sysfs, kernfs: move dir core code to fs/kernfs/dir.c

Move core dir code to fs/kernfs/dir.c.  fs/sysfs/dir.c now only
contains sysfs_warn_dup() and sysfs wrappers around kernfs interfaces.
The respective declarations in fs/sysfs/sysfs.h are moved to
fs/kernfs/kernfs-internal.h.

This is pure relocation.

v2: sysfs_symlink_target_lock was mistakenly relocated to kernfs.  It
    should remain with sysfs.  Fixed.
Signed-off-by: NTejun Heo <tj@kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

fs/kernfs/kernfs-internal.h

@@ -14,6 +14,7 @@
 #include <linux/lockdep.h>
 #include <linux/fs.h>
 #include <linux/rbtree.h>
+#include <linux/mutex.h>
 
 #include <linux/kernfs.h>
 
@@ -125,4 +126,20 @@ int sysfs_setxattr(struct dentry *dentry, const char *name, const void *value,
 		   size_t size, int flags);
 int sysfs_inode_init(void);
 
+/*
+ * dir.c
+ */
+extern struct mutex sysfs_mutex;
+extern const struct dentry_operations sysfs_dentry_ops;
+extern const struct file_operations sysfs_dir_operations;
+extern const struct inode_operations sysfs_dir_inode_operations;
+
+struct sysfs_dirent *sysfs_get_active(struct sysfs_dirent *sd);
+void sysfs_put_active(struct sysfs_dirent *sd);
+void sysfs_addrm_start(struct sysfs_addrm_cxt *acxt);
+int sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd,
+		  struct sysfs_dirent *parent_sd);
+void sysfs_addrm_finish(struct sysfs_addrm_cxt *acxt);
+struct sysfs_dirent *sysfs_new_dirent(const char *name, umode_t mode, int type);
+
 #endif	/* __KERNFS_INTERNAL_H */

fs/sysfs/sysfs.h

@@ -34,22 +34,9 @@ extern struct kmem_cache *sysfs_dir_cachep;
 /*
  * dir.c
  */
-extern struct mutex sysfs_mutex;
 extern spinlock_t sysfs_symlink_target_lock;
-extern const struct dentry_operations sysfs_dentry_ops;
 
-extern const struct file_operations sysfs_dir_operations;
-extern const struct inode_operations sysfs_dir_inode_operations;
-
-struct sysfs_dirent *sysfs_get_active(struct sysfs_dirent *sd);
-void sysfs_put_active(struct sysfs_dirent *sd);
-void sysfs_addrm_start(struct sysfs_addrm_cxt *acxt);
 void sysfs_warn_dup(struct sysfs_dirent *parent, const char *name);
-int sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd,
-		  struct sysfs_dirent *parent_sd);
-void sysfs_addrm_finish(struct sysfs_addrm_cxt *acxt);
-
-struct sysfs_dirent *sysfs_new_dirent(const char *name, umode_t mode, int type);
 
 /*
  * file.c