drivers/md/Kconfig - LeafOS-Devices/android_kernel_samsung_gta4xl - Gitiles

 #
 # Block device driver configuration
 #

 menuconfig MD
 	bool "Multiple devices driver support (RAID and LVM)"
 	depends on BLOCK
 	select SRCU
 	help
 	  Support multiple physical spindles through a single logical device.
 	  Required for RAID and logical volume management.

 if MD

 config BLK_DEV_MD
 	tristate "RAID support"
 	---help---
 	  This driver lets you combine several hard disk partitions into one
 	  logical block device. This can be used to simply append one
 	  partition to another one or to combine several redundant hard disks
 	  into a RAID1/4/5 device so as to provide protection against hard
 	  disk failures. This is called "Software RAID" since the combining of
 	  the partitions is done by the kernel. "Hardware RAID" means that the
 	  combining is done by a dedicated controller; if you have such a
 	  controller, you do not need to say Y here.

 	  More information about Software RAID on Linux is contained in the
 	  Software RAID mini-HOWTO, available from
 	  <http://www.tldp.org/docs.html#howto>. There you will also learn
 	  where to get the supporting user space utilities raidtools.

 	  If unsure, say N.

 config MD_AUTODETECT
 	bool "Autodetect RAID arrays during kernel boot"
 	depends on BLK_DEV_MD=y
 	default y
 	---help---
 	  If you say Y here, then the kernel will try to autodetect raid
 	  arrays as part of its boot process.

 	  If you don't use raid and say Y, this autodetection can cause
 	  a several-second delay in the boot time due to various
 	  synchronisation steps that are part of this step.

 	  If unsure, say Y.

 config MD_LINEAR
 	tristate "Linear (append) mode"
 	depends on BLK_DEV_MD
 	---help---
 	  If you say Y here, then your multiple devices driver will be able to
 	  use the so-called linear mode, i.e. it will combine the hard disk
 	  partitions by simply appending one to the other.

 	  To compile this as a module, choose M here: the module
 	  will be called linear.

 	  If unsure, say Y.

 config MD_RAID0
 	tristate "RAID-0 (striping) mode"
 	depends on BLK_DEV_MD
 	---help---
 	  If you say Y here, then your multiple devices driver will be able to
 	  use the so-called raid0 mode, i.e. it will combine the hard disk
 	  partitions into one logical device in such a fashion as to fill them
 	  up evenly, one chunk here and one chunk there. This will increase
 	  the throughput rate if the partitions reside on distinct disks.

 	  Information about Software RAID on Linux is contained in the
 	  Software-RAID mini-HOWTO, available from
 	  <http://www.tldp.org/docs.html#howto>. There you will also
 	  learn where to get the supporting user space utilities raidtools.

 	  To compile this as a module, choose M here: the module
 	  will be called raid0.

 	  If unsure, say Y.

 config MD_RAID1
 	tristate "RAID-1 (mirroring) mode"
 	depends on BLK_DEV_MD
 	---help---
 	  A RAID-1 set consists of several disk drives which are exact copies
 	  of each other.  In the event of a mirror failure, the RAID driver
 	  will continue to use the operational mirrors in the set, providing
 	  an error free MD (multiple device) to the higher levels of the
 	  kernel.  In a set with N drives, the available space is the capacity
 	  of a single drive, and the set protects against a failure of (N - 1)
 	  drives.

 	  Information about Software RAID on Linux is contained in the
 	  Software-RAID mini-HOWTO, available from
 	  <http://www.tldp.org/docs.html#howto>.  There you will also
 	  learn where to get the supporting user space utilities raidtools.

 	  If you want to use such a RAID-1 set, say Y.  To compile this code
 	  as a module, choose M here: the module will be called raid1.

 	  If unsure, say Y.

 config MD_RAID10
 	tristate "RAID-10 (mirrored striping) mode"
 	depends on BLK_DEV_MD
 	---help---
 	  RAID-10 provides a combination of striping (RAID-0) and
 	  mirroring (RAID-1) with easier configuration and more flexible
 	  layout.
 	  Unlike RAID-0, but like RAID-1, RAID-10 requires all devices to
 	  be the same size (or at least, only as much as the smallest device
 	  will be used).
 	  RAID-10 provides a variety of layouts that provide different levels
 	  of redundancy and performance.

 	  RAID-10 requires mdadm-1.7.0 or later, available at:

 	  https://www.kernel.org/pub/linux/utils/raid/mdadm/

 	  If unsure, say Y.

 config MD_RAID456
 	tristate "RAID-4/RAID-5/RAID-6 mode"
 	depends on BLK_DEV_MD
 	select RAID6_PQ
 	select LIBCRC32C
 	select ASYNC_MEMCPY
 	select ASYNC_XOR
 	select ASYNC_PQ
 	select ASYNC_RAID6_RECOV
 	---help---
 	  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.

