1 files changed, 43 insertions, 21 deletions

diff --git a/migration/block-dirty-bitmap.c b/migration/block-dirty-bitmap.c
index 405a259296..eb4ffeac4d 100644
--- a/migration/block-dirty-bitmap.c
+++ b/migration/block-dirty-bitmap.c
@@ -132,6 +132,7 @@ typedef struct LoadBitmapState {
     BlockDriverState *bs;
     BdrvDirtyBitmap *bitmap;
     bool migrated;
+    bool enabled;
 } LoadBitmapState;
 
 /* State of the dirty bitmap migration (DBM) during load process */
@@ -142,8 +143,10 @@ typedef struct DBMLoadState {
     BlockDriverState *bs;
     BdrvDirtyBitmap *bitmap;
 
-    GSList *enabled_bitmaps;
-    QemuMutex lock; /* protect enabled_bitmaps */
+    bool before_vm_start_handled; /* set in dirty_bitmap_mig_before_vm_start */
+
+    GSList *bitmaps;
+    QemuMutex lock; /* protect bitmaps */
 } DBMLoadState;
 
 typedef struct DBMState {
@@ -526,6 +529,7 @@ static int dirty_bitmap_load_start(QEMUFile *f, DBMLoadState *s)
     Error *local_err = NULL;
     uint32_t granularity = qemu_get_be32(f);
     uint8_t flags = qemu_get_byte(f);
+    LoadBitmapState *b;
 
     if (s->bitmap) {
         error_report("Bitmap with the same name ('%s') already exists on "
@@ -552,45 +556,59 @@ static int dirty_bitmap_load_start(QEMUFile *f, DBMLoadState *s)
 
     bdrv_disable_dirty_bitmap(s->bitmap);
     if (flags & DIRTY_BITMAP_MIG_START_FLAG_ENABLED) {
-        LoadBitmapState *b;
-
         bdrv_dirty_bitmap_create_successor(s->bitmap, &local_err);
         if (local_err) {
             error_report_err(local_err);
             return -EINVAL;
         }
-
-        b = g_new(LoadBitmapState, 1);
-        b->bs = s->bs;
-        b->bitmap = s->bitmap;
-        b->migrated = false;
-        s->enabled_bitmaps = g_slist_prepend(s->enabled_bitmaps, b);
     }
 
+    b = g_new(LoadBitmapState, 1);
+    b->bs = s->bs;
+    b->bitmap = s->bitmap;
+    b->migrated = false;
+    b->enabled = flags & DIRTY_BITMAP_MIG_START_FLAG_ENABLED;
+
+    s->bitmaps = g_slist_prepend(s->bitmaps, b);
+
     return 0;
 }
 
-void dirty_bitmap_mig_before_vm_start(void)
+/*
+ * before_vm_start_handle_item
+ *
+ * g_slist_foreach helper
+ *
+ * item is LoadBitmapState*
+ * opaque is DBMLoadState*
+ */
+static void before_vm_start_handle_item(void *item, void *opaque)
 {
-    DBMLoadState *s = &dbm_state.load;
-    GSList *item;
-
-    qemu_mutex_lock(&s->lock);
-
-    for (item = s->enabled_bitmaps; item; item = g_slist_next(item)) {
-        LoadBitmapState *b = item->data;
+    DBMLoadState *s = opaque;
+    LoadBitmapState *b = item;
 
+    if (b->enabled) {
         if (b->migrated) {
             bdrv_enable_dirty_bitmap(b->bitmap);
         } else {
             bdrv_dirty_bitmap_enable_successor(b->bitmap);
         }
+    }
 
+    if (b->migrated) {
+        s->bitmaps = g_slist_remove(s->bitmaps, b);
         g_free(b);
     }
+}
 
-    g_slist_free(s->enabled_bitmaps);
-    s->enabled_bitmaps = NULL;
+void dirty_bitmap_mig_before_vm_start(void)
+{
+    DBMLoadState *s = &dbm_state.load;
+    qemu_mutex_lock(&s->lock);
+
+    assert(!s->before_vm_start_handled);
+    g_slist_foreach(s->bitmaps, before_vm_start_handle_item, s);
+    s->before_vm_start_handled = true;
 
     qemu_mutex_unlock(&s->lock);
 }
@@ -607,11 +625,15 @@ static void dirty_bitmap_load_complete(QEMUFile *f, DBMLoadState *s)
         bdrv_reclaim_dirty_bitmap(s->bitmap, &error_abort);
     }
 
-    for (item = s->enabled_bitmaps; item; item = g_slist_next(item)) {
+    for (item = s->bitmaps; item; item = g_slist_next(item)) {
         LoadBitmapState *b = item->data;
 
         if (b->bitmap == s->bitmap) {
             b->migrated = true;
+            if (s->before_vm_start_handled) {
+                s->bitmaps = g_slist_remove(s->bitmaps, b);
+                g_free(b);
+            }
             break;
         }
     }