xref: /linux/block/Kconfig (revision a1ff5a7d78a036d6c2178ee5acd6ba4946243800)
1# SPDX-License-Identifier: GPL-2.0
2#
3# Block layer core configuration
4#
5menuconfig BLOCK
6       bool "Enable the block layer" if EXPERT
7       default y
8       select FS_IOMAP
9       select SBITMAP
10       help
11	 Provide block layer support for the kernel.
12
13	 Disable this option to remove the block layer support from the
14	 kernel. This may be useful for embedded devices.
15
16	 If this option is disabled:
17
18	   - block device files will become unusable
19	   - some filesystems (such as ext3) will become unavailable.
20
21	 Also, SCSI character devices and USB storage will be disabled since
22	 they make use of various block layer definitions and facilities.
23
24	 Say Y here unless you know you really don't want to mount disks and
25	 suchlike.
26
27if BLOCK
28
29config BLOCK_LEGACY_AUTOLOAD
30	bool "Legacy autoloading support"
31	default y
32	help
33	  Enable loading modules and creating block device instances based on
34	  accesses through their device special file.  This is a historic Linux
35	  feature and makes no sense in a udev world where device files are
36	  created on demand, but scripts that manually create device nodes and
37	  then call losetup might rely on this behavior.
38
39config BLK_RQ_ALLOC_TIME
40	bool
41
42config BLK_CGROUP_RWSTAT
43	bool
44
45config BLK_CGROUP_PUNT_BIO
46	bool
47
48config BLK_DEV_BSG_COMMON
49	tristate
50
51config BLK_ICQ
52	bool
53
54config BLK_DEV_BSGLIB
55	bool "Block layer SG support v4 helper lib"
56	select BLK_DEV_BSG_COMMON
57	help
58	  Subsystems will normally enable this if needed. Users will not
59	  normally need to manually enable this.
60
61	  If unsure, say N.
62
63config BLK_DEV_INTEGRITY
64	bool "Block layer data integrity support"
65	select CRC_T10DIF
66	select CRC64_ROCKSOFT
67	help
68	Some storage devices allow extra information to be
69	stored/retrieved to help protect the data.  The block layer
70	data integrity option provides hooks which can be used by
71	filesystems to ensure better data integrity.
72
73	Say yes here if you have a storage device that provides the
74	T10/SCSI Data Integrity Field or the T13/ATA External Path
75	Protection.  If in doubt, say N.
76
77config BLK_DEV_WRITE_MOUNTED
78	bool "Allow writing to mounted block devices"
79	default y
80	help
81	When a block device is mounted, writing to its buffer cache is very
82	likely going to cause filesystem corruption. It is also rather easy to
83	crash the kernel in this way since the filesystem has no practical way
84	of detecting these writes to buffer cache and verifying its metadata
85	integrity. However there are some setups that need this capability
86	like running fsck on read-only mounted root device, modifying some
87	features on mounted ext4 filesystem, and similar. If you say N, the
88	kernel will prevent processes from writing to block devices that are
89	mounted by filesystems which provides some more protection from runaway
90	privileged processes and generally makes it much harder to crash
91	filesystem drivers. Note however that this does not prevent
92	underlying device(s) from being modified by other means, e.g. by
93	directly submitting SCSI commands or through access to lower layers of
94	storage stack. If in doubt, say Y. The configuration can be overridden
95	with the bdev_allow_write_mounted boot option.
96
97config BLK_DEV_ZONED
98	bool "Zoned block device support"
99	help
100	Block layer zoned block device support. This option enables
101	support for ZAC/ZBC/ZNS host-managed and host-aware zoned block
102	devices.
103
104	Say yes here if you have a ZAC, ZBC, or ZNS storage device.
105
106config BLK_DEV_THROTTLING
107	bool "Block layer bio throttling support"
108	depends on BLK_CGROUP
109	select BLK_CGROUP_RWSTAT
110	help
111	Block layer bio throttling support. It can be used to limit
112	the IO rate to a device. IO rate policies are per cgroup and
113	one needs to mount and use blkio cgroup controller for creating
114	cgroups and specifying per device IO rate policies.
