From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Michael S. Tsirkin" Subject: Re: [PATCH] virtio-blk: check host supplied logical block size Date: Wed, 15 Jul 2020 07:53:04 -0400 Message-ID: <20200715075151-mutt-send-email-mst@kernel.org> References: <20200715095518.3724-1-mlevitsk@redhat.com> <20200715060233-mutt-send-email-mst@kernel.org> <5dd5af8032160eb49a4f0e38749e2d9cd968a0d6.camel@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <5dd5af8032160eb49a4f0e38749e2d9cd968a0d6.camel@redhat.com> Sender: linux-block-owner@vger.kernel.org To: Maxim Levitsky Cc: linux-kernel@vger.kernel.org, Stefan Hajnoczi , "open list:BLOCK LAYER" , "open list:VIRTIO CORE AND NET DRIVERS" , Paolo Bonzini , Jason Wang , Jens Axboe List-Id: virtualization@lists.linuxfoundation.org On Wed, Jul 15, 2020 at 01:19:55PM +0300, Maxim Levitsky wrote: > On Wed, 2020-07-15 at 06:06 -0400, Michael S. Tsirkin wrote: > > On Wed, Jul 15, 2020 at 12:55:18PM +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 > > > --- > > > drivers/block/virtio_blk.c | 20 ++++++++++++++++++-- > > > 1 file changed, 18 insertions(+), 2 deletions(-) > > > > > > diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c > > > index 980df853ee497..36dda31cc4e96 100644 > > > --- a/drivers/block/virtio_blk.c > > > +++ b/drivers/block/virtio_blk.c > > > @@ -681,6 +681,12 @@ static const struct blk_mq_ops virtio_mq_ops = > > > { > > > static unsigned int virtblk_queue_depth; > > > module_param_named(queue_depth, virtblk_queue_depth, uint, 0444); > > > > > > + > > > +static bool virtblk_valid_block_size(unsigned int blksize) > > > +{ > > > + return blksize >= 512 && blksize <= PAGE_SIZE && > > > is_power_of_2(blksize); > > > +} > > > + > > > > Is this a blk core assumption? in that case, does not this belong > > in blk core? > > It is a blk core assumption. > I had checked other drivers and these that have variable block size all > check this manually like that. > > I don't mind fixing all of them but I am a bit afraid to create > too much mess. You don't have to, start by adding this in blk core and using in virtio. Patches to update all drivers can then come separately. > > > > > static int virtblk_probe(struct virtio_device *vdev) > > > { > > > struct virtio_blk *vblk; > > > @@ -809,9 +815,16 @@ 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 (!virtblk_valid_block_size(blk_size)) { > > > + dev_err(&vdev->dev, > > > + "%s failure: unsupported logical block > > > size %d\n", > > > + __func__, blk_size); > > > + err = -EINVAL; > > > + goto out_cleanup_queue; > > > + } > > > blk_queue_logical_block_size(q, blk_size); > > > - else > > > + } else > > > blk_size = queue_logical_block_size(q); > > > > > > /* Use topology information if available */ > > > > OK so if we are doing this pls add {} around blk_size = > > queue_logical_block_size(q); > > too. > Will do. > > > > > > @@ -872,6 +885,9 @@ static int virtblk_probe(struct virtio_device > > > *vdev) > > > device_add_disk(&vdev->dev, vblk->disk, virtblk_attr_groups); > > > return 0; > > > > > > +out_cleanup_queue: > > > + blk_cleanup_queue(vblk->disk->queue); > > > + vblk->disk->queue = NULL; > > > out_free_tags: > > > blk_mq_free_tag_set(&vblk->tag_set); > > > out_put_disk: > > > -- > > > 2.26.2 > > > Best regards, > Maxim Levitsky