[net-next-2.6.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/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_GPL(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;

/* RLIM_NOFILE defaults to 1024. That seems like a reasonable default here. */
static unsigned int		nlm_max_connections = 1024;

/*
 * 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);
}

static void restart_grace(void)
{
	if (nlmsvc_ops) {
		cancel_delayed_work_sync(&grace_period_end);
		locks_end_grace(&lockd_manager);
		nlmsvc_invalidate_all();
		set_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]);

		/* update sv_maxconn if it has changed */
		rqstp->rq_server->sv_maxconn = nlm_max_connections;

		if (signalled()) {
			flush_signals(current);
			restart_grace();
			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);
	locks_end_grace(&lockd_manager);
	if (nlmsvc_ops)
		nlmsvc_invalidate_all();
	nlm_shutdown_hosts();
	unlock_kernel();
	return 0;
}

static int create_lockd_listener(struct svc_serv *serv, const char *name,
				 const int family, const unsigned short port)
{
	struct svc_xprt *xprt;

	xprt = svc_find_xprt(serv, name, family, 0);
	if (xprt == NULL)
		return svc_create_xprt(serv, name, family, port,
						SVC_SOCK_DEFAULTS);
	svc_xprt_put(xprt);
	return 0;
}

static int create_lockd_family(struct svc_serv *serv, const int family)
{
	int err;

	err = create_lockd_listener(serv, "udp", family, nlm_udpport);
	if (err < 0)
		return err;

	return create_lockd_listener(serv, "tcp", family, nlm_tcpport);
}

/*
 * 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;
	int err;

	err = create_lockd_family(serv, PF_INET);
	if (err < 0)
		goto out_err;

#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
	err = create_lockd_family(serv, PF_INET6);
	if (err < 0 && err != -EAFNOSUPPORT)
		goto out_err;
#endif	/* CONFIG_IPV6 || CONFIG_IPV6_MODULE */

	warned = 0;
	return 0;

out_err:
	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, 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);
	serv->sv_maxconn = nlm_max_connections;

