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_BITMAP 41 bool "MD RAID bitmap support" 42 default y 43 depends on BLK_DEV_MD 44 help 45 If you say Y here, support for the write intent bitmap will be 46 enabled. The bitmap can be used to optimize resync speed after power 47 failure or readding a disk, limiting it to recorded dirty sectors in 48 bitmap. 49 50 This feature can be added to existing MD array or MD array can be 51 created with bitmap via mdadm(8). 52 53 If unsure, say Y. 54 55config MD_AUTODETECT 56 bool "Autodetect RAID arrays during kernel boot" 57 depends on BLK_DEV_MD=y 58 default y 59 help 60 If you say Y here, then the kernel will try to autodetect raid 61 arrays as part of its boot process. 62 63 If you don't use raid and say Y, this autodetection can cause 64 a several-second delay in the boot time due to various 65 synchronisation steps that are part of this step. 66 67 If unsure, say Y. 68 69config MD_BITMAP_FILE 70 bool "MD bitmap file support (deprecated)" 71 default y 72 depends on MD_BITMAP 73 help 74 If you say Y here, support for write intent bitmaps in files on an 75 external file system is enabled. This is an alternative to the internal 76 bitmaps near the MD superblock, and very problematic code that abuses 77 various kernel APIs and can only work with files on a file system not 78 actually sitting on the MD device. 79 80config MD_LINEAR 81 tristate "Linear (append) mode" 82 depends on BLK_DEV_MD 83 help 84 If you say Y here, then your multiple devices driver will be able to 85 use the so-called linear mode, i.e. it will combine the hard disk 86 partitions by simply appending one to the other. 87 88 To compile this as a module, choose M here: the module 89 will be called linear. 90 91 If unsure, say Y. 92 93config MD_RAID0 94 tristate "RAID-0 (striping) mode" 95 depends on BLK_DEV_MD 96 help 97 If you say Y here, then your multiple devices driver will be able to 98 use the so-called raid0 mode, i.e. it will combine the hard disk 99 partitions into one logical device in such a fashion as to fill them 100 up evenly, one chunk here and one chunk there. This will increase 101 the throughput rate if the partitions reside on distinct disks. 102 103 Information about Software RAID on Linux is contained in the 104 Software-RAID mini-HOWTO, available from 105 <https://www.tldp.org/docs.html#howto>. There you will also 106 learn where to get the supporting user space utilities raidtools. 107 108 To compile this as a module, choose M here: the module 109 will be called raid0. 110 111 If unsure, say Y. 112 113config MD_RAID1 114 tristate "RAID-1 (mirroring) mode" 115 depends on BLK_DEV_MD 116 help 117 A RAID-1 set consists of several disk drives which are exact copies 118 of each other. In the event of a mirror failure, the RAID driver 119 will continue to use the operational mirrors in the set, providing 120 an error free MD (multiple device) to the higher levels of the 121 kernel. In a set with N drives, the available space is the capacity 122 of a single drive, and the set protects against a failure of (N - 1) 123 drives. 124 125 Information about Software RAID on Linux is contained in the 126 Software-RAID mini-HOWTO, available from 127 <https://www.tldp.org/docs.html#howto>. There you will also 128 learn where to get the supporting user space utilities raidtools. 129 130 If you want to use such a RAID-1 set, say Y. To compile this code 131 as a module, choose M here: the module will be called raid1. 132 133 If unsure, say Y. 134 135config MD_RAID10 136 tristate "RAID-10 (mirrored striping) mode" 137 depends on BLK_DEV_MD 138 help 139 RAID-10 provides a combination of striping (RAID-0) and 140 mirroring (RAID-1) with easier configuration and more flexible 141 layout. 142 Unlike RAID-0, but like RAID-1, RAID-10 requires all devices to 143 be the same size (or at least, only as much as the smallest device 144 will be used). 145 RAID-10 provides a variety of layouts that provide different levels 146 of redundancy and performance. 147 148 RAID-10 requires mdadm-1.7.0 or later, available at: 149 150 https://www.kernel.org/pub/linux/utils/raid/mdadm/ 151 152 If unsure, say Y. 153 154config MD_RAID456 155 tristate "RAID-4/RAID-5/RAID-6 mode" 156 depends on BLK_DEV_MD 157 select RAID6_PQ 158 select CRC32 159 select ASYNC_MEMCPY 160 select ASYNC_XOR 161 select ASYNC_PQ 162 select ASYNC_RAID6_RECOV 163 help 164 A RAID-5 set of N drives with a capacity of C MB per drive provides 165 the capacity of C * (N - 1) MB, and protects against a failure 166 of a single drive. For a given sector (row) number, (N - 1) drives 167 contain data sectors, and one drive contains the parity protection. 