[BLOCK] Move all core block layer code to new block/ directory

drivers/block/ is right now a mix of core and driver parts. Lets move
the core parts to a new top level directory. Al will move the fs/
related block parts to block/ next.

Signed-off-by: Jens Axboe <axboe@suse.de>

block/Kconfig.iosched

@@ -0,0 +1,69 @@
+
+menu "IO Schedulers"
+
+config IOSCHED_NOOP
+	bool
+	default y
+	---help---
+	  The no-op I/O scheduler is a minimal scheduler that does basic merging
+	  and sorting. Its main uses include non-disk based block devices like
+	  memory devices, and specialised software or hardware environments
+	  that do their own scheduling and require only minimal assistance from
+	  the kernel.
+
+config IOSCHED_AS
+	tristate "Anticipatory I/O scheduler"
+	default y
+	---help---
+	  The anticipatory I/O scheduler is the default disk scheduler. It is
+	  generally a good choice for most environments, but is quite large and
+	  complex when compared to the deadline I/O scheduler, it can also be
+	  slower in some cases especially some database loads.
+
+config IOSCHED_DEADLINE
+	tristate "Deadline I/O scheduler"
+	default y
+	---help---
+	  The deadline I/O scheduler is simple and compact, and is often as
+	  good as the anticipatory I/O scheduler, and in some database
+	  workloads, better. In the case of a single process performing I/O to
+	  a disk at any one time, its behaviour is almost identical to the
+	  anticipatory I/O scheduler and so is a good choice.
+
+config IOSCHED_CFQ
+	tristate "CFQ I/O scheduler"
+	default y
+	---help---
+	  The CFQ I/O scheduler tries to distribute bandwidth equally
+	  among all processes in the system. It should provide a fair
+	  working environment, suitable for desktop systems.
+
+choice
+	prompt "Default I/O scheduler"
+	default DEFAULT_AS
+	help
+	  Select the I/O scheduler which will be used by default for all
+	  block devices.
+
+	config DEFAULT_AS
+		bool "Anticipatory" if IOSCHED_AS
+
+	config DEFAULT_DEADLINE
+		bool "Deadline" if IOSCHED_DEADLINE
+
+	config DEFAULT_CFQ
+		bool "CFQ" if IOSCHED_CFQ
+
+	config DEFAULT_NOOP
+		bool "No-op"
+
+endchoice
+
+config DEFAULT_IOSCHED
+	string
+	default "anticipatory" if DEFAULT_AS
+	default "deadline" if DEFAULT_DEADLINE
+	default "cfq" if DEFAULT_CFQ
+	default "noop" if DEFAULT_NOOP
+
+endmenu