	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_GPL(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_GPL(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);
module_param(nlm_max_connections, uint, 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
1da177e4 LT	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
1da177e4 LT	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>
353ab6e9	27	#include <linux/mutex.h>
d751a7cd	28	#include <linux/kthread.h>
83144186	29	#include <linux/freezer.h>
1da177e4 LT	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>
24e36663	36	#include <net/ip.h>
1da177e4 LT	37	#include <linux/lockd/lockd.h>
	38	#include <linux/nfs.h>
	39
	40	#define NLMDBG_FACILITY NLMDBG_SVC
	41	#define LOCKD_BUFSIZE (1024 + NLMSVC_XDRSIZE)
	42	#define ALLOWED_SIGS (sigmask(SIGKILL))
	43
	44	static struct svc_program nlmsvc_program;
	45
	46	struct nlmsvc_binding * nlmsvc_ops;
2de59872	47	EXPORT_SYMBOL_GPL(nlmsvc_ops);
1da177e4	48
353ab6e9	49	static DEFINE_MUTEX(nlmsvc_mutex);
1da177e4	50	static unsigned int nlmsvc_users;
d751a7cd	51	static struct task_struct *nlmsvc_task;
abd1ec4e	52	static struct svc_rqst *nlmsvc_rqst;
1da177e4 LT	53	unsigned long nlmsvc_timeout;
1da177e4 LT	54
1da177e4 LT	55	/*
	56	* These can be set at insmod time (useful for NFS as root filesystem),
	57	* and also changed through the sysctl interface. -- Jamie Lokier, Aug 2003
	58	*/
	59	static unsigned long nlm_grace_period;
	60	static unsigned long nlm_timeout = LOCKD_DFLT_TIMEO;
	61	static int nlm_udpport, nlm_tcpport;
	62
c72a476b JL	63	/* RLIM_NOFILE defaults to 1024. That seems like a reasonable default here. */
	64	static unsigned int nlm_max_connections = 1024;
	65
1da177e4 LT	66	/*
	67	* Constants needed for the sysctl interface.
	68	*/
	69	static const unsigned long nlm_grace_period_min = 0;
	70	static const unsigned long nlm_grace_period_max = 240;
	71	static const unsigned long nlm_timeout_min = 3;
	72	static const unsigned long nlm_timeout_max = 20;
	73	static const int nlm_port_min = 0, nlm_port_max = 65535;
	74
90d5b180	75	#ifdef CONFIG_SYSCTL
1da177e4	76	static struct ctl_table_header * nlm_sysctl_table;
90d5b180	77	#endif
1da177e4	78
9a8db97e	79	static unsigned long get_lockd_grace_period(void)
1da177e4	80	{
1da177e4 LT	81	/* Note: nlm_timeout should always be nonzero */
1da177e4 LT	82	if (nlm_grace_period)
9a8db97e	83	return roundup(nlm_grace_period, nlm_timeout) * HZ;
1da177e4	84	else
9a8db97e ME	85	return nlm_timeout * 5 * HZ;
	86	}
	87
af558e33 BF	88	static struct lock_manager lockd_manager = {
af558e33 BF	89	};
9a8db97e	90
c8ab5f2a	91	static void grace_ender(struct work_struct *not_used)
9a8db97e	92	{
af558e33	93	locks_end_grace(&lockd_manager);
1da177e4 LT	94	}
1da177e4 LT	95
c8ab5f2a BF	96	static DECLARE_DELAYED_WORK(grace_period_end, grace_ender);
	97
	98	static void set_grace_period(void)
1da177e4	99	{
af558e33	100	unsigned long grace_period = get_lockd_grace_period();
c8ab5f2a	101
