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Re: [linux-lvm] Re: [PATCH] 64 bit scsi read/write



On Thu, Jul 05, 2001 at 03:35:31AM -0400, Ben LaHaise wrote:
> On Thu, 5 Jul 2001, Ragnar Kjørstad wrote:
> 
> > What do you mean?
> > Is it not feasible to fix this in LVM as well, or do you just not know
> > what needs to be done to LVM?
> 
> Fixing LVM is not on the radar of my priorities.  The code is sorely in
> need of a rewrite and violates several of the basic planning tenents that
> any good code in the block layer should follow.  Namely, it should have 1)
> planned on supporting 64 bit offsets, 2) never used multiplication,
> division or modulus on block numbers, and 3) don't allocate memory
> structures that are indexed by block numbers.

	It would seem to me that it would be nearly impossible to write
something that does the kind of block remapping that LVM does without
violating tenets 2 and 3.

	To me, that's like saying that no code that deals with memory
can have a data structure indexed by address, and you can't do masking
operations on memory addresses.  That would completely kill virtual
memory right there.

Have fun (if at all possible),
-- 
"It does me no injury for my neighbor to say there are twenty gods or no God.
It neither picks my pocket nor breaks my leg."  --- Thomas Jefferson
"Go to Heaven for the climate, Hell for the company."  -- Mark Twain
-- Eric Hopper (hopper omnifarious org  http://www.omnifarious.org/~hopper) --

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