xref: /openbmc/linux/drivers/md/Kconfig (revision ba61bb17)
1#
2# Block device driver configuration
3#
4
5menuconfig MD
6	bool "Multiple devices driver support (RAID and LVM)"
7	depends on BLOCK
8	select SRCU
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	---help---
18	  This driver lets you combine several hard disk partitions into one
19	  logical block device. This can be used to simply append one
20	  partition to another one or to combine several redundant hard disks
21	  into a RAID1/4/5 device so as to provide protection against hard
22	  disk failures. This is called "Software RAID" since the combining of
23	  the partitions is done by the kernel. "Hardware RAID" means that the
24	  combining is done by a dedicated controller; if you have such a
25	  controller, you do not need to say Y here.
26
27	  More information about Software RAID on Linux is contained in the
28	  Software RAID mini-HOWTO, available from
29	  <http://www.tldp.org/docs.html#howto>. There you will also learn
30	  where to get the supporting user space utilities raidtools.
31
32	  If unsure, say N.
33
34config MD_AUTODETECT
35	bool "Autodetect RAID arrays during kernel boot"
36	depends on BLK_DEV_MD=y
37	default y
38	---help---
39	  If you say Y here, then the kernel will try to autodetect raid
40	  arrays as part of its boot process.
41
42	  If you don't use raid and say Y, this autodetection can cause
43	  a several-second delay in the boot time due to various
44	  synchronisation steps that are part of this step.
45
46	  If unsure, say Y.
47
48config MD_LINEAR
49	tristate "Linear (append) mode"
50	depends on BLK_DEV_MD
51	---help---
52	  If you say Y here, then your multiple devices driver will be able to
53	  use the so-called linear mode, i.e. it will combine the hard disk
54	  partitions by simply appending one to the other.
55
56	  To compile this as a module, choose M here: the module
57	  will be called linear.
58
59	  If unsure, say Y.
60
61config MD_RAID0
62	tristate "RAID-0 (striping) mode"
63	depends on BLK_DEV_MD
64	---help---
65	  If you say Y here, then your multiple devices driver will be able to
66	  use the so-called raid0 mode, i.e. it will combine the hard disk
67	  partitions into one logical device in such a fashion as to fill them
68	  up evenly, one chunk here and one chunk there. This will increase
69	  the throughput rate if the partitions reside on distinct disks.
70
71	  Information about Software RAID on Linux is contained in the
72	  Software-RAID mini-HOWTO, available from
73	  <http://www.tldp.org/docs.html#howto>. There you will also
74	  learn where to get the supporting user space utilities raidtools.
75
76	  To compile this as a module, choose M here: the module
77	  will be called raid0.
78
79	  If unsure, say Y.
80
81config MD_RAID1
82	tristate "RAID-1 (mirroring) mode"
83	depends on BLK_DEV_MD
84	---help---
85	  A RAID-1 set consists of several disk drives which are exact copies
86	  of each other.  In the event of a mirror failure, the RAID driver
87	  will continue to use the operational mirrors in the set, providing
88	  an error free MD (multiple device) to the higher levels of the
89	  kernel.  In a set with N drives, the available space is the capacity
90	  of a single drive, and the set protects against a failure of (N - 1)
91	  drives.
92
93	  Information about Software RAID on Linux is contained in the
94	  Software-RAID mini-HOWTO, available from
95	  <http://www.tldp.org/docs.html#howto>.  There you will also
96	  learn where to get the supporting user space utilities raidtools.
97
98	  If you want to use such a RAID-1 set, say Y.  To compile this code
99	  as a module, choose M here: the module will be called raid1.
100
101	  If unsure, say Y.
102
103config MD_RAID10
104	tristate "RAID-10 (mirrored striping) mode"
105	depends on BLK_DEV_MD
106	---help---
107	  RAID-10 provides a combination of striping (RAID-0) and
108	  mirroring (RAID-1) with easier configuration and more flexible
109	  layout.
110	  Unlike RAID-0, but like RAID-1, RAID-10 requires all devices to
111	  be the same size (or at least, only as much as the smallest device
112	  will be used).
