Merge git://git.kernel.org/pub/scm/linux/kernel/git/agk/linux-2.6-dm

<cipher>

    Encryption cipher and an optional IV generation mode.

    (In format cipher-chainmode-ivopts:ivmode).

    (In format cipher[:keycount]-chainmode-ivopts:ivmode).

    Examples:

       des

       aes-cbc-essiv:sha256

    Key used for encryption. It is encoded as a hexadecimal number.

    You can only use key sizes that are valid for the selected cipher.

<keycount>

    Multi-key compatibility mode. You can define <keycount> keys and

    then sectors are encrypted according to their offsets (sector 0 uses key0;

    sector 1 uses key1 etc.).  <keycount> must be a power of two.

<iv_offset>

    The IV offset is a sector count that is added to the sector number

    before creating the IV.

Device-mapper RAID (dm-raid) is a bridge from DM to MD.  It

provides a way to use device-mapper interfaces to access the MD RAID

drivers.

As with all device-mapper targets, the nominal public interfaces are the

constructor (CTR) tables and the status outputs (both STATUSTYPE_INFO

and STATUSTYPE_TABLE).  The CTR table looks like the following:

1: <s> <l> raid \

2:      <raid_type> <#raid_params> <raid_params> \

3:      <#raid_devs> <meta_dev1> <dev1> .. <meta_devN> <devN>

Line 1 contains the standard first three arguments to any device-mapper

target - the start, length, and target type fields.  The target type in

this case is "raid".

Line 2 contains the arguments that define the particular raid

type/personality/level, the required arguments for that raid type, and

any optional arguments.  Possible raid types include: raid4, raid5_la,

raid5_ls, raid5_rs, raid6_zr, raid6_nr, and raid6_nc.  (raid1 is

planned for the future.)  The list of required and optional parameters

is the same for all the current raid types.  The required parameters are

positional, while the optional parameters are given as key/value pairs.

The possible parameters are as follows:

 <chunk_size>           Chunk size in sectors.

 [[no]sync]             Force/Prevent RAID initialization

 [rebuild <idx>]        Rebuild the drive indicated by the index

 [daemon_sleep <ms>]    Time between bitmap daemon work to clear bits

 [min_recovery_rate <kB/sec/disk>]      Throttle RAID initialization

 [max_recovery_rate <kB/sec/disk>]      Throttle RAID initialization

 [max_write_behind <sectors>]           See '-write-behind=' (man mdadm)

 [stripe_cache <sectors>]               Stripe cache size for higher RAIDs

Line 3 contains the list of devices that compose the array in

metadata/data device pairs.  If the metadata is stored separately, a '-'

is given for the metadata device position.  If a drive has failed or is

missing at creation time, a '-' can be given for both the metadata and

data drives for a given position.

NB. Currently all metadata devices must be specified as '-'.

Examples:

# RAID4 - 4 data drives, 1 parity

# No metadata devices specified to hold superblock/bitmap info

# Chunk size of 1MiB

# (Lines separated for easy reading)

0 1960893648 raid \

        raid4 1 2048 \

        5 - 8:17 - 8:33 - 8:49 - 8:65 - 8:81

# RAID4 - 4 data drives, 1 parity (no metadata devices)

# Chunk size of 1MiB, force RAID initialization,

#       min recovery rate at 20 kiB/sec/disk

0 1960893648 raid \

        raid4 4 2048 min_recovery_rate 20 sync\

        5 - 8:17 - 8:33 - 8:49 - 8:65 - 8:81

Performing a 'dmsetup table' should display the CTR table used to

construct the mapping (with possible reordering of optional

parameters).

Performing a 'dmsetup status' will yield information on the state and

health of the array.  The output is as follows:

1: <s> <l> raid \

2:      <raid_type> <#devices> <1 health char for each dev> <resync_ratio>

Line 1 is standard DM output.  Line 2 is best shown by example:

        0 1960893648 raid raid4 5 AAAAA 2/490221568

Here we can see the RAID type is raid4, there are 5 devices - all of

which are 'A'live, and the array is 2/490221568 complete with recovery.

         Allow volume managers to mirror logical volumes, also

         needed for live data migration tools such as 'pvmove'.

config DM_RAID

       tristate "RAID 4/5/6 target (EXPERIMENTAL)"

       depends on BLK_DEV_DM && EXPERIMENTAL

       select MD_RAID456

       select BLK_DEV_MD

       ---help---

	 A dm target that supports RAID4, RAID5 and RAID6 mappings

	 A RAID-5 set of N drives with a capacity of C MB per drive provides

	 the capacity of C * (N - 1) MB, and protects against a failure

	 of a single drive. For a given sector (row) number, (N - 1) drives

	 contain data sectors, and one drive contains the parity protection.

	 For a RAID-4 set, the parity blocks are present on a single drive,

	 while a RAID-5 set distributes the parity across the drives in one

	 of the available parity distribution methods.

	 A RAID-6 set of N drives with a capacity of C MB per drive

	 provides the capacity of C * (N - 2) MB, and protects

	 against a failure of any two drives. For a given sector

	 (row) number, (N - 2) drives contain data sectors, and two

	 drives contains two independent redundancy syndromes.  Like

	 RAID-5, RAID-6 distributes the syndromes across the drives

	 in one of the available parity distribution methods.

config DM_LOG_USERSPACE

	tristate "Mirror userspace logging (EXPERIMENTAL)"

	depends on DM_MIRROR && EXPERIMENTAL && NET

obj-$(CONFIG_DM_MIRROR)		+= dm-mirror.o dm-log.o dm-region-hash.o

obj-$(CONFIG_DM_LOG_USERSPACE)	+= dm-log-userspace.o

obj-$(CONFIG_DM_ZERO)		+= dm-zero.o

obj-$(CONFIG_DM_RAID)	+= dm-raid.o

ifeq ($(CONFIG_DM_UEVENT),y)

dm-mod-objs			+= dm-uevent.o