[PATCH -next 3/3] configfs: Add subsys_to_item helper

[Shang XiaoJing <shangxiaojing@huawei.com>]

Add helper function subsys_to_item, which get the corresponding
config_item of the configfs_subsystem.

Signed-off-by: Shang XiaoJing <shangxiaojing@huawei.com>
---
 fs/configfs/dir.c | 22 ++++++++++++++--------
 1 file changed, 14 insertions(+), 8 deletions(-)

diff --git a/fs/configfs/dir.c b/fs/configfs/dir.c
index b5614b66add2..e4386eab3428 100644
--- a/fs/configfs/dir.c
+++ b/fs/configfs/dir.c
@@ -281,7 +281,7 @@ static void configfs_remove_dirent(struct dentry *dentry)
 
 /**
  *	configfs_create_dir - create a directory for an config_item.
- *	@item:		config_itemwe're creating directory for.
+ *	@item:		config_item we're creating directory for.
  *	@dentry:	config_item's dentry.
  *	@frag:		config_item's fragment.
  *
@@ -616,6 +616,12 @@ static inline struct dentry *group_to_dentry(struct config_group *group)
 	return group->cg_item.ci_dentry;
 }
 
+static inline
+struct config_item *subsys_to_item(struct configfs_subsystem *subsys)
+{
+	return &subsys->su_group.cg_item;
+}
+
 static int configfs_attach_group(struct config_item *parent_item,
 				 struct config_item *item,
 				 struct dentry *dentry,
@@ -1119,7 +1125,7 @@ int configfs_depend_item(struct configfs_subsystem *subsys,
 {
 	int ret;
 	struct configfs_dirent *subsys_sd;
-	struct config_item *s_item = &subsys->su_group.cg_item;
+	struct config_item *s_item = subsys_to_item(subsys);
 	struct dentry *root;
 
 	/*
@@ -1238,11 +1244,11 @@ int configfs_depend_item_unlocked(struct configfs_subsystem *caller_subsys,
 		 */
 		subsys_sd = configfs_find_subsys_dentry(
 				group_to_dentry(root)->d_fsdata,
-				&target_subsys->su_group.cg_item);
+				subsys_to_item(target_subsys));
 		if (!subsys_sd)
 			goto out_root_unlock;
 	} else {
-		subsys_sd = target_subsys->su_group.cg_item.ci_dentry->d_fsdata;
+		subsys_sd = subsys_to_item(target_subsys)->ci_dentry->d_fsdata;
 	}
 
 	/* Now we can execute core of depend item */
@@ -1315,11 +1321,11 @@ static int configfs_mkdir(struct user_namespace *mnt_userns, struct inode *dir,
 	 * being created.  We don't want to safely pin the new item but
 	 * fail to pin the subsystem it sits under.
 	 */
-	if (!subsys->su_group.cg_item.ci_type) {
+	if (!subsys_to_item(subsys)->ci_type) {
 		ret = -EINVAL;
 		goto out_put;
 	}
-	subsys_owner = subsys->su_group.cg_item.ci_type->ct_owner;
+	subsys_owner = subsys_to_item(subsys)->ci_type->ct_owner;
 	if (!try_module_get(subsys_owner)) {
 		ret = -EINVAL;
 		goto out_put;
@@ -1469,8 +1475,8 @@ static int configfs_rmdir(struct inode *dir, struct dentry *dentry)
 	}
 
 	/* configfs_mkdir() shouldn't have allowed this */
-	BUG_ON(!subsys->su_group.cg_item.ci_type);
-	subsys_owner = subsys->su_group.cg_item.ci_type->ct_owner;
+	BUG_ON(!subsys_to_item(subsys)->ci_type);
+	subsys_owner = subsys_to_item(subsys)->ci_type->ct_owner;
 
 	/*
 	 * Ensure that no racing symlink() will make detach_prep() fail while
-- 
2.17.1