NLM: Convert lockd to use kthreads
Have lockd_up start lockd using kthread_run. With this change, lockd_down now blocks until lockd actually exits, so there's no longer need for the waitqueue code at the end of lockd_down. This also means that only one lockd can be running at a time which simplifies the code within lockd's main loop. This also adds a check for kthread_should_stop in the main loop of nlmsvc_retry_blocked and after that function returns. There's no sense continuing to retry blocks if lockd is coming down anyway. Signed-off-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
This commit is contained in:
Jeff Layton
J. Bruce Fields
Родитель
7086721f9c
Коммит
d751a7cd06
132
fs/lockd/svc.c
132
fs/lockd/svc.c
|
|
@ -25,6 +25,7 @@
|
|||
#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>
|
||||
|
|
@ -48,14 +49,11 @@ EXPORT_SYMBOL(nlmsvc_ops);
|
|||
|
||||
static DEFINE_MUTEX(nlmsvc_mutex);
|
||||
static unsigned int nlmsvc_users;
|
||||
static pid_t nlmsvc_pid;
|
||||
static struct task_struct *nlmsvc_task;
|
||||
static struct svc_serv *nlmsvc_serv;
|
||||
int nlmsvc_grace_period;
|
||||
unsigned long nlmsvc_timeout;
|
||||
|
||||
static DECLARE_COMPLETION(lockd_start_done);
|
||||
static DECLARE_WAIT_QUEUE_HEAD(lockd_exit);
|
||||
|
||||
/*
|
||||
* These can be set at insmod time (useful for NFS as root filesystem),
|
||||
* and also changed through the sysctl interface. -- Jamie Lokier, Aug 2003
|
||||
|
|
@ -111,35 +109,30 @@ static inline void clear_grace_period(void)
|
|||
/*
|
||||
* This is the lockd kernel thread
|
||||
*/
|
||||
static void
|
||||
lockd(struct svc_rqst *rqstp)
|
||||
static int
|
||||
lockd(void *vrqstp)
|
||||
{
|
||||
int err = 0;
|
||||
struct svc_rqst *rqstp = vrqstp;
|
||||
unsigned long grace_period_expire;
|
||||
|
||||
/* Lock module and set up kernel thread */
|
||||
/* lockd_up is waiting for us to startup, so will
|
||||
* be holding a reference to this module, so it
|
||||
* is safe to just claim another reference
|
||||
*/
|
||||
__module_get(THIS_MODULE);
|
||||
lock_kernel();
|
||||
|
||||
/*
|
||||
* Let our maker know we're running.
|
||||
*/
|
||||
nlmsvc_pid = current->pid;
|
||||
nlmsvc_serv = rqstp->rq_server;
|
||||
complete(&lockd_start_done);
|
||||
|
||||
daemonize("lockd");
|
||||
/* try_to_freeze() is called from svc_recv() */
|
||||
set_freezable();
|
||||
|
||||
/* Process request with signals blocked, but allow SIGKILL. */
|
||||
/* 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;
|
||||
|
|
@ -148,10 +141,9 @@ lockd(struct svc_rqst *rqstp)
|
|||
|
||||
/*
|
||||
* The main request loop. We don't terminate until the last
|
||||
* NFS mount or NFS daemon has gone away, and we've been sent a
|
||||
* signal, or else another process has taken over our job.
|
||||
* NFS mount or NFS daemon has gone away.
|
||||
*/
|
||||
while ((nlmsvc_users || !signalled()) && nlmsvc_pid == current->pid) {
|
||||
while (!kthread_should_stop()) {
|
||||
long timeout = MAX_SCHEDULE_TIMEOUT;
|
||||
RPC_IFDEBUG(char buf[RPC_MAX_ADDRBUFLEN]);
|
||||
|
||||
|
|
@ -161,6 +153,7 @@ lockd(struct svc_rqst *rqstp)
|
|||
nlmsvc_invalidate_all();
|
||||
grace_period_expire = set_grace_period();
|
||||
}
|
||||
continue;
|
||||
}
|
||||
|
||||
/*
|
||||
|
|
@ -195,28 +188,19 @@ lockd(struct svc_rqst *rqstp)
|
|||
}
|
||||
|
||||
flush_signals(current);
|
||||
if (nlmsvc_ops)
|
||||
nlmsvc_invalidate_all();
|
||||
nlm_shutdown_hosts();
|
||||
|
||||
/*
|
||||
* Check whether there's a new lockd process before
|
||||
* shutting down the hosts and clearing the slot.
|
||||
*/
|
||||
if (!nlmsvc_pid || current->pid == nlmsvc_pid) {
|
||||
if (nlmsvc_ops)
|
||||
nlmsvc_invalidate_all();
|
||||
nlm_shutdown_hosts();
|
||||
nlmsvc_pid = 0;
|
||||
nlmsvc_serv = NULL;
|
||||
} else
|
||||
printk(KERN_DEBUG
|
||||
"lockd: new process, skipping host shutdown\n");
|
||||
wake_up(&lockd_exit);
|
||||
unlock_kernel();
|
||||
|
||||
nlmsvc_task = NULL;
|
||||
nlmsvc_serv = NULL;
|
||||
|
||||
/* Exit the RPC thread */
|
||||
svc_exit_thread(rqstp);
|
||||
|
||||
/* Release module */
|
||||
unlock_kernel();
|
||||
module_put_and_exit(0);
|
||||
return 0;
|
||||
}
|
||||
|
||||
/*
|
||||
|
|
@ -261,14 +245,15 @@ static int make_socks(struct svc_serv *serv, int proto)
|
|||
int
|
||||
lockd_up(int proto) /* Maybe add a 'family' option when IPv6 is supported ?? */
|
||||
{
|
||||
struct svc_serv * serv;
|
||||
int error = 0;
|
||||
struct svc_serv *serv;
|
||||
struct svc_rqst *rqstp;
|
||||
int error = 0;
|
||||
|
||||
mutex_lock(&nlmsvc_mutex);
|
||||
/*
|
||||
* Check whether we're already up and running.
