1# SPDX-License-Identifier: GPL-2.0-only 2# 3# Block device driver configuration 4# 5 6menuconfig MD 7 bool "Multiple devices driver support (RAID and LVM)" 8 depends on BLOCK 9 help 10 Support multiple physical spindles through a single logical device. 11 Required for RAID and logical volume management. 12 13if MD 14 15config BLK_DEV_MD 16 tristate "RAID support" 17 select BLOCK_HOLDER_DEPRECATED if SYSFS 18 select BUFFER_HEAD 19 # BLOCK_LEGACY_AUTOLOAD requirement should be removed 20 # after relevant mdadm enhancements - to make "names=yes" 21 # the default - are widely available. 22 select BLOCK_LEGACY_AUTOLOAD 23 help 24 This driver lets you combine several hard disk partitions into one 25 logical block device. This can be used to simply append one 26 partition to another one or to combine several redundant hard disks 27 into a RAID1/4/5 device so as to provide protection against hard 28 disk failures. This is called "Software RAID" since the combining of 29 the partitions is done by the kernel. "Hardware RAID" means that the 30 combining is done by a dedicated controller; if you have such a 31 controller, you do not need to say Y here. 32 33 More information about Software RAID on Linux is contained in the 34 Software RAID mini-HOWTO, available from 35 <https://www.tldp.org/docs.html#howto>. There you will also learn 36 where to get the supporting user space utilities raidtools. 37 38 If unsure, say N. 39 40config MD_BITMAP 41 bool "MD RAID bitmap support" 42 default y 43 depends on BLK_DEV_MD 44 help 45 If you say Y here, support for the write intent bitmap will be 46 enabled. The bitmap can be used to optimize resync speed after power 47 failure or readding a disk, limiting it to recorded dirty sectors in 48 bitmap. 49 50 This feature can be added to existing MD array or MD array can be 51 created with bitmap via mdadm(8). 52 53 If unsure, say Y. 54 55config MD_LLBITMAP 56 bool "MD RAID lockless bitmap support" 57 depends on BLK_DEV_MD 58 help 59 If you say Y here, support for the lockless write intent bitmap will 60 be enabled. 61 62 Note, this is an experimental feature. 63 64 If unsure, say N. 65 66config MD_AUTODETECT 67 bool "Autodetect RAID arrays during kernel boot" 68 depends on BLK_DEV_MD=y 69 default y 70 help 71 If you say Y here, then the kernel will try to autodetect raid 72 arrays as part of its boot process. 73 74 If you don't use raid and say Y, this autodetection can cause 75 a several-second delay in the boot time due to various 76 synchronisation steps that are part of this step. 77 78 If unsure, say Y. 79 80config MD_BITMAP_FILE 81 bool "MD bitmap file support (deprecated)" 82 default y 83 depends on MD_BITMAP 84 help 85 If you say Y here, support for write intent bitmaps in files on an 86 external file system is enabled. This is an alternative to the internal 87 bitmaps near the MD superblock, and very problematic code that abuses 88 various kernel APIs and can only work with files on a file system not 89 actually sitting on the MD device. 90 91config MD_LINEAR 92 tristate "Linear (append) mode" 93 depends on BLK_DEV_MD 94 help 95 If you say Y here, then your multiple devices driver will be able to 96 use the so-called linear mode, i.e. it will combine the hard disk 97 partitions by simply appending one to the other. 98 99 To compile this as a module, choose M here: the module 100 will be called linear. 101 102 If unsure, say Y. 103 104config MD_RAID0 105 tristate "RAID-0 (striping) mode" 106 depends on BLK_DEV_MD 107 help 108 If you say Y here, then your multiple devices driver will be able to 109 use the so-called raid0 mode, i.e. it will combine the hard disk 110 partitions into one logical device in such a fashion as to fill them 111 up evenly, one chunk here and one chunk there. This will increase 112 the throughput rate if the partitions reside on distinct disks. 