[LU-13094] Handle ENOENT lookup failure correctly on MDT

• Type: Bug
• Resolution: Not a Bug
• Priority: Minor
• Severity: 3
• Assignee: Qian Yingjin
• Reporter: Qian Yingjin

Description

In current Lustre code, lookup() or getattr() via IT_LOOKUP or IT_GETATTR in mdt_intent_getattr will treat -ENOENT error wrongly as follows:

        rc = mdt_getattr_name_lock(info, lhc, child_bits, ldlm_rep);
	ldlm_rep->lock_policy_res2 = clear_serious(rc);

        if (mdt_get_disposition(ldlm_rep, DISP_LOOKUP_NEG))
                ldlm_rep->lock_policy_res2 = 0;

When DISP_LOOKUP_NEG is set, we can not set the status of intent lock with 0. Otherwise, the client will cache and validate the dentry incorrectly.