-/* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*-
- * vim:expandtab:shiftwidth=8:tabstop=8:
- *
+/*
* GPL HEADER START
*
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
/*
* Copyright (c) 2008, 2010, Oracle and/or its affiliates. All rights reserved.
* Use is subject to license terms.
+ *
+ * Copyright (c) 2012, Intel Corporation.
*/
/*
* This file is part of Lustre, http://www.lustre.org/
#include "tracefile.h"
struct lc_watchdog {
- cfs_timer_t lcw_timer; /* kernel timer */
- cfs_list_t lcw_list;
- cfs_time_t lcw_last_touched;
- cfs_task_t *lcw_task;
- cfs_atomic_t lcw_refcount;
+ spinlock_t lcw_lock; /* check or change lcw_list */
+ int lcw_refcount; /* must hold lcw_pending_timers_lock */
+ cfs_timer_t lcw_timer; /* kernel timer */
+ cfs_list_t lcw_list; /* chain on pending list */
+ cfs_time_t lcw_last_touched; /* last touched stamp */
+ cfs_task_t *lcw_task; /* owner task */
+ void (*lcw_callback)(pid_t, void *);
+ void *lcw_data;
- void (*lcw_callback)(pid_t, void *);
- void *lcw_data;
-
- pid_t lcw_pid;
+ pid_t lcw_pid;
enum {
LC_WATCHDOG_DISABLED,
* and lcw_stop_completion when it exits.
* Wake lcw_event_waitq to signal timer callback dispatches.
*/
-static cfs_completion_t lcw_start_completion;
-static cfs_completion_t lcw_stop_completion;
-static cfs_waitq_t lcw_event_waitq;
+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.
/*
* Number of outstanding watchdogs.
* When it hits 1, we start the dispatcher.
- * When it hits 0, we stop the distpatcher.
+ * When it hits 0, we stop the dispatcher.
*/
static __u32 lcw_refcount = 0;
-static CFS_DECLARE_MUTEX(lcw_refcount_sem);
+static DEFINE_MUTEX(lcw_refcount_mutex);
/*
* List of timers that have fired that need their callbacks run by the
* dispatcher.
*/
/* BH lock! */
-static cfs_spinlock_t lcw_pending_timers_lock = CFS_SPIN_LOCK_UNLOCKED;
-static cfs_list_t lcw_pending_timers = \
- CFS_LIST_HEAD_INIT(lcw_pending_timers);
+static DEFINE_SPINLOCK(lcw_pending_timers_lock);
+static cfs_list_t lcw_pending_timers = CFS_LIST_HEAD_INIT(lcw_pending_timers);
/* Last time a watchdog expired */
static cfs_time_t lcw_last_watchdog_time;
lcw_dump(struct lc_watchdog *lcw)
{
ENTRY;
-#if defined(HAVE_TASKLIST_LOCK)
- cfs_read_lock(&tasklist_lock);
-#elif defined(HAVE_TASK_RCU)
rcu_read_lock();
-#else
- CERROR("unable to dump stack because of missing export\n");
- RETURN_EXIT;
-#endif
- if (lcw->lcw_task == NULL) {
+ if (lcw->lcw_task == NULL) {
LCONSOLE_WARN("Process " LPPID " was not found in the task "
"list; watchdog callback may be incomplete\n",
(int)lcw->lcw_pid);
libcfs_debug_dumpstack(lcw->lcw_task);
}
-#if defined(HAVE_TASKLIST_LOCK)
- cfs_read_unlock(&tasklist_lock);
-#elif defined(HAVE_TASK_RCU)
rcu_read_unlock();
-#endif
EXIT;
}
lcw->lcw_state = LC_WATCHDOG_EXPIRED;
- cfs_spin_lock_bh(&lcw_pending_timers_lock);
- cfs_list_add(&lcw->lcw_list, &lcw_pending_timers);
- cfs_waitq_signal(&lcw_event_waitq);
- cfs_spin_unlock_bh(&lcw_pending_timers_lock);
+ spin_lock_bh(&lcw->lcw_lock);
+ LASSERT(cfs_list_empty(&lcw->lcw_list));
- EXIT;
-}
-
-static inline void lcw_get(struct lc_watchdog *lcw)
