linux-fsdevel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: "H. Peter Anvin" <hpa@zytor.com>
To: linux-fsdevel@vger.kernel.org
Subject: Re: clean unmount?
Date: 12 Mar 2003 20:40:38 -0800	[thread overview]
Message-ID: <b4p246$6j8$1@cesium.transmeta.com> (raw)
In-Reply-To: 20030310234800.GA4357@win.tue.nl

Followup to:  <20030310234800.GA4357@win.tue.nl>
By author:    Andries Brouwer <aebr@win.tue.nl>
In newsgroup: linux.dev.fs.devel
> 
> My docs say "high-order" instead of "low-order".
> Are there people with a Windows system so that they can check?
> 
> Andries
> 
> http://www.win.tue.nl/~aeb/linux/fs/fat/fat-1.html#ss1.3.1
> 

The FAT spec claims it's the high bits, which makes sense because
0x..FF8 and 0x..FFF are all technically valid EOCs (in fact, Linux for
a long time wrote 0x...FF8 instead of the correct 0x...FFF):

For FAT16 and FAT32, the file system driver may use the high two bits
of the FAT[1] entry for dirty volume flags (all other bits, are always
left set to 1). Note that the bit location is different for FAT16 and
FAT32, because they are the high 2 bits of the entry. For FAT16:
ClnShutBitMask = 0x8000; HrdErrBitMask = 0x4000; For FAT32:
ClnShutBitMask = 0x08000000; HrdErrBitMask = 0x04000000; Bit
ClnShutBitMask   If bit is 1, volume is  clean . If bit is 0, volume
is  dirty . This indicates that the file system driver did not
Dismount the volume properly the last time it had the volume
mounted. It would be a good idea to run a Chkdsk/Scandisk disk repair
utility on it, because it may be damaged. Bit HrdErrBitMask   If this
bit is 1, no disk read/write errors were encountered. If this bit is
0, the file system driver encountered a disk I/O error on the Volume
the last time it was mounted, which is an indicator that some sectors
may have gone bad on the volume. It would be a good idea to run a
Chkdsk/Scandisk disk repair utility that does surface analysis on it
to look for new bad sectors.
-- 
<hpa@transmeta.com> at work, <hpa@zytor.com> in private!
"Unix gives you enough rope to shoot yourself in the foot."
Architectures needed: ia64 m68k mips64 ppc ppc64 s390 s390x sh v850 x86-64

  reply	other threads:[~2003-03-13  4:40 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2003-03-07  5:26 clean unmount? anil  vijarnia
2003-03-10 23:12 ` Bryan Henderson
2003-03-10 23:23   ` Matthew Wilcox
2003-03-10 23:48     ` Andries Brouwer
2003-03-13  4:40       ` H. Peter Anvin [this message]
  -- strict thread matches above, loose matches on Subject: below --
2003-03-07  5:24 anil  vijarnia

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to='b4p246$6j8$1@cesium.transmeta.com' \
    --to=hpa@zytor.com \
    --cc=linux-fsdevel@vger.kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).