+++ /dev/null
-/* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*-
- * vim:expandtab:shiftwidth=8:tabstop=8:
- *
- * Copyright (C) 2004 Cluster File Systems, Inc.
- * Author: Jacob Berkman <jacob@clusterfs.com>
- *
- * This file is part of Lustre, http://www.lustre.org.
- *
- * Lustre is free software; you can redistribute it and/or
- * modify it under the terms of version 2 of the GNU General Public
- * License as published by the Free Software Foundation.
- *
- * Lustre is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with Lustre; if not, write to the Free Software
- * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
- */
-
-#define DEBUG_SUBSYSTEM S_PORTALS
-
-#include <linux/kp30.h>
-#include <linux/libcfs.h>
-#include <linux/portals_compat25.h>
-
-
-
-struct lc_watchdog {
- struct timer_list lcw_timer; /* kernel timer */
- struct list_head lcw_list;
- struct timeval lcw_last_touched;
- struct task_struct *lcw_task;
-
- void (*lcw_callback)(struct lc_watchdog *,
- struct task_struct *,
- void *data);
- void *lcw_data;
-
- int lcw_pid;
- int lcw_time; /* time until watchdog fires, in ms */
-
- enum {
- LC_WATCHDOG_DISABLED,
- LC_WATCHDOG_ENABLED,
- LC_WATCHDOG_EXPIRED
- } lcw_state;
-};
-
-/*
- * The dispatcher will complete lcw_start_completion when it starts,
- * and lcw_stop_completion when it exits.
- * Wake lcw_event_waitq to signal timer callback dispatches.
- */
-static struct completion lcw_start_completion;
-static struct completion lcw_stop_completion;
-static wait_queue_head_t lcw_event_waitq;
-
-/*
- * Set this and wake lcw_event_waitq to stop the dispatcher.
- */
-enum {
- LCW_FLAG_STOP = 0
-};
-static unsigned long lcw_flags = 0;
-
-/*
- * Number of outstanding watchdogs.
- * When it hits 1, we start the dispatcher.
- * When it hits 0, we stop the distpatcher.
- */
-static __u32 lcw_refcount = 0;
-static DECLARE_MUTEX(lcw_refcount_sem);
-
-/*
- * List of timers that have fired that need their callbacks run by the
- * dispatcher.
- */
-static spinlock_t lcw_pending_timers_lock = SPIN_LOCK_UNLOCKED;
-static struct list_head lcw_pending_timers = \
- LIST_HEAD_INIT(lcw_pending_timers);
-
-static struct task_struct *lcw_lookup_task(struct lc_watchdog *lcw)
-{
- struct task_struct *tsk;
- unsigned long flags;
- ENTRY;
-
- read_lock_irqsave(&tasklist_lock, flags);
- tsk = find_task_by_pid(lcw->lcw_pid);
- read_unlock_irqrestore(&tasklist_lock, flags);
- if (!tsk) {
- CWARN("Process %d was not found in the task list; "
- "watchdog callback may be incomplete\n", lcw->lcw_pid);
- } else if (tsk != lcw->lcw_task) {
- tsk = NULL;
- CWARN("The current process %d did not set the watchdog; "
- "watchdog callback may be incomplete\n", lcw->lcw_pid);
- }
-
- RETURN(tsk);
-}
-
-static void lcw_cb(unsigned long data)
-{
- struct lc_watchdog *lcw = (struct lc_watchdog *)data;
- struct task_struct *tsk;
- unsigned long flags;
-
- ENTRY;
-
- if (lcw->lcw_state != LC_WATCHDOG_ENABLED) {
- EXIT;
- return;
- }
-
- lcw->lcw_state = LC_WATCHDOG_EXPIRED;
-
- CWARN("Watchdog triggered for pid %d: it was inactive for %dus\n",
- lcw->lcw_pid, (lcw->lcw_time * 1000) / HZ);
-
- tsk = lcw_lookup_task(lcw);
- if (tsk != NULL)
- portals_debug_dumpstack(tsk);
-
- spin_lock_irqsave(&lcw_pending_timers_lock, flags);
