.

wcfs/client/wcfs.cpp

@@ -126,37 +126,42 @@ error _Conn::close() {
 
     xerr::Contextf E("%s: close", v(wconn));
 
-//  xerr::Contextf E("wcfs %s: close %s", v(wconn._wc->mountpoint), v(wconn.at));
-    // XXX + conn # e.g. from wconn._wlink.id? or wlink.close should include its id itself?
-    //       (or ._wlink._f.fd() ?)
-
     error err, eret;
     auto reterr1 = [&eret](error err) {
         if (eret == nil && err != nil)
             eret = err;
     };
 
+    bool alreadyClosed = false;
     wconn._mu.lock();
-    defer([&]() {
-        wconn._mu.unlock();
-    });
-
-    wconn._downErr = errConnClosed; // XXX ok to change even if it was !nil before?
+    alreadyClosed = (wconn._downErr == errConnClosed);
+    wconn._downErr = errConnClosed;
+    wconn._mu.unlock();
+    if (alreadyClosed)
+        return nil;
 
-    err = wconn._wlink->close();    // XXX ok under mu?
+    // close wlink and signal to pinner to stop outside of wconn.mu
+    err = wconn._wlink->close();    // XXX ok under atMu?
     if (err != nil)
         reterr1(err);
     wconn._pinCancel();
-    err = wconn._pinWG->wait();     // XXX ok under mu?
+    err = wconn._pinWG->wait();     // XXX ok under atMu?
     if (!errors::Is(err, context::canceled)) // canceled - ok
         reterr1(err);
 
-    // close all files - both that have no mappings and that still have opened mappings.
+
+    // pinner is stopped - now close all files - both that have no mappings and
+    // that still have opened mappings.
     //
     // NOTE after file is closed mappings could continue to survive, but we can no
     // longer maintain consistent view. For this reason we change mappings to
     // something that gives EFAULT on access. XXX implement
+    wconn._mu.lock();
+    defer([&]() {
+        wconn._mu.unlock();
+    });
 
+    // XXX f locking
     for (auto _ : wconn._filehTab) {
         auto f = _.second;
         err = f->_headf->close(); // XXX mark fileh as down so that fileh.close does not say "bad fd"
@@ -211,7 +216,7 @@ error _Conn::__pinner(context::Context ctx) {
         if (err != nil) {
             // it is ok if we receive EOF due to us closing the connection
             if (err == io::EOF_) {
-                wconn._mu.lock();
+                wconn._mu.lock();   // <- XXX
                 err = (wconn._downErr == errConnClosed) ? nil : io::ErrUnexpectedEOF;
                 wconn._mu.unlock();
             }