113 114 Information about Software RAID on Linux is contained in the 115 Software-RAID mini-HOWTO, available from 116 <https://www.tldp.org/docs.html#howto>. There you will also 117 learn where to get the supporting user space utilities raidtools. 118 119 To compile this as a module, choose M here: the module 120 will be called raid0. 121 122 If unsure, say Y. 123 124config MD_RAID1 125 tristate "RAID-1 (mirroring) mode" 126 depends on BLK_DEV_MD 127 help 128 A RAID-1 set consists of several disk drives which are exact copies 129 of each other. In the event of a mirror failure, the RAID driver 130 will continue to use the operational mirrors in the set, providing 131 an error free MD (multiple device) to the higher levels of the 132 kernel. In a set with N drives, the available space is the capacity 133 of a single drive, and the set protects against a failure of (N - 1) 134 drives. 135 136 Information about Software RAID on Linux is contained in the 137 Software-RAID mini-HOWTO, available from 138 <https://www.tldp.org/docs.html#howto>. There you will also 139 learn where to get the supporting user space utilities raidtools. 140 141 If you want to use such a RAID-1 set, say Y. To compile this code 142 as a module, choose M here: the module will be called raid1. 143 144 If unsure, say Y. 145 146config MD_RAID10 147 tristate "RAID-10 (mirrored striping) mode" 148 depends on BLK_DEV_MD 149 help 150 RAID-10 provides a combination of striping (RAID-0) and 151 mirroring (RAID-1) with easier configuration and more flexible 152 layout. 153 Unlike RAID-0, but like RAID-1, RAID-10 requires all devices to 154 be the same size (or at least, only as much as the smallest device 155 will be used). 156 RAID-10 provides a variety of layouts that provide different levels 157 of redundancy and performance. 158 159 RAID-10 requires mdadm-1.7.0 or later, available at: 160 161 https://www.kernel.org/pub/linux/utils/raid/mdadm/ 162 163 If unsure, say Y. 164 165config MD_RAID456 166 tristate "RAID-4/RAID-5/RAID-6 mode" 167 depends on BLK_DEV_MD 168 select RAID6_PQ 169 select CRC32 170 select ASYNC_MEMCPY 171 select ASYNC_XOR 172 select ASYNC_PQ 173 select ASYNC_RAID6_RECOV 174 help 175 A RAID-5 set of N drives with a capacity of C MB per drive provides 176 the capacity of C * (N - 1) MB, and protects against a failure 177 of a single drive. For a given sector (row) number, (N - 1) drives 178 contain data sectors, and one drive contains the parity protection. 179 For a RAID-4 set, the parity blocks are present on a single drive, 180 while a RAID-5 set distributes the parity across the drives in one 181 of the available parity distribution methods. 182 183 A RAID-6 set of N drives with a capacity of C MB per drive 184 provides the capacity of C * (N - 2) MB, and protects 185 against a failure of any two drives. For a given sector 186 (row) number, (N - 2) drives contain data sectors, and two 187 drives contains two independent redundancy syndromes. Like 188 RAID-5, RAID-6 distributes the syndromes across the drives 189 in one of the available parity distribution methods. 190 191 Information about Software RAID on Linux is contained in the 192 Software-RAID mini-HOWTO, available from 193 <https://www.tldp.org/docs.html#howto>. There you will also 194 learn where to get the supporting user space utilities raidtools. 195 196 If you want to use such a RAID-4/RAID-5/RAID-6 set, say Y. To 197 compile this code as a module, choose M here: the module 198 will be called raid456. 199 200 If unsure, say Y. 201 202config MD_CLUSTER 203 tristate "Cluster Support for MD" 204 select MD_BITMAP 205 depends on BLK_DEV_MD 206 depends on DLM 207 default n 208 help 209 Clustering support for MD devices. This enables locking and 210 synchronization across multiple systems on the cluster, so all 211 nodes in the cluster can access the MD devices simultaneously. 