[PATCH v3 1/3] ovl: Let helper ovl_i_path_real() return the realinode

[Zhihao Cheng]

Let helper ovl_i_path_real() return the realinode to prepare for
checking non-null realinode in rcu walking path.

Signed-off-by: Zhihao Cheng <chengzhihao1@xxxxxxxxxx>
---
 fs/overlayfs/overlayfs.h | 2 +-
 fs/overlayfs/util.c      | 7 ++++---
 2 files changed, 5 insertions(+), 4 deletions(-)

diff --git a/fs/overlayfs/overlayfs.h b/fs/overlayfs/overlayfs.h
index 4d0b278f5630..7398de332527 100644
--- a/fs/overlayfs/overlayfs.h
+++ b/fs/overlayfs/overlayfs.h
@@ -382,7 +382,7 @@ enum ovl_path_type ovl_path_type(struct dentry *dentry);
 void ovl_path_upper(struct dentry *dentry, struct path *path);
 void ovl_path_lower(struct dentry *dentry, struct path *path);
 void ovl_path_lowerdata(struct dentry *dentry, struct path *path);
-void ovl_i_path_real(struct inode *inode, struct path *path);
+struct inode *ovl_i_path_real(struct inode *inode, struct path *path);
 enum ovl_path_type ovl_path_real(struct dentry *dentry, struct path *path);
 enum ovl_path_type ovl_path_realdata(struct dentry *dentry, struct path *path);
 struct dentry *ovl_dentry_upper(struct dentry *dentry);
diff --git a/fs/overlayfs/util.c b/fs/overlayfs/util.c
index 923d66d131c1..00d31e38b57d 100644
--- a/fs/overlayfs/util.c
+++ b/fs/overlayfs/util.c
@@ -250,7 +250,7 @@ struct dentry *ovl_i_dentry_upper(struct inode *inode)
 	return ovl_upperdentry_dereference(OVL_I(inode));
 }
 
-void ovl_i_path_real(struct inode *inode, struct path *path)
+struct inode *ovl_i_path_real(struct inode *inode, struct path *path)
 {
 	path->dentry = ovl_i_dentry_upper(inode);
 	if (!path->dentry) {
@@ -259,6 +259,8 @@ void ovl_i_path_real(struct inode *inode, struct path *path)
 	} else {
 		path->mnt = ovl_upper_mnt(OVL_FS(inode->i_sb));
 	}
+
+	return path->dentry ? d_inode(path->dentry) : NULL;
 }
 
 struct inode *ovl_inode_upper(struct inode *inode)
@@ -1105,8 +1107,7 @@ void ovl_copyattr(struct inode *inode)
 	vfsuid_t vfsuid;
 	vfsgid_t vfsgid;
 
-	ovl_i_path_real(inode, &realpath);
-	realinode = d_inode(realpath.dentry);
+	realinode = ovl_i_path_real(inode, &realpath);
 	real_idmap = mnt_idmap(realpath.mnt);
 
 	vfsuid = i_uid_into_vfsuid(real_idmap, realinode);
-- 
2.39.2