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 # BLOCK_LEGACY_AUTOLOAD requirement should be removed 19 # after relevant mdadm enhancements - to make "names=yes" 20 # the default - are widely available. 21 select BLOCK_LEGACY_AUTOLOAD 22 help 23 This driver lets you combine several hard disk partitions into one 24 logical block device. This can be used to simply append one 25 partition to another one or to combine several redundant hard disks 26 into a RAID1/4/5 device so as to provide protection against hard 27 disk failures. This is called "Software RAID" since the combining of 28 the partitions is done by the kernel. "Hardware RAID" means that the 29 combining is done by a dedicated controller; if you have such a 30 controller, you do not need to say Y here. 31 32 More information about Software RAID on Linux is contained in the 33 Software RAID mini-HOWTO, available from 34 <https://www.tldp.org/docs.html#howto>. There you will also learn 35 where to get the supporting user space utilities raidtools. 36 37 If unsure, say N. 38 39config MD_AUTODETECT 40 bool "Autodetect RAID arrays during kernel boot" 41 depends on BLK_DEV_MD=y 42 default y 43 help 44 If you say Y here, then the kernel will try to autodetect raid 45 arrays as part of its boot process. 46 47 If you don't use raid and say Y, this autodetection can cause 48 a several-second delay in the boot time due to various 49 synchronisation steps that are part of this step. 50 51 If unsure, say Y. 52 53config MD_LINEAR 54 tristate "Linear (append) mode (deprecated)" 55 depends on BLK_DEV_MD 56 help 57 If you say Y here, then your multiple devices driver will be able to 58 use the so-called linear mode, i.e. it will combine the hard disk 59 partitions by simply appending one to the other. 60 61 To compile this as a module, choose M here: the module 62 will be called linear. 63 64 If unsure, say Y. 65 66config MD_RAID0 67 tristate "RAID-0 (striping) mode" 68 depends on BLK_DEV_MD 69 help 70 If you say Y here, then your multiple devices driver will be able to 71 use the so-called raid0 mode, i.e. it will combine the hard disk 72 partitions into one logical device in such a fashion as to fill them 73 up evenly, one chunk here and one chunk there. This will increase 74 the throughput rate if the partitions reside on distinct disks. 75 76 Information about Software RAID on Linux is contained in the 77 Software-RAID mini-HOWTO, available from 78 <https://www.tldp.org/docs.html#howto>. There you will also 79 learn where to get the supporting user space utilities raidtools. 80 81 To compile this as a module, choose M here: the module 82 will be called raid0. 83 84 If unsure, say Y. 85 86config MD_RAID1 87 tristate "RAID-1 (mirroring) mode" 88 depends on BLK_DEV_MD 89 help 90 A RAID-1 set consists of several disk drives which are exact copies 91 of each other. In the event of a mirror failure, the RAID driver 92 will continue to use the operational mirrors in the set, providing 93 an error free MD (multiple device) to the higher levels of the 94 kernel. In a set with N drives, the available space is the capacity 95 of a single drive, and the set protects against a failure of (N - 1) 96 drives. 97 98 Information about Software RAID on Linux is contained in the 99 Software-RAID mini-HOWTO, available from 100 <https://www.tldp.org/docs.html#howto>. There you will also 101 learn where to get the supporting user space utilities raidtools. 102 103 If you want to use such a RAID-1 set, say Y. To compile this code 104 as a module, choose M here: the module will be called raid1. 105 106 If unsure, say Y. 107 108config MD_RAID10 109 tristate "RAID-10 (mirrored striping) mode" 110 depends on BLK_DEV_MD 111 help 112 RAID-10 provides a combination of striping (RAID-0) and 113 mirroring (RAID-1) with easier configuration and more flexible 114 layout. 115 Unlike RAID-0, but like RAID-1, RAID-10 requires all devices to 116 be the same size (or at least, only as much as the smallest device 117 will be used). 118 RAID-10 provides a variety of layouts that provide different levels 119 of redundancy and performance. 