vfs: drop lock/unlock super

Removed s_lock from super_block and removed lock/unlock super.
Signed-off-by: Marco Stornelli <marco.stornelli@gmail.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

fs/super.c

@@ -186,14 +186,7 @@ static struct super_block *alloc_super(struct file_system_type *type, int flags)
 		spin_lock_init(&s->s_inode_lru_lock);
 		INIT_LIST_HEAD(&s->s_mounts);
 		init_rwsem(&s->s_umount);
-		mutex_init(&s->s_lock);
 		lockdep_set_class(&s->s_umount, &type->s_umount_key);
-		/*
-		 * The locking rules for s_lock are up to the
-		 * filesystem. For example ext3fs has different
-		 * lock ordering than usbfs:
-		 */
-		lockdep_set_class(&s->s_lock, &type->s_lock_key);
 		/*
 		 * sget() can have s_umount recursion.
 		 *
@@ -394,22 +387,6 @@ bool grab_super_passive(struct super_block *sb)
 	return false;
 }
 
-/*
- * Superblock locking.  We really ought to get rid of these two.
- */
-void lock_super(struct super_block * sb)
-{
-	mutex_lock(&sb->s_lock);
-}
-
-void unlock_super(struct super_block * sb)
-{
-	mutex_unlock(&sb->s_lock);
-}
-
-EXPORT_SYMBOL(lock_super);
-EXPORT_SYMBOL(unlock_super);
-
 /**
  *	generic_shutdown_super	-	common helper for ->kill_sb()
  *	@sb: superblock to kill

include/linux/fs.h

@@ -1507,7 +1507,6 @@ struct super_block {
 	unsigned long		s_magic;
 	struct dentry		*s_root;
 	struct rw_semaphore	s_umount;
-	struct mutex		s_lock;
 	int			s_count;
 	atomic_t		s_active;
 #ifdef CONFIG_SECURITY