[PATCH v15 06/17] Use callback to deal with skb_release_data() specially.

From: xiaohui . xin
Date: Tue Nov 09 2010 - 03:45:25 EST


From: Xin Xiaohui <xiaohui.xin@xxxxxxxxx>

If buffer is external, then use the callback to destruct
buffers.

Signed-off-by: Xin Xiaohui <xiaohui.xin@xxxxxxxxx>
Signed-off-by: Zhao Yu <yzhao81new@xxxxxxxxx>
Reviewed-by: Jeff Dike <jdike@xxxxxxxxxxxxxxx>
---
include/linux/skbuff.h | 7 ++++---
net/core/skbuff.c | 7 +++++++
2 files changed, 11 insertions(+), 3 deletions(-)

diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index 696e690..6e1e991 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -199,14 +199,15 @@ struct skb_shared_info {
struct sk_buff *frag_list;
struct skb_shared_hwtstamps hwtstamps;

+ /* Intermediate layers must ensure that destructor_arg
+ * remains valid until skb destructor */
+ void * destructor_arg;
+
/*
* Warning : all fields before dataref are cleared in __alloc_skb()
*/
atomic_t dataref;

- /* Intermediate layers must ensure that destructor_arg
- * remains valid until skb destructor */
- void * destructor_arg;
/* must be last field, see pskb_expand_head() */
skb_frag_t frags[MAX_SKB_FRAGS];
};
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index c83b421..68e197e 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -343,6 +343,13 @@ static void skb_release_data(struct sk_buff *skb)
if (skb_has_frags(skb))
skb_drop_fraglist(skb);

+ if (skb->dev && dev_is_mpassthru(skb->dev)) {
+ struct skb_ext_page *ext_page =
+ skb_shinfo(skb)->destructor_arg;
+ if (ext_page && ext_page->dtor)
+ ext_page->dtor(ext_page);
+ }
+
kfree(skb->head);
}
}
--
1.7.3

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