Re: [RFC PATCH 54/61] afs: Wait on PG_fscache before modifying/releasing a page

[David Howells]

Matthew Wilcox <willy@xxxxxxxxxxxxx> wrote:

> > PG_fscache is going to be used to indicate that a page is being written to
> > the cache, and that the page should not be modified or released until it's
> > finished.
> > 
> > Make afs_invalidatepage() and afs_releasepage() wait for it.
> 
> Well, why?  Keeping a refcount on the page will prevent it from going
> away while it's being written to storage.  And the fact that it's
> being written to this cache is no reason to delay the truncate of a file
> (is it?)

Won't that screw up ITER_MAPPING?  Does that mean that ITER_MAPPING isn't
viable?

David