af558e33	102	locks_start_grace(&lockd_manager);
c8ab5f2a BF	103	cancel_delayed_work_sync(&grace_period_end);
c8ab5f2a BF	104	schedule_delayed_work(&grace_period_end, grace_period);
1da177e4 LT	105	}
1da177e4 LT	106
89996df4 BF	107	static void restart_grace(void)
	108	{
	109	if (nlmsvc_ops) {
	110	cancel_delayed_work_sync(&grace_period_end);
	111	locks_end_grace(&lockd_manager);
	112	nlmsvc_invalidate_all();
	113	set_grace_period();
	114	}
	115	}
	116
1da177e4 LT	117	/*
	118	* This is the lockd kernel thread
	119	*/
d751a7cd JL	120	static int
d751a7cd JL	121	lockd(void *vrqstp)
1da177e4	122	{
f97c650d	123	int err = 0, preverr = 0;
d751a7cd	124	struct svc_rqst *rqstp = vrqstp;
1da177e4	125
d751a7cd	126	/* try_to_freeze() is called from svc_recv() */
83144186	127	set_freezable();
1da177e4	128
d751a7cd	129	/* Allow SIGKILL to tell lockd to drop all of its locks */
1da177e4 LT	130	allow_signal(SIGKILL);
1da177e4 LT	131
1da177e4 LT	132	dprintk("NFS locking service started (ver " LOCKD_VERSION ").\n");
1da177e4 LT	133
d751a7cd JL	134	/*
	135	* FIXME: it would be nice if lockd didn't spend its entire life
	136	* running under the BKL. At the very least, it would be good to
	137	* have someone clarify what it's intended to protect here. I've
	138	* seen some handwavy posts about posix locking needing to be
	139	* done under the BKL, but it's far from clear.
	140	*/
	141	lock_kernel();
	142
1da177e4 LT	143	if (!nlm_timeout)
	144	nlm_timeout = LOCKD_DFLT_TIMEO;
	145	nlmsvc_timeout = nlm_timeout * HZ;
	146
c8ab5f2a	147	set_grace_period();
1da177e4 LT	148
	149	/*
	150	* The main request loop. We don't terminate until the last
d751a7cd	151	* NFS mount or NFS daemon has gone away.
1da177e4	152	*/
d751a7cd	153	while (!kthread_should_stop()) {
1da177e4	154	long timeout = MAX_SCHEDULE_TIMEOUT;
5216a8e7	155	RPC_IFDEBUG(char buf[RPC_MAX_ADDRBUFLEN]);
1da177e4	156
c72a476b JL	157	/* update sv_maxconn if it has changed */
	158	rqstp->rq_server->sv_maxconn = nlm_max_connections;
	159
1da177e4 LT	160	if (signalled()) {
1da177e4 LT	161	flush_signals(current);
89996df4	162	restart_grace();
d751a7cd	163	continue;
1da177e4 LT	164	}
1da177e4 LT	165
8fafa900 BF	166	timeout = nlmsvc_retry_blocked();
8fafa900 BF	167
1da177e4 LT	168	/*
	169	* Find a socket with data available and call its
	170	* recvfrom routine.
	171	*/
6fb2b47f	172	err = svc_recv(rqstp, timeout);
f97c650d JL	173	if (err == -EAGAIN \|\| err == -EINTR) {
f97c650d JL	174	preverr = err;
1da177e4	175	continue;
f97c650d	176	}
1da177e4	177	if (err < 0) {
f97c650d JL	178	if (err != preverr) {
	179	printk(KERN_WARNING "%s: unexpected error "
	180	"from svc_recv (%d)\n", __func__, err);
	181	preverr = err;
	182	}
	183	schedule_timeout_interruptible(HZ);
	184	continue;
1da177e4	185	}
f97c650d	186	preverr = err;
1da177e4	187
ad06e4bd CL	188	dprintk("lockd: request from %s\n",
ad06e4bd CL	189	svc_print_addr(rqstp, buf, sizeof(buf)));
1da177e4	190
6fb2b47f	191	svc_process(rqstp);
1da177e4	192	}
