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