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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 select BLOCK_HOLDER_DEPRECATED if SYSFS
19 help
20 This driver lets you combine several hard disk partitions into one
21 logical block device. This can be used to simply append one
22 partition to another one or to combine several redundant hard disks
23 into a RAID1/4/5 device so as to provide protection against hard
24 disk failures. This is called "Software RAID" since the combining of
25 the partitions is done by the kernel. "Hardware RAID" means that the
26 combining is done by a dedicated controller; if you have such a
27 controller, you do not need to say Y here.
28
29 More information about Software RAID on Linux is contained in the
30 Software RAID mini-HOWTO, available from
31 <https://www.tldp.org/docs.html#howto>. There you will also learn
32 where to get the supporting user space utilities raidtools.
33
34 If unsure, say N.
35
36config MD_AUTODETECT
37 bool "Autodetect RAID arrays during kernel boot"
38 depends on BLK_DEV_MD=y
39 default y
40 help
41 If you say Y here, then the kernel will try to autodetect raid
42 arrays as part of its boot process.
43
44 If you don't use raid and say Y, this autodetection can cause
45 a several-second delay in the boot time due to various
46 synchronisation steps that are part of this step.
47
48 If unsure, say Y.
49
50config MD_LINEAR
51 tristate "Linear (append) mode (deprecated)"
52 depends on BLK_DEV_MD
53 help
54 If you say Y here, then your multiple devices driver will be able to
55 use the so-called linear mode, i.e. it will combine the hard disk
56 partitions by simply appending one to the other.
57
58 To compile this as a module, choose M here: the module
59 will be called linear.
60
61 If unsure, say Y.
62
63config MD_RAID0
64 tristate "RAID-0 (striping) mode"
65 depends on BLK_DEV_MD
66 help
67 If you say Y here, then your multiple devices driver will be able to
68 use the so-called raid0 mode, i.e. it will combine the hard disk
69 partitions into one logical device in such a fashion as to fill them
70 up evenly, one chunk here and one chunk there. This will increase
71 the throughput rate if the partitions reside on distinct disks.
72
73 Information about Software RAID on Linux is contained in the
74 Software-RAID mini-HOWTO, available from
75 <https://www.tldp.org/docs.html#howto>. There you will also
76 learn where to get the supporting user space utilities raidtools.
77
78 To compile this as a module, choose M here: the module
79 will be called raid0.
80
81 If unsure, say Y.
82
83config MD_RAID1
84 tristate "RAID-1 (mirroring) mode"
85 depends on BLK_DEV_MD
86 help
87 A RAID-1 set consists of several disk drives which are exact copies
88 of each other. In the event of a mirror failure, the RAID driver
89 will continue to use the operational mirrors in the set, providing
90 an error free MD (multiple device) to the higher levels of the
91 kernel. In a set with N drives, the available space is the capacity
92 of a single drive, and the set protects against a failure of (N - 1)
93 drives.
94
95 Information about Software RAID on Linux is contained in the
96 Software-RAID mini-HOWTO, available from
97 <https://www.tldp.org/docs.html#howto>. There you will also
98 learn where to get the supporting user space utilities raidtools.
99
100 If you want to use such a RAID-1 set, say Y. To compile this code
101 as a module, choose M here: the module will be called raid1.
102
103 If unsure, say Y.
104
105config MD_RAID10
106 tristate "RAID-10 (mirrored striping) mode"
107 depends on BLK_DEV_MD
108 help
109 RAID-10 provides a combination of striping (RAID-0) and
110 mirroring (RAID-1) with easier configuration and more flexible
111 layout.
112 Unlike RAID-0, but like RAID-1, RAID-10 requires all devices to
113 be the same size (or at least, only as much as the smallest device
114 will be used).
115 RAID-10 provides a variety of layouts that provide different levels
116 of redundancy and performance.
117
118 RAID-10 requires mdadm-1.7.0 or later, available at:
119
120 https://www.kernel.org/pub/linux/utils/raid/mdadm/
121
122 If unsure, say Y.
123
124config MD_RAID456
125 tristate "RAID-4/RAID-5/RAID-6 mode"
126 depends on BLK_DEV_MD
127 select RAID6_PQ
128 select LIBCRC32C
129 select ASYNC_MEMCPY
130 select ASYNC_XOR
131 select ASYNC_PQ
132 select ASYNC_RAID6_RECOV
133 help
134 A RAID-5 set of N drives with a capacity of C MB per drive provides
135 the capacity of C * (N - 1) MB, and protects against a failure
136 of a single drive. For a given sector (row) number, (N - 1) drives
137 contain data sectors, and one drive contains the parity protection.