2bd61579	193	flush_signals(current);
c8ab5f2a	194	cancel_delayed_work_sync(&grace_period_end);
2c5e7615	195	locks_end_grace(&lockd_manager);
d751a7cd JL	196	if (nlmsvc_ops)
	197	nlmsvc_invalidate_all();
	198	nlm_shutdown_hosts();
d751a7cd	199	unlock_kernel();
d751a7cd	200	return 0;
1da177e4 LT	201	}
1da177e4 LT	202
eb16e907 CL	203	static int create_lockd_listener(struct svc_serv serv, const char name,
eb16e907 CL	204	const int family, const unsigned short port)
d3fe5ea7 CL	205	{
	206	struct svc_xprt *xprt;
	207
eb16e907	208	xprt = svc_find_xprt(serv, name, family, 0);
d3fe5ea7	209	if (xprt == NULL)
eb16e907 CL	210	return svc_create_xprt(serv, name, family, port,
eb16e907 CL	211	SVC_SOCK_DEFAULTS);
d3fe5ea7 CL	212	svc_xprt_put(xprt);
	213	return 0;
	214	}
	215
eb16e907 CL	216	static int create_lockd_family(struct svc_serv *serv, const int family)
	217	{
	218	int err;
	219
	220	err = create_lockd_listener(serv, "udp", family, nlm_udpport);
	221	if (err < 0)
	222	return err;
	223
	224	return create_lockd_listener(serv, "tcp", family, nlm_tcpport);
	225	}
	226
482fb94e	227	/*
8c3916f4 CL	228	* Ensure there are active UDP and TCP listeners for lockd.
	229	*
	230	* Even if we have only TCP NFS mounts and/or TCP NFSDs, some
	231	* local services (such as rpc.statd) still require UDP, and
	232	* some NFS servers do not yet support NLM over TCP.
	233	*
	234	* Returns zero if all listeners are available; otherwise a
	235	* negative errno value is returned.
482fb94e	236	*/
8c3916f4	237	static int make_socks(struct svc_serv *serv)
24e36663	238	{
482fb94e	239	static int warned;
0dba7c2a	240	int err;
482fb94e	241
eb16e907	242	err = create_lockd_family(serv, PF_INET);
0dba7c2a CL	243	if (err < 0)
	244	goto out_err;
	245
eb16e907 CL	246	#if defined(CONFIG_IPV6) \|\| defined(CONFIG_IPV6_MODULE)
	247	err = create_lockd_family(serv, PF_INET6);
	248	if (err < 0 && err != -EAFNOSUPPORT)
0dba7c2a	249	goto out_err;
eb16e907	250	#endif /* CONFIG_IPV6 \|\| CONFIG_IPV6_MODULE */
0dba7c2a CL	251
	252	warned = 0;
	253	return 0;
	254
	255	out_err:
	256	if (warned++ == 0)
7dcf91ec	257	printk(KERN_WARNING
0dba7c2a	258	"lockd_up: makesock failed, error=%d\n", err);
24e36663 N	259	return err;
	260	}
	261
1da177e4 LT	262	/*
	263	* Bring up the lockd process if it's not already up.
	264	*/
26a41409	265	int lockd_up(void)
1da177e4	266	{
d751a7cd	267	struct svc_serv *serv;
d751a7cd	268	int error = 0;
1da177e4	269
353ab6e9	270	mutex_lock(&nlmsvc_mutex);
1da177e4 LT	271	/*
	272	* Check whether we're already up and running.
	273	*/
8c3916f4	274	if (nlmsvc_rqst)
1da177e4 LT	275	goto out;
	276
	277	/*
	278	* Sanity check: if there's no pid,
	279	* we should be the first user ...
	280	*/
4a3ae42d	281	if (nlmsvc_users)
1da177e4 LT	282	printk(KERN_WARNING
	283	"lockd_up: no pid, %d users??\n", nlmsvc_users);
	284
	285	error = -ENOMEM;
49a9072f	286	serv = svc_create(&nlmsvc_program, LOCKD_BUFSIZE, NULL);
1da177e4 LT	287	if (!serv) {
	288	printk(KERN_WARNING "lockd_up: create service failed\n");
