The 07/01/2020 12:51, Nikolay Aleksandrov wrote:
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>
> On 01/07/2020 10:22, Horatiu Vultur wrote:
> > This patch extends the function br_fill_ifinfo to return also the MRP
> > status for each instance on a bridge. It also adds a new filter
> > RTEXT_FILTER_MRP to return the MRP status only when this is set, not to
> > interfer with the vlans. The MRP status is return only on the bridge
> > interfaces.
> >
> > Signed-off-by: Horatiu Vultur <horatiu.vultur@xxxxxxxxxxxxx>
> > ---
> > include/uapi/linux/rtnetlink.h | 1 +
> > net/bridge/br_netlink.c | 29 ++++++++++++++++++++++++++++-
> > 2 files changed, 29 insertions(+), 1 deletion(-)
> >
> > diff --git a/include/uapi/linux/rtnetlink.h b/include/uapi/linux/rtnetlink.h
> > index 879e64950a0a2..9b814c92de123 100644
> > --- a/include/uapi/linux/rtnetlink.h
> > +++ b/include/uapi/linux/rtnetlink.h
> > @@ -778,6 +778,7 @@ enum {
> > #define RTEXT_FILTER_BRVLAN (1 << 1)
> > #define RTEXT_FILTER_BRVLAN_COMPRESSED (1 << 2)
> > #define RTEXT_FILTER_SKIP_STATS (1 << 3)
> > +#define RTEXT_FILTER_MRP (1 << 4)
> >
> > /* End of information exported to user level */
> >
> > diff --git a/net/bridge/br_netlink.c b/net/bridge/br_netlink.c
> > index 240e260e3461c..6ecb7c7453dcb 100644
> > --- a/net/bridge/br_netlink.c
> > +++ b/net/bridge/br_netlink.c
> > @@ -453,6 +453,32 @@ static int br_fill_ifinfo(struct sk_buff *skb,
> > rcu_read_unlock();
> > if (err)
> > goto nla_put_failure;
> > +
> > + nla_nest_end(skb, af);
> > + }
> > +
> > + if (filter_mask & RTEXT_FILTER_MRP) {
> > + struct nlattr *af;
> > + int err;
> > +
> > + /* RCU needed because of the VLAN locking rules (rcu || rtnl) */
> > + rcu_read_lock();
Hi Nik,
>
> If you're using RCU, then in the previous patch (02) you should be using RCU primitives
> to walk the list and deref the ports.
> Alternatively if you rely on rtnl only then drop these RCU locks here as they're misleading.
>
> I'd prefer to just use RCU for it in case we drop rtnl one day when dumping.
Thanks for the comments. I will create a new series where I will use the
RCU.
>
> > + if (!br_mrp_enabled(br) || port) {
> > + rcu_read_unlock();
> > + goto done;
> > + }
> > + af = nla_nest_start_noflag(skb, IFLA_AF_SPEC);
> > + if (!af) {
> > + rcu_read_unlock();
> > + goto nla_put_failure;
> > + }
> > +
> > + err = br_mrp_fill_info(skb, br);
> > +
> > + rcu_read_unlock();
> > + if (err)
> > + goto nla_put_failure;
> > +
> > nla_nest_end(skb, af);
> > }
> >
> > @@ -516,7 +542,8 @@ int br_getlink(struct sk_buff *skb, u32 pid, u32 seq,
> > struct net_bridge_port *port = br_port_get_rtnl(dev);
> >
> > if (!port && !(filter_mask & RTEXT_FILTER_BRVLAN) &&
> > - !(filter_mask & RTEXT_FILTER_BRVLAN_COMPRESSED))
> > + !(filter_mask & RTEXT_FILTER_BRVLAN_COMPRESSED) &&
> > + !(filter_mask & RTEXT_FILTER_MRP))
> > return 0;
> >
> > return br_fill_ifinfo(skb, port, pid, seq, RTM_NEWLINK, nlflags,
> >
>
--
/Horatiu
