From: Amir Goldstein <amir73il@gmail.com>

factor out ovl_iterate_merged() and move some code into
ovl_iterate_real() for easier use of the scoped ovl cred guard.

Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
---
 fs/overlayfs/readdir.c | 60 +++++++++++++++++++++++++-------------------------
 1 file changed, 30 insertions(+), 30 deletions(-)

diff --git a/fs/overlayfs/readdir.c b/fs/overlayfs/readdir.c
index 12f0bb1480d7..dd76186ae739 100644
--- a/fs/overlayfs/readdir.c
+++ b/fs/overlayfs/readdir.c
@@ -804,6 +804,18 @@ static int ovl_iterate_real(struct file *file, struct dir_context *ctx)
 		.xinowarn = ovl_xino_warn(ofs),
 	};
 
+	/*
+	 * With xino, we need to adjust d_ino of lower entries.
+	 * On same fs, if parent is merge, then need to adjust d_ino for '..',
+	 * and if dir is impure then need to adjust d_ino for copied up entries.
+	 * Otherwise, we can iterate the real dir directly.
+	 */
+	if (!ovl_xino_bits(ofs) &&
+	    !(ovl_same_fs(ofs) &&
+	      (ovl_is_impure_dir(file) ||
+	       OVL_TYPE_MERGE(ovl_path_type(dir->d_parent)))))
+		return iterate_dir(od->realfile, ctx);
+
 	if (rdt.xinobits && lower_layer)
 		rdt.fsid = lower_layer->fsid;
 
@@ -832,44 +844,20 @@ static int ovl_iterate_real(struct file *file, struct dir_context *ctx)
 	return err;
 }
 
-
-static int ovl_iterate(struct file *file, struct dir_context *ctx)
+static int ovl_iterate_merged(struct file *file, struct dir_context *ctx)
 {
 	struct ovl_dir_file *od = file->private_data;
 	struct dentry *dentry = file->f_path.dentry;
-	struct ovl_fs *ofs = OVL_FS(dentry->d_sb);
 	struct ovl_cache_entry *p;
-	const struct cred *old_cred;
 	int err;
 
-	old_cred = ovl_override_creds(dentry->d_sb);
-	if (!ctx->pos)
-		ovl_dir_reset(file);
-
-	if (od->is_real) {
-		/*
-		 * If parent is merge, then need to adjust d_ino for '..', if
-		 * dir is impure then need to adjust d_ino for copied up
-		 * entries.
-		 */
-		if (ovl_xino_bits(ofs) ||
-		    (ovl_same_fs(ofs) &&
-		     (ovl_is_impure_dir(file) ||
-		      OVL_TYPE_MERGE(ovl_path_type(dentry->d_parent))))) {
-			err = ovl_iterate_real(file, ctx);
-		} else {
-			err = iterate_dir(od->realfile, ctx);
-		}
-		goto out;
-	}
-
 	if (!od->cache) {
 		struct ovl_dir_cache *cache;
 
 		cache = ovl_cache_get(dentry);
 		err = PTR_ERR(cache);
 		if (IS_ERR(cache))
-			goto out;
+			return err;
 
 		od->cache = cache;
 		ovl_seek_cursor(od, ctx->pos);
@@ -881,7 +869,7 @@ static int ovl_iterate(struct file *file, struct dir_context *ctx)
 			if (!p->ino || p->check_xwhiteout) {
 				err = ovl_cache_update(&file->f_path, p, !p->ino);
 				if (err)
-					goto out;
+					return err;
 			}
 		}
 		/* ovl_cache_update() sets is_whiteout on stale entry */
@@ -892,12 +880,24 @@ static int ovl_iterate(struct file *file, struct dir_context *ctx)
 		od->cursor = p->l_node.next;
 		ctx->pos++;
 	}
-	err = 0;
-out:
-	ovl_revert_creds(old_cred);
 	return err;
 }
 
+static int ovl_iterate(struct file *file, struct dir_context *ctx)
+{
+	struct ovl_dir_file *od = file->private_data;
+
+	if (!ctx->pos)
+		ovl_dir_reset(file);
+
+	with_ovl_creds(file_dentry(file)->d_sb) {
+		if (od->is_real)
+			return ovl_iterate_real(file, ctx);
+
+		return ovl_iterate_merged(file, ctx);
+	}
+}
+
 static loff_t ovl_dir_llseek(struct file *file, loff_t offset, int origin)
 {
 	loff_t res;

-- 
2.47.3