[U-Boot] [PATCH v2 2/3] efi_loader: disk: install FILE_SYSTEM_PROTOCOL only if available

[Heinrich Schuchardt]

On 9/12/19 6:51 AM, AKASHI Takahiro wrote:
> In the current implementation, EFI_SIMPLEFILE_SYSTEM_PROTOCOL is always
> installed to all the partitions even if some of them may house no file
> system.
>
> With this patch, that protocol will be installed only if FAT file system
> exists.
>
> Signed-off-by: AKASHI Takahiro <takahiro.akashi at linaro.org>
> ---
>  lib/efi_loader/efi_disk.c | 16 +++++++++++++++-
>  1 file changed, 15 insertions(+), 1 deletion(-)
>
> diff --git a/lib/efi_loader/efi_disk.c b/lib/efi_loader/efi_disk.c
> index 7a6b06821a47..d72f455901f2 100644
> --- a/lib/efi_loader/efi_disk.c
> +++ b/lib/efi_loader/efi_disk.c
> @@ -9,6 +9,7 @@
>  #include <blk.h>
>  #include <dm.h>
>  #include <efi_loader.h>
> +#include <fs.h>
>  #include <part.h>
>  #include <malloc.h>
>
> @@ -217,6 +218,19 @@ efi_fs_from_path(struct efi_device_path *full_path)
>  	return handler->protocol_interface;
>  }
>
> +static int efi_fs_exists(struct blk_desc *desc, int part)
> +{
> +	if (fs_set_blk_dev_with_part(desc, part))
> +		return 0;
> +
> +	if (strcmp(fs_get_type_name(), "fat"))

Before your patch we could use any supported file system (e.g. EXT2). I
see no need for a restriction to FAT. You could compare the string to
"unsupported":

if (!strcmp(fs_get_type_name(), "unsupported"))
	return 0;

But wouldn't it be preferable to have a function to access fs_type (in
fs/fs.c) directly instead of a string representation?

Otherwise we should convert the string "unsupported" of fstypes[] into a
constant in fs.h so that we can be sure we are using the same value.

Best regards

Heinrich

> +		return 0;
> +
> +	fs_close();
> +
> +	return 1;
> +}
> +
>  /*
>   * Create a handle for a partition or disk
>   *
> @@ -270,7 +284,7 @@ static efi_status_t efi_disk_add_dev(
>  			       diskobj->dp);
>  	if (ret != EFI_SUCCESS)
>  		return ret;
> -	if (part >= 1) {
> +	if (part >= 1 && efi_fs_exists(desc, part)) {
>  		diskobj->volume = efi_simple_file_system(desc, part,
>  							 diskobj->dp);
>  		ret = efi_add_protocol(&diskobj->header,
>