net: Add a flow_cache_flush_deferred function

flow_cach_flush() might sleep but can be called from
atomic context via the xfrm garbage collector. So add
a flow_cache_flush_deferred() function and use this if
the xfrm garbage colector is invoked from within the
packet path.

Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Acked-by: Timo Teräs <timo.teras@iki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 12 insertions, 0 deletions

diff --git a/net/core/flow.c b/net/core/flow.c
index 8ae42de9c79e..e318c7e98042 100644
--- a/net/core/flow.c
+++ b/net/core/flow.c
@@ -358,6 +358,18 @@ void flow_cache_flush(void)
         put_online_cpus();
 }
 
+static void flow_cache_flush_task(struct work_struct *work)
+{
+        flow_cache_flush();
+}
+
+static DECLARE_WORK(flow_cache_flush_work, flow_cache_flush_task);
+
+void flow_cache_flush_deferred(void)
+{
+        schedule_work(&flow_cache_flush_work);
+}
+
 static int __cpuinit flow_cache_cpu_prepare(struct flow_cache *fc, int cpu)
 {
         struct flow_cache_percpu *fcp = per_cpu_ptr(fc->percpu, cpu);