Function vdev_open

freebsd/contrib/openzfs/module/zfs/vdev.c:1774–2038

* Prepare a virtual device for access. */

 * Prepare a virtual device for access.
 */
int
vdev_open(vdev_t *vd)
{
	spa_t *spa = vd->vdev_spa;
	int error;
	uint64_t osize = 0;
	uint64_t max_osize = 0;
	uint64_t asize, max_asize, psize;
	uint64_t logical_ashift = 0;
	uint64_t physical_ashift = 0;

	ASSERT(vd->vdev_open_thread == curthread ||
	    spa_config_held(spa, SCL_STATE_ALL, RW_WRITER) == SCL_STATE_ALL);
	ASSERT(vd->vdev_state == VDEV_STATE_CLOSED ||
	    vd->vdev_state == VDEV_STATE_CANT_OPEN ||
	    vd->vdev_state == VDEV_STATE_OFFLINE);

	vd->vdev_stat.vs_aux = VDEV_AUX_NONE;
	vd->vdev_cant_read = B_FALSE;
	vd->vdev_cant_write = B_FALSE;
	vd->vdev_min_asize = vdev_get_min_asize(vd);

	/*
	 * If this vdev is not removed, check its fault status.  If it's
	 * faulted, bail out of the open.
	 */
	if (!vd->vdev_removed && vd->vdev_faulted) {
		ASSERT(vd->vdev_children == 0);
		ASSERT(vd->vdev_label_aux == VDEV_AUX_ERR_EXCEEDED ||
		    vd->vdev_label_aux == VDEV_AUX_EXTERNAL);
		vdev_set_state(vd, B_TRUE, VDEV_STATE_FAULTED,
		    vd->vdev_label_aux);
		return (SET_ERROR(ENXIO));
	} else if (vd->vdev_offline) {
		ASSERT(vd->vdev_children == 0);
		vdev_set_state(vd, B_TRUE, VDEV_STATE_OFFLINE, VDEV_AUX_NONE);
		return (SET_ERROR(ENXIO));
	}

	error = vd->vdev_ops->vdev_op_open(vd, &osize, &max_osize,
	    &logical_ashift, &physical_ashift);
	/*
	 * Physical volume size should never be larger than its max size, unless
	 * the disk has shrunk while we were reading it or the device is buggy
	 * or damaged: either way it's not safe for use, bail out of the open.
	 */
	if (osize > max_osize) {
		vdev_set_state(vd, B_TRUE, VDEV_STATE_CANT_OPEN,
		    VDEV_AUX_OPEN_FAILED);
		return (SET_ERROR(ENXIO));
	}

	/*
	 * Reset the vdev_reopening flag so that we actually close
	 * the vdev on error.
	 */
	vd->vdev_reopening = B_FALSE;
	if (zio_injection_enabled && error == 0)