ocfs2/dlm: return in progress if master can not clear the refmap bit right now

ocfs2/dlm: return in progress if master can not clear the refmap bit right now

Master returns in-progress to non-master node when it can not clear the
refmap bit right now.  And non-master node will not purge the lock
resource until receiving deref done message.

Signed-off-by: xuejiufei <[email protected]>
Cc: Mark Fasheh <[email protected]>
Cc: Joel Becker <[email protected]>
Cc: Junxiao Bi <[email protected]>
Reviewed-by: Joseph Qi <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>