On Thu, 2010-02-04 at 18:04 +0100, Patrick McHardy wrote: > Patrick McHardy wrote: > > Alexey Dobriyan wrote: > >> Jon Masters correctly points out that conntrack hash sizes > >> (nf_conntrack_htable_size) are global (not per-netns) and > >> modifiable at runtime via /sys/module/nf_conntrack/hashsize . > >> > >> Steps to reproduce: > >> clone(CLONE_NEWNET) > >> [grow /sys/module/nf_conntrack/hashsize] > >> exit() > >> > >> At netns exit we are going to scan random memory for conntracks to be killed. > >> > >> Apparently there is a code which deals with hashtable resize for > >> init_net (and it was there befode netns conntrack code), so prohibit > >> hashsize modification if there is more than one netns exists. > >> > >> To change hashtable sizes, you need to reload module. > >> > >> Expectation hashtable size was simply glued to a variable with no code > >> to rehash expectations, so it was a bug to allow writing to it. > >> Make "expect_hashsize" readonly. > >> > >> This is temporarily until we figure out what to do. > > > > How about alternatively moving nf_conntrack_hsize into the > > per-namespace struct? It doesn't look more complicated or > > intrusive and would allow to still change the init_net > > hashsize. Also seems less hackish :) > > How about this (so far untested) patch? The htable_size is moved into > the per-namespace struct and initialized from the current (global) > value of nf_conntrack_htable_size. Changes through sysfs are still > permitted, but only affect the init namespace and newly created ones. I moved the random seed into the per-ns context aswell. I think that's better than having a global one, and you don't need to rehash all. Jon. -- To unsubscribe from this list: send the line "unsubscribe netfilter-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
