Keep track of mixed nonrotational (ssd+hdd) devices.

include/sys/vdev_impl.h

@@ -154,6 +154,8 @@ struct vdev {
 	boolean_t	vdev_expanding;	/* expand the vdev?		*/
 	boolean_t	vdev_reopening;	/* reopen in progress?		*/
 	boolean_t	vdev_nonrot;	/* true if solid state		*/
+	boolean_t	vdev_nonrot_some; /* true if at least one solid state */
+	boolean_t	vdev_nonrot_mix; /* true if partial solid state	*/
 	int		vdev_open_error; /* error on last open		*/
 	kthread_t	*vdev_open_thread; /* thread opening children	*/
 	uint64_t	vdev_crtxg;	/* txg when top-level was added */

module/zfs/vdev.c

@@ -1125,6 +1125,9 @@ vdev_open_child(void *arg)
 	vd->vdev_open_error = vdev_open(vd);
 	vd->vdev_open_thread = NULL;
 	vd->vdev_parent->vdev_nonrot &= vd->vdev_nonrot;
+	vd->vdev_parent->vdev_nonrot_some |= vd->vdev_nonrot;
+	vd->vdev_parent->vdev_nonrot_mix =
+	    vd->vdev_parent->vdev_nonrot ^ vd->vdev_parent->vdev_nonrot_some;
 }
 
 static boolean_t
@@ -1163,7 +1166,9 @@ vdev_open_children(vdev_t *vd)
 			vd->vdev_child[c]->vdev_open_error =
 			    vdev_open(vd->vdev_child[c]);
 			vd->vdev_nonrot &= vd->vdev_child[c]->vdev_nonrot;
+			vd->vdev_nonrot_some |= vd->vdev_child[c]->vdev_nonrot;
 		}
+		vd->vdev_nonrot_mix = vd->vdev_nonrot ^ vd->vdev_nonrot_some;
 		return;
 	}
 	tq = taskq_create("vdev_open", children, minclsyspri,
@@ -1175,8 +1180,11 @@ vdev_open_children(vdev_t *vd)
 
 	taskq_destroy(tq);
 
-	for (c = 0; c < children; c++)
+	for (c = 0; c < children; c++) {
 		vd->vdev_nonrot &= vd->vdev_child[c]->vdev_nonrot;
+		vd->vdev_nonrot_some |= vd->vdev_child[c]->vdev_nonrot;
+	}
+	vd->vdev_nonrot_mix = vd->vdev_nonrot ^ vd->vdev_nonrot_some;
 }
 
 /*

module/zfs/vdev_disk.c

@@ -320,6 +320,8 @@ vdev_disk_open(vdev_t *v, uint64_t *psize, uint64_t *max_psize,
 
 	/* Inform the ZIO pipeline that we are non-rotational */
 	v->vdev_nonrot = blk_queue_nonrot(bdev_get_queue(vd->vd_bdev));
+	v->vdev_nonrot_some = v->vdev_nonrot;
+	v->vdev_nonrot_mix = B_FALSE;
 
 	/* Physical volume size in bytes */
 	*psize = bdev_capacity(vd->vd_bdev);

module/zfs/vdev_file.c

@@ -59,6 +59,8 @@ vdev_file_open(vdev_t *vd, uint64_t *psize, uint64_t *max_psize,
 
 	/* Rotational optimizations only make sense on block devices */
 	vd->vdev_nonrot = B_TRUE;
+	vd->vdev_nonrot_some = vd->vdev_nonrot;
+	vd->vdev_nonrot_mix = B_FALSE;
 
 	/*
 	 * We must have a pathname, and it must be absolute.