115
116	See Documentation/admin-guide/cgroup-v1/blkio-controller.rst for more information.
117
118config BLK_WBT
119	bool "Enable support for block device writeback throttling"
120	help
121	Enabling this option enables the block layer to throttle buffered
122	background writeback from the VM, making it more smooth and having
123	less impact on foreground operations. The throttling is done
124	dynamically on an algorithm loosely based on CoDel, factoring in
125	the realtime performance of the disk.
126
127config BLK_WBT_MQ
128	bool "Enable writeback throttling by default"
129	default y
130	depends on BLK_WBT
131	help
132	Enable writeback throttling by default for request-based block devices.
133
134config BLK_CGROUP_IOLATENCY
135	bool "Enable support for latency based cgroup IO protection"
136	depends on BLK_CGROUP
137	help
138	Enabling this option enables the .latency interface for IO throttling.
139	The IO controller will attempt to maintain average IO latencies below
140	the configured latency target, throttling anybody with a higher latency
141	target than the victimized group.
142
143	Note, this is an experimental interface and could be changed someday.
144
145config BLK_CGROUP_FC_APPID
146	bool "Enable support to track FC I/O Traffic across cgroup applications"
147	depends on BLK_CGROUP && NVME_FC
148	help
149	  Enabling this option enables the support to track FC I/O traffic across
150	  cgroup applications. It enables the Fabric and the storage targets to
151	  identify, monitor, and handle FC traffic based on VM tags by inserting
152	  application specific identification into the FC frame.
153
154config BLK_CGROUP_IOCOST
155	bool "Enable support for cost model based cgroup IO controller"
156	depends on BLK_CGROUP
157	select BLK_RQ_ALLOC_TIME
158	help
159	Enabling this option enables the .weight interface for cost
160	model based proportional IO control.  The IO controller
161	distributes IO capacity between different groups based on
162	their share of the overall weight distribution.
163
164config BLK_CGROUP_IOPRIO
165	bool "Cgroup I/O controller for assigning an I/O priority class"
166	depends on BLK_CGROUP
167	help
168	Enable the .prio interface for assigning an I/O priority class to
169	requests. The I/O priority class affects the order in which an I/O
170	scheduler and block devices process requests. Only some I/O schedulers
171	and some block devices support I/O priorities.
172
173config BLK_DEBUG_FS
174	bool "Block layer debugging information in debugfs"
175	default y
176	depends on DEBUG_FS
177	help
178	Include block layer debugging information in debugfs. This information
179	is mostly useful for kernel developers, but it doesn't incur any cost
180	at runtime.
181
182	Unless you are building a kernel for a tiny system, you should
183	say Y here.
184
185config BLK_SED_OPAL
186	bool "Logic for interfacing with Opal enabled SEDs"
187	depends on KEYS
188	select PSERIES_PLPKS if PPC_PSERIES
189	select PSERIES_PLPKS_SED if PPC_PSERIES
190	help
191	Builds Logic for interfacing with Opal enabled controllers.
192	Enabling this option enables users to setup/unlock/lock
193	Locking ranges for SED devices using the Opal protocol.
194
195config BLK_INLINE_ENCRYPTION
196	bool "Enable inline encryption support in block layer"
197	help
198	  Build the blk-crypto subsystem. Enabling this lets the
199	  block layer handle encryption, so users can take
200	  advantage of inline encryption hardware if present.
201
202config BLK_INLINE_ENCRYPTION_FALLBACK
203	bool "Enable crypto API fallback for blk-crypto"
204	depends on BLK_INLINE_ENCRYPTION
205	select CRYPTO
206	select CRYPTO_SKCIPHER
207	help
208	  Enabling this lets the block layer handle inline encryption
209	  by falling back to the kernel crypto API when inline
210	  encryption hardware is not present.
211
212source "block/partitions/Kconfig"
213
214config BLK_MQ_PCI
215	def_bool PCI
216
217config BLK_MQ_VIRTIO
218	bool
219	depends on VIRTIO
220	default y
221
222config BLK_PM
223	def_bool PM
224
225# do not use in new code
226config BLOCK_HOLDER_DEPRECATED
227	bool
228
229config BLK_MQ_STACKING
230	bool
231
232source "block/Kconfig.iosched"
233
234endif # BLOCK
235