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_LINEAR 65 tristate "Linear (append) 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 linear mode, i.e. it will combine the hard disk 70 partitions by simply appending one to the other. 71 72 To compile this as a module, choose M here: the module 73 will be called linear. 74 75 If unsure, say Y. 76 77config MD_RAID0 78 tristate "RAID-0 (striping) mode" 79 depends on BLK_DEV_MD 80 help 81 If you say Y here, then your multiple devices driver will be able to 82 use the so-called raid0 mode, i.e. it will combine the hard disk 83 partitions into one logical device in such a fashion as to fill them 84 up evenly, one chunk here and one chunk there. This will increase 85 the throughput rate if the partitions reside on distinct disks. 86 87 Information about Software RAID on Linux is contained in the 88 Software-RAID mini-HOWTO, available from 89 <https://www.tldp.org/docs.html#howto>. There you will also 90 learn where to get the supporting user space utilities raidtools. 91 92 To compile this as a module, choose M here: the module 93 will be called raid0. 94 95 If unsure, say Y. 96 97config MD_RAID1 98 tristate "RAID-1 (mirroring) mode" 99 depends on BLK_DEV_MD 100 help 101 A RAID-1 set consists of several disk drives which are exact copies 102 of each other. In the event of a mirror failure, the RAID driver 103 will continue to use the operational mirrors in the set, providing 104 an error free MD (multiple device) to the higher levels of the 105 kernel. In a set with N drives, the available space is the capacity 106 of a single drive, and the set protects against a failure of (N - 1) 107 drives. 108 109 Information about Software RAID on Linux is contained in the 110 Software-RAID mini-HOWTO, available from 111 <https://www.tldp.org/docs.html#howto>. There you will also 112 learn where to get the supporting user space utilities raidtools. 113 114 If you want to use such a RAID-1 set, say Y. To compile this code 115 as a module, choose M here: the module will be called raid1. 116 117 If unsure, say Y. 118 119config MD_RAID10 120 tristate "RAID-10 (mirrored striping) mode" 121 depends on BLK_DEV_MD 122 help 123 RAID-10 provides a combination of striping (RAID-0) and 124 mirroring (RAID-1) with easier configuration and more flexible 125 layout. 126 Unlike RAID-0, but like RAID-1, RAID-10 requires all devices to 127 be the same size (or at least, only as much as the smallest device 128 will be used). 129 RAID-10 provides a variety of layouts that provide different levels 130 of redundancy and performance. 131 132 RAID-10 requires mdadm-1.7.0 or later, available at: 133 134 https://www.kernel.org/pub/linux/utils/raid/mdadm/ 135 136 If unsure, say Y. 137 138config MD_RAID456 139 tristate "RAID-4/RAID-5/RAID-6 mode" 140 depends on BLK_DEV_MD 141 select RAID6_PQ 142 select LIBCRC32C 143 select ASYNC_MEMCPY 144 select ASYNC_XOR 145 select ASYNC_PQ 146 select ASYNC_RAID6_RECOV 147 help 148 A RAID-5 set of N drives with a capacity of C MB per drive provides 149 the capacity of C * (N - 1) MB, and protects against a failure 150 of a single drive. For a given sector (row) number, (N - 1) drives 151 contain data sectors, and one drive contains the parity protection. 152 For a RAID-4 set, the parity blocks are present on a single drive, 153 while a RAID-5 set distributes the parity across the drives in one 154 of the available parity distribution methods. 155 156 A RAID-6 set of N drives with a capacity of C MB per drive 157 provides the capacity of C * (N - 2) MB, and protects 158 against a failure of any two drives. For a given sector 159 (row) number, (N - 2) drives contain data sectors, and two 160 drives contains two independent redundancy syndromes. Like 161 RAID-5, RAID-6 distributes the syndromes across the drives 162 in one of the available parity distribution methods. 