Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
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linux
1# SPDX-License-Identifier: GPL-2.0-only
2#
3# Block device driver configuration
4#
5
6menuconfig MD
7 bool "Multiple devices driver support (RAID and LVM)"
8 depends on BLOCK
9 help
10 Support multiple physical spindles through a single logical device.
11 Required for RAID and logical volume management.
12
13if MD
14
15config BLK_DEV_MD
16 tristate "RAID support"
17 select BLOCK_HOLDER_DEPRECATED if SYSFS
18 select BUFFER_HEAD
19 # BLOCK_LEGACY_AUTOLOAD requirement should be removed
20 # after relevant mdadm enhancements - to make "names=yes"
21 # the default - are widely available.
22 select BLOCK_LEGACY_AUTOLOAD
23 help
24 This driver lets you combine several hard disk partitions into one
25 logical block device. This can be used to simply append one
26 partition to another one or to combine several redundant hard disks
27 into a RAID1/4/5 device so as to provide protection against hard
28 disk failures. This is called "Software RAID" since the combining of
29 the partitions is done by the kernel. "Hardware RAID" means that the
30 combining is done by a dedicated controller; if you have such a
31 controller, you do not need to say Y here.
32
33 More information about Software RAID on Linux is contained in the
34 Software RAID mini-HOWTO, available from
35 <https://www.tldp.org/docs.html#howto>. There you will also learn
36 where to get the supporting user space utilities raidtools.
37
38 If unsure, say N.
39
40config MD_BITMAP
41 bool "MD RAID bitmap support"
42 default y
43 depends on BLK_DEV_MD
44 help
45 If you say Y here, support for the write intent bitmap will be
46 enabled. The bitmap can be used to optimize resync speed after power
47 failure or readding a disk, limiting it to recorded dirty sectors in
48 bitmap.
49
50 This feature can be added to existing MD array or MD array can be
51 created with bitmap via mdadm(8).
52
53 If unsure, say Y.
54
55config MD_LLBITMAP
56 bool "MD RAID lockless bitmap support"
57 depends on BLK_DEV_MD
58 help
59 If you say Y here, support for the lockless write intent bitmap will
60 be enabled.
61
62 Note, this is an experimental feature.
63
64 If unsure, say N.
65
66config MD_AUTODETECT
67 bool "Autodetect RAID arrays during kernel boot"
68 depends on BLK_DEV_MD=y
69 default y
70 help
71 If you say Y here, then the kernel will try to autodetect raid
72 arrays as part of its boot process.
73
74 If you don't use raid and say Y, this autodetection can cause
75 a several-second delay in the boot time due to various
76 synchronisation steps that are part of this step.
77
78 If unsure, say Y.
79
80config MD_BITMAP_FILE
81 bool "MD bitmap file support (deprecated)"
82 default y
83 depends on MD_BITMAP
84 help
85 If you say Y here, support for write intent bitmaps in files on an
86 external file system is enabled. This is an alternative to the internal
87 bitmaps near the MD superblock, and very problematic code that abuses
88 various kernel APIs and can only work with files on a file system not
89 actually sitting on the MD device.
90
91config MD_LINEAR
92 tristate "Linear (append) mode"
93 depends on BLK_DEV_MD
94 help
95 If you say Y here, then your multiple devices driver will be able to
96 use the so-called linear mode, i.e. it will combine the hard disk
97 partitions by simply appending one to the other.
98
99 To compile this as a module, choose M here: the module
100 will be called linear.
101
102 If unsure, say Y.
103
104config MD_RAID0
105 tristate "RAID-0 (striping) mode"
106 depends on BLK_DEV_MD
107 help
108 If you say Y here, then your multiple devices driver will be able to
109 use the so-called raid0 mode, i.e. it will combine the hard disk
110 partitions into one logical device in such a fashion as to fill them
111 up evenly, one chunk here and one chunk there. This will increase
112 the throughput rate if the partitions reside on distinct disks.
113
114 Information about Software RAID on Linux is contained in the
115 Software-RAID mini-HOWTO, available from
116 <https://www.tldp.org/docs.html#howto>. There you will also
117 learn where to get the supporting user space utilities raidtools.
