From 37cb0620073cb64101d9307931c135c70b2e3f04 Mon Sep 17 00:00:00 2001 From: Ying Xue Date: Tue, 10 Dec 2013 20:45:41 -0800 Subject: tipc: remove TIPC usage of field af_packet_priv in struct net_device TIPC is currently using the field 'af_packet_priv' in struct net_device as a handle to find the bearer instance associated to the given network device. But, by doing so it is blocking other networking cleanups, such as the one discussed here: http://patchwork.ozlabs.org/patch/178044/ This commit removes this usage from TIPC. Instead, we introduce a new field, 'tipc_ptr', to the net_device structure, to serve this purpose. When TIPC bearer is enabled, the bearer object is associated to 'tipc_ptr'. When a TIPC packet arrives in the recv_msg() upcall from a networking device, the bearer object can now be obtained from 'tipc_ptr'. When a bearer is disabled, the bearer object is detached from its underlying network device by setting 'tipc_ptr' to NULL. Additionally, an RCU lock is used to protect the new pointer. Henceforth, the existing tipc_net_lock is used in write mode to serialize write accesses to this pointer, while the new RCU lock is applied on the read side to ensure that the pointer is 100% valid within its wrapped area for all readers. Signed-off-by: Ying Xue Cc: Patrick McHardy Reviewed-by: Paul Gortmaker Signed-off-by: Jon Maloy Signed-off-by: David S. Miller --- net/tipc/bearer.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'net/tipc/bearer.h') diff --git a/net/tipc/bearer.h b/net/tipc/bearer.h index e50266aa4d10..91b8d8b92373 100644 --- a/net/tipc/bearer.h +++ b/net/tipc/bearer.h @@ -105,6 +105,7 @@ struct tipc_media { /** * struct tipc_bearer - Generic TIPC bearer structure + * @dev: ptr to associated network device * @usr_handle: pointer to additional media-specific information about bearer * @mtu: max packet size bearer can support * @lock: spinlock for controlling access to bearer @@ -127,6 +128,7 @@ struct tipc_media { * care of initializing all other fields. */ struct tipc_bearer { + struct net_device *dev; void *usr_handle; /* initalized by media */ u32 mtu; /* initalized by media */ struct tipc_media_addr addr; /* initalized by media */ -- cgit v1.2.3