Re: [net-next 1/1] tipc: apply bearer link tolerance on running links

[David Miller]

From: Jon Maloy 
Date: Wed, 14 Feb 2018 13:34:39 +0100

> Currently, the default link tolerance set in struct tipc_bearer only
> has effect on links going up after that moment. I.e., a user has to
> reset all the node's links across that bearer to have the new value
> applied. This is too limiting and disturbing on a running cluster to
> be useful.
> 
> We now change this so that also already existing links are updated
> dynamically, without any need for a reset, when the bearer value is
> changed. We leverage the already existing per-link functionality
> for this to achieve the wanted effect.
> 
> Acked-by: Ying Xue 
> Signed-off-by: Jon Maloy 

Applied, thanks Jon.

[net-next 1/1] tipc: apply bearer link tolerance on running links

[Jon Maloy]

Currently, the default link tolerance set in struct tipc_bearer only
has effect on links going up after that moment. I.e., a user has to
reset all the node's links across that bearer to have the new value
applied. This is too limiting and disturbing on a running cluster to
be useful.

We now change this so that also already existing links are updated
dynamically, without any need for a reset, when the bearer value is
changed. We leverage the already existing per-link functionality
for this to achieve the wanted effect.

Acked-by: Ying Xue 
Signed-off-by: Jon Maloy 
---
 net/tipc/bearer.c |  8 +---
 net/tipc/link.c   |  3 ++-
 net/tipc/node.c   | 24 
 net/tipc/node.h   |  1 +
 4 files changed, 32 insertions(+), 4 deletions(-)

diff --git a/net/tipc/bearer.c b/net/tipc/bearer.c
index c800147..83d284f 100644
--- a/net/tipc/bearer.c
+++ b/net/tipc/bearer.c
@@ -946,11 +946,11 @@ int tipc_nl_bearer_add(struct sk_buff *skb, struct 
genl_info *info)
 
 int tipc_nl_bearer_set(struct sk_buff *skb, struct genl_info *info)
 {
-   int err;
-   char *name;
struct tipc_bearer *b;
struct nlattr *attrs[TIPC_NLA_BEARER_MAX + 1];
struct net *net = sock_net(skb->sk);
+   char *name;
+   int err;
 
if (!info->attrs[TIPC_NLA_BEARER])
return -EINVAL;
@@ -982,8 +982,10 @@ int tipc_nl_bearer_set(struct sk_buff *skb, struct 
genl_info *info)
return err;
}
 
-   if (props[TIPC_NLA_PROP_TOL])
+   if (props[TIPC_NLA_PROP_TOL]) {
b->tolerance = nla_get_u32(props[TIPC_NLA_PROP_TOL]);
+   tipc_node_apply_tolerance(net, b);
+   }
if (props[TIPC_NLA_PROP_PRIO])
b->priority = nla_get_u32(props[TIPC_NLA_PROP_PRIO]);
if (props[TIPC_NLA_PROP_WIN])
diff --git a/net/tipc/link.c b/net/tipc/link.c
index 2d6b2ae..3c23046 100644
--- a/net/tipc/link.c
+++ b/net/tipc/link.c
@@ -2126,7 +2126,8 @@ void tipc_link_set_tolerance(struct tipc_link *l, u32 tol,
 struct sk_buff_head *xmitq)
 {
l->tolerance = tol;
-   tipc_link_build_proto_msg(l, STATE_MSG, 0, 0, 0, tol, 0, xmitq);
+   if (link_is_up(l))
+   tipc_link_build_proto_msg(l, STATE_MSG, 0, 0, 0, tol, 0, xmitq);
 }
 
 void tipc_link_set_prio(struct tipc_link *l, u32 prio,
diff --git a/net/tipc/node.c b/net/tipc/node.c
index 9036d87..389193d 100644
--- a/net/tipc/node.c
+++ b/net/tipc/node.c
@@ -1618,6 +1618,30 @@ void tipc_rcv(struct net *net, struct sk_buff *skb, 
struct tipc_bearer *b)
kfree_skb(skb);
 }
 
+void tipc_node_apply_tolerance(struct net *net, struct tipc_bearer *b)
+{
+   struct tipc_net *tn = tipc_net(net);
+   int bearer_id = b->identity;
+   struct sk_buff_head xmitq;
+   struct tipc_link_entry *e;
+   struct tipc_node *n;
+
+   __skb_queue_head_init();
+
+   rcu_read_lock();
+
+   list_for_each_entry_rcu(n, >node_list, list) {
+   tipc_node_write_lock(n);
+   e = >links[bearer_id];
+   if (e->link)
+   tipc_link_set_tolerance(e->link, b->tolerance, );
+   tipc_node_write_unlock(n);
+   tipc_bearer_xmit(net, bearer_id, , >maddr);
+   }
+
+   rcu_read_unlock();
+}
+
 int tipc_nl_peer_rm(struct sk_buff *skb, struct genl_info *info)
 {
struct net *net = sock_net(skb->sk);
diff --git a/net/tipc/node.h b/net/tipc/node.h
index acd58d2..4ce5e3a 100644
--- a/net/tipc/node.h
+++ b/net/tipc/node.h
@@ -65,6 +65,7 @@ void tipc_node_check_dest(struct net *net, u32 onode,
  struct tipc_media_addr *maddr,
  bool *respond, bool *dupl_addr);
 void tipc_node_delete_links(struct net *net, int bearer_id);
+void tipc_node_apply_tolerance(struct net *net, struct tipc_bearer *b);
 int tipc_node_get_linkname(struct net *net, u32 bearer_id, u32 node,
   char *linkname, size_t len);
 int tipc_node_xmit(struct net *net, struct sk_buff_head *list, u32 dnode,
-- 
2.1.4