[linux-block.git] / fs / lockd / svc.c

/*
 * linux/fs/lockd/svc.c
 *
 * This is the central lockd service.
 *
 * FIXME: Separate the lockd NFS server functionality from the lockd NFS
 * 	  client functionality. Oh why didn't Sun create two separate
 *	  services in the first place?
 *
 * Authors:	Olaf Kirch (okir@monad.swb.de)
 *
 * Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
 */

#include <linux/module.h>
#include <linux/init.h>
#include <linux/sysctl.h>
#include <linux/moduleparam.h>

#include <linux/sched.h>
#include <linux/errno.h>
#include <linux/in.h>
#include <linux/uio.h>
#include <linux/slab.h>
#include <linux/smp.h>
#include <linux/smp_lock.h>
#include <linux/mutex.h>
#include <linux/kthread.h>
#include <linux/freezer.h>

#include <linux/sunrpc/types.h>
#include <linux/sunrpc/stats.h>
#include <linux/sunrpc/clnt.h>
#include <linux/sunrpc/svc.h>
#include <linux/sunrpc/svcsock.h>
#include <net/ip.h>
#include <linux/lockd/lockd.h>
#include <linux/lockd/sm_inter.h>
#include <linux/nfs.h>

#define NLMDBG_FACILITY		NLMDBG_SVC
#define LOCKD_BUFSIZE		(1024 + NLMSVC_XDRSIZE)
#define ALLOWED_SIGS		(sigmask(SIGKILL))

static struct svc_program	nlmsvc_program;

struct nlmsvc_binding *		nlmsvc_ops;
EXPORT_SYMBOL(nlmsvc_ops);

static DEFINE_MUTEX(nlmsvc_mutex);
static unsigned int		nlmsvc_users;
static struct task_struct	*nlmsvc_task;
static struct svc_rqst		*nlmsvc_rqst;
unsigned long			nlmsvc_timeout;

/*
 * These can be set at insmod time (useful for NFS as root filesystem),
 * and also changed through the sysctl interface.  -- Jamie Lokier, Aug 2003
 */
static unsigned long		nlm_grace_period;
static unsigned long		nlm_timeout = LOCKD_DFLT_TIMEO;
static int			nlm_udpport, nlm_tcpport;
int				nsm_use_hostnames = 0;

/*
 * Constants needed for the sysctl interface.
 */
static const unsigned long	nlm_grace_period_min = 0;
static const unsigned long	nlm_grace_period_max = 240;
static const unsigned long	nlm_timeout_min = 3;
static const unsigned long	nlm_timeout_max = 20;
static const int		nlm_port_min = 0, nlm_port_max = 65535;

#ifdef CONFIG_SYSCTL
static struct ctl_table_header * nlm_sysctl_table;
#endif

static unsigned long get_lockd_grace_period(void)
{
	/* Note: nlm_timeout should always be nonzero */
	if (nlm_grace_period)
		return roundup(nlm_grace_period, nlm_timeout) * HZ;
	else
		return nlm_timeout * 5 * HZ;
}

static struct lock_manager lockd_manager = {
};

static void grace_ender(struct work_struct *not_used)
{
	locks_end_grace(&lockd_manager);
}

static DECLARE_DELAYED_WORK(grace_period_end, grace_ender);

static void set_grace_period(void)
{
	unsigned long grace_period = get_lockd_grace_period();

	locks_start_grace(&lockd_manager);
	cancel_delayed_work_sync(&grace_period_end);
	schedule_delayed_work(&grace_period_end, grace_period);
}

/*
 * This is the lockd kernel thread
 */
static int
lockd(void *vrqstp)
{
	int		err = 0, preverr = 0;
	struct svc_rqst *rqstp = vrqstp;

	/* try_to_freeze() is called from svc_recv() */
	set_freezable();

	/* Allow SIGKILL to tell lockd to drop all of its locks */
	allow_signal(SIGKILL);

	dprintk("NFS locking service started (ver " LOCKD_VERSION ").\n");

	/*
	 * FIXME: it would be nice if lockd didn't spend its entire life
	 * running under the BKL. At the very least, it would be good to
	 * have someone clarify what it's intended to protect here. I've
	 * seen some handwavy posts about posix locking needing to be
	 * done under the BKL, but it's far from clear.
	 */
	lock_kernel();

	if (!nlm_timeout)
		nlm_timeout = LOCKD_DFLT_TIMEO;
	nlmsvc_timeout = nlm_timeout * HZ;

	set_grace_period();

	/*
	 * The main request loop. We don't terminate until the last
	 * NFS mount or NFS daemon has gone away.
	 */
	while (!kthread_should_stop()) {
		long timeout = MAX_SCHEDULE_TIMEOUT;
		RPC_IFDEBUG(char buf[RPC_MAX_ADDRBUFLEN]);

		if (signalled()) {
			flush_signals(current);
			if (nlmsvc_ops) {
				nlmsvc_invalidate_all();
				set_grace_period();
			}
			continue;
		}

		timeout = nlmsvc_retry_blocked();

