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Message-Id: <d8ae2b225a566fb1addf970db79cbcea834b4ad0.1496070490.git.pabeni@redhat.com>
Date: Mon, 29 May 2017 17:27:23 +0200
From: Paolo Abeni <pabeni@...hat.com>
To: netdev@...r.kernel.org
Cc: "David S. Miller" <davem@...emloft.net>,
Eric Dumazet <edumazet@...gle.com>
Subject: [PATCH net-next 1/3] net: factor out a helper to decrement the skb refcount
The same code is replicated in 3 different places; move it to a
common helper.
Signed-off-by: Paolo Abeni <pabeni@...hat.com>
---
include/linux/skbuff.h | 13 +++++++++++++
net/core/datagram.c | 4 +---
net/core/skbuff.c | 14 ++++----------
3 files changed, 18 insertions(+), 13 deletions(-)
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index 45a59c1..3c25fca 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -867,6 +867,19 @@ static inline unsigned int skb_napi_id(const struct sk_buff *skb)
#endif
}
+/* decrement the reference count and return true if we can free the skb */
+static inline bool skb_unref(struct sk_buff *skb)
+{
+ if (unlikely(!skb))
+ return false;
+ if (likely(atomic_read(&skb->users) == 1))
+ smp_rmb();
+ else if (likely(!atomic_dec_and_test(&skb->users)))
+ return false;
+
+ return true;
+}
+
void kfree_skb(struct sk_buff *skb);
void kfree_skb_list(struct sk_buff *segs);
void skb_tx_error(struct sk_buff *skb);
diff --git a/net/core/datagram.c b/net/core/datagram.c
index bc46118..e5311a7 100644
--- a/net/core/datagram.c
+++ b/net/core/datagram.c
@@ -330,9 +330,7 @@ void __skb_free_datagram_locked(struct sock *sk, struct sk_buff *skb, int len)
{
bool slow;
- if (likely(atomic_read(&skb->users) == 1))
- smp_rmb();
- else if (likely(!atomic_dec_and_test(&skb->users))) {
+ if (!skb_unref(skb)) {
sk_peek_offset_bwd(sk, len);
return;
}
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 780b7c1..c81b828 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -694,12 +694,9 @@ EXPORT_SYMBOL(__kfree_skb);
*/
void kfree_skb(struct sk_buff *skb)
{
- if (unlikely(!skb))
- return;
- if (likely(atomic_read(&skb->users) == 1))
- smp_rmb();
- else if (likely(!atomic_dec_and_test(&skb->users)))
+ if (!skb_unref(skb))
return;
+
trace_kfree_skb(skb, __builtin_return_address(0));
__kfree_skb(skb);
}
@@ -746,12 +743,9 @@ EXPORT_SYMBOL(skb_tx_error);
*/
void consume_skb(struct sk_buff *skb)
{
- if (unlikely(!skb))
- return;
- if (likely(atomic_read(&skb->users) == 1))
- smp_rmb();
- else if (likely(!atomic_dec_and_test(&skb->users)))
+ if (!skb_unref(skb))
return;
+
trace_consume_skb(skb);
__kfree_skb(skb);
}
--
2.9.4
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