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Date:   Sun, 26 Jun 2022 01:02:23 -0700
From:   Christoph Hellwig <hch@infradead.org>
To:     "Darrick J. Wong" <djwong@kernel.org>
Cc:     Eric Biggers <ebiggers@kernel.org>, linux-fsdevel@vger.kernel.org,
        linux-ext4@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net,
        linux-xfs@vger.kernel.org, linux-api@vger.kernel.org,
        linux-fscrypt@vger.kernel.org, linux-block@vger.kernel.org,
        linux-kernel@vger.kernel.org, Keith Busch <kbusch@kernel.org>
Subject: Re: [PATCH v3 1/8] statx: add direct I/O alignment information
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 <20220616201506.124209-2-ebiggers@kernel.org>
 <YrSNlFgW6X4pUelg@magnolia>
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On Thu, Jun 23, 2022 at 08:58:12AM -0700, Darrick J. Wong wrote:
> Hmm.  Does the XFS port of XFS_IOC_DIOINFO to STATX_DIOALIGN look like
> this?
> 
> 	struct xfs_buftarg	*target = xfs_inode_buftarg(ip);
> 
> 	kstat.dio_mem_align = target->bt_logical_sectorsize;
> 	kstat.dio_offset_align = target->bt_logical_sectorsize;
> 	kstat.result_mask |= STATX_DIOALIGN;

Yes, I think so.  And it would be very good to include the XFS conversion
with this series as the only file systems that already supports
reporting alignment constraints.

I also suspect that lifting XFS_IOC_DIOINFO to common code by calling
->getattr would be useful because now all existing software using that
will also do the right thing on ext4 and f2fs now.