linux-kernel - Re: [PATCH] ubi: put MTD device after it is not used

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Date:   Wed, 28 Nov 2018 09:05:16 +0100
From:   Boris Brezillon <boris.brezillon@...tlin.com>
To:     Pan Bian <bianpan2016@....com>
Cc:     Artem Bityutskiy <dedekind1@...il.com>,
        Richard Weinberger <richard@....at>,
        David Woodhouse <dwmw2@...radead.org>,
        Brian Norris <computersforpeace@...il.com>,
        Marek Vasut <marek.vasut@...il.com>,
        linux-mtd@...ts.infradead.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH] ubi: put MTD device after it is not used

On Wed, 28 Nov 2018 10:57:33 +0800
Pan Bian <bianpan2016@....com> wrote:

> The MTD device reference is dropped via put_mtd_device, however its
> field ->index is read and passed to ubi_msg. To fix this, the patch
> moves the reference dropping after calling ubi_msg.
> 
> Signed-off-by: Pan Bian <bianpan2016@....com>

Reviewed-by: Boris Brezillon <boris.brezillon@...tlin.com>

> ---
>  drivers/mtd/ubi/build.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/mtd/ubi/build.c b/drivers/mtd/ubi/build.c
> index a4e3454..09170b7 100644
> --- a/drivers/mtd/ubi/build.c
> +++ b/drivers/mtd/ubi/build.c
> @@ -1101,10 +1101,10 @@ int ubi_detach_mtd_dev(int ubi_num, int anyway)
>  	ubi_wl_close(ubi);
>  	ubi_free_internal_volumes(ubi);
>  	vfree(ubi->vtbl);
> -	put_mtd_device(ubi->mtd);
>  	vfree(ubi->peb_buf);
>  	vfree(ubi->fm_buf);
>  	ubi_msg(ubi, "mtd%d is detached", ubi->mtd->index);
> +	put_mtd_device(ubi->mtd);

Maybe we should move some of these to the dev->release() or
class->dev_release() hook.

>  	put_device(&ubi->dev);
>  	return 0;
>  }