From: Patrick McHardy <kaber@xxxxxxxxx>
Add helpers for GC batch destruction: since element destruction needs
a RCU grace period for all set implementations, add some helper functions
for asynchronous batch destruction. Elements are collected in a batch
structure, which is asynchronously released using RCU once its full.
Signed-off-by: Patrick McHardy <kaber@xxxxxxxxx>
Signed-off-by: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>
---
include/net/netfilter/nf_tables.h | 56 +++++++++++++++++++++++++++++++++++++
net/netfilter/nf_tables_api.c | 25 +++++++++++++++++
2 files changed, 81 insertions(+)
diff --git a/include/net/netfilter/nf_tables.h b/include/net/netfilter/nf_tables.h
index f2726c5..6fd4495 100644
--- a/include/net/netfilter/nf_tables.h
+++ b/include/net/netfilter/nf_tables.h
@@ -460,6 +460,62 @@ static inline struct nft_set_ext *nft_set_elem_ext(const struct nft_set *set,
void nft_set_elem_destroy(const struct nft_set *set, void *elem);
/**
+ * struct nft_set_gc_batch_head - nf_tables set garbage collection batch
+ *
+ * @rcu: rcu head
+ * @set: set the elements belong to
+ * @cnt: count of elements
+ */
+struct nft_set_gc_batch_head {
+ struct rcu_head rcu;
+ const struct nft_set *set;
+ unsigned int cnt;
+};
+
+#define NFT_SET_GC_BATCH_SIZE ((PAGE_SIZE - \
+ sizeof(struct nft_set_gc_batch_head)) / \
+ sizeof(void *))
+
+/**
+ * struct nft_set_gc_batch - nf_tables set garbage collection batch
+ *
+ * @head: GC batch head
+ * @elems: garbage collection elements
+ */
+struct nft_set_gc_batch {
+ struct nft_set_gc_batch_head head;
+ void *elems[NFT_SET_GC_BATCH_SIZE];
+};
+
+struct nft_set_gc_batch *nft_set_gc_batch_alloc(const struct nft_set *set,
+ gfp_t gfp);
+void nft_set_gc_batch_release(struct rcu_head *rcu);
+
+static inline void nft_set_gc_batch_complete(struct nft_set_gc_batch *gcb)
+{
+ if (gcb != NULL)
+ call_rcu(&gcb->head.rcu, nft_set_gc_batch_release);
+}
+
+static inline struct nft_set_gc_batch *
+nft_set_gc_batch_check(const struct nft_set *set, struct nft_set_gc_batch *gcb,
+ gfp_t gfp)
+{
+ if (gcb != NULL) {
+ if (gcb->head.cnt + 1 < ARRAY_SIZE(gcb->elems))
+ return gcb;
+ nft_set_gc_batch_complete(gcb);
+ }
+ return nft_set_gc_batch_alloc(set, gfp);
+}
+
+static inline void nft_set_gc_batch_add(struct nft_set_gc_batch *gcb,
+ void *elem)
+{
+ gcb->elems[gcb->head.cnt++] = elem;
+}
+
+/**
* struct nft_expr_type - nf_tables expression type
*
* @select_ops: function to select nft_expr_ops
diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index 9e032db..138e47f 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -3482,6 +3482,31 @@ static int nf_tables_delsetelem(struct sock *nlsk, struct sk_buff *skb,
return err;
}
+void nft_set_gc_batch_release(struct rcu_head *rcu)
+{
+ struct nft_set_gc_batch *gcb;
+ unsigned int i;
+
+ gcb = container_of(rcu, struct nft_set_gc_batch, head.rcu);
+ for (i = 0; i < gcb->head.cnt; i++)
+ nft_set_elem_destroy(gcb->head.set, gcb->elems[i]);
+ kfree(gcb);
+}
+EXPORT_SYMBOL_GPL(nft_set_gc_batch_release);
+
+struct nft_set_gc_batch *nft_set_gc_batch_alloc(const struct nft_set *set,
+ gfp_t gfp)
+{
+ struct nft_set_gc_batch *gcb;
+
+ gcb = kzalloc(sizeof(*gcb), gfp);
+ if (gcb == NULL)
+ return gcb;
+ gcb->head.set = set;
+ return gcb;
+}
+EXPORT_SYMBOL_GPL(nft_set_gc_batch_alloc);
+
static int nf_tables_fill_gen_info(struct sk_buff *skb, struct net *net,
u32 portid, u32 seq)
{
--
1.7.10.4
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