nodefs: update some comments

nodefs/api.go

@@ -38,14 +38,18 @@
 // tree.  InodeOf can be used to get particular Inode associated with
 // a Operations.
 //
-// XXX ^^^ inodes cleaned on cache clean (FORGET).
+// The kernel can evict inode data to free up memory. It does so by
+// issuing FORGET calls. When a node has no children, and no kernel
+// references, it is removed from the file system trees.
+//
+// File system trees can also be constructed in advance. This is done
+// by instantiating "persistent" inodes. Persistent inodes remain in
+// memory even if the kernel has forgotten them.
 //
 // XXX describe how to mount.
 //
 // XXX node example with Lookup.
 //
-// XXX describe how to pre-add nodes to tree.
-//
 package nodefs
 
 import (

nodefs/bridge.go

@@ -377,7 +377,6 @@ func (b *rawBridge) Rename(cancel <-chan struct{}, input *fuse.RenameIn, oldName
 	status := p1.node.Rename(&fuse.Context{Caller: input.Caller, Cancel: cancel}, oldName, p2.node, newName, input.Flags)
 	if status.Ok() {
 		if input.Flags&unix.RENAME_EXCHANGE != 0 {
-			// XXX - test coverage.
 			p1.ExchangeChild(oldName, p2, newName)
 		} else {
 			p1.MvChild(oldName, p2, newName, true)
@@ -609,7 +608,6 @@ func (b *rawBridge) ReadDir(cancel <-chan struct{}, input *fuse.ReadIn, out *fus
 		f.hasOverflow = false
 	}
 
-	// TODO - should post '..' and '.' ?
 	for f.dirStream.HasNext() {
 		e, status := f.dirStream.Next()
 
@@ -663,7 +661,7 @@ func (b *rawBridge) ReadDirPlus(cancel <-chan struct{}, input *fuse.ReadIn, out
 			b.addNewChild(n, e.Name, child, nil, 0, entryOut)
 			b.setEntryOutTimeout(entryOut)
 			if (e.Mode &^ 07777) != (child.mode &^ 07777) {
-				// XXX should go back and change the
+				// should go back and change the
 				// already serialized entry
 				log.Panicf("mode mismatch between readdir %o and lookup %o", e.Mode, child.mode)
 			}

nodefs/files_darwin.go

@@ -11,8 +11,6 @@ import (
 	"github.com/hanwen/go-fuse/fuse"
 )
 
-// XXX fill out here.
-
 func (f *loopbackFile) Allocate(ctx context.Context, off uint64, sz uint64, mode uint32) fuse.Status {
 	return fuse.ENOSYS
 }

nodefs/inode.go

@@ -333,7 +333,8 @@ retry:
 		lockNodes(lockme...)
 		if n.changeCounter != nChange {
 			unlockNodes(lockme...)
-			n.mu.Lock() // TODO could avoid unlocking and relocking n here.
+			// could avoid unlocking and relocking n here.
+			n.mu.Lock()
 			continue retry
 		}
 
@@ -391,7 +392,8 @@ retry:
 		lockNodes(lockme...)
 		if n.changeCounter != nChange {
 			unlockNodes(lockme...)
-			n.mu.Lock() // TODO could avoid unlocking and relocking n here.
+			// could avoid unlocking and relocking n here.
+			n.mu.Lock()
 			continue retry
 		}
 
@@ -467,7 +469,6 @@ retry:
 		unlockNodes(n, newParent, oldChild, destChild)
 
 		if destChild != nil {
-			// XXX would be better to do this under lock above too.
 			destChild.removeRef(0, false)
 		}
 		return true
@@ -539,7 +540,7 @@ func (n *Inode) NotifyEntry(name string) fuse.Status {
 	return n.bridge.server.EntryNotify(n.nodeID.Ino, name)
 }
 
-// XXX DeleteNotify ?
+// XXX naming: DeleteNotify ?
 func (n *Inode) NotifyDelete(name string, child *Inode) fuse.Status {
 	// XXX arg ordering?
 	return n.bridge.server.DeleteNotify(n.nodeID.Ino, child.nodeID.Ino, name)

nodefs/simple_test.go

@@ -550,8 +550,6 @@ func TestReadDir(t *testing.T) {
 	defer f.Close()
 
 	// add entries after opening the directory
-
-	// XXX what about ".." and "." ?
 	want := map[string]bool{}
 	for i := 0; i < 110; i++ {
 		// 40 bytes of filename, so 110 entries overflows a