From mboxrd@z Thu Jan  1 00:00:00 1970
Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133])
	(using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits))
	(No client certificate requested)
	by smtp.subspace.kernel.org (Postfix) with ESMTPS id 796E12C82
	for <nvdimm@lists.linux.dev>; Fri, 15 Oct 2021 06:41:37 +0000 (UTC)
DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed;
	d=infradead.org; s=bombadil.20210309; h=In-Reply-To:Content-Type:MIME-Version
	:References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To:
	Content-Transfer-Encoding:Content-ID:Content-Description;
	bh=G5S9y2nrrDptxuOLoJNOSSyaTHp02MaC9gd62byHcIA=; b=R+dIUYtEXxFA2exYyciVgSKT8P
	qzqHlPTAFgWqgf9++8AocTdLtaWHaPNsLR3dk6Ywj4i49KnXkndgi53DN/al/ZisyhTWfAIXnxZWP
	HyE6FiUSRwVvz2C5cULLmG1HQ6yEJhFIazKoRlVz3eJEBkP9O09nsq5DE4Gv54sUuA+hIH9i4UcHc
	gEQSuRUBTFRb/eBYssnKtdYgbFe9Yu6Y9n4YcSruMyGYKcQIoJ9Y+iWBmn3SocGFHdgfH7ZI2YBDx
	qOaIp8PE0trLuxiaZO6/VNmeJlug089okBR/79IBjBJ8YVQMnTWqt2bLFDXZtdQLvN6FXm/RfdwtF
	eg4yBWfg==;
Received: from hch by bombadil.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux))
	id 1mbGuO-005Zjs-AH; Fri, 15 Oct 2021 06:41:36 +0000
Date: Thu, 14 Oct 2021 23:41:36 -0700
From: Christoph Hellwig <hch@infradead.org>
To: Shiyang Ruan <ruansy.fnst@fujitsu.com>
Cc: linux-kernel@vger.kernel.org, linux-xfs@vger.kernel.org,
	nvdimm@lists.linux.dev, linux-mm@kvack.org,
	linux-fsdevel@vger.kernel.org, djwong@kernel.org,
	dan.j.williams@intel.com, david@fromorbit.com, hch@infradead.org,
	jane.chu@oracle.com
Subject: Re: [PATCH v7 7/8] xfs: Implement ->notify_failure() for XFS
Message-ID: <YWkioFQrfKAL8PvR@infradead.org>
References: <20210924130959.2695749-1-ruansy.fnst@fujitsu.com>
 <20210924130959.2695749-8-ruansy.fnst@fujitsu.com>
Precedence: bulk
X-Mailing-List: nvdimm@lists.linux.dev
List-Id: <nvdimm.lists.linux.dev>
List-Subscribe: <mailto:nvdimm+subscribe@lists.linux.dev>
List-Unsubscribe: <mailto:nvdimm+unsubscribe@lists.linux.dev>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20210924130959.2695749-8-ruansy.fnst@fujitsu.com>
X-SRS-Rewrite: SMTP reverse-path rewritten from <hch@infradead.org> by bombadil.infradead.org. See http://www.infradead.org/rpr.html

On Fri, Sep 24, 2021 at 09:09:58PM +0800, Shiyang Ruan wrote:
> +void fs_dax_register_holder(struct dax_device *dax_dev, void *holder,
> +		const struct dax_holder_operations *ops)
> +{
> +	dax_set_holder(dax_dev, holder, ops);
> +}
> +EXPORT_SYMBOL_GPL(fs_dax_register_holder);
> +
> +void fs_dax_unregister_holder(struct dax_device *dax_dev)
> +{
> +	dax_set_holder(dax_dev, NULL, NULL);
> +}
> +EXPORT_SYMBOL_GPL(fs_dax_unregister_holder);
> +
> +void *fs_dax_get_holder(struct dax_device *dax_dev)
> +{
> +	return dax_get_holder(dax_dev);
> +}
> +EXPORT_SYMBOL_GPL(fs_dax_get_holder);

These should not be in a XFS patch.  But why do we even need this
wrappers?

> @@ -377,6 +385,8 @@ xfs_close_devices(
>  
>  		xfs_free_buftarg(mp->m_logdev_targp);
>  		xfs_blkdev_put(logdev);
> +		if (dax_logdev)
> +			fs_dax_unregister_holder(dax_logdev);
>  		fs_put_dax(dax_logdev);

I'd prefer to include the fs_dax_unregister_holder in the fs_put_dax
call to avoid callers failing to unregister it.

> @@ -411,6 +425,9 @@ xfs_open_devices(
>  	struct block_device	*logdev = NULL, *rtdev = NULL;
>  	int			error;
>  
> +	if (dax_ddev)
> +		fs_dax_register_holder(dax_ddev, mp,
> +				&xfs_dax_holder_operations);

I'd include the holder registration with fs_dax_get_by_bdev as well.