drivers/md/Kconfig

   1 # SPDX-License-Identifier: GPL-2.0-only
   2 #
   3 # Block device driver configuration
   4 #
   5
   6 menuconfig MD
   7         bool "Multiple devices driver support (RAID and LVM)"
   8         depends on BLOCK
   9         select SRCU
  10         help
  11           Support multiple physical spindles through a single logical device.
  12           Required for RAID and logical volume management.
  13
  14 if MD
  15
  16 config BLK_DEV_MD
  17         tristate "RAID support"
  18         help
  19           This driver lets you combine several hard disk partitions into one
  20           logical block device. This can be used to simply append one
  21           partition to another one or to combine several redundant hard disks
  22           into a RAID1/4/5 device so as to provide protection against hard
  23           disk failures. This is called "Software RAID" since the combining of
  24           the partitions is done by the kernel. "Hardware RAID" means that the
  25           combining is done by a dedicated controller; if you have such a
  26           controller, you do not need to say Y here.
  27
  28           More information about Software RAID on Linux is contained in the
  29           Software RAID mini-HOWTO, available from
  30           <https://www.tldp.org/docs.html#howto>. There you will also learn
  31           where to get the supporting user space utilities raidtools.
  32
  33           If unsure, say N.
  34
  35 config MD_AUTODETECT
  36         bool "Autodetect RAID arrays during kernel boot"
  37         depends on BLK_DEV_MD=y
  38         default y
  39         help
  40           If you say Y here, then the kernel will try to autodetect raid
  41           arrays as part of its boot process.
  42
  43           If you don't use raid and say Y, this autodetection can cause
  44           a several-second delay in the boot time due to various
  45           synchronisation steps that are part of this step.
  46
  47           If unsure, say Y.
  48
  49 config MD_LINEAR
  50         tristate "Linear (append) mode"
  51         depends on BLK_DEV_MD
  52         help
  53           If you say Y here, then your multiple devices driver will be able to
  54           use the so-called linear mode, i.e. it will combine the hard disk
  55           partitions by simply appending one to the other.
  56
  57           To compile this as a module, choose M here: the module
  58           will be called linear.
  59
  60           If unsure, say Y.
  61
  62 config MD_RAID0
  63         tristate "RAID-0 (striping) mode"
  64         depends on BLK_DEV_MD
  65         help
  66           If you say Y here, then your multiple devices driver will be able to
  67           use the so-called raid0 mode, i.e. it will combine the hard disk
  68           partitions into one logical device in such a fashion as to fill them
  69           up evenly, one chunk here and one chunk there. This will increase
  70           the throughput rate if the partitions reside on distinct disks.
  71
  72           Information about Software RAID on Linux is contained in the
  73           Software-RAID mini-HOWTO, available from
  74           <https://www.tldp.org/docs.html#howto>. There you will also
  75           learn where to get the supporting user space utilities raidtools.
  76
  77           To compile this as a module, choose M here: the module
  78           will be called raid0.
  79
  80           If unsure, say Y.
  81
  82 config MD_RAID1
  83         tristate "RAID-1 (mirroring) mode"
  84         depends on BLK_DEV_MD
  85         help
  86           A RAID-1 set consists of several disk drives which are exact copies
  87           of each other.  In the event of a mirror failure, the RAID driver
  88           will continue to use the operational mirrors in the set, providing
  89           an error free MD (multiple device) to the higher levels of the
  90           kernel.  In a set with N drives, the available space is the capacity
  91           of a single drive, and the set protects against a failure of (N - 1)
  92           drives.
  93
  94           Information about Software RAID on Linux is contained in the
  95           Software-RAID mini-HOWTO, available from
  96           <https://www.tldp.org/docs.html#howto>.  There you will also
  97           learn where to get the supporting user space utilities raidtools.
  98
  99           If you want to use such a RAID-1 set, say Y.  To compile this code
 100           as a module, choose M here: the module will be called raid1.
