--- a/src/os/unix/ngx_files.c
+++ b/src/os/unix/ngx_files.c
@@ -389,7 +389,7 @@ ngx_unlock_fd(ngx_fd_t fd)
 #if (NGX_HAVE_O_DIRECT)
 
 ngx_int_t
-ngx_directio(ngx_fd_t fd)
+ngx_directio_on(ngx_fd_t fd)
 {
     int  flags;
 
@@ -402,4 +402,19 @@ ngx_directio(ngx_fd_t fd)
     return fcntl(fd, F_SETFL, flags | O_DIRECT);
 }
 
+
+ngx_int_t
+ngx_directio_off(ngx_fd_t fd)
+{
+    int  flags;
+
+    flags = fcntl(fd, F_GETFL);
+
+    if (flags == -1) {
+        return -1;
+    }
+
+    return fcntl(fd, F_SETFL, flags & ~O_DIRECT);
+}
+
 #endif