Index: sys/geom/geom_disk.c
===================================================================
--- sys/geom/geom_disk.c
+++ sys/geom/geom_disk.c
@@ -225,8 +225,16 @@
 	if (bp2->bio_error == 0)
 		bp2->bio_error = bp->bio_error;
 	bp2->bio_completed += bp->bio_completed;
-	if ((bp->bio_cmd & (BIO_READ|BIO_WRITE|BIO_DELETE|BIO_FLUSH)) != 0)
+	switch (bp->bio_cmd) {
+	case BIO_READ:
+	case BIO_WRITE:
+	case BIO_DELETE:
+	case BIO_FLUSH:
 		devstat_end_transaction_bio_bt(sc->dp->d_devstat, bp, &now);
+		break;
+	default:
+		break;
+	}
 	bp2->bio_inbed++;
 	if (bp2->bio_children == bp2->bio_inbed) {
 		mtx_unlock(&sc->done_mtx);
Index: sys/geom/geom_io.c
===================================================================
--- sys/geom/geom_io.c
+++ sys/geom/geom_io.c
@@ -479,6 +479,7 @@
 	struct g_provider *pp;
 	struct mtx *mtxp;
 	int direct, error, first;
+	uint8_t cmd;
 
 	KASSERT(cp != NULL, ("NULL cp in g_io_request"));
 	KASSERT(bp != NULL, ("NULL bp in g_io_request"));
@@ -500,16 +501,17 @@
 	bp->_bio_cflags = bp->bio_cflags;
 #endif
 
-	if (bp->bio_cmd & (BIO_READ|BIO_WRITE|BIO_GETATTR)) {
+	cmd = bp->bio_cmd;
+	if (cmd == BIO_READ || cmd == BIO_WRITE || cmd == BIO_GETATTR) {
 		KASSERT(bp->bio_data != NULL,
 		    ("NULL bp->data in g_io_request(cmd=%hhu)", bp->bio_cmd));
 	}
-	if (bp->bio_cmd & (BIO_DELETE|BIO_FLUSH)) {
+	if (cmd == BIO_DELETE || cmd == BIO_FLUSH) {
 		KASSERT(bp->bio_data == NULL,
 		    ("non-NULL bp->data in g_io_request(cmd=%hhu)",
 		    bp->bio_cmd));
 	}
-	if (bp->bio_cmd & (BIO_READ|BIO_WRITE|BIO_DELETE)) {
+	if (cmd == BIO_READ || cmd == BIO_WRITE || cmd == BIO_DELETE)) {
 		KASSERT(bp->bio_offset % cp->provider->sectorsize == 0,
 		    ("wrong offset %jd for sectorsize %u",
 		    bp->bio_offset, cp->provider->sectorsize));