[TCP]: Bidir flow must not disregard SACK blocks for lost marking
authorIlpo Järvinen <ilpo.jarvinen@helsinki.fi>
Tue, 31 Jul 2007 02:51:12 +0000 (19:51 -0700)
committerDavid S. Miller <davem@sunset.davemloft.net>
Tue, 31 Jul 2007 09:28:31 +0000 (02:28 -0700)
commitb8ed601cefe7a4014b93560bd846caf44f25b1c1
tree37df7bdfa7cb88195502e36440a21ce3897c9e40
parent1e757f9996114f713a79d3fbcd08739efcfc5c34
[TCP]: Bidir flow must not disregard SACK blocks for lost marking

It's possible that new SACK blocks that should trigger new LOST
markings arrive with new data (which previously made is_dupack
false). In addition, I think this fixes a case where we get
a cumulative ACK with enough SACK blocks to trigger the fast
recovery (is_dupack would be false there too).

I'm not completely pleased with this solution because readability
of the code is somewhat questionable as 'is_dupack' in SACK case
is no longer about dupacks only but would mean something like
'lost_marker_work_todo' too... But because of Eifel stuff done
in CA_Recovery, the FLAG_DATA_SACKED check cannot be placed to
the if statement which seems attractive solution. Nevertheless,
I didn't like adding another variable just for that either... :-)

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
net/ipv4/tcp_input.c