118
119 To compile this as a module, choose M here: the module
120 will be called raid0.
121
122 If unsure, say Y.
123
124config MD_RAID1
125 tristate "RAID-1 (mirroring) mode"
126 depends on BLK_DEV_MD
127 help
128 A RAID-1 set consists of several disk drives which are exact copies
129 of each other. In the event of a mirror failure, the RAID driver
130 will continue to use the operational mirrors in the set, providing
131 an error free MD (multiple device) to the higher levels of the
132 kernel. In a set with N drives, the available space is the capacity
133 of a single drive, and the set protects against a failure of (N - 1)
134 drives.
135
136 Information about Software RAID on Linux is contained in the
137 Software-RAID mini-HOWTO, available from
138 <https://www.tldp.org/docs.html#howto>. There you will also
139 learn where to get the supporting user space utilities raidtools.
140
141 If you want to use such a RAID-1 set, say Y. To compile this code
142 as a module, choose M here: the module will be called raid1.
143
144 If unsure, say Y.
145
146config MD_RAID10
147 tristate "RAID-10 (mirrored striping) mode"
148 depends on BLK_DEV_MD
149 help
150 RAID-10 provides a combination of striping (RAID-0) and
151 mirroring (RAID-1) with easier configuration and more flexible
152 layout.
153 Unlike RAID-0, but like RAID-1, RAID-10 requires all devices to
154 be the same size (or at least, only as much as the smallest device
155 will be used).
156 RAID-10 provides a variety of layouts that provide different levels
157 of redundancy and performance.
158
159 RAID-10 requires mdadm-1.7.0 or later, available at:
160
161 https://www.kernel.org/pub/linux/utils/raid/mdadm/
162
163 If unsure, say Y.
164
165config MD_RAID456
166 tristate "RAID-4/RAID-5/RAID-6 mode"
167 depends on BLK_DEV_MD
168 select RAID6_PQ
169 select CRC32
170 select ASYNC_MEMCPY
171 select ASYNC_XOR
172 select ASYNC_PQ
173 select ASYNC_RAID6_RECOV
174 help
175 A RAID-5 set of N drives with a capacity of C MB per drive provides
176 the capacity of C * (N - 1) MB, and protects against a failure
177 of a single drive. For a given sector (row) number, (N - 1) drives
178 contain data sectors, and one drive contains the parity protection.
179 For a RAID-4 set, the parity blocks are present on a single drive,
180 while a RAID-5 set distributes the parity across the drives in one
181 of the available parity distribution methods.
182
183 A RAID-6 set of N drives with a capacity of C MB per drive
184 provides the capacity of C * (N - 2) MB, and protects
185 against a failure of any two drives. For a given sector
186 (row) number, (N - 2) drives contain data sectors, and two
187 drives contains two independent redundancy syndromes. Like
188 RAID-5, RAID-6 distributes the syndromes across the drives
189 in one of the available parity distribution methods.
190
191 Information about Software RAID on Linux is contained in the
192 Software-RAID mini-HOWTO, available from
193 <https://www.tldp.org/docs.html#howto>. There you will also
194 learn where to get the supporting user space utilities raidtools.
195
196 If you want to use such a RAID-4/RAID-5/RAID-6 set, say Y. To
197 compile this code as a module, choose M here: the module
198 will be called raid456.
199
200 If unsure, say Y.
201
202config MD_CLUSTER
203 tristate "Cluster Support for MD"
204 select MD_BITMAP
205 depends on BLK_DEV_MD
206 depends on DLM
207 default n
208 help
209 Clustering support for MD devices. This enables locking and
210 synchronization across multiple systems on the cluster, so all
211 nodes in the cluster can access the MD devices simultaneously.
212
213 This brings the redundancy (and uptime) of RAID levels across the
214 nodes of the cluster. Currently, it can work with raid1 and raid10
215 (limited support).
