Re: Question related to XFS sync , especially fsync

[Iustin Pop <iusty@xxxxxxxxx>]

On Wed, Jan 16, 2008 at 12:55:17PM +0530, Gopala Krishna wrote:
> If there is a user level system call to deal with the extent information
> etc, we can use , but many file system is not providing that. Basically if
> we give file it should eb in aposition to display metadata informations
> including extents and corresponding logical block numbers and device
> offsets.
> 
> I have to do it programitically and hence if I have some system call rather
> than command, that would be helpful. Freeze/unfreeze is a command it seems
> right?

Well, most commands are backed by a system call, right? For example,
strace xfs_freeze to see what system calls it does. IIRC, only xfs_db
has to access the raw device.

For the block mapping, look at xfs_bmap (and its backend xfs_io), which
should do exactly what you want.

iustin