Re: [patch v8 3/7] nbd: check sock index in nbd_read_stat()

Ming Lei
2021-09-22T09:22:17Z

On Sun, Sep 19, 2021 at 06:34:28PM +0800, yukuai (C) wrote:
> On 2021/09/16 17:33, Yu Kuai wrote:
> > The sock that clent send request in nbd_send_cmd() and receive reply
> > in nbd_read_stat() should be the same.
> >
> > Signed-off-by: Yu Kuai <yukuai3@huawei.com>
> > ---
> > drivers/block/nbd.c | 4 ++++
> > 1 file changed, 4 insertions(+)
> >
> > diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c
> > index 614c6ab2b8fe..c724a5bd7fa4 100644
> > --- a/drivers/block/nbd.c
> > +++ b/drivers/block/nbd.c
> > @@ -746,6 +746,10 @@ static struct nbd_cmd *nbd_read_stat(struct nbd_device *nbd, int index)
> > ret = -ENOENT;
> > goto out;
> > }
> > + if (cmd->index != index) {
> > + dev_err(disk_to_dev(nbd->disk), "Unexpected reply %d from different sock %d (expected %d)",
> > + tag, index, cmd->index);
> > + }
> > if (cmd->cmd_cookie != nbd_handle_to_cookie(handle)) {
> > dev_err(disk_to_dev(nbd->disk), "Double reply on req %p, cmd_cookie %u, handle cookie %u\n",
> > req, cmd->cmd_cookie, nbd_handle_to_cookie(handle));
> >
>
> Hi, Ming
>
> Any suggestions about this patch?

I think this one relies on nbd protocol between server and client, and
does the protocol require both request and reply xmitted via same
socket?

Thanks,
Ming