ndb - bug#30172

  Backup can assert with "big" table definitions
  Correct condition before fetching next meta-table
  Increase meta-buffer, to cope with atleast 2 tables

ndb/src/kernel/blocks/backup/Backup.cpp

@@ -374,15 +374,17 @@ Backup::execCONTINUEB(Signal* signal)
     ptr.p->files.getPtr(filePtr, ptr.p->ctlFilePtr);
     FsBuffer & buf = filePtr.p->operation.dataBuffer;
     
-    if(buf.getFreeSize() + buf.getMinRead() < buf.getUsableSize()) {
+    if(buf.getFreeSize() < buf.getMaxWrite()) {
       jam();
       TablePtr tabPtr LINT_SET_PTR;
       c_tablePool.getPtr(tabPtr, Tdata2);
       
-      DEBUG_OUT("Backup - Buffer full - " << buf.getFreeSize()
-		<< " + " << buf.getMinRead()
-		<< " < " << buf.getUsableSize()
-		<< " - tableId = " << tabPtr.p->tableId);
+      DEBUG_OUT("Backup - Buffer full - " 
+                << buf.getFreeSize()
+		<< " < " << buf.getMaxWrite()
+                << " (sz: " << buf.getUsableSize()
+                << " getMinRead: " << buf.getMinRead()
+		<< ") - tableId = " << tabPtr.p->tableId);
       
       signal->theData[0] = BackupContinueB::BUFFER_FULL_META;
       signal->theData[1] = Tdata1;

ndb/src/kernel/blocks/backup/Backup.hpp

@@ -518,7 +518,7 @@ public:
   Uint32 m_diskless;
 
   STATIC_CONST(NO_OF_PAGES_META_FILE = 
-	       (MAX_WORDS_META_FILE + BACKUP_WORDS_PER_PAGE - 1) / 
+	       (2*MAX_WORDS_META_FILE + BACKUP_WORDS_PER_PAGE - 1) / 
 	       BACKUP_WORDS_PER_PAGE);
   
   /**