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DEFINITIONS
This source file includes following definitions.
- get_lockd_grace_period
- grace_ender
- set_grace_period
- lockd
- make_socks
- lockd_up
- lockd_down
- is_callback
- lockd_authenticate
- param_set_min_max
- exit_nlm
/*
* 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 */
};