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authorEric Dumazet <eric.dumazet@gmail.com>2009-11-04 05:43:23 -0800
committerDavid S. Miller <davem@davemloft.net>2009-11-04 05:43:23 -0800
commitc6d14c84566d6b70ad9dc1618db0dec87cca9300 (patch)
tree5ec75245cfda4d61e6b4506b6217f047ff4af01a
parentd0075634cf9d288988f57392a1f132d2053af961 (diff)
downloadlinux-2.6.34-ux500-c6d14c84566d6b70ad9dc1618db0dec87cca9300.tar.gz
net: Introduce for_each_netdev_rcu() iterator
Adds RCU management to the list of netdevices. Convert some for_each_netdev() users to RCU version, if it can avoid read_lock-ing dev_base_lock Ie: read_lock(&dev_base_loack); for_each_netdev(net, dev) some_action(); read_unlock(&dev_base_lock); becomes : rcu_read_lock(); for_each_netdev_rcu(net, dev) some_action(); rcu_read_unlock(); Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--include/linux/netdevice.h2
-rw-r--r--net/core/dev.c30
-rw-r--r--net/decnet/af_decnet.c6
-rw-r--r--net/decnet/dn_fib.c6
-rw-r--r--net/decnet/dn_route.c6
-rw-r--r--net/ipv4/devinet.c30
-rw-r--r--net/ipv6/addrconf.c20
-rw-r--r--net/ipv6/anycast.c6
-rw-r--r--net/netrom/nr_route.c15
-rw-r--r--net/rose/rose_route.c18
-rw-r--r--net/sctp/protocol.c6
11 files changed, 68 insertions, 77 deletions
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index bcf1083857f..5077de02831 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -1081,6 +1081,8 @@ extern rwlock_t dev_base_lock; /* Device list lock */
#define for_each_netdev(net, d) \
list_for_each_entry(d, &(net)->dev_base_head, dev_list)
+#define for_each_netdev_rcu(net, d) \
+ list_for_each_entry_rcu(d, &(net)->dev_base_head, dev_list)
#define for_each_netdev_safe(net, d, n) \
list_for_each_entry_safe(d, n, &(net)->dev_base_head, dev_list)
#define for_each_netdev_continue(net, d) \
diff --git a/net/core/dev.c b/net/core/dev.c
index 76a1502efe6..bf629ac08b8 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -175,7 +175,7 @@ static struct list_head ptype_all __read_mostly; /* Taps */
* The @dev_base_head list is protected by @dev_base_lock and the rtnl
* semaphore.
*
- * Pure readers hold dev_base_lock for reading.
+ * Pure readers hold dev_base_lock for reading, or rcu_read_lock()
*
* Writers must hold the rtnl semaphore while they loop through the
* dev_base_head list, and hold dev_base_lock for writing when they do the
@@ -212,7 +212,7 @@ static int list_netdevice(struct net_device *dev)
ASSERT_RTNL();
write_lock_bh(&dev_base_lock);
- list_add_tail(&dev->dev_list, &net->dev_base_head);
+ list_add_tail_rcu(&dev->dev_list, &net->dev_base_head);
hlist_add_head_rcu(&dev->name_hlist, dev_name_hash(net, dev->name));
hlist_add_head_rcu(&dev->index_hlist,
dev_index_hash(net, dev->ifindex));
@@ -229,7 +229,7 @@ static void unlist_netdevice(struct net_device *dev)
/* Unlink dev from the device chain */
write_lock_bh(&dev_base_lock);
- list_del(&dev->dev_list);
+ list_del_rcu(&dev->dev_list);
hlist_del_rcu(&dev->name_hlist);
hlist_del_rcu(&dev->index_hlist);
write_unlock_bh(&dev_base_lock);
@@ -799,15 +799,15 @@ struct net_device *dev_get_by_flags(struct net *net, unsigned short if_flags,
struct net_device *dev, *ret;
ret = NULL;
- read_lock(&dev_base_lock);
- for_each_netdev(net, dev) {
+ rcu_read_lock();
+ for_each_netdev_rcu(net, dev) {
if (((dev->flags ^ if_flags) & mask) == 0) {
dev_hold(dev);
ret = dev;
break;
}
}
- read_unlock(&dev_base_lock);
+ rcu_read_unlock();
return ret;
}
EXPORT_SYMBOL(dev_get_by_flags);
@@ -3077,18 +3077,18 @@ static int dev_ifconf(struct net *net, char __user *arg)
* in detail.
