On Wed, 26 Jul 2000, Stephen C. Tweedie wrote:
> Hi,
>
> On Wed, Jul 26, 2000 at 02:05:11PM -0400, Alexander Viro wrote:
> >
> > Here is one more for you:
> > Suppose we grow the last fragment/tail/whatever. Do you copy the
> > data out of that shared block? If so, how do you update buffer_heads in
> > pages that cover the relocated data? (Same goes for reiserfs, if they are
> > doing something similar). BTW, our implementation of UFS is fucked up in
> > that respect, so variant from there will not work.
>
> For tail writes, I'd imagine we would just end up using the page cache
> as a virtual cache as NFS uses it, and doing plain copy into the
> buffer cache pages.
Ouch. I _really_ don't like it - we end up with special behaviour on one
page in the pagecache. And getting data migration from buffer cache to
page cache, which is Not Nice(tm). Yuck... Besides, when do we decide that
tail is going to be, erm, merged? What will happen with the page then?