		/*
		 * Find a socket with data available and call its
		 * recvfrom routine.
		 */
		err = svc_recv(rqstp, timeout);
		if (err == -EAGAIN || err == -EINTR) {
			preverr = err;
			continue;
		}
		if (err < 0) {
			if (err != preverr) {
				printk(KERN_WARNING "%s: unexpected error "
					"from svc_recv (%d)\n", __func__, err);
				preverr = err;
			}
			schedule_timeout_interruptible(HZ);
			continue;
		}
		preverr = err;

		dprintk("lockd: request from %s\n",
				svc_print_addr(rqstp, buf, sizeof(buf)));

		svc_process(rqstp);
	}
	flush_signals(current);
	cancel_delayed_work_sync(&grace_period_end);
	if (nlmsvc_ops)
		nlmsvc_invalidate_all();
	nlm_shutdown_hosts();
	unlock_kernel();
	return 0;
}

/*
 * Ensure there are active UDP and TCP listeners for lockd.
 *
 * Even if we have only TCP NFS mounts and/or TCP NFSDs, some
 * local services (such as rpc.statd) still require UDP, and
 * some NFS servers do not yet support NLM over TCP.
 *
 * Returns zero if all listeners are available; otherwise a
 * negative errno value is returned.
 */
static int make_socks(struct svc_serv *serv)
{
	static int warned;
	struct svc_xprt *xprt;
	int err = 0;

	xprt = svc_find_xprt(serv, "udp", 0, 0);
	if (!xprt)
		err = svc_create_xprt(serv, "udp", nlm_udpport,
				      SVC_SOCK_DEFAULTS);
	else
		svc_xprt_put(xprt);
	if (err >= 0) {
		xprt = svc_find_xprt(serv, "tcp", 0, 0);
		if (!xprt)
			err = svc_create_xprt(serv, "tcp", nlm_tcpport,
					      SVC_SOCK_DEFAULTS);
		else
			svc_xprt_put(xprt);
	}
	if (err >= 0) {
		warned = 0;
		err = 0;
	} else if (warned++ == 0)
		printk(KERN_WARNING
		       "lockd_up: makesock failed, error=%d\n", err);
	return err;
}

/*
 * Bring up the lockd process if it's not already up.
 */
int lockd_up(void)
{
	struct svc_serv *serv;
	int		error = 0;

	mutex_lock(&nlmsvc_mutex);
	/*
	 * Check whether we're already up and running.
	 */
	if (nlmsvc_rqst)
		goto out;

	/*
	 * Sanity check: if there's no pid,
	 * we should be the first user ...
	 */
	if (nlmsvc_users)
		printk(KERN_WARNING
			"lockd_up: no pid, %d users??\n", nlmsvc_users);

	error = -ENOMEM;
	serv = svc_create(&nlmsvc_program, LOCKD_BUFSIZE, AF_INET, NULL);
	if (!serv) {
		printk(KERN_WARNING "lockd_up: create service failed\n");
		goto out;
	}

	error = make_socks(serv);
	if (error < 0)
		goto destroy_and_out;

	/*
	 * Create the kernel thread and wait for it to start.
	 */
	nlmsvc_rqst = svc_prepare_thread(serv, &serv->sv_pools[0]);
	if (IS_ERR(nlmsvc_rqst)) {
		error = PTR_ERR(nlmsvc_rqst);
		nlmsvc_rqst = NULL;
		printk(KERN_WARNING
			"lockd_up: svc_rqst allocation failed, error=%d\n",
			error);
		goto destroy_and_out;
	}

	svc_sock_update_bufs(serv);

	nlmsvc_task = kthread_run(lockd, nlmsvc_rqst, serv->sv_name);
	if (IS_ERR(nlmsvc_task)) {
		error = PTR_ERR(nlmsvc_task);
		svc_exit_thread(nlmsvc_rqst);
		nlmsvc_task = NULL;
		nlmsvc_rqst = NULL;
		printk(KERN_WARNING
			"lockd_up: kthread_run failed, error=%d\n", error);
		goto destroy_and_out;
	}

	/*
	 * Note: svc_serv structures have an initial use count of 1,
	 * so we exit through here on both success and failure.
	 */
destroy_and_out:
	svc_destroy(serv);
out:
	if (!error)
		nlmsvc_users++;
	mutex_unlock(&nlmsvc_mutex);
	return error;
}
EXPORT_SYMBOL(lockd_up);

