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Commit 1e5289e121372a3494402b1b131b41bfe1cf9b7f

Authored by Yan, Zheng
Committed by David S. Miller
1 parent 260fcbeb1a
Exists in master and in 6 other branches imx_3.10.17_1.0.1_ga, imx_3.10.53_1.1.0_ga, imx_3.14.28_1.0.0_ga, smarc-imx_3.10.53_1.1.0_ga, smarc-imx_3.14.28_1.0.0_ga, smarc-l5.0.0_1.0.0-ga

tcp: properly update lost_cnt_hint during shifting 

lost_skb_hint is used by tcp_mark_head_lost() to mark the first unhandled skb.
lost_cnt_hint is the number of packets or sacked packets before the lost_skb_hint;
When shifting a skb that is before the lost_skb_hint, if tcp_is_fack() is ture,
the skb has already been counted in the lost_cnt_hint; if tcp_is_fack() is false,
tcp_sacktag_one() will increase the lost_cnt_hint. So tcp_shifted_skb() does not
need to adjust the lost_cnt_hint by itself. When shifting a skb that is equal to
lost_skb_hint, the shifted packets will not be counted by tcp_mark_head_lost().
So tcp_shifted_skb() should adjust the lost_cnt_hint even tcp_is_fack(tp) is true.

Signed-off-by: Zheng Yan <zheng.z.yan@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Showing 1 changed file with 1 additions and 3 deletions Side-by-side Diff

net/ipv4/tcp_input.c
Diff comments   View file @ 1e5289e
... ... @@ -1389,9 +1389,7 @@
1389 1389  
1390 1390 BUG_ON(!pcount);
1391 1391  
1392   - /* Tweak before seqno plays */
1393   - if (!tcp_is_fack(tp) && tcp_is_sack(tp) && tp->lost_skb_hint &&
1394   - !before(TCP_SKB_CB(tp->lost_skb_hint)->seq, TCP_SKB_CB(skb)->seq))
  1392 + if (skb == tp->lost_skb_hint)
1395 1393 tp->lost_cnt_hint += pcount;
1396 1394  
1397 1395 TCP_SKB_CB(prev)->end_seq += shifted;