unix-2.6.0.0 does not provide access to st_blksize and st_blocks

[JohnWiegley]

There is currently no clear way in Haskell to determine how much disk space a file actually occupies on disk -- only it's apparent byte size. Case in point, the popular git-annex tool has had to rely on a hack because there is no way to get at the st_blocks information in the POSIX stat record.

I recommend adding two functions to Common.hsc in unix, which are in the attached patch.

[igloo]

Thanks for the suggestion. However, library API changes need to be discussed on the libraries list first, and then a ticket opened once consensus is reached; please see  http://www.haskell.org/haskellwiki/Library_submissions for details.