block/Kconfig

   1 #
   2 # Block layer core configuration
   3 #
   4 menuconfig BLOCK
   5        bool "Enable the block layer" if EXPERT
   6        default y
   7        select SBITMAP
   8        select SRCU
   9        help
  10          Provide block layer support for the kernel.
  11
  12          Disable this option to remove the block layer support from the
  13          kernel. This may be useful for embedded devices.
  14
  15          If this option is disabled:
  16
  17            - block device files will become unusable
  18            - some filesystems (such as ext3) will become unavailable.
  19
  20          Also, SCSI character devices and USB storage will be disabled since
  21          they make use of various block layer definitions and facilities.
  22
  23          Say Y here unless you know you really don't want to mount disks and
  24          suchlike.
  25
  26 if BLOCK
  27
  28 config LBDAF
  29         bool "Support for large (2TB+) block devices and files"
  30         depends on !64BIT
  31         default y
  32         help
  33           Enable block devices or files of size 2TB and larger.
  34
  35           This option is required to support the full capacity of large
  36           (2TB+) block devices, including RAID, disk, Network Block Device,
  37           Logical Volume Manager (LVM) and loopback.
  38
  39           This option also enables support for single files larger than
  40           2TB.
  41
  42           The ext4 filesystem requires that this feature be enabled in
  43           order to support filesystems that have the huge_file feature
  44           enabled.  Otherwise, it will refuse to mount in the read-write
  45           mode any filesystems that use the huge_file feature, which is
  46           enabled by default by mke2fs.ext4.
  47
  48           The GFS2 filesystem also requires this feature.
  49
  50           If unsure, say Y.
  51
  52 config BLK_SCSI_REQUEST
  53         bool
  54
  55 config BLK_DEV_BSG
  56         bool "Block layer SG support v4"
  57         default y
  58         select BLK_SCSI_REQUEST
  59         help
  60           Saying Y here will enable generic SG (SCSI generic) v4 support
  61           for any block device.
  62
  63           Unlike SG v3 (aka block/scsi_ioctl.c drivers/scsi/sg.c), SG v4
  64           can handle complicated SCSI commands: tagged variable length cdbs
  65           with bidirectional data transfers and generic request/response
  66           protocols (e.g. Task Management Functions and SMP in Serial
  67           Attached SCSI).
  68
  69           This option is required by recent UDEV versions to properly
  70           access device serial numbers, etc.
  71
  72           If unsure, say Y.
  73
  74 config BLK_DEV_BSGLIB
  75         bool "Block layer SG support v4 helper lib"
  76         default n
  77         select BLK_DEV_BSG
  78         select BLK_SCSI_REQUEST
  79         help
  80           Subsystems will normally enable this if needed. Users will not
  81           normally need to manually enable this.
  82
  83           If unsure, say N.
  84
  85 config BLK_DEV_INTEGRITY
  86         bool "Block layer data integrity support"
  87         select CRC_T10DIF if BLK_DEV_INTEGRITY
  88         ---help---
  89         Some storage devices allow extra information to be
  90         stored/retrieved to help protect the data.  The block layer
  91         data integrity option provides hooks which can be used by
  92         filesystems to ensure better data integrity.
  93
  94         Say yes here if you have a storage device that provides the
  95         T10/SCSI Data Integrity Field or the T13/ATA External Path
  96         Protection.  If in doubt, say N.
  97
  98 config BLK_DEV_ZONED
  99         bool "Zoned block device support"
 100         ---help---
 101         Block layer zoned block device support. This option enables
 102         support for ZAC/ZBC host-managed and host-aware zoned block devices.
 103
 104         Say yes here if you have a ZAC or ZBC storage device.
 105
 106 config BLK_DEV_THROTTLING
 107         bool "Block layer bio throttling support"
 108         depends on BLK_CGROUP=y
 109         default n
 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/cgroups/blkio-controller.txt for more information.
 117
 118 config BLK_DEV_THROTTLING_LOW
 119         bool "Block throttling .low limit interface support (EXPERIMENTAL)"
 120         depends on BLK_DEV_THROTTLING
 121         default n
 122         ---help---
 123         Add .low limit interface for block throttling. The low limit is a best
 124         effort limit to prioritize cgroups. Depending on the setting, the limit
 125         can be used to protect cgroups in terms of bandwidth/iops and better
 126         utilize disk resource.
 127
 128         Note, this is an experimental interface and could be changed someday.
 129
 130 config BLK_CMDLINE_PARSER
 131         bool "Block device command line partition parser"
 132         default n
 133         ---help---
 134         Enabling this option allows you to specify the partition layout from
 135         the kernel boot args.  This is typically of use for embedded devices
 136         which don't otherwise have any standardized method for listing the
 137         partitions on a block device.
 138
 139         See Documentation/block/cmdline-partition.txt for more information.
 140
 141 config BLK_WBT
 142         bool "Enable support for block device writeback throttling"
 143         default n
 144         ---help---
 145         Enabling this option enables the block layer to throttle buffered
 146         background writeback from the VM, making it more smooth and having
 147         less impact on foreground operations. The throttling is done
 148         dynamically on an algorithm loosely based on CoDel, factoring in
 149         the realtime performance of the disk.
 150
 151 config BLK_WBT_SQ
 152         bool "Single queue writeback throttling"
 153         default n
 154         depends on BLK_WBT
 155         ---help---
 156         Enable writeback throttling by default on legacy single queue devices
 157
 158 config BLK_WBT_MQ
 159         bool "Multiqueue writeback throttling"
 160         default y
 161         depends on BLK_WBT
 162         ---help---
 163         Enable writeback throttling by default on multiqueue devices.
 164         Multiqueue currently doesn't have support for IO scheduling,
 165         enabling this option is recommended.
 166
 167 config BLK_DEBUG_FS
 168         bool "Block layer debugging information in debugfs"
 169         default y
 170         depends on DEBUG_FS
 171         ---help---
 172         Include block layer debugging information in debugfs. This information
 173         is mostly useful for kernel developers, but it doesn't incur any cost
 174         at runtime.
 175
 176         Unless you are building a kernel for a tiny system, you should
 177         say Y here.
 178
 179 config BLK_SED_OPAL
 180         bool "Logic for interfacing with Opal enabled SEDs"
 181         ---help---
 182         Builds Logic for interfacing with Opal enabled controllers.
 183         Enabling this option enables users to setup/unlock/lock
 184         Locking ranges for SED devices using the Opal protocol.
 185
 186 menu "Partition Types"
 187
 188 source "block/partitions/Kconfig"
 189
 190 endmenu
 191
 192 endif # BLOCK
 193
 194 config BLOCK_COMPAT
 195         bool
 196         depends on BLOCK && COMPAT
 197         default y
 198
 199 config BLK_MQ_PCI
 200         bool
 201         depends on BLOCK && PCI
 202         default y
 203
 204 config BLK_MQ_VIRTIO
 205         bool
 206         depends on BLOCK && VIRTIO
 207         default y
 208
 209 source block/Kconfig.iosched