138 For a RAID-4 set, the parity blocks are present on a single drive,
139 while a RAID-5 set distributes the parity across the drives in one
140 of the available parity distribution methods.
141
142 A RAID-6 set of N drives with a capacity of C MB per drive
143 provides the capacity of C * (N - 2) MB, and protects
144 against a failure of any two drives. For a given sector
145 (row) number, (N - 2) drives contain data sectors, and two
146 drives contains two independent redundancy syndromes. Like
147 RAID-5, RAID-6 distributes the syndromes across the drives
148 in one of the available parity distribution methods.
149
150 Information about Software RAID on Linux is contained in the
151 Software-RAID mini-HOWTO, available from
152 <https://www.tldp.org/docs.html#howto>. There you will also
153 learn where to get the supporting user space utilities raidtools.
154
155 If you want to use such a RAID-4/RAID-5/RAID-6 set, say Y. To
156 compile this code as a module, choose M here: the module
157 will be called raid456.
158
159 If unsure, say Y.
160
161config MD_MULTIPATH
162 tristate "Multipath I/O support (deprecated)"
163 depends on BLK_DEV_MD
164 help
165 MD_MULTIPATH provides a simple multi-path personality for use
166 the MD framework. It is not under active development. New
167 projects should consider using DM_MULTIPATH which has more
168 features and more testing.
169
170 If unsure, say N.
171
172config MD_FAULTY
173 tristate "Faulty test module for MD (deprecated)"
174 depends on BLK_DEV_MD
175 help
176 The "faulty" module allows for a block device that occasionally returns
177 read or write errors. It is useful for testing.
178
179 In unsure, say N.
180
181
182config MD_CLUSTER
183 tristate "Cluster Support for MD"
184 depends on BLK_DEV_MD
185 depends on DLM
186 default n
187 help
188 Clustering support for MD devices. This enables locking and
189 synchronization across multiple systems on the cluster, so all
190 nodes in the cluster can access the MD devices simultaneously.
191
192 This brings the redundancy (and uptime) of RAID levels across the
193 nodes of the cluster. Currently, it can work with raid1 and raid10
194 (limited support).
195
196 If unsure, say N.
197
198source "drivers/md/bcache/Kconfig"
199
200config BLK_DEV_DM_BUILTIN
201 bool
202
203config BLK_DEV_DM
204 tristate "Device mapper support"
205 select BLOCK_HOLDER_DEPRECATED if SYSFS
206 select BLK_DEV_DM_BUILTIN
207 select BLK_MQ_STACKING
208 depends on DAX || DAX=n
209 help
210 Device-mapper is a low level volume manager. It works by allowing
211 people to specify mappings for ranges of logical sectors. Various
212 mapping types are available, in addition people may write their own
213 modules containing custom mappings if they wish.
214
215 Higher level volume managers such as LVM2 use this driver.
216
217 To compile this as a module, choose M here: the module will be
218 called dm-mod.
219
220 If unsure, say N.
221
222config DM_DEBUG
223 bool "Device mapper debugging support"
224 depends on BLK_DEV_DM
225 help
226 Enable this for messages that may help debug device-mapper problems.
227
228 If unsure, say N.
229
230config DM_BUFIO
231 tristate
232 depends on BLK_DEV_DM
233 help
234 This interface allows you to do buffered I/O on a device and acts
235 as a cache, holding recently-read blocks in memory and performing
236 delayed writes.
237
238config DM_DEBUG_BLOCK_MANAGER_LOCKING
239 bool "Block manager locking"
240 depends on DM_BUFIO
241 help
242 Block manager locking can catch various metadata corruption issues.
243
244 If unsure, say N.
245
246config DM_DEBUG_BLOCK_STACK_TRACING
247 bool "Keep stack trace of persistent data block lock holders"
248 depends on STACKTRACE_SUPPORT && DM_DEBUG_BLOCK_MANAGER_LOCKING
249 select STACKTRACE
250 help
251 Enable this for messages that may help debug problems with the
252 block manager locking used by thin provisioning and caching.
253
254 If unsure, say N.
255
256config DM_BIO_PRISON
257 tristate
258 depends on BLK_DEV_DM
259 help
260 Some bio locking schemes used by other device-mapper targets
261 including thin provisioning.
