From: Neal Cardwell Date: Sun, 26 Feb 2012 10:06:19 +0000 (+0000) Subject: tcp: fix false reordering signal in tcp_shifted_skb X-Git-Tag: v3.2.12~23 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=83833f94ab0c78ab1e4cddd3e075a0929fba246b;p=pandora-kernel.git tcp: fix false reordering signal in tcp_shifted_skb [ Upstream commit 4c90d3b30334833450ccbb02f452d4972a3c3c3f ] When tcp_shifted_skb() shifts bytes from the skb that is currently pointed to by 'highest_sack' then the increment of TCP_SKB_CB(skb)->seq implicitly advances tcp_highest_sack_seq(). This implicit advancement, combined with the recent fix to pass the correct SACKed range into tcp_sacktag_one(), caused tcp_sacktag_one() to think that the newly SACKed range was before the tcp_highest_sack_seq(), leading to a call to tcp_update_reordering() with a degree of reordering matching the size of the newly SACKed range (typically just 1 packet, which is a NOP, but potentially larger). This commit fixes this by simply calling tcp_sacktag_one() before the TCP_SKB_CB(skb)->seq advancement that can advance our notion of the highest SACKed sequence. Correspondingly, we can simplify the code a little now that tcp_shifted_skb() should update the lost_cnt_hint in all cases where skb == tp->lost_skb_hint. Signed-off-by: Neal Cardwell Acked-by: Yuchung Cheng Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- Reading git-diff-tree failed