	289	goto out;
	290	}
	291
8c3916f4 CL	292	error = make_socks(serv);
8c3916f4 CL	293	if (error < 0)
1da177e4	294	goto destroy_and_out;
1da177e4 LT	295
	296	/*
	297	* Create the kernel thread and wait for it to start.
	298	*/
abd1ec4e JL	299	nlmsvc_rqst = svc_prepare_thread(serv, &serv->sv_pools[0]);
	300	if (IS_ERR(nlmsvc_rqst)) {
	301	error = PTR_ERR(nlmsvc_rqst);
	302	nlmsvc_rqst = NULL;
d751a7cd JL	303	printk(KERN_WARNING
	304	"lockd_up: svc_rqst allocation failed, error=%d\n",
	305	error);
	306	goto destroy_and_out;
	307	}
	308
	309	svc_sock_update_bufs(serv);
c72a476b	310	serv->sv_maxconn = nlm_max_connections;
d751a7cd	311
abd1ec4e	312	nlmsvc_task = kthread_run(lockd, nlmsvc_rqst, serv->sv_name);
d751a7cd JL	313	if (IS_ERR(nlmsvc_task)) {
d751a7cd JL	314	error = PTR_ERR(nlmsvc_task);
abd1ec4e	315	svc_exit_thread(nlmsvc_rqst);
d751a7cd	316	nlmsvc_task = NULL;
abd1ec4e	317	nlmsvc_rqst = NULL;
1da177e4	318	printk(KERN_WARNING
d751a7cd	319	"lockd_up: kthread_run failed, error=%d\n", error);
1da177e4 LT	320	goto destroy_and_out;
1da177e4 LT	321	}
1da177e4 LT	322
	323	/*
	324	* Note: svc_serv structures have an initial use count of 1,
	325	* so we exit through here on both success and failure.
	326	*/
	327	destroy_and_out:
	328	svc_destroy(serv);
	329	out:
4a3ae42d N	330	if (!error)
4a3ae42d N	331	nlmsvc_users++;
353ab6e9	332	mutex_unlock(&nlmsvc_mutex);
1da177e4 LT	333	return error;
1da177e4 LT	334	}
2de59872	335	EXPORT_SYMBOL_GPL(lockd_up);
1da177e4 LT	336
	337	/*
	338	* Decrement the user count and bring down lockd if we're the last.
	339	*/
	340	void
	341	lockd_down(void)
	342	{
353ab6e9	343	mutex_lock(&nlmsvc_mutex);
1da177e4 LT	344	if (nlmsvc_users) {
	345	if (--nlmsvc_users)
	346	goto out;
d751a7cd JL	347	} else {
	348	printk(KERN_ERR "lockd_down: no users! task=%p\n",
	349	nlmsvc_task);
	350	BUG();
1da177e4	351	}
1da177e4	352
d751a7cd JL	353	if (!nlmsvc_task) {
	354	printk(KERN_ERR "lockd_down: no lockd running.\n");
	355	BUG();
1da177e4	356	}
d751a7cd	357	kthread_stop(nlmsvc_task);
abd1ec4e JL	358	svc_exit_thread(nlmsvc_rqst);
	359	nlmsvc_task = NULL;
	360	nlmsvc_rqst = NULL;
1da177e4	361	out:
353ab6e9	362	mutex_unlock(&nlmsvc_mutex);
1da177e4	363	}
2de59872	364	EXPORT_SYMBOL_GPL(lockd_down);
1da177e4	365
90d5b180 CL	366	#ifdef CONFIG_SYSCTL
90d5b180 CL	367
1da177e4 LT	368	/*
	369	* Sysctl parameters (same as module parameters, different interface).
	370	*/
	371
1da177e4 LT	372	static ctl_table nlm_sysctls[] = {
	373	{
	374	.ctl_name = CTL_UNNUMBERED,
	375	.procname = "nlm_grace_period",
	376	.data = &nlm_grace_period,
7ee91ec1	377	.maxlen = sizeof(unsigned long),
1da177e4 LT	378	.mode = 0644,
	379	.proc_handler = &proc_doulongvec_minmax,
	380	.extra1 = (unsigned long *) &nlm_grace_period_min,
	381	.extra2 = (unsigned long *) &nlm_grace_period_max,
	382	},
	383	{
	384	.ctl_name = CTL_UNNUMBERED,
	385	.procname = "nlm_timeout",
	386	.data = &nlm_timeout,
7ee91ec1	387	.maxlen = sizeof(unsigned long),
