mount system call for nullfs

[Theron Tarigo]

On 04/12/18 21:30, Alfonso Sabato Siciliano wrote:
> Hello,
>
> I would use "mount" system call
>
>   int mount(const char *type, const char *dir, int flags, void *data);
>
> to mount a nullfs, the problem is about *data;
>
> Where can I find docs? Example? Code?
Hi Alfonso,

The MOUNT(2) manual says:

      The data argument is a pointer to a structure that contains the type
      specific arguments to mount.  The format for these argument 
structures is
      described in the manual page for each file system.  By convention file
      system manual pages are named by prefixing ``mount_'' to the name 
of the
      file system as returned by lsvfs(1).  Thus the NFS file system is
      described by the mount_nfs(8) manual page.  It should be noted that a
      manual page for default file systems, known as UFS and UFS2, does not
      exist.

Try looking at /usr/src/sbin/mount_nullfs/ for example.

Cheers,
Theron