.

wcfs/internal/wcfs_misc.h

@@ -28,6 +28,9 @@ using std::string;
 #include <tuple>
 using std::tuple;
 
+// nil is synonim for nullptr and NULL.
+const nullptr_t nil = nullptr;
+
 // error mimics error from Go.
 struct error {
     string err;

wcfs/internal/wcfs_virtmem.cpp

@@ -123,7 +123,7 @@ struct _Mapping {
         return blk_start + (mem_stop - mem_start) / file->blksize;
     }
 
-    void _remmapblk(int64_t blk, Tid at);
+    error _remmapblk(int64_t blk, Tid at);
 };
 
 
@@ -211,7 +211,7 @@ void Conn::_pin1(SrvReq *req) {
         virt_lock();
         TODO (mmap->file->blksize != mmap->fileh->ramh->ram->pagesize);
         if (!__fileh_page_isdirty(mmap->fileh, req->blk))
-            mmap->_remmapblk(req->blk, req->at);
+            mmap->_remmapblk(req->blk, req->at);    // XXX err
         virt_unlock();
         //trace("\t-> remmaped");   XXX
     }
@@ -234,7 +234,7 @@ void Conn::_pin1(SrvReq *req) {
 //
 // at=None means unpin to head/ .   XXX -> C
 // NOTE this does not check wrt virtmem already mapped blk as RW.
-void _Mapping::_remmapblk(int64_t blk, Tid at) {
+error _Mapping::_remmapblk(int64_t blk, Tid at) {
     // XXX err context?
     _Mapping *mmap = this;
 
@@ -248,8 +248,9 @@ void _Mapping::_remmapblk(int64_t blk, Tid at) {
     }
     else {
         // TODO share @rev fd until wconn is resynced?
-        fsfile = f->wconn->_wc->_open("@%s/bigfile/%s" % (h(at), h(f->foid)), "rb")
-        defer(fsfile.close)
+        fsfile = f->wconn->_wc->_open("@%s/bigfile/%s" % (h(at), h(f->foid)), "rb");
+        // XXX err
+        defer(fsfile.close);
     }
 
     struct stat st;
@@ -260,12 +261,14 @@ void _Mapping::_remmapblk(int64_t blk, Tid at) {
 
     // block is beyond file size - mmap with zeros   (assumes head/f size ↑=)
     if ((blk+1)*f->blksize > st.st_size) {
-        mm.map_zero_into_ro(blkmem);
+        mm.map_zero_into_ro(blkmem);    // XXX err
     }
     // block is inside file - mmap file data
     else {
-        mm.map_into_ro(blkmem, fsfile.fd, blk*f->blksize);
+        mm.map_into_ro(blkmem, fsfile.fd, blk*f->blksize);  // XXX err
     }
+
+    return nil;
 }