120 121 RAID-10 requires mdadm-1.7.0 or later, available at: 122 123 https://www.kernel.org/pub/linux/utils/raid/mdadm/ 124 125 If unsure, say Y. 126 127config MD_RAID456 128 tristate "RAID-4/RAID-5/RAID-6 mode" 129 depends on BLK_DEV_MD 130 select RAID6_PQ 131 select LIBCRC32C 132 select ASYNC_MEMCPY 133 select ASYNC_XOR 134 select ASYNC_PQ 135 select ASYNC_RAID6_RECOV 136 help 137 A RAID-5 set of N drives with a capacity of C MB per drive provides 138 the capacity of C * (N - 1) MB, and protects against a failure 139 of a single drive. For a given sector (row) number, (N - 1) drives 140 contain data sectors, and one drive contains the parity protection. 141 For a RAID-4 set, the parity blocks are present on a single drive, 142 while a RAID-5 set distributes the parity across the drives in one 143 of the available parity distribution methods. 144 145 A RAID-6 set of N drives with a capacity of C MB per drive 146 provides the capacity of C * (N - 2) MB, and protects 147 against a failure of any two drives. For a given sector 148 (row) number, (N - 2) drives contain data sectors, and two 149 drives contains two independent redundancy syndromes. Like 150 RAID-5, RAID-6 distributes the syndromes across the drives 151 in one of the available parity distribution methods. 152 153 Information about Software RAID on Linux is contained in the 154 Software-RAID mini-HOWTO, available from 155 <https://www.tldp.org/docs.html#howto>. There you will also 156 learn where to get the supporting user space utilities raidtools. 157 158 If you want to use such a RAID-4/RAID-5/RAID-6 set, say Y. To 159 compile this code as a module, choose M here: the module 160 will be called raid456. 161 162 If unsure, say Y. 163 164config MD_MULTIPATH 165 tristate "Multipath I/O support (deprecated)" 166 depends on BLK_DEV_MD 167 help 168 MD_MULTIPATH provides a simple multi-path personality for use 169 the MD framework. It is not under active development. New 170 projects should consider using DM_MULTIPATH which has more 171 features and more testing. 172 173 If unsure, say N. 174 175config MD_FAULTY 176 tristate "Faulty test module for MD (deprecated)" 177 depends on BLK_DEV_MD 178 help 179 The "faulty" module allows for a block device that occasionally returns 180 read or write errors. It is useful for testing. 181 182 In unsure, say N. 183 184 185config MD_CLUSTER 186 tristate "Cluster Support for MD" 187 depends on BLK_DEV_MD 188 depends on DLM 189 default n 190 help 191 Clustering support for MD devices. This enables locking and 192 synchronization across multiple systems on the cluster, so all 193 nodes in the cluster can access the MD devices simultaneously. 194 195 This brings the redundancy (and uptime) of RAID levels across the 196 nodes of the cluster. Currently, it can work with raid1 and raid10 197 (limited support). 198 199 If unsure, say N. 200 201source "drivers/md/bcache/Kconfig" 202 203config BLK_DEV_DM_BUILTIN 204 bool 205 206config BLK_DEV_DM 207 tristate "Device mapper support" 208 select BLOCK_HOLDER_DEPRECATED if SYSFS 209 select BLK_DEV_DM_BUILTIN 210 select BLK_MQ_STACKING 211 depends on DAX || DAX=n 212 help 213 Device-mapper is a low level volume manager. It works by allowing 214 people to specify mappings for ranges of logical sectors. Various 215 mapping types are available, in addition people may write their own 216 modules containing custom mappings if they wish. 217 218 Higher level volume managers such as LVM2 use this driver. 219 220 To compile this as a module, choose M here: the module will be 221 called dm-mod. 222 223 If unsure, say N. 224 225config DM_DEBUG 226 bool "Device mapper debugging support" 227 depends on BLK_DEV_DM 228 help 229 Enable this for messages that may help debug device-mapper problems. 230 231 If unsure, say N. 232 233config DM_BUFIO 234 tristate 235 depends on BLK_DEV_DM 236 help 237 This interface allows you to do buffered I/O on a device and acts 238 as a cache, holding recently-read blocks in memory and performing 239 delayed writes. 240 241config DM_DEBUG_BLOCK_MANAGER_LOCKING 242 bool "Block manager locking" 243 depends on DM_BUFIO 244 help 245 Block manager locking can catch various metadata corruption issues. 246 247 If unsure, say N. 248 249config DM_DEBUG_BLOCK_STACK_TRACING 250 bool "Keep stack trace of persistent data block lock holders" 251 depends on STACKTRACE_SUPPORT && DM_DEBUG_BLOCK_MANAGER_LOCKING 252 select STACKTRACE 253 help 254 Enable this for messages that may help debug problems with the 255 block manager locking used by thin provisioning and caching. 