Date:   Tue, 14 Dec 2021 07:47:21 -0800
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 v8 6/9] mm: Introduce mf_dax_kill_procs() for fsdax case
Message-ID: <Ybi8icn3W7vOEQV+@infradead.org>
References: <20211202084856.1285285-1-ruansy.fnst@fujitsu.com>
 <20211202084856.1285285-7-ruansy.fnst@fujitsu.com>
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On Thu, Dec 02, 2021 at 04:48:53PM +0800, Shiyang Ruan wrote:
> @@ -254,6 +254,15 @@ static inline bool dax_mapping(struct address_space *mapping)
>  {
>  	return mapping->host && IS_DAX(mapping->host);
>  }
> +static inline unsigned long pgoff_address(pgoff_t pgoff,
> +		struct vm_area_struct *vma)

Empty lines between functions please.

Also this name is a bit generic for something in dax.h, but then again
it does not seem to be DAX-specific, so it might want to move into
a generic MM header with a proper name and kerneldoc comment.

I think a calling conventions that puts the vma before the pgoff would
seem a little more logical as well.

Last but not least such a move should be in a separate patch.

> +extern int mf_dax_kill_procs(struct address_space *mapping, pgoff_t index,
> +			     unsigned long count, int mf_flags);

No need for the extern here.

> -static unsigned long dev_pagemap_mapping_shift(struct page *page,
> +static unsigned long dev_pagemap_mapping_shift(unsigned long address,
>  		struct vm_area_struct *vma)

Passing the vma first would seem more logical again.

> +	if (is_zone_device_page(p)) {
> +		/*
> +		 * Since page->mapping is no more used for fsdax, we should
> +		 * calculate the address in a fsdax way.
> +		 */

		/*
		 * Since page->mapping is not used for fsdax, we need
		 * calculate the address based on the vma.
		 */

> +static void collect_procs_fsdax(struct page *page, struct address_space *mapping,
> +		pgoff_t pgoff, struct list_head *to_kill)

Overly long line here.