Re: [syzbot] [block?] WARNING in blkdev_put (2)

From: Julian Ruess
Date: Mon Mar 06 2023 - 10:00:49 EST


On Thu, 2023-03-02 at 20:33 +0100, Alexander Egorenkov wrote:
>
> Hi,
>
> we are seeing a similar problem on s390x architecture when
> partitioning
> a NVMe disk on linux-next.
>
>
>   [   70.403015]  nvme0n1: p1
>   [   70.403197] ------------[ cut here ]------------
>   [   70.403199] WARNING: CPU: 8 PID: 2452 at block/bdev.c:845
> blkdev_put+0x280/0x298

...

> The problem appeared about a week ago.
>
> Regards
> Alex

Hi all,

I bisected this to:

commit e5cfefa97bccf956ea0bb6464c1f6c84fd7a8d9f
Author: Yu Kuai <yukuai3@xxxxxxxxxx>
Date: Fri Feb 17 10:22:00 2023 +0800

block: fix scan partition for exclusively open device again

As explained in commit 36369f46e917 ("block: Do not reread
partition table
on exclusively open device"), reread partition on the device that
is
exclusively opened by someone else is problematic.

This patch will make sure partition scan will only be proceed if
current
thread open the device exclusively, or the device is not opened
exclusively, and in the later case, other scanners and exclusive
openers
will be blocked temporarily until partition scan is done.

Fixes: 10c70d95c0f2 ("block: remove the bd_openers checks in
blk_drop_partitions")
Cc: <stable@xxxxxxxxxxxxxxx>
Suggested-by: Jan Kara <jack@xxxxxxx>
Signed-off-by: Yu Kuai <yukuai3@xxxxxxxxxx>
Reviewed-by: Christoph Hellwig <hch@xxxxxx>
Link:
https://lore.kernel.org/r/20230217022200.3092987-3-yukuai1@xxxxxxxxxxxxxxx

Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>



Regards
Julian

--
Julian Ruess
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