[PATCH v2 06/42] ovl: port ovl_create_tmpfile() 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 | 28 ++++++++++++----------------
 1 file changed, 12 insertions(+), 16 deletions(-)

diff --git a/fs/overlayfs/dir.c b/fs/overlayfs/dir.c
index 1a801fa40dd1..86b72bf87833 100644
--- a/fs/overlayfs/dir.c
+++ b/fs/overlayfs/dir.c
@@ -1323,7 +1323,7 @@ static int ovl_rename(struct mnt_idmap *idmap, struct inode *olddir,
 static int ovl_create_tmpfile(struct file *file, struct dentry *dentry,
 			      struct inode *inode, umode_t mode)
 {
-	const struct cred *old_cred, *new_cred = NULL;
+	const struct cred *new_cred __free(put_cred) = NULL;
 	struct path realparentpath;
 	struct file *realfile;
 	struct ovl_file *of;
@@ -1332,27 +1332,25 @@ static int ovl_create_tmpfile(struct file *file, struct dentry *dentry,
 	int flags = file->f_flags | OVL_OPEN_FLAGS;
 	int err;
 
-	old_cred = ovl_override_creds(dentry->d_sb);
+	scoped_class(override_creds_ovl, old_cred, dentry->d_sb) {
 		new_cred = ovl_setup_cred_for_create(dentry, inode, mode, old_cred);
-	err = PTR_ERR(new_cred);
-	if (IS_ERR(new_cred)) {
-		new_cred = NULL;
-		goto out_revert_creds;
-	}
+		if (IS_ERR(new_cred))
+			return PTR_ERR(new_cred);
 
 		ovl_path_upper(dentry->d_parent, &realparentpath);
-	realfile = backing_tmpfile_open(&file->f_path, flags, &realparentpath,
-					mode, current_cred());
+		realfile = backing_tmpfile_open(&file->f_path, flags,
+						&realparentpath, mode,
+						current_cred());
 		err = PTR_ERR_OR_ZERO(realfile);
-	pr_debug("tmpfile/open(%pd2, 0%o) = %i\n", realparentpath.dentry, mode, err);
+		pr_debug("tmpfile/open(%pd2, 0%o) = %i\n",
+			 realparentpath.dentry, mode, err);
 		if (err)
-		goto out_revert_creds;
+			return err;
 
 		of = ovl_file_alloc(realfile);
 		if (!of) {
 			fput(realfile);
-		err = -ENOMEM;
-		goto out_revert_creds;
+			return -ENOMEM;
 		}
 
 		/* ovl_instantiate() consumes the newdentry reference on success */
@@ -1364,9 +1362,7 @@ static int ovl_create_tmpfile(struct file *file, struct dentry *dentry,
 			dput(newdentry);
 			ovl_file_free(of);
 		}
-out_revert_creds:
-	ovl_revert_creds(old_cred);
-	put_cred(new_cred);
+	}
 	return err;
 }
 

-- 
2.47.3