NFSD: Replace use of NFSD_MAY_LOCK in nfsd4_lock()

NFSv4 LOCK operations should not avoid the set of authorization
checks that apply to all other NFSv4 operations. Also, the
"no_auth_nlm" export option should apply only to NLM LOCK requests.
It's not necessary or sensible to apply it to NFSv4 LOCK operations.

Instead, set no permission bits when calling fh_verify(). Subsequent
stateid processing handles authorization checks.

Reported-by: NeilBrown <neilb@suse.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

fs/nfsd/nfs4state.c

@@ -7965,11 +7965,9 @@ nfsd4_lock(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
 	if (check_lock_length(lock->lk_offset, lock->lk_length))
 		 return nfserr_inval;
 
-	if ((status = fh_verify(rqstp, &cstate->current_fh,
-				S_IFREG, NFSD_MAY_LOCK))) {
-		dprintk("NFSD: nfsd4_lock: permission denied!\n");
+	status = fh_verify(rqstp, &cstate->current_fh, S_IFREG, 0);
+	if (status != nfs_ok)
 		return status;
-	}
 	sb = cstate->current_fh.fh_dentry->d_sb;
 
 	if (lock->lk_is_new) {