Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754307Ab3HFF3i (ORCPT ); Tue, 6 Aug 2013 01:29:38 -0400 Received: from g6t0184.atlanta.hp.com ([15.193.32.61]:46914 "EHLO g6t0184.atlanta.hp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752086Ab3HFF2s (ORCPT ); Tue, 6 Aug 2013 01:28:48 -0400 From: Davidlohr Bueso To: Andrew Morton , Jens Axboe Cc: Matt Domsch , Jim Hull , Karel Zak , Peter Jones , Chegu Vinod , Aswin Chandramouleeswaran , linux-kernel@vger.kernel.org, Davidlohr Bueso Subject: [PATCH 1/8] partitions/efi: use lba-aware partition records Date: Mon, 5 Aug 2013 22:21:09 -0700 Message-Id: <1375766476-4204-2-git-send-email-davidlohr@hp.com> X-Mailer: git-send-email 1.7.11.7 In-Reply-To: <1375766476-4204-1-git-send-email-davidlohr@hp.com> References: <1375766476-4204-1-git-send-email-davidlohr@hp.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3165 Lines: 78 The kernel's GPT implementation currently uses the generic 'struct partition' type for dealing with legacy MBR partition records. While this is is useful for disklabels that we designed for CHS addressing, such as msdos, it doesn't adapt well to newer standards that use LBA instead, such as GUID partition tables. Furthermore, these generic partition structures do not have all the required fields to properly follow the UEFI specs. While a CHS address can be translated to LBA, it's much simpler and cleaner to just replace the partition type. This patch adds a new 'gpt_record' type that is fully compliant with EFI and will allow, in the next patches, to add more checks to properly verify a protective MBR, which is paramount to probing a device that makes use of GPT. Signed-off-by: Davidlohr Bueso --- block/partitions/efi.c | 7 +++---- block/partitions/efi.h | 16 +++++++++++++++- 2 files changed, 18 insertions(+), 5 deletions(-) diff --git a/block/partitions/efi.c b/block/partitions/efi.c index c85fc89..3ebd3d8 100644 --- a/block/partitions/efi.c +++ b/block/partitions/efi.c @@ -149,11 +149,10 @@ static u64 last_lba(struct block_device *bdev) bdev_logical_block_size(bdev)) - 1ULL; } -static inline int -pmbr_part_valid(struct partition *part) +static inline int pmbr_part_valid(gpt_record *part) { - if (part->sys_ind == EFI_PMBR_OSTYPE_EFI_GPT && - le32_to_cpu(part->start_sect) == 1UL) + if (part->os_type == EFI_PMBR_OSTYPE_EFI_GPT && + le32_to_cpu(part->start_sector) == 1UL) return 1; return 0; } diff --git a/block/partitions/efi.h b/block/partitions/efi.h index b69ab72..46cf1a4 100644 --- a/block/partitions/efi.h +++ b/block/partitions/efi.h @@ -101,11 +101,25 @@ typedef struct _gpt_entry { efi_char16_t partition_name[72 / sizeof (efi_char16_t)]; } __attribute__ ((packed)) gpt_entry; +typedef struct _gpt_record { + u8 boot_indicator; /* unused by EFI, set to 0x80 for bootable */ + u8 start_head; /* unused by EFI, pt start in CHS */ + u8 start_sector; /* unused by EFI, pt start in CHS */ + u8 start_track; + u8 os_type; /* EFI and legacy non-EFI OS types */ + u8 end_head; /* unused by EFI, pt end in CHS */ + u8 end_sector; /* unused by EFI, pt end in CHS */ + u8 end_track; /* unused by EFI, pt end in CHS */ + __le32 starting_lba; /* used by EFI - start addr of the on disk pt */ + __le32 size_in_lba; /* used by EFI - size of pt in LBA */ +} __attribute__ ((packed)) gpt_record; + + typedef struct _legacy_mbr { u8 boot_code[440]; __le32 unique_mbr_signature; __le16 unknown; - struct partition partition_record[4]; + gpt_record partition_record[4]; __le16 signature; } __attribute__ ((packed)) legacy_mbr; -- 1.7.11.7 -- 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/