node_device_udev: Don't take `mdevctlLock` for `mdevctl list` and add comments about...

Commit a99d876a0f58 ("node_device: Use automatic mutex management") replaced the
locking mechanism and accidentally removed the comment with the reason why the
lock is taken. The reason was to "ensure only a single thread can query mdevctl
at a time", but this reason is no longer valid or maybe it never was. Therefore,
let's remove this lock and add a comment to `mdevCtl` what it protects.

Reviewed-by: Jonathon Jongsma <jjongsma@redhat.com>
Reviewed-by: Boris Fiuczynski <fiuczy@linux.ibm.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 3e3c20a6d4d1604fd25b48bb38a434e2bd1b7455..29d2a7677b768c398b618d404a507009bbc3bcc4 100644 (file)
--- a/src/node_device/node_device_udev.c
+++ b/src/node_device/node_device_udev.c
@@ -72,8 +72,9 @@ struct _udevEventData {
     /* init thread */
     virThread *initThread;
 
-    GList *mdevctlMonitors;
+    /* Protects @mdevctlMonitors */
     virMutex mdevctlLock;
+    GList *mdevctlMonitors;
     int mdevctlTimeout;
 };
 
@@ -2069,9 +2070,6 @@ udevPCITranslateInit(bool privileged G_GNUC_UNUSED)
 static void
 mdevctlUpdateThreadFunc(void *opaque G_GNUC_UNUSED)
 {
-    udevEventData *priv = driver->privateData;
-    VIR_LOCK_GUARD lock = virLockGuardLock(&priv->mdevctlLock);
-
     if (nodeDeviceUpdateMediatedDevices() < 0)
         VIR_WARN("mdevctl failed to update mediated devices");
 }