From: Vyacheslav Yurkov <Vyacheslav.Yurkov@xxxxxxxxxx>
Enable optimizations only if user opted-in for any of extended features.
If optimization is enabled, it 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 | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/fs/overlayfs/dir.c b/fs/overlayfs/dir.c
index 93efe7048a77..03a22954fe61 100644
--- a/fs/overlayfs/dir.c
+++ b/fs/overlayfs/dir.c
@@ -320,6 +320,7 @@ static bool ovl_type_origin(struct dentry *dentry)
static int ovl_create_upper(struct dentry *dentry, struct inode *inode,
struct ovl_cattr *attr)
{
+ struct ovl_fs *ofs = OVL_FS(dentry->d_sb);
struct dentry *upperdir = ovl_dentry_upper(dentry->d_parent);
struct inode *udir = upperdir->d_inode;
struct dentry *newdentry;
@@ -338,7 +339,8 @@ 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)) {
+ if (ovl_type_merge(dentry->d_parent) && d_is_dir(newdentry) &&
+ !ovl_allow_offline_changes(ofs)) {
/* Setting opaque here is just an optimization, allow to fail */
ovl_set_opaque(dentry, newdentry);
}
--
2.25.1
