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         select CRYPTO
 274         select CRYPTO_CBC
 275         select CRYPTO_ESSIV
 276         help
 277           This device-mapper target allows you to create a device that
 278           transparently encrypts the data on it. You'll need to activate
 279           the ciphers you're going to use in the cryptoapi configuration.
 280
 281           For further information on dm-crypt and userspace tools see:
 282           <https://gitlab.com/cryptsetup/cryptsetup/wikis/DMCrypt>
 283
 284           To compile this code as a module, choose M here: the module will
 285           be called dm-crypt.
 286
 287           If unsure, say N.
 288
 289 config DM_SNAPSHOT
 290        tristate "Snapshot target"
 291        depends on BLK_DEV_DM
 292        select DM_BUFIO
 293         help
 294          Allow volume managers to take writable snapshots of a device.
 295
 296 config DM_THIN_PROVISIONING
 297        tristate "Thin provisioning target"
 298        depends on BLK_DEV_DM
 299        select DM_PERSISTENT_DATA
 300        select DM_BIO_PRISON
 301         help
 302          Provides thin provisioning and snapshots that share a data store.
 303
 304 config DM_CACHE
 305        tristate "Cache target (EXPERIMENTAL)"
 306        depends on BLK_DEV_DM
 307        default n
 308        select DM_PERSISTENT_DATA
 309        select DM_BIO_PRISON
 310         help
 311          dm-cache attempts to improve performance of a block device by
 312          moving frequently used data to a smaller, higher performance
 313          device.  Different 'policy' plugins can be used to change the
 314          algorithms used to select which blocks are promoted, demoted,
 315          cleaned etc.  It supports writeback and writethrough modes.
 316
 317 config DM_CACHE_SMQ
 318        tristate "Stochastic MQ Cache Policy (EXPERIMENTAL)"
 319        depends on DM_CACHE
 320        default y
 321         help
 322          A cache policy that uses a multiqueue ordered by recent hits
 323          to select which blocks should be promoted and demoted.
 324          This is meant to be a general purpose policy.  It prioritises
 325          reads over writes.  This SMQ policy (vs MQ) offers the promise
 326          of less memory utilization, improved performance and increased
 327          adaptability in the face of changing workloads.
 328
 329 config DM_WRITECACHE
 330         tristate "Writecache target"
 331         depends on BLK_DEV_DM
 332         help
 333            The writecache target caches writes on persistent memory or SSD.
 334            It is intended for databases or other programs that need extremely
 335            low commit latency.
 336
 337            The writecache target doesn't cache reads because reads are supposed
 338            to be cached in standard RAM.
 339
 340 config DM_EBS
 341         tristate "Emulated block size target (EXPERIMENTAL)"
 342         depends on BLK_DEV_DM
 343         select DM_BUFIO
 344         help
 345           dm-ebs emulates smaller logical block size on backing devices
 346           with larger ones (e.g. 512 byte sectors on 4K native disks).
 347
 348 config DM_ERA
 349        tristate "Era target (EXPERIMENTAL)"
 350        depends on BLK_DEV_DM
 351        default n
 352        select DM_PERSISTENT_DATA
 353        select DM_BIO_PRISON
 354         help
 355          dm-era tracks which parts of a block device are written to
 356          over time.  Useful for maintaining cache coherency when using
 357          vendor snapshots.
 358
 359 config DM_CLONE
 360        tristate "Clone target (EXPERIMENTAL)"
 361        depends on BLK_DEV_DM
 362        default n
 363        select DM_PERSISTENT_DATA
 364         help
 365          dm-clone produces a one-to-one copy of an existing, read-only source
 366          device into a writable destination device. The cloned device is
 367          visible/mountable immediately and the copy of the source device to the
 368          destination device happens in the background, in parallel with user
 369          I/O.
 370
 371          If unsure, say N.
 372
 373 config DM_MIRROR
 374        tristate "Mirror target"
 375        depends on BLK_DEV_DM
 376         help
 377          Allow volume managers to mirror logical volumes, also
 378          needed for live data migration tools such as 'pvmove'.
 379
 380 config DM_LOG_USERSPACE
 381         tristate "Mirror userspace logging"
 382         depends on DM_MIRROR && NET
 383         select CONNECTOR
 384         help
 385           The userspace logging module provides a mechanism for
 386           relaying the dm-dirty-log API to userspace.  Log designs
 387           which are more suited to userspace implementation (e.g.
 388           shared storage logs) or experimental logs can be implemented
 389           by leveraging this framework.
