Re: Linux & FAT32 label

From: Pali RohÃr
Date: Sat Dec 16 2017 - 17:45:21 EST

On Thursday 09 November 2017 22:21:31 Pali RohÃr wrote:
> So from all tests and discussion I would propose new unification:
> 1. Read label only from the root directory. If label in root directory
> is missing then disk would be treated as without label. Label from
> boot sector would not be read.
> --> Reason: Windows XP and mlabel ignores what is written in boot
> sector. Windows XP even do not update boot sector, so label
> stored in boot sector is incorrect after any change done by
> Windows XP.
> This logic is used by all tested MS-DOS and Windows versions,
> plus also by mtools on Linux.
> 2. Write label to to both location, boot sector and root directory.
> --> Reason: MS-DOS 6.22, MS-DOS 7.10, Windows 98 and also mtools on
> Linux do this. This is also what is written in FAT specification.
> It also provides backward compatibility with old dosfslabel
> versions which read label only from boot sector.
> 2. Process 'NO NAME ' label in root directory as 'NO NAME' name. Not
> as empty label.
> --> Reason: 'NO NAME ' is regular entry in root directory and both
> Windows XP and mlabel handle it in this way.
> 3. Process 'NO NAME ' label in boot directory as empty label. Not as
> label with name 'NO NAME'.
> --> Reason: On Windows XP when formatting empty disk and label is not
> specified then 'NO NAME ' is stored to boot sector.
> Also in FAT specification is written that empty label is stored
> as 'NO NAME '.
> With this change we would get compatibility with MS-DOS, Windows (both
> DOS-based and NT-based) and also with Linux mtools, modulo problems DOS
> code page.
> There are just two negatives:
> 1) Labels set by old dosfslabel versions (which stored them only to boot
> sector) would not be visible. But they are already not visible on
> MS-DOS or Windows machines, and also via mlabel (from mtools).
> 2) Behavior of blkid and fatlabel would be changed as both tools have
> different as proposed above, and based on tests they also differ each
> from other.
> Andreas, Karel, what do you think about it?

Andreas, any comments? It is OK?

More then month passed... and I would like to move forward.

Pali RohÃr