[tipc-discussion] [PATCH net-next v4 04/10] tipc: move registration of TIPC packet handler to media start

[Ying X. <yin...@wi...>]

When TIPC packet handler is registered into networking stack, it's
enough to register once for all same type of media. So we should move
the registration/unregistration of TIPC packet handler to media start
and media stop routines.

In doing so, we can also delete all the work_struct related setup and
cleanup infrastructures because media start/stop routines are now
executed under process context.

Signed-off-by: Ying Xue <yin...@wi...>
---
 net/tipc/eth_media.c |   41 ++++++-----------------------------------
 net/tipc/ib_media.c  |   40 ++++++----------------------------------
 2 files changed, 12 insertions(+), 69 deletions(-)

diff --git a/net/tipc/eth_media.c b/net/tipc/eth_media.c
index 80850aa..7b867ae 100644
--- a/net/tipc/eth_media.c
+++ b/net/tipc/eth_media.c
@@ -45,21 +45,16 @@
  * @bearer: ptr to associated "generic" bearer structure
  * @hlist: Ethernet media hash chain
  * @dev: ptr to associated Ethernet network device
- * @setup: work item used when enabling bearer
- * @cleanup: work item used when disabling bearer
  */
 struct eth_media {
 	struct tipc_bearer *bearer;
 	struct hlist_node hlist;
 	struct net_device *dev;
-	struct work_struct setup;
-	struct work_struct cleanup;
 };
 
 static struct tipc_media eth_media_info;
 static struct hlist_head *media_hlist;
 static int eth_started;
-static struct packet_type tipc_packet_type __read_mostly;
 
 static inline struct hlist_head *media_hashfn(int ifindex)
 {
@@ -157,14 +152,6 @@ static int recv_msg(struct sk_buff *buf, struct net_device *dev,
 }
 
 /**
- * setup_media - setup association between Ethernet bearer and interface
- */
-static void setup_media(struct work_struct *work)
-{
-	dev_add_pack(&tipc_packet_type);
-}
-
-/**
  * enable_media - attach TIPC bearer to an Ethernet interface
  */
 static int enable_media(struct tipc_bearer *tb_ptr)
@@ -184,8 +171,6 @@ static int enable_media(struct tipc_bearer *tb_ptr)
 		return -ENOMEM;
 
 	eb_ptr->dev = dev;
-	INIT_WORK(&eb_ptr->setup, setup_media);
-	schedule_work(&eb_ptr->setup);
 
 	/* Associate TIPC bearer with Ethernet bearer */
 	eb_ptr->bearer = tb_ptr;
@@ -201,34 +186,17 @@ static int enable_media(struct tipc_bearer *tb_ptr)
 }
 
 /**
- * cleanup_media - break association between Ethernet bearer and interface
- *
- * This routine must be invoked from a work queue because it can sleep.
- */
-static void cleanup_media(struct work_struct *work)
-{
-	struct eth_media *eb_ptr =
-		container_of(work, struct eth_media, cleanup);
-
-	dev_remove_pack(&tipc_packet_type);
-	dev_put(eb_ptr->dev);
-	kfree(eb_ptr);
-}
-
-/**
  * disable_media - detach TIPC bearer from an Ethernet interface
  *
- * Mark Ethernet bearer as inactive so that incoming buffers are thrown away,
- * then get worker thread to complete bearer cleanup.  (Can't do cleanup
- * here because cleanup code needs to sleep and caller holds spinlocks.)
+ * Mark Ethernet bearer as inactive so that incoming buffers are thrown away.
  */
 static void disable_media(struct tipc_bearer *tb_ptr)
 {
 	struct eth_media *eb_ptr = (struct eth_media *)tb_ptr->usr_handle;
 
 	hlist_del(&eb_ptr->hlist);
-	INIT_WORK(&eb_ptr->cleanup, cleanup_media);
-	schedule_work(&eb_ptr->cleanup);
+	dev_put(eb_ptr->dev);
+	kfree(eb_ptr);
 }
 
