get db truncate working

git-svn-id: file:///svn/tokudb.1131b+1080a@6191 c7de825b-a66e-492c-adef-691d508d4ae1

newbrt/brt.c

@@ -2344,10 +2344,10 @@ int toku_brt_reopen(BRT brt, const char *fname, const char *fname_in_env, TOKUTX
     // set the cachefile
     r = toku_cachefile_set_fd(brt->cf, fd, fname_in_env);
     assert(r == 0);
+    brt->h = 0;  // set_fd should close the header
     toku_logger_log_fopen(txn, fname_in_env, toku_cachefile_filenum(brt->cf));
 
     // init the tree header
-    assert(brt->h == 0);
     r = toku_read_brt_header_and_store_in_cachefile(brt->cf, &brt->h);
     if (r == -1) {
         r = brt_alloc_init_header(brt, NULL, txn);

newbrt/cachetable.c

@@ -260,6 +260,12 @@ int toku_cachefile_set_fd (CACHEFILE cf, int fd, const char *fname) {
     if (r != 0) { 
         r=errno; close(fd); return r; 
     }
+    if (cf->close_userdata && (r = cf->close_userdata(cf, cf->userdata))) {
+        return r;
+    }
+    cf->close_userdata = NULL;
+    cf->userdata = NULL;
+
     close(cf->fd);
     cf->fd = -1;
     if (cf->fname) {