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authorPaul Durrant <pdurrant@amazon.com>2019-12-11 15:29:54 +0000
committerJuergen Gross <jgross@suse.com>2019-12-20 13:44:38 +0100
commit672b7763cb2c723fd6f92a3879cc60d2fb11e56a (patch)
tree0c02679348828cabd2b20ebfd564490ca20b8aa7
parentc534374ecf044384ddd24474b91fd0d31e720464 (diff)
downloadlinux-672b7763cb2c723fd6f92a3879cc60d2fb11e56a.tar.bz2
xenbus: limit when state is forced to closed
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>
-rw-r--r--drivers/xen/xenbus/xenbus_probe.c12
-rw-r--r--include/xen/xenbus.h1
2 files changed, 11 insertions, 2 deletions
diff --git a/drivers/xen/xenbus/xenbus_probe.c b/drivers/xen/xenbus/xenbus_probe.c
index 5aa29396c9e3..378486b79f96 100644
--- a/drivers/xen/xenbus/xenbus_probe.c
+++ b/drivers/xen/xenbus/xenbus_probe.c
@@ -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);
- xenbus_switch_state(dev, XenbusStateClosed);
+ /*
+ * 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);
diff --git a/include/xen/xenbus.h b/include/xen/xenbus.h
index 869c816d5f8c..24228a102141 100644
--- a/include/xen/xenbus.h
+++ b/include/xen/xenbus.h
@@ -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,