[NET]: Fix gen_estimator timer removal race

[Patrick McHardy]

This is an updated version of the gen_estimator fix
that relies on all changes happening under the rtnl
and just fixes the race between timer rearming and
timer removal.



[NET]: Fix gen_estimator timer removal race

As noticed by Jarek Poplawski <[EMAIL PROTECTED]>, the timer removal in
gen_kill_estimator races with the timer function rearming the timer.

Check whether the timer list is empty before rearming the timer
in the timer function to fix this.

Signed-off-by: Patrick McHardy <[EMAIL PROTECTED]>

---
commit 369edff5c22c6838cb632c24a1971f1ce6823991
tree b0f47f8469ed9fc47e8fc6b597b204aac816133a
parent ba609a9d97ba231c3d94443c50579ceb5fc33867
author Patrick McHardy <[EMAIL PROTECTED]> Wed, 04 Jul 2007 17:45:26 +0200
committer Patrick McHardy <[EMAIL PROTECTED]> Wed, 04 Jul 2007 17:45:26 +0200

 net/core/gen_estimator.c |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)

diff --git a/net/core/gen_estimator.c b/net/core/gen_estimator.c
index 17daf4c..cc84d8d 100644
--- a/net/core/gen_estimator.c
+++ b/net/core/gen_estimator.c
@@ -128,7 +128,8 @@ static void est_timer(unsigned long arg)
                spin_unlock(e->stats_lock);
        }
 
-       mod_timer(&elist[idx].timer, jiffies + ((HZ<<idx)/4));
+       if (elist[idx].list != NULL)
+               mod_timer(&elist[idx].timer, jiffies + ((HZ<<idx)/4));
        read_unlock(&est_lock);
 }