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 select SRCU 10 help 11 Support multiple physical spindles through a single logical device. 12 Required for RAID and logical volume management. 13 14if MD 15 16config 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 35config 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 49config MD_LINEAR 50 tristate "Linear (append) mode (deprecated)" 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 62config 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 82config 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 104config 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 123config 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 160config MD_MULTIPATH 161 tristate "Multipath I/O support (deprecated)" 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 171config MD_FAULTY 172 tristate "Faulty test module for MD (deprecated)" 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 181config 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 197source "drivers/md/bcache/Kconfig" 198 199config BLK_DEV_DM_BUILTIN 200 bool 201 202config 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 219config 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 227config 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 235config 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 243config 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 253config 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 260source "drivers/md/persistent-data/Kconfig" 261 262config 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 269config 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 290config 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 297config 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 305config 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 318config 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 330config 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 341config 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 349config 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 360config 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 374config 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 381config 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 392config 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 419config 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 426config 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 437config 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 446config 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 456config 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 467config 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 476config 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 485config 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 494config 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 506config DM_UEVENT 507 bool "DM uevents" 508 depends on BLK_DEV_DM 509 help 510 Generate udev events for DM events. 511 512config 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 518config 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 538config 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 552config 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 561config 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 573config 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 587config 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 603config 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 623config 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 643endif # MD 644