block/Kconfig

   1 # SPDX-License-Identifier: GPL-2.0
   2 #
   3 # Block layer core configuration
   4 #
   5 menuconfig 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
  27 if BLOCK
  28
  29 config 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
  39 config BLK_RQ_ALLOC_TIME
  40         bool
  41
  42 config BLK_CGROUP_RWSTAT
  43         bool
  44
  45 config BLK_CGROUP_PUNT_BIO
  46         bool
  47
  48 config BLK_DEV_BSG_COMMON
  49         tristate
  50
  51 config BLK_ICQ
  52         bool
  53
  54 config 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
  63 config 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
  75 config BLK_DEV_INTEGRITY_T10
  76         tristate
  77         depends on BLK_DEV_INTEGRITY
  78         select CRC_T10DIF
  79         select CRC64_ROCKSOFT
  80
  81 config 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
 101 config 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
 111 config 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
 123 config 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
 134 config 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
 143 config 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
 150 config 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
 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
 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
 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
 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
 180 config 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
 189 config 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
 201 config BLK_DEBUG_FS_ZONED
 202        bool
 203        default BLK_DEBUG_FS && BLK_DEV_ZONED
 204
 205 config 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
 215 config 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
 222 config 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
 232 source "block/partitions/Kconfig"
 233
 234 config BLK_MQ_PCI
 235         def_bool PCI
 236
 237 config BLK_MQ_VIRTIO
 238         bool
 239         depends on VIRTIO
 240         default y
 241
 242 config BLK_PM
 243         def_bool PM
 244
 245 # do not use in new code
 246 config BLOCK_HOLDER_DEPRECATED
 247         bool
 248
 249 config BLK_MQ_STACKING
 250         bool
 251
 252 source "block/Kconfig.iosched"
 253
 254 endif # BLOCK