Re: Question related to XFS sync , especially fsync

[David Chinner <dgc@sgi.com>]

On Mon, Jan 14, 2008 at 05:44:22PM +0530, Gopala Krishna wrote:
> Hi,
> I am seeing some strange problem with XFS and would like to know  the
> expected behavior and if it is faulty is there any patches to resolve the
> problem.
> 
> Problem:
> ======
> Basically I am extracting metadata information for a given file by reading
> the inode structure from the particular disk offset (based on it's  position
> calculated by published inode structure and super block structure
>  information). Before reading the metada data information from the disk, I
> am calling fsync (I used to call sync, but later I changed to fsync, since
> sync is not guranteed to flush all meta data)  to ensure all metadata
> related to file is flushed to disk. Later I am reading particular disk
> offset as per calculation.   I am getting XFS magic field properly after
> mapping to XFs inode structure. However I am not getting dimode properly in
> some cases (not all cases) and it shows 00000 even for regular file and
> directory.

How are you finding and reading the inode off disk?

Cheers,

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