262
263source "drivers/md/persistent-data/Kconfig"
264
265config DM_UNSTRIPED
266 tristate "Unstriped target"
267 depends on BLK_DEV_DM
268 help
269 Unstripes I/O so it is issued solely on a single drive in a HW
270 RAID0 or dm-striped target.
271
272config DM_CRYPT
273 tristate "Crypt target support"
274 depends on BLK_DEV_DM
275 depends on (ENCRYPTED_KEYS || ENCRYPTED_KEYS=n)
276 depends on (TRUSTED_KEYS || TRUSTED_KEYS=n)
277 select CRYPTO
278 select CRYPTO_CBC
279 select CRYPTO_ESSIV
280 help
281 This device-mapper target allows you to create a device that
282 transparently encrypts the data on it. You'll need to activate
283 the ciphers you're going to use in the cryptoapi configuration.
284
285 For further information on dm-crypt and userspace tools see:
286 <https://gitlab.com/cryptsetup/cryptsetup/wikis/DMCrypt>
287
288 To compile this code as a module, choose M here: the module will
289 be called dm-crypt.
290
291 If unsure, say N.
292
293config DM_SNAPSHOT
294 tristate "Snapshot target"
295 depends on BLK_DEV_DM
296 select DM_BUFIO
297 help
298 Allow volume managers to take writable snapshots of a device.
299
300config DM_THIN_PROVISIONING
301 tristate "Thin provisioning target"
302 depends on BLK_DEV_DM
303 select DM_PERSISTENT_DATA
304 select DM_BIO_PRISON
305 help
306 Provides thin provisioning and snapshots that share a data store.
307
308config DM_CACHE
309 tristate "Cache target (EXPERIMENTAL)"
310 depends on BLK_DEV_DM
311 default n
312 select DM_PERSISTENT_DATA
313 select DM_BIO_PRISON
314 help
315 dm-cache attempts to improve performance of a block device by
316 moving frequently used data to a smaller, higher performance
317 device. Different 'policy' plugins can be used to change the
318 algorithms used to select which blocks are promoted, demoted,
319 cleaned etc. It supports writeback and writethrough modes.
320
321config DM_CACHE_SMQ
322 tristate "Stochastic MQ Cache Policy (EXPERIMENTAL)"
323 depends on DM_CACHE
324 default y
325 help
326 A cache policy that uses a multiqueue ordered by recent hits
327 to select which blocks should be promoted and demoted.
328 This is meant to be a general purpose policy. It prioritises
329 reads over writes. This SMQ policy (vs MQ) offers the promise
330 of less memory utilization, improved performance and increased
331 adaptability in the face of changing workloads.
332
333config DM_WRITECACHE
334 tristate "Writecache target"
335 depends on BLK_DEV_DM
336 help
337 The writecache target caches writes on persistent memory or SSD.
338 It is intended for databases or other programs that need extremely
339 low commit latency.
340
341 The writecache target doesn't cache reads because reads are supposed
342 to be cached in standard RAM.
343
344config DM_EBS
345 tristate "Emulated block size target (EXPERIMENTAL)"
346 depends on BLK_DEV_DM && !HIGHMEM
347 select DM_BUFIO
348 help
349 dm-ebs emulates smaller logical block size on backing devices
350 with larger ones (e.g. 512 byte sectors on 4K native disks).
351
352config DM_ERA
353 tristate "Era target (EXPERIMENTAL)"
354 depends on BLK_DEV_DM
355 default n
356 select DM_PERSISTENT_DATA
357 select DM_BIO_PRISON
358 help
359 dm-era tracks which parts of a block device are written to
360 over time. Useful for maintaining cache coherency when using
361 vendor snapshots.
362
363config DM_CLONE
364 tristate "Clone target (EXPERIMENTAL)"
365 depends on BLK_DEV_DM
366 default n
367 select DM_PERSISTENT_DATA
368 help
369 dm-clone produces a one-to-one copy of an existing, read-only source
370 device into a writable destination device. The cloned device is
371 visible/mountable immediately and the copy of the source device to the
372 destination device happens in the background, in parallel with user
373 I/O.
374
375 If unsure, say N.
376
377config DM_MIRROR
378 tristate "Mirror target"
379 depends on BLK_DEV_DM
380 help
381 Allow volume managers to mirror logical volumes, also
382 needed for live data migration tools such as 'pvmove'.
