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/*
* 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/smp.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>
#include "netns.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;
int lockd_net_id;
/*
* 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");
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();
return 0;
}
static int create_lockd_listener(struct svc_serv *serv, const char *name,
struct net *net, const int family,
const unsigned short port)
{
struct svc_xprt *xprt;
xprt = svc_find_xprt(serv, name, net, family, 0);
if (xprt == NULL)
return svc_create_xprt(serv, name, net, family, port,
SVC_SOCK_DEFAULTS);
svc_xprt_put(xprt);
return 0;
}
static int create_lockd_family(struct svc_serv *serv, struct net *net,
const int family)
{
int err;
err = create_lockd_listener(serv, "udp", net, family, nlm_udpport);
if (err < 0)
return err;
return create_lockd_listener(serv, "tcp", net, 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, struct net *net)
{
static int warned;
int err;
err = create_lockd_family(serv, net, PF_INET);
if (err < 0)
goto out_err;
err = create_lockd_family(serv, net, PF_INET6);
if (err < 0 && err != -EAFNOSUPPORT)
goto out_err;
warned = 0;
return 0;
out_err:
if (warned++ == 0)
printk(KERN_WARNING
"lockd_up: makesock failed, error=%d\n", err);
return err;
}
static int lockd_up_net(struct net *net)
{
struct lockd_net *ln = net_generic(net, lockd_net_id);
struct svc_serv *serv = nlmsvc_rqst->rq_server;
int error;
if (ln->nlmsvc_users)
return 0;
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