*/
void *dev_seq_start(struct seq_file *seq, loff_t *pos)
- __acquires(dev_base_lock)
+ __acquires(RCU)
{
struct net *net = seq_file_net(seq);
loff_t off;
struct net_device *dev;
- read_lock(&dev_base_lock);
+ rcu_read_lock();
if (!*pos)
return SEQ_START_TOKEN;
off = 1;
- for_each_netdev(net, dev)
+ for_each_netdev_rcu(net, dev)
if (off++ == *pos)
return dev;
@@ -3097,16 +3097,18 @@ void *dev_seq_start(struct seq_file *seq, loff_t *pos)
void *dev_seq_next(struct seq_file *seq, void *v, loff_t *pos)
{
- struct net *net = seq_file_net(seq);
+ struct net_device *dev = (v == SEQ_START_TOKEN) ?
+ first_net_device(seq_file_net(seq)) :
+ next_net_device((struct net_device *)v);
+
++*pos;
- return v == SEQ_START_TOKEN ?
- first_net_device(net) : next_net_device((struct net_device *)v);
+ return rcu_dereference(dev);
}
void dev_seq_stop(struct seq_file *seq, void *v)
- __releases(dev_base_lock)
+ __releases(RCU)
{
- read_unlock(&dev_base_lock);
+ rcu_read_unlock();
}
static void dev_seq_printf_stats(struct seq_file *seq, struct net_device *dev)
diff --git a/net/decnet/af_decnet.c b/net/decnet/af_decnet.c
index 664965c87e1..2e355841ca9 100644
--- a/net/decnet/af_decnet.c
+++ b/net/decnet/af_decnet.c
@@ -749,9 +749,9 @@ static int dn_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
if (!(saddr->sdn_flags & SDF_WILD)) {
if (le16_to_cpu(saddr->sdn_nodeaddrl)) {
- read_lock(&dev_base_lock);
+ rcu_read_lock();
ldev = NULL;
- for_each_netdev(&init_net, dev) {
+ for_each_netdev_rcu(&init_net, dev) {
if (!dev->dn_ptr)
continue;
if (dn_dev_islocal(dev, dn_saddr2dn(saddr))) {
@@ -759,7 +759,7 @@ static int dn_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
break;
}
}
- read_unlock(&dev_base_lock);
+ rcu_read_unlock();
if (ldev == NULL)
return -EADDRNOTAVAIL;
}
diff --git a/net/decnet/dn_fib.c b/net/decnet/dn_fib.c
index 27ea2e9b080..fd641f65e09 100644
--- a/net/decnet/dn_fib.c
+++ b/net/decnet/dn_fib.c
@@ -607,8 +607,8 @@ static void dn_fib_del_ifaddr(struct dn_ifaddr *ifa)
ASSERT_RTNL();
/* Scan device list */
- read_lock(&dev_base_lock);
- for_each_netdev(&init_net, dev) {
+ rcu_read_lock();
+ for_each_netdev_rcu(&init_net, dev) {
dn_db = dev->dn_ptr;
if (dn_db == NULL)
continue;
@@ -619,7 +619,7 @@ static void dn_fib_del_ifaddr(struct dn_ifaddr *ifa)
}
}
}
- read_unlock(&dev_base_lock);
+ rcu_read_unlock();
if (found_it == 0) {
fib_magic(RTM_DELROUTE, RTN_LOCAL, ifa->ifa_local, 16, ifa);
diff --git a/net/decnet/dn_route.c b/net/decnet/dn_route.c
index 57662cabaf9..860286a3921 100644
--- a/net/decnet/dn_route.c
+++ b/net/decnet/dn_route.c
@@ -908,8 +908,8 @@ static int dn_route_output_slow(struct dst_entry **pprt, const struct flowi *old
dev_put(dev_out);
goto out;
}
- read_lock(&dev_base_lock);
- for_each_netdev(&init_net, dev) {
+ rcu_read_lock();
+ for_each_netdev_rcu(&init_net, dev) {