216
217 If unsure, say N.
218
219source "drivers/md/bcache/Kconfig"
220
221config BLK_DEV_DM_BUILTIN
222 bool
223
224config BLK_DEV_DM
225 tristate "Device mapper support"
226 select BLOCK_HOLDER_DEPRECATED if SYSFS
227 select BLK_DEV_DM_BUILTIN
228 select BLK_MQ_STACKING
229 select CRYPTO_LIB_SHA256 if IMA
230 depends on DAX || DAX=n
231 help
232 Device-mapper is a low level volume manager. It works by allowing
233 people to specify mappings for ranges of logical sectors. Various
234 mapping types are available, in addition people may write their own
235 modules containing custom mappings if they wish.
236
237 Higher level volume managers such as LVM2 use this driver.
238
239 To compile this as a module, choose M here: the module will be
240 called dm-mod.
241
242 If unsure, say N.
243
244config DM_DEBUG
245 bool "Device mapper debugging support"
246 depends on BLK_DEV_DM
247 help
248 Enable this for messages that may help debug device-mapper problems.
249
250 If unsure, say N.
251
252config DM_BUFIO
253 tristate
254 depends on BLK_DEV_DM
255 help
256 This interface allows you to do buffered I/O on a device and acts
257 as a cache, holding recently-read blocks in memory and performing
258 delayed writes.
259
260config DM_DEBUG_BLOCK_MANAGER_LOCKING
261 bool "Block manager locking"
262 depends on DM_BUFIO
263 help
264 Block manager locking can catch various metadata corruption issues.
265
266 If unsure, say N.
267
268config DM_DEBUG_BLOCK_STACK_TRACING
269 bool "Keep stack trace of persistent data block lock holders"
270 depends on STACKTRACE_SUPPORT && DM_DEBUG_BLOCK_MANAGER_LOCKING
271 select STACKTRACE
272 help
273 Enable this for messages that may help debug problems with the
274 block manager locking used by thin provisioning and caching.
275
276 If unsure, say N.
277
278config DM_BIO_PRISON
279 tristate
280 depends on BLK_DEV_DM
281 help
282 Some bio locking schemes used by other device-mapper targets
283 including thin provisioning.
284
285source "drivers/md/persistent-data/Kconfig"
286
287config DM_UNSTRIPED
288 tristate "Unstriped target"
289 depends on BLK_DEV_DM
290 help
291 Unstripes I/O so it is issued solely on a single drive in a HW
292 RAID0 or dm-striped target.
293
294config DM_CRYPT
295 tristate "Crypt target support"
296 depends on BLK_DEV_DM
297 depends on (ENCRYPTED_KEYS || ENCRYPTED_KEYS=n)
298 depends on (TRUSTED_KEYS || TRUSTED_KEYS=n)
299 select CRC32
300 select CRYPTO
301 select CRYPTO_CBC
302 select CRYPTO_ESSIV
303 select CRYPTO_LIB_AES
304 select CRYPTO_LIB_MD5 # needed by lmk IV mode
305 help
306 This device-mapper target allows you to create a device that
307 transparently encrypts the data on it. You'll need to activate
308 the ciphers you're going to use in the cryptoapi configuration.
309
310 For further information on dm-crypt and userspace tools see:
311 <https://gitlab.com/cryptsetup/cryptsetup/wikis/DMCrypt>
312
313 To compile this code as a module, choose M here: the module will
314 be called dm-crypt.
315
316 If unsure, say N.
317
318config DM_SNAPSHOT
319 tristate "Snapshot target"
320 depends on BLK_DEV_DM
321 select DM_BUFIO
322 help
323 Allow volume managers to take writable snapshots of a device.
324
325config DM_THIN_PROVISIONING
326 tristate "Thin provisioning target"
327 depends on BLK_DEV_DM
328 select DM_PERSISTENT_DATA
329 select DM_BIO_PRISON
330 help
331 Provides thin provisioning and snapshots that share a data store.
332
333config DM_CACHE
334 tristate "Cache target (EXPERIMENTAL)"
335 depends on BLK_DEV_DM
336 default n
337 select DM_PERSISTENT_DATA
338 select DM_BIO_PRISON
339 help
340 dm-cache attempts to improve performance of a block device by
341 moving frequently used data to a smaller, higher performance
342 device. Different 'policy' plugins can be used to change the
343 algorithms used to select which blocks are promoted, demoted,
344 cleaned etc. It supports writeback and writethrough modes.
