Messages in this thread | | | Date | Wed, 4 Aug 2010 09:44:46 -0500 | Subject | Re: [PATCH v2 2/3] genhd, efi: add efi partition metadata to hd_structs | From | Will Drewry <> |
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On Wed, Aug 4, 2010 at 4:00 AM, Karel Zak <kzak@redhat.com> wrote: > 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?
For GPT, at least, the partition type isn't directly encoded anywhere else and it can be vendor specific. For instance, if a vendor wants to make an auto-configuring, they could reserve a VENDOR-ROOT-PRI0-PART-TYPE-GUID then easily create a mount path for it. Of course, that could easily be kludged by reusing a UUID.
> >> + 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?
Since the type was partition specific, I left the data untouched. It sounds like it'd be more useful to expose the data in a generic way which would mean converting it, I guess?
>> + 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@redhat.com> > http://karelzak.blogspot.com > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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