6.1-stable review patch. If anyone has any objections, please let me know.
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From: Pedro Tammela pctammela@mojatatu.com
[ Upstream commit 93775590b1ee98bf2976b1f4a1ed24e9ff76170f ]
As of today tc-filter/chain events are unconditionally built and sent to RTNLGRP_TC. As with the introduction of rtnl_notify_needed we can check before-hand if they are really needed. This will help to alleviate system pressure when filters are concurrently added without the rtnl lock as in tc-flower.
Reviewed-by: Jiri Pirko jiri@nvidia.com Reviewed-by: Simon Horman horms@kernel.org Signed-off-by: Pedro Tammela pctammela@mojatatu.com Link: https://lore.kernel.org/r/20231208192847.714940-8-pctammela@mojatatu.com Signed-off-by: Jakub Kicinski kuba@kernel.org Stable-dep-of: 369609fc6272 ("tc: Ensure we have enough buffer space when sending filter netlink notifications") Signed-off-by: Sasha Levin sashal@kernel.org --- net/sched/cls_api.c | 12 ++++++++++++ 1 file changed, 12 insertions(+)
diff --git a/net/sched/cls_api.c b/net/sched/cls_api.c index 445ab1b0537da..2b44b82877f5a 100644 --- a/net/sched/cls_api.c +++ b/net/sched/cls_api.c @@ -1885,6 +1885,9 @@ static int tfilter_notify(struct net *net, struct sk_buff *oskb, u32 portid = oskb ? NETLINK_CB(oskb).portid : 0; int err = 0;
+ if (!unicast && !rtnl_notify_needed(net, n->nlmsg_flags, RTNLGRP_TC)) + return 0; + skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL); if (!skb) return -ENOBUFS; @@ -1914,6 +1917,9 @@ static int tfilter_del_notify(struct net *net, struct sk_buff *oskb, u32 portid = oskb ? NETLINK_CB(oskb).portid : 0; int err;
+ if (!rtnl_notify_needed(net, n->nlmsg_flags, RTNLGRP_TC)) + return tp->ops->delete(tp, fh, last, rtnl_held, extack); + skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL); if (!skb) return -ENOBUFS; @@ -2731,6 +2737,9 @@ static int tc_chain_notify(struct tcf_chain *chain, struct sk_buff *oskb, struct sk_buff *skb; int err = 0;
+ if (!unicast && !rtnl_notify_needed(net, flags, RTNLGRP_TC)) + return 0; + skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL); if (!skb) return -ENOBUFS; @@ -2760,6 +2769,9 @@ static int tc_chain_notify_delete(const struct tcf_proto_ops *tmplt_ops, struct net *net = block->net; struct sk_buff *skb;
+ if (!rtnl_notify_needed(net, flags, RTNLGRP_TC)) + return 0; + skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL); if (!skb) return -ENOBUFS;