staging: lustre: lnet: Stop Infinite CON RACE Condition

staging: lustre: lnet: Stop Infinite CON RACE Condition

In current code, when a CON RACE occurs, the passive side will
let the node with the higher NID value win the race.

We have a field case where a node can have a "stuck"
connection which never goes away and is the trigger of a
never-ending loop of re-connections.

This patch introduces a counter to how many times a
connection in a connecting state has been the cause of a CON RACE
rejection. After 20 times (constant MAX_CONN_RACES_BEFORE_ABORT),
we assume the connection is stuck and let the other side (with
lower NID) win.

Signed-off-by: Doug Oucharek <doug.s.oucharek@intel.com>
Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-7646
Reviewed-on: http://review.whamcloud.com/19430
Reviewed-by: Amir Shehata <amir.shehata@intel.com>
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>
Signed-off-by: James Simmons <jsimmons@infradead.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>