 	  Information about Software RAID on Linux is contained in the
 	  Software-RAID mini-HOWTO, available from
 	  <http://www.tldp.org/docs.html#howto>. There you will also
 	  learn where to get the supporting user space utilities raidtools.

 	  If you want to use such a RAID-4/RAID-5/RAID-6 set, say Y.  To
 	  compile this code as a module, choose M here: the module
 	  will be called raid456.

 	  If unsure, say Y.

 config MD_MULTIPATH
 	tristate "Multipath I/O support"
 	depends on BLK_DEV_MD
 	help
 	  MD_MULTIPATH provides a simple multi-path personality for use
 	  the MD framework.  It is not under active development.  New
 	  projects should consider using DM_MULTIPATH which has more
 	  features and more testing.

 	  If unsure, say N.

 config MD_FAULTY
 	tristate "Faulty test module for MD"
 	depends on BLK_DEV_MD
 	help
 	  The "faulty" module allows for a block device that occasionally returns
 	  read or write errors.  It is useful for testing.

 	  In unsure, say N.


 config MD_CLUSTER
 	tristate "Cluster Support for MD (EXPERIMENTAL)"
 	depends on BLK_DEV_MD
 	depends on DLM
 	default n
 	---help---
 	Clustering support for MD devices. This enables locking and
 	synchronization across multiple systems on the cluster, so all
 	nodes in the cluster can access the MD devices simultaneously.

 	This brings the redundancy (and uptime) of RAID levels across the
 	nodes of the cluster.

 	If unsure, say N.

 source "drivers/md/bcache/Kconfig"

 config BLK_DEV_DM_BUILTIN
 	bool

 config BLK_DEV_DM
 	tristate "Device mapper support"
 	select BLK_DEV_DM_BUILTIN
 	select DAX
 	---help---
 	  Device-mapper is a low level volume manager.  It works by allowing
 	  people to specify mappings for ranges of logical sectors.  Various
 	  mapping types are available, in addition people may write their own
 	  modules containing custom mappings if they wish.

 	  Higher level volume managers such as LVM2 use this driver.

 	  To compile this as a module, choose M here: the module will be
 	  called dm-mod.

 	  If unsure, say N.

 config DM_MQ_DEFAULT
 	bool "request-based DM: use blk-mq I/O path by default"
 	depends on BLK_DEV_DM
 	---help---
 	  This option enables the blk-mq based I/O path for request-based
 	  DM devices by default.  With the option the dm_mod.use_blk_mq
 	  module/boot option defaults to Y, without it to N, but it can
 	  still be overriden either way.

 	  If unsure say N.

 config DM_DEBUG
 	bool "Device mapper debugging support"
 	depends on BLK_DEV_DM
 	---help---
 	  Enable this for messages that may help debug device-mapper problems.

 	  If unsure, say N.

 config DM_BUFIO
        tristate
        depends on BLK_DEV_DM
        ---help---
 	 This interface allows you to do buffered I/O on a device and acts
 	 as a cache, holding recently-read blocks in memory and performing
 	 delayed writes.

 config DM_DEBUG_BLOCK_MANAGER_LOCKING
        bool "Block manager locking"
        depends on DM_BUFIO
        ---help---
 	 Block manager locking can catch various metadata corruption issues.

 	 If unsure, say N.

 config DM_DEBUG_BLOCK_STACK_TRACING
        bool "Keep stack trace of persistent data block lock holders"
        depends on STACKTRACE_SUPPORT && DM_DEBUG_BLOCK_MANAGER_LOCKING
        select STACKTRACE
        ---help---
 	 Enable this for messages that may help debug problems with the
 	 block manager locking used by thin provisioning and caching.

 	 If unsure, say N.

 config DM_BIO_PRISON
        tristate
        depends on BLK_DEV_DM
        ---help---
 	 Some bio locking schemes used by other device-mapper targets
 	 including thin provisioning.

 source "drivers/md/persistent-data/Kconfig"

 config DM_CRYPT
 	tristate "Crypt target support"
 	depends on BLK_DEV_DM
 	select CRYPTO
 	select CRYPTO_CBC
 	---help---
 	  This device-mapper target allows you to create a device that
 	  transparently encrypts the data on it. You'll need to activate
 	  the ciphers you're going to use in the cryptoapi configuration.

 	  For further information on dm-crypt and userspace tools see:
 	  <https://gitlab.com/cryptsetup/cryptsetup/wikis/DMCrypt>

 	  To compile this code as a module, choose M here: the module will
 	  be called dm-crypt.

 	  If unsure, say N.

 config DM_DEFAULT_KEY
 	tristate "Default-key target support"
 	depends on BLK_DEV_DM
 	depends on BLK_INLINE_ENCRYPTION
 	# dm-default-key doesn't require -o inlinecrypt, but it does currently
 	# rely on the inline encryption hooks being built into the kernel.
 	depends on FS_ENCRYPTION_INLINE_CRYPT
 	help
 	  This device-mapper target allows you to create a device that
 	  assigns a default encryption key to bios that aren't for the
 	  contents of an encrypted file.

