Re: [RFC PATCH 0/8] fsdax: introduce FS query interface to support reflink
On Fri, Aug 07, 2020 at 09:13:28PM +0800, Shiyang Ruan wrote:
This patchset is a try to resolve the problem of tracking shared
page
for fsdax.
Instead of per-page tracking method, this patchset introduces a query
interface: get_shared_files(), which is implemented by each FS, to
obtain the owners of a shared page. It returns an owner list of this
shared page. Then, the memory-failure() iterates the list to be able
to notify each process using files that sharing this page.
The design of the tracking method is as follow:
1. dax_assocaite_entry() associates the owner's info to this page
I think that's the first problem with this design. dax_associate_entry is
a horrendous idea which needs to be ripped out, not made more important.
It's all part of the general problem of trying to do something on a
per-page basis instead of per-extent basis.