 101
 102           If unsure, say Y.
 103
 104 config MD_RAID10
 105         tristate "RAID-10 (mirrored striping) mode"
 106         depends on BLK_DEV_MD
 107         help
 108           RAID-10 provides a combination of striping (RAID-0) and
 109           mirroring (RAID-1) with easier configuration and more flexible
 110           layout.
 111           Unlike RAID-0, but like RAID-1, RAID-10 requires all devices to
 112           be the same size (or at least, only as much as the smallest device
 113           will be used).
 114           RAID-10 provides a variety of layouts that provide different levels
 115           of redundancy and performance.
 116
 117           RAID-10 requires mdadm-1.7.0 or later, available at:
 118
 119           https://www.kernel.org/pub/linux/utils/raid/mdadm/
 120
 121           If unsure, say Y.
 122
 123 config MD_RAID456
 124         tristate "RAID-4/RAID-5/RAID-6 mode"
 125         depends on BLK_DEV_MD
 126         select RAID6_PQ
 127         select LIBCRC32C
 128         select ASYNC_MEMCPY
 129         select ASYNC_XOR
 130         select ASYNC_PQ
 131         select ASYNC_RAID6_RECOV
 132         help
 133           A RAID-5 set of N drives with a capacity of C MB per drive provides
 134           the capacity of C * (N - 1) MB, and protects against a failure
 135           of a single drive. For a given sector (row) number, (N - 1) drives
 136           contain data sectors, and one drive contains the parity protection.
 137           For a RAID-4 set, the parity blocks are present on a single drive,
 138           while a RAID-5 set distributes the parity across the drives in one
 139           of the available parity distribution methods.
 140
 141           A RAID-6 set of N drives with a capacity of C MB per drive
 142           provides the capacity of C * (N - 2) MB, and protects
 143           against a failure of any two drives. For a given sector
 144           (row) number, (N - 2) drives contain data sectors, and two
 145           drives contains two independent redundancy syndromes.  Like
 146           RAID-5, RAID-6 distributes the syndromes across the drives
 147           in one of the available parity distribution methods.
 148
 149           Information about Software RAID on Linux is contained in the
 150           Software-RAID mini-HOWTO, available from
 151           <https://www.tldp.org/docs.html#howto>. There you will also
 152           learn where to get the supporting user space utilities raidtools.
 153
 154           If you want to use such a RAID-4/RAID-5/RAID-6 set, say Y.  To
 155           compile this code as a module, choose M here: the module
 156           will be called raid456.
 157
 158           If unsure, say Y.
 159
 160 config MD_MULTIPATH
 161         tristate "Multipath I/O support"
 162         depends on BLK_DEV_MD
 163         help
 164           MD_MULTIPATH provides a simple multi-path personality for use
 165           the MD framework.  It is not under active development.  New
 166           projects should consider using DM_MULTIPATH which has more
 167           features and more testing.
 168
 169           If unsure, say N.
 170
 171 config MD_FAULTY
 172         tristate "Faulty test module for MD"
 173         depends on BLK_DEV_MD
 174         help
 175           The "faulty" module allows for a block device that occasionally returns
 176           read or write errors.  It is useful for testing.
 177
 178           In unsure, say N.
 179
 180
 181 config MD_CLUSTER
 182         tristate "Cluster Support for MD"
 183         depends on BLK_DEV_MD
 184         depends on DLM
 185         default n
 186         help
 187         Clustering support for MD devices. This enables locking and
 188         synchronization across multiple systems on the cluster, so all
 189         nodes in the cluster can access the MD devices simultaneously.
 190
 191         This brings the redundancy (and uptime) of RAID levels across the
 192         nodes of the cluster. Currently, it can work with raid1 and raid10
 193         (limited support).
 194
 195         If unsure, say N.
 196
 197 source "drivers/md/bcache/Kconfig"
 198
 199 config BLK_DEV_DM_BUILTIN
 200         bool
 201
 202 config BLK_DEV_DM
 203         tristate "Device mapper support"
 204         select BLK_DEV_DM_BUILTIN
 205         depends on DAX || DAX=n
 206         help
 207           Device-mapper is a low level volume manager.  It works by allowing
 208           people to specify mappings for ranges of logical sectors.  Various
 209           mapping types are available, in addition people may write their own
 210           modules containing custom mappings if they wish.
