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Date:   Tue, 21 Sep 2021 09:43:18 +0100
From:   Christoph Hellwig <hch@infradead.org>
To:     "Darrick J. Wong" <djwong@kernel.org>
Cc:     chandan.babu@oracle.com, chandanrlinux@gmail.com,
        linux-xfs@vger.kernel.org
Subject: Re: [PATCH 03/14] xfs: dynamically allocate btree scrub context
 structure
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On Fri, Sep 17, 2021 at 06:29:26PM -0700, Darrick J. Wong wrote:
> From: Darrick J. Wong <djwong@kernel.org>
> 
> Reorganize struct xchk_btree so that we can dynamically size the context
> structure to fit the type of btree cursor that we have.  This will
> enable us to use memory more efficiently once we start adding very tall
> btree types.

So bs->levels[0].has_lastkey replaces bs->firstkey?  Can you explain
a bit more how this works for someone not too familiar with the scrub
code.

> +static inline size_t
> +xchk_btree_sizeof(unsigned int levels)
> +{
> +	return sizeof(struct xchk_btree) +
> +				(levels * sizeof(struct xchk_btree_levels));

This should probably use struct_size().