[PATCH 4/4] block: freeze the queue earlier in del_gendisk

From: Christoph Hellwig <hch@lst.de>
To: axboe@kernel.dk
Cc: shinichiro.kawasaki@wdc.com, dan.j.williams@intel.com,
	yukuai3@huawei.com, ming.lei@redhat.com,
	linux-block@vger.kernel.org
Subject: [PATCH 4/4] block: freeze the queue earlier in del_gendisk
Date: Tue, 14 Jun 2022 09:48:27 +0200	[thread overview]
Message-ID: <20220614074827.458955-5-hch@lst.de> (raw)
In-Reply-To: <20220614074827.458955-1-hch@lst.de>

Freeze the queue earlier in del_gendisk so that the state does not
change while we remove debugfs and sysfs files.

Ming mentioned that being able to observer request in debugfs might
be useful while the queue is being frozen in del_gendisk, which is
made possible by this change.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 block/genhd.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/block/genhd.c b/block/genhd.c
index e0675772178b0..278227ba1d531 100644
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -623,6 +623,7 @@ 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");
@@ -646,8 +647,6 @@ 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->queue);
 
 	blk_sync_queue(q);
-- 
2.30.2

