time: Move common updates to a function

This is a backport of cc06268c6a87db156af2daed6e96a936b955cc82

While not a bugfix itself, it allows following fixes to backport
in a more straightforward manner.

CC: Thomas Gleixner <tglx@linutronix.de>
CC: Eric Dumazet <eric.dumazet@gmail.com>
CC: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit c7e2580578671c4d19a1a83e6fdb2482cc136283)

Signed-off-by: Joe Jin <joe.jin@oracle.com>

diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
index 4e6cd20a1683d8b83c036f1ab6d3ce594f4145fc..d9efcdd37bfd6e55526dbecbc7f3ff7c9cd9d71b 100644 (file)
--- a/kernel/time/timekeeping.c
+++ b/kernel/time/timekeeping.c
@@ -166,6 +166,19 @@ static struct timespec total_sleep_time;
  */
 static struct timespec raw_time;
 
+/* must hold write on xtime_lock */
+static void timekeeping_update(bool clearntp)
+{
+       if (clearntp) {
+               timekeeper.ntp_error = 0;
+               ntp_clear();
+       }
+       update_vsyscall(&xtime, &wall_to_monotonic,
+                        timekeeper.clock, timekeeper.mult);
+}
+
+
+
 /* flag for if timekeeping is suspended */
 int __read_mostly timekeeping_suspended;
 
@@ -375,11 +388,7 @@ int do_settimeofday(const struct timespec *tv)
 
        xtime = *tv;
 
-       timekeeper.ntp_error = 0;
-       ntp_clear();
-
-       update_vsyscall(&xtime, &wall_to_monotonic, timekeeper.clock,
-                               timekeeper.mult);
+       timekeeping_update(true);
 
        write_sequnlock_irqrestore(&xtime_lock, flags);
 
@@ -412,11 +421,7 @@ int timekeeping_inject_offset(struct timespec *ts)
        xtime = timespec_add(xtime, *ts);
        wall_to_monotonic = timespec_sub(wall_to_monotonic, *ts);
 
-       timekeeper.ntp_error = 0;
-       ntp_clear();
-
-       update_vsyscall(&xtime, &wall_to_monotonic, timekeeper.clock,
-                               timekeeper.mult);
+       timekeeping_update(true);
 
        write_sequnlock_irqrestore(&xtime_lock, flags);
 
@@ -639,10 +644,7 @@ void timekeeping_inject_sleeptime(struct timespec *delta)
 
        __timekeeping_inject_sleeptime(delta);
 
-       timekeeper.ntp_error = 0;
-       ntp_clear();
-       update_vsyscall(&xtime, &wall_to_monotonic, timekeeper.clock,
-                               timekeeper.mult);
+       timekeeping_update(true);
 
        write_sequnlock_irqrestore(&xtime_lock, flags);
 
@@ -947,9 +949,7 @@ static void update_wall_time(void)
                wall_to_monotonic.tv_sec -= leap;
        }
 
-       /* check to see if there is a new clocksource to use */
-       update_vsyscall(&xtime, &wall_to_monotonic, timekeeper.clock,
-                               timekeeper.mult);
+       timekeeping_update(false);
 }
 
 /**