.

wcfs/wcfs.go

@@ -602,9 +602,7 @@ type BigFileDir struct {
 
 	// δ tail of tracked BTree nodes of all BigFiles + -> which file
 	// (used only for head/, not revX/)
-	// XXX read/write access protected by zheadMu
-//	δFmu   sync.RWMutex		// zheadMu.W  |  zheadMu.R + δFmu.X	XXX kill δFmu
-	δFtail *zdata.ΔFtail
+	δFtail *zdata.ΔFtail		// read/write access protected by zheadMu.{R,W}
 }
 
 // /(head|<rev>)/bigfile/<bigfileX>	- served by BigFile.
@@ -859,9 +857,7 @@ retry:
 	bfdir := head.bfdir
 
 	// invalidate kernel cache for data in changed files
-	// NOTE no δFmu lock needed because zhead is WLocked
 
-//	δF, err := bfdir.δFtail.Update(δZ, zhead) // δF <- δZ |tracked
 	δF, err := bfdir.δFtail.Update(δZ) // δF <- δZ |tracked
 	if err != nil {
 		return err
@@ -1524,14 +1520,10 @@ func (f *BigFile) readPinWatchers(ctx context.Context, blk int64, treepath []btr
 //	fmt.Printf("S: read #%d -> pin watchers (#%d)\n", blk, len(f.watchTab))
 
 	// update δFtail index	XXX -> move upper into readBlk ?
-	// (δFtail is just for δZ -> δF invalidation handling and is needed without isolation protocol)
-	// XXX ^^^ no - also need to query to send pins
 	// see "3) for */head/data the following invariant is maintained..."
 	bfdir := f.head.bfdir
 	δFtail := bfdir.δFtail
-//	bfdir.δFmu.Lock()		// XXX locking correct? XXX -> better push down?
 	δFtail.Track(f.zfile, blk, treepath, blkcov, zblk)	// XXX pass in zblk.rev here?
-//	bfdir.δFmu.Unlock()
 
 	// make sure that file[blk] on clients side stays as of @w.at state.
 
@@ -2084,7 +2076,7 @@ func (bfdir *BigFileDir) lookup(out *fuse.Attr, name string, fctx *fuse.Context)
 	}
 
 	// not there - without bfdir lock proceed to open BigFile from ZODB
-	f, err = bfdir.head.bigopen(fctx, oid)
+	f, err = bfdir.head.bigfopen(fctx, oid)
 	if err != nil {
 		return nil, err
 	}
@@ -2192,14 +2184,14 @@ func (root *Root) lookup(name string, fctx *fuse.Context) (_ *Head, err error) {
 }
 
 
-// bigopen opens BigFile corresponding to oid on head.zconn.
+// bigfopen opens BigFile corresponding to oid on head.zconn.
 //
 // A ZBigFile corresponding to oid is activated and statted.
 //
-// head.zconn must be locked.
-func (head *Head) bigopen(ctx context.Context, oid zodb.Oid) (_ *BigFile, err error) {
+// head.zheadMu must be locked.
+func (head *Head) bigfopen(ctx context.Context, oid zodb.Oid) (_ *BigFile, err error) {
 	zconn := head.zconn
-	defer xerr.Contextf(&err, "bigopen %s @%s", oid, zconn.At())
+	defer xerr.Contextf(&err, "bigfopen %s @%s", oid, zconn.At())
 
 	// XXX better ctx = transaction.PutIntoContext(ctx, txn)
 	ctx, cancel := xcontext.Merge(ctx, zconn.TxnCtx)
@@ -2254,9 +2246,7 @@ func (head *Head) bigopen(ctx context.Context, oid zodb.Oid) (_ *BigFile, err er
 	// only head/ needs δFtail, f.δtail and watches.
 	if head.rev == 0 {
 		// see "3) for */head/data the following invariant is maintained..."
-//		head.bfdir.δFmu.Lock()	// XXX locking ok?
 		head.bfdir.δFtail.Track(f.zfile, -1, sizePath, blkCov, nil)
-//		head.bfdir.δFmu.Unlock()
 
 		f.watchTab = make(map[*Watch]struct{})
 	}