Message-ID: <51e294bd-c241-ec7e-97d0-b1a7f3534578@huawei.com>
Date:   Mon, 6 Mar 2023 10:05:57 +0800
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Subject: Re: [PATCH 2/2] mm/damon/paddr: fix folio_nr_pages() after
 folio_put() in damon_pa_mark_accessed_or_deactivate()
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To:     SeongJae Park <sj@kernel.org>,
        Andrew Morton <akpm@linux-foundation.org>
CC:     "Vishal Moola (Oracle)" <vishal.moola@gmail.com>,
        "Matthew Wilcox (Oracle)" <willy@infradead.org>,
        <damon@lists.linux.dev>, <linux-mm@kvack.org>,
        <linux-kernel@vger.kernel.org>, <stable@vger.kernel.org>
References: <20230304193949.296391-1-sj@kernel.org>
 <20230304193949.296391-3-sj@kernel.org>
From:   Kefeng Wang <wangkefeng.wang@huawei.com>
In-Reply-To: <20230304193949.296391-3-sj@kernel.org>
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On 2023/3/5 3:39, SeongJae Park wrote:
> damon_pa_mark_accessed_or_deactivate() is accessing a folio via
> folio_nr_pages() after folio_put() for the folio has invoked.  Fix it.
> 

Reviewed-by: Kefeng Wang <wangkefeng.wang@huawei.com>

> Fixes: f70da5ee8fe1 ("mm/damon: convert damon_pa_mark_accessed_or_deactivate() to use folios")
> Cc: <stable@vger.kernel.org> # 6.3.x
> Signed-off-by: SeongJae Park <sj@kernel.org>
> ---
>   mm/damon/paddr.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/mm/damon/paddr.c b/mm/damon/paddr.c
> index 10f159b315ea..0db724aec5cb 100644
> --- a/mm/damon/paddr.c
> +++ b/mm/damon/paddr.c
> @@ -277,8 +277,8 @@ static inline unsigned long damon_pa_mark_accessed_or_deactivate(
>   			folio_mark_accessed(folio);
>   		else
>   			folio_deactivate(folio);
> -		folio_put(folio);
>   		applied += folio_nr_pages(folio);
> +		folio_put(folio);
>   	}
>   	return applied * PAGE_SIZE;
>   }