Messages in this thread | | | From | Jason Andryuk <> | Date | Thu, 12 Dec 2019 11:31:48 -0500 | Subject | Re: [Xen-devel] [PATCH net-next] xen-netback: get rid of old udev related code |
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On Thu, Dec 12, 2019 at 8:56 AM Paul Durrant <pdurrant@amazon.com> wrote: > > In the past it used to be the case that the Xen toolstack relied upon > udev to execute backend hotplug scripts. However this has not been the > case for many releases now and removal of the associated code in > xen-netback shortens the source by more than 100 lines, and removes much > complexity in the interaction with the xenstore backend state. > > NOTE: xen-netback is the only xenbus driver to have a functional uevent() > method. The only other driver to have a method at all is > pvcalls-back, and currently pvcalls_back_uevent() simply returns 0. > Hence this patch also facilitates further cleanup. > > Signed-off-by: Paul Durrant <pdurrant@amazon.com> > --- > Cc: Wei Liu <wei.liu@kernel.org> > Cc: "David S. Miller" <davem@davemloft.net> > --- > drivers/net/xen-netback/common.h | 11 --- > drivers/net/xen-netback/xenbus.c | 125 ++++--------------------------- > 2 files changed, 14 insertions(+), 122 deletions(-) > > diff --git a/drivers/net/xen-netback/common.h b/drivers/net/xen-netback/common.h > index 05847eb91a1b..e48da004c1a3 100644
<snip>
> -static inline void backend_switch_state(struct backend_info *be, > - enum xenbus_state state) > -{ > - struct xenbus_device *dev = be->dev; > - > - pr_debug("%s -> %s\n", dev->nodename, xenbus_strstate(state)); > - be->state = state; > - > - /* If we are waiting for a hotplug script then defer the > - * actual xenbus state change. > - */ > - if (!be->have_hotplug_status_watch) > - xenbus_switch_state(dev, state);
have_hotplug_status_watch prevents xen-netback from switching to connected state unless the the backend scripts have written "hotplug-status" "success". I had always thought that was intentional so the frontend doesn't connect when the backend is unconnected. i.e. if the backend scripts fails, it writes "hotplug-status" "error" and the frontend doesn't connect.
That behavior is independent of using udev to run the scripts. I'm not opposed to removing it, but I think it at least warrants mentioning in the commit message.
Regards, Jason
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