Revert "block: freeze the queue earlier in del_gendisk"

Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2155901

commit 4c66a32
Author: Christoph Hellwig <hch@lst.de>
Date:   Mon Sep 19 16:40:49 2022 +0200

    Revert "block: freeze the queue earlier in del_gendisk"

    This reverts commit a09b314.

    Dusty Mabe reported consistent hang during CoreOS shutdown with a MD
    RAID1 setup.  Although apparently similar hangs happened before,
    and this patch most likely is not the root cause it made it much
    more severe.  Revert it until we can figure out what is going on
    with the md driver.

    Signed-off-by: Christoph Hellwig <hch@lst.de>
    Link: https://lore.kernel.org/r/20220919144049.978907-1-hch@lst.de
    Signed-off-by: Jens Axboe <axboe@kernel.dk>

Signed-off-by: Ming Lei <ming.lei@redhat.com>

Author: Ming Lei

block/genhd.c

@@ -613,7 +613,6 @@ void del_gendisk(struct gendisk *disk)
 	 * Prevent new I/O from crossing bio_queue_enter().
 	 */
 	blk_queue_start_drain(q);
-	blk_mq_freeze_queue_wait(q);
 
 	if (!(disk->flags & GENHD_FL_HIDDEN)) {
 		sysfs_remove_link(&disk_to_dev(disk)->kobj, "bdi");
@@ -637,6 +636,8 @@ void del_gendisk(struct gendisk *disk)
 	pm_runtime_set_memalloc_noio(disk_to_dev(disk), false);
 	device_del(disk_to_dev(disk));
 
+	blk_mq_freeze_queue_wait(q);
+
 	blk_throtl_cancel_bios(disk);
 
 	blk_sync_queue(q);