113	  RAID-10 provides a variety of layouts that provide different levels
114	  of redundancy and performance.
115
116	  RAID-10 requires mdadm-1.7.0 or later, available at:
117
118	  https://www.kernel.org/pub/linux/utils/raid/mdadm/
119
120	  If unsure, say Y.
121
122config MD_RAID456
123	tristate "RAID-4/RAID-5/RAID-6 mode"
124	depends on BLK_DEV_MD
125	select RAID6_PQ
126	select LIBCRC32C
127	select ASYNC_MEMCPY
128	select ASYNC_XOR
129	select ASYNC_PQ
130	select ASYNC_RAID6_RECOV
131	---help---
132	  A RAID-5 set of N drives with a capacity of C MB per drive provides
133	  the capacity of C * (N - 1) MB, and protects against a failure
134	  of a single drive. For a given sector (row) number, (N - 1) drives
135	  contain data sectors, and one drive contains the parity protection.
136	  For a RAID-4 set, the parity blocks are present on a single drive,
137	  while a RAID-5 set distributes the parity across the drives in one
138	  of the available parity distribution methods.
139
140	  A RAID-6 set of N drives with a capacity of C MB per drive
141	  provides the capacity of C * (N - 2) MB, and protects
142	  against a failure of any two drives. For a given sector
143	  (row) number, (N - 2) drives contain data sectors, and two
144	  drives contains two independent redundancy syndromes.  Like
145	  RAID-5, RAID-6 distributes the syndromes across the drives
146	  in one of the available parity distribution methods.
147
148	  Information about Software RAID on Linux is contained in the
149	  Software-RAID mini-HOWTO, available from
150	  <http://www.tldp.org/docs.html#howto>. There you will also
151	  learn where to get the supporting user space utilities raidtools.
152
153	  If you want to use such a RAID-4/RAID-5/RAID-6 set, say Y.  To
154	  compile this code as a module, choose M here: the module
155	  will be called raid456.
156
157	  If unsure, say Y.
158
159config MD_MULTIPATH
160	tristate "Multipath I/O support"
161	depends on BLK_DEV_MD
162	help
163	  MD_MULTIPATH provides a simple multi-path personality for use
164	  the MD framework.  It is not under active development.  New
165	  projects should consider using DM_MULTIPATH which has more
166	  features and more testing.
167
168	  If unsure, say N.
169
170config MD_FAULTY
171	tristate "Faulty test module for MD"
172	depends on BLK_DEV_MD
173	help
174	  The "faulty" module allows for a block device that occasionally returns
175	  read or write errors.  It is useful for testing.
176
177	  In unsure, say N.
178
179
180config MD_CLUSTER
181	tristate "Cluster Support for MD"
182	depends on BLK_DEV_MD
183	depends on DLM
184	default n
185	---help---
186	Clustering support for MD devices. This enables locking and
187	synchronization across multiple systems on the cluster, so all
188	nodes in the cluster can access the MD devices simultaneously.
189
190	This brings the redundancy (and uptime) of RAID levels across the
191	nodes of the cluster. Currently, it can work with raid1 and raid10
192	(limited support).
193
194	If unsure, say N.
195
196source "drivers/md/bcache/Kconfig"
197
198config BLK_DEV_DM_BUILTIN
199	bool
200
201config BLK_DEV_DM
202	tristate "Device mapper support"
203	select BLK_DEV_DM_BUILTIN
204	depends on DAX || DAX=n
205	---help---
206	  Device-mapper is a low level volume manager.  It works by allowing
207	  people to specify mappings for ranges of logical sectors.  Various
208	  mapping types are available, in addition people may write their own
209	  modules containing custom mappings if they wish.
210
211	  Higher level volume managers such as LVM2 use this driver.
212
213	  To compile this as a module, choose M here: the module will be
214	  called dm-mod.
