Next btrfs development cycle - 5.9

Next btrfs development cycle - 5.9

[David Sterba]

From: David Sterba <dsterba@suse.cz>

Hi,

a friendly reminder of the timetable and what's expected at this phase.

5.6 - current
5.7 - upcoming, urgent regression fixes only
5.8 - development closed, pull request in prep, fixes or regressions only
5.9 - development open, until 5.8-rc5 (at least)

(https://btrfs.wiki.kernel.org/index.php/Developer%27s_FAQ#Development_schedule)


Current status
--------------

The pull request branch has been forked off misc-next, it's named misc-5.8.
Merge window most likely opens on Monday.

Fixes, improvements, hilights:

* improved global reserve utilization
* speedup dead root detection during orphan cleanup
* send: emit file capabilities after chown
* direct io port to iomap infrastructure

Cleanups:

* backref iterators factored out, used for normal backrefs and relocation
* direct io simplified and cleaned up
* block group reading
* set/get helpers
* REF_COWS renamed to SHAREABLE


Merge outlook
-------------

From now on only selected fixes will be merged to 5.8 queue.  In 5.9 I'd like
to do a stabilization release, we've had quite some core updates in 5.7.
So, merge less intrusive features (ioctls, sysfs updates, ...) and reasonable
cleanups, besides the usual fixes.

I have looked at the following patchsets and think that we should be able to
finalize them in time:

* device mirror balancing - besides the manual mirror selection we need a
			    better default balancing policy and may need to
			    experiment a bit to find replacement for the
			    pid-based one

* ioctl to dump chunks - to replace search tree ioctl where possible, eg. df or
                         usage, (also this might be used as a heuristic for
			 balancing or to suggest what to balance but that would
			 be a bonus)

The authenticated checksums patchset is on a good track, the core is done but
as this is a security-related feature we don't want to rush it.


Git development repos
---------------------

  k.org: https://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux.git
  devel1: https://gitlab.com/kdave/btrfs-devel
  devel2: https://github.com/kdave/btrfs-devel