[PATCH v2 net-next 2/3] net: modify skb_rbtree_purge to return the truesize of all purged skbs.

[Peter Oskolkov <posk@google.com>]

Tested: see the next patch is the series.

Suggested-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Peter Oskolkov <posk@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Florian Westphal <fw@strlen.de>

---
 include/linux/skbuff.h | 2 +-
 net/core/skbuff.c      | 6 +++++-
 2 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index fd3cb1b247df..47848367c816 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -2585,7 +2585,7 @@ static inline void __skb_queue_purge(struct sk_buff_head *list)
 		kfree_skb(skb);
 }
 
-void skb_rbtree_purge(struct rb_root *root);
+unsigned int skb_rbtree_purge(struct rb_root *root);
 
 void *netdev_alloc_frag(unsigned int fragsz);
 
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 51b0a9126e12..8d574a88125d 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -2858,23 +2858,27 @@ EXPORT_SYMBOL(skb_queue_purge);
 /**
  *	skb_rbtree_purge - empty a skb rbtree
  *	@root: root of the rbtree to empty
+ *	Return value: the sum of truesizes of all purged skbs.
  *
  *	Delete all buffers on an &sk_buff rbtree. Each buffer is removed from
  *	the list and one reference dropped. This function does not take
  *	any lock. Synchronization should be handled by the caller (e.g., TCP
  *	out-of-order queue is protected by the socket lock).
  */
-void skb_rbtree_purge(struct rb_root *root)
+unsigned int skb_rbtree_purge(struct rb_root *root)
 {
 	struct rb_node *p = rb_first(root);
+	unsigned int sum = 0;
 
 	while (p) {
 		struct sk_buff *skb = rb_entry(p, struct sk_buff, rbnode);
 
 		p = rb_next(p);
 		rb_erase(&skb->rbnode, root);
+		sum += skb->truesize;
 		kfree_skb(skb);
 	}
+	return sum;
 }
 
 /**
-- 
2.18.0.597.ga71716f1ad-goog