	304	if (atomic_dec_and_test(&host->h_count)) {
	305	BUG_ON(!list_empty(&host->h_lockowners));
	306	BUG_ON(!list_empty(&host->h_granted));
	307	BUG_ON(!list_empty(&host->h_reclaim));
	308	}
1da177e4 LT	309	}
	310	}
	311
cf712c24 OK	312	/*
	313	* We were notified that the host indicated by address &sin
	314	* has rebooted.
	315	* Release all resources held by that peer.
	316	*/
5c8dd29c	317	void nlm_host_rebooted(const struct sockaddr_in *sin,
48df020a CL	318	const char *hostname,
48df020a CL	319	unsigned int hostname_len,
5c8dd29c	320	u32 new_state)
cf712c24	321	{
0cea3276 OK	322	struct hlist_head *chain;
0cea3276 OK	323	struct hlist_node *pos;
5c8dd29c	324	struct nsm_handle *nsm;
0cea3276	325	struct nlm_host *host;
cf712c24	326
5c8dd29c OK	327	dprintk("lockd: nlm_host_rebooted(%s, %u.%u.%u.%u)\n",
	328	hostname, NIPQUAD(sin->sin_addr));
	329
	330	/* Find the NSM handle for this peer */
	331	if (!(nsm = __nsm_find(sin, hostname, hostname_len, 0)))
db4e4c9a OK	332	return;
db4e4c9a OK	333
5c8dd29c OK	334	/* When reclaiming locks on this peer, make sure that
	335	* we set up a new notification */
	336	nsm->sm_monitored = 0;
	337
	338	/* Mark all hosts tied to this NSM state as having rebooted.
	339	* We run the loop repeatedly, because we drop the host table
	340	* lock for this.
	341	* To avoid processing a host several times, we match the nsmstate.
	342	*/
	343	again: mutex_lock(&nlm_host_mutex);
0cea3276 OK	344	for (chain = nlm_hosts; chain < nlm_hosts + NLM_HOST_NRHASH; ++chain) {
0cea3276 OK	345	hlist_for_each_entry(host, pos, chain, h_hash) {
5c8dd29c OK	346	if (host->h_nsmhandle == nsm
	347	&& host->h_nsmstate != new_state) {
	348	host->h_nsmstate = new_state;
	349	host->h_state++;
	350
	351	nlm_get_host(host);
	352	mutex_unlock(&nlm_host_mutex);
	353
	354	if (host->h_server) {
	355	/* We're server for this guy, just ditch
	356	* all the locks he held. */
	357	nlmsvc_free_host_resources(host);
	358	} else {
	359	/* He's the server, initiate lock recovery. */
	360	nlmclnt_recovery(host);
	361	}
	362
	363	nlm_release_host(host);
	364	goto again;
	365	}
	366	}
cf712c24	367	}
5c8dd29c OK	368
5c8dd29c OK	369	mutex_unlock(&nlm_host_mutex);
cf712c24 OK	370	}
cf712c24 OK	371
1da177e4 LT	372	/*
	373	* Shut down the hosts module.
	374	* Note that this routine is called only at server shutdown time.
	375	*/
	376	void
	377	nlm_shutdown_hosts(void)
	378	{
0cea3276 OK	379	struct hlist_head *chain;
0cea3276 OK	380	struct hlist_node *pos;
1da177e4	381	struct nlm_host *host;
1da177e4 LT	382
1da177e4 LT	383	dprintk("lockd: shutting down host module\n");
353ab6e9	384	mutex_lock(&nlm_host_mutex);
1da177e4 LT	385
	386	/* First, make all hosts eligible for gc */
	387	dprintk("lockd: nuking all hosts...\n");
0cea3276	388	for (chain = nlm_hosts; chain < nlm_hosts + NLM_HOST_NRHASH; ++chain) {
d801b861	389	hlist_for_each_entry(host, pos, chain, h_hash) {
1da177e4	390	host->h_expires = jiffies - 1;
d801b861 JL	391	if (host->h_rpcclnt) {
	392	rpc_shutdown_client(host->h_rpcclnt);
	393	host->h_rpcclnt = NULL;
	394	}
	395	}
1da177e4 LT	396	}
	397
	398	/* Then, perform a garbage collection pass */
	399	nlm_gc_hosts();
353ab6e9	400	mutex_unlock(&nlm_host_mutex);
1da177e4 LT	401
	402	/* complain if any hosts are left */
	403	if (nrhosts) {
	404	printk(KERN_WARNING "lockd: couldn't shutdown host module!\n");
	405	dprintk("lockd: %d hosts left:\n", nrhosts);
0cea3276 OK	406	for (chain = nlm_hosts; chain < nlm_hosts + NLM_HOST_NRHASH; ++chain) {
0cea3276 OK	407	hlist_for_each_entry(host, pos, chain, h_hash) {
1da177e4 LT	408	dprintk(" %s (cnt %d use %d exp %ld)\n",
	409	host->h_name, atomic_read(&host->h_count),
	410	host->h_inuse, host->h_expires);
	411	}
	412	}
	413	}
	414	}
	415
	416	/*
	417	* Garbage collect any unused NLM hosts.
	418	* This GC combines reference counting for async operations with
	419	* mark & sweep for resources held by remote clients.
