netdev - [PATCH net-next v2 07/10] net: sched: implement functions to put and flush all chains

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Date:   Mon, 17 Sep 2018 10:17:37 +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 v2 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 c3c7d4e2f84c..58b2d8443f6a 100644
--- a/net/sched/cls_api.c
+++ b/net/sched/cls_api.c
@@ -538,6 +538,31 @@ static void tcf_qdisc_put(struct Qdisc *q, bool rtnl_held)
 		qdisc_put_unlocked(q);
 }
 
+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.
  */
@@ -795,8 +820,6 @@ 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);
@@ -813,32 +836,14 @@ 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