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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