[LU-4187] unstable code in lov_unpackmd

• Type: Bug
• Resolution: Fixed
• Priority: Minor
• Fix Version/s: Lustre 2.6.0
• Affects Version/s: Lustre 2.6.0
• Severity: 3
• Assignee: WC Triage
• Reporter: Oleg Drokin

Description

Playing with the stack tool for detecting unstable code (http://css.csail.mit.edu/stack/) I uncovered this gem:

        if (*lsmp && !lmm) {
                lov_free_memmd(lsmp);
                RETURN(0);
        }

        pattern = le32_to_cpu(lmm->lmm_pattern); <<-- *dereferencing lmm*
        lsm_size = lov_alloc_memmd(lsmp, stripe_count, pattern, magic);
        if (lsm_size < 0)
                RETURN(lsm_size);

        /* If we are passed a pointer but nothing to unpack, we only alloc */
        if (!lmm) <<--  *Now we make sure it's not NULL?*
                RETURN(lsm_size);

After further looking, it appears that the lmm is never passed in as NULL, which ould allow us the opportunity to further simplify this I guess.

Issue Links

• is related to: LU-2753 Tracking bug for static code analysis fixes.