- if (list_empty(&lcw->lcw_list)) {
- list_add(&lcw->lcw_list, &lcw_pending_timers);
- wake_up(&lcw_event_waitq);
- }
- spin_unlock_irqrestore(&lcw_pending_timers_lock, flags);
-
- EXIT;
-}
-
-static int is_watchdog_fired(void)
-{
- unsigned long flags;
- int rc;
-
- if (test_bit(LCW_FLAG_STOP, &lcw_flags))
- return 1;
-
- spin_lock_irqsave(&lcw_pending_timers_lock, flags);
- rc = !list_empty(&lcw_pending_timers);
- spin_unlock_irqrestore(&lcw_pending_timers_lock, flags);
- return rc;
-}
-
-static int lcw_dispatch_main(void *data)
-{
- int rc = 0;
- unsigned long flags;
- struct lc_watchdog *lcw;
- struct task_struct *tsk;
-
- ENTRY;
-
- kportal_daemonize("lc_watchdogd");
-
- SIGNAL_MASK_LOCK(current, flags);
- sigfillset(¤t->blocked);
- RECALC_SIGPENDING;
- SIGNAL_MASK_UNLOCK(current, flags);
-
- complete(&lcw_start_completion);
-
- while (1) {
- wait_event_interruptible(lcw_event_waitq, is_watchdog_fired());
- CDEBUG(D_INFO, "Watchdog got woken up...\n");
- if (test_bit(LCW_FLAG_STOP, &lcw_flags)) {
- CDEBUG(D_INFO, "LCW_FLAG_STOP was set, shutting down...\n");
-
- spin_lock_irqsave(&lcw_pending_timers_lock, flags);
- rc = !list_empty(&lcw_pending_timers);
- spin_unlock_irqrestore(&lcw_pending_timers_lock, flags);
- if (rc) {
- CERROR("pending timers list was not empty at "
- "time of watchdog dispatch shutdown\n");
- }
- break;
- }
-
- spin_lock_irqsave(&lcw_pending_timers_lock, flags);
- while (!list_empty(&lcw_pending_timers)) {
-
- lcw = list_entry(lcw_pending_timers.next,
- struct lc_watchdog,
- lcw_list);
- list_del_init(&lcw->lcw_list);
- spin_unlock_irqrestore(&lcw_pending_timers_lock, flags);
-
- CDEBUG(D_INFO, "found lcw for pid %d\n", lcw->lcw_pid);
-
- if (lcw->lcw_state != LC_WATCHDOG_DISABLED) {
- /*
- * sanity check the task against our
- * watchdog
- */
- tsk = lcw_lookup_task(lcw);
- lcw->lcw_callback(lcw, tsk, lcw->lcw_data);
- }
-
- spin_lock_irqsave(&lcw_pending_timers_lock, flags);
- }
- spin_unlock_irqrestore(&lcw_pending_timers_lock, flags);
- }
-
- complete(&lcw_stop_completion);
-
- RETURN(rc);
-}
-
-static void lcw_dispatch_start(void)
-{
- int rc;
-
- ENTRY;
- LASSERT(lcw_refcount == 1);
-
- init_completion(&lcw_stop_completion);
- init_completion(&lcw_start_completion);
- init_waitqueue_head(&lcw_event_waitq);
-
- CDEBUG(D_INFO, "starting dispatch thread\n");
- rc = kernel_thread(lcw_dispatch_main, NULL, 0);
- if (rc < 0) {
- CERROR("error spawning watchdog dispatch thread: %d\n", rc);
- EXIT;
- return;
- }
- wait_for_completion(&lcw_start_completion);
- CDEBUG(D_INFO, "watchdog dispatcher initialization complete.\n");
-
- EXIT;
-}
-
-static void lcw_dispatch_stop(void)
-{
- ENTRY;
- LASSERT(lcw_refcount == 0);
-
- CDEBUG(D_INFO, "trying to stop watchdog dispatcher.\n");
-
- set_bit(LCW_FLAG_STOP, &lcw_flags);
- wake_up(&lcw_event_waitq);
-
- wait_for_completion(&lcw_stop_completion);
-
- CDEBUG(D_INFO, "watchdog dispatcher has shut down.\n");
-
- EXIT;
-}
-
-struct lc_watchdog *lc_watchdog_add(int time,
- void (*callback)(struct lc_watchdog *,
- struct task_struct *,
- void *),
- void *data)
-{
- struct lc_watchdog *lcw = NULL;
- ENTRY;
-
- PORTAL_ALLOC(lcw, sizeof(*lcw));
- if (!lcw) {
- CDEBUG(D_INFO, "Could not allocate new lc_watchdog\n");
