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

[Dave Chinner <david@xxxxxxxxxxxxx>]

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?

Cheers,

Dave.
-- 
Dave Chinner
david@xxxxxxxxxxxxx