Re: [PATCH 13/17] xfs: test swapext with reflink

Re: [PATCH 13/17] xfs: test swapext with reflink

[Darrick J. Wong]

On Tue, Aug 09, 2016 at 04:29:43PM +1000, Dave Chinner wrote:
> On Mon, Aug 08, 2016 at 10:41:32AM -0700, Darrick J. Wong wrote:
> > On Mon, Aug 08, 2016 at 04:13:59PM +0800, Eryu Guan wrote:
> > > On Thu, Jul 21, 2016 at 04:47:38PM -0700, Darrick J. Wong wrote:
> > > > Add a few tests to stress the new swapext code for reflink and rmap.
> > > > +_reflink_range "$testdir/file1" 0 "$testdir/file2" 0 $bytes >> "$seqres.full"
> > > > +
> > > > +echo "Defrag the big file"
> > > > +old_nextents=$(xfs_io -c 'stat -v' $testdir/file1 | grep 'nextents' | cut -d ' ' -f 3)
> > > 
> > > There's a "_count_extents" helper, does that work for this case?
> > 
> > It can, though stat -v reports GETFSXATTR results, which should be faster than
> > _count_extents because the latter FIEMAPs the entire file and counts lines.
> > Seeing as XFS records the extent count in the inode, we might as well use it.
> 
> perhaps put a special xfs case in _count_extents() that does this
> rather than FIEMAP?

Ok.  Seems simple enough to do.

--D

> 
> Cheers,
> 
> Dave.
> -- 
> Dave Chinner
> david@fromorbit.com