On Tue, Jan 19, 2021 at 07:26:17AM +0800, Qu Wenruo wrote:

On 2021/1/19 上午7:17, David Sterba wrote:

quoted

On Sat, Jan 16, 2021 at 03:15:15PM +0800, Qu Wenruo wrote:
As the subpage support is
sort of an isolated feature we could afford to get the first batch of
code in and continue polishing. Read-only suppot with 64k/4k is a good
milestone so I'm not worried too much about some smaller things left
behind, as long as the default case page size == sectorsize works.

Yeah, that's the core design of current subpage support, all subpage
will be handled in a different routine, leaving minimal impact to
existing code.

quoted

Tests of this branch are still running but so far so good. I'll add it
as a topic branch to for-next for testing and my current plan is to push
it to misc-next soon, targeting 5.12.

That's great to hear.

quoted

quoted

In the subpage branch
- Metadata read write and balance
   Not yet full tested due to data write still has bugs need to be
   solved.
   But considering that metadata operations from previous iteration
   is mostly untouched, metadata read write should be pretty stable.

I assume the bugs are for the 64k/4k usecase.

Yes, at least the 4K case passes fstests in my local env.

I'd done a pre-merge pass last week with fixups in changlogs, subjects
and some coding style fixes but that was before Josef's comments. Some
of them still need updates but I also don't want to throw away my
changes.  (Ideally I don't have to do them at all, you can get the gist
of what are the most common things I'm fixing by comparing both versions.)

Please have a look at the branch ext/qu/subpage-v4 in my github repo,
the patches are in the same order as in this posted patchset. If the
patch does not change you can keep it as is, I'll reuse what I have.

For the final merge of the read-only support, patch 1 could be dropped
as discussed. The rest is hopefully ok to go, please resend, thanks.