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| author | Ranko Zivojnovic <ranko@spidernet.net> | 2007-07-17 01:28:32 (GMT) |
|---|---|---|
| committer | David S. Miller <davem@sunset.davemloft.net> | 2007-07-18 08:46:50 (GMT) |
| commit | 0929c2dd83317813425b937fbc0041013b8685ff (patch) | |
| tree | 00b7dfc35f18dd059b8ea5a6d0a151754c19a974 /net/sched | |
| parent | dd121c4bbf60336773485e91b5cfc57596b45151 (diff) | |
| download | linux-fsl-qoriq-0929c2dd83317813425b937fbc0041013b8685ff.tar.xz | |
[NET]: gen_estimator deadlock fix
-Fixes ABBA deadlock noted by Patrick McHardy <kaber@trash.net>:
> There is at least one ABBA deadlock, est_timer() does:
> read_lock(&est_lock)
> spin_lock(e->stats_lock) (which is dev->queue_lock)
>
> and qdisc_destroy calls htb_destroy under dev->queue_lock, which
> calls htb_destroy_class, then gen_kill_estimator and this
> write_locks est_lock.
To fix the ABBA deadlock the rate estimators are now kept on an rcu list.
-The est_lock changes the use from protecting the list to protecting
the update to the 'bstat' pointer in order to avoid NULL dereferencing.
-The 'interval' member of the gen_estimator structure removed as it is
not needed.
Signed-off-by: Ranko Zivojnovic <ranko@spidernet.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/sched')
0 files changed, 0 insertions, 0 deletions