1da177e4 LT	388	.mode = 0644,
	389	.proc_handler = &proc_doulongvec_minmax,
	390	.extra1 = (unsigned long *) &nlm_timeout_min,
	391	.extra2 = (unsigned long *) &nlm_timeout_max,
	392	},
	393	{
	394	.ctl_name = CTL_UNNUMBERED,
	395	.procname = "nlm_udpport",
	396	.data = &nlm_udpport,
	397	.maxlen = sizeof(int),
	398	.mode = 0644,
	399	.proc_handler = &proc_dointvec_minmax,
	400	.extra1 = (int *) &nlm_port_min,
	401	.extra2 = (int *) &nlm_port_max,
	402	},
	403	{
	404	.ctl_name = CTL_UNNUMBERED,
	405	.procname = "nlm_tcpport",
	406	.data = &nlm_tcpport,
	407	.maxlen = sizeof(int),
	408	.mode = 0644,
	409	.proc_handler = &proc_dointvec_minmax,
	410	.extra1 = (int *) &nlm_port_min,
	411	.extra2 = (int *) &nlm_port_max,
	412	},
abd1f500 OK	413	{
	414	.ctl_name = CTL_UNNUMBERED,
	415	.procname = "nsm_use_hostnames",
	416	.data = &nsm_use_hostnames,
	417	.maxlen = sizeof(int),
	418	.mode = 0644,
	419	.proc_handler = &proc_dointvec,
	420	},
460f5cac OK	421	{
	422	.ctl_name = CTL_UNNUMBERED,
	423	.procname = "nsm_local_state",
	424	.data = &nsm_local_state,
	425	.maxlen = sizeof(int),
	426	.mode = 0644,
	427	.proc_handler = &proc_dointvec,
	428	},
1da177e4 LT	429	{ .ctl_name = 0 }
	430	};
	431
	432	static ctl_table nlm_sysctl_dir[] = {
	433	{
	434	.ctl_name = CTL_UNNUMBERED,
	435	.procname = "nfs",
	436	.mode = 0555,
	437	.child = nlm_sysctls,
	438	},
	439	{ .ctl_name = 0 }
	440	};
	441
	442	static ctl_table nlm_sysctl_root[] = {
	443	{
	444	.ctl_name = CTL_FS,
	445	.procname = "fs",
	446	.mode = 0555,
	447	.child = nlm_sysctl_dir,
	448	},
	449	{ .ctl_name = 0 }
	450	};
	451
90d5b180 CL	452	#endif /* CONFIG_SYSCTL */
90d5b180 CL	453
1da177e4	454	/*
405ae7d3	455	* Module (and sysfs) parameters.
1da177e4 LT	456	*/
	457
	458	#define param_set_min_max(name, type, which_strtol, min, max) \
	459	static int param_set_##name(const char val, struct kernel_param kp) \
	460	{ \
	461	char *endp; \
	462	__typeof__(type) num = which_strtol(val, &endp, 0); \
	463	if (endp == val \|\| *endp \|\| num < (min) \|\| num > (max)) \
	464	return -EINVAL; \
	465	((int ) kp->arg) = num; \
	466	return 0; \
	467	}
	468
	469	static inline int is_callback(u32 proc)
	470	{
	471	return proc == NLMPROC_GRANTED
	472	\|\| proc == NLMPROC_GRANTED_MSG
	473	\|\| proc == NLMPROC_TEST_RES
	474	\|\| proc == NLMPROC_LOCK_RES
	475	\|\| proc == NLMPROC_CANCEL_RES
	476	\|\| proc == NLMPROC_UNLOCK_RES
	477	\|\| proc == NLMPROC_NSM_NOTIFY;
	478	}
	479
	480
	481	static int lockd_authenticate(struct svc_rqst *rqstp)
	482	{
	483	rqstp->rq_client = NULL;
	484	switch (rqstp->rq_authop->flavour) {
	485	case RPC_AUTH_NULL:
	486	case RPC_AUTH_UNIX:
	487	if (rqstp->rq_proc == 0)
	488	return SVC_OK;
	489	if (is_callback(rqstp->rq_proc)) {
	490	/* Leave it to individual procedures to
	491	* call nlmsvc_lookup_host(rqstp)
	492	*/
	493	return SVC_OK;
	494	}
	495	return svc_set_client(rqstp);
	496	}
	497	return SVC_DENIED;
	498	}
	499
	500
	501	param_set_min_max(port, int, simple_strtol, 0, 65535)
