SUNRPC: ensure correct error is reported by xs_tcp_setup_socket()
authorNeilBrown <neilb@suse.com>
Thu, 25 May 2017 07:00:32 +0000 (17:00 +1000)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Fri, 13 Apr 2018 17:48:14 +0000 (19:48 +0200)
commit67eed62b4dd22d388dbc55ec9b5e0077f67305de
tree3f0124c0b8fe94c883019ed48b41472e6cf0e861
parentd5cbc16656aee364a80af20a476d23bd11301225
SUNRPC: ensure correct error is reported by xs_tcp_setup_socket()

[ Upstream commit 6ea44adce91526700535b3150f77f8639ae8c82d ]

If you attempt a TCP mount from an host that is unreachable in a way
that triggers an immediate error from kernel_connect(), that error
does not propagate up, instead EAGAIN is reported.

This results in call_connect_status receiving the wrong error.

A case that it easy to demonstrate is to attempt to mount from an
address that results in ENETUNREACH, but first deleting any default
route.
Without this patch, the mount.nfs process is persistently runnable
and is hard to kill.  With this patch it exits as it should.

The problem is caused by the fact that xs_tcp_force_close() eventually
calls
      xprt_wake_pending_tasks(xprt, -EAGAIN);
which causes an error return of -EAGAIN.  so when xs_tcp_setup_sock()
calls
      xprt_wake_pending_tasks(xprt, status);
the status is ignored.

Fixes: 4efdd92c9211 ("SUNRPC: Remove TCP client connection reset hack")
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
net/sunrpc/xprtsock.c