Messages in this thread |  | | Date | Sun, 06 Jan 2013 20:59:39 -0800 (PST) | Subject | Re: [PATCH] tcp: fix MSG_SENDPAGE_NOTLAST logic | From | David Miller <> |
| |
From: Eric Dumazet <eric.dumazet@gmail.com> Date: Sun, 06 Jan 2013 20:21:49 -0800
> From: Eric Dumazet <edumazet@google.com> > > commit 35f9c09fe9c72e (tcp: tcp_sendpages() should call tcp_push() once) > added an internal flag : MSG_SENDPAGE_NOTLAST meant to be set on all > frags but the last one for a splice() call. > > The condition used to set the flag in pipe_to_sendpage() relied on > splice() user passing the exact number of bytes present in the pipe, > or a smaller one. > > But some programs pass an arbitrary high value, and the test fails. > > The effect of this bug is a lack of tcp_push() at the end of a > splice(pipe -> socket) call, and possibly very slow or erratic TCP > sessions. > > We should both test sd->total_len and fact that another fragment > is in the pipe (pipe->nrbufs > 1) > > Many thanks to Willy for providing very clear bug report, bisection > and test programs. > > Reported-by: Willy Tarreau <w@1wt.eu> > Bisected-by: Willy Tarreau <w@1wt.eu> > Tested-by: Willy Tarreau <w@1wt.eu> > Signed-off-by: Eric Dumazet <edumazet@google.com>
Applied and queued up for -stable, thanks everyone.
|  |