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 (deprecated)" 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_MULTIPATH 176 tristate "Multipath I/O support (deprecated)" 177 depends on BLK_DEV_MD 178 help 179 MD_MULTIPATH provides a simple multi-path personality for use 180 the MD framework. It is not under active development. New 181 projects should consider using DM_MULTIPATH which has more 182 features and more testing. 183 184 If unsure, say N. 185 186config MD_FAULTY 187 tristate "Faulty test module for MD (deprecated)" 188 depends on BLK_DEV_MD 189 help 190 The "faulty" module allows for a block device that occasionally returns 191 read or write errors. It is useful for testing. 192 193 In unsure, say N. 194 195 196config MD_CLUSTER 197 tristate "Cluster Support for MD" 198 depends on BLK_DEV_MD 199 depends on DLM 200 default n 201 help 202 Clustering support for MD devices. This enables locking and 203 synchronization across multiple systems on the cluster, so all 204 nodes in the cluster can access the MD devices simultaneously. 205 206 This brings the redundancy (and uptime) of RAID levels across the 207 nodes of the cluster. Currently, it can work with raid1 and raid10 208 (limited support). 209 210 If unsure, say N. 211 212source "drivers/md/bcache/Kconfig" 213 214config BLK_DEV_DM_BUILTIN 215 bool 216 217config BLK_DEV_DM 218 tristate "Device mapper support" 219 select BLOCK_HOLDER_DEPRECATED if SYSFS 220 select BLK_DEV_DM_BUILTIN 221 select BLK_MQ_STACKING 222 depends on DAX || DAX=n 223 help 224 Device-mapper is a low level volume manager. It works by allowing 225 people to specify mappings for ranges of logical sectors. Various 226 mapping types are available, in addition people may write their own 227 modules containing custom mappings if they wish. 228 229 Higher level volume managers such as LVM2 use this driver. 230 231 To compile this as a module, choose M here: the module will be 232 called dm-mod. 233 234 If unsure, say N. 235 236config DM_DEBUG 237 bool "Device mapper debugging support" 238 depends on BLK_DEV_DM 239 help 240 Enable this for messages that may help debug device-mapper problems. 241 242 If unsure, say N. 243 244config DM_BUFIO 245 tristate 246 depends on BLK_DEV_DM 247 help 248 This interface allows you to do buffered I/O on a device and acts 249 as a cache, holding recently-read blocks in memory and performing 250 delayed writes. 251 252config DM_DEBUG_BLOCK_MANAGER_LOCKING 253 bool "Block manager locking" 254 depends on DM_BUFIO 255 help 256 Block manager locking can catch various metadata corruption issues. 257 258 If unsure, say N. 259 260config DM_DEBUG_BLOCK_STACK_TRACING 261 bool "Keep stack trace of persistent data block lock holders" 262 depends on STACKTRACE_SUPPORT && DM_DEBUG_BLOCK_MANAGER_LOCKING 263 select STACKTRACE 264 help 265 Enable this for messages that may help debug problems with the 266 block manager locking used by thin provisioning and caching. 267 268 If unsure, say N. 269 270config DM_BIO_PRISON 271 tristate 272 depends on BLK_DEV_DM 273 help 274 Some bio locking schemes used by other device-mapper targets 275 including thin provisioning. 276 277source "drivers/md/persistent-data/Kconfig" 278 279config DM_UNSTRIPED 280 tristate "Unstriped target" 281 depends on BLK_DEV_DM 282 help 283 Unstripes I/O so it is issued solely on a single drive in a HW 284 RAID0 or dm-striped target. 285 286config DM_CRYPT 287 tristate "Crypt target support" 288 depends on BLK_DEV_DM 289 depends on (ENCRYPTED_KEYS || ENCRYPTED_KEYS=n) 290 depends on (TRUSTED_KEYS || TRUSTED_KEYS=n) 291 select CRYPTO 292 select CRYPTO_CBC 293 select CRYPTO_ESSIV 294 help 295 This device-mapper target allows you to create a device that 296 transparently encrypts the data on it. You'll need to activate 297 the ciphers you're going to use in the cryptoapi configuration. 298 299 For further information on dm-crypt and userspace tools see: 300 <https://gitlab.com/cryptsetup/cryptsetup/wikis/DMCrypt> 301 302 To compile this code as a module, choose M here: the module will 303 be called dm-crypt. 