215
216	  If unsure, say N.
217
218config DM_MQ_DEFAULT
219	bool "request-based DM: use blk-mq I/O path by default"
220	depends on BLK_DEV_DM
221	---help---
222	  This option enables the blk-mq based I/O path for request-based
223	  DM devices by default.  With the option the dm_mod.use_blk_mq
224	  module/boot option defaults to Y, without it to N, but it can
225	  still be overriden either way.
226
227	  If unsure say N.
228
229config DM_DEBUG
230	bool "Device mapper debugging support"
231	depends on BLK_DEV_DM
232	---help---
233	  Enable this for messages that may help debug device-mapper problems.
234
235	  If unsure, say N.
236
237config DM_BUFIO
238       tristate
239       depends on BLK_DEV_DM
240       ---help---
241	 This interface allows you to do buffered I/O on a device and acts
242	 as a cache, holding recently-read blocks in memory and performing
243	 delayed writes.
244
245config DM_DEBUG_BLOCK_MANAGER_LOCKING
246       bool "Block manager locking"
247       depends on DM_BUFIO
248       ---help---
249	 Block manager locking can catch various metadata corruption issues.
250
251	 If unsure, say N.
252
253config DM_DEBUG_BLOCK_STACK_TRACING
254       bool "Keep stack trace of persistent data block lock holders"
255       depends on STACKTRACE_SUPPORT && DM_DEBUG_BLOCK_MANAGER_LOCKING
256       select STACKTRACE
257       ---help---
258	 Enable this for messages that may help debug problems with the
259	 block manager locking used by thin provisioning and caching.
260
261	 If unsure, say N.
262
263config DM_BIO_PRISON
264       tristate
265       depends on BLK_DEV_DM
266       ---help---
267	 Some bio locking schemes used by other device-mapper targets
268	 including thin provisioning.
269
270source "drivers/md/persistent-data/Kconfig"
271
272config DM_UNSTRIPED
273       tristate "Unstriped target"
274       depends on BLK_DEV_DM
275       ---help---
276	  Unstripes I/O so it is issued solely on a single drive in a HW
277	  RAID0 or dm-striped target.
278
279config DM_CRYPT
280	tristate "Crypt target support"
281	depends on BLK_DEV_DM
282	select CRYPTO
283	select CRYPTO_CBC
284	---help---
285	  This device-mapper target allows you to create a device that
286	  transparently encrypts the data on it. You'll need to activate
287	  the ciphers you're going to use in the cryptoapi configuration.
288
289	  For further information on dm-crypt and userspace tools see:
290	  <https://gitlab.com/cryptsetup/cryptsetup/wikis/DMCrypt>
291
292	  To compile this code as a module, choose M here: the module will
293	  be called dm-crypt.
294
295	  If unsure, say N.
296
297config DM_SNAPSHOT
298       tristate "Snapshot target"
299       depends on BLK_DEV_DM
300       select DM_BUFIO
301       ---help---
302         Allow volume managers to take writable snapshots of a device.
303
304config DM_THIN_PROVISIONING
305       tristate "Thin provisioning target"
306       depends on BLK_DEV_DM
307       select DM_PERSISTENT_DATA
308       select DM_BIO_PRISON
309       ---help---
310         Provides thin provisioning and snapshots that share a data store.
311
312config DM_CACHE
313       tristate "Cache target (EXPERIMENTAL)"
314       depends on BLK_DEV_DM
315       default n
316       select DM_PERSISTENT_DATA
317       select DM_BIO_PRISON
318       ---help---
319         dm-cache attempts to improve performance of a block device by
320         moving frequently used data to a smaller, higher performance
321         device.  Different 'policy' plugins can be used to change the
322         algorithms used to select which blocks are promoted, demoted,
323         cleaned etc.  It supports writeback and writethrough modes.
324
325config DM_CACHE_SMQ
326       tristate "Stochastic MQ Cache Policy (EXPERIMENTAL)"
327       depends on DM_CACHE
328       default y
329       ---help---
330         A cache policy that uses a multiqueue ordered by recent hits
331         to select which blocks should be promoted and demoted.