168 For a RAID-4 set, the parity blocks are present on a single drive, 169 while a RAID-5 set distributes the parity across the drives in one 170 of the available parity distribution methods. 171 172 A RAID-6 set of N drives with a capacity of C MB per drive 173 provides the capacity of C * (N - 2) MB, and protects 174 against a failure of any two drives. For a given sector 175 (row) number, (N - 2) drives contain data sectors, and two 176 drives contains two independent redundancy syndromes. Like 177 RAID-5, RAID-6 distributes the syndromes across the drives 178 in one of the available parity distribution methods. 179 180 Information about Software RAID on Linux is contained in the 181 Software-RAID mini-HOWTO, available from 182 <https://www.tldp.org/docs.html#howto>. There you will also 183 learn where to get the supporting user space utilities raidtools. 184 185 If you want to use such a RAID-4/RAID-5/RAID-6 set, say Y. To 186 compile this code as a module, choose M here: the module 187 will be called raid456. 188 189 If unsure, say Y. 190 191config MD_CLUSTER 192 tristate "Cluster Support for MD" 193 select MD_BITMAP 194 depends on BLK_DEV_MD 195 depends on DLM 196 default n 197 help 198 Clustering support for MD devices. This enables locking and 199 synchronization across multiple systems on the cluster, so all 200 nodes in the cluster can access the MD devices simultaneously. 201 202 This brings the redundancy (and uptime) of RAID levels across the 203 nodes of the cluster. Currently, it can work with raid1 and raid10 204 (limited support). 205 206 If unsure, say N. 207 208source "drivers/md/bcache/Kconfig" 209 210config BLK_DEV_DM_BUILTIN 211 bool 212 213config BLK_DEV_DM 214 tristate "Device mapper support" 215 select BLOCK_HOLDER_DEPRECATED if SYSFS 216 select BLK_DEV_DM_BUILTIN 217 select BLK_MQ_STACKING 218 depends on DAX || DAX=n 219 help 220 Device-mapper is a low level volume manager. It works by allowing 221 people to specify mappings for ranges of logical sectors. Various 222 mapping types are available, in addition people may write their own 223 modules containing custom mappings if they wish. 224 225 Higher level volume managers such as LVM2 use this driver. 226 227 To compile this as a module, choose M here: the module will be 228 called dm-mod. 229 230 If unsure, say N. 231 232config DM_DEBUG 233 bool "Device mapper debugging support" 234 depends on BLK_DEV_DM 235 help 236 Enable this for messages that may help debug device-mapper problems. 237 238 If unsure, say N. 239 240config DM_BUFIO 241 tristate 242 depends on BLK_DEV_DM 243 help 244 This interface allows you to do buffered I/O on a device and acts 245 as a cache, holding recently-read blocks in memory and performing 246 delayed writes. 247 248config DM_DEBUG_BLOCK_MANAGER_LOCKING 249 bool "Block manager locking" 250 depends on DM_BUFIO 251 help 252 Block manager locking can catch various metadata corruption issues. 253 254 If unsure, say N. 255 256config DM_DEBUG_BLOCK_STACK_TRACING 257 bool "Keep stack trace of persistent data block lock holders" 258 depends on STACKTRACE_SUPPORT && DM_DEBUG_BLOCK_MANAGER_LOCKING 259 select STACKTRACE 260 help 261 Enable this for messages that may help debug problems with the 262 block manager locking used by thin provisioning and caching. 263 264 If unsure, say N. 265 266config DM_BIO_PRISON 267 tristate 268 depends on BLK_DEV_DM 269 help 270 Some bio locking schemes used by other device-mapper targets 271 including thin provisioning. 272 273source "drivers/md/persistent-data/Kconfig" 274 275config DM_UNSTRIPED 276 tristate "Unstriped target" 277 depends on BLK_DEV_DM 278 help 279 Unstripes I/O so it is issued solely on a single drive in a HW 280 RAID0 or dm-striped target. 281 282config DM_CRYPT 283 tristate "Crypt target support" 284 depends on BLK_DEV_DM 285 depends on (ENCRYPTED_KEYS || ENCRYPTED_KEYS=n) 286 depends on (TRUSTED_KEYS || TRUSTED_KEYS=n) 287 select CRC32 288 select CRYPTO 289 select CRYPTO_CBC 290 select CRYPTO_ESSIV 291 help 292 This device-mapper target allows you to create a device that 293 transparently encrypts the data on it. You'll need to activate 294 the ciphers you're going to use in the cryptoapi configuration. 