null_blk: Move driver into its own directory

Move null_blk driver code into the new sub-directory
drivers/block/null_blk.

Suggested-by: Bart Van Assche <[e-mail]>
Signed-off-by: Damien Le Moal <[e-mail]>
Reviewed-by: Johannes Thumshirn <[e-mail]>
Signed-off-by: Jens Axboe <[e-mail]>

drivers/block/Kconfig

···
 
 if BLK_DEV
 
-config BLK_DEV_NULL_BLK
-	tristate "Null test block driver"
-	select CONFIGFS_FS
-
-config BLK_DEV_NULL_BLK_FAULT_INJECTION
-	bool "Support fault injection for Null test block driver"
-	depends on BLK_DEV_NULL_BLK && FAULT_INJECTION
+source "drivers/block/null_blk/Kconfig"
 
 config BLK_DEV_FD
 	tristate "Normal floppy disk support"

drivers/block/Makefile

···
 obj-$(CONFIG_ZRAM) += zram/
 obj-$(CONFIG_BLK_DEV_RNBD)	+= rnbd/
 
-obj-$(CONFIG_BLK_DEV_NULL_BLK)	+= null_blk.o
-null_blk-objs	:= null_blk_main.o
-ifeq ($(CONFIG_BLK_DEV_ZONED), y)
-null_blk-$(CONFIG_TRACING) += null_blk_trace.o
-endif
-null_blk-$(CONFIG_BLK_DEV_ZONED) += null_blk_zoned.o
+obj-$(CONFIG_BLK_DEV_NULL_BLK)	+= null_blk/
 
 skd-y		:= skd_main.o
 swim_mod-y	:= swim.o swim_asm.o

drivers/block/null_blk/Kconfig

···
+# SPDX-License-Identifier: GPL-2.0
+#
+# Null block device driver configuration
+#
+
+config BLK_DEV_NULL_BLK
+	tristate "Null test block driver"
+	select CONFIGFS_FS
+
+config BLK_DEV_NULL_BLK_FAULT_INJECTION
+	bool "Support fault injection for Null test block driver"
+	depends on BLK_DEV_NULL_BLK && FAULT_INJECTION

drivers/block/null_blk/Makefile

···
+# SPDX-License-Identifier: GPL-2.0
+
+# needed for trace events
+ccflags-y			+= -I$(src)
+
+obj-$(CONFIG_BLK_DEV_NULL_BLK)	+= null_blk.o
+null_blk-objs			:= main.o
+ifeq ($(CONFIG_BLK_DEV_ZONED), y)
+null_blk-$(CONFIG_TRACING) 	+= trace.o
+endif
+null_blk-$(CONFIG_BLK_DEV_ZONED) += zoned.o

drivers/block/null_blk_trace.c drivers/block/null_blk/trace.c

···
  *
  * Copyright (C) 2020 Western Digital Corporation or its affiliates.
  */
-#include "null_blk_trace.h"
+#include "trace.h"
 
 /*
  * Helper to use for all null_blk traces to extract disk name.

drivers/block/null_blk_trace.h drivers/block/null_blk/trace.h

···
 #undef TRACE_INCLUDE_PATH
 #define TRACE_INCLUDE_PATH .
 #undef TRACE_INCLUDE_FILE
-#define TRACE_INCLUDE_FILE null_blk_trace
+#define TRACE_INCLUDE_FILE trace
 
 /* This part must be outside protection */
 #include <trace/define_trace.h>

drivers/block/null_blk_zoned.c drivers/block/null_blk/zoned.c

···
 #include "null_blk.h"
 
 #define CREATE_TRACE_POINTS
-#include "null_blk_trace.h"
+#include "trace.h"
 
 #define MB_TO_SECTS(mb) (((sector_t)mb * SZ_1M) >> SECTOR_SHIFT)