On Tue, 4 Nov 2014 09:48:32 +0800 "billbonaparte" <programme110@xxxxxxxxx> wrote: > (sorry to send this e-mail again, last mail is rejected by server due to > non-acceptable content) There is several issues with your submission. I'll take care of resubmitting a patch in your name (so you will get credit in the git log). If you care to know, issues are: 1. you are not sending to the appropriate mailing lists, 2. patch is as an attachment (should be inlined), 3. the patch have style and white-space issues. > Florian Westphal [mailto:fw@xxxxxxxxx] wrote: > >Correct. This is broken since the central spin lock removal, since > >nf_conntrack_lock no longer protects both get_next_corpse and > >conntrack_confirm. > > > >Please send a patch, moving dying check after removal of conntrack from > >the percpu list, > > Since unconfirmed conntrack is stored in unconfirmed-list which is per-cpu > list and protected by per-cpu spin-lock, we can remove it from > uncomfirmed-list and insert it into ct-hash-table separately. that is to > say, we can remove it from uncomfirmed-list without holding corresponding > hash-lock, then check if it is dying. > if it is dying, we add it to the dying-list, then quit > __nf_conntrack_confirm. we do this to follow the rules that the conntrack > must alternatively at unconfirmed-list or dying-list when it is abort to be > destroyed. In the resubmit. I'll take a slightly more conservative approach, by keeping the DYING check under the hash-lock, as it is currently. I guess we could do it without holding the hash-lock, but I want to keep the fix as simple as possible. > >> 2. operation on ct->status should be atomic, because it race aginst > >> get_next_corpse. [...] > if there is a race at operating ct->status, there will be in alternative > case: > 1) IPS_DYING bit which set in get_next_corpse override other bits (e.g. > IPS_SRC_NAT_DONE_BIT), or > 2) other bits (e.g. IPS_SRC_NAT_DONE_BIT) which set in nf_nat_setup_info > override IPS_DYING bit. Notice the set_bit() is atomic, so we don't have these issues (of bits getting overridden). -- Best regards, Jesper Dangaard Brouer MSc.CS, Sr. Network Kernel Developer at Red Hat Author of http://www.iptv-analyzer.org LinkedIn: http://www.linkedin.com/in/brouer -- 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