383
384config DM_LOG_USERSPACE
385 tristate "Mirror userspace logging"
386 depends on DM_MIRROR && NET
387 select CONNECTOR
388 help
389 The userspace logging module provides a mechanism for
390 relaying the dm-dirty-log API to userspace. Log designs
391 which are more suited to userspace implementation (e.g.
392 shared storage logs) or experimental logs can be implemented
393 by leveraging this framework.
394
395config DM_RAID
396 tristate "RAID 1/4/5/6/10 target"
397 depends on BLK_DEV_DM
398 select MD_RAID0
399 select MD_RAID1
400 select MD_RAID10
401 select MD_RAID456
402 select BLK_DEV_MD
403 help
404 A dm target that supports RAID1, RAID10, RAID4, RAID5 and RAID6 mappings
405
406 A RAID-5 set of N drives with a capacity of C MB per drive provides
407 the capacity of C * (N - 1) MB, and protects against a failure
408 of a single drive. For a given sector (row) number, (N - 1) drives
409 contain data sectors, and one drive contains the parity protection.
410 For a RAID-4 set, the parity blocks are present on a single drive,
411 while a RAID-5 set distributes the parity across the drives in one
412 of the available parity distribution methods.
413
414 A RAID-6 set of N drives with a capacity of C MB per drive
415 provides the capacity of C * (N - 2) MB, and protects
416 against a failure of any two drives. For a given sector
417 (row) number, (N - 2) drives contain data sectors, and two
418 drives contains two independent redundancy syndromes. Like
419 RAID-5, RAID-6 distributes the syndromes across the drives
420 in one of the available parity distribution methods.
421
422config DM_ZERO
423 tristate "Zero target"
424 depends on BLK_DEV_DM
425 help
426 A target that discards writes, and returns all zeroes for
427 reads. Useful in some recovery situations.
428
429config DM_MULTIPATH
430 tristate "Multipath target"
431 depends on BLK_DEV_DM
432 # nasty syntax but means make DM_MULTIPATH independent
433 # of SCSI_DH if the latter isn't defined but if
434 # it is, DM_MULTIPATH must depend on it. We get a build
435 # error if SCSI_DH=m and DM_MULTIPATH=y
436 depends on !SCSI_DH || SCSI
437 help
438 Allow volume managers to support multipath hardware.
439
440config DM_MULTIPATH_QL
441 tristate "I/O Path Selector based on the number of in-flight I/Os"
442 depends on DM_MULTIPATH
443 help
444 This path selector is a dynamic load balancer which selects
445 the path with the least number of in-flight I/Os.
446
447 If unsure, say N.
448
449config DM_MULTIPATH_ST
450 tristate "I/O Path Selector based on the 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.
456
457 If unsure, say N.
458
459config DM_MULTIPATH_HST
460 tristate "I/O Path Selector based on historical service time"
461 depends on DM_MULTIPATH
462 help
463 This path selector is a dynamic load balancer which selects
464 the path expected to complete the incoming I/O in the shortest
465 time by comparing estimated service time (based on historical
466 service time).
467
468 If unsure, say N.
469
470config DM_MULTIPATH_IOA
471 tristate "I/O Path Selector based on CPU submission"
472 depends on DM_MULTIPATH
473 help
474 This path selector selects the path based on the CPU the IO is
475 executed on and the CPU to path mapping setup at path addition time.
476
477 If unsure, say N.
478
479config DM_DELAY
480 tristate "I/O delaying target"
481 depends on BLK_DEV_DM
482 help
483 A target that delays reads and/or writes and can send
484 them to different devices. Useful for testing.
485
486 If unsure, say N.
487
488config DM_DUST
489 tristate "Bad sector simulation target"
490 depends on BLK_DEV_DM
491 help
492 A target that simulates bad sector behavior.
493 Useful for testing.
494
495 If unsure, say N.
496
497config DM_INIT
498 bool "DM \"dm-mod.create=\" parameter support"
499 depends on BLK_DEV_DM=y
500 help
501 Enable "dm-mod.create=" parameter to create mapped devices at init time.
502 This option is useful to allow mounting rootfs without requiring an
503 initramfs.
504 See Documentation/admin-guide/device-mapper/dm-init.rst for dm-mod.create="..."
505 format.