163 164 Information about Software RAID on Linux is contained in the 165 Software-RAID mini-HOWTO, available from 166 <https://www.tldp.org/docs.html#howto>. There you will also 167 learn where to get the supporting user space utilities raidtools. 168 169 If you want to use such a RAID-4/RAID-5/RAID-6 set, say Y. To 170 compile this code as a module, choose M here: the module 171 will be called raid456. 172 173 If unsure, say Y. 174 175config MD_CLUSTER 176 tristate "Cluster Support for MD" 177 depends on BLK_DEV_MD 178 depends on DLM 179 default n 180 help 181 Clustering support for MD devices. This enables locking and 182 synchronization across multiple systems on the cluster, so all 183 nodes in the cluster can access the MD devices simultaneously. 184 185 This brings the redundancy (and uptime) of RAID levels across the 186 nodes of the cluster. Currently, it can work with raid1 and raid10 187 (limited support). 188 189 If unsure, say N. 190 191source "drivers/md/bcache/Kconfig" 192 193config BLK_DEV_DM_BUILTIN 194 bool 195 196config BLK_DEV_DM 197 tristate "Device mapper support" 198 select BLOCK_HOLDER_DEPRECATED if SYSFS 199 select BLK_DEV_DM_BUILTIN 200 select BLK_MQ_STACKING 201 depends on DAX || DAX=n 202 help 203 Device-mapper is a low level volume manager. It works by allowing 204 people to specify mappings for ranges of logical sectors. Various 205 mapping types are available, in addition people may write their own 206 modules containing custom mappings if they wish. 207 208 Higher level volume managers such as LVM2 use this driver. 209 210 To compile this as a module, choose M here: the module will be 211 called dm-mod. 212 213 If unsure, say N. 214 215config DM_DEBUG 216 bool "Device mapper debugging support" 217 depends on BLK_DEV_DM 218 help 219 Enable this for messages that may help debug device-mapper problems. 220 221 If unsure, say N. 222 223config DM_BUFIO 224 tristate 225 depends on BLK_DEV_DM 226 help 227 This interface allows you to do buffered I/O on a device and acts 228 as a cache, holding recently-read blocks in memory and performing 229 delayed writes. 230 231config DM_DEBUG_BLOCK_MANAGER_LOCKING 232 bool "Block manager locking" 233 depends on DM_BUFIO 234 help 235 Block manager locking can catch various metadata corruption issues. 236 237 If unsure, say N. 238 239config DM_DEBUG_BLOCK_STACK_TRACING 240 bool "Keep stack trace of persistent data block lock holders" 241 depends on STACKTRACE_SUPPORT && DM_DEBUG_BLOCK_MANAGER_LOCKING 242 select STACKTRACE 243 help 244 Enable this for messages that may help debug problems with the 245 block manager locking used by thin provisioning and caching. 246 247 If unsure, say N. 248 249config DM_BIO_PRISON 250 tristate 251 depends on BLK_DEV_DM 252 help 253 Some bio locking schemes used by other device-mapper targets 254 including thin provisioning. 255 256source "drivers/md/persistent-data/Kconfig" 257 258config DM_UNSTRIPED 259 tristate "Unstriped target" 260 depends on BLK_DEV_DM 261 help 262 Unstripes I/O so it is issued solely on a single drive in a HW 263 RAID0 or dm-striped target. 264 265config DM_CRYPT 266 tristate "Crypt target support" 267 depends on BLK_DEV_DM 268 depends on (ENCRYPTED_KEYS || ENCRYPTED_KEYS=n) 269 depends on (TRUSTED_KEYS || TRUSTED_KEYS=n) 270 select CRYPTO 271 select CRYPTO_CBC 272 select CRYPTO_ESSIV 273 help 274 This device-mapper target allows you to create a device that 275 transparently encrypts the data on it. You'll need to activate 276 the ciphers you're going to use in the cryptoapi configuration. 277 278 For further information on dm-crypt and userspace tools see: 279 <https://gitlab.com/cryptsetup/cryptsetup/wikis/DMCrypt> 280 281 To compile this code as a module, choose M here: the module will 282 be called dm-crypt. 283 284 If unsure, say N. 285 286config DM_SNAPSHOT 287 tristate "Snapshot target" 288 depends on BLK_DEV_DM 289 select DM_BUFIO 290 help 291 Allow volume managers to take writable snapshots of a device. 292 293config DM_THIN_PROVISIONING 294 tristate "Thin provisioning target" 295 depends on BLK_DEV_DM 296 select DM_PERSISTENT_DATA 297 select DM_BIO_PRISON 298 help 299 Provides thin provisioning and snapshots that share a data store. 