 211
 212           Higher level volume managers such as LVM2 use this driver.
 213
 214           To compile this as a module, choose M here: the module will be
 215           called dm-mod.
 216
 217           If unsure, say N.
 218
 219 config DM_DEBUG
 220         bool "Device mapper debugging support"
 221         depends on BLK_DEV_DM
 222         help
 223           Enable this for messages that may help debug device-mapper problems.
 224
 225           If unsure, say N.
 226
 227 config DM_BUFIO
 228        tristate
 229        depends on BLK_DEV_DM
 230         help
 231          This interface allows you to do buffered I/O on a device and acts
 232          as a cache, holding recently-read blocks in memory and performing
 233          delayed writes.
 234
 235 config DM_DEBUG_BLOCK_MANAGER_LOCKING
 236        bool "Block manager locking"
 237        depends on DM_BUFIO
 238         help
 239          Block manager locking can catch various metadata corruption issues.
 240
 241          If unsure, say N.
 242
 243 config DM_DEBUG_BLOCK_STACK_TRACING
 244        bool "Keep stack trace of persistent data block lock holders"
 245        depends on STACKTRACE_SUPPORT && DM_DEBUG_BLOCK_MANAGER_LOCKING
 246        select STACKTRACE
 247         help
 248          Enable this for messages that may help debug problems with the
 249          block manager locking used by thin provisioning and caching.
 250
 251          If unsure, say N.
 252
 253 config DM_BIO_PRISON
 254        tristate
 255        depends on BLK_DEV_DM
 256         help
 257          Some bio locking schemes used by other device-mapper targets
 258          including thin provisioning.
 259
 260 source "drivers/md/persistent-data/Kconfig"
 261
 262 config DM_UNSTRIPED
 263        tristate "Unstriped target"
 264        depends on BLK_DEV_DM
 265         help
 266           Unstripes I/O so it is issued solely on a single drive in a HW
 267           RAID0 or dm-striped target.
 268
 269 config DM_CRYPT
 270         tristate "Crypt target support"
 271         depends on BLK_DEV_DM
 272         depends on (ENCRYPTED_KEYS || ENCRYPTED_KEYS=n)
 273         depends on (TRUSTED_KEYS || TRUSTED_KEYS=n)
 274         select CRYPTO
 275         select CRYPTO_CBC
 276         select CRYPTO_ESSIV
 277         help
 278           This device-mapper target allows you to create a device that
 279           transparently encrypts the data on it. You'll need to activate
 280           the ciphers you're going to use in the cryptoapi configuration.
 281
 282           For further information on dm-crypt and userspace tools see:
 283           <https://gitlab.com/cryptsetup/cryptsetup/wikis/DMCrypt>
 284
 285           To compile this code as a module, choose M here: the module will
 286           be called dm-crypt.
 287
 288           If unsure, say N.
 289
 290 config DM_SNAPSHOT
 291        tristate "Snapshot target"
 292        depends on BLK_DEV_DM
 293        select DM_BUFIO
 294         help
 295          Allow volume managers to take writable snapshots of a device.
 296
 297 config DM_THIN_PROVISIONING
 298        tristate "Thin provisioning target"
 299        depends on BLK_DEV_DM
 300        select DM_PERSISTENT_DATA
 301        select DM_BIO_PRISON
 302         help
 303          Provides thin provisioning and snapshots that share a data store.
 304
 305 config DM_CACHE
 306        tristate "Cache target (EXPERIMENTAL)"
 307        depends on BLK_DEV_DM
 308        default n
 309        select DM_PERSISTENT_DATA
 310        select DM_BIO_PRISON
 311         help
 312          dm-cache attempts to improve performance of a block device by
 313          moving frequently used data to a smaller, higher performance
 314          device.  Different 'policy' plugins can be used to change the
 315          algorithms used to select which blocks are promoted, demoted,
 316          cleaned etc.  It supports writeback and writethrough modes.