-{
- cfs_atomic_inc(&lcw->lcw_refcount);
-}
+ spin_lock_bh(&lcw_pending_timers_lock);
+ lcw->lcw_refcount++; /* +1 for pending list */
+ cfs_list_add(&lcw->lcw_list, &lcw_pending_timers);
+ wake_up(&lcw_event_waitq);
-static inline void lcw_put(struct lc_watchdog *lcw)
-{
- if (cfs_atomic_dec_and_test(&lcw->lcw_refcount)) {
- LASSERT(cfs_list_empty(&lcw->lcw_list));
- LIBCFS_FREE(lcw, sizeof(*lcw));
- }
+ spin_unlock_bh(&lcw_pending_timers_lock);
+ spin_unlock_bh(&lcw->lcw_lock);
+ EXIT;
}
static int is_watchdog_fired(void)
{
- int rc;
+ int rc;
- if (cfs_test_bit(LCW_FLAG_STOP, &lcw_flags))
- return 1;
+ if (test_bit(LCW_FLAG_STOP, &lcw_flags))
+ return 1;
- cfs_spin_lock_bh(&lcw_pending_timers_lock);
- rc = !cfs_list_empty(&lcw_pending_timers);
- cfs_spin_unlock_bh(&lcw_pending_timers_lock);
- return rc;
+ spin_lock_bh(&lcw_pending_timers_lock);
+ rc = !cfs_list_empty(&lcw_pending_timers);
+ spin_unlock_bh(&lcw_pending_timers_lock);
+ return rc;
}
static void lcw_dump_stack(struct lc_watchdog *lcw)
static int lcw_dispatch_main(void *data)
{
int rc = 0;
- unsigned long flags;
- struct lc_watchdog *lcw, *lcwcb;
+ struct lc_watchdog *lcw;
+ CFS_LIST_HEAD (zombies);
ENTRY;
- cfs_daemonize("lc_watchdogd");
-
- SIGNAL_MASK_LOCK(current, flags);
- sigfillset(¤t->blocked);
- RECALC_SIGPENDING;
- SIGNAL_MASK_UNLOCK(current, flags);
-
- cfs_complete(&lcw_start_completion);
+ complete(&lcw_start_completion);
while (1) {
- cfs_wait_event_interruptible(lcw_event_waitq,
- is_watchdog_fired(), rc);
- CDEBUG(D_INFO, "Watchdog got woken up...\n");
- if (cfs_test_bit(LCW_FLAG_STOP, &lcw_flags)) {
- CDEBUG(D_INFO, "LCW_FLAG_STOP was set, shutting down...\n");
-
- cfs_spin_lock_bh(&lcw_pending_timers_lock);
- rc = !cfs_list_empty(&lcw_pending_timers);
- cfs_spin_unlock_bh(&lcw_pending_timers_lock);
- if (rc) {
- CERROR("pending timers list was not empty at "
- "time of watchdog dispatch shutdown\n");
- }
- break;
- }
+ int dumplog = 1;
- lcwcb = NULL;
- cfs_spin_lock_bh(&lcw_pending_timers_lock);
+ rc = 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 set, shutting down...\n");
+
+ spin_lock_bh(&lcw_pending_timers_lock);
+ rc = !cfs_list_empty(&lcw_pending_timers);
+ spin_unlock_bh(&lcw_pending_timers_lock);
+ if (rc) {
+ CERROR("pending timers list was not empty at "
+ "time of watchdog dispatch shutdown\n");
+ }
+ break;
+ }
+
+ spin_lock_bh(&lcw_pending_timers_lock);
while (!cfs_list_empty(&lcw_pending_timers)) {
+ int is_dumplog;
lcw = cfs_list_entry(lcw_pending_timers.next,
- struct lc_watchdog,
- lcw_list);
- lcw_get(lcw);
+ struct lc_watchdog, lcw_list);
+ /* +1 ref for callback to make sure lwc wouldn't be
+ * deleted after releasing lcw_pending_timers_lock */
+ lcw->lcw_refcount++;
+ spin_unlock_bh(&lcw_pending_timers_lock);
+
+ /* lock ordering */
+ spin_lock_bh(&lcw->lcw_lock);
+ spin_lock_bh(&lcw_pending_timers_lock);
+
+ if (cfs_list_empty(&lcw->lcw_list)) {
+ /* already removed from pending list */
+ lcw->lcw_refcount--; /* -1 ref for callback */
+ if (lcw->lcw_refcount == 0)
+ cfs_list_add(&lcw->lcw_list, &zombies);
