Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
MIME-Version: 1.0
References: <20200331114116.21642-1-maco@android.com>
In-Reply-To: <20200331114116.21642-1-maco@android.com>
From:   Martijn Coenen <maco@android.com>
Date:   Tue, 14 Apr 2020 10:13:04 +0200
Message-ID: <CAB0TPYHt=8EDMUKijn62SmNUEHpt0dGKxxe3uz9BVmwPrVkznQ@mail.gmail.com>
Subject: Re: [PATCH] loop: Call loop_config_discard() only after new config is applied.
To:     Jens Axboe <axboe@kernel.dk>, Christoph Hellwig <hch@lst.de>
Cc:     Ming Lei <ming.lei@redhat.com>,
        Bart Van Assche <bvanassche@acm.org>,
        Chaitanya Kulkarni <Chaitanya.Kulkarni@wdc.com>,
        linux-block <linux-block@vger.kernel.org>,
        LKML <linux-kernel@vger.kernel.org>, kernel-team@android.com
Content-Type: text/plain; charset="UTF-8"
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

Folks, any thoughts about this one?

Thanks,
Martijn

On Tue, Mar 31, 2020 at 1:41 PM Martijn Coenen <maco@android.com> wrote:
>
> loop_set_status() calls loop_config_discard() to configure discard for
> the loop device; however, the discard configuration depends on whether
> the loop device uses encryption, and when we call it the encryption
> configuration has not been updated yet. Move the call down so we apply
> the correct discard configuration based on the new configuration.
>
> Signed-off-by: Martijn Coenen <maco@android.com>
> ---
>  drivers/block/loop.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/block/loop.c b/drivers/block/loop.c
> index 739b372a5112..7c9dcb6007a6 100644
> --- a/drivers/block/loop.c
> +++ b/drivers/block/loop.c
> @@ -1312,8 +1312,6 @@ loop_set_status(struct loop_device *lo, const struct loop_info64 *info)
>                 }
>         }
>
> -       loop_config_discard(lo);
> -
>         memcpy(lo->lo_file_name, info->lo_file_name, LO_NAME_SIZE);
>         memcpy(lo->lo_crypt_name, info->lo_crypt_name, LO_NAME_SIZE);
>         lo->lo_file_name[LO_NAME_SIZE-1] = 0;
> @@ -1337,6 +1335,8 @@ loop_set_status(struct loop_device *lo, const struct loop_info64 *info)
>                 lo->lo_key_owner = uid;
>         }
>
> +       loop_config_discard(lo);
> +
>         /* update dio if lo_offset or transfer is changed */
>         __loop_update_dio(lo, lo->use_dio);
>
> --
> 2.26.0.rc2.310.g2932bb562d-goog
>