212 213 This brings the redundancy (and uptime) of RAID levels across the 214 nodes of the cluster. Currently, it can work with raid1 and raid10 215 (limited support). 216 217 If unsure, say N. 218 219source "drivers/md/bcache/Kconfig" 220 221config BLK_DEV_DM_BUILTIN 222 bool 223 224config BLK_DEV_DM 225 tristate "Device mapper support" 226 select BLOCK_HOLDER_DEPRECATED if SYSFS 227 select BLK_DEV_DM_BUILTIN 228 select BLK_MQ_STACKING 229 depends on DAX || DAX=n 230 help 231 Device-mapper is a low level volume manager. It works by allowing 232 people to specify mappings for ranges of logical sectors. Various 233 mapping types are available, in addition people may write their own 234 modules containing custom mappings if they wish. 235 236 Higher level volume managers such as LVM2 use this driver. 237 238 To compile this as a module, choose M here: the module will be 239 called dm-mod. 240 241 If unsure, say N. 242 243config DM_DEBUG 244 bool "Device mapper debugging support" 245 depends on BLK_DEV_DM 246 help 247 Enable this for messages that may help debug device-mapper problems. 248 249 If unsure, say N. 250 251config DM_BUFIO 252 tristate 253 depends on BLK_DEV_DM 254 help 255 This interface allows you to do buffered I/O on a device and acts 256 as a cache, holding recently-read blocks in memory and performing 257 delayed writes. 258 259config DM_DEBUG_BLOCK_MANAGER_LOCKING 260 bool "Block manager locking" 261 depends on DM_BUFIO 262 help 263 Block manager locking can catch various metadata corruption issues. 264 265 If unsure, say N. 266 267config DM_DEBUG_BLOCK_STACK_TRACING 268 bool "Keep stack trace of persistent data block lock holders" 269 depends on STACKTRACE_SUPPORT && DM_DEBUG_BLOCK_MANAGER_LOCKING 270 select STACKTRACE 271 help 272 Enable this for messages that may help debug problems with the 273 block manager locking used by thin provisioning and caching. 274 275 If unsure, say N. 276 277config DM_BIO_PRISON 278 tristate 279 depends on BLK_DEV_DM 280 help 281 Some bio locking schemes used by other device-mapper targets 282 including thin provisioning. 283 284source "drivers/md/persistent-data/Kconfig" 285 286config DM_UNSTRIPED 287 tristate "Unstriped target" 288 depends on BLK_DEV_DM 289 help 290 Unstripes I/O so it is issued solely on a single drive in a HW 291 RAID0 or dm-striped target. 292 293config DM_CRYPT 294 tristate "Crypt target support" 295 depends on BLK_DEV_DM 296 depends on (ENCRYPTED_KEYS || ENCRYPTED_KEYS=n) 297 depends on (TRUSTED_KEYS || TRUSTED_KEYS=n) 298 select CRC32 299 select CRYPTO 300 select CRYPTO_CBC 301 select CRYPTO_ESSIV 302 help 303 This device-mapper target allows you to create a device that 304 transparently encrypts the data on it. You'll need to activate 305 the ciphers you're going to use in the cryptoapi configuration. 306 307 For further information on dm-crypt and userspace tools see: 308 <https://gitlab.com/cryptsetup/cryptsetup/wikis/DMCrypt> 309 310 To compile this code as a module, choose M here: the module will 311 be called dm-crypt. 312 313 If unsure, say N. 314 315config DM_SNAPSHOT 316 tristate "Snapshot target" 317 depends on BLK_DEV_DM 318 select DM_BUFIO 319 help 320 Allow volume managers to take writable snapshots of a device. 321 322config DM_THIN_PROVISIONING 323 tristate "Thin provisioning target" 324 depends on BLK_DEV_DM 325 select DM_PERSISTENT_DATA 326 select DM_BIO_PRISON 327 help 328 Provides thin provisioning and snapshots that share a data store. 329 330config DM_CACHE 331 tristate "Cache target (EXPERIMENTAL)" 332 depends on BLK_DEV_DM 333 default n 334 select DM_PERSISTENT_DATA 335 select DM_BIO_PRISON 336 help 337 dm-cache attempts to improve performance of a block device by 338 moving frequently used data to a smaller, higher performance 339 device. Different 'policy' plugins can be used to change the 340 algorithms used to select which blocks are promoted, demoted, 341 cleaned etc. It supports writeback and writethrough modes. 