Index: lib/geom/nop/gnop.8
===================================================================
--- lib/geom/nop/gnop.8
+++ lib/geom/nop/gnop.8
@@ -24,7 +24,7 @@
 .\"
 .\" $FreeBSD$
 .\"
-.Dd December 2, 2019
+.Dd December 3, 2019
 .Dt GNOP 8
 .Os
 .Sh NAME
@@ -123,8 +123,8 @@
 Additional options:
 .Bl -tag -width "-c count_until_fail"
 .It Fl c Ar count_until_fail
-Specifies the number of I/O requests to allow before setting the read and write
-failure probabilities to 100%.
+Specifies the number of I/O requests to allow before setting the read, write and
+delay failure probabilities.
 .It Fl d Ar delaymsec
 Specifies the delay of the requests in milliseconds.
 Note that requests will be delayed before they are sent to the backing device.
Index: sys/geom/nop/g_nop.c
===================================================================
--- sys/geom/nop/g_nop.c
+++ sys/geom/nop/g_nop.c
@@ -194,6 +194,23 @@
 	g_free(data);
 }
 
+static void
+g_nop_fetch_delays(struct g_nop_softc *sc, u_int *failprobp, u_int *delayprobp,
+    u_int *delaytimep)
+{
+
+	if (sc->sc_count_until_fail != 0) {
+		sc->sc_count_until_fail -= 1;
+		*failprobp = 0;
+		*delayprobp = 0;
+		*delaytimep = 0;
+	} else {
+		*failprobp = sc->sc_rfailprob;
+		*delayprobp = sc->sc_rdelayprob;
+		*delaytimep = sc->sc_delaymsec;
+	}
+}
+
 static void
 g_nop_start(struct bio *bp)
 {
@@ -210,24 +227,16 @@
 
 	G_NOP_LOGREQ(bp, "Request received.");
 	mtx_lock(&sc->sc_lock);
-	if (sc->sc_count_until_fail != 0 && --sc->sc_count_until_fail == 0) {
-		sc->sc_rfailprob = 100;
-		sc->sc_wfailprob = 100;
-	}
 	switch (bp->bio_cmd) {
 	case BIO_READ:
 		sc->sc_reads++;
 		sc->sc_readbytes += bp->bio_length;
-		failprob = sc->sc_rfailprob;
-		delayprob = sc->sc_rdelayprob;
-		delaytime = sc->sc_delaymsec;
+		g_nop_fetch_delays(sc, &failprob, &delayprob, &delaytime);
 		break;
 	case BIO_WRITE:
 		sc->sc_writes++;
 		sc->sc_wrotebytes += bp->bio_length;
-		failprob = sc->sc_wfailprob;
-		delayprob = sc->sc_wdelayprob;
-		delaytime = sc->sc_delaymsec;
+		g_nop_fetch_delays(sc, &failprob, &delayprob, &delaytime);
 		break;
 	case BIO_DELETE:
 		sc->sc_deletes++;
@@ -261,6 +270,7 @@
 		break;
 	}
 	mtx_unlock(&sc->sc_lock);
+
 	if (failprob > 0) {
 		u_int rval;