/*
 * Decrement the user count and bring down lockd if we're the last.
 */
void
lockd_down(void)
{
	mutex_lock(&nlmsvc_mutex);
	if (nlmsvc_users) {
		if (--nlmsvc_users)
			goto out;
	} else {
		printk(KERN_ERR "lockd_down: no users! task=%p\n",
			nlmsvc_task);
		BUG();
	}

	if (!nlmsvc_task) {
		printk(KERN_ERR "lockd_down: no lockd running.\n");
		BUG();
	}
	kthread_stop(nlmsvc_task);
	svc_exit_thread(nlmsvc_rqst);
	nlmsvc_task = NULL;
	nlmsvc_rqst = NULL;
out:
	mutex_unlock(&nlmsvc_mutex);
}
EXPORT_SYMBOL(lockd_down);

#ifdef CONFIG_SYSCTL

/*
 * Sysctl parameters (same as module parameters, different interface).
 */

static ctl_table nlm_sysctls[] = {
	{
		.ctl_name	= CTL_UNNUMBERED,
		.procname	= "nlm_grace_period",
		.data		= &nlm_grace_period,
		.maxlen		= sizeof(unsigned long),
		.mode		= 0644,
		.proc_handler	= &proc_doulongvec_minmax,
		.extra1		= (unsigned long *) &nlm_grace_period_min,
		.extra2		= (unsigned long *) &nlm_grace_period_max,
	},
	{
		.ctl_name	= CTL_UNNUMBERED,
		.procname	= "nlm_timeout",
		.data		= &nlm_timeout,
		.maxlen		= sizeof(unsigned long),
		.mode		= 0644,
		.proc_handler	= &proc_doulongvec_minmax,
		.extra1		= (unsigned long *) &nlm_timeout_min,
		.extra2		= (unsigned long *) &nlm_timeout_max,
	},
	{
		.ctl_name	= CTL_UNNUMBERED,
		.procname	= "nlm_udpport",
		.data		= &nlm_udpport,
		.maxlen		= sizeof(int),
		.mode		= 0644,
		.proc_handler	= &proc_dointvec_minmax,
		.extra1		= (int *) &nlm_port_min,
		.extra2		= (int *) &nlm_port_max,
	},
	{
		.ctl_name	= CTL_UNNUMBERED,
		.procname	= "nlm_tcpport",
		.data		= &nlm_tcpport,
		.maxlen		= sizeof(int),
		.mode		= 0644,
		.proc_handler	= &proc_dointvec_minmax,
		.extra1		= (int *) &nlm_port_min,
		.extra2		= (int *) &nlm_port_max,
	},
	{
		.ctl_name	= CTL_UNNUMBERED,
		.procname	= "nsm_use_hostnames",
		.data		= &nsm_use_hostnames,
		.maxlen		= sizeof(int),
		.mode		= 0644,
		.proc_handler	= &proc_dointvec,
	},
	{
		.ctl_name	= CTL_UNNUMBERED,
		.procname	= "nsm_local_state",
		.data		= &nsm_local_state,
		.maxlen		= sizeof(int),
		.mode		= 0644,
		.proc_handler	= &proc_dointvec,
	},
	{ .ctl_name = 0 }
};

static ctl_table nlm_sysctl_dir[] = {
	{
		.ctl_name	= CTL_UNNUMBERED,
		.procname	= "nfs",
		.mode		= 0555,
		.child		= nlm_sysctls,
	},
	{ .ctl_name = 0 }
};

static ctl_table nlm_sysctl_root[] = {
	{
		.ctl_name	= CTL_FS,
		.procname	= "fs",
		.mode		= 0555,
		.child		= nlm_sysctl_dir,
	},
	{ .ctl_name = 0 }
};

#endif	/* CONFIG_SYSCTL */

/*
 * Module (and sysfs) parameters.
 */

#define param_set_min_max(name, type, which_strtol, min, max)		\
static int param_set_##name(const char *val, struct kernel_param *kp)	\
{									\
	char *endp;							\
	__typeof__(type) num = which_strtol(val, &endp, 0);		\
	if (endp == val || *endp || num < (min) || num > (max))		\
		return -EINVAL;						\
	*((int *) kp->arg) = num;					\
	return 0;							\
}

static inline int is_callback(u32 proc)
{
	return proc == NLMPROC_GRANTED
		|| proc == NLMPROC_GRANTED_MSG
		|| proc == NLMPROC_TEST_RES
		|| proc == NLMPROC_LOCK_RES
		|| proc == NLMPROC_CANCEL_RES
		|| proc == NLMPROC_UNLOCK_RES
		|| proc == NLMPROC_NSM_NOTIFY;
}


static int lockd_authenticate(struct svc_rqst *rqstp)
{
	rqstp->rq_client = NULL;
	switch (rqstp->rq_authop->flavour) {
		case RPC_AUTH_NULL:
		case RPC_AUTH_UNIX:
			if (rqstp->rq_proc == 0)
				return SVC_OK;
			if (is_callback(rqstp->rq_proc)) {
				/* Leave it to individual procedures to
				 * call nlmsvc_lookup_host(rqstp)
				 */
				return SVC_OK;
			}
			return svc_set_client(rqstp);
	}
	return SVC_DENIED;
}


param_set_min_max(port, int, simple_strtol, 0, 65535)
param_set_min_max(grace_period, unsigned long, simple_strtoul,
		  nlm_grace_period_min, nlm_grace_period_max)
param_set_min_max(timeout, unsigned long, simple_strtoul,
		  nlm_timeout_min, nlm_timeout_max)

