5.4-stable review patch. If anyone has any objections, please let me know.
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From: Pablo Neira Ayuso pablo@netfilter.org
commit 96b33300fba880ec0eafcf3d82486f3463b4b6da upstream.
rbtree GC does not modify the datastructure, instead it collects expired elements and it enqueues a GC transaction. Use a read spinlock instead to avoid data contention while GC worker is running.
Fixes: f6c383b8c31a ("netfilter: nf_tables: adapt set backend to use GC transaction API") Signed-off-by: Pablo Neira Ayuso pablo@netfilter.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/netfilter/nft_set_rbtree.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-)
--- a/net/netfilter/nft_set_rbtree.c +++ b/net/netfilter/nft_set_rbtree.c @@ -626,8 +626,7 @@ static void nft_rbtree_gc(struct work_st if (!gc) goto done;
- write_lock_bh(&priv->lock); - write_seqcount_begin(&priv->count); + read_lock_bh(&priv->lock); for (node = rb_first(&priv->root); node != NULL; node = rb_next(node)) {
/* Ruleset has been updated, try later. */ @@ -676,8 +675,7 @@ dead_elem: }
try_later: - write_seqcount_end(&priv->count); - write_unlock_bh(&priv->lock); + read_unlock_bh(&priv->lock);
if (gc) nft_trans_gc_queue_async_done(gc);