345
346config DM_CACHE_SMQ
347 tristate "Stochastic MQ Cache Policy (EXPERIMENTAL)"
348 depends on DM_CACHE
349 default y
350 help
351 A cache policy that uses a multiqueue ordered by recent hits
352 to select which blocks should be promoted and demoted.
353 This is meant to be a general purpose policy. It prioritises
354 reads over writes. This SMQ policy (vs MQ) offers the promise
355 of less memory utilization, improved performance and increased
356 adaptability in the face of changing workloads.
357
358config DM_WRITECACHE
359 tristate "Writecache target"
360 depends on BLK_DEV_DM
361 help
362 The writecache target caches writes on persistent memory or SSD.
363 It is intended for databases or other programs that need extremely
364 low commit latency.
365
366 The writecache target doesn't cache reads because reads are supposed
367 to be cached in standard RAM.
368
369config DM_EBS
370 tristate "Emulated block size target (EXPERIMENTAL)"
371 depends on BLK_DEV_DM && !HIGHMEM
372 select DM_BUFIO
373 help
374 dm-ebs emulates smaller logical block size on backing devices
375 with larger ones (e.g. 512 byte sectors on 4K native disks).
376
377config DM_ERA
378 tristate "Era target (EXPERIMENTAL)"
379 depends on BLK_DEV_DM
380 default n
381 select DM_PERSISTENT_DATA
382 select DM_BIO_PRISON
383 help
384 dm-era tracks which parts of a block device are written to
385 over time. Useful for maintaining cache coherency when using
386 vendor snapshots.
387
388config DM_CLONE
389 tristate "Clone target (EXPERIMENTAL)"
390 depends on BLK_DEV_DM
391 default n
392 select DM_PERSISTENT_DATA
393 help
394 dm-clone produces a one-to-one copy of an existing, read-only source
395 device into a writable destination device. The cloned device is
396 visible/mountable immediately and the copy of the source device to the
397 destination device happens in the background, in parallel with user
398 I/O.
399
400 If unsure, say N.
401
402config DM_MIRROR
403 tristate "Mirror target"
404 depends on BLK_DEV_DM
405 help
406 Allow volume managers to mirror logical volumes, also
407 needed for live data migration tools such as 'pvmove'.
408
409config DM_LOG_USERSPACE
410 tristate "Mirror userspace logging"
411 depends on DM_MIRROR && NET
412 select CONNECTOR
413 help
414 The userspace logging module provides a mechanism for
415 relaying the dm-dirty-log API to userspace. Log designs
416 which are more suited to userspace implementation (e.g.
417 shared storage logs) or experimental logs can be implemented
418 by leveraging this framework.
419
420config DM_RAID
421 tristate "RAID 1/4/5/6/10 target"
422 depends on BLK_DEV_DM
423 select MD_RAID0
424 select MD_RAID1
425 select MD_RAID10
426 select MD_RAID456
427 select MD_BITMAP
428 select BLK_DEV_MD
429 help
430 A dm target that supports RAID1, RAID10, RAID4, RAID5 and RAID6 mappings
431
432 A RAID-5 set of N drives with a capacity of C MB per drive provides
433 the capacity of C * (N - 1) MB, and protects against a failure
434 of a single drive. For a given sector (row) number, (N - 1) drives
435 contain data sectors, and one drive contains the parity protection.
436 For a RAID-4 set, the parity blocks are present on a single drive,
437 while a RAID-5 set distributes the parity across the drives in one
438 of the available parity distribution methods.
439
440 A RAID-6 set of N drives with a capacity of C MB per drive
441 provides the capacity of C * (N - 2) MB, and protects
442 against a failure of any two drives. For a given sector
443 (row) number, (N - 2) drives contain data sectors, and two
444 drives contains two independent redundancy syndromes. Like
445 RAID-5, RAID-6 distributes the syndromes across the drives
446 in one of the available parity distribution methods.
447
448config DM_ZERO
449 tristate "Zero target"
450 depends on BLK_DEV_DM
451 help
452 A target that discards writes, and returns all zeroes for
453 reads. Useful in some recovery situations.
