[PATCH RFC 2/6] skbuff: add an api to orphan frags
From: "Michael S. Tsirkin" <mst@redhat.com>
Date: 2012-05-07 13:54:34
Subsystem:
networking [general], the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
Many places do
if ((skb_shinfo(skb)->tx_flags & SKBTX_DEV_ZEROCOPY))
skb_copy_ubufs(skb, gfp_mask);
to copy and invoke frag destructors if necessary.
Add an inline helper for this.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---
include/linux/skbuff.h | 24 ++++++++++++++++++++++++
1 files changed, 24 insertions(+), 0 deletions(-)
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index bb78f70..28d842e 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h@@ -1711,6 +1711,30 @@ static inline void skb_orphan(struct sk_buff *skb) } /** + * skb_orphan_frags - orphan the frags contained in a buffer + * @skb: buffer to orphan frags from + * @gfp_mask: allocation mask for replacement pages + * + * For each frag in the SKB which needs a destructor (i.e. has an + * owner) create a copy of that frag and release the original + * page by calling the destructor. + */ +static inline int skb_orphan_frags(struct sk_buff *skb, gfp_t gfp_mask) +{ + if (likely(!(skb_shinfo(skb)->tx_flags & SKBTX_DEV_ZEROCOPY))) + return 0; + return skb_copy_ubufs(skb, gfp_mask); +} + + +static inline void skb_copy_frag_destructor(struct sk_buff *to, + struct sk_buff *from) +{ + skb_shinfo(to)->tx_flags |= skb_shinfo(from)->tx_flags & + SKBTX_DEV_ZEROCOPY; +} + +/** * __skb_queue_purge - empty a list * @list: list to empty *
--
MST