From b0c21badf174eb00160f842398f3918d7b365853 Mon Sep 17 00:00:00 2001 From: David Vrabel Date: Wed, 4 Mar 2015 11:14:48 +0000 Subject: [PATCH] xen-netback: refactor xenvif_handle_frag_list() When handling a from-guest frag list, xenvif_handle_frag_list() replaces the frags before calling the destructor to clean up the original (foreign) frags. Whilst this is safe (the destructor doesn't actually use the frags), it looks odd. Reorder the function to be less confusing. Signed-off-by: David Vrabel Signed-off-by: David S. Miller --- drivers/net/xen-netback/netback.c | 21 +++++++++------------ 1 file changed, 9 insertions(+), 12 deletions(-) diff --git a/drivers/net/xen-netback/netback.c b/drivers/net/xen-netback/netback.c index f1d84fb1eba8..cab9f5257f57 100644 --- a/drivers/net/xen-netback/netback.c +++ b/drivers/net/xen-netback/netback.c @@ -1390,27 +1390,24 @@ static int xenvif_handle_frag_list(struct xenvif_queue *queue, struct sk_buff *s skb_frag_size_set(&frags[i], len); } + /* Copied all the bits from the frag list -- free it. */ + skb_frag_list_init(skb); + xenvif_skb_zerocopy_prepare(queue, nskb); + kfree_skb(nskb); + /* Release all the original (foreign) frags. */ for (f = 0; f < skb_shinfo(skb)->nr_frags; f++) skb_frag_unref(skb, f); - - /* swap out with old one */ - memcpy(skb_shinfo(skb)->frags, - frags, - i * sizeof(skb_frag_t)); - skb_shinfo(skb)->nr_frags = i; - skb->truesize += i * PAGE_SIZE; - - /* remove traces of mapped pages and frag_list */ - skb_frag_list_init(skb); uarg = skb_shinfo(skb)->destructor_arg; /* increase inflight counter to offset decrement in callback */ atomic_inc(&queue->inflight_packets); uarg->callback(uarg, true); skb_shinfo(skb)->destructor_arg = NULL; - xenvif_skb_zerocopy_prepare(queue, nskb); - kfree_skb(nskb); + /* Fill the skb with the new (local) frags. */ + memcpy(skb_shinfo(skb)->frags, frags, i * sizeof(skb_frag_t)); + skb_shinfo(skb)->nr_frags = i; + skb->truesize += i * PAGE_SIZE; return 0; } -- 2.20.1