path: root/include/net/sch_generic.h
diff options
authorVlad Buslov <vladbu@mellanox.com>2019-08-26 16:44:57 +0300
committerDavid S. Miller <davem@davemloft.net>2019-08-26 14:17:43 -0700
commit4f8116c85057239ff37519debdd5d45b38ad8130 (patch)
tree35d4263c8dcf2addf88801cf9e43e49426f1cad7 /include/net/sch_generic.h
parentcirrus: cs89x0: remove set but not used variable 'lp' (diff)
net: sched: protect block offload-related fields with rw_semaphore
In order to remove dependency on rtnl lock, extend tcf_block with 'cb_lock' rwsem and use it to protect flow_block->cb_list and related counters from concurrent modification. The lock is taken in read mode for read-only traversal of cb_list in tc_setup_cb_call() and write mode in all other cases. This approach ensures that: - cb_list is not changed concurrently while filters is being offloaded on block. - block->nooffloaddevcnt is checked while holding the lock in read mode, but is only changed by bind/unbind code when holding the cb_lock in write mode to prevent concurrent modification. Signed-off-by: Vlad Buslov <vladbu@mellanox.com> Acked-by: Jiri Pirko <jiri@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'include/net/sch_generic.h')
1 files changed, 2 insertions, 0 deletions
diff --git a/include/net/sch_generic.h b/include/net/sch_generic.h
index d9f359af0b93..a3eaf5f9d28f 100644
--- a/include/net/sch_generic.h
+++ b/include/net/sch_generic.h
@@ -13,6 +13,7 @@
#include <linux/refcount.h>
#include <linux/workqueue.h>
#include <linux/mutex.h>
+#include <linux/rwsem.h>
#include <net/gen_stats.h>
#include <net/rtnetlink.h>
#include <net/flow_offload.h>
@@ -396,6 +397,7 @@ struct tcf_block {
refcount_t refcnt;
struct net *net;
struct Qdisc *q;
+ struct rw_semaphore cb_lock; /* protects cb_list and offload counters */
struct flow_block flow_block;
struct list_head owner_list;
bool keep_dst;