+ spin_unlock_bh(&lcw->lcw_lock);
+ /* still hold lcw_pending_timers_lock */
+ continue;
+ }
+
cfs_list_del_init(&lcw->lcw_list);
- cfs_spin_unlock_bh(&lcw_pending_timers_lock);
+ lcw->lcw_refcount--; /* -1 ref for pending list */
+
+ spin_unlock_bh(&lcw_pending_timers_lock);
+ spin_unlock_bh(&lcw->lcw_lock);
CDEBUG(D_INFO, "found lcw for pid " LPPID "\n",
lcw->lcw_pid);
lcw_dump_stack(lcw);
- if (lcwcb == NULL &&
- lcw->lcw_state != LC_WATCHDOG_DISABLED)
- lcwcb = lcw;
- else
- lcw_put(lcw);
- cfs_spin_lock_bh(&lcw_pending_timers_lock);
- }
- cfs_spin_unlock_bh(&lcw_pending_timers_lock);
+ is_dumplog = lcw->lcw_callback == lc_watchdog_dumplog;
+ if (lcw->lcw_state != LC_WATCHDOG_DISABLED &&
+ (dumplog || !is_dumplog)) {
+ lcw->lcw_callback(lcw->lcw_pid, lcw->lcw_data);
+ if (dumplog && is_dumplog)
+ dumplog = 0;
+ }
+
+ spin_lock_bh(&lcw_pending_timers_lock);
+ lcw->lcw_refcount--; /* -1 ref for callback */
+ if (lcw->lcw_refcount == 0)
+ cfs_list_add(&lcw->lcw_list, &zombies);
+ }
+ spin_unlock_bh(&lcw_pending_timers_lock);
- /* only do callback once for this batch of lcws */
- if (lcwcb != NULL) {
- lcwcb->lcw_callback(lcwcb->lcw_pid, lcwcb->lcw_data);
- lcw_put(lcwcb);
+ while (!cfs_list_empty(&zombies)) {
+ lcw = cfs_list_entry(lcw_pending_timers.next,
+ struct lc_watchdog, lcw_list);
+ cfs_list_del(&lcw->lcw_list);
+ LIBCFS_FREE(lcw, sizeof(*lcw));
}
}
- cfs_complete(&lcw_stop_completion);
+ complete(&lcw_stop_completion);
- RETURN(rc);
+ RETURN(rc);
}
static void lcw_dispatch_start(void)
{
- int rc;
-
- ENTRY;
- LASSERT(lcw_refcount == 1);
-
- cfs_init_completion(&lcw_stop_completion);
- cfs_init_completion(&lcw_start_completion);
- cfs_waitq_init(&lcw_event_waitq);
-
- CDEBUG(D_INFO, "starting dispatch thread\n");
- rc = cfs_kernel_thread(lcw_dispatch_main, NULL, 0);
- if (rc < 0) {
- CERROR("error spawning watchdog dispatch thread: %d\n", rc);
- EXIT;
- return;
- }
- cfs_wait_for_completion(&lcw_start_completion);
- CDEBUG(D_INFO, "watchdog dispatcher initialization complete.\n");
-
- EXIT;
+ cfs_task_t *task;
+
+ 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");
+ task = kthread_run(lcw_dispatch_main, NULL, "lc_watchdogd");
+ if (IS_ERR(task)) {
+ CERROR("error spawning watchdog dispatch thread: %ld\n",
+ PTR_ERR(task));
+ 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);
+ ENTRY;
+ LASSERT(lcw_refcount == 0);
- CDEBUG(D_INFO, "trying to stop watchdog dispatcher.\n");
+ CDEBUG(D_INFO, "trying to stop watchdog dispatcher.\n");
- cfs_set_bit(LCW_FLAG_STOP, &lcw_flags);
- cfs_waitq_signal(&lcw_event_waitq);
+ set_bit(LCW_FLAG_STOP, &lcw_flags);
+ wake_up(&lcw_event_waitq);
- cfs_wait_for_completion(&lcw_stop_completion);
+ wait_for_completion(&lcw_stop_completion);
- CDEBUG(D_INFO, "watchdog dispatcher has shut down.\n");
+ CDEBUG(D_INFO, "watchdog dispatcher has shut down.\n");
- EXIT;
+ EXIT;
}
struct lc_watchdog *lc_watchdog_add(int timeout,
RETURN(ERR_PTR(-ENOMEM));
}
- lcw->lcw_task = cfs_current();
- lcw->lcw_pid = cfs_curproc_pid();
- lcw->lcw_callback = (callback != NULL) ? callback : lc_watchdog_dumplog;
- lcw->lcw_data = data;
