Re: cp -a refuses to devolve file mode

[Kamil Dudka]

On Tuesday 03 February 2009 19:03:33 Elmar Stellnberger wrote:
> cp -a refuses to devolve the file mode when I copy a certain file
> between two ext3 volumes
>
> whereas it does not report any error:
> > cat syncit
>
> cp -a /home/./downloads/system/freebsd/bootstrap/etch/debootstrap
> /mnt/home-mirror/home/./downloads/system/freebsd/bootstrap/etch/debootstrap
> echo $?
> for i in /home /mnt/home-mirror/home; do ls -l
> "$i/./downloads/system/freebsd/bootstrap/etch/debootstrap"; done
>
> >./syncit
>
> 0
> lrwxr-xr-x 1 root users 34 Jan 21 04:56
> /home/./downloads/system/freebsd/bootstrap/etch/debootstrap ->
> /compat/linux/usr/sbin/debootstrap
> lrwxrwxrwx 1 root users 34 Feb  3 17:06
> /mnt/home-mirror/home/./downloads/system/freebsd/bootstrap/etch/debootstrap
> -> /compat/linux/usr/sbin/debootstrap
>
> The file mode should be the same since cp has just successfully copied
> that file.
> I could not reproduce this behaviour in an artificial test setting.
> Please answer me as soon as possible to issue further tests
> since I do not know for how long this anomaly will hold.
See chmod(1) man page:
  chmod never changes the permissions of symbolic links; the chmod system call
  cannot change their permissions. This is not a problem since the permissions
  of symbolic links are never used.

I know you are using cp, but I think this is related to cp as well.


Kamil