From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: with ECARTIS (v1.0.0; list xfs); Mon, 25 Jun 2007 16:28:32 -0700 (PDT) Received: from larry.melbourne.sgi.com (larry.melbourne.sgi.com [134.14.52.130]) by oss.sgi.com (8.12.10/8.12.10/SuSE Linux 0.7) with SMTP id l5PNSPtL004343 for ; Mon, 25 Jun 2007 16:28:27 -0700 Date: Tue, 26 Jun 2007 09:28:17 +1000 From: David Chinner Subject: Re: Wrong Data Pointer-XFS File system Message-ID: <20070625232817.GC31489@sgi.com> References: <11246839.post@talk.nabble.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <11246839.post@talk.nabble.com> Sender: xfs-bounce@oss.sgi.com Errors-to: xfs-bounce@oss.sgi.com List-Id: xfs To: Sandy1 Cc: linux-xfs@oss.sgi.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