 	  This ensures that all blocks on-disk will be encrypted with
 	  some key, without the performance hit of file contents being
 	  encrypted twice when fscrypt (File-Based Encryption) is used.

 	  It is only appropriate to use dm-default-key when key
 	  configuration is tightly controlled, like it is in Android,
 	  such that all fscrypt keys are at least as hard to compromise
 	  as the default key.

 config DM_SNAPSHOT
        tristate "Snapshot target"
        depends on BLK_DEV_DM
        select DM_BUFIO
        ---help---
          Allow volume managers to take writable snapshots of a device.

 config DM_THIN_PROVISIONING
        tristate "Thin provisioning target"
        depends on BLK_DEV_DM
        select DM_PERSISTENT_DATA
        select DM_BIO_PRISON
        ---help---
          Provides thin provisioning and snapshots that share a data store.

 config DM_CACHE
        tristate "Cache target (EXPERIMENTAL)"
        depends on BLK_DEV_DM
        default n
        select DM_PERSISTENT_DATA
        select DM_BIO_PRISON
        ---help---
          dm-cache attempts to improve performance of a block device by
          moving frequently used data to a smaller, higher performance
          device.  Different 'policy' plugins can be used to change the
          algorithms used to select which blocks are promoted, demoted,
          cleaned etc.  It supports writeback and writethrough modes.

 config DM_CACHE_SMQ
        tristate "Stochastic MQ Cache Policy (EXPERIMENTAL)"
        depends on DM_CACHE
        default y
        ---help---
          A cache policy that uses a multiqueue ordered by recent hits
          to select which blocks should be promoted and demoted.
          This is meant to be a general purpose policy.  It prioritises
          reads over writes.  This SMQ policy (vs MQ) offers the promise
          of less memory utilization, improved performance and increased
          adaptability in the face of changing workloads.

 config DM_ERA
        tristate "Era target (EXPERIMENTAL)"
        depends on BLK_DEV_DM
        default n
        select DM_PERSISTENT_DATA
        select DM_BIO_PRISON
        ---help---
          dm-era tracks which parts of a block device are written to
          over time.  Useful for maintaining cache coherency when using
          vendor snapshots.

 config DM_MIRROR
        tristate "Mirror target"
        depends on BLK_DEV_DM
        ---help---
          Allow volume managers to mirror logical volumes, also
          needed for live data migration tools such as 'pvmove'.

 config DM_LOG_USERSPACE
 	tristate "Mirror userspace logging"
 	depends on DM_MIRROR && NET
 	select CONNECTOR
 	---help---
 	  The userspace logging module provides a mechanism for
 	  relaying the dm-dirty-log API to userspace.  Log designs
 	  which are more suited to userspace implementation (e.g.
 	  shared storage logs) or experimental logs can be implemented
 	  by leveraging this framework.

 config DM_RAID
        tristate "RAID 1/4/5/6/10 target"
        depends on BLK_DEV_DM
        select MD_RAID0
        select MD_RAID1
        select MD_RAID10
        select MD_RAID456
        select BLK_DEV_MD
        ---help---
 	 A dm target that supports RAID1, RAID10, 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_ZERO
 	tristate "Zero target"
 	depends on BLK_DEV_DM
 	---help---
 	  A target that discards writes, and returns all zeroes for
 	  reads.  Useful in some recovery situations.

 config DM_MULTIPATH
 	tristate "Multipath target"
 	depends on BLK_DEV_DM
 	# nasty syntax but means make DM_MULTIPATH independent
 	# of SCSI_DH if the latter isn't defined but if
 	# it is, DM_MULTIPATH must depend on it.  We get a build
 	# error if SCSI_DH=m and DM_MULTIPATH=y
 	depends on !SCSI_DH || SCSI
 	---help---
 	  Allow volume managers to support multipath hardware.

 config DM_MULTIPATH_QL
 	tristate "I/O Path Selector based on the number of in-flight I/Os"
 	depends on DM_MULTIPATH
 	---help---
 	  This path selector is a dynamic load balancer which selects
 	  the path with the least number of in-flight I/Os.

 	  If unsure, say N.

 config DM_MULTIPATH_ST
 	tristate "I/O Path Selector based on the service time"
 	depends on DM_MULTIPATH
 	---help---
 	  This path selector is a dynamic load balancer which selects
 	  the path expected to complete the incoming I/O in the shortest
 	  time.

 	  If unsure, say N.

 config DM_DELAY
 	tristate "I/O delaying target"
 	depends on BLK_DEV_DM
 	---help---
 	A target that delays reads and/or writes and can send
 	them to different devices.  Useful for testing.

