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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 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