From 4f8116c85057239ff37519debdd5d45b38ad8130 Mon Sep 17 00:00:00 2001 From: Vlad Buslov Date: Mon, 26 Aug 2019 16:44:57 +0300 Subject: 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 Acked-by: Jiri Pirko Signed-off-by: David S. Miller --- include/net/sch_generic.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'include/net') 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 #include #include +#include #include #include #include @@ -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; -- cgit v1.2.3