 	If unsure, say N.

 config DM_UEVENT
 	bool "DM uevents"
 	depends on BLK_DEV_DM
 	---help---
 	Generate udev events for DM events.

 config DM_FLAKEY
        tristate "Flakey target"
        depends on BLK_DEV_DM
        ---help---
          A target that intermittently fails I/O for debugging purposes.

 config DM_VERITY
 	tristate "Verity target support"
 	depends on BLK_DEV_DM
 	select CRYPTO
 	select CRYPTO_HASH
 	select DM_BUFIO
 	---help---
 	  This device-mapper target creates a read-only device that
 	  transparently validates the data on one underlying device against
 	  a pre-generated tree of cryptographic checksums stored on a second
 	  device.

 	  You'll need to activate the digests you're going to use in the
 	  cryptoapi configuration.

 	  To compile this code as a module, choose M here: the module will
 	  be called dm-verity.

 	  If unsure, say N.

 config DM_VERITY_FEC
 	bool "Verity forward error correction support"
 	depends on DM_VERITY
 	select REED_SOLOMON
 	select REED_SOLOMON_DEC8
 	---help---
 	  Add forward error correction support to dm-verity. This option
 	  makes it possible to use pre-generated error correction data to
 	  recover from corrupted blocks.

 	  If unsure, say N.

 config DM_SWITCH
 	tristate "Switch target support (EXPERIMENTAL)"
 	depends on BLK_DEV_DM
 	---help---
 	  This device-mapper target creates a device that supports an arbitrary
 	  mapping of fixed-size regions of I/O across a fixed set of paths.
 	  The path used for any specific region can be switched dynamically
 	  by sending the target a message.

 	  To compile this code as a module, choose M here: the module will
 	  be called dm-switch.

 	  If unsure, say N.

 config DM_LOG_WRITES
 	tristate "Log writes target support"
 	depends on BLK_DEV_DM
 	---help---
 	  This device-mapper target takes two devices, one device to use
 	  normally, one to log all write operations done to the first device.
 	  This is for use by file system developers wishing to verify that
 	  their fs is writing a consistent file system at all times by allowing
 	  them to replay the log in a variety of ways and to check the
 	  contents.

 	  To compile this code as a module, choose M here: the module will
 	  be called dm-log-writes.

 	  If unsure, say N.

 config DM_INTEGRITY
 	tristate "Integrity target support"
 	depends on BLK_DEV_DM
 	select BLK_DEV_INTEGRITY
 	select DM_BUFIO
 	select CRYPTO
 	select ASYNC_XOR
 	---help---
 	  This device-mapper target emulates a block device that has
 	  additional per-sector tags that can be used for storing
 	  integrity information.

 	  This integrity target is used with the dm-crypt target to
 	  provide authenticated disk encryption or it can be used
 	  standalone.

 	  To compile this code as a module, choose M here: the module will
 	  be called dm-integrity.

 config DM_ZONED
 	tristate "Drive-managed zoned block device target support"
 	depends on BLK_DEV_DM
 	depends on BLK_DEV_ZONED
 	---help---
 	  This device-mapper target takes a host-managed or host-aware zoned
 	  block device and exposes most of its capacity as a regular block
 	  device (drive-managed zoned block device) without any write
 	  constraints. This is mainly intended for use with file systems that
 	  do not natively support zoned block devices but still want to
 	  benefit from the increased capacity offered by SMR disks. Other uses
 	  by applications using raw block devices (for example object stores)
 	  are also possible.

 	  To compile this code as a module, choose M here: the module will
 	  be called dm-zoned.

 	  If unsure, say N.

 config DM_VERITY_AVB
 	tristate "Support AVB specific verity error behavior"
 	depends on DM_VERITY
 	---help---
 	  Enables Android Verified Boot platform-specific error
 	  behavior. In particular, it will modify the vbmeta partition
 	  specified on the kernel command-line when non-transient error
 	  occurs (followed by a panic).

 config DM_ANDROID_VERITY
 	bool "Android verity target support"
 	depends on BLK_DEV_DM=y
 	depends on DM_VERITY=y
 	depends on X509_CERTIFICATE_PARSER
 	depends on SYSTEM_TRUSTED_KEYRING
 	depends on CRYPTO_RSA
 	depends on KEYS
 	depends on ASYMMETRIC_KEY_TYPE
 	depends on ASYMMETRIC_PUBLIC_KEY_SUBTYPE
 	---help---
 	  This device-mapper target is virtually a VERITY target. This
 	  target is setup by reading the metadata contents piggybacked
 	  to the actual data blocks in the block device. The signature
 	  of the metadata contents are verified against the key included
 	  in the system keyring. Upon success, the underlying verity
 	  target is setup.

 config DM_ANDROID_VERITY_AT_MOST_ONCE_DEFAULT_ENABLED
 	bool "Verity will validate blocks at most once"
 	depends on DM_VERITY
 	---help---
 	  Default enables at_most_once option for dm-verity

 	  Verify data blocks only the first time they are read from the
 	  data device, rather than every time.  This reduces the overhead
 	  of dm-verity so that it can be used on systems that are memory
 	  and/or CPU constrained.  However, it provides a reduced level
 	  of security because only offline tampering of the data device's
 	  content will be detected, not online tampering.

