From: Karel Zak <kzak@redhat.com>
To: "Pali Rohár" <pali.rohar@gmail.com>
Cc: "Andreas Bombe" <aeb@debian.org>,
util-linux@vger.kernel.org, linux-kernel@vger.kernel.org,
"Andrius Štikonas" <andrius@stikonas.eu>,
"Curtis Gedak" <gedakc@gmail.com>,
"Andy Shevchenko" <andy.shevchenko@gmail.com>,
"Pavel Machek" <pavel@ucw.cz>
Subject: Re: Linux & FAT32 label
Date: Mon, 20 Nov 2017 12:12:56 +0100 [thread overview]
Message-ID: <20171120111256.zqvmpzdcf6ncyi5m@ws.net.home> (raw)
In-Reply-To: <20171119124440.ffxx64zjmwedmtdp@pali>
On Sun, Nov 19, 2017 at 01:44:40PM +0100, Pali Rohár wrote:
> On Thursday 09 November 2017 22:21:31 Pali Rohár 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?
>
> Also for other people, do any have comments on my proposed solution?
Go ahead and send patch :-) (also with LABEL_FATBOOT=)
Karel
--
Karel Zak <kzak@redhat.com>
http://karelzak.blogspot.com
next prev parent reply other threads:[~2017-11-20 11:13 UTC|newest]
Thread overview: 49+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-10-04 15:33 Linux & FAT32 label Pali Rohár
2017-10-11 21:24 ` Pali Rohár
2017-10-11 21:29 ` Pali Rohár
2017-10-11 21:44 ` Pali Rohár
2017-10-12 8:56 ` Karel Zak
2017-10-12 9:21 ` Pali Rohár
2017-10-12 10:13 ` Karel Zak
2017-10-12 20:49 ` Pali Rohár
2017-10-16 1:12 ` Andreas Bombe
2017-10-16 7:28 ` Pali Rohár
2017-10-30 15:29 ` Pali Rohár
2017-10-31 8:35 ` Andy Shevchenko
2017-11-05 13:39 ` Pali Rohár
2017-11-05 13:56 ` Andy Shevchenko
2017-11-05 14:07 ` Pali Rohár
2017-11-05 14:25 ` Andy Shevchenko
2017-11-05 14:34 ` Pali Rohár
2017-11-05 14:51 ` Andy Shevchenko
2017-11-05 14:56 ` Pali Rohár
2017-11-06 10:14 ` Karel Zak
2017-11-09 8:59 ` Pali Rohár
2017-11-09 11:02 ` Karel Zak
2017-11-05 20:35 ` Theodore Ts'o
2017-11-05 21:12 ` Pali Rohár
2017-11-07 17:28 ` Theodore Ts'o
2017-11-09 9:01 ` Pali Rohár
2017-11-09 16:21 ` Theodore Ts'o
2017-11-09 17:33 ` Pali Rohár
2017-11-05 14:12 ` Andrius Štikonas
2017-10-15 6:59 ` Pavel Machek
2017-10-15 22:04 ` Pali Rohár
2017-10-16 1:12 ` Andreas Bombe
2017-11-05 13:06 ` Pali Rohár
2017-11-09 21:21 ` Pali Rohár
2017-11-19 12:44 ` Pali Rohár
2017-11-20 11:12 ` Karel Zak [this message]
2017-11-22 8:52 ` Pali Rohár
2017-11-22 11:03 ` Karel Zak
2017-11-22 14:29 ` Andrius Štikonas
2017-11-23 9:01 ` Pali Rohár
2017-11-26 19:19 ` Pali Rohár
2017-11-27 12:13 ` Karel Zak
2018-02-14 21:52 ` Pali Rohár
2018-02-14 21:54 ` Pali Rohár
2018-02-15 10:21 ` Karel Zak
2018-03-07 8:28 ` Pali Rohár
2017-11-29 23:21 ` Pali Rohár
2018-01-29 16:49 ` Pali Rohár
2017-12-16 22:45 ` Pali Rohár
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