1 # SPDX-License-Identifier: GPL-2.0
3 # Block layer core configuration
6 bool "Enable the block layer" if EXPERT
11 Provide block layer support for the kernel.
13 Disable this option to remove the block layer support from the
14 kernel. This may be useful for embedded devices.
16 If this option is disabled:
18 - block device files will become unusable
19 - some filesystems (such as ext3) will become unavailable.
21 Also, SCSI character devices and USB storage will be disabled since
22 they make use of various block layer definitions and facilities.
24 Say Y here unless you know you really don't want to mount disks and
29 config BLOCK_LEGACY_AUTOLOAD
30 bool "Legacy autoloading support"
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.
39 config BLK_RQ_ALLOC_TIME
42 config BLK_CGROUP_RWSTAT
45 config BLK_CGROUP_PUNT_BIO
48 config BLK_DEV_BSG_COMMON
55 bool "Block layer SG support v4 helper lib"
56 select BLK_DEV_BSG_COMMON
58 Subsystems will normally enable this if needed. Users will not
59 normally need to manually enable this.
63 config BLK_DEV_INTEGRITY
64 bool "Block layer data integrity support"
66 Some storage devices allow extra information to be
67 stored/retrieved to help protect the data. The block layer
68 data integrity option provides hooks which can be used by
69 filesystems to ensure better data integrity.
71 Say yes here if you have a storage device that provides the
72 T10/SCSI Data Integrity Field or the T13/ATA External Path
73 Protection. If in doubt, say N.
75 config BLK_DEV_INTEGRITY_T10
77 depends on BLK_DEV_INTEGRITY
81 config BLK_DEV_WRITE_MOUNTED
82 bool "Allow writing to mounted block devices"
85 When a block device is mounted, writing to its buffer cache is very
86 likely going to cause filesystem corruption. It is also rather easy to
87 crash the kernel in this way since the filesystem has no practical way
88 of detecting these writes to buffer cache and verifying its metadata
89 integrity. However there are some setups that need this capability
90 like running fsck on read-only mounted root device, modifying some
91 features on mounted ext4 filesystem, and similar. If you say N, the
92 kernel will prevent processes from writing to block devices that are
93 mounted by filesystems which provides some more protection from runaway
94 privileged processes and generally makes it much harder to crash
95 filesystem drivers. Note however that this does not prevent
96 underlying device(s) from being modified by other means, e.g. by
97 directly submitting SCSI commands or through access to lower layers of
98 storage stack. If in doubt, say Y. The configuration can be overridden
99 with the bdev_allow_write_mounted boot option.
102 bool "Zoned block device support"
103 select MQ_IOSCHED_DEADLINE
105 Block layer zoned block device support. This option enables
106 support for ZAC/ZBC/ZNS host-managed and host-aware zoned block
109 Say yes here if you have a ZAC, ZBC, or ZNS storage device.
111 config BLK_DEV_THROTTLING
112 bool "Block layer bio throttling support"
113 depends on BLK_CGROUP
114 select BLK_CGROUP_RWSTAT
116 Block layer bio throttling support. It can be used to limit
117 the IO rate to a device. IO rate policies are per cgroup and
118 one needs to mount and use blkio cgroup controller for creating
119 cgroups and specifying per device IO rate policies.
121 See Documentation/admin-guide/cgroup-v1/blkio-controller.rst for more information.
123 config BLK_DEV_THROTTLING_LOW
124 bool "Block throttling .low limit interface support (EXPERIMENTAL)"
125 depends on BLK_DEV_THROTTLING
127 Add .low limit interface for block throttling. The low limit is a best
128 effort limit to prioritize cgroups. Depending on the setting, the limit
129 can be used to protect cgroups in terms of bandwidth/iops and better
130 utilize disk resource.
132 Note, this is an experimental interface and could be changed someday.
135 bool "Enable support for block device writeback throttling"
137 Enabling this option enables the block layer to throttle buffered
138 background writeback from the VM, making it more smooth and having
139 less impact on foreground operations. The throttling is done
140 dynamically on an algorithm loosely based on CoDel, factoring in
141 the realtime performance of the disk.
144 bool "Enable writeback throttling by default"
148 Enable writeback throttling by default for request-based block devices.
150 config BLK_CGROUP_IOLATENCY
151 bool "Enable support for latency based cgroup IO protection"
152 depends on BLK_CGROUP
154 Enabling this option enables the .latency interface for IO throttling.
155 The IO controller will attempt to maintain average IO latencies below
156 the configured latency target, throttling anybody with a higher latency
157 target than the victimized group.
159 Note, this is an experimental interface and could be changed someday.
161 config BLK_CGROUP_FC_APPID
162 bool "Enable support to track FC I/O Traffic across cgroup applications"
163 depends on BLK_CGROUP && NVME_FC
165 Enabling this option enables the support to track FC I/O traffic across
166 cgroup applications. It enables the Fabric and the storage targets to
167 identify, monitor, and handle FC traffic based on VM tags by inserting
168 application specific identification into the FC frame.
170 config BLK_CGROUP_IOCOST
171 bool "Enable support for cost model based cgroup IO controller"
172 depends on BLK_CGROUP
173 select BLK_RQ_ALLOC_TIME
175 Enabling this option enables the .weight interface for cost
176 model based proportional IO control. The IO controller
177 distributes IO capacity between different groups based on
178 their share of the overall weight distribution.
180 config BLK_CGROUP_IOPRIO
181 bool "Cgroup I/O controller for assigning an I/O priority class"
182 depends on BLK_CGROUP
184 Enable the .prio interface for assigning an I/O priority class to
185 requests. The I/O priority class affects the order in which an I/O
186 scheduler and block devices process requests. Only some I/O schedulers
187 and some block devices support I/O priorities.
190 bool "Block layer debugging information in debugfs"
194 Include block layer debugging information in debugfs. This information
195 is mostly useful for kernel developers, but it doesn't incur any cost
198 Unless you are building a kernel for a tiny system, you should
201 config BLK_DEBUG_FS_ZONED
203 default BLK_DEBUG_FS && BLK_DEV_ZONED
206 bool "Logic for interfacing with Opal enabled SEDs"
208 select PSERIES_PLPKS if PPC_PSERIES
209 select PSERIES_PLPKS_SED if PPC_PSERIES
211 Builds Logic for interfacing with Opal enabled controllers.
212 Enabling this option enables users to setup/unlock/lock
213 Locking ranges for SED devices using the Opal protocol.
215 config BLK_INLINE_ENCRYPTION
216 bool "Enable inline encryption support in block layer"
218 Build the blk-crypto subsystem. Enabling this lets the
219 block layer handle encryption, so users can take
220 advantage of inline encryption hardware if present.
222 config BLK_INLINE_ENCRYPTION_FALLBACK
223 bool "Enable crypto API fallback for blk-crypto"
224 depends on BLK_INLINE_ENCRYPTION
226 select CRYPTO_SKCIPHER
228 Enabling this lets the block layer handle inline encryption
229 by falling back to the kernel crypto API when inline
230 encryption hardware is not present.
232 source "block/partitions/Kconfig"
245 # do not use in new code
246 config BLOCK_HOLDER_DEPRECATED
249 config BLK_MQ_STACKING
252 source "block/Kconfig.iosched"