In a overlayfs with casefold enabled, all new dentries should have casefold enabled as well. Check this at ovl_create_real(). Reviewed-by: Amir Goldstein Signed-off-by: André Almeida --- Changes from v5: - Change pr_warn message --- fs/overlayfs/dir.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/fs/overlayfs/dir.c b/fs/overlayfs/dir.c index 70b8687dc45e8e33079c865ae302ac58464224a6..fc1116f36a30e7217939b087435955e18a40ad2e 100644 --- a/fs/overlayfs/dir.c +++ b/fs/overlayfs/dir.c @@ -187,6 +187,13 @@ struct dentry *ovl_create_real(struct ovl_fs *ofs, struct dentry *parent, /* mkdir is special... */ newdentry = ovl_do_mkdir(ofs, dir, newdentry, attr->mode); err = PTR_ERR_OR_ZERO(newdentry); + /* expect to inherit casefolding from workdir/upperdir */ + if (!err && ofs->casefold != ovl_dentry_casefolded(newdentry)) { + pr_warn_ratelimited("wrong inherited casefold (%pd2)\n", + newdentry); + dput(newdentry); + err = -EINVAL; + } break; case S_IFCHR: -- 2.50.1