LXC: resolve issues in lxcDomainSetMaxMemory

This patch changes the setmaxmem function to support the '--live',
'--config', and '--current' flags by revectoring the code through
the setmem function using the VIR_DOMAIN_MEM_MAXIMUM flag. The
setmem code is refactored to handle both cases depending on the flag.

The changed maxmem code for the MEM_MAXIMUM path will not allow
modification to the memory values of an active guest unless the --config
switch is used.
Signed-off-by: NChen Hanxiao <chenhanxiao@cn.fujitsu.com>

src/lxc/lxc_driver.c

@@ -680,37 +680,6 @@ lxcDomainGetMaxMemory(virDomainPtr dom)
     return ret;
 }
 
-static int lxcDomainSetMaxMemory(virDomainPtr dom, unsigned long newmax)
-{
-    virDomainObjPtr vm;
-    int ret = -1;
-
-    if (!(vm = lxcDomObjFromDomain(dom)))
-        goto cleanup;
-
-    if (virDomainSetMaxMemoryEnsureACL(dom->conn, vm->def) < 0)
-        goto cleanup;
-
-    if (newmax < vm->def->mem.cur_balloon) {
-        if (!virDomainObjIsActive(vm)) {
-            vm->def->mem.cur_balloon = newmax;
-        } else {
-            virReportError(VIR_ERR_OPERATION_INVALID, "%s",
-                           _("Cannot set max memory lower than current"
-                             " memory for an active domain"));
-            goto cleanup;
-        }
-    }
-
-    vm->def->mem.max_balloon = newmax;
-    ret = 0;
-
- cleanup:
-    if (vm)
-        virObjectUnlock(vm);
-    return ret;
-}
-
 static int lxcDomainSetMemoryFlags(virDomainPtr dom, unsigned long newmem,
                                    unsigned int flags)
 {
@@ -721,10 +690,10 @@ static int lxcDomainSetMemoryFlags(virDomainPtr dom, unsigned long newmem,
     virLXCDomainObjPrivatePtr priv;
     virLXCDriverPtr driver = dom->conn->privateData;
     virLXCDriverConfigPtr cfg = NULL;
-    unsigned long oldmax = 0;
 
     virCheckFlags(VIR_DOMAIN_AFFECT_LIVE |
-                  VIR_DOMAIN_AFFECT_CONFIG, -1);
+                  VIR_DOMAIN_AFFECT_CONFIG |
+                  VIR_DOMAIN_MEM_MAXIMUM, -1);
 
     if (!(vm = lxcDomObjFromDomain(dom)))
         goto cleanup;
@@ -743,32 +712,50 @@ static int lxcDomainSetMemoryFlags(virDomainPtr dom, unsigned long newmem,
                                         &persistentDef) < 0)
         goto cleanup;
 
-    if (flags & VIR_DOMAIN_AFFECT_LIVE)
-        oldmax = vm->def->mem.max_balloon;
-    if (flags & VIR_DOMAIN_AFFECT_CONFIG) {
-        if (!oldmax || oldmax > persistentDef->mem.max_balloon)
-            oldmax = persistentDef->mem.max_balloon;
-    }
+    if (flags & VIR_DOMAIN_MEM_MAXIMUM) {
+        if (flags & VIR_DOMAIN_AFFECT_LIVE) {
+            virReportError(VIR_ERR_OPERATION_INVALID, "%s",
+                           _("Cannot resize the max memory "
+                             "on an active domain"));
+            goto cleanup;
+        }
 
-    if (newmem > oldmax) {
-        virReportError(VIR_ERR_INVALID_ARG,
-                       "%s", _("Cannot set memory higher than max memory"));
-        goto cleanup;
-    }
+        if (flags & VIR_DOMAIN_AFFECT_CONFIG) {
+            persistentDef->mem.max_balloon = newmem;
+            if (persistentDef->mem.cur_balloon > newmem)
+                persistentDef->mem.cur_balloon = newmem;
+            if (virDomainSaveConfig(cfg->configDir, persistentDef) < 0)
+                goto cleanup;
+        }
+    } else {
+        unsigned long oldmax = 0;
 
-    if (flags & VIR_DOMAIN_AFFECT_LIVE) {
-        if (virCgroupSetMemory(priv->cgroup, newmem) < 0) {
-            virReportError(VIR_ERR_OPERATION_FAILED,
-                           "%s", _("Failed to set memory for domain"));
-            goto cleanup;
+        if (flags & VIR_DOMAIN_AFFECT_LIVE)
+            oldmax = vm->def->mem.max_balloon;
+        if (flags & VIR_DOMAIN_AFFECT_CONFIG) {
+            if (!oldmax || oldmax > persistentDef->mem.max_balloon)
+                oldmax = persistentDef->mem.max_balloon;
         }
-    }
 
-    if (flags & VIR_DOMAIN_AFFECT_CONFIG) {
-        sa_assert(persistentDef);
-        persistentDef->mem.cur_balloon = newmem;
-        if (virDomainSaveConfig(cfg->configDir, persistentDef) < 0)
+        if (newmem > oldmax) {
+            virReportError(VIR_ERR_INVALID_ARG,
+                           "%s", _("Cannot set memory higher than max memory"));
             goto cleanup;
+        }
+
+        if (flags & VIR_DOMAIN_AFFECT_LIVE) {
+            if (virCgroupSetMemory(priv->cgroup, newmem) < 0) {
+                virReportError(VIR_ERR_OPERATION_FAILED,
+                               "%s", _("Failed to set memory for domain"));
+                goto cleanup;
+            }
+        }
+
+        if (flags & VIR_DOMAIN_AFFECT_CONFIG) {
+            persistentDef->mem.cur_balloon = newmem;
+            if (virDomainSaveConfig(cfg->configDir, persistentDef) < 0)
+                goto cleanup;
+        }
     }
 
     ret = 0;
@@ -786,6 +773,11 @@ static int lxcDomainSetMemory(virDomainPtr dom, unsigned long newmem)
     return lxcDomainSetMemoryFlags(dom, newmem, VIR_DOMAIN_AFFECT_LIVE);
 }
 
+static int lxcDomainSetMaxMemory(virDomainPtr dom, unsigned long newmax)
+{
+    return lxcDomainSetMemoryFlags(dom, newmax, VIR_DOMAIN_MEM_MAXIMUM);
+}
+
 static int
 lxcDomainSetMemoryParameters(virDomainPtr dom,
                              virTypedParameterPtr params,