|  | # | 
|  | # Block layer core configuration | 
|  | # | 
|  | menuconfig BLOCK | 
|  | bool "Enable the block layer" if EXPERT | 
|  | default y | 
|  | help | 
|  | Provide block layer support for the kernel. | 
|  |  | 
|  | Disable this option to remove the block layer support from the | 
|  | kernel. This may be useful for embedded devices. | 
|  |  | 
|  | If this option is disabled: | 
|  |  | 
|  | - block device files will become unusable | 
|  | - some filesystems (such as ext3) will become unavailable. | 
|  |  | 
|  | Also, SCSI character devices and USB storage will be disabled since | 
|  | they make use of various block layer definitions and facilities. | 
|  |  | 
|  | Say Y here unless you know you really don't want to mount disks and | 
|  | suchlike. | 
|  |  | 
|  | if BLOCK | 
|  |  | 
|  | config LBDAF | 
|  | bool "Support for large (2TB+) block devices and files" | 
|  | depends on !64BIT | 
|  | default y | 
|  | help | 
|  | Enable block devices or files of size 2TB and larger. | 
|  |  | 
|  | This option is required to support the full capacity of large | 
|  | (2TB+) block devices, including RAID, disk, Network Block Device, | 
|  | Logical Volume Manager (LVM) and loopback. | 
|  |  | 
|  | This option also enables support for single files larger than | 
|  | 2TB. | 
|  |  | 
|  | The ext4 filesystem requires that this feature be enabled in | 
|  | order to support filesystems that have the huge_file feature | 
|  | enabled.  Otherwise, it will refuse to mount in the read-write | 
|  | mode any filesystems that use the huge_file feature, which is | 
|  | enabled by default by mke2fs.ext4. | 
|  |  | 
|  | The GFS2 filesystem also requires this feature. | 
|  |  | 
|  | If unsure, say Y. | 
|  |  | 
|  | config BLK_DEV_BSG | 
|  | bool "Block layer SG support v4" | 
|  | default y | 
|  | help | 
|  | Saying Y here will enable generic SG (SCSI generic) v4 support | 
|  | for any block device. | 
|  |  | 
|  | Unlike SG v3 (aka block/scsi_ioctl.c drivers/scsi/sg.c), SG v4 | 
|  | can handle complicated SCSI commands: tagged variable length cdbs | 
|  | with bidirectional data transfers and generic request/response | 
|  | protocols (e.g. Task Management Functions and SMP in Serial | 
|  | Attached SCSI). | 
|  |  | 
|  | This option is required by recent UDEV versions to properly | 
|  | access device serial numbers, etc. | 
|  |  | 
|  | If unsure, say Y. | 
|  |  | 
|  | config BLK_DEV_BSGLIB | 
|  | bool "Block layer SG support v4 helper lib" | 
|  | default n | 
|  | select BLK_DEV_BSG | 
|  | help | 
|  | Subsystems will normally enable this if needed. Users will not | 
|  | normally need to manually enable this. | 
|  |  | 
|  | If unsure, say N. | 
|  |  | 
|  | config BLK_DEV_INTEGRITY | 
|  | bool "Block layer data integrity support" | 
|  | select CRC_T10DIF if BLK_DEV_INTEGRITY | 
|  | ---help--- | 
|  | Some storage devices allow extra information to be | 
|  | stored/retrieved to help protect the data.  The block layer | 
|  | data integrity option provides hooks which can be used by | 
|  | filesystems to ensure better data integrity. | 
|  |  | 
|  | Say yes here if you have a storage device that provides the | 
|  | T10/SCSI Data Integrity Field or the T13/ATA External Path | 
|  | Protection.  If in doubt, say N. | 
|  |  | 
|  | config BLK_DEV_THROTTLING | 
|  | bool "Block layer bio throttling support" | 
|  | depends on BLK_CGROUP=y | 
|  | default n | 
|  | ---help--- | 
|  | Block layer bio throttling support. It can be used to limit | 
|  | the IO rate to a device. IO rate policies are per cgroup and | 
|  | one needs to mount and use blkio cgroup controller for creating | 
|  | cgroups and specifying per device IO rate policies. | 
|  |  | 
|  | See Documentation/cgroups/blkio-controller.txt for more information. | 
|  |  | 
|  | config BLK_CMDLINE_PARSER | 
|  | bool "Block device command line partition parser" | 
|  | default n | 
|  | ---help--- | 
|  | Enabling this option allows you to specify the partition layout from | 
|  | the kernel boot args.  This is typically of use for embedded devices | 
|  | which don't otherwise have any standardized method for listing the | 
|  | partitions on a block device. | 
|  |  | 
|  | See Documentation/block/cmdline-partition.txt for more information. | 
|  |  | 
|  | menu "Partition Types" | 
|  |  | 
|  | source "block/partitions/Kconfig" | 
|  |  | 
|  | endmenu | 
|  |  | 
|  | endif # BLOCK | 
|  |  | 
|  | config BLOCK_COMPAT | 
|  | bool | 
|  | depends on BLOCK && COMPAT | 
|  | default y | 
|  |  | 
|  | source block/Kconfig.iosched |