The patch titled Subject: block: partition: msdos: provide UUIDs for partitions has been removed from the -mm tree. Its filename was block-partition-msdos-provide-uuids-for-partitions.patch This patch was dropped because it was merged into mainline or a subsystem tree ------------------------------------------------------ From: Stephen Warren <swarren@xxxxxxxxxx> Subject: 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@xxxxxxxxxx> Cc: Jens Axboe <axboe@xxxxxxxxx> Cc: Tejun Heo <tj@xxxxxxxxxx> Cc: Will Drewry <wad@xxxxxxxxxxxx> Cc: Kay Sievers <kay.sievers@xxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- block/partitions/msdos.c | 21 +++++++++++++++++++-- init/do_mounts.c | 4 ++++ 2 files changed, 23 insertions(+), 2 deletions(-) diff -puN block/partitions/msdos.c~block-partition-msdos-provide-uuids-for-partitions block/partitions/msdos.c --- a/block/partitions/msdos.c~block-partition-msdos-provide-uuids-for-partitions +++ a/block/partitions/msdos.c @@ -94,6 +94,17 @@ static int aix_magic_present(struct pars 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 pars */ 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 } 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_partit 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_partit #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_partit 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 -puN init/do_mounts.c~block-partition-msdos-provide-uuids-for-partitions init/do_mounts.c --- a/init/do_mounts.c~block-partition-msdos-provide-uuids-for-partitions +++ a/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. * _ Patches currently in -mm which might be from swarren@xxxxxxxxxx are linux-next.patch -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html