net: make napi_frag_unref reuse skb_page_unref

The implementations of these 2 functions are almost identical. Remove
the implementation of napi_frag_unref, and make it a call into
skb_page_unref so we don't duplicate the implementation.
Signed-off-by: Mina Almasry <almasrymina@google.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Link: https://lore.kernel.org/r/20240408153000.2152844-2-almasrymina@google.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

include/linux/skbuff.h

@@ -3522,10 +3522,10 @@ int skb_cow_data_for_xdp(struct page_pool *pool, struct sk_buff **pskb,
 bool napi_pp_put_page(struct page *page);
 
 static inline void
-skb_page_unref(const struct sk_buff *skb, struct page *page)
+skb_page_unref(struct page *page, bool recycle)
 {
 #ifdef CONFIG_PAGE_POOL
-	if (skb->pp_recycle && napi_pp_put_page(page))
+	if (recycle && napi_pp_put_page(page))
 		return;
 #endif
 	put_page(page);
@@ -3534,13 +3534,7 @@ skb_page_unref(const struct sk_buff *skb, struct page *page)
 static inline void
 napi_frag_unref(skb_frag_t *frag, bool recycle)
 {
-	struct page *page = skb_frag_page(frag);
-
-#ifdef CONFIG_PAGE_POOL
-	if (recycle && napi_pp_put_page(page))
-		return;
-#endif
-	put_page(page);
+	skb_page_unref(skb_frag_page(frag), recycle);
 }
 
 /**

net/ipv4/esp4.c

@@ -114,7 +114,7 @@ static void esp_ssg_unref(struct xfrm_state *x, void *tmp, struct sk_buff *skb)
 	 */
 	if (req->src != req->dst)
 		for (sg = sg_next(req->src); sg; sg = sg_next(sg))
-			skb_page_unref(skb, sg_page(sg));
+			skb_page_unref(sg_page(sg), skb->pp_recycle);
 }
 
 #ifdef CONFIG_INET_ESPINTCP

net/ipv6/esp6.c

@@ -131,7 +131,7 @@ static void esp_ssg_unref(struct xfrm_state *x, void *tmp, struct sk_buff *skb)
 	 */
 	if (req->src != req->dst)
 		for (sg = sg_next(req->src); sg; sg = sg_next(sg))
-			skb_page_unref(skb, sg_page(sg));
+			skb_page_unref(sg_page(sg), skb->pp_recycle);
 }
 
 #ifdef CONFIG_INET6_ESPINTCP