@@ -77,12 +77,11 @@ struct ipmr_result {
* Note that the changes are semaphored via rtnl_lock.
*/
-static DEFINE_RWLOCK(mrt_lock);
+static DEFINE_SPINLOCK(mrt_lock);
static struct net_device *vif_dev_read(const struct vif_device *vif)
{
- return rcu_dereference_check(vif->dev,
- lockdep_is_held(&mrt_lock));
+ return rcu_dereference(vif->dev);
}
/* Multicast router control variables */
@@ -664,7 +663,7 @@ static int vif_delete(struct mr_table *mrt, int vifi, int notify,
if (!dev)
return -EADDRNOTAVAIL;
- write_lock_bh(&mrt_lock);
+ spin_lock(&mrt_lock);
call_ipmr_vif_entry_notifiers(net, FIB_EVENT_VIF_DEL, v, dev,
vifi, mrt->id);
RCU_INIT_POINTER(v->dev, NULL);
@@ -683,7 +682,7 @@ static int vif_delete(struct mr_table *mrt, int vifi, int notify,
WRITE_ONCE(mrt->maxvif, tmp + 1);
}
- write_unlock_bh(&mrt_lock);
+ spin_unlock(&mrt_lock);
dev_set_allmulti(dev, -1);
@@ -785,7 +784,7 @@ static void ipmr_expire_process(struct timer_list *t)
spin_unlock(&mfc_unres_lock);
}
-/* Fill oifs list. It is called under write locked mrt_lock. */
+/* Fill oifs list. It is called under locked mrt_lock. */
static void ipmr_update_thresholds(struct mr_table *mrt, struct mr_mfc *cache,
unsigned char *ttls)
{
@@ -897,7 +896,7 @@ static int vif_add(struct net *net, struct mr_table *mrt,
v->remote = vifc->vifc_rmt_addr.s_addr;
/* And finish update writing critical data */
- write_lock_bh(&mrt_lock);
+ spin_lock(&mrt_lock);
rcu_assign_pointer(v->dev, dev);
netdev_tracker_alloc(dev, &v->dev_tracker, GFP_ATOMIC);
if (v->flags & VIFF_REGISTER) {
@@ -906,7 +905,7 @@ static int vif_add(struct net *net, struct mr_table *mrt,
}
if (vifi+1 > mrt->maxvif)
WRITE_ONCE(mrt->maxvif, vifi + 1);
- write_unlock_bh(&mrt_lock);
+ spin_unlock(&mrt_lock);
call_ipmr_vif_entry_notifiers(net, FIB_EVENT_VIF_ADD, v, dev,
vifi, mrt->id);
return 0;
@@ -1211,12 +1210,12 @@ static int ipmr_mfc_add(struct net *net, struct mr_table *mrt,
mfc->mfcc_mcastgrp.s_addr, parent);
rcu_read_unlock();
if (c) {
- write_lock_bh(&mrt_lock);
+ spin_lock(&mrt_lock);
c->_c.mfc_parent = mfc->mfcc_parent;
ipmr_update_thresholds(mrt, &c->_c, mfc->mfcc_ttls);
if (!mrtsock)
c->_c.mfc_flags |= MFC_STATIC;
- write_unlock_bh(&mrt_lock);
+ spin_unlock(&mrt_lock);
call_ipmr_mfc_entry_notifiers(net, FIB_EVENT_ENTRY_REPLACE, c,
mrt->id);
mroute_netlink_event(mrt, c, RTM_NEWROUTE);
mrt_lock is only held in write mode, from process context only. We can switch to a mere spinlock, and avoid blocking BH. Also, vif_dev_read() is always called under standard rcu_read_lock(). Signed-off-by: Eric Dumazet <edumazet@google.com> --- net/ipv4/ipmr.c | 19 +++++++++---------- 1 file changed, 9 insertions(+), 10 deletions(-)