[PATCH 22/32] netvm: filter emergency skbs.

Peter Zijlstra
2008-10-02T13:05:26Z

[-- Attachment #1: netvm-sk_filter.patch --]
[-- Type: text/plain, Size: 996 bytes --]

Toss all emergency packets not for a SOCK_MEMALLOC socket. This ensures our
precious memory reserve doesn't get stuck waiting for user-space.

The correctness of this approach relies on the fact that networks must be
assumed lossy.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
---
net/core/filter.c | 3 +++
1 file changed, 3 insertions(+)

Index: linux-2.6/net/core/filter.c
===================================================================
--- linux-2.6.orig/net/core/filter.c
+++ linux-2.6/net/core/filter.c
@@ -81,6 +81,9 @@ int sk_filter(struct sock *sk, struct sk
int err;
struct sk_filter *filter;

+ if (skb_emergency(skb) && !sk_has_memalloc(sk))
+ return -ENOMEM;
+
err = security_sock_rcv_skb(sk, skb);
if (err)
return err;