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_DEV_BSG
  53         bool "Block layer SG support v4"
  54         default y
  55         help
  56           Saying Y here will enable generic SG (SCSI generic) v4 support
  57           for any block device.
  58
  59           Unlike SG v3 (aka block/scsi_ioctl.c drivers/scsi/sg.c), SG v4
  60           can handle complicated SCSI commands: tagged variable length cdbs
  61           with bidirectional data transfers and generic request/response
  62           protocols (e.g. Task Management Functions and SMP in Serial
  63           Attached SCSI).
  64
  65           This option is required by recent UDEV versions to properly
  66           access device serial numbers, etc.
  67
  68           If unsure, say Y.
  69
  70 config BLK_DEV_BSGLIB
  71         bool "Block layer SG support v4 helper lib"
  72         default n
  73         select BLK_DEV_BSG
  74         help
  75           Subsystems will normally enable this if needed. Users will not
  76           normally need to manually enable this.
  77
  78           If unsure, say N.
  79
  80 config BLK_DEV_INTEGRITY
  81         bool "Block layer data integrity support"
  82         select CRC_T10DIF if BLK_DEV_INTEGRITY
  83         ---help---
  84         Some storage devices allow extra information to be
  85         stored/retrieved to help protect the data.  The block layer
  86         data integrity option provides hooks which can be used by
  87         filesystems to ensure better data integrity.
  88
  89         Say yes here if you have a storage device that provides the
  90         T10/SCSI Data Integrity Field or the T13/ATA External Path
  91         Protection.  If in doubt, say N.
  92
  93 config BLK_DEV_ZONED
  94         bool "Zoned block device support"
  95         ---help---
  96         Block layer zoned block device support. This option enables
  97         support for ZAC/ZBC host-managed and host-aware zoned block devices.
  98
  99         Say yes here if you have a ZAC or ZBC storage device.
 100
 101 config BLK_DEV_THROTTLING
 102         bool "Block layer bio throttling support"
 103         depends on BLK_CGROUP=y
 104         default n
 105         ---help---
 106         Block layer bio throttling support. It can be used to limit
 107         the IO rate to a device. IO rate policies are per cgroup and
 108         one needs to mount and use blkio cgroup controller for creating
 109         cgroups and specifying per device IO rate policies.
 110
 111         See Documentation/cgroups/blkio-controller.txt for more information.
 112
 113 config BLK_CMDLINE_PARSER
 114         bool "Block device command line partition parser"
 115         default n
 116         ---help---
 117         Enabling this option allows you to specify the partition layout from
 118         the kernel boot args.  This is typically of use for embedded devices
 119         which don't otherwise have any standardized method for listing the
 120         partitions on a block device.
 121
 122         See Documentation/block/cmdline-partition.txt for more information.
 123
 124 config BLK_WBT
 125         bool "Enable support for block device writeback throttling"
 126         default n
 127         ---help---
 128         Enabling this option enables the block layer to throttle buffered
 129         background writeback from the VM, making it more smooth and having
 130         less impact on foreground operations. The throttling is done
 131         dynamically on an algorithm loosely based on CoDel, factoring in
 132         the realtime performance of the disk.
 133
 134 config BLK_WBT_SQ
 135         bool "Single queue writeback throttling"
 136         default n
 137         depends on BLK_WBT
 138         ---help---
 139         Enable writeback throttling by default on legacy single queue devices
 140
 141 config BLK_WBT_MQ
 142         bool "Multiqueue writeback throttling"
 143         default y
 144         depends on BLK_WBT
 145         ---help---
 146         Enable writeback throttling by default on multiqueue devices.
 147         Multiqueue currently doesn't have support for IO scheduling,
 148         enabling this option is recommended.
 149
 150 menu "Partition Types"
 151
 152 source "block/partitions/Kconfig"
 153
 154 endmenu
 155
 156 endif # BLOCK
 157
 158 config BLOCK_COMPAT
 159         bool
 160         depends on BLOCK && COMPAT
 161         default y
 162
 163 config BLK_MQ_PCI
 164         bool
 165         depends on BLOCK && PCI
 166         default y
 167
 168 source block/Kconfig.iosched