Re: Rock Ridge features in grub-mkrescue

[Thomas Schmitt]

Hi,

the only workaround i see is a xorriso wrapper script which manipulates
the xorriso arguments.

E.g. by adding a new case to the sed runs at

  
http://libburnia-project.org/browser/libisoburn/trunk/frontend/grub-mkrescue-sed.sh#L171


Free Software Supporter wrote:
> Currently, however, when the grub-mkrescue program is invoked with a
> -R flag, the richer ownership and permission information that the user
> presumably expects is suppressed from the ISO image.

On the first glimpse this looks like a xorriso bug.
But regrettably it is a feature of mkisofs and genisoimage.
I tried:

  genisoimage -r -R -o test.iso ./my_dir
  mount -o loop test.iso /mnt/iso
  ls -l /mnt/iso

Even more regrettably i missed the opportunity to let non-mkisofs
option --norock disable the -r attribute mangling for the next
-R option to follow.

And even worse, the option -r is implemented by a -find run on
the composed ISO directory tree when the mkisofs emulation ends.
So there is no chance to easily revoke the changes of ownership
and permissions by generic xorriso commands.
It must be avoided or revoked inside the emulation mode.


> Proposed Fix:
> If the -R flag is present among the invocation
> arguments for grub-mkrescue, then the -r flag is not automatically
> added to its invocation of the xorriso program.

The logic in this proposal is correct.

Nevertheless, i would prefer if grub-mkrescue would not think too much
about the user provided xorriso arguments.

So how about a dedicated grub-mkrescue argument

  --no-xorrisofs-r

It would omit xorriso -as mkisofs option -r and leave it to the user
whether to add -r or --norock. (Option -R is enabled by default, as
i deem an ISO without Rock Ridge severly crippled.)


Option --norock is available since xorriso-1.2.4 of july 2012.
I never promised that it would uphold the -r mangling.
Now i ponder whether i shall consider it a bug that it does not
reset the special effect of -r.


Have a nice day :)

Thomas