Date:   Fri, 10 Mar 2023 14:53:19 -0800
From:   Eric Biggers <ebiggers@kernel.org>
To:     stable@vger.kernel.org, Sasha Levin <sashal@kernel.org>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc:     Jens Axboe <axboe@kernel.dk>,
        Mike Cloaked <mike.cloaked@gmail.com>,
        linux-block@vger.kernel.org, linux-kernel@vger.kernel.org,
        Yu Kuai <yukuai3@huawei.com>, Genes Lists <lists@sapience.com>
Subject: Re: Possible kernel fs block code regression in 6.2.3 umounting usb
 drives
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On Fri, Mar 10, 2023 at 04:08:21PM -0500, Genes Lists wrote:
> On 3/10/23 15:23, Jens Axboe wrote:
> > On 3/10/23 1:16 PM, Eric Biggers wrote:
> ...
> > But I would revert:
> > 
> > bfe46d2efe46c5c952f982e2ca94fe2ec5e58e2a
> > 57a425badc05c2e87e9f25713e5c3c0298e4202c
> > 
> > in that order from 6.2.3 and see if that helps. Adding Yu.
> > 
> Confirm the 2 Reverts fixed in my tests as well (nvme + sata drives).
> Nasty crash - some needed to be power cycled as they hung on shutdown.
> 
> Thank you!
> 
> gene
> 
> 

Great, thanks.  BTW, 6.1 is also affected.  A simple reproducer is to run:

	dmsetup create dev --table "0 128 zero"
	dmsetup remove dev

The following kconfigs are needed for the bug to be hit:

	CONFIG_BLK_CGROUP=y
	CONFIG_BLK_DEV_THROTTLING=y
	CONFIG_BLK_DEV_THROTTLING_LOW=y

Sasha or Greg, can you please revert the indicated commits from 6.1 and 6.2?

- Eric