Re: Possible kernel fs block code regression in 6.2.3 umounting usb drives

From: Eric Biggers
Date: Fri Mar 10 2023 - 17:55:11 EST


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