From: Vlad Buslov <vladbu@mellanox.com>
Date: Mon, 26 Aug 2019 16:44:58 +0300
Subject: net: sched: change tcf block offload counter type to atomic_t
Patch-mainline: v5.4-rc1
Git-commit: 97394bef5622cb32fd1e5d152251090da6c238b9
References: bsc#1154353

As a preparation for running proto ops functions without rtnl lock, change
offload counter type to atomic. This is necessary to allow updating the
counter by multiple concurrent users when offloading filters to hardware
from unlocked classifiers.

Signed-off-by: Vlad Buslov <vladbu@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 include/net/sch_generic.h |    7 ++++---
 net/sched/cls_api.c       |    2 +-
 2 files changed, 5 insertions(+), 4 deletions(-)

--- a/include/net/sch_generic.h
+++ b/include/net/sch_generic.h
@@ -14,6 +14,7 @@
 #include <linux/workqueue.h>
 #include <linux/mutex.h>
 #include <linux/rwsem.h>
+#include <linux/atomic.h>
 #include <net/gen_stats.h>
 #include <net/rtnetlink.h>
 #include <net/flow_offload.h>
@@ -401,7 +402,7 @@ struct tcf_block {
 	struct flow_block flow_block;
 	struct list_head owner_list;
 	bool keep_dst;
-	unsigned int offloadcnt; /* Number of oddloaded filters */
+	atomic_t offloadcnt; /* Number of oddloaded filters */
 	unsigned int nooffloaddevcnt; /* Number of devs unable to do offload */
 	struct {
 		struct tcf_chain *chain;
@@ -443,7 +444,7 @@ static inline void tcf_block_offload_inc
 	if (*flags & TCA_CLS_FLAGS_IN_HW)
 		return;
 	*flags |= TCA_CLS_FLAGS_IN_HW;
-	block->offloadcnt++;
+	atomic_inc(&block->offloadcnt);
 }
 
 static inline void tcf_block_offload_dec(struct tcf_block *block, u32 *flags)
@@ -451,7 +452,7 @@ static inline void tcf_block_offload_dec
 	if (!(*flags & TCA_CLS_FLAGS_IN_HW))
 		return;
 	*flags &= ~TCA_CLS_FLAGS_IN_HW;
-	block->offloadcnt--;
+	atomic_dec(&block->offloadcnt);
 }
 
 static inline void
--- a/net/sched/cls_api.c
+++ b/net/sched/cls_api.c
@@ -629,7 +629,7 @@ static void tc_indr_block_call(struct tc
 
 static bool tcf_block_offload_in_use(struct tcf_block *block)
 {
-	return block->offloadcnt;
+	return atomic_read(&block->offloadcnt);
 }
 
 static int tcf_block_offload_cmd(struct tcf_block *block,