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Subject: Re: [PATCH stable-5.10] mm/memory-failure: fix an incorrect use of
 tail pages
To: Matthew Wilcox <willy@infradead.org>, <stable@vger.kernel.org>, Greg
 Kroah-Hartman <gregkh@linuxfoundation.org>
References: <20240307124841.2838010-1-liushixin2@huawei.com>
CC: Andrew Morton <akpm@linux-foundation.org>, Sasha Levin
	<sashal@kernel.org>, Dan Williams <dan.j.williams@intel.com>, Naoya Horiguchi
	<n-horiguchi@ah.jp.nec.com>, <linux-kernel@vger.kernel.org>,
	<linux-mm@kvack.org>
From: Liu Shixin <liushixin2@huawei.com>
Message-ID: <026db58d-feea-8191-616a-3e6dca592786@huawei.com>
Date: Mon, 25 Mar 2024 11:36:49 +0800
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Hi,

After backport commit c79c5a0a00a9 ("mm/memory-failure: check the mapcount of the precise page"),

I got an error message as written on the patch. The problem can be fixed by the patch or just revert.

Now I prefer to revert because I think it is related to folio and no impact in stable, or maybe I'm wrong.


Thanks,


On 2024/3/7 20:48, Liu Shixin wrote:
> When backport commit c79c5a0a00a9 to 5.10-stable, there is a mistake change.
> The head page instead of tail page should be passed to try_to_unmap(),
> otherwise unmap will failed as follows.
>
>  Memory failure: 0x121c10: failed to unmap page (mapcount=1)
>  Memory failure: 0x121c10: recovery action for unmapping failed page: Ignored
>
> Fixes: 70168fdc743b ("mm/memory-failure: check the mapcount of the precise page")
> Signed-off-by: Liu Shixin <liushixin2@huawei.com>
> ---
>  mm/memory-failure.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/mm/memory-failure.c b/mm/memory-failure.c
> index f320ff02cc19..dba2936292cf 100644
> --- a/mm/memory-failure.c
> +++ b/mm/memory-failure.c
> @@ -1075,7 +1075,7 @@ static bool hwpoison_user_mappings(struct page *p, unsigned long pfn,
>  				unmap_success = false;
>  			}
>  		} else {
> -			unmap_success = try_to_unmap(p, ttu);
> +			unmap_success = try_to_unmap(hpage, ttu);
>  		}
>  	}
>  	if (!unmap_success)