MODULE_AUTHOR("Olaf Kirch <okir@monad.swb.de>");
MODULE_DESCRIPTION("NFS file locking service version " LOCKD_VERSION ".");
MODULE_LICENSE("GPL");

module_param_call(nlm_grace_period, param_set_grace_period, param_get_ulong,
		  &nlm_grace_period, 0644);
module_param_call(nlm_timeout, param_set_timeout, param_get_ulong,
		  &nlm_timeout, 0644);
module_param_call(nlm_udpport, param_set_port, param_get_int,
		  &nlm_udpport, 0644);
module_param_call(nlm_tcpport, param_set_port, param_get_int,
		  &nlm_tcpport, 0644);
module_param(nsm_use_hostnames, bool, 0644);

/*
 * Initialising and terminating the module.
 */

static int __init init_nlm(void)
{
#ifdef CONFIG_SYSCTL
	nlm_sysctl_table = register_sysctl_table(nlm_sysctl_root);
	return nlm_sysctl_table ? 0 : -ENOMEM;
#else
	return 0;
#endif
}

static void __exit exit_nlm(void)
{
	/* FIXME: delete all NLM clients */
	nlm_shutdown_hosts();
#ifdef CONFIG_SYSCTL
	unregister_sysctl_table(nlm_sysctl_table);
#endif
}

module_init(init_nlm);
module_exit(exit_nlm);

/*
 * Define NLM program and procedures
 */
static struct svc_version	nlmsvc_version1 = {
		.vs_vers	= 1,
		.vs_nproc	= 17,
		.vs_proc	= nlmsvc_procedures,
		.vs_xdrsize	= NLMSVC_XDRSIZE,
};
static struct svc_version	nlmsvc_version3 = {
		.vs_vers	= 3,
		.vs_nproc	= 24,
		.vs_proc	= nlmsvc_procedures,
		.vs_xdrsize	= NLMSVC_XDRSIZE,
};
#ifdef CONFIG_LOCKD_V4
static struct svc_version	nlmsvc_version4 = {
		.vs_vers	= 4,
		.vs_nproc	= 24,
		.vs_proc	= nlmsvc_procedures4,
		.vs_xdrsize	= NLMSVC_XDRSIZE,
};
#endif
static struct svc_version *	nlmsvc_version[] = {
	[1] = &nlmsvc_version1,
	[3] = &nlmsvc_version3,
#ifdef CONFIG_LOCKD_V4
	[4] = &nlmsvc_version4,
#endif
};

static struct svc_stat		nlmsvc_stats;

