Commit 57b55a7e authored by Alexander Duyck's avatar Alexander Duyck Committed by David S. Miller
Browse files

tcp: Move code related to head frag in tcp_try_coalesce 



This change reorders the code related to the use of an skb->head_frag so it
is placed before we check the rest of the frags.  This allows the code to
read more linearly instead of like some sort of loop.

Signed-off-by: default avatarAlexander Duyck <alexander.h.duyck@intel.com>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Acked-by: default avatarEric Dumazet <edumazet@google.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent c73c3d9c

net/ipv4/tcp_input.c

+25 −17
Original line number Diff line number Diff line
@@ -4562,9 +4562,31 @@ merge: 
	if (skb_has_frag_list(to) || skb_has_frag_list(from))

		return false;



	if (skb_headlen(from) == 0 &&

	    (skb_shinfo(to)->nr_frags +

	     skb_shinfo(from)->nr_frags <= MAX_SKB_FRAGS)) {

	if (skb_headlen(from) != 0) {

		struct page *page;

		unsigned int offset;



		if (skb_shinfo(to)->nr_frags +

		    skb_shinfo(from)->nr_frags >= MAX_SKB_FRAGS)

			return false;



		if (!from->head_frag || skb_cloned(from))

			return false;



		delta = from->truesize - SKB_DATA_ALIGN(sizeof(struct sk_buff));



		page = virt_to_head_page(from->head);

		offset = from->data - (unsigned char *)page_address(page);



		skb_fill_page_desc(to, skb_shinfo(to)->nr_frags,

				   page, offset, skb_headlen(from));

		*fragstolen = true;

		goto copyfrags;

	} else {

		if (skb_shinfo(to)->nr_frags +

		    skb_shinfo(from)->nr_frags > MAX_SKB_FRAGS)

			return false;



		delta = from->truesize -

			SKB_TRUESIZE(skb_end_pointer(from) - from->head);

copyfrags:
@@ -4587,20 +4609,6 @@ copyfrags: 
		to->data_len += len;

		goto merge;

	}

	if (from->head_frag && !skb_cloned(from)) {

		struct page *page;

		unsigned int offset;



		if (skb_shinfo(to)->nr_frags + skb_shinfo(from)->nr_frags >= MAX_SKB_FRAGS)

			return false;

		page = virt_to_head_page(from->head);

		offset = from->data - (unsigned char *)page_address(page);

		skb_fill_page_desc(to, skb_shinfo(to)->nr_frags,

				   page, offset, skb_headlen(from));

		*fragstolen = true;

		delta = from->truesize - SKB_DATA_ALIGN(sizeof(struct sk_buff));

		goto copyfrags;

	}

	return false;

}

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