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net: sched: protect chain->explicitly_created with block->lock

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In order to remove dependency on rtnl lock, protect
tcf_chain->explicitly_created flag with block->lock. Consolidate code that
checks and resets 'explicitly_created' flag into __tcf_chain_put() to
execute it atomically with rest of code that puts chain reference.

Signed-off-by: Vlad Buslov <vladbu@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Vlad Buslov 2019-02-11 10:55:33 +02:00 committed by David S. Miller
parent c266f64dbf
commit 91052fa1c6
1 changed files with 13 additions and 6 deletions
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19
net/sched/cls_api.c
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@ -370,13 +370,22 @@ EXPORT_SYMBOL(tcf_chain_get_by_act);
static void tc_chain_tmplt_del(struct tcf_chain *chain); static void tc_chain_tmplt_del(struct tcf_chain *chain);
static void __tcf_chain_put(struct tcf_chain *chain, bool by_act) static void __tcf_chain_put(struct tcf_chain *chain, bool by_act,
bool explicitly_created)
{ {
struct tcf_block *block = chain->block; struct tcf_block *block = chain->block;
bool is_last, free_block = false; bool is_last, free_block = false;
unsigned int refcnt; unsigned int refcnt;
mutex_lock(&block->lock); mutex_lock(&block->lock);
if (explicitly_created) {
if (!chain->explicitly_created) {
mutex_unlock(&block->lock);
return;
}
chain->explicitly_created = false;
}
if (by_act) if (by_act)
chain->action_refcnt--; chain->action_refcnt--;
@ -402,19 +411,18 @@ static void __tcf_chain_put(struct tcf_chain *chain, bool by_act)
static void tcf_chain_put(struct tcf_chain *chain) static void tcf_chain_put(struct tcf_chain *chain)
{ {
__tcf_chain_put(chain, false); __tcf_chain_put(chain, false, false);
} }
void tcf_chain_put_by_act(struct tcf_chain *chain) void tcf_chain_put_by_act(struct tcf_chain *chain)
{ {
__tcf_chain_put(chain, true); __tcf_chain_put(chain, true, false);
} }
EXPORT_SYMBOL(tcf_chain_put_by_act); EXPORT_SYMBOL(tcf_chain_put_by_act);
static void tcf_chain_put_explicitly_created(struct tcf_chain *chain) static void tcf_chain_put_explicitly_created(struct tcf_chain *chain)
{ {
if (chain->explicitly_created) __tcf_chain_put(chain, false, true);
tcf_chain_put(chain);
} }
static void tcf_chain_flush(struct tcf_chain *chain) static void tcf_chain_flush(struct tcf_chain *chain)
@ -2305,7 +2313,6 @@ replay:
* to the chain previously taken during addition. * to the chain previously taken during addition.
*/ */
tcf_chain_put_explicitly_created(chain); tcf_chain_put_explicitly_created(chain);
chain->explicitly_created = false;
break; break;
case RTM_GETCHAIN: case RTM_GETCHAIN:
err = tc_chain_notify(chain, skb, n->nlmsg_seq, err = tc_chain_notify(chain, skb, n->nlmsg_seq,