.

bigfile/virtmem.c

@@ -230,9 +230,12 @@ int fileh_mmap(VMA *vma, BigFileH *fileh, pgoff_t pgoffset, pgoff_t pglen)
     sigsegv_block(&save_sigset);
     virt_lock();
 
-    /* alloc vma->page_ismappedv[] */
+    /* start preparing vma */
     bzero(vma, sizeof(*vma));
+    vma->fileh       = fileh;
+    vma->f_pgoffset  = pgoffset;
 
+    /* alloc vma->page_ismappedv[] */
     vma->page_ismappedv = bitmap_alloc0(pglen);
     if (!vma->page_ismappedv)
         goto fail;
@@ -241,26 +244,41 @@ int fileh_mmap(VMA *vma, BigFileH *fileh, pgoff_t pgoffset, pgoff_t pglen)
     vma->mmap_overlay = (fops->mmap_setup_read != NULL);
 
     if (vma->mmap_overlay) {
-        /* wcfs: mmap(base, READ) + mmap(fileh->dirty_pages) over it */
+        /* wcfs: mmap(base, READ) */
         TODO (file->blksize != fileh->ramh->ram->pagesize);
         addr = fops->mmap_setup_read(file, pgoffset, pglen, vma);
-        if (!addr)
-            goto fail;
-        // XXX + mmap(fileh->dirty_pages)
     } else {
         /* !wcfs: allocate address space somewhere */
         addr = mem_valloc(NULL, len);
-        if (!addr)
-            goto fail;
     }
+    if (!addr)
+        goto fail;
 
-
-    /* everything allocated - link it up */
+    /* vma address range known */
     vma->addr_start  = (uintptr_t)addr;
     vma->addr_stop   = vma->addr_start + len;
 
-    vma->fileh       = fileh;
-    vma->f_pgoffset  = pgoffset;
+    /* wcfs: mmap(fileh->dirty_pages) over base */
+    if (vma->mmap_overlay) {
+        Page* page;
+        struct list_head *hpage;
+
+        list_for_each(hpage, &fileh->dirty_pages) {
+            page = list_entry(hpage, typeof(*page), in_dirty);
+            BUG_ON(page->state != PAGE_DIRTY);
+
+            if (!(pgoffset <= page->f_pgoffset && page->f_pgoffset < pgoffset + pglen))
+                continue; /* page is out of requested mmap coverage */
+
+            // XXX err
+            // XXX notify watcher that we mmaped RAM page in its range?
+            page_mmap(page, vma_page_addr(vma, page), PROT_READ | PROT_WRITE);
+            bitmap_set_bit(vma->page_ismappedv, page->f_pgoffset - vma->f_pgoffset);
+            page_incref(page);
+        }
+    }
+
+    /* everything allocated - link it up */
 
     // XXX need to init vma->virt_list first?
     /* hook vma to fileh->mmaps */
@@ -276,7 +294,7 @@ out:
 
 fail:
     free(vma->page_ismappedv);
-    vma->page_ismappedv = NULL;
+    bzero(vma, sizeof(*vma));
     err = -1;
     goto out;
 }