On Saturday 28 November 2015 10:49:59 Antonio Quartulli wrote:
Simon Wunderlich:
From: Simon Wunderlich simon@open-mesh.com
Signed-off-by: Simon Wunderlich simon@open-mesh.com
net/batman-adv/multicast.c | 2 ++ 1 file changed, 2 insertions(+)
diff --git a/net/batman-adv/multicast.c b/net/batman-adv/multicast.c index 8abf488..d984eee 100644 --- a/net/batman-adv/multicast.c +++ b/net/batman-adv/multicast.c @@ -801,7 +801,9 @@ void batadv_mcast_free(struct batadv_priv *bat_priv)
batadv_tvlv_container_unregister(bat_priv, BATADV_TVLV_MCAST, 1); batadv_tvlv_handler_unregister(bat_priv, BATADV_TVLV_MCAST, 1);
spin_lock_bh(&bat_priv->tt.commit_lock);
batadv_mcast_mla_tt_retract(bat_priv, NULL);
spin_unlock_bh(&bat_priv->tt.commit_lock);
Linus,
can you please comment as of why batadv_mcast_mla_tt_retract() requires to hold the tt.commit_lock ?
Maybe the relevant parts of the Oops can be added to the commit message:
WARNING: CPU: 0 PID: 238 at net/batman-adv/multicast.c:142 batadv_mcast_mla_tt_retract+0x94/0x205 [batman_adv]() [...] Call Trace: [<ffffffff815fc597>] dump_stack+0x4b/0x64 [<ffffffff810b34dc>] warn_slowpath_common+0xbc/0x120 [<ffffffffa0024ec5>] ? batadv_mcast_mla_tt_retract+0x94/0x205 [batman_adv] [<ffffffff810b3705>] warn_slowpath_null+0x15/0x20 [<ffffffffa0024ec5>] batadv_mcast_mla_tt_retract+0x94/0x205 [batman_adv] [<ffffffffa00273fe>] batadv_mcast_free+0x36/0x39 [batman_adv] [<ffffffffa0020c77>] batadv_mesh_free+0x7d/0x13f [batman_adv] [<ffffffffa0036a6b>] batadv_softif_free+0x15/0x25 [batman_adv] [...]
I see it calls batadv_tt_local_remove() but this does not really requires the lock. Maybe you wanted to perform *all* the removes before TT could do a commit ? Or is there any other reason?
Cheers,
mcast.mla_list is protected by tt.commit_lock (see batadv_mcast_mla_tt_add, batadv_mcast_mla_list_free and batadv_mcast_mla_tt_retract).
Kind regards, Sven