public inbox for linux-xfs@vger.kernel.org
 help / color / mirror / Atom feed
From: David Chinner <dgc@sgi.com>
To: Sandy1 <sundeep.saini@rediffmail.com>
Cc: linux-xfs@oss.sgi.com
Subject: Re: Wrong Data Pointer-XFS File system
Date: Tue, 26 Jun 2007 09:28:17 +1000	[thread overview]
Message-ID: <20070625232817.GC31489@sgi.com> (raw)
In-Reply-To: <11246839.post@talk.nabble.com>

On Thu, Jun 21, 2007 at 11:23:35PM -0700, Sandy1 wrote:
> 
> Hi,
> I am Using SuSe 10.0 with Xfs file system. I am working on a File system
> based project. During the initial research in On disk layout of File system
> , i found data pointer problem. I was not able to get the data location as
> per pointed by "absolute block no." in "xfs_bmbt_rec" extent pointers.

The xfs_bmbt_rec holds the address in FSB format, not DADDR format.

> When i create any file in 0th (zero`th) AG in that case i am able to reach
> on proper location by using "absolute block no." pointer.
> 
> But when i create any file in 1st or in 2nd AG and so on. I never got the
> file data at the location pointed by "absolute block no.". I always found
> the file data before the the pointed address.

FSB notation is sparse representation.

> I am not getting any value in Superblock that tells me about difference in
> pointer location with actual data.
> 
> This value always becomes multiple of the AG number.
> 
> Please help to get out from this problem.
> 
> Is there any other calculation for finding the data locations.

man xfs_db. Search for "convert".

Cheers,

Dave.
-- 
Dave Chinner
Principal Engineer
SGI Australian Software Group

  reply	other threads:[~2007-06-25 23:28 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-06-22  6:23 Wrong Data Pointer-XFS File system Sandy1
2007-06-25 23:28 ` David Chinner [this message]
2007-06-26 14:10   ` Sandy1

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=20070625232817.GC31489@sgi.com \
    --to=dgc@sgi.com \
    --cc=linux-xfs@oss.sgi.com \
    --cc=sundeep.saini@rediffmail.com \
    /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