 317
 318 config DM_CACHE_SMQ
 319        tristate "Stochastic MQ Cache Policy (EXPERIMENTAL)"
 320        depends on DM_CACHE
 321        default y
 322         help
 323          A cache policy that uses a multiqueue ordered by recent hits
 324          to select which blocks should be promoted and demoted.
 325          This is meant to be a general purpose policy.  It prioritises
 326          reads over writes.  This SMQ policy (vs MQ) offers the promise
 327          of less memory utilization, improved performance and increased
 328          adaptability in the face of changing workloads.
 329
 330 config DM_WRITECACHE
 331         tristate "Writecache target"
 332         depends on BLK_DEV_DM
 333         help
 334            The writecache target caches writes on persistent memory or SSD.
 335            It is intended for databases or other programs that need extremely
 336            low commit latency.
 337
 338            The writecache target doesn't cache reads because reads are supposed
 339            to be cached in standard RAM.
 340
 341 config DM_EBS
 342         tristate "Emulated block size target (EXPERIMENTAL)"
 343         depends on BLK_DEV_DM
 344         select DM_BUFIO
 345         help
 346           dm-ebs emulates smaller logical block size on backing devices
 347           with larger ones (e.g. 512 byte sectors on 4K native disks).
 348
 349 config DM_ERA
 350        tristate "Era target (EXPERIMENTAL)"
 351        depends on BLK_DEV_DM
 352        default n
 353        select DM_PERSISTENT_DATA
 354        select DM_BIO_PRISON
 355         help
 356          dm-era tracks which parts of a block device are written to
 357          over time.  Useful for maintaining cache coherency when using
 358          vendor snapshots.
 359
 360 config DM_CLONE
 361        tristate "Clone target (EXPERIMENTAL)"
 362        depends on BLK_DEV_DM
 363        default n
 364        select DM_PERSISTENT_DATA
 365         help
 366          dm-clone produces a one-to-one copy of an existing, read-only source
 367          device into a writable destination device. The cloned device is
 368          visible/mountable immediately and the copy of the source device to the
 369          destination device happens in the background, in parallel with user
 370          I/O.
 371
 372          If unsure, say N.
 373
 374 config DM_MIRROR
 375        tristate "Mirror target"
 376        depends on BLK_DEV_DM
 377         help
 378          Allow volume managers to mirror logical volumes, also
 379          needed for live data migration tools such as 'pvmove'.
 380
 381 config DM_LOG_USERSPACE
 382         tristate "Mirror userspace logging"
 383         depends on DM_MIRROR && NET
 384         select CONNECTOR
 385         help
 386           The userspace logging module provides a mechanism for
 387           relaying the dm-dirty-log API to userspace.  Log designs
 388           which are more suited to userspace implementation (e.g.
 389           shared storage logs) or experimental logs can be implemented
 390           by leveraging this framework.
 391
 392 config DM_RAID
 393        tristate "RAID 1/4/5/6/10 target"
 394        depends on BLK_DEV_DM
 395        select MD_RAID0
 396        select MD_RAID1
 397        select MD_RAID10
 398        select MD_RAID456
 399        select BLK_DEV_MD
 400         help
 401          A dm target that supports RAID1, RAID10, RAID4, RAID5 and RAID6 mappings
 402
 403          A RAID-5 set of N drives with a capacity of C MB per drive provides
 404          the capacity of C * (N - 1) MB, and protects against a failure
 405          of a single drive. For a given sector (row) number, (N - 1) drives
 406          contain data sectors, and one drive contains the parity protection.
 407          For a RAID-4 set, the parity blocks are present on a single drive,
 408          while a RAID-5 set distributes the parity across the drives in one
 409          of the available parity distribution methods.
 410
 411          A RAID-6 set of N drives with a capacity of C MB per drive
 412          provides the capacity of C * (N - 2) MB, and protects
 413          against a failure of any two drives. For a given sector
 414          (row) number, (N - 2) drives contain data sectors, and two
 415          drives contains two independent redundancy syndromes.  Like
 416          RAID-5, RAID-6 distributes the syndromes across the drives
 417          in one of the available parity distribution methods.