 	  Hash blocks are still verified each time they are read from the
 	  hash device, since verification of hash blocks is less performance
 	  critical than data blocks, and a hash block will not be verified
 	  any more after all the data blocks it covers have been verified anyway.

 	  If unsure, say N.

 config DM_BOW
 	tristate "Backup block device"
 	depends on BLK_DEV_DM
 	select DM_BUFIO
 	---help---
 	  This device-mapper target takes a device and keeps a log of all
 	  changes using free blocks identified by issuing a trim command.
 	  This can then be restored by running a command line utility,
 	  or committed by simply replacing the target.

 	  If unsure, say N.

 endif # MD
	#
	# Block device driver configuration
	#

	menuconfig MD
	bool "Multiple devices driver support (RAID and LVM)"
	depends on BLOCK
	select SRCU
	help
	Support multiple physical spindles through a single logical device.
	Required for RAID and logical volume management.

	if MD

	config BLK_DEV_MD
	tristate "RAID support"
	---help---
	This driver lets you combine several hard disk partitions into one
	logical block device. This can be used to simply append one
	partition to another one or to combine several redundant hard disks
	into a RAID1/4/5 device so as to provide protection against hard
	disk failures. This is called "Software RAID" since the combining of
	the partitions is done by the kernel. "Hardware RAID" means that the
	combining is done by a dedicated controller; if you have such a
	controller, you do not need to say Y here.

	More information about Software RAID on Linux is contained in the
	Software RAID mini-HOWTO, available from
	<http://www.tldp.org/docs.html#howto>. There you will also learn
	where to get the supporting user space utilities raidtools.

	If unsure, say N.

	config MD_AUTODETECT
	bool "Autodetect RAID arrays during kernel boot"
	depends on BLK_DEV_MD=y
	default y
	---help---
	If you say Y here, then the kernel will try to autodetect raid
	arrays as part of its boot process.

	If you don't use raid and say Y, this autodetection can cause
	a several-second delay in the boot time due to various
	synchronisation steps that are part of this step.

	If unsure, say Y.

	config MD_LINEAR
	tristate "Linear (append) mode"
	depends on BLK_DEV_MD
	---help---
	If you say Y here, then your multiple devices driver will be able to
	use the so-called linear mode, i.e. it will combine the hard disk
	partitions by simply appending one to the other.

	To compile this as a module, choose M here: the module
	will be called linear.

	If unsure, say Y.

	config MD_RAID0
	tristate "RAID-0 (striping) mode"
	depends on BLK_DEV_MD
	---help---
	If you say Y here, then your multiple devices driver will be able to
	use the so-called raid0 mode, i.e. it will combine the hard disk
	partitions into one logical device in such a fashion as to fill them
	up evenly, one chunk here and one chunk there. This will increase
	the throughput rate if the partitions reside on distinct disks.

	Information about Software RAID on Linux is contained in the
	Software-RAID mini-HOWTO, available from
	<http://www.tldp.org/docs.html#howto>. There you will also
	learn where to get the supporting user space utilities raidtools.

	To compile this as a module, choose M here: the module
	will be called raid0.

	If unsure, say Y.

	config MD_RAID1
	tristate "RAID-1 (mirroring) mode"
	depends on BLK_DEV_MD
	---help---
	A RAID-1 set consists of several disk drives which are exact copies
	of each other. In the event of a mirror failure, the RAID driver
	will continue to use the operational mirrors in the set, providing
	an error free MD (multiple device) to the higher levels of the
	kernel. In a set with N drives, the available space is the capacity
	of a single drive, and the set protects against a failure of (N - 1)
	drives.

	Information about Software RAID on Linux is contained in the
	Software-RAID mini-HOWTO, available from
	<http://www.tldp.org/docs.html#howto>. There you will also
	learn where to get the supporting user space utilities raidtools.

	If you want to use such a RAID-1 set, say Y. To compile this code
	as a module, choose M here: the module will be called raid1.

	If unsure, say Y.

	config MD_RAID10
	tristate "RAID-10 (mirrored striping) mode"
	depends on BLK_DEV_MD
	---help---
	RAID-10 provides a combination of striping (RAID-0) and
	mirroring (RAID-1) with easier configuration and more flexible
	layout.
	Unlike RAID-0, but like RAID-1, RAID-10 requires all devices to
	be the same size (or at least, only as much as the smallest device
	will be used).
	RAID-10 provides a variety of layouts that provide different levels
	of redundancy and performance.

	RAID-10 requires mdadm-1.7.0 or later, available at:

	https://www.kernel.org/pub/linux/utils/raid/mdadm/

	If unsure, say Y.

	config MD_RAID456
	tristate "RAID-4/RAID-5/RAID-6 mode"
	depends on BLK_DEV_MD
	select RAID6_PQ
	select LIBCRC32C
	select ASYNC_MEMCPY
	select ASYNC_XOR
	select ASYNC_PQ
	select ASYNC_RAID6_RECOV
	---help---
	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.

