title: Usage of mount_nodev inside rootfs_mount
body: <p>I am trying to understand how kernel mounting the filesystem. While checking the source, I have observed that <code>do_mounts.c</code> file having the source related to mounting (rootfs file system is registered inside <code>init_rootfs()</code>).</p>
  
  <p><code>rootfs_mount()</code> function was called by <code>start_kernel()</code> initially, I could not able to understand the usage of <code>mount_nodev()</code> inside <code>rootfs_mount()</code>. Could you please help me to understand the logic behind calling <code>rootfs_mount()</code> from <code>start_kernel()</code>, as it is not mounting any filesystem. </p>
  
  <p>Actual filesystem mounting is initiated by calling <code>mount_nfs_root()</code> or <code>mount_block_root()</code> functions from <code>kernel_init()</code>, please tell me if my understanding is different.</p>