md: move the early init autodetect code to drivers/md/

Just like the NFS and CIFS root code this better lives with the
driver it is tightly integrated with.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Song Liu <song@kernel.org>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/md/Makefile

@@ -43,6 +43,9 @@ obj-$(CONFIG_MD_FAULTY)		+= faulty.o
 obj-$(CONFIG_MD_CLUSTER)	+= md-cluster.o
 obj-$(CONFIG_BCACHE)		+= bcache/
 obj-$(CONFIG_BLK_DEV_MD)	+= md-mod.o
+ifeq ($(CONFIG_BLK_DEV_MD),y)
+obj-y				+= md-autodetect.o
+endif
 obj-$(CONFIG_BLK_DEV_DM)	+= dm-mod.o
 obj-$(CONFIG_BLK_DEV_DM_BUILTIN) += dm-builtin.o
 obj-$(CONFIG_DM_UNSTRIPED)	+= dm-unstripe.o

drivers/md/md-autodetect.c

@@ -1,10 +1,15 @@
 // SPDX-License-Identifier: GPL-2.0
+#include <linux/kernel.h>
+#include <linux/blkdev.h>
+#include <linux/init.h>
+#include <linux/syscalls.h>
+#include <linux/mount.h>
+#include <linux/major.h>
 #include <linux/delay.h>
+#include <linux/raid/detect.h>
 #include <linux/raid/md_u.h>
 #include <linux/raid/md_p.h>
 
-#include "do_mounts.h"
-
 /*
  * When md (and any require personalities) are compiled into the kernel
  * (not a module), arrays can be assembles are boot time using with AUTODETECT
@@ -114,6 +119,12 @@ static int __init md_setup(char *str)
 	return 1;
 }
 
+static inline int create_dev(char *name, dev_t dev)
+{
+	ksys_unlink(name);
+	return ksys_mknod(name, S_IFBLK|0600, new_encode_dev(dev));
+}
+
 static void __init md_setup_drive(void)
 {
 	int minor, i, ent, partitioned;

include/linux/raid/detect.h

@@ -1,3 +1,11 @@
 /* SPDX-License-Identifier: GPL-2.0 */
 
 void md_autodetect_dev(dev_t dev);
+
+#ifdef CONFIG_BLK_DEV_MD
+void md_run_setup(void);
+#else
+static inline void md_run_setup(void)
+{
+}
+#endif

init/Makefile

@@ -18,7 +18,6 @@ obj-y                          += init_task.o
 mounts-y			:= do_mounts.o
 mounts-$(CONFIG_BLK_DEV_RAM)	+= do_mounts_rd.o
 mounts-$(CONFIG_BLK_DEV_INITRD)	+= do_mounts_initrd.o
-mounts-$(CONFIG_BLK_DEV_MD)	+= do_mounts_md.o
 
 # dependencies on generated files need to be listed explicitly
 $(obj)/version.o: include/generated/compile.h

init/do_mounts.c

@@ -23,6 +23,7 @@
 #include <linux/nfs_fs.h>
 #include <linux/nfs_fs_sb.h>
 #include <linux/nfs_mount.h>
+#include <linux/raid/detect.h>
 #include <uapi/linux/mount.h>
 
 #include "do_mounts.h"

init/do_mounts.h

@@ -41,13 +41,3 @@ bool __init initrd_load(void);
 static inline bool initrd_load(void) { return false; }
 
 #endif
-
-#ifdef CONFIG_BLK_DEV_MD
-
-void md_run_setup(void);
-
-#else
-
-static inline void md_run_setup(void) {}
-
-#endif