NLM: Fix arguments to NLM_CANCEL call

 The OpenGroup docs state that the arguments "block", "exclusive" and
 "alock" must exactly match the arguments for the lock call that we are
 trying to cancel.
 Currently, "block" is always set to false, which is wrong.

 See bug# 5956 on bugzilla.kernel.org.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

fs/lockd/clntproc.c

@@ -28,6 +28,7 @@ static int	nlmclnt_lock(struct nlm_rqst *, struct file_lock *);
 static int	nlmclnt_unlock(struct nlm_rqst *, struct file_lock *);
 static int	nlm_stat_to_errno(u32 stat);
 static void	nlmclnt_locks_init_private(struct file_lock *fl, struct nlm_host *host);
+static int	nlmclnt_cancel(struct nlm_host *, int , struct file_lock *);
 
 static const struct rpc_call_ops nlmclnt_unlock_ops;
 static const struct rpc_call_ops nlmclnt_cancel_ops;
@@ -598,7 +599,7 @@ nlmclnt_lock(struct nlm_rqst *req, struct file_lock *fl)
 	nlmclnt_finish_block(req);
 	/* Cancel the blocked request if it is still pending */
 	if (resp->status == NLM_LCK_BLOCKED)
-		nlmclnt_cancel(host, fl);
+		nlmclnt_cancel(host, req->a_args.block, fl);
 out:
 	nlmclnt_release_lockargs(req);
 	return status;
@@ -728,8 +729,7 @@ static const struct rpc_call_ops nlmclnt_unlock_ops = {
  * We always use an async RPC call for this in order not to hang a
  * process that has been Ctrl-C'ed.
  */
-int
-nlmclnt_cancel(struct nlm_host *host, struct file_lock *fl)
+static int nlmclnt_cancel(struct nlm_host *host, int block, struct file_lock *fl)
 {
 	struct nlm_rqst	*req;
 	unsigned long	flags;
@@ -750,6 +750,7 @@ nlmclnt_cancel(struct nlm_host *host, struct file_lock *fl)
 	req->a_flags = RPC_TASK_ASYNC;
 
 	nlmclnt_setlockargs(req, fl);
+	req->a_args.block = block;
 
 	status = nlmclnt_async_call(req, NLMPROC_CANCEL, &nlmclnt_cancel_ops);
 	if (status < 0) {

include/linux/lockd/lockd.h

@@ -148,7 +148,6 @@ struct nlm_rqst * nlmclnt_alloc_call(void);
 int		  nlmclnt_prepare_block(struct nlm_rqst *req, struct nlm_host *host, struct file_lock *fl);
 void		  nlmclnt_finish_block(struct nlm_rqst *req);
 long		  nlmclnt_block(struct nlm_rqst *req, long timeout);
-int		  nlmclnt_cancel(struct nlm_host *, struct file_lock *);
 u32		  nlmclnt_grant(struct nlm_lock *);
 void		  nlmclnt_recovery(struct nlm_host *, u32);
 int		  nlmclnt_reclaim(struct nlm_host *, struct file_lock *);