[PATCH 6.1.y 4/4] block: set QUEUE_FLAG_DYING unconditionally in blk_mark_disk_dead()

[Sasha Levin <sashal@kernel.org>]

From: 胡连勤 <hulianqin@vivo.com>

[ Upstream commit 7e9a46004b471eaf69b082c473d865316a4158e0 ]

Disks created via blk_mq_alloc_disk_for_queue() (e.g. SCSI SD disks)
do not have GD_OWNS_QUEUE set.  Currently __blk_mark_disk_dead() only
sets QUEUE_FLAG_DYING when GD_OWNS_QUEUE is set, so for such disks
blk_queue_enter() and __bio_queue_enter() cannot detect the dying
state via blk_queue_dying() and remain blocked waiting for I/O that
will never complete after surprise removal.

blk_mark_disk_dead() is the explicit "surprise removal" API -- the
caller has already decided the disk is dead.  Setting QUEUE_FLAG_DYING
unconditionally here is appropriate: any in-flight I/O from other
threads should get -ENODEV immediately from blk_queue_enter()
regardless of GD_OWNS_QUEUE ownership.

For disks that already have GD_OWNS_QUEUE set, __blk_mark_disk_dead()
will set the flag again which is harmless.

Fixes: 6f8191fdf41d ("block: simplify disk shutdown")
Cc: stable@vger.kernel.org
Signed-off-by: Lianqin Hu <hulianqin@vivo.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://patch.msgid.link/PUZPR06MB62247E82E66A3ED46CC3E6C7D2DC2@PUZPR06MB6224.apcprd06.prod.outlook.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
[ adapted the newer helper-based implementation to the existing 6.1 function body. ]
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 block/genhd.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/block/genhd.c b/block/genhd.c
index c058a01c1b3a1..753dfa846e3ea 100644
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -585,6 +585,7 @@ EXPORT_SYMBOL(device_add_disk);
  */
 void blk_mark_disk_dead(struct gendisk *disk)
 {
+	blk_queue_flag_set(QUEUE_FLAG_DYING, disk->queue);
 	set_bit(GD_DEAD, &disk->state);
 	blk_queue_start_drain(disk->queue);
 }
-- 
2.53.0