304 305 If unsure, say N. 306 307config DM_SNAPSHOT 308 tristate "Snapshot target" 309 depends on BLK_DEV_DM 310 select DM_BUFIO 311 help 312 Allow volume managers to take writable snapshots of a device. 313 314config DM_THIN_PROVISIONING 315 tristate "Thin provisioning target" 316 depends on BLK_DEV_DM 317 select DM_PERSISTENT_DATA 318 select DM_BIO_PRISON 319 help 320 Provides thin provisioning and snapshots that share a data store. 321 322config DM_CACHE 323 tristate "Cache target (EXPERIMENTAL)" 324 depends on BLK_DEV_DM 325 default n 326 select DM_PERSISTENT_DATA 327 select DM_BIO_PRISON 328 help 329 dm-cache attempts to improve performance of a block device by 330 moving frequently used data to a smaller, higher performance 331 device. Different 'policy' plugins can be used to change the 332 algorithms used to select which blocks are promoted, demoted, 333 cleaned etc. It supports writeback and writethrough modes. 334 335config DM_CACHE_SMQ 336 tristate "Stochastic MQ Cache Policy (EXPERIMENTAL)" 337 depends on DM_CACHE 338 default y 339 help 340 A cache policy that uses a multiqueue ordered by recent hits 341 to select which blocks should be promoted and demoted. 342 This is meant to be a general purpose policy. It prioritises 343 reads over writes. This SMQ policy (vs MQ) offers the promise 344 of less memory utilization, improved performance and increased 345 adaptability in the face of changing workloads. 346 347config DM_WRITECACHE 348 tristate "Writecache target" 349 depends on BLK_DEV_DM 350 help 351 The writecache target caches writes on persistent memory or SSD. 352 It is intended for databases or other programs that need extremely 353 low commit latency. 354 355 The writecache target doesn't cache reads because reads are supposed 356 to be cached in standard RAM. 357 358config DM_EBS 359 tristate "Emulated block size target (EXPERIMENTAL)" 360 depends on BLK_DEV_DM && !HIGHMEM 361 select DM_BUFIO 362 help 363 dm-ebs emulates smaller logical block size on backing devices 364 with larger ones (e.g. 512 byte sectors on 4K native disks). 365 366config DM_ERA 367 tristate "Era target (EXPERIMENTAL)" 368 depends on BLK_DEV_DM 369 default n 370 select DM_PERSISTENT_DATA 371 select DM_BIO_PRISON 372 help 373 dm-era tracks which parts of a block device are written to 374 over time. Useful for maintaining cache coherency when using 375 vendor snapshots. 376 377config DM_CLONE 378 tristate "Clone target (EXPERIMENTAL)" 379 depends on BLK_DEV_DM 380 default n 381 select DM_PERSISTENT_DATA 382 help 383 dm-clone produces a one-to-one copy of an existing, read-only source 384 device into a writable destination device. The cloned device is 385 visible/mountable immediately and the copy of the source device to the 386 destination device happens in the background, in parallel with user 387 I/O. 388 389 If unsure, say N. 390 391config DM_MIRROR 392 tristate "Mirror target" 393 depends on BLK_DEV_DM 394 help 395 Allow volume managers to mirror logical volumes, also 396 needed for live data migration tools such as 'pvmove'. 397 398config DM_LOG_USERSPACE 399 tristate "Mirror userspace logging" 400 depends on DM_MIRROR && NET 401 select CONNECTOR 402 help 403 The userspace logging module provides a mechanism for 404 relaying the dm-dirty-log API to userspace. Log designs 405 which are more suited to userspace implementation (e.g. 406 shared storage logs) or experimental logs can be implemented 407 by leveraging this framework. 408 409config DM_RAID 410 tristate "RAID 1/4/5/6/10 target" 411 depends on BLK_DEV_DM 412 select MD_RAID0 413 select MD_RAID1 414 select MD_RAID10 415 select MD_RAID456 416 select BLK_DEV_MD 417 help 418 A dm target that supports RAID1, RAID10, RAID4, RAID5 and RAID6 mappings 419 420 A RAID-5 set of N drives with a capacity of C MB per drive provides 421 the capacity of C * (N - 1) MB, and protects against a failure 422 of a single drive. For a given sector (row) number, (N - 1) drives 423 contain data sectors, and one drive contains the parity protection. 