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 help 104 Block layer zoned block device support. This option enables 105 support for ZAC/ZBC/ZNS host-managed and host-aware zoned block 106 devices. 107 108 Say yes here if you have a ZAC, ZBC, or ZNS storage device. 109 110config BLK_DEV_THROTTLING 111 bool "Block layer bio throttling support" 112 depends on BLK_CGROUP 113 select BLK_CGROUP_RWSTAT 114 help 115 Block layer bio throttling support. It can be used to limit 116 the IO rate to a device. IO rate policies are per cgroup and 117 one needs to mount and use blkio cgroup controller for creating 118 cgroups and specifying per device IO rate policies. 119 120 See Documentation/admin-guide/cgroup-v1/blkio-controller.rst for more information. 121 122config BLK_WBT 123 bool "Enable support for block device writeback throttling" 124 help 125 Enabling this option enables the block layer to throttle buffered 126 background writeback from the VM, making it more smooth and having 127 less impact on foreground operations. The throttling is done 128 dynamically on an algorithm loosely based on CoDel, factoring in 129 the realtime performance of the disk. 130 131config BLK_WBT_MQ 132 bool "Enable writeback throttling by default" 133 default y 134 depends on BLK_WBT 135 help 136 Enable writeback throttling by default for request-based block devices. 137 138config BLK_CGROUP_IOLATENCY 139 bool "Enable support for latency based cgroup IO protection" 140 depends on BLK_CGROUP 141 help 142 Enabling this option enables the .latency interface for IO throttling. 143 The IO controller will attempt to maintain average IO latencies below 144 the configured latency target, throttling anybody with a higher latency 145 target than the victimized group. 146 147 Note, this is an experimental interface and could be changed someday. 148 149config BLK_CGROUP_FC_APPID 150 bool "Enable support to track FC I/O Traffic across cgroup applications" 151 depends on BLK_CGROUP && NVME_FC 152 help 153 Enabling this option enables the support to track FC I/O traffic across 154 cgroup applications. It enables the Fabric and the storage targets to 155 identify, monitor, and handle FC traffic based on VM tags by inserting 156 application specific identification into the FC frame. 157 158config BLK_CGROUP_IOCOST 159 bool "Enable support for cost model based cgroup IO controller" 160 depends on BLK_CGROUP 161 select BLK_RQ_ALLOC_TIME 162 help 163 Enabling this option enables the .weight interface for cost 164 model based proportional IO control. The IO controller 165 distributes IO capacity between different groups based on 166 their share of the overall weight distribution. 167 168config BLK_CGROUP_IOPRIO 169 bool "Cgroup I/O controller for assigning an I/O priority class" 170 depends on BLK_CGROUP 171 help 172 Enable the .prio interface for assigning an I/O priority class to 173 requests. The I/O priority class affects the order in which an I/O 174 scheduler and block devices process requests. Only some I/O schedulers 175 and some block devices support I/O priorities. 176 177config BLK_DEBUG_FS 178 bool "Block layer debugging information in debugfs" 179 default y 180 depends on DEBUG_FS 181 help 182 Include block layer debugging information in debugfs. This information 183 is mostly useful for kernel developers, but it doesn't incur any cost 184 at runtime. 185 186 Unless you are building a kernel for a tiny system, you should 187 say Y here. 188 189config BLK_SED_OPAL 190 bool "Logic for interfacing with Opal enabled SEDs" 191 depends on KEYS 192 select PSERIES_PLPKS if PPC_PSERIES 193 select PSERIES_PLPKS_SED if PPC_PSERIES 194 help 195 Builds Logic for interfacing with Opal enabled controllers. 196 Enabling this option enables users to setup/unlock/lock 197 Locking ranges for SED devices using the Opal protocol. 198 199config BLK_INLINE_ENCRYPTION 200 bool "Enable inline encryption support in block layer" 201 help 202 Build the blk-crypto subsystem. Enabling this lets the 203 block layer handle encryption, so users can take 204 advantage of inline encryption hardware if present. 205 206config BLK_INLINE_ENCRYPTION_FALLBACK 207 bool "Enable crypto API fallback for blk-crypto" 208 depends on BLK_INLINE_ENCRYPTION 209 select CRYPTO 210 select CRYPTO_SKCIPHER 211 help 212 Enabling this lets the block layer handle inline encryption 213 by falling back to the kernel crypto API when inline 214 encryption hardware is not present. 215 216source "block/partitions/Kconfig" 217 218config BLK_MQ_PCI 219 def_bool PCI 220 221config BLK_MQ_VIRTIO 222 bool 223 depends on VIRTIO 224 default y 225 226config BLK_PM 227 def_bool PM 228 229# do not use in new code 230config BLOCK_HOLDER_DEPRECATED 231 bool 232 233config BLK_MQ_STACKING 234 bool 235 236source "block/Kconfig.iosched" 237 238endif # BLOCK 239