block/Kconfig

   1 #
   2 # Block layer core configuration
   3 #
   4 menuconfig BLOCK
   5        bool "Enable the block layer" if EXPERT
   6        default y
   7        help
   8          Provide block layer support for the kernel.
   9
  10          Disable this option to remove the block layer support from the
  11          kernel. This may be useful for embedded devices.
  12
  13          If this option is disabled:
  14
  15            - block device files will become unusable
  16            - some filesystems (such as ext3) will become unavailable.
  17
  18          Also, SCSI character devices and USB storage will be disabled since
  19          they make use of various block layer definitions and facilities.
  20
  21          Say Y here unless you know you really don't want to mount disks and
  22          suchlike.
  23
  24 if BLOCK
  25
  26 config LBDAF
  27         bool "Support for large (2TB+) block devices and files"
  28         depends on !64BIT
  29         default y
  30         help
  31           Enable block devices or files of size 2TB and larger.
  32
  33           This option is required to support the full capacity of large
  34           (2TB+) block devices, including RAID, disk, Network Block Device,
  35           Logical Volume Manager (LVM) and loopback.
  36
  37           This option also enables support for single files larger than
  38           2TB.
  39
  40           The ext4 filesystem requires that this feature be enabled in
  41           order to support filesystems that have the huge_file feature
  42           enabled.  Otherwise, it will refuse to mount in the read-write
  43           mode any filesystems that use the huge_file feature, which is
  44           enabled by default by mke2fs.ext4.
  45
  46           The GFS2 filesystem also requires this feature.
  47
  48           If unsure, say Y.
  49
  50 config BLK_DEV_BSG
  51         bool "Block layer SG support v4"
  52         default y
  53         help
  54           Saying Y here will enable generic SG (SCSI generic) v4 support
  55           for any block device.
  56
  57           Unlike SG v3 (aka block/scsi_ioctl.c drivers/scsi/sg.c), SG v4
  58           can handle complicated SCSI commands: tagged variable length cdbs
  59           with bidirectional data transfers and generic request/response
  60           protocols (e.g. Task Management Functions and SMP in Serial
  61           Attached SCSI).
  62
  63           This option is required by recent UDEV versions to properly
  64           access device serial numbers, etc.
  65
  66           If unsure, say Y.
  67
  68 config BLK_DEV_BSGLIB
  69         bool "Block layer SG support v4 helper lib"
  70         default n
  71         select BLK_DEV_BSG
  72         help
  73           Subsystems will normally enable this if needed. Users will not
  74           normally need to manually enable this.
  75
  76           If unsure, say N.
  77
  78 config BLK_DEV_INTEGRITY
  79         bool "Block layer data integrity support"
  80         select CRC_T10DIF if BLK_DEV_INTEGRITY
  81         ---help---
  82         Some storage devices allow extra information to be
  83         stored/retrieved to help protect the data.  The block layer
  84         data integrity option provides hooks which can be used by
  85         filesystems to ensure better data integrity.
  86
  87         Say yes here if you have a storage device that provides the
  88         T10/SCSI Data Integrity Field or the T13/ATA External Path
  89         Protection.  If in doubt, say N.
  90
  91 config BLK_DEV_DAX
  92         bool "Block device DAX support"
  93         depends on FS_DAX
  94         depends on BROKEN
  95         help
  96           When DAX support is available (CONFIG_FS_DAX) raw block
  97           devices can also support direct userspace access to the
  98           storage capacity via MMAP(2) similar to a file on a
  99           DAX-enabled filesystem.  However, the DAX I/O-path disables
 100           some standard I/O-statistics, and the MMAP(2) path has some
 101           operational differences due to bypassing the page
 102           cache.  If in doubt, say N.
 103
 104 config BLK_DEV_THROTTLING
 105         bool "Block layer bio throttling support"
 106         depends on BLK_CGROUP=y
 107         default n
 108         ---help---
 109         Block layer bio throttling support. It can be used to limit
 110         the IO rate to a device. IO rate policies are per cgroup and
 111         one needs to mount and use blkio cgroup controller for creating
 112         cgroups and specifying per device IO rate policies.
 113
 114         See Documentation/cgroups/blkio-controller.txt for more information.
 115
 116 config BLK_CMDLINE_PARSER
 117         bool "Block device command line partition parser"
 118         default n
 119         ---help---
 120         Enabling this option allows you to specify the partition layout from
 121         the kernel boot args.  This is typically of use for embedded devices
 122         which don't otherwise have any standardized method for listing the
 123         partitions on a block device.
 124
 125         See Documentation/block/cmdline-partition.txt for more information.
 126
 127 menu "Partition Types"
 128
 129 source "block/partitions/Kconfig"
 130
 131 endmenu
 132
 133 endif # BLOCK
 134
 135 config BLOCK_COMPAT
 136         bool
 137         depends on BLOCK && COMPAT
 138         default y
 139
 140 source block/Kconfig.iosched