[LU-15549] client doesn't send layout version if it's 0

• Type: Bug
• Resolution: Unresolved
• Priority: Minor
• Labels: flr-improvement
• Severity: 3
• Assignee: Alex Zhuravlev
• Reporter: Alex Zhuravlev

Description

the client doesn't set OBD_MD_LAYOUT_VERSION if current layout version is 0

                        if (io->ci_layout_version > 0) {
                                /* verify layout version */
                                oa->o_valid |= OBD_MD_LAYOUT_VERSION;

then OST just skips layout version check:

        /* need to verify layout version */
        if (oa->o_valid & OBD_MD_LAYOUT_VERSION) {
                rc = ofd_verify_layout_version(env, fo, oa);

all regular layouts are created with version 0, meaning that if client doesn't notice layout change for a reason (LU-15300 or eviction from MDS), then OST won't check version even if it's changed and propagated to OST already. this can result in silent data corruption.