On Thu, Sep 14, 2023 at 8:24 AM Mariusz Tkaczyk
<mariusz.tkaczyk@xxxxxxxxxxxxxxx> wrote:
>
> If there are multiple arrays in system and one mddevice is marked
> with MD_DELETED and md_seq_next() is called in the middle of removal
> then it _get()s proper device but it may _put() deleted one. As a result,
> active counter may never be zeroed for mddevice and it cannot
> be removed.
>
> Put the device which has been _get with previous md_seq_next() call.
>
> Cc: Yu Kuai <yukuai3@xxxxxxxxxx>
> Fixes: 12a6caf27324 ("md: only delete entries from all_mddevs when the disk is freed")
> Reported-by: AceLan Kao <acelan@xxxxxxxxx>
> Closes: https://bugzilla.kernel.org/show_bug.cgi?id=217798
>
> Signed-off-by: Mariusz Tkaczyk <mariusz.tkaczyk@xxxxxxxxxxxxxxx>
Applied to md-fixes, with minor changes in the commit log.
Thanks,
Song
> ---
> drivers/md/md.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/md/md.c b/drivers/md/md.c
> index 0fe7ab6e8ab9..b8f232840f7c 100644
> --- a/drivers/md/md.c
> +++ b/drivers/md/md.c
> @@ -8256,7 +8256,7 @@ static void *md_seq_next(struct seq_file *seq, void *v, loff_t *pos)
> spin_unlock(&all_mddevs_lock);
>
> if (to_put)
> - mddev_put(mddev);
> + mddev_put(to_put);
> return next_mddev;
>
> }
> --
> 2.26.2
>
