bridge: add rcu_read_lock on transmit

Long ago, when bridge was converted to RCU, rcu lock was equivalent
to having preempt disabled. RCU has changed a lot since then and
bridge code was still assuming the since transmit was called with
bottom half disabled, it was RCU safe.

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Tested-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
stephen hemminger 2010-07-27 08:26:30 +00:00 committed by David S. Miller
parent ff847ac2d3
commit eeaf61d889
4 changed files with 8 additions and 6 deletions

View File

@ -22,7 +22,7 @@
#include <asm/uaccess.h>
#include "br_private.h"
/* net device transmit always called with no BH (preempt_disabled) */
/* net device transmit always called with BH disabled */
netdev_tx_t br_dev_xmit(struct sk_buff *skb, struct net_device *dev)
{
struct net_bridge *br = netdev_priv(dev);
@ -46,6 +46,7 @@ netdev_tx_t br_dev_xmit(struct sk_buff *skb, struct net_device *dev)
skb_reset_mac_header(skb);
skb_pull(skb, ETH_HLEN);
rcu_read_lock();
if (is_multicast_ether_addr(dest)) {
if (br_multicast_rcv(br, NULL, skb))
goto out;
@ -61,6 +62,7 @@ netdev_tx_t br_dev_xmit(struct sk_buff *skb, struct net_device *dev)
br_flood_deliver(br, skb);
out:
rcu_read_unlock();
return NETDEV_TX_OK;
}

View File

@ -214,7 +214,7 @@ void br_fdb_delete_by_port(struct net_bridge *br,
spin_unlock_bh(&br->hash_lock);
}
/* No locking or refcounting, assumes caller has no preempt (rcu_read_lock) */
/* No locking or refcounting, assumes caller has rcu_read_lock */
struct net_bridge_fdb_entry *__br_fdb_get(struct net_bridge *br,
const unsigned char *addr)
{

View File

@ -37,7 +37,7 @@ static int br_pass_frame_up(struct sk_buff *skb)
netif_receive_skb);
}
/* note: already called with rcu_read_lock (preempt_disabled) */
/* note: already called with rcu_read_lock */
int br_handle_frame_finish(struct sk_buff *skb)
{
const unsigned char *dest = eth_hdr(skb)->h_dest;
@ -108,7 +108,7 @@ drop:
goto out;
}
/* note: already called with rcu_read_lock (preempt_disabled) */
/* note: already called with rcu_read_lock */
static int br_handle_local_finish(struct sk_buff *skb)
{
struct net_bridge_port *p = rcu_dereference(skb->dev->br_port);
@ -133,7 +133,7 @@ static inline int is_link_local(const unsigned char *dest)
/*
* Called via br_handle_frame_hook.
* Return NULL if skb is handled
* note: already called with rcu_read_lock (preempt_disabled)
* note: already called with rcu_read_lock
*/
struct sk_buff *br_handle_frame(struct net_bridge_port *p, struct sk_buff *skb)
{

View File

@ -131,7 +131,7 @@ void br_send_tcn_bpdu(struct net_bridge_port *p)
/*
* Called from llc.
*
* NO locks, but rcu_read_lock (preempt_disabled)
* NO locks, but rcu_read_lock
*/
void br_stp_rcv(const struct stp_proto *proto, struct sk_buff *skb,
struct net_device *dev)