diff options
| author | Ying Xue <ying.xue@windriver.com> | 2014-04-21 06:55:47 +0400 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2014-04-23 05:17:53 +0400 |
| commit | 2231c5af451e4b7ae3cc56eaa4653af6ede51109 (patch) | |
| tree | 7c7e78e9adc9f746f64290530d40ce7a9b155fb7 | |
| parent | 7a2f7d18e79b09c5c5a65fb1fa0e31ad046b3116 (diff) | |
| download | linux-2231c5af451e4b7ae3cc56eaa4653af6ede51109.tar.xz | |
tipc: use RCU to protect media_ptr pointer
Now the media_ptr pointer is protected with tipc_net_lock write lock
on write side; tipc_net_lock read lock is used to read side. As the
part of effort of eliminating tipc_net_lock, we decide to adjust the
locking policy of media_ptr pointer protection: on write side, RTNL
lock is use while on read side RCU read lock is applied.
Signed-off-by: Ying Xue <ying.xue@windriver.com>
Reviewed-by: Jon Maloy <jon.maloy@ericsson.com>
Reviewed-by: Erik Hugne <erik.hugne@ericsson.com>
Tested-by: Erik Hugne <erik.hugne@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | net/tipc/bearer.c | 13 | ||||
| -rw-r--r-- | net/tipc/bearer.h | 2 |
2 files changed, 11 insertions, 4 deletions
diff --git a/net/tipc/bearer.c b/net/tipc/bearer.c index e0625e9e2c72..c24a35114fd7 100644 --- a/net/tipc/bearer.c +++ b/net/tipc/bearer.c @@ -458,7 +458,7 @@ int tipc_enable_l2_media(struct tipc_bearer *b) return -ENODEV; /* Associate TIPC bearer with Ethernet bearer */ - b->media_ptr = dev; + rcu_assign_pointer(b->media_ptr, dev); memset(b->bcast_addr.value, 0, sizeof(b->bcast_addr.value)); memcpy(b->bcast_addr.value, dev->broadcast, b->media->hwaddr_len); b->bcast_addr.media_id = b->media->type_id; @@ -477,7 +477,10 @@ int tipc_enable_l2_media(struct tipc_bearer *b) */ void tipc_disable_l2_media(struct tipc_bearer *b) { - struct net_device *dev = (struct net_device *)b->media_ptr; + struct net_device *dev; + + dev = (struct net_device *)rtnl_dereference(b->media_ptr); + RCU_INIT_POINTER(b->media_ptr, NULL); RCU_INIT_POINTER(dev->tipc_ptr, NULL); dev_put(dev); } @@ -492,8 +495,12 @@ int tipc_l2_send_msg(struct sk_buff *buf, struct tipc_bearer *b, struct tipc_media_addr *dest) { struct sk_buff *clone; + struct net_device *dev; int delta; - struct net_device *dev = (struct net_device *)b->media_ptr; + + dev = (struct net_device *)rcu_dereference_rtnl(b->media_ptr); + if (!dev) + return 0; clone = skb_clone(buf, GFP_ATOMIC); if (!clone) diff --git a/net/tipc/bearer.h b/net/tipc/bearer.h index 2fa86bd67c0a..a983b3005e71 100644 --- a/net/tipc/bearer.h +++ b/net/tipc/bearer.h @@ -128,7 +128,7 @@ struct tipc_media { * care of initializing all other fields. */ struct tipc_bearer { - void *media_ptr; /* initalized by media */ + void __rcu *media_ptr; /* initalized by media */ u32 mtu; /* initalized by media */ struct tipc_media_addr addr; /* initalized by media */ char name[TIPC_MAX_BEARER_NAME]; |