Re: [PATCH v2 2/3] genhd, efi: add efi partition metadata tohd_structs

From: Karel Zak
Date: Wed Aug 04 2010 - 05:01:40 EST


On Tue, Aug 03, 2010 at 09:04:42PM -0500, Will Drewry wrote:
> This change extends the partition_meta_info structure to
> support EFI GPT-specific metadata and ensures that data
> is copied in on partition scanning.

Why do want to store GPT-specific data (efi_guid_t) to
partition_meta_info? I think it would be better to use label and uuid
in a generic format (e.g. string or u8 uuid[16]) -- then you don't
have to use things like union, disklabel specific code to compare
uuids, etc. IMHO your current code is too complicated.

> + info = alloc_part_info(NULL);
> + if (!info) {
> + printk(KERN_WARNING
> + "unable to allocate memory for part->info\n");
> + continue;
> + }
> + info->format = PARTITION_META_INFO_FORMAT_EFI;
> + memcpy(info->efi.uuid.b, ptes[i].unique_partition_guid.b,
> + sizeof(info->efi.uuid.b));
> + memcpy(info->efi.type.b, ptes[i].partition_type_guid.b,
> + sizeof(info->efi.type.b));

why do you need to partition type?

> + memcpy(info->efi.label, ptes[i].partition_name,
> + sizeof(info->efi.label));

the partition name is in UTF8LE, is it correct to use it in raw
format?

> + state->parts[i + 1].info = info;
> }
> kfree(ptes);
> kfree(gpt);
> diff --git a/include/linux/genhd.h b/include/linux/genhd.h
> index 7b6644a..beb98e3 100644
> --- a/include/linux/genhd.h
> +++ b/include/linux/genhd.h
> @@ -91,11 +91,25 @@ struct disk_stats {
> enum partition_meta_info_format_t {
> /* Partition info format */
> PARTITION_META_INFO_FORMAT_NONE = 0,
> + PARTITION_META_INFO_FORMAT_EFI,
> + /* Place additional formats here. */
> + PARTITION_META_INFO_FORMAT_MAX,
> };
>
> +#ifdef CONFIG_EFI_PARTITION
> +#include <linux/efi.h>
> +#endif
> +
> struct partition_meta_info {
> enum partition_meta_info_format_t format;
> union {
> +#ifdef CONFIG_EFI_PARTITION
> + struct {
> + efi_guid_t uuid;
> + efi_guid_t type;
> + efi_char16_t label[72 / sizeof(efi_char16_t)];
> + } efi;
> +#endif
> };
> };
>
> --
> 1.7.0.4
>

--
Karel Zak <kzak@xxxxxxxxxx>
http://karelzak.blogspot.com
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/