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 help 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. 70 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. 74 75config BLK_DEV_INTEGRITY_T10 76 tristate 77 depends on BLK_DEV_INTEGRITY 78 select CRC_T10DIF 79 select CRC64_ROCKSOFT 80 81config BLK_DEV_WRITE_MOUNTED 82 bool "Allow writing to mounted block devices" 83 default y 84 help 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. 100 101config BLK_DEV_ZONED 102 bool "Zoned block device support" 103 select MQ_IOSCHED_DEADLINE 104 help 105 Block layer zoned block device support. This option enables 106 support for ZAC/ZBC/ZNS host-managed and host-aware zoned block 107 devices. 108 109 Say yes here if you have a ZAC, ZBC, or ZNS storage device. 110 111config BLK_DEV_THROTTLING 112 bool "Block layer bio throttling support" 113 depends on BLK_CGROUP 114 select BLK_CGROUP_RWSTAT 115 help 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. 120 121 See Documentation/admin-guide/cgroup-v1/blkio-controller.rst for more information. 122 123config BLK_DEV_THROTTLING_LOW 124 bool "Block throttling .low limit interface support (EXPERIMENTAL)" 125 depends on BLK_DEV_THROTTLING 126 help 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. 131 132 Note, this is an experimental interface and could be changed someday. 133 134config BLK_WBT 135 bool "Enable support for block device writeback throttling" 136 help 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. 142 143config BLK_WBT_MQ 144 bool "Enable writeback throttling by default" 145 default y 146 depends on BLK_WBT 147 help 148 Enable writeback throttling by default for request-based block devices. 149 150config BLK_CGROUP_IOLATENCY 151 bool "Enable support for latency based cgroup IO protection" 152 depends on BLK_CGROUP 153 help 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. 158 159 Note, this is an experimental interface and could be changed someday. 160 161config BLK_CGROUP_FC_APPID 162 bool "Enable support to track FC I/O Traffic across cgroup applications" 163 depends on BLK_CGROUP && NVME_FC 164 help 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. 169 170config 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 174 help 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. 179 180config BLK_CGROUP_IOPRIO 181 bool "Cgroup I/O controller for assigning an I/O priority class" 182 depends on BLK_CGROUP 183 help 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. 188 189config BLK_DEBUG_FS 190 bool "Block layer debugging information in debugfs" 191 default y 192 depends on DEBUG_FS 193 help 194 Include block layer debugging information in debugfs. This information 195 is mostly useful for kernel developers, but it doesn't incur any cost 196 at runtime. 197 198 Unless you are building a kernel for a tiny system, you should 199 say Y here. 200 201config BLK_DEBUG_FS_ZONED 202 bool 203 default BLK_DEBUG_FS && BLK_DEV_ZONED 204 205config BLK_SED_OPAL 206 bool "Logic for interfacing with Opal enabled SEDs" 207 depends on KEYS 208 select PSERIES_PLPKS if PPC_PSERIES 209 select PSERIES_PLPKS_SED if PPC_PSERIES 210 help 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. 214 215config BLK_INLINE_ENCRYPTION 216 bool "Enable inline encryption support in block layer" 217 help 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. 221 222config BLK_INLINE_ENCRYPTION_FALLBACK 223 bool "Enable crypto API fallback for blk-crypto" 224 depends on BLK_INLINE_ENCRYPTION 225 select CRYPTO 226 select CRYPTO_SKCIPHER 227 help 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. 231 232source "block/partitions/Kconfig" 233 234config BLK_MQ_PCI 235 def_bool PCI 236 237config BLK_MQ_VIRTIO 238 bool 239 depends on VIRTIO 240 default y 241 242config BLK_PM 243 def_bool PM 244 245# do not use in new code 246config BLOCK_HOLDER_DEPRECATED 247 bool 248 249config BLK_MQ_STACKING 250 bool 251 252source "block/Kconfig.iosched" 253 254endif # BLOCK 255