424 For a RAID-4 set, the parity blocks are present on a single drive, 425 while a RAID-5 set distributes the parity across the drives in one 426 of the available parity distribution methods. 427 428 A RAID-6 set of N drives with a capacity of C MB per drive 429 provides the capacity of C * (N - 2) MB, and protects 430 against a failure of any two drives. For a given sector 431 (row) number, (N - 2) drives contain data sectors, and two 432 drives contains two independent redundancy syndromes. Like 433 RAID-5, RAID-6 distributes the syndromes across the drives 434 in one of the available parity distribution methods. 435 436config DM_ZERO 437 tristate "Zero target" 438 depends on BLK_DEV_DM 439 help 440 A target that discards writes, and returns all zeroes for 441 reads. Useful in some recovery situations. 442 443config DM_MULTIPATH 444 tristate "Multipath target" 445 depends on BLK_DEV_DM 446 # nasty syntax but means make DM_MULTIPATH independent 447 # of SCSI_DH if the latter isn't defined but if 448 # it is, DM_MULTIPATH must depend on it. We get a build 449 # error if SCSI_DH=m and DM_MULTIPATH=y 450 depends on !SCSI_DH || SCSI 451 help 452 Allow volume managers to support multipath hardware. 453 454config DM_MULTIPATH_QL 455 tristate "I/O Path Selector based on the number of in-flight I/Os" 456 depends on DM_MULTIPATH 457 help 458 This path selector is a dynamic load balancer which selects 459 the path with the least number of in-flight I/Os. 460 461 If unsure, say N. 462 463config DM_MULTIPATH_ST 464 tristate "I/O Path Selector based on the service time" 465 depends on DM_MULTIPATH 466 help 467 This path selector is a dynamic load balancer which selects 468 the path expected to complete the incoming I/O in the shortest 469 time. 470 471 If unsure, say N. 472 473config DM_MULTIPATH_HST 474 tristate "I/O Path Selector based on historical service time" 475 depends on DM_MULTIPATH 476 help 477 This path selector is a dynamic load balancer which selects 478 the path expected to complete the incoming I/O in the shortest 479 time by comparing estimated service time (based on historical 480 service time). 481 482 If unsure, say N. 483 484config DM_MULTIPATH_IOA 485 tristate "I/O Path Selector based on CPU submission" 486 depends on DM_MULTIPATH 487 help 488 This path selector selects the path based on the CPU the IO is 489 executed on and the CPU to path mapping setup at path addition time. 490 491 If unsure, say N. 492 493config DM_DELAY 494 tristate "I/O delaying target" 495 depends on BLK_DEV_DM 496 help 497 A target that delays reads and/or writes and can send 498 them to different devices. Useful for testing. 499 500 If unsure, say N. 501 502config DM_DUST 503 tristate "Bad sector simulation target" 504 depends on BLK_DEV_DM 505 help 506 A target that simulates bad sector behavior. 507 Useful for testing. 508 509 If unsure, say N. 510 511config DM_INIT 512 bool "DM \"dm-mod.create=\" parameter support" 513 depends on BLK_DEV_DM=y 514 help 515 Enable "dm-mod.create=" parameter to create mapped devices at init time. 516 This option is useful to allow mounting rootfs without requiring an 517 initramfs. 518 See Documentation/admin-guide/device-mapper/dm-init.rst for dm-mod.create="..." 519 format. 520 521 If unsure, say N. 522 523config DM_UEVENT 524 bool "DM uevents" 525 depends on BLK_DEV_DM 526 help 527 Generate udev events for DM events. 528 529config DM_FLAKEY 530 tristate "Flakey target" 531 depends on BLK_DEV_DM 532 help 533 A target that intermittently fails I/O for debugging purposes. 534 535config DM_VERITY 536 tristate "Verity target support" 537 depends on BLK_DEV_DM 538 select CRYPTO 539 select CRYPTO_HASH 540 select DM_BUFIO 541 help 542 This device-mapper target creates a read-only device that 543 transparently validates the data on one underlying device against 544 a pre-generated tree of cryptographic checksums stored on a second 545 device. 546 547 You'll need to activate the digests you're going to use in the 548 cryptoapi configuration. 