| # | 
 | # 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_DAX | 
 | 	bool "Block device DAX support" | 
 | 	depends on FS_DAX | 
 | 	depends on BROKEN | 
 | 	help | 
 | 	  When DAX support is available (CONFIG_FS_DAX) raw block | 
 | 	  devices can also support direct userspace access to the | 
 | 	  storage capacity via MMAP(2) similar to a file on a | 
 | 	  DAX-enabled filesystem.  However, the DAX I/O-path disables | 
 | 	  some standard I/O-statistics, and the MMAP(2) path has some | 
 | 	  operational differences due to bypassing the page | 
 | 	  cache.  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 |