506
507 If unsure, say N.
508
509config DM_UEVENT
510 bool "DM uevents"
511 depends on BLK_DEV_DM
512 help
513 Generate udev events for DM events.
514
515config DM_FLAKEY
516 tristate "Flakey target"
517 depends on BLK_DEV_DM
518 help
519 A target that intermittently fails I/O for debugging purposes.
520
521config DM_VERITY
522 tristate "Verity target support"
523 depends on BLK_DEV_DM
524 select CRYPTO
525 select CRYPTO_HASH
526 select DM_BUFIO
527 help
528 This device-mapper target creates a read-only device that
529 transparently validates the data on one underlying device against
530 a pre-generated tree of cryptographic checksums stored on a second
531 device.
532
533 You'll need to activate the digests you're going to use in the
534 cryptoapi configuration.
535
536 To compile this code as a module, choose M here: the module will
537 be called dm-verity.
538
539 If unsure, say N.
540
541config DM_VERITY_VERIFY_ROOTHASH_SIG
542 def_bool n
543 bool "Verity data device root hash signature verification support"
544 depends on DM_VERITY
545 select SYSTEM_DATA_VERIFICATION
546 help
547 Add ability for dm-verity device to be validated if the
548 pre-generated tree of cryptographic checksums passed has a pkcs#7
549 signature file that can validate the roothash of the tree.
550
551 By default, rely on the builtin trusted keyring.
552
553 If unsure, say N.
554
555config DM_VERITY_VERIFY_ROOTHASH_SIG_SECONDARY_KEYRING
556 bool "Verity data device root hash signature verification with secondary keyring"
557 depends on DM_VERITY_VERIFY_ROOTHASH_SIG
558 depends on SECONDARY_TRUSTED_KEYRING
559 help
560 Rely on the secondary trusted keyring to verify dm-verity signatures.
561
562 If unsure, say N.
563
564config DM_VERITY_FEC
565 bool "Verity forward error correction support"
566 depends on DM_VERITY
567 select REED_SOLOMON
568 select REED_SOLOMON_DEC8
569 help
570 Add forward error correction support to dm-verity. This option
571 makes it possible to use pre-generated error correction data to
572 recover from corrupted blocks.
573
574 If unsure, say N.
575
576config DM_SWITCH
577 tristate "Switch target support (EXPERIMENTAL)"
578 depends on BLK_DEV_DM
579 help
580 This device-mapper target creates a device that supports an arbitrary
581 mapping of fixed-size regions of I/O across a fixed set of paths.
582 The path used for any specific region can be switched dynamically
583 by sending the target a message.
584
585 To compile this code as a module, choose M here: the module will
586 be called dm-switch.
587
588 If unsure, say N.
589
590config DM_LOG_WRITES
591 tristate "Log writes target support"
592 depends on BLK_DEV_DM
593 help
594 This device-mapper target takes two devices, one device to use
595 normally, one to log all write operations done to the first device.
596 This is for use by file system developers wishing to verify that
597 their fs is writing a consistent file system at all times by allowing
598 them to replay the log in a variety of ways and to check the
599 contents.
600
601 To compile this code as a module, choose M here: the module will
602 be called dm-log-writes.
603
604 If unsure, say N.
605
606config DM_INTEGRITY
607 tristate "Integrity target support"
608 depends on BLK_DEV_DM
609 select BLK_DEV_INTEGRITY
610 select DM_BUFIO
611 select CRYPTO
612 select CRYPTO_SKCIPHER
613 select ASYNC_XOR
614 select DM_AUDIT if AUDIT
615 help
616 This device-mapper target emulates a block device that has
617 additional per-sector tags that can be used for storing
618 integrity information.
619
620 This integrity target is used with the dm-crypt target to
621 provide authenticated disk encryption or it can be used
622 standalone.
623
624 To compile this code as a module, choose M here: the module will
625 be called dm-integrity.
626
627config DM_ZONED
628 tristate "Drive-managed zoned block device target support"
629 depends on BLK_DEV_DM
630 depends on BLK_DEV_ZONED
631 select CRC32
632 help
633 This device-mapper target takes a host-managed or host-aware zoned
634 block device and exposes most of its capacity as a regular block
635 device (drive-managed zoned block device) without any write
636 constraints. This is mainly intended for use with file systems that
637 do not natively support zoned block devices but still want to
638 benefit from the increased capacity offered by SMR disks. Other uses
639 by applications using raw block devices (for example object stores)
640 are also possible.
641
642 To compile this code as a module, choose M here: the module will
643 be called dm-zoned.