342 343config DM_CACHE_SMQ 344 tristate "Stochastic MQ Cache Policy (EXPERIMENTAL)" 345 depends on DM_CACHE 346 default y 347 help 348 A cache policy that uses a multiqueue ordered by recent hits 349 to select which blocks should be promoted and demoted. 350 This is meant to be a general purpose policy. It prioritises 351 reads over writes. This SMQ policy (vs MQ) offers the promise 352 of less memory utilization, improved performance and increased 353 adaptability in the face of changing workloads. 354 355config DM_WRITECACHE 356 tristate "Writecache target" 357 depends on BLK_DEV_DM 358 help 359 The writecache target caches writes on persistent memory or SSD. 360 It is intended for databases or other programs that need extremely 361 low commit latency. 362 363 The writecache target doesn't cache reads because reads are supposed 364 to be cached in standard RAM. 365 366config DM_EBS 367 tristate "Emulated block size target (EXPERIMENTAL)" 368 depends on BLK_DEV_DM && !HIGHMEM 369 select DM_BUFIO 370 help 371 dm-ebs emulates smaller logical block size on backing devices 372 with larger ones (e.g. 512 byte sectors on 4K native disks). 373 374config DM_ERA 375 tristate "Era target (EXPERIMENTAL)" 376 depends on BLK_DEV_DM 377 default n 378 select DM_PERSISTENT_DATA 379 select DM_BIO_PRISON 380 help 381 dm-era tracks which parts of a block device are written to 382 over time. Useful for maintaining cache coherency when using 383 vendor snapshots. 384 385config DM_CLONE 386 tristate "Clone target (EXPERIMENTAL)" 387 depends on BLK_DEV_DM 388 default n 389 select DM_PERSISTENT_DATA 390 help 391 dm-clone produces a one-to-one copy of an existing, read-only source 392 device into a writable destination device. The cloned device is 393 visible/mountable immediately and the copy of the source device to the 394 destination device happens in the background, in parallel with user 395 I/O. 396 397 If unsure, say N. 398 399config DM_MIRROR 400 tristate "Mirror target" 401 depends on BLK_DEV_DM 402 help 403 Allow volume managers to mirror logical volumes, also 404 needed for live data migration tools such as 'pvmove'. 405 406config DM_LOG_USERSPACE 407 tristate "Mirror userspace logging" 408 depends on DM_MIRROR && NET 409 select CONNECTOR 410 help 411 The userspace logging module provides a mechanism for 412 relaying the dm-dirty-log API to userspace. Log designs 413 which are more suited to userspace implementation (e.g. 414 shared storage logs) or experimental logs can be implemented 415 by leveraging this framework. 416 417config DM_RAID 418 tristate "RAID 1/4/5/6/10 target" 419 depends on BLK_DEV_DM 420 select MD_RAID0 421 select MD_RAID1 422 select MD_RAID10 423 select MD_RAID456 424 select MD_BITMAP 425 select BLK_DEV_MD 426 help 427 A dm target that supports RAID1, RAID10, RAID4, RAID5 and RAID6 mappings 428 429 A RAID-5 set of N drives with a capacity of C MB per drive provides 430 the capacity of C * (N - 1) MB, and protects against a failure 431 of a single drive. For a given sector (row) number, (N - 1) drives 432 contain data sectors, and one drive contains the parity protection. 433 For a RAID-4 set, the parity blocks are present on a single drive, 434 while a RAID-5 set distributes the parity across the drives in one 435 of the available parity distribution methods. 436 437 A RAID-6 set of N drives with a capacity of C MB per drive 438 provides the capacity of C * (N - 2) MB, and protects 439 against a failure of any two drives. For a given sector 440 (row) number, (N - 2) drives contain data sectors, and two 441 drives contains two independent redundancy syndromes. Like 442 RAID-5, RAID-6 distributes the syndromes across the drives 443 in one of the available parity distribution methods. 444 445config DM_ZERO 446 tristate "Zero target" 447 depends on BLK_DEV_DM 448 help 449 A target that discards writes, and returns all zeroes for 450 reads. Useful in some recovery situations. 