[PATCH net-next 1/4] net: shaper: drop redundant xa_lock() bracketing
From: Jakub Kicinski <kuba@kernel.org>
Date: 2026-06-09 18:32:26
Subsystem:
networking [general], the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
The shaper insertion and update code takes xa_lock() explicitly. Paolo explained that the locking was purely to avoid re-taking the lock in loops. But it may be mis-read as if it was expecting readers to be fenced off by xa_lock. Readers of XArray are purely under RCU. Remove explicit taking of xa_lock(). All writers to hierarchy->shapers are serialized by the netdev instance lock (or run after netdev is made inaccessible to readers). Signed-off-by: Jakub Kicinski <kuba@kernel.org> --- net/shaper/shaper.c | 10 ++-------- 1 file changed, 2 insertions(+), 8 deletions(-)
diff --git a/net/shaper/shaper.c b/net/shaper/shaper.c
index dea9270f3e57..a5b42b697a93 100644
--- a/net/shaper/shaper.c
+++ b/net/shaper/shaper.c@@ -429,7 +429,6 @@ static void net_shaper_commit(struct net_shaper_binding *binding, int index; int i; - xa_lock(&hierarchy->shapers); for (i = 0; i < nr_shapers; ++i) { index = net_shaper_handle_to_index(&shapers[i].handle);
@@ -442,7 +441,6 @@ static void net_shaper_commit(struct net_shaper_binding *binding, /* ... publish to lockless readers. */ smp_store_release(&cur->valid, true); } - xa_unlock(&hierarchy->shapers); } /* Rollback all the tentative inserts from the hierarchy. */
@@ -455,14 +453,12 @@ static void net_shaper_rollback(struct net_shaper_binding *binding) if (!hierarchy) return; - xa_lock(&hierarchy->shapers); xa_for_each(&hierarchy->shapers, index, cur) { if (cur->valid) continue; - __xa_erase(&hierarchy->shapers, index); + xa_erase(&hierarchy->shapers, index); kfree_rcu(cur, rcu); } - xa_unlock(&hierarchy->shapers); } static int net_shaper_parse_handle(const struct nlattr *attr,
@@ -1472,12 +1468,10 @@ static void net_shaper_flush(struct net_shaper_binding *binding) if (!hierarchy) return; - xa_lock(&hierarchy->shapers); xa_for_each(&hierarchy->shapers, index, cur) { - __xa_erase(&hierarchy->shapers, index); + xa_erase(&hierarchy->shapers, index); kfree(cur); } - xa_unlock(&hierarchy->shapers); kfree(hierarchy); }
--
2.54.0