* [PATCH 1/2] ipv6: rework the lock in addrconf_permanent_addr
@ 2016-04-01 8:45 roy.qing.li
0 siblings, 0 replies; 3+ messages in thread
From: roy.qing.li @ 2016-04-01 8:45 UTC (permalink / raw)
To: netdev
From: Li RongQing <roy.qing.li@gmail.com>
1. nothing of idev is changed, so read lock is enough
2. ifp is changed, so used ifp->lock or cmpxchg to protect it
Signed-off-by: Li RongQing <roy.qing.li@gmail.com>
---
net/ipv6/addrconf.c | 26 ++++++++++++++++++++------
1 file changed, 20 insertions(+), 6 deletions(-)
diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index 27aed1a..f6e7605b 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -3184,14 +3184,21 @@ static void addrconf_gre_config(struct net_device *dev)
static void l3mdev_check_host_rt(struct inet6_dev *idev,
struct inet6_ifaddr *ifp)
{
+ struct rt6_info *rt = NULL;
+
+ spin_lock(&ifp->lock);
if (ifp->rt) {
u32 tb_id = l3mdev_fib_table(idev->dev) ? : RT6_TABLE_LOCAL;
if (tb_id != ifp->rt->rt6i_table->tb6_id) {
- ip6_del_rt(ifp->rt);
+ rt = ifp->rt;
ifp->rt = NULL;
}
}
+ spin_unlock(&ifp->lock);
+
+ if (rt)
+ ip6_del_rt(rt);
}
#else
static void l3mdev_check_host_rt(struct inet6_dev *idev,
@@ -3203,6 +3210,8 @@ static void l3mdev_check_host_rt(struct inet6_dev *idev,
static int fixup_permanent_addr(struct inet6_dev *idev,
struct inet6_ifaddr *ifp)
{
+ struct rt6_info *prev;
+
l3mdev_check_host_rt(idev, ifp);
if (!ifp->rt) {
@@ -3212,7 +3221,12 @@ static int fixup_permanent_addr(struct inet6_dev *idev,
if (unlikely(IS_ERR(rt)))
return PTR_ERR(rt);
- ifp->rt = rt;
+ prev = cmpxchg(&ifp->rt, NULL, rt);
+
+ /*if cmpxchg failed*/
+ if (prev) {
+ ip6_rt_put(rt);
+ }
}
if (!(ifp->flags & IFA_F_NOPREFIXROUTE)) {
@@ -3234,21 +3248,21 @@ static void addrconf_permanent_addr(struct net_device *dev)
if (!idev)
return;
- write_lock_bh(&idev->lock);
+ read_lock_bh(&idev->lock);
list_for_each_entry_safe(ifp, tmp, &idev->addr_list, if_list) {
if ((ifp->flags & IFA_F_PERMANENT) &&
fixup_permanent_addr(idev, ifp) < 0) {
- write_unlock_bh(&idev->lock);
+ read_unlock_bh(&idev->lock);
ipv6_del_addr(ifp);
- write_lock_bh(&idev->lock);
+ read_lock_bh(&idev->lock);
net_info_ratelimited("%s: Failed to add prefix route for address %pI6c; dropping\n",
idev->dev->name, &ifp->addr);
}
}
- write_unlock_bh(&idev->lock);
+ read_unlock_bh(&idev->lock);
}
static int addrconf_notify(struct notifier_block *this, unsigned long event,
--
2.1.4
^ permalink raw reply related [flat|nested] 3+ messages in thread* [PATCH 1/2] ipv6: rework the lock in addrconf_permanent_addr
@ 2016-04-01 9:26 roy.qing.li
2016-04-01 18:44 ` David Miller
0 siblings, 1 reply; 3+ messages in thread
From: roy.qing.li @ 2016-04-01 9:26 UTC (permalink / raw)
To: netdev
From: Li RongQing <roy.qing.li@gmail.com>
1. nothing of idev is changed, so read lock is enough
2. ifp is changed, so used ifp->lock or cmpxchg to protect it
