rclone/cmd/mount/dir.go
Nick Craig-Wood 6ca7198f57 mount: fix disappearing cwd problem - fixes #4104
Before this change, the current working directory could disappear
according to the Linux kernel.

This was caused by mount returning different nodes with the same
information in.

This change uses vfs.Node.SetSys to cache the information so we always
return the same node.
2020-05-04 11:38:07 +01:00

215 lines
5.9 KiB
Go

// +build linux,go1.13 darwin,go1.13 freebsd,go1.13
package mount
import (
"context"
"os"
"time"
"bazil.org/fuse"
fusefs "bazil.org/fuse/fs"
"github.com/pkg/errors"
"github.com/rclone/rclone/cmd/mountlib"
"github.com/rclone/rclone/fs"
"github.com/rclone/rclone/fs/log"
"github.com/rclone/rclone/vfs"
)
// Dir represents a directory entry
type Dir struct {
*vfs.Dir
}
// Check interface satisfied
var _ fusefs.Node = (*Dir)(nil)
// Attr updates the attributes of a directory
func (d *Dir) Attr(ctx context.Context, a *fuse.Attr) (err error) {
defer log.Trace(d, "")("attr=%+v, err=%v", a, &err)
a.Valid = mountlib.AttrTimeout
a.Gid = d.VFS().Opt.GID
a.Uid = d.VFS().Opt.UID
a.Mode = os.ModeDir | d.VFS().Opt.DirPerms
modTime := d.ModTime()
a.Atime = modTime
a.Mtime = modTime
a.Ctime = modTime
a.Crtime = modTime
// FIXME include Valid so get some caching?
// FIXME fs.Debugf(d.path, "Dir.Attr %+v", a)
return nil
}
// Check interface satisfied
var _ fusefs.NodeSetattrer = (*Dir)(nil)
// Setattr handles attribute changes from FUSE. Currently supports ModTime only.
func (d *Dir) Setattr(ctx context.Context, req *fuse.SetattrRequest, resp *fuse.SetattrResponse) (err error) {
defer log.Trace(d, "stat=%+v", req)("err=%v", &err)
if d.VFS().Opt.NoModTime {
return nil
}
if req.Valid.MtimeNow() {
err = d.SetModTime(time.Now())
} else if req.Valid.Mtime() {
err = d.SetModTime(req.Mtime)
}
return translateError(err)
}
// Check interface satisfied
var _ fusefs.NodeRequestLookuper = (*Dir)(nil)
// Lookup looks up a specific entry in the receiver.
//
// Lookup should return a Node corresponding to the entry. If the
// name does not exist in the directory, Lookup should return ENOENT.
//
// Lookup need not to handle the names "." and "..".
func (d *Dir) Lookup(ctx context.Context, req *fuse.LookupRequest, resp *fuse.LookupResponse) (node fusefs.Node, err error) {
defer log.Trace(d, "name=%q", req.Name)("node=%+v, err=%v", &node, &err)
mnode, err := d.Dir.Stat(req.Name)
if err != nil {
return nil, translateError(err)
}
resp.EntryValid = mountlib.AttrTimeout
// Check the mnode to see if it has a fuse Node cached
// We must return the same fuse nodes for vfs Nodes
node, ok := mnode.Sys().(fusefs.Node)
if ok {
return node, nil
}
switch x := mnode.(type) {
case *vfs.File:
node = &File{x}
case *vfs.Dir:
node = &Dir{x}
default:
panic("bad type")
}
// Cache the node for later
mnode.SetSys(node)
return node, nil
}
// Check interface satisfied
var _ fusefs.HandleReadDirAller = (*Dir)(nil)
// ReadDirAll reads the contents of the directory
func (d *Dir) ReadDirAll(ctx context.Context) (dirents []fuse.Dirent, err error) {
itemsRead := -1
defer log.Trace(d, "")("item=%d, err=%v", &itemsRead, &err)
