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.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: NDavidlohr Bueso <davidlohr@hp.com>
Reviewed-by: NKarel Zak <kzak@redhat.com>
Acked-by: NMatt Fleming <matt.fleming@intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Read block device partition table from command line.  The partition used
for fixed block device (eMMC) embedded device.  It is no MBR, save
storage space.  Bootloader can be easily accessed by absolute address of
data on the block device.  Users can easily change the partition.

This code reference MTD partition, source "drivers/mtd/cmdlinepart.c"
About the partition verbose reference
"Documentation/block/cmdline-partition.txt"

[akpm@linux-foundation.org: fix printk text]
[yongjun_wei@trendmicro.com.cn: fix error return code in parse_parts()]
Signed-off-by: NCai Zhiyong <caizhiyong@huawei.com>
Cc: Karel Zak <kzak@redhat.com>
Cc: "Wanglin (Albert)" <albert.wanglin@huawei.com>
Cc: Marius Groeger <mag@sysgo.de>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Brian Norris <computersforpeace@gmail.com>
Cc: Artem Bityutskiy <dedekind@infradead.org>
Signed-off-by: NWei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Graft AIX partitions enumeration into partitions/msdos.c

There is already a AIX disks detection logic in msdos.c.  When an AIX disk
has been found, and if configured to, call the aix partitions recognizer.
This avoids removal of AIX disks protection from msdos.c, avoids code
duplication, and ensures that AIX partitions enumeration is called before
plain msdos partitions enumeration.
Signed-off-by: NPhilippe De Muyter <phdm@macqel.be>
Cc: Karel Zak <kzak@redhat.com>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add partitions/aix.h and partitions/aix.c.

AIX LVM permits to make "logical volumes" which are made of multiple
slices of multiple disks.  The new code allows only access to the
"logical volumes" which are made of one slice on the probed disk, a
slice being a contiguous disk area.  The code also detects "logical
volumes" made of multiple slices on the probed disk, but can not
describe them to the partition layer, because the partition layer
generic code does not support that.  When such non-contiguous "logical
volumes" are detected, a diagnostic message is printed.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: NPhilippe De Muyter <phdm@macqel.be>
Cc: Karel Zak <kzak@redhat.com>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: NPhilippe De Muyter <phdm@macqel.be>
Cc: Karel Zak <kzak@redhat.com>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

In alloc_read_gpt_entries and alloc_read_gpt_header, the kzalloc'ated
zones are either totally overwritten by the following read_lba call,
or freed.  As kmalloc is cheaper than kzalloc, use kmalloc.
Signed-off-by: NPhilippe De Muyter <phdm@macqel.be>
Cc: Matt Domsch <Matt_Domsch@dell.com>
Cc: Panagiotis Issaris <takis@issaris.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Currently, sizeof(struct parsed_partitions) may be 64KB in 32bit arch, so
it is easy to trigger page allocation failure by check_partition,
especially in hotplug block device situation(such as, USB mass storage,
MMC card, ...), and Felipe Balbi has observed the failure.

This patch does below optimizations on the allocation of struct
parsed_partitions to try to address the issue:

- make parsed_partitions.parts as pointer so that the pointed memory can
  fit in 32KB buffer, then approximate 32KB memory can be saved

- vmalloc the buffer pointed by parsed_partitions.parts because 32KB is
  still a bit big for kmalloc

- given that many devices have the partition count limit, so only
  allocate disk_max_parts() partitions instead of 256 partitions always
Signed-off-by: NMing Lei <ming.lei@canonical.com>
Reported-by: NFelipe Balbi <balbi@ti.com>
Cc: Jens Axboe <axboe@kernel.dk>
Reviewed-by: NYasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

It isn't necessary to read the information of partitions whose number is
equal and more than state->limit since only maximum state->limit
partitions will be added inside rescan_partitions().

