From: Marc Hartmayer <mhartmay@linux.ibm.com>
Date: Tue, 23 Apr 2024 18:08:53 +0000 (+0200)
Subject: node_device_udev: Don't take `mdevctlLock` for `mdevctl list` and add comments about... 
X-Git-Url: http://xenbits.xensource.com/gitweb?a=commitdiff_plain;h=c320c37917c42a09799c7a639805ae9afff0831d;p=libvirt.git

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

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at a time", but this reason is no longer valid or maybe it never was.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 3e3c20a6d4..29d2a7677b 100644
--- 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");
 }