454
455config DM_MULTIPATH
456 tristate "Multipath target"
457 depends on BLK_DEV_DM
458 # nasty syntax but means make DM_MULTIPATH independent
459 # of SCSI_DH if the latter isn't defined but if
460 # it is, DM_MULTIPATH must depend on it. We get a build
461 # error if SCSI_DH=m and DM_MULTIPATH=y
462 depends on !SCSI_DH || SCSI
463 help
464 Allow volume managers to support multipath hardware.
465
466config DM_MULTIPATH_QL
467 tristate "I/O Path Selector based on the number of in-flight I/Os"
468 depends on DM_MULTIPATH
469 help
470 This path selector is a dynamic load balancer which selects
471 the path with the least number of in-flight I/Os.
472
473 If unsure, say N.
474
475config DM_MULTIPATH_ST
476 tristate "I/O Path Selector based on the service time"
477 depends on DM_MULTIPATH
478 help
479 This path selector is a dynamic load balancer which selects
480 the path expected to complete the incoming I/O in the shortest
481 time.
482
483 If unsure, say N.
484
485config DM_MULTIPATH_HST
486 tristate "I/O Path Selector based on historical service time"
487 depends on DM_MULTIPATH
488 help
489 This path selector is a dynamic load balancer which selects
490 the path expected to complete the incoming I/O in the shortest
491 time by comparing estimated service time (based on historical
492 service time).
493
494 If unsure, say N.
495
496config DM_MULTIPATH_IOA
497 tristate "I/O Path Selector based on CPU submission"
498 depends on DM_MULTIPATH
499 help
500 This path selector selects the path based on the CPU the IO is
501 executed on and the CPU to path mapping setup at path addition time.
502
503 If unsure, say N.
504
505config DM_DELAY
506 tristate "I/O delaying target"
507 depends on BLK_DEV_DM
508 help
509 A target that delays reads and/or writes and can send
510 them to different devices. Useful for testing.
511
512 If unsure, say N.
513
514config DM_DUST
515 tristate "Bad sector simulation target"
516 depends on BLK_DEV_DM
517 help
518 A target that simulates bad sector behavior.
519 Useful for testing.
520
521 If unsure, say N.
522
523config DM_INIT
524 bool "DM \"dm-mod.create=\" parameter support"
525 depends on BLK_DEV_DM=y
526 help
527 Enable "dm-mod.create=" parameter to create mapped devices at init time.
528 This option is useful to allow mounting rootfs without requiring an
529 initramfs.
530 See Documentation/admin-guide/device-mapper/dm-init.rst for dm-mod.create="..."
531 format.
532
533 If unsure, say N.
534
535config DM_UEVENT
536 bool "DM uevents"
537 depends on BLK_DEV_DM
538 help
539 Generate udev events for DM events.
540
541config DM_FLAKEY
542 tristate "Flakey target"
543 depends on BLK_DEV_DM
544 help
545 A target that intermittently fails I/O for debugging purposes.
546
547config DM_VERITY
548 tristate "Verity target support"
549 depends on BLK_DEV_DM
550 select CRYPTO
551 select CRYPTO_HASH
552 select CRYPTO_LIB_SHA256
553 select DM_BUFIO
554 select REED_SOLOMON if DM_VERITY_FEC
555 select REED_SOLOMON_DEC8 if DM_VERITY_FEC
556 help
557 This device-mapper target creates a read-only device that
558 transparently validates the data on one underlying device against
559 a pre-generated tree of cryptographic checksums stored on a second
560 device.
561
562 You'll need to activate the digests you're going to use in the
563 cryptoapi configuration.
564
565 To compile this code as a module, choose M here: the module will
566 be called dm-verity.
567
568 If unsure, say N.
569
570config DM_VERITY_VERIFY_ROOTHASH_SIG
571 bool "Verity data device root hash signature verification support"
572 depends on DM_VERITY
573 select SYSTEM_DATA_VERIFICATION
574 help
575 Add ability for dm-verity device to be validated if the
576 pre-generated tree of cryptographic checksums passed has a pkcs#7
577 signature file that can validate the roothash of the tree.