 418
 419 config DM_ZERO
 420         tristate "Zero target"
 421         depends on BLK_DEV_DM
 422         help
 423           A target that discards writes, and returns all zeroes for
 424           reads.  Useful in some recovery situations.
 425
 426 config DM_MULTIPATH
 427         tristate "Multipath target"
 428         depends on BLK_DEV_DM
 429         # nasty syntax but means make DM_MULTIPATH independent
 430         # of SCSI_DH if the latter isn't defined but if
 431         # it is, DM_MULTIPATH must depend on it.  We get a build
 432         # error if SCSI_DH=m and DM_MULTIPATH=y
 433         depends on !SCSI_DH || SCSI
 434         help
 435           Allow volume managers to support multipath hardware.
 436
 437 config DM_MULTIPATH_QL
 438         tristate "I/O Path Selector based on the number of in-flight I/Os"
 439         depends on DM_MULTIPATH
 440         help
 441           This path selector is a dynamic load balancer which selects
 442           the path with the least number of in-flight I/Os.
 443
 444           If unsure, say N.
 445
 446 config DM_MULTIPATH_ST
 447         tristate "I/O Path Selector based on the service time"
 448         depends on DM_MULTIPATH
 449         help
 450           This path selector is a dynamic load balancer which selects
 451           the path expected to complete the incoming I/O in the shortest
 452           time.
 453
 454           If unsure, say N.
 455
 456 config DM_MULTIPATH_HST
 457         tristate "I/O Path Selector based on historical service time"
 458         depends on DM_MULTIPATH
 459         help
 460           This path selector is a dynamic load balancer which selects
 461           the path expected to complete the incoming I/O in the shortest
 462           time by comparing estimated service time (based on historical
 463           service time).
 464
 465           If unsure, say N.
 466
 467 config DM_MULTIPATH_IOA
 468         tristate "I/O Path Selector based on CPU submission"
 469         depends on DM_MULTIPATH
 470         help
 471           This path selector selects the path based on the CPU the IO is
 472           executed on and the CPU to path mapping setup at path addition time.
 473
 474           If unsure, say N.
 475
 476 config DM_DELAY
 477         tristate "I/O delaying target"
 478         depends on BLK_DEV_DM
 479         help
 480         A target that delays reads and/or writes and can send
 481         them to different devices.  Useful for testing.
 482
 483         If unsure, say N.
 484
 485 config DM_DUST
 486         tristate "Bad sector simulation target"
 487         depends on BLK_DEV_DM
 488         help
 489         A target that simulates bad sector behavior.
 490         Useful for testing.
 491
 492         If unsure, say N.
 493
 494 config DM_INIT
 495         bool "DM \"dm-mod.create=\" parameter support"
 496         depends on BLK_DEV_DM=y
 497         help
 498         Enable "dm-mod.create=" parameter to create mapped devices at init time.
 499         This option is useful to allow mounting rootfs without requiring an
 500         initramfs.
 501         See Documentation/admin-guide/device-mapper/dm-init.rst for dm-mod.create="..."
 502         format.
 503
 504         If unsure, say N.
 505
 506 config DM_UEVENT
 507         bool "DM uevents"
 508         depends on BLK_DEV_DM
 509         help
 510         Generate udev events for DM events.
 511
 512 config DM_FLAKEY
 513        tristate "Flakey target"
 514        depends on BLK_DEV_DM
 515         help
 516          A target that intermittently fails I/O for debugging purposes.
 517
 518 config DM_VERITY
 519         tristate "Verity target support"
 520         depends on BLK_DEV_DM
 521         select CRYPTO
 522         select CRYPTO_HASH
 523         select DM_BUFIO
 524         help
 525           This device-mapper target creates a read-only device that
 526           transparently validates the data on one underlying device against
 527           a pre-generated tree of cryptographic checksums stored on a second
 528           device.
 529
 530           You'll need to activate the digests you're going to use in the
 531           cryptoapi configuration.
