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Date: Wed, 27 May 2015 22:32:19 +0900
From: Minchan Kim <minchan@kernel.org>
To: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
        Marcin Jabrzyk <m.jabrzyk@samsung.com>,
        Nitin Gupta <ngupta@vflare.org>, linux-kernel@vger.kernel.org,
        Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
Subject: Re: [PATCHv2] zram: check comp algorithm availability earlier
Message-ID: <20150527133219.GF11609@blaptop>
References: <1432725612-1068-1-git-send-email-sergey.senozhatsky@gmail.com>
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On Wed, May 27, 2015 at 08:20:12PM +0900, Sergey Senozhatsky wrote:
> Improvement idea by Marcin Jabrzyk.
> 
> comp_algorithm_store() silently accepts any supplied algorithm
> name, because zram performs algorithm availability check later,
> during the device configuration phase in disksize_store() and
> emits the following error:
>   "zram: Cannot initialise %s compressing backend"
> 
> this error line is somewhat generic and, besides, can indicate
> a failed attempt to allocate compression backend's working
> buffers.
> 
> add algorithm availability check to comp_algorithm_store():
> 
>   echo lzz > /sys/block/zram0/comp_algorithm
>   -bash: echo: write error: Invalid argument
> 
> Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
> Reported-by: Marcin Jabrzyk <m.jabrzyk@samsung.com>
Acked-by: Minchan Kim <minchan@kernel.org>

Thanks.

-- 
Kind regards,
Minchan Kim