295 296 For further information on dm-crypt and userspace tools see: 297 <https://gitlab.com/cryptsetup/cryptsetup/wikis/DMCrypt> 298 299 To compile this code as a module, choose M here: the module will 300 be called dm-crypt. 301 302 If unsure, say N. 303 304config DM_SNAPSHOT 305 tristate "Snapshot target" 306 depends on BLK_DEV_DM 307 select DM_BUFIO 308 help 309 Allow volume managers to take writable snapshots of a device. 310 311config DM_THIN_PROVISIONING 312 tristate "Thin provisioning target" 313 depends on BLK_DEV_DM 314 select DM_PERSISTENT_DATA 315 select DM_BIO_PRISON 316 help 317 Provides thin provisioning and snapshots that share a data store. 318 319config DM_CACHE 320 tristate "Cache target (EXPERIMENTAL)" 321 depends on BLK_DEV_DM 322 default n 323 select DM_PERSISTENT_DATA 324 select DM_BIO_PRISON 325 help 326 dm-cache attempts to improve performance of a block device by 327 moving frequently used data to a smaller, higher performance 328 device. Different 'policy' plugins can be used to change the 329 algorithms used to select which blocks are promoted, demoted, 330 cleaned etc. It supports writeback and writethrough modes. 331 332config DM_CACHE_SMQ 333 tristate "Stochastic MQ Cache Policy (EXPERIMENTAL)" 334 depends on DM_CACHE 335 default y 336 help 337 A cache policy that uses a multiqueue ordered by recent hits 338 to select which blocks should be promoted and demoted. 339 This is meant to be a general purpose policy. It prioritises 340 reads over writes. This SMQ policy (vs MQ) offers the promise 341 of less memory utilization, improved performance and increased 342 adaptability in the face of changing workloads. 343 344config DM_WRITECACHE 345 tristate "Writecache target" 346 depends on BLK_DEV_DM 347 help 348 The writecache target caches writes on persistent memory or SSD. 349 It is intended for databases or other programs that need extremely 350 low commit latency. 351 352 The writecache target doesn't cache reads because reads are supposed 353 to be cached in standard RAM. 354 355config DM_EBS 356 tristate "Emulated block size target (EXPERIMENTAL)" 357 depends on BLK_DEV_DM && !HIGHMEM 358 select DM_BUFIO 359 help 360 dm-ebs emulates smaller logical block size on backing devices 361 with larger ones (e.g. 512 byte sectors on 4K native disks). 362 363config DM_ERA 364 tristate "Era target (EXPERIMENTAL)" 365 depends on BLK_DEV_DM 366 default n 367 select DM_PERSISTENT_DATA 368 select DM_BIO_PRISON 369 help 370 dm-era tracks which parts of a block device are written to 371 over time. Useful for maintaining cache coherency when using 372 vendor snapshots. 373 374config DM_CLONE 375 tristate "Clone target (EXPERIMENTAL)" 376 depends on BLK_DEV_DM 377 default n 378 select DM_PERSISTENT_DATA 379 help 380 dm-clone produces a one-to-one copy of an existing, read-only source 381 device into a writable destination device. The cloned device is 382 visible/mountable immediately and the copy of the source device to the 383 destination device happens in the background, in parallel with user 384 I/O. 385 386 If unsure, say N. 387 388config DM_MIRROR 389 tristate "Mirror target" 390 depends on BLK_DEV_DM 391 help 392 Allow volume managers to mirror logical volumes, also 393 needed for live data migration tools such as 'pvmove'. 394 395config DM_LOG_USERSPACE 396 tristate "Mirror userspace logging" 397 depends on DM_MIRROR && NET 398 select CONNECTOR 399 help 400 The userspace logging module provides a mechanism for 401 relaying the dm-dirty-log API to userspace. Log designs 402 which are more suited to userspace implementation (e.g. 403 shared storage logs) or experimental logs can be implemented 404 by leveraging this framework. 405 406config DM_RAID 407 tristate "RAID 1/4/5/6/10 target" 408 depends on BLK_DEV_DM 409 select MD_RAID0 410 select MD_RAID1 411 select MD_RAID10 412 select MD_RAID456 413 select MD_BITMAP 414 select BLK_DEV_MD 415 help 416 A dm target that supports RAID1, RAID10, RAID4, RAID5 and RAID6 mappings 417 418 A RAID-5 set of N drives with a capacity of C MB per drive provides 419 the capacity of C * (N - 1) MB, and protects against a failure 420 of a single drive. For a given sector (row) number, (N - 1) drives 421 contain data sectors, and one drive contains the parity protection. 