linux/net
Yuchung Cheng 98e36d449c tcp: check undo conditions before detecting losses
Currently RACK would mark loss before the undo operations in TCP
loss recovery. This could incorrectly identify real losses as
spurious. For example a sender first experiences a delay spike and
then eventually some packets were lost due to buffer overrun.
In this case, the sender should perform fast recovery b/c not all
the packets were lost.

But the sender may first trigger a (spurious) RTO and reset
cwnd to 1. The following ACKs may used to mark real losses by
tcp_rack_mark_lost. Then in tcp_process_loss this ACK could trigger
F-RTO undo condition and unmark real losses and revert the cwnd
reduction. If there are no more ACKs coming back, eventually the
sender would timeout again instead of performing fast recovery.

The patch fixes this incorrect process by always performing
the undo checks before detecting losses.

Fixes: 4f41b1c58a ("tcp: use RACK to detect losses")
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-01-13 22:37:16 -05:00
..
6lowpan 6lowpan: ndisc: no overreact if no short address is available 2016-09-19 20:19:34 +02:00
9p IB/core: add support to create a unsafe global rkey to ib_create_pd 2016-09-23 13:47:44 -04:00
802 Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
8021q net: make ndo_get_stats64 a void function 2017-01-08 17:51:44 -05:00
appletalk
atm net: atm: Fix warnings in net/atm/lec.c when !CONFIG_PROC_FS 2016-12-28 15:11:32 -05:00
ax25 Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
batman-adv Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2016-12-06 21:33:19 -05:00
bluetooth Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-12-16 10:24:44 -08:00
bridge Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2017-01-09 15:39:11 -05:00
caif Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2016-12-06 21:33:19 -05:00
can ktime: Cleanup ktime_set() usage 2016-12-25 17:21:22 +01:00
ceph libceph: remove now unused finish_request() wrapper 2016-12-14 22:39:08 +01:00
core secure_seq: fix sparse errors 2017-01-12 15:57:10 -05:00
dcb net: dcb: set error code on failures 2016-12-03 23:54:25 -05:00
dccp Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2016-12-03 12:29:53 -05:00
decnet Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
dns_resolver
dsa Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2017-01-11 14:43:39 -05:00
ethernet net: make default TX queue length a defined constant 2016-11-07 20:15:55 -05:00
hsr Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2016-10-30 12:42:58 -04:00
ieee802154 Makefile: drop -D__CHECK_ENDIAN__ from cflags 2016-12-16 00:13:43 +02:00
ipv4 tcp: check undo conditions before detecting losses 2017-01-13 22:37:16 -05:00
ipv6 tcp: add reordering timer in RACK loss detection 2017-01-13 22:37:16 -05:00
ipx ktime: Get rid of the union 2016-12-25 17:21:22 +01:00
irda Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
iucv net/af_iucv: don't use paged skbs for TX on HiperSockets 2017-01-10 21:08:29 -05:00
kcm Merge branch 'work.splice_read' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-10-07 15:36:58 -07:00
key netns: make struct pernet_operations::id unsigned int 2016-11-18 10:59:15 -05:00
l2tp net: make ndo_get_stats64 a void function 2017-01-08 17:51:44 -05:00
l3mdev
lapb Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
llc net: fix sleeping for sk_wait_event() 2016-11-14 13:17:21 -05:00
mac80211 net: make ndo_get_stats64 a void function 2017-01-08 17:51:44 -05:00
mac802154 ktime: Cleanup ktime_set() usage 2016-12-25 17:21:22 +01:00
mpls Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2016-12-06 21:33:19 -05:00
ncsi net/ncsi: Improve HNCDSC AEN handler 2016-10-20 11:23:08 -04:00
netfilter Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf 2017-01-05 11:49:57 -05:00
netlabel netlabel: add CALIPSO to the list of built-in protocols 2017-01-06 22:20:45 -05:00
netlink Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
netrom
nfc genetlink: mark families as __ro_after_init 2016-10-27 16:16:09 -04:00
openvswitch net: make ndo_get_stats64 a void function 2017-01-08 17:51:44 -05:00
packet packet: pdiag_put_ring() should return TX_RING info for TPACKET_V3 2017-01-10 21:02:42 -05:00
phonet netns: make struct pernet_operations::id unsigned int 2016-11-18 10:59:15 -05:00
qrtr net: qrtr: Mark 'buf' as little endian 2017-01-10 20:45:04 -05:00
rds RDS: validate the requested traces user input against max supported 2017-01-06 22:14:26 -05:00
rfkill
rose Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
rxrpc rxrpc: Allow listen(sock, 0) to be used to disable listening 2017-01-09 11:10:02 +00:00
sched net/sched: cls_flower: Support matching on ARP 2017-01-11 11:02:47 -05:00
sctp Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2017-01-11 14:43:39 -05:00
smc smc: ETH_ALEN as memcpy length for mac addresses 2017-01-12 09:47:01 -05:00
strparser strparser: Propagate correct error code in strp_recv() 2016-10-12 01:51:49 -04:00
sunrpc ktime: Get rid of the union 2016-12-25 17:21:22 +01:00
switchdev Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2016-10-30 12:42:58 -04:00
tipc tipc: reduce risk of user starvation during link congestion 2017-01-03 11:13:05 -05:00
unix Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
vmw_vsock Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2016-12-17 20:17:04 -08:00
wimax genetlink: mark families as __ro_after_init 2016-10-27 16:16:09 -04:00
wireless nl80211: fix sched scan netlink socket owner destruction 2017-01-05 10:59:53 +01:00
x25 Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
xfrm ktime: Cleanup ktime_set() usage 2016-12-25 17:21:22 +01:00
compat.c net: Assert at build time the assumptions we make about the CMSG header. 2017-01-04 13:24:19 -05:00
Kconfig Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2017-01-11 14:43:39 -05:00
Makefile smc: establish new socket family 2017-01-09 16:07:38 -05:00
socket.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2017-01-11 14:43:39 -05:00
sysctl_net.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 2016-10-06 09:52:23 -07:00