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" 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" 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" 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 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 289config 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 296config 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 304config 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 317config 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 329config 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 340config 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 348config 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 359config 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 373config 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 380config 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 391config 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 418config 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 425config 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 436config 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 445config 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 455config 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 466config DM_DELAY 467 tristate "I/O delaying target" 468 depends on BLK_DEV_DM 469 help 470 A target that delays reads and/or writes and can send 471 them to different devices. Useful for testing. 472 473 If unsure, say N. 474 475config DM_DUST 476 tristate "Bad sector simulation target" 477 depends on BLK_DEV_DM 478 help 479 A target that simulates bad sector behavior. 480 Useful for testing. 481 482 If unsure, say N. 483 484config DM_INIT 485 bool "DM \"dm-mod.create=\" parameter support" 486 depends on BLK_DEV_DM=y 487 help 488 Enable "dm-mod.create=" parameter to create mapped devices at init time. 489 This option is useful to allow mounting rootfs without requiring an 490 initramfs. 491 See Documentation/admin-guide/device-mapper/dm-init.rst for dm-mod.create="..." 492 format. 493 494 If unsure, say N. 495 496config DM_UEVENT 497 bool "DM uevents" 498 depends on BLK_DEV_DM 499 help 500 Generate udev events for DM events. 501 502config DM_FLAKEY 503 tristate "Flakey target" 504 depends on BLK_DEV_DM 505 help 506 A target that intermittently fails I/O for debugging purposes. 507 508config DM_VERITY 509 tristate "Verity target support" 510 depends on BLK_DEV_DM 511 select CRYPTO 512 select CRYPTO_HASH 513 select DM_BUFIO 514 help 515 This device-mapper target creates a read-only device that 516 transparently validates the data on one underlying device against 517 a pre-generated tree of cryptographic checksums stored on a second 518 device. 519 520 You'll need to activate the digests you're going to use in the 521 cryptoapi configuration. 522 523 To compile this code as a module, choose M here: the module will 524 be called dm-verity. 525 526 If unsure, say N. 527 528config DM_VERITY_VERIFY_ROOTHASH_SIG 529 def_bool n 530 bool "Verity data device root hash signature verification support" 531 depends on DM_VERITY 532 select SYSTEM_DATA_VERIFICATION 533 help 534 Add ability for dm-verity device to be validated if the 535 pre-generated tree of cryptographic checksums passed has a pkcs#7 536 signature file that can validate the roothash of the tree. 537 538 If unsure, say N. 539 540config DM_VERITY_FEC 541 bool "Verity forward error correction support" 542 depends on DM_VERITY 543 select REED_SOLOMON 544 select REED_SOLOMON_DEC8 545 help 546 Add forward error correction support to dm-verity. This option 547 makes it possible to use pre-generated error correction data to 548 recover from corrupted blocks. 549 550 If unsure, say N. 551 552config DM_SWITCH 553 tristate "Switch target support (EXPERIMENTAL)" 554 depends on BLK_DEV_DM 555 help 556 This device-mapper target creates a device that supports an arbitrary 557 mapping of fixed-size regions of I/O across a fixed set of paths. 558 The path used for any specific region can be switched dynamically 559 by sending the target a message. 560 561 To compile this code as a module, choose M here: the module will 562 be called dm-switch. 563 564 If unsure, say N. 565 566config DM_LOG_WRITES 567 tristate "Log writes target support" 568 depends on BLK_DEV_DM 569 help 570 This device-mapper target takes two devices, one device to use 571 normally, one to log all write operations done to the first device. 572 This is for use by file system developers wishing to verify that 573 their fs is writing a consistent file system at all times by allowing 574 them to replay the log in a variety of ways and to check the 575 contents. 576 577 To compile this code as a module, choose M here: the module will 578 be called dm-log-writes. 579 580 If unsure, say N. 581 582config DM_INTEGRITY 583 tristate "Integrity target support" 584 depends on BLK_DEV_DM 585 select BLK_DEV_INTEGRITY 586 select DM_BUFIO 587 select CRYPTO 588 select ASYNC_XOR 589 help 590 This device-mapper target emulates a block device that has 591 additional per-sector tags that can be used for storing 592 integrity information. 593 594 This integrity target is used with the dm-crypt target to 595 provide authenticated disk encryption or it can be used 596 standalone. 597 598 To compile this code as a module, choose M here: the module will 599 be called dm-integrity. 600 601config DM_ZONED 602 tristate "Drive-managed zoned block device target support" 603 depends on BLK_DEV_DM 604 depends on BLK_DEV_ZONED 605 help 606 This device-mapper target takes a host-managed or host-aware zoned 607 block device and exposes most of its capacity as a regular block 608 device (drive-managed zoned block device) without any write 609 constraints. This is mainly intended for use with file systems that 610 do not natively support zoned block devices but still want to 611 benefit from the increased capacity offered by SMR disks. Other uses 612 by applications using raw block devices (for example object stores) 613 are also possible. 614 615 To compile this code as a module, choose M here: the module will 616 be called dm-zoned. 617 618 If unsure, say N. 619 620endif # MD 621