578
579 By default, rely on the builtin trusted keyring.
580
581 If unsure, say N.
582
583config DM_VERITY_VERIFY_ROOTHASH_SIG_SECONDARY_KEYRING
584 bool "Verity data device root hash signature verification with secondary keyring"
585 depends on DM_VERITY_VERIFY_ROOTHASH_SIG
586 depends on SECONDARY_TRUSTED_KEYRING
587 help
588 Rely on the secondary trusted keyring to verify dm-verity signatures.
589
590 If unsure, say N.
591
592config DM_VERITY_VERIFY_ROOTHASH_SIG_PLATFORM_KEYRING
593 bool "Verity data device root hash signature verification with platform keyring"
594 default DM_VERITY_VERIFY_ROOTHASH_SIG_SECONDARY_KEYRING
595 depends on DM_VERITY_VERIFY_ROOTHASH_SIG
596 depends on INTEGRITY_PLATFORM_KEYRING
597 help
598 Rely also on the platform keyring to verify dm-verity signatures.
599
600 If unsure, say N.
601
602config DM_VERITY_FEC
603 bool "Verity forward error correction support"
604 depends on DM_VERITY
605 help
606 Add forward error correction support to dm-verity. This option
607 makes it possible to use pre-generated error correction data to
608 recover from corrupted blocks.
609
610 If unsure, say N.
611
612config DM_SWITCH
613 tristate "Switch target support (EXPERIMENTAL)"
614 depends on BLK_DEV_DM
615 help
616 This device-mapper target creates a device that supports an arbitrary
617 mapping of fixed-size regions of I/O across a fixed set of paths.
618 The path used for any specific region can be switched dynamically
619 by sending the target a message.
620
621 To compile this code as a module, choose M here: the module will
622 be called dm-switch.
623
624 If unsure, say N.
625
626config DM_LOG_WRITES
627 tristate "Log writes target support"
628 depends on BLK_DEV_DM
629 help
630 This device-mapper target takes two devices, one device to use
631 normally, one to log all write operations done to the first device.
632 This is for use by file system developers wishing to verify that
633 their fs is writing a consistent file system at all times by allowing
634 them to replay the log in a variety of ways and to check the
635 contents.
636
637 To compile this code as a module, choose M here: the module will
638 be called dm-log-writes.
639
640 If unsure, say N.
641
642config DM_INTEGRITY
643 tristate "Integrity target support"
644 depends on BLK_DEV_DM
645 select BLK_DEV_INTEGRITY
646 select DM_BUFIO
647 select CRYPTO
648 select CRYPTO_SKCIPHER
649 select ASYNC_XOR
650 select DM_AUDIT if AUDIT
651 help
652 This device-mapper target emulates a block device that has
653 additional per-sector tags that can be used for storing
654 integrity information.
655
656 This integrity target is used with the dm-crypt target to
657 provide authenticated disk encryption or it can be used
658 standalone.
659
660 To compile this code as a module, choose M here: the module will
661 be called dm-integrity.
662
663config DM_ZONED
664 tristate "Drive-managed zoned block device target support"
665 depends on BLK_DEV_DM
666 depends on BLK_DEV_ZONED
667 select CRC32
668 help
669 This device-mapper target takes a host-managed or host-aware zoned
670 block device and exposes most of its capacity as a regular block
671 device (drive-managed zoned block device) without any write
672 constraints. This is mainly intended for use with file systems that
673 do not natively support zoned block devices but still want to
674 benefit from the increased capacity offered by SMR disks. Other uses
675 by applications using raw block devices (for example object stores)
676 are also possible.
677
678 To compile this code as a module, choose M here: the module will
679 be called dm-zoned.
680
681 If unsure, say N.
682
683config DM_AUDIT
684 bool "DM audit events"
685 depends on BLK_DEV_DM
686 depends on AUDIT
687 help
688 Generate audit events for device-mapper.
689
690 Enables audit logging of several security relevant events in the
691 particular device-mapper targets, especially the integrity target.
692
693source "drivers/md/dm-vdo/Kconfig"
694
695source "drivers/md/dm-pcache/Kconfig"
696
697endif # MD