On Fri, 2010-12-10 at 06:52 +0000, Mihir Nanavati wrote:
> I've made the changes in libxenstore as you recommended - xs_daemon|
> domain_open{_readonly} all alias to xs_open.
>
>
> Also, in the case of opening read-only, if it fails using sockets, it
> opens /proc/xen/xenbus with O_RDONLY.
Thanks! I think xs_open should be simplified to:
if (ro)
xsh = get_handle(xs_daemon_socket_ro(), ro);
else
xsh = get_handle(xs_daemon_socket(), ro);
if (!xsh)
xsh = get_handle(xs_domain_dev(), ro);
For future flexibility should we consider passing a flags argument and
defining "XS_OPEN_READONLY 1<<0" instead of having an ro argument?
It's probably worth adding xs_close (with xs_daemon_close as an alias)
for API symmetry as well as adding a comment to the header marking the
aliases as deprecated.
I don't suppose you feel like running sed over the tree to convert the
in tree users, do you ;-)
Ian.
>
>
> ~M
>
> On Thu, Dec 9, 2010 at 3:39 AM, Ian Campbell
> <Ian.Campbell@xxxxxxxxxxxxx> wrote:
>
> On Thu, 2010-12-09 at 10:53 +0000, Vincent Hanquez wrote:
> > On 09/12/10 10:21, Ian Campbell wrote:
> > >> I think there was at least 1 other practical
> differences, but it
> > >> seems to have eluded me.
> >
> > Thinking more about it, it might be related to timeout,
> and/or it might
> > be: If xenstored has decided to not answer you, your thread
> is dead in
> > the water, because you end up stuck in kernel land forever
> (wait not
> > interruptible aka D).
> >
> > (It might have been related to historical reasons, however
> it could
> > still be happening in the unlikely event of xenstored dying)
>
>
> Sounds plausible.
>
> The current driver seems to use wait_event_interruptible and
> attempt to
> do something sane looking with O_NONBLOCK on read but on write
> looks
> like it may end up waiting for a reply forever if xenstored
> has gone
> away, there's even a "FIXME avoid synchronous wait for
> response" in the
> code.
>
> Ian.
>
>
>
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