net: __alloc_skb() cleanup

This patch refactors __alloc_skb() to prepare the following one,
and does not change functionality.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Jason Xing <kerneljasonxing@gmail.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com>
Link: https://patch.msgid.link/20251116202717.1542829-3-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 88b5530f9c460d86e12c98e410774444367e0404..8a0a4ca7fa5dbb2fa3044ee45bb0b9c8c3ca85ea 100644 (file)
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -646,25 +646,33 @@ out:
 struct sk_buff *__alloc_skb(unsigned int size, gfp_t gfp_mask,
                            int flags, int node)
 {
+       struct sk_buff *skb = NULL;
        struct kmem_cache *cache;
-       struct sk_buff *skb;
        bool pfmemalloc;
        u8 *data;
 
-       cache = (flags & SKB_ALLOC_FCLONE)
-               ? net_hotdata.skbuff_fclone_cache : net_hotdata.skbuff_cache;
-
        if (sk_memalloc_socks() && (flags & SKB_ALLOC_RX))
                gfp_mask |= __GFP_MEMALLOC;
 
-       /* Get the HEAD */
-       if ((flags & (SKB_ALLOC_FCLONE | SKB_ALLOC_NAPI)) == SKB_ALLOC_NAPI &&
-           likely(node == NUMA_NO_NODE || node == numa_mem_id()))
+       if (flags & SKB_ALLOC_FCLONE) {
+               cache = net_hotdata.skbuff_fclone_cache;
+               goto fallback;
+       }
+       cache = net_hotdata.skbuff_cache;
+       if (unlikely(node != NUMA_NO_NODE && node != numa_mem_id()))
+               goto fallback;
+
+       if (flags & SKB_ALLOC_NAPI) {
                skb = napi_skb_cache_get(true);
-       else
+               if (unlikely(!skb))
+                       return NULL;
+       }
+       if (!skb) {
+fallback:
                skb = kmem_cache_alloc_node(cache, gfp_mask & ~GFP_DMA, node);
-       if (unlikely(!skb))
-               return NULL;
+               if (unlikely(!skb))
+                       return NULL;
+       }
        prefetchw(skb);
 
        /* We do our best to align skb_shared_info on a separate cache