Worked on enhancing permission-check reliability in overlay-based storage layers for the containers/storage and containers/container-libs repositories. Addressed critical bugs by updating the Exists() and Lexists() functions to use the AT_EACCESS flag with faccessat, ensuring that existence checks accurately reflect effective user permissions and capabilities. This approach reduced permission-denied errors during layer creation and access, particularly in multi-user and CI environments. The work required deep understanding of Linux system calls, file permissions, and Go programming, and involved cross-repository collaboration to maintain consistent permission semantics. These improvements increased the predictability and maintainability of storage operations across both codebases.