linux/include/net
Vladimir Oltean a57d8c217a net: dsa: flush switchdev workqueue before tearing down CPU/DSA ports
Sometimes when unbinding the mv88e6xxx driver on Turris MOX, these error
messages appear:

mv88e6085 d0032004.mdio-mii:12: port 1 failed to delete be:79:b4:9e:9e:96 vid 1 from fdb: -2
mv88e6085 d0032004.mdio-mii:12: port 1 failed to delete be:79:b4:9e:9e:96 vid 0 from fdb: -2
mv88e6085 d0032004.mdio-mii:12: port 1 failed to delete d8:58:d7:00:ca:6d vid 100 from fdb: -2
mv88e6085 d0032004.mdio-mii:12: port 1 failed to delete d8:58:d7:00:ca:6d vid 1 from fdb: -2
mv88e6085 d0032004.mdio-mii:12: port 1 failed to delete d8:58:d7:00:ca:6d vid 0 from fdb: -2

(and similarly for other ports)

What happens is that DSA has a policy "even if there are bugs, let's at
least not leak memory" and dsa_port_teardown() clears the dp->fdbs and
dp->mdbs lists, which are supposed to be empty.

But deleting that cleanup code, the warnings go away.

=> the FDB and MDB lists (used for refcounting on shared ports, aka CPU
and DSA ports) will eventually be empty, but are not empty by the time
we tear down those ports. Aka we are deleting them too soon.

The addresses that DSA complains about are host-trapped addresses: the
local addresses of the ports, and the MAC address of the bridge device.

The problem is that offloading those entries happens from a deferred
work item scheduled by the SWITCHDEV_FDB_DEL_TO_DEVICE handler, and this
races with the teardown of the CPU and DSA ports where the refcounting
is kept.

In fact, not only it races, but fundamentally speaking, if we iterate
through the port list linearly, we might end up tearing down the shared
ports even before we delete a DSA user port which has a bridge upper.

So as it turns out, we need to first tear down the user ports (and the
unused ones, for no better place of doing that), then the shared ports
(the CPU and DSA ports). In between, we need to ensure that all work
items scheduled by our switchdev handlers (which only run for user
ports, hence the reason why we tear them down first) have finished.

