On Fri, Jul 17, 2015 at 12:10:09PM +0200, Florian Westphal wrote:
> Toralf Förster <[email protected]> wrote:
> > I do run a server with a 64 bit hardened Gentoo Linux (kernel currently
> > 4.0.8).
> > Around 12th of July it started to spew those messages into kern.log :
> >
> > /var/log/kern.log:Jul 12 15:26:07 tor-relay kernel: [538360.650490]
> > nf_conntrack: falling back to vmalloc.
> > /var/log/kern.log:Jul 12 15:26:07 tor-relay kernel: [538360.650615]
> > nf_conntrack: falling back to vmalloc.
> > /var/log/kern.log:Jul 12 15:26:08 tor-relay kernel: [538361.673649]
> > nf_conntrack: falling back to vmalloc.
> > /var/log/kern.log:Jul 12 15:26:08 tor-relay kernel: [538361.673786]
> > nf_conntrack: falling back to vmalloc.
> >
> > I read https://bugzilla.openvz.org/show_bug.cgi?id=3092 but a reboot did
> > not help.
> > I got 1-2 thousends of those lines per day.
>
> Most likely result of 88eab472ec21f01d3e36ff ("netfilter: conntrack:
> adjust nf_conntrack_buckets default value".
I think we can get rid of that warning, it will most likely shown
every time after that patch.
[...]
> Pablo, Patrick -- any idea on how to stop conntrack from becoming active
> in a newly created netns automatically without breaking anything?
>
> With upcoming per netns hooks, we might be able to delay registering
> conntrack, defrag etc. until after a -m conntrack rule has been added.
> Dou you think that could work?
>
> For nft we could create an expression to configure conntrack explicitly
> (inverse NOTRACK).
>
> [ obviously we can also add that for xtables but that would break
> setups if we suddently move to "you must ask for conntrack via
> ruleset" model. ]
With netns in place, I think it's now clear that we need that this is
configurable at ruleset level that we've been discussing for a while.
But users will have to request this new behaviour to avoid breaking
existing setups...
diff --git a/net/netfilter/nf_conntrack_core.c b/net/netfilter/nf_conntrack_core.c
index 13fad86..9b7dc11 100644
--- a/net/netfilter/nf_conntrack_core.c
+++ b/net/netfilter/nf_conntrack_core.c
@@ -1522,10 +1522,8 @@ void *nf_ct_alloc_hashtable(unsigned int *sizep, int nulls)
sz = nr_slots * sizeof(struct hlist_nulls_head);
hash = (void *)__get_free_pages(GFP_KERNEL | __GFP_NOWARN | __GFP_ZERO,
get_order(sz));
- if (!hash) {
- printk(KERN_WARNING "nf_conntrack: falling back to vmalloc.\n");
+ if (!hash)
hash = vzalloc(sz);
- }
if (hash && nulls)
for (i = 0; i < nr_slots; i++)
