Subject: Re: PR #2187 (msdosfs)
To: Trevin Beattie <email@example.com>
From: Dave Huang <firstname.lastname@example.org>
Date: 09/28/1997 12:47:32
On Sun, 28 Sep 1997, Trevin Beattie wrote:
> 12 NT attribute Reserved for use by Windows NT.
> 13 Creation time Milliseconds (thousandths of a second)
> (msec) after the minute the entry was created.
> This field is combined with the previous
> one to provide a higher time resolution.
Combined with the previous one or the next one?
> 14-15 Creation time Time the entry was created. This field is
> accurate to the minute.
> Note: after some experimentation and testing with Norton Disk Doctor, it
> seems the creation time (msec) field is actually (msec % 200), because any
> value >=200 is considered an error.
Hmm... from my experimentation, it's not msec, but 1/100th of a second.
And the creation time field, in bytes 14-15 is the same format as the old
modification time field, i.e. accurate to 2 seconds. If it really was only
accurate to the minute, how would you get millisecond resolution using
just one extra byte? You can't fit 60000 milliseconds into a byte :)
Anyways, as far as I know, 14-15 contain the time accurate to 2 seconds,
and 13 contains the rest of the time, 0 through 199 centiseconds.
> As for point (2), I'm sure there are plenty of people in NetBSD's user base
> who have Windoze 95 and could test the fix on the i386 port, if you can
> provide the testing procedures (or script file). However, we probably
> should also have testers for OS/2 and Windows NT, as well as people using
> other ports besides i386 (using floppies, perhaps?) I don't know how
> common those are.
FWIW, I've been using the patch on both Win95 and NT, and haven't had any
problems at all. And it does get rid of all those "Unrecognized extended
attribute handle" errors from NT's chkdsk.
Am I the only person using NT and NetBSD's msdosfs on the same system?
Since msdosfs currently messes up that "reserved for NT" field each time
you just access a file, it's quite easy to get the unrecognized extended
attribute handle error.
And by the way, Figure 17.7 of the Windows NT Workstation 4.0 Resource Kit
has a (very) brief description of a FAT directory entry.
Even if the full patch isn't commited, I do think that msdosfs should at
least stop messing with the reserved for NT field...
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