644
645 If unsure, say N.
646
647config DM_AUDIT
648 bool "DM audit events"
649 depends on AUDIT
650 help
651 Generate audit events for device-mapper.
652
653 Enables audit logging of several security relevant events in the
654 particular device-mapper targets, especially the integrity target.
655
656endif # MD
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 (deprecated)"
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 (deprecated)"
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 (deprecated)"
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 depends on (TRUSTED_KEYS || TRUSTED_KEYS=n)
274 select CRYPTO
275 select CRYPTO_CBC
276 select CRYPTO_ESSIV
277 help
278 This device-mapper target allows you to create a device that
279 transparently encrypts the data on it. You'll need to activate
280 the ciphers you're going to use in the cryptoapi configuration.
281
282 For further information on dm-crypt and userspace tools see:
283 <https://gitlab.com/cryptsetup/cryptsetup/wikis/DMCrypt>
284
285 To compile this code as a module, choose M here: the module will
286 be called dm-crypt.
287
288 If unsure, say N.
289
290config DM_SNAPSHOT
291 tristate "Snapshot target"
292 depends on BLK_DEV_DM
293 select DM_BUFIO
294 help
295 Allow volume managers to take writable snapshots of a device.
296
297config DM_THIN_PROVISIONING
298 tristate "Thin provisioning target"
299 depends on BLK_DEV_DM
300 select DM_PERSISTENT_DATA
301 select DM_BIO_PRISON
302 help
303 Provides thin provisioning and snapshots that share a data store.
304
305config DM_CACHE
306 tristate "Cache target (EXPERIMENTAL)"
307 depends on BLK_DEV_DM
308 default n
309 select DM_PERSISTENT_DATA
310 select DM_BIO_PRISON
311 help
312 dm-cache attempts to improve performance of a block device by
313 moving frequently used data to a smaller, higher performance
314 device. Different 'policy' plugins can be used to change the
315 algorithms used to select which blocks are promoted, demoted,
316 cleaned etc. It supports writeback and writethrough modes.
317
318config DM_CACHE_SMQ
319 tristate "Stochastic MQ Cache Policy (EXPERIMENTAL)"
320 depends on DM_CACHE
321 default y
322 help
323 A cache policy that uses a multiqueue ordered by recent hits
324 to select which blocks should be promoted and demoted.
325 This is meant to be a general purpose policy. It prioritises
326 reads over writes. This SMQ policy (vs MQ) offers the promise
327 of less memory utilization, improved performance and increased
328 adaptability in the face of changing workloads.
329
330config DM_WRITECACHE
331 tristate "Writecache target"
332 depends on BLK_DEV_DM
333 help
334 The writecache target caches writes on persistent memory or SSD.
335 It is intended for databases or other programs that need extremely
336 low commit latency.
337
338 The writecache target doesn't cache reads because reads are supposed
339 to be cached in standard RAM.
340
341config DM_EBS
342 tristate "Emulated block size target (EXPERIMENTAL)"
343 depends on BLK_DEV_DM
344 select DM_BUFIO
345 help
346 dm-ebs emulates smaller logical block size on backing devices
347 with larger ones (e.g. 512 byte sectors on 4K native disks).
348
349config DM_ERA
350 tristate "Era target (EXPERIMENTAL)"
351 depends on BLK_DEV_DM
352 default n
353 select DM_PERSISTENT_DATA
354 select DM_BIO_PRISON
355 help
356 dm-era tracks which parts of a block device are written to
357 over time. Useful for maintaining cache coherency when using
358 vendor snapshots.
359
360config DM_CLONE
361 tristate "Clone target (EXPERIMENTAL)"
362 depends on BLK_DEV_DM
363 default n
364 select DM_PERSISTENT_DATA
365 help
366 dm-clone produces a one-to-one copy of an existing, read-only source
367 device into a writable destination device. The cloned device is
368 visible/mountable immediately and the copy of the source device to the
369 destination device happens in the background, in parallel with user
370 I/O.
371
372 If unsure, say N.
373
374config DM_MIRROR
375 tristate "Mirror target"
376 depends on BLK_DEV_DM
377 help
378 Allow volume managers to mirror logical volumes, also
379 needed for live data migration tools such as 'pvmove'.
380
381config DM_LOG_USERSPACE
382 tristate "Mirror userspace logging"
383 depends on DM_MIRROR && NET
384 select CONNECTOR
385 help
386 The userspace logging module provides a mechanism for
387 relaying the dm-dirty-log API to userspace. Log designs
388 which are more suited to userspace implementation (e.g.
