mirror of
https://github.com/archlinuxarm/PKGBUILDs.git
synced 2024-11-28 22:57:37 +00:00
114 lines
4.1 KiB
Diff
114 lines
4.1 KiB
Diff
From d33b98fc82b0908e91fb05ae081acaed7323f9d2 Mon Sep 17 00:00:00 2001
|
|
From: Stephen Warren <swarren@nvidia.com>
|
|
Date: Thu, 8 Nov 2012 16:12:28 -0800
|
|
Subject: [PATCH] block: partition: msdos: provide UUIDs for partitions
|
|
|
|
The MSDOS/MBR partition table includes a 32-bit unique ID, often referred
|
|
to as the NT disk signature. When combined with a partition number within
|
|
the table, this can form a unique ID similar in concept to EFI/GPT's
|
|
partition UUID. Constructing and recording this value in struct
|
|
partition_meta_info allows MSDOS partitions to be referred to on the
|
|
kernel command-line using the following syntax:
|
|
|
|
root=PARTUUID=0002dd75-01
|
|
|
|
Signed-off-by: Stephen Warren <swarren@nvidia.com>
|
|
Cc: Tejun Heo <tj@kernel.org>
|
|
Cc: Will Drewry <wad@chromium.org>
|
|
Cc: Kay Sievers <kay.sievers@vrfy.org>
|
|
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
Signed-off-by: Jens Axboe <axboe@kernel.dk>
|
|
---
|
|
block/partitions/msdos.c | 21 +++++++++++++++++++--
|
|
init/do_mounts.c | 4 ++++
|
|
2 files changed, 23 insertions(+), 2 deletions(-)
|
|
|
|
diff --git a/block/partitions/msdos.c b/block/partitions/msdos.c
|
|
index 5f79a66..8752a5d 100644
|
|
--- a/block/partitions/msdos.c
|
|
+++ b/block/partitions/msdos.c
|
|
@@ -94,6 +94,17 @@ static int aix_magic_present(struct parsed_partitions *state, unsigned char *p)
|
|
return ret;
|
|
}
|
|
|
|
+static void set_info(struct parsed_partitions *state, int slot,
|
|
+ u32 disksig)
|
|
+{
|
|
+ struct partition_meta_info *info = &state->parts[slot].info;
|
|
+
|
|
+ snprintf(info->uuid, sizeof(info->uuid), "%08x-%02x", disksig,
|
|
+ slot);
|
|
+ info->volname[0] = 0;
|
|
+ state->parts[slot].has_info = true;
|
|
+}
|
|
+
|
|
/*
|
|
* Create devices for each logical partition in an extended partition.
|
|
* The logical partitions form a linked list, with each entry being
|
|
@@ -106,7 +117,8 @@ static int aix_magic_present(struct parsed_partitions *state, unsigned char *p)
|
|
*/
|
|
|
|
static void parse_extended(struct parsed_partitions *state,
|
|
- sector_t first_sector, sector_t first_size)
|
|
+ sector_t first_sector, sector_t first_size,
|
|
+ u32 disksig)
|
|
{
|
|
struct partition *p;
|
|
Sector sect;
|
|
@@ -166,6 +178,7 @@ static void parse_extended(struct parsed_partitions *state,
|
|
}
|
|
|
|
put_partition(state, state->next, next, size);
|
|
+ set_info(state, state->next, disksig);
|
|
if (SYS_IND(p) == LINUX_RAID_PARTITION)
|
|
state->parts[state->next].flags = ADDPART_FLAG_RAID;
|
|
loopct = 0;
|
|
@@ -437,6 +450,7 @@ int msdos_partition(struct parsed_partitions *state)
|
|
struct partition *p;
|
|
struct fat_boot_sector *fb;
|
|
int slot;
|
|
+ u32 disksig;
|
|
|
|
data = read_part_sector(state, 0, §);
|
|
if (!data)
|
|
@@ -491,6 +505,8 @@ int msdos_partition(struct parsed_partitions *state)
|
|
#endif
|
|
p = (struct partition *) (data + 0x1be);
|
|
|
|
+ disksig = le32_to_cpup((__le32 *)(data + 0x1b8));
|
|
+
|
|
/*
|
|
* Look for partitions in two passes:
|
|
* First find the primary and DOS-type extended partitions.
|
|
@@ -515,11 +531,12 @@ int msdos_partition(struct parsed_partitions *state)
|
|
put_partition(state, slot, start, n);
|
|
|
|
strlcat(state->pp_buf, " <", PAGE_SIZE);
|
|
- parse_extended(state, start, size);
|
|
+ parse_extended(state, start, size, disksig);
|
|
strlcat(state->pp_buf, " >", PAGE_SIZE);
|
|
continue;
|
|
}
|
|
put_partition(state, slot, start, size);
|
|
+ set_info(state, slot, disksig);
|
|
if (SYS_IND(p) == LINUX_RAID_PARTITION)
|
|
state->parts[slot].flags = ADDPART_FLAG_RAID;
|
|
if (SYS_IND(p) == DM6_PARTITION)
|
|
diff --git a/init/do_mounts.c b/init/do_mounts.c
|
|
index c950d7c..1d1b634 100644
|
|
--- a/init/do_mounts.c
|
|
+++ b/init/do_mounts.c
|
|
@@ -189,6 +189,10 @@ done:
|
|
* used when disk name of partitioned disk ends on a digit.
|
|
* 6) PARTUUID=00112233-4455-6677-8899-AABBCCDDEEFF representing the
|
|
* unique id of a partition if the partition table provides it.
|
|
+ * The UUID may be either an EFI/GPT UUID, or refer to an MSDOS
|
|
+ * partition using the format SSSSSSSS-PP, where SSSSSSSS is a zero-
|
|
+ * filled hex representation of the 32-bit "NT disk signature", and PP
|
|
+ * is a zero-filled hex representation of the 1-based partition number.
|
|
* 7) PARTUUID=<UUID>/PARTNROFF=<int> to select a partition in relation to
|
|
* a partition with a known unique id.
|
|
*
|
|
--
|
|
2.1.3
|
|
|