netdev - [PATCH net-next v3 07/10] net: sched: implement functions to put and flush all chains

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Date:   Mon, 24 Sep 2018 19:22:55 +0300
From:   Vlad Buslov <vladbu@...lanox.com>
To:     netdev@...r.kernel.org
Cc:     jhs@...atatu.com, xiyou.wangcong@...il.com, jiri@...nulli.us,
        davem@...emloft.net, stephen@...workplumber.org,
        ktkhai@...tuozzo.com, nicolas.dichtel@...nd.com,
        gregkh@...uxfoundation.org, mark.rutland@....com, leon@...nel.org,
        paulmck@...ux.vnet.ibm.com, fw@...len.de, dsahern@...il.com,
        christian@...uner.io, lucien.xin@...il.com,
        jakub.kicinski@...ronome.com, jbenc@...hat.com,
        Vlad Buslov <vladbu@...lanox.com>
Subject: [PATCH net-next v3 07/10] net: sched: implement functions to put and flush all chains

Extract code that flushes and puts all chains on tcf block to two
standalone function to be shared with functions that locklessly get/put
reference to block.

Signed-off-by: Vlad Buslov <vladbu@...lanox.com>
Acked-by: Jiri Pirko <jiri@...lanox.com>
---
 net/sched/cls_api.c | 55 +++++++++++++++++++++++++++++------------------------
 1 file changed, 30 insertions(+), 25 deletions(-)

diff --git a/net/sched/cls_api.c b/net/sched/cls_api.c
index 90843b6a8fa9..cb7422af5e51 100644
--- a/net/sched/cls_api.c
+++ b/net/sched/cls_api.c
@@ -527,6 +527,31 @@ static struct tcf_block *tcf_block_lookup(struct net *net, u32 block_index)
 	return idr_find(&tn->idr, block_index);
 }
 
+static void tcf_block_flush_all_chains(struct tcf_block *block)
+{
+	struct tcf_chain *chain;
+
+	/* Hold a refcnt for all chains, so that they don't disappear
+	 * while we are iterating.
+	 */
+	list_for_each_entry(chain, &block->chain_list, list)
+		tcf_chain_hold(chain);
+
+	list_for_each_entry(chain, &block->chain_list, list)
+		tcf_chain_flush(chain);
+}
+
+static void tcf_block_put_all_chains(struct tcf_block *block)
+{
+	struct tcf_chain *chain, *tmp;
+
+	/* At this point, all the chains should have refcnt >= 1. */
+	list_for_each_entry_safe(chain, tmp, &block->chain_list, list) {
+		tcf_chain_put_explicitly_created(chain);
+		tcf_chain_put(chain);
+	}
+}
+
 /* Find tcf block.
  * Set q, parent, cl when appropriate.
  */
@@ -786,8 +811,6 @@ EXPORT_SYMBOL(tcf_block_get);
 void tcf_block_put_ext(struct tcf_block *block, struct Qdisc *q,
 		       struct tcf_block_ext_info *ei)
 {
-	struct tcf_chain *chain, *tmp;
-
 	if (!block)
 		return;
 	tcf_chain0_head_change_cb_del(block, ei);
@@ -804,32 +827,14 @@ void tcf_block_put_ext(struct tcf_block *block, struct Qdisc *q,
 
 		if (tcf_block_shared(block))
 			tcf_block_remove(block, block->net);
-
-		if (!free_block) {
-			/* Hold a refcnt for all chains, so that they don't
-			 * disappear while we are iterating.
-			 */
-			list_for_each_entry(chain, &block->chain_list, list)
-				tcf_chain_hold(chain);
-
-			list_for_each_entry(chain, &block->chain_list, list)
-				tcf_chain_flush(chain);
-		}
-
+		if (!free_block)
+			tcf_block_flush_all_chains(block);
 		tcf_block_offload_unbind(block, q, ei);
 
-		if (free_block) {
+		if (free_block)
 			kfree(block);
-		} else {
-			/* At this point, all the chains should have
-			 * refcnt >= 1.
-			 */
-			list_for_each_entry_safe(chain, tmp, &block->chain_list,
-						 list) {
-				tcf_chain_put_explicitly_created(chain);
-				tcf_chain_put(chain);
-			}
-		}
+		else
+			tcf_block_put_all_chains(block);
 	} else {
 		tcf_block_offload_unbind(block, q, ei);
 	}
-- 
2.7.5