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Subject: Re: [PATCH] lightnvm: pblk: stop taking the free lock in in
 pblk_lines_free
To:     hans@owltronix.com
Cc:     javier@javigon.com, linux-block@vger.kernel.org,
        linux-kernel@vger.kernel.org,
        Hans Holmberg <hans.holmberg@cnexlabs.com>
References: <20190122101531.30893-1-hans@owltronix.com>
From:   =?UTF-8?Q?Matias_Bj=c3=b8rling?= <mb@lightnvm.io>
Message-ID: <a0bceb9f-4f8a-1b69-8ef3-f2bc0747a3b5@lightnvm.io>
Date:   Tue, 22 Jan 2019 20:48:58 +0100
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On 1/22/19 11:15 AM, hans@owltronix.com wrote:
> From: Hans Holmberg <hans.holmberg@cnexlabs.com>
> 
> pblk_line_meta_free might sleep (it can end up calling vfree, depending
> on how we allocate lba lists), and this can lead to a BUG()
> if we wake up on a different cpu and release the lock.
> 
> As there is no point of grabbing the free lock when pblk has shut down,
> remove the lock.
> 
> Signed-off-by: Hans Holmberg <hans.holmberg@cnexlabs.com>
> ---
>   drivers/lightnvm/pblk-init.c | 2 --
>   1 file changed, 2 deletions(-)
> 
> diff --git a/drivers/lightnvm/pblk-init.c b/drivers/lightnvm/pblk-init.c
> index f9a3e47b6a93..eb0135c77805 100644
> --- a/drivers/lightnvm/pblk-init.c
> +++ b/drivers/lightnvm/pblk-init.c
> @@ -584,14 +584,12 @@ static void pblk_lines_free(struct pblk *pblk)
>   	struct pblk_line *line;
>   	int i;
>   
> -	spin_lock(&l_mg->free_lock);
>   	for (i = 0; i < l_mg->nr_lines; i++) {
>   		line = &pblk->lines[i];
>   
>   		pblk_line_free(line);
>   		pblk_line_meta_free(l_mg, line);
>   	}
> -	spin_unlock(&l_mg->free_lock);
>   
>   	pblk_line_mg_free(pblk);
>   
> 

Thanks Hans. Applied for 5.1.