 390
 391 config DM_RAID
 392        tristate "RAID 1/4/5/6/10 target"
 393        depends on BLK_DEV_DM
 394        select MD_RAID0
 395        select MD_RAID1
 396        select MD_RAID10
 397        select MD_RAID456
 398        select BLK_DEV_MD
 399         help
 400          A dm target that supports RAID1, RAID10, RAID4, RAID5 and RAID6 mappings
 401
 402          A RAID-5 set of N drives with a capacity of C MB per drive provides
 403          the capacity of C * (N - 1) MB, and protects against a failure
 404          of a single drive. For a given sector (row) number, (N - 1) drives
 405          contain data sectors, and one drive contains the parity protection.
 406          For a RAID-4 set, the parity blocks are present on a single drive,
 407          while a RAID-5 set distributes the parity across the drives in one
 408          of the available parity distribution methods.
 409
 410          A RAID-6 set of N drives with a capacity of C MB per drive
 411          provides the capacity of C * (N - 2) MB, and protects
 412          against a failure of any two drives. For a given sector
 413          (row) number, (N - 2) drives contain data sectors, and two
 414          drives contains two independent redundancy syndromes.  Like
 415          RAID-5, RAID-6 distributes the syndromes across the drives
 416          in one of the available parity distribution methods.
 417
 418 config DM_ZERO
 419         tristate "Zero target"
 420         depends on BLK_DEV_DM
 421         help
 422           A target that discards writes, and returns all zeroes for
 423           reads.  Useful in some recovery situations.
 424
 425 config DM_MULTIPATH
 426         tristate "Multipath target"
 427         depends on BLK_DEV_DM
 428         # nasty syntax but means make DM_MULTIPATH independent
 429         # of SCSI_DH if the latter isn't defined but if
 430         # it is, DM_MULTIPATH must depend on it.  We get a build
 431         # error if SCSI_DH=m and DM_MULTIPATH=y
 432         depends on !SCSI_DH || SCSI
 433         help
 434           Allow volume managers to support multipath hardware.
 435
 436 config DM_MULTIPATH_QL
 437         tristate "I/O Path Selector based on the number of in-flight I/Os"
 438         depends on DM_MULTIPATH
 439         help
 440           This path selector is a dynamic load balancer which selects
 441           the path with the least number of in-flight I/Os.
 442
 443           If unsure, say N.
 444
 445 config DM_MULTIPATH_ST
 446         tristate "I/O Path Selector based on the service time"
 447         depends on DM_MULTIPATH
 448         help
 449           This path selector is a dynamic load balancer which selects
 450           the path expected to complete the incoming I/O in the shortest
 451           time.
 452
 453           If unsure, say N.
 454
 455 config DM_MULTIPATH_HST
 456         tristate "I/O Path Selector based on historical service time"
 457         depends on DM_MULTIPATH
 458         help
 459           This path selector is a dynamic load balancer which selects
 460           the path expected to complete the incoming I/O in the shortest
 461           time by comparing estimated service time (based on historical
 462           service time).
 463
 464           If unsure, say N.
 465
 466 config DM_MULTIPATH_IOA
 467         tristate "I/O Path Selector based on CPU submission"
 468         depends on DM_MULTIPATH
 469         help
 470           This path selector selects the path based on the CPU the IO is
 471           executed on and the CPU to path mapping setup at path addition time.
 472
 473           If unsure, say N.
 474
 475 config DM_DELAY
 476         tristate "I/O delaying target"
 477         depends on BLK_DEV_DM
 478         help
 479         A target that delays reads and/or writes and can send
 480         them to different devices.  Useful for testing.
 481
 482         If unsure, say N.
 483
 484 config DM_DUST
 485         tristate "Bad sector simulation target"
 486         depends on BLK_DEV_DM
 487         help
 488         A target that simulates bad sector behavior.
 489         Useful for testing.
 490
 491         If unsure, say N.
 492
 493 config DM_INIT
 494         bool "DM \"dm-mod.create=\" parameter support"
 495         depends on BLK_DEV_DM=y
 496         help
 497         Enable "dm-mod.create=" parameter to create mapped devices at init time.
 498         This option is useful to allow mounting rootfs without requiring an
 499         initramfs.
 500         See Documentation/admin-guide/device-mapper/dm-init.rst for dm-mod.create="..."
 501         format.
