Re: [PATCH v3 06/10] dm: track per-add_disk holder relations in DM

[Mike Snitzer]

On Tue, Nov 15 2022 at  9:10P -0500,
Yu Kuai <yukuai1@xxxxxxxxxxxxxxx> wrote:

> From: Christoph Hellwig <hch@xxxxxx>
> 
> dm is a bit special in that it opens the underlying devices.  Commit
> 89f871af1b26 ("dm: delay registering the gendisk") tried to accommodate
> that by allowing to add the holder to the list before add_gendisk and
> then just add them to sysfs once add_disk is called.  But that leads to
> really odd lifetime problems and error handling problems as we can't
> know the state of the kobjects and don't unwind properly.  To fix this
> switch to just registering all existing table_devices with the holder
> code right after add_disk, and remove them before calling del_gendisk.
> 
> Fixes: 89f871af1b26 ("dm: delay registering the gendisk")
> Reported-by: Yu Kuai <yukuai3@xxxxxxxxxx>
> Signed-off-by: Christoph Hellwig <hch@xxxxxx>
> Signed-off-by: Yu Kuai <yukuai3@xxxxxxxxxx>

Reviewed-by: Mike Snitzer <snitzer@xxxxxxxxxx>