300 301config DM_CACHE 302 tristate "Cache target (EXPERIMENTAL)" 303 depends on BLK_DEV_DM 304 default n 305 select DM_PERSISTENT_DATA 306 select DM_BIO_PRISON 307 help 308 dm-cache attempts to improve performance of a block device by 309 moving frequently used data to a smaller, higher performance 310 device. Different 'policy' plugins can be used to change the 311 algorithms used to select which blocks are promoted, demoted, 312 cleaned etc. It supports writeback and writethrough modes. 313 314config DM_CACHE_SMQ 315 tristate "Stochastic MQ Cache Policy (EXPERIMENTAL)" 316 depends on DM_CACHE 317 default y 318 help 319 A cache policy that uses a multiqueue ordered by recent hits 320 to select which blocks should be promoted and demoted. 321 This is meant to be a general purpose policy. It prioritises 322 reads over writes. This SMQ policy (vs MQ) offers the promise 323 of less memory utilization, improved performance and increased 324 adaptability in the face of changing workloads. 325 326config DM_WRITECACHE 327 tristate "Writecache target" 328 depends on BLK_DEV_DM 329 help 330 The writecache target caches writes on persistent memory or SSD. 331 It is intended for databases or other programs that need extremely 332 low commit latency. 333 334 The writecache target doesn't cache reads because reads are supposed 335 to be cached in standard RAM. 336 337config DM_EBS 338 tristate "Emulated block size target (EXPERIMENTAL)" 339 depends on BLK_DEV_DM && !HIGHMEM 340 select DM_BUFIO 341 help 342 dm-ebs emulates smaller logical block size on backing devices 343 with larger ones (e.g. 512 byte sectors on 4K native disks). 344 345config DM_ERA 346 tristate "Era target (EXPERIMENTAL)" 347 depends on BLK_DEV_DM 348 default n 349 select DM_PERSISTENT_DATA 350 select DM_BIO_PRISON 351 help 352 dm-era tracks which parts of a block device are written to 353 over time. Useful for maintaining cache coherency when using 354 vendor snapshots. 355 356config DM_CLONE 357 tristate "Clone target (EXPERIMENTAL)" 358 depends on BLK_DEV_DM 359 default n 360 select DM_PERSISTENT_DATA 361 help 362 dm-clone produces a one-to-one copy of an existing, read-only source 363 device into a writable destination device. The cloned device is 364 visible/mountable immediately and the copy of the source device to the 365 destination device happens in the background, in parallel with user 366 I/O. 367 368 If unsure, say N. 369 370config DM_MIRROR 371 tristate "Mirror target" 372 depends on BLK_DEV_DM 373 help 374 Allow volume managers to mirror logical volumes, also 375 needed for live data migration tools such as 'pvmove'. 376 377config DM_LOG_USERSPACE 378 tristate "Mirror userspace logging" 379 depends on DM_MIRROR && NET 380 select CONNECTOR 381 help 382 The userspace logging module provides a mechanism for 383 relaying the dm-dirty-log API to userspace. Log designs 384 which are more suited to userspace implementation (e.g. 385 shared storage logs) or experimental logs can be implemented 386 by leveraging this framework. 387 388config DM_RAID 389 tristate "RAID 1/4/5/6/10 target" 390 depends on BLK_DEV_DM 391 select MD_RAID0 392 select MD_RAID1 393 select MD_RAID10 394 select MD_RAID456 395 select BLK_DEV_MD 396 help 397 A dm target that supports RAID1, RAID10, RAID4, RAID5 and RAID6 mappings 398 399 A RAID-5 set of N drives with a capacity of C MB per drive provides 400 the capacity of C * (N - 1) MB, and protects against a failure 401 of a single drive. For a given sector (row) number, (N - 1) drives 402 contain data sectors, and one drive contains the parity protection. 403 For a RAID-4 set, the parity blocks are present on a single drive, 404 while a RAID-5 set distributes the parity across the drives in one 405 of the available parity distribution methods. 