Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
Date:   Wed, 23 Oct 2019 18:22:44 +0100
From:   Alessio Balsini <balsini@android.com>
To:     gregkh@linuxfoundation.org
Cc:     stable@vger.kernel.org, linux-kernel@vger.kernel.org,
        kernel-team@android.com, Jens Axboe <axboe@kernel.dk>,
        Sasha Levin <sashal@kernel.org>
Subject: Re: [PATCH 4.4 4.9 4.14] loop: Add LOOP_SET_DIRECT_IO to compat ioctl
Message-ID: <20191023172244.GA164146@google.com>
References: <20190805115309.GJ2349@hirez.programming.kicks-ass.net>
 <20191023171736.161697-1-balsini@android.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20191023171736.161697-1-balsini@android.com>
User-Agent: Mutt/1.10.1 (2018-07-13)
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

Ops, please forgive the wrong in-reply-to messge id :)

Cheers,
Alessio

On Wed, Oct 23, 2019 at 06:17:36PM +0100, Alessio Balsini wrote:
> [ Upstream commit fdbe4eeeb1aac219b14f10c0ed31ae5d1123e9b8 ]
> 
> Enabling Direct I/O with loop devices helps reducing memory usage by
> avoiding double caching.  32 bit applications running on 64 bits systems
> are currently not able to request direct I/O because is missing from the
> lo_compat_ioctl.
> 
> This patch fixes the compatibility issue mentioned above by exporting
> LOOP_SET_DIRECT_IO as additional lo_compat_ioctl() entry.
> The input argument for this ioctl is a single long converted to a 1-bit
> boolean, so compatibility is preserved.
> 
> Cc: Jens Axboe <axboe@kernel.dk>
> Signed-off-by: Alessio Balsini <balsini@android.com>
> Signed-off-by: Jens Axboe <axboe@kernel.dk>
> Signed-off-by: Sasha Levin <sashal@kernel.org>
> ---
>  drivers/block/loop.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/drivers/block/loop.c b/drivers/block/loop.c
> index da3902ac16c86..8aadd4d0c3a88 100644
> --- a/drivers/block/loop.c
> +++ b/drivers/block/loop.c
> @@ -1557,6 +1557,7 @@ static int lo_compat_ioctl(struct block_device *bdev, fmode_t mode,
>  		arg = (unsigned long) compat_ptr(arg);
>  	case LOOP_SET_FD:
>  	case LOOP_CHANGE_FD:
> +	case LOOP_SET_DIRECT_IO:
>  		err = lo_ioctl(bdev, mode, cmd, arg);
>  		break;
>  	default:
> -- 
> 2.23.0.866.gb869b98d4c-goog
> 
> -- 
> To unsubscribe from this group and stop receiving emails from it, send an email to kernel-team+unsubscribe@android.com.
>