#define NLM_NRVERS	ARRAY_SIZE(nlmsvc_version)
static struct svc_program	nlmsvc_program = {
	.pg_prog		= NLM_PROGRAM,		/* program number */
	.pg_nvers		= NLM_NRVERS,		/* number of entries in nlmsvc_version */
	.pg_vers		= nlmsvc_version,	/* version table */
	.pg_name		= "lockd",		/* service name */
	.pg_class		= "nfsd",		/* share authentication with nfsd */
	.pg_stats		= &nlmsvc_stats,	/* stats table */
	.pg_authenticate = &lockd_authenticate	/* export authentication */
};
Commit	Line	Data
	1	/*
	2	* linux/fs/lockd/svc.c
	3	*
	4	* This is the central lockd service.
	5	*
	6	* FIXME: Separate the lockd NFS server functionality from the lockd NFS
	7	* client functionality. Oh why didn't Sun create two separate
	8	* services in the first place?
	9	*
	10	* Authors: Olaf Kirch (okir@monad.swb.de)
	11	*
	12	* Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
	13	*/
	14
	15	#include <linux/module.h>
	16	#include <linux/init.h>
	17	#include <linux/sysctl.h>
	18	#include <linux/moduleparam.h>
	19
	20	#include <linux/sched.h>
	21	#include <linux/errno.h>
	22	#include <linux/in.h>
	23	#include <linux/uio.h>
	24	#include <linux/slab.h>
	25	#include <linux/smp.h>
	26	#include <linux/smp_lock.h>
	27	#include <linux/mutex.h>
	28	#include <linux/kthread.h>
	29	#include <linux/freezer.h>
	30
	31	#include <linux/sunrpc/types.h>
	32	#include <linux/sunrpc/stats.h>
	33	#include <linux/sunrpc/clnt.h>
	34	#include <linux/sunrpc/svc.h>
	35	#include <linux/sunrpc/svcsock.h>
	36	#include <net/ip.h>
	37	#include <linux/lockd/lockd.h>
	38	#include <linux/lockd/sm_inter.h>
	39	#include <linux/nfs.h>
	40
	41	#define NLMDBG_FACILITY NLMDBG_SVC
	42	#define LOCKD_BUFSIZE (1024 + NLMSVC_XDRSIZE)
	43	#define ALLOWED_SIGS (sigmask(SIGKILL))
	44
	45	static struct svc_program nlmsvc_program;
	46
	47	struct nlmsvc_binding * nlmsvc_ops;
	48	EXPORT_SYMBOL(nlmsvc_ops);
	49
	50	static DEFINE_MUTEX(nlmsvc_mutex);
	51	static unsigned int nlmsvc_users;
	52	static struct task_struct *nlmsvc_task;
	53	static struct svc_rqst *nlmsvc_rqst;
	54	unsigned long nlmsvc_timeout;
	55
	56	/*
	57	* These can be set at insmod time (useful for NFS as root filesystem),
	58	* and also changed through the sysctl interface. -- Jamie Lokier, Aug 2003
	59	*/
	60	static unsigned long nlm_grace_period;
	61	static unsigned long nlm_timeout = LOCKD_DFLT_TIMEO;
	62	static int nlm_udpport, nlm_tcpport;
	63	int nsm_use_hostnames = 0;
	64
	65	/*
	66	* Constants needed for the sysctl interface.
	67	*/
	68	static const unsigned long nlm_grace_period_min = 0;
	69	static const unsigned long nlm_grace_period_max = 240;
	70	static const unsigned long nlm_timeout_min = 3;
	71	static const unsigned long nlm_timeout_max = 20;
	72	static const int nlm_port_min = 0, nlm_port_max = 65535;
	73
	74	#ifdef CONFIG_SYSCTL
	75	static struct ctl_table_header * nlm_sysctl_table;
	76	#endif
	77
	78	static unsigned long get_lockd_grace_period(void)
	79	{
	80	/* Note: nlm_timeout should always be nonzero */
	81	if (nlm_grace_period)
	82	return roundup(nlm_grace_period, nlm_timeout) * HZ;
	83	else
	84	return nlm_timeout * 5 * HZ;
	85	}
	86
	87	static struct lock_manager lockd_manager = {
	88	};
	89
	90	static void grace_ender(struct work_struct *not_used)
	91	{
	92	locks_end_grace(&lockd_manager);
	93	}
	94
	95	static DECLARE_DELAYED_WORK(grace_period_end, grace_ender);
	96
	97	static void set_grace_period(void)
	98	{
	99	unsigned long grace_period = get_lockd_grace_period();
	100
	101	locks_start_grace(&lockd_manager);
	102	cancel_delayed_work_sync(&grace_period_end);
	103	schedule_delayed_work(&grace_period_end, grace_period);
	104	}
	105
	106	/*
	107	* This is the lockd kernel thread
	108	*/
	109	static int
	110	lockd(void *vrqstp)
	111	{
	112	int err = 0, preverr = 0;
	113	struct svc_rqst *rqstp = vrqstp;
	114
	115	/* try_to_freeze() is called from svc_recv() */
	116	set_freezable();
	117
	118	/* Allow SIGKILL to tell lockd to drop all of its locks */
