genhd, efi: add efi partition metadata to hd_structs

This change extends the partition_meta_info structure to
support EFI GPT-specific metadata and ensures that data
is copied in on partition scanning.

Signed-off-by: Will Drewry <wad@chromium.org>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>

1 files changed, 25 insertions, 0 deletions

diff --git a/fs/partitions/efi.c b/fs/partitions/efi.c
index dbb44d4bb8a..ac0ccb5026a 100644
--- a/fs/partitions/efi.c
+++ b/fs/partitions/efi.c
@@ -94,6 +94,7 @@
  *
  ************************************************************/
 #include <linux/crc32.h>
+#include <linux/ctype.h>
 #include <linux/math64.h>
 #include <linux/slab.h>
 #include "check.h"
@@ -604,6 +605,7 @@ int efi_partition(struct parsed_partitions *state)
         gpt_entry *ptes = NULL;
         u32 i;
         unsigned ssz = bdev_logical_block_size(state->bdev) / 512;
+        u8 unparsed_guid[37];
 
         if (!find_valid_gpt(state, &gpt, &ptes) || !gpt || !ptes) {
                 kfree(gpt);
@@ -614,6 +616,9 @@ int efi_partition(struct parsed_partitions *state)
         pr_debug("GUID Partition Table is valid!  Yea!\n");
 
         for (i = 0; i < le32_to_cpu(gpt->num_partition_entries) && i < state->limit-1; i++) {
+                struct partition_meta_info *info;
+                unsigned label_count = 0;
+                unsigned label_max;
                 u64 start = le64_to_cpu(ptes[i].starting_lba);
                 u64 size = le64_to_cpu(ptes[i].ending_lba) -
                            le64_to_cpu(ptes[i].starting_lba) + 1ULL;
@@ -627,6 +632,26 @@ int efi_partition(struct parsed_partitions *state)
                 if (!efi_guidcmp(ptes[i].partition_type_guid,
                                  PARTITION_LINUX_RAID_GUID))
                         state->parts[i + 1].flags = ADDPART_FLAG_RAID;
+
+                info = &state->parts[i + 1].info;
+                /* Instead of doing a manual swap to big endian, reuse the
+                 * common ASCII hex format as the interim.
+                 */
+                efi_guid_unparse(&ptes[i].unique_partition_guid, unparsed_guid);
+                part_pack_uuid(unparsed_guid, info->uuid);
+
+                /* Naively convert UTF16-LE to 7 bits. */
+                label_max = min(sizeof(info->volname) - 1,
+                                sizeof(ptes[i].partition_name));
+                info->volname[label_max] = 0;
+                while (label_count < label_max) {
+                        u8 c = ptes[i].partition_name[label_count] & 0xff;
+                        if (c && !isprint(c))
+                                c = '!';
+                        info->volname[label_count] = c;
+                        label_count++;
+                }
+                state->parts[i + 1].has_info = true;
         }
         kfree(ptes);
         kfree(gpt);