.

bigfile/tests/test_virtmem.c

@@ -1411,8 +1411,11 @@ void test_file_access_mmapbase(void)
 
     /* discard - changes should go away */
     diag("discard");
+    fprintf(stderr, "\n\n\n\n");
     fileh_dirty_discard(fh);
 
+    CHECK_NOPAGE(         100                      );
+
     ok1(!M(vma, 0));    CHECK_NOPAGE(         100                      );
     ok1(!M(vma, 1));    CHECK_NOPAGE(         101                      );
     ok1(!M(vma, 2));    CHECK_NOPAGE(         102                      );
@@ -1423,6 +1426,11 @@ void test_file_access_mmapbase(void)
     ok1(!M(vma2, 2));
     ok1(!M(vma2, 3));
 
+    CHECK_MRU   (/*empty*/);
+    CHECK_DIRTY (/*empty*/);
+
+    // XXX read vma[0] (and other discarded pages) gives pristine data
+
 
     // XXX writeout STORE, MARK, STORE+MARK
 

bigfile/virtmem.c

@@ -39,6 +39,7 @@
 
 static size_t   page_size(const Page *page);
 static void     page_drop_memory(Page *page);
+static void     page_del(Page *page);
 static void    *vma_page_addr(VMA *vma, Page *page);
 static pgoff_t  vma_addr_fpgoffset(VMA *vma, uintptr_t addr);
 static void     vma_mmap_page(VMA *vma, Page *page);
@@ -195,9 +196,10 @@ void fileh_close(BigFileH *fileh)
          * currently being done in another thread */
         BUG_ON(page->state == PAGE_LOADING);
         page_drop_memory(page);
-        list_del(&page->lru);
-        bzero(page, sizeof(*page)); /* just in case */
-        free(page);
+        page_del(page);
+//        list_del(&page->lru);
+//        bzero(page, sizeof(*page)); /* just in case */
+//        free(page);
     }
 
     BUG_ON(!list_empty(&fileh->dirty_pages));
@@ -468,7 +470,10 @@ void fileh_dirty_discard(BigFileH *fileh)
         page = list_entry(hpage, typeof(*page), in_dirty);
         BUG_ON(page->state != PAGE_DIRTY);
 
+        fprintf(stderr, "discard p%ld\n", page->f_pgoffset);
         page_drop_memory(page);
+
+        page_del(page);
         // XXX wcfs: remmap page(s) to base file
     }
 
@@ -768,9 +773,10 @@ VMFaultResult vma_on_pagefault(VMA *vma, uintptr_t addr, int write)
          * removed it from pagemap */
         if (page->state == PAGE_LOADING_INVALIDATED) {
             page_drop_memory(page);
-            list_del(&page->lru);
-            bzero(page, sizeof(*page)); /* just in case */
-            free(page);
+            page_del(page);
+//            list_del(&page->lru);
+//            bzero(page, sizeof(*page)); /* just in case */
+//            free(page);
         }
 
         /* else just mark the page as loaded ok */
@@ -879,9 +885,10 @@ static int __ram_reclaim(RAM *ram)
 
             /* delete page & its entry in fileh->pagemap */
             pagemap_del(&page->fileh->pagemap, page->f_pgoffset);
-            list_del(&page->lru);
-            bzero(page, sizeof(*page)); /* just in case */
-            free(page);
+            page_del(page);
+//            list_del(&page->lru);
+//            bzero(page, sizeof(*page)); /* just in case */
+//            free(page);
         }
 
     }
@@ -966,6 +973,13 @@ static void page_drop_memory(Page *page)
     // XXX touch lru?
 }
 
+/* page_del deletes Page struct (but not page memory - see page_drop_memory). */
+static void page_del(Page *page) {
+    list_del(&page->lru);
+    bzero(page, sizeof(*page)); /* just in case */
+    free(page);
+}
+
 
 
 /* vma: page -> addr  where it should-be mmaped in vma */