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ip6mr: do not acquire mrt_lock before calling ip6mr_cache_unresolved

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rcu_read_lock() protection is good enough.

ip6mr_cache_unresolved() uses a dedicated spinlock (mfc_unres_lock)

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Eric Dumazet 2022-06-23 04:34:43 +00:00 committed by David S. Miller
parent 638cf4a24a
commit db9eb7c8ae
1 changed files with 6 additions and 6 deletions
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12
net/ipv6/ip6mr.c
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@ -730,7 +730,7 @@ static int mif6_delete(struct mr_table *mrt, int vifi, int notify,
if (VIF_EXISTS(mrt, tmp))
break;
}
mrt->maxvif = tmp + 1;
WRITE_ONCE(mrt->maxvif, tmp + 1);
}
write_unlock_bh(&mrt_lock);
@ -927,7 +927,7 @@ static int mif6_add(struct net *net, struct mr_table *mrt,
WRITE_ONCE(mrt->mroute_reg_vif_num, vifi);
#endif
if (vifi + 1 > mrt->maxvif)
mrt->maxvif = vifi + 1;
WRITE_ONCE(mrt->maxvif, vifi + 1);
write_unlock_bh(&mrt_lock);
call_ip6mr_vif_entry_notifiers(net, FIB_EVENT_VIF_ADD,
v, dev, vifi, mrt->id);
@ -2099,11 +2099,13 @@ out_free:
return 0;
}
/* Called with mrt_lock or rcu_read_lock() */
static int ip6mr_find_vif(struct mr_table *mrt, struct net_device *dev)
{
int ct;
for (ct = mrt->maxvif - 1; ct >= 0; ct--) {
/* Pairs with WRITE_ONCE() in mif6_delete()/mif6_add() */
for (ct = READ_ONCE(mrt->maxvif) - 1; ct >= 0; ct--) {
if (rcu_access_pointer(mrt->vif_table[ct].dev) == dev)
break;
}
@ -2249,7 +2251,6 @@ int ip6_mr_input(struct sk_buff *skb)
return err;
}
read_lock(&mrt_lock);
cache = ip6mr_cache_find(mrt,
&ipv6_hdr(skb)->saddr, &ipv6_hdr(skb)->daddr);
if (!cache) {
@ -2270,15 +2271,14 @@ int ip6_mr_input(struct sk_buff *skb)
vif = ip6mr_find_vif(mrt, dev);
if (vif >= 0) {
int err = ip6mr_cache_unresolved(mrt, vif, skb, dev);
read_unlock(&mrt_lock);
return err;
}
read_unlock(&mrt_lock);
kfree_skb(skb);
return -ENODEV;
}
read_lock(&mrt_lock);
ip6_mr_forward(net, mrt, dev, skb, cache);
read_unlock(&mrt_lock);