332         This is meant to be a general purpose policy.  It prioritises
333         reads over writes.  This SMQ policy (vs MQ) offers the promise
334         of less memory utilization, improved performance and increased
335         adaptability in the face of changing workloads.
336
337config DM_WRITECACHE
338	tristate "Writecache target"
339	depends on BLK_DEV_DM
340	---help---
341	   The writecache target caches writes on persistent memory or SSD.
342	   It is intended for databases or other programs that need extremely
343	   low commit latency.
344
345	   The writecache target doesn't cache reads because reads are supposed
346	   to be cached in standard RAM.
347
348config DM_ERA
349       tristate "Era target (EXPERIMENTAL)"
350       depends on BLK_DEV_DM
351       default n
352       select DM_PERSISTENT_DATA
353       select DM_BIO_PRISON
354       ---help---
355         dm-era tracks which parts of a block device are written to
356         over time.  Useful for maintaining cache coherency when using
357         vendor snapshots.
358
359config DM_MIRROR
360       tristate "Mirror target"
361       depends on BLK_DEV_DM
362       ---help---
363         Allow volume managers to mirror logical volumes, also
364         needed for live data migration tools such as 'pvmove'.
365
366config DM_LOG_USERSPACE
367	tristate "Mirror userspace logging"
368	depends on DM_MIRROR && NET
369	select CONNECTOR
370	---help---
371	  The userspace logging module provides a mechanism for
372	  relaying the dm-dirty-log API to userspace.  Log designs
373	  which are more suited to userspace implementation (e.g.
374	  shared storage logs) or experimental logs can be implemented
375	  by leveraging this framework.
376
377config DM_RAID
378       tristate "RAID 1/4/5/6/10 target"
379       depends on BLK_DEV_DM
380       select MD_RAID0
381       select MD_RAID1
382       select MD_RAID10
383       select MD_RAID456
384       select BLK_DEV_MD
385       ---help---
386	 A dm target that supports RAID1, RAID10, RAID4, RAID5 and RAID6 mappings
387
388	 A RAID-5 set of N drives with a capacity of C MB per drive provides
389	 the capacity of C * (N - 1) MB, and protects against a failure
390	 of a single drive. For a given sector (row) number, (N - 1) drives
391	 contain data sectors, and one drive contains the parity protection.
392	 For a RAID-4 set, the parity blocks are present on a single drive,
393	 while a RAID-5 set distributes the parity across the drives in one
394	 of the available parity distribution methods.
395
396	 A RAID-6 set of N drives with a capacity of C MB per drive
397	 provides the capacity of C * (N - 2) MB, and protects
398	 against a failure of any two drives. For a given sector
399	 (row) number, (N - 2) drives contain data sectors, and two
400	 drives contains two independent redundancy syndromes.  Like
401	 RAID-5, RAID-6 distributes the syndromes across the drives
402	 in one of the available parity distribution methods.
403
404config DM_ZERO
405	tristate "Zero target"
406	depends on BLK_DEV_DM
407	---help---
408	  A target that discards writes, and returns all zeroes for
409	  reads.  Useful in some recovery situations.
410
411config DM_MULTIPATH
412	tristate "Multipath target"
413	depends on BLK_DEV_DM
414	# nasty syntax but means make DM_MULTIPATH independent
415	# of SCSI_DH if the latter isn't defined but if
416	# it is, DM_MULTIPATH must depend on it.  We get a build
417	# error if SCSI_DH=m and DM_MULTIPATH=y
418	depends on !SCSI_DH || SCSI
419	---help---
420	  Allow volume managers to support multipath hardware.
421
422config DM_MULTIPATH_QL
423	tristate "I/O Path Selector based on the number of in-flight I/Os"
424	depends on DM_MULTIPATH
425	---help---
426	  This path selector is a dynamic load balancer which selects
427	  the path with the least number of in-flight I/Os.
428
429	  If unsure, say N.
430
431config DM_MULTIPATH_ST
432	tristate "I/O Path Selector based on the service time"
433	depends on DM_MULTIPATH
434	---help---
435	  This path selector is a dynamic load balancer which selects
436	  the path expected to complete the incoming I/O in the shortest
437	  time.
