On Tue, 9 Feb 2021 11:18:05 -0800 Mahesh Bandewar (महेश बंडेवार) wrote:
> On Tue, Feb 9, 2021 at 11:04 AM Jakub Kicinski <k...@kernel.org> wrote:
> > On Tue, 9 Feb 2021 10:49:23 -0800 Mahesh Bandewar (महेश बंडेवार) wrote:
> > > On Tue, Feb 9, 2021 at 8:23 AM Jakub Kicinski <k...@kernel.org> wrote:
> > > > On Tue, 9 Feb 2021 12:54:59 +0100 Petr Machata wrote:
> > > > > This will break user scripts, and it fact breaks kernel's very own
> > > > > selftest. We currently have this internally:
> > > > >
> > > > > diff --git a/tools/testing/selftests/net/fib_nexthops.sh
> > > > > b/tools/testing/selftests/net/fib_nexthops.sh
> > > > > index 4c7d33618437..bf8ed24ab3ba 100755
> > > > > --- a/tools/testing/selftests/net/fib_nexthops.sh
> > > > > +++ b/tools/testing/selftests/net/fib_nexthops.sh
> > > > > @@ -121,8 +121,6 @@ create_ns()
> > > > > set -e
> > > > > ip netns add ${n}
> > > > > ip netns set ${n} $((nsid++))
> > > > > - ip -netns ${n} addr add 127.0.0.1/8 dev lo
> > > > > - ip -netns ${n} link set lo up
> > > > >
> > > > > ip netns exec ${n} sysctl -qw net.ipv4.ip_forward=1
> > > > > ip netns exec ${n} sysctl -qw net.ipv4.fib_multipath_use_neigh=1
> > > > >
> > > > > This now fails because the ip commands are run within a "set -e"
> > > > > block,
> > > > > and kernel rejects addition of a duplicate address.
> > > >
> > > > Thanks for the report, could you send a revert with this explanation?
> > > Rather than revert, shouldn't we just fix the self-test in that regard?
> >
> > The selftest is just a messenger. We all know Linus's stand on
> > regressions, IMO we can't make an honest argument that the change
> > does not break user space after it broke our own selftest. Maybe
> > others disagree..
>
> Actually that was the reason behind encompassing this behavior change
> with a sysctl.
Which as I explained to you is pointless for portable applications.
