From: Theodore Tso <tytso@mit.edu>
To: Etienne Lorrain <etienne_lorrain@yahoo.fr>
Cc: Andreas Dilger <adilger@sun.com>, linux-ext4@vger.kernel.org
Subject: Re: on disk format: value of bg_inode_table_hi?
Date: Thu, 29 Jan 2009 00:12:22 -0500 [thread overview]
Message-ID: <20090129051221.GH8990@mit.edu> (raw)
In-Reply-To: <653674.25270.qm@web23601.mail.ird.yahoo.com>
On Wed, Jan 28, 2009 at 08:47:09PM +0000, Etienne Lorrain wrote:
> > De: Andreas Dilger <adilger@sun.com>
> > Date: Mercredi 28 Janvier 2009, 18h01
> > On Jan 28, 2009 00:20 +0000, Etienne Lorrain wrote:
> > > I have created an ext4 fs on a 64 Mb USB disk by
> > > "mkfs.ext4 /dev/sdb" on debian lenny (no partition).
> > > When I analyse the filesystem using my own tools, I
> > > seem to read at least some bg_inode_table_hi values which
> > > are not null, on such a very small filesystem.
bg_inode_table_hi doesn't exist on a small filesystem. You need to
take a look at if INCOMPAT_64BIT is not set, or if INCOMPAT_64BIT is
set and s_desc_size is 32, then only the first 32 bytes of struct
ext4_group_desc are in use --- which look exactly the same as
ext2_group_desc.
So there is no problem here. Just a misunderstanding of the
filesystem format.
- Ted
next prev parent reply other threads:[~2009-01-29 5:12 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-01-28 0:20 on disk format: value of bg_inode_table_hi? Etienne Lorrain
2009-01-28 18:01 ` Andreas Dilger
2009-01-28 20:47 ` Etienne Lorrain
2009-01-29 5:12 ` Theodore Tso [this message]
2009-01-29 11:47 ` Etienne Lorrain
2009-01-30 4:19 ` Theodore Tso
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=20090129051221.GH8990@mit.edu \
--to=tytso@mit.edu \
--cc=adilger@sun.com \
--cc=etienne_lorrain@yahoo.fr \
--cc=linux-ext4@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).