| Message ID | 20110309.200437.226773227.davem@davemloft.net |
|---|---|
| State | Accepted, archived |
| Delegated to: | David Miller |
| Headers | show |
Hi, this patch solved the issue I reported. Applied the patch on -rc8. Regards //Ernst On Thu, Mar 10, 2011 at 05:04, David Miller <davem@davemloft.net> wrote: > From: David Miller <davem@davemloft.net> > Date: Wed, 09 Mar 2011 19:20:12 -0800 (PST) > >> From: David Miller <davem@davemloft.net> >> Date: Wed, 09 Mar 2011 15:58:18 -0800 (PST) >> >>> Ok, the following should address both bugs, #29252 and #30462, please >>> give it some testing. >>> >>> -------------------- >>> ipv6: Don't create clones of nonexthop routes forever. >> >> Nevermind, this patch has problems, I'm still debugging and trying to >> come up with a proper fix. >> >> Thanks in advance for your patience. > > Ok, I'm more confident in this version of the fix. It passes all of > my tests, and I've added instrumentation to make sure various cases > are performing the operations the way I expect them to. > > -------------------- > ipv6: Don't create clones of host routes. > MIME-Version: 1.0 > Content-Type: text/plain; charset=UTF-8 > Content-Transfer-Encoding: 8bit > > Addresses https://bugzilla.kernel.org/show_bug.cgi?id=29252 > Addresses https://bugzilla.kernel.org/show_bug.cgi?id=30462 > > In commit d80bc0fd262ef840ed4e82593ad6416fa1ba3fc4 ("ipv6: Always > clone offlink routes.") we forced the kernel to always clone offlink > routes. > > The reason we do that is to make sure we never bind an inetpeer to a > prefixed route. > > The logic turned on here has existed in the tree for many years, > but was always off due to a protecting CPP define. So perhaps > it's no surprise that there is a logic bug here. > > The problem is that we canot clone a route that is already a > host route (ie. has DST_HOST set). Because if we do, an identical > entry already exists in the routing tree and therefore the > ip6_rt_ins() call is going to fail. > > This sets off a series of failures and high cpu usage, because when > ip6_rt_ins() fails we loop retrying this operation a few times in > order to handle a race between two threads trying to clone and insert > the same host route at the same time. > > Fix this by simply using the route as-is when DST_HOST is set. > > Reported-by: slash@ac.auone-net.jp > Reported-by: Ernst Sjöstrand <ernstp@gmail.com> > Signed-off-by: David S. Miller <davem@davemloft.net> > --- > net/ipv6/route.c | 4 +++- > 1 files changed, 3 insertions(+), 1 deletions(-) > > diff --git a/net/ipv6/route.c b/net/ipv6/route.c > index 904312e..e7db701 100644 > --- a/net/ipv6/route.c > +++ b/net/ipv6/route.c > @@ -739,8 +739,10 @@ restart: > > if (!rt->rt6i_nexthop && !(rt->rt6i_flags & RTF_NONEXTHOP)) > nrt = rt6_alloc_cow(rt, &fl->fl6_dst, &fl->fl6_src); > - else > + else if (!(rt->dst.flags & DST_HOST)) > nrt = rt6_alloc_clone(rt, &fl->fl6_dst); > + else > + goto out2; > > dst_release(&rt->dst); > rt = nrt ? : net->ipv6.ip6_null_entry; > -- > 1.7.4.1 > > -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
From: Ernst Sjöstrand <ernstp@gmail.com> Date: Fri, 11 Mar 2011 20:44:39 +0100 > this patch solved the issue I reported. Applied the patch on -rc8. Thank you for testing. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/net/ipv6/route.c b/net/ipv6/route.c index 904312e..e7db701 100644 --- a/net/ipv6/route.c +++ b/net/ipv6/route.c @@ -739,8 +739,10 @@ restart: if (!rt->rt6i_nexthop && !(rt->rt6i_flags & RTF_NONEXTHOP)) nrt = rt6_alloc_cow(rt, &fl->fl6_dst, &fl->fl6_src); - else + else if (!(rt->dst.flags & DST_HOST)) nrt = rt6_alloc_clone(rt, &fl->fl6_dst); + else + goto out2; dst_release(&rt->dst); rt = nrt ? : net->ipv6.ip6_null_entry;