| # | 
 | # Block layer core configuration | 
 | # | 
 | menuconfig BLOCK | 
 |        bool "Enable the block layer" if EMBEDDED | 
 |        default y | 
 |        help | 
 | 	 This permits the block layer to be removed from the kernel if it's not | 
 | 	 needed (on some embedded devices for example).  If this option is | 
 | 	 disabled, then blockdev files will become unusable and some | 
 | 	 filesystems (such as ext3) will become unavailable. | 
 |  | 
 | 	 This option will also disable SCSI character devices and USB storage | 
 | 	 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 LBD | 
 | 	bool "Support for Large Block Devices" | 
 | 	depends on !64BIT | 
 | 	help | 
 | 	  Say Y here if you want to attach large (bigger than 2TB) discs to | 
 | 	  your machine, or if you want to have a raid or loopback device | 
 | 	  bigger than 2TB.  Otherwise say N. | 
 |  | 
 | config BLK_DEV_IO_TRACE | 
 | 	bool "Support for tracing block io actions" | 
 | 	depends on SYSFS | 
 | 	select RELAY | 
 | 	select DEBUG_FS | 
 | 	help | 
 | 	  Say Y here, if you want to be able to trace the block layer actions | 
 | 	  on a given queue. Tracing allows you to see any traffic happening | 
 | 	  on a block device queue. For more information (and the user space | 
 | 	  support tools needed), fetch the blktrace app from: | 
 |  | 
 | 	  git://brick.kernel.dk/data/git/blktrace.git | 
 |  | 
 | config LSF | 
 | 	bool "Support for Large Single Files" | 
 | 	depends on !64BIT | 
 | 	help | 
 | 	  Say Y here if you want to be able to handle very large files (bigger | 
 | 	  than 2TB), otherwise say N. | 
 |  | 
 | 	  If unsure, say Y. | 
 |  | 
 | config BLK_DEV_BSG | 
 | 	bool "Block layer SG support v4 (EXPERIMENTAL)" | 
 | 	depends on EXPERIMENTAL | 
 | 	---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). | 
 |  | 
 | endif # BLOCK | 
 |  | 
 | config BLOCK_COMPAT | 
 | 	bool | 
 | 	depends on BLOCK && COMPAT | 
 | 	default y | 
 |  | 
 | source block/Kconfig.iosched |