github.com/scaleoutsean/fusego@v0.0.0-20220224074057-4a6429e46bb8/samples/mount_sample/mount.go (about)

     1  // Copyright 2015 Google Inc. All Rights Reserved.
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //     http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  // A simple tool for mounting sample file systems, used by the tests in
    16  // samples/.
    17  package main
    18  
    19  import (
    20  	"context"
    21  	"errors"
    22  	"flag"
    23  	"fmt"
    24  	"log"
    25  	"os"
    26  	"runtime"
    27  	"syscall"
    28  
    29  	"github.com/scaleoutsean/fusego"
    30  	"github.com/scaleoutsean/fusego/samples/flushfs"
    31  )
    32  
    33  var fType = flag.String("type", "", "The name of the samples/ sub-dir.")
    34  var fMountPoint = flag.String("mount_point", "", "Path to mount point.")
    35  var fReadyFile = flag.Uint64("ready_file", 0, "FD to signal when ready.")
    36  
    37  var fFlushesFile = flag.Uint64("flushfs.flushes_file", 0, "")
    38  var fFsyncsFile = flag.Uint64("flushfs.fsyncs_file", 0, "")
    39  var fFlushError = flag.Int("flushfs.flush_error", 0, "")
    40  var fFsyncError = flag.Int("flushfs.fsync_error", 0, "")
    41  
    42  var fReadOnly = flag.Bool("read_only", false, "Mount in read-only mode.")
    43  var fDebug = flag.Bool("debug", false, "Enable debug logging.")
    44  
    45  func makeFlushFS() (fuse.Server, error) {
    46  	// Check the flags.
    47  	if *fFlushesFile == 0 || *fFsyncsFile == 0 {
    48  		return nil, fmt.Errorf("You must set the flushfs flags.")
    49  	}
    50  
    51  	// Set up the files.
    52  	flushes := os.NewFile(uintptr(*fFlushesFile), "(flushes file)")
    53  	fsyncs := os.NewFile(uintptr(*fFsyncsFile), "(fsyncs file)")
    54  
    55  	// Set up errors.
    56  	var flushErr error
    57  	var fsyncErr error
    58  
    59  	if *fFlushError != 0 {
    60  		flushErr = syscall.Errno(*fFlushError)
    61  	}
    62  
    63  	if *fFsyncError != 0 {
    64  		fsyncErr = syscall.Errno(*fFsyncError)
    65  	}
    66  
    67  	// Report flushes and fsyncs by writing the contents followed by a newline.
    68  	report := func(f *os.File, outErr error) func(string) error {
    69  		return func(s string) error {
    70  			buf := []byte(s)
    71  			buf = append(buf, '\n')
    72  
    73  			if _, err := f.Write(buf); err != nil {
    74  				return fmt.Errorf("Write: %v", err)
    75  			}
    76  
    77  			return outErr
    78  		}
    79  	}
    80  
    81  	reportFlush := report(flushes, flushErr)
    82  	reportFsync := report(fsyncs, fsyncErr)
    83  
    84  	// Create the file system.
    85  	return flushfs.NewFileSystem(reportFlush, reportFsync)
    86  }
    87  
    88  func makeFS() (fuse.Server, error) {
    89  	switch *fType {
    90  	default:
    91  		return nil, fmt.Errorf("Unknown FS type: %v", *fType)
    92  
    93  	case "flushfs":
    94  		return makeFlushFS()
    95  	}
    96  }
    97  
    98  func getReadyFile() (*os.File, error) {
    99  	if *fReadyFile == 0 {
   100  		return nil, errors.New("You must set --ready_file.")
   101  	}
   102  
   103  	return os.NewFile(uintptr(*fReadyFile), "(ready file)"), nil
   104  }
   105  
   106  func main() {
   107  	flag.Parse()
   108  
   109  	// Allow parallelism in the file system implementation, to help flush out
   110  	// bugs like https://github.com/scaleoutsean/fusego/issues/4.
   111  	runtime.GOMAXPROCS(2)
   112  
   113  	// Grab the file to signal when ready.
   114  	readyFile, err := getReadyFile()
   115  	if err != nil {
   116  		log.Fatalf("getReadyFile: %v", err)
   117  	}
   118  
   119  	// Create an appropriate file system.
   120  	server, err := makeFS()
   121  	if err != nil {
   122  		log.Fatalf("makeFS: %v", err)
   123  	}
   124  
   125  	// Mount the file system.
   126  	if *fMountPoint == "" {
   127  		log.Fatalf("You must set --mount_point.")
   128  	}
   129  
   130  	cfg := &fuse.MountConfig{
   131  		ReadOnly: *fReadOnly,
   132  	}
   133  
   134  	if *fDebug {
   135  		cfg.DebugLogger = log.New(os.Stderr, "fuse: ", 0)
   136  	}
   137  
   138  	mfs, err := fuse.Mount(*fMountPoint, server, cfg)
   139  	if err != nil {
   140  		log.Fatalf("Mount: %v", err)
   141  	}
   142  
   143  	// Signal that it is ready.
   144  	_, err = readyFile.Write([]byte("x"))
   145  	if err != nil {
   146  		log.Fatalf("readyFile.Write: %v", err)
   147  	}
   148  
   149  	// Wait for it to be unmounted.
   150  	if err = mfs.Join(context.Background()); err != nil {
   151  		log.Fatalf("Join: %v", err)
   152  	}
   153  }