[PATCH v2 1/3] nodedev: Wait for device initialization in all public API callbacks

[Michal Privoznik <mprivozn@xxxxxxxxxx>]

Although I have not experienced this in real life, there is a
possible race condition when creating new device, getting its XML
or parent or listing its capabilities.  If the nodedev driver is
still enumerating devices (in a separate thread) and one of
virNodeDeviceGetXMLDesc(), virNodeDeviceGetParent(),
virNodeDeviceNumOfCaps(), virNodeDeviceListCaps() or
virNodeDeviceCreate() is called then it can lead to spurious
results because the device enumeration thread is removing devices
from or adding them to the internal list of devices (among with
their states).

Therefore, wait for things to settle down before proceeding with
nodeDeviceCreate().

Signed-off-by: Michal Privoznik <mprivozn@xxxxxxxxxx>
---
 src/node_device/node_device_driver.c | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/src/node_device/node_device_driver.c b/src/node_device/node_device_driver.c
index 5f8995172d..7aee8201e8 100644
--- a/src/node_device/node_device_driver.c
+++ b/src/node_device/node_device_driver.c
@@ -340,6 +340,9 @@ nodeDeviceGetXMLDesc(virNodeDevicePtr device,
 
     virCheckFlags(0, NULL);
 
+    if (nodeDeviceInitWait() < 0)
+        return NULL;
+
     if (!(obj = nodeDeviceObjFindByName(device->name)))
         return NULL;
     def = virNodeDeviceObjGetDef(obj);
@@ -368,6 +371,9 @@ nodeDeviceGetParent(virNodeDevicePtr device)
     virNodeDeviceDef *def;
     char *ret = NULL;
 
+    if (nodeDeviceInitWait() < 0)
+        return NULL;
+
     if (!(obj = nodeDeviceObjFindByName(device->name)))
         return NULL;
     def = virNodeDeviceObjGetDef(obj);
@@ -395,6 +401,9 @@ nodeDeviceNumOfCaps(virNodeDevicePtr device)
     virNodeDeviceDef *def;
     int ret = -1;
 
+    if (nodeDeviceInitWait() < 0)
+        return -1;
+
     if (!(obj = nodeDeviceObjFindByName(device->name)))
         return -1;
     def = virNodeDeviceObjGetDef(obj);
@@ -423,6 +432,9 @@ nodeDeviceListCaps(virNodeDevicePtr device,
     int ret = -1;
     size_t i = 0;
 
+    if (nodeDeviceInitWait() < 0)
+        return -1;
+
     if (!(obj = nodeDeviceObjFindByName(device->name)))
         return -1;
     def = virNodeDeviceObjGetDef(obj);
@@ -1399,6 +1411,9 @@ nodeDeviceCreate(virNodeDevice *device,
 
     virCheckFlags(0, -1);
 
+    if (nodeDeviceInitWait() < 0)
+        return -1;
+
     if (!(obj = nodeDeviceObjFindByName(device->name)))
         return -1;
 
-- 
2.26.3