USB: g_mass_storage: Mass Storage Function created

The f_mass_storage.c has been changed into a composite function.
mass_storage.c file has been introduced which defines a
g_mass_storage gadget based on composite framework.

Signed-off-by: Michal Nazarewicz <m.nazarewicz@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/usb/gadget/Kconfig

@@ -732,6 +732,24 @@ config USB_FILE_STORAGE_TEST
 	  behavior of USB Mass Storage hosts.  Not needed for
 	  normal operation.
 
+config USB_MASS_STORAGE
+	tristate "Mass Storage Gadget"
+	depends on BLOCK
+	help
+	  The Mass Storage Gadget acts as a USB Mass Storage disk drive.
+	  As its storage repository it can use a regular file or a block
+	  device (in much the same way as the "loop" device driver),
+	  specified as a module parameter or sysfs option.
+
+	  This is heavily based on File-backed Storage Gadget and in most
+	  cases you will want to use FSG instead.  This gadget is mostly
+	  here to test the functionality of the Mass Storage Function
+	  which may be used with composite framework.
+
+	  Say "y" to link the driver statically, or "m" to build
+	  a dynamically linked module called "g_file_storage".  If unsure,
+	  consider File-backed Storage Gadget.
+
 config USB_G_SERIAL
 	tristate "Serial Gadget (with CDC ACM and CDC OBEX support)"
 	help

drivers/usb/gadget/Makefile

@@ -39,6 +39,7 @@ g_serial-objs			:= serial.o
 g_midi-objs			:= gmidi.o
 gadgetfs-objs			:= inode.o
 g_file_storage-objs		:= file_storage.o
+g_mass_storage-objs		:= mass_storage.o
 g_printer-objs			:= printer.o
 g_cdc-objs			:= cdc2.o
 
@@ -47,6 +48,7 @@ obj-$(CONFIG_USB_AUDIO)		+= g_audio.o
 obj-$(CONFIG_USB_ETH)		+= g_ether.o
 obj-$(CONFIG_USB_GADGETFS)	+= gadgetfs.o
 obj-$(CONFIG_USB_FILE_STORAGE)	+= g_file_storage.o
+obj-$(CONFIG_USB_MASS_STORAGE)	+= g_mass_storage.o
 obj-$(CONFIG_USB_G_SERIAL)	+= g_serial.o
 obj-$(CONFIG_USB_G_PRINTER)	+= g_printer.o
 obj-$(CONFIG_USB_MIDI_GADGET)	+= g_midi.o