vdev_disk_close: take disk write lock before destroying it

Many IO operations are submitted to the kernel async, and so the zio can
complete and followup actions before the submission call returns. If one
of the followup actions closes the disk (eg during pool create/import),
the initiator may be left holding a lock on the disk at destruction.

Instead, take the write lock before finishing up and decoupling the disk
state from the vdev proper. The caller will hold until all IO is
submitted and locks released.

Sponsored-by: Klara, Inc.
Sponsored-by: Wasabi Technology, Inc.
Reviewed-by: Brian Behlendorf <[email protected]>
Reviewed-by: Alexander Motin <[email protected]>
Signed-off-by: Rob Norris <[email protected]>
Closes #17719

module/os/linux/zfs/vdev_disk.c

@@ -471,13 +471,17 @@ vdev_disk_close(vdev_t *v)
 	if (v->vdev_reopening || vd == NULL)
 		return;
 
+	rw_enter(&vd->vd_lock, RW_WRITER);
+
 	if (vd->vd_bdh != NULL)
 		vdev_blkdev_put(vd->vd_bdh, spa_mode(v->vdev_spa),
 		    zfs_vdev_holder);
 
+	v->vdev_tsd = NULL;
+
+	rw_exit(&vd->vd_lock);
 	rw_destroy(&vd->vd_lock);
 	kmem_free(vd, sizeof (vdev_disk_t));
-	v->vdev_tsd = NULL;
 }
 
 /*