From: Daniel P. Berrange <berrange@redhat.com>
Date: Fri, 9 Oct 2009 09:32:37 +0000 (+0100)
Subject: Filter out stale domains from xenstore listing
X-Git-Url: http://xenbits.xensource.com/gitweb?a=commitdiff_plain;h=7c34bb2681f48e2a4e76de7f54c58b630a861777;p=libvirt.git

Filter out stale domains from xenstore listing

The xenstore database sometimes has stale domain IDs which are not
present in the hypervisor anymore. Filter these out to avoid causing
confusion

* src/xen/xs_internal.c: Filter domain IDs against HV's list
* src/xen/xen_hypervisor.h, src/xen/xen_hypervisor.c: Add new
  xenHypervisorHasDomain() method for checking ID validity
---

diff --git a/src/xen/xen_hypervisor.c b/src/xen/xen_hypervisor.c
index f25629af16..6d8bfdd517 100644
--- a/src/xen/xen_hypervisor.c
+++ b/src/xen/xen_hypervisor.c
@@ -2789,6 +2789,28 @@ xenHypervisorDomainGetOSType (virDomainPtr dom)
     return ostype;
 }
 
+int
+xenHypervisorHasDomain(virConnectPtr conn,
+                       int id)
+{
+    xenUnifiedPrivatePtr priv;
+    xen_getdomaininfo dominfo;
+
+    priv = (xenUnifiedPrivatePtr) conn->privateData;
+    if (priv->handle < 0)
+        return 0;
+
+    XEN_GETDOMAININFO_CLEAR(dominfo);
+
+    if (virXen_getdomaininfo(priv->handle, id, &dominfo) < 0)
+        return 0;
+
+    if (XEN_GETDOMAININFO_DOMAIN(dominfo) != id)
+        return 0;
+
+    return 1;
+}
+
 virDomainPtr
 xenHypervisorLookupDomainByID(virConnectPtr conn,
                               int id)
diff --git a/src/xen/xen_hypervisor.h b/src/xen/xen_hypervisor.h
index 766f676836..5971a90eb8 100644
--- a/src/xen/xen_hypervisor.h
+++ b/src/xen/xen_hypervisor.h
@@ -23,7 +23,9 @@ int    xenHypervisorInit                 (void);
 virCapsPtr xenHypervisorMakeCapabilities (virConnectPtr conn);
 
 /* The following calls are made directly by the Xen proxy: */
-
+int
+        xenHypervisorHasDomain(virConnectPtr conn,
+                               int id);
 virDomainPtr
         xenHypervisorLookupDomainByID   (virConnectPtr conn,
                                          int id);
diff --git a/src/xen/xs_internal.c b/src/xen/xs_internal.c
index f8ef00b616..0cca9b5807 100644
--- a/src/xen/xs_internal.c
+++ b/src/xen/xs_internal.c
@@ -543,8 +543,9 @@ int
 xenStoreNumOfDomains(virConnectPtr conn)
 {
     unsigned int num;
-    char **idlist;
-    int ret = -1;
+    char **idlist = NULL, *endptr;
+    int i, ret = -1, realnum = 0;
+    long id;
     xenUnifiedPrivatePtr priv;
 
     if (conn == NULL) {
@@ -557,10 +558,22 @@ xenStoreNumOfDomains(virConnectPtr conn)
         virXenStoreError(conn, VIR_ERR_INVALID_ARG, __FUNCTION__);
         return(-1);
     }
+
     idlist = xs_directory(priv->xshandle, 0, "/local/domain", &num);
     if (idlist) {
-        free(idlist);
-        ret = num;
+        for (i = 0; i < num; i++) {
+            id = strtol(idlist[i], &endptr, 10);
+            if ((endptr == idlist[i]) || (*endptr != 0))
+                goto out;
+
+            /* Sometimes xenstore has stale domain IDs, so filter
+               against the hypervisor's info */
+            if (xenHypervisorHasDomain(conn, (int)id))
+                realnum++;
+        }
+out:
+        VIR_FREE (idlist);
+        ret = realnum;
     }
     return(ret);
 }
@@ -577,7 +590,7 @@ xenStoreNumOfDomains(virConnectPtr conn)
  * Returns the number of domain found or -1 in case of error
  */
 static int
-xenStoreDoListDomains(xenUnifiedPrivatePtr priv, int *ids, int maxids)
+xenStoreDoListDomains(virConnectPtr conn, xenUnifiedPrivatePtr priv, int *ids, int maxids)
 {
     char **idlist = NULL, *endptr;
     unsigned int num, i;
@@ -595,7 +608,11 @@ xenStoreDoListDomains(xenUnifiedPrivatePtr priv, int *ids, int maxids)
         id = strtol(idlist[i], &endptr, 10);
         if ((endptr == idlist[i]) || (*endptr != 0))
             goto out;
-        ids[ret++] = (int) id;
+
+        /* Sometimes xenstore has stale domain IDs, so filter
+           against the hypervisor's info */
+        if (xenHypervisorHasDomain(conn, (int)id))
+            ids[ret++] = (int) id;
     }
 
 out:
@@ -627,7 +644,7 @@ xenStoreListDomains(virConnectPtr conn, int *ids, int maxids)
     priv = (xenUnifiedPrivatePtr) conn->privateData;
 
     xenUnifiedLock(priv);
-    ret = xenStoreDoListDomains(priv, ids, maxids);
+    ret = xenStoreDoListDomains(conn, priv, ids, maxids);
     xenUnifiedUnlock(priv);
 
     return(ret);
@@ -1299,7 +1316,7 @@ retry:
         virReportOOMError(NULL);
         return -1;
     }
-    nread = xenStoreDoListDomains(priv, new_domids, new_domain_cnt);
+    nread = xenStoreDoListDomains(conn, priv, new_domids, new_domain_cnt);
     if (nread != new_domain_cnt) {
         // mismatch. retry this read
         VIR_FREE(new_domids);
@@ -1380,7 +1397,7 @@ retry:
         virReportOOMError(NULL);
         return -1;
     }
-    nread = xenStoreDoListDomains(priv, new_domids, new_domain_cnt);
+    nread = xenStoreDoListDomains(conn, priv, new_domids, new_domain_cnt);
     if (nread != new_domain_cnt) {
         // mismatch. retry this read
         VIR_FREE(new_domids);