	Information about Software RAID on Linux is contained in the
	Software-RAID mini-HOWTO, available from
	<http://www.tldp.org/docs.html#howto>. There you will also
	learn where to get the supporting user space utilities raidtools.

	If you want to use such a RAID-4/RAID-5/RAID-6 set, say Y. To
	compile this code as a module, choose M here: the module
	will be called raid456.

	If unsure, say Y.

	config MD_MULTIPATH
	tristate "Multipath I/O support"
	depends on BLK_DEV_MD
	help
	MD_MULTIPATH provides a simple multi-path personality for use
	the MD framework. It is not under active development. New
	projects should consider using DM_MULTIPATH which has more
	features and more testing.

	If unsure, say N.

	config MD_FAULTY
	tristate "Faulty test module for MD"
	depends on BLK_DEV_MD
	help
	The "faulty" module allows for a block device that occasionally returns
	read or write errors. It is useful for testing.

	In unsure, say N.


	config MD_CLUSTER
	tristate "Cluster Support for MD (EXPERIMENTAL)"
	depends on BLK_DEV_MD
	depends on DLM
	default n
	---help---
	Clustering support for MD devices. This enables locking and
	synchronization across multiple systems on the cluster, so all
	nodes in the cluster can access the MD devices simultaneously.

	This brings the redundancy (and uptime) of RAID levels across the
	nodes of the cluster.

	If unsure, say N.

	source "drivers/md/bcache/Kconfig"

	config BLK_DEV_DM_BUILTIN
	bool

	config BLK_DEV_DM
	tristate "Device mapper support"
	select BLK_DEV_DM_BUILTIN
	select DAX
	---help---
	Device-mapper is a low level volume manager. It works by allowing
	people to specify mappings for ranges of logical sectors. Various
	mapping types are available, in addition people may write their own
	modules containing custom mappings if they wish.

	Higher level volume managers such as LVM2 use this driver.

	To compile this as a module, choose M here: the module will be
	called dm-mod.

	If unsure, say N.

	config DM_MQ_DEFAULT
	bool "request-based DM: use blk-mq I/O path by default"
	depends on BLK_DEV_DM
	---help---
	This option enables the blk-mq based I/O path for request-based
	DM devices by default. With the option the dm_mod.use_blk_mq
	module/boot option defaults to Y, without it to N, but it can
	still be overriden either way.

	If unsure say N.

	config DM_DEBUG
	bool "Device mapper debugging support"
	depends on BLK_DEV_DM
	---help---
	Enable this for messages that may help debug device-mapper problems.

	If unsure, say N.

	config DM_BUFIO
	tristate
	depends on BLK_DEV_DM
	---help---
	This interface allows you to do buffered I/O on a device and acts
	as a cache, holding recently-read blocks in memory and performing
	delayed writes.

	config DM_DEBUG_BLOCK_MANAGER_LOCKING
	bool "Block manager locking"
	depends on DM_BUFIO
	---help---
	Block manager locking can catch various metadata corruption issues.

	If unsure, say N.

	config DM_DEBUG_BLOCK_STACK_TRACING
	bool "Keep stack trace of persistent data block lock holders"
	depends on STACKTRACE_SUPPORT && DM_DEBUG_BLOCK_MANAGER_LOCKING
	select STACKTRACE
	---help---
	Enable this for messages that may help debug problems with the
	block manager locking used by thin provisioning and caching.

	If unsure, say N.

	config DM_BIO_PRISON
	tristate
	depends on BLK_DEV_DM
	---help---
	Some bio locking schemes used by other device-mapper targets
	including thin provisioning.

	source "drivers/md/persistent-data/Kconfig"

	config DM_CRYPT
	tristate "Crypt target support"
	depends on BLK_DEV_DM
	select CRYPTO
	select CRYPTO_CBC
	---help---
	This device-mapper target allows you to create a device that
	transparently encrypts the data on it. You'll need to activate
	the ciphers you're going to use in the cryptoapi configuration.

	For further information on dm-crypt and userspace tools see:
	<https://gitlab.com/cryptsetup/cryptsetup/wikis/DMCrypt>

	To compile this code as a module, choose M here: the module will
	be called dm-crypt.

	If unsure, say N.

	config DM_DEFAULT_KEY
	tristate "Default-key target support"
	depends on BLK_DEV_DM
	depends on BLK_INLINE_ENCRYPTION
	# dm-default-key doesn't require -o inlinecrypt, but it does currently
	# rely on the inline encryption hooks being built into the kernel.
	depends on FS_ENCRYPTION_INLINE_CRYPT
	help
	This device-mapper target allows you to create a device that
	assigns a default encryption key to bios that aren't for the
	contents of an encrypted file.

