From f8ed289fab843fbc9251aa2f5c3d416f09b5fc7e Mon Sep 17 00:00:00 2001 From: Nikolay Aleksandrov Date: Fri, 2 Oct 2015 15:05:11 +0200 Subject: [PATCH] bridge: vlan: use br_vlan_(get|put)_master to deal with refcounts Introduce br_vlan_(get|put)_master which take a reference (or create the master vlan first if it didn't exist) and drop a reference respectively. Signed-off-by: Nikolay Aleksandrov Signed-off-by: David S. Miller --- net/bridge/br_vlan.c | 56 ++++++++++++++++++++++++++++++-------------- 1 file changed, 39 insertions(+), 17 deletions(-) diff --git a/net/bridge/br_vlan.c b/net/bridge/br_vlan.c index d97a55e97830..6e41fba47e97 100644 --- a/net/bridge/br_vlan.c +++ b/net/bridge/br_vlan.c @@ -146,6 +146,40 @@ static int __vlan_vid_del(struct net_device *dev, struct net_bridge *br, return err; } +/* Returns a master vlan, if it didn't exist it gets created. In all cases a + * a reference is taken to the master vlan before returning. + */ +static struct net_bridge_vlan *br_vlan_get_master(struct net_bridge *br, u16 vid) +{ + struct net_bridge_vlan *masterv; + + masterv = br_vlan_find(br->vlgrp, vid); + if (!masterv) { + /* missing global ctx, create it now */ + if (br_vlan_add(br, vid, 0)) + return NULL; + masterv = br_vlan_find(br->vlgrp, vid); + if (WARN_ON(!masterv)) + return NULL; + } + atomic_inc(&masterv->refcnt); + + return masterv; +} + +static void br_vlan_put_master(struct net_bridge_vlan *masterv) +{ + if (!br_vlan_is_master(masterv)) + return; + + if (atomic_dec_and_test(&masterv->refcnt)) { + rhashtable_remove_fast(&masterv->br->vlgrp->vlan_hash, + &masterv->vnode, br_vlan_rht_params); + __vlan_del_list(masterv); + kfree_rcu(masterv, rcu); + } +} + /* This is the shared VLAN add function which works for both ports and bridge * devices. There are four possible calls to this function in terms of the * vlan entry type: @@ -196,16 +230,9 @@ static int __vlan_add(struct net_bridge_vlan *v, u16 flags) goto out_filt; } - masterv = br_vlan_find(br->vlgrp, v->vid); - if (!masterv) { - /* missing global ctx, create it now */ - err = br_vlan_add(br, v->vid, 0); - if (err) - goto out_filt; - masterv = br_vlan_find(br->vlgrp, v->vid); - WARN_ON(!masterv); - } - atomic_inc(&masterv->refcnt); + masterv = br_vlan_get_master(br, v->vid); + if (!masterv) + goto out_filt; v->brvlan = masterv; } @@ -240,7 +267,7 @@ out_filt: if (p) { __vlan_vid_del(dev, br, v->vid); if (masterv) { - atomic_dec(&masterv->refcnt); + br_vlan_put_master(masterv); v->brvlan = NULL; } } @@ -289,12 +316,7 @@ static int __vlan_del(struct net_bridge_vlan *v) kfree_rcu(v, rcu); } - if (atomic_dec_and_test(&masterv->refcnt)) { - rhashtable_remove_fast(&masterv->br->vlgrp->vlan_hash, - &masterv->vnode, br_vlan_rht_params); - __vlan_del_list(masterv); - kfree_rcu(masterv, rcu); - } + br_vlan_put_master(masterv); out: return err; } -- 2.20.1