linux/fs/lockd/svc.c
Scott Mayhew cb7d224f82 lockd: unregister notifier blocks if the service fails to come up completely
If the lockd service fails to start up then we need to be sure that the
notifier blocks are not registered, otherwise a subsequent start of the
service could cause the same notifier to be registered twice, leading to
soft lockups.

Signed-off-by: Scott Mayhew <smayhew@redhat.com>
Cc: stable@vger.kernel.org
Fixes: 0751ddf77b "lockd: Register callbacks on the inetaddr_chain..."
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2016-06-30 16:35:07 -04:00

778 lines
18 KiB
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/smp.h>
#include <linux/mutex.h>
#include <linux/kthread.h>
#include <linux/freezer.h>
#include <linux/inetdevice.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 <linux/sunrpc/svc_xprt.h>
#include <net/ip.h>
#include <net/addrconf.h>
#include <net/ipv6.h>
#include <linux/lockd/lockd.h>
#include <linux/nfs.h>
#include "netns.h"
#include "procfs.h"
#define NLMDBG_FACILITY NLMDBG_SVC
#define LOCKD_BUFSIZE (1024 + NLMSVC_XDRSIZE)
#define ALLOWED_SIGS (sigmask(SIGKILL))
static struct svc_program nlmsvc_program;
const 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 void grace_ender(struct work_struct *grace)
{
struct delayed_work *dwork = to_delayed_work(grace);
struct lockd_net *ln = container_of(dwork, struct lockd_net,
grace_period_end);
locks_end_grace(&ln->lockd_manager);
}
static void set_grace_period(struct net *net)
{
unsigned long grace_period = get_lockd_grace_period();
struct lockd_net *ln = net_generic(net, lockd_net_id);
locks_start_grace(net, &ln->lockd_manager);
cancel_delayed_work_sync(&ln->grace_period_end);
schedule_delayed_work(&ln->grace_period_end, grace_period);
}
static void restart_grace(void)
{
if (nlmsvc_ops) {
struct net *net = &init_net;
struct lockd_net *ln = net_generic(net, lockd_net_id);
cancel_delayed_work_sync(&ln->grace_period_end);
locks_end_grace(&ln->lockd_manager);
nlmsvc_invalidate_all();
set_grace_period(net);
}
}
/*
* This is the lockd kernel thread
*/
static int
lockd(void *vrqstp)
{
int err = 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");
/*
* 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)
continue;
dprintk("lockd: request from %s\n",
svc_print_addr(rqstp, buf, sizeof(buf)));
svc_process(rqstp);
}
flush_signals(current);
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);
svc_shutdown_net(serv, net);
return err;
}
static int lockd_up_net(struct svc_serv *serv, struct net *net)
{
struct lockd_net *ln = net_generic(net, lockd_net_id);
int error;
if (ln->nlmsvc_users++)
return 0;
error = svc_bind(serv, net);
if (error)
goto err_bind;
error = make_socks(serv, net);
if (error < 0)
goto err_bind;
set_grace_period(net);
dprintk("lockd_up_net: per-net data created; net=%p\n", net);
return 0;
err_bind:
ln->nlmsvc_users--;
return error;
}
static void lockd_down_net(struct svc_serv *serv, struct net *net)
{
struct lockd_net *ln = net_generic(net, lockd_net_id);
if (ln->nlmsvc_users) {