	119	allow_signal(SIGKILL);
	120
	121	dprintk("NFS locking service started (ver " LOCKD_VERSION ").\n");
	122
	123	/*
	124	* FIXME: it would be nice if lockd didn't spend its entire life
	125	* running under the BKL. At the very least, it would be good to
	126	* have someone clarify what it's intended to protect here. I've
	127	* seen some handwavy posts about posix locking needing to be
	128	* done under the BKL, but it's far from clear.
	129	*/
	130	lock_kernel();
	131
	132	if (!nlm_timeout)
	133	nlm_timeout = LOCKD_DFLT_TIMEO;
	134	nlmsvc_timeout = nlm_timeout * HZ;
	135
	136	set_grace_period();
	137
	138	/*
	139	* The main request loop. We don't terminate until the last
	140	* NFS mount or NFS daemon has gone away.
	141	*/
	142	while (!kthread_should_stop()) {
	143	long timeout = MAX_SCHEDULE_TIMEOUT;
	144	RPC_IFDEBUG(char buf[RPC_MAX_ADDRBUFLEN]);
	145
	146	if (signalled()) {
	147	flush_signals(current);
	148	if (nlmsvc_ops) {
	149	nlmsvc_invalidate_all();
	150	set_grace_period();
	151	}
	152	continue;
	153	}
	154
	155	timeout = nlmsvc_retry_blocked();
	156
	157	/*
	158	* Find a socket with data available and call its
	159	* recvfrom routine.
	160	*/
	161	err = svc_recv(rqstp, timeout);
	162	if (err == -EAGAIN \|\| err == -EINTR) {
	163	preverr = err;
	164	continue;
	165	}
	166	if (err < 0) {
	167	if (err != preverr) {
	168	printk(KERN_WARNING "%s: unexpected error "
	169	"from svc_recv (%d)\n", __func__, err);
	170	preverr = err;
	171	}
	172	schedule_timeout_interruptible(HZ);
	173	continue;
	174	}
	175	preverr = err;
	176
	177	dprintk("lockd: request from %s\n",
	178	svc_print_addr(rqstp, buf, sizeof(buf)));
	179
	180	svc_process(rqstp);
	181	}
	182	flush_signals(current);
	183	cancel_delayed_work_sync(&grace_period_end);
	184	if (nlmsvc_ops)
	185	nlmsvc_invalidate_all();
	186	nlm_shutdown_hosts();
	187	unlock_kernel();
	188	return 0;
	189	}
	190
	191	/*
	192	* Ensure there are active UDP and TCP listeners for lockd.
	193	*
	194	* Even if we have only TCP NFS mounts and/or TCP NFSDs, some
	195	* local services (such as rpc.statd) still require UDP, and
	196	* some NFS servers do not yet support NLM over TCP.
	197	*
	198	* Returns zero if all listeners are available; otherwise a
	199	* negative errno value is returned.
	200	*/
	201	static int make_socks(struct svc_serv *serv)
	202	{
	203	static int warned;
	204	struct svc_xprt *xprt;
	205	int err = 0;
	206
	207	xprt = svc_find_xprt(serv, "udp", 0, 0);
	208	if (!xprt)
	209	err = svc_create_xprt(serv, "udp", nlm_udpport,
	210	SVC_SOCK_DEFAULTS);
	211	else
	212	svc_xprt_put(xprt);
	213	if (err >= 0) {
	214	xprt = svc_find_xprt(serv, "tcp", 0, 0);
	215	if (!xprt)
	216	err = svc_create_xprt(serv, "tcp", nlm_tcpport,
	217	SVC_SOCK_DEFAULTS);
	218	else
	219	svc_xprt_put(xprt);
	220	}
	221	if (err >= 0) {
	222	warned = 0;
	223	err = 0;
	224	} else if (warned++ == 0)
	225	printk(KERN_WARNING
	226	"lockd_up: makesock failed, error=%d\n", err);
	227	return err;
	228	}
	229
	230	/*
	231	* Bring up the lockd process if it's not already up.
	232	*/
	233	int lockd_up(void)
	234	{
	235	struct svc_serv *serv;
	236	int error = 0;
	237
	238	mutex_lock(&nlmsvc_mutex);
	239	/*
	240	* Check whether we're already up and running.
	241	*/
	242	if (nlmsvc_rqst)
	243	goto out;
	244
	245	/*
	246	* Sanity check: if there's no pid,
	247	* we should be the first user ...
	248	*/
	249	if (nlmsvc_users)
	250	printk(KERN_WARNING
	251	"lockd_up: no pid, %d users??\n", nlmsvc_users);
	252
	253	error = -ENOMEM;
	254	serv = svc_create(&nlmsvc_program, LOCKD_BUFSIZE, AF_INET, NULL);
	255	if (!serv) {
	256	printk(KERN_WARNING "lockd_up: create service failed\n");
	257	goto out;
	258	}
	259
	260	error = make_socks(serv);
	261	if (error < 0)
	262	goto destroy_and_out;
	263
	264	/*
	265	* Create the kernel thread and wait for it to start.
	266	*/
	267	nlmsvc_rqst = svc_prepare_thread(serv, &serv->sv_pools[0]);
	268	if (IS_ERR(nlmsvc_rqst)) {
