NEW TAR

Peter Jeremy PeterJeremy at optushome.com.au
Tue Jul 20 01:42:37 PDT 2004


On Mon, 2004-Jul-19 21:29:54 -0700, Tim Kientzle wrote:
>I have some ideas about sparse file handling,
>but they're not gtar-compatible.  (The gtar
>approach has a number of drawbacks.  The primary
>one being that on many systems it requires reading
>the entire file twice, once to find holes and again
>to actually archive the file.

Actually, it's not possible to accurately determine the holes in a
file by reading it - you can't differentiate between a hole and a
allocated block of zeroes.  What you need is a (new) syscall that
invokes a new VOP_... and returns a bitmap of allocated blocks.  This
would be non-trival unfortunately.

-- 
Peter Jeremy


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