This is the mail archive of the
cygwin-developers
mailing list for the Cygwin project.
Re: New mount option "bind"
On Aug 11 09:52, Christopher Faylor wrote:
> On Wed, Aug 11, 2010 at 01:36:59PM +0200, Corinna Vinschen wrote:
> >Hi guys,
> >
> >I added a new mount option "bind" which I took from Linux. It allows to
> >remount an existing POSIX directory into another POSIX directory. So
> >the path on the left side of the fstab line can be a POSIX path as well.
> >At Cygwin startup, when its added to the mount table, it's converted to
> >a Win32 path using the already existing entries in the mount table to
> >evaluate the path. So, the path is either relative to a path which
> >preceeds the "bind" path in /etc/fstab, or it's eventually relative to
> >the root dir.
> >
> >The motivation for this was that this allows to specify mount points
> >while retaining relocatability of the Cygwin install tree. So, even if
> >you don't know in which path the Cygwin installation has been installed,
> >you can do stuff like this now:
> >
> > $ cat /etc/fstab
> > /var /usr/var none bind
> >
> > $ mount
> > C:/cygwin/bin on /usr/bin type ntfs (binary,auto)
> > C:/cygwin/lib on /usr/lib type ntfs (binary,auto)
> > C:/cygwin/var on /usr/var type ntfs (binary,bind) <<<<<<<<<<
> > C:/cygwin on / type ntfs (binary,auto)
> > C: on /cygdrive/c type ntfs (binary,posix=0,user,noumount,auto)
> >
> >I also updated the docs to describe this new option. If you find a
> >problem with this option, or if the documentation is not good enough,
> >please feel free to send patches.
>
> If the mount for /var changes then is that reflected by /usr/var? I
> believe that's how it works for linux.
No, that doesn't work in Cygwin. The path is converted to a Win32 path
as soon as it's read from the fstab file or when you call `mount -o bind ...'
Our mount table does not allow to keep the POSIX->POSIX mapping right
now, but we could add that at some point. OTOH, I think this scenario
is really seldom. Usually you have the bind entries in fstab and that
doesn't change a lot on the fly.
Corinna
--
Corinna Vinschen Please, send mails regarding Cygwin to
Cygwin Project Co-Leader cygwin AT cygwin DOT com
Red Hat