438
439	  If unsure, say N.
440
441config DM_DELAY
442	tristate "I/O delaying target"
443	depends on BLK_DEV_DM
444	---help---
445	A target that delays reads and/or writes and can send
446	them to different devices.  Useful for testing.
447
448	If unsure, say N.
449
450config DM_UEVENT
451	bool "DM uevents"
452	depends on BLK_DEV_DM
453	---help---
454	Generate udev events for DM events.
455
456config DM_FLAKEY
457       tristate "Flakey target"
458       depends on BLK_DEV_DM
459       ---help---
460         A target that intermittently fails I/O for debugging purposes.
461
462config DM_VERITY
463	tristate "Verity target support"
464	depends on BLK_DEV_DM
465	select CRYPTO
466	select CRYPTO_HASH
467	select DM_BUFIO
468	---help---
469	  This device-mapper target creates a read-only device that
470	  transparently validates the data on one underlying device against
471	  a pre-generated tree of cryptographic checksums stored on a second
472	  device.
473
474	  You'll need to activate the digests you're going to use in the
475	  cryptoapi configuration.
476
477	  To compile this code as a module, choose M here: the module will
478	  be called dm-verity.
479
480	  If unsure, say N.
481
482config DM_VERITY_FEC
483	bool "Verity forward error correction support"
484	depends on DM_VERITY
485	select REED_SOLOMON
486	select REED_SOLOMON_DEC8
487	---help---
488	  Add forward error correction support to dm-verity. This option
489	  makes it possible to use pre-generated error correction data to
490	  recover from corrupted blocks.
491
492	  If unsure, say N.
493
494config DM_SWITCH
495	tristate "Switch target support (EXPERIMENTAL)"
496	depends on BLK_DEV_DM
497	---help---
498	  This device-mapper target creates a device that supports an arbitrary
499	  mapping of fixed-size regions of I/O across a fixed set of paths.
500	  The path used for any specific region can be switched dynamically
501	  by sending the target a message.
502
503	  To compile this code as a module, choose M here: the module will
504	  be called dm-switch.
505
506	  If unsure, say N.
507
508config DM_LOG_WRITES
509	tristate "Log writes target support"
510	depends on BLK_DEV_DM
511	---help---
512	  This device-mapper target takes two devices, one device to use
513	  normally, one to log all write operations done to the first device.
514	  This is for use by file system developers wishing to verify that
515	  their fs is writing a consistent file system at all times by allowing
516	  them to replay the log in a variety of ways and to check the
517	  contents.
518
519	  To compile this code as a module, choose M here: the module will
520	  be called dm-log-writes.
521
522	  If unsure, say N.
523
524config DM_INTEGRITY
525	tristate "Integrity target support"
526	depends on BLK_DEV_DM
527	select BLK_DEV_INTEGRITY
528	select DM_BUFIO
529	select CRYPTO
530	select ASYNC_XOR
531	---help---
532	  This device-mapper target emulates a block device that has
533	  additional per-sector tags that can be used for storing
534	  integrity information.
535
536	  This integrity target is used with the dm-crypt target to
537	  provide authenticated disk encryption or it can be used
538	  standalone.
539
540	  To compile this code as a module, choose M here: the module will
541	  be called dm-integrity.
542
543config DM_ZONED
544	tristate "Drive-managed zoned block device target support"
545	depends on BLK_DEV_DM
546	depends on BLK_DEV_ZONED
547	---help---
548	  This device-mapper target takes a host-managed or host-aware zoned
549	  block device and exposes most of its capacity as a regular block
550	  device (drive-managed zoned block device) without any write
551	  constraints. This is mainly intended for use with file systems that
552	  do not natively support zoned block devices but still want to
553	  benefit from the increased capacity offered by SMR disks. Other uses
554	  by applications using raw block devices (for example object stores)
555	  are also possible.
556
557	  To compile this code as a module, choose M here: the module will
558	  be called dm-zoned.
559
560	  If unsure, say N.
561
562endif # MD
563