if (!dev->dn_ptr)
continue;
if (!dn_dev_islocal(dev, oldflp->fld_src))
@@ -922,7 +922,7 @@ static int dn_route_output_slow(struct dst_entry **pprt, const struct flowi *old
dev_out = dev;
break;
}
- read_unlock(&dev_base_lock);
+ rcu_read_unlock();
if (dev_out == NULL)
goto out;
dev_hold(dev_out);
diff --git a/net/ipv4/devinet.c b/net/ipv4/devinet.c
index ccccaae50b2..8aa7a134c1f 100644
--- a/net/ipv4/devinet.c
+++ b/net/ipv4/devinet.c
@@ -876,19 +876,16 @@ __be32 inet_select_addr(const struct net_device *dev, __be32 dst, int scope)
if (!addr)
addr = ifa->ifa_local;
} endfor_ifa(in_dev);
-no_in_dev:
- rcu_read_unlock();
+no_in_dev:
if (addr)
- goto out;
+ goto out_unlock;
/* Not loopback addresses on loopback should be preferred
in this case. It is importnat that lo is the first interface
in dev_base list.
*/
- read_lock(&dev_base_lock);
- rcu_read_lock();
- for_each_netdev(net, dev) {
+ for_each_netdev_rcu(net, dev) {
if ((in_dev = __in_dev_get_rcu(dev)) == NULL)
continue;
@@ -896,12 +893,11 @@ no_in_dev:
if (ifa->ifa_scope != RT_SCOPE_LINK &&
ifa->ifa_scope <= scope) {
addr = ifa->ifa_local;
- goto out_unlock_both;
+ goto out_unlock;
}
} endfor_ifa(in_dev);
}
-out_unlock_both:
- read_unlock(&dev_base_lock);
+out_unlock:
rcu_read_unlock();
out:
return addr;
@@ -962,9 +958,8 @@ __be32 inet_confirm_addr(struct in_device *in_dev,
return confirm_addr_indev(in_dev, dst, local, scope);
net = dev_net(in_dev->dev);
- read_lock(&dev_base_lock);
rcu_read_lock();
- for_each_netdev(net, dev) {
+ for_each_netdev_rcu(net, dev) {
if ((in_dev = __in_dev_get_rcu(dev))) {
addr = confirm_addr_indev(in_dev, dst, local, scope);
if (addr)
@@ -972,7 +967,6 @@ __be32 inet_confirm_addr(struct in_device *in_dev,
}
}
rcu_read_unlock();
- read_unlock(&dev_base_lock);
return addr;
}
@@ -1240,18 +1234,18 @@ static void devinet_copy_dflt_conf(struct net *net, int i)
{
struct net_device *dev;
- read_lock(&dev_base_lock);
- for_each_netdev(net, dev) {
+ rcu_read_lock();
+ for_each_netdev_rcu(net, dev) {
struct in_device *in_dev;
- rcu_read_lock();
+
in_dev = __in_dev_get_rcu(dev);
if (in_dev && !test_bit(i, in_dev->cnf.state))
in_dev->cnf.data[i] = net->ipv4.devconf_dflt->data[i];
- rcu_read_unlock();
}
- read_unlock(&dev_base_lock);
+ rcu_read_unlock();
}
+/* called with RTNL locked */
static void inet_forward_change(struct net *net)
{
struct net_device *dev;
@@ -1260,7 +1254,6 @@ static void inet_forward_change(struct net *net)
IPV4_DEVCONF_ALL(net, ACCEPT_REDIRECTS) = !on;
IPV4_DEVCONF_DFLT(net, FORWARDING) = on;
- read_lock(&dev_base_lock);
for_each_netdev(net, dev) {
struct in_device *in_dev;
if (on)
@@ -1271,7 +1264,6 @@ static void inet_forward_change(struct net *net)
IN_DEV_CONF_SET(in_dev, FORWARDING, on);
rcu_read_unlock();
}
- read_unlock(&dev_base_lock);
}
static int devinet_conf_proc(ctl_table *ctl, int write,
diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index 91864840961..024bba30de2 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -481,9 +481,8 @@ static void addrconf_forward_change(struct net *net, __s32 newf)
struct net_device *dev;
struct inet6_dev *idev;
- read_lock(&dev_base_lock);
- for_each_netdev(net, dev) {
- rcu_read_lock();
+ rcu_read_lock();
+ for_each_netdev_rcu(net, dev) {
idev = __in6_dev_get(dev);
if (idev) {
int changed = (!idev->cnf.forwarding) ^ (!newf);
@@ -491,9 +490,8 @@ static void addrconf_forward_change(struct net *net, __s32 newf)
if (changed)
dev_forward_change(idev);
}
- rcu_read_unlock();
}
- read_unlock(&dev_base_lock);
+ rcu_read_unlock();
}
static int addrconf_fixup_forwarding(struct ctl_table *table, int *p, int old)
@@ -1137,10 +1135,9 @@ int ipv6_dev_get_saddr(struct net *net, struct net_device *dst_dev,
hiscore->rule = -1;
hiscore->ifa = NULL;
- read_lock(&dev_base_lock);
rcu_read_lock();
- for_each_netdev(net, dev) {
+ for_each_netdev_rcu(net, dev) {
struct inet6_dev *idev;
/* Candidate Source Address (section 4)
@@ -1235,7 +1232,6 @@ try_nextdev:
read_unlock_bh(&idev->lock);
}
rcu_read_unlock();
- read_unlock(&dev_base_lock);
if (!hiscore->ifa)
return -EADDRNOTAVAIL;
@@ -4052,9 +4048,8 @@ static void addrconf_disable_change(struct net *net, __s32 newf)
struct net_device *dev;
struct inet6_dev *idev;
- read_lock(&dev_base_lock);
- for_each_netdev(net, dev) {
- rcu_read_lock();
+ rcu_read_lock();
+ for_each_netdev_rcu(net, dev) {
idev = __in6_dev_get(dev);
if (idev) {
int changed = (!idev->cnf.disable_ipv6) ^ (!newf);
@@ -4062,9 +4057,8 @@ static void addrconf_disable_change(struct net *net, __s32 newf)
if (changed)
dev_disable_change(idev);
}
- rcu_read_unlock();
}
- read_unlock(&dev_base_lock);
+ rcu_read_unlock();
}
static int addrconf_disable_ipv6(struct ctl_table *table, int *p, int old)
diff --git a/net/ipv6/anycast.c b/net/ipv6/anycast.c
index 1ae58bec1de..2f00ca83f04 100644
--- a/net/ipv6/anycast.c
+++ b/net/ipv6/anycast.c
@@ -404,13 +404,13 @@ int ipv6_chk_acast_addr(struct net *net, struct net_device *dev,
if (dev)
return ipv6_chk_acast_dev(dev, addr);
- read_lock(&dev_base_lock);
- for_each_netdev(net, dev)
+ rcu_read_lock();
+ for_each_netdev_rcu(net, dev)
if (ipv6_chk_acast_dev(dev, addr)) {
found = 1;
break;
}
- read_unlock(&dev_base_lock);
+ rcu_read_unlock();
return found;
}
diff --git a/net/netrom/nr_route.c b/net/netrom/nr_route.c
index 4eb1ac9a767..aacba76070f 100644
--- a/net/netrom/nr_route.c
+++ b/net/netrom/nr_route.c
@@ -597,15 +597,15 @@ struct net_device *nr_dev_first(void)
{
struct net_device *dev, *first = NULL;
- read_lock(&dev_base_lock);
- for_each_netdev(&init_net, dev) {
+ rcu_read_lock();
+ for_each_netdev_rcu(&init_net, dev) {
if ((dev->flags & IFF_UP) && dev->type == ARPHRD_NETROM)
if (first == NULL || strncmp(dev->name, first->name, 3) < 0)
