[PATCH net-next 0/2] overhaul node action flags

[PATCH net-next 0/2] overhaul node action flags

[Ying Xue]

We currently have two problems with the node flags field:
 - The naming of the individual action flags is unclear and confusing
 - The flags are often not cleared individually,  making it hard to follow
   where this happens.

So the series aims to solve above two problems.


Ying Xue (2):
  tipc: rename enum names of node flags
  tipc: don't directly overwrite node action_flags

 net/tipc/link.c |    6 +++---
 net/tipc/node.c |   19 +++++++++++--------
 net/tipc/node.h |   29 +++++++++++++----------------
 3 files changed, 27 insertions(+), 27 deletions(-)

-- 
1.7.9.5

[PATCH net-next 1/2] tipc: rename enum names of node flags

[Ying Xue]

Rename node flags to action_flags as well as its enum names so
that they can reflect its real meanings.

Signed-off-by: Ying Xue <ying.xue@windriver.com>
Reviewed-by: Jon Maloy <jon.maloy@ericsson.com>
---
 net/tipc/link.c |    6 +++---
 net/tipc/node.c |   17 +++++++++--------
 net/tipc/node.h |   29 +++++++++++++----------------
 3 files changed, 25 insertions(+), 27 deletions(-)

diff --git a/net/tipc/link.c b/net/tipc/link.c
index dce2bef..26abb16 100644
--- a/net/tipc/link.c
+++ b/net/tipc/link.c
@@ -1489,12 +1489,12 @@ void tipc_rcv(struct sk_buff *head, struct tipc_bearer *b_ptr)
 			goto unlock_discard;
 
 		/* Verify that communication with node is currently allowed */
-		if ((n_ptr->flags & TIPC_NODE_DOWN) &&
+		if ((n_ptr->action_flags & TIPC_WAIT_PEER_LINKS_DOWN) &&
 		    msg_user(msg) == LINK_PROTOCOL &&
 		    (msg_type(msg) == RESET_MSG ||
 		    msg_type(msg) == ACTIVATE_MSG) &&
 		    !msg_redundant_link(msg))
-			n_ptr->flags &= ~TIPC_NODE_DOWN;
+			n_ptr->action_flags &= ~TIPC_WAIT_PEER_LINKS_DOWN;
 
 		if (tipc_node_blocked(n_ptr))
 			goto unlock_discard;
@@ -1853,7 +1853,7 @@ static void tipc_link_proto_rcv(struct tipc_link *l_ptr, struct sk_buff *buf)
 			 * peer has lost contact -- don't allow peer's links
 			 * to reactivate before we recognize loss & clean up
 			 */
-			l_ptr->owner->flags = TIPC_NODE_RESET;
+			l_ptr->owner->action_flags = TIPC_WAIT_OWN_LINKS_DOWN;
 		}
 
 		link_state_event(l_ptr, RESET_MSG);
diff --git a/net/tipc/node.c b/net/tipc/node.c
index 74efebc..bb66a26 100644
--- a/net/tipc/node.c
+++ b/net/tipc/node.c
@@ -108,7 +108,7 @@ struct tipc_node *tipc_node_create(u32 addr)
 			break;
 	}
 	list_add_tail_rcu(&n_ptr->list, &temp_node->list);
-	n_ptr->flags = TIPC_NODE_DOWN;
+	n_ptr->action_flags = TIPC_WAIT_PEER_LINKS_DOWN;
 	n_ptr->signature = INVALID_NODE_SIG;
 
 	tipc_num_nodes++;
@@ -267,7 +267,7 @@ void tipc_node_detach_link(struct tipc_node *n_ptr, struct tipc_link *l_ptr)
 