389 shared storage logs) or experimental logs can be implemented
390 by leveraging this framework.
391
392config DM_RAID
393 tristate "RAID 1/4/5/6/10 target"
394 depends on BLK_DEV_DM
395 select MD_RAID0
396 select MD_RAID1
397 select MD_RAID10
398 select MD_RAID456
399 select BLK_DEV_MD
400 help
401 A dm target that supports RAID1, RAID10, RAID4, RAID5 and RAID6 mappings
402
403 A RAID-5 set of N drives with a capacity of C MB per drive provides
404 the capacity of C * (N - 1) MB, and protects against a failure
405 of a single drive. For a given sector (row) number, (N - 1) drives
406 contain data sectors, and one drive contains the parity protection.
407 For a RAID-4 set, the parity blocks are present on a single drive,
408 while a RAID-5 set distributes the parity across the drives in one
409 of the available parity distribution methods.
410
411 A RAID-6 set of N drives with a capacity of C MB per drive
412 provides the capacity of C * (N - 2) MB, and protects
413 against a failure of any two drives. For a given sector
414 (row) number, (N - 2) drives contain data sectors, and two
415 drives contains two independent redundancy syndromes. Like
416 RAID-5, RAID-6 distributes the syndromes across the drives
417 in one of the available parity distribution methods.
418
419config DM_ZERO
420 tristate "Zero target"
421 depends on BLK_DEV_DM
422 help
423 A target that discards writes, and returns all zeroes for
424 reads. Useful in some recovery situations.
425
426config DM_MULTIPATH
427 tristate "Multipath target"
428 depends on BLK_DEV_DM
429 # nasty syntax but means make DM_MULTIPATH independent
430 # of SCSI_DH if the latter isn't defined but if
431 # it is, DM_MULTIPATH must depend on it. We get a build
432 # error if SCSI_DH=m and DM_MULTIPATH=y
433 depends on !SCSI_DH || SCSI
434 help
435 Allow volume managers to support multipath hardware.
436
437config DM_MULTIPATH_QL
438 tristate "I/O Path Selector based on the number of in-flight I/Os"
439 depends on DM_MULTIPATH
440 help
441 This path selector is a dynamic load balancer which selects
442 the path with the least number of in-flight I/Os.
443
444 If unsure, say N.
445
446config DM_MULTIPATH_ST
447 tristate "I/O Path Selector based on the service time"
448 depends on DM_MULTIPATH
449 help
450 This path selector is a dynamic load balancer which selects
451 the path expected to complete the incoming I/O in the shortest
452 time.
453
454 If unsure, say N.
455
456config DM_MULTIPATH_HST
457 tristate "I/O Path Selector based on historical service time"
458 depends on DM_MULTIPATH
459 help
460 This path selector is a dynamic load balancer which selects
461 the path expected to complete the incoming I/O in the shortest
462 time by comparing estimated service time (based on historical
463 service time).
464
465 If unsure, say N.
466
467config DM_MULTIPATH_IOA
468 tristate "I/O Path Selector based on CPU submission"
469 depends on DM_MULTIPATH
470 help
471 This path selector selects the path based on the CPU the IO is
472 executed on and the CPU to path mapping setup at path addition time.
473
474 If unsure, say N.
475
476config DM_DELAY
477 tristate "I/O delaying target"
478 depends on BLK_DEV_DM
479 help
480 A target that delays reads and/or writes and can send
481 them to different devices. Useful for testing.
482
483 If unsure, say N.
484
485config DM_DUST
486 tristate "Bad sector simulation target"
487 depends on BLK_DEV_DM
488 help
489 A target that simulates bad sector behavior.
490 Useful for testing.
491
492 If unsure, say N.
493
494config DM_INIT
495 bool "DM \"dm-mod.create=\" parameter support"
496 depends on BLK_DEV_DM=y
497 help
498 Enable "dm-mod.create=" parameter to create mapped devices at init time.
499 This option is useful to allow mounting rootfs without requiring an
500 initramfs.
501 See Documentation/admin-guide/device-mapper/dm-init.rst for dm-mod.create="..."
502 format.
