Killed off the --fuse.debug flag.

debug.go

-// Copyright 2015 Google Inc. All Rights Reserved.
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-package fuse
-
-import (
-	"flag"
-	"io"
-	"io/ioutil"
-	"log"
-	"os"
-	"sync"
-)
-
-var fEnableDebug = flag.Bool(
-	"fuse.debug",
-	false,
-	"Write FUSE debugging messages to stderr.")
-
-var gDebugLogger *log.Logger
-var gDebugLoggerOnce sync.Once
-
-func initDebugDebugLogger() {
-	if !flag.Parsed() {
-		panic("initDebugDebugLogger called before flags available.")
-	}
-
-	var writer io.Writer = ioutil.Discard
-	if *fEnableDebug {
-		writer = os.Stderr
-	}
-
-	const flags = log.Ldate | log.Ltime | log.Lmicroseconds
-	gDebugLogger = log.New(writer, "", flags)
-}
-
-func getDebugLogger() *log.Logger {
-	gDebugLoggerOnce.Do(initDebugDebugLogger)
-	return gDebugLogger
-}

fuseops/ops.go

@@ -49,7 +49,7 @@ type Op interface {
 
 	// Log information tied to this operation, with semantics equivalent to
 	// log.Printf, except that the format is different and logging is suppressed
-	// if --fuse.debug is not set.
+	// if no debug logger was set when mounting.
 	Logf(format string, v ...interface{})
 }
 

mounted_file_system.go

@@ -84,6 +84,10 @@ type MountConfig struct {
 	// logging is performed.
 	ErrorLogger *log.Logger
 
+	// A logger to use for logging debug information. If nil, no debug logging is
+	// performed.
+	DebugLogger *log.Logger
+
 	// OS X only.
 	//
 	// Normally on OS X we mount with the novncache option
@@ -189,7 +193,11 @@ func Mount(
 	dir string,
 	server Server,
 	config *MountConfig) (mfs *MountedFileSystem, err error) {
-	debugLogger := getDebugLogger()
+	// Arrange for a non-nil debug logger.
+	debugLogger := config.DebugLogger
+	if debugLogger == nil {
+		debugLogger = log.New(ioutil.Discard, "", 0)
+	}
 
 	// Initialize the struct.
 	mfs = &MountedFileSystem{

samples/in_process.go

@@ -18,6 +18,7 @@ import (
 	"fmt"
 	"io"
 	"io/ioutil"
+	"log"
 	"os"
 	"time"
 
@@ -59,7 +60,12 @@ type SampleTest struct {
 //
 // REQUIRES: t.Server has been set.
 func (t *SampleTest) SetUp(ti *ogletest.TestInfo) {
-	err := t.initialize(ti.Ctx, t.Server, &t.MountConfig)
+	cfg := t.MountConfig
+	if *fDebug {
+		cfg.DebugLogger = log.New(os.Stderr, "fuse: ", 0)
+	}
+
+	err := t.initialize(ti.Ctx, t.Server, &cfg)
 	if err != nil {
 		panic(err)
 	}

samples/mount_sample/mount.go

@@ -40,6 +40,7 @@ var fFlushError = flag.Int("flushfs.flush_error", 0, "")
 var fFsyncError = flag.Int("flushfs.fsync_error", 0, "")
 
 var fReadOnly = flag.Bool("read_only", false, "Mount in read-only mode.")
+var fDebug = flag.Bool("debug", false, "Enable debug logging.")
 
 func makeFlushFS() (server fuse.Server, err error) {
 	// Check the flags.
@@ -140,6 +141,10 @@ func main() {
 		ReadOnly: *fReadOnly,
 	}
 
+	if *fDebug {
+		cfg.DebugLogger = log.New(os.Stderr, "fuse: ", 0)
+	}
+
 	mfs, err := fuse.Mount(*fMountPoint, server, cfg)
 	if err != nil {
 		log.Fatalf("Mount: %v", err)

samples/subprocess.go

@@ -276,7 +276,7 @@ func (t *SubprocessTest) initialize(ctx context.Context) (err error) {
 	// Handle debug mode.
 	if *fDebug {
 		mountCmd.Stderr = os.Stderr
-		mountCmd.Args = append(mountCmd.Args, "--fuse.debug")
+		mountCmd.Args = append(mountCmd.Args, "--debug")
 	}
 
 	// Start the command.