diff options
| author | Eric Dumazet <edumazet@google.com> | 2013-01-06 18:21:49 +0000 |
|---|---|---|
| committer | Paul Gortmaker <paul.gortmaker@windriver.com> | 2014-02-10 16:10:52 -0500 |
| commit | fb883a89a99481dca7cd6b9ef942c35165ff2d54 (patch) | |
| tree | 973a2dc112ee165ee1d43e99ce3b679ef2effc88 /fs | |
| parent | 9e1847c09be4a53358f5b5188cafe8b395a774cc (diff) | |
tcp: fix MSG_SENDPAGE_NOTLAST logic
commit ae62ca7b03217be5e74759dc6d7698c95df498b3 upstream.
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>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/splice.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/fs/splice.c b/fs/splice.c index 3bec7c63be64..1c991d6a64b4 100644 --- a/fs/splice.c +++ b/fs/splice.c @@ -640,8 +640,10 @@ static int pipe_to_sendpage(struct pipe_inode_info *pipe, ret = buf->ops->confirm(pipe, buf); if (!ret) { more = (sd->flags & SPLICE_F_MORE) ? MSG_MORE : 0; - if (sd->len < sd->total_len) + + if (sd->len < sd->total_len && pipe->nrbufs > 1) more |= MSG_SENDPAGE_NOTLAST; + if (file->f_op && file->f_op->sendpage) ret = file->f_op->sendpage(file, buf->page, buf->offset, sd->len, &pos, more); |