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Date: Fri, 15 Mar 2024 13:57:51 -0400
From: Kent Overstreet <kent.overstreet@linux.dev>
To: Martin Steigerwald <martin@lichtvoll.de>
Cc: linux-bcachefs@vger.kernel.org, linux-fsdevel@vger.kernel.org, 
	linux-kernel@vger.kernel.org
Subject: Re: bcachefs: do not run 6.7: upgrade to 6.8 immediately if you have
 a multi device fs
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On Fri, Mar 15, 2024 at 09:57:34AM +0100, Martin Steigerwald wrote:
> Hi Kent, hi.
> 
> Kent Overstreet - 15.03.24, 05:41:09 CET:
> > there's a bug in 6.7 with filesystems that are mid upgrade and then get
> > downgraded not getting marked in the superblock as downgraded, and this
> > translates to a really horrific bug in splitbrain detection when the old
> > version isn't updating member sequence nmubers and you go back to the
> > new version - this results in every device being kicked out of the fs.
> 
> I take it that single device BCacheFS filesystems can be upgraded just fine?
> 
> I can also recreate and repopulate once I upgraded to 6.8. Still waiting a 
> bit.

No need to recreate and repopulate - you just don't want to be going
back to 6.7 from a newer version.