406 407 A RAID-6 set of N drives with a capacity of C MB per drive 408 provides the capacity of C * (N - 2) MB, and protects 409 against a failure of any two drives. For a given sector 410 (row) number, (N - 2) drives contain data sectors, and two 411 drives contains two independent redundancy syndromes. Like 412 RAID-5, RAID-6 distributes the syndromes across the drives 413 in one of the available parity distribution methods. 414 415config DM_ZERO 416 tristate "Zero target" 417 depends on BLK_DEV_DM 418 help 419 A target that discards writes, and returns all zeroes for 420 reads. Useful in some recovery situations. 421 422config DM_MULTIPATH 423 tristate "Multipath target" 424 depends on BLK_DEV_DM 425 # nasty syntax but means make DM_MULTIPATH independent 426 # of SCSI_DH if the latter isn't defined but if 427 # it is, DM_MULTIPATH must depend on it. We get a build 428 # error if SCSI_DH=m and DM_MULTIPATH=y 429 depends on !SCSI_DH || SCSI 430 help 431 Allow volume managers to support multipath hardware. 432 433config DM_MULTIPATH_QL 434 tristate "I/O Path Selector based on the number of in-flight I/Os" 435 depends on DM_MULTIPATH 436 help 437 This path selector is a dynamic load balancer which selects 438 the path with the least number of in-flight I/Os. 439 440 If unsure, say N. 441 442config DM_MULTIPATH_ST 443 tristate "I/O Path Selector based on the service time" 444 depends on DM_MULTIPATH 445 help 446 This path selector is a dynamic load balancer which selects 447 the path expected to complete the incoming I/O in the shortest 448 time. 449 450 If unsure, say N. 451 452config DM_MULTIPATH_HST 453 tristate "I/O Path Selector based on historical 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 by comparing estimated service time (based on historical 459 service time). 460 461 If unsure, say N. 462 463config DM_MULTIPATH_IOA 464 tristate "I/O Path Selector based on CPU submission" 465 depends on DM_MULTIPATH 466 help 467 This path selector selects the path based on the CPU the IO is 468 executed on and the CPU to path mapping setup at path addition time. 469 470 If unsure, say N. 471 472config DM_DELAY 473 tristate "I/O delaying target" 474 depends on BLK_DEV_DM 475 help 476 A target that delays reads and/or writes and can send 477 them to different devices. Useful for testing. 478 479 If unsure, say N. 480 481config DM_DUST 482 tristate "Bad sector simulation target" 483 depends on BLK_DEV_DM 484 help 485 A target that simulates bad sector behavior. 486 Useful for testing. 487 488 If unsure, say N. 489 490config DM_INIT 491 bool "DM \"dm-mod.create=\" parameter support" 492 depends on BLK_DEV_DM=y 493 help 494 Enable "dm-mod.create=" parameter to create mapped devices at init time. 495 This option is useful to allow mounting rootfs without requiring an 496 initramfs. 497 See Documentation/admin-guide/device-mapper/dm-init.rst for dm-mod.create="..." 498 format. 499 500 If unsure, say N. 501 502config DM_UEVENT 503 bool "DM uevents" 504 depends on BLK_DEV_DM 505 help 506 Generate udev events for DM events. 507 508config DM_FLAKEY 509 tristate "Flakey target" 510 depends on BLK_DEV_DM 511 help 512 A target that intermittently fails I/O for debugging purposes. 513 514config DM_VERITY 515 tristate "Verity target support" 516 depends on BLK_DEV_DM 517 select CRYPTO 518 select CRYPTO_HASH 519 select DM_BUFIO 520 help 521 This device-mapper target creates a read-only device that 522 transparently validates the data on one underlying device against 523 a pre-generated tree of cryptographic checksums stored on a second 524 device. 525 526 You'll need to activate the digests you're going to use in the 527 cryptoapi configuration. 528 529 To compile this code as a module, choose M here: the module will 530 be called dm-verity. 531 532 If unsure, say N. 533 534config DM_VERITY_VERIFY_ROOTHASH_SIG 535 bool "Verity data device root hash signature verification support" 536 depends on DM_VERITY 537 select SYSTEM_DATA_VERIFICATION 538 help 539 Add ability for dm-verity device to be validated if the 540 pre-generated tree of cryptographic checksums passed has a pkcs#7 541 signature file that can validate the roothash of the tree. 542 543 By default, rely on the builtin trusted keyring. 