Re: [PATCH 02/10] block: virtio-blk: check logical block size

Christoph Hellwig
2020-07-21T15:14:43Z

On Tue, Jul 21, 2020 at 01:52:31PM +0300, Maxim Levitsky wrote:
> Linux kernel only supports logical block sizes which are power of two,
> at least 512 bytes and no more that PAGE_SIZE.
>
> Check this instead of crashing later on.
>
> Note that there is no need to check physical block size since it is
> only a hint, and virtio-blk already only supports power of two values.
>
> Bugzilla link: https://bugzilla.redhat.com/show_bug.cgi?id=1664619
>
> Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
> ---
> drivers/block/virtio_blk.c | 15 +++++++++++++--
> 1 file changed, 13 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c
> index 980df853ee497..b5ee87cba00ed 100644
> --- a/drivers/block/virtio_blk.c
> +++ b/drivers/block/virtio_blk.c
> @@ -809,10 +809,18 @@ static int virtblk_probe(struct virtio_device *vdev)
> err = virtio_cread_feature(vdev, VIRTIO_BLK_F_BLK_SIZE,
> struct virtio_blk_config, blk_size,
> &blk_size);
> - if (!err)
> + if (!err) {
> + if (!blk_is_valid_logical_block_size(blk_size)) {
> + dev_err(&vdev->dev,
> + "%s failure: invalid logical block size %d\n",
> + __func__, blk_size);
> + err = -EINVAL;
> + goto out_cleanup_queue;
> + }
> blk_queue_logical_block_size(q, blk_size);

Hmm, I wonder if we should simply add the check and warning to
blk_queue_logical_block_size and add an error in that case. Then
drivers only have to check the error return, which might add a lot
less boiler plate code.