Re: [PATCH v7 12/13] ext4: switch to multigrain timestamps

[Jeff Layton]

On Wed, 2023-09-20 at 16:53 +0200, Christian Brauner wrote:
> > You could put it behind an EXPERIMENTAL Kconfig option so that the
> > code stays in and can be used by the brave or foolish while it is
> > still being refined.
> 
> Given that the discussion has now fully gone back to the drawing board
> and this is a regression the honest thing to do is to revert the five
> patches that introduce the infrastructure:
> 
> ffb6cf19e063 ("fs: add infrastructure for multigrain timestamps")
> d48c33972916 ("tmpfs: add support for multigrain timestamps")
> e44df2664746 ("xfs: switch to multigrain timestamps")
> 0269b585868e ("ext4: switch to multigrain timestamps")
> 50e9ceef1d4f ("btrfs: convert to multigrain timestamps")
> 
> The conversion to helpers and cleanups are sane and should stay and can
> be used for any solution that gets built on top of it.
> 
> I'd appreciate a look at the branch here:
> git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs.git vfs.ctime.revert
> 
> survives xfstests.

I think that's probably the wisest course of action. I need some time to
ponder the options for this series anyway, and another cycle in next
wouldn't hurt.

The branch itself looks fine, but you might want to reverse the order of
the patches in case someone lands there in the middle of a bisect. IOW,
I think you want to revert the "convert to multigrain" patches before
you revert the infrastructure. 
-- 
Jeff Layton <jlayton@xxxxxxxxxx>