 532
 533           To compile this code as a module, choose M here: the module will
 534           be called dm-verity.
 535
 536           If unsure, say N.
 537
 538 config DM_VERITY_VERIFY_ROOTHASH_SIG
 539         def_bool n
 540         bool "Verity data device root hash signature verification support"
 541         depends on DM_VERITY
 542         select SYSTEM_DATA_VERIFICATION
 543         help
 544           Add ability for dm-verity device to be validated if the
 545           pre-generated tree of cryptographic checksums passed has a pkcs#7
 546           signature file that can validate the roothash of the tree.
 547
 548           By default, rely on the builtin trusted keyring.
 549
 550           If unsure, say N.
 551
 552 config DM_VERITY_VERIFY_ROOTHASH_SIG_SECONDARY_KEYRING
 553         bool "Verity data device root hash signature verification with secondary keyring"
 554         depends on DM_VERITY_VERIFY_ROOTHASH_SIG
 555         depends on SECONDARY_TRUSTED_KEYRING
 556         help
 557           Rely on the secondary trusted keyring to verify dm-verity signatures.
 558
 559           If unsure, say N.
 560
 561 config DM_VERITY_FEC
 562         bool "Verity forward error correction support"
 563         depends on DM_VERITY
 564         select REED_SOLOMON
 565         select REED_SOLOMON_DEC8
 566         help
 567           Add forward error correction support to dm-verity. This option
 568           makes it possible to use pre-generated error correction data to
 569           recover from corrupted blocks.
 570
 571           If unsure, say N.
 572
 573 config DM_SWITCH
 574         tristate "Switch target support (EXPERIMENTAL)"
 575         depends on BLK_DEV_DM
 576         help
 577           This device-mapper target creates a device that supports an arbitrary
 578           mapping of fixed-size regions of I/O across a fixed set of paths.
 579           The path used for any specific region can be switched dynamically
 580           by sending the target a message.
 581
 582           To compile this code as a module, choose M here: the module will
 583           be called dm-switch.
 584
 585           If unsure, say N.
 586
 587 config DM_LOG_WRITES
 588         tristate "Log writes target support"
 589         depends on BLK_DEV_DM
 590         help
 591           This device-mapper target takes two devices, one device to use
 592           normally, one to log all write operations done to the first device.
 593           This is for use by file system developers wishing to verify that
 594           their fs is writing a consistent file system at all times by allowing
 595           them to replay the log in a variety of ways and to check the
 596           contents.
 597
 598           To compile this code as a module, choose M here: the module will
 599           be called dm-log-writes.
 600
 601           If unsure, say N.
 602
 603 config DM_INTEGRITY
 604         tristate "Integrity target support"
 605         depends on BLK_DEV_DM
 606         select BLK_DEV_INTEGRITY
 607         select DM_BUFIO
 608         select CRYPTO
 609         select CRYPTO_SKCIPHER
 610         select ASYNC_XOR
 611         help
 612           This device-mapper target emulates a block device that has
 613           additional per-sector tags that can be used for storing
 614           integrity information.
 615
 616           This integrity target is used with the dm-crypt target to
 617           provide authenticated disk encryption or it can be used
 618           standalone.
 619
 620           To compile this code as a module, choose M here: the module will
 621           be called dm-integrity.
 622
 623 config DM_ZONED
 624         tristate "Drive-managed zoned block device target support"
 625         depends on BLK_DEV_DM
 626         depends on BLK_DEV_ZONED
 627         select CRC32
 628         help
 629           This device-mapper target takes a host-managed or host-aware zoned
 630           block device and exposes most of its capacity as a regular block
 631           device (drive-managed zoned block device) without any write
 632           constraints. This is mainly intended for use with file systems that
 633           do not natively support zoned block devices but still want to
 634           benefit from the increased capacity offered by SMR disks. Other uses
 635           by applications using raw block devices (for example object stores)
 636           are also possible.
 637
 638           To compile this code as a module, choose M here: the module will
 639           be called dm-zoned.
 640
 641           If unsure, say N.
 642
 643 endif # MD