[PATCH v4] xfs: probe data buffer from page cache for unwritten extents

[Christoph Hellwig]

On Sat, Jul 21, 2012 at 02:24:36PM +0800, Jie Liu wrote:
> >Output:
> >
> >HOLE/DATA at 512K 786432 / 528384   <- undiscovered hole here
> >HOLE/DATA at 516K 786432 / 528384   <- okay, data but we should
> >                                        return next page as hole.
> >HOLE/DATA at 520K 532480 / 819200   <- hole is discovered because
> >                                       there is no trailing data
> Oops! for xfs_seek_hole(), I should use min_t() to pre-claculate
> offset before searching page cache.
> Thanks for your prompt feedback.  I'll do some extra tests and post
> the revised soon.

Yes, the above test cases should go into xfstests.

Thanks to both of you to spend all the effort on this feature.