Re: msync(2) bug(?), returns AOP_WRITEPAGE_ACTIVATE to userland

["Pekka Enberg" <penberg@cs.helsinki.fi>]

Hi Hugh,

On 10/22/07, Hugh Dickins <hugh@veritas.com> wrote:
> I don't disagree with your unionfs_writepages patch, Pekka, but I think
> it should be viewed as an optimization (don't waste time trying to write
> a group of pages when we know that nothing will be done) rather than as
> essential.

Ok, so tmpfs needs your fix still.

On 10/22/07, Hugh Dickins <hugh@veritas.com> wrote:
> > So now I wonder if we still need the patch to prevent AOP_WRITEPAGE_ACTIVATE
> > from being returned to userland.  I guess we still need it, b/c even with
> > your patch, generic_writepages() can return AOP_WRITEPAGE_ACTIVATE back to
> > the VFS and we need to ensure that doesn't "leak" outside the kernel.
>
> Can it now?  Current git has a patch from Andrew which bears a striking
> resemblance to that from Pekka, stopping the leak from write_cache_pages.

I don't think it can, it looks ok now.

                             Pekka

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