pivot_root()

pivot_root()

[Lai Zit Seng]

Not sure where to post this, forgive me if there is a better place to 
post...

I'm trying to use pivot_root() to change root to a directory that is not 
a mount point, i.e. it is under a mount point of a different device from 
the current root device.

E.g.

# /root is mounted from /dev/sda1
pivot_root("/root/somewhere", "/root/somewhere/initrd");

But pivot_root() returns EINVAL. Both /root/somewhere and 
/root/somewhere/initrd exists.

Any pointers about what might be wrong? Many thanks :)

Regards,

.lzs

Re: pivot_root()

[serue]

Quoting Lai Zit Seng (lzs@pobox.com):
> Not sure where to post this, forgive me if there is a better place to 
> post...
> 
> I'm trying to use pivot_root() to change root to a directory that is not 
> a mount point, i.e. it is under a mount point of a different device from 
> the current root device.
> 
> E.g.
> 
> # /root is mounted from /dev/sda1
> pivot_root("/root/somewhere", "/root/somewhere/initrd");
> 
> But pivot_root() returns EINVAL. Both /root/somewhere and 
> /root/somewhere/initrd exists.
> 
> Any pointers about what might be wrong? Many thanks :)

Try first doing

	mount --bind <newroot> <newroot>

See the comments above fs/namespace.c:sys_pivot_root() for the
explanation.

-serge

Re: pivot_root()

[Lai Zit Seng]

Yes you're right. Thanks!

Regards,

.lzs
http://thinkingfarm.com/~lzs/

On Mon, 16 May 2005 serue@us.ibm.com wrote:
> Try first doing
>
> 	mount --bind <newroot> <newroot>
>
> See the comments above fs/namespace.c:sys_pivot_root() for the
> explanation.
>
> -serge