From: Yu Ning <ning.yu@xxxxxxxxxx>
The time returned by gettimeofday() is affected by discontinuous jumps
in the system time, so it causes an issue that autofs may not auto
unmount a mount point if system time is manually changed by the system
administrator.
To fix the issue we need to convert to using a monotonic clock source
instead of the clock source used by gettimeofday().
Convert the alarm_handler() to use a monotonic clock source.
Signed-off-by: Yu Ning <ning.yu@xxxxxxxxxx>
---
CHANGELOG | 1 +
lib/alarm.c | 28 ++++++++++++++++++++++------
2 files changed, 23 insertions(+), 6 deletions(-)
diff --git a/CHANGELOG b/CHANGELOG
index 6eb4daf..c7cbc0f 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -19,6 +19,7 @@
- fix error handling of is_mounted().
- Add a mode option for master map entries.
- define monotonic clock helper functions.
+- use monotonic clock for alarm thread condition wait.
21/04/2015 autofs-5.1.1
=======================
diff --git a/lib/alarm.c b/lib/alarm.c
index 0f04ef8..e6a880b 100755
--- a/lib/alarm.c
+++ b/lib/alarm.c
@@ -23,7 +23,7 @@ struct alarm {
};
static pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER;
-static pthread_cond_t cond = PTHREAD_COND_INITIALIZER;
+static pthread_cond_t cond;
static LIST_HEAD(alarms);
#define alarm_lock() \
@@ -46,7 +46,7 @@ int alarm_add(struct autofs_point *ap, time_t seconds)
struct list_head *head;
struct list_head *p;
struct alarm *new;
- time_t now = time(NULL);
+ time_t now = monotonic_time(NULL);
time_t next_alarm = 0;
unsigned int empty = 1;
int status;
@@ -175,17 +175,18 @@ static void *alarm_handler(void *arg)
first = list_entry(head->next, struct alarm, list);
- now = time(NULL);
+ now = monotonic_time(NULL);
if (first->time > now) {
- struct timeval usecs;
+ struct timespec nsecs;
+
/*
* Wait for alarm to trigger or a new alarm
* to be added.
*/
- gettimeofday(&usecs, NULL);
+ clock_gettime(CLOCK_MONOTONIC, &nsecs);
expire.tv_sec = first->time;
- expire.tv_nsec = usecs.tv_usec * 1000;
+ expire.tv_nsec = nsecs.tv_nsec;
status = pthread_cond_timedwait(&cond, &mutex, &expire);
if (status && status != ETIMEDOUT)
@@ -212,6 +213,7 @@ int alarm_start_handler(void)
pthread_t thid;
pthread_attr_t attrs;
pthread_attr_t *pattrs = &attrs;
+ pthread_condattr_t condattrs;
int status;
status = pthread_attr_init(pattrs);
@@ -224,8 +226,22 @@ int alarm_start_handler(void)
#endif
}
+ status = pthread_condattr_init(&condattrs);
+ if (status)
+ fatal(status);
+
+ status = pthread_condattr_setclock(&condattrs, CLOCK_MONOTONIC);
+ if (status)
+ fatal(status);
+
+ status = pthread_cond_init(&cond, &condattrs);
+ if (status)
+ fatal(status);
+
status = pthread_create(&thid, pattrs, alarm_handler, NULL);
+ pthread_condattr_destroy(&condattrs);
+
if (pattrs)
pthread_attr_destroy(pattrs);
--
To unsubscribe from this list: send the line "unsubscribe autofs" in
