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