Syslinux - May 2014 - NTFS problems

So there seem to be some shortcomings in NTFS, still.

1. Symlinks are not supported.  Proper symlinks exist in NTFS since
   Vista, so we should support them.

2. readdir() seems to be broken.

I have been using the following test load to generate disk images:

http://www.zytor.com/~hpa/syslinux/exttest-20140521.tar.xz

Anyone who has been involved with the NTFS code who has a chance to take
a look?

Thanks to Ady2 for helping spotting the problems.

	-hpa

On Tue, May 27, 2014 at 11:20 PM, H. Peter Anvin <hpa at zytor.com>
wrote:
> So there seem to be some shortcomings in NTFS, still.
>
> 1. Symlinks are not supported.  Proper symlinks exist in NTFS since
>    Vista, so we should support them.
>
> 2. readdir() seems to be broken.
>
> I have been using the following test load to generate disk images:
>
> http://www.zytor.com/~hpa/syslinux/exttest-20140521.tar.xz
>
> Anyone who has been involved with the NTFS code who has a chance to take
> a look?
Pcacjr, here you go :-)
>
> Thanks to Ady2 for helping spotting the problems.
>
>         -hpa
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-- 
Raphael S. Carvalho

> So there seem to be some shortcomings in NTFS, still.
> 
> 1. Symlinks are not supported.  Proper symlinks exist in NTFS since
>    Vista, so we should support them.
 
FWIW, Windows itself doesn't support symlinks for booting in NTFS. 
Prior to Vista, symlinks are not supported by default (a driver is 
needed).

Moreover, under Windows, expanding an archive containing symlinks, 
most frequently won't restore the symlink attribute. For instance, 
expanding an official "syslinux-version.tar.xz" archive under Windows 
on NTFS, most frequently will have both, "./libinstaller/advconst.h" 
and "./com32/include/syslinux/advconst.h", as independent, not 
symlinked files; therefore compiling in these circumstances will 
probably fail.

Considering the aforementioned situations, IMHO supporting symlinks 
for NTFS in Syslinux deserves a low priority. Just tell users to 
avoid symlinks in NTFS when regards to booting.
 
> 
> 2. readdir() seems to be broken.
 
The behavior can be seen by:
1_ Install EXTLINUX 6.03-pre12 or newer on NTFS;
2_ Copy *.c32;
3_ Boot this NTFS partition;
4_ In the Syslinux "boot:" prompt, execute ls.c32.

This, IMHO, is indeed a matter of importance to correctly support 
NTFS in Syslinux.
 
As a remainder, Syslinux on NTFS is currently supporting a cluster 
size up to 4096 bytes (included). Currently Syslinux will fail to 
boot NTFS volumes with allocation units higher than 4KiB.

Hopefully Paulo can take a look promptly.

TIA,
Ady.