Merge pull request #29 from willscott/feat/dirpage

off-by-one issues with dir cookies
willscott · Mar 21, 2021 · 08e2b9d · 08e2b9d
2 parents bc34151 + 3ba0536
commit 08e2b9d
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Showing 3 changed files with 30 additions and 8 deletions.
diff --git a/helpers/cachinghandler.go b/helpers/cachinghandler.go
@@ -49,6 +49,13 @@ func (c *CachingHandler) FromHandle(fh []byte) (billy.Filesystem, []string, erro
 
 	if cache, ok := c.activeHandles.Get(id); ok {
 		f, ok := cache.(entry)
+		for _, k := range c.activeHandles.Keys() {
+			e, _ := c.activeHandles.Peek(k)
+			candidate := e.(entry)
+			if hasPrefix(f.p, candidate.p) {
+				_, _ = c.activeHandles.Get(k)
+			}
+		}
 		if ok {
 			return f.f, f.p, nil
 		}
@@ -60,3 +67,15 @@ func (c *CachingHandler) FromHandle(fh []byte) (billy.Filesystem, []string, erro
 func (c *CachingHandler) HandleLimit() int {
 	return c.cacheLimit
 }
+
+func hasPrefix(path, prefix []string) bool {
+	if len(prefix) > len(path) {
+		return false
+	}
+	for i, e := range prefix {
+		if path[i] != e {
+			return false
+		}
+	}
+	return true
+}
diff --git a/nfs_onreaddir.go b/nfs_onreaddir.go
@@ -67,15 +67,16 @@ func onReadDir(ctx context.Context, w *response, userHandle Handler) error {
 	vHash := sha256.New()
 
 	for i, c := range contents {
+		actualI := i + 2
 		if started {
 			entities = append(entities, readDirEntity{
 				FileID: 1337, //todo: does this matter?
 				Name:   []byte(c.Name()),
-				Cookie: uint64(i + 3),
+				Cookie: uint64(actualI),
 				Next:   1,
 			})
 			maxBytes += 512 // TODO: better estimation.
-		} else if uint64(i) == obj.Cookie {
+		} else if uint64(actualI) == obj.Cookie {
 			started = true
 			everStarted = true
 		}
@@ -119,7 +120,7 @@ func onReadDir(ctx context.Context, w *response, userHandle Handler) error {
 		if err := xdr.Write(writer, []byte(".")); err != nil { // name
 			return &NFSStatusError{NFSStatusServerFault, err}
 		}
-		if err := xdr.Write(writer, uint64(1)); err != nil { // cookie
+		if err := xdr.Write(writer, uint64(0)); err != nil { // cookie
 			return &NFSStatusError{NFSStatusServerFault, err}
 		}
 		if err := xdr.Write(writer, uint32(1)); err != nil { // next
@@ -138,7 +139,7 @@ func onReadDir(ctx context.Context, w *response, userHandle Handler) error {
 		if err := xdr.Write(writer, []byte("..")); err != nil { //name
 			return &NFSStatusError{NFSStatusServerFault, err}
 		}
-		if err := xdr.Write(writer, uint64(2)); err != nil { // cookie
+		if err := xdr.Write(writer, uint64(1)); err != nil { // cookie
 			return &NFSStatusError{NFSStatusServerFault, err}
 		}
 	}

diff --git a/nfs_onreaddirplus.go b/nfs_onreaddirplus.go
@@ -67,14 +67,16 @@ func onReadDirPlus(ctx context.Context, w *response, userHandle Handler) error {
 	vHash := sha256.New()
 
 	for i, c := range contents {
+		// index of contents doesn't include '.' and '..'
+		actualI := i + 2
 		if started {
 			handle := userHandle.ToHandle(fs, append(p, c.Name()))
 			attrs := ToFileAttribute(c)
 			attrs.Fileid = binary.BigEndian.Uint64(handle[0:8])
 			entities = append(entities, readDirPlusEntity{
 				FileID:        binary.BigEndian.Uint64(handle[0:8]),
 				Name:          []byte(c.Name()),
-				Cookie:        uint64(i + 3),
+				Cookie:        uint64(actualI),
 				HasAttributes: 1,
 				Attributes:    attrs,
 				HasHandle:     1,
@@ -83,7 +85,7 @@ func onReadDirPlus(ctx context.Context, w *response, userHandle Handler) error {
 			})
 			dirBytes += uint32(len(c.Name()) + 20)
 			maxBytes += 512 // TODO: better estimation.
-		} else if uint64(i) == obj.Cookie {
+		} else if uint64(actualI) == obj.Cookie {
 			started = true
 			everStarted = true
 		}
@@ -127,7 +129,7 @@ func onReadDirPlus(ctx context.Context, w *response, userHandle Handler) error {
 		if err := xdr.Write(writer, []byte(".")); err != nil { // name
 			return &NFSStatusError{NFSStatusServerFault, err}
 		}
-		if err := xdr.Write(writer, uint64(1)); err != nil { // cookie
+		if err := xdr.Write(writer, uint64(0)); err != nil { // cookie
 			return &NFSStatusError{NFSStatusServerFault, err}
 		}
 		if err := xdr.Write(writer, uint32(0)); err != nil { // hasAttribute
@@ -152,7 +154,7 @@ func onReadDirPlus(ctx context.Context, w *response, userHandle Handler) error {
 		if err := xdr.Write(writer, []byte("..")); err != nil { //name
 			return &NFSStatusError{NFSStatusServerFault, err}
 		}
-		if err := xdr.Write(writer, uint64(2)); err != nil { // cookie
+		if err := xdr.Write(writer, uint64(1)); err != nil { // cookie
 			return &NFSStatusError{NFSStatusServerFault, err}
 		}
 		if err := xdr.Write(writer, uint32(0)); err != nil { // hasAttribute