diff options
| -rw-r--r-- | fs/overlayfs/super.c | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c index 31ef24dfcf88..94ca095b2a9e 100644 --- a/fs/overlayfs/super.c +++ b/fs/overlayfs/super.c @@ -1402,6 +1402,18 @@ static bool ovl_lower_uuid_ok(struct ovl_fs *ofs, const uuid_t *uuid) if (!ofs->config.nfs_export && !ovl_upper_mnt(ofs)) return true; + /* + * We allow using single lower with null uuid for index and nfs_export + * for example to support those features with single lower squashfs. + * To avoid regressions in setups of overlay with re-formatted lower + * squashfs, do not allow decoding origin with lower null uuid unless + * user opted-in to one of the new features that require following the + * lower inode of non-dir upper. + */ + if (!ofs->config.index && !ofs->config.metacopy && !ofs->config.xino && + uuid_is_null(uuid)) + return false; + for (i = 0; i < ofs->numfs; i++) { /* * We use uuid to associate an overlay lower file handle with a |