451 452config DM_MULTIPATH 453 tristate "Multipath target" 454 depends on BLK_DEV_DM 455 # nasty syntax but means make DM_MULTIPATH independent 456 # of SCSI_DH if the latter isn't defined but if 457 # it is, DM_MULTIPATH must depend on it. We get a build 458 # error if SCSI_DH=m and DM_MULTIPATH=y 459 depends on !SCSI_DH || SCSI 460 help 461 Allow volume managers to support multipath hardware. 462 463config DM_MULTIPATH_QL 464 tristate "I/O Path Selector based on the number of in-flight I/Os" 465 depends on DM_MULTIPATH 466 help 467 This path selector is a dynamic load balancer which selects 468 the path with the least number of in-flight I/Os. 469 470 If unsure, say N. 471 472config DM_MULTIPATH_ST 473 tristate "I/O Path Selector based on the service time" 474 depends on DM_MULTIPATH 475 help 476 This path selector is a dynamic load balancer which selects 477 the path expected to complete the incoming I/O in the shortest 478 time. 479 480 If unsure, say N. 481 482config DM_MULTIPATH_HST 483 tristate "I/O Path Selector based on historical service time" 484 depends on DM_MULTIPATH 485 help 486 This path selector is a dynamic load balancer which selects 487 the path expected to complete the incoming I/O in the shortest 488 time by comparing estimated service time (based on historical 489 service time). 490 491 If unsure, say N. 492 493config DM_MULTIPATH_IOA 494 tristate "I/O Path Selector based on CPU submission" 495 depends on DM_MULTIPATH 496 help 497 This path selector selects the path based on the CPU the IO is 498 executed on and the CPU to path mapping setup at path addition time. 499 500 If unsure, say N. 501 502config DM_DELAY 503 tristate "I/O delaying target" 504 depends on BLK_DEV_DM 505 help 506 A target that delays reads and/or writes and can send 507 them to different devices. Useful for testing. 508 509 If unsure, say N. 510 511config DM_DUST 512 tristate "Bad sector simulation target" 513 depends on BLK_DEV_DM 514 help 515 A target that simulates bad sector behavior. 516 Useful for testing. 517 518 If unsure, say N. 519 520config DM_INIT 521 bool "DM \"dm-mod.create=\" parameter support" 522 depends on BLK_DEV_DM=y 523 help 524 Enable "dm-mod.create=" parameter to create mapped devices at init time. 525 This option is useful to allow mounting rootfs without requiring an 526 initramfs. 527 See Documentation/admin-guide/device-mapper/dm-init.rst for dm-mod.create="..." 528 format. 529 530 If unsure, say N. 531 532config DM_UEVENT 533 bool "DM uevents" 534 depends on BLK_DEV_DM 535 help 536 Generate udev events for DM events. 537 538config DM_FLAKEY 539 tristate "Flakey target" 540 depends on BLK_DEV_DM 541 help 542 A target that intermittently fails I/O for debugging purposes. 543 544config DM_VERITY 545 tristate "Verity target support" 546 depends on BLK_DEV_DM 547 select CRYPTO 548 select CRYPTO_HASH 549 select DM_BUFIO 550 help 551 This device-mapper target creates a read-only device that 552 transparently validates the data on one underlying device against 553 a pre-generated tree of cryptographic checksums stored on a second 554 device. 555 556 You'll need to activate the digests you're going to use in the 557 cryptoapi configuration. 558 559 To compile this code as a module, choose M here: the module will 560 be called dm-verity. 561 562 If unsure, say N. 563 564config DM_VERITY_VERIFY_ROOTHASH_SIG 565 bool "Verity data device root hash signature verification support" 566 depends on DM_VERITY 567 select SYSTEM_DATA_VERIFICATION 568 help 569 Add ability for dm-verity device to be validated if the 570 pre-generated tree of cryptographic checksums passed has a pkcs#7 571 signature file that can validate the roothash of the tree. 572 573 By default, rely on the builtin trusted keyring. 