Re: [PATCH 3/6] vfs: support FS_XFLAG_REFLINK and FS_XFLAG_COWEXTSIZE

["Darrick J. Wong" <darrick.wong@xxxxxxxxxx>]

On Sun, Sep 11, 2016 at 05:58:08AM -0700, Christoph Hellwig wrote:
> On Tue, Sep 06, 2016 at 12:15:15PM -0700, Darrick J. Wong wrote:
> > So far I've put the reflink flag to use in xfs_scrub to look for
> > obvious signs of brokenness such as extents that overlap or have the
> > shared flag set but the inode flag is off; and to skip various kinds
> > of checks that don't have to happen when blocks don't overlap.
> > 
> > I doubt there's much of a use for the flag outside of the XFS utilities.
> > For a while I pondered only exposing the fsxattr flag if the caller had
> > CAP_SYS_ADMIN (the level of priviledge required to run scrub) but
> > decided that I wouldn't change the existing interface like that unless
> > I had a really good reason.
> 
> I don't think CAP_SYS_ADMIN is nessecarily the right thing, but it's
> still an XFS implementation detail which I don't think we should
> pollute a flags API for normal user space applications with.

I can work around it in xfs_scrub, so I'll give back the xflag bit for
reflink.

--D