 static void node_established_contact(struct tipc_node *n_ptr)
 {
-	n_ptr->flags |= TIPC_NODE_UP;
+	n_ptr->action_flags |= TIPC_NOTIFY_NODE_UP;
 	n_ptr->bclink.oos_state = 0;
 	n_ptr->bclink.acked = tipc_bclink_get_last_sent();
 	tipc_bclink_add_node(n_ptr->addr);
@@ -311,7 +311,8 @@ static void node_lost_contact(struct tipc_node *n_ptr)
 	/* Notify subscribers and prevent re-contact with node until
 	 * cleanup is done.
 	 */
-	n_ptr->flags = TIPC_NODE_DOWN | TIPC_NODE_LOST;
+	n_ptr->action_flags = TIPC_WAIT_PEER_LINKS_DOWN |
+			      TIPC_NOTIFY_NODE_DOWN;
 }
 
 struct sk_buff *tipc_node_get_nodes(const void *req_tlv_area, int req_tlv_space)
@@ -459,18 +460,18 @@ void tipc_node_unlock(struct tipc_node *node)
 	int pkt_sz = 0;
 	u32 addr = 0;
 
-	if (likely(!node->flags)) {
+	if (likely(!node->action_flags)) {
 		spin_unlock_bh(&node->lock);
 		return;
 	}
 
-	if (node->flags & TIPC_NODE_LOST) {
+	if (node->action_flags & TIPC_NOTIFY_NODE_DOWN) {
 		list_replace_init(&node->nsub, &nsub_list);
-		node->flags &= ~TIPC_NODE_LOST;
+		node->action_flags &= ~TIPC_NOTIFY_NODE_DOWN;
 	}
-	if (node->flags & TIPC_NODE_UP) {
+	if (node->action_flags & TIPC_NOTIFY_NODE_UP) {
 		link = node->active_links[0];
-		node->flags &= ~TIPC_NODE_UP;
+		node->action_flags &= ~TIPC_NOTIFY_NODE_UP;
 		if (link) {
 			pkt_sz = ((link->max_pkt - INT_H_SIZE) / ITEM_SIZE) *
 				  ITEM_SIZE;
diff --git a/net/tipc/node.h b/net/tipc/node.h
index 38f710f..3c19113 100644
--- a/net/tipc/node.h
+++ b/net/tipc/node.h
@@ -47,20 +47,17 @@
  */
 #define INVALID_NODE_SIG 0x10000
 
-/* Flags used to block (re)establishment of contact with a neighboring node
- * TIPC_NODE_DOWN: indicate node is down and it's used to block the node's
- *                 links until RESET or ACTIVE message arrives
- * TIPC_NODE_RESET: indicate node is reset
- * TIPC_NODE_LOST: indicate node is lost and it's used to notify subscriptions
- *                 when node lock is released
- * TIPC_NODE_UP: indicate node is up and it's used to deliver local name table
- *               when node lock is released
+/* Flags used to take different actions according to flag type
+ * TIPC_WAIT_PEER_LINKS_DOWN: wait to see that peer's links are down
+ * TIPC_WAIT_OWN_LINKS_DOWN: wait until peer node is declared down
+ * TIPC_NOTIFY_NODE_DOWN: notify node is down
+ * TIPC_NOTIFY_NODE_UP: notify node is up
  */
 enum {
-	TIPC_NODE_DOWN	= (1 << 1),
-	TIPC_NODE_RESET	= (1 << 2),
-	TIPC_NODE_LOST	= (1 << 3),
-	TIPC_NODE_UP	= (1 << 4)
+	TIPC_WAIT_PEER_LINKS_DOWN	= (1 << 1),
+	TIPC_WAIT_OWN_LINKS_DOWN	= (1 << 2),
+	TIPC_NOTIFY_NODE_DOWN		= (1 << 3),
+	TIPC_NOTIFY_NODE_UP		= (1 << 4)
 };
 
