[Ocfs2-devel] [PATCH] ocfs2: make ocfs2_adjust_resv_from_alloc simple.

[Mark Fasheh]

On Tue, Apr 06, 2010 at 03:40:32PM +0800, Tao Ma wrote:
> When we allocate some bits from the reservation, we always
> allocate from the r_start(see ocfs2_resmap_resv_bits).
> So there should be no sense for checking between r_start
> and start. And I don't think we will change this behaviour
> somehow later by allocating from some bits after r_start.
> Why not make ocfs2_adjust_resv_from_alloc simple now?

I wanted ocfs2_resmap_claimed_bits() to be able to accept as many types of
input as possible. That way, it would stay ready to handle other types of
bitmaps. You're correct however that it's not really practical to allow for
allocation which would split our reservation.

Btw, if we took this to it's logical conclusion I think we'd be able to get
rid of the 'cstart' variable to ocfs2_resmap_claimed_bits(). It's good to at
least track what the caller *thought* the start of the allocation was so
IMHO we should leave that part of the api untouched.


Can you please add a comment in reservations.h that
ocfs2_resmap_claimed_bits() expects that 'start' is the same as we passed
back from ocfs2_resmap_resv_bits(). Also, there's a check at the top of
ocfs2_resmap_claimed_bits() which can become:

BUG_ON(cstart != resv->r_start);
	--Mark

--
Mark Fasheh