Re: [PATCH v9 4/6] efivarfs: automatically update super block flag

From: Ard Biesheuvel
Date: Tue Dec 12 2023 - 02:11:56 EST


On Tue, 12 Dec 2023 at 06:39, Masahisa Kojima
<masahisa.kojima@xxxxxxxxxx> wrote:
>
> Hi Ard,
>
> On Mon, 11 Dec 2023 at 19:02, Ard Biesheuvel <ardb@xxxxxxxxxx> wrote:
> >
> > On Fri, 13 Oct 2023 at 09:47, Masahisa Kojima
> > <masahisa.kojima@xxxxxxxxxx> wrote:
> > >
> > > efivar operation is updated when the tee_stmm_efi module is probed.
> > > tee_stmm_efi module supports SetVariable runtime service,
> > > but user needs to manually remount the efivarfs as RW to enable
> > > the write access if the previous efivar operation does not support
> > > SerVariable and efivarfs is mounted as read-only.
> > >
> > > This commit notifies the update of efivar operation to
> > > efivarfs subsystem, then drops SB_RDONLY flag if the efivar
> > > operation supports SetVariable.
> > >
> > > Signed-off-by: Masahisa Kojima <masahisa.kojima@xxxxxxxxxx>
> >
> > Unfortunately, I have identified a problem with this approach.
> >
> > There are cases where there are multiple instances of struct
> > superblock are associated with the efivarfs file system [0].
> >
> > So I reworked the patch a little - please take the time to double
> > check that I did not make any mistakes here.
> >
> > [0] https://lore.kernel.org/linux-efi/20231208163925.3225018-8-ardb@xxxxxxxxxx/T/#u
>
> I think you are referring to this patch[1]?
> The modification should be OK, also I have tested it works as expected.
>
> Thank you very much for fixing this.
>

Thank you Masahisa.