Re: linux-next: build warning after merge of the net-next tree

On Tue, 8 Sep 2020 13:00:00 +1000 Stephen Rothwell wrote:

Hi all,

After merging the net-next tree, today's linux-next build (powerpc
ppc64_defconfig) produced this warning:

net/bridge/br_multicast.c: In function 'br_multicast_find_port':
net/bridge/br_multicast.c:1818:21: warning: unused variable 'br' [-Wunused-variable]
 1818 |  struct net_bridge *br = mp->br;
      |                     ^~

Introduced by commit

  0436862e417e ("net: bridge: mcast: support for IGMPv3/MLDv2 ALLOW_NEW_SOURCES report")

Maybe turning mlock_dereference into a static inline function would help.

Or perhaps provide a better definition of whatever is making the
reference disappear? RCU_LOCKDEP_WARN()?

Thanks for the report!