422 For a RAID-4 set, the parity blocks are present on a single drive, 423 while a RAID-5 set distributes the parity across the drives in one 424 of the available parity distribution methods. 425 426 A RAID-6 set of N drives with a capacity of C MB per drive 427 provides the capacity of C * (N - 2) MB, and protects 428 against a failure of any two drives. For a given sector 429 (row) number, (N - 2) drives contain data sectors, and two 430 drives contains two independent redundancy syndromes. Like 431 RAID-5, RAID-6 distributes the syndromes across the drives 432 in one of the available parity distribution methods. 433 434config DM_ZERO 435 tristate "Zero target" 436 depends on BLK_DEV_DM 437 help 438 A target that discards writes, and returns all zeroes for 439 reads. Useful in some recovery situations. 440 441config DM_MULTIPATH 442 tristate "Multipath target" 443 depends on BLK_DEV_DM 444 # nasty syntax but means make DM_MULTIPATH independent 445 # of SCSI_DH if the latter isn't defined but if 446 # it is, DM_MULTIPATH must depend on it. We get a build 447 # error if SCSI_DH=m and DM_MULTIPATH=y 448 depends on !SCSI_DH || SCSI 449 help 450 Allow volume managers to support multipath hardware. 451 452config DM_MULTIPATH_QL 453 tristate "I/O Path Selector based on the number of in-flight I/Os" 454 depends on DM_MULTIPATH 455 help 456 This path selector is a dynamic load balancer which selects 457 the path with the least number of in-flight I/Os. 458 459 If unsure, say N. 460 461config DM_MULTIPATH_ST 462 tristate "I/O Path Selector based on the service time" 463 depends on DM_MULTIPATH 464 help 465 This path selector is a dynamic load balancer which selects 466 the path expected to complete the incoming I/O in the shortest 467 time. 468 469 If unsure, say N. 470 471config DM_MULTIPATH_HST 472 tristate "I/O Path Selector based on historical service time" 473 depends on DM_MULTIPATH 474 help 475 This path selector is a dynamic load balancer which selects 476 the path expected to complete the incoming I/O in the shortest 477 time by comparing estimated service time (based on historical 478 service time). 479 480 If unsure, say N. 481 482config DM_MULTIPATH_IOA 483 tristate "I/O Path Selector based on CPU submission" 484 depends on DM_MULTIPATH 485 help 486 This path selector selects the path based on the CPU the IO is 487 executed on and the CPU to path mapping setup at path addition time. 488 489 If unsure, say N. 490 491config DM_DELAY 492 tristate "I/O delaying target" 493 depends on BLK_DEV_DM 494 help 495 A target that delays reads and/or writes and can send 496 them to different devices. Useful for testing. 497 498 If unsure, say N. 499 500config DM_DUST 501 tristate "Bad sector simulation target" 502 depends on BLK_DEV_DM 503 help 504 A target that simulates bad sector behavior. 505 Useful for testing. 506 507 If unsure, say N. 508 509config DM_INIT 510 bool "DM \"dm-mod.create=\" parameter support" 511 depends on BLK_DEV_DM=y 512 help 513 Enable "dm-mod.create=" parameter to create mapped devices at init time. 514 This option is useful to allow mounting rootfs without requiring an 515 initramfs. 516 See Documentation/admin-guide/device-mapper/dm-init.rst for dm-mod.create="..." 517 format. 518 519 If unsure, say N. 520 521config DM_UEVENT 522 bool "DM uevents" 523 depends on BLK_DEV_DM 524 help 525 Generate udev events for DM events. 526 527config DM_FLAKEY 528 tristate "Flakey target" 529 depends on BLK_DEV_DM 530 help 531 A target that intermittently fails I/O for debugging purposes. 532 533config DM_VERITY 534 tristate "Verity target support" 535 depends on BLK_DEV_DM 536 select CRYPTO 537 select CRYPTO_HASH 538 select DM_BUFIO 539 help 540 This device-mapper target creates a read-only device that 541 transparently validates the data on one underlying device against 542 a pre-generated tree of cryptographic checksums stored on a second 543 device. 544 545 You'll need to activate the digests you're going to use in the 546 cryptoapi configuration. 547 548 To compile this code as a module, choose M here: the module will 549 be called dm-verity. 