|
||||
*/
|
||||
if (nlmsvc_pid) {
|
||||
if (nlmsvc_serv) {
|
||||
if (proto)
|
||||
error = make_socks(nlmsvc_serv, proto);
|
||||
goto out;
|
||||
|
|
@ -295,13 +280,28 @@ lockd_up(int proto) /* Maybe add a 'family' option when IPv6 is supported ?? */
|
|||
/*
|
||||
* Create the kernel thread and wait for it to start.
|
||||
*/
|
||||
error = svc_create_thread(lockd, serv);
|
||||
if (error) {
|
||||
rqstp = svc_prepare_thread(serv, &serv->sv_pools[0]);
|
||||
if (IS_ERR(rqstp)) {
|
||||
error = PTR_ERR(rqstp);
|
||||
printk(KERN_WARNING
|
||||
"lockd_up: create thread failed, error=%d\n", error);
|
||||
"lockd_up: svc_rqst allocation failed, error=%d\n",
|
||||
error);
|
||||
goto destroy_and_out;
|
||||
}
|
||||
|
||||
svc_sock_update_bufs(serv);
|
||||
nlmsvc_serv = rqstp->rq_server;
|
||||
|
||||
nlmsvc_task = kthread_run(lockd, rqstp, serv->sv_name);
|
||||
if (IS_ERR(nlmsvc_task)) {
|
||||
error = PTR_ERR(nlmsvc_task);
|
||||
nlmsvc_task = NULL;
|
||||
nlmsvc_serv = NULL;
|
||||
printk(KERN_WARNING
|
||||
"lockd_up: kthread_run failed, error=%d\n", error);
|
||||
svc_exit_thread(rqstp);
|
||||
goto destroy_and_out;
|
||||
}
|
||||
wait_for_completion(&lockd_start_done);
|
||||
|
||||
/*
|
||||
* Note: svc_serv structures have an initial use count of 1,
|
||||
|
|
@ -323,37 +323,21 @@ EXPORT_SYMBOL(lockd_up);
|
|||
void
|
||||
lockd_down(void)
|
||||
{
|
||||
static int warned;
|
||||
|
||||
mutex_lock(&nlmsvc_mutex);
|
||||
if (nlmsvc_users) {
|
||||
if (--nlmsvc_users)
|
||||
goto out;
|
||||
} else
|
||||
printk(KERN_WARNING "lockd_down: no users! pid=%d\n", nlmsvc_pid);
|
||||
|
||||
if (!nlmsvc_pid) {
|
||||
if (warned++ == 0)
|
||||
printk(KERN_WARNING "lockd_down: no lockd running.\n");
|
||||
goto out;
|
||||
} else {
|
||||
printk(KERN_ERR "lockd_down: no users! task=%p\n",
|
||||
nlmsvc_task);
|
||||
BUG();
|
||||
}
|
||||
warned = 0;
|
||||
|
||||
kill_proc(nlmsvc_pid, SIGKILL, 1);
|
||||
/*
|
||||
* Wait for the lockd process to exit, but since we're holding
|
||||
* the lockd semaphore, we can't wait around forever ...
|
||||
*/
|
||||
clear_thread_flag(TIF_SIGPENDING);
|
||||
interruptible_sleep_on_timeout(&lockd_exit, HZ);
|
||||
if (nlmsvc_pid) {
|
||||
printk(KERN_WARNING
|
||||
"lockd_down: lockd failed to exit, clearing pid\n");
|
||||
nlmsvc_pid = 0;
|
||||
if (!nlmsvc_task) {
|
||||
printk(KERN_ERR "lockd_down: no lockd running.\n");
|
||||
BUG();
|
||||
}
|
||||
spin_lock_irq(¤t->sighand->siglock);
|
||||
recalc_sigpending();
|
||||
spin_unlock_irq(¤t->sighand->siglock);
|
||||
kthread_stop(nlmsvc_task);
|
||||
out:
|
||||
mutex_unlock(&nlmsvc_mutex);
|
||||
}
|
||||
|
|
|
|||
|
|
@ -29,6 +29,7 @@
|
|||
#include <linux/sunrpc/svc.h>
|
||||
#include <linux/lockd/nlm.h>
|
||||
#include <linux/lockd/lockd.h>
|
||||
#include <linux/kthread.h>
|
||||
|
||||
#define NLMDBG_FACILITY NLMDBG_SVCLOCK
|
||||
|
||||
|
|
@ -887,7 +888,7 @@ nlmsvc_retry_blocked(void)
|
|||
unsigned long timeout = MAX_SCHEDULE_TIMEOUT;
|
||||
struct nlm_block *block;
|
||||
|
||||
while (!list_empty(&nlm_blocked)) {
|
||||
while (!list_empty(&nlm_blocked) && !kthread_should_stop()) {
|
||||
block = list_entry(nlm_blocked.next, struct nlm_block, b_list);
|
||||
|
||||
if (block->b_when == NLM_NEVER)
|
||||
|
|
|
|||
Загрузка…
Ссылка в новой задаче