256 257 If unsure, say N. 258 259config DM_BIO_PRISON 260 tristate 261 depends on BLK_DEV_DM 262 help 263 Some bio locking schemes used by other device-mapper targets 264 including thin provisioning. 265 266source "drivers/md/persistent-data/Kconfig" 267 268config DM_UNSTRIPED 269 tristate "Unstriped target" 270 depends on BLK_DEV_DM 271 help 272 Unstripes I/O so it is issued solely on a single drive in a HW 273 RAID0 or dm-striped target. 274 275config DM_CRYPT 276 tristate "Crypt target support" 277 depends on BLK_DEV_DM 278 depends on (ENCRYPTED_KEYS || ENCRYPTED_KEYS=n) 279 depends on (TRUSTED_KEYS || TRUSTED_KEYS=n) 280 select CRYPTO 281 select CRYPTO_CBC 282 select CRYPTO_ESSIV 283 help 284 This device-mapper target allows you to create a device that 285 transparently encrypts the data on it. You'll need to activate 286 the ciphers you're going to use in the cryptoapi configuration. 287 288 For further information on dm-crypt and userspace tools see: 289 <https://gitlab.com/cryptsetup/cryptsetup/wikis/DMCrypt> 290 291 To compile this code as a module, choose M here: the module will 292 be called dm-crypt. 293 294 If unsure, say N. 295 296config DM_SNAPSHOT 297 tristate "Snapshot target" 298 depends on BLK_DEV_DM 299 select DM_BUFIO 300 help 301 Allow volume managers to take writable snapshots of a device. 302 303config DM_THIN_PROVISIONING 304 tristate "Thin provisioning target" 305 depends on BLK_DEV_DM 306 select DM_PERSISTENT_DATA 307 select DM_BIO_PRISON 308 help 309 Provides thin provisioning and snapshots that share a data store. 310 311config DM_CACHE 312 tristate "Cache target (EXPERIMENTAL)" 313 depends on BLK_DEV_DM 314 default n 315 select DM_PERSISTENT_DATA 316 select DM_BIO_PRISON 317 help 318 dm-cache attempts to improve performance of a block device by 319 moving frequently used data to a smaller, higher performance 320 device. Different 'policy' plugins can be used to change the 321 algorithms used to select which blocks are promoted, demoted, 322 cleaned etc. It supports writeback and writethrough modes. 323 324config DM_CACHE_SMQ 325 tristate "Stochastic MQ Cache Policy (EXPERIMENTAL)" 326 depends on DM_CACHE 327 default y 328 help 329 A cache policy that uses a multiqueue ordered by recent hits 330 to select which blocks should be promoted and demoted. 331 This is meant to be a general purpose policy. It prioritises 332 reads over writes. This SMQ policy (vs MQ) offers the promise 333 of less memory utilization, improved performance and increased 334 adaptability in the face of changing workloads. 335 336config DM_WRITECACHE 337 tristate "Writecache target" 338 depends on BLK_DEV_DM 339 help 340 The writecache target caches writes on persistent memory or SSD. 341 It is intended for databases or other programs that need extremely 342 low commit latency. 343 344 The writecache target doesn't cache reads because reads are supposed 345 to be cached in standard RAM. 346 347config DM_EBS 348 tristate "Emulated block size target (EXPERIMENTAL)" 349 depends on BLK_DEV_DM && !HIGHMEM 350 select DM_BUFIO 351 help 352 dm-ebs emulates smaller logical block size on backing devices 353 with larger ones (e.g. 512 byte sectors on 4K native disks). 354 355config DM_ERA 356 tristate "Era target (EXPERIMENTAL)" 357 depends on BLK_DEV_DM 358 default n 359 select DM_PERSISTENT_DATA 360 select DM_BIO_PRISON 361 help 362 dm-era tracks which parts of a block device are written to 363 over time. Useful for maintaining cache coherency when using 364 vendor snapshots. 365 366config DM_CLONE 367 tristate "Clone target (EXPERIMENTAL)" 368 depends on BLK_DEV_DM 369 default n 370 select DM_PERSISTENT_DATA 371 help 372 dm-clone produces a one-to-one copy of an existing, read-only source 373 device into a writable destination device. The cloned device is 374 visible/mountable immediately and the copy of the source device to the 375 destination device happens in the background, in parallel with user 376 I/O. 377 378 If unsure, say N. 379 380config DM_MIRROR 381 tristate "Mirror target" 382 depends on BLK_DEV_DM 383 help 384 Allow volume managers to mirror logical volumes, also 385 needed for live data migration tools such as 'pvmove'. 386 387config DM_LOG_USERSPACE 388 tristate "Mirror userspace logging" 389 depends on DM_MIRROR && NET 390 select CONNECTOR 391 help 392 The userspace logging module provides a mechanism for 393 relaying the dm-dirty-log API to userspace. Log designs 394 which are more suited to userspace implementation (e.g. 395 shared storage logs) or experimental logs can be implemented 396 by leveraging this framework. 