544 545 If unsure, say N. 546 547config DM_VERITY_VERIFY_ROOTHASH_SIG_SECONDARY_KEYRING 548 bool "Verity data device root hash signature verification with secondary keyring" 549 depends on DM_VERITY_VERIFY_ROOTHASH_SIG 550 depends on SECONDARY_TRUSTED_KEYRING 551 help 552 Rely on the secondary trusted keyring to verify dm-verity signatures. 553 554 If unsure, say N. 555 556config DM_VERITY_VERIFY_ROOTHASH_SIG_PLATFORM_KEYRING 557 bool "Verity data device root hash signature verification with platform keyring" 558 default DM_VERITY_VERIFY_ROOTHASH_SIG_SECONDARY_KEYRING 559 depends on DM_VERITY_VERIFY_ROOTHASH_SIG 560 depends on INTEGRITY_PLATFORM_KEYRING 561 help 562 Rely also on the platform keyring to verify dm-verity signatures. 563 564 If unsure, say N. 565 566config DM_VERITY_FEC 567 bool "Verity forward error correction support" 568 depends on DM_VERITY 569 select REED_SOLOMON 570 select REED_SOLOMON_DEC8 571 help 572 Add forward error correction support to dm-verity. This option 573 makes it possible to use pre-generated error correction data to 574 recover from corrupted blocks. 575 576 If unsure, say N. 577 578config DM_SWITCH 579 tristate "Switch target support (EXPERIMENTAL)" 580 depends on BLK_DEV_DM 581 help 582 This device-mapper target creates a device that supports an arbitrary 583 mapping of fixed-size regions of I/O across a fixed set of paths. 584 The path used for any specific region can be switched dynamically 585 by sending the target a message. 586 587 To compile this code as a module, choose M here: the module will 588 be called dm-switch. 589 590 If unsure, say N. 591 592config DM_LOG_WRITES 593 tristate "Log writes target support" 594 depends on BLK_DEV_DM 595 help 596 This device-mapper target takes two devices, one device to use 597 normally, one to log all write operations done to the first device. 598 This is for use by file system developers wishing to verify that 599 their fs is writing a consistent file system at all times by allowing 600 them to replay the log in a variety of ways and to check the 601 contents. 602 603 To compile this code as a module, choose M here: the module will 604 be called dm-log-writes. 605 606 If unsure, say N. 607 608config DM_INTEGRITY 609 tristate "Integrity target support" 610 depends on BLK_DEV_DM 611 select BLK_DEV_INTEGRITY 612 select DM_BUFIO 613 select CRYPTO 614 select CRYPTO_SKCIPHER 615 select ASYNC_XOR 616 select DM_AUDIT if AUDIT 617 help 618 This device-mapper target emulates a block device that has 619 additional per-sector tags that can be used for storing 620 integrity information. 621 622 This integrity target is used with the dm-crypt target to 623 provide authenticated disk encryption or it can be used 624 standalone. 625 626 To compile this code as a module, choose M here: the module will 627 be called dm-integrity. 628 629config DM_ZONED 630 tristate "Drive-managed zoned block device target support" 631 depends on BLK_DEV_DM 632 depends on BLK_DEV_ZONED 633 select CRC32 634 help 635 This device-mapper target takes a host-managed or host-aware zoned 636 block device and exposes most of its capacity as a regular block 637 device (drive-managed zoned block device) without any write 638 constraints. This is mainly intended for use with file systems that 639 do not natively support zoned block devices but still want to 640 benefit from the increased capacity offered by SMR disks. Other uses 641 by applications using raw block devices (for example object stores) 642 are also possible. 643 644 To compile this code as a module, choose M here: the module will 645 be called dm-zoned. 646 647 If unsure, say N. 648 649config DM_AUDIT 650 bool "DM audit events" 651 depends on BLK_DEV_DM 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 659source "drivers/md/dm-vdo/Kconfig" 660 661endif # MD 662