- RETURN(ERR_PTR(-ENOMEM));
- }
-
- lcw->lcw_task = current;
- lcw->lcw_pid = current->pid;
- lcw->lcw_time = (time * HZ) / 1000;
- lcw->lcw_callback = callback ? callback : lc_watchdog_dumplog;
- lcw->lcw_data = data;
- lcw->lcw_state = LC_WATCHDOG_DISABLED;
-
- INIT_LIST_HEAD(&lcw->lcw_list);
-
- lcw->lcw_timer.function = lcw_cb;
- lcw->lcw_timer.data = (unsigned long)lcw;
- lcw->lcw_timer.expires = jiffies + lcw->lcw_time;
- init_timer(&lcw->lcw_timer);
-
- down(&lcw_refcount_sem);
- if (++lcw_refcount == 1)
- lcw_dispatch_start();
- up(&lcw_refcount_sem);
-
- /* Keep this working in case we enable them by default */
- if (lcw->lcw_state == LC_WATCHDOG_ENABLED) {
- do_gettimeofday(&lcw->lcw_last_touched);
- add_timer(&lcw->lcw_timer);
- }
-
- RETURN(lcw);
-}
-EXPORT_SYMBOL(lc_watchdog_add);
-
-static long
-timeval_sub(struct timeval *large, struct timeval *small)
-{
- return (large->tv_sec - small->tv_sec) * 1000000 +
- (large->tv_usec - small->tv_usec);
-}
-
-static void lcw_update_time(struct lc_watchdog *lcw, const char *message)
-{
- struct timeval newtime;
- unsigned long timediff;
-
- do_gettimeofday(&newtime);
- if (lcw->lcw_state == LC_WATCHDOG_EXPIRED) {
- timediff = timeval_sub(&newtime, &lcw->lcw_last_touched);
- CWARN("Expired watchdog for pid %d %s after %lu.%.4lus\n",
- lcw->lcw_pid,
- message,
- timediff / 1000000,
- (timediff % 1000000) / 100);
- }
- lcw->lcw_last_touched = newtime;
-}
-
-void lc_watchdog_touch(struct lc_watchdog *lcw)
-{
- unsigned long flags;
- ENTRY;
- LASSERT(lcw != NULL);
-
- spin_lock_irqsave(&lcw_pending_timers_lock, flags);
- if (!list_empty(&lcw->lcw_list))
- list_del_init(&lcw->lcw_list);
- spin_unlock_irqrestore(&lcw_pending_timers_lock, flags);
-
- lcw_update_time(lcw, "touched");
- lcw->lcw_state = LC_WATCHDOG_ENABLED;
-
- mod_timer(&lcw->lcw_timer, jiffies + lcw->lcw_time);
-
- EXIT;
-}
-EXPORT_SYMBOL(lc_watchdog_touch);
-
-void lc_watchdog_disable(struct lc_watchdog *lcw)
-{
- unsigned long flags;
- ENTRY;
- LASSERT(lcw != NULL);
-
- spin_lock_irqsave(&lcw_pending_timers_lock, flags);
- if (!list_empty(&lcw->lcw_list))
- list_del_init(&lcw->lcw_list);
- spin_unlock_irqrestore(&lcw_pending_timers_lock, flags);
-
- lcw_update_time(lcw, "disabled");
- lcw->lcw_state = LC_WATCHDOG_DISABLED;
-
- EXIT;
-}
-EXPORT_SYMBOL(lc_watchdog_disable);
-
-void lc_watchdog_delete(struct lc_watchdog *lcw)
-{
- unsigned long flags;
- ENTRY;
- LASSERT(lcw != NULL);
-
- del_timer(&lcw->lcw_timer);
-
- lcw_update_time(lcw, "deleted");
-
- spin_lock_irqsave(&lcw_pending_timers_lock, flags);
- if (!list_empty(&lcw->lcw_list))
- list_del_init(&lcw->lcw_list);
- spin_unlock_irqrestore(&lcw_pending_timers_lock, flags);
-
- down(&lcw_refcount_sem);
- if (--lcw_refcount == 0)
- lcw_dispatch_stop();
- up(&lcw_refcount_sem);
-
- PORTAL_FREE(lcw, sizeof(*lcw));
-
- EXIT;
-}
-EXPORT_SYMBOL(lc_watchdog_delete);
-
-/*
- * Provided watchdog handlers
- */
-
-extern void portals_debug_dumplog_internal(void *arg);
-
-void lc_watchdog_dumplog(struct lc_watchdog *lcw,
- struct task_struct *tsk,
- void *data)
-{
- tsk = tsk ? tsk : current;
- portals_debug_dumplog_internal((void *)(long)tsk->pid);
-}
-EXPORT_SYMBOL(lc_watchdog_dumplog);
git://git.whamcloud.com / fs / lustre-release.git / blobdiff