conditionally enable direct io (#20)

* enable direct io

* set directio to false by default

Author: luke-lombardi

pkg/blobfs_node.go

@@ -149,7 +149,11 @@ func (n *FSNode) Opendir(ctx context.Context) syscall.Errno {
 func (n *FSNode) Open(ctx context.Context, flags uint32) (fh fs.FileHandle, fuseFlags uint32, errno syscall.Errno) {
 	n.log("Open called with flags: %v", flags)
 
-	return nil, 0, fs.OK
+	if n.filesystem.Config.BlobFs.DirectIO {
+		flags |= fuse.FOPEN_DIRECT_IO
+	}
+
+	return nil, flags, fs.OK
 }
 
 func (n *FSNode) Read(ctx context.Context, f fs.FileHandle, dest []byte, off int64) (fuse.ReadResult, syscall.Errno) {

pkg/config.default.yaml

@@ -9,6 +9,7 @@ grpcMessageSizeBytes: 1000000000
 grpcDialTimeoutS: 1
 discoveryIntervalS: 5
 discoveryMode: metadata
+directIO: false
 blobfs:
   enabled: false
   mountPoint: /tmp/test

pkg/types.go

@@ -95,6 +95,7 @@ type BlobFsConfig struct {
 	Sources            []SourceConfig `key:"sources" json:"sources"`
 	MaxBackgroundTasks int            `key:"maxBackgroundTasks" json:"max_background_tasks"`
 	MaxReadAheadKB     int            `key:"maxReadAheadKB" json:"max_read_ahead_kb"`
+	DirectIO           bool           `key:"directIO" json:"direct_io"`
 }
 
 type SourceConfig struct {