550 551 If unsure, say N. 552 553config DM_VERITY_VERIFY_ROOTHASH_SIG 554 bool "Verity data device root hash signature verification support" 555 depends on DM_VERITY 556 select SYSTEM_DATA_VERIFICATION 557 help 558 Add ability for dm-verity device to be validated if the 559 pre-generated tree of cryptographic checksums passed has a pkcs#7 560 signature file that can validate the roothash of the tree. 561 562 By default, rely on the builtin trusted keyring. 563 564 If unsure, say N. 565 566config DM_VERITY_VERIFY_ROOTHASH_SIG_SECONDARY_KEYRING 567 bool "Verity data device root hash signature verification with secondary keyring" 568 depends on DM_VERITY_VERIFY_ROOTHASH_SIG 569 depends on SECONDARY_TRUSTED_KEYRING 570 help 571 Rely on the secondary trusted keyring to verify dm-verity signatures. 572 573 If unsure, say N. 574 575config DM_VERITY_VERIFY_ROOTHASH_SIG_PLATFORM_KEYRING 576 bool "Verity data device root hash signature verification with platform keyring" 577 default DM_VERITY_VERIFY_ROOTHASH_SIG_SECONDARY_KEYRING 578 depends on DM_VERITY_VERIFY_ROOTHASH_SIG 579 depends on INTEGRITY_PLATFORM_KEYRING 580 help 581 Rely also on the platform keyring to verify dm-verity signatures. 582 583 If unsure, say N. 584 585config DM_VERITY_FEC 586 bool "Verity forward error correction support" 587 depends on DM_VERITY 588 select REED_SOLOMON 589 select REED_SOLOMON_DEC8 590 help 591 Add forward error correction support to dm-verity. This option 592 makes it possible to use pre-generated error correction data to 593 recover from corrupted blocks. 594 595 If unsure, say N. 596 597config DM_SWITCH 598 tristate "Switch target support (EXPERIMENTAL)" 599 depends on BLK_DEV_DM 600 help 601 This device-mapper target creates a device that supports an arbitrary 602 mapping of fixed-size regions of I/O across a fixed set of paths. 603 The path used for any specific region can be switched dynamically 604 by sending the target a message. 605 606 To compile this code as a module, choose M here: the module will 607 be called dm-switch. 608 609 If unsure, say N. 610 611config DM_LOG_WRITES 612 tristate "Log writes target support" 613 depends on BLK_DEV_DM 614 help 615 This device-mapper target takes two devices, one device to use 616 normally, one to log all write operations done to the first device. 617 This is for use by file system developers wishing to verify that 618 their fs is writing a consistent file system at all times by allowing 619 them to replay the log in a variety of ways and to check the 620 contents. 621 622 To compile this code as a module, choose M here: the module will 623 be called dm-log-writes. 624 625 If unsure, say N. 626 627config DM_INTEGRITY 628 tristate "Integrity target support" 629 depends on BLK_DEV_DM 630 select BLK_DEV_INTEGRITY 631 select DM_BUFIO 632 select CRYPTO 633 select CRYPTO_SKCIPHER 634 select ASYNC_XOR 635 select DM_AUDIT if AUDIT 636 help 637 This device-mapper target emulates a block device that has 638 additional per-sector tags that can be used for storing 639 integrity information. 640 641 This integrity target is used with the dm-crypt target to 642 provide authenticated disk encryption or it can be used 643 standalone. 644 645 To compile this code as a module, choose M here: the module will 646 be called dm-integrity. 647 648config DM_ZONED 649 tristate "Drive-managed zoned block device target support" 650 depends on BLK_DEV_DM 651 depends on BLK_DEV_ZONED 652 select CRC32 653 help 654 This device-mapper target takes a host-managed or host-aware zoned 655 block device and exposes most of its capacity as a regular block 656 device (drive-managed zoned block device) without any write 657 constraints. This is mainly intended for use with file systems that 658 do not natively support zoned block devices but still want to 659 benefit from the increased capacity offered by SMR disks. Other uses 660 by applications using raw block devices (for example object stores) 661 are also possible. 662 663 To compile this code as a module, choose M here: the module will 664 be called dm-zoned. 665 666 If unsure, say N. 667 668config DM_AUDIT 669 bool "DM audit events" 670 depends on BLK_DEV_DM 671 depends on AUDIT 672 help 673 Generate audit events for device-mapper. 674 675 Enables audit logging of several security relevant events in the 676 particular device-mapper targets, especially the integrity target. 677 678source "drivers/md/dm-vdo/Kconfig" 679 680endif # MD 681