 502
 503         If unsure, say N.
 504
 505 config DM_UEVENT
 506         bool "DM uevents"
 507         depends on BLK_DEV_DM
 508         help
 509         Generate udev events for DM events.
 510
 511 config DM_FLAKEY
 512        tristate "Flakey target"
 513        depends on BLK_DEV_DM
 514         help
 515          A target that intermittently fails I/O for debugging purposes.
 516
 517 config DM_VERITY
 518         tristate "Verity target support"
 519         depends on BLK_DEV_DM
 520         select CRYPTO
 521         select CRYPTO_HASH
 522         select DM_BUFIO
 523         help
 524           This device-mapper target creates a read-only device that
 525           transparently validates the data on one underlying device against
 526           a pre-generated tree of cryptographic checksums stored on a second
 527           device.
 528
 529           You'll need to activate the digests you're going to use in the
 530           cryptoapi configuration.
 531
 532           To compile this code as a module, choose M here: the module will
 533           be called dm-verity.
 534
 535           If unsure, say N.
 536
 537 config DM_VERITY_VERIFY_ROOTHASH_SIG
 538         def_bool n
 539         bool "Verity data device root hash signature verification support"
 540         depends on DM_VERITY
 541         select SYSTEM_DATA_VERIFICATION
 542         help
 543           Add ability for dm-verity device to be validated if the
 544           pre-generated tree of cryptographic checksums passed has a pkcs#7
 545           signature file that can validate the roothash of the tree.
 546
 547           By default, rely on the builtin trusted keyring.
 548
 549           If unsure, say N.
 550
 551 config DM_VERITY_VERIFY_ROOTHASH_SIG_SECONDARY_KEYRING
 552         bool "Verity data device root hash signature verification with secondary keyring"
 553         depends on DM_VERITY_VERIFY_ROOTHASH_SIG
 554         depends on SECONDARY_TRUSTED_KEYRING
 555         help
 556           Rely on the secondary trusted keyring to verify dm-verity signatures.
 557
 558           If unsure, say N.
 559
 560 config DM_VERITY_FEC
 561         bool "Verity forward error correction support"
 562         depends on DM_VERITY
 563         select REED_SOLOMON
 564         select REED_SOLOMON_DEC8
 565         help
 566           Add forward error correction support to dm-verity. This option
 567           makes it possible to use pre-generated error correction data to
 568           recover from corrupted blocks.
 569
 570           If unsure, say N.
 571
 572 config DM_SWITCH
 573         tristate "Switch target support (EXPERIMENTAL)"
 574         depends on BLK_DEV_DM
 575         help
 576           This device-mapper target creates a device that supports an arbitrary
 577           mapping of fixed-size regions of I/O across a fixed set of paths.
 578           The path used for any specific region can be switched dynamically
 579           by sending the target a message.
 580
 581           To compile this code as a module, choose M here: the module will
 582           be called dm-switch.
 583
 584           If unsure, say N.
 585
 586 config DM_LOG_WRITES
 587         tristate "Log writes target support"
 588         depends on BLK_DEV_DM
 589         help
 590           This device-mapper target takes two devices, one device to use
 591           normally, one to log all write operations done to the first device.
 592           This is for use by file system developers wishing to verify that
 593           their fs is writing a consistent file system at all times by allowing
 594           them to replay the log in a variety of ways and to check the
 595           contents.
 596
 597           To compile this code as a module, choose M here: the module will
 598           be called dm-log-writes.
 599
 600           If unsure, say N.
 601
 602 config DM_INTEGRITY
 603         tristate "Integrity target support"
 604         depends on BLK_DEV_DM
 605         select BLK_DEV_INTEGRITY
 606         select DM_BUFIO
 607         select CRYPTO
 608         select CRYPTO_SKCIPHER
 609         select ASYNC_XOR
 610         help
 611           This device-mapper target emulates a block device that has
 612           additional per-sector tags that can be used for storing
 613           integrity information.
 614
 615           This integrity target is used with the dm-crypt target to
 616           provide authenticated disk encryption or it can be used
 617           standalone.
 618
 619           To compile this code as a module, choose M here: the module will
 620           be called dm-integrity.
 621
 622 config DM_ZONED
 623         tristate "Drive-managed zoned block device target support"
 624         depends on BLK_DEV_DM
 625         depends on BLK_DEV_ZONED
 626         select CRC32
 627         help
 628           This device-mapper target takes a host-managed or host-aware zoned
 629           block device and exposes most of its capacity as a regular block
 630           device (drive-managed zoned block device) without any write
 631           constraints. This is mainly intended for use with file systems that
 632           do not natively support zoned block devices but still want to
 633           benefit from the increased capacity offered by SMR disks. Other uses
 634           by applications using raw block devices (for example object stores)
 635           are also possible.
 636
 637           To compile this code as a module, choose M here: the module will
 638           be called dm-zoned.
 639
 640           If unsure, say N.
 641
 642 endif # MD