	269	error = PTR_ERR(nlmsvc_rqst);
	270	nlmsvc_rqst = NULL;
	271	printk(KERN_WARNING
	272	"lockd_up: svc_rqst allocation failed, error=%d\n",
	273	error);
	274	goto destroy_and_out;
	275	}
	276
	277	svc_sock_update_bufs(serv);
	278
	279	nlmsvc_task = kthread_run(lockd, nlmsvc_rqst, serv->sv_name);
	280	if (IS_ERR(nlmsvc_task)) {
	281	error = PTR_ERR(nlmsvc_task);
	282	svc_exit_thread(nlmsvc_rqst);
	283	nlmsvc_task = NULL;
	284	nlmsvc_rqst = NULL;
	285	printk(KERN_WARNING
	286	"lockd_up: kthread_run failed, error=%d\n", error);
	287	goto destroy_and_out;
	288	}
	289
	290	/*
	291	* Note: svc_serv structures have an initial use count of 1,
	292	* so we exit through here on both success and failure.
	293	*/
	294	destroy_and_out:
	295	svc_destroy(serv);
	296	out:
	297	if (!error)
	298	nlmsvc_users++;
	299	mutex_unlock(&nlmsvc_mutex);
	300	return error;
	301	}
	302	EXPORT_SYMBOL(lockd_up);
	303
	304	/*
	305	* Decrement the user count and bring down lockd if we're the last.
	306	*/
	307	void
	308	lockd_down(void)
	309	{
	310	mutex_lock(&nlmsvc_mutex);
	311	if (nlmsvc_users) {
	312	if (--nlmsvc_users)
	313	goto out;
	314	} else {
	315	printk(KERN_ERR "lockd_down: no users! task=%p\n",
	316	nlmsvc_task);
	317	BUG();
	318	}
	319
	320	if (!nlmsvc_task) {
	321	printk(KERN_ERR "lockd_down: no lockd running.\n");
	322	BUG();
	323	}
	324	kthread_stop(nlmsvc_task);
	325	svc_exit_thread(nlmsvc_rqst);
	326	nlmsvc_task = NULL;
	327	nlmsvc_rqst = NULL;
	328	out:
	329	mutex_unlock(&nlmsvc_mutex);
	330	}
	331	EXPORT_SYMBOL(lockd_down);
	332
	333	#ifdef CONFIG_SYSCTL
	334
	335	/*
	336	* Sysctl parameters (same as module parameters, different interface).
	337	*/
	338
	339	static ctl_table nlm_sysctls[] = {
	340	{
	341	.ctl_name = CTL_UNNUMBERED,
	342	.procname = "nlm_grace_period",
	343	.data = &nlm_grace_period,
	344	.maxlen = sizeof(unsigned long),
	345	.mode = 0644,
	346	.proc_handler = &proc_doulongvec_minmax,
	347	.extra1 = (unsigned long *) &nlm_grace_period_min,
	348	.extra2 = (unsigned long *) &nlm_grace_period_max,
	349	},
	350	{
	351	.ctl_name = CTL_UNNUMBERED,
	352	.procname = "nlm_timeout",
	353	.data = &nlm_timeout,
	354	.maxlen = sizeof(unsigned long),
	355	.mode = 0644,
	356	.proc_handler = &proc_doulongvec_minmax,
	357	.extra1 = (unsigned long *) &nlm_timeout_min,
	358	.extra2 = (unsigned long *) &nlm_timeout_max,
	359	},
	360	{
	361	.ctl_name = CTL_UNNUMBERED,
	362	.procname = "nlm_udpport",
	363	.data = &nlm_udpport,
	364	.maxlen = sizeof(int),
	365	.mode = 0644,
	366	.proc_handler = &proc_dointvec_minmax,
	367	.extra1 = (int *) &nlm_port_min,
	368	.extra2 = (int *) &nlm_port_max,
	369	},
	370	{
	371	.ctl_name = CTL_UNNUMBERED,
	372	.procname = "nlm_tcpport",
	373	.data = &nlm_tcpport,
	374	.maxlen = sizeof(int),
	375	.mode = 0644,
	376	.proc_handler = &proc_dointvec_minmax,
	377	.extra1 = (int *) &nlm_port_min,
	378	.extra2 = (int *) &nlm_port_max,
	379	},
	380	{
	381	.ctl_name = CTL_UNNUMBERED,
	382	.procname = "nsm_use_hostnames",
	383	.data = &nsm_use_hostnames,
	384	.maxlen = sizeof(int),
	385	.mode = 0644,
	386	.proc_handler = &proc_dointvec,
	387	},
	388	{
	389	.ctl_name = CTL_UNNUMBERED,
	390	.procname = "nsm_local_state",
	391	.data = &nsm_local_state,
	392	.maxlen = sizeof(int),
	393	.mode = 0644,
	394	.proc_handler = &proc_dointvec,
	395	},
	396	{ .ctl_name = 0 }
	397	};
	398
	399	static ctl_table nlm_sysctl_dir[] = {
	400	{
	401	.ctl_name = CTL_UNNUMBERED,
	402	.procname = "nfs",
	403	.mode = 0555,
	404	.child = nlm_sysctls,
	405	},
	406	{ .ctl_name = 0 }
	407	};
	408
	409	static ctl_table nlm_sysctl_root[] = {
	410	{
	411	.ctl_name = CTL_FS,
	412	.procname = "fs",
	413	.mode = 0555,
	414	.child = nlm_sysctl_dir,
	415	},
	416	{ .ctl_name = 0 }
	417	};
	418
	419	#endif /* CONFIG_SYSCTL */
	420
	421	/*
	422	* Module (and sysfs) parameters.
	423	*/
	424
	425	#define param_set_min_max(name, type, which_strtol, min, max) \
