.

wcfs/misc.go

@@ -262,14 +262,7 @@ func mount(mntpt string, root nodefs.Node, opts *fuse.MountOptions) (*fuse.Serve
 	nodefsOpts := nodefs.NewOptions()
 	nodefsOpts.Debug = opts.Debug
 
-	fsconn := nodefs.NewFileSystemConnector(root, nodefsOpts)
-
-	fssrv, err := fuse.NewServer(fsconn.RawFS(), mntpt, opts)
-	if err != nil {
-		return nil, nil, err
-	}
-
-	return fssrv, fsconn, nil
+	return nodefs.Mount(mntpt, root, opts, nodefsOpts)
 }
 
 

wcfs/notes.txt

@@ -37,6 +37,12 @@ the kernel it is fully responsible for invalidating pagecache:
 
 https://lwn.net/ml/linux-fsdevel/20190315212556.9315-1-kirr%40nexedi.com/
 
+As of 2019-Apr-25 the patch entered fuse.git#for-next:
+
+https://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse.git/commit/?id=ad2ba64dd489
+
+and should likely enter mainline when 5.2 merge window opens.
+
 
 Invalidations to wcfs clients are delayed until block access
 ============================================================

wcfs/wcfs.go

@@ -2017,8 +2017,8 @@ func main() {
 		// XXX tune MaxReadAhead? MaxBackground?
 
 		// OS cache that we populate with bigfile data is precious;
-		// we precisely propagate ZODB invalidations into file invalidations.
-		PreciseDataCacheControl: true,
+		// we explicitly propagate ZODB invalidations into file invalidations.
+		ExplicitDataCacheControl: true,
 
 		DisableXAttrs: true,        // we don't use
 		Debug:         *debug,
@@ -2039,10 +2039,10 @@ func main() {
 	if !(supports(fuse.NOTIFY_STORE_CACHE) && supports(fuse.NOTIFY_RETRIEVE_CACHE)) {
 		log.Fatalf("%s does not support pagecache control", kfuse)
 	}
-	// make a bold warning if kernel does not support precise cache invalidation
+	// make a bold warning if kernel does not support explicit cache invalidation
 	// (patch sent upstream; see notes.txt -> "Notes on OS pagecache control")
-	if kinit.Flags & fuse.CAP_PRECISE_INVAL_DATA == 0 {
-		w1 := fmt.Sprintf("%s does not support precise data cache invalidation", kfuse)
+	if kinit.Flags & fuse.CAP_EXPLICIT_INVAL_DATA == 0 {
+		w1 := fmt.Sprintf("%s does not support explicit data cache invalidation", kfuse)
 		w2 := "-> performance will be AWFUL."
 		log.Error(w1); log.Error(w2)
 		fmt.Fprintf(os.Stderr, "W: wcfs: %s\nW: wcfs: %s\n", w1, w2)

wcfs/wcfs_test.py

@@ -371,7 +371,9 @@ class tWatch:
         t.tdb = tdb
 
         # python/stdio lock file object on read/write
-        # however we need both read and write to be working simultaneously
+        # however we need both read and write to be working simultaneously.
+        # fdopen takes ownership of file descriptor and closes it when file object is closed.
+
         #print('\n\n')
         #os.system("ls -l %s" % tdb.path("head"))
         #print('\n\n')