[PULL 1/5] migration: dirty-bitmap: Use struct for alias map inner members

[Eric Blake <eblake@redhat.com>]

From: Peter Krempa <pkrempa@redhat.com>

Currently the alias mapping hash stores just strings of the target
objects internally. In further patches we'll be adding another member
which will need to be stored in the map so pass a copy of the whole
BitmapMigrationBitmapAlias QAPI struct into the map.

Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Message-Id: <fc5f27e1fe16cb75e08a248c2d938de3997b9bfb.1613150869.git.pkrempa@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
[eblake: adjust long lines]
Signed-off-by: Eric Blake <eblake@redhat.com>
---
 migration/block-dirty-bitmap.c | 33 +++++++++++++++++++++------------
 1 file changed, 21 insertions(+), 12 deletions(-)

diff --git a/migration/block-dirty-bitmap.c b/migration/block-dirty-bitmap.c
index c61d382be87c..b39c13ce4ebe 100644
--- a/migration/block-dirty-bitmap.c
+++ b/migration/block-dirty-bitmap.c
@@ -75,6 +75,8 @@
 #include "qemu/id.h"
 #include "qapi/error.h"
 #include "qapi/qapi-commands-migration.h"
+#include "qapi/qapi-visit-migration.h"
+#include "qapi/clone-visitor.h"
 #include "trace.h"

 #define CHUNK_SIZE     (1 << 10)
@@ -224,6 +226,7 @@ static GHashTable *construct_alias_map(const BitmapMigrationNodeAliasList *bbm,
         AliasMapInnerNode *amin;
         GHashTable *bitmaps_map;
         const char *node_map_from, *node_map_to;
+        GDestroyNotify gdn;

         if (!id_wellformed(bmna->alias)) {
             error_setg(errp, "The node alias '%s' is not well-formed",
@@ -263,8 +266,9 @@ static GHashTable *construct_alias_map(const BitmapMigrationNodeAliasList *bbm,
             node_map_to = bmna->node_name;
         }

-        bitmaps_map = g_hash_table_new_full(g_str_hash, g_str_equal,
-                                            g_free, g_free);
+        gdn = (GDestroyNotify) qapi_free_BitmapMigrationBitmapAlias;
+        bitmaps_map = g_hash_table_new_full(g_str_hash, g_str_equal, g_free,
+                                            gdn);

         amin = g_new(AliasMapInnerNode, 1);
         *amin = (AliasMapInnerNode){
@@ -276,7 +280,7 @@ static GHashTable *construct_alias_map(const BitmapMigrationNodeAliasList *bbm,

         for (bmbal = bmna->bitmaps; bmbal; bmbal = bmbal->next) {
             const BitmapMigrationBitmapAlias *bmba = bmbal->value;
-            const char *bmap_map_from, *bmap_map_to;
+            const char *bmap_map_from;

             if (strlen(bmba->alias) > UINT8_MAX) {
                 error_setg(errp,
@@ -293,7 +297,6 @@ static GHashTable *construct_alias_map(const BitmapMigrationNodeAliasList *bbm,

             if (name_to_alias) {
                 bmap_map_from = bmba->name;
-                bmap_map_to = bmba->alias;

                 if (g_hash_table_contains(bitmaps_map, bmba->name)) {
                     error_setg(errp, "The bitmap '%s'/'%s' is mapped twice",
@@ -302,7 +305,6 @@ static GHashTable *construct_alias_map(const BitmapMigrationNodeAliasList *bbm,
                 }
             } else {
                 bmap_map_from = bmba->alias;
-                bmap_map_to = bmba->name;

                 if (g_hash_table_contains(bitmaps_map, bmba->alias)) {
                     error_setg(errp, "The bitmap alias '%s'/'%s' is used twice",
@@ -311,8 +313,8 @@ static GHashTable *construct_alias_map(const BitmapMigrationNodeAliasList *bbm,
                 }
             }

-            g_hash_table_insert(bitmaps_map,
-                                g_strdup(bmap_map_from), g_strdup(bmap_map_to));
+            g_hash_table_insert(bitmaps_map, g_strdup(bmap_map_from),
+                                QAPI_CLONE(BitmapMigrationBitmapAlias, bmba));
         }
     }

@@ -538,11 +540,15 @@ static int add_bitmaps_to_list(DBMSaveState *s, BlockDriverState *bs,
         }

         if (bitmap_aliases) {
-            bitmap_alias = g_hash_table_lookup(bitmap_aliases, bitmap_name);
-            if (!bitmap_alias) {
+            BitmapMigrationBitmapAlias *bmap_inner;
+
+            bmap_inner = g_hash_table_lookup(bitmap_aliases, bitmap_name);
+            if (!bmap_inner) {
                 /* Skip bitmaps with no alias */
                 continue;
             }
+
+            bitmap_alias = bmap_inner->alias;
         } else {
             if (strlen(bitmap_name) > UINT8_MAX) {
                 error_report("Cannot migrate bitmap '%s' on node '%s': "
@@ -1074,13 +1080,16 @@ static int dirty_bitmap_load_header(QEMUFile *f, DBMLoadState *s,

         bitmap_name = s->bitmap_alias;
         if (!s->cancelled && bitmap_alias_map) {
-            bitmap_name = g_hash_table_lookup(bitmap_alias_map,
-                                              s->bitmap_alias);
-            if (!bitmap_name) {
+            BitmapMigrationBitmapAlias *bmap_inner;
+
+            bmap_inner = g_hash_table_lookup(bitmap_alias_map, s->bitmap_alias);
+            if (!bmap_inner) {
                 error_report("Error: Unknown bitmap alias '%s' on node "
                              "'%s' (alias '%s')", s->bitmap_alias,
                              s->bs->node_name, s->node_alias);
                 cancel_incoming_locked(s);
+            } else {
+                bitmap_name = bmap_inner->name;
             }
         }

-- 
2.30.1