Register netlink protocol handlers for message types RTM_NEWTFILTER,
RTM_DELTFILTER, RTM_GETTFILTER as unlocked. Set rtnl_held variable that
tracks rtnl mutex state to be false by default.
Modify tcf_block_release() to release rtnl lock if it was taken before.
Move code that releases block and qdisc to function __tcf_block_release()
that is used internally by regular block release and by chain update
function, which is not unlocked and doesn't need to release rtnl.
Signed-off-by: Vlad Buslov <vla...@mellanox.com>
Acked-by: Jiri Pirko <j...@mellanox.com>
---
net/sched/cls_api.c | 43 ++++++++++++++++++++++++++++++-------------
1 file changed, 30 insertions(+), 13 deletions(-)
diff --git a/net/sched/cls_api.c b/net/sched/cls_api.c
index 848f148f1019..a23aeac8ea4e 100644
--- a/net/sched/cls_api.c
+++ b/net/sched/cls_api.c
@@ -1024,13 +1024,28 @@ static struct tcf_block *tcf_block_find(struct net
*net, struct Qdisc **q,
return ERR_PTR(err);
}
-static void tcf_block_release(struct Qdisc *q, struct tcf_block *block)
+static void __tcf_block_release(struct Qdisc *q, struct tcf_block *block,
+ bool rtnl_held)
{
if (!IS_ERR_OR_NULL(block))
tcf_block_refcnt_put(block);
- if (q)
- qdisc_put(q);
+ if (q) {
+ if (rtnl_held)
+ qdisc_put(q);
+ else
+ qdisc_put_unlocked(q);
+ }
+}
+
+static void tcf_block_release(struct Qdisc *q, struct tcf_block *block,
+ bool *rtnl_held)
+{
+ if (*rtnl_held) {
+ rtnl_unlock();
+ *rtnl_held = false;
+ }
+ __tcf_block_release(q, block, false);
}
struct tcf_block_owner_item {
@@ -1706,7 +1721,7 @@ static int tc_new_tfilter(struct sk_buff *skb, struct
nlmsghdr *n,
void *fh;
int err;
int tp_created;
- bool rtnl_held = true;
+ bool rtnl_held = false;
if (!netlink_ns_capable(skb, net->user_ns, CAP_NET_ADMIN))
return -EPERM;
@@ -1865,7 +1880,7 @@ static int tc_new_tfilter(struct sk_buff *skb, struct
nlmsghdr *n,
if (!tp_created)
tcf_chain_put(chain);
}
- tcf_block_release(q, block);
+ tcf_block_release(q, block, &rtnl_held);
if (err == -EAGAIN) {
/* Take rtnl lock in case EAGAIN is caused by concurrent flush
* of target chain.
@@ -1899,7 +1914,7 @@ static int tc_del_tfilter(struct sk_buff *skb, struct
nlmsghdr *n,
unsigned long cl = 0;
void *fh = NULL;
int err;
- bool rtnl_held = true;
+ bool rtnl_held = false;
if (!netlink_ns_capable(skb, net->user_ns, CAP_NET_ADMIN))
return -EPERM;
@@ -2011,7 +2026,7 @@ static int tc_del_tfilter(struct sk_buff *skb, struct
nlmsghdr *n,
tcf_proto_put(tp, NULL);
tcf_chain_put(chain);
}
- tcf_block_release(q, block);
+ tcf_block_release(q, block, &rtnl_held);
return err;
errout_locked:
@@ -2037,7 +2052,7 @@ static int tc_get_tfilter(struct sk_buff *skb, struct
nlmsghdr *n,
unsigned long cl = 0;
void *fh = NULL;
int err;
- bool rtnl_held = true;
+ bool rtnl_held = false;
err = nlmsg_parse(n, sizeof(*t), tca, TCA_MAX, rtm_tca_policy, extack);
if (err < 0)
@@ -2112,7 +2127,7 @@ static int tc_get_tfilter(struct sk_buff *skb, struct
nlmsghdr *n,
tcf_proto_put(tp, NULL);
tcf_chain_put(chain);
}
- tcf_block_release(q, block);
+ tcf_block_release(q, block, &rtnl_held);
return err;
}
@@ -2561,7 +2576,7 @@ static int tc_ctl_chain(struct sk_buff *skb, struct
nlmsghdr *n,
errout:
tcf_chain_put(chain);
errout_block:
- tcf_block_release(q, block);
+ __tcf_block_release(q, block, true);
if (err == -EAGAIN)
/* Replay the request. */
goto replay;
@@ -2899,10 +2914,12 @@ static int __init tc_filter_init(void)
if (err)
goto err_register_pernet_subsys;
- rtnl_register(PF_UNSPEC, RTM_NEWTFILTER, tc_new_tfilter, NULL, 0);
- rtnl_register(PF_UNSPEC, RTM_DELTFILTER, tc_del_tfilter, NULL, 0);
+ rtnl_register(PF_UNSPEC, RTM_NEWTFILTER, tc_new_tfilter, NULL,
+ RTNL_FLAG_DOIT_UNLOCKED);
+ rtnl_register(PF_UNSPEC, RTM_DELTFILTER, tc_del_tfilter, NULL,
+ RTNL_FLAG_DOIT_UNLOCKED);
rtnl_register(PF_UNSPEC, RTM_GETTFILTER, tc_get_tfilter,
- tc_dump_tfilter, 0);
+ tc_dump_tfilter, RTNL_FLAG_DOIT_UNLOCKED);
rtnl_register(PF_UNSPEC, RTM_NEWCHAIN, tc_ctl_chain, NULL, 0);
rtnl_register(PF_UNSPEC, RTM_DELCHAIN, tc_ctl_chain, NULL, 0);
rtnl_register(PF_UNSPEC, RTM_GETCHAIN, tc_ctl_chain,
--
2.7.5
