Send better syscall status codes

internal/fusefs/fuse.go

@@ -126,6 +126,7 @@ func (n *ITNode) Readdir(ctx context.Context) (fs.DirStream, syscall.Errno) {
 		files, err := myfs.ReadDir(n.path)
 		if err != nil {
 			log.Error("FUSE ReadDir failed").Str("path", n.path).Err(err).Send()
+			// TODO we probably should figure out why it failed
 			return nil, syscall.ENOENT
 		}
 
@@ -209,7 +210,6 @@ func (n *ITNode) Lookup(ctx context.Context, name string, out *fuse.EntryOut) (*
 				return child, 0
 			}
 		}
-		return nil, syscall.ENOENT
 
 	case 2:
 		// FS object
@@ -290,6 +290,8 @@ var _ fs.FileWriter = (*bytesFileWriteHandle)(nil)
 func (fh *bytesFileWriteHandle) Write(ctx context.Context, data []byte, off int64) (written uint32, errno syscall.Errno) {
 	log.Info("Executing Write").Str("path", fh.path).Int("prev_size", len(fh.content)).Int("next_size", len(data)).Send()
 	if off != int64(len(fh.content)) {
+		log.Error("FUSE Write file size changed unexpectedly").Int("expect", int(off)).Int("received", len(fh.content)).Send()
+		return 0, syscall.ENXIO
 	}
 	fh.content = append(fh.content[:], data[:]...)
 	return uint32(len(data)), 0
@@ -320,17 +322,17 @@ func (fh *bytesFileWriteHandle) Flush(ctx context.Context) (errno syscall.Errno)
 	if err != nil {
 		log.Error("FUSE Flush failed during write").Str("path", fh.path).Err(err).Send()
 		fp.Close()
-		return syscall.EROFS
+		return syscall.EIO
 	}
 	if int(nread) != len(fh.content) {
 		log.Error("FUSE Flush failed during write").Str("path", fh.path).Int("expect", len(fh.content)).Int("got", int(nread)).Send()
 		fp.Close()
-		return syscall.EROFS
+		return syscall.EIO
 	}
 	err = fp.Close()
 	if err != nil {
 		log.Error("FUSE Flush failed during close").Str("path", fh.path).Err(err).Send()
-		return syscall.EROFS
+		return syscall.EIO
 	}
 	log.Debug("FUSE Flush done").Str("path", fh.path).Int("size", len(fh.content)).Send()
 
@@ -381,6 +383,7 @@ func (f *ITNode) Open(ctx context.Context, openFlags uint32) (fh fs.FileHandle,
 			log.Debug("FUSE Opening for read").Str("path", f.path).Send()
 			fp, err := myfs.Open(f.path)
 			if err != nil {
+				// TODO we probably should figure out why it failed
 				log.Error("FUSE: Opening failed").Str("path", f.path).Err(err).Send()
 				return nil, 0, syscall.EROFS
 			}
@@ -400,7 +403,7 @@ func (f *ITNode) Open(ctx context.Context, openFlags uint32) (fh fs.FileHandle,
 			if err != nil {
 				log.Error("FUSE Read failed").Str("path", f.path).Err(err).Send()
 				fp.Close()
-				return nil, 0, syscall.EROFS
+				return nil, 0, syscall.EIO
 			}
 
 			fh = &bytesFileReadHandle{
@@ -422,7 +425,8 @@ func (f *ITNode) Open(ctx context.Context, openFlags uint32) (fh fs.FileHandle,
 				sub_ctx, cancel := context.WithCancel(ctx)
 				ans, err := value.gen(sub_ctx)
 				if err != nil {
-					return nil, 0, syscall.EROFS
+					// TODO we probably should figure out why it failed
+					return nil, 0, syscall.EIO
 				}
 
 				fh = &sensorFileReadHandle{
@@ -433,7 +437,7 @@ func (f *ITNode) Open(ctx context.Context, openFlags uint32) (fh fs.FileHandle,
 			}
 		}
 	}
-	return nil, 0, syscall.EROFS
+	return nil, 0, syscall.EINVAL
 }
 
 var _ fs.NodeCreater = (*ITNode)(nil)
@@ -480,6 +484,7 @@ func (f *ITNode) Mkdir(ctx context.Context, name string, mode uint32, out *fuse.
 			Str("path", path).
 			Err(err).
 			Send()
+		// TODO we probably should figure out why it failed
 		return nil, syscall.EROFS
 	}
 
@@ -505,6 +510,10 @@ func (f *ITNode) Mkdir(ctx context.Context, name string, mode uint32, out *fuse.
 
 var _ fs.NodeRenamer = (*ITNode)(nil)
 func (f *ITNode) Rename(ctx context.Context, name string, newParent fs.InodeEmbedder, newName string, flags uint32) syscall.Errno {
+	if f.kind != 2 {
+		return syscall.EROFS
+	}
+
 	p1 := f.path + "/" + name
 	p2 := newParent.EmbeddedInode().Path(nil)[2:] + "/" + newName
 
@@ -516,7 +525,8 @@ func (f *ITNode) Rename(ctx context.Context, name string, newParent fs.InodeEmbe
 			Err(err).
 			Send()
 
-		return syscall.EROFS
+		// TODO we probably should figure out why it failed
+		return syscall.EIO
 	}
 	log.Debug("FUSE Rename sucess").
 		Str("src", p1).
@@ -532,6 +542,10 @@ func (f *ITNode) Rename(ctx context.Context, name string, newParent fs.InodeEmbe
 
 var _ fs.NodeUnlinker = (*ITNode)(nil)
 func (f *ITNode) Unlink(ctx context.Context, name string) syscall.Errno {
+	if f.kind != 2 {
+		return syscall.EROFS
+	}
+
 	delete(inodemap, f.path + "/" + name)
 	err := myfs.Remove(f.path + "/" + name)
 	if err != nil {
@@ -540,7 +554,8 @@ func (f *ITNode) Unlink(ctx context.Context, name string) syscall.Errno {
 			Err(err).
 			Send()
 
-		return syscall.EROFS
+		// TODO we probably should figure out why it failed
+		return syscall.EIO
 	}
 
 	log.Debug("FUSE Unlink success").