Re: problem using xenbus interface

[NAHieu <nahieu@gmail.com>]

On 8/9/05, Rusty Russell <rusty@rustcorp.com.au> wrote:
> On Mon, 2005-08-08 at 21:26 +0900, NAHieu wrote:
> > Hello,
> >
> > I a writing a small kernel module for domU, in which I use xenbus and
> > have some problems:
> >
> > I use xenbus_scanf to read value of "/restart_mode", but the below
> > code always failed (got non-zero err)
> >
> > err = xenbus_scanf("/", "restart_mode", "%s", mode);
> 
> OK, if you start the xenstored with "--trace-file=/tmp/trace" you can
> see what's happening in that file.
> 
> In this case, it's actually a bug in xenbus_scanf: it will ask to read
> "//restart_mode" which is an invalid path since it has two "/" in a row.
> But it's not a big problem because you shouldn't be writing in the top
> level directory anyway...
> 
> I would recommend the following:
> 
> 1) Use xenbus_read here, not xenbus_scanf, since you are just reading a
> single string and xenbus_read won't overflow on long strings.
> 
> 2) Use "restart-mode" not "restart_mode": we've chosen - over _ so far.
> 

Rusty, as I understand, you meant that at the moment, it is "restart-mode"?

But as I checked in the latest -unstable, it is "restart_mode". So it
(and others) will be converted to "restart-mode" in the future?

Thank you a lot,
NAH