Re: shutdown()'s 'how' parameter doesn't seem to be used correctly

On Wed, 2014-02-26 at 15:18 +0000, David Laight wrote:

AFAICT userspace calls shutdown(sock, how) with 'how' set to one of SHUT_RD (0),
SHUT_WR (1) or SHUT_RDWR(2).

The kernel code typically wants the bitmask of RCV_SHUTDOWN (1) | SEND_SHUTDOWN (2).
If you look at the af_unix.c unix_shutdown() there is a comment where it
add's one in order to do the conversion.

But I can't find the conversion before tcp_shutdown() or sctp_shutdown()
checks for 'how & SEND_SHUTDOWN'.
Which implies that shutdown(sock, SHUT_WR) doesn't work.

What have I missed?
Should I be passing 2 or 3 to a direct call to sock->ops->shutdown()?
(We currently pass 2 - which does outward disconnect anyway).

Take a look at inet_shutdown()