| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-ID: <4AFB8246.6060804@gmail.com>
Date: Thu, 12 Nov 2009 04:34:30 +0100
From: Eric Dumazet <eric.dumazet@...il.com>
To: David Miller <davem@...emloft.net>
CC: Stephen Hemminger <shemminger@...tta.com>, netdev@...r.kernel.org
Subject: [PATCH net-next-2.6] ipv6: use RCU to walk list of network devices
Stephen Hemminger a écrit :
> No longer need read_lock(&dev_base_lock), use RCU instead.
> This also needs to be optimized for large number of devices.
>
> Signed-off-by: Stephen Hemminger <shemminger@...tta.com>
I gave a look at your patch Stephen and found we need a new
next_net_device_rcu(struct net_device *dev) as well,
as next_net_device() is not RCU safe.
(followup patch is probably needed to use it in net/ipv4/igmp.c,
after commit 61fbab77a843d2e77232 : IPV4: use rcu to walk list of devices in IGMP)
We also can avoid taking references on inet6_dev structs.
[PATCH net-next-2.6] ipv6: use RCU to walk list of network devices
No longer need read_lock(&dev_base_lock), use RCU instead.
We also can avoid taking references on inet6_dev structs.
Signed-off-by: Eric Dumazet <eric.dumazet@...il.com>
---
include/linux/netdevice.h | 10 +++++++
net/ipv6/anycast.c | 29 +++++++++-----------
net/ipv6/mcast.c | 51 ++++++++++++++++--------------------
3 files changed, 47 insertions(+), 43 deletions(-)
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 083b598..2734a67 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -1093,6 +1093,16 @@ static inline struct net_device *next_net_device(struct net_device *dev)
return lh == &net->dev_base_head ? NULL : net_device_entry(lh);
}
+static inline struct net_device *next_net_device_rcu(struct net_device *dev)
+{
+ struct list_head *lh;
+ struct net *net;
+
+ net = dev_net(dev);
+ lh = rcu_dereference(dev->dev_list.next);
+ return lh == &net->dev_base_head ? NULL : net_device_entry(lh);
+}
+
static inline struct net_device *first_net_device(struct net *net)
{
return list_empty(&net->dev_base_head) ? NULL :
diff --git a/net/ipv6/anycast.c b/net/ipv6/anycast.c
index 2f00ca8..f1c74c8 100644
--- a/net/ipv6/anycast.c
+++ b/net/ipv6/anycast.c
@@ -431,9 +431,9 @@ static inline struct ifacaddr6 *ac6_get_first(struct seq_file *seq)
struct net *net = seq_file_net(seq);
state->idev = NULL;
- for_each_netdev(net, state->dev) {
+ for_each_netdev_rcu(net, state->dev) {
struct inet6_dev *idev;
- idev = in6_dev_get(state->dev);
+ idev = __in6_dev_get(state->dev);
if (!idev)
continue;
read_lock_bh(&idev->lock);
@@ -443,7 +443,6 @@ static inline struct ifacaddr6 *ac6_get_first(struct seq_file *seq)
break;
}
read_unlock_bh(&idev->lock);
- in6_dev_put(idev);
}
return im;
}
@@ -454,16 +453,15 @@ static struct ifacaddr6 *ac6_get_next(struct seq_file *seq, struct ifacaddr6 *im
im = im->aca_next;
while (!im) {
- if (likely(state->idev != NULL)) {
+ if (likely(state->idev != NULL))
read_unlock_bh(&state->idev->lock);
- in6_dev_put(state->idev);
- }
- state->dev = next_net_device(state->dev);
+
+ state->dev = next_net_device_rcu(state->dev);
if (!state->dev) {
state->idev = NULL;
break;
}
- state->idev = in6_dev_get(state->dev);
+ state->idev = __in6_dev_get(state->dev);
if (!state->idev)
continue;
read_lock_bh(&state->idev->lock);
@@ -482,29 +480,30 @@ static struct ifacaddr6 *ac6_get_idx(struct seq_file *seq, loff_t pos)
}
static void *ac6_seq_start(struct seq_file *seq, loff_t *pos)
- __acquires(dev_base_lock)
+ __acquires(RCU)
{
- read_lock(&dev_base_lock);
+ rcu_read_lock();
return ac6_get_idx(seq, *pos);
}
static void *ac6_seq_next(struct seq_file *seq, void *v, loff_t *pos)
{
- struct ifacaddr6 *im;
- im = ac6_get_next(seq, v);
+ struct ifacaddr6 *im = ac6_get_next(seq, v);
+
++*pos;
return im;
}
static void ac6_seq_stop(struct seq_file *seq, void *v)
- __releases(dev_base_lock)
+ __releases(RCU)
{
struct ac6_iter_state *state = ac6_seq_private(seq);
+
if (likely(state->idev != NULL)) {
read_unlock_bh(&state->idev->lock);
- in6_dev_put(state->idev);
+ state->idev = NULL;
}
- read_unlock(&dev_base_lock);
+ rcu_read_unlock();
}
static int ac6_seq_show(struct seq_file *seq, void *v)
diff --git a/net/ipv6/mcast.c b/net/ipv6/mcast.c
index f9fcf69..1f9c444 100644
--- a/net/ipv6/mcast.c
+++ b/net/ipv6/mcast.c