if (--ln->nlmsvc_users == 0) {
nlm_shutdown_hosts_net(net);
cancel_delayed_work_sync(&ln->grace_period_end);
locks_end_grace(&ln->lockd_manager);
svc_shutdown_net(serv, net);
dprintk("lockd_down_net: per-net data destroyed; net=%p\n", net);
}
} else {
printk(KERN_ERR "lockd_down_net: no users! task=%p, net=%p\n",
nlmsvc_task, net);
BUG();
}
}
static int lockd_inetaddr_event(struct notifier_block *this,
unsigned long event, void *ptr)
{
struct in_ifaddr *ifa = (struct in_ifaddr *)ptr;
struct sockaddr_in sin;
if (event != NETDEV_DOWN)
goto out;
if (nlmsvc_rqst) {
dprintk("lockd_inetaddr_event: removed %pI4\n",
&ifa->ifa_local);
sin.sin_family = AF_INET;
sin.sin_addr.s_addr = ifa->ifa_local;
svc_age_temp_xprts_now(nlmsvc_rqst->rq_server,
(struct sockaddr *)&sin);
}
out:
return NOTIFY_DONE;
}
static struct notifier_block lockd_inetaddr_notifier = {
.notifier_call = lockd_inetaddr_event,
};
#if IS_ENABLED(CONFIG_IPV6)
static int lockd_inet6addr_event(struct notifier_block *this,
unsigned long event, void *ptr)
{
struct inet6_ifaddr *ifa = (struct inet6_ifaddr *)ptr;
struct sockaddr_in6 sin6;
if (event != NETDEV_DOWN)
goto out;
if (nlmsvc_rqst) {
dprintk("lockd_inet6addr_event: removed %pI6\n", &ifa->addr);
sin6.sin6_family = AF_INET6;
sin6.sin6_addr = ifa->addr;
svc_age_temp_xprts_now(nlmsvc_rqst->rq_server,
(struct sockaddr *)&sin6);
}
out:
return NOTIFY_DONE;
}
static struct notifier_block lockd_inet6addr_notifier = {
.notifier_call = lockd_inet6addr_event,
};
#endif
static void lockd_unregister_notifiers(void)
{
unregister_inetaddr_notifier(&lockd_inetaddr_notifier);
#if IS_ENABLED(CONFIG_IPV6)
unregister_inet6addr_notifier(&lockd_inet6addr_notifier);
#endif
}
static void lockd_svc_exit_thread(void)
{
lockd_unregister_notifiers();
svc_exit_thread(nlmsvc_rqst);
}
static int lockd_start_svc(struct svc_serv *serv)
{
int error;
if (nlmsvc_rqst)
return 0;
/*
* Create the kernel thread and wait for it to start.
*/
nlmsvc_rqst = svc_prepare_thread(serv, &serv->sv_pools[0], NUMA_NO_NODE);
if (IS_ERR(nlmsvc_rqst)) {
error = PTR_ERR(nlmsvc_rqst);
printk(KERN_WARNING
"lockd_up: svc_rqst allocation failed, error=%d\n",
error);
goto out_rqst;
}
svc_sock_update_bufs(serv);
serv->sv_maxconn = nlm_max_connections;
nlmsvc_task = kthread_create(lockd, nlmsvc_rqst, "%s", serv->sv_name);
if (IS_ERR(nlmsvc_task)) {
error = PTR_ERR(nlmsvc_task);
printk(KERN_WARNING
"lockd_up: kthread_run failed, error=%d\n", error);
goto out_task;
}
nlmsvc_rqst->rq_task = nlmsvc_task;
wake_up_process(nlmsvc_task);
dprintk("lockd_up: service started\n");
return 0;
out_task:
lockd_svc_exit_thread();
nlmsvc_task = NULL;
out_rqst:
nlmsvc_rqst = NULL;
return error;
}
static struct svc_serv_ops lockd_sv_ops = {
.svo_shutdown = svc_rpcb_cleanup,
.svo_enqueue_xprt = svc_xprt_do_enqueue,
};
static struct svc_serv *lockd_create_svc(void)
{
struct svc_serv *serv;
/*
* Check whether we're already up and running.
*/
if (nlmsvc_rqst) {
/*
* Note: increase service usage, because later in case of error
* svc_destroy() will be called.
