1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
|
// Copyright 2020 the Go-FUSE Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// This is main program driver for a loopback filesystem that emulates
// windows semantics (no delete/rename on opened files.)
package main
import (
"context"
"flag"
"fmt"
"log"
"os"
"path"
"sync"
"syscall"
"time"
"github.com/hanwen/go-fuse/v2/fs"
"github.com/hanwen/go-fuse/v2/fuse"
)
// Release decreases the open count. The kernel doesn't wait with
// returning from close(), so if the caller is too quick to
// unlink/rename after calling close(), this may still trigger EBUSY.
// Kludge around this by sleeping for a bit before we check business.
var delay = flag.Duration("delay", 10*time.Microsecond,
"wait this long before checking business")
// WindowsNode is a loopback FS node keeping track of open counts.
type WindowsNode struct {
// WindowsNode inherits most functionality from LoopbackNode.
fs.LoopbackNode
mu sync.Mutex
openCount int
}
func (n *WindowsNode) increment() {
n.mu.Lock()
defer n.mu.Unlock()
n.openCount++
}
func (n *WindowsNode) decrement() {
n.mu.Lock()
defer n.mu.Unlock()
n.openCount--
}
var _ = (fs.NodeOpener)((*WindowsNode)(nil))
func (n *WindowsNode) Open(ctx context.Context, flags uint32) (fs.FileHandle, uint32, syscall.Errno) {
fh, flags, errno := n.LoopbackNode.Open(ctx, flags)
if errno == 0 {
n.increment()
}
return fh, flags, errno
}
var _ = (fs.NodeCreater)((*WindowsNode)(nil))
func (n *WindowsNode) Create(ctx context.Context, name string, flags uint32, mode uint32, out *fuse.EntryOut) (*fs.Inode, fs.FileHandle, uint32, syscall.Errno) {
inode, fh, flags, errno := n.LoopbackNode.Create(ctx, name, flags, mode, out)
if errno == 0 {
wn := inode.Operations().(*WindowsNode)
wn.increment()
}
return inode, fh, flags, errno
}
var _ = (fs.NodeReleaser)((*WindowsNode)(nil))
func (n *WindowsNode) Release(ctx context.Context, f fs.FileHandle) syscall.Errno {
n.decrement()
if fr, ok := f.(fs.FileReleaser); ok {
return fr.Release(ctx)
}
return 0
}
func isBusy(parent *fs.Inode, name string) bool {
time.Sleep(*delay)
if ch := parent.GetChild(name); ch != nil {
if wn, ok := ch.Operations().(*WindowsNode); ok {
wn.mu.Lock()
defer wn.mu.Unlock()
if wn.openCount > 0 {
return true
}
}
}
return false
}
var _ = (fs.NodeUnlinker)((*WindowsNode)(nil))
func (n *WindowsNode) Unlink(ctx context.Context, name string) syscall.Errno {
if isBusy(n.EmbeddedInode(), name) {
return syscall.EBUSY
}
return n.LoopbackNode.Unlink(ctx, name)
}
var _ = (fs.NodeRenamer)((*WindowsNode)(nil))
func (n *WindowsNode) Rename(ctx context.Context, name string, newParent fs.InodeEmbedder, newName string, flags uint32) syscall.Errno {
if isBusy(n.EmbeddedInode(), name) || isBusy(newParent.EmbeddedInode(), newName) {
return syscall.EBUSY
}
return n.LoopbackNode.Rename(ctx, name, newParent, newName, flags)
}
func newWindowsNode(rootData *fs.LoopbackRoot, _ *fs.Inode, _ string, _ *syscall.Stat_t) fs.InodeEmbedder {
n := &WindowsNode{
LoopbackNode: fs.LoopbackNode{
RootData: rootData,
},
}
return n
}
func main() {
log.SetFlags(log.Lmicroseconds)
debug := flag.Bool("debug", false, "print debugging messages.")
flag.Parse()
if flag.NArg() < 2 {
fmt.Printf("usage: %s MOUNTPOINT ORIGINAL\n", path.Base(os.Args[0]))
fmt.Printf("\noptions:\n")
flag.PrintDefaults()
os.Exit(2)
}
orig := flag.Arg(1)
rootData := &fs.LoopbackRoot{
NewNode: newWindowsNode,
Path: orig,
}
sec := time.Second
opts := &fs.Options{
AttrTimeout: &sec,
EntryTimeout: &sec,
}
opts.Debug = *debug
opts.MountOptions.Options = append(opts.MountOptions.Options, "fsname="+orig)
opts.MountOptions.Name = "winfs"
opts.NullPermissions = true
server, err := fs.Mount(flag.Arg(0), newWindowsNode(rootData, nil, "", nil), opts)
if err != nil {
log.Fatalf("Mount fail: %v\n", err)
}
fmt.Println("Mounted!")
server.Wait()
}
|
