Re: [PATCH 2/2] btrfs: tree-checker: Remove comprehensive root owner check

[David Sterba <dsterba@suse.cz>]

On Wed, Apr 03, 2019 at 07:59:19PM +0800, Qu Wenruo wrote:
> Commit 1ba98d086fe3 ("Btrfs: detect corruption when non-root leaf has
> zero item") introduced comprehensive root owner checker.

That's 4.7, so we might want to do stable backport to 4.9+.
> 
> However it's pretty expensive tree search to locate the owner root,
> especially when it get reused by mandatory read and write time
> tree-checker.
> 
> This patch will remove that check, and completely rely on owner based
> empty leaf check, which is much faster and still works fine for most
> case.
> 
> And since we skip the old root owner check, now write time tree check
> can be merged with btrfs_check_leaf_full().

And for that reason the change should be minimal, this patch depends on
current development queue so it's not suitable for the backport.

I'm thinking what to do here, I want to avoid patches that effectively
revert changes that are still in the development branch and haven't been
released.

This means to rework "btrfs: Do mandatory tree block check before
submitting bio", though it's deep in the branch, the scope of changes is
only 2 files so this should not cause any conflicts.