first = dev;
}
if (first)
dev_hold(first);
- read_unlock(&dev_base_lock);
+ rcu_read_unlock();
return first;
}
@@ -617,16 +617,17 @@ struct net_device *nr_dev_get(ax25_address *addr)
{
struct net_device *dev;
- read_lock(&dev_base_lock);
- for_each_netdev(&init_net, dev) {
- if ((dev->flags & IFF_UP) && dev->type == ARPHRD_NETROM && ax25cmp(addr, (ax25_address *)dev->dev_addr) == 0) {
+ rcu_read_lock();
+ for_each_netdev_rcu(&init_net, dev) {
+ if ((dev->flags & IFF_UP) && dev->type == ARPHRD_NETROM &&
+ ax25cmp(addr, (ax25_address *)dev->dev_addr) == 0) {
dev_hold(dev);
goto out;
}
}
dev = NULL;
out:
- read_unlock(&dev_base_lock);
+ rcu_read_unlock();
return dev;
}
diff --git a/net/rose/rose_route.c b/net/rose/rose_route.c
index 9478d9b3d97..d936226916f 100644
--- a/net/rose/rose_route.c
+++ b/net/rose/rose_route.c
@@ -600,13 +600,13 @@ struct net_device *rose_dev_first(void)
{
struct net_device *dev, *first = NULL;
- read_lock(&dev_base_lock);
- for_each_netdev(&init_net, dev) {
+ rcu_read_lock();
+ for_each_netdev_rcu(&init_net, dev) {
if ((dev->flags & IFF_UP) && dev->type == ARPHRD_ROSE)
if (first == NULL || strncmp(dev->name, first->name, 3) < 0)
first = dev;
}
- read_unlock(&dev_base_lock);
+ rcu_read_unlock();
return first;
}
@@ -618,8 +618,8 @@ struct net_device *rose_dev_get(rose_address *addr)
{
struct net_device *dev;
- read_lock(&dev_base_lock);
- for_each_netdev(&init_net, dev) {
+ rcu_read_lock();
+ for_each_netdev_rcu(&init_net, dev) {
if ((dev->flags & IFF_UP) && dev->type == ARPHRD_ROSE && rosecmp(addr, (rose_address *)dev->dev_addr) == 0) {
dev_hold(dev);
goto out;
@@ -627,7 +627,7 @@ struct net_device *rose_dev_get(rose_address *addr)
}
dev = NULL;
out:
- read_unlock(&dev_base_lock);
+ rcu_read_unlock();
return dev;
}
@@ -635,14 +635,14 @@ static int rose_dev_exists(rose_address *addr)
{
struct net_device *dev;
- read_lock(&dev_base_lock);
- for_each_netdev(&init_net, dev) {
+ rcu_read_lock();
+ for_each_netdev_rcu(&init_net, dev) {
if ((dev->flags & IFF_UP) && dev->type == ARPHRD_ROSE && rosecmp(addr, (rose_address *)dev->dev_addr) == 0)
goto out;
}
dev = NULL;
out:
- read_unlock(&dev_base_lock);
+ rcu_read_unlock();
return dev != NULL;
}
diff --git a/net/sctp/protocol.c b/net/sctp/protocol.c
index d9f4cc2c786..fe44c57101d 100644
--- a/net/sctp/protocol.c
+++ b/net/sctp/protocol.c
@@ -205,14 +205,14 @@ static void sctp_get_local_addr_list(void)
struct list_head *pos;
struct sctp_af *af;
- read_lock(&dev_base_lock);
- for_each_netdev(&init_net, dev) {
+ rcu_read_lock();
+ for_each_netdev_rcu(&init_net, dev) {
__list_for_each(pos, &sctp_address_families) {
af = list_entry(pos, struct sctp_af, list);
af->copy_addrlist(&sctp_local_addr_list, dev);
}
}
- read_unlock(&dev_base_lock);
+ rcu_read_unlock();
}
/* Free the existing local addresses. */