xenbus: limit when state is forced to closed (672b7763) · Commits · 戴 / test

If a driver probe() fails then leave the xenstore state alone. There is no reason to modify it as the failure may be due to transient resource allocation issues and hence a subsequent probe() may succeed. If the driver supports re-binding then only force state to closed during remove() only in the case when the toolstack may need to clean up. This can be detected by checking whether the state in xenstore has been set to closing prior to device removal. NOTE: Re-bind support is indicated by new boolean in struct xenbus_driver, which defaults to false. Subsequent patches will add support to some backend drivers. Signed-off-by:

Paul Durrant <pdurrant@amazon.com> Reviewed-by:

Juergen Gross <jgross@suse.com> Signed-off-by:

Juergen Gross <jgross@suse.com>

drivers/xen/xenbus/xenbus_probe.c

+10 −2

Original line number	Diff line number	Diff line
		@@ -255,7 +255,6 @@ fail_put:
		module_put(drv->driver.owner);
		fail:
		xenbus_dev_error(dev, err, "xenbus_dev_probe on %s", dev->nodename);
		xenbus_switch_state(dev, XenbusStateClosed);
		return err;
		}
		EXPORT_SYMBOL_GPL(xenbus_dev_probe);
		@@ -276,7 +275,16 @@ int xenbus_dev_remove(struct device *_dev)

		free_otherend_details(dev);

		/*
		* If the toolstack has forced the device state to closing then set
		* the state to closed now to allow it to be cleaned up.
		* Similarly, if the driver does not support re-bind, set the
		* closed.
		*/
		if (!drv->allow_rebind \|\|
		xenbus_read_driver_state(dev->nodename) == XenbusStateClosing)
		xenbus_switch_state(dev, XenbusStateClosed);

		return 0;
		}
		EXPORT_SYMBOL_GPL(xenbus_dev_remove);

include/xen/xenbus.h

+1 −0

Original line number	Diff line number	Diff line
		@@ -93,6 +93,7 @@ struct xenbus_device_id
		struct xenbus_driver {
		const char name; / defaults to ids[0].devicetype */
		const struct xenbus_device_id *ids;
		bool allow_rebind; /* avoid setting xenstore closed during remove */
		int (probe)(struct xenbus_device dev,
		const struct xenbus_device_id *id);
		void (otherend_changed)(struct xenbus_device dev,

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