+static vdev_t *
+ztest_random_concrete_vdev_leaf(vdev_t *vd)
+{
+ if (vd == NULL)
+ return (NULL);
+
+ if (vd->vdev_children == 0)
+ return (vd);
+
+ vdev_t *eligible[vd->vdev_children];
+ int eligible_idx = 0, i;
+ for (i = 0; i < vd->vdev_children; i++) {
+ vdev_t *cvd = vd->vdev_child[i];
+ if (cvd->vdev_top->vdev_removing)
+ continue;
+ if (cvd->vdev_children > 0 ||
+ (vdev_is_concrete(cvd) && !cvd->vdev_detached)) {
+ eligible[eligible_idx++] = cvd;
+ }
+ }
+ VERIFY(eligible_idx > 0);
+
+ uint64_t child_no = ztest_random(eligible_idx);
+ return (ztest_random_concrete_vdev_leaf(eligible[child_no]));
+}
+
+/* ARGSUSED */
+void
+ztest_initialize(ztest_ds_t *zd, uint64_t id)
+{
+ spa_t *spa = ztest_spa;
+ int error = 0;
+
+ mutex_enter(&ztest_vdev_lock);
+
+ spa_config_enter(spa, SCL_VDEV, FTAG, RW_READER);
+
+ /* Random leaf vdev */
+ vdev_t *rand_vd = ztest_random_concrete_vdev_leaf(spa->spa_root_vdev);
+ if (rand_vd == NULL) {
+ spa_config_exit(spa, SCL_VDEV, FTAG);
+ mutex_exit(&ztest_vdev_lock);
+ return;
+ }
+
+ /*
+ * The random vdev we've selected may change as soon as we
+ * drop the spa_config_lock. We create local copies of things
+ * we're interested in.
+ */
+ uint64_t guid = rand_vd->vdev_guid;
+ char *path = strdup(rand_vd->vdev_path);
+ boolean_t active = rand_vd->vdev_initialize_thread != NULL;
+
+ zfs_dbgmsg("vd %p, guid %llu", rand_vd, guid);
+ spa_config_exit(spa, SCL_VDEV, FTAG);
+
+ uint64_t cmd = ztest_random(POOL_INITIALIZE_FUNCS);
+
+ nvlist_t *vdev_guids = fnvlist_alloc();
+ nvlist_t *vdev_errlist = fnvlist_alloc();
+ fnvlist_add_uint64(vdev_guids, path, guid);
+ error = spa_vdev_initialize(spa, vdev_guids, cmd, vdev_errlist);
+ fnvlist_free(vdev_guids);
+ fnvlist_free(vdev_errlist);
+
+ switch (cmd) {
+ case POOL_INITIALIZE_CANCEL:
+ if (ztest_opts.zo_verbose >= 4) {
+ (void) printf("Cancel initialize %s", path);
+ if (!active)
+ (void) printf(" failed (no initialize active)");
+ (void) printf("\n");
+ }
+ break;
+ case POOL_INITIALIZE_DO:
+ if (ztest_opts.zo_verbose >= 4) {
+ (void) printf("Start initialize %s", path);
+ if (active && error == 0)
+ (void) printf(" failed (already active)");
+ else if (error != 0)
+ (void) printf(" failed (error %d)", error);
+ (void) printf("\n");
+ }
+ break;
+ case POOL_INITIALIZE_SUSPEND:
+ if (ztest_opts.zo_verbose >= 4) {
+ (void) printf("Suspend initialize %s", path);
+ if (!active)
+ (void) printf(" failed (no initialize active)");
+ (void) printf("\n");
+ }
+ break;
+ }
+ free(path);
+ mutex_exit(&ztest_vdev_lock);
+}
+