[PATCH v2] efi_driver: fix duplicate efiblk#0 issue

[Simon Glass]

Hi Masahisa,

On Mon, 3 Jul 2023 at 07:09, Masahisa Kojima <masahisa.kojima at linaro.org> wrote:
>
> The devnum value of the blk_desc structure starts from 0,
> current efi_bl_create_block_device() function creates
> two "efiblk#0" devices for the cases that blk_find_max_devnum()
> returns -ENODEV and blk_find_max_devnum() returns 0(one device
> found in this case).
>
> This commit uses blk_next_free_devnum() instead of blk_find_max_devnum().
>
> Signed-off-by: Masahisa Kojima <masahisa.kojima at linaro.org>
> ---
> Changes in v2:
> - uses blk_next_free_devnum() instead of blk_find_max_devnum()
>
>  lib/efi_driver/efi_block_device.c | 6 ++----
>  1 file changed, 2 insertions(+), 4 deletions(-)
>
> diff --git a/lib/efi_driver/efi_block_device.c b/lib/efi_driver/efi_block_device.c
> index add00eeebb..e3abd90275 100644
> --- a/lib/efi_driver/efi_block_device.c
> +++ b/lib/efi_driver/efi_block_device.c
> @@ -124,10 +124,8 @@ efi_bl_create_block_device(efi_handle_t handle, void *interface)
>         struct efi_block_io *io = interface;
>         struct efi_blk_plat *plat;
>
> -       devnum = blk_find_max_devnum(UCLASS_EFI_LOADER);
> -       if (devnum == -ENODEV)
> -               devnum = 0;
> -       else if (devnum < 0)
> +       devnum = blk_next_free_devnum(UCLASS_EFI_LOADER);

This really should be an internal function but I see it was exported
as part of the virtio work.

How come the EFI and DM block devices are getting out of sync?

Anyway this function is munging around in the internals of the device
and should be fixed before it causes more problems.

For now, I suggest following what most other drivers so which is to
call blk_create_devicef() passing a devnum of -1.

> +       if (devnum < 0)
>                 return EFI_OUT_OF_RESOURCES;
>
>         name = calloc(1, 18); /* strlen("efiblk#2147483648") + 1 */
> --
> 2.34.1
>

Regards,
Simon