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