From 707ec383b369b8da9f009c3ab2236b335ec10788 Mon Sep 17 00:00:00 2001 From: Vladimir Oltean Date: Mon, 21 Sep 2020 03:10:27 +0300 Subject: [PATCH] net: dsa: refuse configuration in prepare phase of dsa_port_vlan_filtering() The current logic beats me a little bit. The comment that "bridge skips -EOPNOTSUPP, so skip the prepare phase" was introduced in commit fb2dabad69f0 ("net: dsa: support VLAN filtering switchdev attr"). I'm not sure: (a) ok, the bridge skips -EOPNOTSUPP, but, so what, where are we returning -EOPNOTSUPP? (b) even if we are, and I'm just not seeing it, what is the causality relationship between the bridge skipping -EOPNOTSUPP and DSA skipping the prepare phase, and just returning zero? One thing is certain beyond doubt though, and that is that DSA currently refuses VLAN filtering from the "commit" phase instead of "prepare", and that this is not a good thing: ip link add br0 type bridge ip link add br1 type bridge vlan_filtering 1 ip link set swp2 master br0 ip link set swp3 master br1 [ 3790.379389] 001: sja1105 spi0.1: VLAN filtering is a global setting [ 3790.379399] 001: ------------[ cut here ]------------ [ 3790.379403] 001: WARNING: CPU: 1 PID: 515 at net/switchdev/switchdev.c:157 switchdev_port_attr_set_now+0x9c/0xa4 [ 3790.379420] 001: swp3: Commit of attribute (id=6) failed. [ 3790.379533] 001: [] (switchdev_port_attr_set_now) from [] (nbp_vlan_init+0x84/0x148) [ 3790.379544] 001: [] (nbp_vlan_init) from [] (br_add_if+0x514/0x670) [ 3790.379554] 001: [] (br_add_if) from [] (do_setlink+0x38c/0xab0) [ 3790.379565] 001: [] (do_setlink) from [] (__rtnl_newlink+0x44c/0x748) [ 3790.379573] 001: [] (__rtnl_newlink) from [] (rtnl_newlink+0x44/0x60) [ 3790.379580] 001: [] (rtnl_newlink) from [] (rtnetlink_rcv_msg+0x124/0x2f8) [ 3790.379590] 001: [] (rtnetlink_rcv_msg) from [] (netlink_rcv_skb+0xb8/0x110) [ 3790.379806] 001: ---[ end trace 0000000000000002 ]--- [ 3790.379819] 001: sja1105 spi0.1 swp3: failed to initialize vlan filtering on this port So move the current logic that may fail (except ds->ops->port_vlan_filtering, that is way harder) into the prepare stage of the switchdev transaction. Signed-off-by: Vladimir Oltean Reviewed-by: Florian Fainelli Signed-off-by: David S. Miller --- net/dsa/port.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) diff --git a/net/dsa/port.c b/net/dsa/port.c index 46c9bf709683..794a03718838 100644 --- a/net/dsa/port.c +++ b/net/dsa/port.c @@ -232,15 +232,15 @@ int dsa_port_vlan_filtering(struct dsa_port *dp, bool vlan_filtering, struct dsa_switch *ds = dp->ds; int err; - /* bridge skips -EOPNOTSUPP, so skip the prepare phase */ - if (switchdev_trans_ph_prepare(trans)) - return 0; + if (switchdev_trans_ph_prepare(trans)) { + if (!ds->ops->port_vlan_filtering) + return -EOPNOTSUPP; - if (!ds->ops->port_vlan_filtering) - return 0; + if (!dsa_port_can_apply_vlan_filtering(dp, vlan_filtering)) + return -EINVAL; - if (!dsa_port_can_apply_vlan_filtering(dp, vlan_filtering)) - return -EINVAL; + return 0; + } if (dsa_port_is_vlan_filtering(dp) == vlan_filtering) return 0;