397 398config DM_RAID 399 tristate "RAID 1/4/5/6/10 target" 400 depends on BLK_DEV_DM 401 select MD_RAID0 402 select MD_RAID1 403 select MD_RAID10 404 select MD_RAID456 405 select BLK_DEV_MD 406 help 407 A dm target that supports RAID1, RAID10, RAID4, RAID5 and RAID6 mappings 408 409 A RAID-5 set of N drives with a capacity of C MB per drive provides 410 the capacity of C * (N - 1) MB, and protects against a failure 411 of a single drive. For a given sector (row) number, (N - 1) drives 412 contain data sectors, and one drive contains the parity protection. 413 For a RAID-4 set, the parity blocks are present on a single drive, 414 while a RAID-5 set distributes the parity across the drives in one 415 of the available parity distribution methods. 416 417 A RAID-6 set of N drives with a capacity of C MB per drive 418 provides the capacity of C * (N - 2) MB, and protects 419 against a failure of any two drives. For a given sector 420 (row) number, (N - 2) drives contain data sectors, and two 421 drives contains two independent redundancy syndromes. Like 422 RAID-5, RAID-6 distributes the syndromes across the drives 423 in one of the available parity distribution methods. 424 425config DM_ZERO 426 tristate "Zero target" 427 depends on BLK_DEV_DM 428 help 429 A target that discards writes, and returns all zeroes for 430 reads. Useful in some recovery situations. 431 432config DM_MULTIPATH 433 tristate "Multipath target" 434 depends on BLK_DEV_DM 435 # nasty syntax but means make DM_MULTIPATH independent 436 # of SCSI_DH if the latter isn't defined but if 437 # it is, DM_MULTIPATH must depend on it. We get a build 438 # error if SCSI_DH=m and DM_MULTIPATH=y 439 depends on !SCSI_DH || SCSI 440 help 441 Allow volume managers to support multipath hardware. 442 443config DM_MULTIPATH_QL 444 tristate "I/O Path Selector based on the number of in-flight I/Os" 445 depends on DM_MULTIPATH 446 help 447 This path selector is a dynamic load balancer which selects 448 the path with the least number of in-flight I/Os. 449 450 If unsure, say N. 451 452config DM_MULTIPATH_ST 453 tristate "I/O Path Selector based on the service time" 454 depends on DM_MULTIPATH 455 help 456 This path selector is a dynamic load balancer which selects 457 the path expected to complete the incoming I/O in the shortest 458 time. 459 460 If unsure, say N. 461 462config DM_MULTIPATH_HST 463 tristate "I/O Path Selector based on historical service time" 464 depends on DM_MULTIPATH 465 help 466 This path selector is a dynamic load balancer which selects 467 the path expected to complete the incoming I/O in the shortest 468 time by comparing estimated service time (based on historical 469 service time). 470 471 If unsure, say N. 472 473config DM_MULTIPATH_IOA 474 tristate "I/O Path Selector based on CPU submission" 475 depends on DM_MULTIPATH 476 help 477 This path selector selects the path based on the CPU the IO is 478 executed on and the CPU to path mapping setup at path addition time. 479 480 If unsure, say N. 481 482config DM_DELAY 483 tristate "I/O delaying target" 484 depends on BLK_DEV_DM 485 help 486 A target that delays reads and/or writes and can send 487 them to different devices. Useful for testing. 488 489 If unsure, say N. 490 491config DM_DUST 492 tristate "Bad sector simulation target" 493 depends on BLK_DEV_DM 494 help 495 A target that simulates bad sector behavior. 496 Useful for testing. 497 498 If unsure, say N. 499 500config DM_INIT 501 bool "DM \"dm-mod.create=\" parameter support" 502 depends on BLK_DEV_DM=y 503 help 504 Enable "dm-mod.create=" parameter to create mapped devices at init time. 505 This option is useful to allow mounting rootfs without requiring an 506 initramfs. 507 See Documentation/admin-guide/device-mapper/dm-init.rst for dm-mod.create="..." 508 format. 509 510 If unsure, say N. 511 512config DM_UEVENT 513 bool "DM uevents" 514 depends on BLK_DEV_DM 515 help 516 Generate udev events for DM events. 517 518config DM_FLAKEY 519 tristate "Flakey target" 520 depends on BLK_DEV_DM 521 help 522 A target that intermittently fails I/O for debugging purposes. 