Re: [PATCH v2 0/3] btrfs: fix problem with balance recovery and snap delete

[David Sterba <dsterba@suse.cz>]

On Fri, Feb 18, 2022 at 02:56:09PM -0500, Josef Bacik wrote:
> v1->v2:
> - reworked the fix based on Filipe's feedback.  Instead of just doing all the
>   snapshot delete at mount time simply keep track of any in-progress drops.
>   Then gate relocation on those drops finishing.  Once the drops finish we
>   unblock relocation and carry on like normal.
> 
> --- Original email ---
> Hello,
> 
> I found a problem where we'll try to add refs to blocks that no longer have
> references because we started a relocation while we had a half deleted snapshot
> in the file system.  This only occurs on a clean mount with a pending snapshot
> delete in place.  I saw this in production but lost the file system before I
> could test my patch.  However I reproduced it locally with some error injection.
> Without my patch we'd fail to run delayed refs with the warning in the commit
> message in the first patch, with my patch we mount and can use the file system.
> 
> The other two patches are just cleanups that i noticed while messing with this
> code.  Thanks,
> 
> Josef
> 
> Josef Bacik (3):
>   btrfs: do not start relocation until in progress drops are done
>   btrfs: use btrfs_fs_info for deleting snapshots and cleaner
>   btrfs: pass btrfs_fs_info to btrfs_recover_relocation

Added as topic branch to for-next, thanks.