[PATCH] ovl: do not set overlay.opaque for new directories

From: Vyacheslav Yurkov
Date: Mon May 03 2021 - 14:49:09 EST


This optimization breaks existing use case when a lower layer directory
appears after directory was created on a merged layer. If overlay.opaque
is applied, new files on lower layer are not visible.

Consider the following scenario:
- /lower and /upper are mounted to /merged
- directory /merged/new-dir is created with a file test1
- overlay is unmounted
- directory /lower/new-dir is created with a file test2
- overlay is mounted again

If opaque is applied by default, file test2 is not going to be visible
without explicitly clearing the overlay.opaque attribute

Signed-off-by: Vyacheslav Yurkov <Vyacheslav.Yurkov@xxxxxxxxxx>
---
fs/overlayfs/dir.c | 5 -----
1 file changed, 5 deletions(-)

diff --git a/fs/overlayfs/dir.c b/fs/overlayfs/dir.c
index 93efe7048a77..f66f96dd9f0c 100644
--- a/fs/overlayfs/dir.c
+++ b/fs/overlayfs/dir.c
@@ -338,11 +338,6 @@ static int ovl_create_upper(struct dentry *dentry, struct inode *inode,
if (IS_ERR(newdentry))
goto out_unlock;

- if (ovl_type_merge(dentry->d_parent) && d_is_dir(newdentry)) {
- /* Setting opaque here is just an optimization, allow to fail */
- ovl_set_opaque(dentry, newdentry);
- }
-
err = ovl_instantiate(dentry, inode, newdentry, !!attr->hardlink);
if (err)
goto out_cleanup;
--
2.25.1