 /**
@@ -96,7 +93,7 @@ struct tipc_node_bclink {
  * @hash: links to adjacent nodes in unsorted hash chain
  * @active_links: pointers to active links to node
  * @links: pointers to all links to node
- * @flags: bit mask of conditions preventing link establishment to node
+ * @action_flags: bit mask of different types of node actions
  * @bclink: broadcast-related info
  * @list: links to adjacent nodes in sorted list of cluster's nodes
  * @working_links: number of working links to node (both active and standby)
@@ -111,7 +108,7 @@ struct tipc_node {
 	struct hlist_node hash;
 	struct tipc_link *active_links[2];
 	struct tipc_link *links[MAX_BEARERS];
-	unsigned int flags;
+	unsigned int action_flags;
 	struct tipc_node_bclink bclink;
 	struct list_head list;
 	int link_cnt;
@@ -144,8 +141,8 @@ static inline void tipc_node_lock(struct tipc_node *node)
 
 static inline bool tipc_node_blocked(struct tipc_node *node)
 {
-	return (node->flags & (TIPC_NODE_DOWN | TIPC_NODE_LOST |
-		TIPC_NODE_RESET));
+	return (node->action_flags & (TIPC_WAIT_PEER_LINKS_DOWN |
+		TIPC_NOTIFY_NODE_DOWN | TIPC_WAIT_OWN_LINKS_DOWN));
 }
 
 #endif
-- 
1.7.9.5

[PATCH net-next 2/2] tipc: don't directly overwrite node action_flags

[Ying Xue]

Each node action flag should be set or cleared separately, instead
we now set the whole flags variable in one shot, and it's turned
out to be hard to see which other flags are affected. Therefore,
for instance, we explicitly clear TIPC_WAIT_OWN_LINKS_DOWN bit in
node_lost_contact().

Signed-off-by: Ying Xue <ying.xue@windriver.com>
Reviewed-by: Jon Maloy <jon.maloy@ericsson.com>
---
 net/tipc/link.c |    2 +-
 net/tipc/node.c |    6 ++++--
 2 files changed, 5 insertions(+), 3 deletions(-)

diff --git a/net/tipc/link.c b/net/tipc/link.c
index 26abb16..2140837 100644
--- a/net/tipc/link.c
+++ b/net/tipc/link.c
@@ -1853,7 +1853,7 @@ static void tipc_link_proto_rcv(struct tipc_link *l_ptr, struct sk_buff *buf)
 			 * peer has lost contact -- don't allow peer's links
 			 * to reactivate before we recognize loss & clean up
 			 */
-			l_ptr->owner->action_flags = TIPC_WAIT_OWN_LINKS_DOWN;
+			l_ptr->owner->action_flags |= TIPC_WAIT_OWN_LINKS_DOWN;
 		}
 
 		link_state_event(l_ptr, RESET_MSG);
diff --git a/net/tipc/node.c b/net/tipc/node.c
index bb66a26..facd561 100644
--- a/net/tipc/node.c
+++ b/net/tipc/node.c
@@ -308,11 +308,13 @@ static void node_lost_contact(struct tipc_node *n_ptr)
 		tipc_link_reset_fragments(l_ptr);
 	}
 
+	n_ptr->action_flags &= ~TIPC_WAIT_OWN_LINKS_DOWN;
+
 	/* Notify subscribers and prevent re-contact with node until
 	 * cleanup is done.
 	 */
-	n_ptr->action_flags = TIPC_WAIT_PEER_LINKS_DOWN |
-			      TIPC_NOTIFY_NODE_DOWN;
+	n_ptr->action_flags |= TIPC_WAIT_PEER_LINKS_DOWN |
+			       TIPC_NOTIFY_NODE_DOWN;
 }
 
 struct sk_buff *tipc_node_get_nodes(const void *req_tlv_area, int req_tlv_space)
-- 
1.7.9.5

Re: [PATCH net-next 0/2] overhaul node action flags

[David Miller]

From: Ying Xue <ying.xue@windriver.com>
Date: Thu, 8 May 2014 08:54:38 +0800

> We currently have two problems with the node flags field:
>  - The naming of the individual action flags is unclear and confusing
>  - The flags are often not cleared individually,  making it hard to follow
>    where this happens.
> 
> So the series aims to solve above two problems.

Series applied, thanks.