On 28/09/2021 17:10, Sebastian Andrzej Siewior wrote: > From: Thomas Gleixner <[email protected]> > > The sequence count bridge_mcast_querier::seq is protected by > net_bridge::multicast_lock but seqcount_init() does not associate the > seqcount with the lock. This leads to a warning on PREEMPT_RT because > preemption is still enabled. > > Let seqcount_init() associate the seqcount with lock that protects the > write section. Remove lockdep_assert_held_once() because lockdep already > checks > whether the associated lock is held. > > Fixes: 67b746f94ff39 ("net: bridge: mcast: make sure querier port/address > updates are consistent") > Reported-by: Mike Galbraith <[email protected]> > Signed-off-by: Thomas Gleixner <[email protected]> > Signed-off-by: Sebastian Andrzej Siewior <[email protected]> > Tested-by: Mike Galbraith <[email protected]> > --- > net/bridge/br_multicast.c | 6 ++---- > net/bridge/br_private.h | 2 +- > 2 files changed, 3 insertions(+), 5 deletions(-) > > --- a/net/bridge/br_multicast.c > +++ b/net/bridge/br_multicast.c > @@ -1677,8 +1677,6 @@ static void br_multicast_update_querier( > int ifindex, > struct br_ip *saddr) > { > - lockdep_assert_held_once(&brmctx->br->multicast_lock); > - > write_seqcount_begin(&querier->seq); > querier->port_ifidx = ifindex; > memcpy(&querier->addr, saddr, sizeof(*saddr)); > @@ -3867,13 +3865,13 @@ void br_multicast_ctx_init(struct net_br > > brmctx->ip4_other_query.delay_time = 0; > brmctx->ip4_querier.port_ifidx = 0; > - seqcount_init(&brmctx->ip4_querier.seq); > + seqcount_spinlock_init(&brmctx->ip4_querier.seq, &br->multicast_lock); > brmctx->multicast_igmp_version = 2; > #if IS_ENABLED(CONFIG_IPV6) > brmctx->multicast_mld_version = 1; > brmctx->ip6_other_query.delay_time = 0; > brmctx->ip6_querier.port_ifidx = 0; > - seqcount_init(&brmctx->ip6_querier.seq); > + seqcount_spinlock_init(&brmctx->ip6_querier.seq, &br->multicast_lock); > #endif > > timer_setup(&brmctx->ip4_mc_router_timer, > --- a/net/bridge/br_private.h > +++ b/net/bridge/br_private.h > @@ -82,7 +82,7 @@ struct bridge_mcast_other_query { > struct bridge_mcast_querier { > struct br_ip addr; > int port_ifidx; > - seqcount_t seq; > + seqcount_spinlock_t seq; > }; > > /* IGMP/MLD statistics */ >
Thanks for fixing it, Acked-by: Nikolay Aleksandrov <[email protected]>
