net: sched: change tcf block offload counter type to atomic_t

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>

diff --git a/include/net/sch_generic.h b/include/net/sch_generic.h
index a3eaf5f9d28ff498b57f05e6b5455cac68f5b8cc..d778c502decd3fd73d2342442bb2ebd090f9827f 100644 (file)
--- 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(struct tcf_block *block, u32 *flags)
        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(struct tcf_block *block, u32 *flags)
        if (!(*flags & TCA_CLS_FLAGS_IN_HW))
                return;
        *flags &= ~TCA_CLS_FLAGS_IN_HW;
-       block->offloadcnt--;
+       atomic_dec(&block->offloadcnt);
 }
 
 static inline void

diff --git a/net/sched/cls_api.c b/net/sched/cls_api.c
index 959b7ca1ca022ca4319a674060a85d5d55cc2250..f2c2f8159e355a3b7b6a8e7c40bee30a560b03fb 100644 (file)
--- a/net/sched/cls_api.c
+++ b/net/sched/cls_api.c
@@ -629,7 +629,7 @@ static void tc_indr_block_call(struct tcf_block *block,
 
 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,