From: Ying Xue <ying.xue@windriver.com>
To: <davem@davemloft.net>
Cc: jon.maloy@ericsson.com, Paul.Gortmaker@windriver.com,
tipc-discussion@lists.sourceforge.net, netdev@vger.kernel.org
Subject: [PATCH net-next 06/11] tipc: use RCU to protect media_ptr pointer
Date: Mon, 21 Apr 2014 10:55:47 +0800 [thread overview]
Message-ID: <1398048952-7825-7-git-send-email-ying.xue@windriver.com> (raw)
In-Reply-To: <1398048952-7825-1-git-send-email-ying.xue@windriver.com>
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>
---
net/tipc/bearer.c | 13 ++++++++++---
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 e0625e9..c24a351 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 2fa86bd..a983b30 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];
--
1.7.9.5
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next prev parent reply other threads:[~2014-04-21 2:55 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-04-21 2:55 [PATCH net-next 00/11] purge tipc_net_lock Ying Xue
2014-04-21 2:55 ` [PATCH net-next 01/11] tipc: replace config_mutex lock with RTNL lock Ying Xue
2014-04-21 2:55 ` [PATCH net-next 02/11] tipc: adjust locking policy of protecting tipc_ptr pointer of net_device Ying Xue
2014-04-21 2:55 ` [PATCH net-next 03/11] tipc: use RTNL lock to protect tipc_net_stop routine Ying Xue
2014-04-21 2:55 ` [PATCH net-next 04/11] tipc: convert bearer_list to RCU list Ying Xue
2014-04-21 2:55 ` [PATCH net-next 05/11] tipc: decouple the relationship between bearer and link Ying Xue
2014-04-21 2:55 ` Ying Xue [this message]
2014-04-21 2:55 ` [PATCH net-next 07/11] tipc: purge tipc_net_lock lock Ying Xue
2014-04-21 2:55 ` [PATCH net-next 08/11] tipc: make media_ptr pointed netdevice valid Ying Xue
2014-04-21 2:55 ` [PATCH net-next 09/11] tipc: use bearer_disable to disable bearer in tipc_l2_device_event Ying Xue
2014-04-21 2:55 ` [PATCH net-next 10/11] tipc: use bc_lock to protect node map in bearer structure Ying Xue
2014-04-21 2:55 ` [PATCH net-next 11/11] tipc: fix race in disc create/delete Ying Xue
2014-04-23 1:18 ` [PATCH net-next 00/11] purge tipc_net_lock David Miller
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