From: Eric Dumazet <edumazet@google.com>
To: "David S . Miller" <davem@davemloft.net>,
Jakub Kicinski <kuba@kernel.org>, Paolo Abeni <pabeni@redhat.com>
Cc: netdev@vger.kernel.org, eric.dumazet@gmail.com,
Eric Dumazet <edumazet@google.com>
Subject: [PATCH v2 net-next 13/19] ip6mr: do not acquire mrt_lock before calling ip6mr_cache_unresolved
Date: Thu, 23 Jun 2022 04:34:43 +0000 [thread overview]
Message-ID: <20220623043449.1217288-14-edumazet@google.com> (raw)
In-Reply-To: <20220623043449.1217288-1-edumazet@google.com>
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>
---
net/ipv6/ip6mr.c | 12 ++++++------
1 file changed, 6 insertions(+), 6 deletions(-)
diff --git a/net/ipv6/ip6mr.c b/net/ipv6/ip6mr.c
index b4ad606e24bdaf12c233f642cee303f06ccfa4eb..089c26af3120d198ccfdda631294ed9712568ac0 100644
--- a/net/ipv6/ip6mr.c
+++ b/net/ipv6/ip6mr.c
@@ -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 @@ static int ip6mr_forward2(struct net *net, struct mr_table *mrt,
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);
--
2.37.0.rc0.104.g0611611a94-goog
next prev parent reply other threads:[~2022-06-23 4:41 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-06-23 4:34 [PATCH v2 net-next 00/19] ipmr: get rid of rwlocks Eric Dumazet
2022-06-23 4:34 ` [PATCH v2 net-next 01/19] ip6mr: do not get a device reference in pim6_rcv() Eric Dumazet
2022-06-23 4:34 ` [PATCH v2 net-next 02/19] ipmr: add rcu protection over (struct vif_device)->dev Eric Dumazet
2022-06-23 4:34 ` [PATCH v2 net-next 03/19] ipmr: change igmpmsg_netlink_event() prototype Eric Dumazet
2022-06-23 4:34 ` [PATCH v2 net-next 04/19] ipmr: ipmr_cache_report() changes Eric Dumazet
2022-06-23 4:34 ` [PATCH v2 net-next 05/19] ipmr: do not acquire mrt_lock in __pim_rcv() Eric Dumazet
2022-06-23 4:34 ` [PATCH v2 net-next 06/19] ipmr: do not acquire mrt_lock in ioctl(SIOCGETVIFCNT) Eric Dumazet
2022-06-23 4:34 ` [PATCH v2 net-next 07/19] ipmr: do not acquire mrt_lock before calling ipmr_cache_unresolved() Eric Dumazet
2022-06-23 4:34 ` [PATCH v2 net-next 08/19] ipmr: do not acquire mrt_lock while calling ip_mr_forward() Eric Dumazet
2022-07-22 19:34 ` Vladimir Oltean
2022-07-22 20:37 ` Eric Dumazet
2022-07-22 21:10 ` Vladimir Oltean
2022-07-22 21:15 ` Vladimir Oltean
2022-06-23 4:34 ` [PATCH v2 net-next 09/19] ipmr: do not acquire mrt_lock in ipmr_get_route() Eric Dumazet
2022-06-23 4:34 ` [PATCH v2 net-next 10/19] ip6mr: ip6mr_cache_report() changes Eric Dumazet
2022-06-23 4:34 ` [PATCH v2 net-next 11/19] ip6mr: do not acquire mrt_lock in pim6_rcv() Eric Dumazet
2022-06-23 4:34 ` [PATCH v2 net-next 12/19] ip6mr: do not acquire mrt_lock in ioctl(SIOCGETMIFCNT_IN6) Eric Dumazet
2022-06-23 4:34 ` Eric Dumazet [this message]
2022-06-23 4:34 ` [PATCH v2 net-next 14/19] ip6mr: do not acquire mrt_lock while calling ip6_mr_forward() Eric Dumazet
2022-06-23 4:34 ` [PATCH v2 net-next 15/19] ip6mr: switch ip6mr_get_route() to rcu_read_lock() Eric Dumazet
2022-06-23 4:34 ` [PATCH v2 net-next 16/19] ipmr: adopt rcu_read_lock() in mr_dump() Eric Dumazet
2022-06-23 4:34 ` [PATCH v2 net-next 17/19] ipmr: convert /proc handlers to rcu_read_lock() Eric Dumazet
2022-06-23 4:34 ` [PATCH v2 net-next 18/19] ipmr: convert mrt_lock to a spinlock Eric Dumazet
2022-06-23 4:34 ` [PATCH v2 net-next 19/19] ip6mr: " Eric Dumazet
2022-06-24 10:50 ` [PATCH v2 net-next 00/19] ipmr: get rid of rwlocks patchwork-bot+netdevbpf
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