ovl: reflow ovl_create_or_link()

Reflow the creation routine in preparation of porting it to a guard.

Link: https://patch.msgid.link/20251117-work-ovl-cred-guard-prepare-v2-3-bd1c97a36d7b@kernel.org
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>

diff --git a/fs/overlayfs/dir.c b/fs/overlayfs/dir.c
index 68f6617b6a77af1bef12cb60585f35aeef195661..9eafddea8192502078c1c26e99f48d49040cc716 100644 (file)
--- a/fs/overlayfs/dir.c
+++ b/fs/overlayfs/dir.c
@@ -650,6 +650,16 @@ static const struct cred *ovl_setup_cred_for_create(struct dentry *dentry,
        return override_cred;
 }
 
+static int ovl_create_handle_whiteouts(struct dentry *dentry,
+                                      struct inode *inode,
+                                      struct ovl_cattr *attr)
+{
+       if (!ovl_dentry_is_whiteout(dentry))
+               return ovl_create_upper(dentry, inode, attr);
+
+       return ovl_create_over_whiteout(dentry, inode, attr);
+}
+
 static int ovl_create_or_link(struct dentry *dentry, struct inode *inode,
                              struct ovl_cattr *attr, bool origin)
 {
@@ -668,29 +678,28 @@ static int ovl_create_or_link(struct dentry *dentry, struct inode *inode,
                                return err;
                }
 
-               if (!attr->hardlink) {
-                       /*
-                        * In the creation cases(create, mkdir, mknod, symlink),
-                        * ovl should transfer current's fs{u,g}id to underlying
-                        * fs. Because underlying fs want to initialize its new
-                        * inode owner using current's fs{u,g}id. And in this
-                        * case, the @inode is a new inode that is initialized
-                        * in inode_init_owner() to current's fs{u,g}id. So use
-                        * the inode's i_{u,g}id to override the cred's fs{u,g}id.
-                        *
-                        * But in the other hardlink case, ovl_link() does not
-                        * 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);
-                       if (IS_ERR(new_cred))
-                               return PTR_ERR(new_cred);
-               }
+               /*
+                * In the creation cases(create, mkdir, mknod, symlink),
+                * ovl should transfer current's fs{u,g}id to underlying
+                * fs. Because underlying fs want to initialize its new
+                * inode owner using current's fs{u,g}id. And in this
+                * case, the @inode is a new inode that is initialized
+                * in inode_init_owner() to current's fs{u,g}id. So use
+                * the inode's i_{u,g}id to override the cred's fs{u,g}id.
+                *
+                * But in the other hardlink case, ovl_link() does not
+                * create a new inode, so just use the ovl mounter's
+                * fs{u,g}id.
+                */
+
+               if (attr->hardlink)
+                       return ovl_create_handle_whiteouts(dentry, inode, attr);
 
-               if (!ovl_dentry_is_whiteout(dentry))
-                       return ovl_create_upper(dentry, inode, attr);
+               new_cred = ovl_setup_cred_for_create(dentry, inode, attr->mode, old_cred);
+               if (IS_ERR(new_cred))
+                       return PTR_ERR(new_cred);
 
-               return ovl_create_over_whiteout(dentry, inode, attr);
+               return ovl_create_handle_whiteouts(dentry, inode, attr);
        }
        return err;
 }