1 files changed, 0 insertions, 106 deletions
diff --git a/external/meta-virtualization/recipes-extended/libvirt/libvirt/lxc_monitor-Avoid-AB-BA-lock-race.patch b/external/meta-virtualization/recipes-extended/libvirt/libvirt/lxc_monitor-Avoid-AB-BA-lock-race.patch
deleted file mode 100644
index fc3880fb..00000000
--- a/external/meta-virtualization/recipes-extended/libvirt/libvirt/lxc_monitor-Avoid-AB-BA-lock-race.patch
+++ /dev/null
@@ -1,106 +0,0 @@
-From 7882c6eca53fe9abe253497a50f6c5ae062176d3 Mon Sep 17 00:00:00 2001
-From: Mark Asselstine <mark.asselstine@windriver.com>
-Date: Mon, 24 Sep 2018 11:11:35 -0400
-Subject: [PATCH] lxc_monitor: Avoid AB / BA lock race
-
-A deadlock situation can occur when autostarting a LXC domain 'guest'
-due to two threads attempting to take opposing locks while holding
-opposing locks (AB BA problem). Thread A takes and holds the 'vm' lock
-while attempting to take the 'client' lock, meanwhile, thread B takes
-and holds the 'client' lock while attempting to take the 'vm' lock.
-
-The potential for this can be seen as follows:
-
-Thread A:
-virLXCProcessAutostartDomain (takes vm lock)
- --> virLXCProcessStart
-  --> virLXCProcessConnectMonitor
-   --> virLXCMonitorNew
-    --> virNetClientSetCloseCallback (wants client lock)
-
-Thread B:
-virNetClientIncomingEvent (takes client lock)
- --> virNetClientIOHandleInput
-  --> virNetClientCallDispatch
-   --> virNetClientCallDispatchMessage
-    --> virNetClientProgramDispatch
-     --> virLXCMonitorHandleEventInit
-      --> virLXCProcessMonitorInitNotify (wants vm lock)
-
-Since these threads are scheduled independently and are preemptible it
-is possible for the deadlock scenario to occur where each thread locks
-their first lock but both will fail to get their second lock and just
-spin forever. You get something like:
-
-virLXCProcessAutostartDomain (takes vm lock)
- --> virLXCProcessStart
-  --> virLXCProcessConnectMonitor
-   --> virLXCMonitorNew
-<...>
-virNetClientIncomingEvent (takes client lock)
- --> virNetClientIOHandleInput
-  --> virNetClientCallDispatch
-   --> virNetClientCallDispatchMessage
-    --> virNetClientProgramDispatch
-     --> virLXCMonitorHandleEventInit
-      --> virLXCProcessMonitorInitNotify (wants vm lock but spins)
-<...>
-    --> virNetClientSetCloseCallback (wants client lock but spins)
-
-Neither thread ever gets the lock it needs to be able to continue
-while holding the lock that the other thread needs.
-
-The actual window for preemption which can cause this deadlock is
-rather small, between the calls to virNetClientProgramNew() and
-execution of virNetClientSetCloseCallback(), both in
-virLXCMonitorNew(). But it can be seen in real world use that this
-small window is enough.
-
-By moving the call to virNetClientSetCloseCallback() ahead of
-virNetClientProgramNew() we can close any possible chance of the
-deadlock taking place. There should be no other implications to the
-move since the close callback (in the unlikely event was called) will
-spin on the vm lock. The remaining work that takes place between the
-old call location of virNetClientSetCloseCallback() and the new
-location is unaffected by the move.
-
-Upstream-Status: Backport commit 7882c6eca53f
-
-Signed-off-by: Mark Asselstine <mark.asselstine@windriver.com>
-Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
----
- src/lxc/lxc_monitor.c | 11 +++++++----
- 1 file changed, 7 insertions(+), 4 deletions(-)
-
-diff --git a/src/lxc/lxc_monitor.c b/src/lxc/lxc_monitor.c
-index e765c16..0b18a14 100644
---- a/src/lxc/lxc_monitor.c
-+++ b/src/lxc/lxc_monitor.c
-@@ -161,6 +161,13 @@ virLXCMonitorPtr virLXCMonitorNew(virDomainObjPtr vm,
-     if (virNetClientRegisterAsyncIO(mon->client) < 0)
-         goto error;
- 
-+    /* avoid deadlock by making this call before assigning virLXCMonitorEvents */
-+    virNetClientSetCloseCallback(mon->client, virLXCMonitorEOFNotify, mon,
-+                                 virLXCMonitorCloseFreeCallback);
-+
-+    /* close callback now has its own reference */
-+    virObjectRef(mon);
-+
-     if (!(mon->program = virNetClientProgramNew(VIR_LXC_MONITOR_PROGRAM,
-                                                 VIR_LXC_MONITOR_PROGRAM_VERSION,
-                                                 virLXCMonitorEvents,
-@@ -175,10 +182,6 @@ virLXCMonitorPtr virLXCMonitorNew(virDomainObjPtr vm,
-     mon->vm = virObjectRef(vm);
-     memcpy(&mon->cb, cb, sizeof(mon->cb));
- 
--    virObjectRef(mon);
--    virNetClientSetCloseCallback(mon->client, virLXCMonitorEOFNotify, mon,
--                                 virLXCMonitorCloseFreeCallback);
--
-  cleanup:
-     VIR_FREE(sockpath);
-     return mon;
--- 
-2.7.4
-