Fix Eval scripts defrag (broken 7.0 in RC1) (#10271)

Remove scripts defragger since it was broken since #10126 (released in 7.0 RC1).
would crash the server if defragger starts in a server that contains eval scripts.

In #10126 the global `lua_script` dict became a dict to a custom `luaScript` struct with an internal `robj`
in it instead of a generic `sds` -> `robj` dict. This means we need custom code to defrag it and since scripts
should never really cause much fragmentation it makes more sense to simply remove the defrag code for scripts.

1 files changed, 27 insertions, 1 deletions

diff --git a/src/defrag.c b/src/defrag.c
index 16b1a4d2d..b0ae487f3 100644
--- a/src/defrag.c
+++ b/src/defrag.c
@@ -128,6 +128,27 @@ robj *activeDefragStringOb(robj* ob, long *defragged) {
     return ret;
 }
 
+/* Defrag helper for lua scripts
+ *
+ * returns NULL in case the allocation wasn't moved.
+ * when it returns a non-null value, the old pointer was already released
+ * and should NOT be accessed. */
+luaScript *activeDefragLuaScript(luaScript *script, long *defragged) {
+    luaScript *ret = NULL;
+
+    /* try to defrag script struct */
+    if ((ret = activeDefragAlloc(script))) {
+        script = ret;
+        (*defragged)++;
+    }
+
+    /* try to defrag actual script object */
+    robj *ob = activeDefragStringOb(script->body, defragged);
+    if (ob) script->body = ob;
+
+    return ret;
+}
+
 /* Defrag helper for dictEntries to be used during dict iteration (called on
  * each step). Returns a stat of how many pointers were moved. */
 long dictIterDefragEntry(dictIterator *iter) {
@@ -256,6 +277,7 @@ long activeDefragZsetEntry(zset *zs, dictEntry *de) {
 #define DEFRAG_SDS_DICT_VAL_IS_SDS 1
 #define DEFRAG_SDS_DICT_VAL_IS_STROB 2
 #define DEFRAG_SDS_DICT_VAL_VOID_PTR 3
+#define DEFRAG_SDS_DICT_VAL_LUA_SCRIPT 4
 
 /* Defrag a dict with sds key and optional value (either ptr, sds or robj string) */
 long activeDefragSdsDict(dict* d, int val_type) {
@@ -280,6 +302,10 @@ long activeDefragSdsDict(dict* d, int val_type) {
             void *newptr, *ptr = dictGetVal(de);
             if ((newptr = activeDefragAlloc(ptr)))
                 de->v.val = newptr, defragged++;
+        } else if (val_type == DEFRAG_SDS_DICT_VAL_LUA_SCRIPT) {
+            void *newptr, *ptr = dictGetVal(de);
+            if ((newptr = activeDefragLuaScript(ptr, &defragged)))
+                de->v.val = newptr;
         }
         defragged += dictIterDefragEntry(di);
     }
@@ -939,7 +965,7 @@ long defragOtherGlobals() {
     /* there are many more pointers to defrag (e.g. client argv, output / aof buffers, etc.
      * but we assume most of these are short lived, we only need to defrag allocations
      * that remain static for a long time */
-    defragged += activeDefragSdsDict(evalScriptsDict(), DEFRAG_SDS_DICT_VAL_IS_STROB);
+    defragged += activeDefragSdsDict(evalScriptsDict(), DEFRAG_SDS_DICT_VAL_LUA_SCRIPT);
     defragged += moduleDefragGlobals();
     return defragged;
 }