snapshot: conf: Use common parsing and formatting functions for source

Disk source elements for snapshots were using separate code from our
config parser. As snapshots can be stored on more than just regular
files, we will need the universal parser to allow us to expose a variety
of snapshot disk targets. This patch reuses the config parsers and
formatters to do the job.

This initial support only changes the code without any visible XML
change.

src/conf/snapshot_conf.c

@@ -128,27 +128,42 @@ virDomainSnapshotDiskDefParseXML(xmlNodePtr node,
         }
     }
 
-    cur = node->children;
-    while (cur) {
-        if (cur->type == XML_ELEMENT_NODE) {
-            if (!def->file &&
-                xmlStrEqual(cur->name, BAD_CAST "source")) {
-                def->file = virXMLPropString(cur, "file");
-            } else if (!def->format &&
-                       xmlStrEqual(cur->name, BAD_CAST "driver")) {
-                char *driver = virXMLPropString(cur, "type");
-                def->format = virStorageFileFormatTypeFromString(driver);
-                if (def->format <= 0) {
-                    virReportError(VIR_ERR_INTERNAL_ERROR,
-                                   _("unknown disk snapshot driver '%s'"),
-                                   driver);
-                    VIR_FREE(driver);
-                    goto cleanup;
-                }
+    def->type = -1;
+
+    for (cur = node->children; cur; cur = cur->next) {
+        if (cur->type != XML_ELEMENT_NODE)
+            continue;
+
+        if (!def->file &&
+            xmlStrEqual(cur->name, BAD_CAST "source")) {
+
+            int backingtype = def->type;
+
+            if (backingtype < 0)
+                backingtype = VIR_DOMAIN_DISK_TYPE_FILE;
+
+            if (virDomainDiskSourceDefParse(cur,
+                                            backingtype,
+                                            &def->file,
+                                            NULL,
+                                            NULL,
+                                            NULL,
+                                            NULL) < 0)
+                goto cleanup;
+
+        } else if (!def->format &&
+                   xmlStrEqual(cur->name, BAD_CAST "driver")) {
+            char *driver = virXMLPropString(cur, "type");
+            def->format = virStorageFileFormatTypeFromString(driver);
+            if (def->format <= 0) {
+                virReportError(VIR_ERR_INTERNAL_ERROR,
+                               _("unknown disk snapshot driver '%s'"),
+                               driver);
                 VIR_FREE(driver);
+                goto cleanup;
             }
+            VIR_FREE(driver);
         }
-        cur = cur->next;
     }
 
     if (!def->snapshot && (def->file || def->format))
@@ -577,6 +592,8 @@ static void
 virDomainSnapshotDiskDefFormat(virBufferPtr buf,
                                virDomainSnapshotDiskDefPtr disk)
 {
+    int type = disk->type;
+
     if (!disk->name)
         return;
 
@@ -584,6 +601,10 @@ virDomainSnapshotDiskDefFormat(virBufferPtr buf,
     if (disk->snapshot > 0)
         virBufferAsprintf(buf, " snapshot='%s'",
                           virDomainSnapshotLocationTypeToString(disk->snapshot));
+
+    if (type < 0)
+        type = VIR_DOMAIN_DISK_TYPE_FILE;
+
     if (!disk->file && disk->format == 0) {
         virBufferAddLit(buf, "/>\n");
         return;
@@ -591,12 +612,14 @@ virDomainSnapshotDiskDefFormat(virBufferPtr buf,
 
     virBufferAddLit(buf, ">\n");
 
-    virBufferAdjustIndent(buf, 6);
     if (disk->format > 0)
-        virBufferEscapeString(buf, "<driver type='%s'/>\n",
+        virBufferEscapeString(buf, "      <driver type='%s'/>\n",
                               virStorageFileFormatTypeToString(disk->format));
-    virBufferEscapeString(buf, "<source file='%s'/>\n", disk->file);
-    virBufferAdjustIndent(buf, -6);
+    virDomainDiskSourceDefFormatInternal(buf,
+                                         type,
+                                         disk->file,
+                                         0, 0, 0, NULL, 0, NULL, NULL, 0);
+
     virBufferAddLit(buf, "    </disk>\n");
 }
 

src/conf/snapshot_conf.h

@@ -51,6 +51,7 @@ struct _virDomainSnapshotDiskDef {
     char *name; /* name matching the <target dev='...' of the domain */
     int index; /* index within snapshot->dom->disks that matches name */
     int snapshot; /* enum virDomainSnapshotLocation */
+    int type; /* enum virDomainDiskType */
     char *file; /* new source file when snapshot is external */
     int format; /* enum virStorageFileFormat */
 };