[PATCH v2 03/42] ovl: port ovl_create_or_link() to cred guard

[Christian Brauner <brauner@kernel.org>]

Use the scoped ovl cred guard.

Signed-off-by: Christian Brauner <brauner@kernel.org>
---
 fs/overlayfs/dir.c | 27 ++++++++++-----------------
 1 file changed, 10 insertions(+), 17 deletions(-)

diff --git a/fs/overlayfs/dir.c b/fs/overlayfs/dir.c
index a5e9ddf3023b..93b81d4b6fb1 100644
--- a/fs/overlayfs/dir.c
+++ b/fs/overlayfs/dir.c
@@ -612,11 +612,10 @@ static int ovl_create_or_link(struct dentry *dentry, struct inode *inode,
 			      struct ovl_cattr *attr, bool origin)
 {
 	int err;
-	const struct cred *old_cred, *new_cred = NULL;
+	const struct cred *new_cred __free(put_cred) = NULL;
 	struct dentry *parent = dentry->d_parent;
 
-	old_cred = ovl_override_creds(dentry->d_sb);
-
+	scoped_class(override_creds_ovl, old_cred, dentry->d_sb) {
 		/*
 		 * When linking a file with copy up origin into a new parent, mark the
 		 * new parent dir "impure".
@@ -624,7 +623,7 @@ static int ovl_create_or_link(struct dentry *dentry, struct inode *inode,
 		if (origin) {
 			err = ovl_set_impure(parent, ovl_dentry_upper(parent));
 			if (err)
-			goto out_revert_creds;
+				return err;
 		}
 
 		if (!attr->hardlink) {
@@ -641,23 +640,17 @@ static int ovl_create_or_link(struct dentry *dentry, struct inode *inode,
 			 * create a new inode, so just use the ovl mounter's
 			 * fs{u,g}id.
 			 */
-		new_cred = ovl_setup_cred_for_create(dentry, inode, attr->mode,
-						     old_cred);
-		err = PTR_ERR(new_cred);
-		if (IS_ERR(new_cred)) {
-			new_cred = NULL;
-			goto out_revert_creds;
-		}
+			new_cred = ovl_setup_cred_for_create(dentry, inode, attr->mode, old_cred);
+			if (IS_ERR(new_cred))
+				return PTR_ERR(new_cred);
 		}
 
 		if (!ovl_dentry_is_whiteout(dentry))
-		err = ovl_create_upper(dentry, inode, attr);
-	else
-		err = ovl_create_over_whiteout(dentry, inode, attr);
+			return ovl_create_upper(dentry, inode, attr);
 
-out_revert_creds:
-	ovl_revert_creds(old_cred);
-	put_cred(new_cred);
+		return ovl_create_over_whiteout(dentry, inode, attr);
+
+	}
 	return err;
 }
 

-- 
2.47.3