From: Stefan Haberland <sth@linux.ibm.com>
Date: Fri, 5 Mar 2021 13:54:39 +0100
Subject: s390/dasd: fix hanging IO request during DASD driver unbind
Git-commit: 66f669a272898feb1c69b770e1504aa2ec7723d1
Patch-mainline: v5.12-rc3
References: bsc#1183754 LTC#192081

Prevent that an IO request is build during device shutdown initiated by
a driver unbind. This request will never be able to be processed or
canceled and will hang forever. This will lead also to a hanging unbind.

Fix by checking not only if the device is in READY state but also check
that there is no device offline initiated before building a new IO request.

Fixes: e443343e509a ("s390/dasd: blk-mq conversion")

Cc: <stable@vger.kernel.org> # v4.14+
Signed-off-by: Stefan Haberland <sth@linux.ibm.com>
Tested-by: Bjoern Walk <bwalk@linux.ibm.com>
Reviewed-by: Jan Hoeppner <hoeppner@linux.ibm.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Acked-by: Petr Tesarik <ptesarik@suse.com>
---
 drivers/s390/block/dasd.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

--- a/drivers/s390/block/dasd.c
+++ b/drivers/s390/block/dasd.c
@@ -2925,7 +2925,8 @@ static blk_status_t do_dasd_request(stru
 
 	basedev = block->base;
 	spin_lock_irq(&dq->lock);
-	if (basedev->state < DASD_STATE_READY) {
+	if (basedev->state < DASD_STATE_READY ||
+	    test_bit(DASD_FLAG_OFFLINE, &basedev->flags)) {
 		DBF_DEV_EVENT(DBF_ERR, basedev,
 			      "device not ready for request %p", req);
 		rc = BLK_STS_IOERR;