574 575 If unsure, say N. 576 577config DM_VERITY_VERIFY_ROOTHASH_SIG_SECONDARY_KEYRING 578 bool "Verity data device root hash signature verification with secondary keyring" 579 depends on DM_VERITY_VERIFY_ROOTHASH_SIG 580 depends on SECONDARY_TRUSTED_KEYRING 581 help 582 Rely on the secondary trusted keyring to verify dm-verity signatures. 583 584 If unsure, say N. 585 586config DM_VERITY_VERIFY_ROOTHASH_SIG_PLATFORM_KEYRING 587 bool "Verity data device root hash signature verification with platform keyring" 588 default DM_VERITY_VERIFY_ROOTHASH_SIG_SECONDARY_KEYRING 589 depends on DM_VERITY_VERIFY_ROOTHASH_SIG 590 depends on INTEGRITY_PLATFORM_KEYRING 591 help 592 Rely also on the platform keyring to verify dm-verity signatures. 593 594 If unsure, say N. 595 596config DM_VERITY_FEC 597 bool "Verity forward error correction support" 598 depends on DM_VERITY 599 select REED_SOLOMON 600 select REED_SOLOMON_DEC8 601 help 602 Add forward error correction support to dm-verity. This option 603 makes it possible to use pre-generated error correction data to 604 recover from corrupted blocks. 605 606 If unsure, say N. 607 608config DM_SWITCH 609 tristate "Switch target support (EXPERIMENTAL)" 610 depends on BLK_DEV_DM 611 help 612 This device-mapper target creates a device that supports an arbitrary 613 mapping of fixed-size regions of I/O across a fixed set of paths. 614 The path used for any specific region can be switched dynamically 615 by sending the target a message. 616 617 To compile this code as a module, choose M here: the module will 618 be called dm-switch. 619 620 If unsure, say N. 621 622config DM_LOG_WRITES 623 tristate "Log writes target support" 624 depends on BLK_DEV_DM 625 help 626 This device-mapper target takes two devices, one device to use 627 normally, one to log all write operations done to the first device. 628 This is for use by file system developers wishing to verify that 629 their fs is writing a consistent file system at all times by allowing 630 them to replay the log in a variety of ways and to check the 631 contents. 632 633 To compile this code as a module, choose M here: the module will 634 be called dm-log-writes. 635 636 If unsure, say N. 637 638config DM_INTEGRITY 639 tristate "Integrity target support" 640 depends on BLK_DEV_DM 641 select BLK_DEV_INTEGRITY 642 select DM_BUFIO 643 select CRYPTO 644 select CRYPTO_SKCIPHER 645 select ASYNC_XOR 646 select DM_AUDIT if AUDIT 647 help 648 This device-mapper target emulates a block device that has 649 additional per-sector tags that can be used for storing 650 integrity information. 651 652 This integrity target is used with the dm-crypt target to 653 provide authenticated disk encryption or it can be used 654 standalone. 655 656 To compile this code as a module, choose M here: the module will 657 be called dm-integrity. 658 659config DM_ZONED 660 tristate "Drive-managed zoned block device target support" 661 depends on BLK_DEV_DM 662 depends on BLK_DEV_ZONED 663 select CRC32 664 help 665 This device-mapper target takes a host-managed or host-aware zoned 666 block device and exposes most of its capacity as a regular block 667 device (drive-managed zoned block device) without any write 668 constraints. This is mainly intended for use with file systems that 669 do not natively support zoned block devices but still want to 670 benefit from the increased capacity offered by SMR disks. Other uses 671 by applications using raw block devices (for example object stores) 672 are also possible. 673 674 To compile this code as a module, choose M here: the module will 675 be called dm-zoned. 676 677 If unsure, say N. 678 679config DM_AUDIT 680 bool "DM audit events" 681 depends on BLK_DEV_DM 682 depends on AUDIT 683 help 684 Generate audit events for device-mapper. 685 686 Enables audit logging of several security relevant events in the 687 particular device-mapper targets, especially the integrity target. 688 689source "drivers/md/dm-vdo/Kconfig" 690 691source "drivers/md/dm-pcache/Kconfig" 692 693endif # MD 694