Signed-off-by: Li RongQing <roy.qing.li@gmail.com>
---
net/ipv6/addrconf.c | 26 ++++++++++++++++++++------
1 file changed, 20 insertions(+), 6 deletions(-)
diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index 27aed1a..f6e7605b 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -3184,14 +3184,21 @@ static void addrconf_gre_config(struct net_device *dev)
static void l3mdev_check_host_rt(struct inet6_dev *idev,
struct inet6_ifaddr *ifp)
{
+ struct rt6_info *rt = NULL;
+
+ spin_lock(&ifp->lock);
if (ifp->rt) {
u32 tb_id = l3mdev_fib_table(idev->dev) ? : RT6_TABLE_LOCAL;
if (tb_id != ifp->rt->rt6i_table->tb6_id) {
- ip6_del_rt(ifp->rt);
+ rt = ifp->rt;
ifp->rt = NULL;
}
}
+ spin_unlock(&ifp->lock);
+
+ if (rt)
+ ip6_del_rt(rt);
}
#else
static void l3mdev_check_host_rt(struct inet6_dev *idev,
@@ -3203,6 +3210,8 @@ static void l3mdev_check_host_rt(struct inet6_dev *idev,
static int fixup_permanent_addr(struct inet6_dev *idev,
struct inet6_ifaddr *ifp)
{
+ struct rt6_info *prev;
+
l3mdev_check_host_rt(idev, ifp);
if (!ifp->rt) {
@@ -3212,7 +3221,12 @@ static int fixup_permanent_addr(struct inet6_dev *idev,
if (unlikely(IS_ERR(rt)))
return PTR_ERR(rt);
- ifp->rt = rt;
+ prev = cmpxchg(&ifp->rt, NULL, rt);
+
+ /*if cmpxchg failed*/
+ if (prev) {
+ ip6_rt_put(rt);
+ }
}
if (!(ifp->flags & IFA_F_NOPREFIXROUTE)) {
@@ -3234,21 +3248,21 @@ static void addrconf_permanent_addr(struct net_device *dev)
if (!idev)
return;
- write_lock_bh(&idev->lock);
+ read_lock_bh(&idev->lock);
list_for_each_entry_safe(ifp, tmp, &idev->addr_list, if_list) {
if ((ifp->flags & IFA_F_PERMANENT) &&
fixup_permanent_addr(idev, ifp) < 0) {
- write_unlock_bh(&idev->lock);
+ read_unlock_bh(&idev->lock);
ipv6_del_addr(ifp);
- write_lock_bh(&idev->lock);
+ read_lock_bh(&idev->lock);
net_info_ratelimited("%s: Failed to add prefix route for address %pI6c; dropping\n",
idev->dev->name, &ifp->addr);
}
}
- write_unlock_bh(&idev->lock);
+ read_unlock_bh(&idev->lock);
}
static int addrconf_notify(struct notifier_block *this, unsigned long event,
--
2.1.4
^ permalink raw reply related [flat|nested] 3+ messages in thread* Re: [PATCH 1/2] ipv6: rework the lock in addrconf_permanent_addr
2016-04-01 9:26 roy.qing.li
@ 2016-04-01 18:44 ` David Miller
0 siblings, 0 replies; 3+ messages in thread
From: David Miller @ 2016-04-01 18:44 UTC (permalink / raw)
To: roy.qing.li; +Cc: netdev
From: roy.qing.li@gmail.com
Date: Fri, 1 Apr 2016 17:26:58 +0800
> From: Li RongQing <roy.qing.li@gmail.com>
>
> 1. nothing of idev is changed, so read lock is enough
> 2. ifp is changed, so used ifp->lock or cmpxchg to protect it
>
> Signed-off-by: Li RongQing <roy.qing.li@gmail.com>
You posted this patch twice and didn't post patch 2/2.
I'm tossing this from patchwork, please resubmit this
properly.
^ permalink raw reply [flat|nested] 3+ messages in thread
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