[PATCH] avoid unnnecessary mtd read when read can be satisfied by write buffer

[Jörn Engel]

On Thu, 1 June 2006 16:05:07 +0100, David Woodhouse wrote:
> 
> My point is that for any given problem, raw caching of flash is not the
> answer -- something more cunning is going to be better.

Not necessarily.  JFFS2, all metadata is not just cached, but cannot
even get evicted from cache.  Logfs*) currently doesn't cache metadata
at all, which is fairly bad.  But there is no requirement to pin the
metadata into memory, so it can have a dynamic cache with a shrinker.
And now the caching should be based on a (device, offset) tupel.
Nothing cunning about it, except to decide whether any given offset
contains metadata or file data, which is already cached elsewhere.

*) No code released yet, yadda yadda

Jörn

-- 
The wise man seeks everything in himself; the ignorant man tries to get
everything from somebody else.
-- unknown