 /**
@@ -380,6 +348,8 @@ int tipc_eth_media_start(void)
 		return res;
 	}
 
+	dev_add_pack(&tipc_packet_type);
+
 	eth_started = 1;
 	return res;
 }
@@ -394,6 +364,7 @@ void tipc_eth_media_stop(void)
 
 	flush_scheduled_work();
 	unregister_netdevice_notifier(&notifier);
+	dev_remove_pack(&tipc_packet_type);
 	kfree(media_hlist);
 	eth_started = 0;
 }
diff --git a/net/tipc/ib_media.c b/net/tipc/ib_media.c
index 7d35f47..1bb9bd5 100644
--- a/net/tipc/ib_media.c
+++ b/net/tipc/ib_media.c
@@ -48,21 +48,17 @@
  * @bearer: ptr to associated "generic" bearer structure
  * @hlist: Infiniband media hash chain
  * @dev: ptr to associated Infiniband network device
- * @cleanup: work item used when disabling bearer
  */
 
 struct ib_media {
 	struct tipc_bearer *bearer;
 	struct hlist_node hlist;
 	struct net_device *dev;
-	struct work_struct setup;
-	struct work_struct cleanup;
 };
 
 static struct tipc_media ib_media_info;
 static struct hlist_head *media_hlist;
 static int ib_started;
-static struct packet_type tipc_packet_type __read_mostly;
 
 static inline struct hlist_head *media_hashfn(int ifindex)
 {
@@ -160,14 +156,6 @@ static int recv_msg(struct sk_buff *buf, struct net_device *dev,
 }
 
 /**
- * setup_bearer - setup association between InfiniBand bearer and interface
- */
-static void setup_media(struct work_struct *work)
-{
-	dev_add_pack(&tipc_packet_type);
-}
-
-/**
  * enable_media - attach TIPC bearer to an InfiniBand interface
  */
 static int enable_media(struct tipc_bearer *tb_ptr)
@@ -187,8 +175,6 @@ static int enable_media(struct tipc_bearer *tb_ptr)
 		return -ENOMEM;
 
 	ib_ptr->dev = dev;
-	INIT_WORK(&ib_ptr->setup, setup_media);
-	schedule_work(&ib_ptr->setup);
 
 	/* Associate TIPC bearer with InfiniBand bearer */
 	ib_ptr->bearer = tb_ptr;
@@ -204,34 +190,17 @@ static int enable_media(struct tipc_bearer *tb_ptr)
 }
 
 /**
- * cleanup_bearer - break association between InfiniBand bearer and interface
- *
- * This routine must be invoked from a work queue because it can sleep.
- */
-static void cleanup_bearer(struct work_struct *work)
-{
-	struct ib_media *ib_ptr =
-		container_of(work, struct ib_media, cleanup);
-
-	dev_remove_pack(&tipc_packet_type);
-	dev_put(ib_ptr->dev);
-	kfree(ib_ptr);
-}
-
-/**
  * disable_media - detach TIPC bearer from an InfiniBand interface
  *
- * Mark InfiniBand bearer as inactive so that incoming buffers are thrown away,
- * then get worker thread to complete bearer cleanup.  (Can't do cleanup
- * here because cleanup code needs to sleep and caller holds spinlocks.)
+ * Mark InfiniBand bearer as inactive so that incoming buffers are thrown away.
  */
 static void disable_media(struct tipc_bearer *tb_ptr)
 {
 	struct ib_media *ib_ptr = (struct ib_media *)tb_ptr->usr_handle;
 
 	hlist_del(&ib_ptr->hlist);
-	INIT_WORK(&ib_ptr->cleanup, cleanup_bearer);
-	schedule_work(&ib_ptr->cleanup);
+	dev_put(ib_ptr->dev);
+	kfree(ib_ptr);
 }
 
 /**
@@ -381,6 +350,8 @@ int tipc_ib_media_start(void)
 		return res;
 	}
 
+	dev_add_pack(&tipc_packet_type);
+
 	ib_started = 1;
 	return res;
 }
@@ -395,6 +366,7 @@ void tipc_ib_media_stop(void)
 
 	flush_scheduled_work();
 	unregister_netdevice_notifier(&notifier);
+	dev_remove_pack(&tipc_packet_type);
 	kfree(media_hlist);
 	ib_started = 0;
 }
-- 
1.7.9.5