	426	static int param_set_##name(const char val, struct kernel_param kp) \
	427	{ \
	428	char *endp; \
	429	__typeof__(type) num = which_strtol(val, &endp, 0); \
	430	if (endp == val \|\| *endp \|\| num < (min) \|\| num > (max)) \
	431	return -EINVAL; \
	432	((int ) kp->arg) = num; \
	433	return 0; \
	434	}
	435
	436	static inline int is_callback(u32 proc)
	437	{
	438	return proc == NLMPROC_GRANTED
	439	\|\| proc == NLMPROC_GRANTED_MSG
	440	\|\| proc == NLMPROC_TEST_RES
	441	\|\| proc == NLMPROC_LOCK_RES
	442	\|\| proc == NLMPROC_CANCEL_RES
	443	\|\| proc == NLMPROC_UNLOCK_RES
	444	\|\| proc == NLMPROC_NSM_NOTIFY;
	445	}
	446
	447
	448	static int lockd_authenticate(struct svc_rqst *rqstp)
	449	{
	450	rqstp->rq_client = NULL;
	451	switch (rqstp->rq_authop->flavour) {
	452	case RPC_AUTH_NULL:
	453	case RPC_AUTH_UNIX:
	454	if (rqstp->rq_proc == 0)
	455	return SVC_OK;
	456	if (is_callback(rqstp->rq_proc)) {
	457	/* Leave it to individual procedures to
	458	* call nlmsvc_lookup_host(rqstp)
	459	*/
	460	return SVC_OK;
	461	}
	462	return svc_set_client(rqstp);
	463	}
	464	return SVC_DENIED;
	465	}
	466
	467
	468	param_set_min_max(port, int, simple_strtol, 0, 65535)
	469	param_set_min_max(grace_period, unsigned long, simple_strtoul,
	470	nlm_grace_period_min, nlm_grace_period_max)
	471	param_set_min_max(timeout, unsigned long, simple_strtoul,
	472	nlm_timeout_min, nlm_timeout_max)
	473
	474	MODULE_AUTHOR("Olaf Kirch <okir@monad.swb.de>");
	475	MODULE_DESCRIPTION("NFS file locking service version " LOCKD_VERSION ".");
	476	MODULE_LICENSE("GPL");
	477
	478	module_param_call(nlm_grace_period, param_set_grace_period, param_get_ulong,
	479	&nlm_grace_period, 0644);
	480	module_param_call(nlm_timeout, param_set_timeout, param_get_ulong,
	481	&nlm_timeout, 0644);
	482	module_param_call(nlm_udpport, param_set_port, param_get_int,
	483	&nlm_udpport, 0644);
	484	module_param_call(nlm_tcpport, param_set_port, param_get_int,
	485	&nlm_tcpport, 0644);
	486	module_param(nsm_use_hostnames, bool, 0644);
	487
	488	/*
	489	* Initialising and terminating the module.
	490	*/
	491
	492	static int __init init_nlm(void)
	493	{
	494	#ifdef CONFIG_SYSCTL
	495	nlm_sysctl_table = register_sysctl_table(nlm_sysctl_root);
	496	return nlm_sysctl_table ? 0 : -ENOMEM;
	497	#else
	498	return 0;
	499	#endif
	500	}
	501
	502	static void __exit exit_nlm(void)
	503	{
	504	/* FIXME: delete all NLM clients */
	505	nlm_shutdown_hosts();
	506	#ifdef CONFIG_SYSCTL
	507	unregister_sysctl_table(nlm_sysctl_table);
	508	#endif
	509	}
	510
	511	module_init(init_nlm);
	512	module_exit(exit_nlm);
	513
	514	/*
	515	* Define NLM program and procedures
	516	*/
	517	static struct svc_version nlmsvc_version1 = {
	518	.vs_vers = 1,
	519	.vs_nproc = 17,
	520	.vs_proc = nlmsvc_procedures,
	521	.vs_xdrsize = NLMSVC_XDRSIZE,
	522	};
	523	static struct svc_version nlmsvc_version3 = {
	524	.vs_vers = 3,
	525	.vs_nproc = 24,
	526	.vs_proc = nlmsvc_procedures,
	527	.vs_xdrsize = NLMSVC_XDRSIZE,
	528	};
	529	#ifdef CONFIG_LOCKD_V4
	530	static struct svc_version nlmsvc_version4 = {
	531	.vs_vers = 4,
	532	.vs_nproc = 24,
	533	.vs_proc = nlmsvc_procedures4,
	534	.vs_xdrsize = NLMSVC_XDRSIZE,
	535	};
	536	#endif
	537	static struct svc_version * nlmsvc_version[] = {
	538	[1] = &nlmsvc_version1,
	539	[3] = &nlmsvc_version3,
	540	#ifdef CONFIG_LOCKD_V4
	541	[4] = &nlmsvc_version4,
	542	#endif
	543	};
	544
	545	static struct svc_stat nlmsvc_stats;
	546
	547	#define NLM_NRVERS ARRAY_SIZE(nlmsvc_version)
	548	static struct svc_program nlmsvc_program = {
	549	.pg_prog = NLM_PROGRAM, /* program number */
	550	.pg_nvers = NLM_NRVERS, /* number of entries in nlmsvc_version */
	551	.pg_vers = nlmsvc_version, /* version table */
	552	.pg_name = "lockd", /* service name */
	553	.pg_class = "nfsd", /* share authentication with nfsd */
	554	.pg_stats = &nlmsvc_stats, /* stats table */
	555	.pg_authenticate = &lockd_authenticate /* export authentication */
	556	};