- lcw->lcw_state = LC_WATCHDOG_DISABLED;
+ spin_lock_init(&lcw->lcw_lock);
+ lcw->lcw_refcount = 1; /* refcount for owner */
+ lcw->lcw_task = cfs_current();
+ lcw->lcw_pid = current_pid();
+ lcw->lcw_callback = (callback != NULL) ? callback : lc_watchdog_dumplog;
+ lcw->lcw_data = data;
+ lcw->lcw_state = LC_WATCHDOG_DISABLED;
CFS_INIT_LIST_HEAD(&lcw->lcw_list);
cfs_timer_init(&lcw->lcw_timer, lcw_cb, lcw);
- cfs_atomic_set(&lcw->lcw_refcount, 1);
- cfs_down(&lcw_refcount_sem);
- if (++lcw_refcount == 1)
- lcw_dispatch_start();
- cfs_up(&lcw_refcount_sem);
+ mutex_lock(&lcw_refcount_mutex);
+ if (++lcw_refcount == 1)
+ lcw_dispatch_start();
+ mutex_unlock(&lcw_refcount_mutex);
/* Keep this working in case we enable them by default */
if (lcw->lcw_state == LC_WATCHDOG_ENABLED) {
lcw->lcw_last_touched = newtime;
}
+static void lc_watchdog_del_pending(struct lc_watchdog *lcw)
+{
+ spin_lock_bh(&lcw->lcw_lock);
+ if (unlikely(!cfs_list_empty(&lcw->lcw_list))) {
+ spin_lock_bh(&lcw_pending_timers_lock);
+ cfs_list_del_init(&lcw->lcw_list);
+ lcw->lcw_refcount--; /* -1 ref for pending list */
+ spin_unlock_bh(&lcw_pending_timers_lock);
+ }
+
+ spin_unlock_bh(&lcw->lcw_lock);
+}
+
void lc_watchdog_touch(struct lc_watchdog *lcw, int timeout)
{
ENTRY;
LASSERT(lcw != NULL);
- LASSERT(cfs_atomic_read(&lcw->lcw_refcount) > 0);
- cfs_spin_lock_bh(&lcw_pending_timers_lock);
- cfs_list_del_init(&lcw->lcw_list);
- cfs_spin_unlock_bh(&lcw_pending_timers_lock);
+ lc_watchdog_del_pending(lcw);
lcw_update_time(lcw, "resumed");
lcw->lcw_state = LC_WATCHDOG_ENABLED;
{
ENTRY;
LASSERT(lcw != NULL);
- LASSERT(cfs_atomic_read(&lcw->lcw_refcount) > 0);
- cfs_spin_lock_bh(&lcw_pending_timers_lock);
- if (!cfs_list_empty(&lcw->lcw_list))
- cfs_list_del_init(&lcw->lcw_list);
- cfs_spin_unlock_bh(&lcw_pending_timers_lock);
+ lc_watchdog_del_pending(lcw);
lcw_update_time(lcw, "completed");
lcw->lcw_state = LC_WATCHDOG_DISABLED;
void lc_watchdog_delete(struct lc_watchdog *lcw)
{
+ int dead;
+
ENTRY;
LASSERT(lcw != NULL);
- LASSERT(cfs_atomic_read(&lcw->lcw_refcount) > 0);
cfs_timer_disarm(&lcw->lcw_timer);
lcw_update_time(lcw, "stopped");
- cfs_spin_lock_bh(&lcw_pending_timers_lock);
- if (!cfs_list_empty(&lcw->lcw_list))
- cfs_list_del_init(&lcw->lcw_list);
- cfs_spin_unlock_bh(&lcw_pending_timers_lock);
- lcw_put(lcw);
+ spin_lock_bh(&lcw->lcw_lock);
+ spin_lock_bh(&lcw_pending_timers_lock);
+ if (unlikely(!cfs_list_empty(&lcw->lcw_list))) {
+ cfs_list_del_init(&lcw->lcw_list);
+ lcw->lcw_refcount--; /* -1 ref for pending list */
+ }
- cfs_down(&lcw_refcount_sem);
- if (--lcw_refcount == 0)
- lcw_dispatch_stop();
- cfs_up(&lcw_refcount_sem);
+ lcw->lcw_refcount--; /* -1 ref for owner */
+ dead = lcw->lcw_refcount == 0;
+ spin_unlock_bh(&lcw_pending_timers_lock);
+ spin_unlock_bh(&lcw->lcw_lock);
- EXIT;
+ if (dead)
+ LIBCFS_FREE(lcw, sizeof(*lcw));
+
+ mutex_lock(&lcw_refcount_mutex);
+ if (--lcw_refcount == 0)
+ lcw_dispatch_stop();
+ mutex_unlock(&lcw_refcount_mutex);
+
+ EXIT;
}
EXPORT_SYMBOL(lc_watchdog_delete);
git://git.whamcloud.com / fs / lustre-release.git / blobdiff