[PATCH net] net: bridge: mcast: Associate the seqcount with its protecting lock.
From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: 2021-09-28 14:11:28
Also in:
bridge
From: Thomas Gleixner <redacted>
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 <redacted>
Signed-off-by: Thomas Gleixner <redacted>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Tested-by: Mike Galbraith <redacted>
---
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 */