[PATCH -stable,4.19.x 12/40] netfilter: nf_tables: remove busy mark and gc batch API

Pablo Neira Ayuso
2024-06-13T01:02:26Z

commit a2dd0233cbc4d8a0abb5f64487487ffc9265beb5 upstream.

Ditch it, it has been replace it by the GC transaction API and it has no
clients anymore.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
include/net/netfilter/nf_tables.h | 97 +------------------------------
net/netfilter/nf_tables_api.c | 28 +--------
2 files changed, 5 insertions(+), 120 deletions(-)

diff --git a/include/net/netfilter/nf_tables.h b/include/net/netfilter/nf_tables.h
index 97c7ceb1b39d..cf63b52f3c94 100644
--- a/include/net/netfilter/nf_tables.h
+++ b/include/net/netfilter/nf_tables.h
@@ -652,62 +652,6 @@ void nft_set_elem_destroy(const struct nft_set *set, void *elem,
void nf_tables_set_elem_destroy(const struct nft_ctx *ctx,
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_ops;
/**
* struct nft_expr_type - nf_tables expression type
@@ -1314,47 +1258,12 @@ static inline void nft_set_elem_change_active(const struct net *net,
ext->genmask ^= nft_genmask_next(net);
}

-/*
- * We use a free bit in the genmask field to indicate the element
- * is busy, meaning it is currently being processed either by
- * the netlink API or GC.
- *
- * Even though the genmask is only a single byte wide, this works
- * because the extension structure if fully constant once initialized,
- * so there are no non-atomic write accesses unless it is already
- * marked busy.
- */
-#define NFT_SET_ELEM_BUSY_MASK (1 << 2)
-
-#if defined(__LITTLE_ENDIAN_BITFIELD)
-#define NFT_SET_ELEM_BUSY_BIT 2
-#elif defined(__BIG_ENDIAN_BITFIELD)
-#define NFT_SET_ELEM_BUSY_BIT (BITS_PER_LONG - BITS_PER_BYTE + 2)
-#else
-#error
-#endif
-
-static inline int nft_set_elem_mark_busy(struct nft_set_ext *ext)
-{
- unsigned long *word = (unsigned long *)ext;
-
- BUILD_BUG_ON(offsetof(struct nft_set_ext, genmask) != 0);
- return test_and_set_bit(NFT_SET_ELEM_BUSY_BIT, word);
-}
-
-static inline void nft_set_elem_clear_busy(struct nft_set_ext *ext)
-{
- unsigned long *word = (unsigned long *)ext;
-
- clear_bit(NFT_SET_ELEM_BUSY_BIT, word);
-}
-
-#define NFT_SET_ELEM_DEAD_MASK (1 << 3)
+#define NFT_SET_ELEM_DEAD_MASK (1 << 2)

#if defined(__LITTLE_ENDIAN_BITFIELD)
-#define NFT_SET_ELEM_DEAD_BIT 3
+#define NFT_SET_ELEM_DEAD_BIT 2
#elif defined(__BIG_ENDIAN_BITFIELD)
-#define NFT_SET_ELEM_DEAD_BIT (BITS_PER_LONG - BITS_PER_BYTE + 3)
+#define NFT_SET_ELEM_DEAD_BIT (BITS_PER_LONG - BITS_PER_BYTE + 2)
#else
#error
#endif
diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index 934cf7654ae3..aea8063f056d 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -4766,7 +4766,8 @@ static int nft_add_set_elem(struct nft_ctx *ctx, struct nft_set *set,
if (trans == NULL)
goto err4;

- ext->genmask = nft_genmask_cur(ctx->net) | NFT_SET_ELEM_BUSY_MASK;
+ ext->genmask = nft_genmask_cur(ctx->net);
+
err = set->ops->insert(ctx->net, set, &elem, &ext2);
if (err) {
if (err == -EEXIST) {
@@ -5059,31 +5060,6 @@ static int nf_tables_delsetelem(struct net *net, struct sock *nlsk,
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], true);
- 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);
-
/*
* Stateful objects
*/
--
2.30.2