[PATCH v11 06/17]Use callback to deal with skb_release_data() specially.

xiaohui.xin
2010-09-25T04:10:45Z

From: Xin Xiaohui <xiaohui.xin@intel.com>

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

Signed-off-by: Xin Xiaohui <xiaohui.xin@intel.com>
Signed-off-by: Zhao Yu <yzhao81new@gmail.com>
Reviewed-by: Jeff Dike <jdike@linux.intel.com>

---
include/linux/skbuff.h | 3 ++-
net/core/skbuff.c | 8 ++++++++
2 files changed, 10 insertions(+), 1 deletions(-)

diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index 74af06c..ab29675 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -197,10 +197,11 @@ struct skb_shared_info {
union skb_shared_tx tx_flags;
struct sk_buff *frag_list;
struct skb_shared_hwtstamps hwtstamps;
- skb_frag_t frags[MAX_SKB_FRAGS];
/* Intermediate layers must ensure that destructor_arg
* remains valid until skb destructor */
void * destructor_arg;
+
+ skb_frag_t frags[MAX_SKB_FRAGS];
};

/* The structure is for a skb which pages may point to
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 93c4e06..117d82b 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -217,6 +217,7 @@ struct sk_buff *__alloc_skb(unsigned int size, gfp_t gfp_mask,
shinfo->gso_type = 0;
shinfo->ip6_frag_id = 0;
shinfo->tx_flags.flags = 0;
+ shinfo->destructor_arg = NULL;
skb_frag_list_init(skb);
memset(&shinfo->hwtstamps, 0, sizeof(shinfo->hwtstamps));

@@ -350,6 +351,13 @@ 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