Allow buffer pool to be specified in MountOptions.

fuse/api.go

@@ -232,6 +232,9 @@ type MountOptions struct {
 	// file system implements extended attributes, and you are not
 	// interested in security labels.
 	IgnoreSecurityLabels bool // ignoring labels should be provided as a fusermount mount option.
+
+	// If given, use this buffer pool instead of the global one.
+	Buffers BufferPool
 }
 
 // DefaultFileSystem implements a FileSystem that returns ENOSYS for every operation.

fuse/mountstate.go

@@ -32,9 +32,6 @@ type MountState struct {
 	// Dump debug info onto stdout.
 	Debug bool
 
-	// For efficient reads and writes.
-	buffers *BufferPoolImpl
-
 	latencies *LatencyMap
 
 	opts           *MountOptions
@@ -66,6 +63,9 @@ func (ms *MountState) Mount(mountPoint string, opts *MountOptions) error {
 		}
 	}
 	o := *opts
+	if o.Buffers == nil {
+		o.Buffers = defaultBufferPool
+	}
 	if o.MaxWrite < 0 {
 		o.MaxWrite = 0
 	}
@@ -136,7 +136,6 @@ func NewMountState(fs RawFileSystem) *MountState {
 	ms := new(MountState)
 	ms.mountPoint = ""
 	ms.fileSystem = fs
-	ms.buffers = NewBufferPool()
 	return ms
 }
 
@@ -155,7 +154,7 @@ func (ms *MountState) OperationCounts() map[string]int {
 }
 
 func (ms *MountState) BufferPoolStats() string {
-	s := ms.buffers.String()
+	s := ms.opts.Buffers.String()
 
 	var r int
 	ms.reqMu.Lock()
@@ -230,7 +229,7 @@ func (ms *MountState) returnRequest(req *request) {
 	ms.recordStats(req)
 
 	if req.bufferPoolOutputBuf != nil {
-		ms.buffers.FreeBuffer(req.bufferPoolOutputBuf)
+		ms.opts.Buffers.FreeBuffer(req.bufferPoolOutputBuf)
 		req.bufferPoolOutputBuf = nil
 	}
 
@@ -330,9 +329,9 @@ func (ms *MountState) AllocOut(req *request, size uint32) []byte {
 		return req.bufferPoolOutputBuf
 	}
 	if req.bufferPoolOutputBuf != nil {
-		ms.buffers.FreeBuffer(req.bufferPoolOutputBuf)
+		ms.opts.Buffers.FreeBuffer(req.bufferPoolOutputBuf)
 	}
-	req.bufferPoolOutputBuf = ms.buffers.AllocBuffer(size)
+	req.bufferPoolOutputBuf = ms.opts.Buffers.AllocBuffer(size)
 	return req.bufferPoolOutputBuf
 }
 
@@ -470,3 +469,8 @@ func (ms *MountState) writeEntryNotify(parent uint64, name string) Status {
 	}
 	return result
 }
+
+var defaultBufferPool BufferPool
+func init() {
+	defaultBufferPool = NewBufferPool()
+}

fuse/pressure_test.go

@@ -33,7 +33,12 @@ func TestMemoryPressure(t *testing.T) {
 	CheckSuccess(err)
 	nfs := NewPathNodeFs(fs, nil)
 	o := &FileSystemOptions{PortableInodes: true}
-	state, _, err := MountNodeFileSystem(dir, nfs, o)
+
+	conn := NewFileSystemConnector(nfs, o)
+	state := NewMountState(conn)
+	bufs := NewBufferPool()
+	
+	err = state.Mount(dir, &MountOptions{Buffers: bufs})
 	if err != nil {
 		t.Fatalf("mount failed: %v", err)
 	}
@@ -58,7 +63,8 @@ func TestMemoryPressure(t *testing.T) {
 		}(i)
 	}
 	time.Sleep(100 * time.Millisecond)
-	created := state.buffers.createdBuffers + state.outstandingReadBufs
+	created := bufs.createdBuffers + state.outstandingReadBufs
+
 	t.Logf("Have %d read bufs", state.outstandingReadBufs)
 	if created > 2*_MAX_READERS {
 		t.Errorf("created %d buffers, max reader %d", created, _MAX_READERS)