That is also what other kind of partitions are doing.
Signed-off-by: NMing Lei <ming.lei@canonical.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

UEFI 2.3.1D will include a change to the spec language mandating that a
GPT header must be greater than *or equal to* the size of the defined
structure.  While verifying that this would work on Linux, I discovered
that we're not actually checking the minimum bound at all.

The result of this is that when we verify the checksum, it's possible that
on a malformed header (with header_size of 0), we won't actually verify
any data.

[akpm@linux-foundation.org: fix printk warning]
Signed-off-by: NPeter Jones <pjones@redhat.com>
Acked-by: NMatt Fleming <matt.fleming@intel.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Stephen Warren <swarren@nvidia.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

AIX formatted disks do not always have the MSDOS 55aa signature.
This happens e.g. for unbootable AIX disks.

Up to now, such disks were not recognized as AIX disks, because of the
missing 55aa.  Fix that by inverting the two tests.  Let's first
check for the AIX magic strings, and only if that fails check for
the MSDOS magic word.
Signed-off-by: NPhilippe De Muyter <phdm@macqel.be>
Cc: Andreas Mohr <andi@lisas.de>
Cc: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Olaf Hering <olh@suse.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The Kconfig currently enables MSDOS partitions by default because they
are assumed to be essential, but it's necessary to enable "advanced
partition selection" in order to get GPT support. IMO GPT partitions
are becoming common enought to deserve the same treatment MSDOS
partitions get.

(Side note: I got bit by a disk that had MSDOS and GPT partition
tables, but for some reason the MSDOS table was different from the
GPT one. I was stupid enought to disable "advanced partition
selection" in my .config, which disabled GPT partitioning and made
my btrfs pool unbootable because it couldn't find the partitions)
Signed-off-by: NDiego Calleja <diegocg@gmail.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

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: NStephen 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: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

This will allow other types of UUID to be stored here, aside from true
UUIDs.  This also simplifies code that uses this field, since it's usually
constructed from a, used as a, or compared to other, strings.

Note: A simplistic approach here would be to set uuid_str[36]=0 whenever a
/PARTNROFF option was found to be present.  However, this modifies the
input string, and causes subsequent calls to devt_from_partuuid() not to
see the /PARTNROFF option, which causes different results.  In order to
avoid misleading future maintainers, this parameter is marked const.
Signed-off-by: NStephen 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: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

In some usage scenarios it is desireable to work with disk images or
virtualized DASD devices. One problem that prevents such applications
is the partition detection in ibm.c. Currently it works only for
devices that support the BIODASDINFO2 ioctl, in other words, it only
works for devices that belong to the DASD device driver.

The information gained from the BIODASDINFO2 ioctl is only for a small
set of legacy cases abolutely necessary. All current VOL1, LNX1 and
CMS1 type of disk labels can be interpreted correctly without this
information, as long as the generic HDIO_GETGEO ioctl works and
provides a correct disk geometry.

This patch makes the ibm.c partition detection as independent as
possible from the BIODASDINFO2 ioctl. Only the following two cases are
still restricted to real DASDs:
- An FBA DASD, or LDL formatted ECKD DASD without any disk label.
- An old style LNX1 label (without large volume support) on a disk
  with inconsistent device geometry.
Signed-off-by: NStefan Weinhuber <wein@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

To avoid confusion while formatting a DASD device change the level of
the "Expected VOL1 label not found" message from warning to info.
Signed-off-by: NStefan Haberland <stefan.haberland@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

From: Ben Hutchings <ben@decadent.org.uk>

Extended VBLKs (those larger than the preset VBLK size) are divided
into fragments, each with its own VBLK header.  Our LDM implementation
generally assumes that each VBLK is contiguous in memory, so these
fragments must be assembled before further processing.

Currently the reassembly seems to be done quite wrongly - no VBLK
header is copied into the contiguous buffer, and the length of the
header is subtracted twice from each fragment.  Also the total
length of the reassembled VBLK is calculated incorrectly.
Signed-off-by: NBen Hutchings <ben@decadent.org.uk>
Signed-off-by: NAnton Altaparmakov <anton@tuxera.com>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>