nfsd: wake blocked file lock waiters before sending callback
When a blocked NFS lock is "awoken" we send a callback to the server and
then wake any hosts waiting on it. If a client attempts to get a lock
and then drops off the net, we could end up waiting for a long time
until we end up waking locks blocked on that request.
So, wake any other waiting lock requests before sending the callback.
Do this by calling locks_delete_block in a new "prepare" phase for
CB_NOTIFY_LOCK callbacks.
URL: https://bugzilla.kernel.org/show_bug.cgi?id=203363
Fixes: 16306a61d3b7 ("fs/locks: always delete_block after waiting.")
Reported-by: Slawomir Pryczek <slawek1211 at gmail.com>
Cc: Neil Brown <neilb at suse.com>
Cc: stable at vger.kernel.org
Signed-off-by: Jeff Layton <jlayton at kernel.org>
Signed-off-by: J. Bruce Fields <bfields at redhat.com>
UnifiedSplitRaw