	502	param_set_min_max(grace_period, unsigned long, simple_strtoul,
	503	nlm_grace_period_min, nlm_grace_period_max)
	504	param_set_min_max(timeout, unsigned long, simple_strtoul,
	505	nlm_timeout_min, nlm_timeout_max)
	506
	507	MODULE_AUTHOR("Olaf Kirch <okir@monad.swb.de>");
	508	MODULE_DESCRIPTION("NFS file locking service version " LOCKD_VERSION ".");
	509	MODULE_LICENSE("GPL");
	510
	511	module_param_call(nlm_grace_period, param_set_grace_period, param_get_ulong,
	512	&nlm_grace_period, 0644);
	513	module_param_call(nlm_timeout, param_set_timeout, param_get_ulong,
	514	&nlm_timeout, 0644);
	515	module_param_call(nlm_udpport, param_set_port, param_get_int,
	516	&nlm_udpport, 0644);
	517	module_param_call(nlm_tcpport, param_set_port, param_get_int,
	518	&nlm_tcpport, 0644);
abd1f500	519	module_param(nsm_use_hostnames, bool, 0644);
c72a476b	520	module_param(nlm_max_connections, uint, 0644);
1da177e4 LT	521
	522	/*
	523	* Initialising and terminating the module.
	524	*/
	525
	526	static int __init init_nlm(void)
	527	{
90d5b180	528	#ifdef CONFIG_SYSCTL
0b4d4147	529	nlm_sysctl_table = register_sysctl_table(nlm_sysctl_root);
1da177e4	530	return nlm_sysctl_table ? 0 : -ENOMEM;
90d5b180 CL	531	#else
	532	return 0;
	533	#endif
1da177e4 LT	534	}
	535
	536	static void __exit exit_nlm(void)
	537	{
	538	/* FIXME: delete all NLM clients */
	539	nlm_shutdown_hosts();
90d5b180	540	#ifdef CONFIG_SYSCTL
1da177e4	541	unregister_sysctl_table(nlm_sysctl_table);
90d5b180	542	#endif
1da177e4 LT	543	}
	544
	545	module_init(init_nlm);
	546	module_exit(exit_nlm);
	547
	548	/*
	549	* Define NLM program and procedures
	550	*/
	551	static struct svc_version nlmsvc_version1 = {
	552	.vs_vers = 1,
	553	.vs_nproc = 17,
	554	.vs_proc = nlmsvc_procedures,
	555	.vs_xdrsize = NLMSVC_XDRSIZE,
	556	};
	557	static struct svc_version nlmsvc_version3 = {
	558	.vs_vers = 3,
	559	.vs_nproc = 24,
	560	.vs_proc = nlmsvc_procedures,
	561	.vs_xdrsize = NLMSVC_XDRSIZE,
	562	};
	563	#ifdef CONFIG_LOCKD_V4
	564	static struct svc_version nlmsvc_version4 = {
	565	.vs_vers = 4,
	566	.vs_nproc = 24,
	567	.vs_proc = nlmsvc_procedures4,
	568	.vs_xdrsize = NLMSVC_XDRSIZE,
	569	};
	570	#endif
	571	static struct svc_version * nlmsvc_version[] = {
	572	[1] = &nlmsvc_version1,
	573	[3] = &nlmsvc_version3,
	574	#ifdef CONFIG_LOCKD_V4
	575	[4] = &nlmsvc_version4,
	576	#endif
	577	};
	578
	579	static struct svc_stat nlmsvc_stats;
	580
e8c96f8c	581	#define NLM_NRVERS ARRAY_SIZE(nlmsvc_version)
1da177e4 LT	582	static struct svc_program nlmsvc_program = {
	583	.pg_prog = NLM_PROGRAM, /* program number */
	584	.pg_nvers = NLM_NRVERS, /* number of entries in nlmsvc_version */
	585	.pg_vers = nlmsvc_version, /* version table */
	586	.pg_name = "lockd", /* service name */
	587	.pg_class = "nfsd", /* share authentication with nfsd */
	588	.pg_stats = &nlmsvc_stats, /* stats table */
	589	.pg_authenticate = &lockd_authenticate /* export authentication */
	590	};