	420	*/
	421	static void
	422	nlm_gc_hosts(void)
	423	{
0cea3276 OK	424	struct hlist_head *chain;
	425	struct hlist_node pos, next;
	426	struct nlm_host *host;
1da177e4 LT	427
1da177e4 LT	428	dprintk("lockd: host garbage collection\n");
0cea3276 OK	429	for (chain = nlm_hosts; chain < nlm_hosts + NLM_HOST_NRHASH; ++chain) {
0cea3276 OK	430	hlist_for_each_entry(host, pos, chain, h_hash)
1da177e4 LT	431	host->h_inuse = 0;
	432	}
	433
	434	/* Mark all hosts that hold locks, blocks or shares */
	435	nlmsvc_mark_resources();
	436
0cea3276 OK	437	for (chain = nlm_hosts; chain < nlm_hosts + NLM_HOST_NRHASH; ++chain) {
0cea3276 OK	438	hlist_for_each_entry_safe(host, pos, next, chain, h_hash) {
1da177e4 LT	439	if (atomic_read(&host->h_count) \|\| host->h_inuse
	440	\|\| time_before(jiffies, host->h_expires)) {
	441	dprintk("nlm_gc_hosts skipping %s (cnt %d use %d exp %ld)\n",
	442	host->h_name, atomic_read(&host->h_count),
	443	host->h_inuse, host->h_expires);
1da177e4 LT	444	continue;
	445	}
	446	dprintk("lockd: delete host %s\n", host->h_name);
0cea3276	447	hlist_del_init(&host->h_hash);
977faf39	448
c53c1bb9	449	nlm_destroy_host(host);
1da177e4 LT	450	nrhosts--;
	451	}
	452	}
	453
	454	next_gc = jiffies + NLM_HOST_COLLECT;
	455	}
	456
8dead0db OK	457
	458	/*
	459	* Manage NSM handles
	460	*/
	461	static LIST_HEAD(nsm_handles);
d8421202	462	static DEFINE_SPINLOCK(nsm_lock);
8dead0db OK	463
	464	static struct nsm_handle *
	465	__nsm_find(const struct sockaddr_in *sin,
48df020a	466	const char *hostname, unsigned int hostname_len,
8dead0db OK	467	int create)
	468	{
	469	struct nsm_handle *nsm = NULL;
a95e56e7	470	struct nsm_handle *pos;
8dead0db OK	471
	472	if (!sin)
	473	return NULL;
	474
	475	if (hostname && memchr(hostname, '/', hostname_len) != NULL) {
	476	if (printk_ratelimit()) {
	477	printk(KERN_WARNING "Invalid hostname \"%.*s\" "
	478	"in NFS lock request\n",
	479	hostname_len, hostname);
	480	}
	481	return NULL;
	482	}
	483
d8421202 BF	484	retry:
d8421202 BF	485	spin_lock(&nsm_lock);
a95e56e7	486	list_for_each_entry(pos, &nsm_handles, sm_link) {
8dead0db	487
abd1f500	488	if (hostname && nsm_use_hostnames) {
a95e56e7 BF	489	if (strlen(pos->sm_name) != hostname_len
a95e56e7 BF	490	\|\| memcmp(pos->sm_name, hostname, hostname_len))
abd1f500	491	continue;
a95e56e7	492	} else if (!nlm_cmp_addr(&pos->sm_addr, sin))
8dead0db	493	continue;
a95e56e7	494	atomic_inc(&pos->sm_count);
d8421202	495	kfree(nsm);
a95e56e7	496	nsm = pos;
d8421202	497	goto found;
8dead0db	498	}
d8421202 BF	499	if (nsm) {
	500	list_add(&nsm->sm_link, &nsm_handles);
	501	goto found;
8dead0db	502	}
d8421202 BF	503	spin_unlock(&nsm_lock);
	504
	505	if (!create)
	506	return NULL;
8dead0db OK	507
8dead0db OK	508	nsm = kzalloc(sizeof(*nsm) + hostname_len + 1, GFP_KERNEL);
a95e56e7	509	if (nsm == NULL)
d8421202 BF	510	return NULL;
d8421202 BF	511
a95e56e7 BF	512	nsm->sm_addr = *sin;
	513	nsm->sm_name = (char *) (nsm + 1);
	514	memcpy(nsm->sm_name, hostname, hostname_len);
	515	nsm->sm_name[hostname_len] = '\0';
	516	atomic_set(&nsm->sm_count, 1);
d8421202	517	goto retry;
a95e56e7	518
d8421202 BF	519	found:
d8421202 BF	520	spin_unlock(&nsm_lock);
8dead0db OK	521	return nsm;
	522	}
	523
c585646d	524	static struct nsm_handle *
48df020a CL	525	nsm_find(const struct sockaddr_in sin, const char hostname,
48df020a CL	526	unsigned int hostname_len)
8dead0db OK	527	{
	528	return __nsm_find(sin, hostname, hostname_len, 1);
	529	}
	530
	531	/*
	532	* Release an NSM handle
	533	*/
	534	void
	535	nsm_release(struct nsm_handle *nsm)
	536	{
	537	if (!nsm)
	538	return;
d8421202	539	if (atomic_dec_and_lock(&nsm->sm_count, &nsm_lock)) {
164f98ad	540	list_del(&nsm->sm_link);
d8421202	541	spin_unlock(&nsm_lock);
164f98ad	542	kfree(nsm);
8dead0db OK	543	}
8dead0db OK	544	}