Fixes: 161ca59d39 ("net: dsa: reference count the MDB entries at the cross-chip notifier level")
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Link: https://lore.kernel.org/r/20210914134726.2305133-1-vladimir.oltean@nxp.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-09-15 15:09:46 -07:00
..
9p
bluetooth Bluetooth: Store advertising handle so it can be re-enabled 2021-08-16 17:53:48 +02:00
caif
iucv
netfilter netfilter: add netfilter hooks to SRv6 data plane 2021-08-30 01:51:36 +02:00
netns Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf-next 2021-08-30 10:57:54 +01:00
nfc
phonet
sctp
tc_act
6lowpan.h
Space.h
act_api.h
addrconf.h
af_ieee802154.h
af_rxrpc.h
af_unix.h af_unix: Add unix_stream_proto for sockmap 2021-08-16 18:43:39 -07:00
af_vsock.h
ah.h
arp.h
atmclip.h
ax25.h
ax88796.h
bareudp.h
bond_3ad.h
bond_alb.h
bond_options.h
bonding.h
bpf_sk_storage.h
busy_poll.h
calipso.h
cfg80211-wext.h
cfg80211.h nl80211: add support for BSS coloring 2021-08-17 11:58:21 +02:00
cfg802154.h
checksum.h
cipso_ipv4.h
cls_cgroup.h
codel.h
codel_impl.h
codel_qdisc.h
compat.h
datalink.h
dcbevent.h
dcbnl.h
devlink.h devlink: Use xarray to store devlink instances 2021-08-14 13:59:10 +01:00
dn.h
dn_dev.h
dn_fib.h
dn_neigh.h
dn_nsp.h
dn_route.h
dsa.h net: dsa: flush switchdev workqueue before tearing down CPU/DSA ports 2021-09-15 15:09:46 -07:00
dsfield.h
dst.h
dst_cache.h
dst_metadata.h
dst_ops.h
erspan.h
esp.h
espintcp.h
ethoc.h
failover.h
fib_notifier.h
fib_rules.h
firewire.h
flow.h flow: fix object-size-mismatch warning in flowi{4,6}_to_flowi_common() 2021-09-02 11:44:19 +01:00
flow_dissector.h
flow_offload.h Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2021-08-19 18:09:18 -07:00
fou.h
fq.h
fq_impl.h
garp.h
gen_stats.h
genetlink.h
geneve.h
gre.h
gro.h
gro_cells.h
gtp.h
gue.h
hwbm.h
icmp.h
ieee80211_radiotap.h mac80211: Use flex-array for radiotap header bitmap 2021-08-13 09:58:25 +02:00
ieee802154_netdev.h
if_inet6.h ipv6: add IFLA_INET6_RA_MTU to expose mtu value 2021-08-27 17:29:18 -07:00
ife.h
ila.h
inet6_connection_sock.h
inet6_hashtables.h
inet_common.h
inet_connection_sock.h
inet_ecn.h
inet_frag.h
inet_hashtables.h
inet_sock.h
inet_timewait_sock.h
inetpeer.h
ioam6.h
ip.h
ip6_checksum.h
ip6_fib.h ipv6: correct comments about fib6_node sernum 2021-08-24 09:59:01 +01:00
ip6_route.h
ip6_tunnel.h
ip_fib.h
ip_tunnels.h
ip_vs.h
ipcomp.h
ipconfig.h
ipv6.h
ipv6_frag.h
ipv6_stubs.h
iw_handler.h
kcm.h
l3mdev.h
lag.h
lapb.h
lib80211.h
llc.h
llc_c_ac.h
llc_c_ev.h
llc_c_st.h
llc_conn.h
llc_if.h
llc_pdu.h
llc_s_ac.h
llc_s_ev.h
llc_s_st.h
llc_sap.h
lwtunnel.h netfilter: add netfilter hooks to SRv6 data plane 2021-08-30 01:51:36 +02:00
mac80211.h mac80211: introduce individual TWT support in AP mode 2021-08-24 10:30:43 +02:00
mac802154.h
macsec.h
mctp.h
mctpdevice.h mctp: Remove the repeated declaration 2021-08-25 11:23:14 +01:00
mip6.h
mld.h
mpls.h
mpls_iptunnel.h
mptcp.h mptcp: MP_FAIL suboption sending 2021-08-25 11:02:34 +01:00
mrp.h
ncsi.h
ndisc.h
neighbour.h
net_failover.h
net_namespace.h
net_ratelimit.h
netevent.h
netlabel.h
netlink.h
netprio_cgroup.h
netrom.h
nexthop.h
nl802154.h
nsh.h
p8022.h
page_pool.h
pie.h
ping.h
pkt_cls.h sch_htb: Fix inconsistency when leaf qdisc creation fails 2021-08-30 16:33:59 -07:00
pkt_sched.h
pptp.h
protocol.h
psample.h
psnap.h
raw.h
rawv6.h
red.h
regulatory.h
request_sock.h
rose.h
route.h
rpl.h
rsi_91x.h
rtnetlink.h
rtnh.h
sch_generic.h
scm.h
secure_seq.h
seg6.h
seg6_hmac.h
seg6_local.h
selftests.h
slhc_vj.h
smc.h
snmp.h
sock.h sock: remove one redundant SKB_FRAG_PAGE_ORDER macro 2021-08-26 10:46:20 +01:00
sock_reuseport.h
stp.h
strparser.h
switchdev.h
tcp.h
tcp_states.h
timewait_sock.h
tipc.h
tls.h
tls_toe.h
transp_v6.h
tso.h
tun_proto.h
udp.h
udp_tunnel.h
udplite.h
vsock_addr.h
vxlan.h
wext.h
x25.h
x25device.h
xdp.h
xdp_priv.h
xdp_sock.h
xdp_sock_drv.h
xfrm.h
xsk_buff_pool.h