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authorEric Dumazet <edumazet@google.com>2014-09-29 13:29:15 -0700
committerDavid S. Miller <davem@davemloft.net>2014-10-01 16:34:25 -0400
commitd0bf4a9e92b9a93ffeeacbd7b6cb83e0ee3dc2ef (patch)
tree1ba29128caa07307632b6219c1692308ec89983a /include/linux/skbuff.h
parentb248230c34970a6c1c17c591d63b464e8d2cfc33 (diff)
net: cleanup and document skb fclone layout
Lets use a proper structure to clearly document and implement skb fast clones. Then, we might experiment more easily alternative layouts. This patch adds a new skb_fclone_busy() helper, used by tcp and xfrm, to stop leaking of implementation details. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'include/linux/skbuff.h')
-rw-r--r--include/linux/skbuff.h25
1 files changed, 25 insertions, 0 deletions
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index 262efdbc346..d8f7d74d5a4 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -781,6 +781,31 @@ struct sk_buff *alloc_skb_with_frags(unsigned long header_len,
int *errcode,
gfp_t gfp_mask);
+/* Layout of fast clones : [skb1][skb2][fclone_ref] */
+struct sk_buff_fclones {
+ struct sk_buff skb1;
+
+ struct sk_buff skb2;
+
+ atomic_t fclone_ref;
+};
+
+/**
+ * skb_fclone_busy - check if fclone is busy
+ * @skb: buffer
+ *
+ * Returns true is skb is a fast clone, and its clone is not freed.
+ */
+static inline bool skb_fclone_busy(const struct sk_buff *skb)
+{
+ const struct sk_buff_fclones *fclones;
+
+ fclones = container_of(skb, struct sk_buff_fclones, skb1);
+
+ return skb->fclone == SKB_FCLONE_ORIG &&
+ fclones->skb2.fclone == SKB_FCLONE_CLONE;
+}
+
static inline struct sk_buff *alloc_skb_fclone(unsigned int size,
gfp_t priority)
{