	This ensures that all blocks on-disk will be encrypted with
	some key, without the performance hit of file contents being
	encrypted twice when fscrypt (File-Based Encryption) is used.

	It is only appropriate to use dm-default-key when key
	configuration is tightly controlled, like it is in Android,
	such that all fscrypt keys are at least as hard to compromise
	as the default key.

	config DM_SNAPSHOT
	tristate "Snapshot target"
	depends on BLK_DEV_DM
	select DM_BUFIO
	---help---
	Allow volume managers to take writable snapshots of a device.

	config DM_THIN_PROVISIONING
	tristate "Thin provisioning target"
	depends on BLK_DEV_DM
	select DM_PERSISTENT_DATA
	select DM_BIO_PRISON
	---help---
	Provides thin provisioning and snapshots that share a data store.

	config DM_CACHE
	tristate "Cache target (EXPERIMENTAL)"
	depends on BLK_DEV_DM
	default n
	select DM_PERSISTENT_DATA
	select DM_BIO_PRISON
	---help---
	dm-cache attempts to improve performance of a block device by
	moving frequently used data to a smaller, higher performance
	device. Different 'policy' plugins can be used to change the
	algorithms used to select which blocks are promoted, demoted,
	cleaned etc. It supports writeback and writethrough modes.

	config DM_CACHE_SMQ
	tristate "Stochastic MQ Cache Policy (EXPERIMENTAL)"
	depends on DM_CACHE
	default y
	---help---
	A cache policy that uses a multiqueue ordered by recent hits
	to select which blocks should be promoted and demoted.
	This is meant to be a general purpose policy. It prioritises
	reads over writes. This SMQ policy (vs MQ) offers the promise
	of less memory utilization, improved performance and increased
	adaptability in the face of changing workloads.

	config DM_ERA
	tristate "Era target (EXPERIMENTAL)"
	depends on BLK_DEV_DM
	default n
	select DM_PERSISTENT_DATA
	select DM_BIO_PRISON
	---help---
	dm-era tracks which parts of a block device are written to
	over time. Useful for maintaining cache coherency when using
	vendor snapshots.

	config DM_MIRROR
	tristate "Mirror target"
	depends on BLK_DEV_DM
	---help---
	Allow volume managers to mirror logical volumes, also
	needed for live data migration tools such as 'pvmove'.

	config DM_LOG_USERSPACE
	tristate "Mirror userspace logging"
	depends on DM_MIRROR && NET
	select CONNECTOR
	---help---
	The userspace logging module provides a mechanism for
	relaying the dm-dirty-log API to userspace. Log designs
	which are more suited to userspace implementation (e.g.
	shared storage logs) or experimental logs can be implemented
	by leveraging this framework.

	config DM_RAID
	tristate "RAID 1/4/5/6/10 target"
	depends on BLK_DEV_DM
	select MD_RAID0
	select MD_RAID1
	select MD_RAID10
	select MD_RAID456
	select BLK_DEV_MD
	---help---
	A dm target that supports RAID1, RAID10, 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_ZERO
	tristate "Zero target"
	depends on BLK_DEV_DM
	---help---
	A target that discards writes, and returns all zeroes for
	reads. Useful in some recovery situations.

	config DM_MULTIPATH
	tristate "Multipath target"
	depends on BLK_DEV_DM
	# nasty syntax but means make DM_MULTIPATH independent
	# of SCSI_DH if the latter isn't defined but if
	# it is, DM_MULTIPATH must depend on it. We get a build
	# error if SCSI_DH=m and DM_MULTIPATH=y
	depends on !SCSI_DH \|\| SCSI
	---help---
	Allow volume managers to support multipath hardware.

	config DM_MULTIPATH_QL
	tristate "I/O Path Selector based on the number of in-flight I/Os"
	depends on DM_MULTIPATH
	---help---
	This path selector is a dynamic load balancer which selects
	the path with the least number of in-flight I/Os.

	If unsure, say N.

	config DM_MULTIPATH_ST
	tristate "I/O Path Selector based on the service time"
	depends on DM_MULTIPATH
	---help---
	This path selector is a dynamic load balancer which selects
	the path expected to complete the incoming I/O in the shortest
	time.

	If unsure, say N.

	config DM_DELAY
	tristate "I/O delaying target"
	depends on BLK_DEV_DM
	---help---
	A target that delays reads and/or writes and can send
	them to different devices. Useful for testing.

	If unsure, say N.

	config DM_UEVENT
	bool "DM uevents"
	depends on BLK_DEV_DM
	---help---
	Generate udev events for DM events.

	config DM_FLAKEY
	tristate "Flakey target"
	depends on BLK_DEV_DM
	---help---
	A target that intermittently fails I/O for debugging purposes.

	config DM_VERITY
	tristate "Verity target support"
	depends on BLK_DEV_DM
	select CRYPTO
	select CRYPTO_HASH
	select DM_BUFIO
	---help---
	This device-mapper target creates a read-only device that
	transparently validates the data on one underlying device against
	a pre-generated tree of cryptographic checksums stored on a second
	device.

