Re: [XFS Tests Punch Hole 2/3 v3] XFS TESTS: Add Fallocate Punch Hole Test Routines

[Joel Becker <jlbec@xxxxxxxxxxxx>]

On Thu, May 19, 2011 at 11:31:44AM +1000, Dave Chinner wrote:
> > +#
> > +# This test is successful when the following conditions are met:
> > +#  - ls shows that the number of blocks occupied by the file
> > +#    has decreased by the number of blocks punched out.
> 
> There's no guarantee that a filesystem will punch the number of
> blocks you expect.

        Cluster allocated filesystems like ocfs2 are certainly going to
punch some multiple of clusters, not exact blocks.  Eg if the hole is
punched in the middle of a cluster.

Joel

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