549 550 To compile this code as a module, choose M here: the module will 551 be called dm-verity. 552 553 If unsure, say N. 554 555config DM_VERITY_VERIFY_ROOTHASH_SIG 556 def_bool n 557 bool "Verity data device root hash signature verification support" 558 depends on DM_VERITY 559 select SYSTEM_DATA_VERIFICATION 560 help 561 Add ability for dm-verity device to be validated if the 562 pre-generated tree of cryptographic checksums passed has a pkcs#7 563 signature file that can validate the roothash of the tree. 564 565 By default, rely on the builtin trusted keyring. 566 567 If unsure, say N. 568 569config DM_VERITY_VERIFY_ROOTHASH_SIG_SECONDARY_KEYRING 570 bool "Verity data device root hash signature verification with secondary keyring" 571 depends on DM_VERITY_VERIFY_ROOTHASH_SIG 572 depends on SECONDARY_TRUSTED_KEYRING 573 help 574 Rely on the secondary trusted keyring to verify dm-verity signatures. 575 576 If unsure, say N. 577 578config DM_VERITY_FEC 579 bool "Verity forward error correction support" 580 depends on DM_VERITY 581 select REED_SOLOMON 582 select REED_SOLOMON_DEC8 583 help 584 Add forward error correction support to dm-verity. This option 585 makes it possible to use pre-generated error correction data to 586 recover from corrupted blocks. 587 588 If unsure, say N. 589 590config DM_SWITCH 591 tristate "Switch target support (EXPERIMENTAL)" 592 depends on BLK_DEV_DM 593 help 594 This device-mapper target creates a device that supports an arbitrary 595 mapping of fixed-size regions of I/O across a fixed set of paths. 596 The path used for any specific region can be switched dynamically 597 by sending the target a message. 598 599 To compile this code as a module, choose M here: the module will 600 be called dm-switch. 601 602 If unsure, say N. 603 604config DM_LOG_WRITES 605 tristate "Log writes target support" 606 depends on BLK_DEV_DM 607 help 608 This device-mapper target takes two devices, one device to use 609 normally, one to log all write operations done to the first device. 610 This is for use by file system developers wishing to verify that 611 their fs is writing a consistent file system at all times by allowing 612 them to replay the log in a variety of ways and to check the 613 contents. 614 615 To compile this code as a module, choose M here: the module will 616 be called dm-log-writes. 617 618 If unsure, say N. 619 620config DM_INTEGRITY 621 tristate "Integrity target support" 622 depends on BLK_DEV_DM 623 select BLK_DEV_INTEGRITY 624 select DM_BUFIO 625 select CRYPTO 626 select CRYPTO_SKCIPHER 627 select ASYNC_XOR 628 select DM_AUDIT if AUDIT 629 help 630 This device-mapper target emulates a block device that has 631 additional per-sector tags that can be used for storing 632 integrity information. 633 634 This integrity target is used with the dm-crypt target to 635 provide authenticated disk encryption or it can be used 636 standalone. 637 638 To compile this code as a module, choose M here: the module will 639 be called dm-integrity. 640 641config DM_ZONED 642 tristate "Drive-managed zoned block device target support" 643 depends on BLK_DEV_DM 644 depends on BLK_DEV_ZONED 645 select CRC32 646 help 647 This device-mapper target takes a host-managed or host-aware zoned 648 block device and exposes most of its capacity as a regular block 649 device (drive-managed zoned block device) without any write 650 constraints. This is mainly intended for use with file systems that 651 do not natively support zoned block devices but still want to 652 benefit from the increased capacity offered by SMR disks. Other uses 653 by applications using raw block devices (for example object stores) 654 are also possible. 655 656 To compile this code as a module, choose M here: the module will 657 be called dm-zoned. 658 659 If unsure, say N. 660 661config DM_AUDIT 662 bool "DM audit events" 663 depends on AUDIT 664 help 665 Generate audit events for device-mapper. 666 667 Enables audit logging of several security relevant events in the 668 particular device-mapper targets, especially the integrity target. 669 670endif # MD 671