sysfs: Make sysfs_mount static

This patch modifies the users of sysfs_mount to use sysfs_root
instead (which is what they are looking for).  It then
makes sysfs_mount static to keep people from using it
by accident.

The net result is slightly faster and cleaner code.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Tejun Heo <htejun@gmail.com>
Cc: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

fs/sysfs/dir.c

@@ -737,10 +737,8 @@ int sysfs_create_dir(struct kobject * kobj)
 
 	if (kobj->parent)
 		parent_sd = kobj->parent->sd;
-	else if (sysfs_mount && sysfs_mount->mnt_sb)
-		parent_sd = sysfs_mount->mnt_sb->s_root->d_fsdata;
 	else
-		return -EFAULT;
+		parent_sd = &sysfs_root;
 
 	error = create_dir(kobj, parent_sd, kobject_name(kobj), &sd);
 	if (!error)

fs/sysfs/mount.c

@@ -14,7 +14,7 @@
 /* Random magic number */
 #define SYSFS_MAGIC 0x62656572
 
-struct vfsmount *sysfs_mount;
+static struct vfsmount *sysfs_mount;
 struct super_block * sysfs_sb = NULL;
 struct kmem_cache *sysfs_dir_cachep;
 

fs/sysfs/symlink.c

@@ -60,10 +60,9 @@ int sysfs_create_link(struct kobject * kobj, struct kobject * target, const char
 
 	BUG_ON(!name);
 
-	if (!kobj) {
-		if (sysfs_mount && sysfs_mount->mnt_sb)
-			parent_sd = sysfs_mount->mnt_sb->s_root->d_fsdata;
-	} else
+	if (!kobj)
+		parent_sd = &sysfs_root;
+	else
 		parent_sd = kobj->sd;
 
 	error = -EFAULT;

fs/sysfs/sysfs.h

@@ -51,7 +51,6 @@ struct sysfs_addrm_cxt {
 	int			cnt;
 };
 
-extern struct vfsmount * sysfs_mount;
 extern struct sysfs_dirent sysfs_root;
 extern struct kmem_cache *sysfs_dir_cachep;