nodedev: immediate update of active config on udev events

When an udev add, change or remove event occurs the mdev active config data
requires an update via mdevctl as the udev does not contain all config data.
This update needs to occur immediately and to be finished before the libvirt
nodedev event is issued to keep the API usage reliable.

After this change, scheduleMdevctlUpdate call is already called in
`udevAddOneDevice` and can therefore be removed in `udevHandleOneDevice`.

Signed-off-by: Boris Fiuczynski <fiuczy@linux.ibm.com>
Reviewed-by: Jonathon Jongsma <jjongsma@redhat.com>
Signed-off-by: Marc Hartmayer <mhartmay@linux.ibm.com>

diff --git a/src/node_device/node_device_udev.c b/src/node_device/node_device_udev.c
index 3a7a02cf15221fb5def456b9317f2f57b405a71c..42d169d852b5f12c1f5b215779946b7729e2d25f 100644 (file)
--- a/src/node_device/node_device_udev.c
+++ b/src/node_device/node_device_udev.c
@@ -1440,9 +1440,6 @@ udevGetDeviceDetails(struct udev_device *device,
 }
 
 
-static void scheduleMdevctlUpdate(udevEventData *data, bool force);
-
-
 static int
 udevRemoveOneDeviceSysPath(const char *path)
 {
@@ -1475,7 +1472,8 @@ udevRemoveOneDeviceSysPath(const char *path)
     virNodeDeviceObjEndAPI(&obj);
 
     /* cannot check for mdev_types since they have already been removed */
-    scheduleMdevctlUpdate(driver->privateData, false);
+    if (nodeDeviceUpdateMediatedDevices() < 0)
+        VIR_WARN("mdevctl failed to update mediated devices");
 
     virObjectEventStateQueue(driver->nodeDeviceEventState, event);
     return 0;
@@ -1535,6 +1533,7 @@ udevSetParent(struct udev_device *device,
 static int
 udevAddOneDevice(struct udev_device *device)
 {
+    g_autofree char *sysfs_path = NULL;
     virNodeDeviceDef *def = NULL;
     virNodeDeviceObj *obj = NULL;
     virNodeDeviceDef *objdef;
@@ -1549,6 +1548,9 @@ udevAddOneDevice(struct udev_device *device)
     def = g_new0(virNodeDeviceDef, 1);
 
     def->sysfs_path = g_strdup(udev_device_get_syspath(device));
+    /* Create a copy of sysfs_path so it can be safely accessed, even without
+     * holding the @obj lock during the VIR_WARN(...) call at the end. */
+    sysfs_path = g_strdup(def->sysfs_path);
 
     udevGetStringProperty(device, "DRIVER", &def->driver);
 
@@ -1605,8 +1607,13 @@ udevAddOneDevice(struct udev_device *device)
     has_mdev_types = virNodeDeviceObjHasCap(obj, VIR_NODE_DEV_CAP_MDEV_TYPES);
     virNodeDeviceObjEndAPI(&obj);
 
-    if (has_mdev_types)
-        scheduleMdevctlUpdate(driver->privateData, false);
+    /* The added mdev needs an immediate active config update before the event
+     * is issued so that full device information is available at the time that
+     * the 'created' event is emitted. */
+    if ((has_mdev_types || is_mdev) && (nodeDeviceUpdateMediatedDevices() < 0)) {
+        VIR_WARN("Update of mediated device %s failed",
+                 NULLSTR_EMPTY(sysfs_path));
+    }
 
     ret = 0;
 
@@ -1758,19 +1765,12 @@ nodeStateCleanup(void)
 static int
 udevHandleOneDevice(struct udev_device *device)
 {
-    virNodeDevCapType dev_cap_type;
     const char *action = udev_device_get_action(device);
 
     VIR_DEBUG("udev action: '%s': %s", action, udev_device_get_syspath(device));
 
-    if (STREQ(action, "add") || STREQ(action, "change")) {
-        int ret = udevAddOneDevice(device);
-        if (ret == 0 &&
-            udevGetDeviceType(device, &dev_cap_type) == 0 &&
-            dev_cap_type == VIR_NODE_DEV_CAP_MDEV)
-            scheduleMdevctlUpdate(driver->privateData, false);
-        return ret;
-    }
+    if (STREQ(action, "add") || STREQ(action, "change"))
+        return udevAddOneDevice(device);
 
     if (STREQ(action, "remove"))
         return udevRemoveOneDevice(device);