Commit 96b33300 authored by Pablo Neira Ayuso's avatar Pablo Neira Ayuso
Browse files

netfilter: nft_set_rbtree: use read spinlock to avoid datapath contention 



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: f6c383b8 ("netfilter: nf_tables: adapt set backend to use GC transaction API")
Signed-off-by: default avatarPablo Neira Ayuso <pablo@netfilter.org>
parent f15f29fd

net/netfilter/nft_set_rbtree.c

+2 −4
Original line number Diff line number Diff line
@@ -622,8 +622,7 @@ static void nft_rbtree_gc(struct work_struct *work) 
	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. */
@@ -673,8 +672,7 @@ static void nft_rbtree_gc(struct work_struct *work) 
	gc = nft_trans_gc_catchall(gc, gc_seq);



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);