[libvirt] [PATCH v2 08/14] rpc: Correct locking and simplify the function

[Marc Hartmayer]

The lock for @client must not only be held for the duration of
checking whether the client wants to close, but also for as long as
we're closing the client. The same applies to the tracking of
authentications.

Signed-off-by: Marc Hartmayer <mhartmay at linux.vnet.ibm.com>
---
 src/libvirt_remote.syms      |  5 +++--
 src/rpc/virnetserver.c       | 20 ++++++++++++++------
 src/rpc/virnetserverclient.c | 35 ++++++++++++++++++-----------------
 src/rpc/virnetserverclient.h |  5 +++--
 4 files changed, 38 insertions(+), 27 deletions(-)

diff --git a/src/libvirt_remote.syms b/src/libvirt_remote.syms
index cecd71c49e7f..4e684ef69514 100644
--- a/src/libvirt_remote.syms
+++ b/src/libvirt_remote.syms
@@ -125,6 +125,7 @@ virNetServerUpdateServices;
 # rpc/virnetserverclient.h
 virNetServerClientAddFilter;
 virNetServerClientClose;
+virNetServerClientCloseLocked;
 virNetServerClientDelayedClose;
 virNetServerClientGetAuth;
 virNetServerClientGetFD;
@@ -138,7 +139,7 @@ virNetServerClientGetUNIXIdentity;
 virNetServerClientImmediateClose;
 virNetServerClientInit;
 virNetServerClientInitKeepAlive;
-virNetServerClientIsClosed;
+virNetServerClientIsClosedLocked;
 virNetServerClientIsLocal;
 virNetServerClientIsSecure;
 virNetServerClientLocalAddrStringSASL;
@@ -156,7 +157,7 @@ virNetServerClientSetCloseHook;
 virNetServerClientSetDispatcher;
 virNetServerClientSetReadonly;
 virNetServerClientStartKeepAlive;
-virNetServerClientWantClose;
+virNetServerClientWantCloseLocked;
 
 
 # rpc/virnetservermdns.h
diff --git a/src/rpc/virnetserver.c b/src/rpc/virnetserver.c
index 43f889e2a037..57cbfb59ab53 100644
--- a/src/rpc/virnetserver.c
+++ b/src/rpc/virnetserver.c
@@ -285,8 +285,10 @@ int virNetServerAddClient(virNetServerPtr srv,
         goto error;
     srv->clients[srv->nclients-1] = virObjectRef(client);
 
-    if (virNetServerClientNeedAuth(client))
+    virObjectLock(client);
+    if (virNetServerClientNeedAuthLocked(client))
         virNetServerTrackPendingAuthLocked(srv);
+    virObjectUnlock(client);
 
     virNetServerCheckLimits(srv);
 
@@ -847,6 +849,7 @@ void
 virNetServerProcessClients(virNetServerPtr srv)
 {
     size_t i;
+    virNetServerClientPtr client;
 
     virObjectLock(srv);
 
@@ -855,15 +858,18 @@ virNetServerProcessClients(virNetServerPtr srv)
         /* Coverity 5.3.0 couldn't see that srv->clients is non-NULL
          * if srv->nclients is non-zero.  */
         sa_assert(srv->clients);
-        if (virNetServerClientWantClose(srv->clients[i]))
-            virNetServerClientClose(srv->clients[i]);
-        if (virNetServerClientIsClosed(srv->clients[i])) {
-            virNetServerClientPtr client = srv->clients[i];
 
+        client = srv->clients[i];
+        virObjectLock(client);
+        if (virNetServerClientWantCloseLocked(client))
+            virNetServerClientCloseLocked(client);
+
+        if (virNetServerClientIsClosedLocked(client)) {
             VIR_DELETE_ELEMENT(srv->clients, i, srv->nclients);
 
