tcp: tcp_sendpages() should call tcp_push() once
authorEric Dumazet <eric.dumazet@gmail.com>
Thu, 5 Apr 2012 03:05:35 +0000 (03:05 +0000)
committerVarun Wadekar <vwadekar@nvidia.com>
Wed, 18 Apr 2012 13:20:36 +0000 (18:20 +0530)
commitdb655f53ffd51a3590e68404c93acb44d3a09b5c
tree61a94e3b3d0c697101ae77cd3192ca452169109c
parent39b97bf8d11e326225b7014fd60e572398c450ce
tcp: tcp_sendpages() should call tcp_push() once

commit 2f533844242 (tcp: allow splice() to build full TSO packets) added
a regression for splice() calls using SPLICE_F_MORE.

We need to call tcp_flush() at the end of the last page processed in
tcp_sendpages(), or else transmits can be deferred and future sends
stall.

Add a new internal flag, MSG_SENDPAGE_NOTLAST, acting like MSG_MORE, but
with different semantic.

For all sendpage() providers, its a transparent change. Only
sock_sendpage() and tcp_sendpages() can differentiate the two different
flags provided by pipe_to_sendpage()

Reported-by: Tom Herbert <therbert@google.com>
Cc: Nandita Dukkipati <nanditad@google.com>
Cc: Neal Cardwell <ncardwell@google.com>
Cc: Tom Herbert <therbert@google.com>
Cc: Yuchung Cheng <ycheng@google.com>
Cc: H.K. Jerry Chu <hkchu@google.com>
Cc: Maciej Żenczykowski <maze@google.com>
Cc: Mahesh Bandewar <maheshb@google.com>
Cc: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail>com>
Signed-off-by: David S. Miller <davem@davemloft.net>
fs/splice.c
include/linux/socket.h
net/ipv4/tcp.c
net/socket.c