fs: dlm: make F_SETLK use unkillable wait_event

While a non-waiting posix lock request (F_SETLK) is waiting for
user space processing (in dlm_controld), wait for that processing
to complete with an unkillable wait_event(). This makes F_SETLK
behave the same way for F_RDLCK, F_WRLCK and F_UNLCK. F_SETLKW
continues to use wait_event_killable().

Cc: stable@vger.kernel.org
Signed-off-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>

Author: Alexander Aring

fs/dlm/plock.c

@@ -155,25 +155,29 @@ int dlm_posix_lock(dlm_lockspace_t *lockspace, u64 number, struct file *file,
 
 	send_op(op);
 
-	rv = wait_event_killable(recv_wq, (op->done != 0));
-	if (rv == -ERESTARTSYS) {
-		spin_lock(&ops_lock);
-		/* recheck under ops_lock if we got a done != 0,
-		 * if so this interrupt case should be ignored
-		 */
-		if (op->done != 0) {
+	if (op->info.wait) {
+		rv = wait_event_killable(recv_wq, (op->done != 0));
+		if (rv == -ERESTARTSYS) {
+			spin_lock(&ops_lock);
+			/* recheck under ops_lock if we got a done != 0,
+			 * if so this interrupt case should be ignored
+			 */
+			if (op->done != 0) {
+				spin_unlock(&ops_lock);
+				goto do_lock_wait;
+			}
+			list_del(&op->list);
 			spin_unlock(&ops_lock);
-			goto do_lock_wait;
-		}
-		list_del(&op->list);
-		spin_unlock(&ops_lock);
 
-		log_debug(ls, "%s: wait interrupted %x %llx pid %d",
-			  __func__, ls->ls_global_id,
-			  (unsigned long long)number, op->info.pid);
-		do_unlock_close(&op->info);
-		dlm_release_plock_op(op);
-		goto out;
+			log_debug(ls, "%s: wait interrupted %x %llx pid %d",
+				  __func__, ls->ls_global_id,
+				  (unsigned long long)number, op->info.pid);
+			do_unlock_close(&op->info);
+			dlm_release_plock_op(op);
+			goto out;
+		}
+	} else {
+		wait_event(recv_wq, (op->done != 0));
 	}
 
 do_lock_wait: