qemu: backup: Split up code traversing checkpoint list looking for bitmaps

The algorithm is getting quite complex. Split out the lookup of range of
backing chain storage sources and bitmaps contained in them which
correspond to one checkpoint.

Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>

diff --git a/src/qemu/qemu_backup.c b/src/qemu/qemu_backup.c
index b317b841cdfa608362c92a4cafadeb0103866bf6..8d75b59db2898659c40b5f8f8fd88ff8e98aa6dd 100644 (file)
--- a/src/qemu/qemu_backup.c
+++ b/src/qemu/qemu_backup.c
@@ -173,72 +173,83 @@ qemuBackupDiskDataCleanup(virDomainObjPtr vm,
 }
 
 
+static int
+qemuBackupGetBitmapMergeRange(virStorageSourcePtr from,
+                              const char *bitmapname,
+                              virJSONValuePtr *actions,
+                              virStorageSourcePtr *to,
+                              const char *diskdst,
+                              virHashTablePtr blockNamedNodeData)
+{
+    g_autoptr(virJSONValue) act = virJSONValueNewArray();
+    virStorageSourcePtr tmpsrc = NULL;
+    virStorageSourcePtr n;
+    bool foundbitmap = false;
+
+    for (n = from; virStorageSourceIsBacking(n); n = n->backingStore) {
+        qemuBlockNamedNodeDataBitmapPtr bitmap = NULL;
+
+        if (!(bitmap = qemuBlockNamedNodeDataGetBitmapByName(blockNamedNodeData,
+                                                             n,
+                                                             bitmapname)))
+            break;
+
+        foundbitmap = true;
+
+        if (bitmap->inconsistent) {
+            virReportError(VIR_ERR_INVALID_ARG,
+                           _("bitmap '%s' for image '%s%u' is inconsistent"),
+                           bitmap->name, diskdst, n->id);
+            return -1;
+        }
+
+        if (qemuMonitorTransactionBitmapMergeSourceAddBitmap(act,
+                                                             n->nodeformat,
+                                                             bitmapname) < 0)
+            return -1;
+
+        tmpsrc = n;
+    }
+
+    if (!foundbitmap) {
+        virReportError(VIR_ERR_INVALID_ARG,
+                       _("failed to find bitmap '%s' in image '%s%u'"),
+                       bitmapname, diskdst, from->id);
+        return -1;
+    }
+
+    *actions = g_steal_pointer(&act);
+    *to = tmpsrc;
+
+    return 0;
+}
+
+
 virJSONValuePtr
 qemuBackupDiskPrepareOneBitmapsChain(virDomainMomentDefPtr *incremental,
                                      virStorageSourcePtr backingChain,
                                      virHashTablePtr blockNamedNodeData,
                                      const char *diskdst)
 {
-    qemuBlockNamedNodeDataBitmapPtr bitmap;
     g_autoptr(virJSONValue) ret = NULL;
     size_t incridx = 0;
+    virStorageSourcePtr n = backingChain;
 
     ret = virJSONValueNewArray();
 
-    if (!(bitmap = qemuBlockNamedNodeDataGetBitmapByName(blockNamedNodeData,
-                                                         backingChain,
-                                                         incremental[0]->name))) {
-        virReportError(VIR_ERR_INVALID_ARG,
-                       _("failed to find bitmap '%s' in image '%s%u'"),
-                       incremental[0]->name, diskdst, backingChain->id);
-        return NULL;
-    }
+    for (incridx = 0; incremental[incridx]; incridx++) {
+        g_autoptr(virJSONValue) tmp = virJSONValueNewArray();
+        virStorageSourcePtr tmpsrc = NULL;
 
-    while (bitmap) {
-        if (bitmap->inconsistent) {
-            virReportError(VIR_ERR_INVALID_ARG,
-                           _("bitmap '%s' for image '%s%u' is inconsistent"),
-                           bitmap->name, diskdst, backingChain->id);
+        if (qemuBackupGetBitmapMergeRange(n, incremental[incridx]->name,
+                                          &tmp, &tmpsrc, diskdst,
+                                          blockNamedNodeData) < 0)
             return NULL;
-        }
 
-        if (qemuMonitorTransactionBitmapMergeSourceAddBitmap(ret,
-                                                             backingChain->nodeformat,
-                                                             bitmap->name) < 0)
+        if (virJSONValueArrayConcat(ret, tmp) < 0)
             return NULL;
 
-        if (backingChain->backingStore &&
-            (bitmap = qemuBlockNamedNodeDataGetBitmapByName(blockNamedNodeData,
-                                                            backingChain->backingStore,
-                                                            incremental[incridx]->name))) {
-            backingChain = backingChain->backingStore;
-            continue;
-        }
-
-        if (incremental[incridx + 1]) {
-            if ((bitmap = qemuBlockNamedNodeDataGetBitmapByName(blockNamedNodeData,
-                                                                backingChain,
-                                                                incremental[incridx + 1]->name))) {
-                incridx++;
-                continue;
-            }
-
-            if (backingChain->backingStore &&
-                (bitmap = qemuBlockNamedNodeDataGetBitmapByName(blockNamedNodeData,
-                                                                backingChain->backingStore,
-                                                                incremental[incridx + 1]->name))) {
-                incridx++;
-                backingChain = backingChain->backingStore;
-                continue;
-            }
-
-            virReportError(VIR_ERR_INVALID_ARG,
-                           _("failed to find bitmap '%s' in image '%s%u'"),
-                           incremental[incridx]->name, diskdst, backingChain->id);
-            return NULL;
-        } else {
-            break;
-        }
+        n = tmpsrc;
     }
 
     return g_steal_pointer(&ret);