Re: [patch 1/2] mm: dont clear PG_uptodate in invalidate_complete_page2()

From: Miklos Szeredi
Date: Wed Jun 25 2008 - 12:03:26 EST


> > > Is this nfs/fuse problem you described:
> > > http://marc.info/?l=linux-fsdevel&m=121396920822693&w=2
> >
> > Yes.
>
> I do not know fuse good enough, but it looks like if your patch only
> fixes issue for pages which are in splice buffer during invalidation,
> any subsequent call for splice() will get correct new data (at least
> invoke readpage(s)), but in the description of error there was a
> long timeout between reading and writing, so it was a fresh splice()
> call, which suddenly started to return errors.
>
> Is it possible that by having uptodate bit in place, but page was
> actually freed but not removed from all trees and so on, so it
> masked read errors? This may be not the right conclusion though :)

No, the mechanics of the problem are well understood. Only the
solution is problematic :)

Miklos
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