503
504 If unsure, say N.
505
506config DM_UEVENT
507 bool "DM uevents"
508 depends on BLK_DEV_DM
509 help
510 Generate udev events for DM events.
511
512config DM_FLAKEY
513 tristate "Flakey target"
514 depends on BLK_DEV_DM
515 help
516 A target that intermittently fails I/O for debugging purposes.
517
518config DM_VERITY
519 tristate "Verity target support"
520 depends on BLK_DEV_DM
521 select CRYPTO
522 select CRYPTO_HASH
523 select DM_BUFIO
524 help
525 This device-mapper target creates a read-only device that
526 transparently validates the data on one underlying device against
527 a pre-generated tree of cryptographic checksums stored on a second
528 device.
529
530 You'll need to activate the digests you're going to use in the
531 cryptoapi configuration.
532
533 To compile this code as a module, choose M here: the module will
534 be called dm-verity.
535
536 If unsure, say N.
537
538config DM_VERITY_VERIFY_ROOTHASH_SIG
539 def_bool n
540 bool "Verity data device root hash signature verification support"
541 depends on DM_VERITY
542 select SYSTEM_DATA_VERIFICATION
543 help
544 Add ability for dm-verity device to be validated if the
545 pre-generated tree of cryptographic checksums passed has a pkcs#7
546 signature file that can validate the roothash of the tree.
547
548 By default, rely on the builtin trusted keyring.
549
550 If unsure, say N.
551
552config DM_VERITY_VERIFY_ROOTHASH_SIG_SECONDARY_KEYRING
553 bool "Verity data device root hash signature verification with secondary keyring"
554 depends on DM_VERITY_VERIFY_ROOTHASH_SIG
555 depends on SECONDARY_TRUSTED_KEYRING
556 help
557 Rely on the secondary trusted keyring to verify dm-verity signatures.
558
559 If unsure, say N.
560
561config DM_VERITY_FEC
562 bool "Verity forward error correction support"
563 depends on DM_VERITY
564 select REED_SOLOMON
565 select REED_SOLOMON_DEC8
566 help
567 Add forward error correction support to dm-verity. This option
568 makes it possible to use pre-generated error correction data to
569 recover from corrupted blocks.
570
571 If unsure, say N.
572
573config DM_SWITCH
574 tristate "Switch target support (EXPERIMENTAL)"
575 depends on BLK_DEV_DM
576 help
577 This device-mapper target creates a device that supports an arbitrary
578 mapping of fixed-size regions of I/O across a fixed set of paths.
579 The path used for any specific region can be switched dynamically
580 by sending the target a message.
581
582 To compile this code as a module, choose M here: the module will
583 be called dm-switch.
584
585 If unsure, say N.
586
587config DM_LOG_WRITES
588 tristate "Log writes target support"
589 depends on BLK_DEV_DM
590 help
591 This device-mapper target takes two devices, one device to use
592 normally, one to log all write operations done to the first device.
593 This is for use by file system developers wishing to verify that
594 their fs is writing a consistent file system at all times by allowing
595 them to replay the log in a variety of ways and to check the
596 contents.
597
598 To compile this code as a module, choose M here: the module will
599 be called dm-log-writes.
600
601 If unsure, say N.
602
603config DM_INTEGRITY
604 tristate "Integrity target support"
605 depends on BLK_DEV_DM
606 select BLK_DEV_INTEGRITY
607 select DM_BUFIO
608 select CRYPTO
609 select CRYPTO_SKCIPHER
610 select ASYNC_XOR
611 help
612 This device-mapper target emulates a block device that has
613 additional per-sector tags that can be used for storing
614 integrity information.
615
616 This integrity target is used with the dm-crypt target to
617 provide authenticated disk encryption or it can be used
618 standalone.
619
620 To compile this code as a module, choose M here: the module will
621 be called dm-integrity.
622
623config DM_ZONED
624 tristate "Drive-managed zoned block device target support"
625 depends on BLK_DEV_DM
626 depends on BLK_DEV_ZONED
627 select CRC32
628 help
629 This device-mapper target takes a host-managed or host-aware zoned
630 block device and exposes most of its capacity as a regular block
631 device (drive-managed zoned block device) without any write
632 constraints. This is mainly intended for use with file systems that
633 do not natively support zoned block devices but still want to
634 benefit from the increased capacity offered by SMR disks. Other uses
635 by applications using raw block devices (for example object stores)
636 are also possible.
637
638 To compile this code as a module, choose M here: the module will
639 be called dm-zoned.
640
641 If unsure, say N.
642
643endif # MD