Re: [PATCH 6.1 0000/1146] 6.1.2-rc1 review

[Walt Holman <walt@holmansrus.com>]

----- On Dec 29, 2022, at 1:13 AM, Greg KH gregkh@linuxfoundation.org wrote:

> On Wed, Dec 28, 2022 at 04:29:39PM -0600, Walt Holman wrote:
>> > This is the start of the stable review cycle for the 6.1.2 release.
>> > There are 1146 patches in this series, all will be posted as a response
>> > to this one.  If anyone has any issues with these being applied, please
>> > let me know.
>> > 
>> > Responses should be made by Fri, 30 Dec 2022 14:41:29 +0000.
>> > Anything received after that time might be too late.
>> > 
>> > The whole patch series can be found in one patch at:
>> > [ https://www.kernel.org/pub/linux/kernel/v6.x/stable-review/patch-6.1.2-rc1.gz
>> > | https://www.kernel.org/pub/linux/kernel/v6.x/stable-review/patch-6.1.2-rc1.gz
>> > ] > or in the git tree and branch at:
>> > 	git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.git
>> > 	linux-6.1.y
>> > and the diffstat can be found below.
>> > 
>> > thanks,
>> > 
>> > greg k-h
>> > 
>> > -------------
>> 
>> Hello,
>> 
>> I'm getting a NULL Pointer Dereference when shutting down or rebooting. It
>> happens just as it tries to shut down the swap device ( /dev/dm-3 ). This
>> happens late in the shutdown process and nothing gets saved in the logs.
>> However, I've attached a photo of my screen showing the Oops and stack trace.
>> Let me know if there's anything you'd like me to try.
> 
> Does this happen with 6.1.1 also?
> 
> Can you use 'git bisect' to track down the offending change?
> 
> thanks,
> 
> greg k-h

Bisecting the kernel results in the following:

273d29fa4beb3954c970b6377a2aa6ee442b1430 is the first bad commit
commit 273d29fa4beb3954c970b6377a2aa6ee442b1430
Author: Christoph Hellwig <hch@lst.de>
Date:   Tue Nov 1 16:00:47 2022 +0100

    blk-mq: move the srcu_struct used for quiescing to the tagset
    
    [ Upstream commit 80bd4a7aab4c9ce59bf5e35fdf52aa23d8a3c9f5 ]
    
    All I/O submissions have fairly similar latencies, and a tagset-wide
    quiesce is a fairly common operation.
    
    Signed-off-by: Christoph Hellwig <hch@lst.de>
    Reviewed-by: Keith Busch <kbusch@kernel.org>
    Reviewed-by: Ming Lei <ming.lei@redhat.com>
    Reviewed-by: Chao Leng <lengchao@huawei.com>
    Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
    Reviewed-by: Hannes Reinecke <hare@suse.de>
    Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
    Link: https://lore.kernel.org/r/20221101150050.3510-12-hch@lst.de
    [axboe: fix whitespace]
    Signed-off-by: Jens Axboe <axboe@kernel.dk>
    Stable-dep-of: d36a9ea5e776 ("block: fix use-after-free of q->q_usage_counter")
    Signed-off-by: Sasha Levin <sashal@kernel.org>

 block/blk-core.c       | 27 +++++----------------------
 block/blk-mq.c         | 33 +++++++++++++++++++++++++--------
 block/blk-mq.h         | 14 +++++++-------
 block/blk-sysfs.c      |  9 ++-------
 block/blk.h            |  9 +--------
 block/genhd.c          |  2 +-
 include/linux/blk-mq.h |  4 ++++
 include/linux/blkdev.h |  9 ---------
 8 files changed, 45 insertions(+), 62 deletions(-)

-Walt