	You'll need to activate the digests you're going to use in the
	cryptoapi configuration.

	To compile this code as a module, choose M here: the module will
	be called dm-verity.

	If unsure, say N.

	config DM_VERITY_FEC
	bool "Verity forward error correction support"
	depends on DM_VERITY
	select REED_SOLOMON
	select REED_SOLOMON_DEC8
	---help---
	Add forward error correction support to dm-verity. This option
	makes it possible to use pre-generated error correction data to
	recover from corrupted blocks.

	If unsure, say N.

	config DM_SWITCH
	tristate "Switch target support (EXPERIMENTAL)"
	depends on BLK_DEV_DM
	---help---
	This device-mapper target creates a device that supports an arbitrary
	mapping of fixed-size regions of I/O across a fixed set of paths.
	The path used for any specific region can be switched dynamically
	by sending the target a message.

	To compile this code as a module, choose M here: the module will
	be called dm-switch.

	If unsure, say N.

	config DM_LOG_WRITES
	tristate "Log writes target support"
	depends on BLK_DEV_DM
	---help---
	This device-mapper target takes two devices, one device to use
	normally, one to log all write operations done to the first device.
	This is for use by file system developers wishing to verify that
	their fs is writing a consistent file system at all times by allowing
	them to replay the log in a variety of ways and to check the
	contents.

	To compile this code as a module, choose M here: the module will
	be called dm-log-writes.

	If unsure, say N.

	config DM_INTEGRITY
	tristate "Integrity target support"
	depends on BLK_DEV_DM
	select BLK_DEV_INTEGRITY
	select DM_BUFIO
	select CRYPTO
	select ASYNC_XOR
	---help---
	This device-mapper target emulates a block device that has
	additional per-sector tags that can be used for storing
	integrity information.

	This integrity target is used with the dm-crypt target to
	provide authenticated disk encryption or it can be used
	standalone.

	To compile this code as a module, choose M here: the module will
	be called dm-integrity.

	config DM_ZONED
	tristate "Drive-managed zoned block device target support"
	depends on BLK_DEV_DM
	depends on BLK_DEV_ZONED
	---help---
	This device-mapper target takes a host-managed or host-aware zoned
	block device and exposes most of its capacity as a regular block
	device (drive-managed zoned block device) without any write
	constraints. This is mainly intended for use with file systems that
	do not natively support zoned block devices but still want to
	benefit from the increased capacity offered by SMR disks. Other uses
	by applications using raw block devices (for example object stores)
	are also possible.

	To compile this code as a module, choose M here: the module will
	be called dm-zoned.

	If unsure, say N.

	config DM_VERITY_AVB
	tristate "Support AVB specific verity error behavior"
	depends on DM_VERITY
	---help---
	Enables Android Verified Boot platform-specific error
	behavior. In particular, it will modify the vbmeta partition
	specified on the kernel command-line when non-transient error
	occurs (followed by a panic).

	config DM_ANDROID_VERITY
	bool "Android verity target support"
	depends on BLK_DEV_DM=y
	depends on DM_VERITY=y
	depends on X509_CERTIFICATE_PARSER
	depends on SYSTEM_TRUSTED_KEYRING
	depends on CRYPTO_RSA
	depends on KEYS
	depends on ASYMMETRIC_KEY_TYPE
	depends on ASYMMETRIC_PUBLIC_KEY_SUBTYPE
	---help---
	This device-mapper target is virtually a VERITY target. This
	target is setup by reading the metadata contents piggybacked
	to the actual data blocks in the block device. The signature
	of the metadata contents are verified against the key included
	in the system keyring. Upon success, the underlying verity
	target is setup.

	config DM_ANDROID_VERITY_AT_MOST_ONCE_DEFAULT_ENABLED
	bool "Verity will validate blocks at most once"
	depends on DM_VERITY
	---help---
	Default enables at_most_once option for dm-verity

	Verify data blocks only the first time they are read from the
	data device, rather than every time. This reduces the overhead
	of dm-verity so that it can be used on systems that are memory
	and/or CPU constrained. However, it provides a reduced level
	of security because only offline tampering of the data device's
	content will be detected, not online tampering.

	Hash blocks are still verified each time they are read from the
	hash device, since verification of hash blocks is less performance
	critical than data blocks, and a hash block will not be verified
	any more after all the data blocks it covers have been verified anyway.

	If unsure, say N.

	config DM_BOW
	tristate "Backup block device"
	depends on BLK_DEV_DM
	select DM_BUFIO
	---help---
	This device-mapper target takes a device and keeps a log of all
	changes using free blocks identified by issuing a trim command.
	This can then be restored by running a command line utility,
	or committed by simply replacing the target.

	If unsure, say N.

	endif # MD