items, err := d.Dir.ReadDirAll()
if err != nil {
return nil, translateError(err)
}
for _, node := range items {
name := node.Name()
if len(name) >= mountlib.MaxLeafSize {
fs.Errorf(d, "Name too long (%d bytes) for FUSE, skipping: %s", len(name), name)
continue
}
var dirent = fuse.Dirent{
// Inode FIXME ???
Type: fuse.DT_File,
Name: name,
}
if node.IsDir() {
dirent.Type = fuse.DT_Dir
}
dirents = append(dirents, dirent)
}
itemsRead = len(dirents)
return dirents, nil
}
var _ fusefs.NodeCreater = (*Dir)(nil)
// Create makes a new file
func (d *Dir) Create(ctx context.Context, req *fuse.CreateRequest, resp *fuse.CreateResponse) (node fusefs.Node, handle fusefs.Handle, err error) {
defer log.Trace(d, "name=%q", req.Name)("node=%v, handle=%v, err=%v", &node, &handle, &err)
file, err := d.Dir.Create(req.Name, int(req.Flags))
if err != nil {
return nil, nil, translateError(err)
}
fh, err := file.Open(int(req.Flags) | os.O_CREATE)
if err != nil {
return nil, nil, translateError(err)
}
node = &File{file}
file.SetSys(node) // cache the FUSE node for later
return node, &FileHandle{fh}, err
}
var _ fusefs.NodeMkdirer = (*Dir)(nil)
// Mkdir creates a new directory
func (d *Dir) Mkdir(ctx context.Context, req *fuse.MkdirRequest) (node fusefs.Node, err error) {
defer log.Trace(d, "name=%q", req.Name)("node=%+v, err=%v", &node, &err)
dir, err := d.Dir.Mkdir(req.Name)
if err != nil {
return nil, translateError(err)
}
node = &Dir{dir}
dir.SetSys(node) // cache the FUSE node for later
return node, nil
}
var _ fusefs.NodeRemover = (*Dir)(nil)
// Remove removes the entry with the given name from
// the receiver, which must be a directory. The entry to be removed
// may correspond to a file (unlink) or to a directory (rmdir).
func (d *Dir) Remove(ctx context.Context, req *fuse.RemoveRequest) (err error) {
defer log.Trace(d, "name=%q", req.Name)("err=%v", &err)
err = d.Dir.RemoveName(req.Name)
if err != nil {
return translateError(err)
}
return nil
}
// Check interface satisfied
var _ fusefs.NodeRenamer = (*Dir)(nil)
// Rename the file
func (d *Dir) Rename(ctx context.Context, req *fuse.RenameRequest, newDir fusefs.Node) (err error) {
defer log.Trace(d, "oldName=%q, newName=%q, newDir=%+v", req.OldName, req.NewName, newDir)("err=%v", &err)
destDir, ok := newDir.(*Dir)
if !ok {
return errors.Errorf("Unknown Dir type %T", newDir)
}
err = d.Dir.Rename(req.OldName, req.NewName, destDir.Dir)
if err != nil {
return translateError(err)
}
return nil
}
// Check interface satisfied
var _ fusefs.NodeFsyncer = (*Dir)(nil)
// Fsync the directory
func (d *Dir) Fsync(ctx context.Context, req *fuse.FsyncRequest) (err error) {
defer log.Trace(d, "")("err=%v", &err)
err = d.Dir.Sync()
if err != nil {
return translateError(err)
}
return nil
}
// Check interface satisfied
var _ fusefs.NodeLinker = (*Dir)(nil)
// Link creates a new directory entry in the receiver based on an
// existing Node. Receiver must be a directory.
func (d *Dir) Link(ctx context.Context, req *fuse.LinkRequest, old fusefs.Node) (newNode fusefs.Node, err error) {
defer log.Trace(d, "req=%v, old=%v", req, old)("new=%v, err=%v", &newNode, &err)
return nil, fuse.ENOSYS
}