@@ -2375,9 +2375,9 @@ static inline struct ifmcaddr6 *igmp6_mc_get_first(struct seq_file *seq)
struct net *net = seq_file_net(seq);
state->idev = NULL;
- for_each_netdev(net, state->dev) {
+ for_each_netdev_rcu(net, state->dev) {
struct inet6_dev *idev;
- idev = in6_dev_get(state->dev);
+ idev = __in6_dev_get(state->dev);
if (!idev)
continue;
read_lock_bh(&idev->lock);
@@ -2387,7 +2387,6 @@ static inline struct ifmcaddr6 *igmp6_mc_get_first(struct seq_file *seq)
break;
}
read_unlock_bh(&idev->lock);
- in6_dev_put(idev);
}
return im;
}
@@ -2398,16 +2397,15 @@ static struct ifmcaddr6 *igmp6_mc_get_next(struct seq_file *seq, struct ifmcaddr
im = im->next;
while (!im) {
- if (likely(state->idev != NULL)) {
+ if (likely(state->idev != NULL))
read_unlock_bh(&state->idev->lock);
- in6_dev_put(state->idev);
- }
- state->dev = next_net_device(state->dev);
+
+ state->dev = next_net_device_rcu(state->dev);
if (!state->dev) {
state->idev = NULL;
break;
}
- state->idev = in6_dev_get(state->dev);
+ state->idev = __in6_dev_get(state->dev);
if (!state->idev)
continue;
read_lock_bh(&state->idev->lock);
@@ -2426,31 +2424,31 @@ static struct ifmcaddr6 *igmp6_mc_get_idx(struct seq_file *seq, loff_t pos)
}
static void *igmp6_mc_seq_start(struct seq_file *seq, loff_t *pos)
- __acquires(dev_base_lock)
+ __acquires(RCU)
{
- read_lock(&dev_base_lock);
+ rcu_read_lock();
return igmp6_mc_get_idx(seq, *pos);
}
static void *igmp6_mc_seq_next(struct seq_file *seq, void *v, loff_t *pos)
{
- struct ifmcaddr6 *im;
- im = igmp6_mc_get_next(seq, v);
+ struct ifmcaddr6 *im = igmp6_mc_get_next(seq, v);
+
++*pos;
return im;
}
static void igmp6_mc_seq_stop(struct seq_file *seq, void *v)
- __releases(dev_base_lock)
+ __releases(RCU)
{
struct igmp6_mc_iter_state *state = igmp6_mc_seq_private(seq);
+
if (likely(state->idev != NULL)) {
read_unlock_bh(&state->idev->lock);
- in6_dev_put(state->idev);
state->idev = NULL;
}
state->dev = NULL;
- read_unlock(&dev_base_lock);
+ rcu_read_unlock();
}
static int igmp6_mc_seq_show(struct seq_file *seq, void *v)
@@ -2507,9 +2505,9 @@ static inline struct ip6_sf_list *igmp6_mcf_get_first(struct seq_file *seq)
state->idev = NULL;
state->im = NULL;
- for_each_netdev(net, state->dev) {
+ for_each_netdev_rcu(net, state->dev) {
struct inet6_dev *idev;
- idev = in6_dev_get(state->dev);
+ idev = __in6_dev_get(state->dev);
if (unlikely(idev == NULL))
continue;
read_lock_bh(&idev->lock);
@@ -2525,7 +2523,6 @@ static inline struct ip6_sf_list *igmp6_mcf_get_first(struct seq_file *seq)
spin_unlock_bh(&im->mca_lock);
}
read_unlock_bh(&idev->lock);
- in6_dev_put(idev);
}
return psf;
}
@@ -2539,16 +2536,15 @@ static struct ip6_sf_list *igmp6_mcf_get_next(struct seq_file *seq, struct ip6_s
spin_unlock_bh(&state->im->mca_lock);
state->im = state->im->next;
while (!state->im) {
- if (likely(state->idev != NULL)) {
+ if (likely(state->idev != NULL))
read_unlock_bh(&state->idev->lock);
- in6_dev_put(state->idev);
- }
- state->dev = next_net_device(state->dev);
+
+ state->dev = next_net_device_rcu(state->dev);
if (!state->dev) {
state->idev = NULL;
goto out;
}
- state->idev = in6_dev_get(state->dev);
+ state->idev = __in6_dev_get(state->dev);
if (!state->idev)
continue;
read_lock_bh(&state->idev->lock);
@@ -2573,9 +2569,9 @@ static struct ip6_sf_list *igmp6_mcf_get_idx(struct seq_file *seq, loff_t pos)
}
static void *igmp6_mcf_seq_start(struct seq_file *seq, loff_t *pos)
- __acquires(dev_base_lock)
+ __acquires(RCU)
{
- read_lock(&dev_base_lock);
+ rcu_read_lock();
return *pos ? igmp6_mcf_get_idx(seq, *pos - 1) : SEQ_START_TOKEN;
}
@@ -2591,7 +2587,7 @@ static void *igmp6_mcf_seq_next(struct seq_file *seq, void *v, loff_t *pos)
}
static void igmp6_mcf_seq_stop(struct seq_file *seq, void *v)
- __releases(dev_base_lock)
+ __releases(RCU)
{
struct igmp6_mcf_iter_state *state = igmp6_mcf_seq_private(seq);
if (likely(state->im != NULL)) {
@@ -2600,11 +2596,10 @@ static void igmp6_mcf_seq_stop(struct seq_file *seq, void *v)
}
if (likely(state->idev != NULL)) {
read_unlock_bh(&state->idev->lock);
- in6_dev_put(state->idev);
state->idev = NULL;
}
state->dev = NULL;
- read_unlock(&dev_base_lock);
+ rcu_read_unlock();
}
static int igmp6_mcf_seq_show(struct seq_file *seq, void *v)
--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Powered by blists - more mailing lists