*/
svc_get(nlmsvc_rqst->rq_server);
return nlmsvc_rqst->rq_server;
}
/*
* 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);
if (!nlm_timeout)
nlm_timeout = LOCKD_DFLT_TIMEO;
nlmsvc_timeout = nlm_timeout * HZ;
serv = svc_create(&nlmsvc_program, LOCKD_BUFSIZE, &lockd_sv_ops);
if (!serv) {
printk(KERN_WARNING "lockd_up: create service failed\n");
return ERR_PTR(-ENOMEM);
}
register_inetaddr_notifier(&lockd_inetaddr_notifier);
#if IS_ENABLED(CONFIG_IPV6)
register_inet6addr_notifier(&lockd_inet6addr_notifier);
#endif
dprintk("lockd_up: service created\n");
return serv;
}
/*
* Bring up the lockd process if it's not already up.
*/
int lockd_up(struct net *net)
{
struct svc_serv *serv;
int error;
mutex_lock(&nlmsvc_mutex);
serv = lockd_create_svc();
if (IS_ERR(serv)) {
error = PTR_ERR(serv);
goto err_create;
}
error = lockd_up_net(serv, net);
if (error < 0)
goto err_net;
error = lockd_start_svc(serv);
if (error < 0)
goto err_start;
nlmsvc_users++;
/*
* Note: svc_serv structures have an initial use count of 1,
* so we exit through here on both success and failure.
*/
err_put:
svc_destroy(serv);
err_create:
mutex_unlock(&nlmsvc_mutex);
return error;
err_start:
lockd_down_net(serv, net);
err_net:
lockd_unregister_notifiers();
goto err_put;
}
EXPORT_SYMBOL_GPL(lockd_up);
/*
* Decrement the user count and bring down lockd if we're the last.
*/
void
lockd_down(struct net *net)
{
mutex_lock(&nlmsvc_mutex);
lockd_down_net(nlmsvc_rqst->rq_server, net);
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);
dprintk("lockd_down: service stopped\n");
lockd_svc_exit_thread();
dprintk("lockd_down: service destroyed\n");
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 struct ctl_table nlm_sysctls[] = {
{
.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,
},
{
.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,
},
{
.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,
},
{
.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,
},
{
.procname = "nsm_use_hostnames",
.data = &nsm_use_hostnames,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec,
},
{
.procname = "nsm_local_state",
.data = &nsm_local_state,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec,
},
{ }
};
static struct ctl_table nlm_sysctl_dir[] = {
{
.procname = "nfs",
.mode = 0555,
.child = nlm_sysctls,
},
{ }
};
static struct ctl_table nlm_sysctl_root[] = {
{
.procname = "fs",
.mode = 0555,
.child = nlm_sysctl_dir,
},
{ }
};
#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; \
*((type *) 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);
static int lockd_init_net(struct net *net)
{
struct lockd_net *ln = net_generic(net, lockd_net_id);
INIT_DELAYED_WORK(&ln->grace_period_end, grace_ender);
INIT_LIST_HEAD(&ln->lockd_manager.list);
ln->lockd_manager.block_opens = false;
INIT_LIST_HEAD(&ln->nsm_handles);
return 0;
}
static void lockd_exit_net(struct net *net)
{
}
static struct pernet_operations lockd_net_ops = {
.init = lockd_init_net,
.exit = lockd_exit_net,
.id = &lockd_net_id,
.size = sizeof(struct lockd_net),
};
/*
* Initialising and terminating the module.
*/
static int __init init_nlm(void)
{
int err;
#ifdef CONFIG_SYSCTL
err = -ENOMEM;
nlm_sysctl_table = register_sysctl_table(nlm_sysctl_root);
if (nlm_sysctl_table == NULL)
goto err_sysctl;
#endif
err = register_pernet_subsys(&lockd_net_ops);
if (err)
goto err_pernet;
err = lockd_create_procfs();
if (err)
goto err_procfs;
return 0;
err_procfs:
unregister_pernet_subsys(&lockd_net_ops);
err_pernet:
#ifdef CONFIG_SYSCTL
unregister_sysctl_table(nlm_sysctl_table);
err_sysctl:
#endif
return err;
}
static void __exit exit_nlm(void)
{
/* FIXME: delete all NLM clients */
nlm_shutdown_hosts();
lockd_remove_procfs();
unregister_pernet_subsys(&lockd_net_ops);
#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 */
};