Re: [PATCH] ntfs3: provide block_invalidate_folio to fix memory leak

[Namjae Jeon <linkinjeon@kernel.org>]

2022-05-30 21:00 GMT+09:00, Mikulas Patocka <mpatocka@redhat.com>:
>
>
> On Mon, 30 May 2022, manualinux@yahoo.es wrote:
>
>>
>> Hello again,
>>
>> When you have time, try moving a large file from a SpadFS partition to
>> an NTFS partition mounted with the NTFS3 driver and with a 5.18 kernel,
>> and then, move the same file back again, to the SpadFS partition. At
>> that very moment is when the size of the file remains permanently in
>> the system memory (in my particular case). This does not happen if we
>> do it to another Linux file system, nor does it happen if we do it from
>> a NTFS partition to another XFS or Ext4 partition.
>>
>> So no ccache or anything, I swap files quite often between the SpadFS
>> partition and an external hard disk with an NTFS partition. Anyway,
>> this problem is really unusual, and it must have some technical
>> explanation, because with the ntfs-3g driver this doesn't happen.
>>
>> If this information is of any use to you I will be satisfied.
>>
>> Regards,
>>
>> José Luis Lara Carrascal - Webmaster de Manualinux - GNU/Linux en
>> Español (https://manualinux.es)
>
> Hi
>
> SpadFS is innocent here :)
>
> The NTFS3 driver in the kernel 5.18 contains the same bug as SpadFS did -
> missing the invalidate_folio method. This patch adds this method and fixes
> the bug.
>
> Mikulas
>
>
>
> Author: Mikulas Patocka <mpatocka@redhat.com>
>
> The ntfs3 filesystem lacks the 'invalidate_folio' method and it causes
> memory leak. If you write to the filesystem and then unmount it, the
> cached written data are not freed and they are permanently leaked.
>
> Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
> Reported-by: José Luis Lara Carrascal <manualinux@yahoo.es>
> Fixes: 7ba13abbd31e ("fs: Turn block_invalidatepage into
> block_invalidate_folio")
> Cc: stable@vger.kernel.org	# v5.18

Reviewed-by: Namjae Jeon <linkinjeon@kernel.org>
>
> ---
>  fs/ntfs3/inode.c |    1 +
>  1 file changed, 1 insertion(+)
>
> Index: linux-2.6/fs/ntfs3/inode.c

> ===================================================================
> --- linux-2.6.orig/fs/ntfs3/inode.c	2022-05-16 16:57:24.000000000 +0200
> +++ linux-2.6/fs/ntfs3/inode.c	2022-05-30 13:36:45.000000000 +0200
linux-2.6 ? Probably you will submit the patch again ?

> @@ -1951,6 +1951,7 @@ const struct address_space_operations nt
>  	.direct_IO	= ntfs_direct_IO,
>  	.bmap		= ntfs_bmap,
>  	.dirty_folio	= block_dirty_folio,
> +	.invalidate_folio = block_invalidate_folio,
>  };
>
>  const struct address_space_operations ntfs_aops_cmpr = {