-            if (virNetServerClientNeedAuth(client))
+            if (virNetServerClientNeedAuthLocked(client))
                 virNetServerTrackCompletedAuthLocked(srv);
+            virObjectUnlock(client);
 
             virNetServerCheckLimits(srv);
 
@@ -872,6 +878,8 @@ virNetServerProcessClients(virNetServerPtr srv)
             virObjectLock(srv);
 
             goto reprocess;
+        } else {
+            virObjectUnlock(client);
         }
     }
 
diff --git a/src/rpc/virnetserverclient.c b/src/rpc/virnetserverclient.c
index afe4fb47a256..dee94450dfa3 100644
--- a/src/rpc/virnetserverclient.c
+++ b/src/rpc/virnetserverclient.c
@@ -987,17 +987,15 @@ void virNetServerClientDispose(void *obj)
  * Full free of the client is done later in a safe point
  * where it can be guaranteed it is no longer in use
  */
-void virNetServerClientClose(virNetServerClientPtr client)
+void
+virNetServerClientCloseLocked(virNetServerClientPtr client)
 {
     virNetServerClientCloseFunc cf;
     virKeepAlivePtr ka;
 
-    virObjectLock(client);
     VIR_DEBUG("client=%p", client);
-    if (!client->sock) {
-        virObjectUnlock(client);
+    if (!client->sock)
         return;
-    }
 
     if (client->keepalive) {
         virKeepAliveStop(client->keepalive);
@@ -1048,20 +1046,25 @@ void virNetServerClientClose(virNetServerClientPtr client)
         virObjectUnref(client->sock);
         client->sock = NULL;
     }
-
-    virObjectUnlock(client);
 }
 
 
-bool virNetServerClientIsClosed(virNetServerClientPtr client)
+void
+virNetServerClientClose(virNetServerClientPtr client)
 {
-    bool closed;
     virObjectLock(client);
-    closed = client->sock == NULL ? true : false;
+    virNetServerClientCloseLocked(client);
     virObjectUnlock(client);
-    return closed;
 }
 
+
+bool
+virNetServerClientIsClosedLocked(virNetServerClientPtr client)
+{
+    return client->sock == NULL ? true : false;
+}
+
+
 void virNetServerClientDelayedClose(virNetServerClientPtr client)
 {
     virObjectLock(client);
@@ -1076,13 +1079,11 @@ void virNetServerClientImmediateClose(virNetServerClientPtr client)
     virObjectUnlock(client);
 }
 
-bool virNetServerClientWantClose(virNetServerClientPtr client)
+
+bool
+virNetServerClientWantCloseLocked(virNetServerClientPtr client)
 {
-    bool wantClose;
-    virObjectLock(client);
-    wantClose = client->wantClose;
-    virObjectUnlock(client);
-    return wantClose;
+    return client->wantClose;
 }
 
 
diff --git a/src/rpc/virnetserverclient.h b/src/rpc/virnetserverclient.h
index 1182d53c7059..b7752a61fa8e 100644
--- a/src/rpc/virnetserverclient.h
+++ b/src/rpc/virnetserverclient.h
@@ -124,11 +124,12 @@ void virNetServerClientSetDispatcher(virNetServerClientPtr client,
                                      virNetServerClientDispatchFunc func,
                                      void *opaque);
 void virNetServerClientClose(virNetServerClientPtr client);
-bool virNetServerClientIsClosed(virNetServerClientPtr client);
+void virNetServerClientCloseLocked(virNetServerClientPtr client);
+bool virNetServerClientIsClosedLocked(virNetServerClientPtr client);
 
 void virNetServerClientDelayedClose(virNetServerClientPtr client);
 void virNetServerClientImmediateClose(virNetServerClientPtr client);
-bool virNetServerClientWantClose(virNetServerClientPtr client);
+bool virNetServerClientWantCloseLocked(virNetServerClientPtr client);
 
 int virNetServerClientInit(virNetServerClientPtr client);
 
-- 
2.13.4