[PATCH] xfstests 255: add a seek_data/seek_hole tester

[Sunil Mushran]

On 8/30/2011 8:29 PM, Dave Chinner wrote:
> And that's -exactly- the ambiguous, vague definition that has raised
> all these questions in the first place. I was in doubt about whether
> unwritten extents can be considered a hole, and by your definition
> that means it should be data. But Andreas seems to be in no doubt it
> should be considered a hole.

Fair enough. Let me rephrase.

Data:
A range in a file when read could return something other than nulls.

Hole:
A range in a file when read only returns nulls.

Considering preallocated extents only return null, they should
be considered holes.