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tcp: tcp_sendpages() should call tcp_push() once

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commit 2f53384424 (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>
This commit is contained in:
Eric Dumazet
2012-04-05 03:05:35 +00:00
committed by David S. Miller
parent 78d50217ba
commit 35f9c09fe9
4 changed files with 9 additions and 6 deletions
Download Patch File Download Diff File Expand all files Collapse all files

6
net/socket.c
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@@ -811,9 +811,9 @@ static ssize_t sock_sendpage(struct file *file, struct page *page,
sock = file->private_data;
flags = !(file->f_flags & O_NONBLOCK) ? 0 : MSG_DONTWAIT;
if (more)
flags |= MSG_MORE;
flags = (file->f_flags & O_NONBLOCK) ? MSG_DONTWAIT : 0;
/* more is a combination of MSG_MORE and MSG_SENDPAGE_NOTLAST */
flags |= more;
return kernel_sendpage(sock, page, offset, size, flags);
}