523 524config DM_VERITY 525 tristate "Verity target support" 526 depends on BLK_DEV_DM 527 select CRYPTO 528 select CRYPTO_HASH 529 select DM_BUFIO 530 help 531 This device-mapper target creates a read-only device that 532 transparently validates the data on one underlying device against 533 a pre-generated tree of cryptographic checksums stored on a second 534 device. 535 536 You'll need to activate the digests you're going to use in the 537 cryptoapi configuration. 538 539 To compile this code as a module, choose M here: the module will 540 be called dm-verity. 541 542 If unsure, say N. 543 544config DM_VERITY_VERIFY_ROOTHASH_SIG 545 def_bool n 546 bool "Verity data device root hash signature verification support" 547 depends on DM_VERITY 548 select SYSTEM_DATA_VERIFICATION 549 help 550 Add ability for dm-verity device to be validated if the 551 pre-generated tree of cryptographic checksums passed has a pkcs#7 552 signature file that can validate the roothash of the tree. 553 554 By default, rely on the builtin trusted keyring. 555 556 If unsure, say N. 557 558config DM_VERITY_VERIFY_ROOTHASH_SIG_SECONDARY_KEYRING 559 bool "Verity data device root hash signature verification with secondary keyring" 560 depends on DM_VERITY_VERIFY_ROOTHASH_SIG 561 depends on SECONDARY_TRUSTED_KEYRING 562 help 563 Rely on the secondary trusted keyring to verify dm-verity signatures. 564 565 If unsure, say N. 566 567config DM_VERITY_FEC 568 bool "Verity forward error correction support" 569 depends on DM_VERITY 570 select REED_SOLOMON 571 select REED_SOLOMON_DEC8 572 help 573 Add forward error correction support to dm-verity. This option 574 makes it possible to use pre-generated error correction data to 575 recover from corrupted blocks. 576 577 If unsure, say N. 578 579config DM_SWITCH 580 tristate "Switch target support (EXPERIMENTAL)" 581 depends on BLK_DEV_DM 582 help 583 This device-mapper target creates a device that supports an arbitrary 584 mapping of fixed-size regions of I/O across a fixed set of paths. 585 The path used for any specific region can be switched dynamically 586 by sending the target a message. 587 588 To compile this code as a module, choose M here: the module will 589 be called dm-switch. 590 591 If unsure, say N. 592 593config DM_LOG_WRITES 594 tristate "Log writes target support" 595 depends on BLK_DEV_DM 596 help 597 This device-mapper target takes two devices, one device to use 598 normally, one to log all write operations done to the first device. 599 This is for use by file system developers wishing to verify that 600 their fs is writing a consistent file system at all times by allowing 601 them to replay the log in a variety of ways and to check the 602 contents. 603 604 To compile this code as a module, choose M here: the module will 605 be called dm-log-writes. 606 607 If unsure, say N. 608 609config DM_INTEGRITY 610 tristate "Integrity target support" 611 depends on BLK_DEV_DM 612 select BLK_DEV_INTEGRITY 613 select DM_BUFIO 614 select CRYPTO 615 select CRYPTO_SKCIPHER 616 select ASYNC_XOR 617 select DM_AUDIT if AUDIT 618 help 619 This device-mapper target emulates a block device that has 620 additional per-sector tags that can be used for storing 621 integrity information. 622 623 This integrity target is used with the dm-crypt target to 624 provide authenticated disk encryption or it can be used 625 standalone. 626 627 To compile this code as a module, choose M here: the module will 628 be called dm-integrity. 629 630config DM_ZONED 631 tristate "Drive-managed zoned block device target support" 632 depends on BLK_DEV_DM 633 depends on BLK_DEV_ZONED 634 select CRC32 635 help 636 This device-mapper target takes a host-managed or host-aware zoned 637 block device and exposes most of its capacity as a regular block 638 device (drive-managed zoned block device) without any write 639 constraints. This is mainly intended for use with file systems that 640 do not natively support zoned block devices but still want to 641 benefit from the increased capacity offered by SMR disks. Other uses 642 by applications using raw block devices (for example object stores) 643 are also possible. 644 645 To compile this code as a module, choose M here: the module will 646 be called dm-zoned. 647 648 If unsure, say N. 649 650config DM_AUDIT 651 bool "DM audit events" 652 depends on AUDIT 653 help 654 Generate audit events for device-mapper. 655 656 Enables audit logging of several security relevant events in the 657 particular device-mapper targets, especially the integrity target. 658 659endif # MD 660